android 使用代理模式切换不同的框架

我们平时在开发迭代中,随着版本的更新以及需求的变化,可能这时候框架不能达到我们的要求,而这个时候另外有个框架可以达到,那我们如果要换的框架的话，这会涉及很多代码要改动,比如网络框架最早是用xutils，然后volley,现在大部分用的是okhttp,那么我们怎么用一行代码把app项目中的网络请求从volley切换到okhttp呢？而不是去全局改动代码,这样工作量就大了,今天就解决这个问题.   其实就是把请求抽象出来,然后利用java的多态根据设置的是用那个请求就行了.

public interface IHttpRequest {
    public void get(String url, Map,Object> params,ICallBack iCallBack);
    public void post(String url, Map,Object> params,ICallBack iCallBack);
}

这是抽取出来的,这里我们使用静态代理的方式：

public class HttpRequestProxy implements IHttpRequest {
    private static IHttpRequest iHttpRequest;

    private HttpRequestProxy() {
    }

    private static class Holder {
        private static final HttpRequestProxy INSTANCE = new HttpRequestProxy();
    }

    public static HttpRequestProxy getInstance() {
        return Holder.INSTANCE;
    }

    public void init(NetRequestType netRequestType) {
        switch (netRequestType) {
            case OKHTTP:
                iHttpRequest = new OkHttpRequest();
                break;
            case XUTIL:
                iHttpRequest = new XUtilsRequest();
                break;
            case VOLLEY:
                iHttpRequest = new VolleyRequest();
                break;
        }
    }

    @Override
    public void get(String url, Map, Object> params, ICallBack iCallBack) {
        if (null != iHttpRequest)
            iHttpRequest.get(url, params, iCallBack);
    }

    @Override
    public void post(String url, Map, Object> params, ICallBack iCallBack) {
        if (null != iHttpRequest)
            iHttpRequest.post(url, params, iCallBack);
    }
}

然后其实我们只要针对不同的网络请求设置进来就ok了,比如使用Okhttp:

public class OkHttpRequest implements IHttpRequest {
    @Override
    public void get(String url, Map, Object> params, ICallBack iCallBack) {
        if(TextUtils.isEmpty(url)){
            return;
        }
        StringBuffer stringBuffer = new StringBuffer(url);
        if(null!=params&&!params.isEmpty()){
            stringBuffer.append("?");
            for (Map.Entry, Object> entry : params.entrySet()) {
                stringBuffer.append(entry.getKey()).append("=").append(entry.getValue().toString()).append("&");
            }
            stringBuffer.deleteCharAt(stringBuffer.length()-1);
        }
        OkHttpClient client = new OkHttpClient();
        Log.e("OkHttpRequest","url="+stringBuffer.toString());
        Request request = new Request.Builder().get().url(stringBuffer.toString()).build();
        Call call = client.newCall(request);
        //异步调用并设置回调函数
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
            }
            @Override
            public void onResponse(Call call, final Response response) throws IOException {
                if(response.isSuccessful()){
                     String json = response.body().string();
                     Log.e("OkHttpRequest","json--->"+json);
                }
            }
        });
    }
    @Override
    public void post(String url, Map, Object> params, ICallBack iCallBack) {

    }
}

如果是volley的话,也是这么搞定的，其实就是里层封装好了,上层根据不同的需求,切换下就行了,在这还有请求回调以及json变成实体bean的

public interface ICallBack {
     void onSuccess(String json);
     void onFail(Exception e);
}

在这把所有的请求结果全都是string,当然你也可以定义其他了,

public abstract class HttpCallBack<Result> implements ICallBack {
    @Override
    public void onSuccess(String json) {
        Gson gson = new Gson();
        Class clazz = getClassType(this);
        Result obj = (Result) gson.fromJson(json,clazz);
        onSuccess(obj);
    }
    public abstract void onSuccess(Result obj);
    private Class getClassType(Object object) {
        if(null==object){
            return null;
        }
        Type type = object.getClass().getGenericSuperclass();
        Type[] params = ((ParameterizedType)type).getActualTypeArguments();
        return (Class) params[0];
    }

    @Override
    public void onFail(Exception e) {

    }
}

在这只是对返回结果的一种处理而已,当我们要进行切换的时候,只要在Application中调用一行代码:

public class MyApp extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        HttpRequestProxy.getInstance().init(NetRequestType.OKHTTP);
    }
}

这就是网络框架的切换.这是架构师必懂的啊,可惜我是菜鸟!

上层调用:

Map,Object> params = new HashMap<>();
params.put("key","71e58b5b2f930eaf1f937407acde08fe");
params.put("num",20);
HttpRequestProxy.getInstance().get("http://api.tianapi.com/social/", params, new HttpCallBack() {
    @Override
    public void onSuccess(Personal personal) {

    }
    @Override
    public void onFail(Exception e) {
        super.onFail(e);
    }
});