javassist.bytecode.annotation.AnnotationsWriter Maven / Gradle / Ivy
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/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package javassist.bytecode.annotation;
import java.io.IOException;
import java.io.OutputStream;
import javassist.bytecode.ByteArray;
import javassist.bytecode.ConstPool;
/**
* A convenience class for constructing a
* ..Annotations_attribute.
* See the source code of the AnnotationsAttribute.Copier class.
*
* The following code snippet is an example of use of this class:
*
*
* ConstPool pool = ...;
* output = new ByteArrayOutputStream();
* writer = new AnnotationsWriter(output, pool);
*
* writer.numAnnotations(1);
* writer.annotation("Author", 2);
* writer.memberValuePair("name"); // element_value_pair
* writer.constValueIndex("chiba");
* writer.memberValuePair("address"); // element_value_pair
* writer.constValueIndex("tokyo");
*
* writer.close();
* byte[] attribute_info = output.toByteArray();
* AnnotationsAttribute anno
* = new AnnotationsAttribute(pool, AnnotationsAttribute.visibleTag,
* attribute_info);
*
*
* The code snippet above generates the annotation attribute
* corresponding to this annotation:
*
*
* @Author(name = "chiba", address = "tokyo")
*
*
* @see javassist.bytecode.AnnotationsAttribute
* @see javassist.bytecode.ParameterAnnotationsAttribute
*/
public class AnnotationsWriter {
protected OutputStream output;
private ConstPool pool;
/**
* Constructs with the given output stream.
*
* @param os the output stream.
* @param cp the constant pool.
*/
public AnnotationsWriter(OutputStream os, ConstPool cp) {
output = os;
pool = cp;
}
/**
* Obtains the constant pool given to the constructor.
*/
public ConstPool getConstPool() {
return pool;
}
/**
* Closes the output stream.
*
*/
public void close() throws IOException {
output.close();
}
/**
* Writes num_parameters in
* Runtime(In)VisibleParameterAnnotations_attribute.
* This method must be followed by num calls to
* numAnnotations().
*/
public void numParameters(int num) throws IOException {
output.write(num);
}
/**
* Writes num_annotations in
* Runtime(In)VisibleAnnotations_attribute.
* This method must be followed by num calls to
* annotation().
*/
public void numAnnotations(int num) throws IOException {
write16bit(num);
}
/**
* Writes annotation.
* This method must be followed by numMemberValuePairs
* calls to memberValuePair().
*
* @param type the annotation interface name.
* @param numMemberValuePairs num_element_value_pairs
* in annotation.
*/
public void annotation(String type, int numMemberValuePairs)
throws IOException
{
annotation(pool.addUtf8Info(type), numMemberValuePairs);
}
/**
* Writes annotation.
* This method must be followed by numMemberValuePairs
* calls to memberValuePair().
*
* @param typeIndex type_index in annotation.
* @param numMemberValuePairs num_element_value_pairs
* in annotation.
*/
public void annotation(int typeIndex, int numMemberValuePairs)
throws IOException
{
write16bit(typeIndex);
write16bit(numMemberValuePairs);
}
/**
* Writes an element of a element_value_pairs array
* in annotation.
* This method must be followed by a
* call to constValueIndex(), enumConstValue(),
* etc.
*
* @param memberName the element name.
*/
public void memberValuePair(String memberName) throws IOException {
memberValuePair(pool.addUtf8Info(memberName));
}
/**
* Writes an element of a element_value_pairs array
* in annotation.
* This method must be followed by a
* call to constValueIndex(), enumConstValue(),
* etc.
*
* @param memberNameIndex element_name_index
* in element_value_pairs array.
*/
public void memberValuePair(int memberNameIndex) throws IOException {
write16bit(memberNameIndex);
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(boolean value) throws IOException {
constValueIndex('Z', pool.addIntegerInfo(value ? 1 : 0));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(byte value) throws IOException {
constValueIndex('B', pool.addIntegerInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(char value) throws IOException {
constValueIndex('C', pool.addIntegerInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(short value) throws IOException {
constValueIndex('S', pool.addIntegerInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(int value) throws IOException {
constValueIndex('I', pool.addIntegerInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(long value) throws IOException {
constValueIndex('J', pool.addLongInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(float value) throws IOException {
constValueIndex('F', pool.addFloatInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(double value) throws IOException {
constValueIndex('D', pool.addDoubleInfo(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param value the constant value.
*/
public void constValueIndex(String value) throws IOException {
constValueIndex('s', pool.addUtf8Info(value));
}
/**
* Writes tag and const_value_index
* in element_value.
*
* @param tag tag in element_value.
* @param index const_value_index
* in element_value.
*/
public void constValueIndex(int tag, int index)
throws IOException
{
output.write(tag);
write16bit(index);
}
/**
* Writes tag and enum_const_value
* in element_value.
*
* @param typeName the type name of the enum constant.
* @param constName the simple name of the enum constant.
*/
public void enumConstValue(String typeName, String constName)
throws IOException
{
enumConstValue(pool.addUtf8Info(typeName),
pool.addUtf8Info(constName));
}
/**
* Writes tag and enum_const_value
* in element_value.
*
* @param typeNameIndex type_name_index
* in element_value.
* @param constNameIndex const_name_index
* in element_value.
*/
public void enumConstValue(int typeNameIndex, int constNameIndex)
throws IOException
{
output.write('e');
write16bit(typeNameIndex);
write16bit(constNameIndex);
}
/**
* Writes tag and class_info_index
* in element_value.
*
* @param name the class name.
*/
public void classInfoIndex(String name) throws IOException {
classInfoIndex(pool.addUtf8Info(name));
}
/**
* Writes tag and class_info_index
* in element_value.
*
* @param index class_info_index
*/
public void classInfoIndex(int index) throws IOException {
output.write('c');
write16bit(index);
}
/**
* Writes tag and annotation_value
* in element_value.
* This method must be followed by a call to annotation().
*/
public void annotationValue() throws IOException {
output.write('@');
}
/**
* Writes tag and array_value
* in element_value.
* This method must be followed by numValues calls
* to constValueIndex(), enumConstValue(),
* etc.
*
* @param numValues num_values
* in array_value.
*/
public void arrayValue(int numValues) throws IOException {
output.write('[');
write16bit(numValues);
}
protected void write16bit(int value) throws IOException {
byte[] buf = new byte[2];
ByteArray.write16bit(value, buf, 0);
output.write(buf);
}
}