优化代码

* 错别字

* long l->L

* 使xml中不存在的属性不会把java bean中已有的属性覆盖成null
比如：me.chanjar.weixin.mp.api.WxMpInMemoryConfigStorage#accessTokenLock

weixin-java-common/src/main/java/me/chanjar/weixin/common/util/xml/XStreamInitializer.java

@@ -1,6 +1,7 @@
 package me.chanjar.weixin.common.util.xml;
 
 import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider;
 import com.thoughtworks.xstream.core.util.QuickWriter;
 import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
 import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
@@ -13,7 +14,7 @@ import java.io.Writer;
 public class XStreamInitializer {
 
   public static XStream getInstance() {
-    XStream xstream = new XStream(new XppDriver() {
+    XStream xstream = new XStream(new PureJavaReflectionProvider(), new XppDriver() {
 
       @Override
       public HierarchicalStreamWriter createWriter(Writer out) {
@@ -42,6 +43,7 @@ public class XStreamInitializer {
         };
       }
     });
+
     xstream.ignoreUnknownElements();
     xstream.setMode(XStream.NO_REFERENCES);
     xstream.addPermission(NullPermission.NULL);