使用OKHttpClient访问网络

使用OKHttpClient前要引入依赖：

在build.gradle(Moduel :app)中添加

implementation 'com.squareup.okhttp3:okhttp:3.14.1'
implementation 'com.squareup.okhttp3:logging-interceptor:3.14.1'
implementation 'com.squareup.okio:okio:1.6.0'

1. GET（同步或异步）

        //创建OKHttpClientOkHttpClient okHttpClient=new OkHttpClient.Builder().connectTimeout(50, TimeUnit.SECONDS).readTimeout(50,TimeUnit.SECONDS).writeTimeout(50,TimeUnit.SECONDS).build();//创建请求Request request=new Request.Builder().url( new URL("http://www.baidu.com") ).get() //GET方式用.build();//创建CallCall call=okHttpClient.newCall(request);//同步Response response=call.execute();Boolean bool=response.isSuccessful();//判断是否连接成功ResponseBody responseBody=response.body();//获取ResponseBody//异步Response response=call.enqueue(new Callback() {public void onFailure(Call call, IOException e) {//连接失败调用}public void onResponse(Call call, Response response) throws IOException {//连接成功调用ResponseBody responseBody=response.body();//获取ResponseBody}});

2. POST（同步或异步）

        //创建OKHttpClientOkHttpClient okHttpClient=new OkHttpClient.Builder().connectTimeout(50, TimeUnit.SECONDS).readTimeout(50,TimeUnit.SECONDS).writeTimeout(50,TimeUnit.SECONDS).build();//创建RequestBody或FormBody或MultipartBodyRequestBody requestBody = RequestBody.create( MediaType.parse("application/x-www-form-urlencode;charset=utf-8"), "username="+ URLEncoder.encode("myUserName")+"&password="+URLEncoder.encode("123456"));FormBody formBody = new FormBody.Builder().add("name","myUserName").add("sex","男").add("age","20").build();MultipartBody multipartBody=new MultipartBody.Builder().addFormDataPart("name","myUserName").addFormDataPart("sex","女").addFormDataPart("File",file.toString(),requestBody).build();//创建请求Request request=new Request.Builder().url( new URL("http://www.baidu.com") ).post(requestBody) //POST方式用，参数为RequestBody或FormBody或MultipartBody.build();//创建CallCall call=okHttpClient.newCall(request);//同步Response response=call.execute();Boolean bool=response.isSuccessful();//判断是否连接成功ResponseBody responseBody=response.body();//获取ResponseBody//异步Response response=call.enqueue(new Callback() {public void onFailure(Call call, IOException e) {//连接失败调用}public void onResponse(Call call, Response response) throws IOException {//连接成功调用ResponseBody responseBody=response.body();//获取ResponseBody}});

RequestBody.create()中的参数 MediaType的 .pase()方法的参数决定了网络文件的类型及编码方式

MultipartBody可添加多种类型数据

3. Response及ResponseBody的使用

    //获取返回类型String contentType = response.header("Content-Type");//判断返回值类型if(contentType!=null&&contentType.equals("application/octet-stream")){//返回类型为 流ResponseBody responseBody = response.body();InputStream inputStream=responseBody.byteStream();}else if(contentType!=null&&contentType.equals("application/json")){//返回类型为 jsonResponseBody responseBody = response.body();String json=responseBody.toString();}

4. 网络文件类型

text/html   HTML格式
text/pain   纯文本格式
image/jpeg  jpg图片格式
application/json   JSON数据格式
application/octet-stream   二进制流数据
application/x-www-form-urlencode   form表单encType属性的默认格式，表单数据以Key/value的形式发送到服务器端
multipart/form-data   表单上传文件的格式