Java Reference
In-Depth Information
catch (IOException e)
{
System.out.println(
"Error reading from keyboard.");
}
}
}
28. ObjectOutputStream outputThisWay =
new ObjectOutputStream(
new FileOutputStream("bindata.dat"));
29. outputThisWay.writeDouble(v1);
outputThisWay.writeDouble(v2);
30. outputThisWay.writeUTF("Hello");
31. outputThisWay.close();
32. ObjectInputStream inputThing =
new ObjectInputStream(
new FileInputStream("someStuff"));
33. number = inputThing.readDouble();
34. inputThing.close();
35. If a number is written to a file with writeInt , it should be read only with readInt .
If you use readLong or readDouble to read the number, something will go wrong.
36. You should not use readUTF to read a string from a text file. You should use
readUTF only to read a string from a binary file. Moreover, the string should have
been written to that file using writeUTF .
37. When opening a binary file for either output or input in the ways discussed in this
chapter, a FileNotFoundException might be thrown and other IOException s
may be thrown.
38. An EOFException is thrown when your program tries to read the (nonexisting)
fourth number.
39. It is not an infinite loop because when the end of the file is reached, an exception
will be thrown, and that will end the entire try block.
40. You add the two words implements Serializable to the beginning of the class
definition. You also must do this for the classes for the instance variables and so on
for all levels of class instance variables within classes.
41. import java.io.Serializable; or import java.io.*;
42. The return type is Object , which means the returned value usually needs to be
type cast.
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