import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;
public final class JarResources {
Hashtable htSizes = new Hashtable();
Hashtable htJarContents = new Hashtable();
private String jarFileName;
public JarResources(String jarFileName) throws Exception {
this.jarFileName = jarFileName;
ZipFile zf = new ZipFile(jarFileName);
Enumeration e = zf.entries();
while (e.hasMoreElements()) {
ZipEntry ze = (ZipEntry) e.nextElement();
htSizes.put(ze.getName(), new Integer((int) ze.getSize()));
}
zf.close();
// extract resources and put them into the hashtable.
FileInputStream fis = new FileInputStream(jarFileName);
BufferedInputStream bis = new BufferedInputStream(fis);
ZipInputStream zis = new ZipInputStream(bis);
ZipEntry ze = null;
while ((ze = zis.getNextEntry()) != null) {
if (ze.isDirectory()) {
continue;
}
int size = (int) ze.getSize();
// -1 means unknown size.
if (size == -1) {
size = ((Integer) htSizes.get(ze.getName())).intValue();
}
byte[] b = new byte[(int) size];
int rb = 0;
int chunk = 0;
while (((int) size - rb) > 0) {
chunk = zis.read(b, rb, (int) size - rb);
if (chunk == -1) {
break;
}
rb += chunk;
}
htJarContents.put(ze.getName(), b);
}
}
public byte[] getResource(String name) {
return (byte[]) htJarContents.get(name);
}
private String dumpZipEntry(ZipEntry ze) {
StringBuffer sb = new StringBuffer();
if (ze.isDirectory()) {
sb.append("d ");
} else {
sb.append("f ");
}
if (ze.getMethod() == ZipEntry.STORED) {
sb.append("stored ");
} else {
sb.append("defalted ");
}
sb.append(ze.getName());
sb.append("\t");
sb.append("" + ze.getSize());
if (ze.getMethod() == ZipEntry.DEFLATED) {
sb.append("/" + ze.getCompressedSize());
}
return (sb.toString());
}
public static void main(String[] args) throws Exception {
JarResources jr = new JarResources("a.jar");
byte[] buff = jr.getResource("b.gif");
}
}