java泛型边界深入探讨，示例代码
package org.rui.generics.bounds;
import java.awt.Color;
/**
* 边界
* 下面展示了边界基本要素。
* @author lenovo
*
*/
interface HasColor{java.awt.Color getColor();}
class Colored<T extends HasColor>
{
T item;
Colored(T item){this.item=item;}
T getItem(){return item;}
java.awt.Color color(){return item.getColor();}
}
///////////////////////////////////////////////////
class Dimensio{public int x,y,z;}//尺码
//!class ColoredDimension<T extends HasColor & Dimensio>
class ColoredDimension<T extends Dimensio & HasColor>
{
T item;
ColoredDimension(T item){this.item=item;}
T getItem(){return item;}
java.awt.Color color(){return item.getColor();}
int getX(){return item.x;}
int getY(){return item.y;}
int getZ(){return item.z;}
}
///////////////立方体///////////////////////////////////////////////
interface Weight{int weight();}
class Solid<T extends Dimensio & HasColor & Weight>
{
T item;
Solid(T item){this.item=item;}
T getItem(){return item;}
java.awt.Color color(){return item.getColor();}
int getX(){return item.x;}
int getY(){return item.y;}
int getZ(){return item.z;}
//
int getWeight(){return item.weight();}
}
//////////////////////////////////////////////////////////////////////
class Bounded extends Dimensio implements HasColor,Weight
{
public int weight(){return 0;}
public Color getColor() {return null;}
}
//////////////////////////////////////////////////////////////////////////
public class BasicBounds {
public static void main(String[] args)
{
Solid<Bounded> solid=new Solid<Bounded>(new Bounded());
solid.color();
solid.getY();
solid.getWeight();
}
}
package org.rui.generics.bounds;
import java.awt.Color;
/**
* 边界
* 看上去包含可以通过继承消除沉余。
* 下面可以看到在继承的每个层次上添加边界的限制
* @author lenovo
*
*/
class holdItem<T>
{
T item;
holdItem(T item){this.item=item;}
T getItem(){return item;}
}
interface HasColor2{java.awt.Color getColor();}
class Colored2<T extends HasColor2> extends holdItem<T>
{
//T item;
Colored2(T item){super(item);}
//T getItem(){return item;}
java.awt.Color color(){return item.getColor();}
}
///////////////////////////////////////////////////
class Dimensio2{public int x,y,z;}//尺码
class ColoredDimension2<T extends Dimensio2 & HasColor2> extends Colored2<T>
{
ColoredDimension2(T item){super(item);}
int getX(){return item.x;}
int getY(){return item.y;}
int getZ(){return item.z;}
}
///////////////立方体///////////////////////////////////////////////
interface Weight2{int weight();}
class Solid2<T extends Dimensio2 & HasColor2 & Weight2> extends ColoredDimension2<T>
{
Solid2(T item){super(item);}
int getWeight(){return item.weight();}
}
//////////////////////////////////////////////////////////////////////
class Bounded2 extends Dimensio2 implements HasColor2,Weight2
{
public int weight(){return 0;}
public Color getColor() {return null;}
}
//////////////////////////////////////////////////////////////////////////
public class InheritBounds {
public static void main(String[] args)
{
Solid2<Bounded2> solid=new Solid2<Bounded2>(new Bounded2());
solid.color();
solid.getY();
solid.getWeight();
}
}
package org.rui.generics.bounds;
import java.awt.Color;
import java.util.List;
/**
* 边界
* 多层次的示例
* @author lenovo
*
*/
interface SuperPower{}
//视觉
interface XRayVision extends SuperPower
{
void seeThroughWalls();
}
//听力
interface SuperHearing extends SuperPower
{
void hearSubtleNoises();
}
//闻
interface SuperSmell extends SuperPower
{
void trackBysmell();
}
//////////英雄；男主角////////////////////////////////
class SuperHero<POWER extends SuperPower>
{
POWER power;
SuperHero(POWER power){this.power=power;}
POWER getPower(){return power;}
}
//////////侦查////////////////////////////////
class SuperSleuth<POWER extends XRayVision> extends SuperHero<POWER>
{
SuperSleuth(POWER power){super(power);}
void see(){power.seeThroughWalls();}
}
////////////犬//////////////////////////////
class CanineHero<POWER extends SuperHearing & SuperSmell>
extends SuperHero<POWER>
{
CanineHero(POWER power){super(power);}
void hear(){power.hearSubtleNoises();}
void smell(){power.trackBysmell();}
}
///////////////////////////////////////
class SuperHearSmell implements SuperHearing,SuperSmell
{
@Override
public void trackBysmell() {}
@Override
public void hearSubtleNoises() {}
}
///////////////////////////////////////
class DogBoy extends CanineHero<SuperHearSmell>
{
DogBoy() {super(new SuperHearSmell());}
}
//////////////////////////////////////////////////////////////////////////
public class EpicBattle {
//bounds in generic methods
static <POWER extends SuperHearing>
void userSuperHearing(SuperHero<POWER> hero )
{
hero.getPower().hearSubtleNoises();
}
static <POWER extends SuperHearing & SuperSmell>
void sperFind(SuperHero<POWER> hero)
{
hero.getPower().hearSubtleNoises();
hero.getPower().trackBysmell();
}
public static void main(String[] args)
{
DogBoy dogboy=new DogBoy();
userSuperHearing(dogboy);
sperFind(dogboy);
//YOU can do this
List<? extends SuperHearing> audioBoys;
//but you can 't do this:
//List<? extends SuperHearing & SuperSemll> audioBoys;
}
}
java泛型边界深入探讨，示例代码,布布扣,bubuko.com
原文地址：http://blog.csdn.net/liangrui1988/article/details/28495219
