java类java.beans.Expression的实例源码

public static void main(String[] args) throws Exception {
    Object value = new Object();

    Expression expression = new Expression(value, Object.class, "new", null);
    if (!value.equals(expression.getValue()))
        throw new Error("the value is updated unexpectedly");

    expression.execute();
    if (value.equals(expression.getValue()))
        throw new Error("the value is not updated as expected");
}

@Override
public void writeExpression(Expression expression) {
    if (this.expression == null) {
        this.expression = expression;
    }
    super.writeExpression(expression);
}

protected void initialize(XMLEncoder encoder) {
    encoder.setPersistenceDelegate(Container.class, new PersistenceDelegate() {
        protected Expression instantiate(Object oldInstance, Encoder out) {
            Container container = (Container) oldInstance;
            Component component = container.getComponent();
            return new Expression(container, component, "create", new Object[] {component});
        }
    });
}

protected void initialize(XMLEncoder encoder) {
    encoder.setPersistenceDelegate(
            OuterClass.InnerClass.class,
            new DefaultPersistenceDelegate() {
                protected Expression instantiate(Object oldInstance, Encoder out) {
                    OuterClass.InnerClass inner = (OuterClass.InnerClass) oldInstance;
                    OuterClass outer = inner.getOuter();
                    return new Expression(inner, outer, "getInner", new Object[0]);
                }
            }
    );
}

protected void initialize(XMLEncoder encoder) {
    encoder.setPersistenceDelegate(C.class, new DefaultPersistenceDelegate() {
        protected Expression instantiate(Object oldInstance, Encoder out) {
            C c = (C) oldInstance;
            return new Expression(c, c.getX(), "createC", new Object[] {});
        }
    });
}

@SuppressWarnings("unchecked")
public static <E,R> R getMethodValue(E obj, Method method, Object... args) {
    R value = null;

    try {
        method.setAccessible(true);

        value = (R) method.invoke(obj, args);
    } catch (InvocationTargetException | IllegalAccessException | IllegalArgumentException e) {
        // e.printStackTrace();
        try {
            if (obj != null) {
                Expression expr = new Expression(obj, method.getName(), args);
                expr.execute();
                value = (R) expr.getValue();
            }

            if (value == null) {
                value = (R) method.getDefaultValue();
            }

        } catch (Exception e1) {
            // e1.printStackTrace();
        }
    }

    return value;
}

/**
 * Creates the value of this element.
 *
 * @param type  the base class
 * @param args  the array of arguments
 * @return the value of this element
 * @throws Exception if calculation is failed
 */
@Override
protected final ValueObject getValueObject(Class<?> type, Object[] args) throws Exception {
    if (this.field != null) {
        return ValueObjectImpl.create(FieldElementHandler.getFieldValue(getContextBean(), this.field));
    }
    if (this.idref != null) {
        return ValueObjectImpl.create(getVariable(this.idref));
    }
    Object bean = getContextBean();
    String name;
    if (this.index != null) {
        name = (args.length == 2)
                ? PropertyElementHandler.SETTER
                : PropertyElementHandler.GETTER;
    } else if (this.property != null) {
        name = (args.length == 1)
                ? PropertyElementHandler.SETTER
                : PropertyElementHandler.GETTER;

        if (0 < this.property.length()) {
            name += this.property.substring(0, 1).toUpperCase(ENGLISH) + this.property.substring(1);
        }
    } else {
        name = (this.method != null) && (0 < this.method.length())
                ? this.method
                : "new"; // NON-NLS: the constructor marker
    }
    Expression expression = new Expression(bean, name, args);
    return ValueObjectImpl.create(expression.getValue());
}

public static void main(String[] args) throws Exception {
    Object value = new Object();

    Expression expression = new Expression(value, Object.class, "new", null);
    if (!value.equals(expression.getValue()))
        throw new Error("the value is updated unexpectedly");

    expression.execute();
    if (value.equals(expression.getValue()))
        throw new Error("the value is not updated as expected");
}

@Override
public void writeExpression(Expression expression) {
    if (this.expression == null) {
        this.expression = expression;
    }
    super.writeExpression(expression);
}

protected void initialize(XMLEncoder encoder) {
    encoder.setPersistenceDelegate(Container.class, new PersistenceDelegate() {
        protected Expression instantiate(Object oldInstance, Encoder out) {
            Container container = (Container) oldInstance;
            Component component = container.getComponent();
            return new Expression(container, component, "create", new Object[] {component});
        }
    });
}