我的代码错误的结果

Question

我读过Thinking in Java。我正在读I / O章 根据这本书，然后我在序列化后读取文件“CADState.out”，它无法正确读取。 因为Bruce Eckel说：“好像静态系统根本没有被序列化！...所以如果你想序列化静力学，你必须自己做。”

我已多次在计算机中测试此代码，但它已正确序列化。

也许有人可以帮助我？

（我的电脑 - Java版本7更新67，Mac OS X 10.9.4）

package IO;

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random; 

abstract class Shape implements Serializable {
    public static final int RED = 1, BLUE = 2, GREEN = 3;
    private int xPos, yPos, dimension;
    private static Random rand = new Random(47);
    private static int counter = 0;
    public abstract void setColor(int newColor);
    public abstract int getColor();
    public Shape(int xVal, int yVal, int dim) {
        xPos = xVal;
        yPos = yVal;
        dimension = dim;
    }
    public String toString() {
        return getClass() +
                "color[" + getColor() + "] xPos[" + xPos +
                "] yPos[" + yPos + "] dim[" + dimension + "]\n";
    }
    public static Shape randomFactory() {
        int xVal = rand.nextInt(100);
        int yVal = rand.nextInt(100);
        int dim = rand.nextInt(100);
        switch(counter++ % 3) {
        default:
        case 0: return new Circle(xVal, yVal, dim);
        case 1: return new Square(xVal, yVal, dim);
        case 2: return new Line(xVal, yVal, dim);
        } 
    }
}
class Circle extends Shape {
    private static int color = RED;
    public Circle(int xVal, int yVal, int dim) {
        super(xVal, yVal, dim);
    }
    public void setColor(int newColor) { color = newColor; }
    public int getColor() { return color; }
}
class Square extends Shape {
    private static int color;
    public Square(int xVal, int yVal, int dim) {
        super(xVal, yVal, dim);
        color = RED; 
    }
    public void setColor(int newColor) { color = newColor; }
    public int getColor() { return color; }
}
class Line extends Shape {
    private static int color = RED;
    public static void
    serializeStaticState(ObjectOutputStream os)
            throws IOException { os.writeInt(color); }
    public static void
    deserializeStaticState(ObjectInputStream os)
            throws IOException { color = os.readInt(); }
    public Line(int xVal, int yVal, int dim) {
        super(xVal, yVal, dim);
    }
    public void setColor(int newColor) { color = newColor; }
    public int getColor() { return color; }
}

public class Thirty {

    public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {

        List<Class<? extends Shape>> shapeTypes =
                new ArrayList<Class<? extends Shape>>();
        // Add references to the class objects:
        shapeTypes.add(Circle.class);
        shapeTypes.add(Square.class);
        shapeTypes.add(Line.class);
        List<Shape> shapes = new ArrayList<Shape>();
        // Make some shapes:
        for(int i = 0; i < 10; i++)
            shapes.add(Shape.randomFactory());
        // Set all the static colors to GREEN:
        for(int i = 0; i < 10; i++)
            ((Shape)shapes.get(i)).setColor(Shape.GREEN);
        // Save the state vector:
        ObjectOutputStream out = new ObjectOutputStream(
                new FileOutputStream("CADState.out"));
        out.writeObject(shapeTypes);
        Line.serializeStaticState(out);
        out.writeObject(shapes);
        // Display the shapes:
        System.out.println(shapes);


        ObjectInputStream in = new ObjectInputStream(new FileInputStream("CADState.out"));
        // Read in the same order they were written:
        @SuppressWarnings("unchecked")
        List<Class<? extends Shape>> shapeTypes2 = (List<Class<? extends Shape>>)in.readObject();
        Line.deserializeStaticState(in);

        @SuppressWarnings("unchecked")
        List<Shape> shapes2 = (List<Shape>)in.readObject();
        System.out.println(shapes2);

    }

}

根据书中输出此代码：

[class Circlecolor[3] xPos[58] yPos[55] dim[93]
, class Squarecolor[3] xPos[61] yPos[61] dim[29]
, class Linecolor[3] xPos[68] yPos[0] dim[22]
, class Circlecolor[3] xPos[7] yPos[88] dim[28]
, class Squarecolor[3] xPos[51] yPos[89] dim[9]
, class Linecolor[3] xPos[78] yPos[98] dim[61]
, class Circlecolor[3] xPos[20] yPos[58] dim[16]
, class Squarecolor[3] xPos[40] yPos[11] dim[22]
, class Linecolor[3] xPos[4] yPos[83] dim[6]
, class Circlecolor[3] xPos[75] yPos[10] dim[42]
]
[class Circlecolor[1] xPos[58] yPos[55] dim[93]
, class Squarecolor[0] xPos[61] yPos[61] dim[29]
, class Linecolor[3] xPos[68] yPos[0] dim[22]
, class Circlecolor[1] xPos[7] yPos[88] dim[28]
, class Squarecolor[0] xPos[51] yPos[89] dim[9]
, class Linecolor[3] xPos[78] yPos[98] dim[61]
, class Circlecolor[1] xPos[20] yPos[58] dim[16]
, class Squarecolor[0] xPos[40] yPos[11] dim[22]
, class Linecolor[3] xPos[4] yPos[83] dim[6]
, class Circlecolor[1] xPos[75] yPos[10] dim[42]

在我的电脑上输出此代码：

[class IO.Circlecolor[3] xPos[58] yPos[55] dim[93]
, class IO.Squarecolor[3] xPos[61] yPos[61] dim[29]
, class IO.Linecolor[3] xPos[68] yPos[0] dim[22]
, class IO.Circlecolor[3] xPos[7] yPos[88] dim[28]
, class IO.Squarecolor[3] xPos[51] yPos[89] dim[9]
, class IO.Linecolor[3] xPos[78] yPos[98] dim[61]
, class IO.Circlecolor[3] xPos[20] yPos[58] dim[16]
, class IO.Squarecolor[3] xPos[40] yPos[11] dim[22]
, class IO.Linecolor[3] xPos[4] yPos[83] dim[6]
, class IO.Circlecolor[3] xPos[75] yPos[10] dim[42]
]
[class IO.Circlecolor[3] xPos[58] yPos[55] dim[93]
, class IO.Squarecolor[3] xPos[61] yPos[61] dim[29]
, class IO.Linecolor[3] xPos[68] yPos[0] dim[22]
, class IO.Circlecolor[3] xPos[7] yPos[88] dim[28]
, class IO.Squarecolor[3] xPos[51] yPos[89] dim[9]
, class IO.Linecolor[3] xPos[78] yPos[98] dim[61]
, class IO.Circlecolor[3] xPos[20] yPos[58] dim[16]
, class IO.Squarecolor[3] xPos[40] yPos[11] dim[22]
, class IO.Linecolor[3] xPos[4] yPos[83] dim[6]
, class IO.Circlecolor[3] xPos[75] yPos[10] dim[42]
]

Answer 1

我发现了自己的错误。谢谢那些家伙 - http://www.coderanch.com/t/546558/java-io/java/Serialization-static-variables。 Rob Spoor：变量y是静态的。这意味着只要加载了类，它就会保持相同的值。您在同一JVM实例中进行序列化和反序列化。尝试将序列化和反序列化分成两个类，看看差异。

我已将代码拆分为两个类：Thirty和ThirtyRead。在那之后，一切都开始正常工作。坦率地说，在书中它也是两个类））。但是，我还没有注意到它。我把所有东西放在同一个班级里。

这里的解决方案。第三类：

package IO;

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random; 

abstract class Shape implements Serializable {
    public static final int RED = 1, BLUE = 2, GREEN = 3;
    private int xPos, yPos, dimension;
    private static Random rand = new Random(47);
    private static int counter = 0;
    public abstract void setColor(int newColor);
    public abstract int getColor();
    public Shape(int xVal, int yVal, int dim) {
        xPos = xVal;
        yPos = yVal;
        dimension = dim;
    }
    public String toString() {
        return getClass() +
                "color[" + getColor() + "] xPos[" + xPos +
                "] yPos[" + yPos + "] dim[" + dimension + "]\n";
    }
    public static Shape randomFactory() {
        int xVal = rand.nextInt(100);
        int yVal = rand.nextInt(100);
        int dim = rand.nextInt(100);
        switch(counter++ % 3) {
        default:
        case 0: return new Circle(xVal, yVal, dim);
        case 1: return new Square(xVal, yVal, dim);
        case 2: return new Line(xVal, yVal, dim);
        } 
    }
}
class Circle extends Shape {
    private static int color = RED;
    public Circle(int xVal, int yVal, int dim) {
        super(xVal, yVal, dim);
    }
    public void setColor(int newColor) { color = newColor; }
    public int getColor() { return color; }
}
class Square extends Shape {
    private static int color;
    public Square(int xVal, int yVal, int dim) {
        super(xVal, yVal, dim);
        color = RED; 
    }
    public void setColor(int newColor) { color = newColor; }
    public int getColor() { return color; }
}
class Line extends Shape {
    private static int color = RED;
    public static void
    serializeStaticState(ObjectOutputStream os)
            throws IOException { os.writeInt(color); }
    public static void
    deserializeStaticState(ObjectInputStream os)
            throws IOException { color = os.readInt(); }
    public Line(int xVal, int yVal, int dim) {
        super(xVal, yVal, dim);
    }
    public void setColor(int newColor) { color = newColor; }
    public int getColor() { return color; }
}

public class Thirty {

    public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
        List<Class<? extends Shape>> shapeTypes =
                new ArrayList<Class<? extends Shape>>();
        // Add references to the class objects:
        shapeTypes.add(Circle.class);
        shapeTypes.add(Square.class);
        shapeTypes.add(Line.class);
        List<Shape> shapes = new ArrayList<Shape>();
        // Make some shapes:
        for(int i = 0; i < 10; i++)
            shapes.add(Shape.randomFactory());
        // Set all the static colors to GREEN:
        for(int i = 0; i < 10; i++)
            ((Shape)shapes.get(i)).setColor(Shape.GREEN);
        // Save the state vector:
        ObjectOutputStream out = new ObjectOutputStream(
                new FileOutputStream("CADState.out"));
        out.writeObject(shapeTypes);
        Line.serializeStaticState(out);
        out.writeObject(shapes);
        // Display the shapes:
        System.out.println(shapes);

    }

}

// output
[class IO.Circlecolor[3] xPos[58] yPos[55] dim[93]
, class IO.Squarecolor[3] xPos[61] yPos[61] dim[29]
, class IO.Linecolor[3] xPos[68] yPos[0] dim[22]
, class IO.Circlecolor[3] xPos[7] yPos[88] dim[28]
, class IO.Squarecolor[3] xPos[51] yPos[89] dim[9]
, class IO.Linecolor[3] xPos[78] yPos[98] dim[61]
, class IO.Circlecolor[3] xPos[20] yPos[58] dim[16]
, class IO.Squarecolor[3] xPos[40] yPos[11] dim[22]
, class IO.Linecolor[3] xPos[4] yPos[83] dim[6]
, class IO.Circlecolor[3] xPos[75] yPos[10] dim[42]
]

Class ThirtyRead

    package IO;

    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.ObjectInputStream;
    import java.util.List;

    public class ThirtyRead {

        public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
            // TODO Auto-generated method stub
            ObjectInputStream in = new ObjectInputStream(new FileInputStream("CADState.out"));
            // Read in the same order they were written:
            @SuppressWarnings("unchecked")
            List<Class<? extends Shape>> shapeTypes2 = (List<Class<? extends Shape>>)in.readObject();
            Line.deserializeStaticState(in);

            @SuppressWarnings("unchecked")
            List<Shape> shapes2 = (List<Shape>)in.readObject();
            System.out.println(shapes2);

        }

    }
// output

    [class IO.Circlecolor[1] xPos[58] yPos[55] dim[93]
    , class IO.Squarecolor[0] xPos[61] yPos[61] dim[29]
    , class IO.Linecolor[3] xPos[68] yPos[0] dim[22]
    , class IO.Circlecolor[1] xPos[7] yPos[88] dim[28]
    , class IO.Squarecolor[0] xPos[51] yPos[89] dim[9]
    , class IO.Linecolor[3] xPos[78] yPos[98] dim[61]
    , class IO.Circlecolor[1] xPos[20] yPos[58] dim[16]
    , class IO.Squarecolor[0] xPos[40] yPos[11] dim[22]
    , class IO.Linecolor[3] xPos[4] yPos[83] dim[6]
    , class IO.Circlecolor[1] xPos[75] yPos[10] dim[42]
    ]