Difference between StringBuilder and StringBuffer

Question

What is the main difference between StringBuffer and StringBuilder? Is there any performance issues when deciding on any one of these?

Answer 1

Here is the performance testing result for String vs StringBuffer vs StringBuilder. Finally, StringBuilder won the Test. See below for test code and result.

Code:

private static void performanceTestStringVsStringbuffereVsStringBuilder() {
// String vs StringBiffer vs StringBuilder performance Test

int loop = 100000;
long start = 0;

// String
String str = null;
start = System.currentTimeMillis();
for (int i = 1; i <= loop; i++) {
  str += i + "test";
}
System.out.println("String - " + (System.currentTimeMillis() - start) + " ms");

// String buffer
StringBuffer sbuffer = new StringBuffer();
start = System.currentTimeMillis();
for (int i = 1; i <= loop; i++) {
  sbuffer.append(i).append("test");
}
System.out.println("String Buffer - " + (System.currentTimeMillis() - start) + " ms");

// String builder
start = System.currentTimeMillis();
StringBuilder sbuilder = new StringBuilder();
for (int i = 1; i <= loop; i++) {
  sbuffer.append(i).append("test");
}
System.out.println("String Builder - " + (System.currentTimeMillis() - start) + " ms");

  }

Execute Me on ideone

Result:

100000 iteration for adding a single text

String - 37489 ms
String Buffer - 5 ms
String Builder - 4 ms

10000 iteration for adding a single text

String - 389 ms
String Buffer - 1 ms
String Builder - 1 ms