SpringBoot JPA

偏执的太偏执、 2021-12-20 14:41 240阅读 0赞

# 一、创建步骤![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70]![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 1] #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 2]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 3]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 4]

# 二、目录结构 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 5]

# 三、application.properties配置datasource #

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
    spring.datasource.username=root
    spring.datasource.password=root
    spring.datasource.url=jdbc:mysql://localhost/springboot?userUnicode=true@characterEncoding=UTF8&serverTimezone=UTC

# 四、domain层创建实体类User #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 6]

package com.willam.domain;
    
    import javax.persistence.*;
    
    /**
     * @author ：lijunxuan
     * @date ：Created in 2019/6/28  17:04
     * @description ：
     * @version: 1.0
     */
    @Table(name = "user")
    @Entity
    public class User {
        @Id  //ID代表是主键
        @GeneratedValue(strategy = GenerationType.IDENTITY)  //按照主键自增
        private Integer id;
        //@Column(name="username")   //把数据库里的名字和当前名字做一个绑定关系
        private String  username;
        private String  password;
        private String  name;
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    ", name='" + name + '\'' +
                    '}';
        }
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public String getUsername() {
            return username;
        }
    
        public void setUsername(String username) {
            this.username = username;
        }
    
        public String getPassword() {
            return password;
        }
    
        public void setPassword(String password) {
            this.password = password;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    }

# 五、Controller层UserController #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 7]

package com.willam.Controller;
    
    import com.willam.Service.UserService;
    import com.willam.domain.User;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.List;
    
    /**
     * @author ：lijunxuan
     * @date ：Created in 2019/6/28  17:02
     * @description ：
     * @version: 1.0
     */
    @RestController
    @RequestMapping("/user")
    public class UserController {
        @Autowired
        UserService userService;
    
        /**
         * 查询所有用户
         * @return
         */
        @RequestMapping("/findAll")
        public List<User> findAll(){
                           return userService.findAll();
                     }
    
        /**
         * 通过ID查询用户
         * @param id
         * @return
         */
        @RequestMapping("/findById")
                    public User findById(Integer id){
                        return userService.findById(id);
                    }
    
        /**
         * 添加用户
         * @param user
         *
         */
        @RequestMapping("/add")
                    public void add(User user){
                       userService.add(user);
                    }
    
        /**
         * 通过用户ID删除用户
         * @param id
         *
         */
        @RequestMapping("/deleteById")
        public void deleteById(Integer id){
             userService.deleteById(id);
        }
    
    
    }

# 六、service层 #

## （1）UserService接口 ##

package com.willam.Service;
    
    import com.willam.domain.User;
    
    import java.util.List;
    
    public interface UserService {
        /**
         * 查询所有用户信息
         * @return
         */
        List<User> findAll();
        /**
         * 通过ID查询用户
         * @param id
         * @return
         */
        User findById(Integer id);
        /**
         * 添加用户
         * @param user
         *
         */
        void add(User user);
        /**
         * 通过用户ID删除用户
         * @param id
         *
         */
        void deleteById(Integer id);
    }

## （2）UserServiceImpl实现类 ##

package com.willam.Service.impl;
    
    import com.willam.Dao.UserDao;
    import com.willam.Service.UserService;
    import com.willam.domain.User;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import java.util.List;
    import java.util.Optional;
    
    /**
     * @author ：lijunxuan
     * @date ：Created in 2019/6/28  17:27
     * @description ：
     * @version: 1.0
     */
    @Service
    public class UserServiceImpl implements UserService {
        @Autowired
        UserDao userDao;
        @Override
        public List<User> findAll() {
            return userDao.findAll();
        }
        @Override
        public User findById(Integer id) {
            Optional<User> userById = userDao.findById(id);
            return userById.get();
        }
        @Override
        public void add(User user) {
          userDao.save(user);
        }
        @Override
        public void deleteById(Integer id) {
       userDao.deleteById(id);
        }
    }

# 七、Dao层 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 8]

package com.willam.Dao;
    
    import com.willam.domain.User;
    import org.springframework.data.jpa.repository.JpaRepository;
    import org.springframework.stereotype.Repository;
    
    @Repository
    public interface UserDao extends JpaRepository<User,Integer> {
    }

# 八、 集成Spring Data Redis #

### 实现步骤： ###

1.  添加Redis起步依赖
2.  在application.properties中配置redis端口、地址
3.  注入RedisTemplate操作Redis缓存查询所有用户数据
4.  测试缓存

## 1. 添加Redis起步依赖 ##

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

## 2. 在application.properties中配置redis端口、地址 ##

# Redis 配置(不填也是可以的)
    spring.redis.host=localhost
    spring.redis.port=6379

## 3. 注入RedisTemplate操作Redis缓存查询所有用户数据 ##

#### 将Controller层的findAll方法修改一下 ####

@Resource
        RedisTemplate redisTemplate;
        @RequestMapping("/findAll")
        public List<User> findAll(){
    
            /*如果第一次查询，redis缓存没有数据，就从数据库中获取
            如果有缓存数据，那么从缓存中获取
           */
            String users = (String)redisTemplate.boundValueOps("userDao.findAll").get();
            if (users==null){
                //数据库查询
               List<User> all=userService.findAll();
               users = all.toString();
               redisTemplate.boundValueOps("userDao.findAll").set(users);  //把当前的数据缓存
            }
            return userService.findAll();
                     }

## 4. 测试缓存 ##

打一个断点  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 9]  
地址栏 发送请求 [http://localhost:8080/user/findAll][http_localhost_8080_user_findAll]  
![在这里插入图片描述][20190628190836929.png]  
后台  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 10]  
redis中有缓存则直接走 return userService.findAll();  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 11]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 12]

# 九、 集成定时器 #

## （1）在SpringbootJpaApplication开启定时器 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 13]

## （2）创建Timer类 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 14]

package com.willam.Utils;
    
    import com.willam.Service.UserService;
    import org.springframework.scheduling.annotation.Scheduled;
    import org.springframework.stereotype.Component;
    
    import java.time.LocalDate;
    import java.time.LocalDateTime;
    import java.util.Date;
    
    /**
     * @author ：lijunxuan
     * @date ：Created in 2019/6/28  19:18
     * @description ：
     * @version: 1.0
     */
    @Component //把当前的类加入spring容器
    public class Timer {
        UserService userService;
        /**
         * 定时任务的配置
         * corn 表达式
         * fixedDelay 固定的延迟时间执行，上一个任务执行完成，多久之后下一个任务执行。
         * rateDelay 固定频率执行，每隔固定时间执行任务
         */
        @Scheduled(fixedRate = 2000)
        public void task(){
            System.out.println(new Date());
            System.out.println(LocalDateTime.now());
        }
    }

## （3）测试结果 ##

每隔2秒执行一次  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 15]

# 十、SpringBoot如何代码测试 #

## （1）加入依赖 ##

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>

## （2）编写测试类： ##

*  SpringRunner继承SpringJUnit4ClassRunner，使用哪一个Spring提供的测试引擎都可以。指定运行测试的引擎
 *  @SpringBootTest的属性值指的是引导类的字节码对象

package com.willam;
    
    import com.willam.Service.UserService;
    import com.willam.domain.User;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    
    import javax.annotation.Resource;
    import java.util.List;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest //SpringBoot测试类
    public class SpringbootJpaApplicationTests {
        @Resource
        UserService userService;
    
        @Test
        public void contextLoads() {
            List<User> userList = userService.findAll();
            System.out.println(userList);
        }
    
    }

## （3）测试结果 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 16]

# 十一、Spring Boot 如何打包部署 #

## （1）打成Jar包部署 ##

在cmd切换到项目的路径  
如：H:\\workspace\\IdeaProject\\SpringBoot\\day01\\day01\_springboot\_jpa  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 17]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 18]  
启动命令：

java -jar target/day01_springboot_jpa-0.0.1-SNAPSHOT.jar

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 19]  
启动命令的时候配置jvm参数也是可以的。然后查看一下Java的参数配置结果

java -Xmx80m -Xms20m  -jar target/day01_springboot_demo01-1.0-SNAPSHOT.jar

### 小技巧 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 20]

## （2）打成War包部署 ##

#### 1.执行maven打包命令或者使用IDEA的Maven工具打包，需要修改pom.xml文件中的打包类型。 ####

#### 2. 注册启动类 ####

*  创建 ServletInitializer.java，继承 SpringBootServletInitializer ，覆盖 configure()，把启动类 Application 注册进去。外部 Web 应用服务器构建 Web Application Context 的时候，会把启动类添加进去
 *

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 21]

//web.xml
    public class ServletInitializer extends SpringBootServletInitializer {
        @Override
        protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
            return builder.sources(DemoApplication.class);
        }
    }

#### 3.然后执行打包操作 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 22]

## 启动 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70 23]

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[http_localhost_8080_user_findAll]: http://localhost:8080/user/findAll
[20190628190836929.png]: /images/20211220/54e11ba1d160474e830a415c4e5a1955.png
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