我正在尝试使用hibernate，jsf和mysql将.doc，.pdf，.txt和图像文件保存到我的数据库中。
我创建了一个列来保存BLOB类型的文件。如果我保存.txt类型，则文件会正确保存。
如果我试图保存任何其他格式的文件，那么我得到一个例外。
在我的bean中，我创建了一个字段名称：byte[] file;
如何正确保存，没有任何例外？我是否需要更改mysql列的数据类型或为java类使用不同的字段？
（回应BalusC）
这是我用于文件编写的代码。我正在使用fileInputStream，然后使用hibernate框架保存文件。
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是jsf托管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;
}
}
我的数据库表有以下结构：
Create UploadFile(FILE_NAME` VARCHAR(1000) NOT NULL,
`FILE` BLOB NOT NULL);
答案 0 :(得分：2)
最好将文件保存在某个位置 并保存数据库中的位置
答案 1 :(得分：2)
您的问题看起来像是数据类型问题。 MySQL中的BLOB不是很大。尝试将表的列数据类型设置为LONGBLOB。
答案 2 :(得分：0)
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。
答案 3 :(得分：-1)
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();
}
}
}
这是一个服务器代码。通过该代码，您可以上载存储在数据库中的任何文件，并将该文件存储在服务器端的（img）文件夹中。通过使用它的引用，您可以访问该文件。