本文分为两大方面进行讲解：
一、java实现动态上传多个文件
二、解决文件重命名问题java
供大家参考，具体内容如下
1、动态上传多个文件
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<form name="xx" action="<c:url value='/Up3Servlet'/>" method="post" enctype="multipart/form-data">
<table id="tb" border="1">
<tr>
<td>
File：
</td>
<td>
<input type="file" name="file">
<button onclick="_del(this);">删除</button>
</td>
</tr>
</table>
<br/>
<input type="button" onclick="_submit();" value="上传">
<input onclick="_add();" type="button" value="增加">
</form>
</body>
<script type="text/javascript">
function _add(){
var tb = document.getElementById("tb");
//写入一行
var tr = tb.insertRow();
//写入列
var td = tr.insertCell();
//写入数据
td.innerHTML="File：";
//再声明一个新的td
var td2 = tr.insertCell();
//写入一个input
td2.innerHTML='<input type="file" name="file"/><button onclick="_del(this);">删除</button>';
}
function _del(btn){
var tr = btn.parentNode.parentNode;
//alert(tr.tagName);
//获取tr在table中的下标
var index = tr.rowIndex;
//删除
var tb = document.getElementById("tb");
tb.deleteRow(index);
}
function _submit(){
//遍历所的有文件
var files = document.getElementsByName("file");
if(files.length==0){
alert("没有可以上传的文件");
return false;
}
for(var i=0;i<files.length;i++){
if(files[i].value==""){
alert("第"+(i+1)+"个文件不能为空");
return false;
}
}
document.forms['xx'].submit();
}
</script>
</html>
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遍历所有要上传的文件
2、解决文件的重名的问题
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package cn.hx.servlet;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FileUtils;
public class UpImgServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
String path = getServletContext().getRealPath("/up");
DiskFileItemFactory disk =
new DiskFileItemFactory(1024*10,new File("d:/a"));
ServletFileUpload up = new ServletFileUpload(disk);
try{
List<FileItem> list = up.parseRequest(request);
//只接收图片*.jpg-iamge/jpege.,bmp/imge/bmp,png,
List<String> imgs = new ArrayList<String>();
for(FileItem file :list){
if(file.getContentType().contains("image/")){
String fileName = file.getName();
fileName = fileName.substring(fileName.lastIndexOf("\\")+1);
//获取扩展
String extName = fileName.substring(fileName.lastIndexOf("."));//.jpg
//UUID
String uuid = UUID.randomUUID().toString().replace("-", "");
//新名称
String newName = uuid+extName; //在这里用UUID来生成新的文件夹名字，这样就不会导致重名
FileUtils.copyInputStreamToFile(file.getInputStream(),
new File(path+"/"+newName));
//放到list
imgs.add(newName);
}
file.delete();
}
request.setAttribute("imgs",imgs);
request.getRequestDispatcher("/jsps/imgs.jsp").forward(request, response);
}catch(Exception e){
e.printStackTrace();
}
}
}
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以上实现了java多文件上传，解决了文件重名问题，希望对大家的学习有所帮助。