Reversing a string is a common task in Java, and there are several ways to achieve it. Here’s a simple approach using different techniques to reverse a string effectively.

1. Using a StringBuilder

Java’s StringBuilder class provides a convenient reverse() method, which can be directly used to reverse the contents of a string.

String original = "Hello, World!";
String reversed = new StringBuilder(original).reverse().toString();
System.out.println(reversed);  // Output: !dlroW ,olleH

This method is simple and efficient. It makes use of the mutable StringBuilder class. This class is designed to handle such operations with ease.

2. Using a Character Array

Another approach involves converting the string into a character array. Next, reverse the array in place. Finally, convert it back to a string.

String original = "Hello, World!";
char[] chars = original.toCharArray();

for (int i = 0, j = chars.length - 1; i < j; i++, j--) {
    char temp = chars[i];
    chars[i] = chars[j];
    chars[j] = temp;
}

String reversed = new String(chars);
System.out.println(reversed);  // Output: !dlroW ,olleH

This method gives you control over the reversal process, allowing you to manipulate the characters directly.

3. Using a Loop

A more manual approach is to iterate through the string from the end to the beginning. Append each character to a new string.

String original = "Hello, World!";
String reversed = "";

for (int i = original.length() - 1; i >= 0; i--) {
    reversed += original.charAt(i);
}

System.out.println(reversed);  // Output: !dlroW ,olleH

This method is straightforward but less efficient than the previous ones, especially with larger strings, due to the repeated concatenation.

4. Using Java 8 Streams

For those who enjoy working with streams, you can also reverse a string by converting it to a stream of characters, reversing the order, and then collecting it back into a string.

String original = "Hello, World!";
String reversed = Arrays.stream(original.split(""))
                        .collect(Collectors.collectingAndThen(Collectors.toList(),
                                                              list -> {
                                                                  Collections.reverse(list);
                                                                  return list.stream();
                                                              }))
                        .collect(Collectors.joining());

System.out.println(reversed);  // Output: !dlroW ,olleH

This approach showcases the flexibility and power of Java streams, though it is more verbose than other methods.

Each of these methods provides a way to reverse a string, and you can choose the one that best fits your needs based on readability, performance, or coding style.