Map<Integer, Long> map = new HashMap<>();
map.put(0, 0L);
map.put(1, 1L);
String a = JSON.toJSONString(map);
map = JSON.parseObject(a, Map.class);
Long b = map.get(1);
#########
Exception in thread "main" java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long
json parse时 强制类型转换
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Map<Integer, Long> map = new HashMap<>();
map.put(0, 0L);
map.put(1, 1L);
String a = JSON.toJSONString(map);
// 匿名内部类
map = JSON.parseObject(a, new TypeReference<Map<Integer, Long>>(){});
Long b = map.get(1);
#########
OK！
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