com.asakusafw.runtime.core.util

Class Shared<T>

java.lang.Object

com.asakusafw.runtime.core.util.Shared<T>

Type Parameters:

T - the value type

public abstract class Shared<T>
extends Object

An abstract super class of shared object holder for operator classes. Clients can inherit this class and implement initialValue() to prepare shared value.

Example:

// operator class
public abstract class SomeOperator {
    // shared value container
    static final Shared<Hoge> SHARED = new Shared<Hoge>() {
        @Override protected Hoge initialValue() throws IOException {
            // initializes shared value
            Hoge result = ...;
            return result;
        }
    }
    // operator
    @Update
    public void some(Foo foo) {
        // obtains shared value
        Hoge hoge = SHARED.get();
        ...
    }
}

Since:

0.7.3

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Shared.InitializationException Represents an exception occurred while initializing shared values.

Constructor Summary

Constructors

Constructor and Description
Shared()

Method Summary

Modifier and Type	Method and Description
T	get() Returns the shared value.
protected abstract T	initialValue() Returns the initial shared value.
boolean	isInitialzed() Returns whether this container is initialized or not.
void	remove() Discards the current shared value.
void	set(T value) Manually sets a shared value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Shared

public Shared()

Method Detail

get

public final T get()

Returns the shared value. If this container is not initialized yet, this will prepare an initial value and returns it.

Returns:

the shared value

Throws:

Shared.InitializationException - if failed to initialize the shared value

remove

public final void remove()

Discards the current shared value. After this is invoked, isInitialzed() will return false until this container is re-initialized. If this does not hold a shared value, this does nothing.

set

public final void set(T value)

Manually sets a shared value. The get() method will return the value until remove() is invoked. This forcibly replaces the shared value even if this container is already initialized.

Parameters:

value - the shared value

See Also:

isInitialzed()

isInitialzed

public final boolean isInitialzed()

Returns whether this container is initialized or not.

Returns:

true if this is initialized, or false otherwise

initialValue

protected abstract T initialValue()
                           throws IOException

Returns the initial shared value.

Returns:

the shared value

Throws:

IOException - if initialization was failed