/* * Copyright (c) 2002-2003 by OpenSymphony * All rights reserved. */package com.opensymphony.workflow.query;/** * Nested expressions are used when constructing a workflow query. * A nested expression consists of: * <li>one or more expressions: Each of them can again be a NestedExpression. * <li>operator: The operator used to evaluate the value of the nested expression *     from the specified sub expressions. * * @author Christine Zimmermann */public class NestedExpression extends Expression {    //~ Static fields/initializers /////////////////////////////////////////////    /**    * Constant to specify that all the expressions specified must evaluate to true for    * an item to be included in the search results.    */    public final static int AND = 6;    /**     * Constant to specify that at least one of the expressions specified must evaluate to true     * for an item to be included in the search results.     */    public final static int OR = 7;    //~ Instance fields ////////////////////////////////////////////////////////    private Expression[] expressions = null;    private int expressionOperator = AND;    //~ Constructors ///////////////////////////////////////////////////////////    public NestedExpression() {    }    /**    * Create a NestedExpression that consists of multiple expressions.    * @param expressions an array of expressions for this query.    * @param operator {@link NestedExpression#AND} or {@link NestedExpression#OR}.    */    public NestedExpression(Expression[] expressions, int operator) {        this.expressions = expressions;        this.expressionOperator = operator;    }    //~ Methods ////////////////////////////////////////////////////////////////    public Expression getExpression(int index) {        return expressions[index];    }    /**     * Get the number of expressions in this query.     */    public int getExpressionCount() {        return expressions.length;    }    public void setExpressionOperator(int expressionOperator) {        this.expressionOperator = expressionOperator;    }    /**     * @return {@link NestedExpression#AND} if all the expressions must match,     * or {@link NestedExpression#OR} if only one must match.     */    public int getExpressionOperator() {        return this.expressionOperator;    }    public void setExpressions(Expression[] expressions) {        this.expressions = expressions;    }    public boolean isNested() {        return true;    }}