Java ObjectInputStream defaultReadObject()用法及代码示例

Java中ObjectInputStream类的defaultReadObject()方法用于从此流中读取当前类的非静态和非瞬态字段。

用法:

public void defaultReadObject()

参数：此方法不接受任何参数。

返回值：此方法返回已读取的值。

错误和异常：该函数引发三个异常，如下所述：

ClassNotFoundException：如果找不到序列化对象的类，则会引发异常。
IOException：如果发生I /O错误，则会引发异常。
NotActiveException：如果流当前未读取对象，则抛出异常。

以下示例程序旨在说明上述方法：

程序1:

Java

// Java program to illustrate 
// the above method 
  
import java.io.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
        try { 
            // create a new file 
            // with an ObjectOutputStream 
            FileOutputStream out 
                = new FileOutputStream("Shubham.txt"); 
            ObjectOutputStream out1 
                = new ObjectOutputStream(out); 
  
            // write 
            out1.writeObject(new solve()); 
  
            // Flushes the stream 
            out1.flush(); 
  
            // create an ObjectInputStream 
            // for the file 
            ObjectInputStream example 
                = new ObjectInputStream( 
                    new FileInputStream("Shubham.txt")); 
  
            // Read from the stream 
            solve ans = (solve)example.readObject(); 
            System.out.println(ans.str); 
        } 
  
        catch (Exception ex) { 
            ex.printStackTrace(); 
        } 
    } 
  
    static class solve implements Serializable { 
        String str = "Geeksforgeeks"; 
  
        private void readObject(ObjectInputStream res) 
            throws IOException, 
                   ClassNotFoundException 
        { 
  
            // By using defaultReadObject() method is 
            // to read non-static fields of the present 
            // class from the ObjectInputStream 
            res.defaultReadObject(); 
        } 
    } 
}

输出：

程序2:

Java

// Java program to illustrate 
// the above method 
  
import java.io.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
        try { 
            // create a new file 
            // with an ObjectOutputStream 
            FileOutputStream out 
                = new FileOutputStream("Shubham.txt"); 
            ObjectOutputStream out1 
                = new ObjectOutputStream(out); 
  
            // write 
            out1.writeObject(new solve()); 
  
            // Flushes the stream 
            out1.flush(); 
  
            // create an ObjectInputStream 
            // for the file 
            ObjectInputStream example 
                = new ObjectInputStream( 
                    new FileInputStream("Shubham.txt")); 
  
            // Read from the stream 
            solve ans = (solve)example.readObject(); 
            // System.out.println(ans.str); 
            System.out.println(ans.in); 
        } 
  
        catch (Exception ex) { 
            ex.printStackTrace(); 
        } 
    } 
  
    static class solve implements Serializable { 
  
        // String str = "Geeksforgeeks"; 
        Integer in = new Integer(112414); 
  
        private void readObject(ObjectInputStream res) 
            throws IOException, 
                   ClassNotFoundException 
        { 
            // By using defaultReadObject() method is 
            // to read non-static fields of the present 
            // class from the ObjectInputStream 
            res.defaultReadObject(); 
        } 
    } 
}

输出：

参考：

https://docs.oracle.com/javase/10/docs/api/java/io/ObjectInputStream.html#defaultReadObject()

相关用法

注：本文由纯净天空筛选整理自SHUBHAMSINGH10大神的英文原创作品 ObjectInputStream defaultReadObject() method in Java with examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。