Expert Solutions

 private static int calNoOfFiles(String directoryPath)     {         String fileDelimiter= File.separator;         File fd = new File(directoryPath);         if(!fd.isFile())         {             String list[] = fd.list();             for(int i = 0; i < list.length; i++)             {                 String tempDirPath = directoryPath + fileDelimiter + list[i];                 debug(tempDirPath);                 File ftd = new File(tempDirPath);                 if(ftd.isFile())                     noOfFiles++;                 if(ftd.isDirectory())                     calNoOfFiles(tempDirPath);             }         }         return noOfFiles;     }

Get file extension in java code example public static String getFileExtension(String filePath)     {         File f = new File(filePath);         String name = f.getName();         int k = name.lastIndexOf(".");         String ext = null;         if(k != -1)             ext = name.substring(k + 1, name.length());         return ext;     }

public class Test {             public void MethodOne() {                 System.out.println("Inside Test class");         }                 public class InnerC {             public void MethodOne() {                 System.out.println("Inside InnerC class");             }                     public void test() {                 this.MethodOne();                 Test.this.MethodOne();             }         }                 public static void main(String[] args) {                        Test.InnerC i = new Test().new InnerC();                 i.test();         }     }

Boxing :- Convert primitive data to its wrapper class object.    Example :- char to Charactor               int to Integer               boolean to Boolean               float to Float           double to Double; Unboxing :- Java primitive type  to its wrappers class:    Example :-     Boolean to boolean          Byte to byte,         Character to char,                 Double to double,                 Float to float,         Long to long,                 Integer to int,                 public abstract class Test {         public static void main(String[] args) throws Exception {                 boolean b = true;         //Explicit Boxing         Boolean b1 = new Boolean(b);         //Explicit Unboxing         boolean b2 = b1.booleanValue();                  // Automatic Boxing         b1 = b;          //Automatic Unboxing         b2 = b1;                         int i = 50;         //    Explicit Boxing         Integer i1 = new Integer(i);        

// What is the use of startsWith and endsWith method in String java example public class Test {         public static void main(String[] args) {                    String st = new String("test string test here");                         System.out.println(st.startsWith("test"));             System.out.println(st.startsWith("test", 12));                         System.out.println(st.endsWith("here"));                     } }