我以为这会相对容易,但看来事实并非如此。
我正在使用Java EE 6编写项目中类似Facade的结构的单元测试。
我使用Eclipse Kepler作为IDE,并使用Junit 4.11进行测试。
据我所见,双括号初始化似乎有些“问题”,但我不够了解其原因。
言归正传,我使用以下类在一个集中的地方进行转换:
package com.example-company.util.converters;
import java.util.HashMap;
import java.util.Map;
import com.example-company.model.Location;
import com.example-company.model.Right;
public final class ModelConverters {
private static final Map<Class<?>, ModelConverter<?, String>> modelConverterBacking = new HashMap<Class<?>, ModelConverter<?, String>>();
static {
modelConverterBacking.put(Right.class, new RightConverter());
modelConverterBacking.put(Location.class, new LocationConverter());
};
public static <T> String convert(final T input)
throws IllegalStateException {
@SuppressWarnings("unchecked")
ModelConverter<T, String> modelConverter = (ModelConverter<T, String>) modelConverterBacking
.get(input.getClass());
if (modelConverter == null) {
throw new IllegalStateException("No mapping found for "
+ input.getClass());
}
return modelConverter.convertToView(input);
}
}
就这方面而言,它主要涉及泛型和静态映射的使用。现在我决定为此编写一些单元测试。以下类有些简略,所有未重现问题的测试用例都被删除了。
package com.example-company.test.unit.util.converters;
import static org.junit.Assert.assertEquals;
import com.example-company.model.Location;
import com.example-company.util.converters.ModelConverters;
import org.junit.Test;
public class ModelConvertersFacadeTests {
@Test
public void test_MappingForLocationExists() {
final Location stub = new Location() {
{
setLocationName("");
}
};
String actual = ModelConverters.convert(stub);
assertEquals("", actual);
}
}
到目前为止一切都很好,不应该真的发生什么,至少不是我现在得到的。而这就是:一个花哨的 IllegalStateException
,其堆栈跟踪如下:
java.lang.IllegalStateException: No mapping found for class com.example-company.test.unit.util.converters.ModelConvertersFacadeTests$1
at com.example-company.util.converters.ModelConverters.convert(ModelConverters.java:23)
at com.example-company.test.unit.util.converters.ModelConvertersFacadeTests.test_MappingForLocationExists(ModelConvertersFacadeTests.java:24)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
我所做的第一件事是再次运行它,并设置断点来检查
ModelConverters#convert()
内部发生了什么。让我有些惊讶的是: 似乎
input.getClass()
返回的是 ModelConvertersFacadeTests
。但为什么它不返回 com.example-company.model.Location
呢?
< img alt="Full Debug Perspective, names censored" src="https://istack.dev59.com/PGc11.webp"/>