LocalVariableTable.java

package com.github.miniyk2012.coding2017.coderising.jvm.attr;


import com.github.miniyk2012.coding2017.coderising.jvm.constant.ConstantPool;
import com.github.miniyk2012.coding2017.coderising.jvm.loader.ByteCodeIterator;

import java.util.ArrayList;
import java.util.List;

public class LocalVariableTable extends AttributeInfo{

	List<LocalVariableItem> items = new ArrayList<>();
	
	public LocalVariableTable(int attrNameIndex, int attrLen) {
		super(attrNameIndex, attrLen);		
	}
	
	
	private void addLocalVariableItem(LocalVariableItem item) {
		this.items.add(item);		
	}

	public static LocalVariableTable parse(ByteCodeIterator iter){
	    int nameIndex = iter.nextU2toInt();
	    int attrLen = iter.nextU4toInt();
        LocalVariableTable table = new LocalVariableTable(nameIndex, attrLen);
        int tableLen = iter.nextU2toInt();

        for(int i=0; i<tableLen; i++) {
            LocalVariableItem item = new LocalVariableItem();
            item.setStartPC(iter.nextU2toInt());
            item.setLength(iter.nextU2toInt());
            item.setNameIndex(iter.nextU2toInt());
            item.setDescIndex(iter.nextU2toInt());
            item.setIndex(iter.nextU2toInt());
            table.addLocalVariableItem(item);
        }

        return table;
	}
	
	
	public String toString(ConstantPool pool){
		StringBuilder buffer = new StringBuilder();
		buffer.append("Local Variable Table:\n");
		for(LocalVariableItem item : items){
			buffer.append("startPC:"+item.getStartPC()).append(",");
			buffer.append("name:"+pool.getUTF8String(item.getNameIndex())).append(",");
			buffer.append("desc:"+pool.getUTF8String(item.getDescIndex())).append(",");
			buffer.append("slotIndex:"+ item.getIndex()).append("\n");
		}
		buffer.append("\n");
		return buffer.toString();
	}
}