Question

我们有一个rest api，我可以在其中获取需要下载并保存到我创建的文件夹中的设备的文件列表。所以我可以将文件保存为一个，不知道这是如何工作的。

从WCF api下载文件。传出流内容类型是来自wcf服务的OCTET_STREAM。

首先我获取/创建目录，然后创建文件：

File mediadir = context.getDir("foo", Context.MODE_PRIVATE);
File file = new File(mediadir, "newfile.png"); // the file name I get from the server, it could be any thing
FileOutputStream out = new FileOutputStream(file); // Stream the contents of the file on the server to the localfile?

我试图下载这样的文件：

File mediadir = context.getDir("tvr", Context.MODE_PRIVATE);

    URL url = new URL(urlString);
    URLConnection conexion = url.openConnection();
    conexion.connect();
    int lenghtOfFile = conexion.getContentLength();
    InputStream is = url.openStream();
    FileOutputStream fos = new FileOutputStream(mediadir+"/video.mp4");
    byte data[] = new byte[1024];
    int count = 0;
    long total = 0;
    int progress = 0;
    while ((count=is.read(data)) != -1){
        total += count;
        int progress_temp = (int)total*100/lenghtOfFile;
        if(progress_temp%10 == 0 && progress != progress_temp){
            progress = progress_temp;
        }
        fos.write(data, 0, count);
    }
    is.close();
    fos.close();

一旦到达.connect（）我得到错误 java.net.SocketException：套接字失败：EACCES（权限被拒绝）

我的清单看起来像这样：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.tvrplayer"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />
    <permission  android:name="android.permission.INTERNET"></permission>
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.tvrplayer.MainActivity"
            android:label="@string/app_name"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>


</manifest>

如何将api文件保存到我创建的本地导演中？

我还写了一个网络应用程序来做这个用户浏览器，但我不知道它是如何在Android上工作。

更新

所以在我将线路转移到权限错误消失后，现在我出现了一个新错误：

02-20 09:51:28.909: E/AndroidRuntime(12594): FATAL EXCEPTION: main
02-20 09:51:28.909: E/AndroidRuntime(12594): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.tvrplayer/com.example.tvrplayer.MainActivity}: android.os.NetworkOnMainThreadException
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.ActivityThread.access$600(ActivityThread.java:128)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.os.Handler.dispatchMessage(Handler.java:99)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.os.Looper.loop(Looper.java:137)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.ActivityThread.main(ActivityThread.java:4514)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at java.lang.reflect.Method.invokeNative(Native Method)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at java.lang.reflect.Method.invoke(Method.java:511)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at dalvik.system.NativeStart.main(Native Method)
02-20 09:51:28.909: E/AndroidRuntime(12594): Caused by: android.os.NetworkOnMainThreadException
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.io.IoBridge.connect(IoBridge.java:112)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at java.net.Socket.connect(Socket.java:842)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpConnection.<init>(HttpConnection.java:77)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:351)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:86)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:308)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpEngine.connect(HttpEngine.java:303)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:282)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:232)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at com.example.tvrplayer.MainActivity.download(MainActivity.java:127)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at com.example.tvrplayer.MainActivity.downLoadMedia(MainActivity.java:118)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at com.example.tvrplayer.MainActivity.onCreate(MainActivity.java:52)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.Activity.performCreate(Activity.java:4465)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053)
02-20 09:51:28.909: E/AndroidRuntime(12594):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)
02-20 09:51:28.909: E/AndroidRuntime(12594):    ... 11 more

Answer 1

File path = new File(getActivity().getFilesDir(), "Your Folder Name");
// if the directory doesn't exist it will create one.
path.mkdirs();
File file = new File(path,"Your File Name");
//if the file doesn't exist it will create one
file.createNewFile();

//for write
FileOutputStream fout = new FileOutputStream(file);
ObjectOutputStream os = new ObjectOutputStream(fout);
os.writeObject("Your Object");
os.flush();
os.close();

//for read
FileInputStream fis = new FileInputStream(file);
ObjectInputStream is = new ObjectInputStream(fis);
Your_Object_Type variable = (Your_Object_Type) is.readObject();
is.close();

在我的情况下，我写了一个类对象

<强>编辑：

这是发生的，因为你在主UI-Thread上使用了互联网请求。修改你的代码：

new Thread( new Runnable() {
    @Override
    public void run() {
       try {
           //............
           // your internet code
           //.............
       } catch (Exception e) {
           // TODO Auto-generated catch block
           Log.e(Tag, e.toString());
       }
     }
   }).start();

已编辑2： 如果你想知道文件是否已保存，请检查：

File file = new File(mediadir, "newfile.png");
if(file.exists()){
   //that means the "newfile.png" is exist in otherword it is saved
}else{
      //that means the "newfile.png" does not exist in otherword it is not saved
}

将文件从API保存到内部文件夹

1 个答案: