刚学java遇到个题不知道怎么解决就说用一个接口
public interface Lockable {
public void setkey(int key);//设置密码
public void lock(int key);//锁住对象,外界不可以访问
public void unlock(int key);//解开对象,外界可以访问
public boolean locked();//判断对象是否上锁}
然后在类coin中定义接口的实现方式
-----------------------------------------------------------------------------------public class Coin implements Lockable
{
private int lockkey ; //定义一个字符串用于存入密码
private boolean locked ;//用于判断对象是否上锁
//-----------------------------------
//定义接口
//------------------------------------
public void setkey(int key)
{
lockkey = key ;
}
public void lock(int key)
{
if (lockkey == key )
{
locked = true ;//
System.out.println("It is locked!");
}
else {
locked = false ;//
System.out.println("The key cannot match this lock!");
}
}
public void unlock(int key)
{
if (lockkey == key )
{
locked = false ;//
System.out.println("It is unlocked!");
}
else
{
locked = true ;//
System.out.println("The key cannot match this lock!");
}
}
public boolean locked()
{
return locked ;
}
//--------------------------------
//以下是coin的方法,我把方法的具体内容省略了
//-----------------------------
//-----------------------------------------------------------------
// Sets up the coin by flipping it initially.
//-----------------------------------------------------------------
protected Coin ()
{
} //-----------------------------------------------------------------
// Flips the coin by randomly choosing a face value.
//-----------------------------------------------------------------
protected void flip (){} //-----------------------------------------------------------------
// Returns true if the current face of the coin is heads.
//-----------------------------------------------------------------
protected boolean isHeads ()
{
} //-----------------------------------------------------------------
// Returns the current face of the coin as a string.
//-----------------------------------------------------------------
public String toString()
{
}
}
----------------------------------------------------------------------------------------
完整的题就是:
设计一个接口Lockable,接口中包含如下方法:setKey,lock,unlock和locked .
setKey,lock,unlock方法内均含有一个代表钥匙的整型参数。setKey方法用来建立钥匙。lock和unlock方法分别用来锁住和打开对象,但只有正确的钥匙才能够行使这一权利。locked方法返回一个表明对象是否已经被上锁的布尔值。 Lockable对象内的标准方法都使用protected修饰符进行修饰:
若对象未上锁,则可以调用这些方法;若对象已上锁,则无法调用这些方法。
public interface Lockable {
public void setkey(int key);//设置密码
public void lock(int key);//锁住对象,外界不可以访问
public void unlock(int key);//解开对象,外界可以访问
public boolean locked();//判断对象是否上锁}
然后在类coin中定义接口的实现方式
-----------------------------------------------------------------------------------public class Coin implements Lockable
{
private int lockkey ; //定义一个字符串用于存入密码
private boolean locked ;//用于判断对象是否上锁
//-----------------------------------
//定义接口
//------------------------------------
public void setkey(int key)
{
lockkey = key ;
}
public void lock(int key)
{
if (lockkey == key )
{
locked = true ;//
System.out.println("It is locked!");
}
else {
locked = false ;//
System.out.println("The key cannot match this lock!");
}
}
public void unlock(int key)
{
if (lockkey == key )
{
locked = false ;//
System.out.println("It is unlocked!");
}
else
{
locked = true ;//
System.out.println("The key cannot match this lock!");
}
}
public boolean locked()
{
return locked ;
}
//--------------------------------
//以下是coin的方法,我把方法的具体内容省略了
//-----------------------------
//-----------------------------------------------------------------
// Sets up the coin by flipping it initially.
//-----------------------------------------------------------------
protected Coin ()
{
} //-----------------------------------------------------------------
// Flips the coin by randomly choosing a face value.
//-----------------------------------------------------------------
protected void flip (){} //-----------------------------------------------------------------
// Returns true if the current face of the coin is heads.
//-----------------------------------------------------------------
protected boolean isHeads ()
{
} //-----------------------------------------------------------------
// Returns the current face of the coin as a string.
//-----------------------------------------------------------------
public String toString()
{
}
}
----------------------------------------------------------------------------------------
完整的题就是:
设计一个接口Lockable,接口中包含如下方法:setKey,lock,unlock和locked .
setKey,lock,unlock方法内均含有一个代表钥匙的整型参数。setKey方法用来建立钥匙。lock和unlock方法分别用来锁住和打开对象,但只有正确的钥匙才能够行使这一权利。locked方法返回一个表明对象是否已经被上锁的布尔值。 Lockable对象内的标准方法都使用protected修饰符进行修饰:
若对象未上锁,则可以调用这些方法;若对象已上锁,则无法调用这些方法。
2。Lockable对象内的标准方法是指哪些?
3.按我的理解
应该是外部的类在调用coin类的时候,先调用locked来判断是否coin对象已经上锁
然后再执行相应的语句...
但是找不到什么好方法来实现先调用locked
希望有人能指点一下.