SpringBoot（二）集成Redis-集成Mybatis

我会带着你远行 2022-05-12 13:24 260阅读 0赞

### 集成Redis ###

一：添加依赖

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

二：配置Redis参数

spring：
        redis:
            host: localhost
            port: 6379
            database: 0
            jedis:
              pool:
                max-idle: 8
                min-idle: 1
                max-active: 8
                max-wait: -1

三：注入StringRedisTemplate

@RestController
    public class RedisController {
    	@Autowired
    	private  StringRedisTemplate redis;
    	
    	@GetMapping(value="/test")
    	public Object test() {
    		
    		return null;
    	}
    }

三：获取操作单元

@GetMapping(value="/test")
    	public String test() {
    		//String
    		ValueOperations<String, String> value = redis.opsForValue();
    		//hash
    		HashOperations<String, Object, Object> hash = redis.opsForHash();
    		//set
    		SetOperations<String, String> set = redis.opsForSet();
    		//list
    		ListOperations<String, String> list = redis.opsForList();
    		
    		value.set("string", "今天天气不错");
    		String str = value.get("string");
    		System.out.println(str);
    		return str;
    	}

结果：访问结果

### ![70][] ###

redis数据库：

![70 1][]

### 这里有问题一：我想存储对象怎么办？？ ###

方法一：将对象序列化后，存入

方法二：将对象转化为json格式字符串存入。

### 这里推荐第二种，对象转json格式字符串 ###

一：先导个包

习惯使用fastjson

<dependency>
    			<groupId>com.alibaba</groupId>
    			<artifactId>fastjson</artifactId>
    			<version>1.2.51</version>
    		</dependency>

二：使用

@GetMapping(value="/test")
    	public Object test() {
    		//String
    		ValueOperations<String, String> value = redis.opsForValue();
    		//hash
    		HashOperations<String, Object, Object> hash = redis.opsForHash();
    		//set
    		SetOperations<String, String> set = redis.opsForSet();
    		//list
    		ListOperations<String, String> list = redis.opsForList();
    		
    		//存取字符串
    		value.set("string", "今天天气不错");
    		String str = value.get("string");
    		
    		//存取对象
    		user u = new user(1, "大黄", 2);
    		String jsonStr = JSON.toJSONString(u);
    		value.set("user", jsonStr);
    		
    		jsonStr = value.get("user");
    		u = JSON.parseObject(jsonStr, user.class);
    		
    		return u;
    	}

三：结果

访问结果：

![70 2][]

Redis数据库：

![70 3][]

### 集成mybatis ###

一：添加依赖

<dependency>
    			<groupId>org.mybatis.spring.boot</groupId>
    			<artifactId>mybatis-spring-boot-starter</artifactId>
    			<version>1.3.2</version>
    		</dependency>
                    
    		<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    		</dependency>

二：配置数据库

spring:
      datasource:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/springboot
        username: root
        password: xxxx
    mybatis:
      mapper-locations: classpath:mapper/*mapper.xml   
      type-aliases-package: com.example.demo.bean

type-aliases-package:这个指向bean所在的包

mapper-locations：这个执行配置文件在的位置

三：bean

@Entity
    @JsonIgnoreProperties(value = {"hibernateLazyInitializer", "handler"})
    public class user {
    	@Id
    	@GeneratedValue(strategy= GenerationType.IDENTITY)
    	private int id;
    	private String name;
    	private int age;
            ...
    }

@JsonIgnoreProperties(value = \{"hibernateLazyInitializer", "handler"\})   转换json格式的时候忽略hibernateLazyInitializer

@GeneratedValue(strategy= GenerationType.IDENTITY)       自增长

四：书写Mapper

### 这里有个岔路，传统的xml和注解两种方法 ###

一：xml

userMapper

@Mapper
    public interface userMapper {
    	// 查询全部
    	public List<user> findAll();
    
    	// 根据id查询
    	public user findById(int id);
    }

@Mapper   接口会在编译时生成相对应的实现类

userMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    <mapper namespace="com.example.demo.mapper.userMapper">
    	<select id="findAll" resultType="user">
    		select * from user
    	</select>
    	
    	<select id="findById"  resultType="user" >
    	select * from user where id=#{id}
    	</select>
    	
    </mapper>

ok!!

二：注解方式

@Mapper
    public interface userMapper {
    
    	// 删除id
    	@Delete("delete from user where id=#{id}")
    	public void delete(int id);
    
    	// 添加
    	@Insert("insert into user(age,name) values(#{age},#{name})")
    	public void add(user user);
    
    	// 修改
    	@Update("update user set name=#{name},age=#{age} where id=#{id}")
    	public void update(user user);
    }

OK！！

五：使用

使用的时候注入userMapper

@RestController
    @RequestMapping(value = "/mybatis")
    public class mybatisUserController {
    	@Autowired
    	private userMapper userMapper;
    
    	@GetMapping(value = "/user")
    	public List<user> findAll() {
    		return userMapper.findAll();
    	}
    	
    	@GetMapping(value="/user/{id}")
    	public user findById(@PathVariable("id")int id) {
    		return userMapper.findById(id);
    	}
    	@PostMapping(value="/add")
    	public user add(user user) {
    	    userMapper.add(user);
    	    return user;
    	}
    	
    	@PostMapping(value="/update")
    	public void update(user user) {
    		userMapper.update(user);
    	}
    	@GetMapping(value="/del/{id}")
    	public void del(@PathVariable("id")int id) {
    		userMapper.delete(id);
    	}
    }

[70]: /images/20220504/ed310016f0ab488d9f90ba583cbac93a.png
[70 1]: /images/20220504/16dfbabdffe344298c5d152c73af76a0.png
[70 2]: /images/20220504/19d3d3d511244fa888b18c2f7b9c09aa.png
[70 3]: /images/20220504/454c2155ecdc499dae9a7e595b77a37e.png