retrofit2.0使用拦截器Interceptor统一打印请求与响应的json

开始之前先甩上retrofit和okhttp的github链接：
https://github.com/square/retrofit
https://github.com/square/okhttp

大家都知道一款APP里请求很多，如果能统一打印请求与响应的json自然十分方便。retrofit作为知名网络请求框架，提供了拦截器Interceptor，官方对拦截器的定义：

Interceptors area powerful mechanism that can monitor, rewrite, and retry calls.拦截器可以用来转换，重试，重写请求的机制。

我们就不转换重写了，只是打印一下就好。

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先添加依赖：

compile 'com.squareup.retrofit2:retrofit:2.0.0'compile 'com.squareup.retrofit2:adapter-rxjava:2.0.0'compile 'com.squareup.retrofit2:converter-gson:2.0.0'compile 'com.google.code.gson:gson:2.6.1'compile 'com.squareup.okhttp3:okhttp:3.1.2'compile 'com.squareup.okhttp3:logging-interceptor:3.1.2'compile 'com.orhanobut:logger:2.1.0' // 打印日志

其实okhttp已经为我们提供了一个Interceptor的实现类：HttpLoggingInterceptor。只要稍作设置就可以：

    HttpLoggingInterceptor logInterceptor = new HttpLoggingInterceptor();    if(BuildConfig.DEBUG){        //显示日志        logInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);    }else {        logInterceptor.setLevel(HttpLoggingInterceptor.Level.NONE);    }    okHttpClient.addInterceptor(logInterceptor);

这样请求和响应的日志就都会打印出来啦~
但是有些手机比如联想可能会默认屏蔽这样的日志(之前我就是用联想手机测试，还以为这方法不管用)，可以在手机上设置使其显示。不同的机器设置方式不一样，搜索一下都有~

如果不想设置或者想自己定义一下打印的格式，可以像下面这样写：

public class LoggingInterceptor implements Interceptor {  private final Charset UTF8 = Charset.forName("UTF-8");  @Override  public Response intercept(Chain chain) throws IOException {    Request request = chain.request();    RequestBody requestBody = request.body();    String body = null;    if(requestBody != null) {        Buffer buffer = new Buffer();        requestBody.writeTo(buffer);        Charset charset = UTF8;        MediaType contentType = requestBody.contentType();        if (contentType != null) {            charset = contentType.charset(UTF8);        }        body = buffer.readString(charset);    }    Logger.e("发送请求\nmethod：%s\nurl：%s\nheaders: %sbody：%s",            request.method(), request.url(), request.headers(), body);    long startNs = System.nanoTime();    Response response = chain.proceed(request);    long tookMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNs);    ResponseBody responseBody = response.body();    String rBody = null;    if(HttpEngine.hasBody(response)) {        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) {                e.printStackTrace();            }        }        rBody = buffer.clone().readString(charset);    }    Logger.e("收到响应 %s%s %ss\n请求url：%s\n请求body：%s\n响应body：%s",            response.code(), response.message(), tookMs, response.request().url(), body, rBody);    return response;  }}

在OkHttpClient中添加拦截：

    OkHttpClient.Builder client = new OkHttpClient.Builder()            .connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS)//设置超时时间            .retryOnConnectionFailure(true);    //添加拦截    if (BuildConfig.DEBUG) {        client.addInterceptor(new LoggingInterceptor())    }    Retrofit retrofit = new Retrofit.Builder()            .baseUrl(API)            .client(client.build())            .addConverterFactory(GsonConverterFactory.create())            .addCallAdapterFactory(RxJavaCallAdapterFactory.create())            .build();

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看一些博客里的文章，好像直接通过下面的代码就可以拦截响应，但是我这么写了并没有看到有日志输出...除非像上面那样重写HttpLoggingInterceptor.Logger的log()方法，难道是其实打印了我没找到？......有知道的小伙伴告知一下
HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient httpClient = new OkHttpClient.Builder().addInterceptor(logging).build();
———————————————-2017-07-25———————————————-
还真是其实打印了我没找到，见开头。

参考：
Android Retrofit2.0查看log和JSON字符串（HttpLoggingInterceptor）
OkHttp使用（四）拦截器
https://github.com/jaydenxiao2016/AndroidFire
这里还有一篇：
HttpLoggingInterceptor拦截的log信息为unicode字符时的解决办法

http://www.jianshu.com/p/dfaf8e51f720