Web Services :: Request Sent By The Client Was Syntactically Incorrect When Using Hebrew

I have an apache server with rest APIs accepting Json object and produce Json object.testing the sever using Chrome advanced rest client show no problems.I then tried to create a jave client, using org.jboss.resteasy:

public T sendPostRequest(String url, T input) throws Exception {
ClientRequest request = getNewClientRequest(url);
ObjectMapper om = new ObjectMapper();
final String body = om.writeValueAsString(input);
request.body(MediaType.APPLICATION_JSON, body);
final ClientResponse<String> responseObj = request.post(String.class);
validateResponseString(url, responseObj);
String responseString = responseObj.getEntity(String.class);
responseObj.releaseConnection();

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