spring boot+jpa实现简单的增删改查

本文简单介绍一下spring boot+JPA实现简单的增删改查功能

 

一、项目结构简述

二、搭建spring boot+jap环境

三、代码示例

四、spring boot的启动方式

 

一、项目结构简述

 

1、项目的目录结构注意点

 

问题说明：

①使用内置服务器启动springboot项目时，会从@SpringBootApplication修饰类所在的包开始，加载当前包和所有子包下的类，将由@Component @Repository @Service @Controller修饰的类交由spring进行管理；

②如上图，项目中的启动类为ApplacationController，他与其他层代码的处于同一个包下面，项目启动时会扫描到其他层的代码，就不会报如下错误（如果启动类所在的包与其它层代码所在的包处于平级目录中，即使启动类使用了@ComponentScan注解一样会报下面的错误）：

Action: Consider defining a bean of type 'cn.oschina.dao.PersonRespority' in your configuration.

 

二、搭建spring boot+jap环境

 

1、pom.xml文件

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>cn.oschaina</groupId>
  <artifactId>simple-spring-boot</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>
</parent>


<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
        <!-- 添加Mysql和JPA-->  
        <dependency>  
        <groupId>org.springframework.boot</groupId>  
        <artifactId>spring-boot-starter-data-jpa</artifactId>  
        </dependency>  
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.45</version>
</dependency>
</dependencies>
  
   <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.7.0</version>
        <configuration>
           <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
  
</project>

 

2、application.properites(或者是application.yml)

server.port=8081
server.context-path=/girl
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driverClassName=com.mysql.jdbc.Driver
# Specify the DBMS  
#spring.jpa.database=MYSQL
# Hibernate ddl auto (create, create-drop, update)  
spring.jpa.hibernate.ddl-auto=update
# Show or not log for each sql query  
spring.jpa.show-sql=true
# Naming strategy  
#spring.jpa.hibernate.naming-strategy=org.hibernate.cfg.ImprovedNamingStrategy
# stripped before adding them to the entity manager)  
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

 

三、代码示例

 

1、代码示例

(1)启动类

package cn.oschina;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

/**
 * 应用启动类 自动扫描：
 * 
 * 使用内置服务器启动springboot项目时，会从@SpringBootApplication修饰类所在的包开始，加载当前包和所有子包下的类，
 * 
 * 将由@Component @Repository @Service @Controller修饰的类交由spring进行管理
 * 
 * @author Freedom
 * 
 */
@SpringBootApplication
public class ApplacationController {

	public static void main(String[] args) {
		ConfigurableApplicationContext context = SpringApplication.run(
				ApplacationController.class, args);
		String[] profiles = context.getEnvironment().getActiveProfiles();
		if (profiles != null) {
			for (String profile : profiles) {
				System.out.println("------------start with profile : "
						+ profile);
			}
		}
	}

}

 

（2）控制层

package cn.oschina.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.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import cn.oschina.entity.Person;
import cn.oschina.service.IPersonService;

@RestController
public class PersonController {

	@Autowired
	private IPersonService personService;

	@GetMapping(value = "/persons")
	public List<Person> persons() {
		return personService.findAll();
	}

	@GetMapping("/person/{id}")
	public Person getPersonById(@PathVariable("id") Integer id) {
		return personService.findOne(id);
	}

	@PostMapping("/save")
	public Person savaPerson(@RequestParam("name") String name,
			@RequestParam("age") Integer age) {

		Person p = new Person();
		p.setAge(age);
		p.setName(name);
		return personService.insert(p);
	}

	@PutMapping("/update/{id}")
	public Person updatePerson(@PathVariable("id") Integer id,
			@RequestParam("name") String name) {
		Person p = new Person();
		p.setId(id);
		p.setName(name);
		return personService.update(p);
	}

	@DeleteMapping("/delete/{id}")
	public void deletePerson(@PathVariable("id") Integer id) {
		personService.delete(id);
	}

}

（3）业务层

package cn.oschina.service;

import java.util.List;

import cn.oschina.entity.Person;

/**
 * 对表tbl_person的增删改查
 * 
 * @author Freedom
 * 
 */
public interface IPersonService {

	List<Person> findAll();

	Person findOne(Integer id);

	Person insert(Person p);

	Person update(Person p);

	void delete(Integer id);
}

 

 

package cn.oschina.service;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import cn.oschina.dao.PersonRespority;
import cn.oschina.entity.Person;

/**
 * 对表tbl_person的增删改查
 * 
 * @author Freedom
 * 
 */
@Service
public class PersonService implements IPersonService {

	@Resource
	private PersonRespority personRespority;

	@Override
	public List<Person> findAll() {
		return personRespority.findAll();
	}

	@Override
	public Person findOne(Integer id) {
		return personRespority.findOne(id);
	}

	@Override
	public Person insert(Person p) {
		return personRespority.save(p);
	}

	/**
	 * 更新也是使用save()方法
	 */
	@Override
	public Person update(Person p) {
		return personRespority.save(p);
	}

	@Override
	public void delete(Integer id) {
		personRespority.delete(id);
	}

}

（4）数据访问层

package cn.oschina.dao;

import org.springframework.data.jpa.repository.JpaRepository;

import cn.oschina.entity.Person;

public interface PersonRespority extends JpaRepository<Person, Integer> {

}

   

（5）实体

package cn.oschina.entity;

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

@Entity
@Table(name = "tbl_person")
public class Person {

	@Id
	@GeneratedValue
	private int id;
	private String name;
	private int age;

	public Person() {
	}

	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;
	}

}

 

2、运行分析

（1）POST请求时

 

（2）PUT方式请求说明

 

四、spring boot的启动方式

 

1、@SpringBootApplication注解的类，并且main函数中执行SpringApplication.run方法

public static void main(String[] args) {
		ConfigurableApplicationContext context = SpringApplication.run(
				ApplacationController.class, args);
		String[] profiles = context.getEnvironment().getActiveProfiles();
		if (profiles != null) {
			for (String profile : profiles) {
				System.out.println("------------start with profile : "
						+ profile);
			}
		}
	}

 

2、使用maven指令方式

①找到项目所在的根目录；

②执行mvn spring-boot:run指令；