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Java原生HttpClient的使用詳解

更新時間：2022年04月08日 14:33:36 作者：農(nóng)民工老王

Java開發(fā)語言中實現(xiàn)HTTP請求的方法主要有兩種：一種是JAVA的標準類HttpUrlConnection，比較原生的實現(xiàn)方法；另一種是第三方開源框架HTTPClient。本文就將詳細講講Java中原生HttpClient的使用，需要的可以參考一下

提到Java發(fā)送HTTP請求，大家首先想到的是用apache的HttpClient，或者squareup的OkHttp。而在Java11之前，原生Java對此的支持還是比較差的，雖然可以HttpURLConnection、URLConnection、Socket等自帶的類發(fā)送請求，但是操作比較復(fù)雜。直到Java11發(fā)布，Java本身也自帶了HttpClient。自2020年初，我就在開發(fā)中廣泛使用了這一新特性，感覺使用體驗也還可以?，F(xiàn)總結(jié)成博客，供大家參考。

1.信任證書管理類

package cn.wja.component;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.security.cert.X509Certificate;


class MyX509TrustManager implements X509TrustManager {
    @Override
    public void checkClientTrusted(X509Certificate[] x509Certificates, String s)  {
    }

    @Override
    public void checkServerTrusted(X509Certificate[] x509Certificates, String s)  {
    }

    @Override
    public X509Certificate[] getAcceptedIssuers() {
        return null;
    }

    public static TrustManager[] getTrustManagers() {
        TrustManager[] trustAllCertificates = {new MyX509TrustManager()};
        return trustAllCertificates;
    }
}

2.HttpClient類

package cn.wja.component;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLParameters;
import javax.net.ssl.TrustManager;
import java.net.http.HttpClient;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.time.Duration;

public class MyHttpClient {
    static public HttpClient getClient() throws NoSuchAlgorithmException, KeyManagementException {
        TrustManager[] trustManagers = MyX509TrustManager.getTrustManagers();
        var timeoutInSeconds = 60;
        SSLParameters sslParams = new SSLParameters();
        sslParams.setEndpointIdentificationAlgorithm("");
        SSLContext sc = SSLContext.getInstance("SSL");
        //取消主機名驗證
        System.setProperty("jdk.internal.httpclient.disableHostnameVerification", "true");
        sc.init(null, trustManagers, new SecureRandom());
        return HttpClient.newBuilder()
                .connectTimeout(Duration.ofMillis(timeoutInSeconds * 1000))
                .sslContext(sc)
                .sslParameters(sslParams)
                .followRedirects(HttpClient.Redirect.NEVER)
                .version(HttpClient.Version.HTTP_2)
                .build();
    }
}

3.發(fā)送請求工具類

package cn.wja.util;

import cn.wja.component.MyHttpClient;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;


import static java.nio.charset.StandardCharsets.UTF_8;

public class HttpUtils {

    public static HttpResponse<String> sendGet(String urlStr, String cookieStr) throws Exception {
        HashMap<String, String> hashMap = new HashMap<>();
        hashMap.put("Cookie",cookieStr);
        return sendGet(urlStr,hashMap);
    }


    public static HttpResponse<String> sendGet(String urlStr, Map<String,String> headers) throws KeyManagementException, NoSuchAlgorithmException, IOException, InterruptedException {
        HttpClient client = MyHttpClient.getClient();
        HttpRequest.Builder reqBuilder = getReqBuilder(urlStr);
        reqBuilder.GET();
        for (String key:headers.keySet()){
            reqBuilder.header(key, headers.get(key));
        }
        HttpRequest request = reqBuilder.build();
        HttpResponse<String> result = client.send(request, HttpResponse.BodyHandlers.ofString(UTF_8));
        return result;
    }

    private static HttpResponse<String> sendPost(String contentType, String urlStr, String bodyStr, String cookieStr) throws Exception {
        HttpClient client = MyHttpClient.getClient();
        HttpRequest.Builder reqBuilder = getReqBuilder(urlStr);
        HttpRequest.BodyPublisher bodyPublisher = HttpRequest.BodyPublishers.ofString(bodyStr);
        reqBuilder.header("Content-Type", contentType)
                .POST(bodyPublisher)
                .header("Cookie", cookieStr);
        HttpRequest request = reqBuilder.build();
        HttpResponse<String> result = client.send(request, HttpResponse.BodyHandlers.ofString(UTF_8));
        return result;
    }
    
    public static HttpResponse<String> sendFormPost(String urlStr, String formStr, String cookieStr) throws Exception {
        return sendPost("application/x-www-form-urlencoded;charset=utf-8", urlStr, formStr, cookieStr);
    }

    public static HttpResponse<String> sendJsonPost(String urlStr, String jsonStr, String cookieStr) throws Exception {
        return sendPost("application/json;charset=utf-8", urlStr, jsonStr, cookieStr);
    }

    public static HttpRequest.Builder getReqBuilder(String urlStr) {
        return HttpRequest.newBuilder()
                .uri(URI.create(urlStr))
                .header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:96.0) Gecko/20100101 Firefox/96.0");
    }
}