【JAVA】【工具类】SSL証明書を信頼する

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
 
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
 
/**
 * javaのSSL証明書を信頼するためのユーティリティクラス
 *
 */
public class SslUtil {
  //urlからファイルをダウンロードするメソッド
	public void downloadFileFromUrl(String fileUrl, String fileName) throws Exception {
		URL url = new URL(fileUrl);
		SslUtil.ignoreSsl();
		HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
		urlConnection.setConnectTimeout(6000);
		urlConnection.setReadTimeout(6000);
		if (urlConnection.getResponseCode() != HttpURLConnection.HTTP_OK) {
			System.out.println("接続リクエストの状態：---------------"+urlConnection.getResponseCode());
			throw new RuntimeException("ファイルの読み取りに失敗しました");
		}
		InputStream inputStream = urlConnection.getInputStream();
		byte[] buffer = new byte[1024];
		int len;
		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
		while ((len = inputStream.read(buffer)) != -1) {
			byteArrayOutputStream.write(buffer, 0, len);
		}
		byteArrayOutputStream.close();
		File file = new File("/deployments/" + fileName);
		FileOutputStream fileOutputStream = new FileOutputStream(file);
		fileOutputStream.write(byteArrayOutputStream.toByteArray());
		fileOutputStream.close();
		inputStream.close();
		System.out.println("ダウンロード成功：" + "/deployments/" + fileName);
	}
   /**
	 * HTTPSリクエストのSSL証明書を無視します。openConnectionの前に呼び出す必要があります
	 * 
	 * @throws Exception
	 */
	public static void ignoreSsl() throws Exception {
		HostnameVerifier hv = new HostnameVerifier() {
			public boolean verify(String urlHostName, SSLSession session) {
				return true;
			}
		};
		trustAllHttpsCertificates();
		HttpsURLConnection.setDefaultHostnameVerifier(hv);
	}
   private static void trustAllHttpsCertificates() throws Exception {
		TrustManager[] trustAllCerts = new TrustManager[1];
		TrustManager tm = new miTM();
		trustAllCerts[0] = tm;
		SSLContext sc = SSLContext.getInstance("SSL");
		sc.init(null, trustAllCerts, null);
		HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
	}
   static class miTM implements TrustManager, X509TrustManager {
		public X509Certificate[] getAcceptedIssuers() {
			return null;
		}
 
		public boolean isServerTrusted(X509Certificate[] certs) {
			return true;
		}
 
		public boolean isClientTrusted(X509Certificate[] certs) {
			return true;
		}
 
		public void checkServerTrusted(X509Certificate[] certs, String authType) throws CertificateException {
			return;
		}
 
		public void checkClientTrusted(X509Certificate[] certs, String authType) throws CertificateException {
			return;
		}
	}
 
}