exec-maven-plugin error, even on working example

EDIT5 Updated /

I'm using Maven 3.3.3.
I just create new project and added compile and exec plugin, as examples on web.
I tried to execute, but I got error

[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:java (default-cli) on project QNAProject: An exception occured while executing the Java class. com.jadex.qna.QNAProject.App -> [Help 1]<br>
[ERROR] <br>
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.<br>
[ERROR] Re-run Maven using the -X switch to enable full debug logging.<br>
[ERROR] <br>
[ERROR] For more information about the errors and possible solutions, please read the following articles:<br>
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException<br>

I tried exec-maven-plugin version 1.2.1 and 1.4.0, but got same error. Here is my pom.xml

<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.jadex.qna</groupId>
    <artifactId>QNAProject</artifactId>
    <version>0.1</version>
    <packaging>jar</packaging>

    <name>QNAProject</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.2.1</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>java</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <executable>maven</executable>
                    <mainClass>com.jadex.qna.QNAProject.App</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

I even tried a working example project from several sites,
such as

http://examples.javacodegeeks.com/enterprise-java/maven/create-java-project-with-maven-example/
http://www.mkyong.com/maven/how-to-create-a-java-project-with-maven/

but I got same error.

I unzipped maven at C:\apache-maven-3.3.3 and created environment variable MAVEN_HOME as same path. What is the problem?

====================================

EDIT: Here is the result

Well.. I set MAVEN_HOME, not M2_HOME because tutorial what I found said to set it only...
Of course, echo %MAVEN_HOME% shows

C:\apache-maven-3.3.3

is it wrong?

I added %MAVEN_HOME%\bin to PATH variable, but it did not work too.
And, I'm using eclipse

=====================================

EDIT2: Here is full log. I used goal 'clean exec:java -e -X'

It was too long, so I uploaded to my blog here.
And note that I changed repository folder from C:\Users.....m2 to new local repository folder C:\apache-maven-localrepository

https://arincblossom.wordpress.com/2015/06/15/error-logs/

=======================================

EDIT3: I changed maven-compiler-plugin setting like this

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
                <verbose>true</verbose>
                <fork>true</fork>
                <executable>${env.JAVA_HOME}/bin/javac</executable>
                <compilerVersion>1.5</compilerVersion>
                <!-- <source>1.8</source>
                <target>1.8</target> -->
            </configuration>
        </plugin>

It prevented me from having error from mvn -e compile exec:java but I can't run with mvn exec:java -Dexec.mainClass="com.jadex.qna.QNAProject.App"

=================================

EDIT4: OK, I'll try from the bottom, and post again. Thanks for your sincere helps.

======================================

EDIT5

I reset all the sequences... re-installed eclipse, maven.. and re-created projects... but nothing worked...

I changed eclipse settings to fix JDK path to installed jdk path, not JRE path. then I found that 'mvn -e clean compile exec:java' is working, but I want to just 'mvn clean exec:java' work. It does not work at all.

You can check full source here

https://github.com/arincblossom/MavenTestProject

This is current console message for 'mvn -e clean exec:java'

[WARNING] 
[WARNING] Some problems were encountered while building the effective settings
[WARNING] expected START_TAG or END_TAG not TEXT (position: TEXT seen ...ore artifacts.\n   |\n   | Default: ${user.home}/.m2/repository\n  <l... @53:5)  @ C:\apache-maven-3.3.3\conf\settings.xml, line 53, column 5
[WARNING] expected START_TAG or END_TAG not TEXT (position: TEXT seen ...ore artifacts.\n   |\n   | Default: ${user.home}/.m2/repository\n  <l... @53:5)  @ C:\apache-maven-3.3.3\conf\settings.xml, line 53, column 5
[WARNING] 
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building MavenTestProject 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ MavenTestProject ---
[INFO] Deleting C:\Users\bonavision_laptop\Desktop\Project\JadeX\MavenTestProject\MavenTestProject\target
[INFO] 
[INFO] --- exec-maven-plugin:1.4.0:java (default-cli) @ MavenTestProject ---
[WARNING] 
java.lang.ClassNotFoundException: com.jadex.qna.MavenTestProject.App
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:281)
    at java.lang.Thread.run(Thread.java:745)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.900 s
[INFO] Finished at: 2015-06-15T17:42:19+09:00
[INFO] Final Memory: 8M/153M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.4.0:java (default-cli) on project MavenTestProject: An exception occured while executing the Java class. com.jadex.qna.MavenTestProject.App -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[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/MojoExecutionException

回答1:

The error log which you posted says the following:

java.lang.ClassNotFoundException  com.jadex.qna.QNAProject.App

So it clear what the root source of the error is. You are trying to execute the main() method of a class whose class file Maven cannot find. As this SO article discusses, you can try explicitly compiling first, then executing after the class file has been generated:

mvn -e compile exec:java
mvn exec:java -Dexec.mainClass="com.jadex.qna.QNAProject.App"

回答2:

This issue happens, when it is not compatible with eclipse too.

Try this

mvn clean install eclipse:eclipse

Vote up, if it works to help fellow members

回答3:

I ran into this same problem, it was caused by a port conflict. my tomcat server tried to start on port 8080 but i already had a binding for it. netstat -anto will show you port bindings 0.0.0.0:8080 or similar and it's PID this will help you determin what process is already running the port bidning, either change it in your timcat server or whatever process is using the bidning. Could be caused by an IIS, SKype or similar.