"jar -C" - Changing Input Directory

Java Tools Tutorials - Herong's Tutorial Examples

∟"jar -C" - Changing Input Directory

This section provides a tutorial example on how to 'jar --create -C ...' to change input directory when creating JAR files.

When create a new JAR file with the "jar --create" command, you can use the "-C ..." option to change the input directory from the current directory to the give directory.

The "-C ..." allows us to create a JAR file with all class files organized in a Java package directory tree.

To test this, I created the following Java source code, TempratureConvertorBean.java:

/* TempratureConvertorBean.java
 * Copyright (c) 2005 HerongYang.com. All Rights Reserved.
 */
package com.herongyang;
public class TempratureConvertorBean {
  private double celsius = 0.0;
  private double fahrenheit = 32.0;
  public double getCelsius() {
    return celsius;
  }
  public void setCelsius(double c) {
    celsius = c;
    fahrenheit = 1.8*c + 32.0;
  }
  public double getFahrenheit() {
    return fahrenheit;
  }
  public void setFahrenheit(double f) {
    fahrenheit = f;
    celsius = (f-32.0)/1.8;
  }
  public String getInfo() {
    return new String("My TempraturConvertorBean - Version 1.00");
  }
}

After compiling this source code, I got a Java package directory tree for the Java class file:

herong> mkdir .\cls

herong> javac -d .\cls TempratureConvertorBean.java

herong> tree /F .\cls
.\CLS
|---com
    |---herongyang
            TempratureConvertorBean.class

I used the "jar --create -C ..." command to create a JAR file, herong.jar:

herong> jar --create --verbose --file herong.jar -C .\cls .\com

added manifest
adding: com/(in = 0) (out= 0)(stored 0%)
adding: com/herongyang/(in = 0) (out= 0)(stored 0%)
adding: com/herongyang/TempratureConvertorBean.class(in = 806) (out= 462)

herong> jar --list --verbose --file herong.jar
     0 ... 2018 META-INF/
    66 ... 2018 META-INF/MANIFEST.MF
     0 ... 2018 com/
     0 ... 2018 com/herongyang/
   806 ... 2018 com/herongyang/TempratureConvertorBean.class

Notice that:

"jar --create" command added the manifest file automatically.
"-C .\cls .\com" option and input tells the "jar" command to change the working directory to ".\cls" first. Then archive the entire sub-directory tree of ".\com".