无法使用 spring 引导将数据保存到数据库

Question

When I am running the test class public void testCreate() , the test is running without error but I am not able to save any data to the DB.

I have created a Product.java model class, and then using created a ProductRepository.java extending CrudRepository.java to interact with the MySQL DB.

My Spring boot version is 2.2.0.RELEASE Below are my classes:

Product.java

package com.hibernate.productData.entities;



import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.Table;



@Entity

@Table

public class Product {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    private String name;

    @Column(name="description")
    private String desc;

    private Double price;

    public int getId() {

    return id;

}

public void setId(int id) {this.id = id;}

public String getName() {return name;}

public void setName(String name) {this.name = name;}

public String getDesc() {return desc;}

public void setDesc(String desc) {this.desc = desc;}

public Double getPrice() {return price;}

public void setPrice(Double price) {this.price = price;}

}

ProductRepository.java

package com.hibernate.productData.repository;
import java.util.Optional;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.hibernate.productData.entities.Product;

@Repository
public class ProductRepository implements CrudRepository<Product, Integer>
{
@Override
public <S extends Product> S save(S entity) {
// TODO Auto-generated method stub
return null;
}



@Override

public <S extends Product> Iterable<S> saveAll(Iterable<S> entities) {

// TODO Auto-generated method stub

return null;

}



@Override

public Optional<Product> findById(Integer id) {

// TODO Auto-generated method stub

return null;

}



@Override

public boolean existsById(Integer id) {

// TODO Auto-generated method stub

return false;

}



@Override

public Iterable<Product> findAll() {

// TODO Auto-generated method stub

return null;

}



@Override

public Iterable<Product> findAllById(Iterable<Integer> ids) {

// TODO Auto-generated method stub

return null;

}



@Override

public long count() {

// TODO Auto-generated method stub

return 0;

}



@Override

public void deleteById(Integer id) {

// TODO Auto-generated method stub

}



@Override

public void delete(Product entity) {

// TODO Auto-generated method stub

}



@Override

public void deleteAll(Iterable<? extends Product> entities) {

// TODO Auto-generated method stub

}



@Override

public void deleteAll() {

// TODO Auto-generated method stub

}



}

ProductDataApplicationTests.java

package com.hibernate.productData;



import org.junit.jupiter.api.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.test.context.junit4.SpringRunner;



import com.hibernate.productData.entities.Product;

import com.hibernate.productData.repository.ProductRepository;



@RunWith(SpringRunner.class)

@SpringBootTest

class ProductDataApplicationTests {



@Autowired

ProductRepository repos;

@Test

void contextLoads() {

}

@Test

public void testCreate()

{

Product p = new Product();

p.setId(1);

p.setName("harry potter");

p.setDesc("Awesome");

p.setPrice(100d);

    repos.save(p);

}

}

application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=Pblock@10

pom.xml

<?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>2.2.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.hibernate.productData</groupId>
    <artifactId>productData</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>productData</name>
    <description>Hibernate project</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

</project>

Answer 1

the test is running without error but I am not able to save any data to the DB.

I think that may be because you have overridden the CrudRepository's save method. I have not seen this done anywhere. Try to replace your implementation of ProductRepository with

package com.hibernate.productData.repository;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.hibernate.productData.entities.Product;

@Repository
public interface ProductRepository extends CrudRepository<Product, Integer>
{
}

What I think is happening is that your save method's implementation is being called which does nothing.

Answer 2

The reason behind your values not getting saved in DB is that you have implemented the CrudRepository and if that's what you want to do then you need to provide your implementation for the overridden methods such as save() , saveAll() , etc.

If you want to use the default implementation you can extend the CrudRepository instead of extending it.

package com.hibernate.productData.repository;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.hibernate.productData.entities.Product;

@Repository
public interface ProductRepository extends CrudRepository<Product, Integer>
{
}

I hope this should help you with the issue.