Trying to edit a property file in jar from a ear file. Best way to do it?

Question

I am thinking using truezip API in Java to manipulate with ear file by

1. extract ear into tmp directory,
2. then search through jars in tmp,
3. if found properties in jar,
4. then extract it into tmp,
5. modify that property
6. then pack it back into jar,
7. then pack jar back into ear.

OR is there a better way in using shell script?

Please advise.

Thanks

Answer 1

Using TrueZIP 7, you could use something like this:

public static void main(String args[]) throws IOException {
    // Remember to add the following dependencies to the class path:
    // Compile time artifactId(s): truezip-file
    // Run time artifactId(s): truezip-kernel, truezip-driver-file, truezip-driver-zip
    TFile.setDefaultArchiveDetector(new TDefaultArchiveDetector("ear|jar|war"));
    search(new TFile(args[0])); // e.g. "my.ear"
    TFile.umount(); // commit changes
}

private void search(TFile entry) throws IOException {
    if (entry.isDirectory()) {
        for (TFile member : dir.listFiles())
            search(member);
    } else if (entry.isFile()) {
        if (entry.getName().endsWith(".properties");
            update(entry);
    } // else is special file or non-existent
}

private void update(TFile file) throws IOException {
    Properties properties = new Properties();
    InputStream in = new TFileInputStream(file);
    try {
        properties.load(in);
    } finally {
        in.close();
    }
    // [your updates here]
    OutputStream out = new TFileOutputStream(file);
    try {
        properties.store(out, "updated");
    } finally {
        out.close();
    }
}

Answer 2

I used the answer from @Christian Schlichtherle to get me started on what I was trying to accomplish, but the usage of True Zip has changed quite a bit. I thought I'd post what I needed to do here to hopefully help someone.

You need to create a class that extends TApplication. In my case I'm making it abstract so I can reuse the setup code in my implementing logic classes.

Application.java:

import de.schlichtherle.truezip.file.TApplication;
import de.schlichtherle.truezip.file.TArchiveDetector;
import de.schlichtherle.truezip.file.TConfig;
import de.schlichtherle.truezip.fs.archive.zip.JarDriver;
import de.schlichtherle.truezip.fs.archive.zip.ZipDriver;
import de.schlichtherle.truezip.socket.sl.IOPoolLocator;

/**
 * An abstract class which configures the TrueZIP Path module.
 */
abstract class Application<E extends Exception> extends TApplication<E> {

    /**
     * Runs the setup phase.
     * <p>
     * This method is {@link #run run} only once at the start of the life
     * cycle.
     */
    @Override
    protected void setup() {
        TConfig.get().setArchiveDetector(
                new TArchiveDetector(
                    TArchiveDetector.NULL,
                    new Object[][] {
                        { "zip", new ZipDriver(IOPoolLocator.SINGLETON)},
                        { "ear|jar|war", new JarDriver(IOPoolLocator.SINGLETON)},
                    }));    
    }

}

Then you just extend the abstract class and implement the "work" method as shown.

ChangeProperty.java:

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Properties;
import java.util.ServiceConfigurationError;

import de.schlichtherle.truezip.file.TFile;
import de.schlichtherle.truezip.file.TFileInputStream;
import de.schlichtherle.truezip.file.TFileOutputStream;

public class ChangeProperty extends Application<IOException> {

    public static void main(String args[]) throws IOException {
        try {
            System.exit(new ChangeProperty().run(args));
        } catch (ServiceConfigurationError e) {
            // Ignore this error because what we wanted to accomplish has been done.
        }
    }

    private void search(TFile entry) throws IOException {
        System.out.println("Scanning: " + entry);
        if (entry.isDirectory()) {
            for (TFile member : entry.listFiles())
                search(member);
        } else if (entry.isFile()) {
            if (entry.getName().endsWith(".properties")) {
                update(entry);
            }
        }
    }

    private void update(TFile file) throws IOException {
        System.out.println("Updating: " + file);
        Properties properties = new Properties();
        InputStream in = new TFileInputStream(file);
        try {
            properties.load(in);
        } finally {
            in.close();
        }

        // [your updates here]
        // For example: properties.setProperty(key, newValue);

        OutputStream out = new TFileOutputStream(file);
        try {
            properties.store(out, "updated by loggerlevelchanger");
        } finally {
            out.close();
        }
    }

    @Override
    protected int work(String[] args) throws IOException {
        search(new TFile(args[0]));
        return 0;
    }
}