Running Spring boot App command line with Maven

 

mvn spring-boot:run

for gradle

./gradlew bootRun

How can I create an executable JAR with dependencies using Maven?

 <build>

  <plugins>
    <plugin>
      <artifactId>maven-assembly-plugin</artifactId>
      <configuration>
        <archive>
          <manifest>
            <mainClass>fully.qualified.MainClass</mainClass>
          </manifest>
        </archive>
        <descriptorRefs>
          <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
      </configuration>
    </plugin>
  </plugins>
</build>

and you run it with
mvn clean compile assembly:single
https://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven

Add Oracle drivers to maven

 Oracle is proprietary solution provider and oracle jars are not available in maven. So we need to manually add those jars to our local maven repository.

One of the errors, you can see is below.

Missing artifact com.oracle:ojdbc6:jar:11.2.0 in pom.xml

<dependency>
    <groupId>com.oracle</groupId>
    <artifactId>ojdbc6</artifactId>
    <version>11.2.0</version>
</dependency>

Solution : install manually in maven local local repo, run below command

mvn install:install-file -Dfile={path/to/your/ojdbc.jar} -DgroupId=com.oracle 
-DartifactId=ojdbc6 -Dversion=11.2.0 -Dpackaging=jar

-DgroupId  this may vary, ex: if your group id just "oracle" , you can ommit or empty DgroupId

Then it will looks like below
mvn install:install-file -Dfile={path/to/your/ojdbc.jar} -DgroupId=
-DartifactId=ojdbc6 -Dversion=11.2.0 -Dpackaging=jar

Important Maven Commands

• mvn -version: Finds the Maven version
• mvn compile: Compiles source files
• mvn test-compile: Compiles test files as well as source files
• mvn clean: Deletes target directory
• mvn test:  Runs unit tests
• mvn package: Creates a JAR for the project
• help:effective-settings: Debugs Maven settings
• help:effective-pom: Look at the complete pom after all inheritances from parent poms are resolved
• dependency:tree: Look sat all the dependencies and transitive dependencies
• dependency:sources: Downloads source code for all dependencies
• -debug: Debug flag; can be used with all the above commands

Create quartz scheduler as REST service and persist scheduler data to Database dependencies

This is the POM file file




<?xml version="1.0" encoding="UTF-8"?>
<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">
<modelVersion>4.0.0</modelVersion>

<groupId>com.saap.scheduler</groupId>
<artifactId>saap-scheduler</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>saap-scheduler</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.0.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>
<spring-cloud.version>Greenwich.M1</spring-cloud.version>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-quartz</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5.2</version>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>


</project>

SpringBoot Application error

Below is the Exception comes when you execute : mvn package

Issue: You have more than one class inside the application with 'main" method

solution : Find the other main method and delete or comment that. Or specify the class you need to refer the main method.
Hint : If you create a project using a maven template, most probably it will create a App.java class with main method. So look for that.

You can easily solve by stating the main class. eg: main class is Example.java


<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>

<configuration>
<mainClass>Example.class</mainClass>
<layout>ZIP</layout>
</configuration>
</plugin>
</plugins>
</build>

for more information refer

https://docs.spring.io/spring-boot/docs/current/maven-plugin/usage.html
----------------------------------------------------------------------------------------------------------------

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.0.3.RELEASE:repackage (default) on project SpringBootTest: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:2.0.3.RELEASE:repackage failed: Unable to find main class -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.0.3.RELEASE:repackage (default) on project SpringBootTest: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:2.0.3.RELEASE:repackage failed: Unable to find main class
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:225)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:319)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:2.0.3.RELEASE:repackage failed: Unable to find main class
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:110)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
        ... 19 more
Caused by: java.lang.IllegalStateException: Unable to find main class
        at org.springframework.boot.loader.tools.Repackager.buildManifest(Repackager.java:300)
        at org.springframework.boot.loader.tools.Repackager.repackage(Repackager.java:238)
        at org.springframework.boot.loader.tools.Repackager.repackage(Repackager.java:195)
        at org.springframework.boot.maven.RepackageMojo.repackage(RepackageMojo.java:220)
        at org.springframework.boot.maven.RepackageMojo.execute(RepackageMojo.java:207)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
        ... 20 more
[ERROR]
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginExecutionException

Maven jar dependencies are displayed outside `Maven Dependencies` view

showing the all jars listed in eclipse is a real headache. let's see how to get rid of that.

jars shown outside

1.  Just delete the project from the eclipse. (do not delete from disk, if you not sure about this - better to backup below delete)
2.  go to folder structure of the project and delete generated files. (".settings" folder, "target" folder, "classpath" file, ".project" file ) 

delete generated folders

     3. Import project using wizard  - existing maven project. You will get rid of the issue.

import again as a existing maven project

issue sorted - libraries are not shown now