解决Hibernate中MySQL的中文排序

http://raywithu.iteye.com/blog/1139332 转载请注明出处

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

 

 SELECT *
 FROM BZ_COMPANY
 ORDER BY CONVERT( COMPANY_NAME USING GBK ) ASC

 

 

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。

 

hibernate的Order：

 

 //$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);
     }

 }

 

 

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。

 

然后就有了GBKOrder：

 

 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 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("CONVERT( " + columns[i] + " USING " + encoding + " )");
             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 GBKOrder(propertyName, true);
     }

     /**
      * Descending order
      *
      * @param propertyName
      * @return Order
      */
     public static Order desc(String propertyName) {
         return new GBKOrder(propertyName, false);
     }
 }

 

 

使用例子：

 

 public PageControl findPage(final PageControl pageControl, final Object bean) {
     try {
         final Class clazz = bean.getClass();
         List data = (List) this.getHibernateTemplate().execute(new HibernateCallback() {
             public Object doInHibernate(Session session) throws HibernateException, SQLException {
                 Criteria criteria = session.createCriteria(clazz);
                 criteria.add(Example.create(bean)
                         .ignoreCase()
                         .enableLike(MatchMode.ANYWHERE));
                 if (pageControl != null) {
                     int start = pageControl.getStart();
                     int limit = pageControl.getLimit();
                     criteria.setFirstResult(start);
                     criteria.setMaxResults(limit);
                     String sort = pageControl.getSort();
                     String dir = pageControl.getDir();
                     if (sort != null && dir != null) {
                         criteria.addOrder(dir.equalsIgnoreCase("ASC") ? GBKOrder.asc(sort) : GBKOrder.desc(sort));
                     }
                 }
                 return criteria.list();
             }
         });
         Long totalCount = getTotalCount(bean);
         PageControl rt = new PageControl();
         rt.setData(data);
         rt.setTotalCount(totalCount);
         return rt;
     } catch (RuntimeException e) {
         log.error("find page failed", e);
         throw e;
     }
 }

当然,你有需要的话,不必写死GBK