org.springframework.ws.client.WebServiceTransportException: Proxy Error [502]

I am getting below error when I am trying to call the webservice through my client : I am using Spring WS -> Wss4jSecurityInterceptor. and Using Private and public key for encryption and decryption.

Config :

<bean id="wsClientSecurityInterceptor"
        class="org.springframework.ws.soap.security.wss4j.Wss4jSecurityInterceptor">
        <property name="validationActions" value="Encrypt Signature" />
        <property name="securementActions" value="Signature Encrypt" />
        <property name="securementSignatureKeyIdentifier" value="DirectReference" />
        <开发者_运维问答;property name="securementUsername" value="${ks-hps-hcentive_private.alias}" />
        <property name="securementPassword" value="${ks-hps-hcentive-private-password}" />  
        <property name="securementSignatureCrypto" ref="ks-hps-hcentive-private" />
        <property name="securementSignatureParts" value="{Element}{}Body" />
        <property name="securementEncryptionCrypto" ref="ks-hps-public" />
        <property name="securementEncryptionUser" value="${ws.keys.hps_public.alias}" />    
        <!-- <property name="securementEncryptionKeyIdentifier" value="Thumbprint" /> -->
        <property name="securementEncryptionKeyIdentifier" value="SKIKeyIdentifier" />
        <property name="securementEncryptionSymAlgorithm" value="http://www.w3.org/2001/04/xmlenc#aes256-cbc" />
        <property name="securementEncryptionParts" value="{Element}{http://www.w3.org/2000/09/xmldsig#}Signature;{Content}{}Body" />
        <property name="validationSignatureCrypto" ref="ks-hps-public" />
        <property name="validationDecryptionCrypto" ref="ks-hps-hcentive-private" />
    </bean>

Error Dumstack is :

  DEBUG [client.core.WebServiceTemplate] Received error for request [SaajSoapMessage {http://www.w3.org/2001/04/xmlenc#}EncryptedData]
org.springframework.ws.client.WebServiceTransportException: Proxy Error [502]
    at org.springframework.ws.client.core.WebServiceTemplate.handleError(WebServiceTemplate.java:627)
    at org.springframework.ws.client.core.WebServiceTemplate.doSendAndReceive(WebServiceTemplate.java:551)
    at org.springframework.ws.client.core.WebServiceTemplate.sendAndReceive(WebServiceTemplate.java:502)
    at org.springframework.ws.client.core.WebServiceTemplate.marshalSendAndReceive(WebServiceTemplate.java:351)
    at org.springframework.ws.client.core.WebServiceTemplate.marshalSendAndReceive(WebServiceTemplate.java:345)

If client accepts the response but does not return a reply, it may give you a 502 proxy error if it's operating behind a proxy server.