Module.java
/*
* 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 is derived from <em>Attribute</em> and represents the list of modules required, exported, opened or
* provided by a module. There may be at most one Module attribute in a ClassFile structure.
*
* @see Attribute
* @since 6.4.0
*/
public final class Module extends Attribute {
/**
* The module file name extension.
*
* @since 6.7.0
*/
public static final String EXTENSION = ".jmod";
private static String getClassNameAtIndex(final ConstantPool cp, final int index, final boolean compactClassName) {
final String className = cp.getConstantString(index, Const.CONSTANT_Class);
if (compactClassName) {
return Utility.compactClassName(className, false);
}
return className;
}
private final int moduleNameIndex;
private final int moduleFlags;
private final int moduleVersionIndex;
private ModuleRequires[] requiresTable;
private ModuleExports[] exportsTable;
private ModuleOpens[] opensTable;
private final int usesCount;
private final int[] usesIndex;
private ModuleProvides[] providesTable;
/**
* Constructs object from input stream.
*
* @param nameIndex Index in constant pool
* @param length Content length in bytes
* @param input Input stream
* @param constantPool Array of constants
* @throws IOException if an I/O error occurs.
*/
Module(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
super(Const.ATTR_MODULE, nameIndex, length, constantPool);
moduleNameIndex = input.readUnsignedShort();
moduleFlags = input.readUnsignedShort();
moduleVersionIndex = input.readUnsignedShort();
final int requiresCount = input.readUnsignedShort();
requiresTable = new ModuleRequires[requiresCount];
for (int i = 0; i < requiresCount; i++) {
requiresTable[i] = new ModuleRequires(input);
}
final int exportsCount = input.readUnsignedShort();
exportsTable = new ModuleExports[exportsCount];
for (int i = 0; i < exportsCount; i++) {
exportsTable[i] = new ModuleExports(input);
}
final int opensCount = input.readUnsignedShort();
opensTable = new ModuleOpens[opensCount];
for (int i = 0; i < opensCount; i++) {
opensTable[i] = new ModuleOpens(input);
}
usesCount = input.readUnsignedShort();
usesIndex = new int[usesCount];
for (int i = 0; i < usesCount; i++) {
usesIndex[i] = input.readUnsignedShort();
}
final int providesCount = input.readUnsignedShort();
providesTable = new ModuleProvides[providesCount];
for (int i = 0; i < providesCount; i++) {
providesTable[i] = new ModuleProvides(input);
}
}
/**
* Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
* I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
*
* @param v Visitor object
*/
@Override
public void accept(final Visitor v) {
v.visitModule(this);
}
/**
* @return deep copy of this attribute
*/
@Override
public Attribute copy(final ConstantPool constantPool) {
final Module c = (Module) clone();
c.requiresTable = new ModuleRequires[requiresTable.length];
Arrays.setAll(c.requiresTable, i -> requiresTable[i].copy());
c.exportsTable = new ModuleExports[exportsTable.length];
Arrays.setAll(c.exportsTable, i -> exportsTable[i].copy());
c.opensTable = new ModuleOpens[opensTable.length];
Arrays.setAll(c.opensTable, i -> opensTable[i].copy());
c.providesTable = new ModuleProvides[providesTable.length];
Arrays.setAll(c.providesTable, i -> providesTable[i].copy());
c.setConstantPool(constantPool);
return c;
}
/**
* Dump Module attribute to file stream in binary format.
*
* @param file Output file stream
* @throws IOException if an I/O error occurs.
*/
@Override
public void dump(final DataOutputStream file) throws IOException {
super.dump(file);
file.writeShort(moduleNameIndex);
file.writeShort(moduleFlags);
file.writeShort(moduleVersionIndex);
file.writeShort(requiresTable.length);
for (final ModuleRequires entry : requiresTable) {
entry.dump(file);
}
file.writeShort(exportsTable.length);
for (final ModuleExports entry : exportsTable) {
entry.dump(file);
}
file.writeShort(opensTable.length);
for (final ModuleOpens entry : opensTable) {
entry.dump(file);
}
file.writeShort(usesIndex.length);
for (final int entry : usesIndex) {
file.writeShort(entry);
}
file.writeShort(providesTable.length);
for (final ModuleProvides entry : providesTable) {
entry.dump(file);
}
}
/**
* @return table of exported interfaces
* @see ModuleExports
*/
public ModuleExports[] getExportsTable() {
return exportsTable;
}
/**
* Gets flags for this module.
* @return module flags
* @since 6.10.0
*/
public int getModuleFlags() {
return moduleFlags;
}
/**
* Gets module name.
* @param cp Array of constants
* @return module name
* @since 6.10.0
*/
public String getModuleName(final ConstantPool cp) {
return cp.getConstantString(moduleNameIndex, Const.CONSTANT_Module);
}
/**
* @return table of provided interfaces
* @see ModuleOpens
*/
public ModuleOpens[] getOpensTable() {
return opensTable;
}
/**
* @return table of provided interfaces
* @see ModuleProvides
*/
public ModuleProvides[] getProvidesTable() {
return providesTable;
}
/**
* @return table of required modules
* @see ModuleRequires
*/
public ModuleRequires[] getRequiresTable() {
return requiresTable;
}
/**
* Gets the array of class names for this module's uses.
* @param constantPool Array of constants usually obtained from the ClassFile object
* @param compactClassName false for original constant pool value, true to replace '/' with '.'
* @return array of used class names
* @since 6.10.0
*/
public String[] getUsedClassNames(final ConstantPool constantPool, final boolean compactClassName) {
final String[] usedClassNames = new String[usesCount];
for (int i = 0; i < usesCount; i++) {
usedClassNames[i] = getClassNameAtIndex(constantPool, usesIndex[i], compactClassName);
}
return usedClassNames;
}
/**
* Gets version for this module.
* @param cp Array of constants
* @return version from constant pool, "0" if version index is 0
* @since 6.10.0
*/
public String getVersion(final ConstantPool cp) {
return moduleVersionIndex == 0 ? "0" : cp.getConstantString(moduleVersionIndex, Const.CONSTANT_Utf8);
}
/**
* @return String representation, i.e., a list of packages.
*/
@Override
public String toString() {
final ConstantPool cp = super.getConstantPool();
final StringBuilder buf = new StringBuilder();
buf.append("Module:\n");
buf.append(" name: ").append(Utility.pathToPackage(getModuleName(cp))).append("\n");
buf.append(" flags: ").append(String.format("%04x", moduleFlags)).append("\n");
final String version = getVersion(cp);
buf.append(" version: ").append(version).append("\n");
buf.append(" requires(").append(requiresTable.length).append("):\n");
for (final ModuleRequires module : requiresTable) {
buf.append(" ").append(module.toString(cp)).append("\n");
}
buf.append(" exports(").append(exportsTable.length).append("):\n");
for (final ModuleExports module : exportsTable) {
buf.append(" ").append(module.toString(cp)).append("\n");
}
buf.append(" opens(").append(opensTable.length).append("):\n");
for (final ModuleOpens module : opensTable) {
buf.append(" ").append(module.toString(cp)).append("\n");
}
buf.append(" uses(").append(usesIndex.length).append("):\n");
for (final int index : usesIndex) {
final String className = getClassNameAtIndex(cp, index, true);
buf.append(" ").append(className).append("\n");
}
buf.append(" provides(").append(providesTable.length).append("):\n");
for (final ModuleProvides module : providesTable) {
buf.append(" ").append(module.toString(cp)).append("\n");
}
return buf.substring(0, buf.length() - 1); // remove the last newline
}
}