Hibernate mapping field problem [Improvednamingstrategy]

Hibernate uses JPA for mappings there are 3 rules that can be configured: Defaultnamingstrategy,improvednamingstrategy,ejb3namingstrategy

Here only to say Improvednamingstrategy, other self-looking hibernate code, Improvednamingstrategy code as follows, is a singleton instance:

/** Hibernate, relational persistence for idiomatic java** Copyright (c), 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 genera L public License, as published by the Free software foundation.** This program is distributed in the hope that it'll 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*-details.** you should has received a copy of the GNU Lesser General P Ublic license* along with this distribution; If not, write to:* free software Foundation, inc.* 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, prefers embedded* underscores to mixed case names* @s EE defaultnamingstrategy The default strategy* @author Gavin King*/public class Improvednamingstrategy implements Namings Trategy, Serializable {/** * A convenient singleton instance */public static final Namingstrategy instance = new Improvedn Amingstrategy ();/** * Return the unqualified class name, mixed case converted to * underscores */public String classtotabl Ename (String className) {return addunderscores (stringhelper.unqualify (ClassName));} /** * Return "full" path with underscore seperators, mixed * Case converted to underscores */public String prop Ertytocolumnname (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 (Columnnam e);}    protected static string Addunderscores (string name) {StringBuffer buf = new StringBuffer (Name.replace ('. ', ' _ '));            for (int i=1; I<buf.length ()-1; i++) {if (Character.islowercase (Buf.charat)) &&            Character.isuppercase (Buf.charat (i)) && character.islowercase (Buf.charat (i+1))) {        Buf.insert (i++, ' _ '); }} return Buf.tostring (). toLowerCase ();} public string Collectiontablename (string ownerentity, String ownerentitytable, String associatedentity, String Ociatedentitytable, String PropertyName) {return tableName (ownerentitytable + ' _ ' + propertytocolumnname (prope Rtyname));} /** * Return the argument */public string Joinkeycolumnname (String joinedcolumn, String joinedtable) {return Columnnam E (joinedcolumn);} /** * Return the property name or Propertytablename */public string Foreignkeycolumnname (String propertyname, String Propertyentityname, String propertytablename, String referencedcolumnname) {string Header = PropertyName! = null?    Stringhelper.unqualify (PropertyName): Propertytablename;    if (header = = null) throw new Assertionfailure ("Namingstrategy not properly filled"); Return ColumnName (header); + "_" + referencedcolumnname not used for backward compatibility}/** * Return the column name or the unqualified propert Y name */public string logicalcolumnname (String columnName, String propertyname) {return Stringhelper.isnotempty (Colu Mnname)? ColumnName:StringHelper.unqualify (propertyname);} /** * Returns Either the table name if explicit or * if there is an associated table, the concatenation of owner entity Ta BLE and associated table * Otherwise the concatenation of Owner entity table and the unqualified property name */public St Ring LogicalcollectiontabLename (String tableName, String ownerentitytable, String associatedentitytable, St    Ring PropertyName) {if (tableName! = null) {return tableName; } else {//use of a stringbuffer to workaround a JDK bug return new StringBuffer (ownerentitytable). Append                    ("_"). Append (associatedentitytable! = null?)    AssociatedEntityTable:StringHelper.unqualify (PropertyName)). ToString (); }}/** * Return The column name if explicit or the concatenation of the property name and the referenced column */public St Ring Logicalcollectioncolumnname (String columnName, String propertyname, String referencedcolumn) {return stringhelper            . Isnotempty (ColumnName)? ColumnName:StringHelper.unqualify (PropertyName) + "_" + Referencedcolumn;}}

addunderscores is used for processing when table names and column names in Java rules conform to usernametable (table) and Usernamecolumn (columns) and are parsed into user_name_table and user_name_ column, the specific return is handled by Propertytocolumnname. But, if this rule is configured, Spring +JPA is configured as follows:
-

<prop key= "Hibernate.ejb.naming_strategy" >org.hibernate.cfg.ImprovedNamingStrategy</prop>

will ignore the comment in the @column name, in fact, this name is to map the database field, the result is configured this is not care. I'll go. Look at the hibernate explanation
https://hibernate.atlassian.net/browse/HHH-8616
Think is this is a bug, do not know why this fix bug.

Now there are 7-8 table rules that do not fit this, rewrite the following.

/** 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 mapping Rules * * @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));}}

Change the configuration:

<prop key= "Hibernate.ejb.naming_strategy" >com.sencloud.hibernate.cfg.moshopimprovednamingstrategy</ Prop>

So how do you use this? PropertyName must end with "__" and then unify toLowerCase in the rules. A little bit of that.

@Column (nullable = False, length=100) private String username__;