difference between StringBuffer and StringBuilder in Java
Both StringBuffer
and StringBuilder
in Java are used for the same purpose: to create and manipulate mutable sequences of characters. The main difference between them lies in their synchronization behavior:
StringBuffer
:
- Thread-Safe:
StringBuffer
is synchronized, which means it is thread-safe. Multiple threads can safely useStringBuffer
without external synchronization.
- Slower Performance in Multithreaded Environments:
- Because of synchronization,
StringBuffer
can be slower thanStringBuilder
, especially in multithreaded environments, where synchronization can lead to overhead.
- Because of synchronization,
- Usage:
- Use
StringBuffer
when you need a mutable sequence of characters, and your code is running in a multithreaded environment.
- Use
Example using StringBuffer
:
/*
* Author: Zameer Ali Mohil
* */
public class StringBufferExample {
public static void main(String[] args) {
StringBuffer buffer = new StringBuffer("Hello");
buffer.append(" World"); // Modifies the same StringBuffer object
System.out.println(buffer);
}
}
StringBuilder
:
- Not Thread-Safe:
StringBuilder
is not synchronized, which means it is not thread-safe. Multiple threads should not access aStringBuilder
instance concurrently without proper synchronization.
- Faster Performance in Single-Threaded Environments:
- Because it lacks synchronization,
StringBuilder
can be faster thanStringBuffer
, especially in single-threaded environments.
- Because it lacks synchronization,
- Usage:
- Use
StringBuilder
when you need a mutable sequence of characters and you are sure that your code will be used in a single-threaded environment, or you will handle synchronization explicitly.
- Use
Example using StringBuilder
:
/*
* Author: Zameer Ali Mohil
* */
public class StringBuilderExample {
public static void main(String[] args) {
StringBuilder builder = new StringBuilder("Hello");
builder.append(" World"); // Modifies the same StringBuilder object
System.out.println(builder);
}
}
In both examples, append()
is used to modify the content of the StringBuffer
and StringBuilder
objects. However, it’s important to note that if these examples were run concurrently by multiple threads, you might encounter issues with StringBuffer
if synchronization is not handled properly. In such cases, using StringBuilder
in a single-threaded environment or handling synchronization manually might be a better choice for improved performance.
Aspect | StringBuffer | StringBuilder |
---|---|---|
Thread Safety | Synchronized, thread-safe. Multiple threads can safely access StringBuffer methods simultaneously. | Not synchronized, not thread-safe. Not suitable for concurrent use by multiple threads. |
Performance | Slower compared to StringBuilder due to synchronization. | Faster compared to StringBuffer in single-threaded environments as it lacks synchronization. |
Mutability | Mutable. Can be modified after creation. | Mutable. Can be modified after creation. |
Usage | Suitable for multithreaded applications where thread safety is required. | Suitable for single-threaded environments or when handling synchronization manually. |
Introduced In | Introduced in Java 1.0. | Introduced in Java 5.0. |
Both StringBuffer
and StringBuilder
are classes in Java that allow you to create mutable sequences of characters. The choice between them depends on your specific use case: use StringBuffer
when thread safety is necessary, and use StringBuilder
when you are working in a single-threaded environment or can handle synchronization manually.