httpServlet应用

1.新建class文件继承 HttpServlet

2.重写 init(),doPost(),doGet(),doDestory(),service()方法

(注:service中调用父类的话，请求先经过service()方法判断请求的方式然后根据请求的方式调用doGet或者doPost()方法，而不是调用重写的service方法)

3.在web.xml中添加servlet配置，配置如下：

<servlet>

        <servlet-name>servlet</servlet-name>

        <servlet-class>com.test.servlet.TestServlet</servlet-class>

        <init-param>

            <param-name>aa</param-name>

            <param-value>bb</param-value>

        </init-param>

    </servlet>

    

    <servlet-mapping>

        <servlet-name>servlet</servlet-name>

        <url-pattern>/imgServlet</url-pattern>

    </servlet-mapping>  

init-param是初始化参数在servlet中通过

String cc=this.getInitParameter("aa");

方式获取

向页面输出字符串

PrintWriter out = response.getWriter();  

 out.print(cc);