Utility functions related to Streams : Stream « File Input Output « Java

1. Java
2. File Input Output
3. Stream

Utility functions related to Streams

    
/*
 * 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.
 */

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.io.InputStreamReader;

/**
 * Utility functions related to Streams.
 *
 * @author <a href="mailto:taylor@apache.org">David Sean Taylor</a>
 * @version $Id: Streams.java 516448 2007-03-09 16:25:47Z ate $
 */
public class Streams
{
  static final int BLOCK_SIZE=4096;

  public static void drain(InputStream r,OutputStream w) throws IOException
  {
      byte[] bytes=new byte[BLOCK_SIZE];
      try
      {
        int length=r.read(bytes);
        while(length!=-1)
        {
            if(length!=0)
                {
                    w.write(bytes,0,length);
                }
            length=r.read(bytes);
        }
    }
    finally
    {
      bytes=null;
    }

  }

  public static void drain(Reader r,Writer w) throws IOException
  {
    char[] bytes=new char[BLOCK_SIZE];
    try
    {
        int length=r.read(bytes);
        while(length!=-1)
        {
            if(length!=0)
            {
                w.write(bytes,0,length);
            }
            length=r.read(bytes);
        }
    }
    finally
    {
        bytes=null;
    }

  }

  public static void drain(Reader r,OutputStream os) throws IOException
  {
        Writer w=new OutputStreamWriter(os);
        drain(r,w);
        w.flush();
  }

  public static void drain(InputStream is, Writer w) throws IOException
  {
      Reader r = new InputStreamReader(is);
      drain(r,w);
      w.flush();
  }

  public static byte[] drain(InputStream r) throws IOException
  {
        ByteArrayOutputStream bytes=new ByteArrayOutputStream();
        drain(r,bytes);
        return bytes.toByteArray();
  }

  public static String getAsString(InputStream is)
  {
      int c=0;
      char lineBuffer[]=new char[128], buf[]=lineBuffer;
      int room= buf.length, offset=0;
      try
      {
          loop: while (true)
          {
            // read chars into a buffer which grows as needed
                switch (c = is.read() )
                {
                    case -1: break loop;

                    default: if (--room < 0)
                             {
                                 buf = new char[offset + 128];
                                 room = buf.length - offset - 1;
                                 System.arraycopy(lineBuffer, 0,
                                          buf, 0, offset);
                                 lineBuffer = buf;
                             }
                             buf[offset++] = (char) c;
                             break;
                }
          }
      }
      catch(IOException ioe)
      {
          ioe.printStackTrace();
      }
      if ((c == -1) && (offset == 0))
      {
          return null;
      }
      return String.copyValueOf(buf, 0, offset);
  }



}

   
    
    
    
  

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