diff --git a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/AbstractServiceMessageSource.java b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/AbstractServiceMessageSource.java
index ec075b1..ab9b240 100644
--- a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/AbstractServiceMessageSource.java
+++ b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/AbstractServiceMessageSource.java
@@ -3,6 +3,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.util.LinkedList;
 import java.util.List;
@@ -69,6 +70,7 @@ public final String getMessage(String code, Locale locale, Object... args) {
         return message;
     }
 
+    @Nonnull
     @Override
     public final Locale getLocale() {
         Locale locale = getInternalLocale();
@@ -85,6 +87,7 @@ protected Locale getInternalLocale() {
         return null;
     }
 
+    @Nonnull
     @Override
     public final Locale getDefaultLocale() {
         if (defaultLocale != null) {
@@ -93,6 +96,7 @@ public final Locale getDefaultLocale() {
         return ServiceMessageSource.super.getDefaultLocale();
     }
 
+    @Nonnull
     @Override
     public final List<Locale> getSupportedLocales() {
         if (supportedLocales != null) {
diff --git a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/CompositeServiceMessageSource.java b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/CompositeServiceMessageSource.java
index 8e46454..6f233a5 100644
--- a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/CompositeServiceMessageSource.java
+++ b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/CompositeServiceMessageSource.java
@@ -49,7 +49,6 @@ public void init() {
         forEach(this.serviceMessageSources, ServiceMessageSource::init);
     }
 
-    @Nonnull
     @Override
     public String getMessage(String code, Locale locale, Object... args) {
         String message = null;
@@ -109,7 +108,7 @@ public void setServiceMessageSources(List<? extends ServiceMessageSource> servic
             oldServiceMessageSources.clear();
         }
         this.serviceMessageSources = newServiceMessageSources;
-        logger.debug("Source '{}' sets ServiceMessageSource list, original : {} , sorted : {}", serviceMessageSources, newServiceMessageSources);
+        logger.debug("Source '{}' sets ServiceMessageSource list, sorted : {}", serviceMessageSources, newServiceMessageSources);
     }
 
     @Override
@@ -182,7 +181,7 @@ private ServiceMessageSource getFirstServiceMessageSource() {
 
     private <T> void iterate(Class<T> serviceMessageSourceType, Consumer<T> consumer) {
         this.serviceMessageSources.stream()
-                .filter(serviceMessageSource -> serviceMessageSourceType.isInstance(serviceMessageSource))
+                .filter(serviceMessageSourceType::isInstance)
                 .map(serviceMessageSourceType::cast)
                 .forEach(consumer);
     }
diff --git a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/EmptyServiceMessageSource.java b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/EmptyServiceMessageSource.java
index 7a68e6f..6fde1c8 100644
--- a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/EmptyServiceMessageSource.java
+++ b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/EmptyServiceMessageSource.java
@@ -1,5 +1,6 @@
 package io.microsphere.i18n;
 
+import javax.annotation.Nonnull;
 import java.util.Locale;
 
 /**
@@ -28,6 +29,7 @@ public String getMessage(String code, Locale locale, Object... args) {
         return null;
     }
 
+    @Nonnull
     @Override
     public Locale getLocale() {
         return getDefaultLocale();
diff --git a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/PropertiesResourceServiceMessageSource.java b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/PropertiesResourceServiceMessageSource.java
index d7d1588..ffb3d10 100644
--- a/microsphere-i18n-core/src/main/java/io/microsphere/i18n/PropertiesResourceServiceMessageSource.java
+++ b/microsphere-i18n-core/src/main/java/io/microsphere/i18n/PropertiesResourceServiceMessageSource.java
@@ -26,6 +26,7 @@ public PropertiesResourceServiceMessageSource(String source) {
         super(source);
     }
 
+    @SuppressWarnings({"unchecked", "rawtypes"})
     @Override
     protected final Map<String, String> loadMessages(String resource) {
         Map<String, String> messages = null;
diff --git a/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/DelegatingServiceMessageSource.java b/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/DelegatingServiceMessageSource.java
index e4d9292..8c8d966 100644
--- a/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/DelegatingServiceMessageSource.java
+++ b/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/DelegatingServiceMessageSource.java
@@ -59,7 +59,6 @@ public void afterPropertiesSet() throws Exception {
         init();
     }
 
-    @NonNull
     @Override
     public String getMessage(String code, Locale locale, Object... args) {
         return this.delegate.getMessage(code, locale, args);
diff --git a/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/context/I18nApplicationListener.java b/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/context/I18nApplicationListener.java
index 959c24b..fd6c912 100644
--- a/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/context/I18nApplicationListener.java
+++ b/microsphere-i18n-spring/src/main/java/io/microsphere/i18n/spring/context/I18nApplicationListener.java
@@ -86,6 +86,7 @@ private void initializeServiceMessageSource(ApplicationContext context) {
     }
 
 
+    @SuppressWarnings("unchecked")
     private void initializeAcceptHeaderLocaleResolver(ApplicationContext context) {
         if (ACCEPT_HEADER_LOCALE_RESOLVER_CLASS == null) {
             logger.debug("The class '{}' was not found!", ACCEPT_HEADER_LOCALE_RESOLVER_CLASS_NAME);