diff options
Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/optional/depend/constantpool/ConstantPoolEntry.java')
| -rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/optional/depend/constantpool/ConstantPoolEntry.java | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/optional/depend/constantpool/ConstantPoolEntry.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/optional/depend/constantpool/ConstantPoolEntry.java new file mode 100644 index 00000000..26a0d094 --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/optional/depend/constantpool/ConstantPoolEntry.java @@ -0,0 +1,242 @@ +/* + * 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.tools.ant.taskdefs.optional.depend.constantpool; + +import java.io.DataInputStream; +import java.io.IOException; + +/** + * An entry in the constant pool. This class contains a representation of the + * constant pool entries. It is an abstract base class for all the different + * forms of constant pool entry. + * + * @see ConstantPool + */ +public abstract class ConstantPoolEntry { + + /** Tag value for UTF8 entries. */ + public static final int CONSTANT_UTF8 = 1; + + /** Tag value for Integer entries. */ + public static final int CONSTANT_INTEGER = 3; + + /** Tag value for Float entries. */ + public static final int CONSTANT_FLOAT = 4; + + /** Tag value for Long entries. */ + public static final int CONSTANT_LONG = 5; + + /** Tag value for Double entries. */ + public static final int CONSTANT_DOUBLE = 6; + + /** Tag value for Class entries. */ + public static final int CONSTANT_CLASS = 7; + + /** Tag value for String entries. */ + public static final int CONSTANT_STRING = 8; + + /** Tag value for Field Reference entries. */ + public static final int CONSTANT_FIELDREF = 9; + + /** Tag value for Method Reference entries. */ + public static final int CONSTANT_METHODREF = 10; + + /** Tag value for Interface Method Reference entries. */ + public static final int CONSTANT_INTERFACEMETHODREF = 11; + + /** Tag value for Name and Type entries. */ + public static final int CONSTANT_NAMEANDTYPE = 12; + + /** Tag value for Method Handle entries */ + public static final int CONSTANT_METHODHANDLE = 15; + + /** Tag value for Method Type entries */ + public static final int CONSTANT_METHODTYPE = 16; + + /** Tag value for InvokeDynamic entries*/ + public static final int CONSTANT_INVOKEDYNAMIC = 18; + + /** + * This entry's tag which identifies the type of this constant pool + * entry. + */ + private int tag; + + /** + * The number of slots in the constant pool, occupied by this entry. + */ + private int numEntries; + + /** + * A flag which indicates if this entry has been resolved or not. + */ + private boolean resolved; + + /** + * Initialise the constant pool entry. + * + * @param tagValue the tag value which identifies which type of constant + * pool entry this is. + * @param entries the number of constant pool entry slots this entry + * occupies. + */ + public ConstantPoolEntry(int tagValue, int entries) { + tag = tagValue; + numEntries = entries; + resolved = false; + } + + /** + * Read a constant pool entry from a stream. This is a factory method + * which reads a constant pool entry form a stream and returns the + * appropriate subclass for the entry. + * + * @param cpStream the stream from which the constant pool entry is to + * be read. + * @return the appropriate ConstantPoolEntry subclass representing the + * constant pool entry from the stream. + * @exception IOException if the constant pool entry cannot be read + * from the stream + */ + public static ConstantPoolEntry readEntry(DataInputStream cpStream) + throws IOException { + ConstantPoolEntry cpInfo = null; + int cpTag = cpStream.readUnsignedByte(); + + switch (cpTag) { + + case CONSTANT_UTF8: + cpInfo = new Utf8CPInfo(); + + break; + case CONSTANT_INTEGER: + cpInfo = new IntegerCPInfo(); + + break; + case CONSTANT_FLOAT: + cpInfo = new FloatCPInfo(); + + break; + case CONSTANT_LONG: + cpInfo = new LongCPInfo(); + + break; + case CONSTANT_DOUBLE: + cpInfo = new DoubleCPInfo(); + + break; + case CONSTANT_CLASS: + cpInfo = new ClassCPInfo(); + + break; + case CONSTANT_STRING: + cpInfo = new StringCPInfo(); + + break; + case CONSTANT_FIELDREF: + cpInfo = new FieldRefCPInfo(); + + break; + case CONSTANT_METHODREF: + cpInfo = new MethodRefCPInfo(); + + break; + case CONSTANT_INTERFACEMETHODREF: + cpInfo = new InterfaceMethodRefCPInfo(); + + break; + case CONSTANT_NAMEANDTYPE: + cpInfo = new NameAndTypeCPInfo(); + + break; + case CONSTANT_METHODHANDLE: + cpInfo = new MethodHandleCPInfo(); + + break; + case CONSTANT_METHODTYPE: + cpInfo = new MethodTypeCPInfo(); + + break; + case CONSTANT_INVOKEDYNAMIC: + cpInfo = new InvokeDynamicCPInfo(); + + break; + default: + throw new ClassFormatError("Invalid Constant Pool entry Type " + + cpTag); + } + + cpInfo.read(cpStream); + + return cpInfo; + } + + /** + * Indicates whether this entry has been resolved. In general a constant + * pool entry can reference another constant pool entry by its index + * value. Resolution involves replacing this index value with the + * constant pool entry at that index. + * + * @return true if this entry has been resolved. + */ + public boolean isResolved() { + return resolved; + } + + /** + * Resolve this constant pool entry with respect to its dependents in + * the constant pool. + * + * @param constantPool the constant pool of which this entry is a member + * and against which this entry is to be resolved. + */ + public void resolve(ConstantPool constantPool) { + resolved = true; + } + + /** + * read a constant pool entry from a class stream. + * + * @param cpStream the DataInputStream which contains the constant pool + * entry to be read. + * @exception IOException if there is a problem reading the entry from + * the stream. + */ + public abstract void read(DataInputStream cpStream) throws IOException; + + /** + * Get the Entry's type tag. + * + * @return The Tag value of this entry + */ + public int getTag() { + return tag; + } + + /** + * Get the number of Constant Pool Entry slots within the constant pool + * occupied by this entry. + * + * @return the number of slots used. + */ + public final int getNumEntries() { + return numEntries; + } + +} + |