modify dns cache file create logic and optimize dns cache info create by data

Author: YangSen-qn

library/src/main/java/com/qiniu/android/http/dns/DnsCacheFile.java

@@ -18,15 +18,14 @@ public class DnsCacheFile implements Recorder {
     public DnsCacheFile(String directory) throws IOException {
         this.directory = directory;
         f = new File(directory);
-        if (!f.isDirectory() || !f.exists()) {
+        if (!f.isDirectory()) {
+            throw new IOException("does not mkdir");
+        }
+        if (!f.exists()) {
             boolean r = f.mkdirs();
             if (!r) {
                 throw new IOException("mkdir failed");
             }
-            return;
-        }
-        if (!f.isDirectory()) {
-            throw new IOException("does not mkdir");
         }
     }
 

library/src/main/java/com/qiniu/android/http/dns/DnsCacheInfo.java

@@ -20,12 +20,16 @@ public class DnsCacheInfo implements java.io.Serializable {
     public String localIp;
     public ConcurrentHashMap<String, List<IDnsNetworkAddress>> info;
 
-    public static DnsCacheInfo createDnsCacheInfoByJsonData(byte[] jsonData) {
+    public static DnsCacheInfo createDnsCacheInfoByData(byte[] jsonData) {
         if (jsonData == null){
             return null;
         }
-        DnsCacheInfo dnsCacheInfo = (DnsCacheInfo)StringUtils.toObject(jsonData);
-        return dnsCacheInfo;
+        Object dnsCacheInfo = StringUtils.toObject(jsonData);
+        if (dnsCacheInfo instanceof DnsCacheInfo){
+            return (DnsCacheInfo)dnsCacheInfo;
+        } else {
+            return null;
+        }
     }
 
     public DnsCacheInfo() {

library/src/main/java/com/qiniu/android/http/dns/DnsPrefetcher.java

@@ -8,22 +8,15 @@
 import com.qiniu.android.http.ResponseInfo;
 import com.qiniu.android.http.metrics.UploadRegionRequestMetrics;
 import com.qiniu.android.storage.GlobalConfiguration;
-import com.qiniu.android.storage.Recorder;
 import com.qiniu.android.storage.UpToken;
 import com.qiniu.android.utils.AndroidNetwork;
-import com.qiniu.android.utils.StringUtils;
 import com.qiniu.android.utils.Utils;
 import com.qiniu.android.utils.Wait;
 
-import org.json.JSONArray;
-import org.json.JSONException;
-import org.json.JSONObject;
-
 import java.io.IOException;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -226,7 +219,7 @@ private boolean preFetchHost(String preHost, Dns dns){
 
     private boolean recoverDnsCache(byte[] data){
 
-        DnsCacheInfo dnsCacheInfo = DnsCacheInfo.createDnsCacheInfoByJsonData(data);
+        DnsCacheInfo dnsCacheInfo = DnsCacheInfo.createDnsCacheInfoByData(data);
         if (dnsCacheInfo == null || dnsCacheInfo.info == null || dnsCacheInfo.info.size() == 0){
             return false;
         }