Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Java Articles
Page 309 of 450
Match all occurrences of a regex in Java
public class RegexOccur { public static void main(String args[]) { String str = "java is fun so learn java"; String findStr = "java"; int lastIndex = 0; int count = 0; while(lastIndex != -1) { lastIndex = str.indexOf(findStr,lastIndex); if(lastIndex != -1) { count ++; lastIndex += findStr.length(); } } System.out.println(count); } }Output2
Read MoreHow to prevent object of a class from garbage collection in Java?
If a object is no more referenced by a live reference then it becomes eligible for garbage collection. See the example below −Examplepublic class Tester{ public static void main(String[] args) { test(); } public static void test(){ A a = new A(); } } class A {}When test() method complete execution, the a object is no more referenced and is eligible for garbage collection. Java garbage collector will deallocate the object when it runs.To prevent garbage collection, we can create a static reference to an object and then ...
Read MoreHow to prevent object of a class from garbage collection in Java?
If a object is no more referenced by a live reference then it becomes eligible for garbage collection. See the example below −Examplepublic class Tester{ public static void main(String[] args) { test(); } public static void test(){ A a = new A(); } } class A {}When test() method complete execution, the a object is no more referenced and is eligible for garbage collection. Java garbage collector will deallocate the object when it runs.To prevent garbage collection, we can create a static reference to an object and then ...
Read MoreWhy Java programs running on Android systems do not use the standard Java API and virtual machine?
The standard Java API and virtual machine are mainly designed for desktop as well as server systems. They are not that compatible with mobile devices. Because of this, Google has created a different API and virtual machine for mobile devices. This is known as the Dalvik virtual machine.The Dalvik virtual machine is a key component of the Android runtime and is a part of JVM (Java Virtual Machine) developed specially for Android. The Dalvik virtual machine uses features that are quite important in Java such as memory management, multi-threading etc. The programs in Java are first converted into JVM and ...
Read MoreGenerating password in Java
Generate temporary password is now a requirement on almost every website now-a-days. In case a user forgets the password, system generates a random password adhering to password policy of the company. Following example generates a random password adhering to following conditions −It should contain at least one capital case letter.It should contain at least one lower-case letter.It should contain at least one number.Length should be 8 characters.It should contain one of the following special characters: @, $, #, !.Exampleimport java.util.Random; public class Tester{ public static void main(String[] args) { System.out.println(generatePassword(8)); } private ...
Read MoreGenerating password in Java
Generate temporary password is now a requirement on almost every website now-a-days. In case a user forgets the password, system generates a random password adhering to password policy of the company. Following example generates a random password adhering to following conditions −It should contain at least one capital case letter.It should contain at least one lower-case letter.It should contain at least one number.Length should be 8 characters.It should contain one of the following special characters: @, $, #, !.Exampleimport java.util.Random; public class Tester{ public static void main(String[] args) { System.out.println(generatePassword(8)); } private ...
Read MoreGenerating random numbers in Java
We can generate random numbers using three ways in Java.Using java.util.Random class − Object of Random class can be used to generate random numbers using nextInt(), nextDouble() etc. methods.Using java.lang.Math class − Math.random() methods returns a random double whenever invoked.Using java.util.concurrent.ThreadLocalRandom class − ThreadLocalRandom.current().nextInt() method and similar othjer methods return a random numbers whenever invoked.Exampleimport java.util.Random; import java.util.concurrent.ThreadLocalRandom; public class Tester { public static void main(String[] args) { generateUsingRandom(); generateUsingMathRandom(); generateUsingThreadLocalRandom(); } private static void generateUsingRandom() { Random random = new Random(); ...
Read MoreGenerating random numbers in Java
We can generate random numbers using three ways in Java.Using java.util.Random class − Object of Random class can be used to generate random numbers using nextInt(), nextDouble() etc. methods.Using java.lang.Math class − Math.random() methods returns a random double whenever invoked.Using java.util.concurrent.ThreadLocalRandom class − ThreadLocalRandom.current().nextInt() method and similar othjer methods return a random numbers whenever invoked.Exampleimport java.util.Random; import java.util.concurrent.ThreadLocalRandom; public class Tester { public static void main(String[] args) { generateUsingRandom(); generateUsingMathRandom(); generateUsingThreadLocalRandom(); } private static void generateUsingRandom() { Random random = new Random(); ...
Read MoreGenerating OTP in Java
Generate OTP is now a requirement on most of the website now-a-days. In case of additional authentication, system generates a OTP password adhering to OTP policy of the company. Following example generates a unique OTP adhering to following conditions −It should contain at least one number.Length should be 4 characters.Exampleimport java.util.Random; public class Tester { public static void main(String[] args) { System.out.println(generateOTP(4)); } private static char[] generateOTP(int length) { String numbers = "1234567890"; Random random = new Random(); char[] otp = new ...
Read MoreGenerating OTP in Java
Generate OTP is now a requirement on most of the website now-a-days. In case of additional authentication, system generates a OTP password adhering to OTP policy of the company. Following example generates a unique OTP adhering to following conditions −It should contain at least one number.Length should be 4 characters.Exampleimport java.util.Random; public class Tester { public static void main(String[] args) { System.out.println(generateOTP(4)); } private static char[] generateOTP(int length) { String numbers = "1234567890"; Random random = new Random(); char[] otp = new ...
Read More