当我们使用someClass.metaClass.constructor
来表示由@CompileStatic
注释的类的方法中可用的任何特定类(例如RESTClient
)时,构造函数覆盖将完全无效。
当我们删除@CompileStatic
注释时,此方法正常工作。我想念什么吗?
示例代码:
@CompileStatic
class FooClass {
String getDataFromProvider() {
String url = "https://www.example.com"
RESTClient restClient = new RESTClient(url)
HttpResponseDecorator response = restClient.post([:]) as HttpResponseDecorator
return response
}
}
测试用例:
import groovyx.net.http.HttpResponseDecorator
import groovyx.net.http.RESTClient
import spock.lang.Specification
class FooContentSpec extends Specification {
void "test getDataFromProvider method"() {
given: "Rest url"
String restURL = "https://www.example.com"
and: "Mock RESTClient"
RESTClient mockedRestClient = Mock(RESTClient)
// THIS IS NOT WORKING
RESTClient.metaClass.constructor = { Object url ->
assert restURL == url
return mockedRestClient
}
mockedRestClient.metaClass.post = { Map<String, ?> args ->
return ""
}
when: "We hit the method"
HttpResponseDecorator response = Content.getDataFromProvider()
then: "We should get status 200"
response.statusCode == 200
}
}
根据Groovy Lang文档:
MockFor
和StubFor
不能用于测试静态编译的类,例如使用@CompileStatic
的Java类或Groovy类。要存根和/或模拟这些类,可以使用Spock或Java模拟库之一。
在这种情况下,RESTClient
的构造函数重写应该在我们的测试用例中起作用,因为我们不想在每个测试用例中都使用第三方API。
不幸的是,RESTClient
并没有因为@CompileStatic
注释而被嘲笑,它每次都会命中API。
------------------------------------------------------------
Gradle 3.5
------------------------------------------------------------
Groovy: 2.4.10,
Ant: Apache Ant(TM) version 1.9.6 compiled on June 29 2015,
JVM: 1.8.0_221 (Oracle Corporation 25.221-b11),
OS: Mac OS X 10.15.2 x86_64
答案 0 :(得分:2)
您是正确的@CompileStatic
不能与元类操作一起使用。顾名思义,原因是所有这些都在编译时解析和绑定,因此没有元类查找,因此也没有办法覆盖它。
我建议研究IoC /依赖注入,以便您可以将模拟注入到代码中。使用经典单例使您的代码难以测试。
答案 1 :(得分:2)
在Leonard Brünings的评论之后:
是的,@ CompileStatic将在编译时解析FooClass中RESTClient的构造函数,因此它将不会使用元类在运行时对其进行锁定。如果您想看看它的外观,建议您使用反编译器,例如ByteCode查看器,并查看生成的字节码。
我们针对两种情况反编译了生成的字节码:
@CompileStatic
public class FooClass implements GroovyObject {
public FooClass() {
MetaClass var1 = this.$getStaticMetaClass();
this.metaClass = var1;
}
public String getDataFromProvider() {
String url = "https://www.example.com";
// Directly constructor is getting used
RESTClient restClient = new RESTClient(url);
HttpResponseDecorator response = (HttpResponseDecorator)ScriptBytecodeAdapter.asType(restClient.post(ScriptBytecodeAdapter.createMap(new Object[0])), HttpResponseDecorator.class);
return (String)ShortTypeHandling.castToString(response);
}
}
@CompileStatic
public class FooClass implements GroovyObject {
public FooClass() {
CallSite[] var1 = $getCallSiteArray();
super();
MetaClass var2 = this.$getStaticMetaClass();
this.metaClass = var2;
}
public String getDataFromProvider() {
CallSite[] var1 = $getCallSiteArray();
String url = "https://www.example.com";
// Here Groovy's metaprogramming is into play instead of directly calling constructor
RESTClient restClient = (RESTClient)ScriptBytecodeAdapter.castToType(var1[0].callConstructor(RESTClient.class, url), RESTClient.class);
HttpResponseDecorator response = (HttpResponseDecorator)ScriptBytecodeAdapter.asType(var1[1].call(restClient, ScriptBytecodeAdapter.createMap(new Object[0])), HttpResponseDecorator.class);
return (String)ShortTypeHandling.castToString(response);
}
}
因此@Leonard给出的答案是完全正确的。我们错过了这个简单的Java概念。