change: 代码注释、调整代码.

src/main/java/com/serliunx/ddns/config/AbstractConfiguration.java

@@ -1,5 +1,6 @@
 package com.serliunx.ddns.config;
 
+import com.serliunx.ddns.constant.ConfigurationKeys;
 import com.serliunx.ddns.support.Assert;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

src/main/java/com/serliunx/ddns/constant/ConfigurationKeys.java

@@ -1,4 +1,4 @@
-package com.serliunx.ddns.config;
+package com.serliunx.ddns.constant;
 
 /**
  * 配置文件键常量信息

src/main/java/com/serliunx/ddns/core/instance/AliyunInstance.java

@@ -16,7 +16,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
-import static com.serliunx.ddns.config.ConfigurationKeys.KEY_ALIYUN_ENDPOINT;
+import static com.serliunx.ddns.constant.ConfigurationKeys.KEY_ALIYUN_ENDPOINT;
 import static com.serliunx.ddns.constant.SystemConstants.XML_ROOT_INSTANCE_NAME;
 
 /**

src/main/java/com/serliunx/ddns/support/NetworkContextHolder.java

@@ -5,6 +5,7 @@ import org.slf4j.LoggerFactory;
 
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
@@ -24,16 +25,28 @@ public final class NetworkContextHolder {
     // 外网IP地址获取
     private static final Integer IP_CONTEXT_TIME_OUT = 5;
     private static volatile String IP_ADDRESS;
+    /**
+     * 失败计数
+     * <p>
+     * 失败次数过多后, 会影响
+     */
+    private static final AtomicInteger FAILED_COUNTS = new AtomicInteger();
 
+    // private-ctor
     private NetworkContextHolder() {throw new UnsupportedOperationException();}
 
+    /**
+     * 尝试设置IP地址
+     *
+     * @param i 新的ip地址, 为空时设置会失败
+     */
     public static void setIpAddress(String i) {
         if (i == null
                 || i.isEmpty()) {
             log.error("IP 地址不能为空!");
+            FAILED_COUNTS.incrementAndGet();
             return;
         }
-        
         try {
             IP_LOCK.lock();
             IP_ADDRESS = i;
@@ -41,11 +54,23 @@ public final class NetworkContextHolder {
                 IP_CONTEXT_WAIT_LATCH.countDown();
             }
         } finally {
+            FAILED_COUNTS.set(0);
             IP_LOCK.unlock();
         }
     }
 
+    /**
+     * 获取所缓存的ip的地址
+     * <p>
+     * 设置失败次数过多时将忽略已保存的缓存值，防止多次将旧IP重复更新.
+     *
+     * @return ip地址
+     */
     public static String getIpAddress() {
+        if (FAILED_COUNTS.get() > 10) {
+            log.warn("更新失败次数过多, 不在返回IP地址直到下次成功更新!");
+            return null;
+        }
         if (IP_ADDRESS != null) {
             return IP_ADDRESS;
         }

src/main/java/com/serliunx/ddns/support/SystemInitializer.java

@@ -1,7 +1,7 @@
 package com.serliunx.ddns.support;
 
 import com.serliunx.ddns.config.Configuration;
-import com.serliunx.ddns.config.ConfigurationKeys;
+import com.serliunx.ddns.constant.ConfigurationKeys;
 import com.serliunx.ddns.constant.IpProviderType;
 import com.serliunx.ddns.constant.SystemConstants;
 import com.serliunx.ddns.core.Clearable;
@@ -27,8 +27,8 @@ import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 
-import static com.serliunx.ddns.config.ConfigurationKeys.KEY_TASK_REFRESH_INTERVAL_IP;
+import static com.serliunx.ddns.constant.ConfigurationKeys.KEY_TASK_REFRESH_INTERVAL_IP;
-import static com.serliunx.ddns.config.ConfigurationKeys.KEY_THREAD_POOL_CORE_SIZE;
+import static com.serliunx.ddns.constant.ConfigurationKeys.KEY_THREAD_POOL_CORE_SIZE;
 
 /**
  * 系统初始化
@@ -115,11 +115,17 @@ public final class SystemInitializer implements Refreshable, Clearable {
         return instances;
     }
 
+    /**
+     * 加载实例(不同的容器加载时机不同)
+     */
     private void loadInstances() {
         instances = instanceContext.getInstances();
         log.info("载入 {} 个实例.", instances.size());
     }
 
+    /**
+     * 资源释放
+     */
     @SuppressWarnings("SameParameterValue")
     private void releaseResource(String resourceName) {
         ClassLoader classLoader = SystemConstants.class.getClassLoader();
@@ -146,6 +152,9 @@ public final class SystemInitializer implements Refreshable, Clearable {
         }
     }
 
+    /**
+     * 运行实例
+     */
     private void runInstances() {
         Assert.notNull(scheduledThreadPoolExecutor);
         Assert.notNull(instances);
@@ -164,6 +173,11 @@ public final class SystemInitializer implements Refreshable, Clearable {
         }
     }
 
+    /**
+     * 初始化线程池
+     *
+     * @param coreSize 线程池核心线程数量
+     */
     private void initThreadPool(int coreSize) {
         Assert.isLargerThan(coreSize, 1);
         scheduledThreadPoolExecutor = new ScheduledThreadPoolExecutor(coreSize, ThreadFactoryBuilder.builder()
@@ -182,6 +196,9 @@ public final class SystemInitializer implements Refreshable, Clearable {
         }, "DDNS-ShutDownHook"));
     }
 
+    /**
+     * 初始化定时获取IP地址的任务
+     */
     private void initIpTask() {
         scheduledProvider = new ScheduledProvider(getInternalProvider(),
                 configuration.getLong(KEY_TASK_REFRESH_INTERVAL_IP, 300L));
@@ -192,11 +209,19 @@ public final class SystemInitializer implements Refreshable, Clearable {
         });
     }
 
+    /**
+     * 获取内置的IP供应器（获取IP地址的方式）
+     * <p>
+     * 根据配置文件中的定义{@link ConfigurationKeys#KEY_IP_PROVIDER_TYPE}, 默认为{@link com.serliunx.ddns.support.ipprovider.IpApiProvider}
+     */
     private Provider getInternalProvider() {
         return configuration.getEnum(IpProviderType.class, ConfigurationKeys.KEY_IP_PROVIDER_TYPE,
                 IpProviderType.IP_API).getProvider();
     }
 
+    /**
+     * 关闭线程池逻辑
+     */
     private void checkAndCloseSafely() {
         if (scheduledThreadPoolExecutor == null)
             return;

src/main/java/com/serliunx/ddns/support/okhttp/HttpClient.java

@@ -1,7 +1,7 @@
 package com.serliunx.ddns.support.okhttp;
 
 import com.serliunx.ddns.config.Configuration;
-import com.serliunx.ddns.config.ConfigurationKeys;
+import com.serliunx.ddns.constant.ConfigurationKeys;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
 import okhttp3.Response;