Most answered questions in Java

0 votes
2 answers

Understand working of String Builder and String Buffer

Basically, StringBuffer methods are synchronized while StringBuilder ...READ MORE

Aug 29, 2018 in Java by Sushmita
 • 6,910 points • 831 views
0 votes
2 answers

Is there a destructor in Java?

try (BufferedReader br = new BufferedReader(new FileReader(path))) ...READ MORE

Sep 4, 2018 in Java by Sushmita
 • 6,910 points • 761 views
0 votes
2 answers

How to read the files using Java?

You can use collections. try (Stream<Path> filePathStream=Files.walk(Paths.get("/home/you/Desktop"))) { ...READ MORE

Jul 10, 2018 in Java by Sushmita
 • 6,910 points • 839 views
0 votes
2 answers

What is the use of @Override annotation in Java ? When do we use it ?

@Override annotation is used when we override ...READ MORE

Aug 14, 2019 in Java by Sirajul
 • 59,230 points • 3,124 views
0 votes
2 answers

How to read a text file in Java?

You can use Scanner class to read ...READ MORE

Aug 9, 2018 in Java by Parth
 • 4,630 points • 774 views
0 votes
2 answers

How does '&&' (AND) and '||' (OR) statements work inside an IF condition ?

Short circuit here means that the second ...READ MORE

Sep 19, 2018 in Java by Sushmita
 • 6,910 points • 643 views
0 votes
2 answers

Store String inside a File using Java

We can use Apache Commons IO. It ...READ MORE

Jul 20, 2018 in Java by Sushmita
 • 6,910 points • 1,092 views
0 votes
2 answers

How can I get the filenames of all files in a folder which may or may not contain duplicates

List<String> results = new ArrayList<String>(); File[] files = ...READ MORE

Sep 12, 2018 in Java by Sushmita
 • 6,910 points • 1,649 views
+1 vote
2 answers

What are inner classes and static nested classes?

Nested classes are divided into two categories: ...READ MORE

Dec 3, 2018 in Java by Sushmita
 • 6,910 points • 3,636 views
0 votes
2 answers

Does the finally block always execute in Java?

public static void main(String[] args) { ...READ MORE

Aug 8, 2018 in Java by Sushmita
 • 6,910 points • 1,752 views
0 votes
2 answers

How to break the nested loop in Java?

You can use break with a label for the ...READ MORE

Sep 20, 2018 in Java by Sushmita
 • 6,910 points • 955 views
0 votes
2 answers

Date format conversion in Java

Calendar cal = Calendar.getInstance(); cal.add(Calendar.DATE, 1); Date date = ...READ MORE

Aug 13, 2018 in Java by Sushmita
 • 6,910 points • 727 views
0 votes
2 answers

Remove duplicate elements from an ArrayList in Java

List<String> al = new ArrayList<>(); // add elements ...READ MORE

Jul 26, 2018 in Java by Sushmita
 • 6,910 points • 1,251 views
0 votes
2 answers

How can I invoke a method when the method name is in the form of a given string?

You could probably use method invocation from reflection: Class<?> ...READ MORE

Aug 19, 2019 in Java by Sirajul
 • 59,230 points • 2,606 views
0 votes
2 answers

When to use Static Methods in Java?

A static method has two main purposes: For ...READ MORE

Aug 10, 2018 in Java by samarth295
 • 2,220 points • 15,562 views
0 votes
2 answers

what is the best way to convert an ArrayList to a String

You could probably use the Joiner class ...READ MORE

Aug 19, 2019 in Java by Sirajul
 • 59,230 points • 955 views
0 votes
2 answers

Send HTTP request in Java

import com.google.api.client.http.GenericUrl; import com.google.api.client.http.HttpRequest; import com.google.api.client.http.HttpResponse; import com.google.api.client.http.HttpTransport; import com.google.api.client.http.javanet.NetHttpTransport; import java.io.IOException; import ...READ MORE

Aug 3, 2018 in Java by samarth295
 • 2,220 points • 1,499 views
0 votes
2 answers

What's the best way to check if a String represents an integer in Java?

You can also use regular expression. str.matches("-?\\d+"); It will ...READ MORE

Aug 9, 2018 in Java by Daisy
 • 8,120 points • 3,471 views
0 votes
2 answers

How do I replace character from string at specific indexes?

You could turn the String into a ...READ MORE

Aug 22, 2019 in Java by Sirajul
 • 59,230 points • 22,517 views
0 votes
2 answers

How to round a double to 2 decimal places?

double value = 200.3456; System.out.printf("Value: %.2f", value); You can ...READ MORE

Dec 11, 2018 in Java by Sushmita
 • 6,910 points • 13,967 views
0 votes
2 answers

What is the difference between Set and List in java?

List is an ordered sequence of elements. ...READ MORE

Apr 26, 2018 in Java by Akrati
 • 3,190 points • 62,760 views
0 votes
2 answers

What is the difference between = and equals()?

The equals() method compares the "value" inside String instances ...READ MORE

Aug 13, 2018 in Java by Daisy
 • 8,120 points • 1,113 views
0 votes
2 answers

What is the use of toString method in Java and how can I use it ?

Whenever you require to explore the constructor ...READ MORE

Aug 23, 2018 in Java by Daisy
 • 8,120 points • 3,805 views
0 votes
2 answers

How do I convert an input stream into a byte array

You could probably try this if you ...READ MORE

Aug 29, 2019 in Java by Sirajul
 • 59,230 points • 3,371 views
0 votes
2 answers

Counting no of Occurrence of a particular character inside a string in Java

We can find out the no. of ...READ MORE

Sep 7, 2018 in Java by Sushmita
 • 6,910 points • 2,311 views
0 votes
2 answers

How can I get current time in YYYY:MM:DD HH:MI:Sec:Millisecond format in Java?

public String getCurrentTimeStamp() { ...READ MORE

Sep 21, 2018 in Java by Parth
 • 4,630 points • 6,794 views
0 votes
2 answers

How to find out current working directory in Java?

You can also use java.nio.file.Path and java.nio.file.Paths. Path ...READ MORE

Jul 31, 2018 in Java by Sushmita
 • 6,910 points • 726 views
0 votes
2 answers

Array of Objects

You can also do : A[] a = ...READ MORE

Aug 3, 2018 in Java by sharth
 • 3,370 points • 521 views
0 votes
2 answers

Copying Objects in Java

class DummyBean { private String dummy; ...READ MORE

Aug 6, 2018 in Java by Sushmita
 • 6,910 points • 503 views
0 votes
2 answers

How to convert array into list in Java?

Another workaround if you use apache commons-lang: int[] ...READ MORE

Aug 10, 2018 in Java by samarth295
 • 2,220 points • 674 views
0 votes
2 answers

How to concatenate two arrays in Java?

public <T> T[] concatenate(T[] a, T[] b) ...READ MORE

Jul 19, 2018 in Java by Sushmita
 • 6,910 points • 2,429 views
0 votes
2 answers

What is the difference between implements and extends?

Extends : This is used to get attributes ...READ MORE

Aug 3, 2018 in Java by samarth295
 • 2,220 points • 15,302 views
0 votes
2 answers

How can I convert an 'ArrayList<String> to 'String[]' in Java

In Java 8 or later: String listString = ...READ MORE

Aug 20, 2019 in Java by Sirajul
 • 59,230 points • 2,866 views
0 votes
2 answers

Generate an alpha-numeric string randomly

Java supplies a way of doing this ...READ MORE

Jul 18, 2018 in Java by Daisy
 • 8,120 points • 2,233 views
0 votes
2 answers

How do I read and convert an InputStream object to string type?

You can also use Java Standard Library ...READ MORE

Jul 17, 2018 in Java by Sushmita
 • 6,910 points • 16,721 views
0 votes
2 answers

“Could not find or load main class” mean?

Use the final modifier to enforce good initialization. Avoid returning ...READ MORE

Sep 18, 2018 in Java by Sushmita
 • 6,910 points • 4,178 views
0 votes
2 answers

Performing Iteration over each entry in a 'Map'

In Java 8 you can do it ...READ MORE

Oct 24, 2018 in Java by Sushmita
 • 6,910 points • 805 views
0 votes
2 answers

How to test that an array contains a certain value?

public static final String[] VALUES = new ...READ MORE

Jul 17, 2018 in Java by Sushmita
 • 6,910 points • 833 views
0 votes
2 answers

Ho do I Iterate through a HashMap which contains duplicate values

for (Map.Entry<String, String> item : params.entrySet()) { ...READ MORE

Jul 24, 2018 in Java by samarth295
 • 2,220 points • 4,840 views
0 votes
2 answers

How is hashmap different from hashtable?

HashMap and HashTable: 1) Hashtable and Hashmap implement ...READ MORE

Aug 1, 2018 in Java by samarth295
 • 2,220 points • 5,999 views
0 votes
2 answers

How to convert an array to arraylist?

In Java 9 you can use: List<String> list= List.of("Hello", "World", ...READ MORE

Aug 1, 2018 in Java by samarth295
 • 2,220 points • 801 views
0 votes
2 answers

How can I create File and write data in it using Java?

import java.io.BufferedWriter; import java.io.IOException; import java.nio.file.Files; import java.nio.file.Paths; public class WriteFiles{ ...READ MORE

Jul 26, 2018 in Java by samarth295
 • 2,220 points • 2,566 views
0 votes
2 answers

How do I get the current date and time using Java?

If you require a time stamp in ...READ MORE

Aug 23, 2019 in Java by Sirajul
 • 59,230 points • 2,374 views
0 votes
2 answers

One line initialization of an ArrayList object in Java

In Java 8 or earlier: List<String> string = ...READ MORE

Jul 26, 2018 in Java by samarth295
 • 2,220 points • 4,180 views
0 votes
2 answers

How to round any number to n decimal places in Java?

new BigDecimal(String.valueOf(double)).setScale(yourScale, BigDecimal.ROUND_HALF_UP); will get you a BigDecimal. To ...READ MORE

Aug 26, 2019 in Java by Sirajul
 • 59,230 points • 1,296 views
0 votes
2 answers

What is the syntax to initialize an array?

Rather than learning un-Official websites learn from ...READ MORE

Aug 2, 2018 in Java by samarth295
 • 2,220 points • 704 views
0 votes
2 answers

How to create a 2-D array in java?

int[][] multi = new int[5][]; multi[0] = new ...READ MORE

Jul 16, 2018 in Java by Daisy
 • 8,120 points • 970 views
0 votes
2 answers

Integer to String conversion in java

We can do this in 2 ways: String ...READ MORE

Jul 28, 2018 in Java by samarth295
 • 2,220 points • 855 views
+1 vote
2 answers

How to generate random integers within specific range in Java?

You can achieve that concisely in Java: Random ...READ MORE

Jul 25, 2018 in Java by samarth295
 • 2,220 points • 983 views
0 votes
2 answers

How can I convert a String variable to a primitive int in Java

 Here are two ways illustrating this: Integer x ...READ MORE

Aug 20, 2019 in Java by Sirajul
 • 59,230 points • 1,919 views
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