java 获取当前应用程序路径

package javaapplication1;

import javax.swing.JOptionPane;

/**
 *
 * @author Administrator
 */
public class JavaApplication1 {

    public  static String mystr;
    public  static  String str;

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here

      try{
          int len;
          mystr = java.net.URLDecoder.decode(JavaApplication1.class.getProtectionDomain().getCodeSource().getLocation().getFile().replaceAll("/", "\\\\"),"UTF-8");
          len = mystr.length();
          str = mystr.substring(1,len);
      }catch(java.io.UnsupportedEncodingException e){
        mystr = "";
        str="";
      }    

      JOptionPane.showMessageDialog(null, str);

    }

}