SpringBoot Druid数据源以及监控

1.pom.xml导入坐标

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

<!-- 后面需要用到log4j --> 
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.14</version>
</dependency>

2.application.yaml配置文件中配置Druid

#配置数据源 data-username 会出错，必须使用username
spring:
  datasource:
    username: root
    password: 1511
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/springboot?characterEncoding=utf8
    #指定数据源
    type: com.alibaba.druid.pool.DruidDataSource

    #Spring Boot 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，Maven 地址：https://mvnrepository.com/artifact/log4j/log4j
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

3.新建Druid配置类

@Configuration //声明为配置类
public class DruidConfig  {

    //绑定yaml中的配置，
    //这样yaml中关于Druid的配置就能生效了
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druidDataSource(){
        return new DruidDataSource();
    }
    
}

4.测试

@SpringBootTest
class SpringbootJdbcApplicationTests {


    @Autowired
    private DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {
        //查看默认数据源 class com.zaxxer.hikari.HikariDataSource
        System.out.println(dataSource.getClass());

        // pom导入Druid，配置文件加入type: com.alibaba.druid.pool.DruidDataSource
        // 数据源就改变了 ：class com.alibaba.druid.pool.DruidDataSource

        //获取数据库连接
        System.out.println(dataSource.getConnection());
        System.out.println(dataSource);
    }

}

5.查看控制台输出

com.alibaba.druid.proxy.jdbc.ConnectionProxyImpl@6468a7b6
{
	CreateTime:"2020-12-13 23:27:14",
	ActiveCount:1,
	PoolingCount:4,
	CreateCount:5,
	DestroyCount:0,
	CloseCount:0,
	ConnectCount:1,
	Connections:[
		{ID:797313059, ConnectTime:"2020-12-13 23:27:15", UseCount:0, LastActiveTime:"2020-12-13 23:27:15"},
		{ID:1768639125, ConnectTime:"2020-12-13 23:27:15", UseCount:0, LastActiveTime:"2020-12-13 23:27:15"},
		{ID:1813838419, ConnectTime:"2020-12-13 23:27:15", UseCount:0, LastActiveTime:"2020-12-13 23:27:15"},
		{ID:1298707825, ConnectTime:"2020-12-13 23:27:15", UseCount:0, LastActiveTime:"2020-12-13 23:27:15"}
	]
}

[
	{
	ID:797313059, 
	poolStatements:[
		]
	},
	{
	ID:1768639125, 
	poolStatements:[
		]
	},
	{
	ID:1813838419, 
	poolStatements:[
		]
	},
	{
	ID:1298707825, 
	poolStatements:[
		]
	}
]

启用Druid监控

1.DruidConfig.java类中配置

@Configuration
public class DruidConfig  {

    //绑定yaml中的配置，
    //这样yaml中关于Druid的配置就能生效了
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druidDataSource(){
        return new DruidDataSource();
    }

    //后台监控功能:web.xml ，ServletRegistrationBean
    //因为SpringBoot 内置了servlet容器，所以没有web.xml ，
    //替代方法：ServletRegistrationBean
    @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
        initParameters.put("loginUsername","admin"); //登录key是固定的 不能更改
        initParameters.put("loginPassword","123456");

        //允许谁可以访问
        initParameters.put("allow","");//为空 则所有人都可以访问


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

        return bean;
    }
}

2.输入 http://localhost:8080/druid/index.html 访问

由于未登录，会自动跳转到登录页面，用户名密码必须是上面配置的

登录成功后就可以查看了，很多功能都是Druid自带的

添加Filter过滤器

	//配置filter
    @Bean
    public FilterRegistrationBean filterRegistrationBean(){

        FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>();

        bean.setFilter(new WebStatFilter());

        //可以过滤哪些请求呢？
        HashMap<String, String> initParameters = new HashMap<>();

        //这些东西不进行统计
        initParameters.put("exclusions","*.js,*.css,/druid/*");

        bean.setInitParameters(initParameters);

        return bean;
    }