DB数据源之SpringBoot+MyBatis踏坑过程（七）手动使用Tomcat连接池

DB数据源之SpringBoot+MyBatis踏坑过程（七）手动使用Tomcat连接池

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系列目录连接

DB数据源之SpringBoot+Mybatis踏坑过程实录（一）

1.环境说明

　　springboot2.0以下版本，java7，myeclipse2017 C1，使用的是mySql数据库

　　

　　pom

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>Tit</groupId>
     <artifactId>FM</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>

     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.5.3.RELEASE</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
     <dependencies>

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

         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <version>3.8.1</version>
             <scope>test</scope>
         </dependency>

         <dependency>
             <groupId>org.apache.tomcat.embed</groupId>
             <artifactId>tomcat-embed-logging-juli</artifactId>
             <version>7.0.62</version>
         </dependency>

         <!-- 添加MySQL依赖 -->
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
         </dependency>
         <!-- 添加JDBC依赖 -->
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-jdbc</artifactId>
         </dependency>
         <!-- mybaits基础依赖 -->
         <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis</artifactId>
             <version>3.4.0</version>
         </dependency>
         <!-- mybatis插件依赖 -->
         <dependency>
             <groupId>org.mybatis.spring.boot</groupId>
             <artifactId>mybatis-spring-boot-starter</artifactId>
             <version>1.1.1</version>
         </dependency>
         <!-- mapper依赖 -->
         <dependency>
             <groupId>tk.mybatis</groupId>
             <artifactId>mapper</artifactId>
             <version>3.3.7</version>
         </dependency>

         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-configuration-processor</artifactId>
             <optional>true</optional>
         </dependency>

         <!-- 热部署 -->
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-devtools</artifactId>
             <optional>true</optional>
             <scope>true</scope>
         </dependency>
         <!-- end of 热部署 -->
     </dependencies>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.7</java.version>

         <webVersion>3.0</webVersion>
     </properties>
     <build>
         <finalName>FM</finalName>
         <plugins>
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin </artifactId>
             </plugin>
         </plugins>

     </build>
 </project>

2.配置思路

• 　　确保类单例，使用构造器实例化的sqlSessionFactory只设置一次
• 　　提供getSqlSessionFactory获取sqlSessionFactory
• 　　setSqlSessionFactory时初始化数据源，并设置连接池
• 　　setSqlSessionFactory方法提供参数可对数据源进行更改，以确保数据源故障时可进行重新设置

3.所需类与结构

　　3.1.pom，略

　　3.2.DataConfig.java配置数据源获取SqlSessionFactory类

　　3.3.mapper.xml，略

　　3.4.HelloExample.java测试，略

　　3.5.AppRun.java，Springboot启动类，略

4.代码

　　DataConfig.java代码如下：

 package com.FM.config;

 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.tomcat.jdbc.pool.DataSource;
 import org.apache.tomcat.jdbc.pool.PoolProperties;
 import org.mybatis.spring.SqlSessionFactoryBean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
 /**
  * 单例数据源配置
  * @author Liuyuhang
  *
  */
 @Configuration
 public class DataConfig {

     private static final String url = "jdbc:mysql://xxx.xxx.xxx.xxx:3306/dataBaseName?cuseUnicode=true&characterEncoding=utf-8&useSSL=false";
     private static final String driver = "com.mysql.jdbc.Driver";
     private static final String username = "root";
     private static final String password = "root";

     /**
      * SqlSessionFactory
      */
     private SqlSessionFactory sqlSessionFactory = null;

     /**
      * 单例的类对象
      */
     private static volatile DataConfig dataConfig;

     /**
      * 无参构造
      * @throws Exception
      */
     public DataConfig() throws Exception {
         setSqlSessionFactory();
         System.out.println("DataConfig init");
     }

     /**
      * 双验证单例模式
      * @return
      * @throws Exception
      */
     public static DataConfig getInstence() throws Exception{
         if(null==dataConfig){
             synchronized (DataConfig.class) {
                 if(null==dataConfig){
                     dataConfig = new DataConfig();

                 }
             }
         }
         return dataConfig;
     }

     /**
      * tomcat pool配置
      * @param url
      * @param dirver
      * @param username
      * @param password
      * @return
      */
     public DataSource dataSource(String url, String dirver, String username, String password) {
         PoolProperties p = new PoolProperties();
         p.setUrl(url);
         p.setDriverClassName(dirver);
         p.setUsername(username);
         p.setPassword(password);
         p.setTestWhileIdle(false);
         p.setTestOnBorrow(true);
         p.setValidationQuery("SELECT 1");
         p.setTestOnReturn(false);
         p.setValidationInterval(30000);
         p.setTimeBetweenEvictionRunsMillis(30000);
         p.setMaxActive(100);
         p.setInitialSize(10);
         p.setMaxWait(10000);
         p.setRemoveAbandonedTimeout(60);
         p.setMinEvictableIdleTimeMillis(30000);
         p.setMinIdle(10);
         p.setLogAbandoned(true);
         p.setRemoveAbandoned(true);
         DataSource datasource = new DataSource();
         datasource.setPoolProperties(p);
         return datasource;
     }

     /**
      * setSqlSessionFactory,构造的时候运行一次,可实例化以后也可手动调用修改SqlSessionFactory
      * @throws Exception
      */
     public void setSqlSessionFactory() throws Exception {
         DataSource dataSource = dataSource(url, driver, username, password);
         // 创建sessionFactory
         SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
         factoryBean.setDataSource(dataSource);// 加载数据源
         // 扫描mapper.xml
         Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath:com/FM/mapper/*.xml");
         factoryBean.setMapperLocations(resources);
         // 读取config
         factoryBean.setConfigLocation(new DefaultResourceLoader().getResource("classpath:mybatis-config.xml"));
         this.sqlSessionFactory = factoryBean.getObject();
         System.out.println("setSqlSessionFactory init");
     }

     /**
      * 获取SqlSessionFactory
      * @return
      * @throws Exception
      */
     public SqlSessionFactory getSessionFactory() throws Exception {
         if (null == sqlSessionFactory) {
             setSqlSessionFactory();
         }
         return this.sqlSessionFactory;
     }

 }

5.说明

• 　　在不使用连接池情况下，直接加载数据源时，会导致mysql数据库开启连接数量持续增长到最大值，导致mysql数据库无法使用

6.测试

　　测试时应观察mysql连接数量增长情况，总数量，对数据库进行多次请求。

以上!