The difference between String StringBuilder StringBuffer

1.String is the final type and cannot be inherited is immutable

StringBuffer and StringBuilder can be changed.

2. Speed stringbuilder>stringbuffer>string

StringBuffer is thread-safe

Stringbuidler is thread-insecure

StringS1=“ThisIsOnlyA "+ " simple " +  "test" ; StringBuffer sb = new stringbuilder  ( "this is only a ") . Append ( "simple" ) append ( "test"                

Java compiler directly compiles the first statement above to:

String s2 = “This is only a”; String s3 = “ simple”; String s4 = “ test”; String s1 = s2 + s3 + s4;

3. Using policies

1) A small number of data operations can be string, single-threaded operation with Sringbuilder, multi-threaded operation with StringBuffer

2) do not use string "+" to splice, so the performance is very poor, you should use the following second:

Stringresult= "";  for(Strings: Hugearray) { result= result+   s   ;   }    stringb Uilder sb = new stringbuilder (); for  (string s :  Hugearray) {sb. Append (s} string result = sb tostring ()             

3) StringBuffer used in global variables; StringBuilder is used inside the method

3) generally use StringBuffer directly, as Builder's performance increases by up to 10%-15%, unless the acknowledgement is not running under multithreading and the performance bottleneck is on buffer.

The difference between String StringBuilder StringBuffer