java - 无法通过按位运算获得长整型值

Question

我需要获取以下按位运算的输出以进行进一步处理。不幸的是，每当我尝试将输出转换为 int 或 long 类型时，我都会收到数字格式异常。如何确保输出是我可以处理的类型？

String TYPE = "type";
long TOTAL_MASK = 0xFFFFFFFF;
long BASE_INBOX_TYPE = 20;
long BASE_TYPE_MASK = 0x1F

long type = Integer.valueOf("" + TYPE + " & " + (TOTAL_MASK - BASE_TYPE_MASK) + " | " + BASE_OUTBOX_TYPE + "");

Answer 1

Integer.valueOf(String)用于从文本中解析数字文字，而不是计算任意表达式。根据 javadoc 方法:

The argument is interpreted as representing a signed decimal integer, exactly as if the argument were given to the parseInt(java.lang.String) method.

您需要将表达式编写为代码，例如:

long type = (TOTAL_MASK - BASE_TYPE_MASK) | BASE_OUTBOX_TYPE;