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import java.io.*;  public class Forest implements Serializable {  private Tree tree = new Tree();  public static void main(String [] args) {  Forest f= new Forest();  try {  FileOutputStream fs = new FileOutputStream(”Forest.ser”);  ObjectOutputStream os = new ObjectOutputStream(fs);  os.writeObject(f); os.close();  } catch (Exception ex) { ex.printStackTrace(); }  }  }  class Tree { }  What is the result?() 

  • A、 Compilation fails.
  • B、 An exception is thrown at runtime.
  • C、 An instance of Forest is serialized.
  • D、 A instance of Forest and an instance of Tree are both serialized.

参考答案

更多 “ import java.io.*;  public class Forest implements Serializable {  private Tree tree = new Tree();  public static void main(String [] args) {  Forest f= new Forest();  try {  FileOutputStream fs = new FileOutputStream(”Forest.ser”);  ObjectOutputStream os = new ObjectOutputStream(fs);  os.writeObject(f); os.close();  } catch (Exception ex) { ex.printStackTrace(); }  }  }  class Tree { }  What is the result?() A、 Compilation fails.B、 An exception is thrown at runtime.C、 An instance of Forest is serialized.D、 A instance of Forest and an instance of Tree are both serialized.” 相关考题
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考题 单选题在下列程序的空白处,应填入的正确选项是(  )。import java.io.*; public class writeInt{ public static void main(String[] args){ int[] myArray={10,20,30,40}; try{ DataOutputStream dos=new DataOutputStream(new FileOutputStream("ints.dat")); for(int i=0;i dos.writeInt(myArray[i]); dos.close(); System.out.println("Have written binary file ints.dat"); } } catch(IOException ioe){ System.out.println("IOException"); } } }A start()B close()C read()D write()

考题 单选题在下列程序的空白处,应填入的正确选项是(  )。import java.io.*; public class ObjectStreamTest{ public static void main(string args[])throws IOException{ ObjectOutputStream oos=new ObjectOutputStream(new FileOutputStream("serial.bin")); Java.until.Date d=new Java.until.Date(); oos.______(); ObjectInputStream ois=new ObjectlnputStream(new FileOutputStream("serial.bin")); try{ java.until.date restoredDate=(Java.until.Date)ois.readObject(); System.out.println("read object back from serial.bin file:"+restoredDate); } catch(ClassNotFoundException cnf){ System.out.println("class not found"); } }A readObjectB WriterC BufferedWriterD writeObject

考题 单选题import java.io.*;  public class Forest implements Serializable {  private Tree tree = new Tree();  public static void main(String [] args) {  Forest f= new Forest();  try {  FileOutputStream fs = new FileOutputStream(”Forest.ser”);  ObjectOutputStream os = new ObjectOutputStream(fs);  os.writeObject(f); os.close();  } catch (Exception ex) { ex.printStackTrace(); }  }  }  class Tree { }  What is the result?()A  Compilation fails.B  An exception is thrown at runtime.C  An instance of Forest is serialized.D  A instance of Forest and an instance of Tree are both serialized.

考题 单选题现有:  class Tree {  private static String tree = "tree ";  String getTree ()  {  return tree;  }       }  class Elm extends Tree {  private static String tree = "elm ";  public static void main (String  []  args)  {       new Elm() .go (new Tree())  ;      } }  void go (Tree t)  {  String  s =  t.getTree () +Elm.tree  +  tree  +   (new  Elm() .getTree ()) ;      System.out.println (s) ;}     结果为:()A  elm elm elm elmB  tree elm elm elmC  tree elm elm treeD  tree elm tree elm