Could not find acceptable representation .COM PathVariable Spring boot 2

Solution next error.

In your method RESTful web service add.


@GetMapping("/public/file/{url_filename:.*}")

And create next class.

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

@Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
configurer.favorPathExtension(false).favorParameter(true);
}

}

Caused by: org.hibernate.AnnotationException: No identifier specified for entity

Solution next Error:

you need to add primary key in your table database and  add id(@Id) annotation attribute on your class in java.

Can't serve static html with Spring Boot 2

Solution next error.

Add next class:

package your_package;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class StaticResourceConfiguration implements WebMvcConfigurer {

 private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {
  "classpath:/META-INF/resources/",
  "classpath:/resources/",
  "classpath:/static/",
  "classpath:/public/"
 };

 @Override
 public void addResourceHandlers(ResourceHandlerRegistry registry) {
  registry.addResourceHandler("/**")
   .addResourceLocations(CLASSPATH_RESOURCE_LOCATIONS);
 }

}


and try again access, for example:

http:localhost:8080/your_html.html

or

http:localhost:8080/your_context/your_html.html













References:
https://spring.io/blog/2013/12/19/serving-static-web-content-with-spring-boot

TypeError: Cannot read property 'kind' of undefined - Angular 8

Solution next error Angular 8:

ERROR in ./node_modules/ng-multiselect-dropdown/fesm5/ng-multiselect-dropdown.js
Module build failed (from ./node_modules/@angular-devkit/build-optimizer/src/build-optimizer/webpack-loader.js):     
TypeError: Cannot read property 'kind' of undefined


Change the version angular-devkit with next command:

npm install @angular-devkit/build-angular@0.803.20


check your package.json

And try again.

ng build --prod /











References:
https://github.com/ckeditor/ckeditor4-angular/issues/78

Kotlin + OAuth2 + JWT + SpringBoot2 + JPA

I share example how to integrate Kotlin + OAuth2 + Spring Rest API + SpringBoot 2  + JWT +JPA.

Technologies used:

1. Spring Boot 2.2.6.RELEASE
2. Maven
3. OAuth2
4. Intellij IDEA Community
5. Spring Tools Suite (STS) 4
6. MySql
7. Postman

Code on GitHub:

https://github.com/HenryXiloj/Kotlin-OAuth2-SpringBoot2-JPA

Steps:

Create table on MySql:

CREATE TABLE `users` 
( 
 `id`       INT(11) NOT NULL auto_increment, 
 `username` VARCHAR(255) NOT NULL, 
 `password` VARCHAR(255) NOT NULL, 
 `created` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP() on 
  UPDATE CURRENT_TIMESTAMP(), 
  PRIMARY KEY (`id`) 
)


I saved the password field with Security - Password Enconding (org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder)

INSERT INTO users 
VALUES      (1, 
             'henry', 
             '$2a$04$I9Q2sDc4QGGg5WNTLmsz0.fvGv3OjoZyj81PrSFyGOqMphqfS2qKu'); 

IntelliJ:  File -> open --> choose folder backend


Change the configuration on file application.yml




Run project from IntelliJ :

View -> Tool Windows -> Maven -> Execute Maven Goal-> mvn install

Run project backend.jar with java -jar backend.jar,  in the file configuration you can define context for application, i define context --> backend and port 9000.


Credencials for test:

Test: Get token

Test: Error when you try to access ws, you need to add access_token

Add access_token -> url?access_token=your_token.

References:
https://www.devglan.com/spring-security/spring-boot-security-oauth2-example

Configure Tomcat reverseproxy https to http

If your site using https and you need to access http tomcat, you need to make reverseproxy.

Edit file conf/server.xml and add yellow paragraph:

<Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               proxyName="server.company.com" scheme="https" secure="true" proxyPort="443" />


Restart tomcat.

Try again.





















References:
https://serverfault.com/questions/742922/configure-tomcat-behind-reverseproxy

GIT Tips

1.  Install git

sudo apt install git

2. create file .ssh

sudo mkdir /home/your_user/.ssh  

3. On folder .ssh run next command, (enter and enter doesn't write anything).

ssh-key

4. copy content on file id_rsa.pub

cat /home/your_user/.ssh/id_rsa.pub

5. Open in your browser GitHub or GitLab

GitHub: https://github.com/settings/keys  -> New SSH key

GitLab:https://your_ip_or_hostname/profile/keys --> Add and SSH Key

6. Clone branch or specific branch

Any branch:

git clone <remote-repo>

Specific branch:

git clone --single-branch --branch <branchname> <remote-repo>

8. Discard unstaged changes

git stash

9. Git Checkout Specific file

git checkout <branch_name> -- <paths>

10. Override comment in commit

git commit --amend -m "My_new_comment"

11. Remove local commits

git reset --hard origin/<branch_name>

12. To rollback to commit

git reset --hard sha1_id

13. Create GitHub Branch from Commit

Clone the Repository:

git clone https://github.com/your-username/your-repository.git
cd your-repository

Find the Commit Hash:

git log

Create a New Branch:

git checkout -b new-branch-name commit-hash

Push the New Branch to GitHub:

git push origin new-branch-name

14. Pull All Branches Automatically

To configure your Git repository to automatically track all remote branches, you can set the following:

git config remote.origin.fetch "+refs/heads/*:refs/remotes/origin/*"
git fetch origin

This ensures that all remote branches are fetched and mirrored locally.

15. Long path file:

git config --system core.longpaths true

17. Recovery

git stash list

git stash apply stash@{0}   # most recent
git stash apply stash@{6}   # oldest 6 = n