*æ¬ç¯æç« å·²ææå¾®ä¿¡å ¬ä¼å· guolin_blog ï¼ééï¼ç¬å®¶åå¸
-
åè¨
æ¬æä¼è®²è§£Coroutineçä¼ç¹ï¼ä»¥åä¸æ¥æ¥çä»é¶å¼å§æ¹é Retrofit+Coroutineï¼å¯¹æ¹é ä¸çå ³é®é®é¢è¿è¡è®²è§£ï¼ç»åºè¯¦ç»å¯è¿è¡ç示ä¾ä»£ç ãæåä¼ç»åºDemo,Demoç»è¿ç®åä¿®æ¹å¯ä»¥ç´æ¥è¿ç¨å¨èªå·±çå®é 项ç®ä¸ã
-
Kotlin Coroutine ç®ä»
Kotlin coroutines let you convert callback-based code to sequential code. Code written sequentially is typically easier to read, and can even use language features such as exceptions.
Coroutineå¯ä»¥è®©ä½ æåºäºcallbackç代ç 转æ¢æ顺åºä»£ç .
使ç¨Coroutineä¼æ以ä¸å 个好å¤ï¼
- 顺åºç¼åç代ç æ´æ读
- 使ç¨Coroutineå¯ä»¥ä¸ç»ä»¶ççå½å¨æç¸å ³èï¼å¨çå½å¨æç»æåèªå¨åæ¶Coroutine,èä¸å®æ¹å¯¹Androidå¼åä¸å¸¸ç¨çåºæ¯é½æä¾äºCoroutineScopeï¼ä½ å¯ä»¥ç´æ¥ä½¿ç¨ï¼ä¸ç¨åå ³å¿çå½å¨æé®é¢ï¼æ¯å¦å¨ActivityåFragmentä¸ä½¿ç¨ç viewModelScope
- Coroutineç¸å¯¹äºRxjavaçææ¯ä¼æ´æ读ï¼æ´æç¨ï¼æ´æè°è¯ï¼èä¸æ¯å®æ¹æ¯æï¼æ以æ 论æ¯å¦ä¹ èµæï¼åæç»´æ¤ï¼è¿æ¯Android Studioçæ¯æé½ä¼æ´å¥½ã
- 使ç¨Coroutineå¯ä»¥catchå¼æ¥æ§è¡è¿ç¨ä¸çexceptionï¼ä½¿ç¨callbackå½¢å¼ä¸å¯ä»¥ã
详ç»çCoroutineä»ç»ï¼åèå®æ¹æç¨ Coroutines in Kotlin
-
Retrofit + Coroutine
å¦æå°Coroutineä¸Retrofitç»åèµ·æ¥ï¼å°±è½å°Coroutineçä¼ç¹ç¨äºç½ç»è®¿é®ä»£ç ã
-
Retrofit对Coroutineçæ¯æ
Retrofit ä» 2.6.0çæ¬å¼å§æ¯æCoroutine
![](https://img.laitimes.com/img/9ZDMuAjOiMmIsIjOiQnIsICM38FdsYkRGZkRG9lcvx2bjxiNx8VZ6l2cs0TPR9EeFRUT5VERNhXR6JGaSNjYoJ1MMBjVtJWd0ckW65UbM5WOHJWa5kHT20ESjBjUIF2X0hXZ0xCMx81dvRWYoNHLrdEZwZ1Rh5WNXp1bwNjW1ZUba9VZwlHdssmch1mclRXY39CXldWYtlWPzNXZj9mcw1ycz9WL49zZuBnL3EDN3QzNzYTM5AjMxAjMwIzLc52YucWbp5GZzNmLn9Gbi1yZtl2Lc9CX6MHc0RHaiojIsJye.png)
Retrofit Change Log
-
å¼å§æ建Retrofit + Coroutineç½ç»æ¡æ¶
æ们ç¨Retrofit + Coroutineæ¥åä¸ä¸ªAPIç示ä¾ï¼å ¶ä¸ä¼ç¨å°JetpackçViewModel,LiveDataçç»ä»¶ã
æ们æ¥è®¿é®æéè¯å ¸çAPIï¼æ¥ç¿»è¯ä¸ä¸ªåè¯ã
http://fanyi.youdao.com/translate?doctype=json&i=Hello%20world
æ¤æ¶ä¼è¿åï¼
{
"type": "EN2ZH_CN",
"errorCode": 0,
"elapsedTime": 1,
"translateResult": [
[
{
"src": "Hello world",
"tgt": "ä½ å¥½ï¼ä¸ç"
}
]
]
}
æ们æ¥å®ç°è¿ä¸ªAPIã
1. åå§åretrofit
NetworkBase.kt
package com.jst.network
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
private const val BASE_URL = "http://fanyi.youdao.com/"
val retrofit = Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl(BASE_URL)
.build()
å°retrofitå®ä¾å¯¹è±¡ç´æ¥å®ä¹å¨å ä¸é¢ï¼è¿æ ·å ¶ä»ç±»å¨ç¨çæ¶åå¯ä»¥ç´æ¥ç¨"retrofit"ï¼ä¸ç¨ä½¿ç¨ âç±»å.retrofitâ,ååæ¹ä¾¿
2. å®ä¹Translateæ¥å£ ç¸å ³çç±»
TranslateApiService.kt
interface TranslateApiService {
@FormUrlEncoded
@POST("translate?doctype=json")
suspend fun translate(@Field("i")i:String):Result
}
data class Result(
val type: String,
val elapsedTime: Int,
val translateResult: List<List<TranslateResult>>
) {
data class TranslateResult(
val src:String,
val tgt:String
)
}
object TranslateApi{
val retrofitService: TranslateApiService by lazy { retrofit.create(TranslateApiService::class.java) }
}
kotlinéå¯ä»¥å°å¤ä¸ªç±»å®ä¹å¨ä¸ä¸ªæ件éï¼å 为ä¸ä¸ªAPIæ¥å£ä¼å å«è¥å¹²ä¸ªç¸å ³çç±»ï¼æ以æ们æè¿äºç±»å®ä¹å¨ä¸ä¸ªæ件éä¼æ¹ä¾¿ç®¡çï¼ä¹ä½¿å¾æ们çå·¥ç¨é没æé£ä¹å¤ç¢çæ件ï¼çèµ·æ¥ä¼å¾ç®æ´ã
æ们ä¹æ以ä¼å®ä¹ä¸ä¸ªobject TranslateApiï¼æ¯å 为
retrofit.create(TranslateApiService::class.java)
æ¯ä¸ä¸ªæ¯è¾éçæä½ï¼æ以æ们å°ç»ææ¾å¨objectéä¿åï¼è¿æ ·ä¸æ¬¡åç¨çæ¶åå°±ä¸ä¼éå¤è°ç¨retrofit.create
by lazy{} å¯ä»¥å®ç°å»¶è¿åå§åï¼å½property retrofitService 被第ä¸æ¬¡è®¿é®æ¶æ§è¡lazy{} åéç代ç è¿åä¸ä¸ªTranslateApiServiceå®ä¾èµå¼ç»retrofitServiceï¼ä¸æ¬¡å访é®æ¶ä¼å¤ç¨ä¹åè¿åçTranslateApiServiceå®ä¾ï¼è¯¦è§kotlinéçDelegated Properties
3. å¨ViewModelé访é®Translateæ¥å£
MainViewModel
class MainViewModel : ViewModel() {
private val _translateResult: MutableLiveData<String> = MutableLiveData()
val translateResult: LiveData<String>
get() = _translateResult
fun translate(word: String) {
viewModelScope.launch {
val result = TranslateApi.retrofitService.translate(word)
_translateResult.value = result.translateResult[0][0].tgt
}
}
}
æ们å¯ä»¥çç½ç»è®¿é®ç代ç ï¼å°±ä¸è¡ï¼ä½¿ç¨Coroutine以åè¿é没æcallback,代ç æ¯é¡ºåºä»£ç ï¼å°±åä½ æ³è¦è¡¨è¾¾çé»è¾é£æ ·é¡ºåºåä¸æ¥ãè¿ä»£ç å¯è¯»æ§æ¯ä¸æ¯å¥½å°æ²¡æåã
4. å¨Fragmentéè°ç¨ViewModel
MainFragmentï¼
class MainFragment : Fragment() {
companion object {
fun newInstance() = MainFragment()
}
private val viewModel: MainViewModel by viewModels()
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View {
return inflater.inflate(R.layout.main_fragment, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
val word = "Hello world"
textview.text = "æ£å¨ç¿»è¯â¦â¦"
viewModel.translateResult.observe(viewLifecycleOwner){
textview.text = "åè¯: $word \nç¿»è¯: $it"
}
viewModel.translate(word)
}
}
使ç¨ViewModel+LiveData,æ们ç代ç é»è¾ä¹åå¾å¾æ¸ æ°ã
5. æµè¯è¿è¡
æ们ç示ä¾ä»£ç å·²ç»æ建å®äºï¼è¿è¡ä¸ä¸
è½å¤æ£ç¡®æ¾ç¤ºç¿»è¯ç»æï¼è¯´ææ们çç½ç»è¯·æ±ä»è¯·æ±ååºï¼å°jsonæ°æ®ååºååæ对象è¿æ´å¥æµç¨æ¯æ£å¸¸çã
代ç é»è¾æ¸ æ°ï¼æµè¯ç»ææ£å¸¸ï¼æ¯ä¸æ¯ä¸åé½okäºå¢ï¼
æ¾ç¶ä¸æ¯çï¼æ们å°èèäºä¸ç§æ åµï¼å¦æ没æç½ç»ï¼æè æå¡å¨å¼å¸¸ï¼é£ä¹
val result = TranslateApi.retrofitService.translate(word)
è¿éçresultä¼è¿åä»ä¹å¢ï¼
æ们å°ç½ç»æå¼ï¼åæµè¯ä¸ä¸ï¼
åç°ç¨åºå´©æºäºï¼
æ们è¯å®ä¸è½å¨å¼å¸¸æ åµä¸ç´æ¥è®©ç¨åºå´©æºï¼æ以æ们è¦å¤çå¼å¸¸æ åµã
-
å¼å¸¸æ åµå¤ç
1. åå åæ
ä¹æ以ä¼å´©æºæ¯å 为
val result = TranslateApi.retrofitService.translate(word)
å¨å¼å¸¸æ åµä¸ä¼throw Exceptionï¼èæ们çç¨åºæ²¡æå¤çExceptionï¼æ以ç¨åºå´©æºäºã
2. 解å³æ¹æ¡1ï¼try catch Exception
å¾å®¹ææ们就æ³å°ï¼å¯ä»¥try catch Exception
ä¿®æ¹åç MainViewModelï¼
class MainViewModel : ViewModel() {
private val _translateResult: MutableLiveData<String> = MutableLiveData()
val translateResult: LiveData<String>
get() = _translateResult
fun translate(word: String) {
viewModelScope.launch {
try {
val result = TranslateApi.retrofitService.translate(word)
_translateResult.value = result.translateResult[0][0].tgt
} catch (e: Exception) {
_translateResult.value = e.message
}
}
}
}
å次è¿è¡ï¼åç°ç¨åºä¸å´©æºäºã
è¿æ ·æ¯ä¸æ¯å°±okäºå¢ï¼
å´©æºç¡®å®æ¯ä¸å´©æºäºï¼ä½æ¯èèæ们å¨å¼åè¿ç¨ä¸çå®é éæ±ï¼è¿ç§æ¹æ¡åå¨å 个é®é¢ï¼
- æ们çç½ç»æ¡æ¶ä¾èµäºtry catchçè¯å°±ä¼å¾å®¹æåºé
æ¯å¦ï¼å¼å人åå¾å®¹æå¿äºtry catchï¼èä¸è¿ç§æ åµä¸ä¹æ²¡æç¼è¯æ示ãä»æµè¯çæ¶åç½ç»å¾å¥½ï¼æ以ä¸åæ£å¸¸ï¼ä½æ¯å°ç¨æ·é£ä¸æ¦ç½ç»ä¸å¥½å°±å´©æºäº
- æ¤æ¶çe.messageé没ææ们æ³å±ç¤ºç»ç¨æ·çæ示信æ¯
æ们é常çç½ç»æ¡æ¶å¨å¼å¸¸çæ¶åï¼éè¦æä¾errorCode åerrorMsg,ç®åè¿ç§try catchçæ¹æ¡æ æ³æ»¡è¶³æ们çéæ±ã
åºäºä¸é¢ä¸¤ä¸ªåå ï¼æ们éè¦éæå¼å¸¸å¤çã
-
éæå¼å¸¸å¤ç
æ们ä¸æ³ä¾èµäºtry catch,ä½æ¯åæ³å¤çç½ç»è¯·æ±è¿ç¨ä¸çå¼å¸¸æ åµï¼èä¸è¦å¢å errorCodeåerrorMsgå¼å¸¸ä¿¡æ¯ï¼æ们å¦ä½æ¥å®ç°å¢ï¼
æ们å¯ä»¥èªå®ä¹RetrofitçCallAdapteræ¥æ»¡è¶³æ们çéæ±ã
-
èªå®ä¹CallAdapter
CallAdapteræ¯ç±CallAdapterFactoryçæçï¼æ们å æ¥çä¸ä¸CallAdapterFactoryçå®ä¹
CallAdapter.Factoryï¼
/**
* Creates {@link CallAdapter} instances based on the return type of {@linkplain
* Retrofit#create(Class) the service interface} methods.
*/
abstract class Factory {
/**
* Returns a call adapter for interface methods that return {@code returnType}, or null if it
* cannot be handled by this factory.
*/
public abstract @Nullable CallAdapter<?, ?> get(
Type returnType, Annotation[] annotations, Retrofit retrofit);
/**
* Extract the upper bound of the generic parameter at {@code index} from {@code type}. For
* example, index 1 of {@code Map<String, ? extends Runnable>} returns {@code Runnable}.
*/
protected static Type getParameterUpperBound(int index, ParameterizedType type) {
return Utils.getParameterUpperBound(index, type);
}
/**
* Extract the raw class type from {@code type}. For example, the type representing {@code
* List<? extends Runnable>} returns {@code List.class}.
*/
protected static Class<?> getRawType(Type type) {
return Utils.getRawType(type);
}
}
æºç 注éå·²ç»åçå¾æ¸ æ¥äºï¼è¿éé¢æ¯ä¸ªæ¹æ³ç注éé½è¦è¯»ï¼åé¢åçæ¶åé½ä¼ç¨å°ã
æ»ç»ï¼
Factoryçä½ç¨å°±æ¯æ ¹æ®ä½ å®ä¹çæ¥å£ï¼ä¸ä¾ä¸çTranslateApiServiceï¼çè¿åå¼ç±»åæ¥å¤ææ¯å¦æ¯è¯¥CallAdapteréè¦å¤ççè¿åå¼ç±»åï¼å¦ææ¯ï¼åè¿åä¸ä¸ªå¤ç该è¿åå¼ç±»åçCallAdapterï¼å¦æä¸æ¯ï¼åè¿ånull
CallAdapter:
/**
* Adapts a {@link Call} with response type {@code R} into the type of {@code T}. Instances are
* created by {@linkplain Factory a factory} which is {@linkplain
* Retrofit.Builder#addCallAdapterFactory(Factory) installed} into the {@link Retrofit} instance.
*/
public interface CallAdapter<R, T> {
/**
* Returns the value type that this adapter uses when converting the HTTP response body to a Java
* object. For example, the response type for {@code Call<Repo>} is {@code Repo}. This type is
* used to prepare the {@code call} passed to {@code #adapt}.
*
* <p>Note: This is typically not the same type as the {@code returnType} provided to this call
* adapter's factory.
*/
Type responseType();
/**
* Returns an instance of {@code T} which delegates to {@code call}.
*
* <p>For example, given an instance for a hypothetical utility, {@code Async}, this instance
* would return a new {@code Async<R>} which invoked {@code call} when run.
*
* <pre><code>
* @Override
* public <R> Async<R> adapt(final Call<R> call) {
* return Async.create(new Callable<Response<R>>() {
* @Override
* public Response<R> call() throws Exception {
* return call.execute();
* }
* });
* }
* </code></pre>
*/
T adapt(Call<R> call);
}
è¿éé¢çæ¯ä¸ªæ³¨éä¹é½è¦çï¼è¿éçæ¹æ³åé¢åçæ¶åä¹é½ä¼ç¨å°ã
æ»ç»ï¼
T adapt(Call<R> call);
CallAdapter顾åæä¹å°±æ¯CallçAdapterï¼Callæçæ¯retrofitéçCall对象retrofit2.Call
Callï¼
/**
* An invocation of a Retrofit method that sends a request to a webserver and returns a response.
* Each call yields its own HTTP request and response pair. Use {@link #clone} to make multiple
* calls with the same parameters to the same webserver; this may be used to implement polling or to
* retry a failed call.
*
* <p>Calls may be executed synchronously with {@link #execute}, or asynchronously with {@link
* #enqueue}. In either case the call can be canceled at any time with {@link #cancel}. A call that
* is busy writing its request or reading its response may receive a {@link IOException}; this is
* working as designed.
*
* @param <T> Successful response body type.
*/
public interface Call<T> extends Cloneable {
/**
* Synchronously send the request and return its response.
*
* @throws IOException if a problem occurred talking to the server.
* @throws RuntimeException (and subclasses) if an unexpected error occurs creating the request or
* decoding the response.
*/
Response<T> execute() throws IOException;
/**
* Asynchronously send the request and notify {@code callback} of its response or if an error
* occurred talking to the server, creating the request, or processing the response.
*/
void enqueue(Callback<T> callback);
/**
* Returns true if this call has been either {@linkplain #execute() executed} or {@linkplain
* #enqueue(Callback) enqueued}. It is an error to execute or enqueue a call more than once.
*/
boolean isExecuted();
/**
* Cancel this call. An attempt will be made to cancel in-flight calls, and if the call has not
* yet been executed it never will be.
*/
void cancel();
/** True if {@link #cancel()} was called. */
boolean isCanceled();
/**
* Create a new, identical call to this one which can be enqueued or executed even if this call
* has already been.
*/
Call<T> clone();
/** The original HTTP request. */
Request request();
/**
* Returns a timeout that spans the entire call: resolving DNS, connecting, writing the request
* body, server processing, and reading the response body. If the call requires redirects or
* retries all must complete within one timeout period.
*/
Timeout timeout();
}
è¿ä¸ªCall对象å¯ä»¥å®æåæ¥æå¼æ¥çç½ç»è¯·æ±ã
Retrofitæè¿æ ·çä¸ä¸ªCallå¯¹è±¡ä¼ éç»adaptæ¹æ³ï¼ç¶åä¸åçCallAdapterå¯ä»¥å°è¿ä¸ªCall对象å è£ æä½ éè¦è¿åç»ç¨æ·ä½¿ç¨çT对象ï¼T对象çå é¨æ¯ä½¿ç¨Call对象çç½ç»è¯·æ±çè½åã
æ¯å¦åRxjava,æ们éè¦è®©ç¨æ·å¨å®ä¹ç½ç»æ¥å£çæ¶åç´æ¥è¿åä¸ä¸ªObservable对象
interface MyService {
@GET("/user")
Observable<User> getUser();
}
é£ä¹æ们就å¯ä»¥å®ä¹ä¸ä¸ªRxJavaCallAdapteræ¥å°Call对象å è£ æObservable对象ãå½ç¶å¯¹äºRxJavaçè¿ç§æ åµï¼å®æ¹å·²ç»æä¾äºCallAdapterã
é对æ们ç®åçéæ±ï¼æ们éè¦å¨ç½ç»è¯·æ±æåçæ¶åè¿åæ°æ®Bean对象ï¼å¨ç½ç»è¯·æ±å¤±è´¥çæ¶åè¿åä¸ä¸ªå å«äºerrorCodeåerrorMsgç对象ï¼Kotlinçsealed classæ¯è¾éåæ们çåºæ¯ã
ApiResultï¼
sealed class ApiResult<out T> {
data class Success<out T>(val data: T?):ApiResult<T>()
data class Failure(val errorCode:Int,val errorMsg:String):ApiResult<Nothing>()
}
使ç¨ApiResultåçTranslateApiServiceï¼
interface TranslateApiService {
@FormUrlEncoded
@POST("translate?doctype=json")
suspend fun translate(@Field("i")i:String):ApiResult<Result>
}
æ以æ¥ä¸æ¥æ们çCallAdapterçä»»å¡å°±æ¯å°Call对象å è£ æApiResult对象ã
ä½è¿éé¢è¿æä¸ä¸ªå¾å ³é®çé®é¢ã
-
Retrofit 对suspendæ¹æ³çå é¨å¤ç
ä»å®æ¹æè¿°ä¸æ们å¯ä»¥çå°ï¼
- Retrofit对äºsuspendæ¹æ³ï¼ç¸å½äºå®ä¹äºä¸ä¸ªésuspendæ¹æ³ï¼å¹¶ä¸suspendæ¹æ³åé¢çè¿åå¼å¯¹è±¡Tï¼å®é ä¸ç¸å½äºésuspendæ¹æ³çCall<T>对象
- suspendæ¹æ³çæ§è¡ç¸å½äºæ§è¡äºésuspendæ¹æ³çCall<T>对象çCall.enqueue(callback)
call.enqueue(new Callback<T>() {
//请æ±æåæ¶åçåè°
@Override
public void onResponse(Call<T> call, Response<T> response) {
// å° response.body() ä½ä¸ºsuspendæ¹æ³æåæ¶çè¿åå¼
}
//请æ±å¤±è´¥æ¶åçåè°
@Override
public void onFailure(Call<Translation> call, Throwable throwable) {
// å° throwable ä½ä¸ºsuspendæ¹æ³å¤±è´¥æ¶çå¼å¸¸æåº
}
});
æ以æ们对äºsuspendæ¹æ³èªå®ä¹CallAdapteræ¶è¦å°å®ä½ä¸ºésuspendæ¹æ³æ¥çå¾ ã
æ们å®ä¹ç
interface TranslateApiService {
@FormUrlEncoded
@POST("translate?doctype=json")
suspend fun translate(@Field("i")i:String):ApiResult<Result>
}
ç¸å½äºå®ä¹äº
interface TranslateApiService {
@FormUrlEncoded
@POST("translate?doctype=json")
fun translate(@Field("i")i:String):Call<ApiResult<Result>>
}
æ以æ们çCallAdapterçä½ç¨å°±æ¯å¤çè¿åå¼ç±»å为Call<ApiResult<T>>å½¢å¼çæ¥å£ï¼å¯¹äºCallAdapterçadaptæ¹æ³çä½ç¨å°±æ¯å°retorfitä¼ ç»æ们çCall<T> 转æ¢æCall<ApiResult<T>>
ä¸é¢çä¸ä¸å ·ä½å®ç°
ApiResultCallAdapter.kt:
package com.jst.network.calladapter
import com.jst.network.ApiError
import com.jst.network.ApiResult
import com.jst.network.exception.ApiException
import okhttp3.Request
import okio.Timeout
import retrofit2.*
import java.lang.reflect.ParameterizedType
import java.lang.reflect.Type
class ApiResultCallAdapterFactory : CallAdapter.Factory() {
override fun get(returnType: Type, annotations: Array<Annotation>, retrofit: Retrofit): CallAdapter<*, *>? {
/*å¡æ¯æ£æµä¸éè¿çï¼ç´æ¥æå¼å¸¸ï¼æ示使ç¨è
è¿åå¼ç±»åæ ¼å¼ä¸å¯¹
å 为ApiResultCallAdapterFactoryæ¯ä½¿ç¨è
æ¾å¼è®¾ç½®ä½¿ç¨ç*/
//以ä¸æ¯æ£æ¥æ¯å¦æ¯ Call<ApiResult<T>> ç±»åçreturnType
//æ£æ¥returnTypeæ¯å¦æ¯Call<T>ç±»åç
check(getRawType(returnType) == Call::class.java) { "$returnType must be retrofit2.Call." }
check(returnType is ParameterizedType) { "$returnType must be parameterized. Raw types are not supported" }
//ååºCall<T> éçTï¼æ£æ¥æ¯å¦æ¯ApiResult<T>
val apiResultType = getParameterUpperBound(0, returnType)
check(getRawType(apiResultType) == ApiResult::class.java) { "$apiResultType must be ApiResult." }
check(apiResultType is ParameterizedType) { "$apiResultType must be parameterized. Raw types are not supported" }
//ååºApiResult<T>ä¸çT ä¹å°±æ¯APIè¿åæ°æ®å¯¹åºçæ°æ®ç±»å
val dataType = getParameterUpperBound(0, apiResultType)
return ApiResultCallAdapter<Any>(dataType)
}
}
class ApiResultCallAdapter<T>(private val type: Type) : CallAdapter<T, Call<ApiResult<T>>> {
override fun responseType(): Type = type
override fun adapt(call: Call<T>): Call<ApiResult<T>> {
return ApiResultCall(call)
}
}
class ApiResultCall<T>(private val delegate: Call<T>) : Call<ApiResult<T>> {
/**
* 该æ¹æ³ä¼è¢«Retrofitå¤çsuspendæ¹æ³ç代ç è°ç¨ï¼å¹¶ä¼ è¿æ¥ä¸ä¸ªcallback,å¦æä½ åè°äºcallback.onResponseï¼é£ä¹suspendæ¹æ³å°±ä¼æåè¿å
* å¦æä½ åè°äºcallback.onFailureé£ä¹suspendæ¹æ³å°±ä¼æå¼å¸¸
*
* æ以æ们è¿éçå®ç°æ¯æ°¸è¿åè°callback.onResponse,åªä¸è¿å¨è¯·æ±æåçæ¶åè¿åçæ¯ApiResult.Success对象ï¼
* å¨å¤±è´¥çæ¶åè¿åçæ¯ApiResult.Failure对象ï¼è¿æ ·å¤é¢å¨è°ç¨suspendæ¹æ³çæ¶åå°±ä¸ä¼æå¼å¸¸ï¼ä¸å®ä¼è¿åApiResult.Success æ ApiResult.Failure
*/
override fun enqueue(callback: Callback<ApiResult<T>>) {
//delegate æ¯ç¨æ¥åå®é
çç½ç»è¯·æ±çCall<T>对象ï¼ç½ç»è¯·æ±çæå失败ä¼åè°ä¸åçæ¹æ³
delegate.enqueue(object : Callback<T> {
/**
* ç½ç»è¯·æ±æåè¿åï¼ä¼åè°è¯¥æ¹æ³ï¼æ 论status codeæ¯ä¸æ¯200ï¼
*/
override fun onResponse(call: Call<T>, response: Response<T>) {
if (response.isSuccessful) {//http status æ¯200+
//è¿éæ
å¿response.body()å¯è½ä¼ä¸ºnull(è¿æ²¡ææµå°è¿è¿ç§æ
åµ)ï¼æ以åäºä¸ä¸è¿ç§æ
åµçå¤çï¼
// å¤çäºè¿ç§æ
åµåè¿æä¸ä¸ªå¥½å¤æ¯æ们就è½ä¿è¯æä»¬ä¼ ç»ApiResult.Successç对象就ä¸æ¯nullï¼è¿æ ·å¤é¢ç¨çæ¶åå°±ä¸ç¨å¤ç©ºäº
val apiResult = if (response.body() == null) {
ApiResult.Failure(ApiError.dataIsNull.errorCode, ApiError.dataIsNull.errorMsg)
} else {
ApiResult.Success(response.body()!!)
}
callback.onResponse(this@ApiResultCall, Response.success(apiResult))
} else {//http statusé误
val failureApiResult = ApiResult.Failure(ApiError.httpStatusCodeError.errorCode, ApiError.httpStatusCodeError.errorMsg)
callback.onResponse(this@ApiResultCall, Response.success(failureApiResult))
}
}
/**
* å¨ç½ç»è¯·æ±ä¸åçäºå¼å¸¸ï¼ä¼åè°è¯¥æ¹æ³
*
* 对äºç½ç»è¯·æ±æåï¼ä½æ¯ä¸å¡å¤±è´¥çæ
åµï¼æ们ä¹ä¼å¨å¯¹åºçInterceptorä¸æåºå¼å¸¸ï¼è¿ç§æ
åµä¹ä¼åè°è¯¥æ¹æ³
*/
override fun onFailure(call: Call<T>, t: Throwable) {
val failureApiResult = if (t is ApiException) {//Interceptoréä¼éè¿throw ApiException æ¥ç´æ¥ç»æè¯·æ± åæ¶ApiExceptionéä¼å
å«é误信æ¯
ApiResult.Failure(t.errorCode, t.errorMsg)
} else {
ApiResult.Failure(ApiError.unknownException.errorCode, ApiError.unknownException.errorMsg)
}
callback.onResponse(this@ApiResultCall, Response.success(failureApiResult))
}
})
}
override fun clone(): Call<ApiResult<T>> = ApiResultCall(delegate.clone())
override fun execute(): Response<ApiResult<T>> {
throw UnsupportedOperationException("ApiResultCall does not support synchronous execution")
}
override fun isExecuted(): Boolean {
return delegate.isExecuted
}
override fun cancel() {
delegate.cancel()
}
override fun isCanceled(): Boolean {
return delegate.isCanceled
}
override fun request(): Request {
return delegate.request()
}
override fun timeout(): Timeout {
return delegate.timeout()
}
}
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{
"type": "EN2ZH_CN",
"errorCode": 0,
"elapsedTime": 1,
"translateResult": [
[
{
"src": "Hello world",
"tgt": "ä½ å¥½ï¼ä¸ç"
}
]
]
}
ä¸å¡å¤±è´¥æ¶æå¯è½è¿åçjsonæ ¼å¼ï¼
{
"errorCode": 50,
"errorMsg": "xxx",
}
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å¨errorCodeä¸æ¯0çæ åµä¸ï¼æåºå¼å¸¸ï¼å¼å¸¸ä¿¡æ¯éå å«errorCodeåerrorMsgï¼å¦æä½ å¨Interceptoréæåºäºå¼å¸¸ï¼OkHttpä¼ç»æ¢æ¬æ¬¡è¯·æ±ï¼åè°onFailureæ¹æ³ã
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/**
* ä¸å¡é误 Interceptor
* 对äºrequest: æ
* 对äºresponse:è´è´£è§£æä¸å¡é误ï¼å¨http status æåçåæä¸ï¼
*/
class BusinessErrorInterceptor :Interceptor{
override fun intercept(chain: Interceptor.Chain): Response {
var response = chain.proceed(chain.request())
//http statusä¸æ¯æåçæ
åµä¸ï¼æ们ä¸å¤ç
if (!response.isSuccessful){
return response
}
//å 为response.body().string() åªè½è°ç¨ä¸æ¬¡ï¼æ以è¿é读åresponseBodyä¸ä½¿ç¨response.body().string()ï¼åå ï¼https://juejin.im/post/6844903545628524551
//以ä¸è¯»åresultStringç代ç èéèª
//https://github.com/square/okhttp/blob/master/okhttp-logging-interceptor/src/main/kotlin/okhttp3/logging/HttpLoggingInterceptor.kt
val responseBody = response.body()!!
val source = responseBody.source()
source.request(Long.MAX_VALUE) // Buffer the entire body.
var buffer = source.buffer
val contentType = responseBody.contentType()
val charset: Charset = contentType?.charset(UTF_8) ?: UTF_8
val resultString = buffer.clone().readString(charset)
val jsonObject = JSONObject(resultString)
if (!jsonObject.has("errorCode")) {
return response
}
val errorCode = jsonObject.optInt("errorCode")
//对äºä¸å¡æåçæ
åµä¸åå¤ç
if (errorCode == 0) {
return response
}
//æ们ç示ä¾éæå¡å¨æ²¡æè¿åerrorMsg,ä¸è¬å®é
åºç¨ä¸æå¡å¨é½ä¼æerrorMsg
throw ApiException(errorCode, "some error msg")
}
}
è¿ééè¦æ³¨æresponse.body().string() åªè½è°ç¨ä¸æ¬¡çé®é¢ï¼æ以è¿éæ们ä¸è½è°ç¨response.body().string()ï¼å ·ä½åå ï¼
https://juejin.im/post/6844903545628524551
æ们读åresultStringç代ç èéèªokhttpå®æ¹çHttpLoggingInterceptor.kt
ApiExceptionï¼
è¿ééè¦æ³¨æçæ¯æ们èªå®ä¹çApiExceptionå¿ é¡»ç»§æ¿èªIOExceptionï¼å 为åªæIOExceptionæä¼è¢«OkHttpå¤çï¼ç¶ååè°å°onFailureæ¹æ³ï¼å ¶ä»ç±»åçå¼å¸¸æ¯ç´æ¥å°±å´©æºäºã
åå°åé¢çApiResultCallAdapter.ktï¼æ们å¯ä»¥çå°å¯¹ApiExceptionçå¤ç
ApiResultCallAdapter.ktï¼
/**
* å¨ç½ç»è¯·æ±ä¸åçäºå¼å¸¸ï¼ä¼åè°è¯¥æ¹æ³
*
* 对äºç½ç»è¯·æ±æåï¼ä½æ¯ä¸å¡å¤±è´¥çæ
åµï¼æ们ä¹ä¼å¨å¯¹åºçInterceptorä¸æåºå¼å¸¸ï¼è¿ç§æ
åµä¹ä¼åè°è¯¥æ¹æ³
*/
override fun onFailure(call: Call<T>, t: Throwable) {
val failureApiResult = if (t is ApiException) {//Interceptoréä¼éè¿throw ApiException æ¥ç´æ¥ç»æè¯·æ± åæ¶ApiExceptionéä¼å
å«é误信æ¯
ApiResult.Failure(t.errorCode, t.errorMsg)
} else {
ApiResult.Failure(ApiError.unknownException.errorCode, ApiError.unknownException.errorMsg)
}
callback.onResponse(this@ApiResultCall, Response.success(failureApiResult))
}
æåæ们添å ApiResultCallAdapteråBusinessErrorInterceptor
NetworkBase.ktï¼
private const val BASE_URL = "http://fanyi.youdao.com/"
private val okHttpClient = OkHttpClient.Builder()
.addInterceptor(BusinessErrorInterceptor())
.build()
val retrofit = Retrofit.Builder()
.addCallAdapterFactory(ApiResultCallAdapterFactory())
.addConverterFactory(GsonConverterFactory.create())
.baseUrl(BASE_URL)
.client(okHttpClient)
.build()
-
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æ¤æ¶è°ç¨æ¥å£æ¶ç代ç å°±åæäºï¼
MainViewModelï¼
class MainViewModel : ViewModel() {
private val _translateResult: MutableLiveData<String> = MutableLiveData()
val translateResult: LiveData<String>
get() = _translateResult
fun translate(word: String) {
viewModelScope.launch {
when (val result = TranslateApi.retrofitService.translate(word)) {
is ApiResult.Success -> {
_translateResult.value = result.data.translateResult1[0][0].tgt
}
is ApiResult.Failure -> {
_translateResult.value = "errorCode: ${result.errorCode} errorMsg: ${result.errorMsg}"
}
}
}
}
}
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ç¿»è¯APIå¨åè¯è¿é¿çæ åµä¸ï¼ä¼è¿åé误ã
æ¯å¦æ们翻è¯"IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII"
æ¤æ¶è¿åçjsonï¼
{
"type": "UNSUPPORTED",
"errorCode": 40,
"elapsedTime": 0,
"translateResult": [
[
{
"src": "IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII",
"tgt": "IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII"
}
]
]
}
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https://github.com/ShuangtaoJia/RetrofitWithCoroutineDemo
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