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/**********************************************************************
* Jhove - JSTOR/Harvard Object Validation Environment
* Copyright 2003 by JSTOR and the President and Fellows of Harvard College
*
**********************************************************************/
package edu.harvard.hul.ois.jhove;
import java.io.*;
import java.util.*;
import javax.swing.*;
import edu.harvard.hul.ois.jhove.viewer.ConfigWindow;
/**
*
* Class to write out configuration information to the configuration file.
* To minimize the chance of getting into a bad state, it writes to a
* temporary file, then replaces the old config file with that file,
* rather than directly overwriting the existing file.
*
* @author Gary McGath
*
*/
public class ConfigWriter {
private PrintWriter _confOut;
private File _tempFile;
private File _confFile;
ConfigWindow _parent;
private final static String CLASS_TAG_START = " ";
private final static String CLASS_TAG_CLOSE = " ";
/**
* Constructor.
* Creates a temporary file for writing and creates an OutputStreamWriter
* to write to it. If there is already a file located by
* file, it will not be replaced or overwritten
* until writeFile has successfully written out
* the temporary file.
*
* @param file Location of the configuration file
*
* @param parent The ConfigWindow which invoked this instance.
* May be null if invoked to write a default config file.
*/
public ConfigWriter (File file, ConfigWindow parent) throws IOException
{
_confFile = file;
_parent = parent;
// Set up a temporary file to write to.
String path = file.getParent();
file.getParentFile().mkdirs(); // Make sure the directory exists
_tempFile = File.createTempFile ("jho", ".conf", new File (path));
//_tempFile.createNewFile();
FileOutputStream ostrm = new FileOutputStream (_tempFile);
OutputStreamWriter osw = new OutputStreamWriter (ostrm, "UTF-8");
_confOut = new PrintWriter (osw);
}
/**
* Writes out the content of the file to the temporary file,
* then deletes the existing configuration file (as specified
* by the constructor parameter) and renames the temporary file
* to the configuration file.
*
* If the temporary file can't be written, or the configuration
* file can't be replaced, a warning dialog is put up and the
* configuration file remains unchanged.
*/
public void writeFile (List modules,
List handlers,
File homeDir,
File tempDir,
String encoding,
int bufferSize)
{
writeHead ();
// Write the home and temp directories. Home must always be valid.
_confOut.println (" " +
encodeContent (homeDir.getPath ()) +
" ");
// Write out the encoding
if (encoding != null && encoding.length() > 0) {
_confOut.println (" " +
encodeContent (encoding) + " ");
}
if (tempDir != null) {
_confOut.println (" " +
encodeContent (tempDir.getPath ()) +
" ");
}
// Write the buffer size if not default
if (bufferSize > 0) {
_confOut.println (" " + bufferSize +
" ");
}
// Write out the modules
ListIterator iter = modules.listIterator ();
while (iter.hasNext ()) {
ModuleInfo minfo = iter.next ();
// The class must be non-null, but init may be null.
// If the class is empty, it's a user error (probably
// clicked "Add" and then lost track of it). Don't
// write it out.
if (!"".equals (minfo.clas)) {
_confOut.println (" ");
_confOut.println (CLASS_TAG_START + encodeContent (minfo.clas) +
CLASS_TAG_CLOSE);
if (minfo.init != null && minfo.init.length () > 0) {
_confOut.println (" " + encodeContent (minfo.init) +
" ");
}
/** tuple[2] and beyond are parameters */
if (minfo.params != null) {
for (int i = 0; i < minfo.params.length; i++) {
_confOut.println (" " + encodeContent(minfo.params[i]) +
"");
}
}
_confOut.println (" ");
}
}
// Write out the handlers
ListIterator hiter = handlers.listIterator ();
while (hiter.hasNext ()) {
String handler = hiter.next ()[0];
if (handler.length() > 0) { // Don't write out blank handler names
_confOut.println (" ");
_confOut.println (CLASS_TAG_START + encodeContent (handler) +
CLASS_TAG_CLOSE);
_confOut.println (" ");
}
}
writeTail ();
_confOut.close ();
// Replace the old file with the new.
if (_confFile.exists () && !_confFile.delete ()) {
if (_parent != null) {
JOptionPane.showMessageDialog(_parent,
"Can't replace old config file",
"Error",
JOptionPane.ERROR_MESSAGE);
}
_tempFile.delete ();
}
else {
_tempFile.renameTo (_confFile);
}
}
/* Write the fixed lines which begin the config file */
private void writeHead ()
{
_confOut.println("");
_confOut.println("");
}
/* Write out the fixed end of the config file */
private void writeTail ()
{
_confOut.println(" ");
}
/**
* Encodes a content String in XML-clean form, converting characters
* to entities as necessary. The null string will be
* converted to an empty string.
*/
private static String encodeContent (String content)
{
if (content == null) {
content = "";
}
StringBuffer buffer = new StringBuffer (content);
int n = 0;
while ((n = buffer.indexOf ("&", n)) > -1) {
buffer.insert (n+1, "amp;");
n +=5;
}
n = 0;
while ((n = buffer.indexOf ("<", n)) > -1) {
buffer.replace (n, n+1, "<");
n += 4;
}
n = 0;
while ((n = buffer.indexOf (">", n)) > -1) {
buffer.replace (n, n+1, ">");
n += 4;
}
return buffer.toString ();
}
}