近來公司需要搭建一個https的伺服器來除錯介面（伺服器用的spring boot框架），剛開始接觸就是一頓百度，最後發現網際網路認可的https安全連結的證書需要去CA認證機構申請，由於是除錯階段就採用了java的keytool工具來生成金鑰檔案，下面是生成金鑰檔案的指令和步驟（前提是需要配置好java 的環境變數）。

　　1、首先開啟cmd命令，操作如下：

keytool -genkey -alias tomcat  -storetype PKCS12 -keyalg RSA -keysize 2048  -keystore keystore.p12 -validity 3650
1.-storetype 指定金鑰倉庫型別 
2.-keyalg 生證書的演算法名稱，RSA是一種非對稱加密演算法 
3.-keysize 證書大小 
4.-keystore 生成的證書檔案的儲存路徑 
5.-validity 證書的有效期
根據提示完成操作，儲存在操作時資料內容，最後keystore.p12為生成的金鑰檔案
 

 　　2、開啟spring boot 專案工程，將keykeystore.p12檔案放到專案的resources根目錄中，同時在application.properties中新增如下程式碼：

#你生成的證書名字
server.ssl.key-store=classpath:keystore.p12
# 金鑰庫密碼
server.ssl.key-store-password=第一步生成金鑰檔案時輸入的金鑰
server.ssl.keyStoreType=PKCS12
server.ssl.keyAlias=tomcat

此時工程的https訪問路徑已經配置好了啟動專案，開啟瀏覽器就可以訪問頁面，不過會提示不安全連結，主要還是因為證書是不認的。

　　3、通過java訪問https介面程式碼如下：

import java.io.*;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.HostnameVerifier;
 
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.KeyManager;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

/**
 * 通過https訪問伺服器忽略證書沒被認可也繼續訪問
 */
public class HttpsConnect extends BaseConnect {
    private static String TAG = "HttpConnect";

    private static final class DefaultTrustManager 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;
        }
    }
   protected static byte[] getBytesFromStream(InputStream is) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] kb = new byte[1024];
        int len;
        while ((len = is.read(kb)) != -1) {
            baos.write(kb, 0, len);
        }
        byte[] bytes = baos.toByteArray();
        baos.close();
        is.close();
        return bytes;
    }

    protected static void setBytesToStream(OutputStream os, byte[] bytes) throws IOException {
        ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
        byte[] kb = new byte[1024];
        int len;
        while ((len = bais.read(kb)) != -1) {
            os.write(kb, 0, len);
        }
        os.flush();
        os.close();
        bais.close();
    }


    private static HttpsURLConnection getHttpsURLConnection(String uri, String method) throws IOException {
        SSLContext ctx = null;
        try {
            ctx = SSLContext.getInstance("TLS");
            ctx.init(new KeyManager[0], new TrustManager[]{new DefaultTrustManager()}, new SecureRandom());
        } catch (KeyManagementException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        SSLSocketFactory ssf = ctx.getSocketFactory();

        URL url = new URL(uri);
        HttpsURLConnection httpsConn = (HttpsURLConnection) url.openConnection();
        httpsConn.setRequestProperty("Content-Type", "application/json; charset=utf-8");
        httpsConn.setSSLSocketFactory(ssf);
        httpsConn.setHostnameVerifier(new HostnameVerifier() {
            @Override
            public boolean verify(String arg0, SSLSession arg1) {
                return true;
            }
        });
        httpsConn.setRequestMethod(method);
        if("post".equals(method.toLowerCase())) {
            httpConn.setDoOutput(true);
            httpConn.setDoInput(true);
        }
        return httpsConn;
    }

    public static byte[] doGet(String uri) throws IOException {
        HttpsURLConnection httpsConn = getHttpsURLConnection(uri, "GET");
        return getBytesFromStream(httpsConn.getInputStream());
    }

    public static byte[] doPost(String uri, String data) throws IOException {
        HttpsURLConnection httpsConn = getHttpsURLConnection(uri, "POST");
        setBytesToStream(httpsConn.getOutputStream(), data.getBytes("UTF-8"));
        return getBytesFromStream(httpsConn.getInputStream());
    }

}