content: /**
   * 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.
   */
  
  package org.apache.aries.web.converter.impl;
  
  import java.io.BufferedOutputStream;
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  public class CachedOutputStream extends OutputStream {
  
      private static final int DEFAULT_THRESHOLD = 64 * 1024;
      
      private OutputStream currentStream;
      private long threshold;
      private int totalLength;
      private boolean inmem;
      private List<InputStream> streams;
      private File tempFile;
      private File outputDir;
  
      public CachedOutputStream() {
          this(DEFAULT_THRESHOLD, null);
      }
  
      public CachedOutputStream(long threshold, File outputDir) {
          this.threshold = threshold; 
          this.outputDir = outputDir;
          this.currentStream = new ByteArrayOutputStream(2048);
          this.inmem = true;
          this.streams = new ArrayList<InputStream>(1);
      }
  
      public void flush() throws IOException {
          currentStream.flush();
      }
      
      public void close() throws IOException {
          currentStream.flush();       
          currentStream.close();
      }
  
      public void write(byte[] b) throws IOException {
          write(b, 0, b.length);
      }
      
      public void write(byte[] b, int off, int len) throws IOException {
          totalLength += len;
          if (inmem && totalLength > threshold) {
              createFileOutputStream();
          }
          currentStream.write(b, off, len);
      }
  
      public void write(int b) throws IOException {
          totalLength++;
          if (inmem && totalLength > threshold) {
              createFileOutputStream();
          }
          currentStream.write(b);
      }
  
      private void createFileOutputStream() throws IOException {
          ByteArrayOutputStream bout = (ByteArrayOutputStream) currentStream;
          if (outputDir == null) {
              tempFile = File.createTempFile("cos", "tmp");
          } else {
              tempFile = File.createTempFile("cos", "tmp", outputDir);
          }
          
          currentStream = new BufferedOutputStream(new FileOutputStream(tempFile));
          bout.writeTo(currentStream);
          inmem = false;
      }
  
      public void destroy() {
          streams.clear();
          if (tempFile != null) {
              tempFile.delete();
          }
      }
      
      public int size() {
          return totalLength;
      }
      
      public InputStream getInputStream() throws IOException {
          close();
          if (inmem) {
              return new ByteArrayInputStream(((ByteArrayOutputStream) currentStream).toByteArray());
          } else {
              try {
                  FileInputStream fileInputStream = new FileInputStream(tempFile) {
                      public void close() throws IOException {
                          super.close();
                          maybeDeleteTempFile(this);
                      }
                  };
                  streams.add(fileInputStream);
                  return fileInputStream;
              } catch (FileNotFoundException e) {
                  throw new IOException("Cached file was deleted, " + e.toString());
              }
          }
      }
      
      private void maybeDeleteTempFile(Object stream) {
          streams.remove(stream);
          if (tempFile != null && streams.isEmpty()) {
              tempFile.delete();
              tempFile = null;
          }
      }
  
  }
  