public void sendRestRequest(String xmlFile){

        try{
            String myRequest = generateStringFromResource(xmlFile);
            given().auth().basic(prop.getProperty("restLogin"), prop.getProperty("restPassword"))
                    .contentType("application/xml")
                    .body(myRequest.getBytes(StandardCharsets.UTF_8))
                    .when()
                    .post(prop.getProperty("restURL"))
                    .then().
                    assertThat().statusCode(200).and().
                    assertThat().body("status", equalTo("UPLOADED"));
            }
        catch (Exception e){ LOG.error(String.valueOf(e)); }
    }

public static String generateStringFromResource(String path) throws IOException {
        return new String(Files.readAllBytes(Paths.get(path)));
    }

at io.restassured.internal.ResponseSpecificationImpl$HamcrestAssertionClosure.validate(ResponseSpecificationImpl.groovy:483)
        at io.restassured.internal.ResponseSpecificationImpl$HamcrestAssertionClosure$validate$1.call(Unknown Source)
        at io.restassured.internal.ResponseSpecificationImpl.validateResponseIfRequired(ResponseSpecificationImpl.groovy:655)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:210)
        at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:59)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:166)
        at io.restassured.internal.ResponseSpecificationImpl.statusCode(ResponseSpecificationImpl.groovy:123)
        at io.restassured.specification.ResponseSpecification$statusCode$0.callCurrent(Unknown Source)
        at io.restassured.internal.ResponseSpecificationImpl.statusCode(ResponseSpecificationImpl.groovy:131)
        at io.restassured.internal.ValidatableResponseOptionsImpl.statusCode(ValidatableResponseOptionsImpl.java:119)