1、在pom文件中添加依赖

<!--spring-test依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.1.5.RELEASE</version>
      <scope>test</scope>
    </dependency>
    <!--junit依赖-->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>

2、编写待测程序Max.java

package com.spring;

public class Max {
    private int a;
    private int b;

    public Max(int a, int b) {
        this.a = a;
        this.b = b;
    }

    public int getMax() {
        return a > b ? a : b;
    }
}

3、配置Max的bean

 <bean id="max" class="com.spring.Max">
        <constructor-arg name="a" value="5"/>
        <constructor-arg name="b" value="3"/>
    </bean>

4、创建单元测试代码

• 在Max类的声明的后面按“Alt+Enter”，选择“Create Test”，然后选择JUnit4，并勾选待测方法getMax(),点击OK

  
  Create Test.jpg
  完成创建.jpg

5MaxTest类

在Test包下，会自动创建一个MaxTest类，具体代码如下：

package com.spring;

import org.apache.log4j.Logger;
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 static org.junit.Assert.assertEquals;


@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/spring.xml"})
public class MaxTest {

    private static Logger log = Logger.getLogger(MaxTest.class.getClass());

    @Autowired
    private Max max;

    @Test
    public void getMax() {
        log.debug("test by mqxu");
        assertEquals(5, max.getMax());
    }
}

• 头部两个注解表示指定运行环境和指定配置文件路径，使用了@Autowired自动注入配置文件中的bean，使用assertEquals断言，判断期望值和实际值是否相等，并使用Logger记录日志。

5、运行结果

运行结果.jpg

6、综合练习

• 定义User类，封装account和password属性，提供getter/setter，重载构造方法，重写toString()方法
• 定义UserLogin类，封装User属性，提供getter/setter，并定义public boolean userLogin(User user)；方法，判定某个用户能否登陆成功，指定账号为“admin”，密码为“111”
• 写配置文件，通过构造器注入创建一个User对象并传值，通过setter注入创建UserLogin对象并传值
• 写单元测试，测试某用户能否登陆成功
• User类

package com.spring.ioc;

public class User {
    private String account;
    private String password;

    public User() {
    }

    public User(String account, String password) {
        this.account = account;
        this.password = password;
    }

    public String getAccount() {
        return account;
    }

    public void setAccount(String account) {
        this.account = account;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" + "account='" + account + '\'' + ", password='" + password + '\'' + '}';
    }
}

• UserLogin类

package com.spring.ioc;

public class UserLogin {
    private User user;

    public UserLogin() {
    }

    public UserLogin(User user) {
        this.user = user;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public boolean userLogin(User user) {
        if ("admin".equals(user.getAccount()) && "123".equals(user.getPassword())) {
            return true;
        } else {
            return false;
        }
    }
}

• 配置文件

    <!--配置一个User的bean-->
    <bean id="user" class="com.spring.ioc.User">
        <constructor-arg name="account" value="admin"/>
        <constructor-arg name="password" value="123"/>
    </bean>

    <!--配置一个UserLogin的bean-->
    <bean id="userLogin" class="com.spring.ioc.UserLogin">
        <property name="user" ref="user"/>
    </bean>

• 单元测试类

package com.spring.ioc;

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 static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/applicationContext.xml"})
public class UserLoginTest {
    @Autowired
    private User user;

    @Autowired
    private UserLogin userLogin;

    @Test
    public void userLogin() {
        assertEquals(true, userLogin.userLogin(user));
    }
}

• 运行结果

  
  运行结果.jpg