console

javac Test.java && java -classpath . Test
enties for test.jar:
META-INF/
META-INF/MANIFEST.MF
Test.java
Done for test.jar
process jar tf test.jar: META-INF/
process jar tf test.jar: META-INF/MANIFEST.MF
process jar tf test.jar: Test.java
process zip -d test.jar Test.java: deleting: Test.java
process jar tf test.jar: META-INF/
process jar tf test.jar: META-INF/MANIFEST.MF
enties for test.jar:
META-INF/
META-INF/MANIFEST.MF
Test.java
Done for test.jar

Test.java

import java.io.*;
import java.util.jar.*;
import java.util.*;

public class Test {
  public static final void main(String[] args) throws Exception {
    exec("jar cf test.jar Test.java");
    print(new JarFile("test.jar"));

    exec("jar tf test.jar");
    exec("zip -d test.jar Test.java");
    exec("jar tf test.jar");

    print(new JarFile("test.jar"));
  }

  private static void exec(String cmd) throws Exception {
    Process p = Runtime.getRuntime().exec(cmd);
    p.waitFor();

    BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
    String line;
    while ((line = br.readLine()) != null) {
      System.out.println("process " + cmd + ": " +line);
    }
  }

  private static void print(JarFile jar) {
    System.out.println("enties for " + jar.getName() + ":");
    Enumeration<JarEntry> entries = jar.entries();
    while (entries.hasMoreElements()) {
      System.out.println(entries.nextElement().getName());
    }
    System.out.println("Done for " + jar.getName());
  }
}