package pack;import java.io.UnsupportedEncodingException;import java.lang.reflect.Array;import java.util.Arrays;public class Demo{    /**     *    用gbk编码 utf解码,然后再用utf编码 ,gbk解码,这样转不过来,因为gbk和utf-8里面都有中文,不过 iso8859-1可以     */    public static void main(String[] args) throws Exception{        String s = "哈哈";        byte[] b = s.getBytes("gbk");    //gbk编码        System.out.println(Arrays.toString(b));                String str = new String(b,"utf-8");    //utf-8解码        System.out.println(str);                b = str.getBytes("utf-8");        System.out.println(Arrays.toString(b));        str = new String(b,"gbk");        System.out.println(str);    }}

package pack;import java.io.UnsupportedEncodingException;import java.lang.reflect.Array;import java.util.Arrays;/** * 把联通用gbk编码,然后把字节以二进制形式输出,是110开头,后面是10,所以系统就用utf-8去解码. * 这个是特例,输出二进制时候,前面有很多个1,是32位的,输出低4位,就&上255 */public class Demo{    /**     *    用gbk编码 utf解码,然后再用utf编码 ,gbk解码,这样转不过来,因为gbk和utf-8里面都有中文,不过 iso8859-1可以     */    public static void main(String[] args) throws Exception{        String s = "联通";        byte[] b = s.getBytes("gbk");    //gbk编码        for (byte b1 : b) {            System.out.println(Integer.toBinaryString(b1));        }        System.out.println(Arrays.toString(b));                byte[] bb = s.getBytes("utf-8");    //gbk编码        System.out.println(Arrays.toString(bb));        for(byte b2:bb){            System.out.println(Integer.toBinaryString(b2&255));        }            }}