Add tutorial files for ResultSet2JSON Article (#11912)

* Add tutorial files

* Move script to new folder

* Use Maven/H2 instead of JBang/DuckDB

* Use Java 8

* Usen an older versio of JOOQ

* Format according to Beldung Intellij guide

* Remove dangling commit

* Use 2-space indentation

* Apply formatting from Eclipse

* Add unit test

* Add assertion

* Change test names

* Change method names

Co-authored-by: root <root@localhost.localdomain>
Co-authored-by: Alireza Ghasemi <alireza.ghasemi1@swisscom.com>

persistence-modules/core-java-persistence-2/example.csv

@@ -0,0 +1,4 @@
+Username,Id,First name,Last name
+doe1,7173,John,Doe
+smith3,3722,Dana,Smith
+john22,5490,John,Wang

persistence-modules/core-java-persistence-2/pom.xml

@@ -1,7 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
+<project xmlns="http://maven.apache.org/POM/4.0.0" 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: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">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.core-java-persistence-2</groupId>
     <artifactId>core-java-persistence-2</artifactId>
@@ -41,6 +39,20 @@
             <artifactId>mssql-jdbc</artifactId>
             <version>${mssql.driver.version}</version>
         </dependency>
+
+
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jooq</artifactId>
+            <version>3.11.11</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.json</groupId>
+            <artifactId>json</artifactId>
+            <version>20220320</version>
+        </dependency>
+
     </dependencies>
 
     <properties>

persistence-modules/core-java-persistence-2/src/main/java/com/baeldung/resultset2json/ResultSet2JSON.java

@@ -0,0 +1,137 @@
+package com.baeldung.resultset2json;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import org.jooq.Record;
+import org.jooq.RecordMapper;
+import org.jooq.impl.DSL;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.json.JSONArray;
+
+public class ResultSet2JSON {
+
+    public static void main(String... args) throws ClassNotFoundException, SQLException {
+
+        ResultSet2JSON testClass = new ResultSet2JSON();
+        testClass.convertWithoutJOOQ();
+    }
+
+    public void convertWithoutJOOQ() throws ClassNotFoundException, SQLException {
+        Class.forName("org.h2.Driver");
+        Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc", "user", "password");
+
+        // Create a table
+        Statement stmt = dbConnection.createStatement();
+        stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+        ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+        JSONArray result1 = resultSet2JdbcWithoutJOOQ(resultSet);
+        System.out.println(result1);
+
+        resultSet.close();
+    }
+
+    public void convertUsingJOOQDefaultApproach() throws ClassNotFoundException, SQLException {
+        Class.forName("org.h2.Driver");
+        Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc", "user", "password");
+        // Create a table
+        Statement stmt = dbConnection.createStatement();
+        stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+        ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+        JSONObject result1 = resultSet2JdbcUsingJOOQDefaultApproach(resultSet, dbConnection);
+        System.out.println(result1);
+
+        resultSet.close();
+    }
+
+    public void convertUsingCustomisedJOOQ() throws ClassNotFoundException, SQLException {
+        Class.forName("org.h2.Driver");
+        Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc", "user", "password");
+        // Create a table
+        Statement stmt = dbConnection.createStatement();
+        stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+        ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+        JSONArray result1 = resultSet2JdbcUsingCustomisedJOOQ(resultSet, dbConnection);
+        System.out.println(result1);
+
+        resultSet.close();
+    }
+
+    public static JSONArray resultSet2JdbcWithoutJOOQ(ResultSet resultSet) throws SQLException {
+        ResultSetMetaData md = resultSet.getMetaData();
+        int numCols = md.getColumnCount();
+        List<String> colNames = IntStream.range(0, numCols)
+            .mapToObj(i -> {
+                try {
+                    return md.getColumnName(i + 1);
+                } catch (SQLException e) {
+
+                    e.printStackTrace();
+                    return "?";
+                }
+            })
+            .collect(Collectors.toList());
+
+        JSONArray result = new JSONArray();
+        while (resultSet.next()) {
+            JSONObject row = new JSONObject();
+            colNames.forEach(cn -> {
+                try {
+                    row.put(cn, resultSet.getObject(cn));
+                } catch (JSONException | SQLException e) {
+
+                    e.printStackTrace();
+                }
+            });
+            result.put(row);
+        }
+        return result;
+    }
+
+    public static JSONObject resultSet2JdbcUsingJOOQDefaultApproach(ResultSet resultSet, Connection dbConnection) throws SQLException {
+        JSONObject result = new JSONObject(DSL.using(dbConnection)
+            .fetch(resultSet)
+            .formatJSON());
+        return result;
+    }
+
+    public static JSONArray resultSet2JdbcUsingCustomisedJOOQ(ResultSet resultSet, Connection dbConnection) throws SQLException {
+        ResultSetMetaData md = resultSet.getMetaData();
+        int numCols = md.getColumnCount();
+        List<String> colNames = IntStream.range(0, numCols)
+            .mapToObj(i -> {
+                try {
+                    return md.getColumnName(i + 1);
+                } catch (SQLException e) {
+
+                    e.printStackTrace();
+                    return "?";
+                }
+            })
+            .collect(Collectors.toList());
+
+        List<JSONObject> json = DSL.using(dbConnection)
+            .fetch(resultSet)
+            .map(new RecordMapper<Record, JSONObject>() {
+
+                @Override
+                public JSONObject map(Record r) {
+                    JSONObject obj = new JSONObject();
+                    colNames.forEach(cn -> obj.put(cn, r.get(cn)));
+                    return obj;
+                }
+            });
+    return new JSONArray(json);
+    }
+}

persistence-modules/core-java-persistence-2/src/test/java/com/baeldung/resultset2json/ResultSet2JSONUnitTest.java

@@ -0,0 +1,75 @@
+package com.baeldung.resultset2json;
+
+import static com.baeldung.resultset2json.ResultSet2JSON.resultSet2JdbcWithoutJOOQ;
+import static com.baeldung.resultset2json.ResultSet2JSON.resultSet2JdbcUsingJOOQDefaultApproach;
+import static com.baeldung.resultset2json.ResultSet2JSON.resultSet2JdbcUsingCustomisedJOOQ;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class ResultSet2JSONUnitTest {
+  JSONObject object = new JSONObject(
+    "{\"records\":[[\"doe1\",\"7173\",\"John\",\"Doe\"],[\"smith3\",\"3722\",\"Dana\",\"Smith\"],[\"john22\",\"5490\",\"John\",\"Wang\"]],\"fields\":[{\"schema\":\"PUBLIC\",\"name\":\"USERNAME\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"},{\"schema\":\"PUBLIC\",\"name\":\"ID\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"},{\"schema\":\"PUBLIC\",\"name\":\"First name\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"},{\"schema\":\"PUBLIC\",\"name\":\"Last name\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"}]}");
+
+  JSONArray array = new JSONArray(
+    "[{\"USERNAME\":\"doe1\",\"First name\":\"John\",\"ID\":\"7173\",\"Last name\":\"Doe\"},{\"USERNAME\":\"smith3\",\"First name\":\"Dana\",\"ID\":\"3722\",\"Last name\":\"Smith\"},{\"USERNAME\":\"john22\",\"First name\":\"John\",\"ID\":\"5490\",\"Last name\":\"Wang\"}]");
+
+  @Test
+  void whenResultSetConvertedWithoutJOOQ_shouldMatchJSON() throws SQLException, ClassNotFoundException {
+    Class.forName("org.h2.Driver");
+    Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc1", "user", "password");
+
+    // Create a table
+    Statement stmt = dbConnection.createStatement();
+    stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+    ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+    JSONArray result1 = resultSet2JdbcWithoutJOOQ(resultSet);
+
+    resultSet.close();
+
+    assertTrue(array.similar(result1));
+  }
+
+  @Test
+  void whenResultSetConvertedUsingJOOQDefaultApproach_shouldMatchJSON() throws SQLException, ClassNotFoundException {
+    Class.forName("org.h2.Driver");
+    Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc2", "user", "password");
+    // Create a table
+    Statement stmt = dbConnection.createStatement();
+    stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+    ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+    JSONObject result2 = resultSet2JdbcUsingJOOQDefaultApproach(resultSet, dbConnection);
+
+    resultSet.close();
+
+    assertTrue(object.similar(result2));
+  }
+
+  @Test
+  void whenResultSetConvertedUsingCustomisedJOOQ_shouldMatchJSON() throws SQLException, ClassNotFoundException {
+    Class.forName("org.h2.Driver");
+    Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc3", "user", "password");
+    // Create a table
+    Statement stmt = dbConnection.createStatement();
+    stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+    ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+    JSONArray result3 = resultSet2JdbcUsingCustomisedJOOQ(resultSet, dbConnection);
+
+    resultSet.close();
+
+    assertTrue(array.similar(result3));
+  }
+
+}