问PKIX路径构建失败:导入证书后

EN

javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

private static HttpsURLConnection connection; 

    public static void main(String[] args) {
        BufferedReader reader;
        String line; //every line
        StringBuffer responseContent = new StringBuffer();
        
        try {
            URL url = new URL("https://XXXXXX/XXX/XX");
            connection = (HttpsURLConnection) url.openConnection();
            connection.setAuthenticator(new Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("username", "pass".toCharArray());
                }
            });
            
            
            connection.setRequestMethod("GET");
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(5000);
            
            
            int status = connection.getResponseCode();
            System.out.println(status);
            
            if(status>299) {
                reader = new BufferedReader(new InputStreamReader(connection.getErrorStream()));
                while((line = reader.readLine())!=null) {
                    responseContent.append(line);
                }
            reader.close();
            }else {
                reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                while((line = reader.readLine())!=null) {
                    responseContent.append(line);
                }
                reader.close();
            }
            
        System.out.println(responseContent.toString());
            
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            connection.disconnect();
        }
    
        
    }