diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/beanutil/JavaBeanSerializeUtil.java b/dubbo-common/src/main/java/org/apache/dubbo/common/beanutil/JavaBeanSerializeUtil.java
index 995965ac74..1ce5c455cf 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/beanutil/JavaBeanSerializeUtil.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/beanutil/JavaBeanSerializeUtil.java
@@ -237,12 +237,12 @@ public final class JavaBeanSerializeUtil {
             for (Map.Entry<Object, Object> entry : beanDescriptor) {
                 Object key = entry.getKey();
                 Object value = entry.getValue();
-                if (key != null && key instanceof JavaBeanDescriptor) {
+                if (key instanceof JavaBeanDescriptor) {
                     JavaBeanDescriptor keyDescriptor = (JavaBeanDescriptor) entry.getKey();
                     key = instantiateForDeserialize(keyDescriptor, loader, cache);
                     deserializeInternal(key, keyDescriptor, loader, cache);
                 }
-                if (value != null && value instanceof JavaBeanDescriptor) {
+                if (value instanceof JavaBeanDescriptor) {
                     JavaBeanDescriptor valueDescriptor = (JavaBeanDescriptor) entry.getValue();
                     value = instantiateForDeserialize(valueDescriptor, loader, cache);
                     deserializeInternal(value, valueDescriptor, loader, cache);
diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONArray.java b/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONArray.java
index f5e039c3be..a75bedbdd4 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONArray.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONArray.java
@@ -47,7 +47,7 @@ public class JSONArray implements JSONNode {
      */
     public boolean getBoolean(int index, boolean def) {
         Object tmp = mArray.get(index);
-        return tmp != null && tmp instanceof Boolean ? ((Boolean) tmp).booleanValue() : def;
+        return tmp instanceof Boolean ? ((Boolean) tmp).booleanValue() : def;
     }
 
     /**
@@ -59,7 +59,7 @@ public class JSONArray implements JSONNode {
      */
     public int getInt(int index, int def) {
         Object tmp = mArray.get(index);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).intValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).intValue() : def;
     }
 
     /**
@@ -71,7 +71,7 @@ public class JSONArray implements JSONNode {
      */
     public long getLong(int index, long def) {
         Object tmp = mArray.get(index);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).longValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).longValue() : def;
     }
 
     /**
@@ -83,7 +83,7 @@ public class JSONArray implements JSONNode {
      */
     public float getFloat(int index, float def) {
         Object tmp = mArray.get(index);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).floatValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).floatValue() : def;
     }
 
     /**
@@ -95,7 +95,7 @@ public class JSONArray implements JSONNode {
      */
     public double getDouble(int index, double def) {
         Object tmp = mArray.get(index);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).doubleValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).doubleValue() : def;
     }
 
     /**
diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONObject.java b/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONObject.java
index 052f35269d..c04d4e1405 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONObject.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/json/JSONObject.java
@@ -47,7 +47,7 @@ public class JSONObject implements JSONNode {
      */
     public boolean getBoolean(String key, boolean def) {
         Object tmp = mMap.get(key);
-        return tmp != null && tmp instanceof Boolean ? (Boolean) tmp : def;
+        return tmp instanceof Boolean ? (Boolean) tmp : def;
     }
 
     /**
@@ -59,7 +59,7 @@ public class JSONObject implements JSONNode {
      */
     public int getInt(String key, int def) {
         Object tmp = mMap.get(key);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).intValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).intValue() : def;
     }
 
     /**
@@ -71,7 +71,7 @@ public class JSONObject implements JSONNode {
      */
     public long getLong(String key, long def) {
         Object tmp = mMap.get(key);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).longValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).longValue() : def;
     }
 
     /**
@@ -83,7 +83,7 @@ public class JSONObject implements JSONNode {
      */
     public float getFloat(String key, float def) {
         Object tmp = mMap.get(key);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).floatValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).floatValue() : def;
     }
 
     /**
@@ -95,7 +95,7 @@ public class JSONObject implements JSONNode {
      */
     public double getDouble(String key, double def) {
         Object tmp = mMap.get(key);
-        return tmp != null && tmp instanceof Number ? ((Number) tmp).doubleValue() : def;
+        return tmp instanceof Number ? ((Number) tmp).doubleValue() : def;
     }
 
     /**
diff --git a/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/support/ProviderInvokerWrapper.java b/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/support/ProviderInvokerWrapper.java
index ce079b743e..a1eaad3410 100644
--- a/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/support/ProviderInvokerWrapper.java
+++ b/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/support/ProviderInvokerWrapper.java
@@ -90,7 +90,7 @@ public class ProviderInvokerWrapper<T> implements Invoker {
 
     @Override
     public boolean equals(Object o) {
-        if (o == null || !(o instanceof ProviderInvokerWrapper)) {
+        if (!(o instanceof ProviderInvokerWrapper)) {
             return false;
         }
         ProviderInvokerWrapper other = (ProviderInvokerWrapper) o;
diff --git a/dubbo-remoting/dubbo-remoting-netty/src/main/java/org/apache/dubbo/remoting/transport/netty/NettyHelper.java b/dubbo-remoting/dubbo-remoting-netty/src/main/java/org/apache/dubbo/remoting/transport/netty/NettyHelper.java
index ec73094ce9..64f41b2dae 100644
--- a/dubbo-remoting/dubbo-remoting-netty/src/main/java/org/apache/dubbo/remoting/transport/netty/NettyHelper.java
+++ b/dubbo-remoting/dubbo-remoting-netty/src/main/java/org/apache/dubbo/remoting/transport/netty/NettyHelper.java
@@ -27,7 +27,7 @@ final class NettyHelper {
 
     public static void setNettyLoggerFactory() {
         InternalLoggerFactory factory = InternalLoggerFactory.getDefaultFactory();
-        if (factory == null || !(factory instanceof DubboLoggerFactory)) {
+        if (!(factory instanceof DubboLoggerFactory)) {
             InternalLoggerFactory.setDefaultFactory(new DubboLoggerFactory());
         }
     }
diff --git a/dubbo-rpc/dubbo-rpc-dubbo/src/test/java/org/apache/dubbo/rpc/protocol/dubbo/decode/DubboTelnetDecodeTest.java b/dubbo-rpc/dubbo-rpc-dubbo/src/test/java/org/apache/dubbo/rpc/protocol/dubbo/decode/DubboTelnetDecodeTest.java
index e54d2e6508..28c49cce49 100644
--- a/dubbo-rpc/dubbo-rpc-dubbo/src/test/java/org/apache/dubbo/rpc/protocol/dubbo/decode/DubboTelnetDecodeTest.java
+++ b/dubbo-rpc/dubbo-rpc-dubbo/src/test/java/org/apache/dubbo/rpc/protocol/dubbo/decode/DubboTelnetDecodeTest.java
@@ -452,7 +452,7 @@ public class DubboTelnetDecodeTest {
     }
 
     private static boolean checkTelnetDecoded(Object msg) {
-        if (msg != null && msg instanceof String && !msg.toString().contains("Unsupported command:")) {
+        if (msg instanceof String && !msg.toString().contains("Unsupported command:")) {
             return true;
         }
         return false;