SpringBoot整合几种常见数据访问—JDBC、Mybatis、Druid

JDBC

整合JDBC，简单的在yml中设置相关数据库信息即可

spring:
  datasource:
    username: root
    password: ****
    url: jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver

然后就可以实现controller进行测试

package com.zzh.springboot04data.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;
import java.util.Map;

@RestController
public class JDBCController {

    @Autowired
    JdbcTemplate jdbcTemplate;

    //查询数据库的所有信息
    //没有实体类，数据库中的东西怎么获取？Map
    @GetMapping("/userList")
    public List<Map<String, Object>> userList(){
        String sql = "select * from user";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
        return maps;
    }

    @GetMapping("/addUser")
    public String addUser(){
        String sql = "insert into user(id, username, sex) values (53, '张', '男')";
        jdbcTemplate.update(sql);
        return "update-ok";
    }

    @GetMapping("/updateUser/{id}")
    public String updateUser(@PathVariable("id") int id){
        String sql = "update user set username=?,address=? where id="+id;
        //封装
        Object[] objects = new Object[2];
        objects[0] = "zzh";
        objects[1] = "cd";
        jdbcTemplate.update(sql, objects);
        return "update-ok";
    }

    @GetMapping("/deleteUser/{id}")
    public String deleteUser(@PathVariable("id") int id){
        String sql = "delete from user where id = ?";
        jdbcTemplate.update(sql, id);
        return "delete-ok";
    }
}

Mybatis

1.首先在yml配置文件添加整合mybatis的配置信息

# 整合mybaits
mybatis:
  type-aliases-package: com.zzh.pojo
  mapper-locations: classpath:mybatis/mapper/*.xml

2.然后编写实体类及相应的mapper

package com.zzh.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private int id;
    private String username;
    private String sex;
}

package com.zzh.mapper;

import com.zzh.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

//表示本类是mybatis的mapper 类,核心注解不能少
@Mapper
@Repository
public interface UserMapper {
    List<User> queryUserList();

    User queryUserById(int id);

    int addUser(User user);

    int updateUser(User user);

    int deleteUser(int id);

}

3.最后配置与mapper对应的sql语句

<?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.zzh.mapper.UserMapper">
    <select id="queryUserList" resultType="User">
        select * from user ;
    </select>

    <select id="queryUserById" resultType="User">
        select * from user where id = #{id}
    </select>

    <insert id="addUser" parameterType="User">
        insert into user (id, username, sex) values (#{id}, #{username}, #{sex});
    </insert>

    <update id="updateUser" parameterType="User">
        update user set username=#{username}, sex=#{sex} where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from user where id = #{id}
    </delete>

</mapper>

Druid

是阿里巴巴开源平台上一个数据库连接池实现，结合了C3P0、DBCP、PROXOOL等DB池的优点，同时加入了日志监控。
在yml配置文件中加上以下配置:

	type: com.alibaba.druid.pool.DruidDataSource
    
    # SpringBoot 默认是不注入这些属性值的，需要自己绑定
    # druid 数据源专有配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    
    # 配置监控统计拦截的filters。stat:监控统计，log4j：日志记录，wall：防御sql注入
    # 如果允许时报错，java.lang.ClassNotFoundException：org.apache.log4j.Priority
    # 则导入log4j依赖即可，
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

测试后台监控功能

package com.zzh.springboot04data.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
import java.util.HashMap;

@Configuration
public class DruidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druidDataSource(){
        return new DruidDataSource();
    }

    //后台监控功能
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean<StatViewServlet> bean =
                new ServletRegistrationBean<>(new StatViewServlet(), "/druid/*");

        //后台需要有人登录，账号密码设置
        HashMap<String, String> initParameters = new HashMap<>();
        //增加配置,登陆的key是固定的
        initParameters.put("loginUsername", "admin");
        initParameters.put("loginPassword", "123");

        //允许谁可以访问
        initParameters.put("allow", "");

        //禁止谁访问
        //initParameters.put("name", "ip地址");

        bean.setInitParameters(initParameters); //设置初始化参数
        return bean;
    }
}

然后进行sql语句执行，即可在监控页面查看到sql语句执行情况：

Filter部分简单实现

//filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>();
        
        bean.setFilter(new WebStatFilter());
        
        //可以过滤哪些请求？
        HashMap<String, String> initParameters = new HashMap<>();
        //以下文件不进行统计
        initParameters.put("exclusions", "*.js, *.css, /druid/**");
        

        bean.setInitParameters(initParameters);
        return bean;
    }