Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 .Gb+\E{M
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 s&*yk p
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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 qeaA&(|5
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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 EychR/s
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分页支持类: s` >H
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java代码: -G ?%QG`v
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package com.javaeye.common.util; IG.f=+<0
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import java.util.List; M%=P)cC
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publicclass PaginationSupport { 3n(*E_n
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publicfinalstaticint PAGESIZE = 30; ?ow'^X-
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privateint pageSize = PAGESIZE; ZTf_#eS$
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privateList items; W\ULUK
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privateint totalCount; R40W'N1%q
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privateint[] indexes = newint[0]; =Nl5{qYz^&
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privateint startIndex = 0; jmW^`%;7
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public PaginationSupport(List items, int B!q?_[k,
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totalCount){ d 7i#w
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setPageSize(PAGESIZE); rycJyiw<-
setTotalCount(totalCount); &X w`T9<
setItems(items); %F$N#YG
setStartIndex(0); J%r7<y\
} d)*(KhYie@
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public PaginationSupport(List items, int wr@GN8e`
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totalCount, int startIndex){ }|He?[TR
setPageSize(PAGESIZE); ib50LCm
setTotalCount(totalCount); 3}M\c)
setItems(items); 5!:._TcO
setStartIndex(startIndex); u&3EPu
} YeIe\3x!N
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public PaginationSupport(List items, int $5/\Z
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totalCount, int pageSize, int startIndex){ U+!UL5k
setPageSize(pageSize); U2&HSE|2J
setTotalCount(totalCount); T#e4":A&x
setItems(items); q}Rlo/R
setStartIndex(startIndex); ~|=rwDBZ8l
} R"Y?iZed3
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publicList getItems(){ a#R%8)
return items; )_pt*xo
} x(yX0 ,P/7
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publicvoid setItems(List items){ G"f du(.@
this.items = items; W%zmD Hk~
} qj;l,Kua
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publicint getPageSize(){ {fElto
return pageSize; tBTJmih"
} ,#
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publicvoid setPageSize(int pageSize){ YZ{jP?x
this.pageSize = pageSize; s9:%s*$u
} l)iv\j
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publicint getTotalCount(){ I W8.
return totalCount; g?$e^ls
} z-)*Q
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publicvoid setTotalCount(int totalCount){ 8 +L7E-
if(totalCount > 0){ J2Y 3er
this.totalCount = totalCount; xLLC)~
int count = totalCount / ,?#*eJD
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pageSize; S^)WYF5
if(totalCount % pageSize > 0) yj]ML:n
count++; |#:=\gugh
indexes = newint[count]; w1.MhA
for(int i = 0; i < count; i++){ w2KWa-BO
indexes = pageSize * :MdEr//w
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} t3Qm-J}wSB
}else{ 7rJ9
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this.totalCount = 0; [ArO$X3\
} (,d/JnP
} JgxA^>|9;
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publicint[] getIndexes(){ kkHTbn=!
return indexes; t{[gKV-b
} 7s$6XO!
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publicvoid setIndexes(int[] indexes){ ZtKQ]jV&@
this.indexes = indexes; dqL-'
} KWtu,~O_u
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publicint getStartIndex(){ u% r!?-z
return startIndex; nh?9R&
} 4*YOFU}l
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publicvoid setStartIndex(int startIndex){ @\S]]oLn
if(totalCount <= 0) @yCW8]
this.startIndex = 0; P7cge
elseif(startIndex >= totalCount) %
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this.startIndex = indexes %f>X-*}NI-
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[indexes.length - 1]; n=;';(wR[
elseif(startIndex < 0) `X3Xz!
this.startIndex = 0; rO5u~"v]
else{ 1mY+0
this.startIndex = indexes 0I(uddG3
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[startIndex / pageSize]; %GNUnr$
} ]VzqQ=U%
} p6B .s_G4
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publicint getNextIndex(){ (QA-"9v#i,
int nextIndex = getStartIndex() + .jLMl*6%:
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pageSize; 0zlM.rjEZ
if(nextIndex >= totalCount) r.Y*{!t
return getStartIndex(); T$#FAEz
else =I+l=;05Rd
return nextIndex; Bm65W
} `WraOsoY
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publicint getPreviousIndex(){ ( [K2:n\
int previousIndex = getStartIndex() - y|FBYcn#F
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pageSize; E_ o{c5N
if(previousIndex < 0) %kFTnXHK
return0; 200L
else HGU?bJ~6o
return previousIndex; iMP*]K-O
} |LX rGyk^
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} \[@Q}k[
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抽象业务类 Dq0-Kf,^
java代码: Bf D,z
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/** j|^-1X
* Created on 2005-7-12 Qs}/x[I
*/ v9j4|w
package com.javaeye.common.business; Yio>ft&g]
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import java.io.Serializable; zbF:R[)
import java.util.List; ^yEj]]6
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import org.hibernate.Criteria; lWu9/r 1
import org.hibernate.HibernateException; [dSDg2]
import org.hibernate.Session; [4K9|/J
import org.hibernate.criterion.DetachedCriteria; <3i4NXnL2
import org.hibernate.criterion.Projections; >N+bU{s
import e>])m3xvn
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p
org.springframework.orm.hibernate3.HibernateCallback; hQd@bN8
import }}4sh5z
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org.springframework.orm.hibernate3.support.HibernateDaoS (T>?8K_d
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upport; xA[Wb'
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import com.javaeye.common.util.PaginationSupport; )[@YHE5g
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public abstract class AbstractManager extends s2(w#n)
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HibernateDaoSupport { ~x4{P;y
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privateboolean cacheQueries = false; []2$rJZD9
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privateString queryCacheRegion; EPE!V>
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publicvoid setCacheQueries(boolean L|C1C
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cacheQueries){ .NzW@|
this.cacheQueries = cacheQueries; ;Sx'O
} Dr8WV\4@
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publicvoid setQueryCacheRegion(String 7\\~xSXh
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queryCacheRegion){ E1U 4v&P
this.queryCacheRegion = A}t&-
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queryCacheRegion; ]<\;d
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} Q+u#?['
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publicvoid save(finalObject entity){ ]2aYi9)
getHibernateTemplate().save(entity); `Q1WVd29
} q{9X.-]}
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publicvoid persist(finalObject entity){ ]]h:#A2
getHibernateTemplate().save(entity); Y^94iOk%T
} ?' ez.a}
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publicvoid update(finalObject entity){ P*0nT
getHibernateTemplate().update(entity); z'\}/k+
} pjKl)q
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publicvoid delete(finalObject entity){ OUIUgej
getHibernateTemplate().delete(entity); m! '1$G
} {LB
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publicObject load(finalClass entity, ; mo\ yW1
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finalSerializable id){ 4B3irHs\Q
return getHibernateTemplate().load dm/\uE'l
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(entity, id); j
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} .5KC'?
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publicObject get(finalClass entity, LrM.wr zI/
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finalSerializable id){ 4U! .UNi
return getHibernateTemplate().get "z#?OV5
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(entity, id); "`W1yk5x
} |U#w?eE=
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publicList findAll(finalClass entity){ >Xh(`^}SQ*
return getHibernateTemplate().find("from )- 6s7
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" + entity.getName());
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} _r?;lnWx@
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publicList findByNamedQuery(finalString QS=$#Gp
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namedQuery){ {YKMQI^O/
return getHibernateTemplate \9|]
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().findByNamedQuery(namedQuery); NBg>i7KQ
} -t~B@%
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publicList findByNamedQuery(finalString query, 5%Fn^u:
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finalObject parameter){ dE}b8|</
return getHibernateTemplate Y="&|c=w#L
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().findByNamedQuery(query, parameter); ap'kxOf"1
} #G!Adj+p5
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publicList findByNamedQuery(finalString query, }DUDA%U
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finalObject[] parameters){ );uZ4PNK/?
return getHibernateTemplate 6U>jU[/
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().findByNamedQuery(query, parameters); AINFua4 A
} @6!y(e8"J]
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publicList find(finalString query){ H+#wj|,+\
return getHibernateTemplate().find @aD~YtL"n
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(query); syNb0LR
} ;&^"q{m
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publicList find(finalString query, finalObject ;`of'9|
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parameter){ >ya-
return getHibernateTemplate().find vs0H^L
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(query, parameter); CU>K
} ZesD(
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public PaginationSupport findPageByCriteria /L|}Y242
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(final DetachedCriteria detachedCriteria){ +#JhhW
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return findPageByCriteria ?-F'0-t4%
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 8rG&CxI
} ?jn6Op
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public PaginationSupport findPageByCriteria W &wDH
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(final DetachedCriteria detachedCriteria, finalint +heS\I_Mp
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startIndex){ /qq&'}TZP
return findPageByCriteria j5Wx*~@(
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(detachedCriteria, PaginationSupport.PAGESIZE, v3JIUdU=P
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startIndex); yzNX2u1
} ]ifHA# z`~
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public PaginationSupport findPageByCriteria S,tVOxs^
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(final DetachedCriteria detachedCriteria, finalint s=~7m.m
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pageSize, H6JMN1#t$
finalint startIndex){ Jx9%8Ek
return(PaginationSupport) vzm4
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getHibernateTemplate().execute(new HibernateCallback(){ 2V"gqJHv
publicObject doInHibernate 5GFnfc}
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(Session session)throws HibernateException { (l P4D:X
Criteria criteria = YxkEAb!+
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detachedCriteria.getExecutableCriteria(session); ?ZV0
int totalCount = ^oB1 &G
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((Integer) criteria.setProjection(Projections.rowCount |M/
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()).uniqueResult()).intValue(); OK J%M]<
criteria.setProjection XXwhs-:o
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(null); z+D,:!yF
List items = 5'-9?-S"
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criteria.setFirstResult(startIndex).setMaxResults P~ZV:Of
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(pageSize).list(); wXZY5-h4
PaginationSupport ps = KC-aLq/
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new PaginationSupport(items, totalCount, pageSize, ,L:)ZZgN
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startIndex); (dipKs?K
return ps; ,h`D(,?X
} t RyGxqiG
}, true); 6Vzc:8o>
} 2,Dc]oj
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public List findAllByCriteria(final EF=D}"E6pO
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DetachedCriteria detachedCriteria){ ?E_p ,#9j)
return(List) getHibernateTemplate RTY4%6]O
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().execute(new HibernateCallback(){ hPpXB:(-0
publicObject doInHibernate ;k%sKVP
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(Session session)throws HibernateException { <0
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Criteria criteria = N,,2VSUr
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detachedCriteria.getExecutableCriteria(session); ;f^jB;\<
return criteria.list(); =<h=">}5'
} QGj5\{E_
}, true); gq1Y]t|4F
} 1WN93SQ=
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public int getCountByCriteria(final W}_}<rlF
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DetachedCriteria detachedCriteria){ _rJSkZO
Integer count = (Integer) Z_~DTO2Qg
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getHibernateTemplate().execute(new HibernateCallback(){ gj;G:;1m
publicObject doInHibernate uWj-tzu
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(Session session)throws HibernateException { F_ Cz
Criteria criteria = _-\{kJ
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detachedCriteria.getExecutableCriteria(session); TC#B^m`'p
return 2U+p@}cQUA
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criteria.setProjection(Projections.rowCount <!(n5y_
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()).uniqueResult(); O~0
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} #p`7gFl
}, true); , tj7'c$0
return count.intValue(); 9d}nyJ
} [te7uZv-
} 5g2+Ar(
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用户在web层构造查询条件detachedCriteria,和可选的 8|Y^Jn\p5u
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 S
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PaginationSupport的实例ps。 O;?~#E<6w
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ps.getItems()得到已分页好的结果集 {Dq51
ps.getIndexes()得到分页索引的数组 L1 VTq9[3
ps.getTotalCount()得到总结果数 I|;#VejX
ps.getStartIndex()当前分页索引 d`7] reh
ps.getNextIndex()下一页索引 8E%*o
ps.getPreviousIndex()上一页索引 x,_Ucc.
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 liP{Mu/LO
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 <);u]0
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一下代码重构了。 QLG,r^
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我把原本我的做法也提供出来供大家讨论吧: =oDrN7`,B
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首先,为了实现分页查询,我封装了一个Page类: ;gV8f{X{Z
java代码: 9E?>B3t^
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/*Created on 2005-4-14*/ cA2]VL.r>C
package org.flyware.util.page; #
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/** Mv=;+?z!
* @author Joa _Y {g5t
* =^v Ub
*/ @7'gr>_E
publicclass Page { B=|sLs`I
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/** imply if the page has previous page */ ^yTN(\9
privateboolean hasPrePage; U$bM:d
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/** imply if the page has next page */ a!]%@A6p
privateboolean hasNextPage; 7yl'!uz)9
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/** the number of every page */ "O
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privateint everyPage; -',Y;0b%
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/** the total page number */ W:J00rsv=`
privateint totalPage; MJ08@xGa
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/** the number of current page */ cTp+M L
privateint currentPage; PQr
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/** the begin index of the records by the current xW~@V)OH
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query */ 1| DI'e[X
privateint beginIndex; c 3dZ1v
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/** The default constructor */ 'QU ?O[CH
public Page(){ W9~datIh>
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} o+&sodt|`
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/** construct the page by everyPage e>.xXg6Zn
* @param everyPage 5H5Kt9DoW
* */ ]3'd/v@fT
public Page(int everyPage){ &tIm
this.everyPage = everyPage; r%i{a
} r_m&Jl@4
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/** The whole constructor */ jo~vOu
public Page(boolean hasPrePage, boolean hasNextPage, U"]i.J1
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int everyPage, int totalPage, E?uv&evPK7
int currentPage, int beginIndex){ CjGI}t
this.hasPrePage = hasPrePage; A )cb
this.hasNextPage = hasNextPage; HZ3<}`P_W
this.everyPage = everyPage; i1C'
this.totalPage = totalPage; <0m;|Ai'W
this.currentPage = currentPage; R?Qou!*]
this.beginIndex = beginIndex; J:a^''
} QR)eJ5<
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/** v5o%y:~
* @return {Xj%JE[V
* Returns the beginIndex. T9A5L"-6T
*/ L z
publicint getBeginIndex(){ .9ne'Ta
return beginIndex; *#_jTwQe
} S0 `*
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/** `UR.Rn/x
* @param beginIndex 3^Y-P8.zdB
* The beginIndex to set. $B2@mC([S
*/ RZZB?vx
publicvoid setBeginIndex(int beginIndex){ P}jr 8Z
this.beginIndex = beginIndex; N.?Wev{
} ~nQb;Bdh%
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/** W=*\4B]
* @return ^BZdR<;
* Returns the currentPage. ;1nd~0o
*/ q,GL#L
publicint getCurrentPage(){ )r~Oj3TH
return currentPage; OsXQWSkj~
} ;z68`P-
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/** _u0dt) $
* @param currentPage h|
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* The currentPage to set. fu/c)D6u*m
*/ w#XJ!f6*_9
publicvoid setCurrentPage(int currentPage){ XV&