Struts笔记4

向右看齐 2021-12-03 06:39 229阅读 0赞

**Struts2-拦截器-单个拦截器**

自定义拦截器

1.创建一个继承AbstractInterceptor的类

package com.gyf.web.interceptor; import com.opensymphony.xwork2.ActionInvocation; import com.opensymphony.xwork2.interceptor.AbstractInterceptor; public class MyInterceptor extends AbstractInterceptor{ @Override public String intercept(ActionInvocation invocation) throws Exception { System.out.println("MyInterceptor拦截前....."); //放行 String returnStr = invocation.invoke(); System.out.println("MyInterceptor拦截后....."); return returnStr; } }

2.在Struts.xml文件中声明刚刚创建的拦截器

3.创建一个action和一个jsp页面

package com.gyf.web.action; import com.opensymphony.xwork2.ActionSupport; public class Demo1Action extends ActionSupport{ public String action1() { return SUCCESS; } }

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    
    </head>
    <body>
    Action1.....
    </body>
    </html>

4.在struts.xml中声明一个action

<package name="p1" extends="struts-default" namespace="/">  <interceptors> <interceptor name="MyInterceptor" class="com.gyf.web.interceptor.MyInterceptor"/> </interceptors> <action name="action1" class="com.gyf.web.action.Demo1Action" method="action1"> <interceptor-ref name="MyInterceptor"/> <result>/action1.jsp</result> </action> </package>

![img][]

![img][img 1]

拦截器放行的是什么呢?

![img][img 2]

注意：如果在action中配置了拦截器，那么默认的拦截器就失效了

**Struts2文件上传**

Struts提供了内置标签用于文件上传

文件上传的必要前提条件：表单必须是post方法，enctype类型必须为Multipart/form-data

//上传文件需要三个属性 private File photo;//struts会自动把数据转成文件对象 private String photoContentType;//文件的类型 private String photoFileName;//文件对的名称

**文件上传类型的限制和中文错误显示**

配置Struts.xml来限制文件上传类型

<package name="p1" extends="struts-default" namespace="/">
            <action name="upload" class="com.gyf.web.action.UploadAction" method="upload">
                
                 <interceptor-ref name="defaultStack">
                    <param name="fileUpload.allowedTypes">image/png,image/jpeg</param>
                </interceptor-ref>
                <result name="input">/upload.jsp</result>
            </action>
        </package>

当文件上传类型出错是出现的提示并不是中文，现在把错误信息提示改成中文

![img][img 3]

自己写一个国际化资源包，把key的值改成中文即可

首先创建一个国际化资源包，把提示信息复制到自己创建的国际化资源包，提示信息在这里![img][img 4]

更改国际化资源包的value

value中的 \{0\},\{1\}，\{2\},\{3\}表示的是字段名，和文件名，临时文件，文件类型

struts.messages.error.uploading=Error uploading: {0}
    struts.messages.error.file.too.large=The file is to large to be uploaded: {0} "{1}" "{2}" {3}
    struts.messages.error.content.type.not.allowed="{1}" - {3} \u6587\u4EF6\u7C7B\u578B\u4E0D\u88AB\u5141\u8BB8
    struts.messages.error.file.extension.not.allowed=\u6587\u4EF6\u6269\u5C55\u540D\u4E0D\u4E0D\u6B63\u786E: {0} "{1}" "{2}" {3}

然后在struts.xml文件配置国际化

配置完成

![img][img 5]

**多文件上传**

多文件上传，在Action代码中，只需要把接收的文件字段设置为数组即可

jsp配置

<s:form action="/upload2" enctype="multipart/form-data" method="post">
            <s:textfield label="用户名" name="username"/>
            <s:textfield label="密码" name="password"/>
            <s:file label="照片" name="photo"/>
            <s:file label="照片" name="photo"/>
            <s:file label="照片" name="photo"/>
            <s:submit value="上传"/>
        </s:form>

action类

package com.gyf.web.action; import java.io.File; import com.opensymphony.xwork2.ActionSupport; public class UploadAction extends ActionSupport { private String username; private String password; private File[] photo;//struts会自动把数据转成文件对象 private String[] photoContentType;//文件的类型 private String[] photoFileName;//文件对的名称 public String upload() { for(int i=0;i<photo.length;i++) { File file = photo[i]; System.out.println("文件临时路径: "+file); System.out.println("文件类型: "+photoContentType[i]); System.out.println("文件名: "+photoFileName[i]); } return NONE; } public void setPhoto(File[] photo) { this.photo = photo; } public void setPhotoContentType(String[] photoContentType) { this.photoContentType = photoContentType; } public void setPhotoFileName(String[] photoFileName) { this.photoFileName = photoFileName; } public void setUsername(String username) { this.username = username; } public void setPassword(String password) { this.password = password; } }

struts.xml配置

<action name="upload2" class="com.gyf.web.action.UploadAction2" method="upload2">
                 <interceptor-ref name="defaultStack">
                    <param name="fileUpload.allowedExtensions">png,jpg</param>
                </interceptor-ref>
                <result name="input">/upload2.jsp</result>
            </action>

转载于:https://www.cnblogs.com/train99999/p/11154641.html

[img]: https://www.z4a.net/images/2019/07/08/image.png
[img 1]: https://www.z4a.net/images/2019/07/08/image3b872ecf9115a3b0.png
[img 2]: https://www.z4a.net/images/2019/07/08/image7c0c274af8b00d5f.png
[img 3]: https://www.z4a.net/images/2019/07/08/imagec4f2bec66c2b8e29.png
[img 4]: https://www.z4a.net/images/2019/07/08/imagec9984e941ff8f239.png
[img 5]: https://www.z4a.net/images/2019/07/08/imagec68858ed7103be94.png