对输入的电话号码进行正则匹配，判定是否为电话号码。（正则不是最新的）

final EditText et = (EditText) findViewById(R.id.et);

    et.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void afterTextChanged(Editable editable) {

            String phoneNum = editable.toString();
            boolean b = isPhoneNumber(phoneNum);

            if (b){
                et.setTextColor(Color.rgb(0,255,0));
            }else {
                et.setTextColor(Color.rgb(255,0,0));

            }
        }
    });
}

public boolean isPhoneNumber(String str){

    String regex = "^((13[0-9])|(15[^4,\\D])|(18[0,5-9]))\\d{8}$";

    Pattern p = Pattern.compile(regex);

    Matcher m = p.matcher(str);
    return m.find();
}

来自为知笔记(Wiz)