showimage.java

J2EE 技术 源码 书籍源代码（j2ee编程技术）

import java.io.IOException;

import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/*
 * Created on 2004-6-30
 *
 * To change the template for this generated file go to
 * Window - Preferences - Java - Code Generation - Code and Comments
 */
/**
 * @author haoyulong
 *
 * To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Generation - Code and Comments
 */
public class ShowImage extends HttpServlet {
	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		//TODO Method stub generated by Lomboz
		doPost(request,response);
	}
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		//TODO Method stub generated by Lomboz
		java.sql.Connection conn; 
		java.lang.String strConn; 
		java.sql.Statement Stmt; //语句对象 
		java.sql.ResultSet sqlRst; //结果集对象 

		ServletOutputStream op = response.getOutputStream();
		//PrintWriter out = response.getWriter(); 
		//在数据库中的照片的ID      
		String photoid ="";       
		photoid = request.getParameter("photoid");        
		String SQLString = "select * from album where id =" + photoid; 
		try{
			javax.naming.InitialContext ctx = new javax.naming.InitialContext();
			javax.sql.DataSource ds = (javax.sql.DataSource) ctx.lookup("java:/MySqlDS");
			       
			conn = ds.getConnection();
			Stmt = conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);
//			执行Sql语句 
			sqlRst=Stmt.executeQuery ( SQLString); 
			while(sqlRst.next()){
			java.sql.Blob blob=sqlRst.getBlob( "data" );
			  byte[] ab = blob.getBytes(1, (int)blob.length());
			                response.setContentType("image/gif");
			                response.reset();
			               
			                op.write(ab);
			                op.flush();
			                op.close();



			}

			Stmt.close (); 
			conn.close();
			
			 
			} catch (java.sql.SQLException e){
				e.printStackTrace();

			}catch (NamingException e){
				e.printStackTrace();

			}

		

	}
}