java.io包中的()和()类主要用于对对象(Object)的读写。
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?()
在J2EE中,如果去编译并运行下面的代码,在这里假定在当前目录下没有Hello.txt文件: import java.io.*; public class Mine { public static void main(String argv[]){ Mine m=new Mine(); System.out.println(m.amethod()); } public int amethod() { try { FileInputStream dis=new FileInputStream("Hello.txt"); } catch (FileNotFoundException fne) { System.out.println("No such file found"); return -1; } catch(IOException ioe) { } finally { System.out.println("Doing finally"); } return 0; } } 结果会输出()。
1. import java.io.*; 2. public class Foo implements Serializable { 3. public int x, y; 4. public Foo( int x, int y) { this.x = x; this.y = y; } 5. 6. private void writeObject( ObjectOutputStream s) 7. throws IOException { 8. s.writeInt(x); s.writeInt(y) 9. } 10. 11. private void readObject( ObjectInputStream s) 12. throws IOException, ClassNotFoundException { 13. 14. // insert code here 15. 16. } 17. } Which code, inserted at line 14, will allow this class to correctly serialize and deserialize?()
在JSP中如果要导入java.io.*包,应该使用()指令。
在J2EE中,如果去编译并运行下面的代码,在这里假定在当前目录下没有Hello.txt文件: import java.io.*; public class Mine { public static void main(String argv[]){ Mine m=new Mine(); System.out.println(m.amethod()); } public int amethod() { try { FileInputStream dis=new FileInputStream("Hello.txt"); } catch (FileNotFoundException fne) { System.out.println("No such file found"); return -1; } catch(IOException ioe) { } finally { System.out.println("Doing finally"); } return 0; } } 结果会输出()。