Custom error Check Interceptor

PostCheckInterceptor

package net.stylemilk.app.repository.api;

import android.util.Log;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.stream.MalformedJsonException;

import java.io.EOFException;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;

import okhttp3.Headers;
import okhttp3.Interceptor;
import okhttp3.MediaType;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.ResponseBody;
import okhttp3.internal.http.HttpHeaders;
import okio.Buffer;
import okio.BufferedSource;

/**
 * Created by lyc on 2016-12-14.
 */

public class PostCheckInterceptor implements Interceptor {

	public static final String TAG = PostCheckInterceptor.class.getSimpleName();
	private static final Charset UTF8 = Charset.forName("UTF-8");



	@Override public Response intercept(Chain chain) throws IOException {

		Request request = chain.request();
		Response response;
		try {
			response = chain.proceed(request);
		} catch (Exception e) {
			throw e;
		}

		ResponseBody responseBody = response.body();
		long contentLength = responseBody.contentLength();

		if (HttpHeaders.hasBody(response) && !bodyEncoded(response.headers())) {
			BufferedSource source = responseBody.source();
			source.request(Long.MAX_VALUE); // Buffer the entire body.
			Buffer buffer = source.buffer();
			Charset charset = UTF8;
			MediaType contentType = responseBody.contentType();
			if (contentType != null) {
				try {
					charset = contentType.charset(UTF8);
				} catch (UnsupportedCharsetException e) {
					return response;
				}
			}

			if (!isPlaintext(buffer)) {
				return response;
			}

			if (contentLength != 0) {
				Log.d(TAG, buffer.clone().readString(charset));
				JsonParser jsonParser = new JsonParser();
				try {
					JsonObject jsonObject = (JsonObject) jsonParser.parse(buffer.clone().readString(charset));
					if(jsonObject.get("result") != null) {
						if (!jsonObject.get("result").getAsBoolean()) {
							if(jsonObject.get("msg") != null) {
								throw new IOException(jsonObject.get("msg").getAsString());
							}else{
								return response;
							}
						}
					}
				} catch (ClassCastException cce){
					Log.d(TAG, "ClassCastException");
				} catch (MalformedJsonException e) {
					Log.d(TAG, "MalformedJsonException");
				} catch (NullPointerException e) {
					Log.d(TAG, "NullPointerException");
				}
			}
		}

		return response;
	}

	static boolean isPlaintext(Buffer buffer) {
		try {
			Buffer prefix = new Buffer();
			long byteCount = buffer.size() < 64 ? buffer.size() : 64;
			buffer.copyTo(prefix, 0, byteCount);
			for (int i = 0; i < 16; i++) {
				if (prefix.exhausted()) {
					break;
				}
				int codePoint = prefix.readUtf8CodePoint();
				if (Character.isISOControl(codePoint) && !Character.isWhitespace(codePoint)) {
					return false;
				}
			}
			return true;
		} catch (EOFException e) {
			return false; // Truncated UTF-8 sequence.
		}
	}

	private boolean bodyEncoded(Headers headers) {
		String contentEncoding = headers.get("Content-Encoding");
		return contentEncoding != null && !contentEncoding.equalsIgnoreCase("identity");
	}
}