测试登录Servlet

Question

我试图使用mockito测试我的登录servlet，但它返回错误：

java.lang.NullPointerException：无法调用“java.io.PrintWriter.PrintLN（String）”，因为“out”为null。在Control.LoginPatient.DoPost（LoginPatient.java:55)在Control.LoginPatientTest.TestDoPostSuccessfull（LoginPatientTest.java:64)

下面是我的登录servlet的代码：

package control;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import model.ProfileManager;
import model.Bean.UserBean;

/**
 * Servlet implementation class LoginPatient
 */
@WebServlet("/LoginPatient")
public class LoginPatient extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginPatient() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String fiscal_code=request.getParameter("fiscal_code");
        String user_password= request.getParameter("user_password");
        PrintWriter out = response.getWriter();
        ProfileManager pM=new ProfileManager();
        UserBean patient= pM.ReturnPatientByKey(fiscal_code, user_password);

        if(patient != null) {
            HttpSession session= request.getSession();
            session.setAttribute( "user" , patient);
            session.setMaxInactiveInterval(-1);
            out.println("1");
        }

        else {
            out.println("0"); 
        }
    }

}

这里是我的测试用例：

class LoginPatientTest {

    private LoginPatient loginPatient;
    private HttpServletRequest mockedRequest;
    private HttpServletResponse mockedResponse;
    private ServletContext mockedServletContext;
    private HttpSession mockedSession;
    private PatientBean patient;
    private ProfileManager pm;
    private PrintWriter mockedOut;
    
    /**
     * @throws java.lang.Exception
     */
    @BeforeEach
    void setUp() throws Exception {
        loginPatient = new LoginPatient();
        mockedRequest = Mockito.mock(HttpServletRequest.class);
        mockedResponse = Mockito.mock(HttpServletResponse.class);
        mockedSession = Mockito.mock(HttpSession.class);
        mockedServletContext = Mockito.mock(ServletContext.class);
        mockedOut = Mockito.mock(PrintWriter.class);
        patient = Mockito.mock(PatientBean.class);
        pm = Mockito.mock(ProfileManager.class);
    }

    /**
     * @throws java.lang.Exception
     */
    @AfterEach
    void tearDown() throws Exception {
    }

    /**
     * Test method for {@link control.LoginPatient#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)}.
     * @throws javax.servlet.ServletException
     * @throws java.io.IOException
     */ 
    @Test
    final void testDoPostSuccessful() throws ServletException, IOException{
        
Mockito.doReturn(mockedServletContext).when(mockedRequest).getServletContext();
        Mockito.when(mockedRequest.getParameter("fiscal_code")).thenReturn("fiscalCode");
        Mockito.when(mockedRequest.getParameter("user_password")).thenReturn("password");
        Mockito.when(mockedRequest.getSession()).thenReturn(mockedSession);
        Mockito.when(pm.ReturnPatientByKey("fiscalCode", "password"));
        Mockito.when(mockedResponse.getWriter()).thenReturn(mockedOut);

loginPatient.doPost(mockedRequest, mockedResponse);

        Mockito.verify(mockedOut).println("1");
        Mockito.verify(mockedSession).setAttribute(Mockito.eq("user"), patient);
    }

}

我不用spring

更新：现在它给了我另一个错误：

null

Answer 1

问题1：

在模拟设置中，将mockedOut变量更改为mockedOut=mockito.mock（printwriter.class）；

问题2：

在激发业务逻辑之后，您将mockedout变量取出来。你应该换个顺序。在调用业务逻辑之前模拟所有内容。

//Given

    Mockito.doReturn(mockedServletContext).when(mockedRequest).getServletContext();
    Mockito.when(mockedRequest.getParameter("fiscal_code")).thenReturn("fiscalCode");
    Mockito.when(mockedRequest.getParameter("user_password")).thenReturn("password");
    Mockito.when(mockedRequest.getSession()).thenReturn(mockedSession);
    Mockito.when(pm.ReturnPatientByKey("fiscalCode", "password"));
    Mockito.when(mockedResponse.getWriter()).thenReturn(mockedOut);

//When   
    loginPatient.doPost(mockedRequest, mockedResponse);   


//Then
    Mockito.verify(mockedOut).println("1");
    Mockito.verify(mockedSession).setAttribute(Mockito.eq("user"), patient);