Hibernate 映射字段问题[ImprovedNamingStrategy]

Hibernate 使用JPA 对于映射有3种规则可以配置：DefaultNamingStrategy，ImprovedNamingStrategy，EJB3NamingStrategy

这里只说ImprovedNamingStrategy，其他自行看Hibernate代码，ImprovedNamingStrategy的代码如下，是一个singleton instance：

/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors.  All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA  02110-1301  USA
*/
package org.hibernate.cfg;

import java.io.Serializable;

import org.hibernate.util.StringHelper;
import org.hibernate.AssertionFailure;

/**
* An improved naming strategy that prefers embedded
* underscores to mixed case names
* @see DefaultNamingStrategy the default strategy
* @author Gavin King
*/
public class ImprovedNamingStrategy implements NamingStrategy, Serializable {

/**
 * A convenient singleton instance
 */
public static final NamingStrategy INSTANCE = new ImprovedNamingStrategy();

/**
 * Return the unqualified class name, mixed case converted to
 * underscores
 */
public String classToTableName(String className) {
    return addUnderscores( StringHelper.unqualify(className) );
}
/**
 * Return the full property path with underscore seperators, mixed
 * case converted to underscores
 */
public String propertyToColumnName(String propertyName) {
    return addUnderscores( StringHelper.unqualify(propertyName) );
}
/**
 * Convert mixed case to underscores
 */
public String tableName(String tableName) {
    return addUnderscores(tableName);
}
/**
 * Convert mixed case to underscores
 */
public String columnName(String columnName) {
    return addUnderscores(columnName);
}

protected static String addUnderscores(String name) {
    StringBuffer buf = new StringBuffer( name.replace('.', '_') );
    for (int i=1; i

addUnderscores 用于处理 当表名和列名在Java的种规则符合 UserNameTable（表）和 userNameColumn（列），就会被解析为user_name_table 和 user_name_column ,具体return的处理的是propertyToColumnName。 but呢，如果一旦配置了这个规则，spring ＋jpa配置如下：
-

org.hibernate.cfg.ImprovedNamingStrategy

就会忽略了注释中的@Column中的name，其实这个name地方就是为了映射数据库字段，结果配置了这个就不care了。我去。看下hibernate解释
https://hibernate.atlassian.net/browse/HHH-8616
觉得是这是一个bug，不知道为啥就这样fix bug 了。

现在有7-8张表的规则没有符合这个怎么办呢， 重写了如下。

/*
* Copyright 2012-2014 sencloud.com.cn. All rights reserved.
* Support: http://www.sencloud.com.cn
* License: http://www.sencloud.com.cn/license
*/
package com.sencloud.hibernate.cfg;

import java.io.Serializable;

import org.hibernate.cfg.ImprovedNamingStrategy;
import org.hibernate.cfg.NamingStrategy;
import org.hibernate.util.StringHelper;

/**
* ImprovedNamingStrategy－ hibernate映射规则
* 
* @author xutianlong
* @version 3.0
*/
public class MoShopImprovedNamingStrategy extends ImprovedNamingStrategy
    implements NamingStrategy, Serializable {
/**
 * 
 */
private static final long serialVersionUID = 3088474161734101900L;

public String propertyToColumnName(String propertyName) {
    if (propertyName.endsWith("__")) {
        return propertyName.replace("__", "").toLowerCase();
    }
    return addUnderscores(StringHelper.unqualify(propertyName));
}
}

改下配置：

com.sencloud.hibernate.cfg.MoShopImprovedNamingStrategy

那么怎么使用这个呢？ propertyName必须以 "__"结尾了，然后在规则中统一toLowerCase。 有点那个啥了。

@Column(nullable = false, length=100)
private String userName__;