Question

遇到BufferedReader操作时，我的应用程序崩溃了。我试图在asyncTask classe中实现代码，因为我读过崩溃是由ui线程引起的，但没有任何改变。

public class URLConnectionReader extends AsyncTask<URL, Void, String> {

    String result = null;

    @Override
    protected String doInBackground(URL... params) {

        String result = null;

        URL url = (params[0]);

        try {

            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(
                            url.openStream()
                    )
            );

        }catch (IOException e){
            e.printStackTrace();
        }

        return result;

    }
}

日志

03-02 13:28:43.215  25186-25186/com.example.jsonreader E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.jsonreader, PID: 25186
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.jsonreader/com.example.jsonreader.MainActivity}: android.os.NetworkOnMainThreadException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: android.os.NetworkOnMainThreadException
            at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1147)
            at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
            at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
            at java.net.InetAddress.getAllByName(InetAddress.java:215)
            at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
            at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232)
            at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124)
            at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272)
            at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
            at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:373)
            at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:323)
            at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:190)
            at java.net.URL.openStream(URL.java:470)
            at com.example.jsonreader.URLConnectionReader.doInBackground(URLConnectionReader.java:38)
            at com.example.jsonreader.MainActivity.onCreate(MainActivity.java:27)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

MainActivity代码

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        try {
            URL address = new URL("http://www.youth-stories.com/api/all.php");
            URLConnectionReader reader = new URLConnectionReader();
            String result = reader.doInBackground(address);
            Toast.makeText(getApplicationContext(),result,Toast.LENGTH_LONG).show();
        }catch (IOException e){
            e.printStackTrace();
        }

Answer 1

我解决了使用.get指令

获取数据的问题

String result = reader.execute(address).get();

BufferedReader运行时崩溃

1 个答案: