利用Servlet使用数据流在jsp页面中显示硬盘中的图片

ShowImageFromDiskServlet.java代码如下：

package cn.com.songjy.test.db;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class ShowImageFromDiskServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	private static final Log log = LogFactory
			.getLog(ShowImageFromDiskServlet.class);

	String imagePath;

	public ShowImageFromDiskServlet() {
	}

	@Override
	public void init(ServletConfig config) throws ServletException {

		imagePath = config.getInitParameter("imagePath");

		log.info("图片路径：" + imagePath);
	}

	@Override
	protected void service(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {

		BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(
				response.getOutputStream());

		File file = new File(imagePath);

		BufferedInputStream bufferedInputStream = new BufferedInputStream(
				new FileInputStream(file));

		byte[] buffer = new byte[1024];
		
		for(int len=0;(len=bufferedInputStream.read(buffer))>0;){
			bufferedOutputStream.write(buffer, 0, len);
		}
		
		//bufferedOutputStream.flush();//关闭时会自动刷新，无需显示调用，否则必须显示调用
		bufferedOutputStream.close();
		bufferedInputStream.close();
	}

	/*private byte[] readStream(InputStream in) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		int data = -1;
		try {
			while ((data = in.read()) != -1) {
				baos.write(data);
			}
			return baos.toByteArray();
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}*/

}

spring mvc 通过字节流返回图像

	/**
	 * 通过url请求返回图像的字节流
	 */
	@RequestMapping("icon/{cateogry}")
	public void getIcon(@PathVariable("cateogry") String cateogry, HttpServletRequest request,
			HttpServletResponse response) throws IOException {

		if (StringUtils.isEmpty(cateogry)) {
			cateogry = "";
		}

		String fileName = request.getSession().getServletContext().getRealPath("/") + "resource\\icons\\auth\\"
				+ cateogry.toUpperCase().trim() + ".png";

		File file = new File(fileName);

		// 判断文件是否存在如果不存在就返回默认图标
		if (!(file.exists() && file.canRead())) {
			file = new File(request.getSession().getServletContext().getRealPath("/") + "resource/icons/auth/root.png");
		}

		FileInputStream inputStream = new FileInputStream(file);
		byte[] data = new byte[(int) file.length()];
		int length = inputStream.read(data);
		inputStream.close();

		response.setContentType("image/png");

		OutputStream stream = response.getOutputStream();
		stream.write(data);
		stream.flush();
		stream.close();
	}

通过Servlet 将服务器硬盘图片 展示到浏览器

通过Java HTTP连接将网络图片下载到本地

在jsp页面中响应速度提高的7种方法

又一编辑神器-百度编辑器-Ueditor

教你如何调用百度编辑器ueditor的上传图片、上传文件等模块