文件上传下载

src/com/hellogithub/service/projectService.java

@@ -142,6 +142,7 @@ public class projectService {
     }
 
     public projectEntity selectProById(String id ){
+
         projectEntity projectEntity = projectDao.selectProById(id);
         categoryEntity categoryEntity = categoryDao.retNum(projectEntity.getCategoryId());
         projectEntity.setCategoryName(categoryEntity.getCategoryName());

src/com/hellogithub/servlet/DownLoadServlet.java

@@ -0,0 +1,127 @@
+package com.hellogithub.servlet;
+
+import com.alibaba.fastjson.JSONObject;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.*;
+import java.net.URLEncoder;
+import java.util.HashMap;
+import java.util.UUID;
+
+@WebServlet("/DownLoad")
+public class DownLoadServlet extends HttpServlet {
+
+
+    public void doGet(HttpServletRequest request, HttpServletResponse response)
+            throws ServletException, IOException {
+        response.setCharacterEncoding("UTF-8");
+        response.setContentType("text/html; charset=utf-8");
+
+        String curOrigin = request.getHeader("Origin");
+        response.setHeader("Access-Control-Allow-Origin", curOrigin == null ? "true" : curOrigin);
+        response.setHeader("Access-Control-Allow-Credentials", "true");
+        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, HEAD");
+        response.setHeader("Access-Control-Max-Age", "3600");
+        response.setHeader("Access-Control-Allow-Headers", "access-control-allow-origin, authority, content-type, version-info, X-Requested-With");
+        response.setContentType("application/json;charset=UTF-8");
+
+
+        PrintWriter writer = response.getWriter();
+
+        //得到要下载的文件名
+        String  fileName = request.getParameter("filename");
+        System.out.print(fileName);
+
+        //本地需要进行转码，linux服务器使用就会出现下载乱码
+        //fileName = new String(fileName.getBytes("iso8859-1"),"UTF-8");
+
+//        System.out.print("转码后"+fileName);
+        //上传的文件都是保存在/WEB-INF/upload目录下的子目录当中
+        String fileSaveRootPath=this.getServletContext().getRealPath(File.separator+"WEB-INF"+File.separator+"upload");
+        //通过文件名找出文件的所在目录
+        //String path = findFileSavePathByFileName(fileName,fileSaveRootPath);
+//        String path = "/WEB-INF/upload";
+        //得到要下载的文件
+        File file = new File(fileSaveRootPath + File.separator + fileName);
+        //File file = new File(fileName);
+        System.out.print(file);
+        System.out.print("\n");
+        // 浏览器请求响应转码防止乱码
+        response.setCharacterEncoding("UTF-8");
+        request.setCharacterEncoding("UTF-8");
+        //如果文件不存在
+        if(!file.exists()){
+            setResultError("文件资源已被删除",writer);
+            return;
+        }
+        //处理文件名
+        String realname = fileName.substring(fileName.indexOf("_")+1);
+        //设置响应头，控制浏览器下载该文件
+        response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(realname, "UTF-8"));
+        //读取要下载的文件，保存到文件输入流
+        FileInputStream in = new FileInputStream(fileSaveRootPath +File.separator+ fileName);
+        //创建输出流
+        OutputStream out = response.getOutputStream();
+        //创建缓冲区
+        byte buffer[] = new byte[1024];
+        int len = 0;
+        //循环将输入流中的内容读取到缓冲区当中
+        while((len=in.read(buffer))>0){
+            //输出缓冲区的内容到浏览器，实现文件下载
+            out.write(buffer, 0, len);
+        }
+        //关闭文件输入流
+        in.close();
+        //关闭输出流
+        out.close();
+//        setResultOK("下载成功",writer);
+    }
+
+    /**
+     * @Method: findFileSavePathByFileName
+     * @Description: 通过文件名和存储上传文件根目录找出要下载的文件的所在路径
+     * @Anthor:
+     * @param filename 要下载的文件名
+     * @param saveRootPath 上传文件保存的根目录，也就是/WEB-INF/upload目录
+     * @return 要下载的文件的存储目录
+     */
+    public String findFileSavePathByFileName(String filename,String saveRootPath){
+//        int hashcode = filename.hashCode();
+//        int dir1 = hashcode&0xf;  //0--15
+//        int dir2 = (hashcode&0xf0)>>4;  //0-15
+        //String dir = saveRootPath + "\\" + dir1 + "\\" + dir2;  //upload\2\3  upload\3\5
+        String dir = saveRootPath;
+        File file = new File(dir);
+        if(!file.exists()){
+            //创建目录
+            file.mkdirs();
+        }
+        return dir;
+    }
+
+    public void doPost(HttpServletRequest request, HttpServletResponse response)
+            throws ServletException, IOException {
+        doGet(request, response);
+    }
+
+    public void setResult(Integer code, String msg, PrintWriter writer) {
+        HashMap<String, Object> result = new HashMap<>();
+        result.put("code", code);
+        result.put("msg", msg);
+        String jsonString = JSONObject.toJSONString(result);
+        writer.println(jsonString);
+        writer.close();
+    }
+
+    public void setResultError(String msg, PrintWriter writer) {
+        setResult(500, msg, writer);
+    }
+
+    public void setResultOK(String msg, PrintWriter writer) {
+        setResult(200, msg, writer);
+    }
+}

src/com/hellogithub/servlet/UploadHandleServlet.java

@@ -0,0 +1,235 @@
+package com.hellogithub.servlet;
+
+
+import javax.servlet.annotation.WebServlet;
+
+import com.alibaba.fastjson.JSONObject;
+import org.apache.commons.fileupload.FileItem;
+import org.apache.commons.fileupload.FileUploadBase;
+import org.apache.commons.fileupload.ProgressListener;
+import org.apache.commons.fileupload.disk.DiskFileItemFactory;
+import org.apache.commons.fileupload.servlet.ServletFileUpload;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.*;
+import java.util.HashMap;
+import java.util.List;
+import java.util.UUID;
+
+@WebServlet("/UploadHandle")
+public class UploadHandleServlet extends HttpServlet {
+    public void doGet(HttpServletRequest request, HttpServletResponse response)
+            throws ServletException, IOException {
+        response.setCharacterEncoding("UTF-8");
+        response.setContentType("text/html; charset=utf-8");
+        //        设置响应头允许ajax跨域访问
+        String curOrigin = request.getHeader("Origin");
+        response.setHeader("Access-Control-Allow-Origin", curOrigin == null ? "true" : curOrigin);
+        response.setHeader("Access-Control-Allow-Credentials", "true");
+        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, HEAD");
+        response.setHeader("Access-Control-Max-Age", "3600");
+        response.setHeader("Access-Control-Allow-Headers", "access-control-allow-origin, authority, content-type, version-info, X-Requested-With");
+        response.setContentType("application/json;charset=UTF-8");
+        PrintWriter writer = response.getWriter();
+
+
+            //得到上传文件的保存目录，将上传的文件存放于WEB-INF目录下，不允许外界直接访问，保证上传文件的安全
+            String savePath = this.getServletContext().getRealPath(File.separator+"WEB-INF"+File.separator+"upload");
+            //上传时生成的临时文件保存目录
+            String tempPath = this.getServletContext().getRealPath(File.separator+"WEB-INF"+File.separator+"tmp");
+            File tmpFile = new File(tempPath);
+            if (!tmpFile.exists()) {
+                //创建临时目录
+                tmpFile.mkdir();
+            }
+            //消息提示
+            String message = "";
+            String saveFilename="";
+        try{
+                //使用Apache文件上传组件处理文件上传步骤：
+                //1、创建一个DiskFileItemFactory工厂
+                DiskFileItemFactory factory = new DiskFileItemFactory();
+
+                //设置工厂的缓冲区的大小，当上传的文件大小超过缓冲区的大小时，就会生成一个临时文件存放到指定的临时目录当中。
+
+                factory.setSizeThreshold(1024*100);//设置缓冲区的大小为100KB，如果不指定，那么缓冲区的大小默认是10KB
+
+                //设置上传时生成的临时文件的保存目录
+                factory.setRepository(tmpFile);
+
+
+                //2、创建一个文件上传解析器
+                ServletFileUpload upload = new ServletFileUpload(factory);
+
+                //监听文件上传进度
+                upload.setProgressListener(new ProgressListener(){
+                    public void update(long pBytesRead, long pContentLength, int arg2) {
+                        System.out.println("文件大小为：" + pContentLength + ",当前已处理：" + pBytesRead);
+                        /**
+                         * 文件大小为：14608,当前已处理：4096
+                         文件大小为：14608,当前已处理：7367
+                         文件大小为：14608,当前已处理：11419
+                         文件大小为：14608,当前已处理：14608
+                         */
+                    }
+                });
+
+                //解决上传文件名的中文乱码
+                upload.setHeaderEncoding("UTF-8");
+
+                //3、判断提交上来的数据是否是上传表单的数据
+                if(!ServletFileUpload.isMultipartContent(request)){
+                    //按照传统方式获取数据
+                    return;
+                }
+
+
+
+                //设置上传单个文件的大小的最大值，目前是设置为1024*1024字节，也就是1MB
+                upload.setFileSizeMax(1024*1024*1024);
+
+                //设置上传文件总量的最大值，最大值=同时上传的多个文件的大小的最大值的和，目前设置为10MB
+                upload.setSizeMax(1024*1024*1024*10);
+
+                //4、使用ServletFileUpload解析器解析上传数据，解析结果返回的是一个List<FileItem>集合，每一个FileItem对应一个Form表单的输入项
+
+
+                List<FileItem> list = upload.parseRequest(request);
+
+                for(FileItem item : list){
+
+
+                    //如果fileitem中封装的是普通输入项的数据
+                    if(item.isFormField()){
+                        String name = item.getFieldName();
+                        //解决普通输入项的数据的中文乱码问题
+                        String value = item.getString("UTF-8");
+                        //String value = new String(name.getBytes("iso8859-1"),"UTF-8");
+                        System.out.println(">>>>>>>>>>"+name + "=" + value);
+
+
+                    }else{
+
+                        //如果fileitem中封装的是上传文件
+                        //得到上传的文件名称，
+                        String filename = item.getName();
+                        //filename = item.getString("UTF-8");
+                        //filename = new String(filename.getBytes("iso8859-1"),"UTF-8");
+                        System.out.println(filename);
+                        if(filename==null || filename.trim().equals("")){
+                            continue;
+                        }
+                        //注意：不同的浏览器提交的文件名是不一样的，有些浏览器提交上来的文件名是带有路径的，如：  c:\a\b\1.txt，而有些只是单纯的文件名，如：1.txt
+                        //处理获取到的上传文件的文件名的路径部分，只保留文件名部分
+                        filename = filename.substring(filename.lastIndexOf(File.separator)+1);
+                        //得到上传文件的扩展名
+                        String fileExtName = filename.substring(filename.lastIndexOf(".")+1);
+                        //如果需要限制上传的文件类型，那么可以通过文件的扩展名来判断上传的文件类型是否合法
+                        System.out.println("上传的文件的扩展名是："+fileExtName);
+                        //获取item中的上传文件的输入流
+                        InputStream in = item.getInputStream();
+                        //得到文件保存的名称
+                        saveFilename = makeFileName(filename);
+
+                        //得到文件的保存目录
+                        String realSavePath = makePath(saveFilename, savePath);
+                        System.out.print(realSavePath+"\\"+saveFilename);
+                        //创建一个文件输出流
+                        FileOutputStream out = new FileOutputStream(realSavePath +File.separator+ saveFilename);
+                        //创建一个缓冲区
+                        byte buffer[] = new byte[1024];
+                        //判断输入流中的数据是否已经读完的标识
+                        int len = 0;
+                        //循环将输入流读入到缓冲区当中，(len=in.read(buffer))>0就表示in里面还有数据
+                        while((len=in.read(buffer))>0){
+                            //使用FileOutputStream输出流将缓冲区的数据写入到指定的目录(savePath + "\\" + filename)当中
+                            out.write(buffer, 0, len);
+                        }
+                        //关闭输入流
+                        in.close();
+                        //关闭输出流
+                        out.close();
+                        //删除处理文件上传时生成的临时文件
+                        item.delete();
+                        message = "文件上传成功！";
+                    }
+                }
+            }catch (FileUploadBase.FileSizeLimitExceededException e) {
+                e.printStackTrace();
+                setResultError("单个文件超出最大值",writer);
+                return;
+            }catch (FileUploadBase.SizeLimitExceededException e) {
+                e.printStackTrace();
+                setResultError("上传文件的总的大小超出限制的最大值",writer);
+                return;
+            }catch (Exception e) {
+                message= "文件上传失败！";
+                setResultError("文件上传失败",writer);
+                e.printStackTrace();
+            }
+            writer.println(saveFilename);
+            setResultOK(message,writer);
+        }
+
+        /**
+         * @Method: makeFileName
+         * @Description: 生成上传文件的文件名，文件名以：uuid+"_"+文件的原始名称
+         * @Anthor:
+         * @param filename 文件的原始名称
+         * @return uuid+"_"+文件的原始名称
+         */
+        private String makeFileName(String filename){  //2.jpg
+            //为防止文件覆盖的现象发生，要为上传文件产生一个唯一的文件名
+            return UUID.randomUUID().toString() + "_" + filename;
+//        return  filename;
+        }
+
+        /**
+         * 为防止一个目录下面出现太多文件，要使用hash算法打散存储
+         * @Method: makePath
+         * @Description:
+         * @Anthor:
+         *
+         * @param filename 文件名，要根据文件名生成存储目录
+         * @param savePath 文件存储路径
+         * @return 新的存储目录
+         */
+        private String makePath(String filename,String savePath){
+            String dir = savePath;
+            //File既可以代表文件也可以代表目录
+            File file = new File(dir);
+            //如果目录不存在
+            if(!file.exists()){
+                //创建目录
+                file.mkdirs();
+            }
+            return dir;
+        }
+
+        public void doPost(HttpServletRequest request, HttpServletResponse response)
+            throws ServletException, IOException {
+
+            doGet(request, response);
+        }
+
+    public void setResult(Integer code, String msg, PrintWriter writer) {
+        HashMap<String, Object> result = new HashMap<>();
+        result.put("code", code);
+        result.put("msg", msg);
+        String jsonString = JSONObject.toJSONString(result);
+        writer.println(jsonString);
+        writer.close();
+    }
+
+    public void setResultError(String msg, PrintWriter writer) {
+        setResult(500, msg, writer);
+    }
+
+    public void setResultOK(String msg, PrintWriter writer) {
+        setResult(200, msg, writer);
+    }
+
+}

src/com/hellogithub/servlet/countNumServlet.java

@@ -38,7 +38,6 @@ public class countNumServlet extends HttpServlet {
         resp.setHeader("Access-Control-Max-Age", "3600");
         resp.setHeader("Access-Control-Allow-Headers", "access-control-allow-origin, authority, content-type, version-info, X-Requested-With");
         resp.setContentType("application/json;charset=UTF-8");
-
         PrintWriter writer = resp.getWriter();
         writer.println(projectService.countAll());
         writer.close();

web/upload.jsp

@@ -0,0 +1,20 @@
+<%@ page language="java" pageEncoding="UTF-8" contentType="text/html;charset=UTF-8"%>
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>文件上传</title>
+</head>
+
+<body>
+<%request.setCharacterEncoding("UTF-8");%>
+<form action="${pageContext.request.contextPath}/UploadHandle" enctype="multipart/form-data" method="post">
+  上传用户：<input type="text" name="username"><br/>
+  上传文件1：<input type="file" name="file1"><br/>
+  上传文件2：<input type="file" name="file2"><br/>
+  <input type="submit" value="提交">
+</form>
+</body>
+<body> <br>
+<input id="btnCancel" class="btn" type="button" value="下载页" onclick="window.location='../FileUploadAndDownLoad/servlet/ListFileServlet'" />
+</body>
+</html>