Hibernate读写Blob/Clob类型数据

Oracle10g中的JDBC驱动已经修正了Hibernate读写Blob/Clob类型数据的问题。操作要点如下：
　　1、首先数据表中的clob类型对应java持久化类的String类型；而blob类型对应byte[]类型。

        2、定义hibernate标签时，持久化类中对应clob类型的属性的hibernate type应为text；而对应blob类型的属性的hibernate type应为binary。

　　3、以后访问这些对应clob和blob类型的属性时，按普通属性处理，不需要特别编码。

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1 楼 kyonee 2007-04-10  

补充:读写BLOB                                     
写BLOB到oracle数据库中：

package dbapp;

import java.sql.*;
import java.io.*;
import java.util.*;
import oracle.jdbc.OracleResultSet;
import oracle.sql.*;

public class WriteAttachment {
public WriteAttachment() {
}

public static void main(String args[]) {
try {
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
String url = "jdbc:oracle:thin:@ljy_hshz:1521:wwj";
String userName = "ljy";
String password = "zxcvbnm";

Connection cn = DriverManager.getConnection(url, userName, password);
//*
PreparedStatement ps = cn.prepareStatement(
"insert into ATTACHMENT(ID,NAME,ATTACH) values(?,?,EMPTY_BLOB())");
ps.setString(1, "001");
ps.setString(2, "wordtest.doc");
ps.executeUpdate();
ps.close();
//*/
Statement sql = cn.createStatement();
cn.setAutoCommit(false);
ResultSet rs = sql.executeQuery("select attach from attachment where id='001' for update");
if (rs.next()) {
BLOB blob = ( (OracleResultSet) rs).getBLOB(1);
OutputStream outStream =blob.getBinaryOutputStream();
File file = new File("d:\\javatest\\wordtest.doc");
FileInputStream in = new FileInputStream(file);
//ps.setBinaryStream(3,in,(int)file.length());
byte[] buffer = new byte[10000];
int length=-1;
while((length=in.read(buffer))!=-1){
outStream.write(buffer,0,length);
System.out.println(length);
}
in.close();
outStream.close();
cn.commit();
}
rs.close();
cn.close();
System.out.println("写入BLOB成功！");
}
catch (SQLException e) {
System.out.println(e.getStackTrace()+e.toString());
e.printStackTrace();
}
catch (IOException ioe) {
System.out.println(ioe.getStackTrace()+ioe.toString());
}

}
}

从oracle数据库中读取BLOB对象：

package dbapp;

import java.sql.*;
import java.io.*;
import java.util.*;
import oracle.jdbc.OracleResultSet;
import oracle.sql.*;


public class ReadAttachment {
public ReadAttachment() {
}
public static void main(String args[]) {
try {
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
String url = "jdbc:oracle:thin:@ljy_hshz:1521:wwj";
String userName = "ljy";
String password = "zxcvbnm";

Connection cn = DriverManager.getConnection(url, userName, password);
PreparedStatement ps=cn.prepareStatement("select name,attach from attachment where id='001'");
ResultSet rs=ps.executeQuery();
if(rs.next()){
String filename="d:\\"+rs.getString(1);
File file=new File(filename);
FileOutputStream outStream=new FileOutputStream(file);
InputStream inStream=rs.getBinaryStream(2);
byte[] buffer=new byte[10000];
int length=-1;
while((length=inStream.read(buffer))!=-1){
System.out.println(length);
outStream.write(buffer,0,length);
}
inStream.close();
outStream.close();
}
rs.close();
ps.close();
cn.close();
System.out.println("读出BLOB完毕！");
}
catch (SQLException e) {
System.out.println(e.getStackTrace());
e.printStackTrace();
}
catch(IOException ioe){
System.out.println(ioe.getStackTrace());
}

}

}