最近有个新项目要做，搭建框架的时候，顺便梳理了下MVP模式，特此记录，欢迎大家指正。

项目地址：https://github.com/18702953620/MVPDemo

一 、首先是依赖

compile 'com.google.code.gson:gson:2.8.0'
 compile 'com.squareup.okhttp3:okhttp:3.4.1'
 compile 'com.yanzhenjie:permission:1.0.5'
 compile 'com.squareup.retrofit2:retrofit:2.3.0'
 compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
 compile 'io.reactivex.rxjava2:rxjava:2.1.5'
 //ConverterFactory的String依赖包
 compile 'com.squareup.retrofit2:converter-scalars:2.3.0'
 //ConverterFactory的Gson依赖包
 compile 'com.squareup.retrofit2:converter-gson:2.3.0'
 //CallAdapterFactory的Rx依赖包
 compile 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'

二、ApiServer，定义了一些接口

public interface ApiServer {
    @POST("shopping_login.htm")
    Observable<String> LoginByRx(@Field("username") String username, @Field("password") String password);

}

三、ApiRetrofit，初始化Retrofit、OkHttpClient，加入了拦截器

public class ApiRetrofit {

    public final String BASE_SERVER_URL = "https://wawa-api.vchangyi.com/";

    private static ApiRetrofit apiRetrofit;
    private Retrofit retrofit;
    private OkHttpClient client;
    private ApiServer apiServer;

    private String TAG = "ApiRetrofit";

    /**
     * 请求访问quest
     * response拦截器
     */
    private Interceptor interceptor = new Interceptor() {
        @Override
        public Response intercept(Chain chain) throws IOException {
            Request request = chain.request();
            long startTime = System.currentTimeMillis();
            Response response = chain.proceed(chain.request());
            long endTime = System.currentTimeMillis();
            long duration = endTime - startTime;
            MediaType mediaType = response.body().contentType();
            String content = response.body().string();
            Log.e(TAG, "----------Request Start----------------");
            Log.e(TAG, "| " + request.toString() + request.headers().toString());
            Log.e(TAG, "| Response:" + content);
            Log.e(TAG, "----------Request End:" + duration + "毫秒----------");
            return response.newBuilder()
                    .body(ResponseBody.create(mediaType, content))
                    .build();
        }
    };


    public ApiRetrofit() {
        client = new OkHttpClient.Builder()
                //添加log拦截器
                .addInterceptor(interceptor)
                .connectTimeout(10, TimeUnit.SECONDS)
                .readTimeout(10, TimeUnit.SECONDS)
                .build();

        retrofit = new Retrofit.Builder()
                .baseUrl(BASE_SERVER_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .addConverterFactory(ScalarsConverterFactory.create())
                //支持RxJava2
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .client(client)
                .build();

        apiServer = retrofit.create(ApiServer.class);
    }

    public static ApiRetrofit getInstance() {
        if (apiRetrofit == null) {
            synchronized (Object.class) {
                if (apiRetrofit == null) {
                    apiRetrofit = new ApiRetrofit();
                }
            }
        }
        return apiRetrofit;
    }

    public ApiServer getApiService() {
        return apiServer;
    }

}

四、基类

1.BaseView，其中定义了常用的接口

public interface BaseView {
    /**
     * 显示dialog
     */
    void showLoading();

    /**
     * 隐藏 dialog
     */

    void hideLoading();

    /**
     * 显示错误信息
     *
     * @param msg
     */
    void showError(String msg);

    /**
     * 错误码
     */
    void onErrorCode(BaseModel model);
}

2.BaseModel

public class BaseModel<T> implements Serializable {
    private int errcode;
    private String errmsg;
    private T result;

    public int getErrcode() {
        return errcode;
    }

    public void setErrcode(int errcode) {
        this.errcode = errcode;
    }

    public String getErrmsg() {
        return errmsg;
    }

    public void setErrmsg(String errmsg) {
        this.errmsg = errmsg;
    }

    public T getResult() {
        return result;
    }

    public void setResult(T result) {
        this.result = result;
    }
}

3.BasePresenter

public class BasePresenter<V extends BaseView> {

    private CompositeDisposable compositeDisposable;


    public V baseView;

    protected ApiServer apiServer = ApiRetrofit.getInstance().getApiService();

    public BasePresenter(V baseView) {

        this.baseView = baseView;
    }

    /**
     * 解除绑定
     */
    public void detachView() {
        baseView = null;
        removeDisposable();
    }

    /**
     * 返回 view
     *
     * @return
     */
    public V getBaseView() {
        return baseView;
    }


    public void addDisposable(Observable<?> observable, BaseObserver observer) {
        if (compositeDisposable == null) {
            compositeDisposable = new CompositeDisposable();
        }
        compositeDisposable.add(observable.subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribeWith(observer));


    }

    public void removeDisposable() {
        if (compositeDisposable != null) {
            compositeDisposable.dispose();
        }
    }

}

4.BaseObserver，主要处理了常见的错误

public abstract class BaseObserver<T> extends DisposableObserver<T> {
    protected BaseView view;
    /**
     * 解析数据失败
     */
    public static final int PARSE_ERROR = 1001;
    /**
     * 网络问题
     */
    public static final int BAD_NETWORK = 1002;
    /**
     * 连接错误
     */
    public static final int CONNECT_ERROR = 1003;
    /**
     * 连接超时
     */
    public static final int CONNECT_TIMEOUT = 1004;


    public BaseObserver(BaseView view) {
        this.view = view;
    }

    @Override
    protected void onStart() {
        if (view != null) {
            view.showLoading();
        }
    }

    @Override
    public void onNext(T o) {
        try {
            BaseModel model = (BaseModel) o;
            if (model.getErrcode() == 0) {
                onSuccess(o);
            } else {
                if (view != null) {
                    view.onErrorCode(model);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            onError(e.toString());
        }


    }

    @Override
    public void onError(Throwable e) {
        if (view != null) {
            view.hideLoading();
        }
        if (e instanceof HttpException) {
            //   HTTP错误
            onException(BAD_NETWORK);
        } else if (e instanceof ConnectException
                || e instanceof UnknownHostException) {
            //   连接错误
            onException(CONNECT_ERROR);
        } else if (e instanceof InterruptedIOException) {
            //  连接超时
            onException(CONNECT_TIMEOUT);
        } else if (e instanceof JsonParseException
                || e instanceof JSONException
                || e instanceof ParseException) {
            //  解析错误
            onException(PARSE_ERROR);
        } else {
            if (e != null) {
                onError(e.toString());
            } else {
                onError("未知错误");
            }
        }

    }

    private void onException(int unknownError) {
        switch (unknownError) {
            case CONNECT_ERROR:
                onError("连接错误");
                break;

            case CONNECT_TIMEOUT:
                onError("连接超时");
                break;

            case BAD_NETWORK:
                onError("网络问题");
                break;

            case PARSE_ERROR:
                onError("解析数据失败");
                break;

            default:
                break;
        }
    }


    @Override
    public void onComplete() {
        if (view != null) {
            view.hideLoading();
        }

    }
    public abstract void onSuccess(T o);

    public abstract void onError(String msg);
}

5.BaseActivity，实现BaseView，处理了Presenter的生命周期。

public abstract class BaseActivity<P extends BasePresenter> extends AppCompatActivity implements BaseView {
    public Context context;
    private ProgressDialog dialog;
    public Toast toast;
    protected P presenter;

    protected abstract P createPresenter();

    protected abstract int getLayoutId();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        context = this;
        setContentView(getLayoutId());
        presenter = createPresenter();
        initView();
        initData();
    }

    public void initData() {
    }

    public void initView() {
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (presenter != null) {
            presenter.detachView();
        }
    }

   /**
     * @param s
     */
    public void showtoast(String s) {
        if (toast == null) {
            toast = Toast.makeText(getApplicationContext(), s, Toast.LENGTH_LONG);
        }
        toast.show();
    }

    private void closeLoadingDialog() {
        if (dialog != null && dialog.isShowing()) {
            dialog.dismiss();
        }
    }


    private void showLoadingDialog() {

        if (dialog == null) {
            dialog = new ProgressDialog(context);
        }
        dialog.setCancelable(false);
        dialog.show();
    }

    @Override
    public void showLoading() {
        showLoadingDialog();
    }


    @Override
    public void hideLoading() {
        closeLoadingDialog();
    }


    @Override
    public void showError(String msg) {
        showtoast(msg);
    }

    @Override
    public void onErrorCode(BaseModel model) {
    }

    @Override
    public void showLoadingFileDialog() {
        showFileDialog();
    }

    @Override
    public void hideLoadingFileDialog() {
        hideFileDialog();
    }

    @Override
    public void onProgress(long totalSize, long downSize) {
        if (dialog != null) {
            dialog.setProgress((int) (downSize * 100 / totalSize));
        }
    }
}

五、如上，框架已经搭建好了，让我们来看看在实际项目中怎么用。

我们来模拟登陆
1.定义LoginView 继承于BaseView

public interface LoginView extends BaseView {
    void onLoginSucc();
}

2.定义LoginPresenter 继承于BasePresenter

public class LoginPresenter extends BasePresenter<LoginView> {
    public LoginPresenter(LoginView baseView) {
        super(baseView);
    }

    public void login(String name, String pwd) {

        addDisposable(apiServer.LoginByRx(name, pwd), new BaseObserver(baseView) {
            @Override
            public void onSuccess(Object o) {
                baseView.onLoginSucc();

            }

            @Override
            public void onError(String msg) {
                baseView.showError(msg);

            }
        });
    }
}

3.LoginActivity 中使用

public class LoginActivity extends BaseActivity<LoginPresenter> implements LoginView {

    private AutoCompleteTextView mEmailView;
    private EditText mPasswordView;

    @Override
    protected LoginPresenter createPresenter() {
        return new LoginPresenter(this);
    }

    @Override
    protected int getLayoutId() {
        return R.layout.activity_login;
    }

    @Override
    public void initView() {
        mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
        mPasswordView = (EditText) findViewById(R.id.password);
        Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
        mEmailSignInButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                //示例代码，示例接口
                presenter.login(mEmailView.getText().toString(), mPasswordView.getText().toString());

            }
        });
    }

    @Override
    public void onLoginSucc() {
        //Login Succ

        showtoast("登录成功");

    }
}

以上就是MVP的实现，MVP的框架很多，适合自己就好。

原文发布时间为：2018-07-31
本文作者： chenghuan3
本文来自云栖社区合作伙伴“ 安卓巴士Android开发者门户”，了解相关信息可以关注“ 安卓巴士Android开发者门户”。