java类转换异常 java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long

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进行类转换的时候，Integer转换为long是出错

E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.example.demo, PID: 13621

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long

at com.example.demo.MainActivity$4.onClick(MainActivity.java:76)

at android.view.View.performClick(View.java:5616)

at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:967)

at android.view.View$PerformClick.run(View.java:22292)

at android.os.Handler.handleCallback(Handler.java:751)

at android.os.Handler.dispatchMessage(Handler.java:95)

at android.os.Looper.loop(Looper.java:154)

at android.app.ActivityThread.main(ActivityThread.java:6077)

at java.lang.reflect.Method.invoke(Native Method)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

我的测试代码为

Map<String,Integer> map = new HashMap<>();map.put("data",1);Integer dd = map.get("data");long data = map.get("data");Long data1 = (long) map.get("data");System.out.println(data);System.out.println(data1);System.out.println((data1==data));Map<String,Object> map1 = new HashMap<>();map1.put("data",dd);System.out.println(map1.get("data"));//正确转换的代码long l = Long.parseLong(map1.get("data").toString());//转换会报错的代码long l = (long)map1.get("data");System.out.println(l);

有此代码测试可见，Integer转long显示转换是可以的，当为隐式转换时就会出错

long l = Long.parseLong(map1.get("data").toString());//转换为String后再转为Long