ant unable to make a war, it stops while compiling classes

I have a build.xml file from which i was building war for three months. but currently it stops when it reaches at compling the code. my version of ant is 1.8. Last time i made war was on last friday evening and it was working fine that time.

here is my build.xml file

<?xml version="1.0" encoding="iso-8859-1"?>
<!-- Written By Waqas Sadiq on 14062011 -->
<project name="smi-core" default="all" basedir="..">

    <property name="name" value="EchelonSurvey"/>

    <property name="common.deploy" value="../deploy"/>
    <property name="home.dir" value="./WebRoot"/>
    <property name="src.dir" value="./src"/>
    <property name="oi.dir" value="./openInviter"/>
    <property name="as.dir" value="./about-us"/>
    <property name="rr.dir" value="./ResponsesReport"/>
    <property name="lib.dir" value="./WebRoot/WEB-INF/lib"/>
    <property name="images.dir" value="./WebRoot/images"/>
    <property name="tabcontent.dir" value="./WebRoot/tabcontent"/>
    <property name="css.dir" value="./WebRoot/css"/>
    <property name="js.dir" value="./WebRoot/js"/>
    <property name="jsp.dir" value="./WebRoot/jsp"/>
    <property name="config.web" value="./WebRoot/WEB-INF"/>
    <property name="config.web.class" value="./WebRoot/WEB-INF/classes"/>
    <property name="build.dir" value="build/buildoutput"/>
    <property name="build.lib" value="${build.dir}/lib"/>
    <property name="build.dest" value="${build.dir}/classes"/>
    <property name="build.war.dir" value="${build.dir}/EchelonSurvey.war"/>
    <property name="sampleapp.name" value="EchelonSurvey"/>
    <property name="build.ship.dir" value="build/ship"/>
    <property name="build.deploy.dir" value="./deploy"/>
    <property name="option.debug" value="on"/>
    <property name="option.optimize" value="off"/>
    <property name="option.deprecation" value="on"/>
    <property name="version" value="1.0"/>
    <property name="vendor.name" value="Stafona"/>
    <property name="deploy.dir" value="./deploy"/>


    <target name="eclipse" if="eclipse.running">
      <property name="build.c开发者_如何学Pythonompiler"
        value="org.eclipse.jdt.core.JDTCompilerAdapter"/>
    </target>

    <path id="classpath">
            <fileset dir="${lib.dir}/">
                <include name="*.jar"/>
            </fileset>
    </path>

    <target name="clean">
            <delete dir="${build.dir}" />
            <delete dir="${build.dest}" />
    </target>


    <target name="prepare" depends="clean">
            <mkdir dir="${build.lib}"/>
            <mkdir dir="${build.dest}"/>

    </target>


    <target name="compile" depends="prepare">
            <delete dir="${config.web.class}"/>
            <mkdir dir ="${config.web.class}"/>

             <copy todir="${config.web.class}">
                <fileset dir="${src.dir}" excludes="**/*.java"/>
             </copy>

            <javac
              destdir="${config.web.class}"
              debug="${option.debug}"
              optimize="${option.optimize}"
              deprecation="${option.deprecation}"
              includeantruntime="false"
            >
              <src path="${src.dir}"/>
              <classpath refid="classpath"/>
            </javac>
            <javac
              destdir="${build.dest}"
              debug="${option.debug}"
              optimize="${option.optimize}"
              deprecation="${option.deprecation}"
            >
              <src path="${src.dir}"/>
              <classpath refid="classpath"/>
            </javac>
    </target>

    <target name="package-EchelonSurvey"
       depends="compile" description="Generates the EchelonSurvey implementation JAR">
            <jar destfile="${build.lib}/${name}.jar">
                    <fileset dir="${build.dest}">
                            <include name="**/**.class"/>

                    </fileset>

                    <manifest>
                            <attribute name="Built-By" value="${vendor.name}"/>
                    </manifest>
            </jar>
    </target>


    <target name ="package-web-war" depends ="package-EchelonSurvey" description ="Generates war package">
            <mkdir dir ="${build.war.dir}"/>

            <mkdir dir ="${build.war.dir}/WEB-INF/classes"/>
            <mkdir dir ="${build.war.dir}/WEB-INF/lib"/>
            <mkdir dir ="${build.war.dir}/js"/>
            <mkdir dir ="${build.war.dir}/jsp"/>
            <mkdir dir ="${build.war.dir}/images"/>
            <mkdir dir ="${build.war.dir}/css"/>
            <copy todir="${build.war.dir}/WEB-INF">
                    <fileset dir="${config.web}">
                            <include name="*.xml"/>
                            <include name="*.log"/>
                            <include name="*.properties"/>
                    </fileset>
            </copy>



            <copy todir="${build.war.dir}/images">
                    <fileset dir="${images.dir}">
                            <include name="**/**.*"/>
                    </fileset>
            </copy>

            <copy todir="${build.war.dir}/tabcontent">
                    <fileset dir="${tabcontent.dir}">
                            <include name="*.*"/>
                    </fileset>
            </copy>





            <copy todir="${build.war.dir}/css">
                    <fileset dir="${css.dir}">
                            <include name="*.*"/>
                    </fileset>
            </copy>

            <copy todir="${build.war.dir}/js">
                    <fileset dir="${js.dir}">
                            <include name="*.*"/>
                    </fileset>
            </copy>



            <copy todir="${build.war.dir}/jsp">
                    <fileset dir="${jsp.dir}">
                            <include name="**/**.jsp"/>
                            <include name="*.html"/>
                    </fileset>
            </copy>


            <copy todir="${build.war.dir}/WEB-INF/classes">
                    <fileset dir="${config.web.class}">
                            <include name="**/**.class"/>
                            <include name="**/**.xml"/>
                            <include name="**/**.properties"/>
                    </fileset>
            </copy>

            <copy todir="${build.war.dir}/WEB-INF/lib">


                    <fileset dir="${lib.dir}">
                            <include name="*.jar"/>
                            <exclude name="EchelonSurvey.jar"/>
                    </fileset>


            </copy>

            <copy todir="${build.war.dir}">
                    <fileset dir="${home.dir}">
                            <include name="*.jsp"/>
                            <include name="*.properties"/>
                            <include name="*.html"/>
                            <include name="*.xml"/>
                            <include name="*.txt"/>
                            <include name="*.do"/>
                    </fileset>
            </copy>

            <jar jarfile ="${build.lib}/${sampleapp.name}.war" basedir ="${build.war.dir}">
                    <manifest>
                            <attribute name="Built-By" value="${vendor.name}"/>
                    </manifest>
            </jar>


            <copy todir="${deploy.dir}">
                    <fileset dir="${build.lib}">
                            <include name="*.war"/>
                            <include name="*.jar"/>

                    </fileset>
            </copy>


            <copy todir="${common.deploy}">
                    <fileset dir="${build.lib}">
                            <include name="*.war"/>
                            <include name="*.jar"/>

                    </fileset>
            </copy>


    </target>


    <target name="all" depends="package-web-war">
    </target>

    <target name="ship" depends="all" description="* Generates a .zip file">
    </target>

    <target name="cleanagain">
            <delete dir="${build.dir}" />
    </target>

</project>

and here is the output from this. I am running this on Ubunto with java 6 installed on it.

Buildfile: /var/tempproject/suleman/EchlonSurvey/build/build.xml

clean:
   [delete] Deleting directory /var/tempproject/suleman/EchlonSurvey/build/buildoutput

prepare:
    [mkdir] Created dir: /var/tempproject/suleman/EchlonSurvey/build/buildoutput/lib
    [mkdir] Created dir: /var/tempproject/suleman/EchlonSurvey/build/buildoutput/classes

compile:
   [delete] Deleting directory /var/tempproject/suleman/EchlonSurvey/WebRoot/WEB-INF/classes
    [mkdir] Created dir: /var/tempproject/suleman/EchlonSurvey/WebRoot/WEB-INF/classes
     [copy] Copying 39 files to /var/tempproject/suleman/EchlonSurvey/WebRoot/WEB-INF/classes
     [copy] Copied 13 empty directories to 9 empty directories under /var/tempproject/suleman/EchlonSurvey/WebRoot/WEB-INF/classes
    [javac] Compiling 225 source files to /var/tempproject/suleman/EchlonSurvey/WebRoot/WEB-INF/classes
Killed