Initial commit from SVN.

Class File Services/src/com/de22/javabytecode/CodeAttribute.java

@@ -0,0 +1,123 @@
+package com.de22.javabytecode;
+
+import com.de22.javabytecode.attribute.*;
+import com.de22.javabytecode.constant.*;
+
+/**
+ * Copyright Wynne Crisman 1999,2006<p>
+ * Defines an attribute in any of the attribute collections.
+ * See the JVM specification 4.7.
+ * Subclasses of this type will provided additional functionality.
+ */
+public abstract class CodeAttribute extends Component {
+	/** The index of the attribute's name in the constant collection. */
+	private short nameIndex = -1;
+/**
+ * CodeAttribute constructor.
+ */
+public CodeAttribute(Type type) {
+	super(type);
+}//CodeAttribute()//
+/**
+ * Gets the attribute's default name as it is stored in the class bytes.
+ * @return The default name identifying the attribute's type.
+ */
+public abstract String getDefaultName();
+/**
+ * Gets the index of the attribute's name in the type's constant pool.
+ * @return The index of the attribute name.
+ */
+public short getNameIndex() {
+	return nameIndex;
+}//getNameIndex()//
+/* (non-Javadoc)
+ * @see com.de22.javabytecode.ITypeComponent#getSize()
+ */
+public abstract int getSize();
+/**
+ * Reads an attribute from the given stream.
+ * @param type The type object that the attribute will belong to.
+ * @param in The input stream to read the attribute from.
+ */
+protected static CodeAttribute readAttribute(Type type, java.io.ObjectInput in) throws java.io.IOException, ClassNotFoundException {
+	CodeAttribute attribute = null;
+	short nameIndex = in.readShort();
+	Constant constant = type.getConstant(nameIndex);
+	ConstantUtf8 constantUtf8 = constant instanceof ConstantUtf8 ? (ConstantUtf8) constant : constant instanceof ConstantString ? (ConstantUtf8) type.getConstant(((ConstantString) constant).getStringIndex()) : null;
+	
+	//This should never occur, but seems to for some compiled java code (probably due to a bad compiler).  We will simply replace the missing string with an empty string.//
+	if(constantUtf8 == null) {
+//		System.out.println("Null constant found (index = " + nameIndex + ") while reading an unidentified attribute.");
+		attribute = new Unidentified(type, "");
+		attribute.nameIndex = nameIndex;
+		attribute.readExternal(in);
+	}//if//
+	else {
+		String name = constantUtf8.getValue();
+		
+		if(name.equalsIgnoreCase("SourceFile")) {
+			attribute = new SourceFile(type);
+		}//if//
+		else if(name.equalsIgnoreCase("Code")) {
+			attribute = new Code(type);
+		}//else if//
+		else if(name.equalsIgnoreCase("Exceptions")) {
+			attribute = new ExceptionIndexes(type);
+		}//else if//
+		else if(name.equalsIgnoreCase("LineNumberTable")) {
+			attribute = new LineNumberTable(type);
+		}//else if//
+		else if(name.equalsIgnoreCase("LocalVariableTable")) {
+			attribute = new LocalVariableTable(type);
+		}//else if//
+		else if(name.equalsIgnoreCase("InnerClasses")) {
+			attribute = new InnerClasses(type);
+		}//else if//
+		else if(name.equalsIgnoreCase("ConstantValue")) {
+			attribute = new ConstantValue(type);
+		}//else if//
+		else if(name.equalsIgnoreCase("Synthetic")) {
+			attribute = new Synthetic(type);
+		}//else if//
+		else {
+			attribute = new Unidentified(type, name);
+		}//else//
+	
+		attribute.nameIndex = nameIndex;
+		attribute.readExternal(in);
+	}//else//
+
+	return attribute;
+}//readAttribute()//
+/**
+ * Reads this object from the given stream.
+ * @param in The input stream to read this object from.
+ */
+public void readExternal(java.io.ObjectInput in) throws java.io.IOException, ClassNotFoundException {
+	if(this.nameIndex == -1) {
+		//There is usually no need to read the name index since it is read in the readAttribute(Type, ObjectInput) method.//
+		nameIndex = in.readShort();
+	}//if//
+
+	//Note: We leave it to the attribute to read the length of the attribute because some will require this info and most will ignore it.//
+}//readExternal()//
+/**
+ * Sets the index of the attribute's name in the type's constant pool.
+ * @param nameIndex The index of the attribute name.
+ */
+public void setNameIndex(short nameIndex) {
+	this.nameIndex = nameIndex;
+}//setNameIndex()//
+/**
+ * Writes this object to the given stream.
+ * @param out The output stream to write this object to.
+ */
+public void writeExternal(java.io.ObjectOutput out) throws java.io.IOException {
+	short nameIndex = getType().getConstantIndex(new ConstantUtf8(getType(), getDefaultName()));
+	
+	//Write the constant index referenceing the attribute name.//
+	out.writeShort(nameIndex);
+	//Write size in bytes of the attribute.//
+	out.writeInt(getSize());
+}//writeExternal()//
+}//CodeAttribute//