深入Java设计模式之适配器模式

package com.lzhsite.technology.designPattern.adapter.Address;
public class Customer
{
    public static final String US = "US";
    public static final String CANADA = "CANADA";
    private String address;
    private String name;
    private String zip;
    private String state;
    private String type;
    public Customer(String address, String name, String zip, String state, String type)
    {
        this.address = address;
        this.name = name;
        this.zip = zip;
        this.state = state;
        this.type = type;
    }
    public boolean isValidAddress()
    {
      //Customer期望能通过调用AddressValidator接口isValidAddress方法，从而实现调用USAddress/CAAddress类的验证方法(实现不同验证器的统一调度)。
        //CAAddress是原来老系统里就存在的类,不能把方法名isValidCanadianAddress直接改为isValidAddress。否者会影响老系统的使用
      //这时就需要一个适配器CAAddressAdapter继承CAAddress，并且实现接口isValidAddress
      //Customer的里根据入参来判断是实例化CAAddressAdapter还是USAddress
      AddressValidator addressValidator = getValidator(type);
        return addressValidator.isValidAddress(address, zip, state);
    }
    private AddressValidator getValidator(String customerType)
    {
        AddressValidator addressValidator = null;
        if (customerType.equals(Customer.US))
        {
            addressValidator = new USAddress();
        }
        if (customerType.equals(Customer.CANADA))
        {
            addressValidator = new CAAddressAdapter();
        }
        return addressValidator;
    }
}

package com.lzhsite.technology.designPattern.adapter.Address;
public interface AddressValidator
{
    public boolean isValidAddress(String address, String zip, String state);
}

package com.lzhsite.technology.designPattern.adapter.Address;
public class USAddress implements AddressValidator
{
    public boolean isValidAddress(String address, String zip, String state)
    {
        if (address.trim().length() < 10)
        {
            return false;
        }
        if (zip.trim().length() < 5 || zip.trim().length() > 10)
        {
            return false;
        }
        if (state.trim().length() != 2)
        {
            return false;
        }
        return true;
    }
}

package com.lzhsite.technology.designPattern.adapter.Address;
public class CAAddressAdapter extends CAAddress implements AddressValidator
{
    public boolean isValidAddress(String address, String zip, String state)
    {
        return isValidCanadianAddress(address, zip, state);
    }
}

package com.lzhsite.technology.designPattern.adapter.Address;
public class CAAddress
{
    public boolean isValidCanadianAddress(String address, String pcode, String prvnc)
    {
        if (address.trim().length() < 15)
        {
            return false;
        }
        if (pcode.trim().length() != 6)
        {
            return false;
        }
        if (prvnc.trim().length() < 6)
        {
            return false;
        }
        return true;
    }
}

package com.lzhsite.technology.designPattern.adapter.Address;
public class CAAddress
{
    public boolean isValidCanadianAddress(String address, String pcode, String prvnc)
    {
        if (address.trim().length() < 15)
        {
            return false;
        }
        if (pcode.trim().length() != 6)
        {
            return false;
        }
        if (prvnc.trim().length() < 6)
        {
            return false;
        }
        return true;
    }
}