Android

Question

我编写了以下代码来向服务器发送请求并从服务器获取响应。但是，当我运行以下代码它不适合我。我基于this link编写了这段代码。

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle bundle) {
        super.onCreate(bundle);
       setContentView(R.layout.activity);
       Button button = (Button)findViewById(R.id.bu1);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    run();
                } catch (Exception e) {
                Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
                }
            }
        });
    }
    private final OkHttpClient client = new OkHttpClient();
    public void run() throws Exception {
        Request request = new Request.Builder()
                .url("http://127.0.0.1:8080/file.php")
                .build();

        Call call = client.newCall(request);
        Response response = call.execute();

        if (!response.isSuccessful()) {
            throw new IOException("Unexpected code " + response);
        }
        String text = response.body().string();
        Toast.makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show();
    }


}

Answer 1

通常错误是因为：

1. 没有互联网许可

2. 在UI线程中

您可以在logcat中确认。

解决方案：

1. 添加清单<uses-permission android:name="android.permission.INTERNET" />

2. 您必须在其他线程中运行或使用异步，如下所示：

   public void run() {
       Request request = new Request.Builder()
               .url("http://127.0.0.1:8080/file.php")
               .build();
   
       Call call = client.newCall(request);
       call.enqueue(new Callback() {
           @Override
           public void onFailure(Request request, IOException e) {
               Log.d("TAG", "Failed: " + e.getMessage());
           }
   
           @Override
           public void onResponse(Response response) throws IOException {
               Log.d("TAG", "OK: " + response.body().string());
           }
       }
   }