cayenne-server/src/main/java/org/apache/cayenne/exp/parser/ASTLocate.java

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package org.apache.cayenne.exp.parser;

import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.util.ConversionUtil;

/**
 * @since 4.0
 */
public class ASTLocate extends ASTFunctionCall {

    ASTLocate(int id) {
        super(id, "LOCATE");
    }

    public ASTLocate(Expression substring, Expression path) {
        super(ExpressionParserTreeConstants.JJTLOCATE, "LOCATE", substring, path);
    }

    public ASTLocate(Expression substring, Expression path, Expression offset) {
        super(ExpressionParserTreeConstants.JJTLOCATE, "LOCATE", substring, path, offset);
    }

    @Override
    protected Object evaluateSubNode(Object o, Object[] evaluatedChildren) throws Exception {
        String substr = ConversionUtil.toString(o);
        String str = ConversionUtil.toString(evaluatedChildren[1]);
        int offset = 0;
        if(evaluatedChildren.length > 2) {
            offset = ConversionUtil.toInt(evaluatedChildren[2], 0);
        }
        // +1 to comply with SQL
        return str.indexOf(substr, offset) + 1;
    }

    @Override
    protected int getRequiredChildrenCount() {
        return 2;
    }

    @Override
    public Expression shallowCopy() {
        return new ASTLocate(id);
    }
}