/*
* reserved comment block
* DO NOT REMOVE OR ALTER!
*/
package com.sun.org.apache.bcel.internal.generic;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
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* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
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* distribution.
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* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
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* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache BCEL" must not be used to endorse or promote products
* derived from this software without prior written permission. For
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* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
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 field. The only extraordinary thing
* one can do is to add a constant value attribute to a field (which must of
* course be compatible with to the declared type).
*
* @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
* @see Field
*/
public class FieldGen extends FieldGenOrMethodGen {
private Object value = null;
/**
* Declare a field. If it is static (isStatic() == true) and has a
* basic type like int or String it may have an initial value
* associated with it as defined by setInitValue().
*
* @param access_flags access qualifiers
* @param type field type
* @param name field name
* @param cp constant pool
*/
public FieldGen(int access_flags, Type type, String name, ConstantPoolGen cp) {
setAccessFlags(access_flags);
setType(type);
setName(name);
setConstantPool(cp);
}
/**
* Instantiate from existing field.
*
* @param field Field object
* @param cp constant pool (must contain the same entries as the field's constant pool)
*/
public FieldGen(Field field, ConstantPoolGen cp) {
this(field.getAccessFlags(), Type.getType(field.getSignature()), field.getName(), cp);
Attribute[] attrs = field.getAttributes();
for(int i=0; i < attrs.length; i++) {
if(attrs[i] instanceof ConstantValue)
setValue(((ConstantValue)attrs[i]).getConstantValueIndex());
else
addAttribute(attrs[i]);
}
}
private void setValue(int index) {
ConstantPool cp = this.cp.getConstantPool();
Constant c = cp.getConstant(index);
value = ((ConstantObject)c).getConstantValue(cp);
}
/**
* Set (optional) initial value of field, otherwise it will be set to null/0/false
* by the JVM automatically.
*/
public void setInitValue(String str) {
checkType(new ObjectType("java.lang.String"));
if(str != null)
value = str;
}
public void setInitValue(long l) {
checkType(Type.LONG);
if(l != 0L)
value = new Long(l);
}
public void setInitValue(int i) {
checkType(Type.INT);
if(i != 0)
value = new Integer(i);
}
public void setInitValue(short s) {
checkType(Type.SHORT);
if(s != 0)
value = new Integer(s);
}
public void setInitValue(char c) {
checkType(Type.CHAR);
if(c != 0)
value = new Integer(c);
}
public void setInitValue(byte b) {
checkType(Type.BYTE);
if(b != 0)
value = new Integer(b);
}
public void setInitValue(boolean b) {
checkType(Type.BOOLEAN);
if(b)
value = new Integer(1);
}
public void setInitValue(float f) {
checkType(Type.FLOAT);
if(f != 0.0)
value = new Float(f);
}
public void setInitValue(double d) {
checkType(Type.DOUBLE);
if(d != 0.0)
value = new Double(d);
}
/** Remove any initial value.
*/
public void cancelInitValue() {
value = null;
}
private void checkType(Type atype) {
if(type == null)
throw new ClassGenException("You haven't defined the type of the field yet");
if(!isFinal())
throw new ClassGenException("Only final fields may have an initial value!");
if(!type.equals(atype))
throw new ClassGenException("Types are not compatible: " + type + " vs. " + atype);
}
/**
* Get field object after having set up all necessary values.
*/
public Field getField() {
String signature = getSignature();
int name_index = cp.addUtf8(name);
int signature_index = cp.addUtf8(signature);
if(value != null) {
checkType(type);
int index = addConstant();
addAttribute(new ConstantValue(cp.addUtf8("ConstantValue"),
2, index, cp.getConstantPool()));
}
return new Field(access_flags, name_index, signature_index, getAttributes(),
cp.getConstantPool());
}
private int addConstant() {
switch(type.getType()) {
case Constants.T_INT: case Constants.T_CHAR: case Constants.T_BYTE:
case Constants.T_BOOLEAN: case Constants.T_SHORT:
return cp.addInteger(((Integer)value).intValue());
case Constants.T_FLOAT:
return cp.addFloat(((Float)value).floatValue());
case Constants.T_DOUBLE:
return cp.addDouble(((Double)value).doubleValue());
case Constants.T_LONG:
return cp.addLong(((Long)value).longValue());
case Constants.T_REFERENCE:
return cp.addString(((String)value));
default:
throw new RuntimeException("Oops: Unhandled : " + type.getType());
}
}
public String getSignature() { return type.getSignature(); }
private ArrayList observers;
/** Add observer for this object.
*/
public void addObserver(FieldObserver o) {
if(observers == null)
observers = new ArrayList();
observers.add(o);
}
/** Remove observer for this object.
*/
public void removeObserver(FieldObserver 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.
*/
public void update() {
if(observers != null)
for(Iterator e = observers.iterator(); e.hasNext(); )
((FieldObserver)e.next()).notify(this);
}
public String getInitValue() {
if(value != null) {
return value.toString();
} else
return null;
}
/**
* Return string representation close to declaration format,
* `public static final short MAX = 100', e.g..
*
* @return String representation of field
*/
public final String toString() {
String name, signature, access; // Short cuts to constant pool
access = Utility.accessToString(access_flags);
access = access.equals("")? "" : (access + " ");
signature = type.toString();
name = getName();
StringBuffer buf = new StringBuffer(access + signature + " " + name);
String value = getInitValue();
if(value != null)
buf.append(" = " + value);
return buf.toString();
}
/** @return deep copy of this field
*/
public FieldGen copy(ConstantPoolGen cp) {
FieldGen fg = (FieldGen)clone();
fg.setConstantPool(cp);
return fg;
}
}