servlet实现文件上传-优快云博客

本文介绍了一个使用Java实现的文件上传类，通过Apache Commons FileUpload库解析HTTP请求中的文件，并保存到指定目录。文章详细展示了如何处理多部分请求，以及如何区分表单字段与文件字段。

package util;

import java.io.File;
import java.util.Iterator;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class Upload {

public static void upload(HttpServletRequest request,HttpServletResponse response,String uploadFlord){
		//请求信息中的内容是否是multipart类型
		boolean isMultipart = ServletFileUpload.isMultipartContent(request);
		//上传文件的存储路径（服务器文件系统上的绝对文件路径）
		String uploadFilePath = request.getSession().getServletContext().getRealPath(uploadFlord);
		if (isMultipart) {
			FileItemFactory factory = new DiskFileItemFactory();
			ServletFileUpload upload = new ServletFileUpload(factory);
			try {
				//解析form表单中所有文件
				List<fileitem> items = upload.parseRequest(request);
				Iterator<fileitem> iter = items.iterator();
				while (iter.hasNext()) {   //依次处理每个文件
					FileItem item = (FileItem) iter.next();
					if (item.isFormField()){  //普通表单字段
						String fieldName = item.getFieldName();   //表单字段的name属性值
						if (fieldName.equals("name")){
							//输出表单字段的值
							response.getWriter().print(item.getString("UTF-8")+"上传了文件。<br />");
						}
					}else{  //文件表单字段
						String fileName = item.getName();
						if (fileName != null && !fileName.equals("")) {
							File fullFile = new File(item.getName());
							File saveFile = new File(uploadFilePath, fullFile.getName());
							item.write(saveFile);
							String uploadFileName = fullFile.getName();
							response.getWriter().print("上传成功后的文件名是："+uploadFileName);			
						}
					}
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		
		
	}
}
</fileitem></fileitem>