数据库中对blob字段和clob字段的存数据和取数据

说明1:首先所有的文件都是以二进制存储
2:二进制文件有.doc .xls .jpg
文本文件有 .txt .html .xml
blob存储字节，clob存储字符
数据表的创建：

create  table CDL_TEST(
       SID varchar(20) not null,
       IMG BLOB,
       DOC CLOB,
       DATA NUMBER
);

图片的存取：
、、、java
package store.img.to.oracle;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;


public class StoreImage {
	private static String user ="System";
	private static String password ="Admin";
	private static String driver ="oracle.jdbc.driver.OracleDriver";
	private static String url ="jdbc:oracle:thin:@localhost:1521:ORCL";
	
	static {
		try {
			Class.forName(driver);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public  Connection getConnetion() {
		Connection conn=null;
		try {
			conn =DriverManager.getConnection(url, user, password);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println(conn.hashCode());
		return conn;
	}
	
	
//	public void insertBlob(String sql1) {
//		Connection conn1 = getConnetion();
//		ResultSet rs =null;
//		try {
//			conn1.setAutoCommit(false);
//			Blob blob =null; //插入空的Blob
//			PreparedStatement pstmt = conn1.prepareStatement("insert into cdl_test(sid,img) values (?,empty_blob())");
//			pstmt.setString(1, "100");
//			pstmt.executeUpdate();
//			pstmt.close();
//			
//			rs=conn1.createStatement().executeQuery(sql1);
//			while(rs.next())
//			{
//				System.out.println("rs length is： ");
//				BLOB b =(BLOB) rs.getBlob("img");
//				System.out.println("bloblegth is "+b.getLength());
//				BufferedInputStream bi = new BufferedInputStream(new FileInputStream("file/img.jpg"));
//				BufferedOutputStream out = new BufferedOutputStream(b.getBinaryOutputStream());
//				int c ;
//				while((c=bi.read())!=-1)
//				{
//					out.write(c);
//				}
//			}
//			conn1.commit();
//		} catch (SQLException e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		} catch (FileNotFoundException e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		} catch (IOException e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		}finally {
//			//流的关闭
//		}
//		
//	}
	
	
	/**
	 * 此方法有一个问题，那就是jdbc的所用的jar包要要求，jar包版本不能太高，最好和oracle中的数据库版本一致。，oracle是11的话，用11的jdbcjar包
	 */
	public void insertBlob() {
		Connection conn1 = getConnetion();
		PreparedStatement pstmt=null ;
		try {
			pstmt=conn1.prepareStatement("insert into cdl_test(sid,img) values ('1',?)");
			File file = new File("file/img.jpg");
			FileInputStream bi = new FileInputStream(file);
			pstmt.setBinaryStream(1, bi, file.length());
			pstmt.executeUpdate();
			
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			//关闭资源
		}
	}
	
	//读取图片
	public void ReadBlob(String sql2) {
		Connection conn = getConnetion();
		FileOutputStream fos=null;
		InputStream is=null;
		ResultSet rs =null;
		try {
			System.out.println("sql2 is "+sql2);
			System.out.println("stmt is "+conn);
			rs= conn.createStatement().executeQuery(sql2);
			while(rs.next())
			{
				System.out.println("rs length is ");
				Blob b = (Blob)rs.getBlob("img");
				File f = new  File("D:/img.jpg");
				fos = new FileOutputStream(f);
			    is = b.getBinaryStream();//读出数据后转为二进制流
				byte[] date = new byte[1024];
				while(is.read(date)!=-1)
				{
					fos.write(date);
				}
			
			}
			conn.commit();
			fos.close();
		} catch (Exception e) {
			// TODO: handle exception
		}finally {
			//流的关闭
		}
	}
	
	public static void main(String[] args) {
			String sql1 = "select * from cdl_test for update";
			String sql2 ="select * from cdl_test";
			StoreImage storeImage = new StoreImage();
			storeImage.insertBlob();
			storeImage.ReadBlob(sql2);
	}
}

文本的存取：

package store.img.to.oracle;


import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import oracle.sql.CLOB;

public class StoreClob {
	private static String user ="System";
	private static String password ="Admin";
	private static String driver ="oracle.jdbc.driver.OracleDriver";
	private static String url ="jdbc:oracle:thin:@localhost:1521:ORCL";
	
	static {
		try {
			Class.forName(driver);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public  Connection getConnetion() {
		Connection conn=null;
		try {
			conn =DriverManager.getConnection(url, user, password);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println(conn.hashCode());
		return conn;
	}
	
	//clob字段中添加数据
	public void insertClob() {
		Connection conn = getConnetion();
		PreparedStatement pstmt=null ;
		try {
			pstmt=conn.prepareStatement("insert into cdl_test(sid,DOC) values ('2',?)");
			String text = new String("我是要被存储在oracle的数据");
			//将字符串转为字符流
			Reader clobReader = new StringReader(text);
			
			pstmt.setCharacterStream(1, clobReader,text.length());
			pstmt.executeUpdate();
			
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			//关闭资源
		}
	}
	
	//读取clob中的字段
	public void readClob() {
		Connection conn = getConnetion();
		Statement pstmt=null ;
		ResultSet rs=null;
		Reader reader=null;
		String readStr=null;
		try {
			pstmt=conn.createStatement();
			rs = pstmt.executeQuery("select doc from  cdl_test where sid='2' ");
			while(rs.next())
			{
				//这里为什么要使用CLOB呢，CLOB才有length方法。Clob没有length方法
				CLOB clob = (CLOB) rs.getClob("doc");
				reader  =  clob.getCharacterStream();
				char charbytes[] = new char[(int) clob.length()];
				reader.read(charbytes);
				readStr = new String(charbytes);
				
			}
			
			File file = new File("D:/text.txt");
			if(file.exists())
			{
				file.delete();
			}
			file.createNewFile();
			PrintWriter pw = new PrintWriter(new FileOutputStream(file));
			pw.write(readStr);
			pw.flush();
			
			pw.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			//关闭资源
		}
	}
	
	public static void main(String[] args) {
		StoreClob clob = new StoreClob();
		clob.insertClob();
		clob.readClob();
	}
	
}