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Apache CXF example source code file (CachedOutputStream.java)

This example Apache CXF source code file (CachedOutputStream.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Apache CXF tags/keywords

bytearrayoutputstream, bytearrayoutputstream, cachedoutputstream, cachedoutputstream, default_temp_dir, file, fileinputstream, fileinputstream, io, ioexception, ioexception, loadingbytearrayoutputstream, pipedoutputstream, string, unknown, util

The Apache CXF CachedOutputStream.java source code

/**
 * 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.cxf.io;

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.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.cxf.helpers.FileUtils;
import org.apache.cxf.helpers.IOUtils;
import org.apache.cxf.helpers.LoadingByteArrayOutputStream;

public class CachedOutputStream extends OutputStream {
    private static final File DEFAULT_TEMP_DIR;
    private static final int DEFAULT_THRESHOLD;
    static {
        String s = System.getProperty("org.apache.cxf.io.CachedOutputStream.Threshold",
                                      "-1");
        int i = Integer.parseInt(s);
        if (i <= 0) {
            i = 64 * 1024;
        }
        DEFAULT_THRESHOLD = i;
        
        s = System.getProperty("org.apache.cxf.io.CachedOutputStream.OutputDirectory");
        if (s != null) {
            File f = new File(s);
            if (f.exists() && f.isDirectory()) {
                DEFAULT_TEMP_DIR = f;
            } else {
                DEFAULT_TEMP_DIR = null;
            }
        } else {
            DEFAULT_TEMP_DIR = null;
        }
    }

    protected boolean outputLocked;
    protected OutputStream currentStream;

    private long threshold = DEFAULT_THRESHOLD;

    private int totalLength;

    private boolean inmem;

    private boolean tempFileFailed;
    private File tempFile;
    private File outputDir = DEFAULT_TEMP_DIR;
    private boolean allowDeleteOfFile = true;

    private List<CachedOutputStreamCallback> callbacks;
    
    private List<Object> streamList = new ArrayList();

    public CachedOutputStream(PipedInputStream stream) throws IOException {
        currentStream = new PipedOutputStream(stream);
        inmem = true;
    }

    public CachedOutputStream() {
        currentStream = new LoadingByteArrayOutputStream(2048);
        inmem = true;
    }

    public CachedOutputStream(long threshold) {
        this.threshold = threshold; 
        currentStream = new LoadingByteArrayOutputStream(2048);
        inmem = true;
    }

    public void holdTempFile() {
        allowDeleteOfFile = false;
    }
    public void releaseTempFileHold() {
        allowDeleteOfFile = true;
    }
    
    public void registerCallback(CachedOutputStreamCallback cb) {
        if (null == callbacks) {
            callbacks = new ArrayList<CachedOutputStreamCallback>();
        }
        callbacks.add(cb);
    }
    
    public void deregisterCallback(CachedOutputStreamCallback cb) {
        if (null != callbacks) {
            callbacks.remove(cb);
        }
    }

    public List<CachedOutputStreamCallback> getCallbacks() {
        return callbacks == null ? null : Collections.unmodifiableList(callbacks);
    }

    /**
     * Perform any actions required on stream flush (freeze headers, reset
     * output stream ... etc.)
     */
    protected void doFlush() throws IOException {
        
    }

    public void flush() throws IOException {
        currentStream.flush();
        if (null != callbacks) {
            for (CachedOutputStreamCallback cb : callbacks) {
                cb.onFlush(this);
            }
        }
        doFlush();
    }

    /**
     * Perform any actions required on stream closure (handle response etc.)
     */
    protected void doClose() throws IOException {
        
    }
    
    /**
     * Perform any actions required after stream closure (close the other related stream etc.)
     */
    protected void postClose() throws IOException {
        
    }

    /**
     * Locks the output stream to prevent additional writes, but maintains
     * a pointer to it so an InputStream can be obtained
     * @throws IOException
     */
    public void lockOutputStream() throws IOException {
        if (outputLocked) {
            return;
        }
        currentStream.flush();
        outputLocked = true;
        if (null != callbacks) {
            for (CachedOutputStreamCallback cb : callbacks) {
                cb.onClose(this);
            }
        }
        doClose();
        streamList.remove(currentStream);
    }
    
    public void close() throws IOException {
        currentStream.flush();
        outputLocked = true;
        if (null != callbacks) {
            for (CachedOutputStreamCallback cb : callbacks) {
                cb.onClose(this);
            }
        }
        doClose();
        currentStream.close();
        maybeDeleteTempFile(currentStream);
        postClose();
    }

    public boolean equals(Object obj) {
        return currentStream.equals(obj);
    }

    /**
     * Replace the original stream with the new one, optionally copying the content of the old one
     * into the new one.
     * When with Attachment, needs to replace the xml writer stream with the stream used by
     * AttachmentSerializer or copy the cached output stream to the "real"
     * output stream, i.e. onto the wire.
     * 
     * @param out the new output stream
     * @param copyOldContent flag indicating if the old content should be copied
     * @throws IOException
     */
    public void resetOut(OutputStream out, boolean copyOldContent) throws IOException {
        if (out == null) {
            out = new ByteArrayOutputStream();
        }

        if (currentStream instanceof CachedOutputStream) {
            CachedOutputStream ac = (CachedOutputStream) currentStream;
            InputStream in = ac.getInputStream();
            IOUtils.copyAndCloseInput(in, out);
        } else {
            if (inmem) {
                if (currentStream instanceof ByteArrayOutputStream) {
                    ByteArrayOutputStream byteOut = (ByteArrayOutputStream) currentStream;
                    if (copyOldContent && byteOut.size() > 0) {
                        byteOut.writeTo(out);
                    }
                } else if (currentStream instanceof PipedOutputStream) {
                    PipedOutputStream pipeOut = (PipedOutputStream) currentStream;
                    IOUtils.copyAndCloseInput(new PipedInputStream(pipeOut), out);
                } else {
                    throw new IOException("Unknown format of currentStream");
                }
            } else {
                // read the file
                currentStream.close();
                if (copyOldContent) {
                    FileInputStream fin = new FileInputStream(tempFile);
                    IOUtils.copyAndCloseInput(fin, out);
                }
                streamList.remove(currentStream);
                tempFile.delete();
                tempFile = null;
                inmem = true;
            }
        }
        currentStream = out;
        outputLocked = false;
    }

    public static void copyStream(InputStream in, OutputStream out, int bufferSize) throws IOException {
        IOUtils.copyAndCloseInput(in, out, bufferSize);
    }

    public int size() {
        return totalLength;
    }

    public byte[] getBytes() throws IOException {
        flush();
        if (inmem) {
            if (currentStream instanceof ByteArrayOutputStream) {
                return ((ByteArrayOutputStream)currentStream).toByteArray();
            } else {
                throw new IOException("Unknown format of currentStream");
            }
        } else {
            // read the file
            FileInputStream fin = new FileInputStream(tempFile);
            return IOUtils.readBytesFromStream(fin);
        }
    }

    public void writeCacheTo(OutputStream out) throws IOException {
        flush();
        if (inmem) {
            if (currentStream instanceof ByteArrayOutputStream) {
                ((ByteArrayOutputStream)currentStream).writeTo(out);
            } else {
                throw new IOException("Unknown format of currentStream");
            }
        } else {
            // read the file
            FileInputStream fin = new FileInputStream(tempFile);
            IOUtils.copyAndCloseInput(fin, out);
        }
    }
    
    public void writeCacheTo(StringBuilder out, int limit) throws IOException {
        writeCacheTo(out, "UTF-8", limit);
    }
    
    public void writeCacheTo(StringBuilder out, String charsetName, int limit) throws IOException {
        flush();
        if (totalLength < limit
            || limit == -1) {
            writeCacheTo(out);
            return;
        }

        int count = 0;
        if (inmem) {
            if (currentStream instanceof ByteArrayOutputStream) {
                byte bytes[] = ((ByteArrayOutputStream)currentStream).toByteArray();
                out.append(IOUtils.newStringFromBytes(bytes, charsetName, 0, limit));
            } else {
                throw new IOException("Unknown format of currentStream");
            }
        } else {
            // read the file
            FileInputStream fin = new FileInputStream(tempFile);
            byte bytes[] = new byte[1024];
            int x = fin.read(bytes);
            while (x != -1) {
                if ((count + x) > limit) {
                    x = limit - count;
                }
                out.append(IOUtils.newStringFromBytes(bytes, charsetName, 0, x));
                count += x;

                if (count >= limit) {
                    x = -1;
                } else {
                    x = fin.read(bytes);
                }
            }
            fin.close();
        }
    }
    
    public void writeCacheTo(StringBuilder out) throws IOException {
        writeCacheTo(out, "UTF-8");
    }
    
    public void writeCacheTo(StringBuilder out, String charsetName) throws IOException {
        flush();
        if (inmem) {
            if (currentStream instanceof ByteArrayOutputStream) {
                byte[] bytes = ((ByteArrayOutputStream)currentStream).toByteArray();
                out.append(IOUtils.newStringFromBytes(bytes, charsetName));
            } else {
                throw new IOException("Unknown format of currentStream");
            }
        } else {
            // read the file
            FileInputStream fin = new FileInputStream(tempFile);
            byte bytes[] = new byte[1024];
            int x = fin.read(bytes);
            while (x != -1) {
                out.append(IOUtils.newStringFromBytes(bytes, charsetName, 0, x));
                x = fin.read(bytes);
            }
            fin.close();
        }
    }


    /**
     * @return the underlying output stream
     */
    public OutputStream getOut() {
        return currentStream;
    }

    public int hashCode() {
        return currentStream.hashCode();
    }

    public String toString() {
        StringBuilder builder = new StringBuilder().append("[")
            .append(CachedOutputStream.class.getName())
            .append(" Content: ");
        try {
            writeCacheTo(builder);
        } catch (IOException e) {
            //ignore
        }
        return builder.append("]").toString();
    }

    protected void onWrite() throws IOException {

    }

    public void write(byte[] b, int off, int len) throws IOException {
        if (!outputLocked) {
            onWrite();
            this.totalLength += len;
            if (inmem && totalLength > threshold && currentStream instanceof ByteArrayOutputStream) {
                createFileOutputStream();
            }
            currentStream.write(b, off, len);
        }
    }

    public void write(byte[] b) throws IOException {
        if (!outputLocked) {
            onWrite();
            this.totalLength += b.length;
            if (inmem && totalLength > threshold && currentStream instanceof ByteArrayOutputStream) {
                createFileOutputStream();
            }
            currentStream.write(b);
        }
    }

    public void write(int b) throws IOException {
        if (!outputLocked) {
            onWrite();
            this.totalLength++;
            if (inmem && totalLength > threshold && currentStream instanceof ByteArrayOutputStream) {
                createFileOutputStream();
            }
            currentStream.write(b);
        }
    }

    private void createFileOutputStream() throws IOException {
        if (tempFileFailed) {
            return;
        }
        ByteArrayOutputStream bout = (ByteArrayOutputStream)currentStream;
        try {
            if (outputDir == null) {
                tempFile = FileUtils.createTempFile("cos", "tmp");
            } else {
                tempFile = FileUtils.createTempFile("cos", "tmp", outputDir, false);
            }
            
            currentStream = new BufferedOutputStream(new FileOutputStream(tempFile));
            bout.writeTo(currentStream);
            inmem = false;
            streamList.add(currentStream);
        } catch (Exception ex) {
            //Could be IOException or SecurityException or other issues.
            //Don't care what, just keep it in memory.
            tempFileFailed = true;
            tempFile = null;
            inmem = true;
            currentStream = bout;
        }
    }

    public File getTempFile() {
        return tempFile != null && tempFile.exists() ? tempFile : null;
    }

    public InputStream getInputStream() throws IOException {
        flush();
        if (inmem) {
            if (currentStream instanceof LoadingByteArrayOutputStream) {
                return ((LoadingByteArrayOutputStream) currentStream).createInputStream();
            } else if (currentStream instanceof ByteArrayOutputStream) {
                return new ByteArrayInputStream(((ByteArrayOutputStream) currentStream).toByteArray());
            } else if (currentStream instanceof PipedOutputStream) {
                return new PipedInputStream((PipedOutputStream) currentStream);
            } else {
                return null;
            }
        } else {
            try {
                FileInputStream fileInputStream = new FileInputStream(tempFile) {
                    public void close() throws IOException {
                        super.close();
                        maybeDeleteTempFile(this);
                    }
                };
                streamList.add(fileInputStream);
                return fileInputStream;
            } catch (FileNotFoundException e) {
                throw new IOException("Cached file was deleted, " + e.toString());
            }
        }
    }
    
    private void maybeDeleteTempFile(Object stream) {
        streamList.remove(stream);
        if (!inmem && tempFile != null && streamList.isEmpty() && allowDeleteOfFile) {
            if (currentStream != null) {
                try {
                    currentStream.close();
                    postClose();
                } catch (Exception e) {
                    //ignore
                }
            }
            tempFile.delete();
            tempFile = null;
            currentStream = new LoadingByteArrayOutputStream(1024);
            inmem = true;
        }
    }

    public void setOutputDir(File outputDir) throws IOException {
        this.outputDir = outputDir;
    }
    public void setThreshold(long threshold) {
        this.threshold = threshold;
    }
}

Other Apache CXF examples (source code examples)

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