How do I Unit Test HTTPServlet?

Question

I want to test my servlet with http://www.easymock.org/

How do I write the Unit Testing Code?

I update my code with your responce.

I just used Google and made this code now.

Here is my Servlet:

 package com.i4ware.plugin.timesheet;

 import java.io.IOException;

 import com.atlassian.jira.issue.Issue;
 import com.atlassian.jira.issue.IssueManager;
 import com.atlassian.jira.project.Project;
 import com.atlassian.jira.project.ProjectManager;
 import org.ofbiz.core.entity.DelegatorInterface;
 import org.ofbiz.core.entity.EntityExpr;
 import org.ofbiz.core.entity.EntityOperator;
 import org.ofbiz.core.entity.GenericEntityException;
 import org.ofbiz.core.entity.GenericValue;
 import org.ofbiz.core.util.UtilMisc;
 import org.apache.commons.lang.StringEscapeUtils;
 import com.atlassian.crowd.embedded.api.User;
 import com.atlassian.jira.security.JiraAuthenticationContext;
 import com.atlassian.jira.web.bean.PagerFilter;
 import com.atlassian.jira.issue.search.SearchResults;
 import com.atlassian.jira.bc.issue.search.SearchService;
 import com.atlassian.jira.issue.search.SearchException;

 import com.atlassian.jira.issue.worklog.Worklog;
 import com.atlassian.jira.issue.worklog.WorklogManager;
 import com.atlassian.jira.issue.worklog.WorklogImpl;

 import com.atlassian.query.Query;
 import com.atlassian.jira.jql.builder.JqlQueryBuilder;
 import com.atlassian.query.order.SortOrder;

 import com.atlassian.jira.issue.status.Status; 

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import com.atlassian.jira.util.json.JSONObject;
 import com.atlassian.jira.util.json.JSONException;
 import com.atlassian.jira.util.json.JSONArray;

 import java.io.UnsupportedEncodingException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
import java.util.Set;
import java.util.TimeZone;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.Collections;
import java.lang.Long;
import java.util.Collection;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.lang.Class;
import java.util.Enumeration;

import org.apache.log4j.Category;

import com.atlassian.upm.api.license.entity.PluginLicense;
import com.atlassian.upm.license.storage.lib.PluginLicenseStoragePluginUnresolvedException;
import com.atlassian.upm.license.storage.lib.ThirdPartyPluginLicenseStorageManager;

import com.atlassian.plugin.webresource.WebResourceManager;
 import com.atlassian.templaterenderer.TemplateRenderer;

import java.text.ParseException;
import java.text.ParsePosition;

 public class UserIsLogedInServlet extends HttpServlet
 {
private static final Category log = Category.getInstance(UserIsLogedInServlet.class);
/** value is made for JSON {"success":true} or {"success":false}. */
private Boolean value;    

private String json;
private String msg;
private final ThirdPartyPluginLicenseStorageManager licenseManager;
private WebResourceManager webResourceManager;
private final TemplateRenderer renderer;

private JiraAuthenticationContext authenticationContext;    

public UserIsLogedInServlet(ThirdPartyPluginLicenseStorageManager licenseManager,
        WebResourceManager webResourceManager,
        TemplateRenderer renderer,
        JiraAuthenticationContext authenticationContext)
{
    this.licenseManager = licenseManager;
    this.webResourceManager = webResourceManager;
    this.renderer = renderer;
    this.authenticationContext = authenticationContext;
}

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
    resp.setContentType("application/json");        

}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{       

    User targetUser = authenticationContext.getLoggedInUser();

    String user = "";

    if (targetUser==null) {

        user = "anonymous";
        value = Boolean.valueOf(!"false"
            .equalsIgnoreCase((String) "false"));
        msg = "You're not loged in.";
    } else {

        user = targetUser.getName();
        value = Boolean.valueOf(!"false"
            .equalsIgnoreCase((String) "true"));
        msg = "You're loged in.";
    }        

    try {

    json = new JSONObject()      
    .put("msg", msg)
    .put("success", value)
    .toString();

    } catch (JSONException err) {
        err.printStackTrace();
        System.out.println("Got an JSONException: " + err.getCause());
    }

    resp.setContentType("application/json");        
    resp.getWriter().write(json);
    resp.getWriter().close();

}
}

Here is code:

package com.i4ware.plugin.timesheet;

import junit.framework.*;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.BeforeClass;
import org.junit.After;
import java.io.*;
import java.security.*;
import javax.servlet.http.*;
import javax.servlet.ServletException;
import javax.servlet.RequestDispatcher;
import static org.easymock.EasyMock.*;
import org.easymock.IMocksControl;
import com.atlassian.upm.api.license.entity.PluginLicense;
import com.atlassian.upm.license.storage.lib.PluginLicenseStoragePluginUnresolvedException;
import com.atlassian.upm.license.storage.lib.ThirdPartyPluginLicenseStorageManager;
import com.atlassian.plugin.webresource.WebResourceManager;
import com.atlassian.templaterenderer.TemplateRenderer;
import com.atlassian.jira.security.JiraAuthenticationContext;

import com.i4ware.plugin.timesheet.UserIsLogedInServlet;

public class UserIsLogedInServletTest extends TestCase {    

private ThirdPartyPluginLicenseStorageManager licenseManager;
private WebResourceManager webResourceManager;
private TemplateRenderer renderer;  
private JiraAuthenticationContext authenticationContext;

private IMocksControl mocks;
private UserIsLogedInServlet servlet;

@BeforeClass
public void setUpBeforeClass() {
    mocks = (IMocksControl) createStrictControl();
    servlet = new UserIsLogedInServlet(licenseManager,webResourceManager,renderer,authenticationContext);
}

@After
public void tearDown() {
    mocks.reset();
}

@Test
public void testGet()throws ServletException, IOException {
    HttpServletRequest request = mocks.createMock(HttpServletRequest.class);
    HttpServletResponse response = mocks.createMock(HttpServletResponse.class);
expect(request.getRequestDispatcher("/plugins/servlet/timesheet/userislogedin")).andReturn(createMock(RequestDispatcher.class));
    replay(request, response);
    servlet.doGet(request, response);
    verify(request, response);
}

@Test
public void testPost() throws ServletException, IOException {
    HttpServletRequest request = mocks.createMock(HttpServletRequest.class);
    HttpServletResponse response = mocks.createMock(HttpServletResponse.class);
expect(request.getRequestDispatcher("/plugins/servlet/timesheet/userislogedin")).andReturn(createMock(RequestDispatcher.class));
    replay(request, response);
    servlet.doPost(request, response);
    verify(request, response);
}

}

I get this error:

Tests run: 2, Failures: 0, Errors: 2, Skipped: 0, Time elapsed: 0.046 sec <<< FAILURE!
testPost(com.i4ware.plugin.timesheet.UserIsLogedInServletTest)  Time elapsed: 0.01 sec  <<< ERROR!
 java.lang.NullPointerException
at  com.i4ware.plugin.timesheet.UserIsLogedInServletTest.testPost(UserIsLogedInServletTest.java:67)

testGet(com.i4ware.plugin.timesheet.UserIsLogedInServletTest)  Time elapsed: 0 sec  <<< ERROR!
java.lang.NullPointerException
at com.i4ware.plugin.timesheet.UserIsLogedInServletTest.testGet(UserIsLogedInServletTest.java:58)

Solution 1

I am more familiar with Mockito, but I believe they are still similar. In fact I think Mockito was branched from EasyMock a few years back.

There is no cookbook approach to unit testing, but this is the basic approach I tend to take:

1) Create a real instance of your servlet class (i.e. new MyServlet())

2) Create a mock HttpRequest using EasyMock

2a) Mock the desired behavior of the request to simulate a real HTTP request. For example, this may mean you simulate the presence of request parameters or headers.

3) Create a mock HttpResponse using EasyMock

4) call the doGet() method of your servlet passing it both the mock request and response.

5) For verification, inspect the mock HttpResponse. Verify that: (a) the expected methods have been called on the object, (b) The expected data has been passed to the object.

I know this is very high-level, but I am just outlining the approach. I assume you know how to accomplish the mocking/verification behaviors using EasyMock.

Hope this is helpful.

Solution 2

You need to mock both HttpServletRequest and HttpServletResponse objects. There are existing implementations, easier to use compared to standard mocks.

Once you have request and response instances, you follow this pattern:

private final MyServlet servlet = new MyServlet();

@Test
public void testServlet() {
    //given
    MockHttpServletRequest req = //...
    MockHttpServletResponse resp = //...

    //when
    servlet.service(req, resp);

    //then
    //verify response headers and body here
}