谷歌應用引擎網址提取服務iurl問題

我想通過使用谷歌應用引擎和JDO上傳一個圖像到數據庫。我從互聯網上得到了一個代碼。谷歌應用引擎網址提取服務iurl問題

http://code.google.com/appengine/articles/java/serving_dynamic_images.html

我試過的例子。但是，我傳遞給URLFetchService提取方法的URL正在引發格式錯誤的異常。那麼這個url值應該是什麼意思。我給了url值的值作爲jsp頁面的文件上傳值。

請找到下面的代碼：

package com.google.appengine.demo.domain; 

import com.google.appengine.api.datastore.Blob; 
import com.google.appengine.api.datastore.Key; 

import javax.jdo.annotations.Extension; 
import javax.jdo.annotations.IdGeneratorStrategy; 
import javax.jdo.annotations.IdentityType; 
import javax.jdo.annotations.PersistenceCapable; 
import javax.jdo.annotations.Persistent; 
import javax.jdo.annotations.PrimaryKey; 

/** 
* JDO-annotated model class for storing movie properties; movie's promotional 
* image is stored as a Blob (large byte array) in the image field. 
*/ 
@PersistenceCapable(identityType = IdentityType.APPLICATION) 
public class Movie { 

    @PrimaryKey 
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) 
    private Key key; 

    @Persistent 
    private String title; 

    @Persistent 
    @Extension(vendorName="datanucleus", key="gae.unindexed", value="true") 
    private String imageType; 

    @Persistent 
    private Blob image; 



    public Long getId() { 
     return key.getId(); 
    } 

    public String getTitle() { 
     return title; 
    } 

    public String getImageType() { 
     return imageType; 
    } 

    public byte[] getImage() { 
     if (image == null) { 
      return null; 
     } 

     return image.getBytes(); 
    } 

    public void setTitle(String title) { 
     this.title = title; 
    } 

    public void setImageType(String imageType) { 
     this.imageType = imageType; 
    } 

    public void setImage(byte[] bytes) { 
     this.image = new Blob(bytes); 
    } 

    //... 
}

JSP

<html> 

<head> 
<title>Image Upload</title> 
</head> 

<body> 
    <form action="/addMovie" method="get" enctype="multipart/form-data" 
     name="productForm" id="productForm"> 
     <br> 
     <br> 
     <table width="400px" align="center" border=0 
      style="background-color: ffeeff;"> 
      <tr> 
       <td align="center" colspan=2 
        style="font-weight: bold; font-size: 20pt;">Image Details</td> 
      </tr> 

      <tr> 
       <td align="center" colspan=2>&nbsp;</td> 
      </tr> 

      <tr> 
       <td>Image Link:</td> 
       <td><input type="file" name="url" ><td> 
      </tr> 

      <tr> 
       <td></td> 
       <td><input type="submit" name="Submit" value="Submit"> 
       </td> 
      </tr> 
      <tr> 
       <td colspan="2">&nbsp;</td> 
      </tr> 

     </table> 
    </form> 
</body> 

</html>

的Servlet

package com.google.appengine.demo.web; 

import java.io.IOException; 
import java.io.PrintWriter; 
import java.net.MalformedURLException; 
import java.net.URL; 

import javax.jdo.PersistenceManager; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 

import pmf.PMF; 

import com.google.appengine.api.urlfetch.HTTPHeader; 
import com.google.appengine.api.urlfetch.HTTPResponse; 
import com.google.appengine.api.urlfetch.URLFetchService; 
import com.google.appengine.api.urlfetch.URLFetchServiceFactory; 
import com.google.appengine.demo.domain.Movie; 

/** 
* GET requests fetch the image at the URL specified by the url query string 
* parameter, then persist this image along with the title specified by the 
* title query string parameter as a new Movie object in App Engine's 
* datastore. 
*/ 
public class StoreMovieServlet extends HttpServlet { 

    /** 
    * 
    */ 
    private static final long serialVersionUID = 1L; 



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


      PrintWriter out = response.getWriter(); 
      try {   
       String url1 = request.getParameter("url");   
       String url ="http://localhost:8877/addMovie?url="+url1; 

      // url = "C:\\my_photo.jpg"; 

       System.out.println("url:: +"+url);    
       URLFetchService fetchService = 
        URLFetchServiceFactory.getURLFetchService(); 
       HTTPResponse fetchResponse = fetchService.fetch(new URL(
         request.getParameter(url1))); 
       String fetchResponseContentType = null; 
       for (HTTPHeader header : fetchResponse.getHeaders()) { 
        // For each request header, check whether the name equals 
        // "Content-Type"; if so, store the value of this header 
        // in a member variable 
        if (header.getName().equalsIgnoreCase("content-type")) { 
         fetchResponseContentType = header.getValue(); 
         break; 
        } 
       }  
       Movie movie = new Movie(); 
       // movie.setTitle(req.getParameter("title")); 
       movie.setImageType(fetchResponseContentType); 

       // Set the movie's promotional image by passing in the bytes pulled 
       // from the image fetched via the URL Fetch service 
       movie.setImage(fetchResponse.getContent()); 
       PersistenceManager pm = PMF.get().getPersistenceManager(); 
       try { 
        // Store the image in App Engine's datastore 
        pm.makePersistent(movie); 
       } finally { 
        pm.close(); 
       } 



      }catch(Exception ex){ 
       ex.printStackTrace(); 
      } 
      finally {    
       out.close(); 
      } 


    } 



    @Override 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws IOException { 
     PrintWriter out = response.getWriter(); 
     try {   
      String url1 = request.getParameter("url");   
      String url ="http://localhost:8877/addMovie?url="+url1; 

     // url = "C:\\my_photo.jpg"; 

      System.out.println("url:: +"+url);    
      URLFetchService fetchService = 
       URLFetchServiceFactory.getURLFetchService(); 
      HTTPResponse fetchResponse = fetchService.fetch(new URL(
        request.getParameter(url1))); 
      String fetchResponseContentType = null; 
      for (HTTPHeader header : fetchResponse.getHeaders()) { 
       // For each request header, check whether the name equals 
       // "Content-Type"; if so, store the value of this header 
       // in a member variable 
       if (header.getName().equalsIgnoreCase("content-type")) { 
        fetchResponseContentType = header.getValue(); 
        break; 
       } 
      }  
      Movie movie = new Movie(); 
      // movie.setTitle(req.getParameter("title")); 
      movie.setImageType(fetchResponseContentType); 

      // Set the movie's promotional image by passing in the bytes pulled 
      // from the image fetched via the URL Fetch service 
      movie.setImage(fetchResponse.getContent()); 
      PersistenceManager pm = PMF.get().getPersistenceManager(); 
      try { 
       // Store the image in App Engine's datastore 
       pm.makePersistent(movie); 
      } finally { 
       pm.close(); 
      } 



     }catch(Exception ex){ 
      ex.printStackTrace(); 
     } 
     finally {    
      out.close(); 
     } 

    } 

    private void storeImage(HttpServletRequest req) throws IOException, 
      MalformedURLException { 
     URLFetchService fetchService = 
      URLFetchServiceFactory.getURLFetchService(); 

     // Fetch the image at the location given by the url query string parameter 
     HTTPResponse fetchResponse = fetchService.fetch(new URL(
       req.getParameter("url"))); 

     String fetchResponseContentType = null; 
     for (HTTPHeader header : fetchResponse.getHeaders()) { 
      // For each request header, check whether the name equals 
      // "Content-Type"; if so, store the value of this header 
      // in a member variable 
      if (header.getName().equalsIgnoreCase("content-type")) { 
       fetchResponseContentType = header.getValue(); 
       break; 
      } 
     } 

     if (fetchResponseContentType != null) { 
      // Create a new Movie instance 
      Movie movie = new Movie(); 
      movie.setTitle(req.getParameter("title")); 
      movie.setImageType(fetchResponseContentType); 

      // Set the movie's promotional image by passing in the bytes pulled 
      // from the image fetched via the URL Fetch service 
      movie.setImage(fetchResponse.getContent()); 

      //... 

      PersistenceManager pm = PMF.get().getPersistenceManager(); 
      try { 
       // Store the image in App Engine's datastore 
       pm.makePersistent(movie); 
      } finally { 
       pm.close(); 
      } 
     } 
    }

的web.xml

<servlet> 
    <servlet-name>StoreMovie</servlet-name> 
    <servlet-class>com.google.appengine.demo.web.StoreMovieServlet</servlet-class> 
</servlet> 
<servlet> 
    <servlet-name>GetImage</servlet-name> 
    <servlet-class>com.google.appengine.demo.web.GetImageServlet</servlet-class> 
</servlet> 
<servlet-mapping> 
    <servlet-name>StoreMovie</servlet-name> 
    <url-pattern>/addMovie</url-pattern> 
</servlet-mapping> 
<servlet-mapping> 
    <servlet-name>GetImage</servlet-name> 
    <url-pattern>/image</url-pattern> 
</servlet-mapping>

來源

2012-03-14 user414967

您發佈的示例代碼是從URL獲取圖像，而您的代碼嘗試從文件系統上傳圖像。

<input type="file">表示您從本地系統中選擇此項。這不會轉化爲網址。你將會把這個圖片上傳到App Engine，然後用它做任何你想做的事情。

Here對於如何使用Apache Commons File Upload jar來做到這一點很不錯。

來源

2012-03-14 18:23:14 Kal

好的。非常感謝！！。還有一個問題。所以，如果我想通過GAE將圖像從本地系統上傳到數據存儲，我是否需要使用Apache公共文件上傳jar？沒有Apache Commons文件上傳jar文件，這是不可能的？我不想將第三方庫添加到我的項目中。 – user414967 2012-03-15 06:16:53

是的。看起來這是唯一的選擇。甚至GAE的官方文檔都提到了fileupload。 http://code.google.com/appengine/kb/java.html#fileforms – Kal 2012-03-15 13:45:56

好的。然後我按照這個apache文件上傳。 – user414967 2012-03-15 14:14:41

谷歌應用引擎網址提取服務iurl問題

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