Struts2之上传文件

Posted 2020-11-30 安徒生敲代码

一、单文件上传

　1.定义form表单

<form action="uploadFile" method="post" enctype="multipart/form-data">
    上传文件:<input type="file" name="myFile">
    <input type="submit" value="提交">
</form>

　　重点:

　　　　(1)form表单上添加属性enctype="multipart/form-data"

　　　　(2)文件选择的input标签type设置为file

　2.定义文件上传Action(根据需求自定义)

package com.yg.study.action;

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

public class FileUploadAction {
    private File myFile;
    private String myFileFileName;

    public File getMyFile() {
        return myFile;
    }


    public void setMyFile(File myFile) {
        this.myFile = myFile;
    }


    public String getMyFileFileName() {
        return myFileFileName;
    }


    public void setMyFileFileName(String myFileFileName) {
        this.myFileFileName = myFileFileName;
    }


    public String upload(){
        String path = this.getClass().getResource("/").getPath();
        //System.out.println(path);
        File file=new File(path, "upload");
        if(!file.exists()){
            file.mkdir();
        }
        try {
            FileUtils.copyFile(myFile, new File(file, myFileFileName));
        } catch (IOException e) {
            
            e.printStackTrace();
        }
        return "success";
    }
}

　　重点:

　　　　(1)定义类型为File,变量名称为form表单中文件选择input标签的name属性的值的变量,这里为myFile,用于接收form表单提交的文件

　　　　(2)定义类型为String,变量名为orm表单中文件选择input标签的name属性的值+"FileName"的变量,这里为myFileFileName,用于接收form表单提交的文件名称

　　　　(3)为上述两个变量提供get和set方法,尤其是set方法不可少,否则变量的值设置不上

　3.配置struts.xml请求映射(根据需求自定义)

<action name="uploadFile" class="com.yg.study.action.FileUploadAction" method="upload">
    <result name="success">/success.jsp</result>
</action>

　4.启动项目

　　启动项目,访问文件上传页面,选择文件,提交即可

       

　5.设置最大文件大小

　　　　struts默认文件上传最大为2M,上传大于2M的文件会报异常

org.apache.commons.fileupload.FileUploadBase$SizeLimitExceededException: the request was rejected because its size (53647459) exceeds the configured maximum (2097152)
    at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:968)
    at org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:310)
    at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:334)
    at org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest.parseRequest(JakartaMultiPartRequest.java:192)
    at org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest.processUpload(JakartaMultiPartRequest.java:131)
    at org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest.parse(JakartaMultiPartRequest.java:92)
    at org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper.<init>(MultiPartRequestWrapper.java:84)
    at org.apache.struts2.dispatcher.Dispatcher.wrapRequest(Dispatcher.java:849)
    at org.apache.struts2.dispatcher.ng.PrepareOperations.wrapRequest(PrepareOperations.java:138)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

　　解决办法:

　　　　在struts.xml文件中添加如下配置:

<constant name="struts.multipart.maxSize" value="104857600"></constant>

　　　　我这里将最大文件大小设置为了100M(根据项目需求自定义即可)

二、多文件上传

　1.定义form表单

<form action="uploadFile" method="post" enctype="multipart/form-data">
    上传文件:<input type="file" name="myFiles" multiple/>
    <input type="submit" value="提交">
</form>

 

　　重点:

　　　　(1)form标签添加属性enctype="multipart/form-data"

　　　　(2)文件上传的input标签type属性设置为file,添加属性multiple或multiple="multiple"以便可以同时选择多个文件

　2.定义Action(根据需求自定义)

package com.yg.study.action;

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

public class FileUploadAction {
    private File[] myFiles;
    private String[] myFilesFileName;

    public File[] getMyFiles() {
        return myFiles;
    }

    public void setMyFiles(File[] myFiles) {
        this.myFiles = myFiles;
    }

    public String[] getMyFilesFileName() {
        return myFilesFileName;
    }

    public void setMyFilesFileName(String[] myFilesFileName) {
        this.myFilesFileName = myFilesFileName;
    }
    
    public String uploadFiles(){
        //获取项目classes文件路径
        String path = this.getClass().getResource("/").getPath();
        System.out.println(path);
        //定义文件上传路径
        File file=new File(path, "upload");
        if(!file.exists()){
            file.mkdir();
        }
        for(int i=0;i<myFiles.length;i++){
            try {
                //使用commons-io包的方法拷贝文件
                FileUtils.copyFile(myFiles[i], new File(file, myFilesFileName[i]));
            } catch (IOException e) {
                
                e.printStackTrace();
            }
        }
        
        return "success";
    }
}

　　重点:

　　　　(1)定义类型为File[],名称与文件上传input标签name属性值相同的变量,这里为myFiles,用于接收上传的文件

　　　　(2)定义类型为String[],名称与(文件上传input标签name属性值+"FileName")相同的变量,这里为myFilesFileName,用于接收上传的文件名

　　　　(3)提供以上两个变量的get和set方法,特别是set方法

　　　　(4)还可以定义类型为String[],名称与(文件上传input标签name属性值+"ContentType")相同的变量,这里如果定义的话就是myFilesContentType,用于接收文件的类型

　3.配置struts.xml请求映射(根据需求自定义)

<action name="uploadFile" class="com.yg.study.action.FileUploadAction" method="uploadFiles">
    <result name="success">/success.jsp</result>
</action>

　4.启动项目

　　　　选择上传的文件,点击提交按钮提交即可