EjbqlLimitVisitor.java

package org.objectweb.jonas_ejb.lib;

import java.util.Stack;

import org.objectweb.jonas_ejb.deployment.ejbql.ASTEJBQL;
import org.objectweb.jonas_ejb.deployment.ejbql.ASTInputParameter;
import org.objectweb.jonas_ejb.deployment.ejbql.ASTIntegerLiteral;
import org.objectweb.jonas_ejb.deployment.ejbql.ASTLimitClause;
import org.objectweb.jonas_ejb.deployment.ejbql.ASTLimitExpression;
import org.objectweb.jonas_ejb.deployment.ejbql.ParseException;
import org.objectweb.jonas_ejb.deployment.ejbql.SimpleNode;

public class EjbqlLimitVisitor extends EjbqlAbstractVisitor {

    private Class[] paramTypes;

    private EjbqlLimiterRange[] ranges = new EjbqlLimiterRange[0];

    public EjbqlLimitVisitor(ASTEJBQL ejbql, Class[] paramTypes) throws Exception {
        this.paramTypes = paramTypes;
        visit(ejbql);
    }

    public EjbqlLimiterRange[] getLimiterRanges() {
        return ranges;
    }

    public Object visit(ASTLimitClause node, Object data) {
        visit((SimpleNode) node, data);
        Stack s = (Stack) data;
        ranges = new EjbqlLimiterRange[s.size()];
        if (s.size() > 1) {
            // s = [row, nbr]
            ranges[1] = (EjbqlLimiterRange) s.pop();
        }
        // s = [row]
        ranges[0] = (EjbqlLimiterRange) s.pop();
        return null;
    }

    public Object visit(ASTLimitExpression node, Object data) {
        visit((SimpleNode) node, data);
        return null;
    }

    public Object visit(ASTIntegerLiteral node, Object data) {
        ((Stack) data).push(new EjbqlLimiterRange(EjbqlLimiterRange.KIND_LITERAL, ((Long) node.value).intValue()));
        return null;
    }

    public Object visit(ASTInputParameter node, Object data) {
        try {
            int pIndex = ((Integer) node.value).intValue() - 1;
            if (pIndex >= paramTypes.length) {
                throw new ParseException("Parameter ?" + (pIndex + 1) + " is out of range (max=" + paramTypes.length
                        + ")");
            }
            // TODO : check if the associated parameter type is compatible to
            // integer
            ((Stack) data).push(new EjbqlLimiterRange(EjbqlLimiterRange.KIND_PARAMETER, pIndex));
            return null;
        } catch (ParseException e) {
            throw new VisitorException(e);
        }
    }

}

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