Tuesday, February 14, 2012

Get files from Jar which is on the repository without downloading the whole Jar from Java

I would like to access the jar file on the repository, search inside it for the certain files, retrieve those files and store them on my hard disc. I don't want to download the whole jar and then to search for it.

So let's assume I have the address of the Jar. Can someone provide me with the code for the rest of the problem?

public void searchInsideJar(final String jarUrl, final String artifactId,
final String artifactVersion) {
InputStream is = null;
OutputStream outStream = null;
JarInputStream jis = null;
int i = 1;
try {
String strDirectory = "C:/Users/ilijab/" + artifactId +artifactVersion;

// Create one directory
boolean success = (new File(strDirectory)).mkdir();
if (success) {
System.out.println("Directory: " + strDirectory + " created");

is = new URL(jarUrl).openStream();
jis = new JarInputStream(is);

while (true) {
JarEntry ent = jis.getNextJarEntry();
if (ent == null) {
if (ent.isDirectory()) {
if (ent.getName().contains("someFile")) {
outStream = new BufferedOutputStream(new FileOutputStream(
strDirectory + "\\" + "someFile" + i));
} catch (Exception ex) {

So, in upper code, how can I save the file I found(the last if) into directory.

1 comment:

  1. Assuming that by "repository", you mean a Maven repository, then i'm afraid this can't be done. Maven repositories let you download artifacts, like jar files, but won't look inside them for you.