Cobertura单元测试覆盖率实例

Cobertura 是一种开源工具，它通过检测基本的代码，并观察在测试包运行时执行了哪些代码和没有执行哪些代码，来测量测试覆盖率。除了找出未测试到的代码并发现 bug 外，Cobertura 还可以通过标记无用的、执行不到的代码来优化代码，还可以提供 API 实际操作的内部信息。

Cobertura跟Maven完美结合，只需要在pom文件中增加一个插件即可：

<plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>cobertura-maven-plugin</artifactId>
         <version>2.7</version>
</plugin> 

项目开发正确过程应该如此：

1.创建一个User对象：

package jmust.demo.Cobertura;

/**
 * Hello world!
 *
 */
public class User
{
    private String userName;
    private String password;
    private String nickName;
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getNickName() {
        return nickName;
    }
    public void setNickName(String nickName) {
        this.nickName = nickName;
    }

    public User(){
        super();
    }

    public User(String userName,String password,String nickName){
        super();
        this.userName = userName;
        this.password = password;
        this.nickName = nickName;
    }
}

2.定义功能接口类：

package jmust.demo.Cobertura.Inter;

import jmust.demo.Cobertura.User;

public interface IUserService {

    public boolean add(User user);
    public boolean delete(String userName);
    public User load(String userName);
    public User login(String userName,String password);
}

3.编写单元测试类：

package jmust.demo.CoberturaTest;

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

import jmust.demo.Cobertura.User;
import jmust.demo.Cobertura.Exception.UserException;
import jmust.demo.Cobertura.Inter.IUserService;
import jmust.demo.Cobertura.Service.UserService;

/**
 * Unit test for simple User.
 */
public class UserServiceTest {
   private IUserService us;
   private User user;

   @Before
   public void setUp(){
       //初始化
       us = new UserService();
       user = new User("admin","123","管理员");
   }

   @Test
   public void addTest(){
       User u = user;
       us.add(u);
       User tu = us.load("admin");
       assertNotNull(tu);
   }

   @Test(expected=UserException.class)
   public void AddExistUsername(){
       us.add(user);
       User tu = new User("admin", "1234", "alskdf");
       boolean state = us.add(tu);
       assertFalse(state);
   }  

   @Test
   public void testDelete(){
       us.add(user);
       User tu = us.load(user.getUserName());
       assertNotNull(tu);
       us.delete(user.getUserName());
       tu = us.load(user.getUserName());
       assertNull(tu);
   }  

   @Test
   public void testLogin(){
       us.add(user);
       String username=user.getUserName();
       String password=user.getPassword();
       User tu = us.login(username, password);
       assertNotNull(tu);
   }  

   @Test(expected=UserException.class)
   public void testNotExistsUserLogin(){
       us.add(user);
       String username="admin1";
       String password="123";
       User tu = us.login(username, password);
       assertNotNull(tu);
   }  

   @Test(expected=UserException.class)
   public void testPasswordErrorUserLogin(){
       us.add(user);
       String username="admin";
       String password="1235";
       User tu = us.login(username, password);
       assertNotNull(tu);
   }
}

4.再编写功能实现类：

package jmust.demo.Cobertura.Service;

import java.util.HashMap;
import java.util.Map;

import jmust.demo.Cobertura.User;
import jmust.demo.Cobertura.Exception.UserException;
import jmust.demo.Cobertura.Inter.IUserService;

public class UserService implements IUserService{

    private Map<String,User> us = new HashMap<String,User>();
    /**
     * 添加
     */
    public boolean add(User user) {
        if(load(user.getUserName()) != null){
            throw new UserException("用户已存在");
        }
        us.put(user.getUserName(), user);
        return true;
    }
    /**
     * 删除
     */
    public boolean delete(String userName) {
        us.remove(userName);

        return true;
    }
    /**
     * 加载
     */
    public User load(String userName) {
        return us.get(userName);
    }
    /**
     * 登录
     */
    public User login(String userName, String password) {
        User u = load(userName);
        if(u == null) throw new UserException("用户不存在");
        if(!u.getPassword().equals(password)) throw new UserException("用户密码不正确");
        return u;
    }

}

到此，项目开发完成了。然后我们来执行，看看它的覆盖率如何：

首先，我们先来把项目打包成jar包，通过maven命令执行,  mvn install或者mvn package或者mvn deploy

然后，我们再继续执行maven命令，mvn cobertura:cobertura ，完成后，会在项目的目录target下有个site文件夹，我们打开里面的index页面，可以看到详细的覆盖率以及代码执行次数等。