Java

Create a basic java spring boot application

This is a basic example for beginners for creating a basic java spring boot application using ‘spring-boot-starter-parent’.

In this tutorial I am using Spring tool suite as my IDE.

Step I. Create a Maven project

I.1:  File->New -> Maven Project (You can do it by write clicking in the blank space of Package Explorer )

I.2: I have selected ‘create a simple project ( skip archetye selection)’ this allow me to kip the Archetype selection

I.3 : Setting group id and artifact id and other project related details

Done with the maven project creation, you can see the IDE automatically create the project folder structure like bellow .

You can see the project details in pom.xml file

 

Add the spring boot dependency

Update the project

write click on project folder->Maven->Update Project

After update we can see JRe updated to 1.8 and added Maven Dependencies

 

Now we can create our application entry point

Crate a class like bellow (sselect the tic ‘public static void main’ to auto generate the function)

Right click in Package Explorer -> New ->Class

Then add @SpringBootApplication annotation to the class and add SpringApplication.run(MyApp.class, args); inside the main function

Now we can create our controller 

Right click in Package Explorer -> New ->Class

 

Add the following code in the file

You are done

Now we can run our application You can press the Green *Play button    Or  you can right click the project folder and select the Run As – >Java Application

Tadaaaaa! Our project is running

Now we can hit the url

We and run Spring boot application from command line also by using the command  mvn spring-boot:run

 

Done


Note

If you are getting the error “Exception in thread “main” java.lang.NoClassDefFoundError: ch/qos/logback/classic/turbo/TurboFilter ” please add the logback-classic dependency in pom file

 

1 Like
By bm on July 19, 2017 | Java, Spring boot | A comment?
Tags: , ,

String Builder and String Buffer

String

String objects are immutable ( once created can not be changed ) and it will stored in the  Constant String Pool , so if you chose to do a lot of manipulations with String objects, you will end up with a lot of abandoned String objects in the String pool. To avoiding this memory loss we can use StringBuilder or StringBuffer and can be modified over and over again without causing memory loss

StringBuilder example

StringBuffers are thread-safe, they have synchronized methods to control access so that only one thread can access a StringBuffer object’s synchronized code at a time. Thus, StringBuffer objects are generally safe to use in a multi-threaded environment where multiple threads may be trying to access the same StringBuffer object at the same time.

 

StringBuffer example

StringBuilder’s access is not synchronized so that it is not thread-safe. The performance of StringBuilder can be better than StringBuffer. Thus, if you are working in a single-threaded environment, using StringBuilder instead of StringBuffer may result in increased performance.

 

 

ref:
https://docs.oracle.com/javase/7/docs/api/java/lang/StringBuilder.html

https://docs.oracle.com/javase/tutorial/java/data/buffers.html

https://docs.oracle.com/javase/7/docs/api/java/lang/StringBuffer.html

  Like
By bm on July 26, 2016 | Android, Java | A comment?
Tags: , , ,

Ubuntu set java version

select / set java version

Set java version

  Like
By bm on April 10, 2014 | Java | A comment?
Tags: