前言
過了一個漫長的中秋+國慶假期,大家伙的鴻蒙內功修煉的怎么樣了?難道像小蒙一樣,都在吃吃喝喝中度過么,哎,罪過罪過,對不起那些雞鴨魚肉啊,趕緊回來寫篇文章收收心,讓我們一起看看,在鴻蒙中如何發送網絡請求吧。
本文會從Java原生訪問入手,進而再使用Retrofit訪問網絡,可以滿足絕大部分開發者對于鴻蒙網絡訪問方面的代碼需求,開始之前需要先做一下基礎配置。
鴻蒙系統網絡訪問基礎配置
1、跟Android類似,要訪問網絡,我們首先要配置網絡訪問權限,在config.json的"module"節點最后,添加上網絡權限代碼
"reqPermissions": [
{
"reason": "",
"name": "ohos.permission.INTERNET"
}
]
2、配置網絡明文訪問白名單
"deviceConfig": {
"default": {
"network": {
"usesCleartext": true,
"securityConfig": {
"domainSettings": {
"cleartextPermitted": true,
"domains": [
{
"subDomains": true,
"name": "www.baidu.com"
}
]
}
}
}
}
}
其中的name即為可以直接http訪問的域名,如果全是https鏈接則可以做該不配置,切記域名是不帶http://的,切記域名是不帶http://的,切記域名是不帶http://的,重要的事說三遍。
Java原生訪問網絡
由于鴻蒙系統支持Java開發,所以我們可以直接使用Java原生的Api來進行網絡訪問 該方式使用了java的url.openConnection() Api來獲取網絡數據
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 { /** *訪問url,獲取內容 * @param urlStr * @return */ public static String httpGet(String urlStr){ StringBuilder sb = new StringBuilder(); try{ //添加https信任 SSLContext sslcontext = SSLContext.getInstance("SSL");//第一個參數為協議,第二個參數為提供者(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;
}
}
最后是測試是否能夠正確訪問的代碼,注意網絡訪問是耗時操作要放線程里面執行
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==="), "網頁返回結果:"+result);
}
}).start();
采用Retrofit訪問網絡
在模塊的build.gradle里添加Retrofit庫的引用,我這邊采用的是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類用來管理獲取OkHttpClient,SSLSocketClient用來提供https支持,ApiResponseConverterFactory是Retrofit的轉換器,將請求結果轉成String輸出
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;
/**
* 提供獲取Retrofit對象的方法
*/
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)//關閉重定向
// .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 {
//獲取這個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);
}
}
//獲取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;
}
//獲取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的轉換器
*/
public class ApiResponseConverterFactory extends Converter.Factory {
public static Converter.Factory create(){
return new ApiResponseConverterFactory();
}
@Override
public Converter responseBodyConverter(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;
}
}
}
開始使用Retrofit書寫業務邏輯
BusinessApiManager.java
package com.example.demo.classone; /** * 服務端訪問接口管理 */ 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.*;
/**
* 服務端訪問接口
*/
public interface BusinessApiService {
/**
* 獲取網頁信息
* @param url
* @return
*/
@GET()
Call getHtmlContent(@Url String url);
}
測試Retrofit是否能夠正常使用
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==="), "網頁返回結果:"+result);
}
@Override
public void onFailure(Call call, Throwable throwable) {
HiLog.warn(new HiLogLabel(HiLog.LOG_APP, 0, "===demo==="), "網頁訪問異常");
}
});
總結
鴻蒙是基于Java開發的,所有Java原生api都是可以直接在鴻蒙系統上使用的,另外只要和java相關的庫都是可以直接引用的,例如在引用retrofit的時候也帶入了RxJava。 更多retrofit的使用方式,可以參考retrofit在android系統中的實現,鴻蒙系統基本兼容。
編輯:hfy
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