spring-data-jpa快速入门（一）——整合阿里Druid

一、概述

　　官网：https://projects.spring.io/spring-data-jpa/

　　1[b].什么是spring-data-jpa[/b]


　　2.spring-data-jpa有什么

　　


　　继承关系图：

　　

二、起步

　　　　基本的HelloWorld完整代码在springboot快速入门中已有介绍，参考这里

　　　　不过由于当时没有引入数据库连接池，这里对它进行改进，使用阿里巴巴druid作为数据源，添加监控

　　　　阿里Druid：https://github.com/alibaba/druid

　　　　整合参考：https://www.jianshu.com/p/e84e2709f383

　　　　1.引入依赖

<!-- alibaba-druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.6</version>
</dependency>

　　// 其他依赖请参见前文

　　2.在application.yml配置文件中配置数据源

　　　　官方参考配置：点击查看

　　　　各配置项解析：https://www.cnblogs.com/lmaplet/p/6170105.html

spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/sakila
username: root
password: root
# druid配置项，默认spring-boot不支持，故需要config类来解析
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
maxPoolPreparedStatementPerConnectionSize: 20
filters: stat,wall,log4j
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
jpa:
hibernate:
ddl-auto: update
show-sql: true

　　3.添加Druid配置类

package com.example.demo.dao;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
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;
import org.springframework.context.annotation.Primary;

import javax.sql.DataSource;
import java.sql.SQLException;

/**
* 阿里Druid配置类
*
* @author zcc ON 2018/2/11
**/
@Configuration
public class DruidConfig {
private static final Logger log = LoggerFactory.getLogger(DruidConfig.class);

@Value("${spring.datasource.url}")
private String dbUrl;

@Value("${spring.datasource.username}")
private String username;

@Value("${spring.datasource.password}")
private String password;

@Value("${spring.datasource.driverClassName}")
private String driverClassName;

@Value("${spring.datasource.initialSize}")
private int initialSize;

@Value("${spring.datasource.minIdle}")
private int minIdle;

@Value("${spring.datasource.maxActive}")
private int maxActive;

@Value("${spring.datasource.maxWait}")
private int maxWait;

@Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillis;

@Value("${spring.datasource.minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillis;

@Value("${spring.datasource.validationQuery}")
private String validationQuery;

@Value("${spring.datasource.testWhileIdle}")
private boolean testWhileIdle;

@Value("${spring.datasource.testOnBorrow}")
private boolean testOnBorrow;

@Value("${spring.datasource.testOnReturn}")
private boolean testOnReturn;

@Value("${spring.datasource.poolPreparedStatements}")
private boolean poolPreparedStatements;

@Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
private int maxPoolPreparedStatementPerConnectionSize;

@Value("${spring.datasource.filters}")
private String filters;

@Value("{spring.datasource.connectionProperties}")
private String connectionProperties;

@Bean
@Primary
public DataSource dataSource() {
DruidDataSource datasource = new DruidDataSource();
log.info("----------- druid datasource ----------");
datasource.setUrl(this.dbUrl);
datasource.setUsername(username);
datasource.setPassword(password);
datasource.setDriverClassName(driverClassName);

datasource.setInitialSize(initialSize);
datasource.setMinIdle(minIdle);
datasource.setMaxActive(maxActive);
datasource.setMaxWait(maxWait);
datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
datasource.setValidationQuery(validationQuery);
datasource.setTestWhileIdle(testWhileIdle);
datasource.setTestOnBorrow(testOnBorrow);
datasource.setTestOnReturn(testOnReturn);
datasource.setPoolPreparedStatements(poolPreparedStatements);
datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
try {
datasource.setFilters(filters);
} catch (SQLException e) {
e.printStackTrace();
}
datasource.setConnectionProperties(connectionProperties);

return datasource;
}

@Bean
public ServletRegistrationBean registrationBean() {
ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet()); // 添加初始化参数：initParams
servletRegistrationBean.addUrlMappings("/druid/*");
// 白名单
servletRegistrationBean.addInitParameter("allow", "127.0.0.1");
// 黑名单
servletRegistrationBean.addInitParameter("deny", "192.168.0.101");
// 登录查看信息的账号密码.
servletRegistrationBean.addInitParameter("loginUsername", "admin");
servletRegistrationBean.addInitParameter("loginPassword", "123456");
// 可重置数据.
servletRegistrationBean.addInitParameter("resetEnable", "false");
return servletRegistrationBean;
}

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

　　其中，@Configuration注解该类，等价 与XML中配置beans；用@Bean标注方法等价于XML中配置bean

　　 　　 @Primary //在同样的DataSource中，首先使用被标注的DataSource

　　4.配置QueryDsl

　　　　后面介绍JPA进行补充！

　　5.测试

　　　　正常调试项目接口（使用IDEA自带插件或者Postman）

　　　　查看监控页面（监控页面由Druid生成）

　　　　　　访问：127.0.0.1:8080/druid/login.html

　　　　　　


　　　　其中，IP白名单（为空则为所有）与监控登录信息在Druid配置中！