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 * Licensed to the Apache Software Foundation (ASF) under one or more
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 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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package com.sun.org.apache.bcel.internal.generic;


import com.sun.org.apache.bcel.internal.Constants;
import com.sun.org.apache.bcel.internal.classfile.*;
import java.util.ArrayList;
import java.util.Iterator;

Template class for building up a java class. May be initialized with an
existing java class (file).
Author:
 M. Dahm
See Also:
JavaClass/**
 * Template class for building up a java class. May be initialized with an
 * existing java class (file).
 *
 * @see JavaClass
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
public class ClassGen extends AccessFlags implements Cloneable {
  /* Corresponds to the fields found in a JavaClass object.
   */
  private String   class_name, super_class_name, file_name;
  private int      class_name_index = -1, superclass_name_index = -1;
  private int      major = Constants.MAJOR_1_1, minor = Constants.MINOR_1_1;

  private ConstantPoolGen cp; // Template for building up constant pool

  // ArrayLists instead of arrays to gather fields, methods, etc.
  private ArrayList   field_vec     = new ArrayList();
  private ArrayList   method_vec    = new ArrayList();
  private ArrayList   attribute_vec = new ArrayList();
  private ArrayList   interface_vec = new ArrayList();

  
Convenience constructor to set up some important values initially.
Params:
class_name – fully qualified class name
super_class_name – fully qualified superclass name
file_name – source file name
access_flags – access qualifiers
interfaces – implemented interfaces
cp – constant pool to use/** Convenience constructor to set up some important values initially.
   *
   * @param class_name fully qualified class name
   * @param super_class_name fully qualified superclass name
   * @param file_name source file name
   * @param access_flags access qualifiers
   * @param interfaces implemented interfaces
   * @param cp constant pool to use
   */
  public ClassGen(String class_name, String super_class_name, String file_name,
                  int access_flags, String[] interfaces, ConstantPoolGen cp) {
    this.class_name       = class_name;
    this.super_class_name = super_class_name;
    this.file_name        = file_name;
    this.access_flags     = access_flags;
    this.cp               = cp;

    // Put everything needed by default into the constant pool and the vectors
    if(file_name != null)
      addAttribute(new SourceFile(cp.addUtf8("SourceFile"), 2,
                                  cp.addUtf8(file_name), cp.getConstantPool()));

    class_name_index      = cp.addClass(class_name);
    superclass_name_index = cp.addClass(super_class_name);

    if(interfaces != null)
      for(int i=0; i < interfaces.length; i++)
        addInterface(interfaces[i]);
  }

  
Convenience constructor to set up some important values initially.
Params:
class_name – fully qualified class name
super_class_name – fully qualified superclass name
file_name – source file name
access_flags – access qualifiers
interfaces – implemented interfaces/** Convenience constructor to set up some important values initially.
   *
   * @param class_name fully qualified class name
   * @param super_class_name fully qualified superclass name
   * @param file_name source file name
   * @param access_flags access qualifiers
   * @param interfaces implemented interfaces
   */
  public ClassGen(String class_name, String super_class_name, String file_name,
                  int access_flags, String[] interfaces) {
    this(class_name, super_class_name, file_name, access_flags, interfaces,
         new ConstantPoolGen());
  }

  
Initialize with existing class.
Params:
clazz – JavaClass object (e.g. read from file)/**
   * Initialize with existing class.
   * @param clazz JavaClass object (e.g. read from file)
   */
  public ClassGen(JavaClass clazz) {
    class_name_index      = clazz.getClassNameIndex();
    superclass_name_index = clazz.getSuperclassNameIndex();
    class_name            = clazz.getClassName();
    super_class_name      = clazz.getSuperclassName();
    file_name             = clazz.getSourceFileName();
    access_flags          = clazz.getAccessFlags();
    cp                    = new ConstantPoolGen(clazz.getConstantPool());
    major                 = clazz.getMajor();
    minor                 = clazz.getMinor();

    Attribute[] attributes = clazz.getAttributes();
    Method[]    methods    = clazz.getMethods();
    Field[]     fields     = clazz.getFields();
    String[]    interfaces = clazz.getInterfaceNames();

    for(int i=0; i < interfaces.length; i++)
      addInterface(interfaces[i]);

    for(int i=0; i < attributes.length; i++)
      addAttribute(attributes[i]);

    for(int i=0; i < methods.length; i++)
      addMethod(methods[i]);

    for(int i=0; i < fields.length; i++)
      addField(fields[i]);
  }

  
Returns:
the (finally) built up Java class object./**
   * @return the (finally) built up Java class object.
   */
  public JavaClass getJavaClass() {
    int[]        interfaces = getInterfaces();
    Field[]      fields     = getFields();
    Method[]     methods    = getMethods();
    Attribute[]  attributes = getAttributes();

    // Must be last since the above calls may still add something to it
    ConstantPool cp         = this.cp.getFinalConstantPool();

    return new JavaClass(class_name_index, superclass_name_index,
                         file_name, major, minor, access_flags,
                         cp, interfaces, fields, methods, attributes);
  }

  
Add an interface to this class, i.e., this class has to implement it.
Params:
name – interface to implement (fully qualified class name)/**
   * Add an interface to this class, i.e., this class has to implement it.
   * @param name interface to implement (fully qualified class name)
   */
  public void addInterface(String name) {
    interface_vec.add(name);
  }

  
Remove an interface from this class.
Params:
name – interface to remove (fully qualified name)/**
   * Remove an interface from this class.
   * @param name interface to remove (fully qualified name)
   */
  public void removeInterface(String name) {
    interface_vec.remove(name);
  }

  
Returns:
major version number of class file/**
   * @return major version number of class file
   */
  public int  getMajor()      { return major; }

  
Set major version number of class file, default value is 45 (JDK 1.1)
Params:
major – major version number/** Set major version number of class file, default value is 45 (JDK 1.1)
   * @param major major version number
   */
  public void setMajor(int major) {
    this.major = major;
  }

  
Set minor version number of class file, default value is 3 (JDK 1.1)
Params:
minor – minor version number/** Set minor version number of class file, default value is 3 (JDK 1.1)
   * @param minor minor version number
   */
  public void setMinor(int minor) {
    this.minor = minor;
  }

  
Returns:
minor version number of class file/**
   * @return minor version number of class file
   */
  public int  getMinor()      { return minor; }

  
Add an attribute to this class.
Params:
a – attribute to add/**
   * Add an attribute to this class.
   * @param a attribute to add
   */
  public void addAttribute(Attribute a)    { attribute_vec.add(a); }

  
Add a method to this class.
Params:
m – method to add/**
   * Add a method to this class.
   * @param m method to add
   */
  public void addMethod(Method m)          { method_vec.add(m); }

  
Convenience method.
Add an empty constructor to this class that does nothing but calling super().
Params:
access – rights for constructor/**
   * Convenience method.
   *
   * Add an empty constructor to this class that does nothing but calling super().
   * @param access rights for constructor
   */
  public void addEmptyConstructor(int access_flags) {
    InstructionList il = new InstructionList();
    il.append(InstructionConstants.THIS); // Push `this'
    il.append(new INVOKESPECIAL(cp.addMethodref(super_class_name,
                                                "<init>", "()V")));
    il.append(InstructionConstants.RETURN);

    MethodGen mg = new MethodGen(access_flags, Type.VOID, Type.NO_ARGS, null,
                       "<init>", class_name, il, cp);
    mg.setMaxStack(1);
    addMethod(mg.getMethod());
  }

  
Add a field to this class.
Params:
f – field to add/**
   * Add a field to this class.
   * @param f field to add
   */
  public void addField(Field f)            { field_vec.add(f); }

  public boolean containsField(Field f)    { return field_vec.contains(f); }

  
Returns:
field object with given name, or null/** @return field object with given name, or null
   */
  public Field containsField(String name) {
    for(Iterator e=field_vec.iterator(); e.hasNext(); ) {
      Field f = (Field)e.next();
      if(f.getName().equals(name))
        return f;
    }

    return null;
  }

  
Returns:
method object with given name and signature, or null/** @return method object with given name and signature, or null
   */
  public Method containsMethod(String name, String signature) {
    for(Iterator e=method_vec.iterator(); e.hasNext();) {
      Method m = (Method)e.next();
      if(m.getName().equals(name) && m.getSignature().equals(signature))
        return m;
    }

    return null;
  }

  
Remove an attribute from this class.
Params:
a – attribute to remove/**
   * Remove an attribute from this class.
   * @param a attribute to remove
   */
  public void removeAttribute(Attribute a) { attribute_vec.remove(a); }

  
Remove a method from this class.
Params:
m – method to remove/**
   * Remove a method from this class.
   * @param m method to remove
   */
  public void removeMethod(Method m)       { method_vec.remove(m); }

  
Replace given method with new one. If the old one does not exist
add the new_ method to the class anyway.
/** Replace given method with new one. If the old one does not exist
   * add the new_ method to the class anyway.
   */
  public void replaceMethod(Method old, Method new_) {
    if(new_ == null)
      throw new ClassGenException("Replacement method must not be null");

    int i = method_vec.indexOf(old);

    if(i < 0)
      method_vec.add(new_);
    else
      method_vec.set(i, new_);
  }

  
Replace given field with new one. If the old one does not exist
add the new_ field to the class anyway.
/** Replace given field with new one. If the old one does not exist
   * add the new_ field to the class anyway.
   */
  public void replaceField(Field old, Field new_) {
    if(new_ == null)
      throw new ClassGenException("Replacement method must not be null");

    int i = field_vec.indexOf(old);

    if(i < 0)
      field_vec.add(new_);
    else
      field_vec.set(i, new_);
  }

  
Remove a field to this class.
Params:
f – field to remove/**
   * Remove a field to this class.
   * @param f field to remove
   */
  public void removeField(Field f)         { field_vec.remove(f); }

  public String getClassName()      { return class_name; }
  public String getSuperclassName() { return super_class_name; }
  public String getFileName()       { return file_name; }

  public void setClassName(String name) {
    class_name = name.replace('/', '.');
    class_name_index = cp.addClass(name);
  }

  public void setSuperclassName(String name) {
    super_class_name = name.replace('/', '.');
    superclass_name_index = cp.addClass(name);
  }

  public Method[] getMethods() {
    Method[] methods = new Method[method_vec.size()];
    method_vec.toArray(methods);
    return methods;
  }

  public void setMethods(Method[] methods) {
    method_vec.clear();
    for(int m=0; m<methods.length; m++)
      addMethod(methods[m]);
  }

  public void setMethodAt(Method method, int pos) {
    method_vec.set(pos, method);
  }

  public Method getMethodAt(int pos) {
    return (Method)method_vec.get(pos);
  }

  public String[] getInterfaceNames() {
    int      size = interface_vec.size();
    String[] interfaces = new String[size];

    interface_vec.toArray(interfaces);
    return interfaces;
  }

  public int[] getInterfaces() {
    int   size = interface_vec.size();
    int[] interfaces = new int[size];

    for(int i=0; i < size; i++)
      interfaces[i] = cp.addClass((String)interface_vec.get(i));

    return interfaces;
  }

  public Field[] getFields() {
    Field[] fields = new Field[field_vec.size()];
    field_vec.toArray(fields);
    return fields;
  }

  public Attribute[] getAttributes() {
    Attribute[] attributes = new Attribute[attribute_vec.size()];
    attribute_vec.toArray(attributes);
    return attributes;
  }

  public ConstantPoolGen getConstantPool() { return cp; }
  public void setConstantPool(ConstantPoolGen constant_pool) {
    cp = constant_pool;
  }

  public void setClassNameIndex(int class_name_index) {
    this.class_name_index = class_name_index;
    class_name = cp.getConstantPool().
      getConstantString(class_name_index, Constants.CONSTANT_Class).replace('/', '.');
  }

  public void setSuperclassNameIndex(int superclass_name_index) {
    this.superclass_name_index = superclass_name_index;
    super_class_name = cp.getConstantPool().
      getConstantString(superclass_name_index, Constants.CONSTANT_Class).replace('/', '.');
  }

  public int getSuperclassNameIndex() { return superclass_name_index; }

  public int getClassNameIndex()   { return class_name_index; }

  private ArrayList observers;

  
Add observer for this object.
/** Add observer for this object.
   */
  public void addObserver(ClassObserver o) {
    if(observers == null)
      observers = new ArrayList();

    observers.add(o);
  }

  
Remove observer for this object.
/** Remove observer for this object.
   */
  public void removeObserver(ClassObserver o) {
    if(observers != null)
      observers.remove(o);
  }

  
Call notify() method on all observers. This method is not called
automatically whenever the state has changed, but has to be
called by the user after he has finished editing the object.
/** Call notify() method on all observers. This method is not called
   * automatically whenever the state has changed, but has to be
   * called by the user after he has finished editing the object.
   */
  public void update() {
    if(observers != null)
      for(Iterator e = observers.iterator(); e.hasNext(); )
        ((ClassObserver)e.next()).notify(this);
  }

  public Object clone() {
    try {
      return super.clone();
    } catch(CloneNotSupportedException e) {
      System.err.println(e);
      return null;
    }
  }
}