org.hibernate.dialect.function.StandardSQLFunction.java Source code

Introduction

Here is the source code for org.hibernate.dialect.function.StandardSQLFunction.java

Source

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.dialect.function;

import java.util.List;

import org.hibernate.engine.spi.Mapping;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.type.Type;

/**
 * Provides a standard implementation that supports the majority of the HQL
 * functions that are translated to SQL. The Dialect and its sub-classes use
 * this class to provide details required for processing of the associated
 * function.
 *
 * @author David Channon
 */
public class StandardSQLFunction implements SQLFunction {
    private final String name;
    private final Type registeredType;

    /**
     * Construct a standard SQL function definition with a variable return type;
     * the actual return type will depend on the types to which the function
     * is applied.
     * <p/>
     * Using this form, the return type is considered non-static and assumed
     * to be the type of the first argument.
     *
     * @param name The name of the function.
     */
    public StandardSQLFunction(String name) {
        this(name, null);
    }

    /**
     * Construct a standard SQL function definition with a static return type.
     *
     * @param name The name of the function.
     * @param registeredType The static return type.
     */
    public StandardSQLFunction(String name, Type registeredType) {
        this.name = name;
        this.registeredType = registeredType;
    }

    /**
     * Function name accessor
     *
     * @return The function name.
     */
    public String getName() {
        return name;
    }

    /**
     * Function static return type accessor.
     *
     * @return The static function return type; or null if return type is
     * not static.
     */
    public Type getType() {
        return registeredType;
    }

    @Override
    public boolean hasArguments() {
        return true;
    }

    @Override
    public boolean hasParenthesesIfNoArguments() {
        return true;
    }

    @Override
    public Type getReturnType(Type firstArgumentType, Mapping mapping) {
        return registeredType == null ? firstArgumentType : registeredType;
    }

    @Override
    public String render(Type firstArgumentType, List arguments, SessionFactoryImplementor sessionFactory) {
        final StringBuilder buf = new StringBuilder();
        buf.append(getRenderedName(arguments)).append('(');
        for (int i = 0; i < arguments.size(); i++) {
            buf.append(arguments.get(i));
            if (i < arguments.size() - 1) {
                buf.append(", ");
            }
        }
        return buf.append(')').toString();
    }

    protected String getRenderedName(List arguments) {
        return getName();
    }

    @Override
    public String toString() {
        return name;
    }

}