Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 M$GD8|*e
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 *rbayH
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 N@VD-}E
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 -LY_7Kg
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。 <omz9d1
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分页支持类: \kRBJ1)|f
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java代码: ~}5(J,1!
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package com.javaeye.common.util; LgaJp_d>9*
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import java.util.List; )dV.A IQ+
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publicclass PaginationSupport { 8]c`n!u=`
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publicfinalstaticint PAGESIZE = 30; }[Y):Yy
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privateint pageSize = PAGESIZE; 4e(@b3y
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privateList items; nMnc&8r
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privateint totalCount; upJishy&I
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privateint[] indexes = newint[0]; P-mrH
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privateint startIndex = 0; E,X,RM~
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public PaginationSupport(List items, int N+tS:$V
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totalCount){ $DVy$)a!u
setPageSize(PAGESIZE); g %Am[fb
setTotalCount(totalCount); M}vPWWcl
setItems(items); 4 A<c@g2
setStartIndex(0); CuGk?i
} zknD(%a
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public PaginationSupport(List items, int =_86{wlk
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totalCount, int startIndex){ W)_B(;$]
setPageSize(PAGESIZE); k9,"`dk@
setTotalCount(totalCount); Y}6)jzBV
setItems(items); UvI!e4_
setStartIndex(startIndex); pI!55w|
} '71btd1
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public PaginationSupport(List items, int H0HYb\TX ?
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totalCount, int pageSize, int startIndex){
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setPageSize(pageSize); y6s$.93
setTotalCount(totalCount); ,>^~u
setItems(items); ]]7T5'.
setStartIndex(startIndex); HfF$>Z'kM
} !d^`YEfE
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publicList getItems(){ S6QG:|#P
return items; mvw:E_
} joG>=o
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publicvoid setItems(List items){ !9
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this.items = items; 9p.>L8
} f[RnL#*xJU
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publicint getPageSize(){ h(L5MZs
return pageSize; 9+:Trc\%N
} 7Av]f3Zr
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publicvoid setPageSize(int pageSize){ `zL9dlZ
this.pageSize = pageSize; J]UHq$B
} '3Ri/V,
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publicint getTotalCount(){ ,Tx8^|b#F
return totalCount; K+\hv~+@
} `et<Z
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publicvoid setTotalCount(int totalCount){ ".\(A f2
if(totalCount > 0){ 5"Yw$DB9
this.totalCount = totalCount; g9XtE
int count = totalCount / .EcM n
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pageSize; u;!Rv E8N
if(totalCount % pageSize > 0) `+uXL9mo
count++; J3]m*i5A
indexes = newint[count]; 4Y!v$r
for(int i = 0; i < count; i++){ ;p9D2&
indexes = pageSize *
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i; KkY22_{ac
} eBB
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}else{ mm 8O
this.totalCount = 0; { SfU!
} `g=~u{0
} *pMA
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publicint[] getIndexes(){ DkIFvsLK
return indexes; 9E^piLA
} Ba6xkEd
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publicvoid setIndexes(int[] indexes){ cF2/}m]
this.indexes = indexes; H
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} =X*E(.6Ip
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publicint getStartIndex(){ b ~gF,^w
return startIndex; LPO" K"'w
} S\A[Z&k0
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publicvoid setStartIndex(int startIndex){ rx/6x(3
if(totalCount <= 0) ;qMlGXW*q
this.startIndex = 0; 6,PLzZ5
elseif(startIndex >= totalCount) brWt
this.startIndex = indexes =S,<yQJ
9o`3g@6z
[indexes.length - 1]; 7 SZR#L
elseif(startIndex < 0) :+Kesa:E
this.startIndex = 0; 0h#M)Ft
else{ TE~@Bl;{?c
this.startIndex = indexes H JiP:{
]@YQi<d2^
[startIndex / pageSize]; C)w*aU,(
} ,whNh
} mxGN[%ve
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publicint getNextIndex(){ m##=iB|;
int nextIndex = getStartIndex() + 9:o3JGHSc
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pageSize; gwJu&HA/
if(nextIndex >= totalCount) I>aa'em
return getStartIndex(); Y>~JI;Cu`
else Q_.Fw\l$`
return nextIndex; F S:WbFmc
} vEGK{rMA
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publicint getPreviousIndex(){
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int previousIndex = getStartIndex() - Z.pw!mu"
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pageSize; 3;:V1_JA
if(previousIndex < 0) ^q\zC%.
return0; LS'=>s"
else 0
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return previousIndex; 7p6J
} ?C35
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} sA}R!
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抽象业务类 kqw? X{
java代码: _+iz?|U
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/** lvi:I+VgA
* Created on 2005-7-12 JB@VP{
*/ U I C? S
package com.javaeye.common.business; ,~(}lvqVH
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import java.io.Serializable; <>_WdAOuD
import java.util.List; QE2^.|d{
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import org.hibernate.Criteria; 6/ipdi[
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import org.hibernate.HibernateException; \DK*>
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import org.hibernate.Session; &,]+>
import org.hibernate.criterion.DetachedCriteria; D|9fHMg%
import org.hibernate.criterion.Projections; vWs c{9
import (}1f]$V
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org.springframework.orm.hibernate3.HibernateCallback; 4tJ4X' U
import 0!`7kZrN
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org.springframework.orm.hibernate3.support.HibernateDaoS ]bb}[#AY
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upport; Y{RB\}f(
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import com.javaeye.common.util.PaginationSupport; W+e*(W|d6
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public abstract class AbstractManager extends =hIT?Z6A
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HibernateDaoSupport { !!%[JR)cS
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privateboolean cacheQueries = false; kTWg31]~
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privateString queryCacheRegion; 92VX5?Cyg
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publicvoid setCacheQueries(boolean @n*D>g
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cacheQueries){ _PUm
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this.cacheQueries = cacheQueries; Gj`Y2X2r
} cE5Zxcn
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publicvoid setQueryCacheRegion(String `sy &dyM
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queryCacheRegion){ b.q"s6u
this.queryCacheRegion = A>%UYA
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queryCacheRegion; GY]6#>D#7
} }, &,Dt
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publicvoid save(finalObject entity){ Gj8[*3d
getHibernateTemplate().save(entity); 5|G3t`$pa
} I7z/GA\x
:*:fun
publicvoid persist(finalObject entity){ kah3Uhr~
getHibernateTemplate().save(entity);
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} Cmx2/N
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publicvoid update(finalObject entity){ =z1o}ga=EA
getHibernateTemplate().update(entity); m$mY<Q
} k5QD5/Ej
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publicvoid delete(finalObject entity){ kJi&9
getHibernateTemplate().delete(entity); tr9Y1vxo{
} &9w%n
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publicObject load(finalClass entity, )]?egw5l
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finalSerializable id){ I=
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return getHibernateTemplate().load 0$ 9;pzr
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(entity, id); e$+f~~K
} a05:iFoJ
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publicObject get(finalClass entity, - b\V(@5
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finalSerializable id){ 6(^Upk=59
return getHibernateTemplate().get dwbY"t[9
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(entity, id); ph12x: @B
} ]n]uN~)9
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publicList findAll(finalClass entity){ NQiecxvt=
return getHibernateTemplate().find("from l9NOzAH3
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" + entity.getName()); l&??2VO/t
} K*U=;*p)
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publicList findByNamedQuery(finalString d?&!y]RS#
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namedQuery){ h3]@M$Y[
return getHibernateTemplate Q@W|GOH3
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().findByNamedQuery(namedQuery); UG"6RW @
} "ex~LB
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publicList findByNamedQuery(finalString query, opcR~tg@r
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finalObject parameter){ J={OOj
return getHibernateTemplate H")N_BB
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().findByNamedQuery(query, parameter); yg-FJ/
} MpIw^a3(r
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publicList findByNamedQuery(finalString query, mB^I@oZ*
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finalObject[] parameters){ WW[`E
return getHibernateTemplate @>#{WI:"~
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().findByNamedQuery(query, parameters); o~o6S=4,}
} 4&oXy,8LC
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publicList find(finalString query){ *0&4mi8
return getHibernateTemplate().find 2 ]DCF
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(query); N[bRp
} eC^0I78x
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publicList find(finalString query, finalObject 6}i&6@Snq?
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parameter){ ),;D;LI{S
return getHibernateTemplate().find TvWU[=4Yk
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(query, parameter); UR/qVO?
} _<%\h?W$
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public PaginationSupport findPageByCriteria WpJD=C%
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(final DetachedCriteria detachedCriteria){ BA1MGh
return findPageByCriteria t(j_eq}J
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); *dG}R#9Nv
} FYXw$7'l
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public PaginationSupport findPageByCriteria +24|_Lx0
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(final DetachedCriteria detachedCriteria, finalint o%Uu.P
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startIndex){ N
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return findPageByCriteria O>SuZ>g+7
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(detachedCriteria, PaginationSupport.PAGESIZE, (0OSGG9
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startIndex); 6^]`-4*W
} @Xq&t}*8
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public PaginationSupport findPageByCriteria MK-a$~<
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(final DetachedCriteria detachedCriteria, finalint '0R/6Z|/Y
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pageSize, BN\fv,
finalint startIndex){ i>tW|N
return(PaginationSupport) ~']&.
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getHibernateTemplate().execute(new HibernateCallback(){ VMxYZkMNd_
publicObject doInHibernate C!ZI&cD9
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(Session session)throws HibernateException { (XbMrPKG
Criteria criteria = FylWbQU9
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detachedCriteria.getExecutableCriteria(session); *=$[}!YG
int totalCount = /'&.aGW4%
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((Integer) criteria.setProjection(Projections.rowCount k_*XJ <S!Y
CF3E]dt
()).uniqueResult()).intValue(); ~@[(N]=q
criteria.setProjection '?{0z!!
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(null); hi ;WFyJTu
List items = <CNE>@-f
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criteria.setFirstResult(startIndex).setMaxResults T>\nWancQM
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(pageSize).list(); H_%d3 RI
PaginationSupport ps = [<D+pqh
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new PaginationSupport(items, totalCount, pageSize, tk`: CT
*
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startIndex); }iPo8Ra
return ps; PoYr:=S?
} QO5OnYh
}, true); ; @7
} eZ!yPdgy|
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public List findAllByCriteria(final W:VW_3
*C4~}4WT\
DetachedCriteria detachedCriteria){ q?;N7P
return(List) getHibernateTemplate
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().execute(new HibernateCallback(){ gf:vb*#Wa
publicObject doInHibernate ?gd'M_-J,
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(Session session)throws HibernateException { ,3VG.u;U
Criteria criteria = (y=dR1p
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detachedCriteria.getExecutableCriteria(session); DapQ}2'_
return criteria.list(); I`/]@BdgY
} dzgs%qtK
}, true); PzIy">plm
} R&NpdW N
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public int getCountByCriteria(final b%3Q$wIJ6
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DetachedCriteria detachedCriteria){ ?@_v,,|
Integer count = (Integer) rumAo'T/%
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getHibernateTemplate().execute(new HibernateCallback(){ rU;
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publicObject doInHibernate 8'3"uv
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(Session session)throws HibernateException { :0nK`$'
Criteria criteria = pt=7~+r
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detachedCriteria.getExecutableCriteria(session); Vn)%C_-]A
return i%xI9BO9
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criteria.setProjection(Projections.rowCount hA@zoIoe
])N|[ |$
()).uniqueResult(); sk#9x`Rw
} 0FG5_t"",\
}, true); hbVE;
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return count.intValue(); |)^clkuGX
} :L]-'\y
} NU|qX {-
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用户在web层构造查询条件detachedCriteria,和可选的 Er`TryN|}
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 XQK^$Iq]V
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PaginationSupport的实例ps。 S2Zx &D/_
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ps.getItems()得到已分页好的结果集 Dz,uS nnm
ps.getIndexes()得到分页索引的数组 \^yXc*C
ps.getTotalCount()得到总结果数 D=2~37CzQ1
ps.getStartIndex()当前分页索引 ,r@xPZPz:e
ps.getNextIndex()下一页索引 *:?QB8YJ
ps.getPreviousIndex()上一页索引 *f{7
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 3*G5F}7%=
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 P=2wkzeJj
w(/7Jt$
一下代码重构了。 sD{j@WEZ
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我把原本我的做法也提供出来供大家讨论吧: b~1iPaIh
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首先,为了实现分页查询,我封装了一个Page类: I[@ts!YD
java代码: ?vvG)nW
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/*Created on 2005-4-14*/ Ih; aBS
package org.flyware.util.page; aUAcRW
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/** 2v4W6R
* @author Joa V)=Z6 ti
* )W#T2Z>N1
*/ 18jJzYawh
publicclass Page { S,XKW(5
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/** imply if the page has previous page */ 46ILs1T6
privateboolean hasPrePage; ;"D~W#0-v
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/** imply if the page has next page */ iZC>)&ax
privateboolean hasNextPage; KVg[#~3
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/** the number of every page */ Z A [ )
privateint everyPage; 00"CC
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/** the total page number */ oI*d/*
privateint totalPage; DjY8nePyE
P`tyBe#=
/** the number of current page */ \Fq1^ 8qa
privateint currentPage; |4Qx=x>
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/** the begin index of the records by the current -'j7SOGk
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query */ GKCM|Y
privateint beginIndex;
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/** The default constructor */ S.1(3j*
public Page(){ 7H4L-J3
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} ]Y{,N x
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/** construct the page by everyPage #,TELzUVE
* @param everyPage -;vT<G3
* */ )y`i@S}J
public Page(int everyPage){ x7HA722w
this.everyPage = everyPage; ]W;:|/,c
} zz&vfO31J
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/** The whole constructor */ b;*c:{W)
public Page(boolean hasPrePage, boolean hasNextPage, EZ/^nG
bi.wYp(*6L
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int everyPage, int totalPage, eSn$k:\W
int currentPage, int beginIndex){ VtWT{y5Ec
this.hasPrePage = hasPrePage; St+ "ih%
this.hasNextPage = hasNextPage; :G#KB'
this.everyPage = everyPage; ?,>5[Ha^?
this.totalPage = totalPage; S@Iw;V
this.currentPage = currentPage; oPsK:GC`U
this.beginIndex = beginIndex; NCn`}QP
} "H$@b`)
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/** F{\=PCZ>7
* @return @y5= J`@=
* Returns the beginIndex. 0yaMe@&,
*/ 57<Di!rt
publicint getBeginIndex(){ x}|+sS,g
return beginIndex; Y.NE^Vn0
} 6A?8tm/0
or!!s
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/** e}e6r3faz
* @param beginIndex {yS;NU`2
* The beginIndex to set. ws[/
*/ 7E\g
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publicvoid setBeginIndex(int beginIndex){ T)~!mifX
this.beginIndex = beginIndex; <aXoB*Y
} C `6S}f,
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/** H{%H^t>
* @return T
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* Returns the currentPage. *{|$FQnR>(
*/ oqYt/4^Q
publicint getCurrentPage(){ IJ_ m
return currentPage; m]P/if7
} d8o ewkiR
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/** vY_eDJ~'
* @param currentPage tF%QH[
* The currentPage to set. uXpv*i{R
*/ /?P!.!W&
publicvoid setCurrentPage(int currentPage){ K{2h9 ]VF
this.currentPage = currentPage; 0m
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} j8a[
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/** 7 >bMzdH
* @return $w/E9EJ)3A
* Returns the everyPage. mX;H((
*/ \<V)-eB
publicint getEveryPage(){ En\Z#0,V
return everyPage; 8kH<$9
} 3+V#[JBJv
`[Sl1saZ$S
/** hl]S'yr
* @param everyPage !}t-j3bCs
* The everyPage to set. V%51k{
*/ r]T0+ oQ>
publicvoid setEveryPage(int everyPage){ T,OS 0;7O
this.everyPage = everyPage; ?Oc
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} kP^*hO!%
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/** `{o$F ::(
* @return RG}}Oh="v
* Returns the hasNextPage. ,H{={aln
*/ d}+W"j;
publicboolean getHasNextPage(){ :c:V%0Yji
return hasNextPage; .&|L|q}
} WFDCPQ@
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/** <u0,Fp
* @param hasNextPage eGvOA\y:
* The hasNextPage to set. :tbd,Uo
*/ 2(+P[( N1,
publicvoid setHasNextPage(boolean hasNextPage){ $r15gfne>
this.hasNextPage = hasNextPage; F0.z i>5
} &d,Wy"WPi
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/** sLhDO'kM
* @return QN g\4%
* Returns the hasPrePage. FmD +8=
*/ VB"(9O]
publicboolean getHasPrePage(){ 5v|EAjB6o
return hasPrePage; =
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} taDQ65
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/** pkk4h2Ah
* @param hasPrePage "dtlME{Bx
* The hasPrePage to set. fRNP#pi0u
*/ o;J;k_[MX
publicvoid setHasPrePage(boolean hasPrePage){ y-a|Lu*
this.hasPrePage = hasPrePage; ^l(^z fsZ
} ^P$7A]!
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/** r?3Aqi"
* @return Returns the totalPage. Yqj+hC6>,
* m&/=&S
*/ ~kb{K;
publicint getTotalPage(){ Uk'U?9O
return totalPage; vpLMhf`
} 1`l;xw1W
_#pnjo
/** 1~Mn'O%
* @param totalPage y6%<zhs
* The totalPage to set. #PFO]j!_b
*/ D^?_"wjW
publicvoid setTotalPage(int totalPage){ MLS;SCl
this.totalPage = totalPage; gtYRV*^q
} Y[G9Vok
VX
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} J?D\$u:
1;&T^Gdj
nk/vGa4
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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 c-*2dV[@
6+PGwCS
个PageUtil,负责对Page对象进行构造: W[|[;{
java代码: 7' eh)[T
] .5OX84
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/*Created on 2005-4-14*/ hQ';{5IKvC
package org.flyware.util.page; $E.XOpl&I
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import org.apache.commons.logging.Log; AP w6
import org.apache.commons.logging.LogFactory; {ERjeuDm]
],&\%jd<
/** ])N%^Qe$U
* @author Joa %wL,v.}
* l &Z(K,6
*/ C*rd;+1A
publicclass PageUtil { <[hz?:G"$
o^GC=Aca`
privatestaticfinal Log logger = LogFactory.getLog 1JeJxzv>C
D^$OCj\
(PageUtil.class); - 9-fX(I
'C~9]Y].
/** j)L1H*
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* Use the origin page to create a new page /s`;9)G]9
* @param page %g w{[
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* @param totalRecords 7#pZa.B)k
* @return }4h0bI
*/ ym%o}(v-
publicstatic Page createPage(Page page, int d~`-AC+
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totalRecords){ RIjM(P
return createPage(page.getEveryPage(), 98UlNP
h=[-Er'B
page.getCurrentPage(), totalRecords); xa#gWIP*
} N-%#\rPq.
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/** @T7PZB&xnl
* the basic page utils not including exception , N
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handler ^:z7E1~
* @param everyPage f3&/r
* @param currentPage |!Ists
* @param totalRecords A.U'Q|
* @return page fU
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*/ IG|\:Xz
publicstatic Page createPage(int everyPage, int ]o*$h$? s
) 4ncutb
currentPage, int totalRecords){ O<X
)p`,`
everyPage = getEveryPage(everyPage); 38wq (
currentPage = getCurrentPage(currentPage); sX'nn
int beginIndex = getBeginIndex(everyPage, 6"%2,`Nu
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currentPage); sHs g_6~
int totalPage = getTotalPage(everyPage, %wW'!p-<
>'Hx1;
totalRecords); uV77E*+7\
boolean hasNextPage = hasNextPage(currentPage, +c?ie4
7K :FeW'N
totalPage); -tyaE
boolean hasPrePage = hasPrePage(currentPage); r*Z_+a8
xwOE+
returnnew Page(hasPrePage, hasNextPage, 0b++17aV
everyPage, totalPage, 5hz_P+Q
currentPage, P`
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\Tkp
beginIndex); PbEQkjE
} }]GbUC!Zb
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privatestaticint getEveryPage(int everyPage){ 4J}3,+
return everyPage == 0 ? 10 : everyPage; L[. <o{
} Yxqj -
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privatestaticint getCurrentPage(int currentPage){ }`]]b+_b>@
return currentPage == 0 ? 1 : currentPage; #90c$ dc
} f?-J#x)
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privatestaticint getBeginIndex(int everyPage, int E9R]sXf8
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currentPage){ uO"8aD`W
return(currentPage - 1) * everyPage; e~
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}
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privatestaticint getTotalPage(int everyPage, int {u4i*udG`)
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totalRecords){ Tk](eQsy.v
int totalPage = 0; PUKVn+h
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if(totalRecords % everyPage == 0) Z@oKz:U
totalPage = totalRecords / everyPage; BA*&N>a
else ;qb Dbg
totalPage = totalRecords / everyPage + 1 ; O{ BW;Deo
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return totalPage; ArX]L$D
} yxY
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privatestaticboolean hasPrePage(int currentPage){ nX 8B;*p6b
return currentPage == 1 ? false : true; g]4yAV<2
} M:(&n@e
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privatestaticboolean hasNextPage(int currentPage, rXDJ:NP
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int totalPage){ zzE]M}s
return currentPage == totalPage || totalPage == b"3uD`
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0 ? false : true; vX 1W@s
} Ys%'#f
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} h[y*CzG
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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。 -)>(8 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 SctJxY(}!
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做法如下: $+!}Vtb
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 &;NNUT>Q
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的信息,和一个结果集List: #whO2Mv
java代码: Gg}LC+Y
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/*Created on 2005-6-13*/ y0&V$uv/
package com.adt.bo; T;:',T[G
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import java.util.List; dFI.`pB
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import org.flyware.util.page.Page; 32iWYN
eSvc/ CU
/** ;4S
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* @author Joa ?v )"%.
*/ WRLu3nBx
publicclass Result { ' F 6au[
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private Page page; XDrlJvrPL
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private List content; bY"eC i{K
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/** HAI1%F236
* The default constructor xyz\;3
*/ lvz:UWo
public Result(){ 72s$
super(); 8,H#t@+MT
} ?4wehcZz
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/** HkfSx rTgQ
* The constructor using fields QAOk
* G8<It5CU
* @param page =B o4yN
* @param content P60]ps!M
*/ +NzD/.gq
public Result(Page page, List content){ My6]k?;}(
this.page = page;
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this.content = content; VvMU)
} Tl/Dq(8JH
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/** *]>OCGsr
* @return Returns the content. [hv3o0".
*/ n_xQSVI0F
publicList getContent(){ .2(@jx,[
return content; >ihe|WN
} (W}i287
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/** +poIgjq0
* @return Returns the page. *{;A\sL
*/ D)/XP
public Page getPage(){ !3X%5=#L4
return page; k+m_L{#m5
} *> &N
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/** L/ICFa.G
* @param content {L2Gb(YLW
* The content to set. vS*0CR\
*/ )Ido|!]0d
public void setContent(List content){ \'^Z_6{w
this.content = content; Med"dHo7
} ss*2TE7
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/** 82@;.%
* @param page 1Sc~Vb|>
* The page to set. {;z
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*/ h> 5~
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publicvoid setPage(Page page){ B|q3;P
this.page = page; !,(bXa\^
} dXK~
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