JMockit对方法体中new出来的对象mock以及对Spring RestTemplate类的mock操作

本文详细介绍了如何使用JMockit对Spring项目中的RestTemplate类进行单元测试，包括对方法体内new出来的对象的mock操作。通过具体示例展示了如何避免NoClassDefFoundError异常，以及如何正确配置pom.xml引入所需依赖。

JMockit对方法体中new出来的对象mock以及对Spring RestTemplate类的mock操作

我们知道在Spring项目中用jmockit编写单元测试。对于sevice类中@Autowired的对象用@Injectable进行mock，然后在Expection中进行相应方法的mock，类似这样：

@RunWith(JMockit.class)
public class ATest{

@Tested
A a=new A();

@Injectable
private B b;

@Test
public void c(){
		new Expectations() {
            	{
            		b.methodA();
            		result="aaa";
            	}
            	};
		...
		a.c();
	}
}

对于方法c中new出来的对象以及Restemplate对象如何基于jmockit进行单测的编写呢？例如：

public class A{
	public String b(){
		RestTemplate restTemplate = new RestTemplate();
        	String resStr = restTemplate.getForObject("url", String.class, token);
        	JSONObject jsonObject = JSONObject.parseObject(resStr);
        	....
	}
}

jmockit单元测试如下：

@RunWith(JMockit.class)
public class ATest{

	@Tested
	A a=new A();

	@Test
	public void b(){
	RestTemplate restTemplate=new RestTemplate();
		new Expectations(RestTemplate.class){
	            {
             	    restTemplate.getForObject(anyString,(Class<T>)any,anyString);
            	    result="{'status':2,'data':{'phone':'18867112222'}}";
            	    result="{'status':1,'data':{'phone':'18867112222'}}";
           	 }
       	 };
	...
	a.b();
}
}

如果报类似如下异常：

java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/util/DefaultIndenter

at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.init(AbstractJackson2HttpMessageConverter.java:97)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.<init>(AbstractJackson2HttpMessageConverter.java:90)
at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.<init>(MappingJackson2HttpMessageConverter.java:66)
at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.<init>(MappingJackson2HttpMessageConverter.java:57)
at org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:61)
at org.springframework.web.client.RestTemplate.<init>(RestTemplate.java:159)
at com.zyhy.izms.service.impl.account.AccountServiceImplTest.xyrjLoginValidator(AccountServiceImplTest.java:326)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.util.DefaultIndenter
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
… 13 more

请在pom.xml中引入RestTemplate需要的jackson相关依赖。

	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-core</artifactId>
		<version>2.9.5</version>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-databind</artifactId>
		<version>2.9.5</version>
	</dependency>