encapsulation

[jaiser roney]

Hi all,

while going through basics of java i come around the below points for encapsulation. Can any one explain the points with example

1)An encapsulated, public class promotes re-use.

2)An encapsulated class allows a programmer to implementation without affecting outside code.

Thanks in advance.

[jaiser roney]

second point is missing a word

appology for the inconvenience

it as
2)An encapsulated class allows a programmer to change an
implementation without affecting outside code.

[Campbell Ritchie]

public class Kettle
{
    private int contents;
    private int temperature;
 . . .
    public void boil()
    {
        temperature = 100; // Celsius
    }

    public void empty()
    {
        contents = 0;
    }

public class Kettle
{
    private Water w;
 . . .
    public void boil()
    {
        w.setTemperature(100); // Celsius
    }

    public void empty()
    {
        s.setVolume(0);
    }

Because the two Kettle classes are encapsulated users of the class cannot tell whether the temperature is maintained by the Kettle or a Water object. And they don't care. They know that calling boil() on a Kettle instance will set its temperature to 100°C and calling empty() will set the amount of water to 0. That's all they need to know.

[jaiser roney]

Thank you Campbell,

I have one more query regarding Threads

How can we make a method thread-safe (but in terminology we are talking about classes as thread safe) by declaring it as static, i know about synchronized concept but is it possible to make thread safe with only static key word.

[Campbell Ritchie]

Please start a new topic for your new question.