package com.googlecode.gwt.test.internal;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.ProtectionDomain;
import java.util.regex.Pattern;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.Loader;
import javassist.NotFoundException;
import javassist.Translator;
import com.google.gwt.dev.javac.CompilationState;
import com.google.gwt.dev.javac.CompiledClass;
import com.google.gwt.dev.shell.JsValueGlue;
import com.google.gwt.dev.util.Name;
import com.googlecode.gwt.test.GwtTest;
import com.googlecode.gwt.test.exceptions.GwtTestException;
import com.googlecode.gwt.test.exceptions.GwtTestPatchException;
import com.googlecode.gwt.test.internal.rewrite.OverlayTypesRewriter;
/**
* <p>
* gwt-test-utils custom {@link ClassLoader} used to load classes referenced inside a test class
* extending {@link GwtTest}.<strong>For internal use only : do not refer directly to this
* classloader in your client code.</strong>
* </p>
* <p>
* It aims to provide JVM-compliant versions of classes referenced in those test classes. To obtain
* JVM-compliant code, this class loader relies on a set of class {@link Patcher} which can be
* configured using the <strong>META-INF\gwt-test-utils.properties</strong> file of your
* application.
* </p>
*
* <p>
* In addition to {@link Patcher}, this classloader also perform some bytecode modification on every
* GWT JavaScriptObject subtype, also known as <strong>Overlay types</strong>.
* </p>
*
*
* @see GwtTranslator
* @see OverlayTypesRewriter
*
* @author Bertrand Paquet
* @author Gael Lazzari
*
*/
public class GwtClassLoader extends Loader {
private static class GwtClassLoaderWithRewriter extends GwtClassLoader {
private static final CtClass JSO_CTCLASS = GwtClassPool.getClass(JsValueGlue.JSO_CLASS);
private final OverlayTypesRewriter overlayRewriter;
private GwtClassLoaderWithRewriter(ConfigurationLoader configurationLoader,
CompilationState compilationState, OverlayTypesRewriter overlayRewriter)
throws NotFoundException, CannotCompileException {
super(configurationLoader, compilationState);
this.overlayRewriter = overlayRewriter;
}
/**
* Performs Overlay type support bytecode manipulation
*
* @param className the name of the class to find
* @param rewriter
* @return the class byte array, or null if class has not been found
* @throws NotFoundException
* @throws CannotCompileException
* @throws IOException
*/
@Override
protected byte[] findClassBytes(String className) throws ClassNotFoundException {
if (overlayRewriter.isJsoIntf(className)) {
// Generate a synthetic JSO interface class.
return overlayRewriter.writeJsoIntf(className);
}
if (isUnsupportedOverlayType(className)) {
throw new GwtTestPatchException(
"Overlay type '"
+ className
+ "' has not been found. Did you forget to inherit some GWT module ? Does your GWT code compile using the -strict option ?");
}
// A JSO impl class needs the class bytes for the original class.
String classFromPool = overlayRewriter.isJsoImpl(className) ? className.substring(0,
className.length() - 1) : className;
// Apply Patchers
byte[] classBytes = super.findClassBytes(classFromPool);
// perform Overlay types bytecode transformation
classBytes = overlayRewriter.rewrite(className, classBytes);
return classBytes;
}
private boolean isUnsupportedOverlayType(String className) {
CtClass classToLoad = null;
try {
classToLoad = GwtClassPool.getClass(className);
} catch (GwtTestPatchException e) {
// nothing to do, it must be a Jso$ class
}
return classToLoad != null && classToLoad.subclassOf(JSO_CTCLASS)
&& classToLoad != JSO_CTCLASS;
}
}
static GwtClassLoader createClassLoader(ConfigurationLoader configurationLoader,
CompilationState compilationState, OverlayTypesRewriter overlayRewriter) {
try {
if (overlayRewriter == null) {
return new GwtClassLoader(configurationLoader, compilationState);
} else {
return new GwtClassLoaderWithRewriter(configurationLoader, compilationState,
overlayRewriter);
}
} catch (Exception e) {
throw new GwtTestException("Error during " + GwtClassLoader.class.getSimpleName()
+ " instanciation :", e);
}
}
private final CompilationState compilationState;
private final Pattern delegatePattern;
private ProtectionDomain domain;
private final ClassPool source;
private final Translator translator;
private GwtClassLoader(ConfigurationLoader configurationLoader, CompilationState compilationState) {
super(GwtClassPool.get());
this.compilationState = compilationState;
this.source = GwtClassPool.get();
this.translator = new GwtTranslator(configurationLoader);
StringBuilder sb = new StringBuilder("^(");
sb = appendPackageToDelegate(sb, "java.");
sb = appendPackageToDelegate(sb, "javax.");
sb = appendPackageToDelegate(sb, "sun.");
sb = appendPackageToDelegate(sb, "com.sun.");
sb = appendPackageToDelegate(sb, "org.w3c.");
sb = appendPackageToDelegate(sb, "org.xml.");
for (String s : configurationLoader.getDelegates()) {
if (s.endsWith(".")) {
sb = appendPackageToDelegate(sb, s);
} else {
sb = appendClassToDelegate(sb, s);
}
}
sb.replace(sb.length() - 1, sb.length(), "");
sb.append(")$");
delegatePattern = Pattern.compile(sb.toString());
}
@Override
public void setDomain(ProtectionDomain domain) {
super.setDomain(domain);
this.domain = domain;
}
@Override
protected Class<?> findClass(String className) throws ClassNotFoundException {
byte[] classfile = findClassBytes(className);
int i = className.lastIndexOf('.');
if (i != -1) {
String pname = className.substring(0, i);
if (getPackage(pname) == null) {
try {
definePackage(pname, null, null, null, null, null, null, null);
} catch (IllegalArgumentException e) {
// ignore. maybe the package object for the same
// name has been created just right away.
}
}
}
try {
if (domain == null) {
return defineClass(className, classfile, 0, classfile.length);
} else {
return defineClass(className, classfile, 0, classfile.length, domain);
}
} catch (Throwable t) {
throw new GwtTestPatchException("Error while defining " + className
+ " from modified bytecode", t);
}
}
protected byte[] findClassBytes(String className) throws ClassNotFoundException {
try {
// Apply Patchers
translator.onLoad(source, className);
try {
return source.get(className).toBytecode();
} catch (NotFoundException e) {
return null;
}
} catch (NotFoundException e) {
// Try and load the class from the compilation state. The generator
// will need to have already been run on the class for this to work.
String internalName = Name.BinaryName.toInternalName(className);
CompiledClass compiledClass = compilationState.getClassFileMap().get(internalName);
if (compiledClass != null) {
addCompiledClass(compiledClass);
try {
return applyPatchers(className);
} catch (Exception e2) {
throw new ClassNotFoundException(
"caught an exception while otaining a class file for generated class "
+ className, e2);
}
} else {
throw new ClassNotFoundException(className);
}
} catch (GwtTestException e) {
throw e;
} catch (Exception e) {
throw new ClassNotFoundException("caught an exception while obtaining a class file for "
+ className, e);
}
}
@Override
protected Class<?> loadClassByDelegation(String name) throws ClassNotFoundException {
return delegatePattern.matcher(name).matches() ? delegateToParent(name) : null;
}
private void addCompiledClass(CompiledClass compiledClass) {
InputStream is = new ByteArrayInputStream(compiledClass.getBytes());
try {
source.makeClass(is);
} catch (Exception e) {
throw new GwtTestPatchException("Error while handling generated class '"
+ compiledClass.getInternalName(), e);
} finally {
try {
is.close();
} catch (IOException e) {
// don't care
}
}
}
private StringBuilder appendClassToDelegate(StringBuilder sb, String className) {
return sb.append(className.replaceAll("\\.", "\\\\\\.").replaceAll("\\$", "\\\\\\$")).append(
"|");
}
private StringBuilder appendPackageToDelegate(StringBuilder sb, String packageName) {
return sb.append(packageName.replaceAll("\\.", "\\\\\\.")).append(".+|");
}
private byte[] applyPatchers(String className) throws NotFoundException, CannotCompileException,
IOException {
// Apply Patchers
translator.onLoad(source, className);
try {
return source.get(className).toBytecode();
} catch (NotFoundException e) {
return null;
}
}
}