1/*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the  "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 *     http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18/*
19 * $Id: WriterChain.java 468654 2006-10-28 07:09:23Z minchau $
20 */
21package org.apache.xml.serializer;
22
23import java.io.IOException;
24
25/**
26 * It is unfortunate that java.io.Writer is a class rather than an interface.
27 * The serializer has a number of classes that extend java.io.Writer
28 * and which send their ouput to a yet another wrapped Writer or OutputStream.
29 *
30 * The purpose of this interface is to force such classes to over-ride all of
31 * the important methods defined on the java.io.Writer class, namely these:
32 * <code>
33 * write(int val)
34 * write(char[] chars)
35 * write(char[] chars, int start, int count)
36 * write(String chars)
37 * write(String chars, int start, int count)
38 * flush()
39 * close()
40 * </code>
41 * In this manner nothing will accidentally go directly to
42 * the base class rather than to the wrapped Writer or OutputStream.
43 *
44 * The purpose of this class is to have a uniform way of chaining the output of one writer to
45 * the next writer in the chain. In addition there are methods to obtain the Writer or
46 * OutputStream that this object sends its output to.
47 *
48 * This interface is only for internal use withing the serializer.
49 * @xsl.usage internal
50 */
51interface WriterChain
52{
53    /** This method forces us to over-ride the method defined in java.io.Writer */
54    public void write(int val) throws IOException;
55    /** This method forces us to over-ride the method defined in java.io.Writer */
56    public void write(char[] chars) throws IOException;
57    /** This method forces us to over-ride the method defined in java.io.Writer */
58    public void write(char[] chars, int start, int count) throws IOException;
59    /** This method forces us to over-ride the method defined in java.io.Writer */
60    public void write(String chars) throws IOException;
61    /** This method forces us to over-ride the method defined in java.io.Writer */
62    public void write(String chars, int start, int count) throws IOException;
63    /** This method forces us to over-ride the method defined in java.io.Writer */
64    public void flush() throws IOException;
65    /** This method forces us to over-ride the method defined in java.io.Writer */
66    public void close() throws IOException;
67
68    /**
69     * If this method returns null, getOutputStream() must return non-null.
70     * Get the writer that this writer sends its output to.
71     *
72     * It is possible that the Writer returned by this method does not
73     * implement the WriterChain interface.
74     */
75    public java.io.Writer getWriter();
76
77    /**
78     * If this method returns null, getWriter() must return non-null.
79     * Get the OutputStream that this writer sends its output to.
80     */
81    public java.io.OutputStream getOutputStream();
82}
83