Groovy整数除法运算符使用及Java迁移条件判断异常解决

Hey there! I’ve run into these exact Groovy gotchas when migrating Java code too—let’s fix them up for you:

Groovy and Java have a key difference in how the / operator works:

• In Java, when you divide two integers with /, it performs integer division (truncating the decimal part to keep only the integer quotient).
• But in Groovy, regardless of whether the operands are integers, / will always return a floating-point result by default.

To get the same integer division behavior as Java, you have a few solid options:

• Use Groovy's built-in intdiv() method (most recommended for broad compatibility):

  // 301.intdiv(100) returns 3, matching Java's 301/100 result
  status_num.intdiv(100)
  

• Cast the division result to an integer explicitly:

  (status_num / 100) as int
  

• If you're using Groovy 3.0 or later, you can also use the // integer division operator:

  status_num // 100
  

This is directly caused by the division behavior difference we just covered!
In Java, 301 / 100 is integer division that results in 3, so 3 == 3 evaluates to true.
In Groovy, though, 301 / 100 returns the float 3.01, and 3.01 == 3 is obviously false.

Switching to an integer division method will make your condition behave exactly like it did in Java. Here's your fixed code:

int status_num = 301
if (status_num.intdiv(100) == 3) {
    throw new GoogleServiceConditionException("Google Search System is under maintenance")
}

内容的提问来源于stack exchange，提问作者SkyWalker