java从ws获取空指针异常。网址

Question

@Inject
private WSClient ws;

@Override
public void getTerminalDetails(String terminalId, String institutionId) {

    String url = "http://localhost:8089/getDetails";
    WSRequest request = ws.url(url);
    CompletionStage<WSResponse>  wsResponse = request.get();
}

我得到以下错误：

Caused by: java.lang.NullPointerException: null at service.impl.TerminalDetailsServiceImpl.getTerminalDetails(TerminalDetailsServiceImpl.java:25)

第25行是：

WSRequest request = ws.url(url);

谁能帮我弄明白我做错了什么吗。我是从SpringBoot迁移过来的新手