Video: Dab tsi yog qhov kev zam hauv chav kawm?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
1. Taw qhia. ClassCastException yog runtime kev zam tsa hauv Java thaum peb sim ua tsis raug pov tseg a chav kawm los ntawm ib hom mus rau lwm tus. Nws yog pov los qhia tias tus lej tau sim ua pov tseg ib yam khoom rau ib qho kev cuam tshuam chav kawm , tab sis ntawm qhov uas nws tsis yog ib qho piv txwv.
Kuj paub yog, dab tsi ua rau ClassCastException?
ClassCastException tshwm sim thaum code tau sim nrum ib yam khoom rau ib hom uas nws tsis yog ib yam khoom. Hauv qhov piv txwv saum toj no, Chav B yog hom A tab sis Chav B tsis yog hom C. Yog li ntawd, koj tau txais ClassCastException.
Kuj Paub, dab tsi yog null pointer exception? NullPointerException yog RuntimeException. Hauv Java, tshwj xeeb null tus nqi tuaj yeem raug xa mus rau qhov khoom siv. NullPointerException raug pov tseg thaum daim ntawv thov sim siv cov khoom siv uas muaj cov null tus nqi. Hu rau tus qauv piv txwv ntawm cov khoom xa los ntawm a null siv.
Hauv qhov no, koj yuav ua li cas zam ClassCastException?
Ceev faj thaum sim muab cov khoom ntawm ib chav kawm mus rau lwm chav kawm. Xyuas kom meej tias hom tshiab yog ib qho ntawm nws cov chav kawm niam txiv. Koj ua tau tiv thaiv tus ClassCastException los ntawm kev siv Generics, vim tias Generics muab tso ua ke cov sijhawm kuaj xyuas thiab tuaj yeem siv los tsim cov ntawv thov kev nyab xeeb.
Dab tsi yog chav kawm tsis pom muaj kev zam hauv Java?
Cov ClassNotFoundException raug pov thaum lub Java Virtual Machine (JVM) sim thauj ib qho tshwj xeeb chav kawm thiab tau teev tseg chav kawm nrhiav tsis tau hauv chav kawm. Cov ClassNotFoundException yog kuaj kev zam thiab yog li, yuav tsum tau tshaj tawm nyob rau hauv ib txoj kev los yog constructor's throws clause.
Pom zoo:
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