JAVA中如何处理BLOB类型的数据啊？

Question

JAVA中 当要向ORACLE中插入或读取BLOB类型的数据时 如何操作啊！

Answer 1

完整代码
http://blog.csdn.net/caoyinghui1986/archive/2008/04/05/2252772.aspx
仅供参考

Answer 2

偶来可耻的蹭点分
参考。import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;import javax.swing.JFileChooser;/*-- 测试表 
create table TestImage(
       img_id int primary key,
       img_content blob
)*/  
public class BlobTestForOracle {
    private static final String DB_DRIVER = "oracle.jdbc.driver.OracleDriver";
    private static final String DB_URL = "jdbc:oracle:thin:@localhost:1521:oratest";
    private static final String DB_USER = "test";
    private static final String DB_PASSWORD = "test";
    
    public BlobTestForOracle(){
        try {
            Class.forName(DB_DRIVER);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
        /**
     * 另存为...
     * 
     * */
    public String chooseFileSave(String title,String fileName){
        JFileChooser chooser = new JFileChooser();
        chooser.setSelectedFile(new File(fileName));
        chooser.setDialogTitle(title);
        int rnt = chooser.showSaveDialog(null);
        if(rnt == JFileChooser.APPROVE_OPTION){
            return chooser.getSelectedFile().getAbsolutePath();
        }else{
            return "";
        }
    }   
    
    /**
     * 打开...
     * 
     * */
    public String chooseFileOpen(String title,String fileName){
        JFileChooser chooser = new JFileChooser();      
        chooser.setSelectedFile(new File(fileName));
        chooser.setDialogTitle(title);
        int rnt = chooser.showOpenDialog(null);
        if(rnt == JFileChooser.APPROVE_OPTION){
            return chooser.getSelectedFile().getAbsolutePath();
        }else{
            return "";
        }
    }
    
    /**
     * 写入blob
     * */
    public void writeFileToDatabaseByRid(String fileName,int rid){
        BufferedInputStream bis = null;
        Connection conn  = null;
        PreparedStatement pstmt = null;
        String strSQL = null;
        File file = null;
        int size = 0;
        try{
            strSQL = "INSERT INTO TestImage(img_id,img_content) VALUES(?,?)";
            conn = DriverManager.getConnection(DB_URL,DB_USER,DB_PASSWORD);
            pstmt = conn.prepareStatement(strSQL);
            fileName = this.chooseFileOpen("请选择一个文件",fileName);
            file = new File(fileName);
            if(! file.exists()){
                System.out.println(file.getAbsolutePath());
                System.out.println("文件貌似不存在!");
                return;
            }
            else if(file.length() > 50 * 1024 * 1024){ // 限制一下文件大小
                System.out.println("文件是不是太大鸟? " + file.length());
                return;
            }
            size = (int)file.length();
            bis = new BufferedInputStream(new FileInputStream(file));
            pstmt.setInt(1, rid);
            pstmt.setBinaryStream(2,bis,size); // 类似于逐一读取，bis流也被耗尽需要reset
            int effect = pstmt.executeUpdate();
            if(effect == 1){
                System.out.println("写入ok!" + file.getAbsolutePath());
            }
            else{
                System.out.println("写入failed!");
            }
            bis.close();
        }catch(IOException ioe){
            ioe.printStackTrace();
        }catch(SQLException sqle){
            sqle.printStackTrace();
        }finally{
        
            if(pstmt != null){
                try {
                    pstmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }               
            }
            
            if(conn != null){
                try{
                    conn.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
        }
    }
    
    /**
     * 从blob读取
     * */
    public void getFileFromDatabaseByRid(String fileName,int rid){
        String strSQL = null;
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rst = null;
        int size = 0;
        File file = null;
        try{
            strSQL = "SELECT * FROM TestImage WHERE img_id = ?";
            conn = DriverManager.getConnection(DB_URL,DB_USER,DB_PASSWORD);
            pstmt = conn.prepareStatement(strSQL);
            pstmt.setInt(1, rid);
            rst = pstmt.executeQuery();
            if(rst.next()){
                fileName = this.chooseFileSave("存储为...", fileName);
                file = new File(fileName);
                if("".equals(file.getName().trim())){
                    System.out.println("failed!");
                    return;
                }
                OutputStream os = new BufferedOutputStream(new FileOutputStream(file));
                BufferedInputStream bis = new BufferedInputStream(rst.getBinaryStream("img_content"));  
                
                byte[] b = new byte[10 * 1024]; // 这里是设置了缓存 byte[] b 设置为 10K                                
                int len = 0; // 返回read一次实际读取的字节数
                while((len = bis.read(b)) != -1){
                    os.write(b,0,len); // 将b数组的内容写(按照len个字节输出)到输出流中，注意这里不要混淆了b.length
                    size += len;
                }
                os.flush();
                os.close();
                bis.close();
                System.out.println("保存文件完毕! " + size + " Byte(s)"); 
            }
            else{
                System.out.println("id : " + rid + " 文件没有找到");
            }
        }catch(IOException ioe){
            ioe.printStackTrace();
        }
        catch(SQLException sqle){
            sqle.printStackTrace();
        }finally{
            if(rst != null){
                try {
                    rst.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            
            if(pstmt != null){
                try {
                    pstmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }               
            }
            
            if(conn != null){
                try{
                    conn.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
        }
    }   
    
    public static void main(String[] args){
        // test
        BlobTestForOracle test = new BlobTestForOracle();
        test.writeFileToDatabaseByRid("C:/a.jpg",123);
        test.getFileFromDatabaseByRid("C:/a.jpg", 123);    }
}