openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/exps/Lit.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.    
 */
package org.apache.openjpa.jdbc.kernel.exps;

import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.kernel.Filters;
import org.apache.openjpa.kernel.exps.Literal;

/**
 * A literal value in a filter.
 *
 * @author Abe White
 */
class Lit
    extends Const
    implements Literal {

    private Object _val;
    private int _ptype;

    /**
     * Constructor. Supply literal value.
     */
    public Lit(Object val, int ptype) {
        _val = val;
        _ptype = ptype;
    }

    public Class getType() {
        return (_val == null) ? Object.class : _val.getClass();
    }

    public void setImplicitType(Class type) {
        _val = Filters.convert(_val, type);
    }

    public int getParseType() {
        return _ptype;
    }

    public Object getValue() { 
        return _val;
    }

    public void setValue(Object val) {
        _val = val;
    }

    public Object getValue(Object[] params) {
        return getValue();
    }

    public ExpState initialize(Select sel, ExpContext ctx, int flags) {
        return new LitExpState();
    }

    /**
     * Expression state.
     */
    private static class LitExpState
        extends ConstExpState {

        public Object sqlValue;
        public int otherLength; 
    } 

    public void calculateValue(Select sel, ExpContext ctx, ExpState state, 
        Val other, ExpState otherState) {
        super.calculateValue(sel, ctx, state, other, otherState);
        LitExpState lstate = (LitExpState) state;
        if (other != null) {
            lstate.sqlValue = other.toDataStoreValue(sel, ctx, otherState,_val);
            lstate.otherLength = other.length(sel, ctx, otherState);
        } else
            lstate.sqlValue = _val;
    }

    public void appendTo(Select sel, ExpContext ctx, ExpState state, 
        SQLBuffer sql, int index) {
        LitExpState lstate = (LitExpState) state;
        if (lstate.otherLength > 1)
            sql.appendValue(((Object[]) lstate.sqlValue)[index], 
                lstate.getColumn(index));
        else
            sql.appendValue(lstate.sqlValue, lstate.getColumn(index));
    }
}