private final String MESSAGE_WARN = "您输入的密码有误，请重新输入！";
private final String CLASS_ONE = "class1";
this.calculateNumberOfClass(CLASS_ONE);
Toast.makeText(this, this.MESSAGE_WARN, 2000).show();
Android编码规范04
原文：http://www.cnblogs.com/gongxing/p/4907818.html
