/** Returns a JarDiff for the given request */
public synchronized DownloadResponse getJarDiffEntry(
ResourceCatalog catalog, DownloadRequest dreq, JnlpResource res) {
if (dreq.getCurrentVersionId() == null) return null;
// check whether the request is from javaws 1.0/1.0.1
// do not generate minimal jardiff if it is from 1.0/1.0.1
boolean doJarDiffWorkAround = isJavawsVersion(dreq, "1.0*");
// First do a lookup to find a match
JarDiffKey key =
new JarDiffKey(
res.getName(),
dreq.getCurrentVersionId(),
res.getReturnVersionId(),
!doJarDiffWorkAround);
JarDiffEntry entry = (JarDiffEntry) _jarDiffEntries.get(key);
// If entry is not found, then the querty has not been made.
if (entry == null) {
if (_log.isInformationalLevel()) {
_log.addInformational(
"servlet.log.info.jardiff.gen",
res.getName(),
dreq.getCurrentVersionId(),
res.getReturnVersionId());
}
File f = generateJarDiff(catalog, dreq, res, doJarDiffWorkAround);
if (f == null) {
_log.addWarning(
"servlet.log.warning.jardiff.failed",
res.getName(),
dreq.getCurrentVersionId(),
res.getReturnVersionId());
}
// Store entry in table
entry = new JarDiffEntry(f);
_jarDiffEntries.put(key, entry);
}
// Check for no JarDiff to return
if (entry.getJarDiffFile() == null) {
return null;
} else {
return DownloadResponse.getFileDownloadResponse(
entry.getJarDiffFile(),
_jarDiffMimeType,
entry.getJarDiffFile().lastModified(),
res.getReturnVersionId());
}
}
public static boolean isJavawsVersion(DownloadRequest dreq, String version) {
String javawsAgent = "javaws";
String jwsVer = dreq.getHttpRequest().getHeader("User-Agent");
// check the request is coming from javaws
if (!jwsVer.startsWith("javaws-")) {
// this is the new style User-Agent string
// User-Agent: JNLP/1.0.1 javaws/1.4.2 (b28) J2SE/1.4.2
StringTokenizer st = new StringTokenizer(jwsVer);
while (st.hasMoreTokens()) {
String verString = st.nextToken();
int index = verString.indexOf(javawsAgent);
if (index != -1) {
verString = verString.substring(index + javawsAgent.length() + 1);
return VersionString.contains(version, verString);
}
}
return false;
}
// extract the version id from the download request
int startIndex = jwsVer.indexOf("-");
if (startIndex == -1) {
return false;
}
int endIndex = jwsVer.indexOf("/");
if (endIndex == -1 || endIndex < startIndex) {
return false;
}
String verId = jwsVer.substring(startIndex + 1, endIndex);
// check whether the versionString contains the versionId
return VersionString.contains(version, verId);
}
private File generateJarDiff(
ResourceCatalog catalog,
DownloadRequest dreq,
JnlpResource res,
boolean doJarDiffWorkAround) {
boolean del_old = false;
boolean del_new = false;
// Lookup up file for request version
DownloadRequest fromDreq = dreq.getFromDownloadRequest();
try {
JnlpResource fromRes = catalog.lookupResource(fromDreq);
/* Get file locations */
String newFilePath = _servletContext.getRealPath(res.getPath());
String oldFilePath = _servletContext.getRealPath(fromRes.getPath());
// fix for 4720897
if (newFilePath == null) {
newFilePath = getRealPath(res.getPath());
if (newFilePath != null) del_new = true;
}
if (oldFilePath == null) {
oldFilePath = getRealPath(fromRes.getPath());
if (oldFilePath != null) del_old = true;
}
if (newFilePath == null || oldFilePath == null) {
return null;
}
// Create temp. file to store JarDiff file in
File tempDir = (File) _servletContext.getAttribute("javax.servlet.context.tempdir");
// fix for 4653036: JarDiffHandler() should use javax.servlet.context.tempdir to store the
// jardiff
File outputFile = File.createTempFile("jnlp", ".jardiff", tempDir);
_log.addDebug(
"Generating Jardiff between "
+ oldFilePath
+ " and "
+ newFilePath
+ " Store in "
+ outputFile);
// Generate JarDiff
OutputStream os = new FileOutputStream(outputFile);
JarDiff.createPatch(oldFilePath, newFilePath, os, !doJarDiffWorkAround);
os.close();
try {
// Check that Jardiff is smaller, or return null
if (outputFile.length() >= (new File(newFilePath).length())) {
_log.addDebug("JarDiff discarded - since it is bigger");
return null;
}
// Check that Jardiff is smaller than the packed version of
// the new file, if the file exists at all
File newFilePacked = new File(newFilePath + ".pack.gz");
if (newFilePacked.exists()) {
_log.addDebug("generated jardiff size: " + outputFile.length());
_log.addDebug("packed requesting file size: " + newFilePacked.length());
if (outputFile.length() >= newFilePacked.length()) {
_log.addDebug("JarDiff discarded - packed version of requesting file is smaller");
return null;
}
}
_log.addDebug("JarDiff generation succeeded");
return outputFile;
} finally {
// delete the temporarily downloaded file
if (del_new) {
new File(newFilePath).delete();
}
if (del_old) {
new File(oldFilePath).delete();
}
}
} catch (IOException ioe) {
_log.addDebug("Failed to genereate jardiff", ioe);
return null;
} catch (ErrorResponseException ere) {
_log.addDebug("Failed to genereate jardiff", ere);
return null;
}
}