Spring Boot H2 简明教程

Spring Boot & H2 - Project Setup

如前一章 Environment Setup 中所述，我们在 Eclipse 中导入了 Spring Boot 生成的项目。现在让我们在 src/main/java 文件夹中创建以下结构。

project structure

  1. com.tutorialspoint.controller.EmployeeController ——一个REST基于控制器实现REST基于API。

  2. com.tutorialspoint.entity.Employee ——一个实体类表示数据库中对应的表。

  3. com.tutorialspoint.repository.EmployeeRepository ——一个存储库接口来执行crud操作库。

  4. com.tutorialspoint.service.EmployeeService ——一个服务类来执行业务操作库函数。

  5. com.tutorialspoint.springbooth2.SprintBootH2Application ——一个SpringBoot应用程序类。

SprintBootH2Application类已存在。我们须创建上述包和相关类和接口如下所示——

Entity - Entity.java

以下为Employee的默认代码。它表示一个带id，name，age和email列的Employee表。

package com.tutorialspoint.entity;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table
public class Employee {
   @Id
   @Column
   private int id;
   @Column
   private String name;
   @Column
   private int age;
   @Column
   private String email;
   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 int getAge() {
      return age;
   }
   public void setAge(int age) {
      this.age = age;
   }
   public String getEmail() {
      return email;
   }
   public void setEmail(String email) {
      this.email = email;
   }
}

Repository - EmployeeRepository.java

以下为实现上述实体创建CRUD操作的存储库的默认代码，Employee。

package com.tutorialspoint.repository;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;
@Repository
public interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
}

Service - EmployeeService.java

以下为实现库函数操作的服务的默认代码。

package com.tutorialspoint.service;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.repository.EmployeeRepository;
@Service
public class EmployeeService {
   @Autowired
   EmployeeRepository repository;
   public Employee getEmployeeById(int id) {
      return null;
   }
   public List<Employee> getAllEmployees(){
      return null;
   }
   public void saveOrUpdate(Employee employee) {
   }
   public void deleteEmployeeById(int id) {
   }
}

Controller - EmployeeController.java

以下为实现REST API的控制器的默认代码。

package com.tutorialspoint.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.service.EmployeeService;
@RestController
@RequestMapping(path = "/emp")
public class EmployeeController {
   @Autowired
   EmployeeService employeeService;
   @GetMapping("/employees")
   public List<Employee> getAllEmployees(){
      return null;
   }
   @GetMapping("/employee/{id}")
   public Employee getEmployee(@PathVariable("id") int id) {
      return null;;
   }
   @DeleteMapping("/employee/{id}")
   public void deleteEmployee(@PathVariable("id") int id) {
   }
   @PostMapping("/employee")
   public void addEmployee(@RequestBody Employee employee) {
   }
   @PutMapping("/employee")
   public void updateEmployee(@RequestBody Employee employee) {
   }
}

Application - SprintBootH2Application.java

以下为用于使用上述类的Application的更新代码。

package com.tutorialspoint.sprintbooth2;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
@ComponentScan({"com.tutorialspoint.controller","com.tutorialspoint.service"})
@EntityScan("com.tutorialspoint.entity")
@EnableJpaRepositories("com.tutorialspoint.repository")
@SpringBootApplication
public class SprintBootH2Application {
   public static void main(String[] args) {
      SpringApplication.run(SprintBootH2Application.class, args);
   }
}

Run/Debug Configuration

在eclipse中创建以下 maven configuration 来运行带目标 spring-boot:run 的springboot应用程序。此配置将有助于运行REST API，我们可以使用POSTMAN对其进行测试。

maven configuration