前言
过了一个漫长的中秋+国庆假期,大家伙的鸿蒙内功修炼的怎么样了?难道像小蒙一样,都在吃吃喝喝中度过么,哎,罪过罪过,对不起那些鸡鸭鱼肉啊,赶紧回来写篇文章收收心,让我们一起看看,在鸿蒙中如何发送网络请求吧。
本文会从Java原生访问入手,进而再使用Retrofit访问网络,可以满足绝大部分开发者对于鸿蒙网络访问方面的代码需求,开始之前需要先做一下基础配置。
鸿蒙系统网络访问基础配置
1、跟Android类似,要访问网络,我们首先要配置网络访问权限,在config.json的"module"节点最后,添加上网络权限代码
"reqPermissions": [ { "reason": "", "name": "ohos.permission.INTERNET" } ]
2、配置网络明文访问白名单
"deviceConfig": { "default": { "network": { "usesCleartext": true, "securityConfig": { "domainSettings": { "cleartextPermitted": true, "domains": [ { "subDomains": true, "name": "www.baidu.com" } ] } } } } }
其中的name即为可以直接http访问的域名,如果全是https链接则可以做该不配置,切记域名是不带http://的,切记域名是不带http://的,切记域名是不带http://的,重要的事说三遍。
Java原生访问网络
由于鸿蒙系统支持Java开发,所以我们可以直接使用Java原生的Api来进行网络访问 该方式使用了java的url.openConnection() Api来获取网络数据
HttpDemo.java
package com.example.demo.classone; import javax.net.ssl.*; import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.security.SecureRandom; public class HttpDemo { /** *访问url,获取内容 * @param urlStr * @return */ public static String httpGet(String urlStr){ StringBuilder sb = new StringBuilder(); try{ //添加https信任 SSLContext sslcontext = SSLContext.getInstance("SSL");//第一个参数为协议,第二个参数为提供者(可以缺省) TrustManager[] tm = {new HttpX509TrustManager()}; sslcontext.init(null, tm, new SecureRandom()); HostnameVerifier ignoreHostnameVerifier = new HostnameVerifier() { public boolean verify(String s, SSLSession sslsession) { System.out.println("WARNING: Hostname is not matched for cert."); return true; } }; HttpsURLConnection.setDefaultHostnameVerifier(ignoreHostnameVerifier); HttpsURLConnection.setDefaultSSLSocketFactory(sslcontext.getSocketFactory()); URL url = new URL(urlStr); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("GET"); connection.setReadTimeout(10000); connection.setConnectTimeout(10000); connection.connect(); int code = connection.getResponseCode(); if (code == HttpURLConnection.HTTP_OK) { BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream())); String temp; while ((temp = reader.readLine()) != null) { sb.append(temp); } reader.close(); } connection.disconnect(); } catch (Exception e) { e.printStackTrace(); return e.getMessage(); } return sb.toString(); } }
HttpX509TrustManager.java
package com.example.demo.classone; import javax.net.ssl.X509TrustManager; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; public class HttpX509TrustManager implements X509TrustManager { @Override public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { } @Override public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { } @Override public X509Certificate[] getAcceptedIssuers() { return null; } }
最后是测试是否能够正确访问的代码,注意网络访问是耗时操作要放线程里面执行
new Thread(new Runnable() { @Override public void run() { String result = HttpDemo.httpGet("http://www.baidu.com"); HiLog.warn(new HiLogLabel(HiLog.LOG_APP, 0, "===demo==="), "网页返回结果:"+result); } }).start();
采用Retrofit访问网络
在模块的build.gradle里添加Retrofit库的引用,我这边采用的是retrofit2的2.5.0版本做示例
implementation 'com.squareup.retrofit2:retrofit:2.5.0' implementation 'com.squareup.retrofit2:converter-gson:2.5.0' implementation 'io.reactivex.rxjava3:rxjava:3.0.4'
新建ApiManager类用来管理获取OkHttpClient,SSLSocketClient用来提供https支持,ApiResponseConverterFactory是Retrofit的转换器,将请求结果转成String输出
ApiManager.java
package com.example.demo.classone; import com.example.demo.DemoAbilityPackage; import ohos.app.Environment; import okhttp3.*; import retrofit2.Retrofit; import java.io.File; import java.util.concurrent.TimeUnit; /** * 提供获取Retrofit对象的方法 */ public class ApiManager { private static final String BUSINESS_BASE_HTTP_URL = "http://www.baidu.com"; private static Retrofit instance; private static OkHttpClient mOkHttpClient; private ApiManager(){} public static Retrofit get(){ if (instance == null){ synchronized (ApiManager.class){ if (instance == null){ setClient(); instance = new Retrofit.Builder().baseUrl(BUSINESS_BASE_HTTP_URL). addConverterFactory(ApiResponseConverterFactory.create()).client(mOkHttpClient).build(); } } } return instance; } private static void setClient(){ if (mOkHttpClient != null){ return; } Cache cache = new Cache(new File(getRootPath(Environment.DIRECTORY_DOCUMENTS),"HttpCache"),1024*1024*100); OkHttpClient.Builder builder = new OkHttpClient.Builder() // .followRedirects(false)//关闭重定向 // .addInterceptor(new AppendUrlParamIntercepter()) .cache(cache) .retryOnConnectionFailure(false) .sslSocketFactory(SSLSocketClient.getSSLSocketFactory()) .hostnameVerifier(SSLSocketClient.getHostnameVerifier()) .readTimeout(8,TimeUnit.SECONDS) .writeTimeout(8,TimeUnit.SECONDS) .connectTimeout(8, TimeUnit.SECONDS); // .protocols(Collections.singletonList(Protocol.HTTP_1_1)); mOkHttpClient = builder.build(); mOkHttpClient.dispatcher().setMaxRequests(100); } private static String getRootPath(String dirs) { String path = DemoAbilityPackage.getInstance().getCacheDir() + "/" + dirs; File file = new File(path); if (!file.exists()) { file.mkdirs(); } return path; } }
SSLSocketClient.java
package com.example.demo.classone; import javax.net.ssl.*; import java.security.SecureRandom; import java.security.cert.X509Certificate; public class SSLSocketClient { //获取这个SSLSocketFactory public static SSLSocketFactory getSSLSocketFactory() { try { SSLContext sslContext = SSLContext.getInstance("SSL"); sslContext.init(null, getTrustManager(), new SecureRandom()); return sslContext.getSocketFactory(); } catch (Exception e) { throw new RuntimeException(e); } } //获取TrustManager private static TrustManager[] getTrustManager() { TrustManager[] trustAllCerts = new TrustManager[]{ new X509TrustManager() { @Override public void checkClientTrusted(X509Certificate[] chain, String authType) { } @Override public void checkServerTrusted(X509Certificate[] chain, String authType) { } @Override public X509Certificate[] getAcceptedIssuers() { return new X509Certificate[]{}; } } }; return trustAllCerts; } //获取HostnameVerifier public static HostnameVerifier getHostnameVerifier() { HostnameVerifier hostnameVerifier = new HostnameVerifier() { @Override public boolean verify(String s, SSLSession sslSession) { return true; } }; return hostnameVerifier; } }
ApiResponseConverterFactory.java
package com.example.demo.classone; import okhttp3.RequestBody; import okhttp3.ResponseBody; import retrofit2.Converter; import retrofit2.Retrofit; import java.io.IOException; import java.lang.annotation.Annotation; import java.lang.reflect.Type; /** * BaseResponse的转换器 */ public class ApiResponseConverterFactory extends Converter.Factory { public static Converter.Factory create(){ return new ApiResponseConverterFactory(); } @Override public ConverterresponseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) { return new StringResponseBodyConverter(); } @Override public Converter, RequestBody> requestBodyConverter(Type type, Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) { return null; } class StringResponseBodyConverter implements Converter { @Override public String convert(ResponseBody value) throws IOException { String s = value.string(); return s; } } }
开始使用Retrofit书写业务逻辑
BusinessApiManager.java
package com.example.demo.classone; /** * 服务端访问接口管理 */ public class BusinessApiManager { private static BusinessApiService instance; public static BusinessApiService get(){ if (instance == null){ synchronized (BusinessApiManager.class){ if (instance == null){ instance = ApiManager.get().create(BusinessApiService.class); } } } return instance; } }
BusinessApiService.java
package com.example.demo.classone; import retrofit2.Call; import retrofit2.http.*; /** * 服务端访问接口 */ public interface BusinessApiService { /** * 获取网页信息 * @param url * @return */ @GET() CallgetHtmlContent(@Url String url); }
测试Retrofit是否能够正常使用
BusinessApiManager.get().getHtmlContent("https://www.baidu.com").enqueue(new Callback() { @Override public void onResponse(Call call, Response response) { if (!response.isSuccessful() || response.body() == null){ onFailure(null,null); return; } String result = response.body(); HiLog.warn(new HiLogLabel(HiLog.LOG_APP, 0, "===demo==="), "网页返回结果:"+result); } @Override public void onFailure(Call call, Throwable throwable) { HiLog.warn(new HiLogLabel(HiLog.LOG_APP, 0, "===demo==="), "网页访问异常"); } });
总结
鸿蒙是基于Java开发的,所有Java原生api都是可以直接在鸿蒙系统上使用的,另外只要和java相关的库都是可以直接引用的,例如在引用retrofit的时候也带入了RxJava。 更多retrofit的使用方式,可以参考retrofit在android系统中的实现,鸿蒙系统基本兼容。
编辑:hfy
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