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)

Answer 1

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
}

Answer 2

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 (ie 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.

Answer 3

I prefer using spring-test and the MockHttpServletRequest and MockHttpServletResponse. They are more stub like than mocks, but work really well.

This answer has information regarding the usage: How to test my servlet using JUnit