implemented JASSIST-170

git-svn-id: http://anonsvn.jboss.org/repos/javassist/trunk@639 30ef5769-5b8d-40dd-aea6-55b5d6557bb3

Readme.html

@@ -284,7 +284,7 @@ <h2>Changes</h2>
 <p>-version 3.17
 <ul>
 	<li>OSGi bundle info is now included in the jar file.
-	<li>JIRA JASSIST-166, 168 have been fixed.
+	<li>JIRA JASSIST-166, 168, 170 have been fixed.
 </ul>
 
 <p>-version 3.16.1 on March 6, 2012

src/main/javassist/CtBehavior.java

@@ -314,19 +314,43 @@ CtClass getReturnType0() throws NotFoundException {
      *
      * <p>Note that the returned string is not the type signature
      * contained in the <code>SignatureAttirbute</code>.  It is
-     * a descriptor.  To obtain a type signature, call the following
-     * methods:
-     * 
-     * <ul><pre>getMethodInfo().getAttribute(SignatureAttribute.tag)
-     * </pre></ul>
+     * a descriptor.
      *
      * @see javassist.bytecode.Descriptor
-     * @see javassist.bytecode.SignatureAttribute
+     * @see #getGenericSignature()
      */
     public String getSignature() {
         return methodInfo.getDescriptor();
     }
 
+    /**
+     * Returns the generic signature of the method.
+     * It represents parameter types including type variables.
+     *
+     * @see SignatureAttribute#toMethodSignature(String)
+     * @since 3.17
+     */
+    public String getGenericSignature() {
+        SignatureAttribute sa
+            = (SignatureAttribute)methodInfo.getAttribute(SignatureAttribute.tag);
+        return sa == null ? null : sa.getSignature();
+    }
+
+    /**
+     * Set the generic signature of the method.
+     * It represents parameter types including type variables.
+     * See {@link javassist.CtClass#setGenericSignature(String)}
+     * for a code sample.
+     *
+     * @param sig       a new generic signature.
+     * @see javassist.bytecode.SignatureAttribute.MethodSignature#encode()
+     * @since 3.17
+     */
+    public void setGenericSignature(String sig) {
+        declaringClass.checkModify();
+        methodInfo.addAttribute(new SignatureAttribute(methodInfo.getConstPool(), sig));
+    }
+
     /**
      * Obtains exceptions that this method/constructor may throw.
      *

src/main/javassist/CtClass.java

@@ -29,6 +29,7 @@
 import javassist.bytecode.ClassFile;
 import javassist.bytecode.Descriptor;
 import javassist.bytecode.Opcode;
+import javassist.bytecode.SignatureAttribute;
 import javassist.expr.ExprEditor;
 
 /* Note:
@@ -387,6 +388,89 @@ public void setName(String name) {
             qualifiedName = name;
     }
 
+    /**
+     * Returns the generic signature of the class.
+     *
+     * <p>The generics of Java is implemented by the erasure technique.
+     * After compilation, all type parameters are dropped off from the
+     * main part of a class file.  However, for reflection, the type
+     * parameters are encoded into generic signatures and attached
+     * to a class file.
+     *
+     * @return null if the generic signature is not included.
+     * @see javassist.bytecode.SignatureAttribute#toClassSignature(String)
+     * @see CtMember#getGenericSignature()
+     * @since 3.17
+     */
+    public String getGenericSignature() { return null; }
+
+    /**
+     * Sets the generic signature of the class.
+     *
+     * <p>The generics of Java is implemented by the erasure technique.
+     * After compilation, all type parameters are dropped off from the
+     * main part of a class file.  However, for reflection, the type
+     * parameters must be encoded into generic signatures and attached
+     * to a class file.
+     *
+     * <p>For example,
+     *
+     * <pre>class List<T> {
+     *     T value;
+     *     T get() { return value; }
+     *     void set(T v) { value = v; }
+     * }
+     * </pre>
+     *
+     * <p>this class is generated by the following code:
+     *
+     * <pre>
+     * ClassPool pool = ClassPool.getDefault();
+     * CtClass cc = pool.makeClass("List");
+     * CtClass objectClass = pool.get(CtClass.javaLangObject);
+     * ClassSignature cs = new ClassSignature(
+     *                         new TypeParameter[] { new TypeParameter("T") });
+     * cc.setGenericSignature(cs.encode());    // &lt;T:Ljava/lang/Object;&gt;Ljava/lang/Object;
+     *
+     * CtField f = new CtField(objClass, "value", cc);
+     * TypeVariable tvar = new TypeVariable("T");
+     * f.setGenericSignature(tvar.encode());   // TT;
+     * cc.addField(f);
+     *
+     * CtMethod m = CtNewMethod.make("public Object get(){return value;}", cc);
+     * MethodSignature ms = new MethodSignature(null, null, tvar, null);
+     * m.setGenericSignature(ms.encode());     // ()TT;
+     * cc.addMethod(m);
+     *
+     * CtMethod m2 = CtNewMethod.make("public void set(Object v){value = v;}", cc);
+     * MethodSignature ms2 = new MethodSignature(null, new Type[] { tvar },
+     *                                           new BaseType("void"), null);
+     * m2.setGenericSignature(ms2.encode());   // (TT;)V;
+     * cc.addMethod(m2);
+     *
+     * cc.writeFile();
+     * </pre>
+     *
+     * <p>The generated class file is equivalent to the following:
+     *
+     * <pre>class List {
+     *     Object value;
+     *     Object get() { return value; }
+     *     void set(Object v) { value = v; }
+     * }</pre>
+     *
+     * <p>but it includes generic signatures for the class, the field,
+     * and the methods so that the type variable <code>T</code> can be
+     * accessible through reflection.
+     *
+     * @param sig       a generic signature.
+     * @see javassist.bytecode.SignatureAttribute.ClassSignature#encode()
+     * @see javassist.bytecode.SignatureAttribute.MethodSignature#encode()
+     * @see CtMember#setGenericSignature(String)
+     * @since 3.17
+     */
+    public void setGenericSignature(String sig) { checkModify(); }
+
     /**
      * Substitutes <code>newName</code> for all occurrences of a class
      * name <code>oldName</code> in the class file.

src/main/javassist/CtClassType.java

@@ -47,6 +47,7 @@
 import javassist.bytecode.InnerClassesAttribute;
 import javassist.bytecode.MethodInfo;
 import javassist.bytecode.ParameterAnnotationsAttribute;
+import javassist.bytecode.SignatureAttribute;
 import javassist.bytecode.annotation.Annotation;
 import javassist.compiler.AccessorMaker;
 import javassist.compiler.CompileError;
@@ -336,6 +337,18 @@ public void setName(String name) throws RuntimeException {
         classPool.classNameChanged(oldname, this);
     }
 
+    public String getGenericSignature() {
+        SignatureAttribute sa
+            = (SignatureAttribute)getClassFile2().getAttribute(SignatureAttribute.tag);
+        return sa == null ? null : sa.getSignature();
+    }
+
+    public void setGenericSignature(String sig) {
+        ClassFile cf = getClassFile();
+        SignatureAttribute sa = new SignatureAttribute(cf.getConstPool(), sig);
+        cf.addAttribute(sa);
+    }
+
     public void replaceClassName(ClassMap classnames)
         throws RuntimeException
     {

src/main/javassist/CtField.java

@@ -327,19 +327,43 @@ private Object[] getAnnotations(boolean ignoreNotFound) throws ClassNotFoundExce
      *
      * <p>Note that the returned string is not the type signature
      * contained in the <code>SignatureAttirbute</code>.  It is
-     * a descriptor.  To obtain a type signature, call the following
-     * methods:
-     * 
-     * <ul><pre>getFieldInfo().getAttribute(SignatureAttribute.tag)
-     * </pre></ul>
+     * a descriptor.
      *
      * @see javassist.bytecode.Descriptor
-     * @see javassist.bytecode.SignatureAttribute
+     * @see #getGenericSignature()
      */
     public String getSignature() {
         return fieldInfo.getDescriptor();
     }
 
+    /**
+     * Returns the generic signature of the field.
+     * It represents a type including type variables.
+     *
+     * @see SignatureAttribute#toFieldSignature(String)
+     * @since 3.17
+     */
+    public String getGenericSignature() {
+        SignatureAttribute sa
+            = (SignatureAttribute)fieldInfo.getAttribute(SignatureAttribute.tag);
+        return sa == null ? null : sa.getSignature();
+    }
+
+    /**
+     * Set the generic signature of the field.
+     * It represents a type including type variables.
+     * See {@link javassist.CtClass#setGenericSignature(String)}
+     * for a code sample.
+     *
+     * @param sig       a new generic signature.
+     * @see javassist.bytecode.SignatureAttribute.ObjectType#encode()
+     * @since 3.17
+     */
+    public void setGenericSignature(String sig) {
+        declaringClass.checkModify();
+        fieldInfo.addAttribute(new SignatureAttribute(fieldInfo.getConstPool(), sig));
+    }
+
     /**
      * Returns the type of the field.
      */

src/main/javassist/CtMember.java

@@ -42,6 +42,8 @@ public Object[] getAnnotations()
         public String getSignature() { return null; }
         public void setAttribute(String name, byte[] data) {}
         public void setModifiers(int mod) {}
+        public String getGenericSignature() { return null; }
+        public void setGenericSignature(String sig) {}
 
         private CtMember methodTail;
         private CtMember consTail;     // constructor tail
@@ -269,6 +271,27 @@ else if (Modifier.isPrivate(mod))
      */
     public abstract String getSignature();
 
+    /**
+     * Returns the generic signature of the member.
+     *
+     * @see javassist.bytecode.SignatureAttribute#toFieldSignature(String)
+     * @see javassist.bytecode.SignatureAttribute#toMethodSignature(String)
+     * @see CtClass#getGenericSignature()
+     * @since 3.17
+     */
+    public abstract String getGenericSignature();
+
+    /**
+     * Sets the generic signature of the member.
+     *
+     * @param sig   a new generic signature.
+     * @see javassist.bytecode.SignatureAttribute.ObjectType#encode()
+     * @see javassist.bytecode.SignatureAttribute.MethodSignature#encode()
+     * @see CtClass#setGenericSignature(String)
+     * @since 3.17
+     */
+    public abstract void setGenericSignature(String sig);
+
     /**
      * Obtains a user-defined attribute with the given name.
      * If that attribute is not found in the class file, this