Java0715/tomcat-demo/src/main/java/com/sf/sysdemo/util/JDBCUtil.java

package com.sf.sysdemo.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

// 工具类
public class JDBCUtil {

    // 提供一个静态的数据源
    private static DataSource dataSource;
    // 静态初始化块
    static {
        Properties properties = new Properties();
        // 获得类加载器
        ClassLoader classLoader = JDBCUtil.class.getClassLoader();
        // 加载指定配置文件 获取输入流
        InputStream inputStream = classLoader.getResourceAsStream("jdbc.properties");
        try {
            // 将输入流加载进 properties对象中
            properties.load(inputStream);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

        // 通过druid提供的工厂类 来创建出数据源
        try {
            dataSource = DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    // 提供数据源
    public static DataSource getDataSource() {
        return dataSource;
    }

    // 提供数据库的连接
    public static Connection getConnection(){
        try {
            Connection connection = dataSource.getConnection();
            return connection;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}