How to save doc, pdf, and image files to mysql database using java?

Question

I am trying to save .doc , .pdf , .txt , and image files into my database using hibernate, jsf, and mysql.

I have created a column to save the file of type BLOB. If I am saving .txt type then files are saved correctly.

If i am trying to save file of any other format then i am getting an exception. In my bean I have created a field name: byte[] file;

How i can save it correctly without any exceptions? Do I need to change datatype for mysql column or use a different field for java class?

---

(in response to BalusC)

This is the code which I am using for file writing. I am using fileInputStream and then saving the file using hibernate framework.

Iterator iter = items.iterator();
while (iter.hasNext()) {
FileItem item = (FileItem) iter.next();

if (item.isFormField()) {
   String name = item.getFieldName();
   String value = item.getString();
} else {
   String fieldName = item.getFieldName();
   String fileName = item.getName();
   String contentType = item.getContentType();
   boolean isInMemory = item.isInMemory();
   long sizeInBytes = item.getSize();
   byte[] fileInBytes=item.get();


   try {
      File uploadedFile = new File("/home/db/webApp", fileName);
      uploadedFile.createNewFile();
      FileInputStream fileInputStream = new FileInputStream(uploadedFile);
      //convert file into array of bytes
      fileInputStream.read(fileInBytes);
      fileInputStream.close();
  } catch (Exception e) {
      e.printStackTrace();
  }

   UploadedFile object= new UploadedFile(); 
   object.setFile(fileInBytes);
   uploadedObject.setFileName(fileName);
   session.save(object);

UploadedFile is jsf managed bean:

public class UploadedFile{
   private String fileName;
   private byte[] file;
   /**
    * @return the fileName
    */
   public String getFileName() {
      return fileName;
   }
   /**
    * @param fileName the fileName to set
    */
   public void setFileName(String fileName) {   
      this.fileName = fileName;
   }
   /**
    * @return the file
    */
  public byte[] getFile() {
     return file;
  }
  /**
   * @param file the file to set
   */
  public void setFile(byte[] file) {
      this.file = file;
   }
}

and my database table has following structure:

Create UploadFile(FILE_NAME` VARCHAR(1000) NOT NULL,
 `FILE` BLOB NOT NULL);

Answer 1

Your problem looks like it's a data type issue. A BLOB in MySQL is not very big. Try setting your table's column data type to a LONGBLOB instead.

Answer 2

最好将文件保存在一个位置并将该位置保存在数据库中

Answer 3

将文件元信息（例如位置）存储在 db 中，但同步 db 和文件系统将是一个问题。

Answer 4

package com.server;


import java.io.*;

import java.sql.*;
import java.util.*;
import java.text.*;
import java.util.regex.*;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.*;
import org.mortbay.jetty.Response;

import javax.servlet.*;
import javax.servlet.http.*;

import java.io.*;   
import java.sql.*;   
import javax.servlet.http.HttpServlet;   
import javax.servlet.http.HttpServletRequest;   
import javax.servlet.http.HttpServletResponse;   
import javax.servlet.ServletInputStream.*;   
import java.io.PrintWriter;   

public class XmlServlet extends HttpServlet {   

public void doPost(HttpServletRequest req,HttpServletResponse res)   
{ 
    File uploadedFile;


    System.out.print("on server");
try{   

Class.forName("com.mysql.jdbc.Driver");   
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3308/image","root","root1");  

PrintWriter out=res.getWriter();   

//out.println("<br>Content type is :: " +contentType);   
//to get the content type information from JSP Request Header   
String contentType = req.getContentType();   
int flag=0;   
FileInputStream fis=null;   
FileOutputStream fileOut=null;   
//here we are checking the content type is not equal to Null and as well as the passed data from mulitpart/form-data is greater than or equal to 0   
if ((contentType != null) && (contentType.indexOf("multipart/form-data") >= 0))   
{   
DataInputStream in = new DataInputStream(req.getInputStream());   
//we are taking the length of Content type data   
int formDataLength = req.getContentLength();   
byte dataBytes[] = new byte[formDataLength];   
int byteRead = 0;   
int totalBytesRead = 0;   

//this loop converting the uploaded file into byte code   
while (totalBytesRead < formDataLength) {   
byteRead = in.read(dataBytes, totalBytesRead,formDataLength);   
totalBytesRead += byteRead;   
}   

String file = new String(dataBytes);   
//for saving the file name   
String saveFile = file.substring(file.indexOf("filename=\"") + 10);   
saveFile = saveFile.substring(0, saveFile.indexOf("\n"));   
out.println("savefiledddd"+saveFile);   
int extension_save=saveFile.lastIndexOf("\"");   
String extension_saveName=saveFile.substring(extension_save);   

//Here we are invoking the absolute path out of the encrypted data   

saveFile = saveFile.substring(saveFile.lastIndexOf("\\")+ 1,saveFile.indexOf("\""));   
int lastIndex = contentType.lastIndexOf("=");   
String boundary = contentType.substring(lastIndex + 1,contentType.length());   
int pos;   

//extracting the index of file   
pos = file.indexOf("filename=\"");   
pos = file.indexOf("\n", pos) + 1;   
pos = file.indexOf("\n", pos) + 1;   
pos = file.indexOf("\n", pos) + 1;   
int boundaryLocation = file.indexOf(boundary, pos) - 4;   
int startPos = ((file.substring(0, pos)).getBytes()).length;   
int endPos = ((file.substring(0, boundaryLocation)).getBytes()).length;   

out.println("savefile"+saveFile);   

int file_No=22;  

 uploadedFile=new File("./war/img");

    uploadedFile.mkdir();


  String kk=uploadedFile.getAbsolutePath();


  String pathname_dir=kk+"/"+saveFile;   
   //String pathname_dir="C:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\jk\\"+saveFile;   
    File filepath=new File(pathname_dir);   
     out.println("filepath_  "+filepath);   
    fileOut = new FileOutputStream(filepath);   
    fileOut.write(dataBytes, startPos, (endPos - startPos));   
    fileOut.flush();   
    out.println("<h1> your files are saved</h1></body></html>");   
     out.close();   

        File database_filename=new File(pathname_dir);   
            fis=new FileInputStream(database_filename);   

int len=(int)database_filename.length();
            PreparedStatement ps = conn.prepareStatement("insert into new (image) values (?)");   
            ps.setBinaryStream(1,fis,len);   
            ps.executeUpdate();   
            ps.close();   
            flag=1;   

}   

if(flag==1)   
{   
fileOut.close();   
fis.close();   
}   
}catch(Exception e)   
{   
System.out.println("Exception Due to"+e);   
e.printStackTrace();   
}   
}   
}   

It's a server code. By that code you can upload any file which is stored in database and store that file on server side at (img) folder. By using the reference of that you can access the file.