All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.ibatis.javassist.CtClass Maven / Gradle / Ivy

The newest version!
/*
 * Javassist, a Java-bytecode translator toolkit.
 * Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
 *
 * 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.  Alternatively, the contents of this file may be used under
 * the terms of the GNU Lesser General Public License Version 2.1 or later,
 * or the Apache License Version 2.0.
 *
 * 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.
 */

package org.apache.ibatis.javassist;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URL;
import java.security.ProtectionDomain;
import java.util.Collection;

import org.apache.ibatis.javassist.bytecode.ClassFile;
import org.apache.ibatis.javassist.bytecode.Descriptor;
import org.apache.ibatis.javassist.bytecode.Opcode;
import org.apache.ibatis.javassist.expr.ExprEditor;

/* Note:
 *
 * This class is an abstract class and several methods just return null
 * or throw an exception.  Those methods are overridden in subclasses
 * of this class.  Read the source code of CtClassType if you are
 * interested in the implementation of Javassist.
 *
 * Subclasses of CtClass are CtClassType, CtPrimitiveType, and CtArray.
 */

/**
 * An instance of CtClass represents a class.
 * It is obtained from ClassPool.
 *
 * @see ClassPool#get(String)
 */
public abstract class CtClass {
    protected String qualifiedName;

    /**
     * If the value of this field is not null, then all class
     * files modified by Javassist are saved under the directory
     * specified by this variable.  For example, if the value is
     * "./debug", then all class files are saved
     * there.  The directory name must not end with a directory
     * separator such as /.
     *
     * 

The default value is null. * * @see #debugWriteFile(String) * @since 3.16 */ public static String debugDump = null; /** * The version number of this release. */ public static final String version = "3.30.2-GA"; /** * Prints the version number and the copyright notice. * *

The following command invokes this method: * *

java -jar javassist.jar
*/ public static void main(String[] args) { System.out.println("Javassist version " + CtClass.version); System.out.println("Copyright (C) 1999-2023 Shigeru Chiba." + " All Rights Reserved."); } static final String javaLangObject = "java.lang.Object"; /** * The CtClass object representing * the boolean type. */ public static CtClass booleanType; /** * The CtClass object representing * the char type. */ public static CtClass charType; /** * The CtClass object representing * the byte type. */ public static CtClass byteType; /** * The CtClass object representing * the short type. */ public static CtClass shortType; /** * The CtClass object representing * the int type. */ public static CtClass intType; /** * The CtClass object representing * the long type. */ public static CtClass longType; /** * The CtClass object representing * the float type. */ public static CtClass floatType; /** * The CtClass object representing * the double type. */ public static CtClass doubleType; /** * The CtClass object representing * the void type. */ public static CtClass voidType; static CtClass[] primitiveTypes; static { primitiveTypes = new CtClass[9]; booleanType = new CtPrimitiveType("boolean", 'Z', "java.lang.Boolean", "booleanValue", "()Z", Opcode.IRETURN, Opcode.T_BOOLEAN, 1); primitiveTypes[0] = booleanType; charType = new CtPrimitiveType("char", 'C', "java.lang.Character", "charValue", "()C", Opcode.IRETURN, Opcode.T_CHAR, 1); primitiveTypes[1] = charType; byteType = new CtPrimitiveType("byte", 'B', "java.lang.Byte", "byteValue", "()B", Opcode.IRETURN, Opcode.T_BYTE, 1); primitiveTypes[2] = byteType; shortType = new CtPrimitiveType("short", 'S', "java.lang.Short", "shortValue", "()S", Opcode.IRETURN, Opcode.T_SHORT, 1); primitiveTypes[3] = shortType; intType = new CtPrimitiveType("int", 'I', "java.lang.Integer", "intValue", "()I", Opcode.IRETURN, Opcode.T_INT, 1); primitiveTypes[4] = intType; longType = new CtPrimitiveType("long", 'J', "java.lang.Long", "longValue", "()J", Opcode.LRETURN, Opcode.T_LONG, 2); primitiveTypes[5] = longType; floatType = new CtPrimitiveType("float", 'F', "java.lang.Float", "floatValue", "()F", Opcode.FRETURN, Opcode.T_FLOAT, 1); primitiveTypes[6] = floatType; doubleType = new CtPrimitiveType("double", 'D', "java.lang.Double", "doubleValue", "()D", Opcode.DRETURN, Opcode.T_DOUBLE, 2); primitiveTypes[7] = doubleType; voidType = new CtPrimitiveType("void", 'V', "java.lang.Void", null, null, Opcode.RETURN, 0, 0); primitiveTypes[8] = voidType; } protected CtClass(String name) { qualifiedName = name; } /** * Converts the object to a string. */ @Override public String toString() { StringBuilder buf = new StringBuilder(getClass().getName()); buf.append('@'); buf.append(Integer.toHexString(hashCode())); buf.append('['); extendToString(buf); buf.append(']'); return buf.toString(); } /** * Implemented in subclasses to add to the {@link #toString()} result. * Subclasses should put a space before each token added to the buffer. */ protected void extendToString(StringBuilder buffer) { buffer.append(getName()); } /** * Returns a ClassPool for this class. */ public ClassPool getClassPool() { return null; } /** * Returns a class file for this class. * *

This method is not available if isFrozen() * is true. */ public ClassFile getClassFile() { checkModify(); return getClassFile2(); } /** * Returns a class file for this class (read only). * Normal applications do not need calling this method. Use * getClassFile(). * *

The ClassFile object obtained by this method * is read only. Changes to this object might not be reflected * on a class file generated by toBytecode(), * toClass(), etc. * *

This method is available even if isFrozen() * is true. However, if the class is frozen, it might be also * pruned. * * @see CtClass#getClassFile() * @see CtClass#isFrozen() * @see CtClass#prune() */ public ClassFile getClassFile2() { return null; } /** * Undocumented method. Do not use; internal-use only. */ public org.apache.ibatis.javassist.compiler.AccessorMaker getAccessorMaker() { return null; } /** * Returns the uniform resource locator (URL) of the class file. */ public URL getURL() throws NotFoundException { throw new NotFoundException(getName()); } /** * Returns true if the definition of the class has been modified. */ public boolean isModified() { return false; } /** * Returns true if the class has been loaded or written out * and thus it cannot be modified any more. * * @see #defrost() * @see #detach() */ public boolean isFrozen() { return true; } /** * Makes the class frozen. * * @see #isFrozen() * @see #defrost() * @since 3.6 */ public void freeze() {} /* Note: this method is overridden by CtClassType */ void checkModify() throws RuntimeException { if (isFrozen()) throw new RuntimeException(getName() + " class is frozen"); // isModified() must return true after this method is invoked. } /** * Defrosts the class so that the class can be modified again. * *

To avoid changes that will be never reflected, * the class is frozen to be unmodifiable if it is loaded or * written out. This method should be called only in a case * that the class will be reloaded or written out later again. * *

If defrost() will be called later, pruning * must be disallowed in advance. * * @see #isFrozen() * @see #stopPruning(boolean) * @see #detach() */ public void defrost() { throw new RuntimeException("cannot defrost " + getName()); } /** * Returns true if this object represents a primitive * Java type: boolean, byte, char, short, int, long, float, double, * or void. */ public boolean isPrimitive() { return false; } /** * Returns true if this object represents an array type. */ public boolean isArray() { return false; } /** * Returns true if this object represents a Kotlin class. * @since 3.26 */ public boolean isKotlin() { return hasAnnotation("kotlin.Metadata"); } /** * If this object represents an array, this method returns the component * type of the array. Otherwise, it returns null. */ public CtClass getComponentType() throws NotFoundException { return null; } /** * Returns true if this class extends or implements * clazz. It also returns true if * this class is the same as clazz. */ public boolean subtypeOf(CtClass clazz) throws NotFoundException { return this == clazz || getName().equals(clazz.getName()); } /** * Obtains the fully-qualified name of the class. */ public String getName() { return qualifiedName; } /** * Obtains the not-qualified class name. */ public final String getSimpleName() { String qname = qualifiedName; int index = qname.lastIndexOf('.'); if (index < 0) return qname; return qname.substring(index + 1); } /** * Obtains the package name. It may be null. */ public final String getPackageName() { String qname = qualifiedName; int index = qname.lastIndexOf('.'); if (index < 0) return null; return qname.substring(0, index); } /** * Sets the class name * * @param name fully-qualified name */ public void setName(String name) { checkModify(); if (name != null) qualifiedName = name; } /** * Returns the generic signature of the class. * *

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. * *

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. * *

For example, * *

class List<T> {
     *     T value;
     *     T get() { return value; }
     *     void set(T v) { value = v; }
     * }
     * 
* *

this class is generated by the following code: * *

     * 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());    // <T:Ljava/lang/Object;>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();
     * 
* *

The generated class file is equivalent to the following: * *

class List {
     *     Object value;
     *     Object get() { return value; }
     *     void set(Object v) { value = v; }
     * }
* *

but it includes generic signatures for the class, the field, * and the methods so that the type variable T can be * accessible through reflection. * *

MethodSignature is a utility class. You can directly * pass the signature string to the setGenericSignature method. * For the specification of the signatures, see Section 4.7.9.1 Signatures * of The Java Virtual Machine Specification (Java SE 8). * * @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 newName for all occurrences of a class * name oldName in the class file. * * @param oldName replaced class name * @param newName substituted class name */ public void replaceClassName(String oldName, String newName) { checkModify(); } /** * Changes class names appearing in the class file according to the * given map. * *

All the class names appearing in the class file are tested * with map to determine whether each class name is * replaced or not. Thus this method can be used for collecting * all the class names in the class file. To do that, first define * a subclass of ClassMap so that get() * records all the given parameters. Then, make an instance of * that subclass as an empty hash-table. Finally, pass that instance * to this method. After this method finishes, that instance would * contain all the class names appearing in the class file. * * @param map the hashtable associating replaced class names * with substituted names. */ public void replaceClassName(ClassMap map) { checkModify(); } /** * Returns a collection of the names of all the classes * referenced in this class. * That collection includes the name of this class. * *

This method may return null. * * @return a Collection<String> object. */ public synchronized Collection getRefClasses() { ClassFile cf = getClassFile2(); if (cf != null) { ClassMap cm = new ClassMap() { /** default serialVersionUID */ private static final long serialVersionUID = 1L; @Override public String put(String oldname, String newname) { return put0(oldname, newname); } @Override public String get(Object jvmClassName) { String n = toJavaName((String)jvmClassName); put0(n, n); return null; } @Override public void fix(String name) {} }; cf.getRefClasses(cm); return cm.values(); } return null; } /** * Determines whether this object represents a class or an interface. * It returns true if this object represents an interface. */ public boolean isInterface() { return false; } /** * Determines whether this object represents an annotation type. * It returns true if this object represents an annotation type. * * @since 3.2 */ public boolean isAnnotation() { return false; } /** * Determines whether this object represents an enum. * It returns true if this object represents an enum. * * @since 3.2 */ public boolean isEnum() { return false; } /** * Returns the modifiers for this class, encoded in an integer. * For decoding, use org.apache.ibatis.javassist.Modifier. * *

If the class is a static nested class (a.k.a. static inner class), * the returned modifiers include Modifier.STATIC. * * @see Modifier */ public int getModifiers() { return 0; } /** * Returns true if the class has the specified annotation type. * * @param annotationType the annotation type. * @return true if the annotation is found, otherwise false. * @since 3.11 */ public boolean hasAnnotation(Class annotationType) { return hasAnnotation(annotationType.getName()); } /** * Returns true if the class has the specified annotation type. * * @param annotationTypeName the name of annotation type. * @return true if the annotation is found, otherwise false. * @since 3.21 */ public boolean hasAnnotation(String annotationTypeName) { return false; } /** * Returns the annotation if the class has the specified annotation type. * For example, if an annotation @Author is associated * with this class, an Author object is returned. * The member values can be obtained by calling methods on * the Author object. * * @param clz the annotation type. * @return the annotation if found, otherwise null. * @since 3.11 */ public Object getAnnotation(Class clz) throws ClassNotFoundException { return null; } /** * Returns the annotations associated with this class. * For example, if an annotation @Author is associated * with this class, the returned array contains an Author * object. The member values can be obtained by calling methods on * the Author object. * * @return an array of annotation-type objects. * @see CtMember#getAnnotations() * @since 3.1 */ public Object[] getAnnotations() throws ClassNotFoundException { return new Object[0]; } /** * Returns the annotations associated with this class. * This method is equivalent to getAnnotations() * except that, if any annotations are not on the classpath, * they are not included in the returned array. * * @return an array of annotation-type objects. * @see #getAnnotations() * @see CtMember#getAvailableAnnotations() * @since 3.3 */ public Object[] getAvailableAnnotations(){ return new Object[0]; } /** * Returns an array of nested classes declared in the class. * Nested classes are inner classes, anonymous classes, local classes, * and static nested classes. This simply calls getNestedClasses(). * * @see #getNestedClasses() * @since 3.15 */ public CtClass[] getDeclaredClasses() throws NotFoundException { return getNestedClasses(); } /** * Returns an array of nested classes declared in the class. * Nested classes are inner classes, anonymous classes, local classes, * and static nested classes. * * @since 3.2 */ public CtClass[] getNestedClasses() throws NotFoundException { return new CtClass[0]; } /** * Sets the modifiers. * *

If the class is a nested class, this method also modifies * the class declaring that nested class (i.e. the enclosing * class is modified). * * @param mod modifiers encoded by * org.apache.ibatis.javassist.Modifier * @see Modifier */ public void setModifiers(int mod) { checkModify(); } /** * Determines whether the class directly or indirectly extends * the given class. If this class extends a class A and * the class A extends a class B, then subclassof(B) returns true. * *

This method returns true if the given class is identical to * the class represented by this object. */ public boolean subclassOf(CtClass superclass) { return false; } /** * Obtains the class object representing the superclass of the * class. * It returns null if this object represents the * java.lang.Object class and thus it does not have * the super class. * *

If this object represents an interface, this method * always returns the java.lang.Object class. * To obtain the super interfaces * extended by that interface, call getInterfaces(). */ public CtClass getSuperclass() throws NotFoundException { return null; } /** * Changes a super class unless this object represents an interface. * The new super class must be compatible with the old one; for example, * it should inherit from the old super class. * *

If this object represents an interface, this method is equivalent * to addInterface(); it appends clazz to * the list of the super interfaces extended by that interface. * Note that an interface can extend multiple super interfaces. * * @see #replaceClassName(String, String) * @see #replaceClassName(ClassMap) */ public void setSuperclass(CtClass clazz) throws CannotCompileException { checkModify(); } /** * Obtains the class objects representing the interfaces implemented * by the class or, if this object represents an interface, the interfaces * extended by that interface. */ public CtClass[] getInterfaces() throws NotFoundException { return new CtClass[0]; } /** * Sets implemented interfaces. If this object represents an interface, * this method sets the interfaces extended by that interface. * * @param list a list of the CtClass objects * representing interfaces, or * null if the class implements * no interfaces. */ public void setInterfaces(CtClass[] list) { checkModify(); } /** * Adds an interface. * * @param anInterface the added interface. */ public void addInterface(CtClass anInterface) { checkModify(); } /** * If this class is a member class or interface of another class, * then the class enclosing this class is returned. * * @return null if this class is a top-level class or an anonymous class. */ public CtClass getDeclaringClass() throws NotFoundException { return null; } /** * Returns the immediately enclosing method of this class. * This method works only with JDK 1.5 or later. * * @return null if this class is not a local class or an anonymous * class. * @deprecated The enclosing method might be a constructor. * Use {@link #getEnclosingBehavior()}. * @see #getEnclosingBehavior() */ @Deprecated public final CtMethod getEnclosingMethod() throws NotFoundException { CtBehavior b = getEnclosingBehavior(); if (b == null) return null; else if (b instanceof CtMethod) return (CtMethod)b; else throw new NotFoundException(b.getLongName() + " is enclosing " + getName()); } /** * Returns the immediately enclosing method of this class. * It might be not a method but a constructor. * This method works only with JDK 1.5 or later. * * @return null if this class is not a local class or an anonymous * class. */ public CtBehavior getEnclosingBehavior() throws NotFoundException { return null; } /** * Makes a new public nested class. If this method is called, * the CtClass, which encloses the nested class, is modified * since a class file includes a list of nested classes. * *

The current implementation only supports a static nested class. * isStatic must be true. * * @param name the simple name of the nested class. * @param isStatic true if the nested class is static. */ public CtClass makeNestedClass(String name, boolean isStatic) { throw new RuntimeException(getName() + " is not a class"); } /** * Returns an array containing CtField objects * representing all the non-private fields of the class. * That array includes non-private fields inherited from the * superclasses. */ public CtField[] getFields() { return new CtField[0]; } /** * Returns the field with the specified name. The returned field * may be a private field declared in a super class or interface. */ public CtField getField(String name) throws NotFoundException { return getField(name, null); } /** * Returns the field with the specified name and type. The returned field * may be a private field declared in a super class or interface. * Unlike Java, the JVM allows a class to have * multiple fields with the same name but different types. * * @param name the field name. * @param desc the type descriptor of the field. It is available by * {@link CtField#getSignature()}. * @see CtField#getSignature() */ public CtField getField(String name, String desc) throws NotFoundException { throw new NotFoundException(name); } /** * @return null if the specified field is not found. */ CtField getField2(String name, String desc) { return null; } /** * Gets all the fields declared in the class. The inherited fields * are not included. * *

Note: the result does not include inherited fields. */ public CtField[] getDeclaredFields() { return new CtField[0]; } /** * Retrieves the field with the specified name among the fields * declared in the class. * *

Note: this method does not search the super classes. */ public CtField getDeclaredField(String name) throws NotFoundException { throw new NotFoundException(name); } /** * Retrieves the field with the specified name and type among the fields * declared in the class. Unlike Java, the JVM allows a class to have * multiple fields with the same name but different types. * *

Note: this method does not search the super classes. * * @param name the field name. * @param desc the type descriptor of the field. It is available by * {@link CtField#getSignature()}. * @see CtField#getSignature() */ public CtField getDeclaredField(String name, String desc) throws NotFoundException { throw new NotFoundException(name); } /** * Gets all the constructors and methods declared in the class. */ public CtBehavior[] getDeclaredBehaviors() { return new CtBehavior[0]; } /** * Returns an array containing CtConstructor objects * representing all the non-private constructors of the class. */ public CtConstructor[] getConstructors() { return new CtConstructor[0]; } /** * Returns the constructor with the given signature, * which is represented by a character string * called method descriptor. * For details of the method descriptor, see the JVM specification * or org.apache.ibatis.javassist.bytecode.Descriptor. * * @param desc method descriptor * @see javassist.bytecode.Descriptor */ public CtConstructor getConstructor(String desc) throws NotFoundException { throw new NotFoundException("no such constructor"); } /** * Gets all the constructors declared in the class. * * @see javassist.CtConstructor */ public CtConstructor[] getDeclaredConstructors() { return new CtConstructor[0]; } /** * Returns a constructor receiving the specified parameters. * * @param params parameter types. */ public CtConstructor getDeclaredConstructor(CtClass[] params) throws NotFoundException { String desc = Descriptor.ofConstructor(params); return getConstructor(desc); } /** * Gets the class initializer (static constructor) * declared in the class. * This method returns null if * no class initializer is not declared. * * @see #makeClassInitializer() * @see javassist.CtConstructor */ public CtConstructor getClassInitializer() { return null; } /** * Returns an array containing CtMethod objects * representing all the non-private methods of the class. * That array includes non-private methods inherited from the * superclasses. */ public CtMethod[] getMethods() { return new CtMethod[0]; } /** * Returns the method with the given name and signature. * The returned method may be declared in a super class. * The method signature is represented by a character string * called method descriptor, * which is defined in the JVM specification. * * @param name method name * @param desc method descriptor * @see CtBehavior#getSignature() * @see javassist.bytecode.Descriptor */ public CtMethod getMethod(String name, String desc) throws NotFoundException { throw new NotFoundException(name); } /** * Gets all methods declared in the class. The inherited methods * are not included. * * @see javassist.CtMethod */ public CtMethod[] getDeclaredMethods() { return new CtMethod[0]; } /** * Retrieves the method with the specified name and parameter types * among the methods declared in the class. * *

Note: this method does not search the superclasses. * * @param name method name * @param params parameter types * @see javassist.CtMethod */ public CtMethod getDeclaredMethod(String name, CtClass[] params) throws NotFoundException { throw new NotFoundException(name); } /** * Retrieves methods with the specified name among the methods * declared in the class. Multiple methods with different parameters * may be returned. * *

Note: this method does not search the superclasses.

* * @param name method name. * @since 3.19 */ public CtMethod[] getDeclaredMethods(String name) throws NotFoundException { throw new NotFoundException(name); } /** * Retrieves the method with the specified name among the methods * declared in the class. If there are multiple methods with * the specified name, then this method returns one of them. * *

Note: this method does not search the superclasses. * * @see javassist.CtMethod */ public CtMethod getDeclaredMethod(String name) throws NotFoundException { throw new NotFoundException(name); } /** * Makes an empty class initializer (static constructor). * If the class already includes a class initializer, * this method returns it. * * @see #getClassInitializer() */ public CtConstructor makeClassInitializer() throws CannotCompileException { throw new CannotCompileException("not a class"); } /** * Adds a constructor. To add a class initializer (static constructor), * call makeClassInitializer(). * * @see #makeClassInitializer() */ public void addConstructor(CtConstructor c) throws CannotCompileException { checkModify(); } /** * Removes a constructor declared in this class. * * @param c removed constructor. * @throws NotFoundException if the constructor is not found. */ public void removeConstructor(CtConstructor c) throws NotFoundException { checkModify(); } /** * Adds a method. */ public void addMethod(CtMethod m) throws CannotCompileException { checkModify(); } /** * Removes a method declared in this class. * * @param m removed method. * @throws NotFoundException if the method is not found. */ public void removeMethod(CtMethod m) throws NotFoundException { checkModify(); } /** * Adds a field. * *

The CtField belonging to another * CtClass cannot be directly added to this class. * Only a field created for this class can be added. * * @see javassist.CtField#CtField(CtField,CtClass) */ public void addField(CtField f) throws CannotCompileException { addField(f, (CtField.Initializer)null); } /** * Adds a field with an initial value. * *

The CtField belonging to another * CtClass cannot be directly added to this class. * Only a field created for this class can be added. * *

The initial value is given as an expression written in Java. * Any regular Java expression can be used for specifying the initial * value. The followings are examples. * *

     * cc.addField(f, "0")               // the initial value is 0.
     * cc.addField(f, "i + 1")           // i + 1.
     * cc.addField(f, "new Point()");    // a Point object.
     * 
* *

Here, the type of variable cc is CtClass. * The type of f is CtField. * *

Note: do not change the modifier of the field * (in particular, do not add or remove static * to/from the modifier) * after it is added to the class by addField(). * * @param init an expression for the initial value. * * @see javassist.CtField.Initializer#byExpr(String) * @see javassist.CtField#CtField(CtField,CtClass) */ public void addField(CtField f, String init) throws CannotCompileException { checkModify(); } /** * Adds a field with an initial value. * *

The CtField belonging to another * CtClass cannot be directly added to this class. * Only a field created for this class can be added. * *

For example, * *

     * CtClass cc = ...;
     * addField(new CtField(CtClass.intType, "i", cc),
     *          CtField.Initializer.constant(1));
     * 
* *

This code adds an int field named "i". The * initial value of this field is 1. * * @param init specifies the initial value of the field. * * @see javassist.CtField#CtField(CtField,CtClass) */ public void addField(CtField f, CtField.Initializer init) throws CannotCompileException { checkModify(); } /** * Removes a field declared in this class. * * @param f removed field. * @throws NotFoundException if the field is not found. */ public void removeField(CtField f) throws NotFoundException { checkModify(); } /** * Obtains an attribute with the given name. * If that attribute is not found in the class file, this * method returns null. * *

This is a convenient method mainly for obtaining * a user-defined attribute. For dealing with attributes, see the * org.apache.ibatis.javassist.bytecode package. For example, the following * expression returns all the attributes of a class file. * *

     * getClassFile().getAttributes()
     * 
* * @param name attribute name * @see javassist.bytecode.AttributeInfo */ public byte[] getAttribute(String name) { return null; } /** * Adds a named attribute. * An arbitrary data (smaller than 64Kb) can be saved in the class * file. Some attribute name are reserved by the JVM. * The attributes with the non-reserved names are ignored when a * class file is loaded into the JVM. * If there is already an attribute with * the same name, this method substitutes the new one for it. * *

This is a convenient method mainly for adding * a user-defined attribute. For dealing with attributes, see the * org.apache.ibatis.javassist.bytecode package. For example, the following * expression adds an attribute info to a class file. * *

     * getClassFile().addAttribute(info)
     * 
* * @param name attribute name * @param data attribute value * @see javassist.bytecode.AttributeInfo */ public void setAttribute(String name, byte[] data) { checkModify(); } /** * Applies the given converter to all methods and constructors * declared in the class. This method calls instrument() * on every CtMethod and CtConstructor object * in the class. * * @param converter specifies how to modify. */ public void instrument(CodeConverter converter) throws CannotCompileException { checkModify(); } /** * Modifies the bodies of all methods and constructors * declared in the class. This method calls instrument() * on every CtMethod and CtConstructor object * in the class. * * @param editor specifies how to modify. */ public void instrument(ExprEditor editor) throws CannotCompileException { checkModify(); } /** * Converts this class to a java.lang.Class object. * Once this method is called, further modifications are not * allowed any more. * To load the class, this method uses the context class loader * of the current thread. If the program is running on some application * server, the context class loader might be inappropriate to load the * class. * *

Warning: In Java 11 or later, the call to this method will * print a warning message:

*
     * WARNING: An illegal reflective access operation has occurred
     * WARNING: Illegal reflective access by javassist.util.proxy.SecurityActions$3 ...
     * WARNING: Please consider reporting this to the maintainers of javassist.util.proxy.SecurityActions$3
     * WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
     * WARNING: All illegal access operations will be denied in a future release
     * 
*

To avoid this message, use {@link #toClass(Class)} * or {@link #toClass(java.lang.invoke.MethodHandles.Lookup)}. * {@link #toClass()} will be unavailable in a future release. *

* *

Warning: A Class object returned by this method may not * work with a security manager or a signed jar file because a * protection domain is not specified.

* *

Note: this method calls toClass() * in ClassPool.

* * @see #toClass(java.lang.invoke.MethodHandles.Lookup) * @see #toClass(Class) * @see ClassPool#toClass(CtClass) */ public Class toClass() throws CannotCompileException { return getClassPool().toClass(this); } /** * Converts this class to a java.lang.Class object. * Once this method is called, further modifications are not * allowed any more. * *

This method is provided for convenience. You should use * {@code toClass(Lookup)} for better compatibility with the * module system. * *

Note: this method calls toClass() * in ClassPool. * *

Warning: A Class object returned by this method may not * work with a security manager or a signed jar file because a * protection domain is not specified. * * @param neighbor A class belonging to the same package that this * class belongs to. It is used to load the class. * @see ClassPool#toClass(CtClass,Class) * @see #toClass(java.lang.invoke.MethodHandles.Lookup) * @since 3.24 */ public Class toClass(Class neighbor) throws CannotCompileException { return getClassPool().toClass(this, neighbor); } /** * Converts this class to a java.lang.Class object. * Once this method is called, further modifications are not * allowed any more. * *

This method is provided for convenience. If you need more * complex functionality, you should write your own class loader. * *

Note: this method calls toClass() * in ClassPool. * *

Warning: A Class object returned by this method may not * work with a security manager or a signed jar file because a * protection domain is not specified. * * @param lookup used when loading the class. It has to have * an access right to define a new class. * @see ClassPool#toClass(CtClass,java.lang.invoke.MethodHandles.Lookup) * @since 3.24 */ public Class toClass(java.lang.invoke.MethodHandles.Lookup lookup) throws CannotCompileException { return getClassPool().toClass(this, lookup); } /** * Converts this class to a java.lang.Class object. * Once this method is called, further modifications are not allowed * any more. * *

The class file represented by this CtClass is * loaded by the given class loader to construct a * java.lang.Class object. Since a private method * on the class loader is invoked through the reflection API, * the caller must have permissions to do that. * *

An easy way to obtain ProtectionDomain object is * to call getProtectionDomain() * in java.lang.Class. It returns the domain that * the class belongs to. * *

This method is provided for convenience. If you need more * complex functionality, you should write your own class loader. * *

Note: this method calls toClass() * in ClassPool. * * @param loader the class loader used to load this class. * If it is null, the class loader returned by * {@link ClassPool#getClassLoader()} is used. * @param domain the protection domain that the class belongs to. * If it is null, the default domain created * by java.lang.ClassLoader is used. * @see ClassPool#toClass(CtClass,java.lang.ClassLoader) * @since 3.3 */ public Class toClass(ClassLoader loader, ProtectionDomain domain) throws CannotCompileException { ClassPool cp = getClassPool(); if (loader == null) loader = cp.getClassLoader(); return cp.toClass(this, null, loader, domain); } /** * Converts this class to a java.lang.Class object. * *

Warning: A Class object returned by this method may not * work with a security manager or a signed jar file because a * protection domain is not specified. * * @deprecated Replaced by {@link #toClass(ClassLoader,ProtectionDomain)} */ @Deprecated public final Class toClass(ClassLoader loader) throws CannotCompileException { return getClassPool().toClass(this, null, loader, null); } /** * Removes this CtClass object from the * ClassPool. * After this method is called, any method cannot be called on the * removed CtClass object. * *

If get() in ClassPool is called * with the name of the removed method, * the ClassPool will read the class file again * and constructs another CtClass object representing * the same class. */ public void detach() { ClassPool cp = getClassPool(); CtClass obj = cp.removeCached(getName()); if (obj != null && obj != this) cp.cacheCtClass(getName(), obj, false); } /** * Disallows (or allows) automatically pruning this CtClass * object. * *

* Javassist can automatically prune a CtClass object * when toBytecode() (or toClass(), * writeFile()) is called. * Since a ClassPool holds all instances of CtClass * even after toBytecode() (or toClass(), * writeFile()) is called, pruning may significantly * save memory consumption. * *

If ClassPool.doPruning is true, the automatic pruning * is on by default. Otherwise, it is off. The default value of * ClassPool.doPruning is false. * * @param stop disallow pruning if true. Otherwise, allow. * @return the previous status of pruning. true if pruning is already stopped. * * @see #detach() * @see #prune() * @see ClassPool#doPruning */ public boolean stopPruning(boolean stop) { return true; } /** * Discards unnecessary attributes, in particular, * CodeAttributes (method bodies) of the class, * to minimize the memory footprint. * After calling this method, the class is read only. * It cannot be modified any more. * Furthermore, toBytecode(), * writeFile(), toClass(), * or instrument() cannot be called. * However, the method names and signatures in the class etc. * are still accessible. * *

toBytecode(), writeFile(), and * toClass() internally call this method if * automatic pruning is on. * *

According to some experiments, pruning does not really reduce * memory consumption. Only about 20%. Since pruning takes time, * it might not pay off. So the automatic pruning is off by default. * * @see #stopPruning(boolean) * @see #detach() * @see ClassPool#doPruning * * @see #toBytecode() * @see #toClass(Class) * @see #writeFile() * @see #instrument(CodeConverter) * @see #instrument(ExprEditor) */ public void prune() {} /* Called by get() in ClassPool. * CtClassType overrides this method. */ void incGetCounter() {} /** * If this method is called, the class file will be * rebuilt when it is finally generated by * toBytecode() and writeFile(). * For a performance reason, the symbol table of the * class file may contain unused entries, for example, * after a method or a filed is deleted. * This method * removes those unused entries. This removal will * minimize the size of the class file. * * @since 3.8.1 */ public void rebuildClassFile() {} /** * Converts this class to a class file. * Once this method is called, further modifications are not * possible any more. * * @return the contents of the class file. */ public byte[] toBytecode() throws IOException, CannotCompileException { ByteArrayOutputStream barray = new ByteArrayOutputStream(); DataOutputStream out = new DataOutputStream(barray); try { toBytecode(out); } finally { out.close(); } return barray.toByteArray(); } /** * Writes a class file represented by this CtClass * object in the current directory. * Once this method is called, further modifications are not * possible any more. * * @see #debugWriteFile() */ public void writeFile() throws NotFoundException, IOException, CannotCompileException { writeFile("."); } /** * Writes a class file represented by this CtClass * object on a local disk. * Once this method is called, further modifications are not * possible any more. * * @param directoryName it must end without a directory separator. * @see #debugWriteFile(String) */ public void writeFile(String directoryName) throws CannotCompileException, IOException { DataOutputStream out = makeFileOutput(directoryName); try { toBytecode(out); } finally { out.close(); } } protected DataOutputStream makeFileOutput(String directoryName) { String classname = getName(); String filename = directoryName + File.separatorChar + classname.replace('.', File.separatorChar) + ".class"; int pos = filename.lastIndexOf(File.separatorChar); if (pos > 0) { String dir = filename.substring(0, pos); if (!dir.equals(".")) new File(dir).mkdirs(); } return new DataOutputStream(new BufferedOutputStream( new DelayedFileOutputStream(filename))); } /** * Writes a class file as writeFile() does although this * method does not prune or freeze the class after writing the class * file. Note that, once writeFile() or toBytecode() * is called, it cannot be called again since the class is pruned and frozen. * This method would be useful for debugging. */ public void debugWriteFile() { debugWriteFile("."); } /** * Writes a class file as writeFile() does although this * method does not prune or freeze the class after writing the class * file. Note that, once writeFile() or toBytecode() * is called, it cannot be called again since the class is pruned and frozen. * This method would be useful for debugging. * * @param directoryName it must end without a directory separator. */ public void debugWriteFile(String directoryName) { try { boolean p = stopPruning(true); writeFile(directoryName); defrost(); stopPruning(p); } catch (Exception e) { throw new RuntimeException(e); } } static class DelayedFileOutputStream extends OutputStream { private FileOutputStream file; private String filename; DelayedFileOutputStream(String name) { file = null; filename = name; } private void init() throws IOException { if (file == null) file = new FileOutputStream(filename); } @Override public void write(int b) throws IOException { init(); file.write(b); } @Override public void write(byte[] b) throws IOException { init(); file.write(b); } @Override public void write(byte[] b, int off, int len) throws IOException { init(); file.write(b, off, len); } @Override public void flush() throws IOException { init(); file.flush(); } @Override public void close() throws IOException { init(); file.close(); } } /** * Converts this class to a class file. * Once this method is called, further modifications are not * possible any more. * *

This method dose not close the output stream in the end. * * @param out the output stream that a class file is written to. */ public void toBytecode(DataOutputStream out) throws CannotCompileException, IOException { throw new CannotCompileException("not a class"); } /** * Makes a unique member name. This method guarantees that * the returned name is not used as a prefix of any methods * or fields visible in this class. * If the returned name is XYZ, then any method or field names * in this class do not start with XYZ. * * @param prefix the prefix of the member name. */ public String makeUniqueName(String prefix) { throw new RuntimeException("not available in " + getName()); } /* Invoked from ClassPool#compress(). * This method is overridden by CtClassType. */ void compress() {} }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy