import java.util.ArrayList;

import java.util.List; 

import org.apache.commons.lang.StringUtils;

import org.junit.Test;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory; 

public class TestString { 

    private final Logger logger = LoggerFactory.getLogger(this.getClass()); 

    @Test

    public void testPlus() {

        String s = "";

        long ts = System.currentTimeMillis();

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

            s = s + String.valueOf(i);

        }

        long te = System.currentTimeMillis();

        logger.info("+ cost {} ms", te - ts);

    } 

    @Test

    public void testConcat() {

        String s = "";

        long ts = System.currentTimeMillis();

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

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

        }

        long te = System.currentTimeMillis();

        logger.info("concat cost {} ms", te - ts);

    } 

    @Test

    public void testJoin() {

        List<String> list = new ArrayList<String>();

        long ts = System.currentTimeMillis();

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

            list.add(String.valueOf(i));

        }

        StringUtils.join(list, "");

        long te = System.currentTimeMillis();

        logger.info("StringUtils.join cost {} ms", te - ts);

    } 

    @Test

    public void testStringBuffer() {

        StringBuffer sb = new StringBuffer();

        long ts = System.currentTimeMillis();

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

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

        }

        sb.toString();

        long te = System.currentTimeMillis();

        logger.info("StringBuffer cost {} ms", te - ts);

    } 

    @Test

    public void testStringBuilder() {

        StringBuilder sb = new StringBuilder();

        long ts = System.currentTimeMillis();

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

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

        }

        sb.toString();

        long te = System.currentTimeMillis();

        logger.info("StringBuilder cost {} ms", te - ts);

    }

}