BAEL-1980 Access an in-memory h2 db from 2 Spring Boot applications (#5230)

* Added Spring-Boot-H2 project

* Optimized imports and formatted code

* Code Formatting changes

* Renamed the client applicaiton

* Removed Name from pom.xml

* formatting changes - applied formatting style

* added souts

* Update SpringBootApp.java

* Update ClientSpringBootApp.java

* Fixed Formatting issues

* Fixed formatting and spelling mistakes

* added H2 shared db example

* a

* patch

* test

* Revert "Fixed formatting and spelling mistakes"

This reverts commit ed56ededec903e85c2d9f2b55e7730682455d5f5.

* Revert "test"

This reverts commit 4a7133dbd1d181cc304348f63998924a9db5acfe.

* Revert "patch"

This reverts commit 404b9ebe74aef4faa2ad62d9867652b62a5445b8.

* Revert "a"

This reverts commit af77f841114e19b0a0eafb15530dbaaaf34b5493.

* Revert "added H2 shared db example"

This reverts commit e16918cae3813fe20172c7e90e27bbec34b5fb5f.

* Updated to have client and server in same directory

* Deleted old files

* removed unwanted directory

* formating

* removed unwanted module

* commentted removed module

* Revert "commentted removed module"

This reverts commit 211ff1441f6bde920d7af3f8cd52c2a682ba3967.

* Revert "removed unwanted module"

This reverts commit 657f9ee45e02269bcfdbf380b9a74ff2370857fc.

* fixed pom.xml issue

* typo fixed

* fixed multiple main class issue

pom.xml

@@ -675,7 +675,7 @@
 				<!-- <module>rule-engines/rulebook</module> --><!-- Wrong Parent -->
 				<module>spring-boot-custom-starter/greeter</module>
 				<module>spring-boot-h2/spring-boot-h2-database</module>
-				<module>spring-boot-h2/spring-boot-h2-remote-app</module>
+				<!--module>spring-boot-h2/spring-boot-h2-remote-app</module-->
 				<!-- <module>guest\webservices\rest-client</module> --><!-- guest post on different site -->
 				<!-- <module>guest\webservices\rest-server</module> --><!-- PMD voilation -->
 				<!-- <module>guest\webservices\spring-rest-service</module> --><!-- guest post on different site -->
@@ -992,7 +992,7 @@
 				<!-- <module>rule-engines/rulebook</module> --><!-- Wrong Parent -->
 				<module>spring-boot-custom-starter/greeter</module>
 				<module>spring-boot-h2/spring-boot-h2-database</module>
-				<module>spring-boot-h2/spring-boot-h2-remote-app</module>
+				<!--module>spring-boot-h2/spring-boot-h2-remote-app</module-->
 				<!-- <module>guest\webservices\rest-client</module> --><!-- guest post on different site -->
 				<!-- <module>guest\webservices\rest-server</module> --><!-- PMD voilation -->
 				<!-- <module>guest\webservices\spring-rest-service</module> --><!-- guest post on different site -->

spring-boot-h2/spring-boot-h2-database/pom.xml

@@ -22,6 +22,8 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.8</java.version>
+        <!-- The main class to start by executing java -jar -->
+        <start-class>com.mycorp.starter.HelloWorldApplication</start-class>
     </properties>
 
     <dependencies>

spring-boot-h2/spring-boot-h2-database/src/main/java/com/baeldung/h2db/demo/client/ClientSpringBootApp.java

@@ -1,4 +1,4 @@
-package com.baeldung.h2db.demo;
+package com.baeldung.h2db.demo.client;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -7,16 +7,20 @@ import javax.annotation.PostConstruct;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.PropertySource;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
 
 @SpringBootApplication
+@ComponentScan("com.baeldung.h2db.demo.client")
 public class ClientSpringBootApp {
 
     @Autowired
     private JdbcTemplate jdbcTemplate;
 
     public static void main(String[] args) {
+        System.setProperty("spring.datasource.url","jdbc:h2:tcp://localhost:9091/mem:mydb");
         SpringApplication.run(ClientSpringBootApp.class, args);
     }
 
@@ -46,4 +50,4 @@ public class ClientSpringBootApp {
                 }
             });
     }
-}
+}

spring-boot-h2/spring-boot-h2-database/src/main/java/com/baeldung/h2db/demo/server/SpringBootApp.java

@@ -1,4 +1,4 @@
-package com.baeldung.h2db.demo;
+package com.baeldung.h2db.demo.server;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -9,10 +9,12 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
 
 @SpringBootApplication
+@ComponentScan("com.baeldung.h2db.demo.server")
 public class SpringBootApp {
 
     @Autowired
@@ -24,8 +26,7 @@ public class SpringBootApp {
 
     @PostConstruct
     private void initDb() {
-        System.out.println(String.format(
-            "****** Creating table: %s, and Inserting test data ******", "Employees"));
+        System.out.println(String.format("****** Creating table: %s, and Inserting test data ******", "Employees"));
 
         String sqlStatements[] = {
             "drop table employees if exists",
@@ -57,4 +58,4 @@ public class SpringBootApp {
     public Server inMemoryH2DatabaseServer() throws SQLException {
         return Server.createTcpServer("-tcp", "-tcpAllowOthers", "-tcpPort", "9091");
     }
-}
+}

spring-boot-h2/spring-boot-h2-remote-app/.gitignore

@@ -1,25 +0,0 @@
-/target/
-!.mvn/wrapper/maven-wrapper.jar
-
-### STS ###
-.apt_generated
-.classpath
-.factorypath
-.project
-.settings
-.springBeans
-.sts4-cache
-
-### IntelliJ IDEA ###
-.idea
-*.iws
-*.iml
-*.ipr
-
-### NetBeans ###
-/nbproject/private/
-/build/
-/nbbuild/
-/dist/
-/nbdist/
-/.nb-gradle/

spring-boot-h2/spring-boot-h2-remote-app/pom.xml

@@ -1,55 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xmlns="http://maven.apache.org/POM/4.0.0"
-         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.h2db</groupId>
-    <artifactId>spring-boot-h2-remote-app</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
-    <packaging>jar</packaging>
-
-    <description>Demo Spring Boot applications that access H2 in memory database created
-        in another Spring Boot application
-    </description>
-
-    <parent>
-        <groupId>org.springframework.boot</groupId>
-        <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
-        <relativePath/> <!-- lookup parent from repository -->
-    </parent>
-
-    <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-        <java.version>1.8</java.version>
-    </properties>
-
-    <dependencies>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-data-jpa</artifactId>
-        </dependency>
-
-        <dependency>
-            <groupId>com.h2database</groupId>
-            <artifactId>h2</artifactId>
-        </dependency>
-
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-test</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-            </plugin>
-        </plugins>
-    </build>
-</project>

spring-boot-h2/spring-boot-h2-remote-app/src/main/resources/application.properties

@@ -1,5 +0,0 @@
-spring.datasource.url=jdbc:h2:tcp://localhost:9091/mem:mydb
-spring.datasource.driverClassName=org.h2.Driver
-spring.datasource.username=sa
-spring.datasource.password=
-spring.jpa.hibernate.ddl-auto=create