蚂蚁没有使用正确的Java版本

Question

I generated an ant file via Eclipse Juno on a Unix machine where Java jdk (and jre) 1.6 are installed. When running ant outside of eclipse, where the build.xml file is located, on that machine, everything goes smoothly.

Now, the problem is when I try to run ant on another machine, where jdk and jre 1.6 are both installed. Here is what I get, on that other machine, which is running RedHat 3 (can't change it):

> ant -version
Apache Ant version 1.5.2-23 compiled on November 12 2003

> java -version
java version "1.6.0_39"
Java(TM) SE Runtime Environment (build 1.6.0_39-b04)
Java HotSpot(TM) Client VM (build 20.14-b01, mixed mode, sharing)

> javac -version
javac 1.6.0_39

> ls -l `which java`
lrwxrwxrwx 1 root root   26 Feb 13 15:22 /usr/bin/java -> /usr/java/default/bin/java*

> ls -l `which javac`
lrwxrwxrwx 1 root root   27 Feb 13 15:22 /usr/bin/javac -> /usr/java/default/bin/javac*

> ls -l /usr/java
total 8
lrwxrwxrwx 1 root root   16 Nov  7 14:19 default -> /usr/java/latest
drwxr-xr-x 7 root root 4096 Feb 13 15:02 jdk1.6.0_39/
drwxr-xr-x 7 root root 4096 Nov  7 14:18 jre1.6.0_37/
lrwxrwxrwx 1 root root   21 Feb 13 15:03 latest -> /usr/java/jdk1.6.0_39

> echo $JAVA_HOME
/usr/java/jdk1.6.0_39/bin/java

And when I add this line in the build.xml file, I get the following results

build.xml:
<echo message="Java version: ${ant.java.version}"/>

> ant 
  [echo] Java version: 1.4

and compilation errors:

  [javac] ...InputManager.java:11: error: Invalid method declaration, method name required.
  [javac]    Map<Double, List<MyObject>> loadFile(File pSelectedFile)
  [javac]              ^
  [javac] ...InputManager.java:11: error: Class or interface declaration expected.
  [javac]    Map<Double, List<MyObject>> loadFile(File pSelectedFile)
  [javac]              ^
  [javac] ...InputManager.java:33: error: Invalid character '@' in input.
  [javac]    @Override
  [javac]           ^
...

Now, the question is: Is my java installation incorrect? Am I doing something wrong with ant?

Here's a quick extract of the build.xml file:

> vim build.xml

<project basedir="." default="build" name="myProject">
  <property environment="env"/>
  <property name="ECLIPSE_HOME" value="/opt/eclipse"/>  <!-- that is also where eclipse is on my 2nd machine -->
  <property name="debuglevel" value="source,lines,vars"/>
  <property name="target" value="1.6"/>
  <property name="source" value="1.6"/>
[some stuff]
  <target name="init">
    <mkdir dir="bin"/>
    <copy includeemptydirs="false" todir="bin">
      <fileset dir="src">
        <exclude name="**/*.java"/>
      </fileset>
    </copy>
  </target>
  <target depends="init" name="build-project">
    <echo message="Java version: ${ant.java.version}"/>
    <javac debug="true" debuglevel="${debuglevel}" destdir="bin" includeantruntime="false" source="${source}" target="${target}">
      <src path="src"/>
      <classpath refid="myProject.classpath"/>
    </javac>
  </target>
</project>

Help is welcome :)

Answer 1

Your version of ant was compiled against an older version of java (2003). Java 1.6 came out in 2006. As I've found out, you can make ant run on an older version like here: http://www.coderanch.com/t/108814/tools/jdk-version-build-xml :

...............

If Ant has been compiled against 1.5 then you can modify the build task to

<javac source="1.4" target="1.4" ...> ...................... But not the other way around. So I'm guessing you need a fresher version of Ant.

From http://ant.apache.org/faq.html#java-version

Redhat ES 3.0 comes installed with ant 1.5.2. Even if you have your PATH and ANT_HOME variables set correctly to a later version of ant, you will always be forced to use the preinstalled version.

To use a later version of ant on this OS you could do the following:

$ ant -version
Apache Ant version 1.5.2-23 compiled on November 12 2003
$ su -
# rpm -e ant ant-libs
# exit
$ hash -r
$ ant -version
Apache Ant version 1.6.2 compiled on July 16 2004