Java Web以输入输出流实现读取数据库图片

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  在web开发中，读取显示图片非常常见，实现方式也有很多，下面介绍一种以流的形式实现读取数据库图片。java环境：eclipse，数据库：MySQL。
  其他过程忽略，只写Servlet和jsp代码。

Servlet写法

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 		public String imgAddr;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       request.setCharacterEncoding("UTF-8");
     	response.setCharacterEncoding("UTF-8");
     	response.setContentType("text/html;charset=UTF-8");

     	HttpSession session = request.getSession();
     	String op = request.getParameter("op");

     	switch (op) {
           case "showimg":
		           imgRead(request, response,imgAddr);
		           break;
	default:
		break;
	}
 }
private void imgRead(HttpServletRequest request, HttpServletResponse response, String imgAddr) throws ServletException, IOException {
		// 本地文件路径
		String filePath = "E:" + File.separator + "Users" + File.separator + "Yohua " + File.separator + "weixinapp "
				+ File.separator + "Medical_master" + File.separator + imgAddr;
		File file = new File(filePath);
		// 获取输出流
		OutputStream outputStream = response.getOutputStream();
		FileInputStream fileInputStream = new FileInputStream(file);
		// 读数据
		byte[] data = new byte[fileInputStream.available()];
		fileInputStream.read(data);
		fileInputStream.close();
		// 回写
		response.setContentType(JPG);
		outputStream.write(data);
		outputStream.flush();
		outputStream.close();
	}

JSP代码

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<body>
<img alt="showImage" src="AdminServlet?op=showimg">
</body>