如何修复jdeprscan检测到的BigDecimal.divide过时方法警告？

Let's break down how to resolve this deprecation warning you're seeing from jdeprscan.

First, the root cause: Java 9 marked the BigDecimal.divide(BigDecimal, int) method as deprecated because it relies on integer constants (like BigDecimal.ROUND_HALF_UP) for rounding modes. The recommended replacement is the overload that uses the RoundingMode enum, which is more type-safe and readable.

Looking at your current code:

/** 
 * Convert duration milliseconds to seconds suitable for displaying.
 * 
 * 246 milliseconds -> '0.246 secs' 
 */ 
public String getDurationForDisplay() { 
    BigDecimal duration = new BigDecimal("" + requestDuration).setScale(3); 
    duration = duration.divide(new BigDecimal("1000"), BigDecimal.ROUND_HALF_UP); 
    return "" + duration + " secs"; 
}

Step-by-Step Fix #

• Replace the deprecated method call: Swap the integer rounding constant with the corresponding RoundingMode enum value.
• Import the enum if missing: Add import java.math.RoundingMode; to the top of your class if it's not already present.

Here's the updated code:

import java.math.RoundingMode;

// ...

/** 
 * Convert duration milliseconds to seconds suitable for displaying.
 * 
 * 246 milliseconds -> '0.246 secs' 
 */ 
public String getDurationForDisplay() { 
    BigDecimal duration = new BigDecimal(String.valueOf(requestDuration)).setScale(3); 
    // Use RoundingMode.HALF_UP instead of BigDecimal.ROUND_HALF_UP
    duration = duration.divide(new BigDecimal("1000"), RoundingMode.HALF_UP); 
    return duration + " secs"; 
}

Bonus Optimizations (Cleaner, More Efficient Code) #

• If requestDuration is a numeric type (like long or int), skip string conversion entirely: new BigDecimal(requestDuration) is more efficient than converting to a string first.
• Extract the 1000 value into a static constant to avoid recreating the BigDecimal object on every method call:

private static final BigDecimal MILLISECONDS_TO_SECONDS = new BigDecimal("1000");

public String getDurationForDisplay() { 
    BigDecimal duration = new BigDecimal(requestDuration).setScale(3); 
    duration = duration.divide(MILLISECONDS_TO_SECONDS, RoundingMode.HALF_UP); 
    return duration + " secs"; 
}

After making these changes, re-run your jdeprscan command, and the deprecation warning should no longer appear.

内容的提问来源于stack exchange，提问作者Hari Sheen