契约类mvp写RecycleView展示列表

最新推荐文章于 2019-11-26 14:38:34 发布

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最新推荐文章于 2019-11-26 14:38:34 发布

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本文链接：https://blog.youkuaiyun.com/qq_42793219/article/details/85556589

本文详细介绍了使用OkHttp进行网络请求的方法，包括GET、POST请求的实现，上传文件功能，以及如何取消所有请求来节省资源。同时，展示了如何在Model、Presenter和View三层架构中应用OkHttp，实现数据获取和解析。

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首先先分包

分包明确后先写入要求中的网络请求方法

public interface OkhttpCallback {
    void failure(String msg);//服务器请求失败：断网，服务器宕机等等因素
    void success(String result);//数据合法
}

private Handler handler  = new Handler() ;

    private OkHttpClient okHttpClient;

    private static OkhttpUtils mInstance;//私有属性


    private OkhttpUtils() {//私有构造方法
        HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
        loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        okHttpClient = new OkHttpClient.Builder()
                .addInterceptor(loggingInterceptor)//添加日志拦截器
                .writeTimeout(5, TimeUnit.SECONDS)
                .connectTimeout(5, TimeUnit.SECONDS)
                .readTimeout(5, TimeUnit.SECONDS)
                .build();//链式调用，构建者模式


    }


    /**
     * 创建实例,双重检验锁，单例模式进行实例化
     *
     * @return
     */
    public static OkhttpUtils getInstance() {

        if (mInstance == null) {
            synchronized (OkhttpUtils.class) {
                if (mInstance == null) {
                    mInstance = new OkhttpUtils();
                }
            }
        }

        return mInstance;

    }

    /**
     * get请求方式
     */
    public void doGet(String url, final OkhttpCallback requestCallback) {

        Request request = new Request.Builder().url(url)
                .get().build();

        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                if (requestCallback != null) {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            requestCallback.failure("网络异常");
                        }
                    });
                }
            }

            @Override
            public void onResponse(Call call, final Response response) throws IOException {
                final String result = response.body().string();
                if (requestCallback != null) {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            requestCallback.success(result);

                        }
                    });
                }
            }
        });


    }

    /**
     * Post请求方式
     */
    public void doPost(String url, HashMap<String, String> parmas, final OkhttpCallback callback) {

        FormBody.Builder builder = new FormBody.Builder();

        for (Map.Entry<String, String> map : parmas.entrySet()) {
            builder.add(map.getKey(), map.getValue());

        }

        RequestBody requestBody = builder.build();

        Request request = new Request.Builder().url(url)
                .post(requestBody).build();

        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {

                if (callback != null) {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            callback.failure("网络异常");
                        }
                    });

                }

            }

            @Override
            public void onResponse(Call call, final Response response) throws IOException {

                if (callback != null) {
                    if (200 == response.code()) {
                        final String result = response.body().string();
                        handler.post(new Runnable() {
                            @Override
                            public void run() {
                                callback.success(result);
                            }
                        });

                    }
                }
            }
        });


    }

    /**
     * 上传头像,文件
     */
    public void uploadFile(String url, HashMap<String, Object> params, final OkhttpCallback okhttpCallback) {


        MultipartBody.Builder builder = new MultipartBody.Builder();
        builder.setType(MultipartBody.FORM);
        for (Map.Entry<String, Object> map : params.entrySet()) {
            String key = map.getKey();
            Object value = map.getValue();
            if (value instanceof File) {
                File file = (File) value;
                builder.addFormDataPart(key, file.getName(), RequestBody.create(MediaType.parse("image/*"), file));

            } else {
                builder.addFormDataPart(key, value.toString());
            }
        }
        Request request = new Request.Builder().url(url).post(builder.build()).build();
        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                if (okhttpCallback != null) {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            okhttpCallback.failure("网络异常");
                        }
                    });
                }
            }

            @Override
            public void onResponse(Call call, final Response response) throws IOException {

                if (okhttpCallback != null) {
                    final String result = response.body().string();
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            okhttpCallback.success(result);
                        }
                    });
                }

            }
        });


    }

    /**
     * 取消所有请求，好处：节省开销：内存开销，cpu的开销（线程开销）
     */
    public void cancelAllTask() {
        if (okHttpClient != null) {
            okHttpClient.dispatcher().cancelAll();
        }
    }


public interface RequestCallback {
    void failure(String msg);//服务器请求失败：断网，服务器宕机等等因素
    void successMsg(String msg);//请求成功，但数据不正确
    void success(User user);//数据合法
    void success(String result);//数据合法
}

model层


public class ProductModel implements ProductContract.IProductModel {
    Handler handler=new Handler();

    @Override
    public void getProductModel( HashMap<String, String> params, final RequestCallback requestCallback) {
        OkhttpUtils.getInstance().doPost(ProductApi.PRODUCT_URL, params, new OkhttpCallback() {
            @Override
            public void failure(String msg) {
                requestCallback.failure("网络不可用");
            }

            @Override
            public void success(String result) {
                paserResult(result,requestCallback);
            }
        });
    }

    private void paserResult(String result, RequestCallback requestCallback) {
        User user = new Gson().fromJson(result, User.class);
        requestCallback.success(user);
    }
}

presenter


public class ProductPresenter extends ProductContract.ProductPresenter {
    ProductModel productModel;
    ProductContract.IProductView iProductView;

    public ProductPresenter(ProductContract.IProductView iProductView) {
        productModel=new ProductModel();
        this.iProductView = iProductView;
    }

    @Override
    public void getProductList(HashMap<String, String> params) {
        String keyword = params.get("keyword");
        String page = params.get("page");
        productModel.getProductModel(params, new RequestCallback() {
            @Override
            public void failure(String msg) {
                iProductView.failure(msg);
            }

            @Override
            public void successMsg(String msg) {

            }

            @Override
            public void success(User user) {
                iProductView.success(user);
            }

            @Override
            public void success(String result) {

            }
        });
    }

}

MainActivity


public class MainActivity extends AppCompatActivity implements ProductContract.IProductView {

    private RecyclerView recyclerView;
    List<User.DataBean> list;
    private ProductPresenter presenter=new ProductPresenter(this);
    private ProductAdapter adapter;
    HashMap<String,String> params= new HashMap<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         recyclerView = findViewById(R.id.recyclerView);
        LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this,1,false);
        recyclerView.setLayoutManager(linearLayoutManager);
        params.put("keywords","手机");
        params.put("page",1+"");
        list=new ArrayList<>();
        presenter.getProductList(params);

    }

    @Override
    public void success(User success) {
        list=success.getData();
        adapter= new ProductAdapter(this,list);
        recyclerView.setAdapter(adapter);
    }

    @Override
    public void failure(String msg) {

    }
}

adapter适配器


public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ViewHolder> {
    private Context context;
    private List<User.DataBean> list;

    public ProductAdapter(Context context, List<User.DataBean> list) {
        this.context = context;
        this.list = list;
    }

    @NonNull
    @Override
    public ProductAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view=LayoutInflater.from(context).inflate(R.layout.item_list,viewGroup,false);
        ViewHolder viewHolder=new ViewHolder(view);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull ProductAdapter.ViewHolder viewHolder, int i) {
        User.DataBean dataBean = list.get(i);
        viewHolder.text.setText(dataBean.getTitle());
        String images = dataBean.getImages();
        String[] imgAttr = images.split("\\|");
        Glide.with(context).load(imgAttr[0]).into(viewHolder.image);

    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        private final ImageView image;
        private final TextView text;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
             image = itemView.findViewById(R.id.image);
             text = itemView.findViewById(R.id.text);
        }
    }
}