java web文件上传详细解析

目录

1. 工具
2. 上传案例
3. 上传详细解析流程

1.工具

MyEclipse10.7、火狐浏览器、fileupload组件(添加的jar包 commons-fileupload-1.2.2.jar、commons-io-2.2.jar )

2.上传案例《先上案例，如果熟悉的同学可以绕过，直接看后面》

1. JSP页面

      2.UploadServlet.java

　　　　

@Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String fieldName = null;
        String fieldValue = null;
        //判断form表单传过来的数据MIME是否是<enctype="multipart/form-data">
        boolean isMultipart = ServletFileUpload.isMultipartContent(request);
        if(!isMultipart){
            throw new RuntimeException("这个表单提交的数据不是《multipart/form-data》类型!");
        }
        //解析请求的内容   --  fileupload组件
        DiskFileItemFactory factory = new DiskFileItemFactory();//产生FileItem的工厂
        ServletFileUpload sfu = new ServletFileUpload(factory);
        List<FileItem> items = new ArrayList<FileItem>();
        try {
            /*
             * [name=null, StoreLocation=C:\tomcat7\temp1\ upload_5629e1cf_156bc94a7ca__7ffe_00000000.tmp1, 
             * size=5bytes, isFormField=true, FieldName=name, name=test1.zip1, 
             * StoreLocation=C:\tomcat7\temp1\ upload_5629e1cf_156bc94a7ca__7ffe_00000001.tmp1, size=154bytes, 
             * isFormField=false, FieldName=file1]  ----->items的值
             */            
            items = sfu.parseRequest(request);
            for(FileItem item:items){
                if(item.isFormField()){    //普通的字段
                    fieldName = item.getFieldName();
                    fieldValue = item.getString();
                }else{//上传文件的处理
                    InputStream in = item.getInputStream();
                    //上传文件的文件名   --test1.zip1
                    String fileName = item.getName();    
                    if(fileName != null){
                        fileName = FilenameUtils.getName(fileName);
                    }
                    //存放路径        --   C:\tomcat7\webapps1\FileUpload\files
                    String realPath = getServletContext().getRealPath("/files");
                    File storeDirectory = new File(realPath);
                    if(storeDirectory.exists()){    //判断文件是否存在
                        storeDirectory.mkdirs();    //若文件不存在则创建一个
                    }
                    //将文件写入到上述文件夹中C:\tomcat7\webapps1\FileUpload\files
                    item.write(new File(storeDirectory,fileName));
                }
            }
        } catch (Exception e) {
            throw new RuntimeException("解析请求失败!");
        }
        PrintWriter out = response.getWriter();
        out.write( fieldName + "=" +fieldValue);
    }

 

3.上传详细解析流程跟踪