1   /*
    2    * $HeadURL: https://svn.apache.org/repos/asf/jakarta/httpcomponents/httpcore/tags/4.0-alpha2/src/java/org/apache/http/io/ContentLengthOutputStream.java $
    3    * $Revision: 390883 $
    4    * $Date: 2006-04-02 20:39:50 +0200 (Sun, 02 Apr 2006) $
    5    *
    6    * ====================================================================
    7    *
    8    *  Copyright 1999-2006 The Apache Software Foundation
    9    *
   10    *  Licensed under the Apache License, Version 2.0 (the "License");
   11    *  you may not use this file except in compliance with the License.
   12    *  You may obtain a copy of the License at
   13    *
   14    *      http://www.apache.org/licenses/LICENSE-2.0
   15    *
   16    *  Unless required by applicable law or agreed to in writing, software
   17    *  distributed under the License is distributed on an "AS IS" BASIS,
   18    *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   19    *  See the License for the specific language governing permissions and
   20    *  limitations under the License.
   21    * ====================================================================
   22    *
   23    * This software consists of voluntary contributions made by many
   24    * individuals on behalf of the Apache Software Foundation.  For more
   25    * information on the Apache Software Foundation, please see
   26    * <http://www.apache.org/>.
   27    *
   28    */
   29   
   30   package org.apache.http.io;
   31   
   32   import java.io.IOException;
   33   import java.io.OutputStream;
   34   
   35   /**
   36    * A stream wrapper that closes itself after a defined number of bytes.
   37    *
   38    * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
   39    *
   40    * @version $Revision: 390883 $
   41    * 
   42    * @since 4.0
   43    */
   44   public class ContentLengthOutputStream extends OutputStream {
   45       
   46       /**
   47        * Wrapped data transmitter that all calls are delegated to.
   48        */
   49       private final HttpDataTransmitter out;
   50   
   51       /**
   52        * The maximum number of bytes that can be written the stream. Subsequent
   53        * write operations will be ignored.
   54        */
   55       private final long contentLength;
   56   
   57       /** Total bytes written */
   58       private long total = 0;
   59   
   60       /** True if the stream is closed. */
   61       private boolean closed = false;
   62   
   63       /**
   64        * Creates a new length limited stream
   65        *
   66        * @param out The data transmitter to wrap
   67        * @param contentLength The maximum number of bytes that can be written to
   68        * the stream. Subsequent write operations will be ignored.
   69        * 
   70        * @since 4.0
   71        */
   72       public ContentLengthOutputStream(final HttpDataTransmitter out, long contentLength) {
   73           super();
   74           if (out == null) {
   75               throw new IllegalArgumentException("HTTP data transmitter may not be null");
   76           }
   77           if (contentLength < 0) {
   78               throw new IllegalArgumentException("Content length may not be negative");
   79           }
   80           this.out = out;
   81           this.contentLength = contentLength;
   82       }
   83   
   84       /**
   85        * <p>Does not close the underlying socket output.</p>
   86        * 
   87        * @throws IOException If an I/O problem occurs.
   88        */
   89       public void close() throws IOException {
   90           if (!this.closed) {
   91               this.closed = true;
   92               this.out.flush();
   93           }
   94       }
   95   
   96       public void flush() throws IOException {
   97           this.out.flush();
   98       }
   99   
  100       public void write(byte[] b, int off, int len) throws IOException {
  101           if (this.closed) {
  102               throw new IOException("Attempted write to closed stream.");
  103           }
  104           if (this.total < this.contentLength) {
  105               long max = this.contentLength - this.total;
  106               if (len > max) {
  107                   len = (int) max;
  108               }
  109               this.out.write(b, off, len);
  110               this.total += len;
  111           }
  112       }
  113   
  114       public void write(byte[] b) throws IOException {
  115           write(b, 0, b.length);
  116       }
  117   
  118       public void write(int b) throws IOException {
  119           if (this.closed) {
  120               throw new IOException("Attempted write to closed stream.");
  121           }
  122           if (this.total < this.contentLength) {
  123               this.out.write(b);
  124               this.total++;
  125           }
  126       }
  127       
  128   }