001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.compress.harmony.unpack200.bytecode.forms; 018 019import org.apache.commons.compress.harmony.pack200.Pack200Exception; 020import org.apache.commons.compress.harmony.unpack200.SegmentConstantPool; 021import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode; 022import org.apache.commons.compress.harmony.unpack200.bytecode.ClassFileEntry; 023import org.apache.commons.compress.harmony.unpack200.bytecode.OperandManager; 024 025/** 026 * Abstract class of all ByteCodeForms which add a nested entry from the globalConstantPool. 027 */ 028public abstract class ReferenceForm extends ByteCodeForm { 029 030 public ReferenceForm(final int opcode, final String name, final int[] rewrite) { 031 super(opcode, name, rewrite); 032 } 033 034 protected abstract int getPoolID(); 035 036 protected abstract int getOffset(OperandManager operandManager); 037 038 protected void setNestedEntries(final ByteCode byteCode, final OperandManager operandManager, final int offset) 039 throws Pack200Exception { 040 final SegmentConstantPool globalPool = operandManager.globalConstantPool(); 041 ClassFileEntry[] nested = null; 042 nested = new ClassFileEntry[] {globalPool.getConstantPoolEntry(getPoolID(), offset)}; 043 if (nested[0] == null) { 044 throw new NullPointerException("Null nested entries are not allowed"); 045 } 046 byteCode.setNested(nested); 047 byteCode.setNestedPositions(new int[][] {{0, 2}}); 048 } 049 050 /* 051 * (non-Javadoc) 052 * 053 * @see 054 * org.apache.commons.compress.harmony.unpack200.bytecode.forms.ByteCodeForm#setByteCodeOperands(org.apache.commons. 055 * compress.harmony.unpack200.bytecode.ByteCode, 056 * org.apache.commons.compress.harmony.unpack200.bytecode.OperandTable, 057 * org.apache.commons.compress.harmony.unpack200.Segment) 058 */ 059 @Override 060 public void setByteCodeOperands(final ByteCode byteCode, final OperandManager operandManager, 061 final int codeLength) { 062 final int offset = getOffset(operandManager); 063 try { 064 setNestedEntries(byteCode, operandManager, offset); 065 } catch (final Pack200Exception ex) { 066 throw new Error("Got a pack200 exception. What to do?"); 067 } 068 } 069}