如Struts2中的拦截器，简单的Demo如下：
Java代码
package com.pattern.templateMethod; /** * 抽象类,充当模板角色 * @author administrator * */ public abstract class AbstractDisplay { //由子类实现的抽象方法 public abstract void open(); public abstract void print(); public abstract void close(); //抽象类实现的方法,final可以保证在子类不会被修改 public final void display() { open(); //先open... for(int i=0; i < 5; i++) { //反复输出5次 print(); } close(); //输出完毕,close } } 2.字符类，输出单个字符Java代码 package com.pattern.templateMethod; public class CharDisplay extends AbstractDisplay { private char ch; //应输出的字符 public CharDisplay(char ch) { //把构造函数传递过来的字符ch,存储在字段内 this.ch = ch; } public void open() { System.out.print("<<"); //输出"<<"作为开始字符串 } public void close() { System.out.println(">>"); //输出 ">>"作为结束字符串 } public void print() { System.out.print(ch); //输出存储在字段的字符 } } 3.字符串类，输出字符串Java代码 package com.pattern.templateMethod; /** * * @author administrator */ public class StringDisplay extends AbstractDisplay { private String string; //应输出的字符串 private int width; //以byte为单位所求出的字符串的"长度" public StringDisplay(String string) { this.string =string; width = string.getBytes().length; } public void open() { //打印头装饰字符串 printLine(); } public void print() { //打印内容 System.out.println("|"+string+"|"); } public void close() { //打印尾装饰字符串 printLine(); } public void printLine() { System.out.print("+"); //输出"+"号表示边框位置 for(int i=0; i < width; ++i) { System.out.print("-"); //当作线段 } System.out.println("+"); //输出"+"号表示边框位置 } } 4.测试类Java代码 package com.pattern.templateMethod; public class Main { public static void main(String[] args) { //建立1个有'A'的CharDisplay的对象 AbstractDisplay d1 = new CharDisplay('A'); //建立1个有"Hello world"的StringDisplay的对象 AbstractDisplay d2 = new StringDisplay("Hello World"); //d1,d2都是AbstractDisplay的子类对象,可以调用继承到的display()方法 d1.display(); d2.display(); } } 输出:C代码 <<AAAAA>> +-----------+ |Hello World| |Hello World| |Hello World| |Hello World| |Hello World| +-----------+
Demo 2
BaseDAO.
package com.test.templatemethod;
public abstract class BaseDao<T> {
public void save(T t) {
if (beforeSave(t)) {
System.out.println("save T");
}
beforeSave(t);
}
protected boolean beforeSave(T t) {
return true;
}
protected void afterSave(T t) {
}
}
UserDAO:
package com.test.templatemethod;
public class UserDao extends BaseDao<User> {
@Override
protected void afterSave(User t) {
System.out.println("do afterSave");
}
@Override
protected boolean beforeSave(User t) {
System.out.println("do beforeSave");
return true;
}
}
User 类
package com.test.templatemethod;
public class User {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
测试类:
package com.test.templatemethod;
public class Test {
public static void main(String[] args) {
User user = new User();
user.setName("test");
UserDao userDao = new UserDao();
userDao.save(user);
}
}
转载于:https://www.cnblogs.com/owenma/p/3474399.html
