你可以使用 BigInteger 整数类， BigDecimal 表示带小数位数的数字。这两个类都在 java.math 包中定义。

You can use the BigInteger class for integers and BigDecimal for numbers with decimal digits. Both classes are defined in java.math package.

示例：

BigInteger reallyBig = new BigInteger("1234567890123456890");
BigInteger notSoBig = new BigInteger("2743561234");
reallyBig = reallyBig.add(notSoBig);