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测试驱动开发

传统的的开发流程：

编码--->测试--->重复--->提交

基于测试驱动的开发流程：

测试--->编码--->重复--->提交

下面是一个简单的用户管理的用测试驱动开发的小小例子：

1、先定义好实体类User：

package com.fjnu.model;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();		// TODO Auto-generated constructor stub	}	public User(String username, String password, String nickname) {		super();		this.username = username;		this.password = password;		this.nickname = nickname;	}	}

2、然后定义好数据操作层的接口IUserService：

package com.fjnu.service;import com.fjnu.model.User;public interface IUserService {	public void add(User user);		public void delete(String username);		public User load(String username);		public User login(String username, String password);}

3、再定义一个异常类UserException，继承RuntimeException。

4、有了这些，就可以针对接口IUserService编写测试类TestUserService了，这个测试类类似于白盒测试，要把各种分支的可能情况都要考虑到并且编写测试代码：

package com.fjnu.service;import static org.junit.Assert.*;import org.junit.Before;import org.junit.Test;import com.fjnu.model.User;import com.fjnu.model.UserException;public class TestUserService {	private IUserService us;	private User baseUser;		@Before	public void setUp(){		// 初始化		us = new UserServiceByMap();		baseUser = new User("admin", "123", "管理员");	}		private void assertUserEquals(User u, User tu){		assertEquals("add方法有错误!", u.getUsername(), tu.getUsername());		assertEquals("add方法有错误!", u.getNickname(), tu.getNickname());		assertEquals("add方法有错误!", u.getPassword(), tu.getPassword());	}		@Test	public void testAdd(){		User u = baseUser;		us.add(u);		User tu = us.load("admin");		assertNotNull(tu);		assertUserEquals(u, tu);		//fail("请加入添加的测试代码");	}		@Test(expected=UserException.class)	public void AddExistUsername(){		us.add(baseUser);		User tu = new User("admin", "1234", "alskdf");		us.add(tu);	}		@Test	public void testDelete(){		us.add(baseUser);		User tu = us.load(baseUser.getUsername());		assertNotNull(tu);		us.delete(baseUser.getUsername());		tu = us.load(baseUser.getUsername());		assertNull(tu);	}		@Test	public void testLogin(){ 		us.add(baseUser);		String username=baseUser.getUsername();		String password=baseUser.getPassword();		User tu = us.login(username, password);		assertUserEquals(baseUser, tu);	}		@Test(expected=UserException.class)	public void testNotExistsUserLogin(){		us.add(baseUser);		String username="admin1";		String password="123";		us.login(username, password); 	}		@Test(expected=UserException.class)	public void testPasswordErrorUserLogin(){		us.add(baseUser);		String username="admin";		String password="1235";		us.login(username, password);	}}

5、编写完测试类之后，就可以实现接口IUserService了：

package com.fjnu.service;import java.util.HashMap;import java.util.Map;import com.fjnu.model.User;import com.fjnu.model.UserException;public class UserServiceByMap implements IUserService {	private Map
   
     us = new HashMap
    
     ();		@Override	public void add(User user) {		// TODO Auto-generated method stub		if(load(user.getUsername()) != null){			throw new UserException("用户名已存在");		}		us.put(user.getUsername(), user);	}	@Override	public void delete(String username) {		// TODO Auto-generated method stub		us.remove(username);	}	@Override	public User load(String username) {		// TODO Auto-generated method stub		return us.get(username);	}	@Override	public User login(String username, String password) {		// TODO Auto-generated method stub		User u = load(username);		if(u==null) throw new UserException("用户名不存在");		if(!u.getPassword().equals(password)) throw new UserException("用户密码不正确");		return u;	}}
    
   

最终：

cobertura框架:测试代码覆盖率