设计模式＝＝责任链（Chain of Responsibility）
/* * 责任链（Chain of Responsibility） * * * 多个处理器对象连成一串，请求在这条链上传递，由该处理这个请求的处理器来处理。发出请求的客户端并不知道哪个对象处理请求。 */package model;public class TestChain { public static void main(String[] args) { String pass1 = "123456"; String pass2 = "123456"; String personId = "123456789012345678"; String email = "huxz@tarena.com.cn"; register(pass1, pass2, personId, email); } public static void register(String pass1, String pass2, String personId, String email) { Filter f1 = new PasswordFilter1(); Filter f2 = new PasswordFilter2(); Filter f3 = new PersonIdFilter(); Filter f4 = new EmailFilter(); f1.setNext(f2); f2.setNext(f3); f3.setNext(f4); System.out.println(f1.doFilter(pass1, pass2, personId, email)); }}abstract class Filter { Filter next = null; public Filter getNext() { return next; } public void setNext(Filter next) { this.next = next; } public String doFilter(String pass1, String pass2, String personId, String email) { if (next == null) return "成功"; else return next.doFilter(pass1, pass2, personId, email); }}class PasswordFilter1 extends Filter { public String doFilter(String pass1, String pass2, String personId, String email) { if (!(pass1.equals(pass2))) return "两次密码输入不一致"; else return super.doFilter(pass1, pass2, personId, email); }}class PasswordFilter2 extends Filter { public String doFilter(String pass1, String pass2, String personId, String email) { if (pass1.length() != 6) return "密码长度必须为6"; else return super.doFilter(pass1, pass2, personId, email); }}class PersonIdFilter extends Filter { public String doFilter(String pass1, String pass2, String personId, String email) { if (personId.length() != 15 && personId.length() != 18) return "身份证号码非法"; else return super.doFilter(pass1, pass2, personId, email); }}class EmailFilter extends Filter { public String doFilter(String pass1, String pass2, String personId, String email) { int i1 = email.indexOf("@"); int i2 = email.indexOf("."); if (i1 == -1 || i2 == -1 || i2 - i1 <= 1 || i1 == 0 || i2 == email.length() - 1) return "email非法"; else return super.doFilter(pass1, pass2, personId, email); }}?