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Android--Retrofit浅入深出

2016-06-15 15:46 411 查看

官网：http://square.github.io/retrofit/

官方定义：

A type-safe HTTP client for Android and Java

一：配置

app:build.gradle:

compile 'com.squareup.retrofit2:retrofit:2.0.2'

二：例子

–1：BaseResponse

public class BaseResponse {
String returnCode;
String msg;
String result;
boolean success;

public String getReturnCode() {
return returnCode;
}

public void setReturnCode(String returnCode) {
this.returnCode = returnCode;
}

public String getMsg() {
return msg;
}

public void setMsg(String msg) {
this.msg = msg;
}

public String getResult() {
return result;
}

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

public boolean isSuccess() {
return success;
}

public void setSuccess(boolean success) {
this.success = success;
}
}

–2:HtppService

public interface HttpService {
@FormUrlEncoded
@POST("/frist/noIntercept/user/login.do")
Call<UserResponse> getUserByLogin(@Field("password") String password, @Field("phone") String phone);

}

–3:User

public class User {
private int id;
private boolean invalid;
private int status;
private long createdDatetime;
private long updatedDatetime;
private int orderTag;
private String name;
private String phone;
private String password;
private String slogan;
private String imagpath;
private int userid;
private int sex;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public boolean isInvalid() {
return invalid;
}

public void setInvalid(boolean invalid) {
this.invalid = invalid;
}

public int getStatus() {
return status;
}

public void setStatus(int status) {
this.status = status;
}

public long getCreatedDatetime() {
return createdDatetime;
}

public void setCreatedDatetime(long createdDatetime) {
this.createdDatetime = createdDatetime;
}

public long getUpdatedDatetime() {
return updatedDatetime;
}

public void setUpdatedDatetime(long updatedDatetime) {
this.updatedDatetime = updatedDatetime;
}

public int getOrderTag() {
return orderTag;
}

public void setOrderTag(int orderTag) {
this.orderTag = orderTag;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getPhone() {
return phone;
}

public void setPhone(String phone) {
this.phone = phone;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

public String getSlogan() {
return slogan;
}

public void setSlogan(String slogan) {
this.slogan = slogan;
}

public String getImagpath() {
return imagpath;
}

public void setImagpath(String imagpath) {
this.imagpath = imagpath;
}

public int getUserid() {
return userid;
}

public void setUserid(int userid) {
this.userid = userid;
}

public int getSex() {
return sex;
}

public void setSex(int sex) {
this.sex = sex;
}
}

–4:BaseResponse

public class UserResponse extends BaseResponse {

private RespData data;

public RespData getData() {
return data;
}

public void setData(RespData data) {
this.data = data;
}

public static class RespData {
private User user;

public User getUser() {
return user;
}

public void setUser(User user) {
this.user = user;
}

}
}

–5:MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String WEB_URL = "http://192.168.1.115:8080";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.start).setOnClickListener(this);
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.start:
getUser();
break;
}
}

private void getUser() {
Retrofit retrofit = new Retrofit.Builder().baseUrl(WEB_URL).addConverterFactory(GsonConverterFactory.create()).build();

HttpService httpService = retrofit.create(HttpService.class);
String phone = "15029206553";
String password = "123456";
Call<UserResponse> call = httpService.getUserByLogin(password, phone);
call.enqueue(new Callback<UserResponse>() {
@Override
public void onResponse(Call<UserResponse> call, Response<UserResponse> response) {
Toast.makeText(MainActivity.this, "respone" + response.body().getData().getUser().getImagpath(), Toast.LENGTH_LONG).show();
}

@Override
public void onFailure(Call<UserResponse> call, Throwable t) {
}
});
}
}

注：可以看出，接口返回的是需要的JAVA对象，不是而不是byte[]或String！Retrofit内部默认使用Gson解析相关数据。

三：相关方法：

—-1：支持：GET, POST, PUT, DELETE, and HEAD！

@GET("users/list")
@GET("/frist/noIntercept/user/login.do")

Call<UserResponse> getUserByLogin(@Query("password") String password, @Query("phone") String phone);

也可以直接在请求接口中显示需要的参数，类似于：

@GET("users/list?sort=desc")

@GET("/frist/noIntercept/user/login.do?password=123456&phone=15029206553")
Call<UserResponse> getUserByLogin();

使用技巧：当我们使用POST方式无参去请求数据的时候，请修改为无参的GET请求。

- - 2：可以动态更新请求块里面的参数和方法，一个相应的参数必须和@Path保持同样的字符串

@GET("group/{id}/users")
Call<List<User>> groupList(@Path("id") int groupId);

@GET("/frist/noIntercept/{user}/login.do?password=123456&phone=15029206553")
Call<UserResponse> getUserByLogin(@Path("user") String user);

也可以使用查询方法来添加相关参数，类似于：

@GET("group/{id}/users")
Call<List<User>> groupList(@Path("id") int groupId, @Query("sort") String sort);

@GET("/frist/noIntercept/{user}/login.do")
Call<UserResponse> getUserByLogin(@Path("user") String user,@Query("password") String password, @Query("phone") String phone);

—-3：Map使用

@GET("group/{id}/users")
Call<List<User>> groupList(@Path("id") int groupId, @QueryMap Map<String, String> options);

使用技巧：对于复杂参数，可以使用Map来组合请求对象。

—-4：JavaBean作为请求体<添加转换器，若没有添加，只能使用response>

@POST("users/new")Call<User> createUser(@Body User user);

public class LoginBean {
String password;
String phone;

public  LoginBean(String password, String phone){
this.password=password;
this.phone=phone;
}
}

@POST("/frist/noIntercept/user/login.do")
Call<UserResponse> getUserByLogin(@Body LoginBean loginBean);
String phone = "15029206553";
String password = "123456";
LoginBean loginBean=new LoginBean(password,phone);
Call<UserResponse> call = httpService.getUserByLogin(loginBean);

注意点：使用此种方式传参，需要修改后台正常获取参数的方式，慎用。

—-5：指定请求编码类型

@FormUrlEncoded
@POST("user/edit")
Call<User> updateUser(@Field("first_name") String first, @Field("last_name") String last);

@FormUrlEncoded
@POST("/frist/noIntercept/user/login.do")
Call<UserResponse> getUserByLogin(@Field("password") String password, @Field("phone") String phone);

—-6：操作Head

@Headers("Cache-Control: max-age=640000")
@GET("widget/list")
Call<List<Widget>> widgetList();

也可以写成下面：

@Headers({
"Accept: application/vnd.github.v3.full+json",
"User-Agent: Retrofit-Sample-App"})
@GET("users/{username}")
Call<User> getUser(@Path("username") String username);

注：当@Headers{}为空时，则会自动忽略。

—-7：每个请求都添加Head:<动态更新>

@GET("user")
Call<User> getUser(@Header("Authorization") String authorization)

—-8：使用ConverterFactory来修改默认返回数据解析<可自定义转换器>

Retrofit默认使用GSON进行相关数据解析。

下面是一个使用GsonConverterFactory生成JSON解析数据的例子：

Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.github.com")
.addConverterFactory(GsonConverterFactory.create())
.build();
GitHubService service = retrofit.create(GitHubService.class);

四：简单封装：

–1：RetrofitUtil:

public class RetrofitUtil {
private static final String WEB_URL = "http://192.168.1.115:8080";

public static HttpService instanceHttpService() {
Retrofit retrofit = new Retrofit.Builder().baseUrl(WEB_URL).addConverterFactory(GsonConverterFactory.create()).build();
HttpService httpService = retrofit.create(HttpService.class);
return httpService;
}
}

–2:MainActivity:

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.start).setOnClickListener(this);
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.start:
getUser();
break;
}
}

private void getUser() {
String phone = "15029206553";
String password = "123456";
Call<UserResponse> call = RetrofitUtil.instanceHttpService().getUserByLogin(password, phone);
call.enqueue(new Callback<UserResponse>() {
@Override
public void onResponse(Call<UserResponse> call, Response<UserResponse> response) {
Toast.makeText(MainActivity.this, "respone" + response.body().getData().getUser().getImagpath(), Toast.LENGTH_LONG).show();
}

@Override
public void onFailure(Call<UserResponse> call, Throwable t) {

}
});
}
}

可以看出来：代码量减少很多。

五：深度封装：

拦截器是一个强大的机制，可以监视，重写，然后重新调用。

–1：

调用链的调用（请求）是每个拦截的执行的一个关键部分：

public class LoggingInterceptor implements Interceptor {

@Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();

long t1 = System.nanoTime();
.....
// request.url(), chain.connection(), request.headers();

Response response = chain.proceed(request);
long t2 = System.nanoTime();
....
// response.request().url(), (t2 - t1) / 1e6d, response.headers();

return response;
}
}

–2：Application interceptors:

—-:拦截器分为应用拦截和网络：

打印拦截器：

HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient httpClient = new OkHttpClient.Builder()
.addInterceptor(logging)//添加打印拦截器
.connectTimeout(30, TimeUnit.SECONDS)//设置请求超时时间
.retryOnConnectionFailure(true)//设置出现错误进行重新连接。
.build();
注意：多了一个.client()方法：
Retrofit retrofit = new Retrofit.Builder().baseUrl(WEB_URL).client(httpClient).addConverterFactory(GsonConverterFactory.create()).build();

因为OKHTTP支持重定向，而Retrofit是基于OKHTTP3建立各种模块的。

–3：重定向

OkHttpClient client = new OkHttpClient.Builder()
.addInterceptor(new LoggingInterceptor())
.build();

Request request = new Request.Builder()
.url("http://www.publicobject.com/helloworld.txt")
.header("User-Agent", "OkHttp Example")
.build();

Response response = client.newCall(request).execute();
response.body().close();

结果为：

INFO: Sending request http://www.publicobject.com/helloworld.txt on null
User-Agent: OkHttp Example

INFO: Received response for https://publicobject.com/helloworld.txt in 1179.7ms
Server: nginx/1.4.6 (Ubuntu)
Content-Type: text/plain
Content-Length: 1759
Connection: keep-alive

–4：网络监听器

.addNetworkInterceptor(new LoggingInterceptor())

应用和网络拦截器比对：

应用拦截器：
--1：不用担心请求时重定向和定向次数
--2：调用次数为一次<缓存>
--3：允许重试，多次调用请求链<okhttp请求是通过链路进行管理的>
--4：可以观察应用的意图，在请求或者返回数据的时候进行相关匹配以及处理
网络拦截器：
--1：观察数据传输

六：特殊需求：

–1：所有网络请求都添加token:

Interceptor mToken = new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Request originalRequest = chain.request();
if (You.token == null || alreadyHasAuthorizationHeader(originalRequest)) {
return chain.proceed(originalRequest);
}
Request authorised = originalRequest.newBuilder()
.header("Authorization", You.token)
.build();
return chain.proceed(authorised);
}
};

public static boolean alreadyHasAuthorizationHeader(Request request) {
if (request != null) {
if (request.headers() != null) {
return true;
} else {
return false;
}
}
return false;
}

–1:

—-：if判断，当你有token的时候才会进行添加，或者请求验证中已经有hrader了，那么就不执行这个token了。

—-：header 的 key 通常是 Authorization，可以修改

2–：添加公私密钥

MarvelSigningInterceptor signingInterceptor = new MarvelSigningInterceptor(KeyValue.MARVEL_PUBLIC_KEY, KeyValue.MARVEL_PRIVATE_KEY);

3–：添加缓存策略

File cacheFile = new File(context.getCacheDir(), "ZhiBookCache");
Cache cache = new Cache(cacheFile, 1024 * 1024 * 50);
Interceptor interceptorCache = new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
if (!NetworkStateUtils.getInstance(context).isConnection()) {
request = request.newBuilder()
.cacheControl(CacheControl.FORCE_CACHE)
.build();
}
Response response = chain.proceed(request);
if (NetworkStateUtils.getInstance(context).isConnection()) {
int maxAge = 0 * 60;
// 有网络时 设置缓存超时时间0个小时
response.newBuilder()
.header("Cache-Control", "public, max-age=" + maxAge)
.removeHeader("Pragma")// 清除头信息，因为服务器如果不支持，会返回一些干扰信息，不清除下面无法生效
.build();
} else {
// 无网络时，设置超时为4周
int maxStale = 60 * 60 * 24 * 28;
response.newBuilder()
.header("Cache-Control", "public, only-if-cached, max-stale=" + maxStale)
.removeHeader("Pragma")
.build();
}
return response;
}
};

七：再次封装：

–1：

public abstract class RCllBack<T> implements Callback<T> {
@Override
public void onResponse(Call<T> call, Response<T> response) {
onSuccess(response.body());
}

@Override
public void onFailure(Call<T> call, Throwable t) {

}

public abstract void onSuccess(T response);
}

–2：

public abstract class RCllBaackComm<T> implements Callback<T> {
@Override
public void onResponse(Call<T> call, Response<T> response) {

BaseResponse resp = (BaseResponse) response.body();
//在此可以根据自己的功能需求进行相关判断
}

@Override
public void onFailure(Call<T> call, Throwable t) {
onFailed(new CommError("网络错误"));
}

public abstract void onSuccess(T response);

public abstract void onFailed(CommError error);

}

概念理解：

onResponse: HTTP有效也就是请求返回为200，返回数据

因此在此方法里面，可以根据自己和服务器返回值的约定进行相关处理；

onFailure:当请求地址不存在或者其他原因<无网络>

以下为三种不同方法用起来的差异：

Call<UserResponse> call = RetrofitUtil.service.getUserByLogin(password, phone);
//1
call.enqueue(new Callback<UserResponse>() {
@Override
public void onResponse(Call<UserResponse> call, Response<UserResponse> response) {
Toast.makeText(MainActivity.this, "respone" + response.body().getData().getUser().getImagpath(), Toast.LENGTH_LONG).show();
}

@Override
public void onFailure(Call<UserResponse> call, Throwable t) {

}
});
//2
call.enqueue(new RCllBack<UserResponse>() {
@Override
public void onSuccess(UserResponse response) {

}
});
//3
call.enqueue(new RCllBaackComm<UserResponse>() {
@Override
public void onSuccess(UserResponse response) {

}

@Override
public void onFailed(CommError error) {

}
});