/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
* This code is licensed under the GPL 2.0 license, availible at the root
* application directory.
*/
package org.vfny.geoserver.servlets;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.logging.Logger;
import javax.servlet.http.HttpServletResponse;
import org.geoserver.ows.DispatcherOutputStream;
import org.geoserver.ows.ServiceStrategy;
/**
* A safe ServiceConfig strategy that uses a temporary file until writeTo
* completes.
*
* @author $author$
* @version $Revision: 1.23 $
*/
public class FileStrategy implements ServiceStrategy {
public String getId() {
return "FILE";
}
/** Buffer size used to copy safe to response.getOutputStream() */
private static int BUFF_SIZE = 4096;
/** Temporary file number */
static int sequence = 0;
/** Class logger */
protected static Logger LOGGER = org.geotools.util.logging.Logging.getLogger("org.vfny.geoserver.servlets");
/** OutputStream provided to writeTo method */
private OutputStream safe;
/** Temporary file used by safe */
private File temp;
/**
* Provides a outputs stream on a temporary file.
*
* <p>
* I have changed this to use a BufferedWriter to agree with SpeedStrategy.
* </p>
*
* @param response Response being handled
*
* @return Outputstream for a temporary file
*
* @throws IOException If temporary file could not be created.
*/
public DispatcherOutputStream getDestination(HttpServletResponse response)
throws IOException {
// REVISIT: Should do more than sequence here
// (In case we are running two GeoServers at once)
// - Could we use response.getHandle() in the filename?
// - ProcessID is traditional, I don't know how to find that in Java
sequence++;
// lets check for file permissions first so we can throw a clear error
try {
temp = File.createTempFile("wfs" + sequence, "tmp");
if (!temp.canRead() || !temp.canWrite()) {
String errorMsg = "Temporary-file permission problem for location: "
+ temp.getPath();
throw new IOException(errorMsg);
}
} catch (IOException e) {
String errorMsg = "Possible file permission problem. Root cause: \n" + e.toString();
IOException newE = new IOException(errorMsg);
throw newE;
}
safe = new BufferedOutputStream(new FileOutputStream(temp));
return new DispatcherOutputStream(safe);
}
/**
* Closes safe output stream, copies resulting file to response.
*
* @throws IOException If temporay file or response is unavailable
* @throws IllegalStateException if flush is called before getDestination
*/
public void flush(HttpServletResponse response) throws IOException {
if ((temp == null) || (response == null) || (safe == null) || !temp.exists()) {
LOGGER.fine("temp is " + temp + ", response is " + response + " safe is " + safe
+ ", temp exists " + temp.exists());
throw new IllegalStateException("flush should only be called after getDestination");
}
InputStream copy = null;
try {
safe.flush();
safe.close();
safe = null;
// service succeeded in producing a response!
// copy result to the real output stream
copy = new BufferedInputStream(new FileInputStream(temp));
OutputStream out = response.getOutputStream();
out = new BufferedOutputStream(out, 1024 * 1024);
byte[] buffer = new byte[BUFF_SIZE];
int b;
while ((b = copy.read(buffer, 0, BUFF_SIZE)) > 0) {
out.write(buffer, 0, b);
}
// Speed Writer closes output Stream
// I would prefer to leave that up to doService...
out.flush();
// out.close();
} catch (IOException ioe) {
throw ioe;
} finally {
if (copy != null) {
try {
copy.close();
} catch (Exception ex) {
}
}
copy = null;
if ((temp != null) && temp.exists()) {
temp.delete();
}
temp = null;
response = null;
safe = null;
}
}
/**
* Clean up after writeTo fails.
*
* @see org.geoserver.ows.ServiceStrategy#abort()
*/
public void abort() {
if (safe != null) {
try {
safe.close();
} catch (IOException ioException) {
}
safe = null;
}
if ((temp != null) && temp.exists()) {
temp.delete();
}
temp = null;
}
public Object clone() throws CloneNotSupportedException {
return new FileStrategy();
}
}