mongodb+GridFS文件的上传下载删除

最新推荐文章于 2025-02-28 20:49:02 发布

昕鸿

最新推荐文章于 2025-02-28 20:49:02 发布

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分类专栏： java 文章标签： mongodb servlet gridfs

本文链接：https://blog.youkuaiyun.com/szs860806/article/details/72528618

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1、背景

最近项目使用mongDB做文件服务器，用于文件存储。所以稍微研究了下mongDB API写了个简单文件上传下载删除示例

2、具体代码

完整demo下载路径：http://download.youkuaiyun.com/detail/szs860806/9846782

代码中有完整注释。这里就不一一赘述了。我这里使用的是fileupload做的上传。这里是使用的jar:

代码是用servlet写的，有点长。

package com.yqfz.Servlet;

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

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 com.mongodb.DB;
import com.mongodb.MongoClient;
import com.mongodb.ServerAddress;
import com.mongodb.gridfs.GridFS;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSInputFile;
import com.yqfz.pojo.FileInfo;
import com.yqfz.util.BaseResult;
import com.yqfz.util.FileUtils;
import com.yqfz.util.PropertiesUtils;

public class IUploadServlet extends HttpServlet
{
    /**
     * 注释内容
     */
    private static final long serialVersionUID = 1L;
    
    // 上传配置
    private static final int MEMORY_THRESHOLD = 1024 * 1024 * 10; // 3MB
    
    private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
    
    private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB
    
    private static final Long DEFAULT_CHUNK_SIZE = 1024 * 1024 * 10L;
    
    private static final String NOT_RENAME = "1";// 不重命名
    
    private String showPath = PropertiesUtils.loadProperty("conf.properties").get("file_show_url"); // 文件显示路径
    
    private MongoClient mongo = null;
    
    private DB db = null;
    
    private GridFS gridFS = null;
    
    private BaseResult baseResult = null;
    
    public void doGet(HttpServletRequest req, HttpServletResponse res)
        throws IOException, ServletException
    {
        doPost(req, res);
    }
    
    public void doPost(HttpServletRequest req, HttpServletResponse res)
        throws IOException, ServletException
    {
        String method = req.getParameter("method");
        if (method.equals("upload"))
        {
            upload(req, res);
        }
        else if (method.equals("delete"))
        {
            delete(req, res);
        }
        else if (method.equals("downloadFile"))
        {
            downloadFile(req, res);
        }
    }
    
    @SuppressWarnings("unchecked")
    private void upload(HttpServletRequest req, HttpServletResponse res)
    {
        baseResult = new BaseResult();
        try
        {
            if (checkForm(req, res))// 检测是否为多媒体上传
                return;
            
            String appDir = req.getParameter("appDir");// 获取上传应用类型
            String type = req.getParameter("type");// 是否需要重命名0或者不传为需要，1为不需要
            System.out.println("打印参数：appDir=" + appDir + ",type=" + type);
            ServletFileUpload upload = initFileUpload();// 初始化fileUpload
            List<FileItem> fileItems = upload.parseRequest(req);
            if (fileItems != null && fileItems.size() > 0)
            {
                initMongo();// 初始化mongoDB
                String fileShowPath = getFileShowPath(appDir);// 获取展示地址
                List<FileInfo> fileList = new ArrayList<FileInfo>();
                for (FileItem item : fileItems)
                {
                    if (!item.isFormField() && item.getSize() > 0)
                    {
                        System.out.println("处理上传的文件 begin");
                        String oldFileName = item.getName();
                        String newFileName = getNewFileName(type, oldFileName);
                        
                        GridFSInputFile file = saveFile(item, newFileName);
                        
                        // 生成文件信息
                        FileInfo fileInfo =
                            new FileInfo(file.getId() + "", newFileName, oldFileName,
                                FileUtils.formetFileSize(item.getSize()), fileShowPath + "/" + newFileName);
                        fileList.add(fileInfo);
                        System.out.println("处理上传的文件 end");
                    }
                }
                
                baseResult.setError("上传成功");
                baseResult.setErrorCode("0000");
                baseResult.setResult(fileList);
            }
            else
            {
                baseResult.setError("没有上传文件");
                baseResult.setErrorCode("1000");
            }
            
            if (!NOT_RENAME.equals(type))
            {
                ajaxOut(baseResult.toString(), res);
            }
        }
        catch (Exception e)
        {
            System.out.println("使用 fileupload 包时发生异常 ...");
            e.printStackTrace();
            baseResult.setError("上传失败");
            baseResult.setErrorCode("1000");
            ajaxOut(baseResult.toString(), res);
        }
    }
    
    private void downloadFile(HttpServletRequest req, HttpServletResponse res)
    {
        baseResult = new BaseResult();
        try
        {
            String appDir = req.getParameter("appDir");
            String filename = req.getParameter("filename");
            System.out.println("打印参数：appDir=" + appDir + ",filename=" + filename);
            initMongo();
            getFileShowPath(appDir);
            GridFSDBFile gridFSDBFile = (GridFSDBFile)gridFS.findOne(filename);
            
            if (gridFSDBFile != null)
            {
                
                OutputStream sos = res.getOutputStream();
                
                res.setCharacterEncoding("UTF-8");
                res.setHeader("Access-Control-Allow-Origin", "*");
                res.setContentType("application/octet-stream");
                res.addHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
                gridFSDBFile.writeTo(sos);
                sos.flush();
                sos.close();
            }
        }
        catch (Exception e)
        {
            System.out.println("下载文件异常 ...");
            e.printStackTrace();
            baseResult.setError("下载文件失败");
            baseResult.setErrorCode("1000");
            ajaxOut(baseResult.toString(), res);
        }
    }
    
    private void delete(HttpServletRequest req, HttpServletResponse res)
    {
        baseResult = new BaseResult();
        try
        {
            String appDir = req.getParameter("appDir");
            String filename = req.getParameter("filename");
            System.out.println("打印参数：appDir=" + appDir + ",filename=" + filename);
            initMongo();
            getFileShowPath(appDir);
            gridFS.remove(filename);
            
            baseResult.setError("删除成功");
            baseResult.setErrorCode("0000");
            ajaxOut(baseResult.toString(), res);
        }
        catch (Exception e)
        {
            System.out.println("删除文件异常 ...");
            e.printStackTrace();
            baseResult.setError("删除文件失败");
            baseResult.setErrorCode("1000");
            ajaxOut(baseResult.toString(), res);
        }
    }
    
    private boolean checkForm(HttpServletRequest req, HttpServletResponse res)
    {
        boolean flag = false;
        if (!ServletFileUpload.isMultipartContent(req))
        {
            baseResult.setError("Error: 表单必须包含 enctype=multipart/form-data");
            baseResult.setErrorCode("1000");
            ajaxOut(baseResult.toString(), res);
            flag = true;
        }
        
        return flag;
    }
    
    public ServletFileUpload initFileUpload()
    {
        // 配置上传参数
        DiskFileItemFactory diskFactory = new DiskFileItemFactory();
        // threshold 极限、临界值，即硬盘缓存 1M
        diskFactory.setSizeThreshold(MEMORY_THRESHOLD);
        // repository 贮藏室，即临时文件目录
        // diskFactory.setRepository(new File(filePath + File.separator + "temp"));
        
        ServletFileUpload upload = new ServletFileUpload(diskFactory);
        // 设置最大文件上传值
        upload.setFileSizeMax(MAX_FILE_SIZE);
        
        // 设置最大请求值 (包含文件和表单数据)
        upload.setSizeMax(MAX_REQUEST_SIZE);
        
        return upload;
    }
    
    @SuppressWarnings("deprecation")
    public void initMongo()
    {
        //用户名密码校验写法3.0后
//        MongoCredential  credential = MongoCredential.createCredential("root", "qyqapp", "123456".toCharArray());
//        mongo = new MongoClient(new ServerAddress("192.168.122.203", 27017),Arrays.asList(credential));
        mongo = new MongoClient(new ServerAddress("192.168.122.203", 27017));
        db = mongo.getDB("qyqapp");
    }
    
    public String getFileShowPath(String appDir)
    {
        String fileShowPath = "";
        if (appDir != null && !"".equals(appDir))
        {
            gridFS = new GridFS(db, appDir);
            fileShowPath = showPath + "/" + appDir;
        }
        else
        {
            gridFS = new GridFS(db);
            fileShowPath = showPath;
        }
        
        return fileShowPath;
    }
    
    public String getNewFileName(String type, String oldFileName)
    {
        String newFileName;
        if (NOT_RENAME.equals(type))
        {
            newFileName = oldFileName;
        }
        else
        {
            newFileName =
                Long.toString(System.currentTimeMillis()) + oldFileName.substring(oldFileName.lastIndexOf("."));
        }
        
        return newFileName;
    }
    
    public GridFSInputFile saveFile(FileItem item, String newFileName)
        throws Exception
    {
        GridFSInputFile file = gridFS.createFile(item.getInputStream());
        file.setChunkSize(DEFAULT_CHUNK_SIZE);
        file.setFilename(newFileName);
        file.setContentType(newFileName.substring(newFileName.lastIndexOf(".")));
        file.put("uploadDate", new Date());
        file.save();
        
        return file;
    }
    
    /**
     * <一句话功能简述> <功能详细描述> 封装返回json数据
     * 
     * @param strContent [参数说明]
     * 
     * @return void [返回类型说明]
     * @exception throws [违例类型] [违例说明]
     * @see [类、类#方法、类#成员]
     */
    public final void ajaxOut(String strContent, HttpServletResponse res)
    {
        System.out.println(strContent);
        res.setContentType("text/html; charset=UTF-8");
        res.setCharacterEncoding("UTF-8");
        res.setHeader("Access-Control-Allow-Origin", "*");
        PrintWriter out;
        try
        {
            out = res.getWriter();
            out.print(strContent);
            out.flush();
            out.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

测试页面：

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
method:<select id="method">
<option value="upload">upload</option>
<option value="delete">delete</option>
<option value="downloadFile">downloadFile</option>
</select><br>
appDir:<input type="text" id="appDir" value="flow"><br>
type:<select id="type"><option value="0">0</option><option value="1">1</option></select><br>
filename:<input type="text" value="" id="filename"><br>
<form name="form1" action="" method="post" enctype="multipart/form-data" οnsubmit="updateAction();">
	<input type="file" name="file" id="file"><br/>
	<input type="submit" value="提交">
</form>

<script type="text/javascript">
	function updateAction(){
		var method = document.getElementById("method").value;
		var appDir = document.getElementById("appDir").value;
		var type = document.getElementById("type").value;
		var filename = document.getElementById("filename").value;
		document.form1.action="/qyqUpload/iupload.do?appDir="+appDir+"&type="+type+"&method="+method+"&filename="+filename
	}

</script>
</body>
</html>

3、注意事项

（1）可以使用

GridFSInputFile file = gridFS.createFile(item.getInputStream());
        file.setChunkSize(DEFAULT_CHUNK_SIZE);

设置分片的大小。我这里设置的是小于10M不分片。想看上传的文件是否分片可以使用可视化工具查看

默认是256kb