Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 mI 74x3 [
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Lemui)
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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 pK0"%eA
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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 &b:1I7Cp*
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分页支持类: >2~=)L
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java代码: Xh56T^,2
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package com.javaeye.common.util; H%D$(W
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import java.util.List; eJg8,7WC
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publicclass PaginationSupport { X&kp;W
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publicfinalstaticint PAGESIZE = 30; 1I:+MBGin
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privateint pageSize = PAGESIZE; :O uA)f
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privateList items; R17?eucZ
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privateint totalCount; 0Vx.nUQ
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privateint[] indexes = newint[0]; !r<pmr3f@7
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privateint startIndex = 0; @;"|@!l|
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public PaginationSupport(List items, int z<Nfm
{;2PL^i
totalCount){ 3W
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setPageSize(PAGESIZE); AIZ]jq
setTotalCount(totalCount); .[_L=_.
setItems(items); &q9T9AOS
setStartIndex(0); v/ _
} c
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public PaginationSupport(List items, int |:gf lseE
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totalCount, int startIndex){ m;,N)<~
setPageSize(PAGESIZE);
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setTotalCount(totalCount); hv?9*tLh0
setItems(items); 'tH_p
setStartIndex(startIndex); [@.!~E)P
} ,y#Kv|R
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public PaginationSupport(List items, int K|epPGRr
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totalCount, int pageSize, int startIndex){ yK=cZw%D
setPageSize(pageSize); .6Pw|xu`Pw
setTotalCount(totalCount); 5?x>9Ca
setItems(items); x<ZJb
setStartIndex(startIndex); Te[n,\Nb
} XuFYYx~ ^3
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publicList getItems(){ Bx<
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return items; lNYt`xp
} @u6B;)'l
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publicvoid setItems(List items){ J cd-
this.items = items; J| w>a
} VZKvaxIk6
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publicint getPageSize(){ .[ICx
return pageSize; RMdk:YvBg
} .(cw>7e3D
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publicvoid setPageSize(int pageSize){ m+]K;}.}R
this.pageSize = pageSize; Fj2BnM3#
} ,?^ p(w
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publicint getTotalCount(){ #V~me
return totalCount; a.k.n<
} 0Qf,@^zL*
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publicvoid setTotalCount(int totalCount){ [M=7M}f;
if(totalCount > 0){ QTk}h_<u
this.totalCount = totalCount; !$gR{XH$]
int count = totalCount / )"7iJb<E
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pageSize; *Q
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if(totalCount % pageSize > 0) [1Qo#w1
count++; +nFu|qM}
indexes = newint[count]; *RJG!t*t
for(int i = 0; i < count; i++){ qm/22:&v5
indexes = pageSize * m#|
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} &w_j/nW^'
}else{ YJT&{jYi
this.totalCount = 0; ~:s>aQ`!
} vApIHI?-
} G[uK -U
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publicint[] getIndexes(){ <L8'! q}
return indexes; oqO(PU
} P@V0Mi),
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publicvoid setIndexes(int[] indexes){ S%Uutj\/W
this.indexes = indexes; &5B'nk"
} 2} /aFR
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publicint getStartIndex(){ f<d`B]$(
return startIndex; s<<ooycBrQ
} ];[}:f
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publicvoid setStartIndex(int startIndex){ yEqps3%
if(totalCount <= 0) *av<E
this.startIndex = 0; E Nhl&J
elseif(startIndex >= totalCount) Q{>+ft U
this.startIndex = indexes -b9\=U[
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[indexes.length - 1]; l<58A7
elseif(startIndex < 0) [}E='m}u9+
this.startIndex = 0;
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else{ On9A U:\
this.startIndex = indexes @k,#L`3^
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[startIndex / pageSize]; "c%0P"u
} F rfM3x6UM
} gwuI-d^
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publicint getNextIndex(){ 'CM|@Zz%
int nextIndex = getStartIndex() + Tztu}t]N
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pageSize; Hw}Xbp[y
if(nextIndex >= totalCount) l*Gvf_UH
return getStartIndex(); @zW]2 c
else K7_UP&`=J
return nextIndex; +SR+gE\s0
} P^~yzI
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publicint getPreviousIndex(){ qd ~BnR$=
int previousIndex = getStartIndex() - ;#W2|'HD
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pageSize; JzQ_{J`k
if(previousIndex < 0) xX&+WR
return0; fgp]x&5Q
else n,y ZRY
return previousIndex; \h/H#jZJ
} ]v UwG--*
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} G:<aB
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抽象业务类 {I%cxQ#y
java代码: ?=Z?6fw
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/** F]O`3e=!
* Created on 2005-7-12 Cw3a0u
*/ ?=sDM& '
package com.javaeye.common.business; :%=Xm
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import java.io.Serializable; yLvDMPj
import java.util.List; iHM%iUV
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import org.hibernate.Criteria; .5_2zat0H
import org.hibernate.HibernateException; ~w+c8c8pW
import org.hibernate.Session; AlaW=leTe
import org.hibernate.criterion.DetachedCriteria; 5{X<y#vAC0
import org.hibernate.criterion.Projections; {UI+$/v#
import y%cP1y)
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org.springframework.orm.hibernate3.HibernateCallback; reu*53r]
import Q~
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org.springframework.orm.hibernate3.support.HibernateDaoS W' VslZG
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upport; (=AWOU+
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import com.javaeye.common.util.PaginationSupport; \';gvr|
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public abstract class AbstractManager extends q6luUx,@m
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HibernateDaoSupport { _
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privateboolean cacheQueries = false; F v2-(
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privateString queryCacheRegion; s/#!VnU6
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publicvoid setCacheQueries(boolean m+[Ux{$
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cacheQueries){ H/
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this.cacheQueries = cacheQueries; Ax7[;|2
} lTgjq:mn
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publicvoid setQueryCacheRegion(String ~q.F<6O
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queryCacheRegion){ $7ZX]%<s
this.queryCacheRegion = mO7]9p
+~$ ]}%
queryCacheRegion; EW OVx*l
} sY&IquK^
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publicvoid save(finalObject entity){ .*Y
getHibernateTemplate().save(entity); *i%.;Z"
} =8.
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publicvoid persist(finalObject entity){ #=A)XlZMd
getHibernateTemplate().save(entity); )7Wf@@R'F
} AQvudx)@"
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publicvoid update(finalObject entity){ /W<;Z;zk
getHibernateTemplate().update(entity); jV1.Yz(`
} hMO=#up&
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publicvoid delete(finalObject entity){ ^6V[=!& H
getHibernateTemplate().delete(entity); "ze|W\Bv!
} &j"?\f?
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publicObject load(finalClass entity, oD.Cs'
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finalSerializable id){ C_JNX9wv
return getHibernateTemplate().load ^hM4j{|&M
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(entity, id); .W!i7
} (hbyEQhF
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publicObject get(finalClass entity, }S-O&Z
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finalSerializable id){ p_%Rt"!
return getHibernateTemplate().get 8(~h"]`!
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(entity, id); 9W2Vo [(
} x'<X!gw
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publicList findAll(finalClass entity){ !%c\N8<>GD
return getHibernateTemplate().find("from )Ql%r?(F+
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" + entity.getName()); e(t\g^X
} @:#eb1<S
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publicList findByNamedQuery(finalString /a4{?? #e
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namedQuery){ 8{sGNCvU
return getHibernateTemplate -uf|w?
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().findByNamedQuery(namedQuery); UP,c |
} 83#mB:^R
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publicList findByNamedQuery(finalString query, (f"4,b^]
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finalObject parameter){ [{,1=AB
return getHibernateTemplate SO!8Di
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().findByNamedQuery(query, parameter); SwMc
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} XwaXdvmK
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publicList findByNamedQuery(finalString query, fNFY$:4X
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finalObject[] parameters){ C~/a-
return getHibernateTemplate f.)O2=
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().findByNamedQuery(query, parameters); $=4QO
} 8$}<, c(
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publicList find(finalString query){ C?eH]hkZ3
return getHibernateTemplate().find }qD\0+`qi
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(query); Q^")jPd
} _oeS Uzq.
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publicList find(finalString query, finalObject `;egv*!P
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parameter){ "^GGac.
return getHibernateTemplate().find \dah^mw"
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(query, parameter); o`-msz
} 6Z"X}L,*
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public PaginationSupport findPageByCriteria $IpccZpA
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(final DetachedCriteria detachedCriteria){ l*G[!u
return findPageByCriteria X"%gQ.1|{j
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ;aVZ"~a+\
} 9hyn`u.
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public PaginationSupport findPageByCriteria qJ-/7-$ ^
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(final DetachedCriteria detachedCriteria, finalint AA>P`C$&M
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startIndex){ La[V$+Y
return findPageByCriteria 3ckclO\|>
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(detachedCriteria, PaginationSupport.PAGESIZE, FGzwhgy
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startIndex); ;!Fn1|)
} q!@4~plz
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public PaginationSupport findPageByCriteria "" EQE>d
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(final DetachedCriteria detachedCriteria, finalint 1< ?4\?j
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pageSize, ]6j{@z?{
finalint startIndex){ C;yZ
return(PaginationSupport) #GFr`o0$^
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getHibernateTemplate().execute(new HibernateCallback(){ <:CkgR$/{
publicObject doInHibernate ))Za&S*<
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(Session session)throws HibernateException { M"L=L5OH-
Criteria criteria = }x,S%M-
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detachedCriteria.getExecutableCriteria(session); ;n;p@Uu[
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int totalCount = Q/Rqa5LI:
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((Integer) criteria.setProjection(Projections.rowCount BnY&f
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()).uniqueResult()).intValue(); k;Y5BB
criteria.setProjection kq-) ^,{y
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(null); D2O~kNd
List items = 3OB"#Ap8<
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criteria.setFirstResult(startIndex).setMaxResults 4skD(au8
yf,z$CR
(pageSize).list(); e|r`/:M
PaginationSupport ps = x?<FJ"8"k
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new PaginationSupport(items, totalCount, pageSize, EdX$(scu~B
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startIndex); !VzC&>'v^9
return ps; ~$J2g
} ia?
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}, true); B)UZ`?>c
} yt2PU_),
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public List findAllByCriteria(final E?@m?@*/
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DetachedCriteria detachedCriteria){ XK vi=0B
return(List) getHibernateTemplate cz$2R
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().execute(new HibernateCallback(){ [D1Up
publicObject doInHibernate 19] E 5'AI
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(Session session)throws HibernateException { +w~oH =
Criteria criteria = Uw:"n]G]D?
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detachedCriteria.getExecutableCriteria(session); d_P` qA
return criteria.list(); T> p&$]OG
} Pzem{y7Ir
}, true); 1 -b_~DF
} &5R&k0i r
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public int getCountByCriteria(final [N'h%1]\
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DetachedCriteria detachedCriteria){ VtohL+
Integer count = (Integer) 1E$|~
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getHibernateTemplate().execute(new HibernateCallback(){ Xwtqi@zlE
publicObject doInHibernate jiC>d@~y
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(Session session)throws HibernateException { phz&zlD
Criteria criteria = .S4u-
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detachedCriteria.getExecutableCriteria(session); 7[wPn`v2
return dF2RH)Ud
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criteria.setProjection(Projections.rowCount +H2Qk4XFB
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()).uniqueResult(); Ea=P2:3*
} 2t,zLwBdnJ
}, true); ," ql5Q4
return count.intValue(); *z2s$EZ
} *lb<$E]="!
} Q59W#e)
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用户在web层构造查询条件detachedCriteria,和可选的 `$NP>%J-
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 %|4UsWZ
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PaginationSupport的实例ps。 XX~,>Q}H=
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ps.getItems()得到已分页好的结果集 wyG;8I
ps.getIndexes()得到分页索引的数组 :Tq~8!s
ps.getTotalCount()得到总结果数 [/ZO q
ps.getStartIndex()当前分页索引 c`Wa^(
ps.getNextIndex()下一页索引 tnIX:6
ps.getPreviousIndex()上一页索引 g=I})s:CTp
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^C%<l(b
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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 B-ESFATc
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一下代码重构了。 YbLW/E\T
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我把原本我的做法也提供出来供大家讨论吧: B1Oq!k
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首先,为了实现分页查询,我封装了一个Page类: BORA(,
java代码: U;I9 bK8
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/*Created on 2005-4-14*/ -.3w^D"l
package org.flyware.util.page; @|)Z"m7
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/** nF/OPd
* @author Joa ~_ a-E
* $]8Q(/mbK
*/ F<w/PMb
publicclass Page { RT5T1K08I
MY/}-*|
/** imply if the page has previous page */ ::F|8
privateboolean hasPrePage; Np)lIGE
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/** imply if the page has next page */ E!AE4B1bd
privateboolean hasNextPage; u]gxFG"
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/** the number of every page */ kNL\m[W8$
privateint everyPage; {y;n:^
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/** the total page number */ _tXlF;
privateint totalPage; %%wNZ{
*9i{,I@
/** the number of current page */ KGpA2Nx
privateint currentPage; ]:\dPw`A
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/** the begin index of the records by the current KY N0
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query */ %PJQ%~
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privateint beginIndex; -!9G0h&i|
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/** The default constructor */ llsfTrp
public Page(){ *\q
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} yiI1x*^
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/** construct the page by everyPage !g.?
* @param everyPage qjc4.,/
* */ RX5dO%
public Page(int everyPage){ YnP5i#"
this.everyPage = everyPage; cs'{5!i]
} wa3}SB
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/** The whole constructor */ rXU\
public Page(boolean hasPrePage, boolean hasNextPage, DFTyMB1H
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