java 内存操作流

package hjw;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
//import org.omg.CORBA_2_3.portable.OutputStream;
public class dm {
    public static void main(String[] args) throws Exception {
        String str="HELLOWORLD";
        ByteArrayInputStream bis=new ByteArrayInputStream(str.getBytes());
        ByteArrayOutputStream bos=new ByteArrayOutputStream();
        int temp=0;
        while((temp=bis.read())!=-1){
            char c=(char) temp;
            bos.write(Character.toLowerCase(c));
        }
        String newStr=bos.toString();
        try{
            bis.close();
            bos.close();
        }catch (IOException e){
            e.printStackTrace();
        }
        System.out.println(newStr);
    }
}
 

完成了大写字母装换成小写字母、、、