Compiling Java 7 code via Maven

Question

My pom file lists

Answer 1

None of the previous answers completely solved my use case.

Needed to remove the directory that was being built. Clean. And then re-install. Looks like a silent permissions issue.

Answer 2

I had this problem when working with eclipse, I had to change the project's build path so that it refers to jre 7

Answer 3

Not sure what the OS is in use here, but you can eliminate a lot of java version futzing un debian/ubuntu with update-java-alternatives to set the default jvm system wide.

#> update-java-alternatives -l
java-1.6.0-openjdk-amd64 1061 /usr/lib/jvm/java-1.6.0-openjdk-amd64
java-1.7.0-openjdk-amd64 1071 /usr/lib/jvm/java-1.7.0-openjdk-amd64
java-6-sun 63 /usr/lib/jvm/java-6-sun
java-7-oracle 1073 /usr/lib/jvm/java-7-oracle

To set a new one, use:

#> update-java-alternatives -s java-7-oracle

No need to set JAVA_HOME for most apps.

Answer 4

For a specific compilation that requires a (non-default /etc/alternatives/java) JVM, consider prefixing the mvn command with JAVA_HOME like this,

JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64/ mvn package

Here we assume the default is Java 8, whereas for the specific project at hand we require Java 7.

Answer 5

I had the same problem and to solve this I follow this blog article: http://www.mkyong.com/java/how-to-set-java_home-environment-variable-on-mac-os-x/

$ vim .bash_profile 

export JAVA_HOME=$(/usr/libexec/java_home)

$ source .bash_profile

$ echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home

special tks to @mkyong

EDIT: Now I'm using: jEnv + sdkman

Answer 6

You might be specifying a wrong version of java. java -version(in your terminal) to check the version of java you are using. Go to maven-compile-plugin for the latest maven compiler version Your plugin may appear like this if you are using java 6 and the latest version of maven compiler plugin is 3.1

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>