大二快乐日记10.24

3. @WebServlet 实现多重映射
Servlet 3.0 增加了对 @WebServlet 注解的支持，我们可以在 urlPatterns 属性中，以字符串数组的形式指定一组映射规则来实现 Servlet 的多重映射。

以 servletDemo 为例，在 @WebServlet 注解的 urlPatterns 属性中添加一组虚拟路径，代码如下。
纯文本复制
package net.biancheng.www;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(
urlPatterns = { "/myServlet", "/myServlet4" })
public class MyServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private int initCount = 0;
private int httpCount = 0;
private int destoryCount = 0;
@Override
public void destroy() {
destoryCount++;
super.destroy();
// 向控制台输出destory方法被调用次数
System.out.println(
"**********************************destroy方法：" + destoryCount + "*******************************");
}
@Override
public void init() throws ServletException {
initCount++;
super.init();
// 向控制台输出init方法被调用次数
System.out.println("init方法：" + initCount);
}
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
httpCount++;
// 控制台输出doGet方法次数
System.out.println("doGet方法：" + httpCount);
// 设置返回页面格式与字符集
resp.setContentType("text/html;charset=UTF-8");
PrintWriter writer = resp.getWriter();
// 向页面输出
writer.write("初始化次数:" + initCount + "<br/>" + "处理请求次数:" + httpCount + "<br/>" + "销毁次数:" + destoryCount);
writer.close();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
}