diff --git a/Aria/src/main/java/com/arialyy/aria/core/inf/ITask.java b/Aria/src/main/java/com/arialyy/aria/core/inf/ITask.java
index 70bee951..117fe6c0 100644
--- a/Aria/src/main/java/com/arialyy/aria/core/inf/ITask.java
+++ b/Aria/src/main/java/com/arialyy/aria/core/inf/ITask.java
@@ -33,63 +33,63 @@ public interface ITask<ENTITY extends AbsEntity> {
   /**
    * 唯一标识符，DownloadTask 为下载地址，UploadTask 为文件路径
    */
-  public String getKey();
+  String getKey();
 
   /**
    * 任务是否正在执行
    *
    * @return true，正在执行；
    */
-  public boolean isRunning();
+  boolean isRunning();
 
   /**
    * 获取信息实体
    */
-  public ENTITY getEntity();
+  ENTITY getEntity();
 
-  public void start();
+  void start();
 
-  public void stop();
+  void stop();
 
-  public void cancel();
+  void cancel();
 
   /**
    * 原始byte速度
    */
-  public long getSpeed();
+  long getSpeed();
 
   /**
    * 转换单位后的速度
    */
-  public String getConvertSpeed();
+  String getConvertSpeed();
 
   /**
    * 获取百分比进度
    */
-  public int getPercent();
+  int getPercent();
 
   /**
    * 原始文件byte长度
    */
-  public long getFileSize();
+  long getFileSize();
 
   /**
    * 转换单位后的文件长度
    */
-  public String getConvertFileSize();
+  String getConvertFileSize();
 
   /**
    * 获取当前进度
    */
-  public long getCurrentProgress();
+  long getCurrentProgress();
 
   /**
    * 获取单位转换后的进度
    *
    * @return 返回 3mb
    */
-  public String getConvertCurrentProgress();
+  String getConvertCurrentProgress();
 
-  public void setTargetName(String targetName);
+  void setTargetName(String targetName);
 
 }
diff --git a/Aria/src/main/java/com/arialyy/aria/core/queue/AbsTaskQueue.java b/Aria/src/main/java/com/arialyy/aria/core/queue/AbsTaskQueue.java
index 8dab1afb..acb59430 100644
--- a/Aria/src/main/java/com/arialyy/aria/core/queue/AbsTaskQueue.java
+++ b/Aria/src/main/java/com/arialyy/aria/core/queue/AbsTaskQueue.java
@@ -26,6 +26,7 @@ import com.arialyy.aria.core.inf.AbsTaskEntity;
 import com.arialyy.aria.core.inf.IEntity;
 import com.arialyy.aria.core.queue.pool.BaseCachePool;
 import com.arialyy.aria.core.queue.pool.BaseExecutePool;
+import java.util.Iterator;
 import java.util.Set;
 
 /**
@@ -52,14 +53,12 @@ abstract class AbsTaskQueue<TASK extends AbsTask, TASK_ENTITY extends AbsTaskEnt
   }
 
   @Override public void removeAllTask() {
-    Set<String> exeKeys = mExecutePool.getAllTask().keySet();
-    for (String key : exeKeys) {
+    for (String key : mExecutePool.getAllTask().keySet()) {
       TASK task = mExecutePool.getAllTask().get(key);
       if (task != null) task.cancel();
     }
-    Set<String> cacheKeys = mCachePool.getAllTask().keySet();
-    for (String key : cacheKeys) {
-      mExecutePool.removeTask(key);
+    for (String key : mCachePool.getAllTask().keySet()) {
+      mCachePool.removeTask(key);
     }
   }
 
@@ -67,14 +66,12 @@ abstract class AbsTaskQueue<TASK extends AbsTask, TASK_ENTITY extends AbsTaskEnt
    * 停止所有任务
    */
   @Override public void stopAllTask() {
-    Set<String> exeKeys = mExecutePool.getAllTask().keySet();
-    for (String key : exeKeys) {
+    for (String key : mExecutePool.getAllTask().keySet()) {
       TASK task = mExecutePool.getAllTask().get(key);
       if (task != null && task.isRunning()) task.stop();
     }
-    Set<String> cacheKeys = mCachePool.getAllTask().keySet();
-    for (String key : cacheKeys) {
-      mExecutePool.removeTask(key);
+    for (String key : mCachePool.getAllTask().keySet()) {
+      mCachePool.removeTask(key);
     }
   }
 
diff --git a/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseCachePool.java b/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseCachePool.java
index 1dd9cd7c..200e72c9 100644
--- a/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseCachePool.java
+++ b/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseCachePool.java
@@ -26,6 +26,7 @@ import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
 
@@ -40,9 +41,9 @@ public class BaseCachePool<TASK extends AbsTask> implements IPool<TASK> {
   private Map<String, TASK> mCacheMap;
   private LinkedBlockingQueue<TASK> mCacheQueue;
 
-  public BaseCachePool() {
+  BaseCachePool() {
     mCacheQueue = new LinkedBlockingQueue<>(MAX_NUM);
-    mCacheMap = new HashMap<>();
+    mCacheMap = new ConcurrentHashMap<>();
   }
 
   /**
diff --git a/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseExecutePool.java b/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseExecutePool.java
index ee9a10a0..b0bd0731 100644
--- a/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseExecutePool.java
+++ b/Aria/src/main/java/com/arialyy/aria/core/queue/pool/BaseExecutePool.java
@@ -25,6 +25,7 @@ import com.arialyy.aria.util.CommonUtil;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -41,7 +42,7 @@ public class BaseExecutePool<TASK extends AbsTask> implements IPool<TASK> {
   BaseExecutePool() {
     mSize = getMaxSize();
     mExecuteQueue = new ArrayBlockingQueue<>(mSize);
-    mExecuteMap = new HashMap<>();
+    mExecuteMap = new ConcurrentHashMap<>();
   }
 
   /**