Example usage for java.util.jar JarFile getInputStream

List of usage examples for java.util.jar JarFile getInputStream

Introduction

In this page you can find the example usage for java.util.jar JarFile getInputStream.

Prototype

public synchronized InputStream getInputStream(ZipEntry ze) throws IOException 

Source Link

Document

Returns an input stream for reading the contents of the specified zip file entry.

Usage

From source file:com.flagleader.builder.BuilderConfig.java

public static void jarExtracting(String paramString1, String paramString2) {
    int i1 = 2048;
    BufferedOutputStream localBufferedOutputStream = null;
    BufferedInputStream localBufferedInputStream = null;
    JarEntry localJarEntry = null;
    JarFile localJarFile = null;
    Enumeration localEnumeration = null;
    try {//from   ww  w  . j av a 2s  .c  o m
        localJarFile = new JarFile(paramString2);
        localEnumeration = localJarFile.entries();
        while (localEnumeration.hasMoreElements()) {
            localJarEntry = (JarEntry) localEnumeration.nextElement();
            if (localJarEntry.isDirectory()) {
                new File(paramString1 + localJarEntry.getName()).mkdirs();
            } else {
                localBufferedInputStream = new BufferedInputStream(localJarFile.getInputStream(localJarEntry));
                byte[] arrayOfByte = new byte[i1];
                FileOutputStream localFileOutputStream = new FileOutputStream(
                        paramString1 + localJarEntry.getName());
                localBufferedOutputStream = new BufferedOutputStream(localFileOutputStream, i1);
                int i2;
                while ((i2 = localBufferedInputStream.read(arrayOfByte, 0, i1)) != -1)
                    localBufferedOutputStream.write(arrayOfByte, 0, i2);
                localBufferedOutputStream.flush();
                localBufferedOutputStream.close();
                localBufferedInputStream.close();
            }
        }
    } catch (Exception localException1) {
        localException1.printStackTrace();
        try {
            if (localBufferedOutputStream != null) {
                localBufferedOutputStream.flush();
                localBufferedOutputStream.close();
            }
            if (localBufferedInputStream != null)
                localBufferedInputStream.close();
        } catch (Exception localException2) {
            localException2.printStackTrace();
        }
    } finally {
        try {
            if (localBufferedOutputStream != null) {
                localBufferedOutputStream.flush();
                localBufferedOutputStream.close();
            }
            if (localBufferedInputStream != null)
                localBufferedInputStream.close();
        } catch (Exception localException3) {
            localException3.printStackTrace();
        }
    }
}

From source file:org.infoglue.deliver.portal.deploy.Deploy.java

/**
 * Prepare a portlet according to Pluto (switch web.xml)
 * //from  w w  w  .  ja  va2 s  .  com
 * @param file .war to prepare
 * @param tmp the resulting updated .war
 * @param appName name of application (context name)
 * @return the portlet application definition (portlet.xml)
 * @throws IOException
 */
public static PortletApplicationDefinition prepareArchive(File file, File tmp, String appName)
        throws IOException {
    PortletApplicationDefinitionImpl portletApp = null;
    try {
        Mapping pdmXml = new Mapping();
        try {
            URL url = Deploy.class.getResource("/" + PORTLET_MAPPING);
            pdmXml.loadMapping(url);
        } catch (Exception e) {
            throw new IOException("Failed to load mapping file " + PORTLET_MAPPING);
        }

        // Open the jar file.
        JarFile jar = new JarFile(file);

        // Extract and parse portlet.xml
        ZipEntry portletEntry = jar.getEntry(PORTLET_XML);
        if (portletEntry == null) {
            throw new IOException("Unable to find portlet.xml");
        }

        InputStream pisDebug = jar.getInputStream(portletEntry);
        StringBuffer sb = new StringBuffer();
        int i;
        while ((i = pisDebug.read()) > -1) {
            sb.append((char) i);
        }
        pisDebug.close();

        InputSource xmlSource = new InputSource(new ByteArrayInputStream(sb.toString().getBytes("UTF-8")));
        DOMParser parser = new DOMParser();
        parser.parse(xmlSource);
        Document portletDocument = parser.getDocument();

        //InputStream pis = jar.getInputStream(portletEntry);
        //Document portletDocument = XmlParser.parsePortletXml(pis);
        //pis.close();
        InputStream pis = jar.getInputStream(portletEntry);

        ZipEntry webEntry = jar.getEntry(WEB_XML);
        InputStream wis = null;
        if (webEntry != null) {
            wis = jar.getInputStream(webEntry);
            /*  webDocument = XmlParser.parseWebXml(wis);
            wis.close();
            */
        }

        Unmarshaller unmarshaller = new Unmarshaller(pdmXml);
        unmarshaller.setWhitespacePreserve(true);
        unmarshaller.setIgnoreExtraElements(true);
        unmarshaller.setIgnoreExtraAttributes(true);

        portletApp = (PortletApplicationDefinitionImpl) unmarshaller.unmarshal(portletDocument);

        // refill structure with necessary information
        Vector structure = new Vector();
        structure.add(appName);
        structure.add(null);
        structure.add(null);
        portletApp.preBuild(structure);

        /*
        // now generate web part
        WebApplicationDefinitionImpl webApp = null;
        if (webDocument != null) {
        Unmarshaller unmarshallerWeb = new Unmarshaller(sdmXml);
                
        // modified by YCLI: START :: to ignore extra elements and
        // attributes
        unmarshallerWeb.setWhitespacePreserve(true);
        unmarshallerWeb.setIgnoreExtraElements(true);
        unmarshallerWeb.setIgnoreExtraAttributes(true);
        // modified by YCLI: END
                
        webApp = (WebApplicationDefinitionImpl) unmarshallerWeb.unmarshal(webDocument);
        } else {
        webApp = new WebApplicationDefinitionImpl();
        DisplayNameImpl dispName = new DisplayNameImpl();
        dispName.setDisplayName(appName);
        dispName.setLocale(Locale.ENGLISH);
        DisplayNameSetImpl dispSet = new DisplayNameSetImpl();
        dispSet.add(dispName);
        webApp.setDisplayNames(dispSet);
        DescriptionImpl desc = new DescriptionImpl();
        desc.setDescription("Automated generated Application Wrapper");
        desc.setLocale(Locale.ENGLISH);
        DescriptionSetImpl descSet = new DescriptionSetImpl();
        descSet.add(desc);
        webApp.setDescriptions(descSet);
        }
                
        org.apache.pluto.om.ControllerFactory controllerFactory = new org.apache.pluto.portalImpl.om.ControllerFactoryImpl();
                
        ServletDefinitionListCtrl servletDefinitionSetCtrl = (ServletDefinitionListCtrl) controllerFactory
            .get(webApp.getServletDefinitionList());
        Collection servletMappings = webApp.getServletMappings();
                
        Iterator portlets = portletApp.getPortletDefinitionList().iterator();
        while (portlets.hasNext()) {
                
        PortletDefinition portlet = (PortletDefinition) portlets.next();
                
        // check if already exists
        ServletDefinition servlet = webApp.getServletDefinitionList()
                .get(portlet.getName());
        if (servlet != null) {
            ServletDefinitionCtrl _servletCtrl = (ServletDefinitionCtrl) controllerFactory
                    .get(servlet);
            _servletCtrl.setServletClass("org.apache.pluto.core.PortletServlet");
        } else {
            servlet = servletDefinitionSetCtrl.add(portlet.getName(),
                    "org.apache.pluto.core.PortletServlet");
        }
                
        ServletDefinitionCtrl servletCtrl = (ServletDefinitionCtrl) controllerFactory
                .get(servlet);
                
        DisplayNameImpl dispName = new DisplayNameImpl();
        dispName.setDisplayName(portlet.getName() + " Wrapper");
        dispName.setLocale(Locale.ENGLISH);
        DisplayNameSetImpl dispSet = new DisplayNameSetImpl();
        dispSet.add(dispName);
        servletCtrl.setDisplayNames(dispSet);
        DescriptionImpl desc = new DescriptionImpl();
        desc.setDescription("Automated generated Portlet Wrapper");
        desc.setLocale(Locale.ENGLISH);
        DescriptionSetImpl descSet = new DescriptionSetImpl();
        descSet.add(desc);
        servletCtrl.setDescriptions(descSet);
        ParameterSet parameters = servlet.getInitParameterSet();
                
        ParameterSetCtrl parameterSetCtrl = (ParameterSetCtrl) controllerFactory
                .get(parameters);
                
        Parameter parameter1 = parameters.get("portlet-class");
        if (parameter1 == null) {
            parameterSetCtrl.add("portlet-class", portlet.getClassName());
        } else {
            ParameterCtrl parameterCtrl = (ParameterCtrl) controllerFactory.get(parameter1);
            parameterCtrl.setValue(portlet.getClassName());
                
        }
        Parameter parameter2 = parameters.get("portlet-guid");
        if (parameter2 == null) {
            parameterSetCtrl.add("portlet-guid", portlet.getId().toString());
        } else {
            ParameterCtrl parameterCtrl = (ParameterCtrl) controllerFactory.get(parameter2);
            parameterCtrl.setValue(portlet.getId().toString());
                
        }
                
        boolean found = false;
        Iterator mappings = servletMappings.iterator();
        while (mappings.hasNext()) {
            ServletMappingImpl servletMapping = (ServletMappingImpl) mappings.next();
            if (servletMapping.getServletName().equals(portlet.getName())) {
                found = true;
                servletMapping.setUrlPattern("/" + portlet.getName().replace(' ', '_')
                        + "/*");
            }
        }
        if (!found) {
            ServletMappingImpl servletMapping = new ServletMappingImpl();
            servletMapping.setServletName(portlet.getName());
            servletMapping.setUrlPattern("/" + portlet.getName().replace(' ', '_') + "/*");
            servletMappings.add(servletMapping);
        }
                
        SecurityRoleRefSet servletSecurityRoleRefs = ((ServletDefinitionImpl) servlet)
                .getInitSecurityRoleRefSet();
                
        SecurityRoleRefSetCtrl servletSecurityRoleRefSetCtrl = (SecurityRoleRefSetCtrl) controllerFactory
                .get(servletSecurityRoleRefs);
                
        SecurityRoleSet webAppSecurityRoles = webApp.getSecurityRoles();
                
        SecurityRoleRefSet portletSecurityRoleRefs = portlet.getInitSecurityRoleRefSet();
                
        Iterator p = portletSecurityRoleRefs.iterator();
        while (p.hasNext()) {
            SecurityRoleRef portletSecurityRoleRef = (SecurityRoleRef) p.next();
                
            if (portletSecurityRoleRef.getRoleLink() == null
                    && webAppSecurityRoles.get(portletSecurityRoleRef.getRoleName()) == null) {
                logger.info("Note: The web application has no security role defined which matches the role name \""
                                + portletSecurityRoleRef.getRoleName()
                                + "\" of the security-role-ref element defined for the wrapper-servlet with the name '"
                                + portlet.getName() + "'.");
                break;
            }
            SecurityRoleRef servletSecurityRoleRef = servletSecurityRoleRefs
                    .get(portletSecurityRoleRef.getRoleName());
            if (null != servletSecurityRoleRef) {
                logger.info("Note: Replaced already existing element of type <security-role-ref> with value \""
                                + portletSecurityRoleRef.getRoleName()
                                + "\" for subelement of type <role-name> for the wrapper-servlet with the name '"
                                + portlet.getName() + "'.");
                servletSecurityRoleRefSetCtrl.remove(servletSecurityRoleRef);
            }
            servletSecurityRoleRefSetCtrl.add(portletSecurityRoleRef);
        }
                
        }
        */

        /*
         * TODO is this necessary? TagDefinitionImpl portletTagLib = new
         * TagDefinitionImpl(); Collection taglibs =
         * webApp.getCastorTagDefinitions(); taglibs.add(portletTagLib);
         */

        // Duplicate jar-file with replaced web.xml
        FileOutputStream fos = new FileOutputStream(tmp);
        JarOutputStream tempJar = new JarOutputStream(fos);
        byte[] buffer = new byte[1024];
        int bytesRead;
        for (Enumeration entries = jar.entries(); entries.hasMoreElements();) {
            JarEntry entry = (JarEntry) entries.nextElement();
            JarEntry newEntry = new JarEntry(entry.getName());
            tempJar.putNextEntry(newEntry);

            if (entry.getName().equals(WEB_XML)) {
                // Swap web.xml
                /*
                log.debug("Swapping web.xml");
                OutputFormat of = new OutputFormat();
                of.setIndenting(true);
                of.setIndent(4); // 2-space indention
                of.setLineWidth(16384);
                of.setDoctype(Constants.WEB_PORTLET_PUBLIC_ID, Constants.WEB_PORTLET_DTD);
                        
                XMLSerializer serializer = new XMLSerializer(tempJar, of);
                Marshaller marshaller = new Marshaller(serializer.asDocumentHandler());
                marshaller.setMapping(sdmXml);
                marshaller.marshal(webApp);
                */

                PortletAppDescriptorService portletAppDescriptorService = new StreamPortletAppDescriptorServiceImpl(
                        appName, pis, null);
                File tmpf = File.createTempFile("infoglue-web-xml", null);
                WebAppDescriptorService webAppDescriptorService = new StreamWebAppDescriptorServiceImpl(appName,
                        wis, new FileOutputStream(tmpf));

                org.apache.pluto.driver.deploy.Deploy d = new org.apache.pluto.driver.deploy.Deploy(
                        webAppDescriptorService, portletAppDescriptorService);
                d.updateDescriptors();
                FileInputStream fis = new FileInputStream(tmpf);
                while ((bytesRead = fis.read(buffer)) != -1) {
                    tempJar.write(buffer, 0, bytesRead);
                }
                tmpf.delete();
            } else {
                InputStream entryStream = jar.getInputStream(entry);
                if (entryStream != null) {
                    while ((bytesRead = entryStream.read(buffer)) != -1) {
                        tempJar.write(buffer, 0, bytesRead);
                    }
                }
            }
        }
        tempJar.flush();
        tempJar.close();
        fos.flush();
        fos.close();
        /*
         * String strTo = dirDelim + "WEB-INF" + dirDelim + "tld" + dirDelim +
         * "portlet.tld"; String strFrom = "webapps" + dirDelim + strTo;
         * 
         * copy(strFrom, webAppsDir + webModule + strTo);
         */
    } catch (Exception e) {
        log.error("Failed to prepare archive", e);
        throw new IOException(e.getMessage());
    }

    return portletApp;
}

From source file:io.joynr.util.JoynrUtil.java

public static void copyDirectoryFromJar(String jarName, String srcDir, File tmpDir) throws IOException {

    JarFile jf = null;
    JarInputStream jarInputStream = null;

    try {/*from w ww. ja v  a2 s .  com*/
        jf = new JarFile(jarName);
        JarEntry je = jf.getJarEntry(srcDir);
        if (je.isDirectory()) {
            FileInputStream fis = new FileInputStream(jarName);
            BufferedInputStream bis = new BufferedInputStream(fis);
            jarInputStream = new JarInputStream(bis);
            JarEntry ze = null;
            while ((ze = jarInputStream.getNextJarEntry()) != null) {
                if (ze.isDirectory()) {
                    continue;
                }
                if (ze.getName().contains(je.getName())) {
                    InputStream is = jf.getInputStream(ze);
                    String name = ze.getName().substring(ze.getName().lastIndexOf("/") + 1);
                    File tmpFile = new File(tmpDir + "/" + name); //File.createTempFile(file.getName(), "tmp");
                    tmpFile.deleteOnExit();
                    OutputStream outputStreamRuntime = new FileOutputStream(tmpFile);
                    copyStream(is, outputStreamRuntime);
                }
            }
        }
    } finally {
        if (jf != null) {
            jf.close();
        }
        if (jarInputStream != null) {
            jarInputStream.close();
        }
    }
}

From source file:edu.stanford.muse.email.JarDocCache.java

/** returns a jar outputstream for the given filename.
 * copies over jar entries if the file was already existing.
 * unfortunately, we can't append to the end of a jar file easily.
 * see e.g.http://stackoverflow.com/questions/2223434/appending-files-to-a-zip-file-with-java
 * and http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4129445
 * may consider using truezip at some point, but the doc is dense.
 *//*from w  ww .  jav a  2 s  .  co m*/
private static JarOutputStream appendOrCreateJar(String filename) throws IOException {
    JarOutputStream jos;
    File f = new File(filename);
    if (!f.exists())
        return new JarOutputStream(new BufferedOutputStream(new FileOutputStream(filename)));

    // bak* is going to be all the previous file entries
    String bakFilename = filename + ".bak";
    File bakFile = new File(bakFilename);
    f.renameTo(new File(bakFilename));
    jos = new JarOutputStream(new BufferedOutputStream(new FileOutputStream(filename)));
    JarFile bakJF;
    try {
        bakJF = new JarFile(bakFilename);
    } catch (Exception e) {
        log.warn("Bad jar file! " + bakFilename + " size " + new File(filename).length() + " bytes");
        Util.print_exception(e, log);
        return new JarOutputStream(new BufferedOutputStream(new FileOutputStream(filename)));
    }

    // copy all entries from bakJF to jos
    Enumeration<JarEntry> bakEntries = bakJF.entries();
    while (bakEntries.hasMoreElements()) {
        JarEntry je = bakEntries.nextElement();
        jos.putNextEntry(je);
        InputStream is = bakJF.getInputStream(je);

        // copy over everything from is to jos
        byte buf[] = new byte[32 * 1024]; // randomly 32K
        int nBytes;
        while ((nBytes = is.read(buf)) != -1)
            jos.write(buf, 0, nBytes);

        jos.closeEntry();
    }
    bakFile.delete();

    return jos;
}

From source file:org.apache.storm.utils.ServerUtils.java

/**
 * Unpack matching files from a jar. Entries inside the jar that do
 * not match the given pattern will be skipped.
 *
 * @param jarFile the .jar file to unpack
 * @param toDir the destination directory into which to unpack the jar
 *///w w w  .  ja  v a 2  s.  com
public static void unJar(File jarFile, File toDir) throws IOException {
    JarFile jar = new JarFile(jarFile);
    try {
        Enumeration<JarEntry> entries = jar.entries();
        while (entries.hasMoreElements()) {
            final JarEntry entry = entries.nextElement();
            if (!entry.isDirectory()) {
                InputStream in = jar.getInputStream(entry);
                try {
                    File file = new File(toDir, entry.getName());
                    ensureDirectory(file.getParentFile());
                    OutputStream out = new FileOutputStream(file);
                    try {
                        copyBytes(in, out, 8192);
                    } finally {
                        out.close();
                    }
                } finally {
                    in.close();
                }
            }
        }
    } finally {
        jar.close();
    }
}

From source file:edu.uci.ics.asterix.event.service.AsterixEventServiceUtil.java

private static void replaceInJar(File sourceJar, String origFile, File replacementFile) throws IOException {
    String srcJarAbsPath = sourceJar.getAbsolutePath();
    String srcJarSuffix = srcJarAbsPath.substring(srcJarAbsPath.lastIndexOf(File.separator) + 1);
    String srcJarName = srcJarSuffix.split(".jar")[0];

    String destJarName = srcJarName + "-managix";
    String destJarSuffix = destJarName + ".jar";
    File destJar = new File(sourceJar.getParentFile().getAbsolutePath() + File.separator + destJarSuffix);
    //  File destJar = new File(sourceJar.getAbsolutePath() + ".modified");
    JarFile sourceJarFile = new JarFile(sourceJar);
    Enumeration<JarEntry> entries = sourceJarFile.entries();
    JarOutputStream jos = new JarOutputStream(new FileOutputStream(destJar));
    byte[] buffer = new byte[2048];
    int read;//from  ww  w  .  j a va 2s. c om
    while (entries.hasMoreElements()) {
        JarEntry entry = (JarEntry) entries.nextElement();
        String name = entry.getName();
        if (name.equals(origFile)) {
            continue;
        }
        InputStream jarIs = sourceJarFile.getInputStream(entry);
        jos.putNextEntry(entry);
        while ((read = jarIs.read(buffer)) != -1) {
            jos.write(buffer, 0, read);
        }
        jarIs.close();
    }
    sourceJarFile.close();
    JarEntry entry = new JarEntry(origFile);
    jos.putNextEntry(entry);
    FileInputStream fis = new FileInputStream(replacementFile);
    while ((read = fis.read(buffer)) != -1) {
        jos.write(buffer, 0, read);
    }
    fis.close();
    jos.close();
    sourceJar.delete();
    destJar.renameTo(sourceJar);
    destJar.setExecutable(true);
}

From source file:net.sf.keystore_explorer.crypto.signing.JarSigner.java

private static String getManifest(JarFile jar) throws IOException {

    JarEntry manifestEntry = jar.getJarEntry(MANIFEST_LOCATION);

    InputStream jis = null;/*from  www  .j av a 2s  .c o  m*/
    ByteArrayOutputStream baos = null;

    try {
        jis = jar.getInputStream(manifestEntry);
        baos = new ByteArrayOutputStream();

        CopyUtil.copyClose(jis, baos);
        baos.close();

        String manifest = baos.toString();

        return manifest;
    } finally {
        IOUtils.closeQuietly(jis);
        IOUtils.closeQuietly(baos);
    }
}

From source file:org.kse.crypto.jcepolicy.JcePolicyUtil.java

/**
 * Get a JCE policy's details./*from  ww  w. ja v a  2  s  .  co  m*/
 *
 * @param jcePolicy
 *            JCE policy
 * @return Policy details
 * @throws CryptoException
 *             If there was a problem getting the policy details
 */
public static String getPolicyDetails(JcePolicy jcePolicy) throws CryptoException {
    JarFile jarFile = null;
    try {
        StringWriter sw = new StringWriter();

        File file = getJarFile(jcePolicy);

        // if there is no policy file at all, return empty string
        if (!file.exists()) {
            return "";
        }

        jarFile = new JarFile(file);

        Enumeration<JarEntry> jarEntries = jarFile.entries();

        while (jarEntries.hasMoreElements()) {
            JarEntry jarEntry = jarEntries.nextElement();

            String entryName = jarEntry.getName();

            if (!jarEntry.isDirectory() && entryName.endsWith(".policy")) {
                sw.write(entryName + ":\n\n");

                InputStreamReader isr = null;
                try {
                    isr = new InputStreamReader(jarFile.getInputStream(jarEntry));
                    CopyUtil.copy(isr, sw);
                } finally {
                    IOUtils.closeQuietly(isr);
                }

                sw.write('\n');
            }
        }

        return sw.toString();
    } catch (IOException ex) {
        throw new CryptoException(
                MessageFormat.format(res.getString("NoGetPolicyDetails.exception.message"), jcePolicy), ex);
    } finally {
        IOUtils.closeQuietly(jarFile);
    }
}

From source file:com.elastica.helper.FileUtility.java

public static void extractJar(final String storeLocation, final Class<?> clz) throws IOException {
    File firefoxProfile = new File(storeLocation);
    String location = clz.getProtectionDomain().getCodeSource().getLocation().getFile();

    JarFile jar = new JarFile(location);
    System.out.println("Extracting jar file::: " + location);
    firefoxProfile.mkdir();//from w w w  .  jav  a 2  s .  c  o  m

    Enumeration<?> jarFiles = jar.entries();
    while (jarFiles.hasMoreElements()) {
        ZipEntry entry = (ZipEntry) jarFiles.nextElement();
        String currentEntry = entry.getName();
        File destinationFile = new File(storeLocation, currentEntry);
        File destinationParent = destinationFile.getParentFile();

        // create the parent directory structure if required
        destinationParent.mkdirs();
        if (!entry.isDirectory()) {
            BufferedInputStream is = new BufferedInputStream(jar.getInputStream(entry));
            int currentByte;

            // buffer for writing file
            byte[] data = new byte[BUFFER];

            // write the current file to disk
            FileOutputStream fos = new FileOutputStream(destinationFile);
            BufferedOutputStream destination = new BufferedOutputStream(fos, BUFFER);

            // read and write till last byte
            while ((currentByte = is.read(data, 0, BUFFER)) != -1) {
                destination.write(data, 0, currentByte);
            }

            destination.flush();
            destination.close();
            is.close();
        }
    }

    FileUtils.deleteDirectory(new File(storeLocation + "\\META-INF"));
    if (OSUtility.isWindows()) {
        new File(storeLocation + "\\" + clz.getCanonicalName().replaceAll("\\.", "\\\\") + ".class").delete();
    } else {
        new File(storeLocation + "/" + clz.getCanonicalName().replaceAll("\\.", "/") + ".class").delete();
    }
}

From source file:JarUtil.java

/**
 * Extracts the given resource from a jar-file to the specified directory.
 * // w  ww  . j  a v  a  2  s.  c o m
 * @param jarFile
 *            The jar file which should be unpacked
 * @param resource
 *            The name of a resource in the jar
 * @param targetDir
 *            The directory to which the jar-content should be extracted.
 * @throws FileNotFoundException
 *             when the jarFile does not exist
 * @throws IOException
 *             when a file could not be written or the jar-file could not
 *             read.
 */
public static void unjar(File jarFile, String resource, File targetDir)
        throws FileNotFoundException, IOException {
    // clear target directory:
    if (targetDir.exists()) {
        targetDir.delete();
    }
    // create new target directory:
    targetDir.mkdirs();
    // read jar-file:
    String targetPath = targetDir.getAbsolutePath() + File.separatorChar;
    byte[] buffer = new byte[1024 * 1024];
    JarFile input = new JarFile(jarFile, false, ZipFile.OPEN_READ);
    Enumeration<JarEntry> enumeration = input.entries();
    for (; enumeration.hasMoreElements();) {
        JarEntry entry = enumeration.nextElement();
        if (!entry.isDirectory()) {
            // do not copy anything from the package cache:
            if (entry.getName().equals(resource)) {
                String path = targetPath + entry.getName();
                File file = new File(path);
                if (!file.getParentFile().exists()) {
                    file.getParentFile().mkdirs();
                }
                FileOutputStream out = new FileOutputStream(file);
                InputStream in = input.getInputStream(entry);
                int read;
                while ((read = in.read(buffer)) != -1) {
                    out.write(buffer, 0, read);
                }
                in.close();
                out.close();
            }
        }
    }
}