封装OKHttp

如果不封装OKHttp，则每发出一个请求，都要写很多重复代码，是无用且繁琐的，所以必须要封装，并且若能够结合GSON，将返回的json数据直接解析为Bean对象，就可以大大简化网络请求过程；更进一步，若能在每个请求都加上进度对话框的功能，就大大美化了网络请求过程。下面开始封装：

①构建OKHttpHelper类

->OKHttpHelper应该是单例的

private  static  OkHttpHelper mInstance;
static {
    mInstance = new OkHttpHelper();
}

private OkHttpHelper(){
    mHttpClient = new OkHttpClient();
    mHttpClient.setConnectTimeout(10, TimeUnit.SECONDS);
    mHttpClient.setReadTimeout(10,TimeUnit.SECONDS);
    mHttpClient.setWriteTimeout(30,TimeUnit.SECONDS);

    mGson = new Gson();

    mHandler = new Handler(Looper.getMainLooper());

};

public static  OkHttpHelper getInstance(){
    return  mInstance;
}
 

->实现request方法

public  void request(final Request request,final  BaseCallback callback){

            callback.onBeforeRequest(request);

            mHttpClient.newCall(request).enqueue(new Callback() {

                @Override
                public void onFailure(Request request, IOException e) {
                    callbackFailure(callback, request, e);
                }

                @Override
                public void onResponse(Response response) throws IOException {
                    callbackResponse(callback,response);
                    if(response.isSuccessful()) {

                        String resultStr = response.body().string();
                        if (callback.mType == String.class){
                            callbackSuccess(callback,response,resultStr);
                        }
                        else {
                            try {
                                Object obj = mGson.fromJson(resultStr, callback.mType);
                                callbackSuccess(callback,response,obj);
                            }
                            catch (com.google.gson.JsonParseException e){ // Json解析的错误
                                callback.onError(response,response.code(),e);
                            }
                        }
                    }
                    else if(response.code() == TOKEN_ERROR||response.code() == TOKEN_EXPIRE ||response.code() == TOKEN_MISSING ){
                        callbackTokenError(callback,response);
                    }else {
                        callbackError(callback,response,null);
                    }
                }
            });
        }
}
private void callbackTokenError(final  BaseCallback callback , final Response response ){

    mHandler.post(new Runnable() {
        @Override
        public void run() {
            callback.onTokenError(response,response.code());
        }
    });
    private void callbackSuccess(final  BaseCallback callback , final Response response, final Object obj ){

        mHandler.post(new Runnable() {
            @Override
            public void run() {
                callback.onSuccess(response, obj);
            }
        });
    }
    private void callbackError(final  BaseCallback callback , final Response response, final Exception e ){

        mHandler.post(new Runnable() {
            @Override
            public void run() {
                callback.onError(response,response.code(),e);
            }
        });
    }
private void callbackFailure(final  BaseCallback callback , final Request request, final IOException e ){

    mHandler.post(new Runnable() {
        @Override
        public void run() {
            callback.onFailure(request,e);
        }
    });
private void callbackResponse(final  BaseCallback callback , final Response response ){

    mHandler.post(new Runnable() {
        @Override
        public void run() {
            callback.onResponse(response);
        }
    });
}
 

->处理GET请求的方法

public void get(String url,Map<String,Object> param,BaseCallback callback){
    Request request = buildGetRequest(url,param);
    request(request,callback);
}
public void get(String url,BaseCallback callback){
    get(url,null,callback);
}
public void post(String url,Map<String,Object> param, BaseCallback callback){
    Request request = buildPostRequest(url,param);
    request(request,callback);
}
 

->处理POST请求的方法

public void post(String url,Map<String,Object> param, BaseCallback callback){

    Request request = buildPostRequest(url,param);
    request(request,callback);
}
 

->构建请求的几个方法

具体实现：

public class OkHttpHelper {

    public static final int TOKEN_MISSING=401;// token 丢失
    public static final int TOKEN_ERROR=402; // token 错误
    public static final int TOKEN_EXPIRE=403; // token 过期

        public static final String TAG="OkHttpHelper";

        private  static  OkHttpHelper mInstance;
        private OkHttpClient mHttpClient;
        private Gson mGson;

        private Handler mHandler;
        static {
            mInstance = new OkHttpHelper();
        }
        private OkHttpHelper(){

            mHttpClient = new OkHttpClient();
            mHttpClient.setConnectTimeout(10, TimeUnit.SECONDS);
            mHttpClient.setReadTimeout(10,TimeUnit.SECONDS);
            mHttpClient.setWriteTimeout(30,TimeUnit.SECONDS);

            mGson = new Gson();

            mHandler = new Handler(Looper.getMainLooper());

        };

        public static  OkHttpHelper getInstance(){
            return  mInstance;
        }

        public void get(String url,Map<String,Object> param,BaseCallback callback){
            Request request = buildGetRequest(url,param);
            request(request,callback);
        }

        public void get(String url,BaseCallback callback){

            get(url,null,callback);
        }

        public void post(String url,Map<String,Object> param, BaseCallback callback){

            Request request = buildPostRequest(url,param);
            request(request,callback);
        }
        public  void request(final Request request,final  BaseCallback callback){

            callback.onBeforeRequest(request);

            mHttpClient.newCall(request).enqueue(new Callback() {

                @Override
                public void onFailure(Request request, IOException e) {
                    callbackFailure(callback, request, e);

                }

                @Override
                public void onResponse(Response response) throws IOException {

//                    callback.onResponse(response);
                    callbackResponse(callback,response);

                    if(response.isSuccessful()) {

                        String resultStr = response.body().string();

                        Log.d(TAG, "result=" + resultStr);

                        if (callback.mType == String.class){
                            callbackSuccess(callback,response,resultStr);
                        }
                        else {
                            try {

                                Object obj = mGson.fromJson(resultStr, callback.mType);
                                callbackSuccess(callback,response,obj);
                            }
                            catch (com.google.gson.JsonParseException e){ // Json解析的错误
                                callback.onError(response,response.code(),e);
                            }
                        }
                    }
                    else if(response.code() == TOKEN_ERROR||response.code() == TOKEN_EXPIRE ||response.code() == TOKEN_MISSING ){

                        callbackTokenError(callback,response);
                    }
                    else {
                        callbackError(callback,response,null);
                    }

                }
            });
        }

    private void callbackTokenError(final  BaseCallback callback , final Response response ){

        mHandler.post(new Runnable() {
            @Override
            public void run() {
                callback.onTokenError(response,response.code());
            }
        });
    }
        private void callbackSuccess(final  BaseCallback callback , final Response response, final Object obj ){

            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callback.onSuccess(response, obj);
                }
            });
        }
        private void callbackError(final  BaseCallback callback , final Response response, final Exception e ){

            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callback.onError(response,response.code(),e);
                }
            });
        }
    private void callbackFailure(final  BaseCallback callback , final Request request, final IOException e ){

        mHandler.post(new Runnable() {
            @Override
            public void run() {
                callback.onFailure(request,e);
            }
        });
    }
    private void callbackResponse(final  BaseCallback callback , final Response response ){

        mHandler.post(new Runnable() {
            @Override
            public void run() {
                callback.onResponse(response);
            }
        });
    }

    private  Request buildPostRequest(String url,Map<String,Object> params){
            return  buildRequest(url,HttpMethodType.POST,params);
        }
        private  Request buildGetRequest(String url,Map<String,Object> param){
            return  buildRequest(url,HttpMethodType.GET,param);
        }

        private  Request buildRequest(String url,HttpMethodType methodType,Map<String,Object> params){
            Request.Builder builder = new Request.Builder()
                    .url(url);

            if (methodType == HttpMethodType.POST){
                RequestBody body = builderFormData(params);
                builder.post(body);
            }
            else if(methodType == HttpMethodType.GET){

                url = buildUrlParams(url,params);
                builder.url(url);

                builder.get();
            }
            return builder.build();
        }
    private   String buildUrlParams(String url ,Map<String,Object> params) {
        if(params == null)
            params = new HashMap<>(1);
        String token = CniaoApplication.getInstance().getToken();
        if(!TextUtils.isEmpty(token))
            params.put("token",token);
        StringBuffer sb = new StringBuffer();
        for (Map.Entry<String, Object> entry : params.entrySet()) {
            sb.append(entry.getKey() + "=" + (entry.getValue()==null?"":entry.getValue().toString()));
            sb.append("&");
        }
        String s = sb.toString();
        if (s.endsWith("&")) {
            s = s.substring(0, s.length() - 1);
        }
        if(url.indexOf("?")>0){
            url = url +"&"+s;
        }else{
            url = url +"?"+s;
        }
        return url;
    }
        private RequestBody builderFormData(Map<String,Object> params){
            FormEncodingBuilder builder = new FormEncodingBuilder();
            if(params !=null){
                for (Map.Entry<String,Object> entry :params.entrySet() ){
                  builder.add(entry.getKey(),entry.getValue()==null?"":entry.getValue().toString());
                }
                String token = CniaoApplication.getInstance().getToken();
                if(!TextUtils.isEmpty(token))
                    builder.add("token", token);
            }
            return  builder.build();
        }
        enum  HttpMethodType{
            GET,
            POST,
        }
}
 

②构建BaseCallback类，主要是传入json数据将要转化的类型

public abstract class BaseCallback<T> {

    public   Type mType;

    static Type getSuperclassTypeParameter(Class<?> subclass)
    {
        Type superclass = subclass.getGenericSuperclass();
        if (superclass instanceof Class)
        {
            throw new RuntimeException("Missing type parameter.");
        }
        ParameterizedType parameterized = (ParameterizedType) superclass;
        return $Gson$Types.canonicalize(parameterized.getActualTypeArguments()[0]);
    }
    public BaseCallback()
    {
        mType = getSuperclassTypeParameter(getClass());
    }

    public  abstract void onBeforeRequest(Request request);

    public abstract  void onFailure(Request request, Exception e) ;

    /**
     *请求成功时调用此方法
     * @param response
     */
    public abstract  void onResponse(Response response);

    /**
     *
     * 状态码大于200，小于300 时调用此方法
     * @param response
     * @param t
     * @throws IOException
     */
    public abstract void onSuccess(Response response,T t) ;

    /**
     * 状态码400，404，403，500等时调用此方法
     * @param response
     * @param code
     * @param e
     */
    public abstract void onError(Response response, int code,Exception e) ;

}
 

③实现SimpleCallback类，传入Context参数，并实现一些具有共同逻辑的方法

public abstract class SimpleCallback<T> extends BaseCallback<T> {

    protected Context mContext;

    public SimpleCallback(Context context){

        mContext = context;

    }

    @Override
    public void onBeforeRequest(Request request) {

    }

    @Override
    public void onFailure(Request request, Exception e) {

    }

    @Override
    public void onResponse(Response response) {

    }

    @Override
    public void onTokenError(Response response, int code) {
        ToastUtils.show(mContext, mContext.getString(R.string.token_error));

        Intent intent = new Intent();
        intent.setClass(mContext, LoginActivity.class);
        mContext.startActivity(intent);

        CniaoApplication.getInstance().clearUser();

    }
}
 

④为OKHttp实现具有对话框功能的封装类

-> spots-dialog开源控件

GitHub地址：https://github.com/d-max/spots-dialog

-> 加入依赖

dependencies {
    compile 'com.github.d-max:spots-dialog:0.4@aar'
}
-> 使用

AlertDialog dialog = new SpotsDialog(context);
dialog.show();
...
dialog.dismiss();
 

-> 实现，在网络开始请求前加载对话框，在请求结束后结束对话框

public abstract class SpotsCallBack<T> extends SimpleCallback<T> {
    private  SpotsDialog mDialog;
    public SpotsCallBack(Context context){
        super(context);
        initSpotsDialog();
    }
    private  void initSpotsDialog(){
        mDialog = new SpotsDialog(mContext,"拼命加载中...");
    }
    public  void showDialog(){
        mDialog.show();
    }
    public  void dismissDialog(){
        mDialog.dismiss();
    }
    public void setLoadMessage(int resId){
        mDialog.setMessage(mContext.getString(resId));
    }
    @Override
    public void onBeforeRequest(Request request) {
        showDialog();
    }
    @Override
    public void onResponse(Response response) {
        dismissDialog();
    }

}
⑤使用OKHttp的封装类来实现广告轮播组件

private ArrayList<Banner> banners = new ArrayList<>();
private OkHttpHelper  mHelper = OkHttpHelper.getInstance();
private  void requestImages2(){
    String url ="http://112.124.22.238:8081/course_api/banner/query?type=1";
    mHelper.get(url, new SpotsCallBack<ArrayList<Banner>>(getContext()) {

        @Override
        public void onSuccess(Response response, ArrayList<Banner> banners) {
            if(banners != null){
                for (Banner ban: banners){
                    TextSliderView textSliderView 
                            = new TextSliderView(HomeFragment.this.getActivity());
                    textSliderView
                            .description(ban.getName())
                            .image(ban.getImgUrl());

                    textSliderView.setOnSliderClickListener(new BaseSliderView.OnSliderClickListener() {
                        @Override
                        public void onSliderClick(BaseSliderView slider) {
                            Toast.makeText(HomeFragment.this.getActivity(), 
"slider 1 clicked", Toast.LENGTH_LONG).show();

                        }
                    });

                    sliderShow.addSlider(textSliderView);
                }
            }
        }

        @Override
        public void onError(Response response, int code, Exception e) {

        }
    });
}