Spring 创建第三方bean对象

1. 介绍

  在Spring中，很多对象都是单实例的，在日常的开发中，我们经常需要使用某些外部的单实例对象，例如数据库连接池，下面我们来讲解下如何在spring中创建第三方bean实例。接下来已druid为例演示。

2. 本地导入

2.1 导入数据库连接池的pom文件

<?xml version="1.0" encoding="UTF-8"?>
<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>com.cmz</groupId>
<artifactId>spring_study</artifactId>
<version>1.0-SNAPSHOT</version>

<dependencies>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.2.3.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.21</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.48</version>
    </dependency>

</dependencies>

</project>

2.2 编写配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--spring 管理第三方bean-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="username" value="root"></property>
        <property name="password" value="root"></property>
        <property name="url" value="jdbc:mysql://192.168.71.133:3306/izone"></property>
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
    </bean>
</beans>

输出

{
    CreateTime:"2020-02-29 16:06:19",
    ActiveCount:0,
    PoolingCount:0,
    CreateCount:0,
    DestroyCount:0,
    CloseCount:0,
    ConnectCount:0,
    Connections:[
    ]
}
二月 29, 2020 4:06:20 下午 com.alibaba.druid.support.logging.JakartaCommonsLoggingImpl info
信息: {dataSource-1} inited
Sat Feb 29 16:06:20 CST 2020 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
com.mysql.jdbc.JDBC4Connection@12c8a2c0

2.3 测试

import com.alibaba.druid.pool.DruidDataSource;
import com.cmz.bean.Person;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.sql.SQLException;

/**
 * @author summer
 * @create 2020-02-29 15:45
 */
public class MyTest7 {
    public static void main(String[] args) throws SQLException {
        ApplicationContext context = new ClassPathXmlApplicationContext("ioc7.xml");
        DruidDataSource dataSource = context.getBean("dataSource", DruidDataSource.class);
        System.out.println(dataSource);
        System.out.println(dataSource.getConnection());
    }
}

3. 引用外部配置文件

3.1 编写连接数据库配置文件

在resource中添加dbconfig.properties

username=root
password=root
url=jdbc:mysql://192.168.71.133:3306/izone
driverClassName=com.mysql.jdbc.Driver

3.2 编写配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
        ">

    <context:property-placeholder location="classpath:dbconfig.properties"></context:property-placeholder>
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="username" value="root"></property>
        <property name="password" value="root"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/test"></property>
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
    </bean>
</beans>

3.3 测试

import com.alibaba.druid.pool.DruidDataSource;
import com.cmz.bean.Person;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.sql.SQLException;

/**
 * @author summer
 * @create 2020-02-29 15:45
 */
public class MyTest7 {
    public static void main(String[] args) throws SQLException {
        ApplicationContext context = new ClassPathXmlApplicationContext("ioc8.xml");
        DruidDataSource dataSource = context.getBean("dataSource", DruidDataSource.class);
        System.out.println(dataSource);
        System.out.println(dataSource.getConnection());
    }
}

输出

{
    CreateTime:"2020-02-29 16:08:45",
    ActiveCount:0,
    PoolingCount:0,
    CreateCount:0,
    DestroyCount:0,
    CloseCount:0,
    ConnectCount:0,
    Connections:[
    ]
}
二月 29, 2020 4:08:45 下午 com.alibaba.druid.support.logging.JakartaCommonsLoggingImpl info
信息: {dataSource-1} inited