Eclipse3.1.1+Weblogic 9.0實現JDBC大數據對象(Blob)處理

1,接上篇在Eclipse3.1.1訪問Weblogic 9.0中數據源的JDBC簡單應用關於數據源配置詳見http://blog.csdn.net/blue_fire2008/archive/2008/05/08/2413398.aspx)在項目TestJDBC中新建類,名爲:TestBlob,源代碼如下:

package myjdbc;

 

import java.sql.*;

import javax.naming.*;

import javax.sql.*;

import javax.transaction.UserTransaction;

 

import java.util.Properties;

import java.io.*;

 

public class TestBlob{

    Connection con=null;

 

    public void addBlob()         //向數據庫bookdb表mypic中添加BLOB數據

    {

        try

        {

            //創建一個PreparedStatement實例

            PreparedStatement pstmt=con.prepareStatement("insert into mypic values('1',?)");

            File file = new File("c://pic1.jpg") ;

            FileInputStream fis = new FileInputStream(file);

            //把輸入流設置爲預處理語句的對象。

            pstmt.setBinaryStream(1, fis, (int)file.length());

            pstmt.executeUpdate();    //執行更新

            pstmt.close();

            fis.close();

        }

        catch(Exception e)

        {

            e.printStackTrace();

        }

    }

       

    public void createTable()         //創建表mypic

    {

        try

        {

            con.createStatement().execute("create table mypic (id char(1) primary key,pic blob);");

        }

        catch(Exception e)

        {

            e.printStackTrace();

        }

    }

    /**

     */

    public void getBlob()        //     從數據庫bookdb表mypic中讀取BLOB數據

    {

        try

        {

            Statement stmt=con.createStatement();

            ResultSet rst=stmt.executeQuery("select * from mypic where id='1'");

            rst.next();

            //獲得blob數據和它的輸入流，然後通過輸入流把數據寫到文件中。

            Blob blob = rst.getBlob("pic") ;

            FileOutputStream out=new FileOutputStream(new File("c:/pic2.jpg"));

            InputStream in=blob.getBinaryStream();

            int i;

            while((i=in.read())!=-1)

            out.write(i);

            in.close();

            out.close();

        }

        catch(Exception e)

        {

            e.printStackTrace();

        }

    }

    public static void main(String[] args)throws Exception

    {

        DataSource ds = null;

        Context ctx = null;

        Connection myCon = null;

        TestBlob test = new TestBlob();

       

        Properties p=new Properties();

        p.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");

        p.put(Context.PROVIDER_URL,"t3://localhost:7001");

       

        try {

            ctx=new InitialContext(p);         

        } catch (Exception e) {

            // TODO: handle exception

            e.printStackTrace();

        }

       

        try

        {           

            ds = (javax.sql.DataSource) ctx.lookup("MySQLDS");

            myCon = ds.getConnection();

           

            test.con = myCon;

            System.out.println("成功建立連接!");

            test.createTable();

            System.out.println("成功建立表!");

            test.addBlob();

            System.out.println("成功將 Blob添加到表字段!");

            test.getBlob();

            System.out.println("成功從表字段pic獲得Blob!");

            myCon.close();

        }

        catch (Exception E)

       {

           myCon.close();

           System.out.println("Init Error: " + E);

       }finally{

       try {

            if (myCon!=null) {

                myCon.close();

            }

        } catch (Exception e) {

            // TODO: handle exception

        }

       }

    }

}

2,啓動MySQL和Weblogic服務器,運行TestBlob,若控制檯顯示如下信息,則表示成功存取大數據對象,在驅動器也可以看到新建的對象.

成功建立連接!

成功建立表!

成功將 Blob添加到表字段!

成功從表字段pic獲得Blob!

3,文件路徑的訪問分隔符是//或/,單個/是不行的.

歡迎轉載,轉載請註明出處!

                                                                                   BLUE_FIRE2008 2008年5月8日於南昌

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