There are several ways to create strings in Java:

1. String literals: String literals are created by enclosing text within double quotes. For example:

String message = "Hello, world!";

2. Using the new keyword: Strings can also be created using the new keyword, though this is less common:

String message = new String("Hello, world!");

Below is an example of a String in Java:

// Java Program to demonstrate
// String
public class StringExample {

// Main Function
public static void main(String args[])
{
String str = new String("Topperworld");
// creating Java string by new keyword
// this statement create two object i.e
// first the object is created in heap
// memory area and second the object is
// created in String constant pool.

System.out.println(str); 
//output = Topperworld
}
}

1. StringBuffer:

The StringBuffer class represents mutable strings. Unlike String, StringBuffer objects can be modified after creation. It provides methods for appending, inserting, deleting, replacing, and reversing characters in the string. StringBuffer is thread-safe, meaning it can be safely used in multi-threaded applications.

StringBuffer stringBuffer = new StringBuffer();
stringBuffer.append("Hello");
stringBuffer.append(" ");
stringBuffer.append("World");

2. StringBuilder:

The StringBuilder class is similar to StringBuffer but is not thread-safe. It provides methods for string manipulation like StringBuffer but does not incur the synchronization overhead. StringBuilder is preferred in single-threaded environments or scenarios where thread safety is not a concern.

StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("Hello");
stringBuilder.append(" ");
stringBuilder.append("World");