尝试发送 Json 对象时应用程序崩溃

Question

我正在尝试使用 okhttp3 将 Json 对象发送到带有 android studio 的服务器，但当我尝试发送 json 时，我的应用程序总是崩溃，当应用程序显示消息已发送时。此外，我需要查看我自己创建的 json 的响应，以确认我的 Json 有效。

public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
OkHttpClient client = new OkHttpClient();
void post(String url, String json) throws IOException {
    RequestBody body = RequestBody.create(JSON, json);
    Request request = new Request.Builder()
            .url(url)
            .post(body)
            .build();
    okhttp3.Call call = client.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(okhttp3.Call call, IOException e) {
            Log.e("TAG", "Failed sending message!");
            Toast.makeText(MainActivity.this,"Failed sending message",Toast.LENGTH_LONG).show();
        }

        @Override
        public void onResponse(okhttp3.Call call, Response response) throws IOException {
            Log.d("TAG", "Message sent successfully!");
            Log.d("TAG", response.body().string());
            Toast.makeText(MainActivity.this,"Message sent successfully!",Toast.LENGTH_LONG).show();

        }
    });
}

我的问题似乎出现在 onResponse 和 onFaliure 函数中。这是我在这些函数中输入的变量的错误：http://prntscr.com/i0dhgi

错误出现在所有 4 个变量上，两个在 onFaliure 中，两个在 onResponse 中

Answer 1

我运行你的代码在我的机器上你需要做的是类似的事情，但确保你的应用程序中有这个 build.gradle compile 'com.android.support:support-annotations:20.0.0' 如果您使用的是旧 android 工作室版本。新版本使用内置注释处理器制作项目

 public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
    OkHttpClient client = new OkHttpClient();
    void post(String url, String json) throws IOException {
        RequestBody body = RequestBody.create(JSON, json);
        Request request = new Request.Builder()
                .url(url)
                .post(body)
                .build();
        okhttp3.Call call = client.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure( @NonNull okhttp3.Call call,@NonNull  IOException e) {
                Log.e("TAG", "Failed sending message!");
//using a toast means updating the UI thread from back thread you have to call Content.runOnUiThread(new Runnable) to sync with the UI thread.
                //Toast.makeText(MainActivity.this,"Failed sending message",Toast.LENGTH_LONG).show();
            }

            @Override
            public void onResponse(@NonNull okhttp3.Call call,@NonNull  Response response) throws IOException {
                Log.d("TAG", "Message sent successfully!");
                Log.d("TAG", response.body().string());
                //Toast.makeText(MainActivity.this,"Message sent successfully!",Toast.LENGTH_LONG).show();

            }
        });
    }

看看我运行带有虚拟值的代码的图片，然后看到 logcat 清楚地说明了线程处理问题！

这是我为您制定的最终解决方案，可以解决问题 注意！您可以将 "MainActivity.this" 替换为您当地的 Context

public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
OkHttpClient client = new OkHttpClient();
void post(String url, String json) throws IOException {
    RequestBody body = RequestBody.create(JSON, json);
    Request request = new Request.Builder()
            .url(url)
            .post(body)
            .build();
    okhttp3.Call call = client.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure( @NonNull okhttp3.Call call,@NonNull  IOException e) {
            MyActivity.this.runOnUiThread(new Runnable() {
        @Override
        public void run() {
           //Handle UI here                        
        // Toast anything you like here//                
        }
    });
        }

        @Override
        public void onResponse(@NonNull okhttp3.Call call,@NonNull  Response response) throws IOException {
              MyActivity.this.runOnUiThread(new Runnable() {
        @Override
        public void run() {
           //Handle UI here                        
          //happy on Response Toast here                
        }
    });
        }

        }
    });
}

尝试发送 Json 对象时应用程序崩溃

App crashes when tries to send Json object

java

android

json

okhttp3