Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~UjGSO)z}
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 y+6o{`0
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 )>-ibf`#?
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 EEZw_ 1
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分页支持类: J6G(_(d
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java代码: _Bp1co85MQ
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package com.javaeye.common.util; H0SQ"?
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import java.util.List; pL%r,Y_^\x
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publicclass PaginationSupport { tl'9IGlc
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publicfinalstaticint PAGESIZE = 30; Gkv{~?95
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privateint pageSize = PAGESIZE; | j a-
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privateList items; [[Y0
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privateint totalCount; w{90`
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privateint[] indexes = newint[0]; !G}+E2fDA
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privateint startIndex = 0; r~n sN*t
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public PaginationSupport(List items, int 1`9xIm*9w
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totalCount){ UaV iI/ks
setPageSize(PAGESIZE); {TRsd
setTotalCount(totalCount); e$uiJNS2
setItems(items); UNi`P9D]3
setStartIndex(0); u% n*gcY
} /?1nHBYPM
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public PaginationSupport(List items, int qTo-pAG`
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totalCount, int startIndex){ n?urE-_
setPageSize(PAGESIZE); -"[<ek
setTotalCount(totalCount); A4?+T+#d
setItems(items); lP!;3iJ B
setStartIndex(startIndex); !\;FNu8_.
} <P;}unq.kw
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public PaginationSupport(List items, int [wB9s{CX
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totalCount, int pageSize, int startIndex){ g}U3y'
setPageSize(pageSize); la?Wnw
setTotalCount(totalCount); t/PlcV_M"
setItems(items); $4T2z-
setStartIndex(startIndex); p/
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} $<|lE/_]
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publicList getItems(){ 3#45m+D
return items; e=QK}gzX
} %9#gB
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publicvoid setItems(List items){ D\YE^8/
this.items = items; !GQ\"Ufs>
} vuFBET,
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publicint getPageSize(){ 2',w[I
return pageSize; K[7EOXLy
} z|(+|pV(
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publicvoid setPageSize(int pageSize){ wB{;bB{
this.pageSize = pageSize; /Y2/!mU</
} F[!ckes<bB
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publicint getTotalCount(){ iIGbHn,/
return totalCount; d@3}U6,
} ]}6w#)]"
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publicvoid setTotalCount(int totalCount){ C}*cx$.
if(totalCount > 0){ ^Mk%z9
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this.totalCount = totalCount; cbu@*NzY,
int count = totalCount / *VkgQ`c
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pageSize; OcSEo7W
if(totalCount % pageSize > 0) Q!FLR>8
count++; #s%-INcR
indexes = newint[count]; ?<yM7O,4
for(int i = 0; i < count; i++){ @&hnL9D8lL
indexes = pageSize * 45H!;Qsk
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} vkRi5!bR
}else{ :p4 "IeKs
this.totalCount = 0; L~^*u_U]
} M-uMZQe
} lRP1&FH0
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publicint[] getIndexes(){ 0J8K9rP;z
return indexes; x4#T G
} M}hrO-C
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publicvoid setIndexes(int[] indexes){ =)OC|?9C\
this.indexes = indexes; .6pOvGKb
} JkA|Qdj~Mr
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publicint getStartIndex(){ p=QYc)3F
return startIndex; <vbIp&
} %AnW~v
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publicvoid setStartIndex(int startIndex){ J%]D%2vnk`
if(totalCount <= 0) ^5 t
this.startIndex = 0; Ut)r&?
elseif(startIndex >= totalCount) 2_t=P|Uo
this.startIndex = indexes r
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[indexes.length - 1]; k 2%S`/:
elseif(startIndex < 0) G 8Y+w
this.startIndex = 0; cxYfZ4++m
else{ ]> Y/r-!
this.startIndex = indexes L {ymI)Y^
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[startIndex / pageSize]; #m8sK(#lo
} p'{xoV
} })IO#,
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publicint getNextIndex(){ "MiD8wX-
int nextIndex = getStartIndex() + p&K\]l}
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pageSize; !1uzX
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if(nextIndex >= totalCount) [[)_BmS5r
return getStartIndex(); <Jp1A#
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else fj'jNE
return nextIndex; NgB 7?]vu
} y$tX-9U
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publicint getPreviousIndex(){ O:.,+,BH
int previousIndex = getStartIndex() - T_OF7?
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pageSize; UlQQP^Na
if(previousIndex < 0) .%0ne:5
return0; S C_|A9
else u&TdWZe
return previousIndex; $X+u={]
} u:`y]
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} J%dJw}
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抽象业务类 |Zq\GA
java代码: xNN@ 1P[*
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/** 77:'I
* Created on 2005-7-12 wh~sZ
*/ uf@U:V
package com.javaeye.common.business; 27#8dV?
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import java.io.Serializable; MPRO
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import java.util.List; 3^G96]E
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import org.hibernate.Criteria; CJqc\I~
import org.hibernate.HibernateException; E:VGji7s
import org.hibernate.Session; <uF [,
import org.hibernate.criterion.DetachedCriteria; _q Tpy)+
import org.hibernate.criterion.Projections; pX<a2FP
import S>ugRasZ$
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org.springframework.orm.hibernate3.HibernateCallback; sS,#0Qt.
import PX 3
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org.springframework.orm.hibernate3.support.HibernateDaoS \OHv|8!EI@
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upport; `X+j2TmS
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import com.javaeye.common.util.PaginationSupport; [a8+(
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public abstract class AbstractManager extends qiNliJ>40E
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HibernateDaoSupport { 2;N@aZX
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privateboolean cacheQueries = false; x9}++r
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privateString queryCacheRegion; KZK,w#9.
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publicvoid setCacheQueries(boolean 0:dB
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cacheQueries){ vbn>mg5
this.cacheQueries = cacheQueries; a8h]n:!
} G6Q4-kcK
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publicvoid setQueryCacheRegion(String m,NMTyJoz
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queryCacheRegion){ `45d"B
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this.queryCacheRegion = POBpJg
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queryCacheRegion; RWahsJTu
} B/Ba5z"r$
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publicvoid save(finalObject entity){ 3Hm7
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getHibernateTemplate().save(entity); q 22/_nSC
} %}F"*.
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publicvoid persist(finalObject entity){ l @A"U)A(
getHibernateTemplate().save(entity); nO@+s
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} kukaim>K
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publicvoid update(finalObject entity){ .! j#3J..u
getHibernateTemplate().update(entity); p}8ratmN
} WTu{,Q
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publicvoid delete(finalObject entity){ |+/$ g.
getHibernateTemplate().delete(entity); )_O.{$
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} |Q u_E
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publicObject load(finalClass entity, @}G|R\2P
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finalSerializable id){ Y:%"K
return getHibernateTemplate().load &enlAV'#)O
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(entity, id); em/Xu
} 2B'^`>+8S
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publicObject get(finalClass entity, Isp_U5M
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finalSerializable id){ di<B ~:l58
return getHibernateTemplate().get sWW\bK0B4
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(entity, id); Heohe|an
} g _x\T+=
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publicList findAll(finalClass entity){ *cy.*@d
return getHibernateTemplate().find("from .9I_NG
ws().IZ
" + entity.getName()); eU"mG3__
} G,/Gq+WX
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publicList findByNamedQuery(finalString q"p#H 8
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namedQuery){ 1G_xP^H!
return getHibernateTemplate d'q;+jnP
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().findByNamedQuery(namedQuery); |3|wdzV
} 7rPLnB]
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publicList findByNamedQuery(finalString query, @d
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finalObject parameter){ >2t
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return getHibernateTemplate DlS&qFs
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().findByNamedQuery(query, parameter); &{hc
} (mY(\mu}
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publicList findByNamedQuery(finalString query, 0.(zTJ
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)
finalObject[] parameters){ 3v G
return getHibernateTemplate o[2Y;kP3*P
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().findByNamedQuery(query, parameters); PgqECd)f
} |/2LWc?
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publicList find(finalString query){ Xv]*;Bq:SK
return getHibernateTemplate().find hX %s]"
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(query); ZG!x$yi$
} R$v i!0
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publicList find(finalString query, finalObject TLX^~W[gOm
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parameter){ v7g
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return getHibernateTemplate().find h
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(query, parameter); *;Ak5.du
} }1@n(#|c
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public PaginationSupport findPageByCriteria G@;Nz i89
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(final DetachedCriteria detachedCriteria){ O&F<oM
return findPageByCriteria "C?:T'dW
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); =tLU]
} G|<] Ma9x
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public PaginationSupport findPageByCriteria ;;D%
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(final DetachedCriteria detachedCriteria, finalint 2c!h2$w
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startIndex){
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return findPageByCriteria 4b]IazL)
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(detachedCriteria, PaginationSupport.PAGESIZE, 1g+LF[*-~
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startIndex); u2f `|+1^y
} 4p*?7g_WVH
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public PaginationSupport findPageByCriteria \-DM-NrZ1U
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(final DetachedCriteria detachedCriteria, finalint cF-Jc}h
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pageSize, Qu!OV]Cc
finalint startIndex){ ;>cLbjD
return(PaginationSupport) $0ym_6n
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getHibernateTemplate().execute(new HibernateCallback(){ :t_}_!~
publicObject doInHibernate ;D6x=v=2
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(Session session)throws HibernateException { wEZqkV
Criteria criteria = p!. /
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detachedCriteria.getExecutableCriteria(session); ftDVxKDE?S
int totalCount = e-&L\M
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((Integer) criteria.setProjection(Projections.rowCount 9)8*FahW
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()).uniqueResult()).intValue(); Vj?*=UL
criteria.setProjection hnH)Jy;>
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(null); cYBrRTrI#
List items = {LjK_J'
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criteria.setFirstResult(startIndex).setMaxResults o}5'v^"6,
)G}sb*+v?
(pageSize).list();
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PaginationSupport ps = { mK pD
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new PaginationSupport(items, totalCount, pageSize, ju
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startIndex); :7zI3Ml@7
return ps; 1c1e+H
} EU`'
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}, true); \"<GL;
} yQ72v'
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public List findAllByCriteria(final (gs`=H*d;
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DetachedCriteria detachedCriteria){ nS?S6G5h
return(List) getHibernateTemplate m-Mhf;
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().execute(new HibernateCallback(){ p\4h$."
publicObject doInHibernate NZC<m$')
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(Session session)throws HibernateException { ylo]`Nq
Criteria criteria = roK4RYJ7)
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detachedCriteria.getExecutableCriteria(session); <v1_F;{n
return criteria.list(); EBN]>zz
} C.B8 J"T-
}, true); ;jpw"-J`
} r;@:S~
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public int getCountByCriteria(final S^_JC
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DetachedCriteria detachedCriteria){ AmUe0CQ:k'
Integer count = (Integer) K6PC&+x
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getHibernateTemplate().execute(new HibernateCallback(){ bCe[nmE2
publicObject doInHibernate oW\Q>c7
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(Session session)throws HibernateException { l,~ N~?
Criteria criteria = +4p2KYO
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detachedCriteria.getExecutableCriteria(session); {Hrr:hC
return OP\^c
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criteria.setProjection(Projections.rowCount tPMgZ
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()).uniqueResult(); 8.
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} 0^|$cvYiL
}, true); EHE6-^F
return count.intValue(); @i1 .5z
} -f
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} 8k*k
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用户在web层构造查询条件detachedCriteria,和可选的 Jq=>H@il
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 bx'B;rZr
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PaginationSupport的实例ps。 +eVpMD(
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ps.getItems()得到已分页好的结果集 @b(gjOE
ps.getIndexes()得到分页索引的数组
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ps.getTotalCount()得到总结果数 jDkc~Wwa
ps.getStartIndex()当前分页索引 vzgudxG'z
ps.getNextIndex()下一页索引 pQ6t]DJ4
ps.getPreviousIndex()上一页索引 U7Sl@-#|
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 c_j)8
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 RdpQJ)3F
19.!$;
一下代码重构了。 ,L;c{[*rh
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我把原本我的做法也提供出来供大家讨论吧: Ij,?G*
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首先,为了实现分页查询,我封装了一个Page类: YfYL?G
java代码: u8)r
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/*Created on 2005-4-14*/ 1Y"y!\t7G
package org.flyware.util.page; %#;(]7Zq
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/** >0G}, S
* @author Joa $y |6<
* "q#kh,-C
*/ 9\;/-0P
publicclass Page { Y3F.hk}O
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/** imply if the page has previous page */ Tx&qp#FS
privateboolean hasPrePage; #._6lESK
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/** imply if the page has next page */ pJ@DHj2@
privateboolean hasNextPage; ?.'oxW
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/** the number of every page */ ;|e 0{Jrz
privateint everyPage; #esu@kMU`
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/** the total page number */ %EhU!K#[
privateint totalPage; )#TJw@dNf^
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/** the number of current page */ EYj2h
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privateint currentPage; %QcG^R
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/** the begin index of the records by the current 9kiy^0
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query */ Hw-oh?=
privateint beginIndex; < $/Yw
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/** The default constructor */ ?z36mj"`o
public Page(){ i /U{dzZ
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} $@!&ML
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/** construct the page by everyPage ,lG wW8$R
* @param everyPage ?;kc%Rz
* */ =kkA
public Page(int everyPage){ 0BZOr-i
this.everyPage = everyPage; #~qp8
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} U@ QU8
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/** The whole constructor */ wOl-iN=
public Page(boolean hasPrePage, boolean hasNextPage, SYhspB
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int everyPage, int totalPage, 9>Z#o<*_/
int currentPage, int beginIndex){ ])";Z
this.hasPrePage = hasPrePage; YQd&rkr
this.hasNextPage = hasNextPage; bI0+J)
this.everyPage = everyPage; ~Am
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this.totalPage = totalPage; w9h5f
this.currentPage = currentPage; w)c#ZJHG
this.beginIndex = beginIndex; K>~cY%3^i
} ,#FH8%Yf
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/** Cjb p-
* @return !ef)Ra-W
* Returns the beginIndex. V0&QEul
*/ X-^Oz@.>
publicint getBeginIndex(){ 8o!^ZOmU<
return beginIndex; y#W8] <dS"
} :fQ*'m,
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/** KFrmH
* @param beginIndex !a&F:Fbm
* The beginIndex to set. DcM+K@1E4^
*/ R')GQ.yYq
publicvoid setBeginIndex(int beginIndex){ +*~3"ww<
this.beginIndex = beginIndex; 87*[o
} `Wt~6D
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/** Q%h
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* @return /{}
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* Returns the currentPage. I!#^F1p1
*/ 6E&