我的改装代码出错了。我想我错过了一些东西或者没有理解某些东西（考虑到我今天已经开始编码并且在一周前就在android中进行了编码。）这是我的完整错误（在运行时的android studio中）：
08-04 09:24:11.230 16349-16349/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.apurva.myapplication, PID: 16349
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.apurva.myapplication/com.example.apurva.myapplication.MainActivity}: retrofit.RetrofitError
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: retrofit.RetrofitError
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:400)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:240)
at $Proxy0.me(Native Method)
at com.example.apurva.myapplication.MainActivity.onCreate(MainActivity.java:19)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
at java.net.InetAddress.getAllByName(InetAddress.java:214)
at com.squareup.okhttp.internal.Network$1.resolveInetAddresses(Network.java:29)
at com.squareup.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:266)
at com.squareup.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:240)
at com.squareup.okhttp.internal.http.RouteSelector.nextUnconnected(RouteSelector.java:156)
at com.squareup.okhttp.internal.http.RouteSelector.next(RouteSelector.java:130)
at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:312)
at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:235)
at com.squareup.okhttp.Call.getResponse(Call.java:262)
at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:219)
at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:192)
at com.squareup.okhttp.Call.execute(Call.java:79)
at retrofit.client.OkClient.execute(OkClient.java:53)
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:326)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:240)
at $Proxy0.me(Native Method)
at com.example.apurva.myapplication.MainActivity.onCreate(MainActivity.java:19)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
我的android项目中的文件：
MainActivity.java
package com.example.apurva.myapplication;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
UserService userService;
String token = "A";
userService = ServiceGenerator.createService(UserService.class, UserService.BASE_URL, token);
User user = userService.me();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
ServiceGenerator.java
package com.example.apurva.myapplication;
import com.squareup.okhttp.OkHttpClient;
import retrofit.RequestInterceptor;
import retrofit.RestAdapter;
import retrofit.client.OkClient;
/**
* Created by apurva on 4/8/15.
*/
public class ServiceGenerator {
private ServiceGenerator() {
}
public static <S> S createService(Class<S> serviceClass, String baseUrl, final String token) {
RestAdapter.Builder builder = new RestAdapter.Builder()
.setEndpoint(baseUrl)
.setClient(new OkClient(new OkHttpClient()));
if (token != null) {
builder.setRequestInterceptor(new RequestInterceptor() {
@Override
public void intercept(RequestFacade request) {
request.addHeader("Authorization", token);
}
});
}
RestAdapter adapter = builder.build();
return adapter.create(serviceClass);
}
}
UserService.java
package com.example.apurva.myapplication;
import com.squareup.okhttp.OkHttpClient;
import retrofit.RequestInterceptor;
import retrofit.RestAdapter;
import retrofit.client.OkClient;
import retrofit.http.POST;
/**
* Created by apurva on 4/8/15.
*/
public interface UserService {
public static final String BASE_URL = "http://localhost:8000/auth";
@POST("/convert-token")
User me();
}
非常感谢您的帮助，错误是运行时，我在构建或运行应用程序时没有任何问题。提前致谢
答案 0 :(得分：1)
您获得的例外不言自明：NetworkOnMainThreadException。即您的代码在主线程中进行网络调用。例外情况也说明了它的确切位置：在MainActivity的19行代码中：
User user = userService.me();
如果您阅读Retrofit documentation，您必须知道当您调用服务方法时Retrofit将同步，即在同一个线程，并且在您的情况下，这是主线程。
要异步拨打电话，您需要传递Callback：
@POST("/convert-token")
void me(Callback<User> cb);
PS我强烈建议您首先阅读Java，因为基本上您没有认识到错误的位置，这是软件开发的基本技能。