javaweb实现文件上传示例代码

2024-02-26 01:23:03 51

本文实例为大家分享了javaweb文件下载的具体实现代码，供大家参考，具体内容如下

文件上传示例

注意：jsp页面编码为"UTF-8"

文件上传的必要条件

1.form表单，必须为POST方式提交

2.enctype="multipart/form-data"

3.必须有

前端jsp页面

<%@pagelanguage="java"import="java.util.*"pageEncoding="UTF-8"%>
<%
Stringpath=request.getContextPath();
StringbasePath=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>




"rel="externalnofollow">

MyJSP'index.jsp'startingpage








functionaddFile(){
vardiv1=document.getElementById("div1");
div1.innerHTML+="
";

}
functiondeleteFile(div){
//他的爷爷删除他的爸爸
div.parentNode.parentNode.removeChild(div.parentNode);

}



文件的描述：

实现文件上传的servlet

packagecom.learning.servlet;

importjava.io.File;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.UnsupportedEncodingException;
importjava.text.SimpleDateFormat;
importjava.util.Date;
importjava.util.List;
importjava.util.UUID;

importjavax.servlet.ServletException;
importjavax.servlet.annotation.WebServlet;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;

importorg.apache.commons.fileupload.FileItem;
importorg.apache.commons.fileupload.FileUploadException;
importorg.apache.commons.fileupload.disk.DiskFileItemFactory;
importorg.apache.commons.fileupload.servlet.ServletFileUpload;
importorg.apache.commons.io.FilenameUtils;

/**
*ServletimplementationclassUpLoadServlet
*/
@WebServlet("/servlet/upLoadServlet")
publicclassUpLoadServletextendsHttpServlet{
privatestaticfinallongserialVersionUID=1L;

/**
*@seeHttpServlet#doGet(HttpServletRequestrequest,HttpServletResponseresponse)
*/
protectedvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
doGet(request,response);
}

/**
*@seeHttpServlet#doPost(HttpServletRequestrequest,HttpServletResponseresponse)
*/
protectedvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{


//文件上传
//判断是否支持文件上传
booleanisMultipartContent=ServletFileUpload
.isMultipartContent(request);
if(!isMultipartContent){
thrownewRuntimeException("不支持");
}

//创建一个DiskFileItemfactory工厂类
DiskFileItemFactorydiskFileItemFactory=newDiskFileItemFactory();
//创建一个ServletFileUpload核心对象
ServletFileUploadfileUpload=newServletFileUpload(diskFileItemFactory);
//设置中文乱码
fileUpload.setHeaderEncoding("UTF-8");
//设置一个文件大小
fileUpload.setFileSizeMax(1024*1024*3);//大小为3M
//设置总文件大小
//fileUpload.setSizeMax(1024*1024*10);//大小为10M

try{
//fileload解析request请求，返回list集合
ListfileItems=fileUpload.parseRequest(request);
for(FileItemfileItem:fileItems){
if(fileItem.isFormField()){
//是文本域(处理文本域的函数)
processFormField(fileItem);
}else{
//文件域(处理文件域的函数)
processUpLoadField1(fileItem);
}
}

}catch(FileUploadExceptione){
e.printStackTrace();
}


}

/**
*@paramfileItem
*
*/
privatevoidprocessUpLoadField1(FileItemfileItem){

try{
//获得文件读取流
InputStreaminputStream=fileItem.getInputStream();

//获得文件名
StringfileName=fileItem.getName();

//对文件名处理
if(fileName!=null){
fileName.substring(fileName.lastIndexOf(File.separator)+1);

}else{
thrownewRuntimeException("文件名不存在");
}

//对文件名重复处理
//fileName=newString(fileName.getBytes("ISO-8859-1"),"UTF-8");
fileName=UUID.randomUUID()+"_"+fileName;

//日期分类
SimpleDateFormatsimpleDateFormat=newSimpleDateFormat("yyyy-MM-dd");
Stringdate=simpleDateFormat.format(newDate());
//创建目录
Fileparent=newFile(this.getServletContext().getRealPath("/WEB-INF/upload/"+date));
if(!parent.exists()){
parent.mkdirs();
}

//上传文件
fileItem.write(newFile(parent,fileName));
//删除临时文件（如果上传文件过大，会产生.tmp的临时文件）
fileItem.delete();

}catch(IOExceptione){
System.out.println("上传失败");
e.printStackTrace();
}catch(Exceptione){

}



}

/**
*@paramfileItem
*/
//文件域
privatevoidprocessUpLoadField(FileItemfileItem){

try{
//获得文件输入流
InputStreaminputStream=fileItem.getInputStream();

//获得是文件名字
Stringfilename=fileItem.getName();
//对文件名字处理
if(filename!=null){
//filename.substring(filename.lastIndexOf(File.separator)+1);
filename=FilenameUtils.getName(filename);
}

//获得路径，创建目录来存放文件
StringrealPath=this.getServletContext().getRealPath("/WEB-INF/load");

FilestoreDirectory=newFile(realPath);//既代表文件又代表目录
//创建指定目录
if(!storeDirectory.exists()){
storeDirectory.mkdirs();
}
//防止文件名一样
filename=UUID.randomUUID()+"_"+filename;
//目录打散防止同一目录文件下文件太多，不好查找

//按照日期分类存放上传的文件
//storeDirectory=makeChildDirectory(storeDirectory);

//多级目录存放上传的文件
storeDirectory=makeChildDirectory(storeDirectory,filename);

FileOutputStreamfileOutputStream=newFileOutputStream(newFile(storeDirectory,filename));
//读取文件，输出到指定的目录中
intlen=1;
byte[]b=newbyte[1024];
while((len=inputStream.read(b))!=-1){
fileOutputStream.write(b,0,len);
}
//关闭流
fileOutputStream.close();
inputStream.close();

}catch(IOExceptione){
e.printStackTrace();
}
}
//按照日期来分类
privateFilemakeChildDirectory(FilestoreDirectory){
SimpleDateFormatsimpleDateFormat=newSimpleDateFormat("yyyy-MM-dd");
Stringdate=simpleDateFormat.format(newDate());
//创建目录
FilechildDirectory=newFile(storeDirectory,date);
if(!childDirectory.exists()){
childDirectory.mkdirs();
}
returnchildDirectory;
}
//多级目录
privateFilemakeChildDirectory(FilestoreDirectory,Stringfilename){
filename=filename.replaceAll("-","");
FilechildDirectory=newFile(storeDirectory,filename.charAt(0)+File.separator+filename.charAt(1));
if(!childDirectory.exists()){
childDirectory.mkdirs();
}
returnchildDirectory;
}
//文本域
privatevoidprocessFormField(FileItemfileItem){
//对于文本域的中文乱码，可以用newString()方式解决
try{
StringfieldName=fileItem.getFieldName();//表单中字段名name，如description
StringfieldValue=fileItem.getString("UTF-8");//description中value
//fieldValue=newString(fieldValue.getBytes("ISO-8859-1"),"UTF-8");
System.out.println(fieldName+":"+fieldValue);
}catch(UnsupportedEncodingExceptione){
//TODOAuto-generatedcatchblock
e.printStackTrace();
}

}

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。

javaweb实现文件上传示例代码

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