建造者模式

public class Cup {
    private String string;    //绳子
    private String cap;       //帽子
    private String cupBody;   //杯体
    public void setString(String string) {
        this.string = string;
    }
    public void setCap(String cap) {
        this.cap = cap;
    }
    public void setCupBody(String cupBody) {
        this.cupBody = cupBody;
    }
    public void show() {
        System.out.println("杯子生产完毕");
    }
}
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public abstract class  Builder {
    protected Cup cup = new Cup();
    public abstract void buildString();
    public abstract void buildCap();
    public abstract void buildCupBody();
    public  Cup getResult() {
        return cup;
    }
}
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public class ClassCup extends Builder {
    @Override
    public void buildString() {
        cup.setString("生产绳子...");
        System.out.println("生产绳子...");
    }
    @Override
    public void buildCap() {
        cup.setCap("生产帽子...");
        System.out.println("生产帽子...");
    }
    @Override
    public void buildCupBody() {
        cup.setCupBody("生产杯体...");
        System.out.println("生产杯体...");
    }
}
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public class Director {
    private Builder builder;
    public Director(Builder builder) {
        this.builder = builder;
    }
    public void create() {
        builder.buildString();
        builder.buildCap();
        builder.buildCupBody();
        builder.getResult().show();
    }
    public static void main(String[] args) {
        Director d = new Director(new ClassCup());
        d.create();
    }
}
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public class AbstractStringBuilder {
    protected char[] value;
    protected int count;
    public AbstractStringBuilder(int capacity) {
        count = 0;
        value = new char[capacity];
    }
    public AbstractStringBuilder append(char c) {
        ensureCapacityInternal(count + 1);
        value[count++] = c;
        return this;
    }
    private void ensureCapacityInternal(int minimumCapacity) {
        // overflow-conscious code
        if (minimumCapacity - value.length > 0)
            expandCapacity(minimumCapacity);
    }
    void expandCapacity(int minimumCapacity) {
        int newCapacity = value.length * 2 + 2;
        if (newCapacity - minimumCapacity < 0)
            newCapacity = minimumCapacity;
        if (newCapacity < 0) {
            if (minimumCapacity < 0) // overflow
                throw new OutOfMemoryError();
            newCapacity = Integer.MAX_VALUE;
        }
        value = Arrays.copyOf(value, newCapacity);
    }
}
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public class StringBuilder extends AbstractStringBuilder {
    public StringBuilder() {
        super(16);
    }
    @Override
    public String toString() {
        // Create a copy, don't share the array
        return new String(value, 0, count);
    }
}
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public class Client {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder();
        final int count = 26;
        for (int i = 0; i < count; i++) {
            sb.append((char) ('a' + i));
        }
        System.out.println(sb.toString());
    }
}
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