[Android] Android MVP 架构下最简单的代码实现

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Android MVP 架构下最简单的代码实现

首先看图：

上图是MVP，下图是MVC

MVP和MVC的区别，在于以前的View层不仅要和model层交互，还要和controller层交互。而在mvp中，view层只和presenter层交互，而model层也和presenter交互，presenter构成了view层和model层的桥梁，也解耦了view层和model层。这一点很关键。我认为，这也是mvp的本质：

解耦view层和model层，让view层和model层通过presenter层进行通信。换个说法就是让诸如网络请求，数据库读写的逻辑，从activity中剥离出来。activit只负责页面的展示，不关心model层的逻辑。

简单的MVP模式，3个class 和 1个interface 就可以实现

各文件主要功能如下：

1个interface：定义activity 要实现的回调方法

3个class：1个Model层定义文件 + 1个业务逻辑 Presenter文件 + 1个Activity文件

列举实现代码

1）interface定义文件

MainCallBack.java

package com.jack.basemvp.basemvp;/**
* 定义要实现的回调方法
*/
public interface MainCallBack {
void getMessage(String message);
void error();
}

2）Model层文件

MainModel.java

package com.jack.basemvp.basemvp;import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;/**
* 定Model
*/
public class MainModel {
public Call getData(String url) {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder().url(url).build();
return client.newCall(request);
}
}

3)Presenter层文件

MainPresenter.java

package com.jack.basemvp.basemvp;import android.support.annotation.NonNull;import java.io.IOException;import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.Response;/**
* 定义业务逻辑 Presenter
*/
public class MainPresenter {
private MainCallBack callBack;
private MainModel model; public MainPresenter(MainCallBack callBack) {
this.callBack = callBack;
model=new MainModel();
} public void getUrlData(String url){
model.getData(url).enqueue(new Callback() {
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
callBack.error();
} @Override
public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
callBack.getMessage(response.body().string());
}
});
}}

4）activity调用

SimpleMvpActivity.java

package com.jack.basemvp.activity;import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;import com.jack.basemvp.R;
import com.jack.basemvp.basemvp.MainCallBack;
import com.jack.basemvp.basemvp.MainPresenter;import java.lang.ref.WeakReference;public class SimpleMvpActivity extends AppCompatActivity implements View.OnClickListener,MainCallBack{
public EditText simple_et;
Button btn_submit_req;
TextView simple_tv; private MainPresenter presenter;
private MyHandler handler; @Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_simple_mvp); simple_et = (EditText) findViewById(R.id.simple_et);
btn_submit_req = (Button) findViewById(R.id.btn_submit_req);
simple_tv = (TextView) findViewById(R.id.simple_tv); handler = new MyHandler(this);
presenter = new MainPresenter(this); btn_submit_req.setOnClickListener(this);
} @Override
public void onClick(View v) {
switch (v.getId()){
case R.id.btn_submit_req:
String url = simple_et.getText().toString();
presenter.getUrlData(url);
break;
}
} @Override
public void getMessage(String message) {
Message msg = handler.obtainMessage(, message);
handler.sendMessage(msg);
} @Override
public void error() {
Message msg = handler.obtainMessage(, "error");
handler.sendMessage(msg);
} private static class MyHandler extends Handler {
private WeakReference<SimpleMvpActivity> reference; private MyHandler(SimpleMvpActivity activity) {
reference = new WeakReference<>(activity);
} @Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
SimpleMvpActivity activity = reference.get();
switch (msg.what) {
case :
activity.simple_tv.setText(msg.obj.toString());
break;
case :
activity.simple_tv.setText(msg.obj.toString());
break;
}
}
}
}