com.opengamma.engine.value.ComputedValue.java Source code

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Here is the source code for com.opengamma.engine.value.ComputedValue.java

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/**
 * Copyright (C) 2009 - present by OpenGamma Inc. and the OpenGamma group of companies
 *
 * Please see distribution for license.
 */
package com.opengamma.engine.value;

import java.io.Serializable;

import org.apache.commons.lang.ObjectUtils;
import org.apache.commons.lang.builder.ToStringStyle;

import com.opengamma.engine.ComputationTargetSpecification;
import com.opengamma.util.ArgumentChecker;
import com.opengamma.util.PublicAPI;

/**
 * A value computed by the engine.
 * <p>
 * A computed value consists of the value itself and the specification that defines it.
 * <p>
 * This class is immutable and thread-safe if the value is immutable.
 */
@PublicAPI
public class ComputedValue implements Serializable {

    //NOTE kirk 2009-12-30 -- This is VERY intentionally NOT generified. Having actually
    //worked with the old version of ComputedValue with generics in the engine, the number
    //of warning suppressions necessary just to get it working wasn't matched by any
    //type of benefit in the additional type information at compile time.

    //REVIEW kirk 2009-12-30 -- I've intentionally not made this an interface as we
    //never actually made use of that functionality. We'll split it if and when we have
    //a compelling reason to do so.

    private static final long serialVersionUID = 1L;

    /**
     * The specification of the value.
     */
    private final ValueSpecification _specification;
    /**
     * The value itself.
     */
    private final Object _value;

    /**
     * Creates a computed value.
     * <p>
     * This combines the value and its specification.
     * 
     * @param specification the specification of the value, not null
     * @param value the actual value
     */
    public ComputedValue(final ValueSpecification specification, final Object value) {
        ArgumentChecker.notNull(specification, "value specification");
        if (value instanceof ComputedValue) {
            throw new IllegalArgumentException("Value must not be a ComputedValue instance");
        }
        _specification = specification;
        _value = value;
    }

    //-------------------------------------------------------------------------
    /**
     * Gets the value specification.
     * 
     * @return the specification, not null
     */
    public ValueSpecification getSpecification() {
        return _specification;
    }

    /**
     * Gets the value.
     * 
     * @return the value, not null
     */
    public Object getValue() {
        return _value;
    }

    //-------------------------------------------------------------------------
    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof ComputedValue)) {
            return false;
        }
        final ComputedValue other = (ComputedValue) obj;
        return ObjectUtils.equals(_specification, other._specification) && ObjectUtils.equals(_value, other._value);
    }

    @Override
    public int hashCode() {
        int result = _specification.hashCode();
        result = 31 * result + (_value != null ? _value.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        final StringBuffer sb = new StringBuffer();
        final ToStringStyle style = ToStringStyle.SHORT_PREFIX_STYLE;
        style.appendStart(sb, this);
        appendFieldsToString(sb, style);
        style.appendEnd(sb, this);
        return sb.toString();
    }

    protected void appendFieldsToString(final StringBuffer sb, final ToStringStyle style) {
        // carefully select useful fields for toString
        final ValueSpecification spec = getSpecification();
        if (spec != null) {
            style.append(sb, "name", spec.getValueName(), null);
            final ComputationTargetSpecification targetSpec = spec.getTargetSpecification();
            style.append(sb, "targetId", targetSpec.getUniqueId(), null);
            style.append(sb, "targetType", targetSpec.getType(), null);
            style.append(sb, "properties", spec.getProperties(), null);
        }
        style.append(sb, "value", getValue(), null);
    }

}