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                        /JAVA Web開發技術應用——監聽器

為什么我每次運行項目時request都initialize了三次

代碼如下

```

public class FirstListener implements ServletRequestListener {

? ?// Public constructor is required by servlet spec
? ?public FirstListener() {
? ?}

@Override
? ?public void requestDestroyed(ServletRequestEvent servletRequestEvent) {
? ? ? ?System.out.println("request destroyed initParam=" + servletRequestEvent.getServletContext().getAttribute("initParam"));
? ?}

? ?@Override
? ?public void requestInitialized(ServletRequestEvent servletRequestEvent) {
? ? ? ?servletRequestEvent.getServletContext().setAttribute("intiParam","yang");
? ? ? ?System.out.println("request initialized");
? ?}
}

```

運行結果

```

Connected to server

[2017-12-23 10:44:47,157] Artifact ListenerDemo:war exploded: Artifact is being deployed, please wait...

[2017-12-23 10:44:47,776] Artifact ListenerDemo:war exploded: Artifact is deployed successfully

[2017-12-23 10:44:47,776] Artifact ListenerDemo:war exploded: Deploy took 619 milliseconds

request initialized

request destroyed initParam=null

request initialized

request destroyed initParam=null

request initialized

request destroyed initParam=null

```

qq_何足道_1

2017-12-23

源自：JAVA Web開發技術應用——監聽器 3-3

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1 回答

qq_何足道_1 提問者
2017-12-23

額，代碼竟然不顯示

我再貼一下

public?class?FirstListener?implements?ServletRequestListener?{

???//?Public?constructor?is?required?by?servlet?spec
???public?FirstListener()?{
???}
@Override
???public?void?requestDestroyed(ServletRequestEvent?servletRequestEvent)?{
???????System.out.println("request?destroyed?initParam="?+?servletRequestEvent.getServletContext().getAttribute("initParam"));
???}

???@Override
???public?void?requestInitialized(ServletRequestEvent?servletRequestEvent)?{
???????servletRequestEvent.getServletContext().setAttribute("intiParam","yang");
???????System.out.println("request?initialized");
???}
}