Android okhttp使用

概要
OKHttpはandroidでネットワークを要求するためによく使われるネットワーク要求フレームワークです.
OKHttpを除いて、Androidの主流のネットリクエストフレームワークは以下の通りです.

Android-Async-Http

Volley

OkHttp

Retrofit

依存ライブラリのインポート
在build.gradleは次の依存性を追加します.

implementation 'com.squareup.okhttp3:okhttp:4.9.0'

ネットワーク権限の追加

getリクエスト

/**
 *    Get  
 *
 * @param url url
 * @return
 */
public String syncGet(String url) {
    String result = "";
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    Request request = new Request.Builder()
            .url(url)
            .get()
            .build();
    final Call call = okHttpClient.newCall(request);
        //4.          ,        
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    //    ,  Response,   IO  
                    Response response = call.execute();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();



    return result;
}

/**
 *    Get  
 *
 * @param url url
 * @return
 */
public void nonSyncGet(String url, Callback responseCallback) {
    String result = null;
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    //2.  Request  
    Request request = new Request.Builder()
            .url(url)
            .get()
            .build();
    Call call =okHttpClient.newCall(request);
    call.enqueue(responseCallback);
}

Postリクエスト
OkHttpではPostメソッドでキー値対データをサーバに転送しFormBodyを使用する.Builderは要求されたパラメータキー値を作成し、RequestBodyオブジェクトを構築します.
key-value:キー値対Stringのコミット:文字列タイプForm:フォームデータStream:ストリームタイプFile:ファイルタイプ

/**
 *   Post  
 *
 * @param url url
 * @return
 */
public String syncPost(String url) {
    String result = null;
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();

    FormBody.Builder mBuild = new FormBody.Builder();
    mBuild.add("name", "tony")
            .add("age", "21");
    RequestBody requestBody= mBuild.build();
    Request request = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    Response response = null;
    try {
        response = okHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            result = response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    return result;
}

/**
 *   Post  
 *
 * @param url url
 * @return
 */
public void nonSyncPost(String url, Callback responseCallback) {
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    FormBody.Builder mBuild = new FormBody.Builder();
    mBuild.add("name", "tony")
            .add("age", "21");
    RequestBody requestBody= mBuild.build();
    Request request = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    try {
        okHttpClient.newCall(request).enqueue(responseCallback);
    } catch (Exception e) {
        e.printStackTrace();
    }
}
/**
 * Post json
 *
 * @param url url
 * @return
 */
public String postJson(String url, Callback responseCallback) {
    String result = null;
    String jsonStr = "json";
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    MediaType mediaType = MediaType.parse("application/json; charset=utf-8");
    RequestBody requestBody = RequestBody.create(mediaType, jsonStr);
    Request request = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    Response response = null;
    try {
        response = okHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            result = response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    return result;
}

/**
 * Post String
 *
 * @param url url
 * @return
 */
public String postString(String url, Callback responseCallback) {
    String result = null;
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    RequestBody requestBody = RequestBody.create(MediaType.parse("text/plain;charset=utf-8"),
            "{username:tony;password:123456}");
    Request request = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    Response response = null;
    try {
        response = okHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            result = response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    return result;
}

postフォームリクエスト

/**
 * Post   
 *
 * @param url url
 * @return
 */
public String postForm(String url, Callback responseCallback) {
    String result = null;
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    MultipartBody.Builder mBuild = new MultipartBody.Builder()
            .setType(MultipartBody.FORM)
            .addFormDataPart("username", "tony")
            .addFormDataPart("password", "123456");
    RequestBody requestBody= mBuild.build();
    Request request = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    Response response = null;
    try {
        response = okHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            result = response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    return result;
}

postアップロードファイル

public void uploadFile(String url) {
    ArrayList filelist = getFileList();
    //1.  OkHttpClient  
    OkHttpClient okHttpClient = new OkHttpClient();
    MultipartBody.Builder multipartBody = new MultipartBody.Builder().setType(MultipartBody.FORM);
    for (int i = 0; i < filelist.size(); i++) {
        String path = filelist.get(i);
        File file = new File(path);
        String fileMimeType = getMimeType(file);
        //        ，      
        MediaType mediaType = MediaType.parse(fileMimeType);
        RequestBody fileBody = RequestBody.create(mediaType, file);
        multipartBody.addFormDataPart("file" + i, file.getName(), fileBody);
    }
    RequestBody requestBody = multipartBody.build();
    Request requestPostFile = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    Response response = null;
    try {
        response = okHttpClient.newCall(requestPostFile).execute();
        if (response.isSuccessful()) {
        } else {
            throw new IOException("Unexpected code " + response);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

参考博文
https://www.jianshu.com/p/bb57bc65e4ce
https://www.jianshu.com/p/b1cf0b574e74