writeblobtodb.java

JAVA读取JPEG图象

//package jdbcblob;
import javax.swing.*;
import java.io.*;
import java.sql.*;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: </p>
 * @author unascribed
 * @version 1.0
 */

public class WriteBlobToDb {

  Connection conn;
  Statement stmt;
  ResultSet rs;
  int bufferSize;

  public WriteBlobToDb() throws SQLException, ClassNotFoundException {

    Class.forName("oracle.jdbc.driver.OracleDriver") ;

    String sourceURL="jdbc:oracle:thin:@localhost:1521:cnaloral";
    String user="system";
    String password="cnaloral8";
    conn=DriverManager.getConnection(sourceURL,user,password) ;
    stmt=conn.createStatement() ;
  }

  public void sendToDb(){
    String pathname,name;
    int amount=0;
    OutputStream out=null;
    BufferedInputStream in=null;

    JFileChooser chooser =new JFileChooser();
    int returnVal=chooser.showOpenDialog(null);
    if (returnVal==JFileChooser.APPROVE_OPTION) {

      pathname=chooser.getSelectedFile() .getAbsolutePath();
      name=chooser.getSelectedFile() .getName() ;
      chooser=null;

    }
    else {
      System.out.println("No file selected for write to db!");
      System.out.println("Program terminating!");
      return;
    };
    try {
      conn.setAutoCommit(false) ;
      stmt.executeUpdate("insert into media values('"+name.trim()+"',empty_blob())") ;
      rs=stmt.executeQuery("select data from media where trim(name)='"+name+"' for update") ;
      if (rs.next()) {
        Blob blob=rs.getBlob(1);
        out=((oracle.sql.BLOB)blob).getBinaryOutputStream();
        bufferSize=((oracle.sql.BLOB )blob).getBufferSize();
        in=new BufferedInputStream(new FileInputStream(pathname),bufferSize);

        byte[] b=new byte[bufferSize];

        int count=in.read(b,0,bufferSize);

        while (count!=-1) {

          out.write(b,0,count);
          amount+=count;
          System.out.println("Processed "+amount+" bytes.");
          count=in.read(b,0,bufferSize);
        };
        System.out.println("Processed "+amount+"bytes.Finished!");

        out.close();
        out=null;
        in.close() ;
        in=null;
        conn.commit();
      };

    }
    catch (Exception ex) {
      ex.printStackTrace() ;
      try { conn.rollback();}catch (Exception ignored) {}
    }
    finally {
      if (out!=null) try{out.close() ;} catch(Exception ignored){};
      if (in!=null) try{in.close() ;} catch(Exception ignored){};
    };
  }

  public static void main(String[] args) {
        try {
        	WriteBlobToDb w = new WriteBlobToDb();
        	w.sendToDb();
        }
        catch(Exception e) {
        	e.printStackTrace();
        }
        finally {
        	System.exit(0);
        }
  }

}