日期:2014-05-16 浏览次数:21118 次
最近使用mysql做一个交易网站,使用hibernate作为持久化框架。
当我使用hibernate的Order进行排序的时候,杯具发生了。中文给我乱排了。
mysql中如果需要正常按照中文排序,其中一种处理方法是
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SELECT * FROM BZ_COMPANY ORDER BY CONVERT( COMPANY_NAME USING GBK ) ASC
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可问题是这样就脱离hibernate了。本打算使用QBC做一些公共的方法的。
然后就去看了下hibernate中Order的实现。
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hibernate的Order:
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//$Id: Order.java,v 1.1 2011/05/29 18:11:15 Surui Exp $
package org.hibernate.criterion;
import java.io.Serializable;
import java.sql.Types;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.type.Type;
/**
* Represents an order imposed upon a <tt>Criteria</tt> result set
* @author Gavin King
*/
public class Order implements Serializable {
private boolean ascending;
private boolean ignoreCase;
private String propertyName;
public String toString() {
return propertyName + ' ' + (ascending?"asc":"desc");
}
public Order ignoreCase() {
ignoreCase = true;
return this;
}
/**
* Constructor for Order.
*/
protected Order(String propertyName, boolean ascending) {
this.propertyName = propertyName;
this.ascending = ascending;
}
/**
* Render the SQL fragment
*
*/
public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException {
String[] columns = criteriaQuery.getColumnsUsingProjection(criteria, propertyName);
Type type = criteriaQuery.getTypeUsingProjection(criteria, propertyName);
StringBuffer fragment = new StringBuffer();
for ( int i=0; i<columns.length; i++ ) {
SessionFactoryImplementor factory = criteriaQuery.getFactory();
boolean lower = ignoreCase && type.sqlTypes( factory )[i]==Types.VARCHAR;
if (lower) {
fragment.append( factory.getDialect().getLowercaseFunction() )
.append('(');
}
fragment.append( columns[i] );
if (lower) fragment.append(')');
fragment.append( ascending ? " asc" : " desc" );
if ( i<columns.length-1 ) fragment.append(", ");
}
return fragment.toString();
}
/**
* Ascending order
*
* @param propertyName
* @return Order
*/
public static Order asc(String propertyName) {
return new Order(propertyName, true);
}
/**
* Descending order
*
* @param propertyName
* @return Order
*/
public static Order desc(String propertyName) {
return new Order(propertyName, false);
}
}
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重点就在toSqlString上了,QBC的Criteria也是toSqlString产生对应sql的,所以只要在这里做手脚,就能达到效果。
当然,不赞成直接改源码。
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然后就有了GBKOrder:
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package comm;
import java.sql.Types;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.criterion.CriteriaQuery;
import org.hibernate.criterion.Order;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.type.Type;
public class GBKOrder extends Order {
private String encoding = "GBK";
private boolean ascending;
private boolean ignoreCase;
private String propertyName;
@Override
public String toString() {
return "CONVERT( " + propertyName + " USING " + encoding + " ) " + (ascending ? "asc" : "desc");
}
@Override
public Order ignoreCase() {
ignoreCase = true;
return this;
}
/**
* Constructor for Order.
*/
protected GBKOrder(String propertyName, boolean ascending) {
super(propertyName, ascending);
this.propertyName = propertyName;
this.ascending = ascending;
}
/**
* Constructor for Order.
*/
protected GBKOrder(String propertyName, String dir) {
super(propertyName, dir.equalsIgnoreCase("ASC") ? true : false);
ascending = dir.equalsIgnoreCase("ASC") ? true : false;
this.propertyName = propertyName;
this.ascending = ascending;
}
/**
* Render the SQL fragment
*
*/
@Override
public String toSqlString(Criteria criteria, CriteriaQuery crite