从配置文件中读取数据获取Connection

配置文件

db.driver=com.mysql.jdbc.Driver
db.url=jdbc\:mysql\://localhost\:3306/mybase
db.user=root
db.pswd=y@ngmin9

#-- 连接池初始化连接数 --
dataSource.initialSize=10
#-- 最大空闲连接 --
dataSource.maxIdle=20
#-- 最小空闲连接 --
dataSource.minIdle=5
#-- 最大连接数 --
dataSource.maxActive=50
#-- 超时等待时间以毫秒为单位 6000毫秒/1000等于60秒 --
dataSource.wait=500

使用普通方式链接数据库

package com.globalroam.util;

import java.io.IOException;
import java.util.Properties;

public class DbUtil {
    private static Properties properties = new Properties();
    public static String driver = null;
    public static String url = null;
    public static String user = null;
    public static String pswd = null;
    
    static{
        try {
            properties.load(DbUtil.class.getClassLoader().getResourceAsStream("resource/db.properties"));
            driver = properties.getProperty("db.driver");
            url = properties.getProperty("db.url");
            user = properties.getProperty("db.user");
            pswd = properties.getProperty("db.pswd");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

使用连接池获取Connection

package com.globalroam.util;

import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

import org.apache.commons.dbcp.BasicDataSource;


public class DBConnectionPool {
    private static BasicDataSource dataSource = null;
    private static Properties properties = new Properties();
    //private static Logger logger = Logger.;
    public static void initDataSource() {
        try {
            properties.load(DBConnectionPool.class.getClass().getResourceAsStream("resource/db.properties"));
            dataSource = new BasicDataSource();
            dataSource.setDriverClassName(properties.getProperty("db.driver"));
            dataSource.setUrl(properties.getProperty("db.url"));
            dataSource.setUsername(properties.getProperty("db.user"));
            dataSource.setPassword(properties.getProperty("db.pswd"));
            
            if(properties.getProperty("dataSource.initialSize") != null) {
                dataSource.setInitialSize(Integer.parseInt(properties.getProperty("dataSource.initialSize")));
            }
            
            if(properties.getProperty("dataSource.maxIdle") != null) {
                dataSource.setMaxIdle(Integer.parseInt(properties.getProperty("dataSource.maxIdle")));
            }
            
            if(properties.getProperty("dataSource.minIdle") != null) {
                dataSource.setMinIdle(Integer.parseInt(properties.getProperty("dataSource.minIdle")));
            }
            
            if(properties.getProperty("dataSource.maxActive") != null && "0".equals(properties.getProperty("dataSource.maxActive"))) {
                dataSource.setMaxActive(Integer.parseInt(properties.getProperty("dataSource.maxActive")));
            }
            
            if(properties.getProperty("dataSource.wait") != null) {
                dataSource.setMaxWait(Integer.parseInt(properties.getProperty("dataSource.wait")));
            }
        } catch (IOException e) {
            e.printStackTrace();
            
        }
    } 
    
    public static Connection getConnection() throws SQLException {
        Connection conn = null;
        if(dataSource == null) {
            initDataSource();
        }
        if(dataSource != null) {
            conn = dataSource.getConnection();
        }
        return conn;
    }
}