java以Blob形式存储，读取图片并在jsp页面显示图片流

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JSP使用心得与体会

封装好的ImageUtil类：目的读取本地的图片文件并存入数据库，然后读出数据库中以Blob形式存储的图片保存到指定目录。

package org.blog.util;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

public class ImageUtil {

private static File file = null;

/**

* 读取图像的二进制流

* @param infile

* @return

public static FileInputStream getByteImage(String infile) {

FileInputStream inputImage = null;

file = new File(infile);

try {

inputImage = new FileInputStream(file);

} catch (FileNotFoundException e) {

e.printStackTrace();

}

return inputImage;

}

/**

* 输出图片

* @param inputStream

* @param path

public static void readBlob(FileInputStream inputStream, String path) {

try {

FileOutputStream fileOutputStream = new FileOutputStream(path);

byte[] buf = new byte[1024];

int len = 0;

while ((len = inputStream.read(buf)) != -1) {

fileOutputStream.write(buf, 0, len);// 写

}

inputStream.close();

fileOutputStream.close();

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

从数据库中读出二进制流显示到jsp页面：

servlet源码：

package servlet;

import java.io.ByteArrayInputStream;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.sql.Blob;

import javax.servlet.ServletException;

import javax.servlet.ServletOutputStream;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.blog.util.ImageUtil;

import org.hibernate.Hibernate;

public class Image extends HttpServlet {

private static final long serialVersionUID = 1L;

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

this.doPost(req, resp);

}

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

try {

FileInputStream in = ImageUtil.getByteImage("D:\\me.jpg");

Blob blob = Hibernate.createBlob(in);

InputStream inputStream = blob.getBinaryStream();// IO流

int length = (int) blob.length();

byte[] b = new byte[length];

inputStream.read(b, 0, length);

PrintWriter out = resp.getWriter();

InputStream is = new ByteArrayInputStream(b);

int a = is.read();

while (a != -1) {

out.print((char) a);

a = is.read();

}

out.flush();

out.close();

/*OutputStream outputStream = resp.getOutputStream();// 从response中获取getOutputStream

outputStream.write(b);// 写

inputStream.close();

outputStream.close();*/

} catch (Exception e) {

System.out.println("error");

}

jsp源码：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>My JSP 'image.jsp' starting page</title>

<!--

-->

</head>

<body>

</body>

</html>

jsp从数据库中读取二进制图片显示在页面上，要求图片在规定的长宽中显示，大的缩写，小的还是原图大小代码

<img id="lg_png" onload="if(this.width>200)this.width=200;if(this.height>80)this.height=80" src='GetPhoServlet.do?objectFlag=2&photo_no=<%= ctVecs.elementAt(2)%>' />

分享到：

如何用jsp读取数据库中的二进制图象 | js实现前台动态添加文本框，后台获取文本框 ...

2013-11-18 22:27
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