JPA 查询通过别名 转实体

首先 说缺点：映射的对象 如果 引用另外一个实体，是没办法映射。
使用的规则：别名和实体的属性要一一对应。
public class test｛     PRivate String name;      private String passWord;      //必须有get set方法，我这里就不写了｝
sql 这样写: select aaa as name,bbb as password from tableName;
使用的：
Page<ApppintmentDepositFlowingReportVO> tList = 
	(Page<ApppintmentDepositFlowingReportVO>) this.query(sql, ApppintmentDepositFlowingReportVO.class, pageable, "A");
最后一个参数 是 为 求 count 用的。后面我会 标出来。
public Page<?> query(String sql, Class<?> classs, Pageable pageable, String header) {		EntityManager em = entityManagerFactory.createEntityManager();		session session = (Session) em.getDelegate();		Sort sort = pageable.getSort();		StringBuilder orderString = new StringBuilder();		if (sort != null) {			Iterator<Order> it = sort.iterator();			if (it != null && it.hasNext()) {				Order order = it.next();				String dir = order.getDirection().toString();				String name = order.getProperty();				orderString.append(" order by ").append(name).append(" ").append(dir);			}		}		SQLQuery query = session.createSQLQuery(sql + orderString.toString());		String countSql = this.getSqlForCount(sql, header);		SQLQuery query2 = session.createSQLQuery(countSql);		Object obj = query2.uniqueResult();		Long totleDatas = SqlResultUtil.getSqlResultLong(obj);		query.setResultTransformer(new XaAliasToBeanResultTransformer(classs));		query.setFirstResult((pageable.getPageNumber()) * pageable.getPageSize());		query.setMaxResults(pageable.getPageSize());		List<?> list = query.list();		PageImpl<?> page = new PageImpl<>(list, pageable, totleDatas.longValue());		em.close();		return page;	}
private String getSqlForCount(String sql, String header) {		int d = sql.indexOf("from");		return "select count(" + header + ".id) " + sql.substring(d);	}
其实关键是这个类：
package com.baihui.base.util;import java.util.Arrays;import org.apache.commons.lang.StringUtils;import org.hibernate.HibernateException;import org.hibernate.property.ChainedPropertyaccessor;import org.hibernate.property.PropertyAccessor;import org.hibernate.property.PropertyAccessorFactory;import org.hibernate.property.Setter;import org.hibernate.transform.AliasToBeanResultTransformer;public class XaAliasToBeanResultTransformer extends AliasToBeanResultTransformer {		public Xa3itAliasToBeanResultTransformer(Class resultClasss) {		super(resultClasss);		this.resultClass = resultClasss;	}	private final Class resultClass;	private boolean isInitialized;	private String[] aliases;	private Setter[] setters;	@Override	public boolean isTransformedValueATupleElement(String[] aliases, int tupleLength) {		return false;	}	@Override	public Object transformTuple(Object[] tuple, String[] aliases) {		Object result;		try {			if ( ! isInitialized ) {				initialize( aliases );			}			else {				//check( aliases );			}						result = resultClass.newInstance();			for ( int i = 0; i < aliases.length; i++ ) {				Setter setter = setters[i];				if ( setter != null ) 				{					Class[] clas = setter.getMethod().getParameterTypes();					Object obj = this.getNewValObject(clas[0], tuple[i]);					setter.set( result, obj, null );				}			}		}		catch ( InstantiationException e ) {			throw new HibernateException( "Could not instantiate resultclass: " + resultClass.getName() );		}		catch ( IllegalAccessException e ) {			throw new HibernateException( "Could not instantiate resultclass: " + resultClass.getName() );		}		return result;	}	private Object getNewValObject(Class clas,Object val)	{		if(val == null)		{			return null;		}		String name = clas.getName();		if(StringUtils.equals(name, "java.lang.Long"))		{			return SqlResultUtil.getSqlResultLong(val);		}		else if(StringUtils.equals(name,"java.lang.Double"))		{			return SqlResultUtil.getSqlResultDouble(val);		}		else if(StringUtils.equals(name,"java.lang.Integer"))		{			return SqlResultUtil.getSqlResultInteger(val);		}		else if(StringUtils.equals(name,"java.util.Date"))		{			return SqlResultUtil.getSqlResultDate(val);		}		else if(StringUtils.equals(name,"boolean"))		{			String v = SqlResultUtil.getSqlResultString(val);			return Boolean.parseBoolean(v);		}				else if(StringUtils.equals(name, "java.lang.Boolean"))		{			String v = SqlResultUtil.getSqlResultString(val);			if(v.toLowerCase().equals("true") || v.toLowerCase().equals("false"))			{				return Boolean.parseBoolean(v);			}			else			{				if(v.equals("1"))				{					return Boolean.TRUE;				}				else				{					return Boolean.FALSE;				}			}		}		else if(StringUtils.equals(name,"java.lang.String"))		{			return SqlResultUtil.getSqlResultString(val);		}		return null;	}	private void initialize(String[] aliases) {		PropertyAccessor propertyAccessor = new ChainedPropertyAccessor(				new PropertyAccessor[] {						PropertyAccessorFactory.getPropertyAccessor( resultClass, null ),						PropertyAccessorFactory.getPropertyAccessor( "field" )				}		);		this.aliases = new String[ aliases.length ];		setters = new Setter[ aliases.length ];		for ( int i = 0; i < aliases.length; i++ ) {			String alias = aliases[ i ];			if ( alias != null ) {//				this.aliases[ i ] = alias;				this.aliases[i] = this.getSqlAliasToJavaAlias(alias);				setters[ i ] = propertyAccessor.getSetter( resultClass, this.aliases[i] );			}		}		isInitialized = true;	}		private String getSqlAliasToJavaAlias(String s)	{		if(s.indexOf("_") > 0)		{			String[] sss = s.split("_");			StringBuilder sb = new StringBuilder(sss[0]);			for(int i = 1 ; i < sss.length;i++)			{				String ss = sss[i];				String head = ss.substring(0,1);				sb.append(head.toUpperCase()).append(ss.substring(1));			}			return sb.toString();		}		else		{			return s;		}	}		private void check(String[] aliases) {		if ( ! Arrays.equals( aliases, this.aliases ) ) {			throw new IllegalStateException(					"aliases are different from what is cached; aliases=" + Arrays.asList( aliases ) +							" cached=" + Arrays.asList( this.aliases ) );		}	}	@Override	public boolean equals(Object o) {		if ( this == o ) {			return true;		}		if ( o == null || getClass() != o.getClass() ) {			return false;		}		Xa3itAliasToBeanResultTransformer that = ( Xa3itAliasToBeanResultTransformer ) o;		if ( ! resultClass.equals( that.resultClass ) ) {			return false;		}		if ( ! Arrays.equals( aliases, that.aliases ) ) {			return false;		}		return true;	}	@Override	public int hashCode() {		int result = resultClass.hashCode();		result = 31 * result + ( aliases != null ? Arrays.hashCode( aliases ) : 0 );		return result;	}}就是  参数中有个 page 因为用的是 spring data：
@ResponseBody@RequestMapping(value = "OperationOrderr", method = RequestMethod.POST)public XaResult<Page<OperationOrderCashierFlowingReportForAOuterVO>> operationOrderCashierFlowingReportForAOuter(HttpServletRequest request,@RequestParam(defaultValue = "0") Integer nextPage,@RequestParam(defaultValue = "10") Integer pageSize,@RequestParam(defaultValue = "[{property:'A.id',direction:'DESC'}]") String sortData,@RequestParam(defaultValue = "{}") String jsonFilter)throws BusinessException {Pageable pageable = WebUitl.buildPageRequest(nextPage, pageSize,sortData);Map<String, Object> filterParams = WebUitl.getParametersstartingWith(jsonFilter, "search_");XaResult<Page<OperationOrderCashierFlowingReportForAOuterVO>> xa = new XaResult<>();try{Page<OperationOrderCashierFlowingReportForAOuterVO> p = this.operationOrderCashierFlowingReportForAOuterService.getResult(pageable, filterParams);xa.success(p);}catch(Exception e){xa.error("数据查询出错");}return xa;}