import java.io.*;
public class ByteArrayDemo
{
public static void main(String[] args)
{
String str="HELLOWORD";
ByteArrayInputStream bis = null;
ByteArrayOutputStream bos = null;
bis=new ByteArrayInputStream(str.getBytes());
bos=new ByteArrayOutputStream();
int temp=0;
while((temp=bis.read())!=-1){
char c=(char)temp; ///读入的数字转换为字符串
bos.write(Character.toLowerCase(c)); ///字符串小写
}
///所有数据都存在ByteArrayOutputStream中了
String newStr=bos.toString(); ///读取内容
try{
bis.close();
bos.close();
}catch(IOException e){
e.printStackTrace();
}
System.out.println(newStr);
}
}