ant gwt compiler task fails - gwt

Question

I'm following this tutorial to create my ant build file that java compiles, than GWT compiles than perform the correct actions to build my .war file.
I use Eclipse and GWT-compile works, and when I run the development mode it works. I have also successfully deployed on tomcat.
The things is when I run my script, the compiles work but it fails on the gwt-compiler task. My ant build script is as follow :
<project name="vlp" default="gwt.compile" basedir=".">
<tstamp />
<!-- ################# PROPERTIES ################ -->
<!-- directory properties -->
<!-- source -->
<property name="projectName" value="VirtualLabPortal" />
<property name="src.dir" location="src" />
<property name="build.dir" location="bin" />
<property name="src.build.dir" location="${build.dir}/src" />
<property name="gwt.build.dir" location="${build.dir}/gwt" />
<property name="gwt.unitCache.dir" location="gwt-unitCache" />
<!-- libraries -->
<property name="src.lib.dir" location="war/WEB-INF/lib" />
<!-- ___________________________________________________________________
| |
| Configure path source/test |
|___________________________________________________________________|
-->
<path id="compile.path">
<fileset dir="${src.lib.dir}" includes="*.jar" />
<fileset dir="${src.lib.dir}/gwt" includes="*.jar" />
</path>
<!-- ___________________________________________________________________
| |
| Clean old compiled source/test/war |
|___________________________________________________________________|
-->
<target name="clean" description="Clean all the old build files.">
<delete dir="${build.dir}" />
<delete dir="${gwt.unitCache.dir}" />
<delete file="${projectWar}" />
<delete file="${src.lib.dir}/${projectJar}" />
</target>
<!-- ___________________________________________________________________
| |
| Compile the source |
|(should exclude gwtview code which is compiled by the gwt compiler)|
|___________________________________________________________________|
-->
<target name="src.compile" depends="clean" description="Compile the source code when everything has been cleaned.">
<mkdir dir="${src.build.dir}" />
<javac encoding="utf-8" destdir="${src.build.dir}" nowarn="true">
<src path="${src.dir}" />
<classpath refid="compile.path" />
</javac>
</target>
<!-- ___________________________________________________________________
| |
| Invoke the GWT compiler |
|___________________________________________________________________|
-->
<property name="module.gwt.xml" location="${src.dir}/com/banctecmtl/ca/vlp" />
<target name="gwt.compile" depends="src.compile">
<java failonerror="true" fork="true" classname="com.google.gwt.dev.Compiler">
<classpath>
<!-- src dir is added to ensure the module.xml file(s) are on the classpath -->
<pathelement location="${module.gwt.xml}" />
<path refid="compile.path" />
</classpath>
<jvmarg value="-Xmx512m" />
<arg line="${projectName} -logLevel ALL -style OBF -war ${build.dir}" />
</java>
</target>
<!-- ___________________________________________________________________
| |
| Copy the config files in the war directory |
|___________________________________________________________________|
-->
<property name="config.dir" location="war/config" />
<target name="copy-resources">
<copy todir="war/config" preservelastmodified="true">
<fileset dir="${config.dir}">
<include name="**.*" />
</fileset>
</copy>
</target>
<!-- ___________________________________________________________________
| |
| Create a Jar to be included in the war |
|___________________________________________________________________|
-->
<property name="projectJar" value="${projectName}.jar" />
<property name="gwt.client.dir" location="com/banctecmtl/ca/vlp/view/webview" />
<target name="jar" depends="src.compile">
<!-- should also depend on gwt.compile -->
<jar jarfile="${src.lib.dir}/${projectJar}" basedir="${src.build.dir}/">
<!-- Don't wrap any of the client only code into the JAR
<exclude name="${gwt.client.dir}/**/*.class"/> -->
<exclude name="${gwt.client.dir}/**/*.class" />
</jar>
</target>
<!-- ___________________________________________________________________
| |
| Create a War from the source |
|___________________________________________________________________|
-->
<property name="projectWar" value="${projectName}.war" />
<target name="war" depends="jar,copy-resources">
<war basedir="war" destfile="${projectWar}" webxml="war/WEB-INF/web.xml">
<exclude name="WEB-INF/**" />
<webinf dir="war/WEB-INF/">
<include name="lib/*.jar" />
<include name="classes/*.properties" />
<exclude name="**/gwt-dev.jar" />
<exclude name="**/gwt-user.jar" />
</webinf>
</war>
</target>
<!-- ___________________________________________________________________
| |
| Deploy to the production server |
|___________________________________________________________________|
-->
<!-- It is possible you can't run this from eclipse,
you need to edit the run configurations and add the
latest jsch library to the classpath -->
<property name="user" value="root" />
<property name="password" value="Banctec01" />
<property name="prodHost" value="vlp" />
<property name="dest" value="/usr/share/tomcat6/webapps/ROOT.war" />
<target name="deploy" depends="war">
<echo message="Copying to : ${user}#${prodHost}:${dest}" />
<scp file="${projectWar}" remoteTofile="${user}#${prodHost}:${dest}" password="${password}" trust="true" />
</target>
</project>
It fails with the following error :
Buildfile: D:\workspace\vlp\build.xml
clean:
[delete] Deleting directory D:\workspace\vlp\war\WEB-INF\classes
src.compile:
[mkdir] Created dir: D:\workspace\vlp\war\WEB-INF\classes
[javac] D:\workspace\vlp\build.xml:42: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 134 source files to D:\workspace\vlp\war\WEB-INF\classes
[javac] Note: D:\workspace\vlp\src\com\banctecmtl\ca\vlp\controller\schedule\ScheduledTaskManager.java uses unchecked or unsafe operations.
[javac] Note: Recompile with -Xlint:unchecked for details.
gwt.compile:
[java] Checking for updates
[java] First launch was 134c3e23387
[java] Last ping was Mon Apr 23 14:42:48 EDT 2012, min wait is 86400000ms
[java] Module location: file:/D:/workspace/vlp/src/com/banctecmtl/ca/vlp/VirtualLabPortal.gwt.xml
[java] Loading inherited module 'com.google.gwt.user.User'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/user/User.gwt.xml
[java] Loading inherited module 'com.google.gwt.animation.Animation'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/animation/Animation.gwt.xml
[java] Loading inherited module 'com.google.gwt.core.Core'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/core/Core.gwt.xml
[java] Loading inherited module 'com.google.gwt.dev.jjs.intrinsic.Intrinsic'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-dev.jar!/com/google/gwt/dev/jjs/intrinsic/Intrinsic.gwt.xml
[java] Loading inherited module 'com.google.gwt.lang.LongLib'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-dev.jar!/com/google/gwt/lang/LongLib.gwt.xml
[java] Loading inherited module 'com.google.gwt.emul.Emulation'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/emul/Emulation.gwt.xml
[java] Loading inherited module 'com.google.gwt.logging.LogImpl'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/logging/LogImpl.gwt.xml
[java] Loading inherited module 'com.google.gwt.xhr.XMLHttpRequest'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/xhr/XMLHttpRequest.gwt.xml
[java] Loading inherited module 'com.google.gwt.core.Core'
[java] Module 'com.google.gwt.core.Core' has already been loaded and will be skipped
[java] Loading inherited module 'com.google.gwt.core.CompilerParameters'
[java] Module location: jar:file:/D:/workspace/vlp/war/WEB-INF/lib/gwt/gwt-user.jar!/com/google/gwt/core/CompilerParameters.gwt.xml
[java] [...]
[java] Loading inherited module 'com.google.gwt.user.User'
[java] Module 'com.google.gwt.user.User' has already been loaded and will be skipped
[java] Public resources found in...
[java] Translatable source found in...
[java] Persistent unit cache dir set to: D:\workspace\vlp\war\..\gwt-unitCache
[java] Compiling module VirtualLabPortal
[java] Looking for previously cached Compilation Units in D:\workspace\vlp\war\..\gwt-unitCache
[java] Loaded 0 units from persistent store.
[java] Starting UnitWriteThread.
[java] Found 0 cached units. Used 0 / 2413 units from cache.
[java] [ERROR] Unexpected internal compiler error
[java] java.lang.RuntimeException: Exception processing units
[java] at com.google.gwt.dev.javac.CompilationStateBuilder$CompileMoreLater.compile(CompilationStateBuilder.java:248)
[java] at com.google.gwt.dev.javac.CompilationStateBuilder.doBuildFrom(CompilationStateBuilder.java:447)
[java] at com.google.gwt.dev.javac.CompilationStateBuilder.buildFrom(CompilationStateBuilder.java:370)
[java] at com.google.gwt.dev.cfg.ModuleDef.getCompilationState(ModuleDef.java:360)
[java] at com.google.gwt.dev.Precompile.precompile(Precompile.java:252)
[java] at com.google.gwt.dev.Precompile.precompile(Precompile.java:233)
[java] at com.google.gwt.dev.Precompile.precompile(Precompile.java:145)
[java] at com.google.gwt.dev.Compiler.run(Compiler.java:232)
[java] at com.google.gwt.dev.Compiler.run(Compiler.java:198)
[java] at com.google.gwt.dev.Compiler$1.run(Compiler.java:170)
[java] at com.google.gwt.dev.CompileTaskRunner.doRun(CompileTaskRunner.java:88)
[java] at com.google.gwt.dev.CompileTaskRunner.runWithAppropriateLogger(CompileTaskRunner.java:82)
[java] at com.google.gwt.dev.Compiler.main(Compiler.java:177)
[java] Caused by: java.lang.NoSuchMethodError: com.google.gwt.dev.jjs.ast.JProgram.serializeTypes(Ljava/util/List;Ljava/io/ObjectOutputStream;)V
[java] at com.google.gwt.dev.javac.CompilationUnitImpl.<init>(CompilationUnitImpl.java:68)
[java] at com.google.gwt.dev.javac.SourceFileCompilationUnit.<init>(SourceFileCompilationUnit.java:48)
[java] at com.google.gwt.dev.javac.CompilationUnitBuilder$ResourceCompilationUnitBuilder.makeUnit(CompilationUnitBuilder.java:154)
[java] at com.google.gwt.dev.javac.CompilationUnitBuilder.build(CompilationUnitBuilder.java:266)
[java] at com.google.gwt.dev.javac.CompilationStateBuilder$CompileMoreLater$1.run(CompilationStateBuilder.java:223)
BUILD FAILED
D:\workspace\vlp\build.xml:60: Java returned: 1
Total time: 36 seconds
I found that changing the gwt-compiler class name to the DevMode is building successfully. Using : classname="com.google.gwt.dev.DevMode" instead of classname="com.google.gwt.dev.Compiler".
EDIT : I refactored the XML above.
The build.xml cleans all the bin directory. I also pointer the javacto the bin/src directory and Google Web Toolkit compiler outputs to : bin/gwt. The compiler still doesn't work...
EDIT : I downloaded the latest SDK right away from google developpers site, and overrided the old librairies found in my classpath and in my eclipse plugin. Still won't work with the ant build script.
Anybody sees what could be the problem here?

Answer 1

All I can say is that the method com.google.gwt.dev.jjs.ast.JProgram.serializeTypes(Ljava/util/List;Ljava/io/ObjectOutputStream;)V is introduced only in gwt-dev 2.4.0. It doesn't exist in gwt-dev 2.3.0.
Which implies there are somewhere, in the classpath, two gwt-dev versions. One of them is 2.4.0, which is why com.google.gwt.dev.javac.CompilationUnitImpl is looking for that method. The other is of 2.3.0 or older, which is why that method isn't found (JProgram class was loaded by the compiler using the older version).
Try to look them up thoroughly. Or try to start a fresh environment in which you put a good eye on what's getting in.

Answer 2

tl;dr: this is due to differences in the linkers provided by Compiler versus DevMode in cases of insufficient or incorrect class context
Tracing the issue
I noticed that the repro you have exists in the current GWT trunk. Specifically, it's failing in this block of code:
ArrayList<CompilationUnit> resultUnits = new ArrayList<CompilationUnit>();
do {
// Compile anything that needs to be compiled.
buildQueue = new LinkedBlockingQueue<CompilationUnitBuilder>();
final ArrayList<CompilationUnit> newlyBuiltUnits = new ArrayList<CompilationUnit>();
final CompilationUnitBuilder sentinel = CompilationUnitBuilder.create((GeneratedUnit) null);
final Throwable[] workerException = new Throwable[1];
Thread buildThread = new Thread() {
#Override
public void run() {
try {
do {
CompilationUnitBuilder builder = buildQueue.take();
if (builder == sentinel) {
return;
}
// Expensive, must serialize GWT AST types to bytes.
CompilationUnit unit = builder.build(); // <-- Right here.
newlyBuiltUnits.add(unit);
} while (true);
} catch (Throwable e) {
workerException[0] = e;
}
}
};
Unwinding the stack further than your trace, we bounce through a factory and ten layers of code, until we finally hit UnifyAst.java. And, lo and behold:
...
mapApi(enclosingType);
// Now the method should be there.
method = methodMap.get(sig);
if (method == null) {
// TODO: error logging
throw new NoSuchMethodError(sig);
}
assert !method.isExternal();
return method;
...
This is the only instance of NoSuchMethodError called by the Precompilation stage of GWT.
Differences in Compiler and DevMode linking
Cool. Now that we've taken the deep dive into why this is exploding, let's figure out why DevMode works when Compiler doesn't. We note that both import the same copy of Util.java, so technically, both types are available statically to our Java compiler (just not the GWT compiler).
Inspecting the linkers, we note that Compiler uses Link.link directly:
Link.link(logger.branch(TreeLogger.TRACE, logMessage), module,
generatedArtifacts, allPerms, resultFiles, options.getWarDir(),
options.getDeployDir(), options.getExtraDir(), precompileOptions);
Whereas DevMode uses a much terser static call, with a separate pass filling in an instance of StandardLinkerContext:
link(loadLogger, module);
...
#Override
protected synchronized void produceOutput(TreeLogger logger, StandardLinkerContext linkerStack,
ArtifactSet artifacts, ModuleDef module, boolean isRelink) throws UnableToCompleteException {
...
linkerStack.produceOutput(linkLogger, artifacts, Visibility.Public, outFileSet);
linkerStack.produceOutput(linkLogger, artifacts, Visibility.Deploy, deployFileSet);
linkerStack.produceOutput(linkLogger, artifacts, Visibility.Private, extraFileSet);
...
}
Great! So, how do I fix it?
As accepted in the middle of writing this post, yair provides one such diagnosis for the issue, noting that the precompilation step is non-robust to conflicting class identities in the context of two versions of GWT. Other class visibility problems where precompilation.getGeneratedArtifacts(); pulls in wrong or insufficient objects may also cause this repro.
I will assume the issue has now been resolved, given yair was given accepted answer status. But it is conceivable for other people running across this post that other classpath or visibility issues may cause this exact issue to recur.

Answer 3

java.io.ObjectOutputStream class isn't supported by GWT compiler.
You have to refer to https://developers.google.com/web-toolkit/doc/latest/RefJreEmulation#Package_java_io before using Java classes to be sure GWT supports it.

Answer 4

You fork a JVM to run Gwt Compiler and the bin directory is in ClassPath.
As Eclipse compiles in development mode, a remaining class in bin may prevent the compiler to process properly some source files.
You should make sure the bin directory is empty before you invoke your Ant target. It may pass then.
I recommend you to use two target directories: one for classes compiled from Java sources and another one for GWT generated files. Then the target war will collect both into the WAR.