0

我正在尝试在 android 的异步任务中进行下载。不幸的是，我收到“unknownHost”错误。对我来说，我似乎拥有适当的权限，但我仍然收到此错误。下面是我的权限、我的错误和功能。对我做错了什么有任何想法吗？

非常感谢你。

克雷格

  11-27 21:51:34.545: D/ImageManager(9381): Error: java.net.UnknownHostException: 

        public void downloadFromUrl(String strUrl, String fileName) { // this is the downloader
        // method
        try {
            File parentDirectory= new File(PATH);
            if (!parentDirectory.exists()) {
                System.err
                        .println("It seems like parent directory does not exist...");
                if (!parentDirectory.mkdirs()) {
                    System.err.println("And we cannot create it...");
                    // we have to return, throw or something else
                }
            }
            URL url = new URL(strUrl);
            File file = new File(PATH + fileName);
            if (!file.exists()) {
                file.createNewFile();
            }

            long startTime = System.currentTimeMillis();
            /* Open a connection to that URL. */
            URLConnection ucon = url.openConnection();

            /*
             * Define InputStreams to read from the URLConnection.
             */
            InputStream is = ucon.getInputStream();
            BufferedInputStream bis = new BufferedInputStream(is);

            /*
             * Read bytes to the Buffer until there is nothing more to read(-1).
             */
            ByteArrayBuffer baf = new ByteArrayBuffer(50);
            int current = 0;
            while ((current = bis.read()) != -1) {
                baf.append((byte) current);
            }

            /* Convert the Bytes read to a String. */
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(baf.toByteArray());
            fos.close();
            Log.d("ImageManager",
                    "download ready in"
                            + ((System.currentTimeMillis() - startTime) / 1000)
                            + " sec");

        } catch (IOException e) {
            Log.d("ImageManager", "Error: " + e);
        }
    }

     <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.craig.musicapp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="15" />

.       <uses-permission android:name="android.permission.INTERNET" />
        <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS" />
        <uses-permission android:name="android.permission.GET_ACCOUNTS" />
        <uses-permission android:name="android.permission.USE_CREDENTIALS" />
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />

    <application
        android:icon="@drawable/jerrygarciahand"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".SearchMusic"
            android:label="@string/search_music"
            android:screenOrientation="portrait" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".ConcertDetailActivity"
            android:screenOrientation="portrait" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".ItemListActivity" />
        </activity>
        <activity
            android:name=".AppInfo"
            android:label="@string/title_item_list" >
        </activity>
    </application>

</manifest>
4

2 回答 2

1

使用此权限..在您的 android 清单文件中

 <uses-permission android:name="android.permission.INTERNET"/>
 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
于 2012-11-28T05:23:31.867 回答
0

所以我是个笨蛋，我想通了。令人惊讶的是，一夜的睡眠可以做什么。

我的网址有“///”而不是“//”。显然，这导致了下载问题。感谢您的所有帮助，希望我下次不会被剥夺睡眠并犯下如此愚蠢的错误:)。

于 2012-11-28T23:27:09.677 回答