Java obtains the code example of the current directory

Current Directory code

The code is as follows:	Copy code
Import java. io .*; Public class Test { Public static void main (String [] args ){ System. out. println ("Current Working Dir:" + new File (""). getAbsolutePath ()); System. out. println ("Current Working Dir:" + System. getProperty ("user. dir "));         } }

Obtain the path of the current jar package

After testing, whether it is a Jar package or Tomcat deployment, the following three methods can be implemented.
 

The code is as follows:

Copy code

Package test;   Public class MyPath { Public static String getProjectPath (){   Java.net. URL url = MyPath. class. getProtectionDomain (). getCodeSource (). getLocation (); String filePath = null; Try { FilePath = java.net. URLDecoder. decode (url. getPath (), "UTF-8 "); } Catch (Exception e ){ E. printStackTrace ();        } If (filePath. endsWith (". jar ")) FilePath = filePath. substring (0, filePath. lastIndexOf ("/") + 1 ); Java. io. File file = new java. io. File (filePath ); FilePath = file. getAbsolutePath (); Return filePath; }   Public static String getRealPath (){ String realPath = MyPath. class. getClassLoader (). getResource (""). getFile (); Java. io. File file = new java. io. File (realPath ); RealPath = file. getAbsolutePath (); Try { RealPath = java.net. URLDecoder. decode (realPath, "UTF-8 "); } Catch (Exception e ){ E. printStackTrace ();        }   Return realPath;     }   Public static String getAppPath (Class <?> Cls ){ // Check whether User-passed parameters are null If (cls = null) Throw new java. lang. IllegalArgumentException ("The parameter cannot be blank! ");   ClassLoader loader = cls. getClassLoader (); // Obtain the full name of the class, including the package name String clsName = cls. getName (); // Check whether the SDK is a Java Base Class Library to prevent users from passing in the built-in JDK class library. If (clsName. startsWith ("java.") | clsName. startsWith ("javax .")){ Throw new java. lang. IllegalArgumentException ("do not transmit the system class! ");         } // Change the full name of the class file to the path format String clsPath = clsName. replace (".", "/") + ". class ";   // Call the getResource method of ClassLoader to pass in the class file name containing path information Java.net. URL url = loader. getResource (clsPath ); // Obtain the path information from the URL object String realPath = url. getPath (); // Remove the protocol name "file:" from the path information :" Int pos = realPath. indexOf ("file :"); If (pos>-1 ){ RealPath = realPath. substring (pos + 5 );         } // Remove the last part of the path information that contains the class file information to obtain the path of the class. Pos = realPath. indexOf (clsPath ); RealPath = realPath. substring (0, pos-1 ); // If the class file is packaged into a JAR file, remove the corresponding JAR and other packaging file names. If (realPath. endsWith ("! ")){ RealPath = realPath. substring (0, realPath. lastIndexOf ("/"));         } Java. io. File file = new java. io. File (realPath ); RealPath = file. getAbsolutePath ();   Try { RealPath = java.net. URLDecoder. decode (realPath, "UTF-8 "); } Catch (Exception e ){ Throw new RuntimeException (e );         } Return realPath; } // GetAppPath definition ends }

Using the Jar package, the running results in Tomcat are as follows:

ProjectPath: D:/J2EE/Tomcat 6.0/webapps/MyService1WebP/WEB-INF/lib
RealPath: D:/J2EE/Tomcat 6.0/webapps/MyService1WebP/WEB-INF/classes
Apppath: D:/J2EE/Tomcat 6.0/webapps/MyService1WebP/WEB-INF/classes