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1   /*
2    * Copyright 2012 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package io.netty.handler.codec.serialization;
17  
18  import io.netty.buffer.ByteBuf;
19  import io.netty.buffer.ByteBufOutputStream;
20  import io.netty.buffer.Unpooled;
21  
22  import java.io.DataOutputStream;
23  import java.io.IOException;
24  import java.io.ObjectOutput;
25  import java.io.ObjectOutputStream;
26  import java.io.OutputStream;
27  
28  /**
29   * An {@link ObjectOutput} which is interoperable with {@link ObjectDecoder}
30   * and {@link ObjectDecoderInputStream}.
31   */
32  public class ObjectEncoderOutputStream extends OutputStream implements
33          ObjectOutput {
34  
35      private final DataOutputStream out;
36      private final int estimatedLength;
37  
38      /**
39       * Creates a new {@link ObjectOutput} with the estimated length of 512
40       * bytes.
41       *
42       * @param out
43       *        the {@link OutputStream} where the serialized form will be
44       *        written out
45       */
46      public ObjectEncoderOutputStream(OutputStream out) {
47          this(out, 512);
48      }
49  
50      /**
51       * Creates a new {@link ObjectOutput}.
52       *
53       * @param out
54       *        the {@link OutputStream} where the serialized form will be
55       *        written out
56       *
57       * @param estimatedLength
58       *        the estimated byte length of the serialized form of an object.
59       *        If the length of the serialized form exceeds this value, the
60       *        internal buffer will be expanded automatically at the cost of
61       *        memory bandwidth.  If this value is too big, it will also waste
62       *        memory bandwidth.  To avoid unnecessary memory copy or allocation
63       *        cost, please specify the properly estimated value.
64       */
65      public ObjectEncoderOutputStream(OutputStream out, int estimatedLength) {
66          if (out == null) {
67              throw new NullPointerException("out");
68          }
69          if (estimatedLength < 0) {
70              throw new IllegalArgumentException("estimatedLength: " + estimatedLength);
71          }
72  
73          if (out instanceof DataOutputStream) {
74              this.out = (DataOutputStream) out;
75          } else {
76              this.out = new DataOutputStream(out);
77          }
78          this.estimatedLength = estimatedLength;
79      }
80  
81      @Override
82      public void writeObject(Object obj) throws IOException {
83          ByteBuf buf = Unpooled.buffer(estimatedLength);
84          try {
85              ObjectOutputStream oout = new CompactObjectOutputStream(new ByteBufOutputStream(buf));
86              try {
87                  oout.writeObject(obj);
88                  oout.flush();
89              } finally {
90                  oout.close();
91              }
92  
93              int objectSize = buf.readableBytes();
94              writeInt(objectSize);
95              buf.getBytes(0, this, objectSize);
96          } finally {
97              buf.release();
98          }
99      }
100 
101     @Override
102     public void write(int b) throws IOException {
103         out.write(b);
104     }
105 
106     @Override
107     public void close() throws IOException {
108         out.close();
109     }
110 
111     @Override
112     public void flush() throws IOException {
113         out.flush();
114     }
115 
116     public final int size() {
117         return out.size();
118     }
119 
120     @Override
121     public void write(byte[] b, int off, int len) throws IOException {
122         out.write(b, off, len);
123     }
124 
125     @Override
126     public void write(byte[] b) throws IOException {
127         out.write(b);
128     }
129 
130     @Override
131     public final void writeBoolean(boolean v) throws IOException {
132         out.writeBoolean(v);
133     }
134 
135     @Override
136     public final void writeByte(int v) throws IOException {
137         out.writeByte(v);
138     }
139 
140     @Override
141     public final void writeBytes(String s) throws IOException {
142         out.writeBytes(s);
143     }
144 
145     @Override
146     public final void writeChar(int v) throws IOException {
147         out.writeChar(v);
148     }
149 
150     @Override
151     public final void writeChars(String s) throws IOException {
152         out.writeChars(s);
153     }
154 
155     @Override
156     public final void writeDouble(double v) throws IOException {
157         out.writeDouble(v);
158     }
159 
160     @Override
161     public final void writeFloat(float v) throws IOException {
162         out.writeFloat(v);
163     }
164 
165     @Override
166     public final void writeInt(int v) throws IOException {
167         out.writeInt(v);
168     }
169 
170     @Override
171     public final void writeLong(long v) throws IOException {
172         out.writeLong(v);
173     }
174 
175     @Override
176     public final void writeShort(int v) throws IOException {
177         out.writeShort(v);
178     }
179 
180     @Override
181     public final void writeUTF(String str) throws IOException {
182         out.writeUTF(str);
183     }
184 }