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我想使用番石榴的集合來創建一個地圖，它將存儲一個類實例作爲鍵和一個整數作爲值。因此，像這樣：番石榴地圖存儲類實例作爲鍵和int值
鍵 - 值
FooOne - 1
FooTwo - 2
FooThree - 3
FooFour - 4
我現在在代碼中有這樣的：
private ClassToInstanceMap<Object> classRanking = MutableClassToInstanceMap.create();
classRanking.put(FooOne.class, 0);
classRanking.put(FooTwo.class, 1);
classRanking.put(FooThree.class, 2);
classRanking.put(FooFour.class, 3);
但運行時拋出一個錯誤：
java.lang.ClassCastException: Cannot cast java.lang.Integer to com.jer.abc.test.FooOne
at java.lang.Class.cast(Unknown Source)
at com.google.common.collect.MutableClassToInstanceMap.cast(MutableClassToInstanceMap.java:82)
at com.google.common.collect.MutableClassToInstanceMap.access$000(MutableClassToInstanceMap.java:36)
at com.google.common.collect.MutableClassToInstanceMap$1.checkKeyValue(MutableClassToInstanceMap.java:67)
at com.google.common.collect.MutableClassToInstanceMap$1.checkKeyValue(MutableClassToInstanceMap.java:64)
at com.google.common.collect.MapConstraints$ConstrainedMap.put(MapConstraints.java:313)
at com.fmr.gps.web.support.PortfolioInsightsSupport.populateRankingMap(PortfolioInsightsSupport.java:33)
at com.fmr.gps.web.support.PortfolioInsightsSupport.<init>(PortfolioInsightsSupport.java:29)
at com.fmr.gps.web.PortfolioInsightsSupportTest.setUp(PortfolioInsightsSupportTest.java:38)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
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.RunBefores.evaluate(RunBefores.java:24)
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:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
所以我想使用普通的老式java地圖，但this thread告訴我做其他事情。那麼有關如何解決這個問題的任何想法？