测试servlet线程安全问题

1.新建一个servletThread的类代码如下：

package eduask;
 import java.io.IOException;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 //Servlet线程安全问题;
 public class ServletThread extends HttpServlet{
 //定义一个全局变量;
 int i=0;
 @Override
 protected void service(HttpServletRequest arg0, HttpServletResponse arg1)
 throws ServletException, IOException {
 synchronized (this) {
 try {
 i++;
 Thread.sleep(1000);
 System.out.println("这是第"+i+"次访问");
 } catch (Exception e) {
 // TODO: handle exception
 }
 }
 }
 }

2.配置web.xml，配置结果如下：

<!-- 测试servlet线程问题 -->
 <servlet>
 <servlet-name>servletThread</servlet-name>
 <servlet-class>eduask.ServletThread</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>servletThread</servlet-name>
 <url-pattern>/servletThread</url-pattern>
 </servlet-mapping>

3.启动tomcat，在浏览器中输入：

​​http://localhost:8080/webDemo/servletThread​​

4.重复刷新5次，则会在控制台显示你已经访问了6次