知道一个汉字如何知道它的unicode码

public String GB2312ToUnicode(String s) {
        String s1="";
        if(s!=null && !s.equals("")) {
            try {
                String s2 = new String(s.getBytes(),"gb2312");
                s = s2;
                int i = s.length();
                for(int j = 0; j<i; j++) {
                    char c = s.charAt(j);
                    if (c == '\n'){
                        s1 = s1 + "<br/>";
                    }else{
                        s1 = s1 + "&#x" + Integer.toHexString(c)+";";
                    }
                }
            }catch(Exception e){ e.printStackTrace();}
        }
        return s1;
    }