Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 >4gGb)
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .w/_Om4T*b
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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 ]]
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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 (Kl96G<Wej
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分页支持类: m{(G%n>E&
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java代码: $"z|^ze
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package com.javaeye.common.util; s2-`}LL
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import java.util.List; wb@TYvDt
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publicclass PaginationSupport {
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publicfinalstaticint PAGESIZE = 30; lkNaSz[
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privateint pageSize = PAGESIZE; FOB9J.w4
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privateList items; (Sr D
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privateint totalCount; x7qVLpcL3z
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privateint[] indexes = newint[0]; 'l+).},
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privateint startIndex = 0; M_wqb'=
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public PaginationSupport(List items, int '+6H= Qn
V)
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totalCount){ 1]wx Ru
setPageSize(PAGESIZE); =Ri'Prx&
setTotalCount(totalCount); C5Fk>[fS
setItems(items); >k gL N
setStartIndex(0); |D `r o
} J7FCW^-`3
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public PaginationSupport(List items, int =D<{uovQB
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totalCount, int startIndex){ '~2S BX?J
setPageSize(PAGESIZE); 02U5N(s
setTotalCount(totalCount); Z x9oj
setItems(items); dd+[FU
setStartIndex(startIndex); 2b|$z"97jj
} %d..L-`]ET
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public PaginationSupport(List items, int 8cq H0{
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totalCount, int pageSize, int startIndex){ }!tJ3G
setPageSize(pageSize); `mN*"1p-
setTotalCount(totalCount); =|lw~CW
setItems(items); GfEg][f
setStartIndex(startIndex); @<$-*,
} pkd#SY
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publicList getItems(){ m_{?py@tZ
return items; mTG v*=l
} 7M~w05tPh
+}IOTw"O`
publicvoid setItems(List items){ "i+fO&LpZ
this.items = items; "c[ D0{\{
} uWs5+
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publicint getPageSize(){ }]0f -}
return pageSize; ]s3U +t?
} u="VJ3
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publicvoid setPageSize(int pageSize){ 4wLp
this.pageSize = pageSize; %i!&Fr
} &&Sl0(6x[T
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publicint getTotalCount(){ YQU#aOl
return totalCount; ^j"*-)R
} m2!y;)F0
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publicvoid setTotalCount(int totalCount){ dA;f`Bi;Q
if(totalCount > 0){ %_*q'6K
this.totalCount = totalCount; B^W0Ik`m
int count = totalCount / 3GkVMYI
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pageSize; _1D'9!+
if(totalCount % pageSize > 0) p=T,JAI t
count++; Ol8ma`}Nq3
indexes = newint[count]; "xS?#^a
for(int i = 0; i < count; i++){ m791w8Vr
indexes = pageSize * 9UD~$_<\
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i; _7?LINF9
} &yFt@g]
}else{ ~(2G7x)
this.totalCount = 0; &"v h=Z-
} 9v_B$F$_T
} 0E9LZOw4T
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publicint[] getIndexes(){ XWQp-H.
return indexes; Z4U8~i
} >L6V!
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publicvoid setIndexes(int[] indexes){ sxq'uF(K
this.indexes = indexes; F\1{b N|3
} E|!rapa
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publicint getStartIndex(){ V#!ftu#c?
return startIndex; R:7j`gHJ|9
} %T3L-{s5
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publicvoid setStartIndex(int startIndex){ YN
Lc )
if(totalCount <= 0) !C&!Wj
this.startIndex = 0; A;~u"g 'z&
elseif(startIndex >= totalCount) /aa'ryl_%
this.startIndex = indexes tlo"tl_]
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[indexes.length - 1]; k(>hboR5n
elseif(startIndex < 0) Q_<CG[,6D1
this.startIndex = 0; X(m&
else{ U0}]3a0
this.startIndex = indexes 4%#C _pE9
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[startIndex / pageSize]; P$MAURFm
} s'yA^
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} $xT'cl/IH
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publicint getNextIndex(){
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int nextIndex = getStartIndex() + ejYJOTT{^
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pageSize; w{$t:l)2,
if(nextIndex >= totalCount) HbWl:y U
return getStartIndex(); FyuCYg
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else T7eo_Mn
return nextIndex; >mzK96
} a%2r]:?^?
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publicint getPreviousIndex(){ Yc+0OBH[
int previousIndex = getStartIndex() - }a= &o6=
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pageSize; =k]Rze I
if(previousIndex < 0) <5*cc8
return0; !Fa2F~#h
else RFyeA.
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return previousIndex; MW%EJT>@z
} ;Wjb}_V:_
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} y"=j[.
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抽象业务类 @C40H/dE
java代码: L5C4#X
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/** |1`|E-S=
* Created on 2005-7-12 o ~"?K2@T
*/ uZ mi
package com.javaeye.common.business;
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import java.io.Serializable; qv<[f=X9|
import java.util.List; oy90|.]G
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import org.hibernate.Criteria; +JE
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import org.hibernate.HibernateException; A@^e4\
import org.hibernate.Session; /I~iUND"G
import org.hibernate.criterion.DetachedCriteria; 2[i:bksjW
import org.hibernate.criterion.Projections; cPe0o'`[
import HpI[Af}l
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org.springframework.orm.hibernate3.HibernateCallback; 7B
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import @$ E&H`da
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org.springframework.orm.hibernate3.support.HibernateDaoS qG.HJD
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upport; WlnmW(uahW
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import com.javaeye.common.util.PaginationSupport; _uL{@(
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public abstract class AbstractManager extends \`?l6'!
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HibernateDaoSupport { -~Kw~RX<(
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privateboolean cacheQueries = false; 0sW=;R2
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privateString queryCacheRegion; H3T4v1o6
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publicvoid setCacheQueries(boolean gE^
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cacheQueries){ \4y7!
this.cacheQueries = cacheQueries; GD?4/HkF
} 9(k5Irv"'h
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publicvoid setQueryCacheRegion(String L2Ynv4llm
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queryCacheRegion){ >YuBi:z
this.queryCacheRegion = 0?525^
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queryCacheRegion; @O b$w1c
} _W]qV2j
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publicvoid save(finalObject entity){ +VSJve |
getHibernateTemplate().save(entity); dM"Suw
} g+h)s!$sB
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publicvoid persist(finalObject entity){ U-(2;F)
getHibernateTemplate().save(entity); cOa.]Kk
} Wi_5.=
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publicvoid update(finalObject entity){ Y3G$(+i8
getHibernateTemplate().update(entity); ]MJyBz+k
} JgXP2|Y !
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publicvoid delete(finalObject entity){ qCg`"/0
getHibernateTemplate().delete(entity); 24Lo.
} tW;?4}JR
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publicObject load(finalClass entity, Vrl)[st!;I
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finalSerializable id){ C=L_@{^Rgb
return getHibernateTemplate().load =E@wi?
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(entity, id); ](yw2c;me
} ~[bS+]d!
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publicObject get(finalClass entity, UD6D![e
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finalSerializable id){ 1SoKnfz{6
return getHibernateTemplate().get L<bZVocOb_
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(entity, id); ZzET8?8
} HlEp
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publicList findAll(finalClass entity){ MJsz
return getHibernateTemplate().find("from pE(\q+1<
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" + entity.getName()); 6v7H?4
} )%'Lm
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publicList findByNamedQuery(finalString b(wzn`Z%Et
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namedQuery){ = Ly7H7Q2
return getHibernateTemplate [v$_BS#u^3
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().findByNamedQuery(namedQuery); b'Cy!d r
} |/K+tH
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publicList findByNamedQuery(finalString query, +tFm DDx=
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finalObject parameter){ ;!U`GN,tH
return getHibernateTemplate z^=.05jB
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().findByNamedQuery(query, parameter); udxLHs
} J{8_4s!Xt>
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publicList findByNamedQuery(finalString query, R=ddQ:W6g
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finalObject[] parameters){ ct='Z E
return getHibernateTemplate j3 d=O!
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().findByNamedQuery(query, parameters); n\k6UD
} q]Gym 7o
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publicList find(finalString query){ DArEIt6Q
return getHibernateTemplate().find [OJ@{{U%
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(query); AnVj
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} v w$VRPW
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publicList find(finalString query, finalObject @=ABO"CQ
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parameter){ Rfh#JO@%[
return getHibernateTemplate().find zA[6rYXY
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(query, parameter); et]-;(M
} \F=w~
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public PaginationSupport findPageByCriteria iyNyj44
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(final DetachedCriteria detachedCriteria){ .lrI|BH?z
return findPageByCriteria cQEK>aAd
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); NyU~8?bp
} xXQ#?::m
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public PaginationSupport findPageByCriteria lO},fM2j
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(final DetachedCriteria detachedCriteria, finalint \[&`PD
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startIndex){ 1c);![O
return findPageByCriteria ~5$V8yfx h
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(detachedCriteria, PaginationSupport.PAGESIZE, X~XpX7d!
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startIndex); Z\8TpwD2
} qH'T~#S
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public PaginationSupport findPageByCriteria S)Cd1`Gf
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(final DetachedCriteria detachedCriteria, finalint ws9F~LmLbr
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pageSize, l]RO'
finalint startIndex){ 01Bs7@"+
return(PaginationSupport) q:N"mp<%
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getHibernateTemplate().execute(new HibernateCallback(){ |0YDCMq(
publicObject doInHibernate 8v)pPJr
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(Session session)throws HibernateException { Ho[Kxe[c
Criteria criteria = n1K"VjZk
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detachedCriteria.getExecutableCriteria(session);
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int totalCount = 5]cmDk
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((Integer) criteria.setProjection(Projections.rowCount _YzItge*
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()).uniqueResult()).intValue(); 8
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criteria.setProjection 7eb^^a?
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(null); /h'V1zL#
List items = k&|L"N|w
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criteria.setFirstResult(startIndex).setMaxResults B$A`-
1<a+91*=e
(pageSize).list(); 8_0j^oh
PaginationSupport ps = A-<\?13uW
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new PaginationSupport(items, totalCount, pageSize, Aat_5p
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startIndex); ],ioY*4G
return ps; @8X)hpHf
} 1(0LX^%
}, true); TJ9JIxnS
} M@@l>"g@
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public List findAllByCriteria(final :-HVK^$%
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DetachedCriteria detachedCriteria){ 6W&huIQ[
return(List) getHibernateTemplate IB#L5yN r
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().execute(new HibernateCallback(){ >?K@zsv}
publicObject doInHibernate F VBuCi?W
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(Session session)throws HibernateException { "w]
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Criteria criteria = R,[dEP
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detachedCriteria.getExecutableCriteria(session); -'btKz*9
return criteria.list(); In)8AK(Hw
} }MBxfZ 4I
}, true); FbB^$ ]*
} h-u63b1"?
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public int getCountByCriteria(final 7Pspx'u
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DetachedCriteria detachedCriteria){ Lqy]bnY
Integer count = (Integer)
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getHibernateTemplate().execute(new HibernateCallback(){ EJ7}h?a]U_
publicObject doInHibernate mX))*e4k
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(Session session)throws HibernateException { dLl/V3C6t
Criteria criteria = -Z)j"J
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detachedCriteria.getExecutableCriteria(session); 5P~{*of
return =Tv;?U C
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criteria.setProjection(Projections.rowCount !}7FC>Cx
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()).uniqueResult(); TZ8:3ti
} Y?G9d6]Lk6
}, true); _E0XUT!rA
return count.intValue(); S*,DX~vig
} BUR96YN.
} ?B>
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用户在web层构造查询条件detachedCriteria,和可选的 !p$z8~
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 <u>l#weG,
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PaginationSupport的实例ps。 ?K9&ye_rgw
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ps.getItems()得到已分页好的结果集 ;{mKt%#
ps.getIndexes()得到分页索引的数组 HD^ Ou5YB
ps.getTotalCount()得到总结果数 ,z A9*
ps.getStartIndex()当前分页索引 h!l&S2)D`
ps.getNextIndex()下一页索引 :l~^un|<2Y
ps.getPreviousIndex()上一页索引 -Lh\]
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ;!H<W[
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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 D; xRgHn
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一下代码重构了。 hgt@Mb
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我把原本我的做法也提供出来供大家讨论吧: G Y? ?q8
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首先,为了实现分页查询,我封装了一个Page类: ?U+^ctwv7
java代码: MR$R#
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/*Created on 2005-4-14*/ )S41N^j.
package org.flyware.util.page; 7K"{}:
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/** 8:*
* @author Joa (9g L
* P`ZzrN
*/ }J=>nL'B
publicclass Page { @\{L%y%a0
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/** imply if the page has previous page */ aU&p7y4C@
privateboolean hasPrePage; 3$<u3Zi6
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/** imply if the page has next page */ 7X+SK&PX
privateboolean hasNextPage; SZVNu*G!H
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/** the number of every page */ u@ MUcW
privateint everyPage; b$7p`Ay
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/** the total page number */ S87E$k
privateint totalPage; DxuT23.
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/** the number of current page */ z;T_%?u
privateint currentPage; %x}iEqk U
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/** the begin index of the records by the current is?#wrV=K
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query */ =|}_ASbzw
privateint beginIndex; 5"~F#vt
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/** The default constructor */ .|XG0 M
public Page(){ b'x26wT?
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} dnEIR5%+.
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/** construct the page by everyPage qr$h51C&
* @param everyPage Sj=x.Tr\
* */ 2A>s
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public Page(int everyPage){ SSr#MIS?
this.everyPage = everyPage; &A/k{(.XP
} 4F[4H\>'
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/** The whole constructor */ _E\Cm
public Page(boolean hasPrePage, boolean hasNextPage, H$D),s
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int everyPage, int totalPage, c{"=p8F_
int currentPage, int beginIndex){ {J&[JA\
this.hasPrePage = hasPrePage; io&FW!J.
this.hasNextPage = hasNextPage; JxP&znng
this.everyPage = everyPage; dG8_3T}i
this.totalPage = totalPage; G 6r2
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this.currentPage = currentPage; Jy^.L$bt
this.beginIndex = beginIndex; .ei5+?V<i
} <cof
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/** ;!~&-I0l
* @return Z]~) ->=}
* Returns the beginIndex. %XC3V7
*/ 5>Kk>[|.
publicint getBeginIndex(){ }Quk n
return beginIndex; &':Ecmo~`
} $@Bd}35 J
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/** ]z77hcjB1
* @param beginIndex cFD3
* The beginIndex to set. rp&XzMwC4
*/ <%Al(Lm0
publicvoid setBeginIndex(int beginIndex){ }Fq~!D
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this.beginIndex = beginIndex; f(Su
} e 48N[p
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/** Be$v%4
* @return rv?4S`Z,x$
* Returns the currentPage. 3<
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*/ 1m~-q4D)V
publicint getCurrentPage(){ W9D~:>^YP
return currentPage; <5 )F9.$
} $-i(xnU/nl
drwD3jx0xv
/** 6*&$ha}X
* @param currentPage Q8H+=L:
* The currentPage to set. 4'~zuUs
*/ ,J&\)
yTP
publicvoid setCurrentPage(int currentPage){ \{EYkk0]
this.currentPage = currentPage; xqQLri}
} -HU4Ow
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/** ?hmuAgOtbh
* @return 8wEUly
* Returns the everyPage. \\ZCi`O
*/ C~-.zQ$
publicint getEveryPage(){ ?/}N
return everyPage; dW5@Z-9
} ,;@vVm'}
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/** }?)U`zF)7}
* @param everyPage n&%0G2m:
* The everyPage to set. 9;7|MPbR
*/ (V x2*Aw]
publicvoid setEveryPage(int everyPage){ OLZs}N+ ;]
this.everyPage = everyPage; h(K}N5`
} ucYweXsO3
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/** &[z<p
* @return WYN0,rv1:+
* Returns the hasNextPage. iLt2L;v>h
*/ j Gp&P
publicboolean getHasNextPage(){ 8n,/hY>w
return hasNextPage; 5wa'SexqE
} $
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/** _iF*BnmN
* @param hasNextPage .% 79(r^
* The hasNextPage to set. TE9Iyl|=
*/ nB;[;dCz
publicvoid setHasNextPage(boolean hasNextPage){ &+]-e;[
this.hasNextPage = hasNextPage; 9e*o$)j_
} m-2!r*(zt
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/** 8ZF!}kb0F
* @return }nRTw2-z
* Returns the hasPrePage. }X/>WiGh:
*/ Ye| (5f
publicboolean getHasPrePage(){ b]4\$ rW7
return hasPrePage; A<y]D.Z"
} vW-o%u*
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/** $ ~%w21?&
* @param hasPrePage '2Lx>nByk
* The hasPrePage to set. m}(M{^\|
*/ DkEf;P
publicvoid setHasPrePage(boolean hasPrePage){ 0|DyYu
this.hasPrePage = hasPrePage; fcTg/EXn
} &u!MI
-asjBSo*D
/** skYHPwJdW
* @return Returns the totalPage. VGf&'nL@,
* V-(*{/^"
*/ D}`MY\H
publicint getTotalPage(){ t2Px?S?
return totalPage; TQtHU6
} %O$=%"D6
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/** !>#gm7
* @param totalPage ceuEsQ}
* The totalPage to set. ..R JHa6B
*/ q`3HHq
publicvoid setTotalPage(int totalPage){ eH V#Mey[
this.totalPage = totalPage; PpLiH9}
} =$y;0]7Lwi
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} I7\T :Q[
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IF cre
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 M.\XG}RR
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个PageUtil,负责对Page对象进行构造: jwg*\HO,s
java代码: 6!HYx
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/*Created on 2005-4-14*/ &;bey4_J
package org.flyware.util.page; ,9M2'6=
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import org.apache.commons.logging.Log; @?jbah#
import org.apache.commons.logging.LogFactory; ;Y,zlq2
e8E' X
/** 3 Q~0b+k
* @author Joa l cM
* aCJ-T8?'
*/ @ULd~
publicclass PageUtil { (-],VB
(+
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privatestaticfinal Log logger = LogFactory.getLog u_}UU
2
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(PageUtil.class); 53$;ZO3
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/** k(M"k!M
* Use the origin page to create a new page O)ose?Z
* @param page AV4fN@BX
* @param totalRecords XSCcumde!
* @return ,|GjrT{vf
*/ 4s9.")G
publicstatic Page createPage(Page page, int If]rg+|U
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totalRecords){ p({Lp}'
return createPage(page.getEveryPage(), `H q*l"8
j"jQiL_*
page.getCurrentPage(), totalRecords); |S~$IFN4
} gb4$W@N7V
M?=I{}!@Q
/** Ljiw9*ZI
* the basic page utils not including exception >xA(*7
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handler OnU-FX<
* @param everyPage 'BUfdb8d
* @param currentPage &'`ki0Xh;
* @param totalRecords NHQoP&OG
* @return page WFzM s
*/ q{%~(A5*H
publicstatic Page createPage(int everyPage, int 5i}g$yjZ<
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currentPage, int totalRecords){ ;<GK{8
everyPage = getEveryPage(everyPage); 3}8L!2_p
currentPage = getCurrentPage(currentPage); *7=`]w5k1
int beginIndex = getBeginIndex(everyPage, PJ=| g7I
r,3\32[?
currentPage); R)4,f~@"
int totalPage = getTotalPage(everyPage, >Q'*~S@v3
#C'E'g0
totalRecords); *VHWvj
boolean hasNextPage = hasNextPage(currentPage, A^$xE6t
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totalPage); 8_ascvs5
boolean hasPrePage = hasPrePage(currentPage); '?
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returnnew Page(hasPrePage, hasNextPage, P_b!^sq9
everyPage, totalPage, w ~"%&SNN
currentPage, E^gN]Z"O
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beginIndex); h6IO ;:P)
} 2.=G
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privatestaticint getEveryPage(int everyPage){ $-|$4lrS
return everyPage == 0 ? 10 : everyPage; {2QP6X sJ
} [$uKI,l
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privatestaticint getCurrentPage(int currentPage){ :>0,MO.^~K
return currentPage == 0 ? 1 : currentPage; MBLDxsZ-
} 6tjV^sjs
}#;.b'`
privatestaticint getBeginIndex(int everyPage, int
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)vN
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currentPage){ wv\V&U$
return(currentPage - 1) * everyPage; $iMLT8U
} Qg]A^{.1
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privatestaticint getTotalPage(int everyPage, int ,j9? 9Z7R
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totalRecords){ 4\nGWi{2
int totalPage = 0; X&| R\v=}
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if(totalRecords % everyPage == 0) *0?@/2&
totalPage = totalRecords / everyPage; bo@
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else Jh<s '&FR
totalPage = totalRecords / everyPage + 1 ; QoZZXCU
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return totalPage; | lZJt
} Fa\jVFIQ
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privatestaticboolean hasPrePage(int currentPage){ Vy| 4k2
return currentPage == 1 ? false : true; 49<t2^1q
} )y Zr]
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privatestaticboolean hasNextPage(int currentPage, yGSZ;BDW:K
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int totalPage){ lzz;L
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return currentPage == totalPage || totalPage == KF5r?|8M
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0 ? false : true; Owgy<@C
} 4eG\>#5
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} M#-E
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 3:8p="$F
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 r:g_mMvB
zUNUH^Il
做法如下: _h1eW9q
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ZBFn
km][QEXs%
的信息,和一个结果集List: ~(yW#'G
java代码: L|:CQ
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/*Created on 2005-6-13*/ ^W9O_5\g4a
package com.adt.bo; %;R&cSZ