In Java, how to append a string more efficiently? [duplicate]

You should use the StringBuilder class.

StringBuilder stringBuilder = new StringBuilder();

stringBuilder.append("Some text");
stringBuilder.append("Some text");
stringBuilder.append("Some text");

String finalString = stringBuilder.toString();

In addition, please visit:

• “How Java optimize the code with StringBuilder?”
• “StringBuilder vs String concatenation in toString() in Java”