Java io

StringBuilder

package dynamic;import java.io.DataInputStream;import java.io.InputStream;import java.util.Scanner;/** * Created by yuan on 2017/2/16. */public class testStrem {    public static void main(String[] args) {        StringBuilder out = new StringBuilder();        out.append("a");        out.append("b");        out.append("b");        out.append("b");        out.append("b");        System.out.println(out.toString());    }}