Most viewed questions in Java

+2 votes
2 answers

How to find all the classes of a package in Java?

Looking on internet I found this page with ...READ MORE

Nov 16, 2020 in Java by Juan
• 340 points
292,467 views
+12 votes
13 answers

Default parameters of XMS and XMX in JVM

Run this code to see all the ...READ MORE

Nov 13, 2018 in Java by anonymous
278,421 views
+8 votes
16 answers

Unable to resolve this error: "javac is not recognized as an internal or external command"

Check your javac path on Windows using Windows Explorer C:\Program Files\Java\jdk1.7.0_02\bin and ...READ MORE

May 23, 2018 in Java by Rishabh
• 3,620 points
266,106 views
+15 votes
25 answers

How can I convert String to JSON object in Java?

Hi @Daisy You can use Google gson  for more ...READ MORE

Feb 7, 2019 in Java by Suresh
• 720 points
210,424 views
+2 votes
11 answers

How to import a jar file in Eclipse?

Click on File > Import. The Import ...READ MORE

Aug 23, 2018 in Java by Daisy
• 8,110 points
205,105 views
+2 votes
14 answers

“A Non-static method cannot be referenced from a static context” error

Hey Techies, Non-static variables are part of the objects ...READ MORE

Dec 10, 2020 in Java by Roshni
• 10,420 points
172,497 views
+2 votes
13 answers

Unable to execute jar- file: “no main manifest attribute”

add a jar/manifest/attributes setting like this: apply plugin: ...READ MORE

Nov 27, 2018 in Java by krishti
122,603 views
+1 vote
13 answers

How does java.net.SocketException: Connection reset happen ?

You can use wireshark to view the ...READ MORE

Dec 7, 2018 in Java by tushh
108,234 views
+1 vote
14 answers

Communications link failure: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException

Your exception seems to indicate that your ...READ MORE

Dec 11, 2020 in Java by Roshni
• 10,420 points
98,505 views
+1 vote
13 answers

How to send HTTP POST requests on Java?

With Apache HttpClient In the old days, this Apache ...READ MORE

Dec 10, 2020 in Java by Rajiv
• 8,880 points
97,375 views
0 votes
13 answers

What is the correct way to add external Jars to IntelliJ IDEA Project?

Adding custom JAR files to the EAR project Copy the custom JAR to the ...READ MORE

Dec 10, 2020 in Java by Nikita
97,098 views
+1 vote
12 answers

Iterate over a JSONObject?

Assuming your JSON object is saved in ...READ MORE

Dec 11, 2020 in Java by Rajiv
• 8,880 points
68,020 views
0 votes
12 answers

Java - sending HTTP parameters via POST method easily

Below are the steps we need to ...READ MORE

Dec 11, 2020 in Java by Rajiv
• 8,880 points
66,771 views
0 votes
6 answers

How can I separate the digits of an int number in Java?

You can also have a look here: To ...READ MORE

Dec 9, 2020 in Java by Roshni
• 10,420 points
61,093 views
+5 votes
4 answers

How to execute a python file with few arguments in java?

You can use Java Runtime.exec() to run python script, ...READ MORE

Mar 27, 2018 in Java by DragonLord999
• 8,450 points

edited Nov 6, 2018 by Omkar 38,199 views
0 votes
6 answers

How can we define global variables in java?

To define Global Variable you can make ...READ MORE

Dec 15, 2020 in Java by Gitika
• 65,870 points
36,057 views
0 votes
3 answers

HttpServletRequest get JSON POST data

Configure the action as given below: Method: Since ...READ MORE

Dec 16, 2020 in Java by Rajiv
• 8,880 points
35,043 views
0 votes
4 answers

“Cannot find symbol” compilation error

The "Cannot find symbol" errors generally occur when you ...READ MORE

Dec 16, 2020 in Java by Gitika
• 65,870 points
31,375 views
+2 votes
4 answers

Javac command not working in my windows 10

Check your javac path on Windows using Windows Explorer C:\Program Files\Java\jdk1.7.0_02\bin and ...READ MORE

Aug 6, 2019 in Java by Sirajul
• 58,990 points
30,395 views
+1 vote
4 answers

How to take multiple integer input in one line using BufferedReader in Java?

To do this, we could read in ...READ MORE

Dec 13, 2020 in Java by Roshni
• 10,420 points
29,996 views
+1 vote
5 answers

How to take input using BufferedReader in Java?

yupp i am explaining every thing .. We ...READ MORE

Feb 1, 2020 in Java by Rohan
• 180 points
29,235 views
+1 vote
12 answers

Hibernate hbm2ddl.auto possible values and their uses

hibernate.hbm2ddl.auto (e.g. none (default value), create-only, drop, create, create-drop, validate, and update) Setting to perform SchemaManagementTool actions automatically as ...READ MORE

Dec 7, 2018 in Java by Shuvodip
28,560 views
0 votes
2 answers

Resolving PKIX path building failed Error?

You need to add the certificate for App2 to ...READ MORE

Sep 24, 2018 in Java by Sushmita
• 6,890 points
27,690 views
+1 vote
10 answers

How to make mock to void methods with mockito

You can use partial mocking to serve ...READ MORE

Dec 7, 2018 in Java by nitesh
26,350 views
+1 vote
7 answers

What is difference between access modifier and access specifier in java

Access Specifier:- This can be understood as ...READ MORE

Feb 14, 2019 in Java by Priyaj
• 58,100 points
26,101 views
+3 votes
4 answers

Using while loop i want to print 10 even numbers

public class Loops { ...READ MORE

Dec 4, 2019 in Java by One of the Simplest ways to answer you q
25,476 views
+1 vote
3 answers

3 dot in parameter in Java

The "Three Dots" in java is called ...READ MORE

Nov 21, 2018 in Java by geek.erkami
• 2,680 points
25,107 views
0 votes
3 answers

Setting time zone of a java.util.Date

Using Java 8 Java 8 introduced a new Date-Time ...READ MORE

Dec 15, 2020 in Java by Gitika
• 65,870 points
22,837 views
0 votes
3 answers

How to clear the console in Java?

import java.io.IOException; public class chkClearScreen {     public static void ...READ MORE

Aug 26, 2020 in Java by ItsJustRaja
22,669 views
0 votes
1 answer

object references an unsaved transient instance - save the transient instance before flushing

You should add cascade="all" (if using xml) ...READ MORE

Sep 26, 2018 in Java by Parth
• 4,630 points
21,816 views
0 votes
1 answer

How to find the nth prime number in Java?

Here is the code to find nth ...READ MORE

Mar 4, 2019 in Java by Priyaj
• 58,100 points
21,679 views
0 votes
1 answer

How can I get the current date and time in UTC or GMT in Java?

This definitely returns UTC time: as String ...READ MORE

Jun 7, 2018 in Java by Rishabh
• 3,620 points
21,420 views
0 votes
1 answer

GSON throwing “Expected BEGIN_OBJECT but was BEGIN_ARRAY”?

This will work: ChannelSearchEnum[] enums = gson.fromJson(yourJson, ChannelSearchEnum[].class); But ...READ MORE

Dec 26, 2018 in Java by Sushmita
• 6,890 points
20,387 views
0 votes
2 answers

Unable to find valid certification path to requested target

Unfortunately - it could be many things ...READ MORE

Dec 15, 2020 in Java by Roshni
• 10,420 points
19,534 views
+1 vote
4 answers

What is the difference between string object and string literal?

A String literal is a Java language concept. This ...READ MORE

Aug 16, 2019 in Java by Sirajul
• 58,990 points
19,031 views
0 votes
1 answer

How to refresh data in ViewPager Fragment ?

Using the ViewPager.OnPageChangeListener is the correct way to go, ...READ MORE

Mar 6, 2019 in Java by developer_1
• 3,310 points
18,833 views
+1 vote
4 answers

What is a simple way to repeat a string in java?

There is already answer wriiten using StringBuilder ...READ MORE

Dec 16, 2020 in Java by Rajiv
• 8,880 points
18,449 views
0 votes
2 answers

What is the difference between Map and HashMap in java?

The basic difference is : Map is ...READ MORE

Aug 28, 2019 in Java by Sirajul
• 58,990 points
18,298 views
0 votes
1 answer

Java execute vs executeQuery vs executeUpdate

I think the major differences between execute, executeQuery, ...READ MORE

Jul 30, 2018 in Java by geek.erkami
• 2,680 points
16,850 views
0 votes
1 answer

How can I solve this: To prevent a memory leak, the JDBC Driver has been forcibly unregistered

What can you do? Ignore these warnings. Tomcat ...READ MORE

Jan 8, 2019 in Java by Daisy
• 8,110 points
16,114 views
+1 vote
1 answer

Setting selected item of Spinner by value rather than by position

Suppose your Spinner is named newSpinner, and it contains ...READ MORE

Aug 10, 2018 in Java by 93.lynn
• 1,620 points
14,948 views
0 votes
4 answers

How can we display an output of float data with 2 decimal places in java? Please help

You can use DecimalFormat. One way to use ...READ MORE

Dec 16, 2020 in Java by Gitika
• 65,870 points
14,852 views
0 votes
1 answer

"No mapping found for HTTP request with URI[....] in DispatherServlet"

Your standard Spring MVC application will serve ...READ MORE

Jun 6, 2018 in Java by prasad
• 160 points
13,414 views
0 votes
2 answers

How can I address the unchecked cast warnings?

@SuppressWarnings("unchecked") READ MORE

Mar 21, 2019 in Java by anonymous
12,870 views
0 votes
2 answers

how can we Create instance for generic type in java

private static class SomeContainer<E> { ...READ MORE

Aug 27, 2018 in Java by Sushmita
• 6,890 points
12,790 views
+1 vote
2 answers

Retrieve all the implementations of an interface in Java

Take a look to this example: https://github.com/burningwave/co ...READ MORE

Dec 20, 2019 in Java by Roberto
• 460 points

edited Jul 6, 2020 by Roberto 12,702 views
0 votes
1 answer

Why is my Spring @Autowired field null?

If you are not coding a web ...READ MORE

Dec 27, 2018 in Java by Daisy
• 8,110 points
12,498 views
0 votes
2 answers

What's the difference between @JoinColumn and mappedBy when using a JPA @OneToMany association?

JPA mapping annotation can be classified as ...READ MORE

Oct 28, 2020 in Java by bjjj
• 140 points
12,495 views
0 votes
1 answer

How to set Encoding in Java ?

Unfortunately, the file.encoding property has to be specified as ...READ MORE

May 29, 2018 in Java by Rishabh
• 3,620 points
12,365 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
• 6,890 points
11,735 views