十七、SpringBoot配置连接池

内置的连接池

目前Spring Boot中默认支持的连接池有dbcp,dbcp2, tomcat, hikari三种连接池。
数据库连接可以使用DataSource池进行自动配置。

1. 由于Tomcat数据源连接池的性能和并发，在tomcat可用时，我们总是优先使用它。
2. 如果HikariCP可用，我们将使用它。
3. 如果Commons DBCP可用，我们将使用它，但在生产环境不推荐使用它。
4. 最后，如果Commons DBCP2可用，我们将使用它。
   

   ---

以上的几种连接池，可以通过在配置application文件中配置。

spring.datasource.url=jdbc:mysql://localhost/test
spring.datasource.username=dbuser
spring.datasource.password=dbpass
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

Spring Boot能够从大多数数据库的url上推断出driver-class-name，你就不需要再指定它了。对于一个将要创建的DataSource连接池，我们需要能够验证Driver是否可用，所以我们会在做任何事情之前检查它。比如，如果你设置spring.datasource.driverClassName=com.mysql.jdbc.Driver，然后这个类就会被加载。

配置Druid连接池

在SpringBoot 的1.5.2版本中不在支持自动配druid，，即无法通过配置项直接支持相应的连接池；这里列出的这些配置项可以通过定制化DataSource来实现。

druid介绍

Druid是一个JDBC组件，它包括三部分：

• DruidDriver 代理Driver，能够提供基于Filter－Chain模式的插件体系。
• DruidDataSource 高效可管理的数据库连接池。
• SQLParser

Druid可以做什么

• 可以监控数据库访问性能，Druid内置提供了一个功能强大的StatFilter插件，能够详细统计SQL的执行性能，这对于线上分析数据库访问性能有帮助。
• 替换DBCP和C3P0。Druid提供了一个高效、功能强大、可扩展性好的数据库连接池。
• 数据库密码加密。直接把数据库密码写在配置文件中，这是不好的行为，容易导致安全问题。DruidDruiver和DruidDataSource都支持PasswordCallback。
• SQL执行日志，Druid提供了不同的LogFilter，能够支持Common-Logging、Log4j和JdkLog，你可以按需要选择相应的LogFilter，监控你应用的数据库访问情况。
• 扩展JDBC，如果你要对JDBC层有编程的需求，可以通过Druid提供的Filter-Chain机制，很方便编写JDBC层的扩展插件。
  

项目地址： https://github.com/alibaba/druid

Spring Boot与Druid的集成

MySQL Driver驱动包：

        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <scope>runtimescope>
        dependency>

阿里系的Druid依赖包：

       <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
            <version>1.0.25version>
        dependency>

application.properties配置信息

# 驱动配置信息
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.url = jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8  
spring.datasource.username = root
spring.datasource.password = adminter
spring.datasource.driverClassName = com.mysql.jdbc.Driver

#连接池的配置信息
## 初始化大小，最小，最大
spring.druid.initialSize=5
spring.druid.minIdle=5
spring.druid.maxActive=20
## 配置获取连接等待超时的时间
spring.druid.maxWait=60000
# 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
spring.druid.timeBetweenEvictionRunsMillis=60000
# 配置一个连接在池中最小生存的时间，单位是毫秒
spring.druid.minEvictableIdleTimeMillis=300000
spring.druid.validationQuery=SELECT 1 FROM DUAL
spring.druid.testWhileIdle=true
spring.druid.testOnBorrow=false
spring.druid.testOnReturn=false
spring.druid.poolPreparedStatements=true
spring.druid.maxPoolPreparedStatementPerConnectionSize=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.druid.filters=stat,wall,log4j
# 通过connectProperties属性来打开mergeSql功能；慢SQL记录
spring.druid.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000

DruidSource配置信息的定制

package com.lf.datasource;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;

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

/**
 * Created by LF on 2017/4/18.
 */
@ConfigurationProperties(prefix = "spring.druid")
public class DruidSource {

    private String dbUrl;

    private String username;

    private String password;

    private String driverClassName;

    private int initialSize;

    private int minIdle;

    private int maxActive;

    private int maxWait;

    private int timeBetweenEvictionRunsMillis;

    private int minEvictableIdleTimeMillis;
    private String validationQuery;

    private boolean testWhileIdle;
    private boolean testOnBorrow;

    private boolean testOnReturn;

    private boolean poolPreparedStatements;

    private int maxPoolPreparedStatementPerConnectionSize;

    private String filters;

    private String connectionProperties;

    public String getDbUrl() {
        return dbUrl;
    }

    public void setDbUrl(String dbUrl) {
        this.dbUrl = dbUrl;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getDriverClassName() {
        return driverClassName;
    }

    public void setDriverClassName(String driverClassName) {
        this.driverClassName = driverClassName;
    }

    public int getInitialSize() {
        return initialSize;
    }

    public void setInitialSize(int initialSize) {
        this.initialSize = initialSize;
    }

    public int getMinIdle() {
        return minIdle;
    }

    public void setMinIdle(int minIdle) {
        this.minIdle = minIdle;
    }

    public int getMaxActive() {
        return maxActive;
    }

    public void setMaxActive(int maxActive) {
        this.maxActive = maxActive;
    }

    public int getMaxWait() {
        return maxWait;
    }

    public void setMaxWait(int maxWait) {
        this.maxWait = maxWait;
    }

    public int getTimeBetweenEvictionRunsMillis() {
        return timeBetweenEvictionRunsMillis;
    }

    public void setTimeBetweenEvictionRunsMillis(int timeBetweenEvictionRunsMillis) {
        this.timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
    }

    public int getMinEvictableIdleTimeMillis() {
        return minEvictableIdleTimeMillis;
    }

    public void setMinEvictableIdleTimeMillis(int minEvictableIdleTimeMillis) {
        this.minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
    }

    public String getValidationQuery() {
        return validationQuery;
    }

    public void setValidationQuery(String validationQuery) {
        this.validationQuery = validationQuery;
    }

    public boolean isTestWhileIdle() {
        return testWhileIdle;
    }

    public void setTestWhileIdle(boolean testWhileIdle) {
        this.testWhileIdle = testWhileIdle;
    }

    public boolean isTestOnBorrow() {
        return testOnBorrow;
    }

    public void setTestOnBorrow(boolean testOnBorrow) {
        this.testOnBorrow = testOnBorrow;
    }

    public boolean isTestOnReturn() {
        return testOnReturn;
    }

    public void setTestOnReturn(boolean testOnReturn) {
        this.testOnReturn = testOnReturn;
    }

    public boolean isPoolPreparedStatements() {
        return poolPreparedStatements;
    }

    public void setPoolPreparedStatements(boolean poolPreparedStatements) {
        this.poolPreparedStatements = poolPreparedStatements;
    }

    public int getMaxPoolPreparedStatementPerConnectionSize() {
        return maxPoolPreparedStatementPerConnectionSize;
    }

    public void setMaxPoolPreparedStatementPerConnectionSize(int maxPoolPreparedStatementPerConnectionSize) {
        this.maxPoolPreparedStatementPerConnectionSize = maxPoolPreparedStatementPerConnectionSize;
    }

    public String getFilters() {
        return filters;
    }

    public void setFilters(String filters) {
        this.filters = filters;
    }

    public String getConnectionProperties() {
        return connectionProperties;
    }

    public void setConnectionProperties(String connectionProperties) {
        this.connectionProperties = connectionProperties;
    }

    @Bean     //声明其为Bean实例
    @Primary  //在同样的DataSource中，首先使用被标注的DataSource
    public DataSource dataSource() throws SQLException {
        DruidDataSource datasource = new DruidDataSource();

        datasource.setUrl(this.dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);

        //configuration
        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);

        datasource.setFilters(filters);


        return datasource;
    }
}

基于注解的配置StatView的Servlet

Filter的实现类：

package com.lf.config;

import com.alibaba.druid.support.http.WebStatFilter;

import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;

/**
 * Created by LF on 2017/4/18.
 */
@WebFilter(filterName = "druidWebStatFilter", urlPatterns = "/*",
        initParams = {
                @WebInitParam(name = "exclusions", value = "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*")//忽略资源
        }
)
public class DruidStatFilter extends WebStatFilter {
}

StatViewServlet:

package com.lf.config;

import com.alibaba.druid.support.http.StatViewServlet;

import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;

/**
 * Created by LF on 2017/4/18.
 */

@WebServlet(urlPatterns = "/druid/*",
        initParams = {
                @WebInitParam(name = "allow", value = "127.0.0.1,192.168.163.1"),// IP白名单(没有配置或者为空，则允许所有访问)
                @WebInitParam(name = "deny", value = "192.168.1.73"),// IP黑名单 (存在共同时，deny优先于allow)
                @WebInitParam(name = "loginUsername", value = "admin"),// 用户名
                @WebInitParam(name = "loginPassword", value = "123456"),// 密码
                @WebInitParam(name = "resetEnable", value = "false")// 禁用HTML页面上的“Reset All”功能
        })
public class DruidStatViewServlet extends StatViewServlet {
    private static final long serialVersionUID = -2688872071445249539L;
}

在启动类上加入@ServletComponentScan注解

基于Java的配置StatView的Servlet

package com.lf.config;

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;

/**
 * Created by LF on 2017/4/18.
 */
@Configuration
public class DruidConfig {
    @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");
        //IP黑名单 (存在共同时，deny优先于allow) : 如果满足deny的话提示:Sorry, you are not permitted to view this page.
        servletRegistrationBean.addInitParameter("deny", "192.168.1.73");
        //登录查看信息的账号密码.
        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 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;
    }
}

运行界面以及介绍

访问地址： http://192.168.163.1:8080/druid/index.html

账号和密码为在servlet中配置的