如何将图像从本地路径显示到Jsp [英] How to display image from local path to Jsp

问题描述

我正在尝试显示图像抛出jsp。图像存储在本地路径中，所以我编写了一个servlet get方法来检索图像，在src属性中我将图片标记和servlet名称作为参数提供给servlet，这是我的代码，

I am trying to display an image throw jsp. Image is stored in local path so I wrote a servlet get method to retrieve image and in src attribute of image tag I am giving the servlet name and image path as parameter to servlet and here is my code,

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLDecoder;

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

/**
 * Servlet implementation class AjaxController2
 */

public class FileServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	
	private static final int DEFAULT_BUFFER_SIZE = 10240; // 10KB.
	private String filePath;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public FileServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
    
    public void init() throws ServletException {

        // Define base path somehow. You can define it as init-param of the servlet.
        this.filePath = "/files";

        // In a Windows environment with the Applicationserver running on the
        // c: volume, the above path is exactly the same as "c:\files".
        // In UNIX, it is just straightforward "/files".
    }
	
	protected final void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("In do get");

        // Get requested file by path info.
        String requestedFile = request.getPathInfo();

        // Check if file is actually supplied to the request URI.
        if (requestedFile == null) {
            // Do your thing if the file is not supplied to the request URI.
            // Throw an exception, or send 404, or show default/warning page, or just ignore it.
            response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
            return;
        }

        // Decode the file name (might contain spaces and on) and prepare file object.
        File file = new File(filePath, URLDecoder.decode(requestedFile, "UTF-8"));

        // Check if file actually exists in filesystem.
        if (!file.exists()) {
            // Do your thing if the file appears to be non-existing.
            // Throw an exception, or send 404, or show default/warning page, or just ignore it.
            response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
            return;
        }

        // Get content type by filename.
        String contentType = getServletContext().getMimeType(file.getName());

        // If content type is unknown, then set the default value.
        // For all content types, see: http://www.w3schools.com/media/media_mimeref.asp
        // To add new content types, add new mime-mapping entry in web.xml.
        if (contentType == null) {
            contentType = "application/octet-stream";
        }

        // Init servlet response.
        response.reset();
        response.setBufferSize(DEFAULT_BUFFER_SIZE);
        response.setContentType(contentType);
        response.setHeader("Content-Length", String.valueOf(file.length()));
        response.setHeader("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"");

        // Prepare streams.
        BufferedInputStream input = null;
        BufferedOutputStream output = null;

        try {
            // Open streams.
            input = new BufferedInputStream(new FileInputStream(file), DEFAULT_BUFFER_SIZE);
            output = new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE);

            // Write file contents to response.
            byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
            int length;
            while ((length = input.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
        } finally {
            // Gently close streams.
            close(output);
            close(input);
        }
	}

	protected final void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("In do post");
		
	}
	

    private static void close(Closeable resource) {
        if (resource != null) {
            try {
                resource.close();
            } catch (IOException e) {
                // Do your thing with the exception. Print it, log it or mail it.
                e.printStackTrace();
            }
        }
    }
	
	
}

web.xml中的servlet条目如下，

in web.xml the servlet entry is as follow,

<servlet>
	<description>
	</description>
	<display-name>FileServlet</display-name>
	<servlet-name>FileServlet</servlet-name>
	<servlet-class>com.myPackage.FileServlet</servlet-class>
</servlet>

<servlet-mapping>
	<servlet-name>FileServlet</servlet-name>
	<url-pattern>/file/*</url-pattern>
</servlet-mapping>

在Jsp中我有img标签如下，



< img alt =Imagesrc =file / D：/uploads/img14.jspwidth =160height =160class =img-thumbnail>



现在我无法在浏览器上显示图像任何人都可以帮助我。

In Jsp I have img tag as follows,

<img alt="Image" src="file/D:/uploads/img14.jsp" width="160" height="160" class="img-thumbnail">

Now I am unable to dislay the image on browser can anyone please help me.

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