不是不會(huì)鹃觉，只是沒(méi)見(jiàn)過(guò)厢钧，代碼只是一種工具，首先要會(huì)用掏呼，應(yīng)用中使用druid連接池坏快，并添加監(jiān)控

• 1.首先引入druid坐標(biāo)

<dependency>
    <groupId>com.alibaba</groupId>
     <artifactId>druid</artifactId>
     <version>1.0.11</version>
</dependency>

• 2.添加druid配置參數(shù)

參考:

數(shù)據(jù)庫(kù)連接池優(yōu)化配置(druid,dbcp,c3p0)

• 配置說(shuō)明：

1：minEvictableIdleTimeMillis(最大空閑時(shí)間)：默認(rèn)為30分鐘憎夷，配置里面不進(jìn)行設(shè)置莽鸿。

2：testOnBorrow ,testOnReturn 默認(rèn)為關(guān)閉，可以設(shè)置為不配置拾给。

3：testWhileIdle(在獲取連接后祥得，確定是否要進(jìn)行連接空閑時(shí)間的檢查)。默認(rèn)為true蒋得。配置里面不再進(jìn)行設(shè)置级及。

• 流程說(shuō)明：

1：在第一次調(diào)用connection的時(shí)候，才會(huì)進(jìn)行 initialSize的初始化额衙。

2：心跳檢測(cè)時(shí)間線程饮焦，會(huì)休眠timeBetweenEvictionRunsMillis時(shí)間，然后只對(duì)(沒(méi)有borrow的線程 減去 minIdle)的線程進(jìn)行檢查窍侧，如果空閑時(shí)間大于minEvictableIdleTimeMillis則進(jìn)行close县踢。

3：testWhileIdle必須設(shè)置為true，在獲取到連接后伟件，先檢查testOnBorrow硼啤，然后再判定testwhileIdle，如果連接空閑時(shí)間大于timeBetweenEvictionRunsMillis斧账，則會(huì)進(jìn)行心跳檢測(cè)谴返。

4：不需要配置validationQuery，如果不配置的情況下會(huì)走ping命令咧织，性能更高嗓袱。

5：連接保存在數(shù)組里面，獲取連接的時(shí)候习绢，獲取數(shù)組的最后一位索抓。在imeBetweenEvictionRunsMillis時(shí)是從前往后進(jìn)行檢查連接的有效性。

在applicatioin.properties中添加配置

druid.url=jdbc:postgresql://139.1X8.1.1X8:1XX0/account
druid.driver-class=org.postgresql.Driver
druid.username=root
druid.password=123
druid.initial-size=1
druid.min-idle=1
druid.max-active=20
druid.test-on-borrow=true
druid.timeBetweenEvictionRunsMillis=9000

• 3.定義配置類(lèi)毯炮，啟動(dòng)讀取druid開(kāi)頭的參數(shù)

driver-class有和driverClass是不一樣的逼肯，所以要引入，參數(shù)容錯(cuò)坐標(biāo)

  <!--配置命名容錯(cuò)處理-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>

@ConfigurationProperties(prefix = "druid")
public class DruidProperties {
    private String url;
    private String username;
    private String password;
    private String driverClass;
    private int maxActive;//最大連接數(shù)
    private int minIdle;//最小連接數(shù)
    private int initialSize;//初始化數(shù)量和
    private boolean testOnBorrow;
    private Long timeBetweenEvictionRunsMillis;//心跳
}

• 4.注入

@Configuration
@EnableConfigurationProperties(DruidProperties.class)
@ConditionalOnClass(DruidDataSource.class)
@ConditionalOnProperty(prefix = "druid", name = "url")
@AutoConfigureBefore(DataSourceAutoConfiguration.class)
public class DruidAutoConfiguration {

    @Autowired
    private DruidProperties properties;

    @Bean
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUrl(properties.getUrl());
        dataSource.setUsername(properties.getUsername());
        dataSource.setPassword(properties.getPassword());
        dataSource.setTimeBetweenEvictionRunsMillis(properties.getTimeBetweenEvictionRunsMillis());
        if (properties.getInitialSize() > 0) {
            dataSource.setInitialSize(properties.getInitialSize());
        }
        if (properties.getMinIdle() > 0) {
            dataSource.setMinIdle(properties.getMinIdle());
        }
        if (properties.getMaxActive() > 0) {
            dataSource.setMaxActive(properties.getMaxActive());
        }
        dataSource.setTestOnBorrow(properties.isTestOnBorrow());
        try {
            dataSource.init();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        return dataSource;
    }
}

• 5.添加攔截器桃煎，攔截器druid性能監(jiān)控

/**
 * @Package: pterosaur.account.config.druid
 * @Description: 監(jiān)控?cái)?shù)據(jù)庫(kù)性能
 * @author: liuxin
 * @date: 17/4/21 上午11:23
 */
@SuppressWarnings("serial")
@WebServlet(urlPatterns = "/druid/*",
        initParams={
                @WebInitParam(name="allow",value="192.168.16.110,127.0.0.1"),// IP白名單 (沒(méi)有配置或者為空篮幢，則允許所有訪問(wèn))
                @WebInitParam(name="deny",value="192.168.16.111"),// IP黑名單 (存在共同時(shí)，deny優(yōu)先于allow)
                @WebInitParam(name="loginUsername",value="test"),// 用戶(hù)名
                @WebInitParam(name="loginPassword",value="test"),// 密碼
                @WebInitParam(name="resetEnable",value="false")// 禁用HTML頁(yè)面上的“Reset All”功能
        })
public class DruidStatViewServlet extends StatViewServlet{
}


/**
 * @Package: pterosaur.account.config.filter
 * @Description: 攔截druid監(jiān)控請(qǐng)求
 * @author: liuxin
 * @date: 17/4/21 上午11:24
 */
@WebFilter(filterName="druidWebStatFilter",urlPatterns="/*",
        initParams={
                @WebInitParam(name="exclusions",value="*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*")// 忽略資源
        })
public class DruidStatFilter extends WebStatFilter{
}

• 6.最終要一步为迈，啟動(dòng)掃描Servlet

@SpringBootApplication
@MapperScan(basePackages = "pterosaur.account.mapper")
@EnableCaching
@ServletComponentScan  //這個(gè)
public class AccountApplication {

    public static void main(String[] args) {
        SpringApplication.run(AccountApplication.class, args);
    }
}