使用场景

在我们实际的开发中, 比如有很多接口都需要传递版本号, 参数的签名的校验信息, token 信息, 请求头信息等等, 那么我们就可以使用 OKHttp 添加拦截器的方式进行公共参数的添加

使用方式

构建 OKHttpClient 可自定义添加拦截器, 贴出重要部分代码

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        OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .addInterceptor(new TokenInterceptor()) // Token 处理的拦截器
                .addInterceptor(new SingInterceptor()) // 签名校验的拦截器处理
                .addInterceptor(new CommonParamsInterceptor()) // 公共参数拦截器
                /*添加拦截器, 设置打印日志的级别*/
                .addInterceptor(new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() {
                    @Override
                    public void log(String message) {
                        LogUtil.e("http-->  ", message);
                    }
                }).setLevel(HttpLoggingInterceptor.Level.BODY))
                .build();

        Retrofit retrofit = new Retrofit.Builder()
                .client(okHttpClient)
                .baseUrl(ApiServer.BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .build();


}

几种添加拦截器的方式

  1. POST 请求添加 RequestBody 添加公共参数, JSON 的 POST 请求

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    @Override
public Response intercept(Chain chain) throws IOException {
    Request request = chain.request();

    if (request.body() instanceof RequestBody) {

        RequestBody body = request.body();// 得到请求体
        Buffer buffer = new Buffer();// 创建缓存
        body.writeTo(buffer);//将请求体内容,写入缓存
        String parameterStr = buffer.readUtf8();// 读取参数字符串

         // 添加公共参数
        JsonObject jsonObject = GsonUtils.fromJson(parameterStr, JsonObject.class);
        jsonObject.addProperty("reqId", ParamsUtil.INSTANCE.getReqId());
        jsonObject.addProperty("stamp", ParamsUtil.INSTANCE.getStamp());
        jsonObject.addProperty("userId", ParamsUtil.INSTANCE.getUserId());
        jsonObject.addProperty("token", token);



        requestBody =RequestBody.create(MediaType.parse("application/json"),GsonUtils.toJson(jsonObject));
        
     }

         // 添加公共参数Header
         Request newRequest = builder
                .url(authorizedUrlBuilder.build().toString())
                .addHeader("Token", token)
                .addHeader("random", random)
                .addHeader("time", time)
                .addHeader("sign", sign)
                .addHeader("Content-Type", "application/json")
                .post(requestBody)
                .build();

   return chain.proceed(newRequest);
}

  2. GET 方式添加 Parameter, 也就是在 URL 的后面拼接参数

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    public Response intercept(Chain chain) throws IOException {
    Request oldRequest = chain.request();

    String path = oldRequest.url().url().toString();
    if (path.contains("user/third-info")) {

        TreeMap<String, String> paramsMap = new TreeMap<>();
        paramsMap.put("id", Constant.Id);
        paramsMap.put("UserType", "3");
        paramsMap.put("sn2", DeviceUtil.INSTANCE.getSn());
        paramsMap.put("userToken", AccountManager.INSTANCE.getToken());
        String paramsJson = GsonUtils.toJson(paramsMap);
        Logger.i(TAG, "paramsJson", paramsJson);

        TreeMap<String, String> sessionMap = new TreeMap<>();
        sessionMap.put("sid", UUID.randomUUID().toString());
        sessionMap.put("time", time.toString());
        String sessionJson = GsonUtils.toJson(sessionMap);

        HttpUrl.Builder builder = oldRequest.url().newBuilder();
        HttpUrl modifiedUrl = builder
                .addQueryParameter("params", paramsJson)
                .addQueryParameter("session", sessionJson)
                .build();

        Set<String> parameterNames = modifiedUrl.queryParameterNames();
        ArrayList<String> nameList = new ArrayList<>();
        nameList.addAll(parameterNames);
        TreeMap<String, String> signMap = new TreeMap<>();
        for (int i = 0; i < nameList.size(); i++) {
            signMap.put(nameList.get(i), modifiedUrl.queryParameterValue(i));
        }

        modifiedUrl = builder.addQueryParameter("sign", sign(signMap)).build();

        Request request = oldRequest.newBuilder().url(modifiedUrl).build();

        return chain.proceed(request);

    }

    return chain.proceed(oldRequest);
}

  3. 添加公共参数header

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    public Response intercept(Chain chain) throws IOException {
        
    Request request = chain.request();
            request=request.newBuilder()
                    .addHeader("userToken", Token)
                    .addHeader("random", "20201019010309")
                    .addHeader("time", "2020-10-19-01-03-09")
                    .build();
               
    return chain.proceed(request);
        
}

  4. From表单添加公共参数

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    public Response intercept(Chain chain) throws IOException {
        
   Request request = chain.request();
              
            if (request.body() instanceof FormBody) {
                // 构造新的请求表单
                FormBody.Builder builder = new FormBody.Builder();
 
                FormBody body = (FormBody) request.body();
                // 将原来的参数放入新的表单中
                for (int i = 0; i < body.size(); i++) {
                    builder.add(body.encodedName(i), body.encodedValue(i));
                }
                // 添加公共参数
                builder.add("sig", ParamsUtil.INSTANCE.getSig());
                request = request.newBuilder().post(builder.build()).build();//构造新的请求体
            }
 
            return chain.proceed(request);
    }
        
}