SoFunction
Updated on 2025-03-09

Summary of common splicing methods for strings in Java

introduction

In Java, string stitching is a very common operation during development. Depending on different requirements and performance considerations, there are many ways to realize string stitching.

1. Use the + operator

This is the most intuitive and common way of string splicing. For a small amount of simple splicing, use+It is a good choice.

Sample code:

String firstName = "John";
String lastName = "Doe";
String fullName = firstName + " " + lastName;
(fullName);  // Output: John Doe

Features:

  • Simple and easy to use.
  • For small number of string splicing, the performance is acceptable.
  • Create a new one every time you splice itStringObject, therefore less efficient for string splicing in large numbers or loops.

2. Use StringBuilder

When multiple string splicing is required (especially within a loop), it is recommended to useStringBuilder. This is becauseStringBuilderis a mutable object that allows the final string to be constructed by appending content without generating a new object every time.

Sample code:

  • Efficiently handle multi-step string stitching.
  • Threads are not safe, but usually this is not a problem.
  • Suitable for constructing dynamic text, logging and other scenarios.

3. Use StringBuffer

andStringBuildersimilar,StringBufferIt is also a class for string stitching, but it provides thread safety and is suitable for string operations in multi-threaded environments.

Sample code:

StringBuffer sbf = new StringBuffer();
("Thread-Safe");
(" Example.");
String example = ();
(example);  // Output: Thread-Safe Example.

Features:

  • Provides thread-safe string stitching function.
  • Compared withStringBuilder, Due to the existence of the synchronization mechanism, the performance is slightly lower in a single-threaded environment.
  • Suitable for situations where thread safety is required.

4. Use  ()

Starting from Java 8, it has been introduced()Method, This method is mainly used to concatenate elements in an array or collection as a single string, which is very suitable for simple list stitching.

Sample code:

List<String> words = ("One", "Two", "Three");
String sentence = (", ", words);
(sentence);  // Output: One, Two, Three

Features:

  • The grammar is concise and easy to read.
  • Limited to stitching tasks in specific formats.
  • Possible internal useStringBuilderimplements, therefore has good performance.

5. Use Stream API (Java 8 and above)

Using the streaming API introduced by Java 8, string stitching can be completed in a functional programming way.

Sample code:

List<String> names = ("Alice", "Bob", "Charlie");
String result = ()
                     .collect((", "));
(result);  // Output: Alice, Bob, Charlie

Features:

  • Provides a declarative processing method.
  • Other stream operations such as filtering, mapping, etc. can be conveniently combined.
  • Suitable for processing collection data.

Summarize

Which method to choose for string splicing depends on the specific usage scenario and personal preferences. For simple short string splicing, it is enough to use + or () directly; for complex or frequent splicing operations, StringBuilder or StringBuffer should be given priority. If you work on Java 8 or above and involve collection operations, then a streaming API may be a better choice.

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