5--安卓网络编程之OKHttp3的使用

implementation 'com.squareup.okhttp3:okhttp:3.11.0'

一、GET请求

注：回调的Callback在子线程执行，不能更新UI

private void doGet() {    //1.获取OkHttpClient对象
    OkHttpClient okHttpClient = new OkHttpClient();    //2.获取Request对象
    Request request = new Request.Builder().get().url("http://www.baidu.com").build();    //3.将Request封装为Call对象
    Call call = okHttpClient.newCall(request);    //4.执行Call
    call.enqueue(new Callback() {        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "onFailure: " + e);
        }        @Override
        public void onResponse(Call call, Response response) throws IOException {
            Log.e(TAG, "onResponse: " + response.body().string());
        }
    });
}

将访问百度的服务器，服务器返回的内容体便是百度首页的html

百度首页html.png

二、POST请求

private void doPost() {    //1.获取OkHttpClient对象
    OkHttpClient okHttpClient = new OkHttpClient();    //2.构造RequestBody
    FormBody body = new FormBody.Builder().add("id", "26").build();
    Request request = new Request.Builder().url(Cons.BASE_URL+"swords/postFind").post(body).build();    //3.将Request封装为Call对象
    Call call = okHttpClient.newCall(request);    //4.执行Call
    call.enqueue(new Callback() {        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "onFailure: " + e);
        }        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String result = response.body().string();
            Log.e(TAG, "onResponse: " + result);
            runOnUiThread(() -> ToastUtil.showAtOnce(MainActivity.this, result));
        }
    });
}

post请求.png

三、POST请求的请求体中添加文本

    private void doPostStr() {        //1.获取OkHttpClient对象
        OkHttpClient okHttpClient = new OkHttpClient();        //2.构造RequestBody
        RequestBody body = RequestBody.create(MediaType.parse("text/plain;chaset=utf-8"),                "轻轻的我走了，\n" +                "正如我轻轻的来；\n" +                "我轻轻的招手，\n" +                "作别西天的云彩。\n" +                "\n" +                "那河畔的金柳，\n" +                "是夕阳中的新娘；\n" +                "波光里的艳影，\n" +                "在我的心头荡漾。\n);
        Request request = new Request.Builder().url(Cons.BASE_URL+"PostString").post(body).build();
        //3.将Request封装为Call对象
        Call call = okHttpClient.newCall(request);
        //4.执行Call
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                Log.e(TAG, "onFailure: " + e);
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String result = response.body().string();
                Log.e(TAG, "onResponse: " + result);

                runOnUiThread(() -> ToastUtil.showAtOnce(MainActivity.this, result));

            }
        });
    }

post请求body中加入文本.png

四、通过流传输文件

private void doPostFile() {
    File file = new File(Environment.getExternalStorageDirectory(), "DCIM/Camera/iv_500x400.png");    //1.获取OkHttpClient对象
    OkHttpClient okHttpClient = new OkHttpClient();    //2.构造Request--任意二进制流：application/octet-stream
    Request request = new Request.Builder()
            .url(Cons.BASE_URL + "PostFile")
            .post(RequestBody.create(MediaType.parse("application/octet-stream"), file)).build();    //3.将Request封装为Call对象
    Call call = okHttpClient.newCall(request);    //4.执行Call
    call.enqueue(new Callback() {        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "onFailure: " + e);
        }        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String result = response.body().string();
            Log.e(TAG, "onResponse: " + result);
            runOnUiThread(() -> ToastUtil.showAtOnce(MainActivity.this, result));
        }
    });
}

上传文件.png

五、通过模拟表单上传文件：MultipartBody

/**
 * 模拟表单上传文件：通过MultipartBody
 */private void doUpload() {
    File file = new File(Environment.getExternalStorageDirectory(), "DCIM/Camera/iv_500x400.png");
    RequestBody fileBody = RequestBody.create(MediaType.parse("application/octet-stream"), file);    //1.获取OkHttpClient对象
    OkHttpClient okHttpClient = new OkHttpClient();    //2.获取Request对象
    RequestBody requestBody = new MultipartBody.Builder()
            .setType(MultipartBody.FORM)
            .addFormDataPart("file", "test.jpg", fileBody)
            .build();
    Request request = new Request.Builder()
            .url(Cons.BASE_URL + "upload")
            .post(requestBody).build();    //3.将Request封装为Call对象
    Call call = okHttpClient.newCall(request);    //4.执行Call
    call.enqueue(new Callback() {        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "onFailure: " + e);
        }        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String result = response.body().string();
            Log.e(TAG, "onResponse: " + result);
            runOnUiThread(() -> ToastUtil.showAtOnce(MainActivity.this, result));
        }
    });
}

六、下载文件：

private void doDownload() {    //1.获取OkHttpClient对象
    OkHttpClient okHttpClient = new OkHttpClient();    //2.获取Request对象
    Request request = new Request.Builder().get().url(Cons.BASE_URL + "imgs/test.jpg").build();    //3.将Request封装为Call对象
    Call call = okHttpClient.newCall(request);    //4.执行Call
    call.enqueue(new Callback() {        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "onFailure: " + e);
        }        @Override
        public void onResponse(Call call, Response response) throws IOException {
            File file = new File(Environment.getExternalStorageDirectory(), "download.jpg");
            InputStream is = response.body().byteStream();
            FileOutputStream fos = new FileOutputStream(file);            byte[] buf = new byte[102];            int len = 0;            while ((len = is.read(buf)) != -1) {
                fos.write(buf, 0, len);
            }
            fos.close();
            is.close();
        }
    });
}

下载本地.png

七、在安卓端显示图片：

有了流，一切都好办：response.body().byteStream()  
关于Bitmap的预处理等操，这里就不多说了，有兴趣的可见1-MI-Android多媒体之Bitmap：

private void showImg() {    //1.获取OkHttpClient对象
    OkHttpClient okHttpClient = new OkHttpClient();    //2.获取Request对象
    Request request = new Request.Builder().get().url(Cons.BASE_URL + "imgs/test.jpg").build();    //3.将Request封装为Call对象
    Call call = okHttpClient.newCall(request);    //4.执行Call
    call.enqueue(new Callback() {        @Override
        public void onFailure(Call call, IOException e) {
            Log.e(TAG, "onFailure: " + e);
        }        @Override
        public void onResponse(Call call, Response response) throws IOException {
            InputStream is = response.body().byteStream();
            Bitmap bitmap = BitmapFactory.decodeStream(is);
            runOnUiThread(()->{
                mIdIvShow.setImageBitmap(bitmap);
            });
        }
    });
}

安卓显示.png

作者：张风捷特烈
链接：https://www.jianshu.com/p/7c286f65f7d1