项目地址
https://github.com/fengxing1234/VolleyOkhttpGson/tree/master
Volley
Android Volley完全解析(一)，初识Volley的基本用法
Android Volley完全解析(二)，使用Volley加载网络图片
Android Volley完全解析(三)，定制自己的Request
Volley是Google开发的HTTP库，它使Android应用程序的网络更容易，最重要的是，更快。
Volley非常适合去进行数据量不大，但通信频繁的网络操作，而对于大数据量的网络操作，比如说下载文件等，Volley的表现就会非常糟糕。
官方给出的Volley优点：
image.png
本人英文不好，用软件翻译一下。。
- 自动调度网络请求。
- 多个并发网络连接。
- 具有标准HTTP缓存一致性的透明磁盘和内存响应缓存。
- 支持请求优先级。
- 取消请求API。
- 可以取消单个请求，也可以设置要取消的请求块或范围。
- 易于定制，例如，重试和退避。
- 强大的排序，可以使用从网络异步获取的数据轻松正确填充UI。
- 调试和跟踪工具。
OkHttp
Gson
使用
- 在Application中初始化HttpClient
public class VolleyApplication extends Application {
private static Context context;
private HttpClient httpClient;
@Override
public void onCreate() {
super.onCreate();
httpClient = new HttpClient(this);
context = this;
}
public HttpClient getClient() {
return httpClient;
}
public static Context getContext() {
return context;
}
}
- 配置
HttpClient类
根据接口文档配置头信息
public Map<String, String> generateHeader(RequestBody requestBody) {
HashMap<String, String> map = new HashMap<>();
map.put("", "8");
map.put("", "123456");
map.put("", DeviceUtil.getUUID(VolleyApplication.getContext()));
map.put("", "1");
String token = "";
if (!"".equals(token)) {
map.put("picc-m-sid", token);
}
return map;
}
- 创建子类实现DataHandler
根据接口文档填充。
public class DataHandler {
public JsonElement getData(NetworkResponse response, JsonObject json) {
return json.get("data");
}
public int getStatusCode(NetworkResponse response, JsonObject json) {
return json.get("state").getAsInt();
}
public String getMessage(NetworkResponse response, JsonObject json) {
return json.get("msg").getAsString();
}
public boolean isSuccess(NetworkResponse response, JsonObject json) {
return getStatusCode(response, json) == 200;
}
public String getStringFromobject(JsonElement element, String name) {
return element.getAsJsonObject().get(name).getAsString();
}
public boolean getBooleanFromobject(JsonElement element, String name) {
return element.getAsJsonObject().get(name).getAsBoolean();
}
public JsonElement parseGsonResponse(NetworkResponse response) throws UnsupportedEncodingException {
//Log.w("fengxing", "parseGsonResponse: "+new String(response.data,HttpHeaderParser.parseCharset(response.headers)) );
//{"flag":true,"data":{"url":"/mcph5Version/downLoad","version":"254"},"state":"200","msg":"成功返回"}
// trim the string to prevent start with blank, and test if the string
// is valid JSON, because the parser don't do this :(. If Json is not
// valid this will return null;
return new JsonParser().parse(new String(response.data, HttpHeaderParser.parseCharset(response.headers)).trim());
}
}
- 定义接口
public Request<?> queryClaimPage(Context context, String page_id, String report_id, Response.Listener<JsonElement> listener, Response.ErrorListener error) {
String url = API_CLAIM_QUERY_CLAIM_PAGE;
JsonBuilder builder = new JsonBuilder();
builder.add("page_id", page_id);
builder.add("report_id", report_id);
RequestBody requestBody = builder.build();
return addGsonRequest(context, POST, url, requestBody, requestBody, listener, error);
}
- 代码中使用
首先初始化HttpClient类
client = HttpClient.getClient(this);
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.test_1:
request = client.getProvinceCity(this, new Response.Listener<JsonElement>() {
@Override
public void onResponse(JsonElement response) {
tv.setText(response.toString());
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
toast(error.getMessage());
}
});
break;
case R.id.test_2:
client.queryClaimPage(this, "4", "08cc85f8db9f4befbebf2e57f97eb016", new Response.Listener<JsonElement>() {
@Override
public void onResponse(JsonElement response) {
tv.setText(response.toString());
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
toast(error.getMessage());
}
});
break;
case R.id.test_cancel:
client.cancelAll(this);
boolean cancel = client.isCancel(request);
Log.d("isCancel", "onClick: " + cancel);
break;
}
}
主要
根据接口文档一般的项目传递的都是Json格式，在定义接口时可以使用``JsonBuilder builder = new JsonBuilder();```来添加参数。
如果有特殊需求例如 使用表单就不能使用JsonBuilder类。应该使用FormBuilder类。
区别在于:
表单的type：application/x-www-form-urlencoded
Json的type:application/json; charset=utf-8
现在就可以正常使用了
取消请求
每一个接口都会传递一个context上下文，如果页面关闭，请求队列还是会在后台请求工作，当请求成功一般都设置设置数据，但是页面关闭了，如果不处理很容易造成崩溃，解决办法就是在页面关闭后者失去焦点时，取消请求。
@Override
protected void onDestroy() {
super.onDestroy();
client.cancelAll(this);
}
request封装
自定义OkRequest类继承Request（Volley）类。
private RequestBody requestBody;
public OkRequest(int method, String url, RequestBody body, @Nullable Response.ErrorListener listener) {
super(method, url, listener);
this.requestBody = body;
}
@Override
public String getUrl() {
if (isRequestBodyNoNeed())
return super.getUrl() + "?" + getParamsString();
else
return super.getUrl();
}
protected String getParamsString() {
Buffer buffer = new Buffer();
try {
requestBody.writeTo(buffer);
} catch (IOException e) {
e.printStackTrace();
}
return buffer.readUtf8();
}
protected boolean isRequestBodyNoNeed() {
return (getMethod() == Method.GET || getMethod() == Method.DELETE) && requestBody != null;
}
public void setRequestBody(RequestBody body) {
this.requestBody = body;
}
public RequestBody getRequestBody() {
return requestBody;
}
@Override
public String getBodyContentType() {
if (!isRequestBodyNoNeed() && requestBody != null) {
return requestBody.contentType().toString();
}
return super.getBodyContentType();
}
@Override
public byte[] getBody() throws AuthFailureError {
if (!isRequestBodyNoNeed() && requestBody != null) {
Buffer buffer = new Buffer();
try {
requestBody.writeTo(buffer);
return buffer.readByteArray();
} catch (IOException e) {
e.printStackTrace();
return null;
} finally {
buffer.close();
}
} else {
return super.getBody();
}
在这里处理url的拼接，请求体，和数据类型（content-type）以及头信息。
头信息我放在了HttpClient类处理。
DataRequest MessageRequest GsonRequest ModelRequest
这四个类都继承OkRequest。区别在与处理数据不通。
-
DataRequest：
-
MessageRequest：
DataRequest和MessageRequest 差不多相同，都时根据业务逻辑和接口文档定义出来的。
适用于这样的返回
{"flag":true,"data":{"url":"/mcph5Version/downLoad","version":"254"},"state":"200","msg":"成功返回"}
DataRequest：取出来的数据data数据。
MessageRequest：取出来的时msg数据。 -
GsonRequest：
获取到的JsonElement数据，可以说时万能的request。
private DataHandler mHandler;
private Response.Listener<JsonElement> mListener;
public GsonRequest(int method, String url, RequestBody requestBody, DataHandler handler, Response.Listener<JsonElement> listener, @Nullable Response.ErrorListener errorListener) {
super(method, url, requestBody, errorListener);
this.mListener = listener;
if(handler == null){
handler = new DataHandler();
}
this.mHandler = handler;
}
public GsonRequest(int method, String url, @NonNull Response.Listener<JsonElement> listener, Response.ErrorListener errorListener) {
this(method, url, null, listener, errorListener);
}
public GsonRequest(int method, String url, RequestBody body, @NonNull Response.Listener<JsonElement> listener, Response.ErrorListener errorListener) {
super(method, url, body, errorListener);
this.mListener = listener;
}
@Override
protected Response<JsonElement> parseNetworkResponse(NetworkResponse response) {
try {
dd(new String(response.data, HttpHeaderParser.parseCharset(response.headers)).trim());
JsonElement element = new JsonParser().parse(new String(response.data, HttpHeaderParser.parseCharset(response.headers)).trim());
return Response.success(element, HttpHeaderParser.parseCacheHeaders(response));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return Response.error(new ParseError(e));
}
}
@Override
protected void deliverResponse(JsonElement response) {
mListener.onResponse(response);
}
}
在成功回调中使用Gson就可以解析出来。
- ModelRequest：
public class ModelRequest<T> extends OkRequest<T> {
private Type type;
private Response.Listener<T> mListener;
private DataHandler mHandler;
public ModelRequest(int method, String url, Type type, @NonNull Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, url, null, type, null, listener, errorListener);
}
public ModelRequest(int method, String url, RequestBody requestBody, Type type, @NonNull Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, url, requestBody, type, null, listener, errorListener);
}
public ModelRequest(int method, String url, Type type, DataHandler dataHandler, @NonNull Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, url, null, type, dataHandler, listener, errorListener);
}
public ModelRequest(int method, String url, RequestBody requestBody, Type type, DataHandler dataHandler, @NonNull Response.Listener<T> listener, Response.ErrorListener errorListener) {
super(method, url, requestBody, errorListener);
this.type = type;
this.mListener = listener;
if (dataHandler == null) {
dataHandler = new DataHandler();
}
mHandler = dataHandler;
}
public Type getType() {
return type;
}
public DataHandler getDataHandler() {
return mHandler;
}
@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
try {
JsonObject json = mHandler.parseGsonResponse(response).getAsJsonObject();
if (mHandler.isSuccess(response, json)) {
return Response.success((T) Model.commonCreate(mHandler.getData(response, json), type), HttpHeaderParser.parseCacheHeaders(response));
} else {
return Response.error(new VolleyRequestError(this, mHandler.getStatusCode(response, json), mHandler.getMessage(response, json)));
}
} catch (UnsupportedEncodingException e) {
return Response.error(new ParseError(e));
}
}
@Override
protected void deliverResponse(T response) {
mListener.onResponse(response);
}
}
使用时需要传入转换的类型，然后由Gson把亲故的数据转换成实体类。
在定义接口时：
public Request<?> queryHospitalInfo(Context context, int now_page, int row_num, String hospital_name, Response.Listener<HospitalInfo> listener, Response.ErrorListener error) {
String url = API_CLAIM_QUERY_HOSPITAL_INFO;
McpJsonBuilder builder = new McpJsonBuilder();
builder.add("now_page", 1);
builder.add("row_num", 20);
builder.add("hospital_name", hospital_name);
RequestBody requestBody = builder.build();
return addModelRequest(context, POST, url, requestBody, requestBody, HospitalInfo.class, listener, error);
}
使用ModelRequest 在定义接口时，需要传入类型，HospitalInfo.class。
如果是一个集合应该这样写：
public Request<?> queryBankInfo(Context context, Response.Listener<List<BankData>> listener, Response.ErrorListener error) {
String url = API_CLAIM_QUERY_BANK_INFO;
McpJsonBuilder builder = new McpJsonBuilder();
RequestBody requestBody = builder.build();
return addModelRequest(context, POST, url, requestBody, requestBody, new TypeToken<List<BankData>>() {
}.getType(), listener, error);
}
其它不变。
设置策略
public <T> Request<?> addModelRequest(Context context, int method, String url,
RequestBody requestBody, Type type, final RequestBody requestBodyForHeader,
RetryPolicy retryPolicy,
Response.Listener<T> listener, @NonNull Response.ErrorListener error) {
ModelRequest<T> request =
new ModelRequest<T>(method, getAbsoluteUrl(url), requestBody, type, mDataHandler, listener,
error) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return generateHeader(requestBodyForHeader);
}
};
request.setRetryPolicy(retryPolicy);
return add(context, request);
}
public Request<?> addMessageRequest(Context context, int method, String url,
RequestBody requestBody, final RequestBody requestBodyForHeader,
RetryPolicy retryPolicy,
Response.Listener<String> listener, @NonNull Response.ErrorListener error) {
MessageRequest request =
new MessageRequest(method, getAbsoluteUrl(url), requestBody, mDataHandler, listener,
error) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return generateHeader(requestBodyForHeader);
}
};
request.setRetryPolicy(retryPolicy);
return add(context, request);
}
public Request<?> addDataRequest(Context context, int method, String url, RequestBody requestBody,
final RequestBody requestBodyForHeader,
RetryPolicy retryPolicy,
Response.Listener<JsonElement> listener,
@NonNull Response.ErrorListener error) {
DataRequest request =
new DataRequest(method, getAbsoluteUrl(url), requestBody, mDataHandler, listener, error) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return generateHeader(requestBodyForHeader);
}
};
request.setRetryPolicy(retryPolicy);
return add(context, request);
}
public Request<?> addGsonRequest(final Context context, int method, String url,
RequestBody requestBody, final RequestBody requestBodyForHeader,
RetryPolicy retryPolicy,
Response.Listener<JsonElement> listener, @NonNull Response.ErrorListener error) {
GsonRequest request =
new GsonRequest(method, getAbsoluteUrl(url), requestBody, mDataHandler, listener,
error) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return generateHeader(requestBodyForHeader);
}
};
request.setRetryPolicy(retryPolicy);
return add(context, request);
}
public Request<?> addGsonRequest(Context context, int method, String url, RequestBody requestBody, RequestBody requestBodyForHeader, Response.Listener<JsonElement> listener, Response.ErrorListener error) {
return addGsonRequest(context, method, url, requestBody, requestBodyForHeader,
new DefaultRetryPolicy(DEFAULT_SOCKET_TIMEOUT_MS, DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT),
listener, error);
}
在定义接口时，这几个方法对应上面的说的request。
这里都时做了相同的几件事：
- 定义头信息
generateHeader方法 - 设置策略
- 把请求添加到队列
- 获取到完整的url
完整的url是由下面组成的
private static final String mDebugApiHost = "http://mtest.baidu.cn/abcd/";
private String getBaseHost() {
return mDebugApiHost;
}
public static final String API_CLAIM_QUERY_CLAIM_PAGE = "/api/claim/query-claim-page";
public Request<?> queryClaimPage(Context context, String page_id, String report_id, Response.Listener<JsonElement> listener, Response.ErrorListener error) {
String url = API_CLAIM_QUERY_CLAIM_PAGE;
JsonBuilder builder = new JsonBuilder();
builder.add("page_id", page_id);
builder.add("report_id", report_id);
RequestBody requestBody = builder.build();
return addGsonRequest(context, POST, url, requestBody, requestBody, listener, error);
}
最后调用VolleyClient的方法，得到完整的url
public String getAbsoluteUrl(String relativeUrl) {
return !relativeUrl.startsWith("http://") && !relativeUrl.startsWith("https://") ? (relativeUrl.startsWith("/") ? this.getHost() + relativeUrl.substring(1) : this.getHost() + relativeUrl) : relativeUrl;
}
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