用于DAO和Web服务的数据库插入方法的Junit测试用例

Question

我正在实施一个基于Web服务的大学管理系统.该系统将某些课程添加到数据库中.下面是我正在使用的代码.

Course.java

public class Course {

    private String courseName;
    private String location;
    private String courseId;


       public String getCourseId()
               {
        return courseId;
            }

    public void setCourseId(String courseId) {
        this.courseId = courseId;
    }

    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

        public String getLocation() {
        return location;
    }
    public void setLocation(String location) {
        this.location = location;
    }
}

然后另一个文件如下

CourseDaoImpl.java

public class CourseDaoImpl implements IDao {
   Connection conn = null;
   Statement stmt = null;

public CourseDaoImpl(){

try {
    Class.forName("com.mysql.jdbc.Driver").newInstance();
    conn = DriverManager.getConnection(
            "jdbc:mysql://localhost:3306/univesitydb", "root", "root");
    stmt = conn.createStatement();

    if (!conn.isClosed())
        System.out.println("Successfully connectiod");
} catch (SQLException e) {
    e.printStackTrace();
} catch (InstantiationException e) {
    e.printStackTrace();
} catch (IllegalAccessException e) {
    e.printStackTrace();
} catch (ClassNotFoundException e) {
    e.printStackTrace();
}
}

      @Override
  public String add(Object object) {

Course c = (Course) object ;

String courseId = c.getCourseId();
String courseName = c.getCourseName();
String location = c.getLocation();

String result = "";
int rowcount;

try {
    String query = "Insert into course (courseId,courseName,location) values"
            + " ('"
            + courseId
            + "', '"
            + courseName
            + "', '"
            + location
            + "')";
    rowcount = stmt.executeUpdate(query);
    if (rowcount > 0) {
        result = "true";
        System.out.println("Course inserted successful");
    } else {
        result = "false:The data could not be inserted in the databse";
    }
} catch (SQLException e) {
    e.printStackTrace();
}

return result;
}

第三个是如下的Web服务文件,它与前两个交互并将数据添加到数据库.

CourseService.java

package edu.service;

          import edu.dao.IDao;
          import edu.dao.impl.CourseDaoImpl;
          import edu.db.entity.Course;

       public class CourseService {

     public String addCourse(String courseId, String courseName, String location)
    {   
       Course c = new Course();
       c.setCourseId(courseId);
       c.setCourseName(courseName);
       c.setLocation(location);     
       IDao dao = new CourseDaoImpl();
       return dao.add(c);   
     }

查看我的代码清单,任何机构都可以建议我如何为我的add方法编写测试用例.我完全初学JAVA的,我帮助了我的朋友来学习这个Java部分,现在需要实现JUnit测试我的数据库的方法,如添加上述课程.

请提出一些我可以学习,阅读和使用的东西来实现我的数据库方法的Junit测试.

Answer 1

这是在spring项目中使用junit的一个示例dao测试.

import java.util.List;

import junit.framework.Assert;

import org.jboss.tools.example.springmvc.domain.Member;
import org.jboss.tools.example.springmvc.repo.MemberDao;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.transaction.TransactionConfiguration;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:test-context.xml",
"classpath:/META-INF/spring/applicationContext.xml"})
@Transactional
@TransactionConfiguration(defaultRollback=true)
public class MemberDaoTest
{
    @Autowired
    private MemberDao memberDao;

    @Test
    public void testFindById()
    {
        Member member = memberDao.findById(0l);

        Assert.assertEquals("John Smith", member.getName());
        Assert.assertEquals("john.smith@mailinator.com", member.getEmail());
        Assert.assertEquals("2125551212", member.getPhoneNumber());
        return;
    }

    @Test
    public void testFindByEmail()
    {
        Member member = memberDao.findByEmail("john.smith@mailinator.com");

        Assert.assertEquals("John Smith", member.getName());
        Assert.assertEquals("john.smith@mailinator.com", member.getEmail());
        Assert.assertEquals("2125551212", member.getPhoneNumber());
        return;
    }

    @Test
    public void testRegister()
    {
        Member member = new Member();
        member.setEmail("jane.doe@mailinator.com");
        member.setName("Jane Doe");
        member.setPhoneNumber("2125552121");

        memberDao.register(member);
        Long id = member.getId();
        Assert.assertNotNull(id);

        Assert.assertEquals(2, memberDao.findAllOrderedByName().size());
        Member newMember = memberDao.findById(id);

        Assert.assertEquals("Jane Doe", newMember.getName());
        Assert.assertEquals("jane.doe@mailinator.com", newMember.getEmail());
        Assert.assertEquals("2125552121", newMember.getPhoneNumber());
        return;
    }

    @Test
    public void testFindAllOrderedByName()
    {
        Member member = new Member();
        member.setEmail("jane.doe@mailinator.com");
        member.setName("Jane Doe");
        member.setPhoneNumber("2125552121");
        memberDao.register(member);

        List<Member> members = memberDao.findAllOrderedByName();
        Assert.assertEquals(2, members.size());
        Member newMember = members.get(0);

        Assert.assertEquals("Jane Doe", newMember.getName());
        Assert.assertEquals("jane.doe@mailinator.com", newMember.getEmail());
        Assert.assertEquals("2125552121", newMember.getPhoneNumber());
        return;
    }
}

Answer 2

您的类的设计将使它们难以测试.使用硬编码连接字符串或在方法中实例化协作者new可以被视为测试反模式.看看DependencyInjection模式.像Spring这样的框架在这里可能会有所帮助.

要对DAO进行测试,您需要在单元测试中控制数据库连接.因此,您要做的第一件事就是将它从DAO中提取到一个类中,您可以模拟或指向特定的测试数据库,您可以在测试运行之前和之后设置和检查它.

测试db/DAO代码的技术解决方案可能是dbunit.您可以在无模式XML中定义测试数据,并让dbunit在测试数据库中填充它.但你仍然需要自己连接所有东西.使用Spring,你可以使用类似spring-test-dbunit的东西,它可以为你提供大量的杠杆和额外的工具.

正如你称自己为初学者,我怀疑这一切都非常令人生畏.您应该问问自己是否真的需要测试数据库代码.如果不是,您至少应该重构代码,这样您就可以轻松模拟所有数据库访问.对于一般的嘲笑,看看Mockito.