package test;

import org.apache.commons.lang.StringUtils;

public class CutString {

//性能最差

public String testPlus() {

String s = "";

for (int i = 0; i < 10000; i++) {

s = s + String.valueOf(i);

}

return s;

}

//较好

public String testConcat() {

String s = "";

for (int i = 0; i < 10000; i++) {

s = s.concat(String.valueOf(i));

}

return s;

}

//性能与testStringBuffer相差无几，比其要好

public String testJoin() {

String[] list = new String[10000];

for (int i = 0; i < 10000; i++) {

list[i] = String.valueOf(i);

}

return StringUtils.join(list, "");

}

public String testStringBuffer() {

StringBuffer sb = new StringBuffer();

long l1 = System.currentTimeMillis();

for (int i = 0; i < 10000; i++) {

sb.append(String.valueOf(i));

}

long l2 = System.currentTimeMillis();

System.out.println(l2-l1);

return sb.toString();

}

//性能最高的方法

public void testStringBuilder() {

StringBuilder sb = new StringBuilder();

for (int i = 0; i < 100000; i++) {

sb.append(String.valueOf(i));

}

sb.toString();

}

public static void main(String[] args) {

System.out.println(new CutString().testStringBuffer());

}

}