OkHttp 使用 | Atu's Blog

github 地址: https://github.com/square/okhttp

1.OkHttp 特点

OkHttp 是一个高效的 Http 客户端，特点如下：

支持 HTTP/HTTP2/SPDY
. socket 自动选择最好的路线，并支持自动重连
. 拥有自动维护的 socket 连接池，减少握手次数
. 拥有队列线程池，轻松写并发
. 拥有 Interceptors 处理请求与响应（如：透明 GZIP 压缩、LOGGING）
基于 Headers 的缓存策略

2.GET 使用方法

同步请求:

OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
     .url(url)
     .build();//http 请求
   Response response = client.newCall(request).execute(); //请求的响应
   ResponseBody responseBody = response.body();//响应体
   //responseBody.body().string();//字符串表示、占内存
   //responseBody.body().bytes();//字节数组表示、占内存
   //responseBody.body().charStream();//字符流表示 （超过 1M）
   //responseBody.body().byteStream();//字节流表示 （超过 1M）

异步请求

OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
     .url(url)
     .build();//http 请求
  Response response = client.newCall(request).enqueue(new Callback() {
           @Override
           public void onFailure(Call call, IOException e) {
           }
           @Override
           public void onResponse(Call call, Response response) throws IOException {
           }
       }); //返回的响应

###3. POST 使用方法

MediaType 类型

/**
   * "application/x-www-form-urlencoded"，是默认的MIME内容编码类型，一般可以用于所有的情况，但是在传输比较大的二进制或者文本数据时效率低。
这时候应该使用"multipart/form-data"。如上传文件或者二进制数据和非ASCII数据。
   */
  public static final MediaType MEDIA_TYPE_NORAML_FORM = MediaType.parse("application/x-www-form-urlencoded;charset=utf-8");
  //既可以提交普通键值对，也可以提交(多个)文件键值对。
  public static final MediaType MEDIA_TYPE_MULTIPART_FORM = MediaType.parse("multipart/form-data;charset=utf-8");
  //只能提交二进制，而且只能提交一个二进制，如果提交文件的话，只能提交一个文件,后台接收参数只能有一个，而且只能是流（或者字节数组）
  public static final MediaType MEDIA_TYPE_STREAM = MediaType.parse("application/octet-stream");
  public static final MediaType MEDIA_TYPE_TEXT = MediaType.parse("text/plain;charset=utf-8");
  public static final MediaType MEDIA_TYPE_JSON = MediaType.parse("application/json;charset=utf-8");

Post 提交 String

OkHttpClient client = new OkHttpClient();
        Request request =new Request.Builder().url(url)
                .post(RequestBody.create(MEDIA_TYPE_TEXT,"提交内容"))//指定提交方式 Post
                .build();
        try {
            Response response = client.newCall(request).execute();
        } catch (IOException e) {
            e.printStackTrace();
        }

FormBody 提交表单

OkHttpClient client = new OkHttpClient();
   RequestBody formBody = new FormBody.Builder()
           .add("key","value")//键值对使用
           .build();
   Request request =new Request.Builder()
           .url(WEATHER_URL)
           .post(formBody)
           .build();
   try {
       Response response = client.newCall(request).execute();
   } catch (IOException e) {
       e.printStackTrace();
   }

Post 提交流

OkHttpClient client = new OkHttpClient();
      File file = new File("文件路径");
      final FileInputStream fileInputStream=new FileInputStream(file);
      RequestBody requestBody = new RequestBody() {
          @Nullable
          @Override
          public MediaType contentType() {
              return MEDIA_TYPE_TEXT;//指定文件类型
          }
          @Override
          public void writeTo(BufferedSink sink) throws IOException {
              OutputStream outputStream = sink.outputStream();//获取 outputStream 、sink也可以直接写入
              int length;
              byte[] buffer = new byte[1024];
              while((length = fileInputStream.read(buffer)) != -1){
                  outputStream.write(buffer,0,length);//写入流
              }
          }
      };
      Request request =new Request.Builder()
              .url(url)
              .post(requestBody)
              .build();
      try {
          Response response = client.newCall(request).execute();
      } catch (IOException e) {
          e.printStackTrace();
      }

Post 提交文件

OkHttpClient client = new OkHttpClient();
     File file = new File("文件路径");
     Request request =new Request.Builder()
             .url(url)
             .post(RequestBody.create(MEDIA_TYPE_TEXT,file))//提交文件
             .build();
     try {
         Response response = client.newCall(request).execute();
     } catch (IOException e) {
         e.printStackTrace();
     }

MultipartBody 提交分块请求(多类型字段)

OkHttpClient client = new OkHttpClient();
      RequestBody requestBody = new MultipartBody.Builder()
              .setType(MultipartBody.FORM)
              .addFormDataPart("title","Square Logo")//string 字段
              .addFormDataPart("image","logo-square.png",RequestBody.create(MediaType.parse("image/png"),new File("website/static/logo-square.png")))//图片
              .build();//构建
      Request request =new Request.Builder()
              .addHeader("Authorization","Client-ID " + "...")//认证头
              .url(WEATHER_URL)
              .post(requestBody)//提交文件
              .build();
      try {
          Response response = client.newCall(request).execute();
      } catch (IOException e) {
          e.printStackTrace();
      }

Post 提交 json

OkHttpClient client = new OkHttpClient();
   Request request =new Request.Builder().url(url)
           .post(RequestBody.create(MEDIA_TYPE_JSON,"提交内容"))//指定提交方式 Post
           .build();
   try {
       Response response = client.newCall(request).execute();
   } catch (IOException e) {
       e.printStackTrace();
   }

  
### 4.OkHttp 设置
1.设置超时、缓存

File sdcache = getExternalCacheDir();//缓存路径
int cacheSize = 10 1024 1024;//缓存时间
OkHttpClient client = new OkHttpClient.Builder()

.connectTimeout(10, TimeUnit.SECONDS)//设置超时 连接
.readTimeout(10,TimeUnit.SECONDS)//设置超时 读入
.writeTimeout(10,TimeUnit.SECONDS)//设置超时 写入
.cache(new Cache(sdcache.getAbsoluteFile(),cacheSize))//设置缓存
.build();

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2.取消请求

call.cancel();//取消请求 call 单独提出来
client.dispatcher().cancelAll();//取消所有请求

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