v_2.0 开发，运行池编写

downloadutil/src/main/java/com/arialyy/downloadutil/core/DownloadTarget.java

@@ -0,0 +1,33 @@
+package com.arialyy.downloadutil.core;
+
+import com.arialyy.downloadutil.core.inf.IDownloader;
+import com.arialyy.downloadutil.core.inf.ITask;
+import com.arialyy.downloadutil.core.pool.CachePool;
+import com.arialyy.downloadutil.core.pool.ExecutePool;
+
+/**
+ * Created by lyy on 2016/8/16.
+ * 任务下载器，提供抽象的方法供具体的实现类操作
+ */
+public abstract class DownloadTarget implements IDownloader, ITask {
+    protected CachePool   mCachePool   = CachePool.getInstance();
+    protected ExecutePool mExecutePool = ExecutePool.getInstance();
+
+    /**
+     * 获取当前运行的任务数
+     *
+     * @return 当前正在执行的任务数
+     */
+    public int getCurrentTaskNum() {
+        return mExecutePool.size();
+    }
+
+    /**
+     * 获取缓存任务数
+     *
+     * @return 获取缓存的任务数
+     */
+    public int getCacheTaskNum() {
+        return mCachePool.size();
+    }
+}

downloadutil/src/main/java/com/arialyy/downloadutil/core/Task.java

@@ -17,7 +17,27 @@ import java.net.HttpURLConnection;
  * 下载任务类
  */
 public class Task {
-    public static final String TAG = "Task";
+    public static final String TAG      = "Task";
+    /**
+     * 任务开始
+     */
+    public static final int    START    = 1;
+    /**
+     * 任务停止
+     */
+    public static final int    STOP     = 2;
+    /**
+     * 任务失败
+     */
+    public static final int    FAILE    = 3;
+    /**
+     * 任务取消
+     */
+    public static final int    CANCEL   = 4;
+    /**
+     * 任务完成
+     */
+    public static final int    COMPLETE = 5;
     DownloadEntity    downloadEntity;
     IDownloadListener listener;
     Handler           outHandler;
@@ -101,6 +121,7 @@ public class Task {
         public void onStart(long startLocation) {
             super.onStart(startLocation);
             downloadEntity.setState(DownloadEntity.STATE_DOWNLOAD_ING);
+            sendInState2Target(START);
             sendIntent(DownloadManager.ACTION_START, startLocation);
         }
 
@@ -117,6 +138,7 @@ public class Task {
         public void onStop(long stopLocation) {
             super.onStop(stopLocation);
             downloadEntity.setState(DownloadEntity.STATE_STOP);
+            sendInState2Target(STOP);
             sendIntent(DownloadManager.ACTION_STOP, stopLocation);
         }
 
@@ -124,6 +146,7 @@ public class Task {
         public void onCancel() {
             super.onCancel();
             downloadEntity.setState(DownloadEntity.STATE_CANCEL);
+            sendInState2Target(CANCEL);
             sendIntent(DownloadManager.ACTION_CANCEL, -1);
             downloadEntity.deleteData();
         }
@@ -133,6 +156,7 @@ public class Task {
             super.onComplete();
             downloadEntity.setState(DownloadEntity.STATE_COMPLETE);
             downloadEntity.setDownloadComplete(true);
+            sendInState2Target(COMPLETE);
             sendIntent(DownloadManager.ACTION_COMPLETE, -1);
         }
 
@@ -140,9 +164,21 @@ public class Task {
         public void onFail() {
             super.onFail();
             downloadEntity.setState(DownloadEntity.STATE_FAIL);
+            sendInState2Target(FAILE);
             sendIntent(DownloadManager.ACTION_FAIL, -1);
         }
 
+        /**
+         * 将任务状态发送给下载器
+         *
+         * @param state {@link Task#START}
+         */
+        private void sendInState2Target(int state) {
+            if (outHandler != null) {
+                outHandler.obtainMessage(state, downloadEntity).sendToTarget();
+            }
+        }
+
         private void sendIntent(String action, long location) {
             downloadEntity.save();
             Intent intent = new Intent();

downloadutil/src/main/java/com/arialyy/downloadutil/core/inf/IDownloader.java

@@ -0,0 +1,31 @@
+package com.arialyy.downloadutil.core.inf;
+
+import com.arialyy.downloadutil.core.Task;
+
+/**
+ * Created by lyy on 2016/8/16.
+ * 下载功能接口
+ */
+public interface IDownloader {
+    /**
+     * 开始任务
+     *
+     * @param task {@link Task}
+     */
+    public void startTask(Task task);
+
+    /**
+     * 停止任务
+     *
+     * @param task {@link Task}
+     */
+    public void stopTask(Task task);
+
+    /**
+     * 取消任务
+     *
+     * @param task {@link Task}
+     */
+    public void cancelTask(Task task);
+
+}

downloadutil/src/main/java/com/arialyy/downloadutil/core/inf/IPool.java

@@ -36,4 +36,11 @@ public interface IPool {
      * @return true:移除成功
      */
     public boolean removeTask(Task task);
+
+    /**
+     * 池子大小
+     *
+     * @return 返回缓存池或者当前任务池大小
+     */
+    public int size();
 }

downloadutil/src/main/java/com/arialyy/downloadutil/core/inf/ITask.java

@@ -0,0 +1,34 @@
+package com.arialyy.downloadutil.core.inf;
+
+import com.arialyy.downloadutil.core.Task;
+
+/**
+ * Created by lyy on 2016/8/16.
+ * 任务功能接口
+ */
+public interface ITask {
+
+    /**
+     * 创建一个新的下载任务
+     *
+     * @param downloadUrl  下载链接
+     * @param downloadPath 保存路径
+     */
+    public void createTask(String downloadUrl, String downloadPath);
+
+    /**
+     * 通过下载链接从缓存池或任务池搜索下载任务
+     *
+     * @param downloadUrl 下载链接
+     * @return {@link Task}
+     */
+    public Task searchTask(String downloadUrl);
+
+    /**
+     * 通过下载链接搜索下载任务
+     *
+     * @param downloadUrl 下载链接
+     * @return {@link com.arialyy.downloadutil.entity.DownloadEntity#STATE_FAIL}
+     */
+    public int getTaskState(String downloadUrl);
+}

downloadutil/src/main/java/com/arialyy/downloadutil/core/pool/CachePool.java

@@ -96,4 +96,9 @@ public class CachePool implements IPool {
             }
         }
     }
+
+    @Override
+    public int size() {
+        return mCacheQueue.size();
+    }
 }

downloadutil/src/main/java/com/arialyy/downloadutil/core/pool/ExecutePool.java

@@ -141,4 +141,9 @@ public class ExecutePool implements IPool {
         }
     }
 
+    @Override
+    public int size() {
+        return mExecuteQueue.size();
+    }
+
 }