diff --git "a/design_document/\345\244\232\347\272\277\347\250\213\345\220\216\345\217\260\344\270\213\350\275\275.md" "b/design_document/\345\244\232\347\272\277\347\250\213\345\220\216\345\217\260\344\270\213\350\275\275.md"
index 2a1c4d299bf46bfa6f09ee0f0942ae5c68bc0949..a5fd9eb627c10873d175fc7de2809114fc9ce732 100644
--- "a/design_document/\345\244\232\347\272\277\347\250\213\345\220\216\345\217\260\344\270\213\350\275\275.md"
+++ "b/design_document/\345\244\232\347\272\277\347\250\213\345\220\216\345\217\260\344\270\213\350\275\275.md"
@@ -1,20 +1,18 @@
 # 多线程后台下载
 
 - 设计的主要类
-  - package com.openthos.appstore.utils.sql.SQLiteHelper
-  - package com.openthos.appstore.utils.sql.DownloadKeeper
-  - package com.openthos.appstore.utils.download.DownLoader
-  - package com.openthos.appstore.utils.download.DownLoadListener
-  - package com.openthos.appstore.utils.download.DownLoadManager
-  - package com.openthos.appstore.utils.download.DownLoadService
-  - package com.openthos.appstore.bean.SQLDownLoadInfo
+  - package com.openthos.appstore.utils.SQLiteHelper
+  - package com.openthos.appstore.utils.DownloadKeeper
+  - package com.openthos.appstore.download.Downloader
+  - package com.openthos.appstore.download.DownloadListener
+  - package com.openthos.appstore.download.DownloadManager
+  - package com.openthos.appstore.download.DownloadService
+  - package com.openthos.appstore.bean.DownloadInfo
   - package com.openthos.appstore.bean.TaskInfo
   
 - 主要实现
   - 首先是两个记录数据的实体类SQLDownLoadInfo.java和TaskInfo.java,这个就不附代码了
   - 在者是数据库表和数据库操作类，数据库表的内容如下：
-
-
     ***
         @Override
         public void onCreate(SQLiteDatabase db) {
@@ -32,35 +30,24 @@
                     + "iconUrl VARCHAR "
                     + ")";
             db.execSQL(downloadsql);
-    
-            String appinstall = "CREATE TABLE IF NOT EXISTS " + APP_INSTALL + " ("
-                    + "id INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL , "
-                    + "name VARCHAR, "
-                    + "packageName VARCHAR, "
-                    + "versionName VARCHAR, "
-                    + "versionCode VARCHAR "
-                    + ")";
-            db.execSQL(appinstall);
         }
     ***
-    
   - 下载监听
     ***
-        public interface DownLoadListener {
-        
-            public void onStart(SQLDownLoadInfo sqlDownLoadInfo);
-        
-            public void onProgress(SQLDownLoadInfo sqlDownLoadInfo, boolean isSupportBreakpoint);
-        
-            public void onStop(SQLDownLoadInfo sqlDownLoadInfo, boolean isSupportBreakpoint);
-        
-            public void onError(SQLDownLoadInfo sqlDownLoadInfo, String error);
-        
-            public void onSuccess(SQLDownLoadInfo sqlDownLoadInfo);
+        public interface DownloadListener {
+
+            public void onStart(DownloadInfo downloadInfo);
+
+            public void onProgress(DownloadInfo downloadInfo, boolean isSupportF);
+
+            public void onStop(DownloadInfo downloadInfo, boolean isSupportFTP);
+
+            public void onError(DownloadInfo downloadInfo, String error);
+
+            public void onSuccess(DownloadInfo downloadInfo);
         }
 
-    ***
-    
+    *** 
   - 后台下载
   ***
        public class AppStoreBinder extends Binder {
@@ -77,12 +64,7 @@
             //添加任务
             public void addTask(String task, String url, String fileName,
                                 String packageName, String iconUrl) {
-                downLoadManager.addTask(task, url, fileName, packageName, iconUrl);
-            }
-    
-            //添加任务
-            public void addTask(String task, String url, String fileName, String packageName) {
-                downLoadManager.addTask(task, url, fileName, packageName);
+                mDownloadManager.addTask(task, url, fileName, packageName, iconUrl);
             }
     
             //开始所有任务
@@ -164,28 +146,19 @@
         }
         
         //添加下载任务
-        public int addTask(String taskID, String url, String fileName,
-                           String packageName, String iconUrl) {
-            return addTask(taskID, url, fileName, packageName, null, iconUrl);
-        }
-            
-        //添加下载任务
-        public int addTask(String taskID, String url, String fileName, String packageName) {
-            return addTask(taskID, url, fileName, packageName, null);
-        }
-       
-        //添加下载任务
-        public int addTask(String taskID, String url,
-                           String fileName, String packageName, String filepath, String iconUrl) {
+        public void addTask(String taskID, String url,
+                            String fileName, String packageName, String iconUrl) {
             if (taskID == null) {
                 taskID = fileName;
             }
-            int state = getAttachmentState(taskID, fileName, filepath);
-            if (state != ADD_TASK) {
-                FileHelper.deleteFile(fileName);
+    
+            DownloadInfo downloadInfoByPkgName = mSQLOperator.getDownloadInfoByPkgName(packageName);
+            if (downloadInfoByPkgName != null) {
+                mSQLOperator.deleteDownloadInfo(mUserID, taskID);
+                deleteTask(taskID);
             }
     
-            SQLDownLoadInfo downloadinfo = new SQLDownLoadInfo();
+            DownloadInfo downloadinfo = new DownloadInfo();
             downloadinfo.setUserID(mUserID);
             downloadinfo.setDownloadSize(0);
             downloadinfo.setFileSize(0);
@@ -194,24 +167,19 @@
             downloadinfo.setUrl(url);
             downloadinfo.setPackageName(packageName);
             downloadinfo.setIconUrl(iconUrl);
-            if (filepath == null) {
-                downloadinfo.setFilePath(FileHelper.getDefaultFile(fileName));
-            } else {
-                downloadinfo.setFilePath(filepath);
-            }
-            DownLoader taskDownLoader = new DownLoader(
-                    mContext, downloadinfo, mPool, mUserID, mIsSupportBreakpoint, true);
-            taskDownLoader.setDownLodSuccesslistener(mDownloadsuccessListener);
-            if (mIsSupportBreakpoint) {
-                taskDownLoader.setSupportBreakpoint(true);
+            downloadinfo.setFilePath(FileHelper.getDownloadUrlPath(url));
+    
+            Downloader taskDownloader = new Downloader(
+                    mContext, downloadinfo, mPool, mUserID, mIsSupportFTP, true);
+            if (mIsSupportFTP) {
+                taskDownloader.setSupportFTP(true);
             } else {
-                taskDownLoader.setSupportBreakpoint(false);
+                taskDownloader.setSupportFTP(false);
             }
-            taskDownLoader.start();
-            mTaskList.add(0, taskDownLoader);
-            return 1;
+            taskDownloader.start();
+            mTaskList.add(0, taskDownloader);
         }
-        
+
         //删除下载任务
         public void deleteTask(String taskID) {
             for (int i = 0; i < mTaskList.size(); i++) {