Why can't connect to remote database via Spring Boot JPA?

Question

Java

The hosting is MySQL database version 10.3, to which I try to connect, but no matter how hard I try, it crashes with a lot of errors.

I set up remote access on the hosting, everyone can connect to the host.
Looking through phpmyadmin, MySQL is running on localhost:3306.

I checked through the application for remote connection to the Sequel PRO database by setting the connection data - everything worked with full access. Accordingly, the problem is not on the hosting side.

I also raised a local server with MySQL, where, having also changed only the data in the application.properties file, I easily joined and created entities.

Could someone explain what's wrong and how to connect to a remote database?

Request Controller File

package com.example.API.Controllers.UserAuthControllers;

import com.example.API.Models.UserPassword;
import com.example.API.Repositories.AuthRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
public class RegistrationController {

    @Autowired
    private AuthRepository authRepository;

    @PostMapping("/auth/registrationCreateRequest")
    public String test(
            @RequestParam(value = "login") String login,
            @RequestParam(value = "passwordHASH") String passwordHASH
    ) {
        UserPassword userPassword = new UserPassword(login, passwordHASH);
        authRepository.save(userPassword);
        return "ok";
    }
}

Entity file for database

package com.example.API.Models;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "users_pwd")
public class UserPassword {

    @Id
    @GeneratedValue
    private int id;
    private String login;
    private String passwordHASH;

    public UserPassword(String login, String passwordHASH) {
        this.login = login;
        this.passwordHASH = passwordHASH;
    }

    public UserPassword() {
    }

    public long getId() {
        return id;
    }

    public String getLogin() {
        return login;
    }

    public void setLogin(String login) {
        this.login = login;
    }

    public String getPasswordHASH() {
        return passwordHASH;
    }

    public void setPasswordHASH(String passwordHASH) {
        this.passwordHASH = passwordHASH;
    }
}

Repository file

package com.example.API.Repositories;

import com.example.API.Models.UserPassword;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface AuthRepository extends JpaRepository<UserPassword, Integer> {
}

application.properties file

# MySQL BD CONNECTION
spring.jpa.database=mysql
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://remoteHost:3306/bdname
spring.datasource.username=username
spring.datasource.password=pwd
spring.jpa.show-sql=false
spring.jpa.hibernate.ddl-auto=none

pom.xml file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.5.6</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.example</groupId>
  <artifactId>API</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>project</name>
  <description>desc</description>
  <properties>
    <java.version>11</java.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <version>2.5.7</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.27</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-jpa</artifactId>
      <version>2.5.7</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-core</artifactId>
      <version>5.6.1.Final</version>
    </dependency>

    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.13.0</version>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-security</artifactId>
      <version>2.5.6</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-test</artifactId>
      <version>5.6.0</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

</project>

Here are the error headers below, when the application crashes, and the error is "The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server." crashes already several times, I think it has the juice, but I couldn’t ask Google or the answers weren’t working for me.

2021-11-19 15:54:36.642  WARN 58707 --- [           main] o.h.e.j.e.i.JdbcEnvironmentInitiator     : HHH000342: Could not obtain connection to query metadata

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

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution

Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
Caused by: org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution

Process finished with exit code 1

Answer 1

Good evening!

No appropriate protocol (protocol is disabled or cipher suites are inappropriate)

Have you tried that?

jdbc:mysql://remoteHost:3306/bdname?autoReconnect=true&useSSL=false

https://stackoverflow.com/questions/67899129/postf...
Here's what they say:

As far as I am concerned, the cause of the issue is that OpenJdk requires TLSv1.2 or TLSv1.3, starting from version 11.0.11. Update: The change will apply to at least OpenJDK 8u292 onward, OpenJDK 11.0.11 onward, and all versions of OpenJDK 16, following the JRE and JDK Crypto Roadmap published by Oracle