fix nullpointer exception

webmagic-core/src/main/java/us/codecraft/webmagic/model/ModelPageProcessor.java

@@ -51,14 +51,14 @@ class ModelPageProcessor implements PageProcessor {
     @Override
     public void process(Page page) {
         for (PageModelExtractor pageModelExtractor : pageModelExtractorList) {
+            extractLinks(page, pageModelExtractor.getHelpUrlRegionSelector(), pageModelExtractor.getHelpUrlPatterns());
+            extractLinks(page, pageModelExtractor.getTargetUrlRegionSelector(), pageModelExtractor.getTargetUrlPatterns());
             Object process = pageModelExtractor.process(page);
             if (process == null || (process instanceof List && ((List) process).size() == 0)) {
                 page.getResultItems().setSkip(true);
             }
             postProcessPageModel(pageModelExtractor.getClazz(), process);
             page.putField(pageModelExtractor.getClazz().getCanonicalName(), process);
-            extractLinks(page, pageModelExtractor.getHelpUrlRegionSelector(), pageModelExtractor.getHelpUrlPatterns());
-            extractLinks(page, pageModelExtractor.getTargetUrlRegionSelector(), pageModelExtractor.getTargetUrlPatterns());
         }
     }
 

webmagic-plugin/webmagic-misc/src/main/java/us/codecraft/webmagic/scheduler/RedisScheduler.java

@@ -56,18 +56,20 @@ public class RedisScheduler implements Scheduler {
     public synchronized Request poll(Task task) {
         Jedis jedis = pool.getResource();
         String url = jedis.lpop(QUEUE_PREFIX + task.getUUID());
+        if (url == null) {
+            return null;
+        }
         String key = ITEM_PREFIX + DigestUtils.shaHex(url);
         byte[] bytes = jedis.get(key.getBytes());
+        if (bytes!=null){
             try {
                 Object o = HessianSerializer.INSTANCE.deSerialize(bytes);
                 return (Request)o;
             } catch (Exception e) {
                 e.printStackTrace();
             }
-        pool.returnResource(jedis);
-        if (url == null) {
-            return null;
         }
+        pool.returnResource(jedis);
         return new Request(url);
     }
 }

webmagic-samples/src/main/java/us/codecraft/webmagic/model/samples/News163.java

@@ -5,6 +5,7 @@ import us.codecraft.webmagic.Site;
 import us.codecraft.webmagic.model.*;
 import us.codecraft.webmagic.pipeline.ConsolePipeline;
 import us.codecraft.webmagic.pipeline.PagedPipeline;
+import us.codecraft.webmagic.scheduler.RedisScheduler;
 
 import java.util.Collection;
 import java.util.List;
@@ -71,7 +72,7 @@ public class News163 implements PagedModel {
 
     public static void main(String[] args) {
         OOSpider.create(Site.me().addStartUrl("http://news.163.com/13/0802/05/958I1E330001124J_2.html"), News163.class)
-                .clearPipeline().pipeline(new PagedPipeline()).pipeline(new ConsolePipeline()).run();
+                .scheduler(new RedisScheduler("localhost")).clearPipeline().pipeline(new PagedPipeline()).pipeline(new ConsolePipeline()).run();
     }
 
 }