Java ObjectInputStream和ObjectOutputStream的區別用法及代碼示例

// Java Program simply illustrating POJO / Model class
// Importing input output class 
import java.io.Serializable;
// Class 1
// Implements Serializable  for POJO class to avoid
// NotSerializableException will be thrown
public class VehicleSpecifications implements Serializable {
    // Member variables of this class
    private String color;
    private String type;
    private String name;
    private double price;
    // Constructors of this class
    // Constructor- 1
    // Default constructor
    public VehicleSpecifications() {}
    // Constructor- 2
    // Parameterized constructor accepting all attributes and
    // helps to create a VehicleSpecifications class
    public VehicleSpecifications(String color, String type,
                                 String name, double price)
    {
        // This keyword refers to current object itself
        this.color = color;
        this.type = type;
        this.name = name;
        this.price = price;
    }
    // Methods of this class
    // Specifically  Getter and Setter methods
    // Method 1
    public double getPrice() { return price; }
    // Method 2
    public void setPrice(double price)
    {
        this.price = price;
    }
    // Method 3
    public String getName() { return name; }
    // Method 4
    public void setName(String name) { this.name = name; }
    // Method 5
    public String getColor() { return color; }
    // Method 6
    public void setColor(final String color)
    {
        this.color = color;
    }
    // Method 7
    public String getType() { return type; }
    // Method 8
    public void setType(final String type)
    {
        this.type = type;
    }
}

// Class 2
// Java Program to Create Few VehicleSpecification and
// Writing in a File
// Importing required classes from packages
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;
// Main class
public class VehicleSpecificationsSerializer {
    // main driver method
    public static void main(String[] args)
    {
        // Output file been passed in a string
        String sampleOutputFile = "VehicleSpecification.db";
        // Try block to check for exceptions
        try {
            // Create a objectoutputstream accepting the
            // file name as VehicleSpecification.db
            ObjectOutputStream vehicleObjectOutput
                = new ObjectOutputStream(
                    new FileOutputStream(sampleOutputFile));
            // Create a list of VehicleSpecifications class
            List<VehicleSpecifications> listSpecifications
                = new ArrayList<VehicleSpecifications>();
            // Add the necessary data using standard add()
            // method Custom input
            listSpecifications.add(
                new VehicleSpecifications("Radiant Red",
                                          "SUV", "WR-V",
                                          1700000f));
            listSpecifications.add(
                new VehicleSpecifications("Metallic Blue",
                                          "SUV", "WR-V",
                                          1800000f));
            listSpecifications.add(
                new VehicleSpecifications(
                    "Black", "SUV", "WR-V", 1900000f));
            // We are writing the whole object into the file
            // which is a list item of VehicleSpecifications
            // object
            vehicleObjectOutput.writeObject(
                listSpecifications);
            // Closing the connection to release memory
            vehicleObjectOutput.close();
        }
        // Catch block to handle the exceptions
        catch (IOException ex) {
            // Print the exceptions along with line number
            // using printStackTrace() method
            ex.printStackTrace();
        }
    }
}

// Java Program to make above code human-readable
// Importing classes from required packages
import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.ArrayList;
import java.util.List;
// Main class
public class VehicleSpecificationsDeSerializer {
    // main driver method
    public static void main(String[] args)
    {
        // Input file
        String sampleInputFile = "VehicleSpecification.db";
        // Try block to check for exceptions
        try {
            // Creating an object of ObjectInputStream class
            ObjectInputStream vehicleObjectInputStream
                = new ObjectInputStream(
                    new FileInputStream(sampleInputFile));
            // Creating a List class object
            // Declaring object of user defined type
            // (VehicleSpecifications)
            List<VehicleSpecifications>
                vehicleSpecificationsListData
                = new ArrayList<VehicleSpecifications>();
            // Using readObject, bringing back the whole
            // list item of VehicleSpecifications into scope
            // readObject which can read class attributes
            // using read methods provided by
            // ObjectInputStream.
            vehicleSpecificationsListData
                = (ArrayList<VehicleSpecifications>)
                      vehicleObjectInputStream.readObject();
            // Iterating over above object created
            for (int i = 0;
                 i < vehicleSpecificationsListData.size();
                 i++) {
                VehicleSpecifications vehicleSpecifications
                    = vehicleSpecificationsListData.get(i);
                // Print and display commands
                System.out.println(
                    "Color .."
                    + vehicleSpecifications.getColor());
                System.out.println(
                    "Name .."
                    + vehicleSpecifications.getName());
                System.out.println(
                    "Price .."
                    + vehicleSpecifications.getPrice());
                System.out.println(
                    "Type .."
                    + vehicleSpecifications.getType());
            }
            // Closing the resources to free up memory space
            vehicleObjectInputStream.close();
        }
        // Catch block to handle the exceptions
        // Catch block 1
        // Handling input output  exceptions
        catch (IOException ex) {
            // Printing the line number where exception
            // occurred using printStackTrace() method
            ex.printStackTrace();
        }
        // Catch block 2
        // Handle exception if class not found
        catch (ClassNotFoundException e) {
            // Again, printing the line number where
            // exception occurred using printStackTrace()
            // method
            e.printStackTrace();
        }
    }
}