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author | patriot1burke <patriot1burke@30ef5769-5b8d-40dd-aea6-55b5d6557bb3> | 2003-04-22 13:47:06 +0000 |
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committer | patriot1burke <patriot1burke@30ef5769-5b8d-40dd-aea6-55b5d6557bb3> | 2003-04-22 13:47:06 +0000 |
commit | 069bceaf72fd0d6ffad14ce4e3e00ca91a280bde (patch) | |
tree | b8230a15d3061c64d5a64bf9efa654d0d6311ff2 /src/main/javassist/CtNewMethod.java | |
parent | f610083ba0adbcb3fe92a504015fb26fb5a42530 (diff) | |
download | javassist-069bceaf72fd0d6ffad14ce4e3e00ca91a280bde.tar.gz javassist-069bceaf72fd0d6ffad14ce4e3e00ca91a280bde.zip |
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git-svn-id: http://anonsvn.jboss.org/repos/javassist/trunk@6 30ef5769-5b8d-40dd-aea6-55b5d6557bb3
Diffstat (limited to 'src/main/javassist/CtNewMethod.java')
-rw-r--r-- | src/main/javassist/CtNewMethod.java | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/src/main/javassist/CtNewMethod.java b/src/main/javassist/CtNewMethod.java new file mode 100644 index 00000000..05532902 --- /dev/null +++ b/src/main/javassist/CtNewMethod.java @@ -0,0 +1,439 @@ +/* + * This file is part of the Javassist toolkit. + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * either http://www.mozilla.org/MPL/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * The Original Code is Javassist. + * + * The Initial Developer of the Original Code is Shigeru Chiba. Portions + * created by Shigeru Chiba are Copyright (C) 1999-2003 Shigeru Chiba. + * All Rights Reserved. + * + * Contributor(s): + * + * The development of this software is supported in part by the PRESTO + * program (Sakigake Kenkyu 21) of Japan Science and Technology Corporation. + */ + +package javassist; + +import javassist.bytecode.*; +import javassist.compiler.Javac; +import javassist.compiler.CompileError; +import javassist.CtMethod.ConstParameter; + +/** + * A collection of static methods for creating a <code>CtMethod</code>. + * An instance of this class does not make any sense. + * + * @see CtClass#addMethod(CtMethod) + */ +public class CtNewMethod { + + /** + * Compiles the given source code and creates a method. + * The source code must include not only the method body + * but the whole declaration, for example, + * + * <ul><pre>"public Object id(Object obj) { return obj; }"</pre></ul> + * + * @param src the source text. + * @param declaring the class to which the created method is added. + */ + public static CtMethod make(String src, CtClass declaring) + throws CannotCompileException + { + return make(src, declaring, null, null); + } + + /** + * Compiles the given source code and creates a method. + * The source code must include not only the method body + * but the whole declaration, for example, + * + * <ul><pre>"public Object id(Object obj) { return obj; }"</pre></ul> + * + * <p>If the source code includes <code>$proceed()</code>, then + * it is compiled into a method call on the specified object. + * + * @param src the source text. + * @param declaring the class to which the created method is added. + * @param delegateObj the source text specifying the object + * that is called on by <code>$proceed()</code>. + * @param delegateMethod the name of the method + * that is called by <code>$proceed()</code>. + */ + public static CtMethod make(String src, CtClass declaring, + String delegateObj, String delegateMethod) + throws CannotCompileException + { + Javac compiler = new Javac(declaring); + try { + if (delegateMethod != null) + compiler.recordProceed(delegateObj, delegateMethod); + + CtMember obj = compiler.compile(src); + if (obj instanceof CtMethod) + return (CtMethod)obj; + } + catch (CompileError e) { + throw new CannotCompileException(e); + } + + throw new CannotCompileException("not a method"); + } + + /** + * Creates a public method. + * + * @param returnType the type of the returned value + * @param mname the method name + * @param parameters a list of the parameter types + * @param exceptions a list of the exception types + * @param src the source text of the method body. + * It must be a block surrounded by <code>{}</code>. + * @param declaring the class to which the created method is added. + */ + public static CtMethod make(CtClass returnType, String mname, + CtClass[] parameters, CtClass[] exceptions, + String body, CtClass declaring) + throws CannotCompileException + { + try { + CtMethod cm + = new CtMethod(returnType, mname, parameters, declaring); + cm.setExceptionTypes(exceptions); + cm.setBody(body); + return cm; + } + catch (NotFoundException e) { + throw new CannotCompileException(e); + } + } + + /** + * Creates a copy of a method. This method is provided for creating + * a new method based on an existing method. + * + * @param src the source method. + * @param declaring the class to which the created method is added. + * @param map the hashtable associating original class names + * with substituted names. + * It can be <code>null</code>. + * + * @see CtMethod#CtMethod(CtMethod,CtClass,ClassMap) + */ + public static CtMethod copy(CtMethod src, CtClass declaring, + ClassMap map) throws CannotCompileException { + return new CtMethod(src, declaring, map); + } + + /** + * Creates a copy of a method with a new name. + * This method is provided for creating + * a new method based on an existing method. + * + * @param src the source method. + * @param name the name of the created method. + * @param declaring the class to which the created method is added. + * @param map the hashtable associating original class names + * with substituted names. + * It can be <code>null</code>. + * + * @see CtMethod#CtMethod(CtMethod,CtClass,ClassMap) + */ + public static CtMethod copy(CtMethod src, String name, CtClass declaring, + ClassMap map) throws CannotCompileException { + CtMethod cm = new CtMethod(src, declaring, map); + cm.setName(name); + return cm; + } + + /** + * Creates a public abstract method. + * + * @param returnType the type of the returned value + * @param mname the method name + * @param parameters a list of the parameter types + * @param exceptions a list of the exception types + * @param declaring the class to which the created method is added. + * + * @see CtMethod#CtMethod(CtClass,String,CtClass[],CtClass) + */ + public static CtMethod abstractMethod(CtClass returnType, + String mname, + CtClass[] parameters, + CtClass[] exceptions, + CtClass declaring) + throws NotFoundException + { + CtMethod cm = new CtMethod(returnType, mname, parameters, declaring); + cm.setExceptionTypes(exceptions); + return cm; + } + + /** + * Creates a public getter method. The getter method returns the value + * of the specified field in the class to which this method is added. + * The created method is initially not static even if the field is + * static. Change the modifiers if the method should be static. + * + * @param methodName the name of the getter + * @param field the field accessed. + */ + public static CtMethod getter(String methodName, CtField field) + throws CannotCompileException + { + FieldInfo finfo = field.getFieldInfo2(); + String fieldType = finfo.getDescriptor(); + String desc = "()" + fieldType; + ConstPool cp = finfo.getConstPool(); + MethodInfo minfo = new MethodInfo(cp, methodName, desc); + minfo.setAccessFlags(AccessFlag.PUBLIC); + + Bytecode code = new Bytecode(cp, 2, 1); + try { + String fieldName = finfo.getName(); + if ((finfo.getAccessFlags() & AccessFlag.STATIC) == 0) { + code.addAload(0); + code.addGetfield(Bytecode.THIS, fieldName, fieldType); + } + else + code.addGetstatic(Bytecode.THIS, fieldName, fieldType); + + code.addReturn(field.getType()); + } + catch (NotFoundException e) { + throw new CannotCompileException(e); + } + + minfo.setCodeAttribute(code.toCodeAttribute()); + return new CtMethod(minfo, field.getDeclaringClass()); + } + + /** + * Creates a public setter method. The setter method assigns the + * value of the first parameter to the specified field + * in the class to which this method is added. + * The created method is initially not static even if the field is + * static. Change the modifiers if the method should be static. + * + * @param methodName the name of the setter + * @param field the field accessed. + */ + public static CtMethod setter(String methodName, CtField field) + throws CannotCompileException + { + FieldInfo finfo = field.getFieldInfo2(); + String fieldType = finfo.getDescriptor(); + String desc = "(" + fieldType + ")V"; + ConstPool cp = finfo.getConstPool(); + MethodInfo minfo = new MethodInfo(cp, methodName, desc); + minfo.setAccessFlags(AccessFlag.PUBLIC); + + Bytecode code = new Bytecode(cp, 3, 3); + try { + String fieldName = finfo.getName(); + if ((finfo.getAccessFlags() & AccessFlag.STATIC) == 0) { + code.addAload(0); + code.addLoad(1, field.getType()); + code.addPutfield(Bytecode.THIS, fieldName, fieldType); + } + else { + code.addLoad(0, field.getType()); + code.addPutstatic(Bytecode.THIS, fieldName, fieldType); + } + + code.addReturn(null); + } + catch (NotFoundException e) { + throw new CannotCompileException(e); + } + + minfo.setCodeAttribute(code.toCodeAttribute()); + return new CtMethod(minfo, field.getDeclaringClass()); + } + + /** + * Creates a method forwarding to a delegate in + * a super class. The created method calls a method specified + * by <code>delegate</code> with all the parameters passed to the + * created method. If the delegate method returns a value, + * the created method returns that value to the caller. + * The delegate method must be declared in a super class. + * + * <p>The following method is an example of the created method. + * + * <ul><pre>int f(int p, int q) { + * return super.f(p, q); + * }</pre></ul> + * + * <p>The name of the created method can be changed by + * <code>setName()</code>. + * + * @param delegate the method that the created method forwards to. + * @param declaring the class to which the created method is + * added. + */ + public static CtMethod delegator(CtMethod delegate, CtClass declaring) + throws CannotCompileException + { + try { + return delegator0(delegate, declaring); + } + catch (NotFoundException e) { + throw new CannotCompileException(e); + } + } + + private static CtMethod delegator0(CtMethod delegate, CtClass declaring) + throws CannotCompileException, NotFoundException + { + MethodInfo deleInfo = delegate.getMethodInfo2(); + String methodName = deleInfo.getName(); + String desc = deleInfo.getDescriptor(); + ConstPool cp = declaring.getClassFile2().getConstPool(); + MethodInfo minfo = new MethodInfo(cp, methodName, desc); + minfo.setAccessFlags(deleInfo.getAccessFlags()); + + ExceptionsAttribute eattr = deleInfo.getExceptionsAttribute(); + if (eattr != null) + minfo.setExceptionsAttribute( + (ExceptionsAttribute)eattr.copy(cp, null)); + + Bytecode code = new Bytecode(cp, 0, 0); + boolean isStatic = Modifier.isStatic(delegate.getModifiers()); + CtClass deleClass = delegate.getDeclaringClass(); + CtClass[] params = delegate.getParameterTypes(); + int s; + if (isStatic) { + s = code.addLoadParameters(params); + code.addInvokestatic(deleClass, methodName, desc); + } + else { + code.addLoad(0, deleClass); + s = code.addLoadParameters(params); + code.addInvokespecial(deleClass, methodName, desc); + } + + code.addReturn(delegate.getReturnType()); + code.setMaxLocals(++s); + code.setMaxStack(s < 2 ? 2 : s); // for a 2-word return value + minfo.setCodeAttribute(code.toCodeAttribute()); + return new CtMethod(minfo, declaring); + } + + /** + * Creates a wrapped method. The wrapped method receives parameters + * in the form of an array of <code>Object</code>. + * + * <p>The body of the created method is a copy of the body of a method + * specified by <code>body</code>. However, it is wrapped in + * parameter-conversion code. + * + * <p>The method specified by <code>body</code> must have this singature: + * + * <ul><code>Object method(Object[] params, <type> cvalue) + * </code></ul> + * + * <p>The type of the <code>cvalue</code> depends on + * <code>constParam</code>. + * If <code>constParam</code> is <code>null</code>, the signature + * must be: + * + * <ul><code>Object method(Object[] params)</code></ul> + * + * <p>The method body copied from <code>body</code> is wrapped in + * parameter-conversion code, which converts parameters specified by + * <code>parameterTypes</code> into an array of <code>Object</code>. + * The returned value is also converted from the <code>Object</code> + * type to the type specified by <code>returnType</code>. Thus, + * the resulting method body is as follows: + * + * <ul><pre>Object[] params = new Object[] { p0, p1, ... }; + * <<i>type</i>> cvalue = <<i>constant-value</i>>; + * <i>... copied method body ...</i> + * Object result = <<i>returned value</i>> + * return (<i><returnType></i>)result; + * </pre></ul> + * + * <p>The variables <code>p0</code>, <code>p2</code>, ... represent + * formal parameters of the created method. + * The value of <code>cvalue</code> is specified by + * <code>constParam</code>. + * + * <p>If the type of a parameter or a returned value is a primitive + * type, then the value is converted into a wrapper object such as + * <code>java.lang.Integer</code>. If the type of the returned value + * is <code>void</code>, the returned value is discarded. + * + * <p><i>Example:</i> + * + * <ul><pre>ClassPool pool = ... ; + * CtClass vec = pool.makeClass("intVector"); + * vec.setSuperclass(pool.get("java.util.Vector")); + * CtMethod addMethod = pool.getMethod("Sample", "add0"); + * + * CtClass[] argTypes = { CtClass.intType }; + * CtMethod m = CtNewMethod.wrapped(CtClass.voidType, "add", argTypes, + * null, addMethod, null, vec); + * vec.addMethod(m);</pre></ul> + * + * <p>where the class <code>Sample</code> is as follows: + * + * <ul><pre>public class Sample extends java.util.Vector { + * public Object add0(Object[] args) { + * super.addElement(args[0]); + * return null; + * } + * }</pre></ul> + * + * <p>This program produces a class <code>intVector</code>: + * + * <ul><pre>public class intVector extends java.util.Vector { + * public void add(int p0) { + * Object[] args = new Object[] { p0 }; + * // begin of copied body + * super.addElement(args[0]); + * Object result = null; + * // end + * } + * }</pre></ul> + * + * <p>Note that the type of the parameter to <code>add()</code> depends + * only on the value of <code>argTypes</code> passed to + * <code>CtNewMethod.wrapped()</code>. Thus, it is easy to + * modify this program to produce a + * <code>StringVector</code> class, which is a vector containing + * only <code>String</code> objects, and other vector classes. + * + * @param returnType the type of the returned value. + * @param mname the method name. + * @param parameters a list of the parameter types. + * @param exceptions a list of the exception types. + * @param body the method body + * @param constParam the constant parameter + * (maybe <code>null</code>). + * @param declaring the class to which the created method is + * added. + */ + public static CtMethod wrapped(CtClass returnType, + String mname, + CtClass[] parameterTypes, + CtClass[] exceptionTypes, + CtMethod body, ConstParameter constParam, + CtClass declaring) + throws CannotCompileException + { + return CtNewWrappedMethod.wrapped(returnType, mname, parameterTypes, + exceptionTypes, body, constParam, declaring); + } +} |