以水果为例讲解简单工厂模式，其中有三种水果，，
*葡萄 Grape
*草莓Strawberry
*苹果Apple
水果并无具体的对象，因此是一个各个水果都适用的接口，以便与其他植物分隔开来。
三种水果均有自己不同的属性，现在实现水果接口及其三种水果的源码。
Fruit：
package SimpleFactory;public interface Fruit {/** * 生长 */void grow();/** * 收获 */void harvest();/** * 种植 */void plant();}Apple：
package SimpleFactory;public class Apple implements Fruit {private int treeAge;//苹果树的树龄@Overridepublic void grow() {log("Apple is growing");}@Overridepublic void harvest() {log("Apple has been harvested");}@Overridepublic void plant() {log("Apple has been planted");}public int getTreeAge() {return treeAge;}public void setTreeAge(int treeAge) {this.treeAge = treeAge;}private void log(String msg){System.err.println(msg);}}Grape:
package SimpleFactory;public class Grape implements Fruit {private boolean seedless;//葡萄有籽或者无籽@Overridepublic void grow() {log("Grape is growing…");}@Overridepublic void harvest() {log("Grape has been harvested");}@Overridepublic void plant() {log("Grape has been planted");}private void log(String msg){System.err.println(msg);}public boolean isSeedless() {return seedless;}public void setSeedless(boolean seedless) {this.seedless = seedless;}}Strawberry:
package SimpleFactory;public class Strawberry implements Fruit {@Overridepublic void grow() {log("Strawberry is growing…");}@Overridepublic void harvest() {log("Strawberry has been harvested.");}@Overridepublic void plant() {log("Strawberry has been planted");}private void log(String msg){System.err.println(msg);}}
实现这三种水果后，还需要一个园丁来照料他们，因此还有一个园丁类，源码为：
package SimpleFactory;public class FruitGardener {/** * 静态工厂方法 * @param which * @return */public static Fruit factory(String which)throws BadFruitException{if(which.equalsIgnoreCase("apple")){return new Apple();}else if(which.equalsIgnoreCase("strawberry")){return new Strawberry();}else if(which.equalsIgnoreCase("grape")){return new Grape();}else{throw new BadFruitException("Bad fruit request");}}}里面有一个BadException，当出现在园子中没有出现的水果时，要抛出异常，因此还有一个异常类。
BadException:
package SimpleFactory;public class BadFruitException extends Exception {public BadFruitException(String msg){super(msg);}}当这些都实现后，便可使用此模式进行收获，源码为：
package SimpleFactory;public class Client {public static void main(String[] args) {try {FruitGardener.factory("grape");FruitGardener.factory("apple");FruitGardener.factory("strawberry");} catch (BadFruitException e) {}}}
如此，便实现简单的工厂模式。
与其临渊羡鱼，不如退而结网。
