java文件上传

1. 所需jar包

commons-io-2.4 --- 我使用的是2.4版本

commons-fileupload-1.3.3 --- 1.3.3版本

上述jar包请到该链接下载：https://pan.baidu.com/s/153wiQJ-kmsF_c6usLFk19Q 提取码：tg3p

2. 代码实现

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


import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;

/**
 * @author ksdhy
 * @date 2020/9/13 8:53
 */
public class Upload extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        if(!ServletFileUpload.isMultipartContent(req)) // 确认文件是不是为二进制流传输
        {
            return; // 非二进制就不理会请求
        }


        FileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);
        try {
            List<FileItem> fileItemList = upload.parseRequest(req);
            for(FileItem item : fileItemList){
                String fileName = item.getFieldName();
                if(item.isFormField()){ // 如果是普通表单组件
                    String value = item.getString("utf-8");
                    System.out.println(fileName + value);
                }else{
                    System.out.println(fileName + item.getName()); // 文件名
                    item.write(new File("E:/",item.getName()));
                }
            }
            resp.getWriter().append("上传成功");
        } catch (FileUploadException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}