子任务可以使用不同的下载器。。。

webmagic-core/src/main/java/us/codecraft/webmagic/Request.java

@@ -1,5 +1,6 @@
 package us.codecraft.webmagic;
 
+import us.codecraft.webmagic.downloader.Downloader;
 import us.codecraft.webmagic.model.HttpRequestBody;
 import us.codecraft.webmagic.utils.Experimental;
 
@@ -26,6 +27,11 @@ public class Request implements Serializable {
 
     private HttpRequestBody requestBody;
 
+    /**
+     * this req use this downloader
+     */
+    private Downloader downloader;
+
     /**
      * Store additional information in extras.
      */
@@ -175,6 +181,14 @@ public class Request implements Serializable {
         return binaryContent;
     }
 
+    public Downloader getDownloader() {
+        return downloader;
+    }
+
+    public void setDownloader(Downloader downloader) {
+        this.downloader = downloader;
+    }
+
     public Request setBinaryContent(boolean binaryContent) {
         this.binaryContent = binaryContent;
         return this;

webmagic-core/src/main/java/us/codecraft/webmagic/Spider.java

@@ -401,7 +401,12 @@ public class Spider implements Runnable, Task {
     }
 
     private void processRequest(Request request) {
-        Page page = downloader.download(request, this);
+        Page page;
+        if (null != request.getDownloader()){
+            page = request.getDownloader().download(request,this);
+        }else {
+            page = downloader.download(request, this);
+        }
         if (page.isDownloadSuccess()){
             onDownloadSuccess(request, page);
         } else {