add some null pointer check for httpclientdownloader

webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientDownloader.java

@@ -17,6 +17,8 @@ import us.codecraft.webmagic.selector.PlainText;
 import us.codecraft.webmagic.utils.UrlUtils;
 
 import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
 
 
 /**
@@ -34,10 +36,23 @@ public class HttpClientDownloader implements Downloader {
 
     @Override
     public Page download(Request request, Task task) {
-        Site site = task.getSite();
+        Site site = null;
+        if (task != null) {
+            site = task.getSite();
+        }
+        int retryTimes = 0;
+        Set<Integer> acceptStatCode;
+        String charset = null;
+        if (site != null) {
+            retryTimes = site.getRetryTimes();
+            acceptStatCode = site.getAcceptStatCode();
+            charset = site.getCharset();
+        } else {
+            acceptStatCode = new HashSet<Integer>();
+            acceptStatCode.add(200);
+        }
         logger.info("downloading page " + request.getUrl());
         HttpClient httpClient = HttpClientPool.getInstance(poolSize).getClient(site);
-        String charset = site.getCharset();
         try {
             HttpGet httpGet = new HttpGet(request.getUrl());
             HttpResponse httpResponse = null;
@@ -49,7 +64,8 @@ public class HttpClientDownloader implements Downloader {
                     retry = false;
                 } catch (IOException e) {
                     tried++;
-                    if (tried > site.getRetryTimes()) {
+
+                    if (tried > retryTimes) {
                         logger.warn("download page " + request.getUrl() + " error", e);
                         return null;
                     }
@@ -58,7 +74,7 @@ public class HttpClientDownloader implements Downloader {
                 }
             } while (retry);
             int statusCode = httpResponse.getStatusLine().getStatusCode();
-            if (site.getAcceptStatCode().contains(statusCode)) {
+            if (acceptStatCode.contains(statusCode)) {
                 //charset
                 if (charset == null) {
                     String value = httpResponse.getEntity().getContentType().getValue();

webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientPool.java

@@ -50,13 +50,17 @@ public class HttpClientPool {
 
     private HttpClient generateClient(Site site) {
         HttpParams params = new BasicHttpParams();
+        if (site != null && site.getUserAgent() != null) {
             params.setParameter(CoreProtocolPNames.USER_AGENT, site.getUserAgent());
+        }
         params.setIntParameter(CoreConnectionPNames.SO_TIMEOUT, 1000);
         params.setIntParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, 2000);
 
         HttpProtocolParamBean paramsBean = new HttpProtocolParamBean(params);
         paramsBean.setVersion(HttpVersion.HTTP_1_1);
+        if (site != null && site.getCharset() != null) {
             paramsBean.setContentCharset(site.getCharset());
+        }
         paramsBean.setUseExpectContinue(false);
 
         SchemeRegistry schemeRegistry = new SchemeRegistry();
@@ -67,7 +71,9 @@ public class HttpClientPool {
         connectionManager.setMaxTotal(poolSize);
         connectionManager.setDefaultMaxPerRoute(100);
         DefaultHttpClient httpClient = new DefaultHttpClient(connectionManager, params);
+        if (site != null) {
             generateCookie(httpClient, site);
+        }
         httpClient.getParams().setIntParameter("http.socket.timeout", 60000);
         httpClient.getParams().setParameter(ClientPNames.COOKIE_POLICY, CookiePolicy.BEST_MATCH);
         return httpClient;
@@ -75,11 +81,13 @@ public class HttpClientPool {
 
     private void generateCookie(DefaultHttpClient httpClient, Site site) {
         CookieStore cookieStore = new BasicCookieStore();
+        if (site.getCookies() != null) {
             for (Map.Entry<String, String> cookieEntry : site.getCookies().entrySet()) {
                 BasicClientCookie cookie = new BasicClientCookie(cookieEntry.getKey(), cookieEntry.getValue());
                 cookie.setDomain(site.getDomain());
                 cookieStore.addCookie(cookie);
             }
+        }
         httpClient.setCookieStore(cookieStore);
     }