javadevjournal/javadevjournal

Source code for the tutorials published on the Javadevjournal site.

Java Dev Journal

Java and Spring development tutorials

Java Dev Journal is a technical blog which publish articles, blog post on the following topics:

• Java
• Spring Boot
• Spring
• Spring MVC
• Spring Security
• REST API
• Shopizer

Spring Boot Course

If you are starting with the Spring Boot, we have a free course on the Spring Boot.Our free Spring Boot course start from the basic and bring you to the speed with the advance concepts of the Spring Boot.The course includes free video lessons to help you lean the concepts more easily.

• Spring Boot Course
• Spring Boot Video Lessons

Build REST API With Spring

Leanr fundamentals of building REST API with Spring. Our free course will help you to quickely start from the basics of the REST.This course help you to impliment these REST principles using Spring framework.

• REST with Spring Series

Techinical Interview Series

If you are preparing for your next job interview, we have an interview series to help you prepare for your next job.

• Spring Core Interview Q/A
• Spring MVC Interview Questions with Answers
• Spring Boot Interview Questions
• Java Interview Questions

Source Code

This repository contains the source code for all the artcile published on the JavaDevJournal.All these projects are maven based.You can download and run the project by following these steps:

Building the Project

To build these mavens based projects,run the following command: mvn clean install

Running Spring Boot Project

To run a Spring Boot module run the command: mvn spring-boot:run

Running Java Project

Find the main class and run it.

Few Popular Articles on Java Dev Journal

• Building a Spring Boot application using IntelliJ IDEA
• Error Handling for REST with Spring
• Spring REST API Validation
• Copy a File or Directory in Java
• REST Pagination in Spring
• How to Make a Deep Copy of an Object in Java
• Log Incoming Requests In Spring
• How to add a filter in Spring Boot
• Spring Singleton vs Singleton Pattern
• Data Conversion for Spring REST API
• Guide to Spring Session
• Internationalization in Spring Boot

Free Developer Tool

Free Online Developer Tool

Free Developers Tools is a free toolset for developers to do some quick tasks like JSON validation, minification etc.Here are some of the free tool you can use

• Free QR Generator
• Free HTML formatters
• Free JSON formatters

Online Compilers

Free Online Compiler Free Online Compilers provide online compilers to various programming languages.Use our online free compilers to run your code in real time and see the results without any wait.

• Online Java Compiler
• Online Python Compiler

javadevjournal's Issues

Eureka Server

Develop Eureka Server

Implementation of Custom UsernamePasswordAuthenticationFilter

Hey, thanks for your very helpful tutorial. I was looking in the CustomAuthenticationFilter and wondering wheather you're actually using your custom UsernamePasswordAuthenticationToken. I appears you're just calling the the parents attemptAuthentication mehtod without passing the custom Token to an authentication Manager. Maybe I'm missing something.

Application isn't loading for me.

I dont see multiple Authentication Providers implementation?

In the article https://www.javadevjournal.com/spring-security/spring-security-multiple-authentication-providers/, I would except to see an implementeation showing how multiple auth providers can be added to an app. For example:

1. LDAP auth provider
2. Oath auth provider
3. LoginForm auth provider
4. DB auth provider
5. ...

, however, all I see is article talking about multiple auth providers but using a single user based auth provider (DB). It does not show at all nor provide example where we have multiple authentication providers. It provides a single CustomAuthenticationProvider using UserDetailsService to get user details from database.
Same thing is with the provided code on this github

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
[2021-06-09 18:03:28.688] - 428
Serious [main] --- org.springframework.boot.SpringApplication: Application run failed
org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:157)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:540)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248)
at com.javadevjournal.SpringBootCustomMessageSourceApplication.main(SpringBootCustomMessageSourceApplication.java:21)
Caused by: org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getWebServerFactory(ServletWebServerApplicationContext.java:206)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:180)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:154)
... 8 more

Eureka Client1

Develop Eureka Client1

spring-config.xml - DefaultCodeVerifier

Hi,
I define bean in spring-config.xml in order to have it istantiated once use method verifyTotp. Here the definition inside the xml:

<bean id="codeVerifier" class="dev.samstevens.totp.code.DefaultCodeVerifier" />

On the server startup I receive error in the logs:

org.springframework.beans.BeanInstantiationException: Failed to instantiate [dev.samstevens.totp.code.DefaultCodeVerifier]: No default constructor found; nested exception is java.lang.NoSuchMethodException: dev.samstevens.totp.code.DefaultCodeVerifier.()

Which workaround/method you suggest to follow?

Thanks in advance for answers.

jdbcUrl Issue you mentioned in a note at the end of your article - simple way to fix it is to rename "url" to "jdbc-url"

Hi and thank you for great article. The note at the bottom about Hikari switch in Springboot 2.0, all I had to do is rename

spring.datasource.url=....

to:

spring.datasource.jdbc-url=....

Given that it is such a simple change, I think it would significantly improve your article if you add that solution instead of having the comment with a url to another site. The url document does have that information as well; however, it is little bit hidden:

Just a suggestion, much appreciated for the article.

Unable to send SimpleMailMessage

Dear Author,

I use spring-boot-starter-mail and implement EmailService in the similar way (I just add error type, which can be throwed by the sendSimpleEmail method)
Service is being called from the RestController:
@GetMapping("/email") public @ResponseBody Object email() { try { mailer.sendSimpleEmail("[email protected]", "Test Subject", "Test message"); // <-- hangs up here return ResponseEntity.ok(new GenericResponse("OK")); } catch (Exception ex) { return ResponseEntity.badRequest().body(new GenericResponse(ex.getMessage())); } }
When the endpoint is called by Postman, it hangs up and returns nothing