net.ontopia.persistence.query.jdo.JDONativeValue.java Source code

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Here is the source code for net.ontopia.persistence.query.jdo.JDONativeValue.java

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/*
 * #!
 * Ontopia Engine
 * #-
 * Copyright (C) 2001 - 2013 The Ontopia Project
 * #-
 * Licensed 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 net.ontopia.persistence.query.jdo;

import java.util.Arrays;
import org.apache.commons.lang3.StringUtils;

/**
 * INTERNAL: JDOQL value: native value expression. Represents the
 * traversal from a variable to the value returned byte the native
 * expression. Syntax: 'A.{args}'. This might be useful when you know
 * that the root variable refers to a database table and that there
 * are a specific column that you want to get at.
 */

public class JDONativeValue implements JDOValueIF {

    // NOTE: Class currently only supports columns references with
    // JDOVariableIF as root. May want to make it more general than
    // that.

    protected JDOVariable root;
    protected String[] args;
    protected Class value_type;

    public JDONativeValue(JDOVariable root, String arg, Class value_type) {
        this(root, new String[] { arg }, value_type);
    }

    public JDONativeValue(JDOVariable root, String[] args, Class value_type) {
        if (root == null)
            throw new NullPointerException("Value root cannot be null.");
        if (args == null || args.length < 1)
            throw new NullPointerException("Field args cannot be null.");
        if (value_type == null)
            throw new NullPointerException("Value value_type cannot be null.");
        this.root = root;
        this.args = args;
        this.value_type = value_type;
    }

    @Override
    public int getType() {
        return NATIVE_VALUE;
    }

    public JDOVariable getRoot() {
        return root;
    }

    public String[] getArguments() {
        return args;
    }

    public Class getValueType() {
        return value_type;
    }

    @Override
    public int hashCode() {
        int hashCode = root.hashCode();
        for (int ix = 0; ix < args.length; ix++) {
            if (args[ix] != null)
                hashCode = (hashCode + args[ix].hashCode()) & 0x7FFFFFFF;
        }
        return hashCode;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj instanceof JDONativeValue) {
            JDONativeValue other = (JDONativeValue) obj;
            if (root.equals(other.root))
                if (Arrays.equals(args, other.args))
                    return true;
        }
        return false;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder(root.toString());
        sb.append(".{");
        sb.append(StringUtils.join(args, ", "));
        sb.append('}');
        return sb.toString();
    }

    @Override
    public void visit(JDOVisitorIF visitor) {
        visitor.visitable(root);
    }

}