How to set a java compiler in Netbeans

Question

I'm getting into Java7 development and I've added JDK7 into Java Platforms and have selected it in the project properties.

But when I'm compiling, I get messages like:

warning: java/lang/Boolean.class(java/lang:Boolean.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.

and

javac: invalid target release: 1.7
/Applications/NetBeans/NetBeans 7.1.app/Contents/Resources/NetBeans/harness/suite.xml:184: The following error occurred while executing this line:
/Applications/NetBeans/NetBeans 7.1.app/Contents/Resources/NetBeans/harness/common.xml:206: Compile failed; see the compiler error output for details.

So as far as I understand Netbeans is using javac 1.6. How can I change in to 1.7?

EDIT:

I'm writing a NetBeans Platform app and in main app Properties I've set: Java Platform = JDK 1.7. And in one of the module's Properties I've set Source level = 1.7.

EDIT2

• Mac OS 10.7.3
• NetBeans IDE 7.1 (Build 201112071828)
• openjdk version "1.7.0-internal"
• OpenJDK Runtime Environment (build 1.7.0-internal-uko_2012_02_15_11_51-b00)
• OpenJDK 64-Bit Server VM (build 23.0-b15, mixed mode)

suite.xml (184 is the second line here)

<target name="build" depends="-init,branding,release,-hide-excluded-modules" description="Build all modules in the suite.">
    <subant target="netbeans" buildpath="${modules.sorted}" inheritrefs="false" inheritall="false">
        <property name="cluster.path.evaluated" value="${cluster.path.evaluated}"/> <!-- Just for speed of pre-7.0 projects -->
    </subant>
</target>

common.xml (206 is the second line here)

<nb-javac srcdir="${src.dir}" destdir="${build.classes.dir}" debug="${build.compiler.debug}" debuglevel="${build.compiler.debuglevel}" encoding="UTF-8"
        deprecation="${build.compiler.deprecation}" optimize="${build.compiler.optimize}" source="${javac.source}" target="${javac.target}" includeantruntime="false">
    <classpath refid="cp"/>
    <compilerarg line="${javac.compilerargs}"/>
    <processorpath refid="processor.cp"/>
</nb-javac>

Answer 1

Right click on your project --> Project Properties

Then in Sources set Source/Binary Format to JDK 7.

EDIT 1 :

There is a NetBeans issue:

Works fine in J2SE project, Web project specific problem. The problem is that fork="false" the JDK 7.0 params are passed to JDK 6.0 compiler. The executable requires fork="true".

On the line 293 of build-iml.xml the

<javac 
      debug="@{debug}" 
      deprecation="${javac.deprecation}" destdir="@{destdir}"
      encoding="${source.encoding}" 
      excludes="@{excludes}"
      executable="${platform.javac}" 
      fork="${javac.fork}" 
      includeantruntime="false"
      includes="@{includes}"  
      source="${javac.source}" 
      srcdir="@{srcdir}"
      target="${javac.target}" 
      tempdir="${java.io.tmpdir}">

should become:

<javac 
      debug="@{debug}" 
      deprecation="${javac.deprecation}" 
      destdir="@{destdir}"
      encoding="${source.encoding}" 
      excludes="@{excludes}"
      executable="${platform.javac}" 
      fork="yes"                          ;as opposed to ${javac.fork}
      includeantruntime="false"
      includes="@{includes}" 
      source="${javac.source}" 
      srcdir="@{srcdir}"
      target="${javac.target}" 
      tempdir="${java.io.tmpdir}">

EDIT 2 (if first tips don't work):

Try to run Netbeans IDE in JDK7.

Edit Netbeans conf file :

Linux

~/.netbeans/7.0/etc/app.conf

Mac Os X

/Applications/NetBeans/NetBeans\ 7.1.app/Contents/Resources/NetBeans/harness/etc/app.conf

Add the jdk7 path in the line jdkhome=.

Or

Launch netbeans using :

netbeans --jdkhome /Java7/Home/dir