org.apache.tomcat.util.bcel.classfile.StackMap Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tomcat.util.bcel.classfile;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.tomcat.util.bcel.Constants;
/**
* This class represents a stack map attribute used for
* preverification of Java classes for the Java 2 Micro Edition
* (J2ME). This attribute is used by the KVM and contained
* within the Code attribute of a method. See CLDC specification
* §5.3.1.2
*
* @version $Id: StackMap.java 1057670 2011-01-11 14:52:05Z markt $
* @author M. Dahm
* @see Code
* @see StackMapEntry
* @see StackMapType
*/
public final class StackMap extends Attribute {
private static final long serialVersionUID = 264958819110329590L;
private int map_length;
private StackMapEntry[] map; // Table of stack map entries
/*
* @param name_index Index of name
* @param length Content length in bytes
* @param map Table of stack map entries
* @param constant_pool Array of constants
*/
public StackMap(int name_index, int length, StackMapEntry[] map, ConstantPool constant_pool) {
super(Constants.ATTR_STACK_MAP, name_index, length, constant_pool);
setStackMap(map);
}
/**
* Construct object from file stream.
* @param name_index Index of name
* @param length Content length in bytes
* @param file Input stream
* @param constant_pool Array of constants
* @throws IOException
*/
StackMap(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
throws IOException {
this(name_index, length, (StackMapEntry[]) null, constant_pool);
map_length = file.readUnsignedShort();
map = new StackMapEntry[map_length];
for (int i = 0; i < map_length; i++) {
map[i] = new StackMapEntry(file, constant_pool);
}
}
/**
* Dump line number table attribute to file stream in binary format.
*
* @param file Output file stream
* @throws IOException
*/
@Override
public final void dump( DataOutputStream file ) throws IOException {
super.dump(file);
file.writeShort(map_length);
for (int i = 0; i < map_length; i++) {
map[i].dump(file);
}
}
/**
* @param map Array of stack map entries
*/
public final void setStackMap( StackMapEntry[] map ) {
this.map = map;
map_length = (map == null) ? 0 : map.length;
}
/**
* @return String representation.
*/
@Override
public final String toString() {
StringBuffer buf = new StringBuffer("StackMap(");
for (int i = 0; i < map_length; i++) {
buf.append(map[i].toString());
if (i < map_length - 1) {
buf.append(", ");
}
}
buf.append(')');
return buf.toString();
}
/**
* @return deep copy of this attribute
*/
@Override
public Attribute copy( ConstantPool _constant_pool ) {
StackMap c = (StackMap) clone();
c.map = new StackMapEntry[map_length];
for (int i = 0; i < map_length; i++) {
c.map[i] = map[i].copy();
}
c.constant_pool = _constant_pool;
return c;
}
}