[javaEE] tomcat内部连接池详解编程语言

在META-INF的目录下，新建context.xml

在程序中获取数据源，通过jndi，这个jndi必须在Servlet中才能获取，并且需要配置web.xml使servlet一启动就拿到数据源

context.xml

 ?xml version="1.0" encoding="utf-8"? 

 Context 

 Resource 

 name="mySource" 

 type="javax.sql.DataSource" 

 username="root" 

 password="root" 

 driverClassName="com.mysql.jdbc.Driver" 

 url="jdbc:mysql:///java" 

 maxActive="8" 

 maxIdle="4" 

 /Context 

import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.sql.DataSource;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub /** protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /** * 创建后就会启动 @Override public void init() throws ServletException { try { //注意导包javax.naming.Context; Context context= new InitialContext(); Context jndi=(Context) context.lookup("java:comp/env"); DataSource source =(DataSource) jndi.lookup("mySource"); //注意导包 java.sql.Connection; Connection conn=source.getConnection(); //获取传输器对象 Statement statement=conn.createStatement(); //获取结果集对象 ResultSet resultSet=statement.executeQuery("select * from user"); //遍历 while(resultSet.next()){ String username=resultSet.getString("username"); System.out.println(username); //关闭资源 resultSet.close(); statement.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); }

web.xml

 servlet 

 servlet-name DataSourceTest /servlet-name 

 servlet-class com.tsh.web.DataSourceTest /servlet-class 

 load-on-startup 1 /load-on-startup 

 /servlet 

 servlet-mapping 

 servlet-name DataSourceTest /servlet-name 

 url-pattern /Servlet/DataSourceTest /url-pattern 

 /servlet-mapping 

 

12686.html

cjavamysqlxml