SpringBoot学习之集成数据库

集成mysql

所需依赖

mysql驱动

		<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

通过jdbc连接数据库

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

在mysql新建表（spring数据库是我已有的）

use spring;
drop table if exists zuser;
create table zuser
(
 id varchar(32) not null comment '主键',
 name varchar(10) default null comment '用户名',
 password varchar(32) default null comment '密码'
);

insert into zuser values ('1','小T','123456');
insert into zuser values ('2','小H','123456');

在application.properties里添加（用的是mysql8.0，url比较麻烦)

#mysql连接信息
spring.datasource.url=jdbc:mysql://localhost:3306/spring?serverTimezone=GMT&useUnicode=true&characterEncoding=UTF-8&useSSL=false&zeroDateTime
#用户名
spring.datasource.username=root
#密码
spring.datasource.password=123456
#驱动
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

建立实体类

package com.zzf.demo.model;

import lombok.Data;

/*
 *
 *@author:zzf
 *@time:2020-11-16
 *
 */
@Data
public class ZUser {
    
    
    //主键
    private String id;
    //用户名
    private String name;
    //密码
    private String password;


}

这里用了lombok插件（需下载），可以生成get/set/toString方法
lombok插件依赖

		<dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

测试

package com.zzf.demo;

import com.zzf.demo.model.ZUser;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@SpringBootTest
class DemoApplicationTests {
    
    

    @Autowired
    private JdbcTemplate jdbcTemplate;
    @Test
    void contextLoads() {
    
    

        String sql="select id,name,password from zuser";
        List<ZUser> userList=jdbcTemplate.query(sql, new RowMapper<ZUser>() {
    
    
            @Override
            public ZUser mapRow(ResultSet resultSet, int i) throws SQLException {
    
    
                ZUser user=new ZUser();
                user.setId(resultSet.getString("id"));
                user.setName(resultSet.getString("name"));
                user.setPassword(resultSet.getString("password"));

                return user;
            }
        });
        System.out.println("查询成功：");
        for (ZUser user:userList
             ) {
    
    
            System.out.println(user.toString());
        }
    }

}

JdbcTemplate 是一个可以对数据库增删查改的工具类

query()是查询

RowMapper对象可以将查询出的每一行数据封装成用户定义的类

效果

集成Druid

Druid是阿里巴巴开源项目的一个数据库连接池，是个JDBC组件，主要用于监控，观察连接处和SQL查询工作情况，包括三部分：

DruidDriver：代理Driver，提供基于Filtter-Chain模式的插件体系
DruidDataSource：高效可管理的数据库连接池
SQLParser：支持所有JDBC兼容的数据库

druid依赖

		<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.21</version>
        </dependency>

druid配置

#mysql连接信息
spring.datasource.url=jdbc:mysql://localhost:3306/spring?serverTimezone=GMT&useUnicode=true&characterEncoding=UTF-8&useSSL=false&zeroDateTime
#用户名
spring.datasource.username=root
#密码
spring.datasource.password=123456
#驱动
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
#数据源类别
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
#初始化大小，最小、最大
spring.datasource.druid.initial-size=5
spring.datasource.druid.min-idle=5
spring.datasource.druid.max-active=20
#获取连接等待超时的时间，单位为毫秒
spring.datasource.druid.max-wait=60000
#间隔多久检测一次，关闭空闲连接
spring.datasource.druid.time-between-eviction-runs-millis=60000
#配置一个连接在池中最小生存时间
spring.datasource.druid.min-evictable-idle-time-millis=300000
spring.datasource.druid.validation-query=select 1 from dual
spring.datasource.druid.test-while-idle=true
spring.datasource.druid.test-on-borrow=false
spring.datasource.druid.test-on-return=false
#打开PSCache，并指定每个连接上PSCache的大小
spring.datasource.druid.pool-prepared-statements=true
spring.datasource.druid.max-pool-prepared-statement-per-connection-size=20
#配置监控统计拦截的filters，去掉后监控界面SQL无法统计，'wall'用于防火墙
spring.datasource.druid.filters=stat,wall,log4j
#通过connecProperties属性打开mergeSql功能；慢SQL记录
spring.datasource.druid.connection-properties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
#合并多个DruidDataSource的监控数据
spring.datasource.druid.use-global-data-source-stat=true

还要引入log4j依赖，否则会报错，可以打印日志
log4j

		<dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

新建log4j.properties文件

log4j.rootLogger=DEBUG, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

开启监控功能

配置类

package com.zzf.demo.filter;

import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/*
 *
 *@author:zzf
 *@time:2020-11-16
 *
 */
@Configuration
public class DruidConfiguration {
    
    
    @Bean
    public ServletRegistrationBean druidStatViewServlet(){
    
    
        //ServletRegistrationBean提供类的进行注册
        ServletRegistrationBean servletRegistrationBean
                =new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        //添加初始化参数：initParams
        //白名单：
        servletRegistrationBean.addInitParameter("allow","127.0.0.1");
        //IP黑名单（如果同时存在,deny优先于allow)
        //如果满足deny提示没有权限访问
        servletRegistrationBean.addInitParameter("deny","192.168.1.73");
        //登录查看账号密码的信息
        servletRegistrationBean.addInitParameter("LoginUsername","admin");
        servletRegistrationBean.addInitParameter("loginPassword","123456");
        //是否能够重置数据
        servletRegistrationBean.addInitParameter("resetEnable","false");
        return servletRegistrationBean;
    }

    @Bean
    public FilterRegistrationBean druidStatFilter(){
    
    

        FilterRegistrationBean filterRegistrationBean
                =new FilterRegistrationBean(new WebStatFilter());
        //添加过滤规则
        filterRegistrationBean.addUrlPatterns("/*");
        //添加需要忽略的格式信息
        filterRegistrationBean.addInitParameter("exclusions",
                "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
        return filterRegistrationBean;

    }
}

相当于ssm中的spring配置文件里的<bean>

运行项目在浏览器输入http://localhost:8080/druid/index.html
登录后可以进入监控界面