File	Doc	Category	Size	Date	Package
Select.java	API Doc	Java SE 5 API	8399	Fri Aug 26 14:55:24 BST 2005	com.sun.org.apache.bcel.internal.generic

Select

• java.lang.Object
  • com.sun.org.apache.bcel.internal.generic.Instruction
    • com.sun.org.apache.bcel.internal.generic.BranchInstruction

Fields Summary
protected int[]	match
protected int[]	indices
protected InstructionHandle[]	targets
protected int	fixed_length
protected int	match_length
protected int	padding

Constructors Summary
Select() Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction(). Not to be used otherwise. // number of pad bytes for alignment
Select(short opcode, int[] match, InstructionHandle[] targets, InstructionHandle target) (Match, target) pairs for switch. `Match' and `targets' must have the same length of course. param match array of matching values param targets instruction targets param target default instruction target super(opcode, target); this.targets = targets; for(int i=0; i < targets.length; i++) notifyTarget(null, targets[i], this); this.match = match; if((match_length = match.length) != targets.length) throw new ClassGenException("Match and target array have not the same length"); indices = new int[match_length];

Methods Summary
public boolean	containsTarget(com.sun.org.apache.bcel.internal.generic.InstructionHandle ih) return true, if ih is target of this instruction if(target == ih) return true; for(int i=0; i < targets.length; i++) if(targets[i] == ih) return true; return false;
void	dispose() Inform targets that they're not targeted anymore. super.dispose(); for(int i=0; i < targets.length; i++) targets[i].removeTargeter(this);
public void	dump(java.io.DataOutputStream out) Dump instruction as byte code to stream out. param out Output stream out.writeByte(opcode); for(int i=0; i < padding; i++) // Padding bytes out.writeByte(0); index = getTargetOffset(); // Write default target offset out.writeInt(index);
public int[]	getIndices() return array of match target offsets return indices;
public int[]	getMatchs() return array of match indices return match;
public com.sun.org.apache.bcel.internal.generic.InstructionHandle[]	getTargets() return array of match targets return targets;
protected void	initFromFile(com.sun.org.apache.bcel.internal.util.ByteSequence bytes, boolean wide) Read needed data (e.g. index) from file. padding = (4 - (bytes.getIndex() % 4)) % 4; // Compute number of pad bytes for(int i=0; i < padding; i++) { byte b; if((b=bytes.readByte()) != 0) throw new ClassGenException("Padding byte != 0: " + b); } // Default branch target common for both cases (TABLESWITCH, LOOKUPSWITCH) index = bytes.readInt();
public void	setTarget(int i, com.sun.org.apache.bcel.internal.generic.InstructionHandle target) Set branch target for `i'th case notifyTarget(targets[i], target, this); targets[i] = target;
public java.lang.String	toString(boolean verbose) return mnemonic for instruction StringBuffer buf = new StringBuffer(super.toString(verbose)); if(verbose) { for(int i=0; i < match_length; i++) { String s = "null"; if(targets[i] != null) s = targets[i].getInstruction().toString(); buf.append("(" + match[i] + ", " + s + " = {" + indices[i] + "})"); } } else buf.append(" ..."); return buf.toString();
protected int	updatePosition(int offset, int max_offset) Since this is a variable length instruction, it may shift the following instructions which then need to update their position. Called by InstructionList.setPositions when setting the position for every instruction. In the presence of variable length instructions `setPositions' performs multiple passes over the instruction list to calculate the correct (byte) positions and offsets by calling this function. param offset additional offset caused by preceding (variable length) instructions param max_offset the maximum offset that may be caused by these instructions return additional offset caused by possible change of this instruction's length position += offset; // Additional offset caused by preceding SWITCHs, GOTOs, etc. short old_length = length; /* Alignment on 4-byte-boundary, + 1, because of tag byte. */ padding = (4 - ((position + 1) % 4)) % 4; length = (short)(fixed_length + padding); // Update length return length - old_length;
public void	updateTarget(com.sun.org.apache.bcel.internal.generic.InstructionHandle old_ih, com.sun.org.apache.bcel.internal.generic.InstructionHandle new_ih) param old_ih old target param new_ih new target boolean targeted = false; if(target == old_ih) { targeted = true; setTarget(new_ih); } for(int i=0; i < targets.length; i++) { if(targets[i] == old_ih) { targeted = true; setTarget(i, new_ih); } } if(!targeted) throw new ClassGenException("Not targeting " + old_ih);