Volley框架解析2--网络框架的快速接入

最新推荐文章于 2019-12-17 11:25:21 发布

原创最新推荐文章于 2019-12-17 11:25:21 发布 · 117 阅读

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本文介绍了Volley框架的核心组件，包括Volley、Request和RequestQueue类的功能及使用方法，并提供了基本的接入方式，如NetRequestUtil类、NetRequestBean类、NetResponseBean类以及NetRequestListener接口。

1. 相关类介绍

Volley 类
Volley框架的接入类，调用静态方法newRequestQueue 可以初始化各个工作线程，等待请求的发起；
常用方法：
public static RequestQueue newRequestQueue(Context context, HttpStack stack)
public static RequestQueue newRequestQueue(Context context)
Request《T》类
请求类，带有网络请求参数，接收原始数据，响应网络回调的能力，接入Volley 框架最核心的类；
内部接口：Method
int GET = 0;
int POST = 1;
int PUT = 2;
int DELETE = 3;

重要属性：
private final int mMethod；
private final String mUrl ；
private RequestQueue mRequestQueue ；
private RetryPolicy mRetryPolicy ；
private final Response.ErrorListener mErrorListener；
private Cache.Entry mCacheEntry；
核心方法：
public Request(int method, String url, Response.ErrorListener listener)
void finish(final String tag)
public String getCacheKey()
protected Map《String, String》getPostParams()
public byte[] getPostBody()
protected Map《String, String》 getParams()
public byte[] getBody()
public final boolean shouldCache()
abstract protected Response《T》 parseNetworkResponse(NetworkResponse response);
abstract protected void deliverResponse(T response);
public void deliverError(VolleyError error)
RequestQueue 类
工作线程的启动入口，网络请求的添加入口
RequestQueue(Cache cache, Network network)
public RequestQueue(Cache cache, Network network, int threadPoolSize)
public RequestQueue(Cache cache, Network network, int threadPoolSize,
ResponseDelivery delivery)
public void start()
public void stop()
public Request add(Request request)
public void cancelAll(final Object tag)
void finish(Request request)

2.基本的框架接入方式

2.1 一个操作入口类：NetRequestUtil
public static  void init(Context context) 
public static void request(NetRequestBean bean, NetRequestListener l) 

2.2 一个请求参数封装类：NetRequestBean
public final static String Url  ；
public String GetParams；
public int method = Request.Method.POST；
public HashMap《String, String》 PostParams；
public long initialTimeoutMs ；
public int maxNumRetries ；
public boolean isShouldCache ；

2.3 一个通用返回数据结构：NetResponseBean
public int Code;
public String ErrMsg;
public String Data;
public boolean IsError;
public String ReturnCode;

2.3 一个请求回调接口NetRequestListener
void onRequest(NetRequestBean bean);
void onSucceed(NetResponseBean bean);
void onFailed(NetResponseBean bean);
void onFinished(NetResponseBean bean);

2.4 一个请求类NetRequest

 

    public class NetRequest extends Request { 

    protected NetRequestListener mNetRequestListener; 

    protected NetRequestBean mNetRequestBean; 

    public NetRequest(NetRequestBean bean, NetRequestListener listener) { 

        super(bean.method, bean.Url, null); 

        mNetRequestBean = bean; 

        mNetRequestListener = listener; 

        mNetRequestListener.onRequest(bean); 

    } 

    @Override 

    protected Response《NetResponseBean》 parseNetworkResponse(NetworkResponse response) { 

        try { 

            String jsonString = 

                    new String(response.data, HttpHeaderParser.parseCharset(response.headers)); 

            NetResponseBean responseBean = new Gson().fromJson(jsonString, NetResponseBean.class); 

            return Response.success(responseBean, HttpHeaderParser.parseCacheHeaders(response)); 

        } catch (UnsupportedEncodingException e) { 

            e.printStackTrace(); 

        } 

        return null; 

    } 

    @Override 

    protected Map《String, String》getParams() throws AuthFailureError { 

        return mNetRequestBean.PostParams; 

    } 

    @Override 

    protected void deliverResponse(NetResponseBean response) { 

        if (response.IsError) { 

            mNetRequestListener.onFailed(response); 

        } else { 

            mNetRequestListener.onSucceed(response); 

        } 

        mNetRequestListener.onFinished(response); 

    } 

    @Override 

    public void deliverError(VolleyError error) { 

        super.deliverError(error); 

        NetResponseBean responseBean = new NetResponseBean(); 

        int code = error.networkResponse.statusCode; 

        if (error instanceof NetworkError) { 

            responseBean.ErrMsg = “网络异常”; 

        } else if (error instanceof ParseError) { 

            responseBean.ErrMsg = “数据解析异常”; 

        } else if (error instanceof ServerError) { 

            responseBean.ErrMsg = “服务器异常”; 

        } 

        responseBean.Code = code; 

        mNetRequestListener.onSucceed(responseBean); 

        mNetRequestListener.onFinished(responseBean); 

    }