Input/output operations

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The Rogue Wave® JViews library provides the following two classes for saving graphic objects to, and loading graphic objects from, a stream:

IlvOutputStream, used by the class IlvManager to save all the graphic objects that it contains
IlvInputStream, allowing a file generated by IlvOutputStream to be read into an IlvManager

Graphic objects can always be written to an IlvOutputStream because they inherit the write method of the IlvGraphic class:

public void write(IlvOutputStream stream) throws IOException

To save the information contained in your class, you can override this method and use the methods of the class IlvOutputStream . When overriding this method, you must not forget to call the write method of the superclass to save the information related to the superclass. You will obtain something that resembles the following example.

public void write(IlvOutputStream stream) throws IOException 
{
  // write fields of super class
  super.write(stream);
  // write fields of my class
  stream.write("color", getColor());
  stream.write("thickness", getThickness());
  ....
}

To read your graphic object from an IlvInputStream , you must create a constructor with an IlvInputStream . This constructor is mandatory even if you have not overridden the write method. The corresponding constructor in the class IlvGraphic is:

public IlvGraphic(IlvInputStream stream) throws IlvReadFileException

Assuming that MyClass is the name of your class, your new constructor will look like this:

public MyClass(IlvInputStream stream) throws IlvReadFileException

In the body of this constructor, you first call the corresponding constructor in the superclass, then you read the information you have saved in the write method. In the above example, the corresponding constructor is:

public MyClass(IlvInputStream stream) throws IlvReadFileException 
{
  super(stream); 
  setColor(stream.readColor("color")); 
  setThickness(stream.readInt("thickness")); 
  ...
}

Important

The recommended way to serialize any IlvManager object is through IVL serialization and not Java™ serialization. Serialization cannot work for managers that contain graphic objects such as IlvIcon or some other classes, since these classes internally manage Java SE objects that are not serializable.

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Graphic objects