解决方案——基类(抽象)

public abstract class Place {

String Name;
String Postcode;
String County;
String Area;

Place () {

        }

public static Place make(String Incoming) {
        if (Incoming.length() < 61) return (null);

        String Name = (Incoming.substring(4,26)).trim();
        String County = (Incoming.substring(27,48)).trim();
        String Postcode = (Incoming.substring(48,61)).trim();
        String Area = (Incoming.substring(61)).trim();

        Place created;
        if (Name.equalsIgnoreCase(Area)) {
                created = new Area(Area,County,Postcode);
        } else {
                created = new District(Name,County,Postcode,Area);
        }
        return (created);
        }

public String getName() {
        return (Name);
        }

public String getPostcode() {
        return (Postcode);
        }

public String getCounty() {
        return (County);
        }

public abstract String getArea();

}

在这里找到你的答案:

Java中的抽象类与接口

抽象类可以有final方法吗?

顺便说一句，这是你最近问的问题。思考一个建立声誉的新问题……

编辑:

刚刚意识到，这个和参考问题的海报有相同或至少相似的名称，但用户id总是不同的。所以，要么，有一个技术问题，键盘有问题再次登录，并找到他的问题的答案，或者这是一种娱乐So社区的游戏;)

解决方案——基类(抽象)

public abstract class Place {

String Name;
String Postcode;
String County;
String Area;

Place () {

        }

public static Place make(String Incoming) {
        if (Incoming.length() < 61) return (null);

        String Name = (Incoming.substring(4,26)).trim();
        String County = (Incoming.substring(27,48)).trim();
        String Postcode = (Incoming.substring(48,61)).trim();
        String Area = (Incoming.substring(61)).trim();

        Place created;
        if (Name.equalsIgnoreCase(Area)) {
                created = new Area(Area,County,Postcode);
        } else {
                created = new District(Name,County,Postcode,Area);
        }
        return (created);
        }

public String getName() {
        return (Name);
        }

public String getPostcode() {
        return (Postcode);
        }

public String getCounty() {
        return (County);
        }

public abstract String getArea();

}

An abstract class is one that isn't fully implemented but provides something of a blueprint for subclasses. It may be partially implemented in that it contains fully-defined concrete methods, but it can also hold abstract methods. These are methods with a signature but no method body. Any subclass must define a body for each abstract method, otherwise it too must be declared abstract. Because abstract classes cannot be instantiated, they must be extended by at least one subclass in order to be utilized. Think of the abstract class as the generic class, and the subclasses are there to fill in the missing information.

抽象类不能直接实例化，但必须从抽象类派生才能使用。一个类必须是抽象的，如果它包含抽象方法:或者直接

abstract class Foo {
    abstract void someMethod();
}

或间接地

interface IFoo {
    void someMethod();
}

abstract class Foo2 implements IFoo {
}

然而，一个类可以是抽象的，而不包含抽象方法。这是一种防止直接瞬化的方法，例如。

abstract class Foo3 {
}

class Bar extends Foo3 {

}

Foo3 myVar = new Foo3(); // illegal! class is abstract
Foo3 myVar = new Bar(); // allowed!

抽象类的后一种风格可以用来创建“类接口”类。与接口不同，抽象类允许包含非抽象方法和实例变量。您可以使用它为扩展类提供一些基本功能。

另一种常见的模式是在抽象类中实现主要功能，并在由扩展类实现的抽象方法中定义部分算法。愚蠢的例子:

abstract class Processor {
    protected abstract int[] filterInput(int[] unfiltered);

    public int process(int[] values) {
        int[] filtered = filterInput(values);
        // do something with filtered input
    }
}

class EvenValues extends Processor {
    protected int[] filterInput(int[] unfiltered) {
        // remove odd numbers
    }
}

class OddValues extends Processor {
    protected int[] filterInput(int[] unfiltered) {
        // remove even numbers
    }
}

什么是抽象类? 好的!让我们举个例子，你对化学了解不多，我们有一个元素碳(符号C)。碳有一些基本的原子结构，你不能改变，但用碳你可以制造很多化合物，如(CO2)，甲烷(CH4)，丁烷(C4H10)。

所以这里碳是抽象类，你不想改变它的基本结构，但你想让他们的孩子(CO2,CH4等)使用它。但是以他们自己的方式