java获得当前路径下的绝对路径的方法，或者某一文件的绝对路径

import java.net.URL;
import java.security.CodeSource;
import java.security.ProtectionDomain;

public class TestPath {

public static void main(String[] args) {
ProtectionDomain domain = TestPath.class.getProtectionDomain();
CodeSource codeSource = domain.getCodeSource();
URL location = codeSource.getLocation();
String path = location.getPath();
System.out.println(path);

URL url = TestPath.class.getClassLoader().getResource("log4j.xml");
String aurl = url.getPath();
System.out.println(aurl);

URL pathUrl = TestPath.class.getResource("");
System.out.println(pathUrl.getPath());
}

}