Java读取数据库Blob对象返回到JSP页面和getOutputStream() has already been called for this response异常处理

来源：互联网发布：sqlserver 优势编辑：程序博客网时间：2024/06/05 09:32

<%@page import="java.sql.Blob"%><%@page import="java.sql.ResultSet"%><%@page import="java.sql.CallableStatement"%><%@page import="java.io.BufferedOutputStream"%><%@page import="java.io.FileInputStream"%><%@page import="java.io.OutputStream"%><%@page import="java.io.InputStream"%><%@page import="java.io.File"%><%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><%//CallableStatement cs = conn.prepareCall("call `xxx`.`xxxx`();");//ResultSet rs = cs.executeQuery(); //if (rs.next()) { //Blob b = rs.getBlob("magazine"); //long size = b.length(); //byte[] bs = b.getBytes(1, (int)size); //} //后面差不多，主要是byte的来源变了File file = new File("C:\\Begin Google Map.pdf");//也可以从文件读取long length = file.length();InputStream stream = new FileInputStream(file);BufferedOutputStream os = new BufferedOutputStream(response.getOutputStream());//用Buffered包裹效率高//OutputStream os = response.getOutputStream();byte[] buf=new byte[(int)length];response.setContentType("application/pdf");try {    int n;    while ((n = stream.read(buf)) != -1)    os.write(buf, 0, n);//这里要这么写，表示读多少写多少} catch (Exception e) {e.printStackTrace();}os.flush();os.close();out.clear();//这两句话一定要加上，否则报getOutputStream() has already been called for this response异常out = pageContext.pushBody();%></body></html>