BAEL-1461

2018-04-19 05:37:34 +01:00 · 2018-04-19 05:37:34 +01:00 · 21bd180c1c
parent 263009fb32
commit 21bd180c1c
28 changed files with 3125 additions and 0 deletions
--- a/pom.xml
+++ b/pom.xml
@ -74,6 +74,7 @@
        <module>dozer</module>

        <module>ethereumj</module>
+        <module>web3j</module>

        <!--<module>ejb</module>-->

--- a/web3j/.gitignore
+++ b/web3j/.gitignore
@ -0,0 +1,3 @@
+.idea
+target
+*.iml
--- a/web3j/README.md
+++ b/web3j/README.md
@ -0,0 +1,4 @@
+## Web3j
+
+### Relevant Articles:
+- [Lightweight Web3](http://www.baeldung.com/lightweight-web3/)
--- a/web3j/dev_ganache/README.md
+++ b/web3j/dev_ganache/README.md
@ -0,0 +1,23 @@
+# Ganache Readme
+
+TL:DR - To set up Ganache visit: http://truffleframework.com/ganache/
+
+# Three Ways to Install Ganache
+
+Ganache is provided in three libraries or distributions:
+
+(1) Ganache - https://github.com/trufflesuite/ganache
+
+This is a pre-built and out-of-the-box solution. Easiest to set up. It provides an interface and server shell for Ganache CLI.
+
+(2) Ganache CLI - https://www.npmjs.com/package/ganache-cli
+
+Ganache CLI abstracts Ganache Core and supplies the default options and arguments used.
+
+(3) Ganache Core - https://www.npmjs.com/package/ganache-core
+
+Basically, only use Ganache Core if you need to build a totally customized option.
+
+# Use
+
+The default port is *8545* on *localhost*
--- a/web3j/dev_truffle/README.md
+++ b/web3j/dev_truffle/README.md
@ -0,0 +1,43 @@
+# Using Truffle
+
+Basic Truffle walkthrough readme.
+
+See also: http://truffleframework.com/docs/
+
+# Bash
+
+Truffle install
+
+```bash
+	$ npm install truffle -g
+	$ truffle version 
+```
+
+Truffle commands:
+
+```bash
+	$ truffle init
+	$ truffle compile
+	$ truffle migrate
+	$ truffle test
+```
+
+# Directory Structure
+
+The command `$ truffle init` will create a directory structure in the specified root according to the following:
+
+```
+root -|
+      |-build               (Compiled Solc JSON Output Dir)  
+      |-contracts           (Solc Contracts to be Compiled and Migrated)  
+      |-migrations          (Specify the Order and Dependencies of Contracts to Be Deployed)  
+      |-test                (Truffle Tests)  
+```
+      
+# Compile
+
+Truffle will compile the smart contracts and expose their **JSON ABI's for use with Web3.js** or **Binary ABI's for use with Web3J**.
+
+# Migration
+
+Truffle will let you deploy your Solc contracts directly to a blockchin of your choice.
--- a/web3j/dev_truffle/build/contracts/ConvertLib.json
+++ b/web3j/dev_truffle/build/contracts/ConvertLib.json
@ -0,0 +1,455 @@
+{
+  "contractName": "ConvertLib",
+  "abi": [
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "amount",
+          "type": "uint256"
+        },
+        {
+          "name": "conversionRate",
+          "type": "uint256"
+        }
+      ],
+      "name": "convert",
+      "outputs": [
+        {
+          "name": "convertedAmount",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
+  ],
+  "bytecode": "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",
+  "deployedBytecode": "0x73000000000000000000000000000000000000000030146060604052600436106056576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff16806396e4ee3d14605b575b600080fd5b8115606557600080fd5b608260048080359060200190919080359060200190919050506098565b6040518082815260200191505060405180910390f35b60008183029050929150505600a165627a7a72305820ab84b2740847d7b84a33de9738ae9cf9aabac1b68e6a64d60bd5020b9b6235e40029",
+  "sourceMap": "28:148:0:-;;132:2:-1;166:7;155:9;146:7;137:37;252:7;246:14;243:1;238:23;232:4;229:33;270:1;265:20;;;;222:63;;265:20;274:9;222:63;;298:9;295:1;288:20;328:4;319:7;311:22;352:7;343;336:24",
+  "deployedSourceMap": "28:148:0:-;;;;;;;;;;;;;;;;;;;;;;;;;;;50:123;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;109:20;154:14;145:6;:23;138:30;;50:123;;;;:::o",
+  "source": "pragma solidity ^0.4.17;\r\n\r\nlibrary ConvertLib{\r\n\tfunction convert(uint amount,uint conversionRate) returns (uint convertedAmount)\r\n\t{\r\n\t\treturn amount * conversionRate;\r\n\t}\r\n}\r\n",
+  "sourcePath": "C:\\workspace\\current_workspace\\web3java\\dev_truffle\\contracts\\ConvertLib.sol",
+  "ast": {
+    "absolutePath": "/C/workspace/current_workspace/web3java/dev_truffle/contracts/ConvertLib.sol",
+    "exportedSymbols": {
+      "ConvertLib": [
+        16
+      ]
+    },
+    "id": 17,
+    "nodeType": "SourceUnit",
+    "nodes": [
+      {
+        "id": 1,
+        "literals": [
+          "solidity",
+          "^",
+          "0.4",
+          ".17"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "0:24:0"
+      },
+      {
+        "baseContracts": [],
+        "contractDependencies": [],
+        "contractKind": "library",
+        "documentation": null,
+        "fullyImplemented": true,
+        "id": 16,
+        "linearizedBaseContracts": [
+          16
+        ],
+        "name": "ConvertLib",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 14,
+              "nodeType": "Block",
+              "src": "133:40:0",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
+                    "id": 12,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftExpression": {
+                      "argumentTypes": null,
+                      "id": 10,
+                      "name": "amount",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 3,
+                      "src": "145:6:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "*",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "id": 11,
+                      "name": "conversionRate",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 5,
+                      "src": "154:14:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "145:23:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "functionReturnParameters": 9,
+                  "id": 13,
+                  "nodeType": "Return",
+                  "src": "138:30:0"
+                }
+              ]
+            },
+            "documentation": null,
+            "id": 15,
+            "implemented": true,
+            "isConstructor": false,
+            "isDeclaredConst": false,
+            "modifiers": [],
+            "name": "convert",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 6,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 3,
+                  "name": "amount",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 15,
+                  "src": "67:11:0",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 2,
+                    "name": "uint",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "67:4:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 5,
+                  "name": "conversionRate",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 15,
+                  "src": "79:19:0",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 4,
+                    "name": "uint",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "79:4:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "66:33:0"
+            },
+            "payable": false,
+            "returnParameters": {
+              "id": 9,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 8,
+                  "name": "convertedAmount",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 15,
+                  "src": "109:20:0",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 7,
+                    "name": "uint",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "109:4:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "108:22:0"
+            },
+            "scope": 16,
+            "src": "50:123:0",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 17,
+        "src": "28:148:0"
+      }
+    ],
+    "src": "0:178:0"
+  },
+  "legacyAST": {
+    "absolutePath": "/C/workspace/current_workspace/web3java/dev_truffle/contracts/ConvertLib.sol",
+    "exportedSymbols": {
+      "ConvertLib": [
+        16
+      ]
+    },
+    "id": 17,
+    "nodeType": "SourceUnit",
+    "nodes": [
+      {
+        "id": 1,
+        "literals": [
+          "solidity",
+          "^",
+          "0.4",
+          ".17"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "0:24:0"
+      },
+      {
+        "baseContracts": [],
+        "contractDependencies": [],
+        "contractKind": "library",
+        "documentation": null,
+        "fullyImplemented": true,
+        "id": 16,
+        "linearizedBaseContracts": [
+          16
+        ],
+        "name": "ConvertLib",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 14,
+              "nodeType": "Block",
+              "src": "133:40:0",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
+                    "id": 12,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftExpression": {
+                      "argumentTypes": null,
+                      "id": 10,
+                      "name": "amount",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 3,
+                      "src": "145:6:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "*",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "id": 11,
+                      "name": "conversionRate",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 5,
+                      "src": "154:14:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "145:23:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "functionReturnParameters": 9,
+                  "id": 13,
+                  "nodeType": "Return",
+                  "src": "138:30:0"
+                }
+              ]
+            },
+            "documentation": null,
+            "id": 15,
+            "implemented": true,
+            "isConstructor": false,
+            "isDeclaredConst": false,
+            "modifiers": [],
+            "name": "convert",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 6,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 3,
+                  "name": "amount",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 15,
+                  "src": "67:11:0",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 2,
+                    "name": "uint",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "67:4:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 5,
+                  "name": "conversionRate",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 15,
+                  "src": "79:19:0",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 4,
+                    "name": "uint",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "79:4:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "66:33:0"
+            },
+            "payable": false,
+            "returnParameters": {
+              "id": 9,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 8,
+                  "name": "convertedAmount",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 15,
+                  "src": "109:20:0",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 7,
+                    "name": "uint",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "109:4:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "108:22:0"
+            },
+            "scope": 16,
+            "src": "50:123:0",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 17,
+        "src": "28:148:0"
+      }
+    ],
+    "src": "0:178:0"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.4.21+commit.dfe3193c.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "2.0.0",
+  "updatedAt": "2018-04-14T03:37:39.678Z"
+}
--- a/web3j/dev_truffle/build/contracts/Example.json
+++ b/web3j/dev_truffle/build/contracts/Example.json
@ -0,0 +1,251 @@
+{
+  "contractName": "Example",
+  "abi": [
+    {
+      "inputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "constant": false,
+      "inputs": [],
+      "name": "ExampleFunction",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x60606040523415600e57600080fd5b60848061001c6000396000f300606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063b818dacd146044575b600080fd5b3415604e57600080fd5b60546056565b005b5600a165627a7a72305820bebcbbdf06550591bc772dfcb0eadc842f95953869feb7a9528bac91487d95240029",
+  "deployedBytecode": "0x606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063b818dacd146044575b600080fd5b3415604e57600080fd5b60546056565b005b5600a165627a7a72305820bebcbbdf06550591bc772dfcb0eadc842f95953869feb7a9528bac91487d95240029",
+  "sourceMap": "28:134:1:-;;;50:45;;;;;;;;28:134;;;;;;",
+  "deployedSourceMap": "28:134:1:-;;;;;;;;;;;;;;;;;;;;;;;;101:58;;;;;;;;;;;;;;;:::o",
+  "source": "pragma solidity ^0.4.17;\r\n\r\ncontract Example {\r\n  function Example() {\r\n    // constructor\r\n  }\r\n\r\n  function ExampleFunction() {\r\n    // example function\r\n  }\r\n}",
+  "sourcePath": "C:\\workspace\\current_workspace\\web3java\\dev_truffle\\contracts\\Example.sol",
+  "ast": {
+    "absolutePath": "/C/workspace/current_workspace/web3java/dev_truffle/contracts/Example.sol",
+    "exportedSymbols": {
+      "Example": [
+        27
+      ]
+    },
+    "id": 28,
+    "nodeType": "SourceUnit",
+    "nodes": [
+      {
+        "id": 18,
+        "literals": [
+          "solidity",
+          "^",
+          "0.4",
+          ".17"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "0:24:1"
+      },
+      {
+        "baseContracts": [],
+        "contractDependencies": [],
+        "contractKind": "contract",
+        "documentation": null,
+        "fullyImplemented": true,
+        "id": 27,
+        "linearizedBaseContracts": [
+          27
+        ],
+        "name": "Example",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 21,
+              "nodeType": "Block",
+              "src": "69:26:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 22,
+            "implemented": true,
+            "isConstructor": true,
+            "isDeclaredConst": false,
+            "modifiers": [],
+            "name": "Example",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 19,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "66:2:1"
+            },
+            "payable": false,
+            "returnParameters": {
+              "id": 20,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "69:0:1"
+            },
+            "scope": 27,
+            "src": "50:45:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 25,
+              "nodeType": "Block",
+              "src": "128:31:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 26,
+            "implemented": true,
+            "isConstructor": false,
+            "isDeclaredConst": false,
+            "modifiers": [],
+            "name": "ExampleFunction",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 23,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "125:2:1"
+            },
+            "payable": false,
+            "returnParameters": {
+              "id": 24,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "128:0:1"
+            },
+            "scope": 27,
+            "src": "101:58:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 28,
+        "src": "28:134:1"
+      }
+    ],
+    "src": "0:162:1"
+  },
+  "legacyAST": {
+    "absolutePath": "/C/workspace/current_workspace/web3java/dev_truffle/contracts/Example.sol",
+    "exportedSymbols": {
+      "Example": [
+        27
+      ]
+    },
+    "id": 28,
+    "nodeType": "SourceUnit",
+    "nodes": [
+      {
+        "id": 18,
+        "literals": [
+          "solidity",
+          "^",
+          "0.4",
+          ".17"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "0:24:1"
+      },
+      {
+        "baseContracts": [],
+        "contractDependencies": [],
+        "contractKind": "contract",
+        "documentation": null,
+        "fullyImplemented": true,
+        "id": 27,
+        "linearizedBaseContracts": [
+          27
+        ],
+        "name": "Example",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 21,
+              "nodeType": "Block",
+              "src": "69:26:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 22,
+            "implemented": true,
+            "isConstructor": true,
+            "isDeclaredConst": false,
+            "modifiers": [],
+            "name": "Example",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 19,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "66:2:1"
+            },
+            "payable": false,
+            "returnParameters": {
+              "id": 20,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "69:0:1"
+            },
+            "scope": 27,
+            "src": "50:45:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 25,
+              "nodeType": "Block",
+              "src": "128:31:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 26,
+            "implemented": true,
+            "isConstructor": false,
+            "isDeclaredConst": false,
+            "modifiers": [],
+            "name": "ExampleFunction",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 23,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "125:2:1"
+            },
+            "payable": false,
+            "returnParameters": {
+              "id": 24,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "128:0:1"
+            },
+            "scope": 27,
+            "src": "101:58:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 28,
+        "src": "28:134:1"
+      }
+    ],
+    "src": "0:162:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.4.21+commit.dfe3193c.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "2.0.0",
+  "updatedAt": "2018-04-14T03:37:39.710Z"
+}
--- a/web3j/dev_truffle/build/contracts/Migrations.json
+++ b/web3j/dev_truffle/build/contracts/Migrations.json
--- a/web3j/dev_truffle/contracts/ConvertLib.sol
+++ b/web3j/dev_truffle/contracts/ConvertLib.sol
@ -0,0 +1,8 @@
+pragma solidity ^0.4.17;
+
+library ConvertLib{
+	function convert(uint amount,uint conversionRate) returns (uint convertedAmount)
+	{
+		return amount * conversionRate;
+	}
+}
--- a/web3j/dev_truffle/contracts/Example.sol
+++ b/web3j/dev_truffle/contracts/Example.sol
@ -0,0 +1,11 @@
+pragma solidity ^0.4.17;
+
+contract Example {
+  function Example() {
+    // constructor
+  }
+
+  function ExampleFunction() {
+    // example function
+  }
+}
--- a/web3j/dev_truffle/contracts/Migrations.sol
+++ b/web3j/dev_truffle/contracts/Migrations.sol
@ -0,0 +1,23 @@
+pragma solidity ^0.4.17;
+
+contract Migrations {
+  address public owner;
+  uint public last_completed_migration;
+
+  modifier restricted() {
+    if (msg.sender == owner) _;
+  }
+
+  function Migrations() public {
+    owner = msg.sender;
+  }
+
+  function setCompleted(uint completed) public restricted {
+    last_completed_migration = completed;
+  }
+
+  function upgrade(address new_address) public restricted {
+    Migrations upgraded = Migrations(new_address);
+    upgraded.setCompleted(last_completed_migration);
+  }
+}
--- a/web3j/dev_truffle/migrations/1_initial_migration.js
+++ b/web3j/dev_truffle/migrations/1_initial_migration.js
@ -0,0 +1,3 @@
+module.exports = deployer => {
+  deployer.deploy(artifacts.require("./Migrations.sol"));
+};
--- a/web3j/dev_truffle/migrations/2_deploy_contracts.js
+++ b/web3j/dev_truffle/migrations/2_deploy_contracts.js
@ -0,0 +1,8 @@
+const  Example = artifacts.require("./Example.sol"),
+  ConvertLib = artifacts.require("./ConvertLib.sol");
+
+module.exports = deployer => {
+  deployer.deploy(ConvertLib);
+  deployer.link(ConvertLib, Example);
+  deployer.deploy(Example);
+};
--- a/web3j/dev_truffle/truffle.js
+++ b/web3j/dev_truffle/truffle.js
@ -0,0 +1,20 @@
+module.exports = {
+  contracts_build_directory: "./build/contracts",
+  networks: {
+    live: {
+      network_id: 1, // Ethereum public network
+      host: 'localhost',
+      port: 8545
+    },
+    testnet: {
+      network_id: 3, // Official Ethereum test network (Ropsten)
+      host: 'localhost',
+      port: 8545
+    },
+    development: {
+      host: 'localhost',
+      port: 8545,
+      network_id: '*'
+    }
+  }
+}
--- a/web3j/pom.xml
+++ b/web3j/pom.xml
@ -0,0 +1,210 @@
+<?xml version="1.0"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.web3j</groupId>
+    <artifactId>Web3j</artifactId>
+    <packaging>war</packaging>
+    <version>1.0.0</version>
+    <name>web3j</name>
+
+     <properties>
+        <hamcrest.version>1.3</hamcrest.version>
+        <jackson.version>2.9.3</jackson.version>
+        <javax-jsp.version>2.3.1</javax-jsp.version>
+        <javax-servlet.version>3.1.0</javax-servlet.version>
+        <jsonpath.version>2.4.0</jsonpath.version>
+        <jstl.version>1.2</jstl.version>
+        <junit.version>4.12</junit.version>
+        <logback.version>1.2.3</logback.version>
+        <maven-surefire.version>2.18.1</maven-surefire.version>
+        <mockito.version>1.10.19</mockito.version>
+        <slf4j.version>1.7.25</slf4j.version>
+        <springframework.version>5.0.5.RELEASE</springframework.version>
+    </properties>
+    <dependencies>
+
+        <!-- Spring Dependencies -->
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-core</artifactId>
+            <version>${springframework.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-web</artifactId>
+            <version>${springframework.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webmvc</artifactId>
+            <version>${springframework.version}</version>
+        </dependency>
+
+        <!-- Servlet -->
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <version>${javax-servlet.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet.jsp.jstl</groupId>
+            <artifactId>jstl-api</artifactId>
+            <version>${jstl.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet.jsp</groupId>
+            <artifactId>javax.servlet.jsp-api</artifactId>
+            <version>${javax-jsp.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>jstl</artifactId>
+            <version>${jstl.version}</version>
+        </dependency>
+
+        <!-- Logging -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>jcl-over-slf4j</artifactId>
+            <version>${slf4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
+        </dependency>
+
+        <!-- Jackson Dependencies -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+
+        <!-- Web3J -->
+        <dependency>
+            <groupId>org.web3j</groupId>
+            <artifactId>core</artifactId>
+            <version>3.3.1</version>
+        </dependency>
+
+        <!-- Testing -->
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>${mockito.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.hamcrest</groupId>
+                    <artifactId>hamcrest-core</artifactId>
+                </exclusion>
+            </exclusions>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.hamcrest</groupId>
+                    <artifactId>hamcrest-core</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-library</artifactId>
+            <version>${hamcrest.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <version>${springframework.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <version>${springframework.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.jayway.jsonpath</groupId>
+            <artifactId>json-path</artifactId>
+            <version>${jsonpath.version}</version>
+        </dependency>
+
+    </dependencies>
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <version>3.1</version>
+                    <configuration>
+                        <source>1.8</source>
+                        <target>1.8</target>
+                    </configuration>
+                </plugin>
+                <plugin>
+                    <groupId>org.apache.tomcat.maven</groupId>
+                    <artifactId>tomcat8-maven-plugin</artifactId>
+                    <version>3.0-r1655215</version>
+                    <configuration>
+                        <path>/javaweb3</path>
+                    </configuration>
+                </plugin>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-war-plugin</artifactId>
+                    <version>3.0.0</version>
+                    <configuration>
+                        <warSourceDirectory>src/main/webapp</warSourceDirectory>
+                        <failOnMissingWebXml>false</failOnMissingWebXml>
+                    </configuration>
+                </plugin>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-surefire-plugin</artifactId>
+                    <version>${maven-surefire.version}</version>
+                    <executions>
+                        <execution>
+                            <id>install</id>
+                            <phase>install</phase>
+                            <goals>
+                                <goal>test</goal>
+                            </goals>
+                            <configuration>
+                                <includes>
+                                    <include>
+                                        test/com/baeldung/web3j/controllers/EthereumRestControllerIntegrationTest.java
+                                    </include>
+                                    <include>
+                                        test/com/baeldung/web3j/controllers/EthereumRestControllerUnitTest.java
+                                    </include>
+                                    <include>
+                                        test/com/baeldung/web3j/services/EthereumContractUnitTest.java
+                                    </include>
+                                </includes>
+                            </configuration>
+                        </execution>
+                    </executions>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+        <finalName>web3j</finalName>
+    </build>
+</project>
--- a/web3j/src/main/java/com/baeldung/web3j/config/AppConfig.java
+++ b/web3j/src/main/java/com/baeldung/web3j/config/AppConfig.java
@ -0,0 +1,68 @@
+package com.baeldung.web3j.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
+import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.resource.PathResourceResolver;
+import org.springframework.web.servlet.view.JstlView;
+import org.springframework.web.servlet.view.UrlBasedViewResolver;
+
+import java.util.concurrent.Executor;
+
+@Configuration
+@EnableWebMvc
+@EnableAsync
+@ComponentScan("com.baeldung.web3j")
+public class AppConfig implements WebMvcConfigurer {
+
+    public void addViewControllers(ViewControllerRegistry registry) {
+        registry.addViewController("/").setViewName("index");
+    }
+
+    /**
+     * Static resource locations including themes
+     */
+    @Override
+    public void addResourceHandlers(ResourceHandlerRegistry registry) {
+        registry.addResourceHandler("/resources/**/*")
+                .addResourceLocations("/", "/resources/")
+                .setCachePeriod(3600)
+                .resourceChain(true)
+                .addResolver(new PathResourceResolver());
+    }
+
+    /**
+     * View resolver for JSP
+     */
+    @Bean
+    public UrlBasedViewResolver viewResolver() {
+        UrlBasedViewResolver resolver = new UrlBasedViewResolver();
+        resolver.setPrefix("/WEB-INF/jsp/");
+        resolver.setSuffix(".jsp");
+        resolver.setViewClass(JstlView.class);
+        return resolver;
+    }
+
+    /**
+     * Configuration for async thread bean
+     *
+     * More: https://docs.spring.io/autorepo/docs/spring-framework/5.0.3.RELEASE/javadoc-api/org/springframework/scheduling/SchedulingTaskExecutor.html
+     */
+    @Bean
+    public Executor asyncExecutor() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(2);
+        executor.setMaxPoolSize(2);
+        executor.setQueueCapacity(500);
+        executor.setThreadNamePrefix("CsvThread");
+        executor.initialize();
+        return executor;
+    }
+
+}
--- a/web3j/src/main/java/com/baeldung/web3j/config/WebAppInitializer.java
+++ b/web3j/src/main/java/com/baeldung/web3j/config/WebAppInitializer.java
@ -0,0 +1,28 @@
+package com.baeldung.web3j.config;
+
+import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
+
+public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
+
+    //AbstractDispatcherServletInitializer override DEFAULT_SERVLET_NAME
+    @Override
+    protected String getServletName() {
+        return "dispatcher";
+    }
+
+    @Override
+    protected Class<?>[] getRootConfigClasses() {
+        return new Class[]{};
+    }
+
+    @Override
+    protected Class<?>[] getServletConfigClasses() {
+        return new Class[]{AppConfig.class};
+    }
+
+    @Override
+    protected String[] getServletMappings() {
+        return new String[]{"/"};
+    }
+
+}
--- a/web3j/src/main/java/com/baeldung/web3j/constants/Constants.java
+++ b/web3j/src/main/java/com/baeldung/web3j/constants/Constants.java
@ -0,0 +1,18 @@
+package com.baeldung.web3j.constants;
+
+public class Constants {
+
+    public static final String API_BLOCK = "/api/block";
+    public static final String API_ACCOUNTS = "/api/accounts";
+    public static final String API_TRANSACTIONS = "/api/transactions";
+    public static final String API_BALANCE = "/api/balance";
+
+    public static final String GENERIC_EXCEPTION = "Exception encountered!";
+    public static final String PLEASE_SUPPLY_REAL_DATA = "Please Supply Real Data!";
+
+    public static final String DEFAULT_ADDRESS = "0x281055afc982d96fab65b3a49cac8b878184cb16";
+    public static final String DEFAULT_CONTRACT_ADDRESS = "00000000000000000000";
+
+
+
+}
--- a/web3j/src/main/java/com/baeldung/web3j/contracts/Example.java
+++ b/web3j/src/main/java/com/baeldung/web3j/contracts/Example.java
@ -0,0 +1,74 @@
+package com.baeldung.web3j.contracts;
+
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import org.web3j.abi.TypeReference;
+import org.web3j.abi.datatypes.Function;
+import org.web3j.abi.datatypes.Type;
+import org.web3j.crypto.Credentials;
+import org.web3j.protocol.Web3j;
+import org.web3j.protocol.core.RemoteCall;
+import org.web3j.protocol.core.methods.response.TransactionReceipt;
+import org.web3j.tx.Contract;
+import org.web3j.tx.TransactionManager;
+
+/**
+ * <p>Auto generated code.
+ * <p><strong>Do not modify!</strong>
+ * <p>Please use the <a href="https://docs.web3j.io/command_line.html">web3j command line tools</a>,
+ * or the org.web3j.codegen.SolidityFunctionWrapperGenerator in the 
+ * <a href="https://github.com/web3j/web3j/tree/master/codegen">codegen module</a> to update.
+ *
+ * <p>Generated with web3j version 3.3.1.
+ */
+public class Example extends Contract {
+    private static final String BINARY = "0x60606040523415600e57600080fd5b60848061001c6000396000f300606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063b818dacd146044575b600080fd5b3415604e57600080fd5b60546056565b005b5600a165627a7a72305820bebcbbdf06550591bc772dfcb0eadc842f95953869feb7a9528bac91487d95240029";
+
+    protected static final HashMap<String, String> _addresses;
+
+    static {
+        _addresses = new HashMap<>();
+    }
+
+    protected Example(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {
+        super(BINARY, contractAddress, web3j, credentials, gasPrice, gasLimit);
+    }
+
+    protected Example(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {
+        super(BINARY, contractAddress, web3j, transactionManager, gasPrice, gasLimit);
+    }
+
+    public static RemoteCall<Example> deploy(Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {
+        return deployRemoteCall(Example.class, web3j, credentials, gasPrice, gasLimit, BINARY, "");
+    }
+
+    public static RemoteCall<Example> deploy(Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {
+        return deployRemoteCall(Example.class, web3j, transactionManager, gasPrice, gasLimit, BINARY, "");
+    }
+
+    public RemoteCall<TransactionReceipt> ExampleFunction() {
+        final Function function = new Function(
+                "ExampleFunction", 
+                Arrays.<Type>asList(), 
+                Collections.<TypeReference<?>>emptyList());
+        return executeRemoteCallTransaction(function);
+    }
+
+    public static Example load(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {
+        return new Example(contractAddress, web3j, credentials, gasPrice, gasLimit);
+    }
+
+    public static Example load(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {
+        return new Example(contractAddress, web3j, transactionManager, gasPrice, gasLimit);
+    }
+
+    protected String getStaticDeployedAddress(String networkId) {
+        return _addresses.get(networkId);
+    }
+
+    public static String getPreviouslyDeployedAddress(String networkId) {
+        return _addresses.get(networkId);
+    }
+}
--- a/web3j/src/main/java/com/baeldung/web3j/controllers/EthereumRestController.java
+++ b/web3j/src/main/java/com/baeldung/web3j/controllers/EthereumRestController.java
@ -0,0 +1,103 @@
+package com.baeldung.web3j.controllers;
+
+import com.baeldung.web3j.constants.Constants;
+import com.baeldung.web3j.helpers.TimeHelper;
+import com.baeldung.web3j.services.Web3Service;
+import com.baeldung.web3j.transfers.ResponseTransfer;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+import org.web3j.protocol.core.methods.response.EthAccounts;
+import org.web3j.protocol.core.methods.response.EthBlockNumber;
+import org.web3j.protocol.core.methods.response.EthGetBalance;
+import org.web3j.protocol.core.methods.response.EthGetTransactionCount;
+
+import java.time.Instant;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Future;
+
+import static com.baeldung.web3j.constants.Constants.GENERIC_EXCEPTION;
+
+@RestController
+public class EthereumRestController {
+
+    @Autowired
+    Web3Service web3Service;
+
+    @RequestMapping(value = Constants.API_BLOCK, method = RequestMethod.GET)
+    public Future<ResponseTransfer> getBlock() {
+        ResponseTransfer responseTransfer = new ResponseTransfer();
+        Instant start = TimeHelper.start();
+
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                CompletableFuture<EthBlockNumber> result = web3Service.getBlockNumber();
+                responseTransfer.setMessage(result.get().toString());
+            } catch (Exception e) {
+                responseTransfer.setMessage(GENERIC_EXCEPTION);
+            }
+            return responseTransfer;
+        }).thenApplyAsync(result -> {
+            result.setPerformance(TimeHelper.stop(start));
+            return result;
+        });
+    }
+
+    @RequestMapping(value = Constants.API_ACCOUNTS, method = RequestMethod.GET)
+    public Future<ResponseTransfer> getAccounts() {
+        ResponseTransfer responseTransfer = new ResponseTransfer();
+        Instant start = TimeHelper.start();
+
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                CompletableFuture<EthAccounts> result = web3Service.getEthAccounts();
+                responseTransfer.setMessage(result.get().toString());
+            } catch (Exception e) {
+                responseTransfer.setMessage(GENERIC_EXCEPTION);
+            }
+            return responseTransfer;
+
+        }).thenApplyAsync(result -> {
+            result.setPerformance(TimeHelper.stop(start));
+            return result;
+        });
+    }
+
+    @RequestMapping(value = Constants.API_TRANSACTIONS, method = RequestMethod.GET)
+    public Future<ResponseTransfer> getTransactions() {
+        ResponseTransfer responseTransfer = new ResponseTransfer();
+        Instant start = TimeHelper.start();
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                CompletableFuture<EthGetTransactionCount> result = web3Service.getTransactionCount();
+                responseTransfer.setMessage(result.get().toString());
+            } catch (Exception e) {
+                responseTransfer.setMessage(GENERIC_EXCEPTION);
+            }
+            return responseTransfer;
+        }).thenApplyAsync(result -> {
+            result.setPerformance(TimeHelper.stop(start));
+            return result;
+        });
+    }
+
+    @RequestMapping(value = Constants.API_BALANCE, method = RequestMethod.GET)
+    public Future<ResponseTransfer> getBalance() {
+        ResponseTransfer responseTransfer = new ResponseTransfer();
+        Instant start = TimeHelper.start();
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                CompletableFuture<EthGetBalance> result = web3Service.getEthBalance();
+                responseTransfer.setMessage(result.get().toString());
+            } catch (Exception e) {
+                responseTransfer.setMessage(GENERIC_EXCEPTION);
+            }
+            return responseTransfer;
+        }).thenApplyAsync(result -> {
+            result.setPerformance(TimeHelper.stop(start));
+            return result;
+        });
+    }
+
+}
--- a/web3j/src/main/java/com/baeldung/web3j/helpers/TimeHelper.java
+++ b/web3j/src/main/java/com/baeldung/web3j/helpers/TimeHelper.java
@ -0,0 +1,16 @@
+package com.baeldung.web3j.helpers;
+
+import java.time.Duration;
+import java.time.Instant;
+
+public class TimeHelper {
+
+    public static Instant start() {
+        return Instant.now();
+    }
+
+    public static Duration stop(Instant start) {
+        Instant end = Instant.now();
+        return Duration.between(start, end);
+    }
+}
--- a/web3j/src/main/java/com/baeldung/web3j/services/Web3Service.java
+++ b/web3j/src/main/java/com/baeldung/web3j/services/Web3Service.java
@ -0,0 +1,156 @@
+package com.baeldung.web3j.services;
+
+import com.baeldung.web3j.contracts.Example;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Service;
+import org.web3j.abi.FunctionEncoder;
+import org.web3j.abi.datatypes.Function;
+import org.web3j.crypto.Credentials;
+import org.web3j.crypto.WalletUtils;
+import org.web3j.protocol.Web3j;
+import org.web3j.protocol.core.DefaultBlockParameter;
+import org.web3j.protocol.core.methods.request.Transaction;
+import org.web3j.protocol.core.methods.response.EthAccounts;
+import org.web3j.protocol.core.methods.response.EthBlockNumber;
+import org.web3j.protocol.core.methods.response.EthGetBalance;
+import org.web3j.protocol.core.methods.response.EthGetTransactionCount;
+import org.web3j.protocol.http.HttpService;
+import org.web3j.tx.Contract;
+import org.web3j.tx.ManagedTransaction;
+
+import java.io.File;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+
+import static com.baeldung.web3j.constants.Constants.DEFAULT_ADDRESS;
+import static com.baeldung.web3j.constants.Constants.GENERIC_EXCEPTION;
+import static com.baeldung.web3j.constants.Constants.PLEASE_SUPPLY_REAL_DATA;
+
+@Service
+public class Web3Service {
+
+    private Web3j web3j = Web3j.build(new HttpService());
+
+    //Create and Init the default Web3J connection
+    public void customInit(String provider) {
+        this.web3j = Web3j.build(new HttpService(provider));
+    }
+
+    //Convert to and from supplied contract ABI bytecode
+    public static String toBinary(String bytecode) {
+        return bytecode.replaceFirst("^0x", "");
+    }
+
+    public static String toByteCode(String binary) {
+        return "0x" + binary;
+    }
+
+    @Async
+    public CompletableFuture<EthBlockNumber> getBlockNumber() {
+        EthBlockNumber result = new EthBlockNumber();
+        try {
+            this.web3j.ethBlockNumber().sendAsync().thenApply(r -> r.getBlockNumber());
+        } catch (Exception ex) {
+            System.out.println(GENERIC_EXCEPTION);
+        }
+        return CompletableFuture.completedFuture(result);
+    }
+
+    @Async
+    public CompletableFuture<EthAccounts> getEthAccounts() {
+        EthAccounts result = new EthAccounts();
+        try {
+            this.web3j.ethAccounts().sendAsync().thenApply(r -> r.getAccounts());
+        } catch (Exception ex) {
+            System.out.println(GENERIC_EXCEPTION);
+        }
+        return CompletableFuture.completedFuture(result);
+    }
+
+    @Async
+    public CompletableFuture<EthGetTransactionCount> getTransactionCount() {
+        EthGetTransactionCount result = new EthGetTransactionCount();
+        try {
+            this.web3j.ethGetTransactionCount(DEFAULT_ADDRESS, DefaultBlockParameter.valueOf("latest")).sendAsync().thenApply(r -> r.getTransactionCount());
+        } catch (Exception ex) {
+            System.out.println(GENERIC_EXCEPTION);
+        }
+        return CompletableFuture.completedFuture(result);
+    }
+
+    @Async
+    public CompletableFuture<EthGetBalance> getEthBalance() {
+        EthGetBalance result = new EthGetBalance();
+        try {
+            this.web3j.ethGetBalance(DEFAULT_ADDRESS, DefaultBlockParameter.valueOf("latest")).sendAsync().thenApply(r -> r.getBalance());
+        } catch (Exception ex) {
+            System.out.println(GENERIC_EXCEPTION);
+        }
+        return CompletableFuture.completedFuture(result);
+    }
+
+    @Async
+    public CompletableFuture<String> fromScratchContractExample() {
+
+        String contractAddress = "";
+
+        try {
+            //Create a wallet
+            WalletUtils.generateNewWalletFile("PASSWORD", new File("/path/to/destination"), true);
+            //Load the credentials from it
+            Credentials credentials = WalletUtils.loadCredentials("PASSWORD", "/path/to/walletfile");
+
+            //Deploy contract to address specified by wallet
+            Example contract = Example.deploy(this.web3j,
+                    credentials,
+                    ManagedTransaction.GAS_PRICE,
+                    Contract.GAS_LIMIT).send();
+
+            //Het the address
+            contractAddress = contract.getContractAddress();
+
+        } catch (Exception ex) {
+            System.out.println(PLEASE_SUPPLY_REAL_DATA);
+            return CompletableFuture.completedFuture(PLEASE_SUPPLY_REAL_DATA);
+        }
+        return CompletableFuture.completedFuture(contractAddress);
+    }
+
+    @Async
+    public CompletableFuture<String> sendTx() {
+        String transactionHash = "";
+
+        try {
+            List inputParams = new ArrayList();
+            List outputParams = new ArrayList();
+            Function function = new Function("fuctionName", inputParams, outputParams);
+
+            String encodedFunction = FunctionEncoder.encode(function);
+
+            BigInteger nonce = BigInteger.valueOf(100);
+            BigInteger gasprice = BigInteger.valueOf(100);
+            BigInteger gaslimit = BigInteger.valueOf(100);
+
+            Transaction transaction = Transaction.createFunctionCallTransaction("FROM_ADDRESS", nonce, gasprice, gaslimit, "TO_ADDRESS", encodedFunction);
+
+            org.web3j.protocol.core.methods.response.EthSendTransaction transactionResponse = web3j.ethSendTransaction(transaction).sendAsync().get();
+            transactionHash = transactionResponse.getTransactionHash();
+
+        } catch (Exception ex) {
+            System.out.println(PLEASE_SUPPLY_REAL_DATA);
+            return CompletableFuture.completedFuture(PLEASE_SUPPLY_REAL_DATA);
+        }
+
+        return CompletableFuture.completedFuture(transactionHash);
+    }
+}
+
+
+
+
+
+
+
+
--- a/web3j/src/main/java/com/baeldung/web3j/transfers/ResponseTransfer.java
+++ b/web3j/src/main/java/com/baeldung/web3j/transfers/ResponseTransfer.java
@ -0,0 +1,28 @@
+package com.baeldung.web3j.transfers;
+
+import java.time.Duration;
+
+public class ResponseTransfer {
+
+    public ResponseTransfer() {}
+
+    private Duration performance;
+    private String message;
+
+    public Duration getPerformance() {
+        return performance;
+    }
+
+    public void setPerformance(Duration performance) {
+        this.performance = performance;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+}
--- a/web3j/src/main/webapp/WEB-INF/.gitkeep
+++ b/web3j/src/main/webapp/WEB-INF/.gitkeep
--- a/web3j/src/main/webapp/resources/.gitkeep
+++ b/web3j/src/main/webapp/resources/.gitkeep
--- a/web3j/src/test/com/baeldung/web3j/controllers/EthereumRestControllerIntegrationTest.java
+++ b/web3j/src/test/com/baeldung/web3j/controllers/EthereumRestControllerIntegrationTest.java
@ -0,0 +1,78 @@
+package com.baeldung.web3j.controllers;
+
+
+import com.baeldung.web3j.config.AppConfig;
+import com.baeldung.web3j.constants.Constants;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.context.WebApplicationContext;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = {AppConfig.class})
+@WebAppConfiguration
+public class EthereumRestControllerIntegrationTest {
+
+    private MockMvc mockMvc;
+
+    private void constructAsyncTest(String endpoint) {
+        try {
+            MvcResult asyncResult = mockMvc
+                    .perform(get(endpoint))
+                    .andReturn();
+
+            mockMvc.perform(asyncDispatch(asyncResult))
+                    .andDo(print())
+                    .andExpect(status().isOk());
+
+        } catch (Exception e) {
+            System.out.println("Exception: " + e);
+        }
+    }
+
+    @Autowired
+    private WebApplicationContext wac;
+
+    @Before
+    public void preTest() throws Exception {
+        mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
+    }
+
+    @Test
+    public void accounts() {
+        constructAsyncTest(Constants.API_ACCOUNTS);
+    }
+
+    @Test
+    public void transactions() {
+        constructAsyncTest(Constants.API_TRANSACTIONS);
+    }
+
+    @Test
+    public void block() {
+        constructAsyncTest(Constants.API_BLOCK);
+    }
+
+    @Test
+    public void balance() {
+        constructAsyncTest(Constants.API_BALANCE);
+    }
+
+    @After
+    public void postTest() {
+        mockMvc = null;
+    }
+}
--- a/web3j/src/test/com/baeldung/web3j/controllers/EthereumRestControllerUnitTest.java
+++ b/web3j/src/test/com/baeldung/web3j/controllers/EthereumRestControllerUnitTest.java
@ -0,0 +1,76 @@
+package com.baeldung.web3j.controllers;
+
+import com.baeldung.web3j.constants.Constants;
+import com.baeldung.web3j.services.Web3Service;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+public class EthereumRestControllerUnitTest {
+
+    private MockMvc mockMvc;
+
+    private void constructAsyncTest(String endpoint) {
+        try {
+            MvcResult asyncResult = mockMvc
+                    .perform(get(endpoint))
+                    .andReturn();
+
+            mockMvc.perform(asyncDispatch(asyncResult))
+                    .andDo(print())
+                    .andExpect(status().isOk());
+
+        } catch (Exception e) {
+            System.out.println("Exception: " + e);
+        }
+    }
+
+    @Mock
+    private Web3Service web3Service;
+
+    @InjectMocks
+    private EthereumRestController ethereumRestController;
+
+    @Before
+    public void preTest() {
+        MockitoAnnotations.initMocks(this);
+        mockMvc = MockMvcBuilders.standaloneSetup(ethereumRestController).build();
+    }
+
+    @Test
+    public void accounts() {
+        constructAsyncTest(Constants.API_ACCOUNTS);
+    }
+
+    @Test
+    public void transactions() {
+        constructAsyncTest(Constants.API_TRANSACTIONS);
+    }
+
+    @Test
+    public void block() {
+        constructAsyncTest(Constants.API_BLOCK);
+    }
+
+    @Test
+    public void balance() {
+        constructAsyncTest(Constants.API_BALANCE);
+    }
+
+    @After
+    public void postTest() {
+        mockMvc = null;
+    }
+
+}
--- a/web3j/src/test/com/baeldung/web3j/services/EthereumContractUnitTest.java
+++ b/web3j/src/test/com/baeldung/web3j/services/EthereumContractUnitTest.java
@ -0,0 +1,37 @@
+package com.baeldung.web3j.services;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.concurrent.CompletableFuture;
+
+import static com.baeldung.web3j.constants.Constants.PLEASE_SUPPLY_REAL_DATA;
+
+public class EthereumContractUnitTest {
+
+    private Web3Service web3Service;
+
+    @Before
+    public void setup() {
+        web3Service = new Web3Service();
+    }
+
+    @Test
+    public void testContract() {
+        CompletableFuture<String> result = web3Service.fromScratchContractExample();
+        assert (result instanceof CompletableFuture);
+    }
+
+    @Test
+    public void sendTx() {
+        CompletableFuture<String> result = web3Service.sendTx();
+        assert (result instanceof CompletableFuture);
+    }
+
+    @After
+    public void cleanup() {
+    }
+}