use java string builder for toString methods

apollo-client/src/main/java/com/ctrip/framework/apollo/model/ConfigChange.java

 package com.ctrip.framework.apollo.model;
 
 
-import com.google.common.base.MoreObjects;
+import com.google.common.base.Objects;
 
 import com.ctrip.framework.apollo.enums.PropertyChangeType;
 
@@ -67,13 +67,13 @@ public class ConfigChange {
 
   @Override
   public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .omitNullValues()
-        .add("namespace", namespace)
-        .add("propertyName", propertyName)
-        .add("oldValue", oldValue)
-        .add("newValue", newValue)
-        .add("changeType", changeType)
-        .toString();
+    final StringBuilder sb = new StringBuilder("ConfigChange{");
+    sb.append("namespace='").append(namespace).append('\'');
+    sb.append(", propertyName='").append(propertyName).append('\'');
+    sb.append(", oldValue='").append(oldValue).append('\'');
+    sb.append(", newValue='").append(newValue).append('\'');
+    sb.append(", changeType=").append(changeType);
+    sb.append('}');
+    return sb.toString();
   }
 }

apollo-core/src/main/java/com/ctrip/framework/apollo/core/dto/ApolloConfig.java

 package com.ctrip.framework.apollo.core.dto;
 
-import com.google.common.base.MoreObjects;
-
 import java.util.Map;
 
 /**
@@ -74,13 +72,13 @@ public class ApolloConfig {
 
   @Override
   public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .omitNullValues()
-        .add("appId", appId)
-        .add("cluster", cluster)
-        .add("namespaceName", namespaceName)
-        .add("releaseKey", releaseKey)
-        .add("configurations", configurations)
-        .toString();
+    final StringBuilder sb = new StringBuilder("ApolloConfig{");
+    sb.append("appId='").append(appId).append('\'');
+    sb.append(", cluster='").append(cluster).append('\'');
+    sb.append(", namespaceName='").append(namespaceName).append('\'');
+    sb.append(", configurations=").append(configurations);
+    sb.append(", releaseKey='").append(releaseKey).append('\'');
+    sb.append('}');
+    return sb.toString();
   }
 }

apollo-core/src/main/java/com/ctrip/framework/apollo/core/dto/ServiceDTO.java

 package com.ctrip.framework.apollo.core.dto;
 
-import com.google.common.base.MoreObjects;
-
 public class ServiceDTO {
 
   private String appName;
@@ -36,11 +34,11 @@ public class ServiceDTO {
 
   @Override
   public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .omitNullValues()
-        .add("appName", appName)
-        .add("instanceId", instanceId)
-        .add("homepageUrl", homepageUrl)
-        .toString();
+    final StringBuilder sb = new StringBuilder("ServiceDTO{");
+    sb.append("appName='").append(appName).append('\'');
+    sb.append(", instanceId='").append(instanceId).append('\'');
+    sb.append(", homepageUrl='").append(homepageUrl).append('\'');
+    sb.append('}');
+    return sb.toString();
   }
 }