How to Convert a Hexadecimal String to an Integer in Java?

How can I convert an 8-character hexadecimal string to an integer in Java and validate the conversion back to the original string?

String hex = "AA0F245C"; Int result = Integer.parseInt(hex, 16); String backToHex = Integer.toHexString(result).toUpperCase();

In Java, you can easily convert an 8-character hexadecimal string to an integer using the `Integer.parseInt()` method. This method reads the string as a base-16 integer. Below are the steps and an explanation of how this works, along with how to convert it back to the original hex string to verify the conversion is accurate.

String hex = "AA0F245C";
int decimalValue = Integer.parseInt(hex, 16);
String recoveredHex = Integer.toHexString(decimalValue).toUpperCase();
System.out.println("Decimal: " + decimalValue); // Outputs: 2852482124
System.out.println("Recovered Hex: " + recoveredHex); // Outputs: AA0F245C

Causes

• Using the wrong method to convert the hex string
• Incorrectly formatted hex string
• Hexadecimal string exceeds the range of an integer

Solutions

• Use `Integer.parseInt(hex, 16)` for conversion.
• Ensure the hexadecimal string is in the correct format (8 characters).
• Verify the converted integer is within the valid range for an int.

Mistake: Using `Integer.decode()` for hex strings without `0x` prefix.

Solution: Use `Integer.parseInt(hex, 16)` instead.

Mistake: Improper initialization of the integer value in the loop.

Solution: Avoid multiplying intermediate results; parse the entire hex string directly.

Mistake: Forgetting to handle NumberFormatException.

Solution: Surround conversion code with try-catch to handle potential exceptions gracefully.