/*
 * 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.bcel.classfile;

import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Arrays;

import org.apache.bcel.Const;

This class represents a bootstrap method attribute, i.e., the bootstrap method ref, the number of bootstrap arguments and an array of the bootstrap arguments.
See Also:
Since:6.0
/** * This class represents a bootstrap method attribute, i.e., the bootstrap * method ref, the number of bootstrap arguments and an array of the * bootstrap arguments. * * @see <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.23"> * The class File Format : The BootstrapMethods Attribute</a> * @since 6.0 */
public class BootstrapMethod implements Cloneable {
Index of the CONSTANT_MethodHandle_info structure in the constant_pool table
/** Index of the CONSTANT_MethodHandle_info structure in the constant_pool table */
private int bootstrap_method_ref;
Array of references to the constant_pool table
/** Array of references to the constant_pool table */
private int[] bootstrap_arguments;
Initialize from another object.
/** * Initialize from another object. */
public BootstrapMethod(final BootstrapMethod c) { this(c.getBootstrapMethodRef(), c.getBootstrapArguments()); }
Construct object from input stream.
Params:
  • input – Input stream
Throws:
/** * Construct object from input stream. * * @param input Input stream * @throws IOException */
BootstrapMethod(final DataInput input) throws IOException { this(input.readUnsignedShort(), input.readUnsignedShort()); for (int i = 0; i < bootstrap_arguments.length; i++) { bootstrap_arguments[i] = input.readUnsignedShort(); } } // helper method private BootstrapMethod(final int bootstrap_method_ref, final int num_bootstrap_arguments) { this(bootstrap_method_ref, new int[num_bootstrap_arguments]); }
Params:
  • bootstrap_method_ref – int index into constant_pool of CONSTANT_MethodHandle
  • bootstrap_arguments – int[] indices into constant_pool of CONSTANT_[type]_info
/** * @param bootstrap_method_ref int index into constant_pool of CONSTANT_MethodHandle * @param bootstrap_arguments int[] indices into constant_pool of CONSTANT_[type]_info */
public BootstrapMethod(final int bootstrap_method_ref, final int[] bootstrap_arguments) { this.bootstrap_method_ref = bootstrap_method_ref; this.bootstrap_arguments = bootstrap_arguments; }
Returns:index into constant_pool of bootstrap_method
/** * @return index into constant_pool of bootstrap_method */
public int getBootstrapMethodRef() { return bootstrap_method_ref; }
Params:
  • bootstrap_method_ref – int index into constant_pool of CONSTANT_MethodHandle
/** * @param bootstrap_method_ref int index into constant_pool of CONSTANT_MethodHandle */
public void setBootstrapMethodRef(final int bootstrap_method_ref) { this.bootstrap_method_ref = bootstrap_method_ref; }
Returns:int[] of bootstrap_method indices into constant_pool of CONSTANT_[type]_info
/** * @return int[] of bootstrap_method indices into constant_pool of CONSTANT_[type]_info */
public int[] getBootstrapArguments() { return bootstrap_arguments; }
Returns:count of number of boostrap arguments
/** * @return count of number of boostrap arguments */
public int getNumBootstrapArguments() { return bootstrap_arguments.length; }
Params:
  • bootstrap_arguments – int[] indices into constant_pool of CONSTANT_[type]_info
/** * @param bootstrap_arguments int[] indices into constant_pool of CONSTANT_[type]_info */
public void setBootstrapArguments(final int[] bootstrap_arguments) { this.bootstrap_arguments = bootstrap_arguments; }
Returns:String representation.
/** * @return String representation. */
@Override public final String toString() { return "BootstrapMethod(" + bootstrap_method_ref + ", " + bootstrap_arguments.length + ", " + Arrays.toString(bootstrap_arguments) + ")"; }
Returns:Resolved string representation
/** * @return Resolved string representation */
public final String toString( final ConstantPool constant_pool ) { final StringBuilder buf = new StringBuilder(); String bootstrap_method_name; bootstrap_method_name = constant_pool.constantToString(bootstrap_method_ref, Const.CONSTANT_MethodHandle); buf.append(Utility.compactClassName(bootstrap_method_name, false)); final int num_bootstrap_arguments = bootstrap_arguments.length; if (num_bootstrap_arguments > 0) { buf.append("\nMethod Arguments:"); for (int i = 0; i < num_bootstrap_arguments; i++) { buf.append("\n ").append(i).append(": "); buf.append(constant_pool.constantToString(constant_pool.getConstant(bootstrap_arguments[i]))); } } return buf.toString(); }
Dump object to file stream in binary format.
Params:
  • file – Output file stream
Throws:
/** * Dump object to file stream in binary format. * * @param file Output file stream * @throws IOException */
public final void dump(final DataOutputStream file) throws IOException { file.writeShort(bootstrap_method_ref); file.writeShort(bootstrap_arguments.length); for (final int bootstrap_argument : bootstrap_arguments) { file.writeShort(bootstrap_argument); } }
Returns:deep copy of this object
/** * @return deep copy of this object */
public BootstrapMethod copy() { try { return (BootstrapMethod) clone(); } catch (final CloneNotSupportedException e) { // TODO should this throw? } return null; } }