数据库连接（二）JNDI应用

package com.jess;


import javax.annotation.Resource;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import java.io.IOException;




@WebServlet("/")

public class MyServlet extends HttpServlet {
    
    // 可以通过lookup获取
    @Resource(lookup = "java:comp/env/dataSource/mysql/jzy2")
    DataSource dataSource2;
    //也可以通过name属性获取
    @Resource(name = "java:comp/env/dataSource/mysql/jzy1")
    DataSource dataSource3;
    @Resource(lookup = "java:comp/env/dataSource/mysql/jzy1")
    DataSource dataSource4;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Context ctx = null;
        try {
            ctx = new InitialContext();
            DataSource dataSource1 =
                    (DataSource) ctx.lookup("java:comp/env/dataSource/mysql/jzy2");
            System.out.println("手动获取资源1");
            System.out.println("dataSource = " + dataSource1);
            System.out.println(dataSource1.getConnection());
            System.out.println("webServlet+Resource注解获取资源2");
            System.out.println("dataSource2 = " + dataSource2);
            System.out.println(dataSource2.getConnection());
            System.out.println("webServlet+Resource注解获取资源3");
            System.out.println("dataSource3 = " + dataSource3);
            System.out.println(dataSource3.getConnection());
            System.out.println("webServlet+Resource注解获取资源4");
            System.out.println("dataSource4 = " + dataSource4);
            System.out.println(dataSource4.getConnection());
            System.out.println("数据库连接成功！");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}