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我是java的初学者，我需要帮助。我有两个班级，一个（宋）看代码是第二个（日期）的孩子。Song 是可序列化的，而 Date 是不可序列化的（我打算以这种方式保留 Date 类）。我正在使用来自 Date 的方法，称为 setDate，它需要三个参数，月、日和年，都是整数。我正在尝试使用自定义序列化（使用 readObject 和 writeObject 方法等）。

package assignment7;

import java.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
*
* @author Owner
*/
public class Song extends Date implements Serializable{


 private String title;
 private String artist;
 private String genre;
 //private String dateOpened;
 //private Date obj = new Date();

 public Song(){

 }
 public void setTitle(String t) {
    title = t;
 }

public void setArtist(String a) {
    artist = a;
}

public void setGenre(String g) {
    genre = g;
}

public void setDateOpen(int m, int d, int y){  
    setDate(m, d, y);
}

public void setDayOpen(){

}

public void setDayOpen(){
Date
}

public void setDayOpen(){

}

public String getDateOpen(){
   return getDate();
}

public String getTitle() {
    return title;
}

public String getArtist() {
    return artist;
}

public String getGenre() {
    return genre;
}

private void writeObject( ObjectOutputStream out ) throws IOException, ClassNotFoundException, NotSerializableException {
    out.defaultWriteObject();

      out.writeObject(getTitle());
      out.writeObject(getArtist());
      out.writeObject(getGenre());
      out.writeObject(getDateOpen());

}

private void readObject( ObjectInputStream in ) throws IOException, NotSerializableException, ClassNotFoundException {
      in.defaultReadObject();

      setTitle((String)in.readObject());
      setArtist((String)in.readObject());
      setGenre((String)in.readObject());
      setDateOpen((int)in.readObject(), (int)in.readObject(), (int)in.readObject());

}

}

问题是 getDateOpen 方法返回一个字符串，而 setDateOpen 需要 3 个整数。有没有办法让 readObjects() 读取 3 个整数并仍然输出序列化字符串？（iv'e 还包括我的老师说不要更改的日期课程）

package assignment7;

import java.util.Scanner;

public class Date
{
private int month;
private int day;
private int year;

public Date() { month = 0; day = 0; year = 0; }
public Date( int m, int d, int y )
{
month = editMonth( m );
day = editDay( d );
year = editYear( y );
}
public void setDate( int m, int d, int y )
{
month = editMonth( m );
day = editDay( d );
year = editYear( y );
}
public String getDate( )
{
return month + "/" + day + "/" + year;
}
public int getMonth() { return month; }
public int getDay() { return day; }
public int getYear() { return year; }

protected int editMonth( int m )
{
if( m >= 1 && m <= 12 )
  return m;
else
{
  Scanner input = new Scanner( System.in );
  while( !( m >= 1 && m <= 12 ) )
  {
    System.out.print( "Month must be 1-12 --- Please re-enter: " );
    m = input.nextInt();
  }
  return m;
  }          
  }

 protected int editDay( int d )
 {
 int [] monthDays = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

 if( d >= 1 && d <= monthDays[month - 1] )
  return d;
 else
 {
  Scanner input = new Scanner( System.in );
  while( !( d >= 1 && d <= monthDays[month - 1] ) )
  {
    System.out.print( "Day must be 1 - " + monthDays[month - 1] + " --- 
  please re-enter: " );
    d = input.nextInt();
  }
  return d;
  }
  }

 protected int editYear( int y )
 {
 if( y >= 1 )
  return y;
 else
 {
  Scanner input = new Scanner(System.in);
  while( y < 1 )
  {
    System.out.print( "Year must be greater than 1 --- please re-enter: " 
   );
    y = input.nextInt();
  }
  return y;
  }
  }
 }
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1 回答 1

1

如果该Date类型仅提供String日期，那么您需要在某个时候传递它。要么解析writeObject并存储ints，要么与 保持String串行形式并解析readObject。

Date只提供一个字符串化的日期可能不是一个好的设计选择。也没有办法 aSong应该是的子类型Date（除非有一些关键的性能问题，这似乎不太可能）。

还要避免 Java 序列化。JSON 似乎是通常的选择。

于 2019-10-10T15:19:33.523 回答