Question

Java中有没有办法实现这样的目标：

    jPanel1.label1
        .setText("something")
        .setEnabled(something)
        .setVisible(something)

而不是一遍又一遍地输入相同的变量名？谢谢！

Answer 1

是。按照builder pattern来实现您的目标。它的每个方法在修改后返回相同的实例。

直接粘贴示例：

public class StreetMap {
    private final Point origin;
    private final Point destination;

    private final Color waterColor;
    private final Color landColor;
    private final Color highTrafficColor;
    private final Color mediumTrafficColor;
    private final Color lowTrafficColor;

    public static class Builder {
        // Required parameters
        private final Point origin;
        private final Point destination;

        // Optional parameters - initialize with default values
        private Color waterColor         = Color.BLUE;
        private Color landColor          = new Color(30, 30, 30);
        private Color highTrafficColor   = Color.RED;
        private Color mediumTrafficColor = Color.YELLOW;
        private Color lowTrafficColor    = Color.GREEN;

        public Builder(Point origin, Point destination) {
            this.origin      = origin;
            this.destination = destination;
        }

        public Builder waterColor(Color color) {
            waterColor = color;
            return this;
        }

        public Builder landColor(Color color) {
            landColor = color;
            return this;
        }

        public Builder highTrafficColor(Color color) {
            highTrafficColor = color;
            return this;
        }

        public Builder mediumTrafficColor(Color color) {
            mediumTrafficColor = color;
            return this;
        }

        public Builder lowTrafficColor(Color color) {
            lowTrafficColor = color;
            return this;
        }

        public StreetMap build() {
            return new StreetMap(this);
        }

    }

    private StreetMap(Builder builder) {
        // Required parameters
        origin      = builder.origin;
        destination = builder.destination;

        // Optional parameters
        waterColor         = builder.waterColor;
        landColor          = builder.landColor;
        highTrafficColor   = builder.highTrafficColor;
        mediumTrafficColor = builder.mediumTrafficColor;
        lowTrafficColor    = builder.lowTrafficColor;
    }

    public static void main(String args[]) {
        StreetMap map = new StreetMap.Builder(new Point(50, 50), new Point(100,
                100)).landColor(Color.GRAY).waterColor(Color.BLUE.brighter())
                .build();
    }
}

更改同一对象的多个属性

1 个答案: