优先级 :注解配置会覆盖 web.xml
中的重复配置
一:通过WebServlet注解配置

极简模式:
java
@WebServlet("/hello")
public class HelloServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) {
// 处理GET请求
}
}
完整形式:
java
@WebServlet(
name = "UserServlet",
urlPatterns = {"/user", "/users/*"},
loadOnStartup = 1,
initParams = {
@WebInitParam(name = "dbUrl", value = "jdbc:mysql://localhost:3306/mydb"),
@WebInitParam(name = "timeout", value = "5000")
},
description = "用户管理Servlet"
)
public class UserServlet extends HttpServlet {
// Servlet实现
}
二:通过web.xml配置
XML
<web-app>
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>com.example.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>
两种方式记得注释掉不用的那个!!!会导致项目异常,页面404