Android使用Retrofit進行網路請求
阿新 • • 發佈：2019-02-02
Retrofit 簡介
用於Android和Java平臺的一款型別安全的HTTP客戶端，通過一個Java介面實現HTTP請求物件，如下：
public interface Github {
@GET("/repos/{owner}/{repo}/contributors")
Call<List<Contributor>> contributors(
@Path("owner") String owner,
@Path("repo") String repo);
}
Android 平臺使用示例
步驟如下：
- 新增 Retrofit 相關依賴庫
//retrofit2 依賴庫
implementation 'com.squareup.retrofit2:retrofit:2.4.0'
//Gson 資料解析器依賴庫
implementation 'com.squareup.retrofit2:converter-gson:2.4.0'
//okhttp3 輸出網路請求日誌依賴庫
implementation 'com.squareup.okhttp3:logging-interceptor:3.4.1'- 建立接收伺服器返回資料對應的實體類
//建立接收伺服器返回資料的類
public class - 建立用於描述網路請求的介面
//建立用於網路請求的介面
public interface Github {
@GET("/repos/{owner}/{repo}/contributors" - *配置列印網路請求日誌
HttpLoggingInterceptor loggingInterceptor;
//列印網路請求相關日誌
loggingInterceptor = new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() {
@Override
public void log(String message) {
//列印retrofit日誌
Log.i("retrofitLog: ", message);
}
});
loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
//為了列印日誌，需要配置OkHttpClient
OkHttpClient client = new OkHttpClient.Builder()
.addInterceptor(loggingInterceptor)
.build();- 建立Retrofit物件
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(API_GITHUB_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create())
.build();- 建立網路請求介面例項
//建立網路介面例項
Github github = retrofit.create(Github.class);
//對傳送請求進行封裝
Call<List<Contributor>> call = github.contributors("square", "retrofit");- 傳送網路請求（非同步 / 同步）並對返回資料進行處理
//傳送同步請求時不能直接在UI執行緒進行，不然會報錯：NetworkOnMainThreadException
//傳送請求，獲取請求的資料
List<Contributor> contributors = call.execute().body();
StringBuilder result = new StringBuilder();
for (Contributor contributor : contributors) {
result.append(contributor.login + " (" + contributor.contributions + ")\n");
}
Log.e("result", result.toString());主要程式碼如下
MainActivity.java
public class MainActivity extends AppCompatActivity { private TextView tv_request_result; public static final String API_GITHUB_URL = "https://api.github.com"; HttpLoggingInterceptor loggingInterceptor; private Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { super.handleMessage(msg); Bundle data = msg.getData(); String result = data.getString("result"); tv_request_result.setText(result); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); //列印網路請求相關日誌 loggingInterceptor = new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() { @Override public void log(String message) { //列印retrofit日誌 Log.i("retrofitLog: ", message); } }); loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY); new Thread(runnable).start(); //不能在UI執行緒中進行網路請求 } private void initView() { tv_request_result = (TextView) findViewById(R.id.tv_request_result); } //傳送網路請求 private String request() throws IOException { //為了列印日誌，需要配置okhttp OkHttpClient client = new OkHttpClient.Builder() .addInterceptor(loggingInterceptor) .build(); //建立Retrofit物件 Retrofit retrofit = new Retrofit.Builder() .baseUrl(API_GITHUB_URL) .client(client) .addConverterFactory(GsonConverterFactory.create()) .build(); //建立網路介面例項 Github github = retrofit.create(Github.class); //對傳送請求進行封裝 Call<List<Contributor>> call = github.contributors("square", "retrofit"); //傳送請求，獲取請求的資料 List<Contributor> contributors = call.execute().body(); StringBuilder result = new StringBuilder(); for (Contributor contributor : contributors) { result.append(contributor.login + " (" + contributor.contributions + ")\n"); } Log.e("result", result.toString()); return result.toString(); } //網路請求執行緒 Runnable runnable = new Runnable() { @Override public void run() { try { String result = request(); Message msg = new Message(); Bundle data = new Bundle(); data.putString("result", result); msg.setData(data); handler.sendMessage(msg); } catch (IOException e) { Log.e("request_erro", e.toString()); } } }; }activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <ScrollView android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:id="@+id/tv_request_result" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="20sp" /> </ScrollView> </LinearLayout>- 程式執行結果
- 網路請求日誌如下：
07-02 16:07:41.145 17443-17462/com.example.xuyue.learnretrofit I/retrofitLog:: --> GET https://api.github.com/repos/square/retrofit/contributors http/1.1
--> END GET
07-02 16:07:43.275 17443-17462/com.example.xuyue.learnretrofit I/retrofitLog:: <-- 200 OK https://api.github.com/repos/square/retrofit/contributors (2129ms)
Server: GitHub.com
Date: Mon, 02 Jul 2018 08:07:45 GMT
Content-Type: application/json; charset=utf-8
Transfer-Encoding: chunked
Status: 200 OK
X-RateLimit-Limit: 60
X-RateLimit-Remaining: 30
X-RateLimit-Reset: 1530522209
Cache-Control: public, max-age=60, s-maxage=60
07-02 16:07:43.276 17443-17462/com.example.xuyue.learnretrofit I/retrofitLog:: Vary: Accept
ETag: W/"0313af265d6c3206fe7e38545918e2bf"
Last-Modified: Mon, 02 Jul 2018 07:42:01 GMT
X-GitHub-Media-Type: github.v3; format=json
Link: <https://api.github.com/repositories/892275/contributors?page=2>; rel="next", <https://api.github.com/repositories/892275/contributors?page=5>; rel="last"
Access-Control-Expose-Headers: ETag, Link, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval
Access-Control-Allow-Origin: *
Strict-Transport-Security: max-age=31536000; includeSubdomains; preload
X-Frame-Options: deny
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Referrer-Policy: origin-when-cross-origin, strict-origin-when-cross-origin
Content-Security-Policy: default-src 'none'
X-Runtime-rack: 0.075905
X-GitHub-Request-Id: 90E0:3CD2:61BDD85:BCDE66D:5B39DD50
07-02 16:07:43.288 17443-17462/com.example.xuyue.learnretrofit I/retrofitLog:: [{"login":"JakeWharton","id":66577,"node_id":"MDQ6VXNlcjY2NTc3","avatar_url":"https://avatars0.githubusercontent.com/u/66577?v=4","gravatar_id":"","url":"https://api.github.com/users/JakeWharton","html_url":"https://github.com/JakeWharton","followers_url":"https://api.github.com/users/JakeWharton/followers","following_url":"https://api.github.com/users/JakeWharton/following{/other_user}","gists_url":"https://api.github.com/users/JakeWharton/gists{/gist_id}","starred_url":"https://api.github.com/users/JakeWharton/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/JakeWharton/subscriptions","organizations_url":"https://api.github.com/users/JakeWharton/orgs","repos_url":"https://api.github.com/users/JakeWharton/repos","events_url":"https://api.github.com/users/JakeWharton/events{/privacy}","received_events_url":"https://api.github.com/users/JakeWharton/received_events","type":"User","site_admin":false,"contributions":911},{"login":"swankjesse","id":133019,"node_id":"MDQ6VXNlcjEzMzAxOQ==","avatar_url":"https://avatars3.githubusercontent.com/u/133019?v=4","gravatar_id":"","url":"https://api.github.com/users/swankjesse","html_url":"https://github.com/swankjesse","followers_url":"https://api.github.com/users/swankjesse/followers","following_url":"https://api.github.com/users/swankjesse/following{/other_user}","gists_url":"https://api.github.com/users/swankjesse/gists{/gist_id}","starred_url":"https://api.github.com/users/swankjesse/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/swankjesse/subscriptions","organizations_url":"https://api.github.com/users/swankjesse/orgs","repos_url":"https://api.github.com/users/swankjesse/repos","events_url":"https://api.github.com/users/swankjesse/events{/privacy}","received_events_url":"https://api.github.com/users/swankjesse/received_events","type":"User","site_admin":false,"contributions":224},{"login":"pforhan","id":331925,"node_id":"MDQ6VXNlcjMzMTkyNQ==","avatar_url":"https://avatars3.githubusercontent.com/u/331925?v=4","gravatar_id":"","url":"https://api.github.com/users/pforhan","html_url":"https://github.com/pforhan","followers_url":"https://api.github.com/users/pforhan/followers","following_url":"https://api.github.com/users/pforhan/following{/other_user}","gists_url":"https://api.github.com/users/pforhan/gists{/gist_id}","starred_url":"https://api.github.com/users/pforhan/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pforhan/subscriptions","organizations_url":"https://api.github.com/users/pforhan/orgs","repos_url":"https://api.github.com/users/pforhan/repos","events_url":"https://api.github.com/users/pforhan/events{/privacy}","received_events_url":"https://api.github.com/users/pforhan/received_events","type":"User","site_admin":false,"contributions":48},{"login":"eburke","id":63761,"node_id":"MDQ6VXNlcjYzNzYx","avatar_url":"https://avatars0.githubusercontent.com/u/63761?v=4","gravatar_id":"","url":"https://api.github.com/users/eburke","html_url":"https://github.com/eburke","followers_url":"https://api.github.com/users/eburke/followers","following_url":"https://api.github.com/users/eburke/following{/other_user}","gists_url":"https://api.github.com/users/eburke/gists{/gist_id}","starred_url":"https://api.github.com/users/eburke/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/eburke/subscriptions","organizations_url":"https://api.github.com/users/eburke/orgs","repos_url":"https://api.github.com/users/eburke/repos","events_url":"https://api.github.com/users/eburke/events{/privacy}","received_events_url":"https://api.github.com/users/eburke/received_events","type":"User","site_admin":false,"contributions":36},{"login":"dnkoutso","id":310370,"node_id":"MDQ6VXNlcjMxMDM3MA==","avatar_url":"https://avatars2.githubusercontent.com/u/310370?v=4","gravatar_id":"","url":"https://api.github.com/users/dnkoutso","html_url":"https://github.com/dnkoutso","followers_url":"https://api.github.com/users/dnkoutso/followers","following_url":"https://api.github.com/users/d
<-- END HTTP (28135-byte body)- 伺服器返回資料示例
{
"login": "JakeWharton",
"id": 66577,
"node_id": "MDQ6VXNlcjY2NTc3",
"avatar_url": "https://avatars0.githubusercontent.com/u/66577?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/JakeWharton",
"html_url": "https://github.com/JakeWharton",
"followers_url": "https://api.github.com/users/JakeWharton/followers",
"following_url": "https://api.github.com/users/JakeWharton/following{/other_user}",
"gists_url": "https://api.github.com/users/JakeWharton/gists{/gist_id}",
"starred_url": "https://api.github.com/users/JakeWharton/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/JakeWharton/subscriptions",
"organizations_url": "https://api.github.com/users/JakeWharton/orgs",
"repos_url": "https://api.github.com/users/JakeWharton/repos",
"events_url": "https://api.github.com/users/JakeWharton/events{/privacy}",
"received_events_url": "https://api.github.com/users/JakeWharton/received_events",
"type": "User",
"site_admin": false,
"contributions": 911
}