Servlet实现将图片写下到网页和实现图片下载的功能

package donghongyujava.servlet;

import java.io.File;

public class ShowImage extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public ShowImage() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

//		showImage(request, response);
		downlodeImage(request, response);
	}

	public void showImage(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		// 读取方式
		// response.setContentType("application/zip");
		response.setContentType("image/jpeg");
		// 获取图片绝对路径
		String path = this.getServletContext().getRealPath("/");
		File file = new File(path + "/images/WIN_20131027_214421.JPG");
		// 创建文件输入流
		FileInputStream is = new FileInputStream(file);
		// 响应输出流
		ServletOutputStream out = response.getOutputStream();
		// 创建缓冲区
		byte[] buffer = new byte[1024];
		int len = 0;
		while ((len = is.read(buffer)) != -1) {
			out.write(buffer, 0, len);
		}
		is.close();
		out.flush();
		out.close();

	}

	public void downlodeImage(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		
		// 获取图片绝对路径
		String path = this.getServletContext().getRealPath("/");
		File file = new File(path + "/images/WIN_20131027_214421.JPG");
		//设置头信息,内容处理的方式,attachment以附件的形式打开,就是进行下载,并设置下载文件的命名
		response.setHeader("Content-Disposition","attachment;filename="+file.getName());
		// 创建文件输入流
		FileInputStream is = new FileInputStream(file);
		// 响应输出流
		ServletOutputStream out = response.getOutputStream();
		// 创建缓冲区
		byte[] buffer = new byte[1024];
		int len = 0;
		while ((len = is.read(buffer)) != -1) {
			out.write(buffer, 0, len);
		}
		is.close();
		out.flush();
		out.close();

	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		this.doGet(request, response);
	}

}