Tutorial Site springboot

Adding Customized Pre-Authentication

Anonymous (anonymous@undisclosed.example.com) — 2018-10-10T10:16:24+00:00

Adding Customized Pre-Authentication Adding a customized pre-authentication in spring boot takes the following 4 steps: * Create an authentication token that extends AbstractAuthenticationToken * Create an authentication filter that extends AbstractAuthenticationProcessingFilter

Adding Customized Properties in Application.properties file

Anonymous (anonymous@undisclosed.example.com) — 2021-05-25T15:41:58+00:00

Adding Customized Properties in Application.properties file * In application.properties files, add your own properties such as mypropertis.version=dev in the empty space. Here we use mypropertis as prefix, you can use whatever you want. * To read such value, create a class as a @Component

Basic Websocket

Anonymous (anonymous@undisclosed.example.com) — 2021-10-07T12:06:09+00:00

Basic Websocket This is going to build a STOMP based websocket on server site. * Add dependency to POM.XML * Add a EnableWebSocketMessageBroker configuration * Add a controller to handle the web socket package. Add dependency to POM.XML Add the following in POM.XML

Calling Stored Procedure with Output parameters

Anonymous (anonymous@undisclosed.example.com) — 2020-12-29T14:51:15+00:00

Calling Stored Procedure with Output parameters Assume we have a stored procedure like this in our database: USE [YOUR_DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER procedure [dbo].[TestParamOutput] @test_input1 INT, @test_input2 INT, @test_input3 INT, @test_input4 INT, @test_output1 INT OUTPUT, @test_output2 INT OUTPUT, @test_output3 INT OUTPUT, @test_output4 INT OUTPUT AS BEGIN SET NOCOUNT ON; SELECT @test_output1 = @test_input1+@test_input2; SELE…

CommandLineRunner

Anonymous (anonymous@undisclosed.example.com) — 2020-06-11T11:14:27+00:00

CommandLineRunner In Spring, CommandLineRunner run right after the application is initialized. It will run only one time, and it is good for initialize values for your application. We can implement it in the root application class, or creating new class with

Deploy SpringBoot 2 on Weblogic 12c

Anonymous (anonymous@undisclosed.example.com) — 2020-11-02T11:24:52+00:00

Deploy SpringBoot 2 on Weblogic 12c Deploying code on old container is a headache. Here is how I solve it. This example is based on SpringBoot 2.3.1.RELEASE, but should work on other 2.x version. * We need to have the following xml config in those files.

Development and Production application.properties

Anonymous (anonymous@undisclosed.example.com) — 2021-01-05T11:17:07+00:00

Development and Production application.properties It is very common to have properties file for local, dev, and prod environment. Mostly use it to handle the database connection setting. To do this: * In the main application.properties file add a line

Display Detail Log in Debug Console

Anonymous (anonymous@undisclosed.example.com) — 2020-05-21T16:25:19+00:00

Display Detail Log in Debug Console * Open the file application.properties * Add lines logging.level.org.springframework.web=DEBUG logging.level.org.hibernate=ERROR

Handling the Trailing Slash in URL

Anonymous (anonymous@undisclosed.example.com) — 2020-06-01T14:51:09+00:00

Handling the Trailing Slash in URL For now, if you use @RequestMapping, @GetMapping, @PostMapping, ... you will see that if you accidentally added a trailing slash “/” in the URL, you will get a 404 HTTP error. To handling this problem, we need to add a path matching configurer.

Having Spring to Create the Database Schema

Anonymous (anonymous@undisclosed.example.com) — 2020-06-01T17:03:06+00:00

Having Spring to Create the Database Schema * Add the following in the application.properties file: spring.jpa.properties.javax.persistence.schema-generation.scripts.action=drop-and-create spring.jpa.properties.javax.persistence.schema-generation.scripts.drop-target=drop.sql spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=create.sql spring.jpa.properties.javax.persistence.schema-generation.scripts.create-source=metadata

Hibinate 5 Ignore @Table, @column Name in Entity?

Anonymous (anonymous@undisclosed.example.com) — 2020-10-23T08:43:47+00:00

Hibinate 5 Ignore @Table, @column Name in Entity? The short answer is Yes. It do it by default. But you can still use the old way. If you want to old behaviors, to use @Table (name = “XxxXxxXxx”) for your Entity, or @Column(name = “YyyYyyYyy”

Mapping URL to Local File System

Anonymous (anonymous@undisclosed.example.com) — 2020-06-01T15:32:06+00:00

Mapping URL to Local File System For File System It is possible for us to map a URL to the sever local file system. Here is how we do it: * Write a WebConfiguration class with @Configuration annotation that implements WebMvcConfigurer. * @Override that method

Multiple Data Sources

Anonymous (anonymous@undisclosed.example.com) — 2021-02-08T14:46:20+00:00

Multiple Data Sources * To have multiple data source, you need to write it in code. You cannot do it alone in application.properties (at least up to now (2021/02/08)). * Add multiple @Configuration with @EnableJpaRepositories. During config, add the package location of the entities related to this data source.

Run Spring Not as Server

Anonymous (anonymous@undisclosed.example.com) — 2020-12-10T14:48:45+00:00

Run Spring Not as Server Under the directory /scr/main/resources/application.properties, add the following line: spring.main.web-application-type=NONE In that case, Spring will run as application, and end once it task is completed. You might want to implements CommandLineRunner in your main application class in that case.

Scheduling Task

Anonymous (anonymous@undisclosed.example.com) — 2018-10-16T09:33:56+00:00

Scheduling Task Scheduling Task include two steps. The First one is to add @EnableScheduling in the application, the second is the put @Scheduled on the top of the task/method. Put @EnableScheduling at the Application class @SpringBootApplication @EnableScheduling public class Application { public static void main(String[] args) throws Exception { SpringApplication.run(Application.class); } }

Spring Basic JPA

Anonymous (anonymous@undisclosed.example.com) — 2020-05-21T17:25:32+00:00

Spring Basic JPA * Assume we have a domain class call cat as shown at the end of this page * Create a new package call doa under your project package * Create an interface name CatRepository that extends CrudRepository package com.example.demo.dao import com.example.demo.domain.Cat import org.springframework.data.repository.CrudRepository interface CatRepository extends CrudRepository{ Cat findById(long id) List findByName(String name) List findByNameAndBr…

Spring Form Input

Anonymous (anonymous@undisclosed.example.com) — 2020-05-26T11:25:06+00:00

Spring Form Input build.gradle Include those in the dependencies. We need the javax.validation library for error handling. implementation 'org.springframework.boot:spring-boot-starter-thymeleaf' implementation 'org.springframework.boot:spring-boot-starter-web' compile group: 'javax.validation', name: 'validation-api', version: '2.0.1.Final'

Spring Form Input From HttpServletRequest

Anonymous (anonymous@undisclosed.example.com) — 2020-05-26T12:30:57+00:00

Spring Form Input From HttpServletRequest From those who do not like what Spring automatically bind the form input to an object, we can do it ourselves by using HttpServletRequest. * In your controller, import javax.servlet.http.HttpServletRequest

Spring JPA DTO Mapping

Anonymous (anonymous@undisclosed.example.com) — 2021-01-12T11:55:44+00:00

Spring JPA DTO Mapping Using SqlResultSetMapping Here has a good example about it. A copy was made here just in case it gone. All credit for the below two code sections go to SternK on stackoverflow. import javax.persistence.NamedNativeQuery; import javax.persistence.SqlResultSetMapping; import javax.persistence.ConstructorResult; import javax.persistence.ColumnResult; @Entity…

Spring RestController

Anonymous (anonymous@undisclosed.example.com) — 2020-05-28T15:17:19+00:00

Spring RestController * Create a package call controllers (could be anything, but this name make it clear) under your project root package. * Create a class call Home (could be anything, but this name make it clear) in the controllers package. *

Spring RestController Better Error Handling

Anonymous (anonymous@undisclosed.example.com) — 2020-05-28T15:22:34+00:00

Spring RestController Better Error Handling Instead of returning the plain old Java object in the mapping method, we can use return a ResponseEntity object. For exmaple: @GetMapping("/") public ResponseEntity index() { try { Book b = bookService.editBookName(1); return ResponseEntity.ok(b); } catch (Exception e) { e.printStackTrace(); return ResponseEntity.status(HttpStatus.CONFLICT).body(null); } }

Spring Simple Ajax Authentication

Anonymous (anonymous@undisclosed.example.com) — 2020-11-04T09:14:27+00:00

Spring Simple Ajax Authentication Assume you have already read . If not, do it because we need to use h2 database to store our users. Unless you want to put the username, and password in your HTTP header every time, otherwise, Ajax authentication is usually use for the very beginning of the JWT authentication when the front-end use their login:password for exchanging the JWT access token, and refresh t…

Spring Simple JWT Authentication

Anonymous (anonymous@undisclosed.example.com) — 2020-06-16T10:16:07+00:00

Spring Simple JWT Authentication * Add dependencies in build.gradle, we use auth0 library here. (compile “com.auth0:java-jwt:3.4.0”) * Create our Authentication Token (JwtAuthToken extends AbstractAuthenticationToken) * Create our Authentication Filter (JwtAuthFilter extends AbstractAuthenticationProcessingFilter)

Spring Simple Username-Password Authentication with H2

Anonymous (anonymous@undisclosed.example.com) — 2020-06-09T16:30:38+00:00

Spring Simple Username-Password Authentication with H2 Basically, we have 6 steps: * Setup the project dependencies * Create User Role entities. User entity implement UserDetails * Create Your own UserDetailsService * Create WebSecurityConfig extends WebSecurityConfigurerAdapter

Spring Using DataSource or JdbcTemplate

Anonymous (anonymous@undisclosed.example.com) — 2020-06-01T10:32:31+00:00

Spring Using DataSource or JdbcTemplate DataSource Simply do @Autowired DataSource dataSource; and we can use the dataSource in our code like: String sql = "YOUR_SQL_QUERY"; //such as "UPDATE Book SET NAME = '" + String.valueOf(iRandom) + "' WHERE ID = 1" Connection connection = dataSource.getConnection(); Statement statement = connection.createStatement(); int iAffectedRowCount = statement.executeUpdate(sql); connection.close();

Spring Web Security

Anonymous (anonymous@undisclosed.example.com) — 2020-05-25T10:21:34+00:00

Spring Web Security Here is how we do it step-by-step. Code are written in Groovy, not JAVA. Dependency For build.gradle, add spring-boot-starter-security in the dependencies. dependencies { implementation 'org.springframework.boot:spring-boot-starter-thymeleaf' implementation 'org.springframework.boot:spring-boot-starter-web' implementation 'org.springframework.boot:spring-boot-starter-security' implementation 'org.springframework.security:spring-security-test' implemen…

Start From Spring Initializr

Anonymous (anonymous@undisclosed.example.com) — 2020-05-21T10:58:33+00:00

Start From Spring Initializr * Go to * Choice your setting * Click the generate button to download the skeleton of the project. * Open your project with Spring IDE or IntelliJ * Let the IDE to download the dependencies * For proxy setting, reference

Table Naming Being Ignored

Anonymous (anonymous@undisclosed.example.com) — 2020-12-11T17:46:29+00:00

Table Naming Being Ignored Since Spring 5, Naming using @Table(name=“XxxXxxXxx”) will get you something like xxx_xxx_xxx for table name instead of the name you typed. To fix it, add spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyJpaImpl spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl

Using H2 As DataSource For Testing

Anonymous (anonymous@undisclosed.example.com) — 2020-12-11T17:20:25+00:00

Using H2 As DataSource For Testing * In build.gradle, add runtimeOnly 'com.h2database:h2 in dependencies section * Open application.properties * Add lines spring.datasource.url=jdbc:h2:mem:testdb spring.datasource.driverClassName=org.h2.Driver spring.datasource.username=sa spring.datasource.password= spring.h2.console.enabled=true

What is JSON Web Token (JWT)

Anonymous (anonymous@undisclosed.example.com) — 2020-11-05T09:28:46+00:00

What is JSON Web Token (JWT) A jwt look like this: (No worry, it has already been expired a long time ago) eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJmYWtlX2xvZ2luIiwiZXhwIjoxNjA0NTM4ODIwLCJyb2xlcyI6IlJPTEVfVVNFUiwifQ.dIhtHS77agSc7_Wrkzn429aZeuWWXkXLopnMYBDJdZs