I am getting Nullpointerexception while mocking a class that is having the below line

IOdataApiBusiness odataApiBusiness = (IOdataApiBusiness) SpringContextInjector.getBeanFromSpringContext(SpringConfigurations.ODATA_API_BUSINESS);

here is the error

java.lang.NullPointerException
    at com.odata.config.SpringContextInjector.getBeanFromSpringContext(SpringContextInjector.java:9)
    at com.odata.util.ApiUtilities.<init>(ApiUtilities.java:63)
    at com.odata.controller.FetchIDPOfficeDetails.getInstitutionDetails(FetchIDPOfficeDetails.java:70)
    at com.odata.controller.FetchIDPOfficeDetailsTest.testGetInstitutionDetails(FetchIDPOfficeDetailsTest.java:111)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:727)
    at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:156)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:147)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:86)

here is SpringContextInjector class:

public class SpringContextInjector {

  public static Object getBeanFromSpringContext(String beanId) {
    ApplicationContext context = ApplicationListenerBean.getContext();
    Object beanObj = context.getBean(beanId);  //getting the error here.
    return beanObj;
  }
}