在使用Springboot的RestTemplate时候，我需要调用一个以Https开头的链接，遇到了如下报错

org.springframework.web.client.ResourceAccessException: I/O error on 
GET request for "": sun.security.validator.ValidatorException: PKIX path 
building failed: sun.security.provider.certpath.SunCertPathBuilderException: 
unable to find valid certification path to requested target; nested exception 
is javax.net.ssl.SSLHandshakeException: 
sun.security.validator.ValidatorException: PKIX path building failed: 
sun.security.provider.certpath.SunCertPathBuilderException: unable to 
find valid certification path to requested target

大意就是我这个是https的请求，比较安全，需要跟服务器建立链接，但是呢你又没有证书所以我就报错了。

如果需要证书，并且服务器是有这个东西，那么你就可以去找证书并且实现即可，如果你没有证书不想做这个东西那么我们就采取禁用ssl证书这样的方式来做了。

主方法：

public void start(){
        RestTemplate restTemplate = new RestTemplate();
        try {
            SSLValidation.turnOffSslChecking();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (KeyManagementException e) {
            e.printStackTrace();
        }
        String url = cloudUrlConfig.getUrl()+ENABLE_RULE_URL;
        ResultDto resultDto = 
              restTemplate.getForObject(url,ResultDto.class)
        i++;
        log.info("开始第{}次使用定时器！",i);
    }

禁用ssl方法

import javax.net.ssl.*;
import java.security.*;
import java.security.cert.X509Certificate;

public class SSLValidation {

    private static final TrustManager[] UNQUESTIONING_TRUST_MANAGER = new TrustManager[]{
            new X509TrustManager() {
                public java.security.cert.X509Certificate[] getAcceptedIssuers(){
                    return null;
                }
                public void checkClientTrusted( X509Certificate[] certs, String authType ){}
                public void checkServerTrusted( X509Certificate[] certs, String authType ){}
            }
    };

    public static void turnOffSslChecking() throws NoSuchAlgorithmException, KeyManagementException {
        // Install the all-trusting trust manager
        final SSLContext sc = SSLContext.getInstance("SSL");
        sc.init( null, UNQUESTIONING_TRUST_MANAGER, null );
        HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
    }

    public static void turnOnSslChecking() throws KeyManagementException, NoSuchAlgorithmException {
        // Return it to the initial state (discovered by reflection, now hardcoded)
        SSLContext.getInstance("SSL").init( null, null, null );
    }

    private SSLValidation(){
        throw new UnsupportedOperationException( "Do not instantiate libraries.");
    }
}