Java Java.io.ObjectInputStream getField getObjectStreamClass() 方法

  • 描述

    java.io.ObjectInputStream.getField.getObjectStreamClass()方法获取描述流中字段的ObjectStreamClass。
  • 声明

    以下是java.io.ObjectInputStream.getField.getObjectStreamClass()方法的声明。
     public abstract ObjectStreamClass getObjectStreamClass()
  • 参数

    不适用
  • 返回值

    此方法返回描述可序列化字段的描述符类。
  • 异常

    不适用
  • 例子

    以下示例显示java.io.ObjectInputStream.getField.getObjectStreamClass()方法的用法。
     
    package com.jc2182;
    import java.io.*;
    
    public class ObjectInputStreamDemo implements Serializable {
       public static void main(String[] args) {
          try {
             // create a new file with an ObjectOutputStream
             FileOutputStream out = new FileOutputStream("test.txt");
             ObjectOutputStream oout = new ObjectOutputStream(out);
    
             // write something in the file
             oout.writeObject(new Example());
             oout.flush();
             oout.close();
    
             // create an ObjectInputStream for the file we created before
             ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt"));
    
             // read an object from the stream and cast it to Example
             Example a = (Example) ois.readObject();
    
             // print var of a
             System.out.println("" + a.var);
    
             // get and print the objectStreamClass
             System.out.println("" + a.v);
    
          } catch (Exception ex) {
             ex.printStackTrace();
          }
       }
    
       static public class Example implements Serializable {
          static String var = "Hello World";
          static ObjectStreamClass v;
          
          // assign a new serialPersistentFields 
          private static final ObjectStreamField[] serialPersistentFields = {
             new ObjectStreamField("var", String.class)
          };
    
          private void readObject(ObjectInputStream in)
             throws IOException, ClassNotFoundException {
    
             // get the field and assign it at var
             ObjectInputStream.GetField fields = in.readFields();
    
             // get var
             var = (String) fields.get("var", "reset");
             v = fields.getObjectStreamClass();
          }
    
          private void writeObject(ObjectOutputStream out) throws IOException {
    
             // write into the ObjectStreamField array the variable string
             ObjectOutputStream.PutField fields = out.putFields();
             fields.put("var", var);
             out.writeFields();
          }
       }
    }
    
    让我们编译并运行以上程序,这将产生以下结果-
     Hello World
    com.tutorialspoint.ObjectInputStreamDemo$Example: static final long serialVersionUID = 1534274623819585475L;