阿里巴巴druid数据连接池的配置及使用

Posted 2021-04-06 不寸

我们来讲解无框架的,使用druid连接池的例子.

1. 引进jar包,如果你有maven的话添加如下配置,

    //这是druid的依赖配置

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.0.9</version>
</dependency>

    如果你没有使用maven,去百度搜索druid的jar包下载.

2.添加数据连接池的文件

在resource文件夹下添加db_server.properties文件.

文件内容

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://{主机地址}/{数据库名}?useUnicode=true&characterEncoding=UTF8&useSSL=true
username=root
password=password
filters=stat
initialSize=2
maxActive=300
maxWait=60000
timeBetweenEvictionRunsMillis=60000
minEvictableIdleTimeMillis=300000
validationQuery=SELECT 1
testWhileIdle=true
testOnBorrow=false
testOnReturn=false
poolPreparedStatements=false
maxPoolPreparedStatementPerConnectionSize=200

  3.添加使用该连接池的类

package action;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.SQLException;
import java.util.Properties;
import org.apache.log4j.Logger;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.alibaba.druid.pool.DruidPooledConnection;
/**
 * 要实现单例模式，保证全局只有一个数据库连接池
 */
public class DBPoolConnection {
 
    private static DBPoolConnection dbPoolConnection = null;
    private static DruidDataSource druidDataSource = null;
    static {
        Properties properties = loadPropertiesFile("classes/db_server.properties");
        try {
            druidDataSource = (DruidDataSource)DruidDataSourceFactory.createDataSource(properties); //DruidDataSrouce工厂模式
        } catch (Exception e) {
            
        }
    }

    /**
     * 数据库连接池单例
     * @return
     */
    public static synchronized DBPoolConnection getInstance(){
        if (null == dbPoolConnection){
            dbPoolConnection = new DBPoolConnection();
        }
        return dbPoolConnection;
    }

    /**
     * 返回druid数据库连接
     * @return
     * @throws SQLException
     */
    public DruidPooledConnection getConnection() throws SQLException{
        return druidDataSource.getConnection();
    }
    /**
     * @param string 配置文件名
     * @return Properties对象
     */
    private static Properties loadPropertiesFile(String fullFile) {
        String webRootPath = null;
        if (null == fullFile || fullFile.equals("")){
            throw new IllegalArgumentException("Properties file path can not be null" + fullFile);
        }
        webRootPath = DBPoolConnection.class.getClassLoader().getResource("").getPath();
        //System.out.println("rootPathis:"+webRootPath);
        webRootPath = new File(webRootPath).getParent();
        InputStream inputStream = null;
        Properties p =null;
        try {
            inputStream = new FileInputStream(new File(webRootPath + File.separator + fullFile));
            p = new Properties();
            p.load(inputStream);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != inputStream){
                    inputStream.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        return p;
    }

}

这里的路径一定要填写清楚,如果你使用的是idea,这样一般是没有错误的,如果你使用的是别的ide,哪有可能报错.

这里的resource一定要标记好是资源文件夹.