Write a program to create deadlock between two threads

Write a program to create deadlock between two threads.

Code:

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 public class MyDeadlock {     String str1 = "Java";     String str2 = "UNIX";           Thread trd1 = new Thread("My Thread 1"){         public void run(){             while(true){                 synchronized(str1){                     synchronized(str2){                         System.out.println(str1 + str2);                     }                 }             }         }     };           Thread trd2 = new Thread("My Thread 2"){         public void run(){             while(true){                 synchronized(str2){                     synchronized(str1){                         System.out.println(str2 + str1);                     }                 }             }         }     };           public static void main(String a[]){         MyDeadlock mdl = new MyDeadlock();         mdl.trd1.start();         mdl.trd2.start();     } }

Right way to check if String is empty in Java

Right way to check if String is empty in Java

What do you most of us do while using String in Java? checking whether String is null or empty right? I am sure you know a couple of ways to test whether String is empty or not, but do you know the right way to do it? When we talk about Strings in Java, we can imagine them as arrays of characters, and they are, but in Java, they also object. An empty Java String is considered as the not null String that contains zero characters, meaning its length is 0. However, a Java String that might only contain the white-space character is not considered as empty, it is considered to contain one character and its length is equal to 1. One of the most popular way of checking whether String is empty or not is String class' isEmpty() method, this looks perfect right, it's readable and returns boolean if String is empty otherwise returns false, but the problem is you can not call this method without checking whether String is null or not. In another word, this is not null safe and it will throw NullPointerException if String is null.