安卓IntentService实例化错误

Question

可能重复：
Android RuntimeException: Unable to instantiate the service

我正在使用IntentService下载我的数据。 我的IntentService类定义如下：

public class DownloadService extends IntentService{
super("DownloadService");
@Override
    protected void onHandleIntent(Intent intent) {
        //download tasks...
    }
}

AndroidManifest.xml:

<appilcation>
<service android:name="DownloadService"/>
..
..
..
</application>

LauncherActivity.java:

@Override
public void onCreate(Bundle savedInstanceState) {
        ..
        ..
        ..
    Intent dwnldService = new Intent(this, DownloadService.class);
    startService(dwnldService);
}

但我仍然收到这个错误：

08-13 08:57:09.416: E/AndroidRuntime(942): FATAL EXCEPTION: main
08-13 08:57:09.416: E/AndroidRuntime(942): java.lang.RuntimeException: Unable to instantiate service com.app.android.DowloadService: java.lang.InstantiationException: can't instantiate class com.app.android.DowloadService; no empty constructor
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.app.ActivityThread.handleCreateService(ActivityThread.java:2237)
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.app.ActivityThread.access$1600(ActivityThread.java:123)
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1201)
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.os.Looper.loop(Looper.java:137)
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.app.ActivityThread.main(ActivityThread.java:4424)
08-13 08:57:09.416: E/AndroidRuntime(942):  at java.lang.reflect.Method.invokeNative(Native Method)
08-13 08:57:09.416: E/AndroidRuntime(942):  at java.lang.reflect.Method.invoke(Method.java:511)
08-13 08:57:09.416: E/AndroidRuntime(942):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
08-13 08:57:09.416: E/AndroidRuntime(942):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
08-13 08:57:09.416: E/AndroidRuntime(942):  at dalvik.system.NativeStart.main(Native Method)
08-13 08:57:09.416: E/AndroidRuntime(942): Caused by: java.lang.InstantiationException: can't instantiate class com.app.android.DowloadService; no empty constructor
08-13 08:57:09.416: E/AndroidRuntime(942):  at java.lang.Class.newInstanceImpl(Native Method)
08-13 08:57:09.416: E/AndroidRuntime(942):  at java.lang.Class.newInstance(Class.java:1319)
08-13 08:57:09.416: E/AndroidRuntime(942):  at android.app.ActivityThread.handleCreateService(ActivityThread.java:2234)

- Debopam Mitra

---

你的 manifest.xml 文件真的写成了 <appilcation> 吗？还是你在提问时重新输入了这个单词，而不是直接复制粘贴呢？ - Till Helge

Answer 1

public DownloadService() {
    super("Download service");
}

尝试将此添加到您的服务中。

- user468311

---

只是在字符串中添加一个空格！这有什么区别呢？ - Debopam Mitra

我明白了。我的构造函数在参数中包括字符串名称，这是不必要的。而且在调用 super 的参数中添加空格也没有关系。 - Debopam Mitra

好的，将构造函数从public DownloadService(String name) {super(name);}更改为public DownloadService() { super("DownloadService");}。这样做不会改变原意，同时使语言更通俗易懂。 - Isham

Answer 2

在你的类中加入默认构造函数，并调用super("name")。

public DownloadService() {
    super("DownloadService");
 }

- Atul Bhardwaj