org.jiemamy.utils.sql.ResultSetUtil.java Source code

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Here is the source code for org.jiemamy.utils.sql.ResultSetUtil.java

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/*
 * Copyright 2007-2012 Jiemamy Project and the Others.
 * Created on 2009/04/14
 *
 * This file is part of Jiemamy.
 *
 * 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 org.jiemamy.utils.sql;

import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.apache.commons.lang.Validate;

import org.jiemamy.JiemamyError;

/**
 * {@link ResultSet}?
 * 
 * @version $Id$
 * @author daisuke
 */
public final class ResultSetUtil {

    /**
     * {@link ResultSet#getAsciiStream(String)}????????
     * ??????? {@link SQLException}??????{@code defaultValue}?
     * 
     * <p>{@link #getValue(Class, ResultSet, int, Object)}??{@link ResultSet#getBinaryStream(int)}?
     * ???????????</p>
     * 
     * @param rs {@link ResultSet}
     * @param columnIndex 
     * @param defaultValue {@link SQLException}??????getter????????
     * @return ???????
     * @throws IllegalArgumentException {@code rs}?{@code null}???
     */
    public static InputStream getAsciiStream(ResultSet rs, int columnIndex, InputStream defaultValue) {
        Validate.notNull(rs);
        try {
            return rs.getAsciiStream(columnIndex);
        } catch (SQLException e) {
            // ignore
        }
        return defaultValue;
    }

    /**
     * {@link ResultSet#getAsciiStream(String)}??????????
     * ??????? {@link SQLException}??????{@code defaultValue}?
     * 
     * <p>{@link #getValue(Class, ResultSet, String, Object)}??{@link ResultSet#getBinaryStream(String)}?
     * ???????????</p>
     * 
     * @param rs {@link ResultSet}
     * @param columnName ??
     * @param defaultValue {@link SQLException}??????getter????????
     * @return ???????
     * @throws IllegalArgumentException {@code rs}?{@code null}???
     */
    public static InputStream getAsciiStream(ResultSet rs, String columnName, InputStream defaultValue) {
        Validate.notNull(rs);
        try {
            return rs.getAsciiStream(columnName);
        } catch (SQLException e) {
            // ignore
        }
        return defaultValue;
    }

    /**
     * {@link ResultSet#getBinaryStream(String)}????????
     * ??????? {@link SQLException}??????{@code defaultValue}?
     * 
     * <p>{@link #getValue(Class, ResultSet, int, Object)}??{@link ResultSet#getAsciiStream(int)}?
     * ???????????</p>
     * 
     * @param rs {@link ResultSet}
     * @param columnIndex 
     * @param defaultValue {@link SQLException}??????getter????????
     * @return ???????
     * @throws IllegalArgumentException {@code rs}?{@code null}???
     */
    public static InputStream getBinaryStream(ResultSet rs, int columnIndex, InputStream defaultValue) {
        Validate.notNull(rs);
        try {
            return rs.getBinaryStream(columnIndex);
        } catch (SQLException e) {
            // ignore
        }
        return defaultValue;
    }

    /**
     * {@link ResultSet#getBinaryStream(String)}??????????
     * ??????? {@link SQLException}??????{@code defaultValue}?
     * 
     * <p>{@link #getValue(Class, ResultSet, String, Object)}??{@link ResultSet#getAsciiStream(String)}?
     * ???????????</p>
     * 
     * @param rs {@link ResultSet}
     * @param columnName ??
     * @param defaultValue {@link SQLException}??????getter????????
     * @return ???????
     * @throws IllegalArgumentException {@code rs}?{@code null}???
     */
    public static InputStream getBinaryStream(ResultSet rs, String columnName, InputStream defaultValue) {
        Validate.notNull(rs);
        try {
            return rs.getBinaryStream(columnName);
        } catch (SQLException e) {
            // ignore
        }
        return defaultValue;
    }

    /**
     * {@link ResultSet}??????????
     * ??????? {@link SQLException}????????
     * ?getter?????????{@code defaultValue}?
     * 
     * @param <T> ???
     * @param returnType ???
     * @param rs ??? {@link ResultSet}
     * @param columnIndex 
     * @param defaultValue {@link SQLException}??????getter????????
     * @return ???????
     * @throws IllegalArgumentException {@code clazz}, {@code rs}, {@code columnName}?{@code null}???
     */
    public static <T> T getValue(Class<T> returnType, ResultSet rs, int columnIndex, T defaultValue) {
        Validate.notNull(returnType);
        Validate.notNull(rs);
        return getValueInternal(returnType, rs, int.class, new Object[] { columnIndex }, defaultValue);
    }

    /**
     * {@link ResultSet}????????????
     * ??????? {@link SQLException}????????
     * ?getter?????????{@code defaultValue}?
     * 
     * @param <T> ???
     * @param returnType ???
     * @param rs ??? {@link ResultSet}
     * @param columnName ??
     * @param defaultValue {@link SQLException}??????getter????????
     * @return ???????
     * @throws IllegalArgumentException {@code clazz}, {@code rs}, {@code columnName}?{@code null}???
     */
    public static <T> T getValue(Class<T> returnType, ResultSet rs, String columnName, T defaultValue) {
        Validate.notNull(returnType);
        Validate.notNull(rs);
        Validate.notNull(columnName);
        return getValueInternal(returnType, rs, String.class, new Object[] { columnName }, defaultValue);
    }

    private static Method findMethod(Class<?> returnType, Class<?> parameterType) {
        for (Method method : ResultSet.class.getMethods()) {
            Class<?>[] parameterTypes = method.getParameterTypes();
            if (parameterTypes.length == 1 && parameterTypes[0].equals(parameterType)
                    && returnType.equals(method.getReturnType()) && method.getName().startsWith("get")) {
                return method;
            }
        }
        return null;
    }

    private static <T> T getValueInternal(Class<T> returnType, ResultSet rs, Class<?> parameterType,
            Object[] parameter, T defaultValue) {
        Method method = findMethod(returnType, parameterType);
        if (method == null) {
            return defaultValue;
        }
        try {
            // bug in JDK http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6456930
            //         return clazz.cast(method.invoke(rs, parameter));
            @SuppressWarnings("unchecked")
            T result = (T) method.invoke(rs, parameter);
            return result;
        } catch (IllegalArgumentException e) {
            throw new JiemamyError("The signature of the method must be verified.", e);
        } catch (IllegalAccessException e) {
            throw new JiemamyError("The method returned by getMethods() must be public.", e);
        } catch (InvocationTargetException e) {
            Throwable cause = e.getCause();
            if (cause instanceof RuntimeException) {
                throw (RuntimeException) cause;
            }
            if (e.getCause() instanceof SQLException == false) {
                throw new JiemamyError("Checked exception which the invocation target thrown is not SQLException.",
                        e.getCause());
            }

            // ignore
        }
        return defaultValue;
    }

    private ResultSetUtil() {
    }

}