Why Maven uses JDK 1.6 but my java -version is 1.7

I'm new to maven, and also to MacOS.

I have setup maven in my terminal, and when getting the version settings (using mvn -v) it seems it uses JDK 1.6, while I have JDK 1.7 installed. Is there anything wrong?

The commands I enter are these:

blues:helloworld Ninja$ java -version

> java version "1.7.0_05" > Java(TM) SE Runtime Environment (build 1.7.0_05-b06) > Java HotSpot(TM) 64-Bit Server VM (build 23.1-b03, mixed mode)`

blues:helloworld Ninja$ mvn -v

> Apache Maven 3.1.0 (893ca28a1da9d5f51ac03827af98bb730128f9f2; 2013-06-28 10:15:32+0800) > Maven home: /usr/local/Cellar/maven/3.1.0/libexec > Java version: 1.6.0_51, vendor: Apple Inc. > Java home: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home > Default locale: zh_CN, platform encoding: EUC_CN > OS name: "mac os x", version: "10.8.4", arch: "x86_64", family: "mac"

add the following to your ~/.mavenrc:

export JAVA_HOME=/Library/Java/JavaVirtualMachines/{jdk-version}/Contents/Home

#Second Solution:

echo export "JAVA_HOME=\$(/usr/libexec/java_home)" >> ~/.bash_profile

Get into

/System/Library/Frameworks/JavaVM.framework/Versions

and update the CurrentJDK symbolic link to point to

/Library/Java/JavaVirtualMachines/YOUR_JDK_VERSION/Contents/

E.g.

cd /System/Library/Frameworks/JavaVM.framework/Versions
sudo rm CurrentJDK
sudo ln -s /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/ CurrentJDK

Now it shall work immediately.

You can also do,

<properties>
      ...  

      <!-- maven-compiler-plugin , aka JAVA Compiler 1.7 -->
      <maven.compiler.target>1.7</maven.compiler.target>
      <maven.compiler.source>1.7</maven.compiler.source>

      ...  
</properties>

You can also explicitly tell maven which java version to compile for. You can try adding the maven-compiler-plugin to your pom.

<project>
  [...]
  <build>
    [...]
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>
    </plugins>
    [...]
  </build>
  [...]
</project>

If you imported a maven project into an IDE, then there is probably a maven setting in your IDE for default compiler that your maven runner is using.

It helped me. Just add it in your pom.xml.

By default maven compiler plugin uses Java 1.5 or 1.6, you have to redefine it in your pom.xml.

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

For Eclipse Users. If you have a Run Configuration that does clean package for example.

In the Run Configuration panel there is a JRE tab where you can specify against which runtime it should run. Note that this configuration overrides whatever is in the pom.xml.

I am late to this question, but I think the best way to handle JDK versions on MacOS is by using the script described at: http://www.jayway.com/2014/01/15/how-to-switch-jdk-version-on-mac-os-x-maverick/

Please check the compatibility. I struggled with mvn 3.2.1 and jdk 1.6.0_37 for many hours. All variables were set but was not working. Finally I upgraded jdk to 1.8.0_60 and mvn 3.3.3 and that worked. Environment Variables as following:

JAVA_HOME=C:\ProgramFiles\Java\jdk1.8.0_60 
MVN_HOME=C:\ProgramFiles\apache-maven\apache-maven-3.3.3 
M2=%MVN_HOME%\bin extend system level Path- ;%M2%;%JAVA_HOME%\bin;

@MasterGaurav's solution works perfectly.

I normally put the Java switch statement into a zsh function:

alias java_ls='/usr/libexec/java_home -V 2>&1 | grep -E "\d.\d.\d[,_]" | cut -d , -f 1 | colrm 1 4 | grep -v Home'

function java_use() {
    export JAVA_HOME=$(/usr/libexec/java_home -v $1)
    echo export "JAVA_HOME=$(/usr/libexec/java_home -v $1)" > ~/.mavenrc
    export PATH=$JAVA_HOME/bin:$PATH
    java -version
}

You can run java_ls to get all of the available JVMs on your machine,
and then java_use 1.7 to use 1.7 for both Java and Maven.