CodeAttr.java

package week08.jvm.attr;

import week08.jvm.attr.AttributeInfo;
import week08.jvm.attr.CodeAttr;
import week08.jvm.attr.LineNumberTable;
import week08.jvm.attr.LocalVariableTable;
import week08.jvm.attr.StackMapTable;
import week08.jvm.clz.ClassFile;
import week08.jvm.cmd.ByteCodeCommand;
import week08.jvm.cmd.CommandParser;
import week08.jvm.constant.ConstantPool;
import week08.jvm.loader.ByteCodeIterator;

public class CodeAttr extends AttributeInfo {
	private int maxStack;
	private int maxLocals;
	private int codeLen;
	private String code;

	public String getCode() {
		return code;
	}

	private ByteCodeCommand[] cmds;

	public ByteCodeCommand[] getCmds() {
		return cmds;
	}

	private LineNumberTable lineNumTable;
	private LocalVariableTable localVarTable;
	private StackMapTable stackMapTable;

	public CodeAttr(int attrNameIndex, int attrLen, int maxStack, int maxLocals, int codeLen, String code,
			ByteCodeCommand[] cmds) {
		super(attrNameIndex, attrLen);
		this.maxStack = maxStack;
		this.maxLocals = maxLocals;
		this.codeLen = codeLen;
		this.code = code;
		this.cmds = cmds;
	}

	public void setLineNumberTable(LineNumberTable t) {
		this.lineNumTable = t;
	}

	public void setLocalVariableTable(LocalVariableTable t) {
		this.localVarTable = t;
	}

	public static CodeAttr parse(ClassFile clzFile, ByteCodeIterator iter) {
		int attrNameIndex = iter.nextU2ToInt();
		int attrLen = iter.nextU4ToInt();
		int maxStack = iter.nextU2ToInt();
		int maxLocals = iter.nextU2ToInt();
		int codeLen = iter.nextU4ToInt();

		String code = iter.nextUxToHexString(codeLen);

		System.out.println(code);

		ByteCodeCommand[] cmds = CommandParser.parse(clzFile, code);

		CodeAttr codeAttr = new CodeAttr(attrNameIndex, attrLen, maxStack, maxLocals, codeLen, code, cmds);

		int exceptionTableLen = iter.nextU2ToInt();

		if (exceptionTableLen > 0) {
			String exTable = iter.nextUxToHexString(exceptionTableLen);
			System.out.println("Encountered exception table,just ignore it");
		}

		int subAttrCount = iter.nextU2ToInt();

		for (int i = 1; i <= subAttrCount; i++) {
			int subAttrIndex = iter.nextU2ToInt();
			String subAttrName = clzFile.getConstantPool().getUTF8String(subAttrIndex);

			iter.back(2);

			if (AttributeInfo.LINE_NUM_TABLE.equalsIgnoreCase(subAttrName)) {
				LineNumberTable t = LineNumberTable.parse(iter);
				codeAttr.setLineNumberTable(t);
			} else if (AttributeInfo.LOCAL_VAR_TABLE.equalsIgnoreCase(subAttrName)) {
				LocalVariableTable t = LocalVariableTable.parse(iter);
				codeAttr.setLocalVariableTable(t);
			} else if (AttributeInfo.STACK_MAP_TABLE.equalsIgnoreCase(subAttrName)) {
				StackMapTable t = StackMapTable.parse(iter);
				codeAttr.setStackMapTable(t);
			} else {
				throw new RuntimeException("Need code to process " + subAttrName);
			}
		}

		return codeAttr;
	}

	public String toString(ConstantPool pool) {
		StringBuilder buffer = new StringBuilder();
		// buffer.append("Code:").append(code).append("\n");
		for (int i = 0; i < cmds.length; i++) {
			buffer.append(cmds[i].toString(pool)).append("\n");
		}
		buffer.append("\n");
		buffer.append(this.lineNumTable.toString());
		buffer.append(this.localVarTable.toString(pool));
		return buffer.toString();
	}

	private void setStackMapTable(StackMapTable t) {
		this.stackMapTable = t;

	}

}