java反射机制(工厂模式)
http://www.phpddt.com/dhtml/338.html
java里面没有typeof，js有。
我终于实现了用反射机制编写的工厂模式。java反射在工厂模式可以体现。
包含产品接口类，具体产品实现类，工厂类，这三种不同的类型
http://wenku.baidu.com/view/8899ecfff705cc175527094d.html
http://wenku.baidu.com/view/8ceb39c52cc58bd63186bd87.html
http://blog.csdn.net/justinavril/article/details/2873664
http://bbs.csdn.net/topics/60429890
http://www.cnblogs.com/pricks/archive/2009/08/11/1543855.html
http://www.cnblogs.com/bingoidea/archive/2009/06/21/1507889.html
http://www.cnblogs.com/octobershiner/archive/2012/03/18/2404751.html
具体java代码三种实现如下：
1、接口实现
/** * */ package factory.realize1; /** * @author wangjian2 * 接口 */ public interface Product { public String getProductName(String type,int id); }
package factory.realize1; public class Route implements Product { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } @Override public String getProductName(String type, int id) { return "RouteNameupdate"; } }
/** * */ package factory.realize1; /** * @author wangjian2 * */ public class Package implements Product { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } @Override public String getProductName(String type, int id) { return "PackageName"; } }
/** * */ package factory.realize1; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; /** * @author wangjian2 * */ public class Factory { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } public void getName(String type,int id){ if("跟团".equals(type)){ Product prd = new Route(); System.out.println(prd.getProductName("", 0)); }else if ("自助游".equals(type)){ Product prd = new Package(); System.out.println(prd.getProductName("", 0)); } } /** * 通过反射将参数传给函数并返回结果 * @param type * @param id */ public void getNameByreflect(String type,int id){ Class<?> cls = null; try {
//获取指定的任意type的所需类的完全限定名(包名+类名)相关联的class对象 cls = Class.forName("factory.realize1."+type);
//获取类对应的任意方法对象 Method getProductName = cls.getMethod("getProductName", new Class[]{String.class,int.class});
//使用该方法 Object result = getProductName.invoke(cls.newInstance(), new Object[]{new String(type),0}); System.out.println(result); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (NoSuchMethodException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalArgumentException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InvocationTargetException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
/** * */ package factory.realize1; /** * @author wangjian2 * */ public class TestExample { /** * @param args */ public static void main(String[] args) { Factory factory = new Factory(); factory.getName("跟团", 0); //反射实现 factory.getNameByreflect("Route", 0); } }
2、抽象类实现
/** * */ package factory.realize2; /** * @author wangjian2 * 抽象类 */ public abstract class Product { public abstract String getProductName(String type,int id); }
package factory.realize2; public class Route extends Product { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } @Override public String getProductName(String type, int id) { return "RouteNameupdate"; } }
/** * */ package factory.realize2; /** * @author wangjian2 * */ public class Package extends Product { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } @Override public String getProductName(String type, int id) { return "PackageName"; } }
/** * */ package factory.realize2; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; /** * @author wangjian2 * */ public class Factory { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } public void getName(String type,int id){ if("跟团".equals(type)){ Product prd = new Route(); System.out.println(prd.getProductName("", 0)); }else if ("自助游".equals(type)){ Product prd = new Package(); System.out.println(prd.getProductName("", 0)); } } /** * 通过反射将参数传给函数并返回结果 * @param type * @param id */ public void getNameByreflect(String type,int id){ Class<?> cls = null; try { cls = Class.forName("factory.realize1."+type); Method getProductName = cls.getMethod("getProductName", new Class[]{String.class,int.class}); Object result = getProductName.invoke(cls.newInstance(), new Object[]{new String(type),0}); System.out.println(result); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (NoSuchMethodException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalArgumentException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InvocationTargetException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
/** * */ package factory.realize2; /** * @author wangjian2 * */ public class TestExample { /** * @param args */ public static void main(String[] args) { Factory factory = new Factory(); factory.getName("跟团", 0); factory.getNameByreflect("Route", 0); } }
3、继承类重写（覆盖）
/** * */ package factory.realize3; /** * @author wangjian2 * 继承类重写（覆盖） */ public class Product { public String getProductName(String type,int id) { return null; } }
package factory.realize3; public class Route extends Product { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } @Override public String getProductName(String type, int id) { return "RouteNameupdate"; } }
/** * */ package factory.realize3; /** * @author wangjian2 * */ public class Package extends Product { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } @Override public String getProductName(String type, int id) { return "PackageName"; } }
/** * */ package factory.realize3; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; /** * @author wangjian2 * */ public class Factory { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } public void getName(String type,int id){ if("跟团".equals(type)){ Product prd = new Route(); System.out.println(prd.getProductName("", 0)); }else if ("自助游".equals(type)){ Product prd = new Package(); System.out.println(prd.getProductName("", 0)); } } /** * 通过反射将参数传给函数并返回结果 * @param type * @param id */ public void getNameByreflect(String type,int id){ Class<?> cls = null; try { cls = Class.forName("factory.realize1."+type); Method getProductName = cls.getMethod("getProductName", new Class[]{String.class,int.class}); Object result = getProductName.invoke(cls.newInstance(), new Object[]{new String(type),0}); System.out.println(result); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (NoSuchMethodException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalArgumentException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InvocationTargetException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
/** * */ package factory.realize3; /** * @author wangjian2 * */ public class TestExample { /** * @param args */ public static void main(String[] args) { Factory factory = new Factory(); factory.getName("跟团", 0); factory.getNameByreflect("Route", 0); } }
个人理解反射机制是为了开发者方便，减少开发量。
http://www.cnblogs.com/rollenholt/archive/2011/09/02/2163758.html
java反射在工厂模式可以体现
http://blog.csdn.net/ritterliu/article/details/7764849