spring boot 笔记1

时间:2021-12-04 15:01:23

demon 目录,公共配置

spring boot 笔记1

SbMybatisApplication.java

package com.example.sb_mybatis;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan; @SpringBootApplication
@MapperScan("com.example.sb_mybatis.mapper")
@ServletComponentScan
public class SbMybatisApplication { public static void main(String[] args) {
SpringApplication.run(SbMybatisApplication.class, args);
}
}

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion> <groupId>com.example</groupId>
<artifactId>sb_mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging> <name>sb_mybatis</name>
<description>Demo project for Spring Boot</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties> <dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency> <dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.6</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.5</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.session</groupId>
<artifactId>spring-session-data-redis</artifactId>
</dependency> </dependencies> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build> </project>

application.properties:

mybatis.config-locations=classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
mybatis.type-aliases-package=com.example.sb_mybatis.entity
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=123456
#Druid
spring.datasource.druid.initial-size=3
spring.datasource.druid.min-idle=3
spring.datasource.druid.max-active=10
spring.datasource.druid.max-wait=60000
spring.datasource.druid.stat-view-servlet.login-username=admin
spring.datasource.druid.stat-view-servlet.login-password=admin
spring.datasource.druid.filter.stat.log-slow-sql=true
spring.datasource.druid.filter.stat.slow-sql-millis=2000
#Redis
# Redis 数据库索引(默认为0)
spring.redis.database=0
# Redis 服务器地址
spring.redis.host=127.0.0.1
# Redis 服务器连接端口
spring.redis.port=6379
# Redis 服务器连接密码(默认为空)
spring.redis.password=
# 连接池最大连接数(使用负值表示没有限制)
spring.redis.pool.max-active=8
# 连接池最大阻塞等待时间(使用负值表示没有限制)
spring.redis.pool.max-wait=-1
# 连接池中的最大空闲连接
spring.redis.pool.max-idle=8
# 连接池中的最小空闲连接
spring.redis.pool.min-idle=0
# 连接超时时间(毫秒)
spring.redis.timeout=10000

spring boot + mybatis

User.java

package com.example.sb_mybatis.entity;

import com.example.sb_mybatis.enums.UserSexEnum;
import lombok.Data; import java.io.Serializable; @Data
public class User implements Serializable {
private Long id;
private String userName;
private String passWord;
private UserSexEnum userSex;
private String nickName; public User(String userName, String passWord, UserSexEnum userSex, String nickName) {
this.userName = userName;
this.passWord = passWord;
this.userSex = userSex;
this.nickName = nickName;
} public User() {
}
}

UserSexEnum.java

package com.example.sb_mybatis.enums;

public enum UserSexEnum {
MAN, WOMAN
}

UserMapper.java

package com.example.sb_mybatis.mapper;

import com.example.sb_mybatis.entity.User;

import java.util.List;

public interface UserMapper {

    List<User> getAll();

    User getOne(Long id);

    void insert(User user);

    void update(User user);

    void delete(Long id);
}

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.sb_mybatis.mapper.UserMapper">
<resultMap id="BaseResultMap" type="com.example.sb_mybatis.entity.User">
<id column="id" property="id" jdbcType="BIGINT"/>
<result column="userName" property="userName" jdbcType="VARCHAR"/>
<result column="passWord" property="passWord" jdbcType="VARCHAR"/>
<result column="user_sex" property="userSex" javaType="com.example.sb_mybatis.enums.UserSexEnum"/>
<result column="nick_name" property="nickName" jdbcType="VARCHAR"/>
</resultMap> <sql id="Base_Column_List">
id, userName, passWord, user_sex, nick_name
</sql> <select id="getAll" resultMap="BaseResultMap">
SELECT
<include refid="Base_Column_List"/>
FROM users
</select> <select id="getOne" parameterType="Long" resultMap="BaseResultMap">
SELECT
<include refid="Base_Column_List"/>
FROM users where id = #{id}
</select> <insert id="insert" parameterType="User">
INSERT INTO users
(userName, passWord, user_sex, nick_name)
values (#{userName},#{passWord},#{userSex},#{nickName})
</insert> <update id="update" parameterType="User" >
UPDATE users SET
userName=#{userName},passWord=#{passWord},user_sex=#{userSex},nick_name=#{nickName}
</update> <delete id="delete" parameterType="Long" >
DELETE FROM users where id=#{id}
</delete>
</mapper>

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias alias="Integer" type="java.lang.Integer"/>
<typeAlias alias="Long" type="java.lang.Long"/>
<typeAlias alias="HashMap" type="java.util.HashMap"/>
<typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap"/>
<typeAlias alias="ArrayList" type="java.util.ArrayList"/>
<typeAlias alias="LinkedList" type="java.util.LinkedList"/>
<typeAlias alias="User" type="com.example.sb_mybatis.entity.User"/>
</typeAliases> </configuration>

测试类,UserService就是直接调用mapper的发方法(代码略)

package com.example.sb_mybatis.service;

import com.example.sb_mybatis.entity.User;
import com.example.sb_mybatis.enums.UserSexEnum;
import org.junit.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 static org.junit.Assert.*; @RunWith(SpringRunner.class)
@SpringBootTest
public class UserServiceTest { @Autowired
UserService service; @Test
public void getAll() {
System.out.println(service.getAll());
} @Test
public void getOne() {
System.out.println(service.getOne(123L));
} @Test
public void insert() {
User u = new User("aaa", "123456", UserSexEnum.MAN, "nickname");
service.insert(u);
} @Test
public void update() {
User u = service.getOne(123L);
u.setNickName("hello");
service.update(u);
} @Test
public void delete() {
service.delete(123L);
}
}

spring boot + redis

缓存

package com.example.sb_mybatis.conf;

import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.core.RedisTemplate; import java.lang.reflect.Method; @Configuration
@EnableCaching
public class RedisConfig extends CachingConfigurerSupport { @Bean
public KeyGenerator keyGenerator() {
return new KeyGenerator() {
@Override
public Object generate(Object target, Method method, Object... params) {
StringBuilder sb = new StringBuilder();
sb.append(target.getClass().getName());
sb.append(method.getName());
for (Object obj : params) {
sb.append(obj.toString());
}
return sb.toString();
}
};
} @Bean
public CacheManager cacheManager(RedisTemplate redisTemplate) {
RedisCacheManager rcm = new RedisCacheManager(redisTemplate);
//设置缓存过期时间
//rcm.setDefaultExpiration(60);//秒
return rcm;
}
}

RedisHttpSession

package com.example.sb_mybatis.conf;

import org.springframework.context.annotation.Configuration;
import org.springframework.session.data.redis.config.annotation.web.http.EnableRedisHttpSession; @Configuration
@EnableRedisHttpSession(maxInactiveIntervalInSeconds = 86400*30)
public class SessionConfig {
}

测试类

package com.example.sb_mybatis.web;

import com.example.sb_mybatis.entity.User;
import com.example.sb_mybatis.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController; import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map; @RestController
public class RedisTest { @Autowired
UserService userService; @RequestMapping("/hello")
@Cacheable(value = "helloCache")
public String hello(String name) {
System.out.println("没有走缓存!");
return "hello " + name;
} @RequestMapping("/condition")
@Cacheable(value = "condition", condition = "#name.length() <= 4")
public String condition(String name) {
System.out.println("没有走缓存!");
return "hello " + name;
} @RequestMapping("/u_list")
@Cacheable(value = "usersCache", key = "#k")
public List<User> getUsers(String k) {
List<User> users = userService.getAll();
System.out.println("执行了数据库操作");
return users;
} @RequestMapping("/u_list_update")
@CachePut(value = "usersCache", key = "#k")
public List<User> getUsers_update(String k) {
List<User> users = userService.getAll();
System.out.println("执行了数据库操作");
return users;
} @RequestMapping("/u_list_del")
@CacheEvict(value = "usersCache", allEntries = true)
public List<User> getUsers_del() {
List<User> users = userService.getAll();
System.out.println("执行了数据库操作");
return users;
} @RequestMapping(value = "/setSession", method = RequestMethod.GET)
public Map<String, Object> setSession (HttpServletRequest request){
Map<String, Object> map = new HashMap<>();
request.getSession().setAttribute("request_Url", request.getRequestURL());
request.getSession().setAttribute("message", request.getRequestURL());
map.put("request Url", request.getRequestURL());
return map;
} @RequestMapping(value = "/getSession")
public Object getSession (HttpServletRequest request){
Map<String, Object> map = new HashMap<>();
map.put("sessionId", request.getSession().getId());
map.put("message", request.getSession().getAttribute("message"));
map.put("request_Url", request.getSession().getAttribute("request_Url"));
System.out.println("==getSession==");
return map;
} }

注意:

@Cacheable(value = "usersCache", key = "#k") 和@CachePut(value = "usersCache", key = "#k")需要指定一个相同的key,

访问时url后加上 ?k=123

如果不指定,@CachePut不能更新redis里@Cacheable对应的值,不知道是不是bug,有待进一步了解。