Java 数据库连接池 Tomcat介绍

目录

• 1、配置参数
• 1.1、基础配置
• 1.2、系统属性
• 1.3、一般参数
• 1.4、增强参数
• 2、使用
• 2.1、直接使用
• 2.1.1、引入依赖
• 2.1.2、使用例子
• 2.2、作为资源配置在 Tomcat 中
• 3.2、在 SpringBoot 中使用
• 3.1.1、引入依赖
• 3.1.2、单数据源
• 3.1.3、多数据源

前言：

Tomcat 连接池是从 Tomcat 7 开始重新编写的高并发连接池，用以取代以前 Tomcat 中使用的 DBCP 1 连接池，它可以配置在 Tomcat 中使用，也可以单独使用。本文主要介绍 Tomcat 连接池的基本使用，文中使用到的软件版本：Java 1.8.0_191、Tomcat 8.5.72、Spring Boot 2.3.12.RELEASE。

1、配置参数

1.1、基础配置

1.2、系统属性

1.3、一般参数

这些参数和 DBCP 一致，但有些默认值不一样。

1.4、增强参数

详细的说明可以参考官网文档：https://tomcat.apache.org/tomcat-8.5-doc/jdbc-pool.html

2、使用

2.1、直接使用

2.1.1、引入依赖

<dependency>

    <groupId>org.apache.tomcat</groupId>

    <artifactId>tomcat-jdbc</artifactId>

    <version>8.5.72</version>

</dependency>

2.1.2、使用例子

package com.abc.demo.general.dbpool;

import org.apache.tomcat.jdbc.pool.DataSource;

import org.apache.tomcat.jdbc.pool.PoolProperties;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class TomcatPoolCase {

    public static void main(String[] args) {

        PoolProperties poolProperties = new PoolProperties();

        poolProperties.setName("Tomcat连接池");

        poolProperties.setUrl("jdbc:mysql://10.40.9.11:3306/mydb?useUnicode=true&characterEncoding=UTF-8");

        poolProperties.setDriverClassName("com.mysql.cj.jdbc.Driver");

        poolProperties.setUsername("root");

        poolProperties.setPassword("123456");

        poolProperties.setJmxEnabled(true);

        poolProperties.setTestWhileIdle(false);

        poolProperties.setTestOnBorrow(true);

        poolProperties.setValidationQuery("SELECT 1");

        poolProperties.setTestOnReturn(false);

        poolProperties.setValidationInterval(30000);

        poolProperties.setTimeBetweenEvictionRunsMillis(30000);

        poolProperties.setMaxActive(100);

        poolProperties.setInitialSize(10);

        poolProperties.setMaxWait(10000);

        poolProperties.setRemoveAbandonedTimeout(60);

        poolProperties.setMinEvictableIdleTimeMillis(30000);

        poolProperties.setMinIdle(10);

        poolProperties.setLogAbandoned(true);

        poolProperties.setRemoveAbandoned(true);

        poolProperties.setJdbcInterceptors(

                "org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;" +

                "org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");

        DataSource datasource = new DataSource();

        datasource.setPoolProperties(poolProperties);

        Connection connection = null;

        try {

            connection = datasource.getConnection();

            Statement st = connection.createStatement();

            ResultSet rs = st.executeQuery("select version()");

            if (rs.next()) {

                System.out.println(rs.getString(1));

            }

        } catch (SQLException e) {

            e.printStackTrace();

        } finally {

            close(connection);

        }

        //实际使用中一般是在应用启动时初始化数据源，应用从数据源中获取连接；并不会关闭数据源。

        datasource.close();

    }

    private static void close(Connection connection) {

        if (connection != null) {

            try {

                connection.close();

            } catch (SQLException e) {

                e.printStackTrace();

            }

        }

    }

}

2.2、作为资源配置在 Tomcat 中

先把对应数据库的驱动包拷贝到 Tomcat 或应用的 lib 目录下，然后在 content.xml 中配置资源，

content.xml 可以在如下位置：

• conf/context.xml：针对所有的应用
• conf/Catalina/localhost：针对单个应用，适合在 Tomcat 外部部署应用
• {应用}/META-INFcontext.xml：针对单个应用

配置资源的例子如下：

<Resource name="jdbc/testDb"

    auth="Container"

    type="javax.sql.DataSource"

    factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"

    testWhileIdle="true"

    testOnBorrow="true"

    testOnReturn="false"

    validationQuery="SELECT 1"

    validationInterval="30000"

    timeBetweenEvictionRunsMillis="30000"

    maxActive="20"

    maxIdle="20"

    minIdle="5"

    maxWait="10000"

    initialSize="5"

    removeAbandonedTimeout="60"

    removeAbandoned="true"

    logAbandoned="true"

    minEvictableIdleTimeMillis="30000"

    jmxEnabled="true"

    jdbcInterceptors="org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;

    org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer"

    username="root"

    password="123456"

    driverClassName="com.mysql.cj.jdbc.Driver"

    url="jdbc:mysql://10.40.9.11:3306/mydb?useUnicode=true&amp;characterEncoding=UTF-8" />

可以通过 jndi 来查找该资源，这里通过 jsp 来演示查找方法：

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="UTF-8"%>

<%@ page import="javax.naming.Context,

                javax.naming.InitialContext,

                javax.sql.DataSource,

                java.sql.*"%>

<%

    Connection connection = null;

    try {

        InitialContext initialContext = new InitialContext();

        Context context = (Context) initialContext.lookup("java:comp/env");

        DataSource dataSource = (DataSource)context.lookup("jdbc/testDb");

        connection = dataSource.getConnection();

        Statement st = connection.createStatement();

        ResultSet rs = st.executeQuery("select version()");

        if (rs.next()) {

            System.out.println(rs.getString(1));

        }

    } catch (Exception e) {

        e.printStackTrace();

    } finally {

        if (connection != null) {

            try {

                connection.close();

            } catch (SQLException e) {

                e.printStackTrace();

            }

        }

    }

%>

<html>

    <body>

        <h3>通过 jndi 查找数据源并获取数据库的版本信息</h3>

    </body>

</html>

3.2、在 SpringBoot 中使用

3.1.1、引入依赖

<parent>

    <groupId>org.springframework.boot</groupId>

    <artifactId>spring-boot-starter-parent</artifactId>

    <version>2.3.12.RELEASE</version>

    <relativePath />

</parent>

<dependencies>

    <dependency>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-web</artifactId>

    </dependency>

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-jdbc</artifactId>

    </dependency>

    <dependency>

        <groupId>org.apache.tomcat</groupId>

        <artifactId>tomcat-jdbc</artifactId>

        <version>8.5.72</version>

    </dependency>

    <dependency>

        <groupId>mysql</groupId>

        <artifactId>mysql-connector-java</artifactId>

    </dependency>

</dependencies>

3.1.2、单数据源

application.yml 配置：

spring:

  datasource:

    tomcat-pool:

      name: Tomcat连接池

      url: jdbc:mysql://10.40.9.11:3306/mydb?useUnicode=true&characterEncoding=UTF-8

      driver-class-name: com.mysql.cj.jdbc.Driver

      username: root

      password: 123456

      test-while-idle: true

      test-on-borrow: true

      validation-query: select 1

      test-on-return: false

      validation-interval: 30000

      time-between-eviction-runs-millis: 30000

      max-active: 100

      initial-size: 10

      max-wait: 10000

      remove-abandoned-timeout: 60

      min-evictable-idle-time-millis: 30000

      min-idle: 10

      log-abandoned: true

      remove-abandoned: true

      jdbc-interceptors: org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer

数据源配置类：

package com.abc.demo.config;

import org.springframework.boot.context.properties.ConfigurationProperties;

import org.springframework.boot.jdbc.DataSourceBuilder;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

@Configuration

public class DataSourceConfig {

    @Bean("dataSource")

    @ConfigurationProperties(prefix = "spring.datasource.tomcat-pool")

    public DataSource dataSource() {

        return DataSourceBuilder.create().type(org.apache.tomcat.jdbc.pool.DataSource.class).build();

    }

}

使用：

@Autowired

private DataSource dataSource;

3.1.3、多数据源

application.yml 配置：

spring:

  datasource:

    tomcat-pool:

      db1:

        name: Tomcat连接池

        url: jdbc:mysql://10.40.9.11:3306/mydb?useUnicode=true&characterEncoding=UTF-8

        driver-class-name: com.mysql.cj.jdbc.Driver

        username: root

        password: 123456

        test-while-idle: true

        test-on-borrow: true

        validation-query: select 1

        test-on-return: false

        validation-interval: 30000

        time-between-eviction-runs-millis: 30000

        max-active: 100

        initial-size: 10

        max-wait: 10000

        remove-abandoned-timeout: 60

        min-evictable-idle-time-millis: 30000

        min-idle: 10

        log-abandoned: true

        remove-abandoned: true

        jdbc-interceptors: org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer

      db2:

        name: Tomcat连接池

        url: jdbc:mysql://10.110.74.187:3306/egmp?useUnicode=true&characterEncoding=UTF-8

        driver-class-name: com.mysql.cj.jdbc.Driver

        username: root

        password: InsYR0ot187!

        test-while-idle: true

        test-on-borrow: true

        validation-query: select 1

        test-on-return: false

        validation-interval: 30000

        time-between-eviction-runs-millis: 30000

        max-active: 100

        initial-size: 10

        max-wait: 10000

        remove-abandoned-timeout: 60

        min-evictable-idle-time-millis: 30000

        min-idle: 10

        log-abandoned: true

        remove-abandoned: true

        jdbc-interceptors: org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer

数据源配置类：

package com.abc.demo.config;

import org.springframework.boot.context.properties.ConfigurationProperties;

import org.springframework.boot.jdbc.DataSourceBuilder;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

@Configuration

public class DataSourceConfig {

    @Bean("dataSource1")

    @ConfigurationProperties(prefix = "spring.datasource.tomcat-pool.db1")

    public DataSource dataSource1() {

        return DataSourceBuilder.create().type(org.apache.tomcat.jdbc.pool.DataSource.class).build();

    }

    @Bean("dataSource2")

    @ConfigurationProperties(prefix = "spring.datasource.tomcat-pool.db2")

    public DataSource dataSource2() {

        return DataSourceBuilder.create().type(org.apache.tomcat.jdbc.pool.DataSource.class).build();

    }

}

使用：

@Autowired

@Qualifier("dataSource1")

private DataSource dataSource1;

@Autowired

@Qualifier("dataSource2")

private DataSource dataSource2;

到此这篇关于 Java 数据库连接池 Tomcat介绍的文章就介绍到这了,更多相关 Java连接池 Tomcat内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！