Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 |YE,) kiF
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 s,$Z("B
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 0HHui7Yy>
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 J+}+"h~.
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分页支持类: N>A{)_k3
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java代码: })o~E
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package com.javaeye.common.util; wovmy{K
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import java.util.List; VG<Hw{ c3r
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publicclass PaginationSupport { 0^GbpSW{
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publicfinalstaticint PAGESIZE = 30; Sc1+(z
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privateint pageSize = PAGESIZE; y:[BP4H ?y
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privateList items; LbJtpwz>z
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privateint totalCount; u\{qH!?t
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privateint[] indexes = newint[0]; Yz&*PPx
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privateint startIndex = 0; Ni2]6U
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public PaginationSupport(List items, int `6a]|7|f
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totalCount){ uP{;*E3?
setPageSize(PAGESIZE); DE*MdfP0
setTotalCount(totalCount); _Kc1
setItems(items); cQ8dc+ {
setStartIndex(0); p=!#],[
} #*!+b
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public PaginationSupport(List items, int kWB, ;7
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totalCount, int startIndex){ `1nRcY
setPageSize(PAGESIZE); f>.4-a?
setTotalCount(totalCount); Tr}R`6d$
setItems(items); puFXPw.3
setStartIndex(startIndex); K*_-5e
} c {1V.
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public PaginationSupport(List items, int ?n!lUr$:y
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totalCount, int pageSize, int startIndex){ !G7h9CF|{
setPageSize(pageSize); CV '&4oq
setTotalCount(totalCount); G49Ng|qn
setItems(items); t,RyeS/
setStartIndex(startIndex); \X&]FZ(*
} cp$.,V
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publicList getItems(){ YzVN2f!n
return items; l;Q
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} /:U1!9.y
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publicvoid setItems(List items){ Ig<}dM.Z[
this.items = items; o6*/o ]]
} |Eb&}m:E$
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publicint getPageSize(){ Zp`~}LV{
return pageSize; V|TA:&:7
} .>P~uZiX!
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publicvoid setPageSize(int pageSize){ 't7Z] G
this.pageSize = pageSize; /mc*Hc8R8
} s}wO7Df=+
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publicint getTotalCount(){ )]73S@P(=
return totalCount; Yt{ji
} ~P/]:=
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publicvoid setTotalCount(int totalCount){ )!i!3
if(totalCount > 0){ QO2Ut!Y
this.totalCount = totalCount; OZ^h\m4
int count = totalCount / Vb2\/e:k
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pageSize; |~eY%LB
if(totalCount % pageSize > 0) hcyn
count++; $.a|ae|K
indexes = newint[count]; 6+iK!&+=
for(int i = 0; i < count; i++){ 8)pB_en3sO
indexes = pageSize * &3I$8v|!?
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i; X@!X6j
} FuuS"G,S
}else{ )A"jVQjI%w
this.totalCount = 0; U+} y
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} Atd1qJ
} uJY.5w
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publicint[] getIndexes(){ 8b7;\C~$p
return indexes; 2 5Q+1
} HyEa_9
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publicvoid setIndexes(int[] indexes){ Jn*Nao_)
this.indexes = indexes; uf]Y^,2
} T`?n,'!(
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publicint getStartIndex(){ l<xFnj
return startIndex; n'?4.tb
} IcFK,y%1
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publicvoid setStartIndex(int startIndex){ b+Vi3V
if(totalCount <= 0) &2{]hRM
this.startIndex = 0; 3u_oRs
elseif(startIndex >= totalCount) *Tp]h 0
this.startIndex = indexes >)^NJ2Fd
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[indexes.length - 1]; (@q3^)I4
elseif(startIndex < 0) 59i]
this.startIndex = 0; YBvd
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else{ :!O><eQw
this.startIndex = indexes s@~/x5jwCs
[D[D`gpjA
[startIndex / pageSize]; o,FUfO}F
} iNJAZ6@+
} ?E7=:h(@t
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publicint getNextIndex(){ .S!-e$EJ
int nextIndex = getStartIndex() + D0 ruTS
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pageSize; Q]#Z9 H
if(nextIndex >= totalCount) ~<,Sh~Ana.
return getStartIndex(); L/x(RCD
else 6m[9b*s7
return nextIndex; }9CrFTbx;
} xNX'~B^4d
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publicint getPreviousIndex(){ t',BI
int previousIndex = getStartIndex() - \Y e%o}.{
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pageSize; j Nc<~{/
if(previousIndex < 0) m}5q]N";x
return0; z0Xa_w=
else nxQ}&n
return previousIndex; G),db%,X2
} tU:FX[&?R
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} ~@P )tl>
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抽象业务类 Rp/-Pv
java代码: U$'y_}V
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/** ?@UAL.y
* Created on 2005-7-12 "'A"U
*/ :woa&(wN;1
package com.javaeye.common.business; H/J<Pd$p
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import java.io.Serializable; D9-Lg%
import java.util.List; yd>}wHt
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import org.hibernate.Criteria; &Rp"rMeW
import org.hibernate.HibernateException; kG^dqqn6
import org.hibernate.Session; >IY,be6>P
import org.hibernate.criterion.DetachedCriteria; };sMU6e
import org.hibernate.criterion.Projections; |+NuYz?
import z+3 9ee
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org.springframework.orm.hibernate3.HibernateCallback; C4NRDwU|.
import (M`|'o!
c_1/W{
org.springframework.orm.hibernate3.support.HibernateDaoS (vQ+e
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upport; BXhWTGiG
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import com.javaeye.common.util.PaginationSupport; <LA^%2jT
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public abstract class AbstractManager extends HFS+QwHW
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HibernateDaoSupport { Q6^x8
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privateboolean cacheQueries = false; J_ J+cRwq
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privateString queryCacheRegion; f=I:DkR
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publicvoid setCacheQueries(boolean D;js.ZF
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cacheQueries){ @E_zR
this.cacheQueries = cacheQueries; CV^c",b_
}
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publicvoid setQueryCacheRegion(String 3s(Ia^
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queryCacheRegion){ .ECHx Dp
this.queryCacheRegion = _;e\:7<m
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queryCacheRegion; +Me2U9
} XDLEVSly7
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publicvoid save(finalObject entity){ fk3kbdI
getHibernateTemplate().save(entity); t(?<#KUB-
} 59!)j>f
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publicvoid persist(finalObject entity){ O&$0&dhc
getHibernateTemplate().save(entity); kx{!b3"
} S,vu]?-8
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publicvoid update(finalObject entity){ ^
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getHibernateTemplate().update(entity); CLK^ gZ
} I@./${o
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publicvoid delete(finalObject entity){ G5c7:iGm/c
getHibernateTemplate().delete(entity); f7+Cz>R
}
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publicObject load(finalClass entity, rn" pKUd
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finalSerializable id){ Qpu3(`d<
return getHibernateTemplate().load JR1*|u
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(entity, id); dlD}Ub
} %f!iHo+Z
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publicObject get(finalClass entity, f\}22}/
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finalSerializable id){ bUvK
return getHibernateTemplate().get ~@fR[sg<
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(entity, id); rYGRz#:~+
} Q!$IQJ]|Y
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publicList findAll(finalClass entity){ -P#nT 2
return getHibernateTemplate().find("from \dV Too
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" + entity.getName()); v*r9j8
} treXOC9^B8
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publicList findByNamedQuery(finalString YzV(nEW
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namedQuery){ Y:pRcO.4g
return getHibernateTemplate V2<i/6~
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().findByNamedQuery(namedQuery); k/#>S*Ne
} e2Jp'93o'
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publicList findByNamedQuery(finalString query, }ywi"k4>
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finalObject parameter){ !}q."%%J_%
return getHibernateTemplate 'v`_Ii|-
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().findByNamedQuery(query, parameter); Zh,]J `
} Wz{%"o
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publicList findByNamedQuery(finalString query, |<Bpv{]P
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finalObject[] parameters){ #!d]PH746
return getHibernateTemplate .)`-Hkxa
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().findByNamedQuery(query, parameters); a: IwA9!L
} U Um|@
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publicList find(finalString query){ ][t6VA
return getHibernateTemplate().find !4B_$6US
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(query); @dV9Dpu
} M=+M8M`Iy
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publicList find(finalString query, finalObject (}0S1)7t
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parameter){ [B,p,Q"
return getHibernateTemplate().find o^PuhVu
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(query, parameter); %~\
} @+t (xCv
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public PaginationSupport findPageByCriteria LE|<O
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(final DetachedCriteria detachedCriteria){ * gHCy4u{
return findPageByCriteria )JX$/-
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); OQc{
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} \!4|tBKVY
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public PaginationSupport findPageByCriteria J7m`]!*t
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(final DetachedCriteria detachedCriteria, finalint sW'6}^Q
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startIndex){ m0C{SBn-M
return findPageByCriteria ~4+8p9f
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(detachedCriteria, PaginationSupport.PAGESIZE, vG3M5G
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startIndex); |Q6h/"2
} 94YA2_f;
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public PaginationSupport findPageByCriteria _[%n ~6
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(final DetachedCriteria detachedCriteria, finalint TR?Bvy2s:g
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pageSize, L,W:,i/C
finalint startIndex){ UI_v3c3b
return(PaginationSupport) |C4o zl=O?
u9,=po=+7f
getHibernateTemplate().execute(new HibernateCallback(){ Q2FQhc@L(:
publicObject doInHibernate +8eVj#N
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(Session session)throws HibernateException { ovSH}h!
Criteria criteria = FF jRf
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detachedCriteria.getExecutableCriteria(session); k1m'Ka-
int totalCount = n@_)fFD%
Z) t{JHm:
((Integer) criteria.setProjection(Projections.rowCount e]Puv)S>{8
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()).uniqueResult()).intValue(); d#4 Wj0x
criteria.setProjection qNy-o\;XN
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(null); =CE HRny
List items = \:h0w;34O
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criteria.setFirstResult(startIndex).setMaxResults OFp#<o,p
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(pageSize).list(); vyujC`61d
PaginationSupport ps = ^SgN(-QH
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new PaginationSupport(items, totalCount, pageSize, ig+k[`W
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startIndex); KjC[q
return ps; 8cB=}XgYS
} kF#{An)P
}, true); TX&[;jsj
} @}ZGY^
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public List findAllByCriteria(final 4_WH
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DetachedCriteria detachedCriteria){ w8O hJv
return(List) getHibernateTemplate y)IGTW o
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().execute(new HibernateCallback(){ S io1Q0
publicObject doInHibernate EkDws`@
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(Session session)throws HibernateException { HhzkMJR8
Criteria criteria = x-tm[x@;o
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detachedCriteria.getExecutableCriteria(session); MK<
return criteria.list(); :{x!g6bK@
} 9fCiLlI
}, true); SlR7h$r'
} }5QZ6i#
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public int getCountByCriteria(final 4fZY8
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DetachedCriteria detachedCriteria){ v`@5enr
Integer count = (Integer) &t[z
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getHibernateTemplate().execute(new HibernateCallback(){ od;Bb
publicObject doInHibernate b0!*mrF]6
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(Session session)throws HibernateException { c(QG4.)m
Criteria criteria = xhw8#
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detachedCriteria.getExecutableCriteria(session); VFQq`!*i
return AN|jFSQ'
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criteria.setProjection(Projections.rowCount Bu*W1w\
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()).uniqueResult(); >1#DPU(g
}
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}, true); tI/mE[W
return count.intValue(); O|A~dj`
} RTdD]pE8Q
} 2+c>O%L
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用户在web层构造查询条件detachedCriteria,和可选的 #u}v7{4
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 'sT}DX(7M
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PaginationSupport的实例ps。 .{'Uvn
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ps.getItems()得到已分页好的结果集 ];d5X
ps.getIndexes()得到分页索引的数组 ,H#qgnp
ps.getTotalCount()得到总结果数 |!jYv'%
ps.getStartIndex()当前分页索引 }J'5EAp
ps.getNextIndex()下一页索引 Lz#$_Am'H
ps.getPreviousIndex()上一页索引 `Yo-5h
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 "tg\yem
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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 M&}oat*
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一下代码重构了。 Xn
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我把原本我的做法也提供出来供大家讨论吧: *`S)@'@:(
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首先,为了实现分页查询,我封装了一个Page类: + hyWo]nW0
java代码: Z CQt1;
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/*Created on 2005-4-14*/ **w*hd]
package org.flyware.util.page; c9ov;Bw6S
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/** c=jI.=mi3
* @author Joa Ck/_UY|
* NZ%~n:/V#
*/ wk@(CKQzI,
publicclass Page { ;+TF3av0zq
{Y@-*pL]
/** imply if the page has previous page */ !rsqr32]
privateboolean hasPrePage; 2XecP'+m
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/** imply if the page has next page */ `
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privateboolean hasNextPage; VATXsD
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/** the number of every page */ @L>NN>?SGQ
privateint everyPage; .^N#|hp^
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/** the total page number */ n%MYX'0
privateint totalPage; OL
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/** the number of current page */ He71h(BHm
privateint currentPage; X-ki%jp3
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/** the begin index of the records by the current =Q=&Ucf_
sh))[V"8
query */ X^_+%U
privateint beginIndex; TLL[F;uZ
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/** The default constructor */ 1KIq$lG{ E
public Page(){ v[yTk[zd0
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} .L(j@I t
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/** construct the page by everyPage J&U0y
* @param everyPage FnQ_=b
* */ @01D1A
public Page(int everyPage){ /&!d
this.everyPage = everyPage; =*>4Gh
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} ;R|#ae@
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/** The whole constructor */ [?f.0q
public Page(boolean hasPrePage, boolean hasNextPage, vyx\N{
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, ZP3F+XKb
int everyPage, int totalPage, {7~ $$AR(
int currentPage, int beginIndex){
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this.hasPrePage = hasPrePage; SnF[mN'
this.hasNextPage = hasNextPage; 6 r-n6#=
this.everyPage = everyPage; B[_b J
*
this.totalPage = totalPage; @G$<6CG\
this.currentPage = currentPage; #M9D"
<pn}
this.beginIndex = beginIndex; \^( vlcy
} [11-`v0
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/** I~]mX;
* @return &eS70hq
* Returns the beginIndex. i7FR78^
*/ -r'seb5
publicint getBeginIndex(){ Oi[9b
return beginIndex; P$
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} "PScM9) \
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/** g!Yh=kA'N
* @param beginIndex MH8%-UV
* The beginIndex to set. 5 /jY=/0.a
*/ jv=f@:[`I
publicvoid setBeginIndex(int beginIndex){ /FV6lR!0^
this.beginIndex = beginIndex; n_&)VF#n(
} n@,eZ!
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/** ]9< 9F ?
* @return q[+:t
* Returns the currentPage. x&/Syb
*/ X6*y/KGN
publicint getCurrentPage(){ +siNU#!
return currentPage; `"":
} )hJjVitG
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/** :XZom+>2n
* @param currentPage ]JPPL4wAT
* The currentPage to set. )[X!/KR90
*/ &Wz:-G7<n
publicvoid setCurrentPage(int currentPage){ SA n=9MG
this.currentPage = currentPage; "<$vU_
} F8;4Oj
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/** d]~1.i
* @return pz}hh^]t
* Returns the everyPage. #&c;RPac!6
*/ ^K8a#-
publicint getEveryPage(){ $v@$oPmMj
return everyPage; 9}$dwl(
} 3CuoBb8
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/** I>~BkR+u%o
* @param everyPage Mf13@XEo
* The everyPage to set. G*p.JsZP
*/ %)ov,p|
publicvoid setEveryPage(int everyPage){ 6;XpLivP7
this.everyPage = everyPage; q ? TI,
} ]!o,S{a&
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/** F
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* @return 1Klu]J%
* Returns the hasNextPage. &n kGdHX/a
*/ k r^#B^
publicboolean getHasNextPage(){ A_U0HVx_
return hasNextPage; -vAG5x/ ,
} Y,}43a0A
Yx c >+mx
/** ^@"f%3
* @param hasNextPage uxiX"0)g>
* The hasNextPage to set. urjp&L&
*/ 8^i,M^f^{
publicvoid setHasNextPage(boolean hasNextPage){ )W JI=jl
this.hasNextPage = hasNextPage; HOb\Hn|6jq
} dh`A(B{hfc
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/** &`W,'qD$
* @return j'cCX[i
* Returns the hasPrePage. k-0e#"B
*/ e}w!]
publicboolean getHasPrePage(){ me\)JCZpb{
return hasPrePage; !gQ(1u|r
} |<icx8hbr
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/** s7LX
* @param hasPrePage )+R3C%
* The hasPrePage to set. _fw'c*j
*/ J1MnkxJmpQ
publicvoid setHasPrePage(boolean hasPrePage){ )A;<'{t #L
this.hasPrePage = hasPrePage; oD`BX
} Ut@)<N
c~;.m<yrf
/** wO
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* @return Returns the totalPage. wt,N<L
* Gl9 a5b
*/ %&GQ]pmcY
publicint getTotalPage(){ LnIJw D
return totalPage; yB[LO(i
} VlvDodV
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ci
/** ]B[Qdn
* @param totalPage B9\o:eY
* The totalPage to set. G9Ezm*I;:
*/ x$sQ .aT
publicvoid setTotalPage(int totalPage){ VtFh1FDI\
this.totalPage = totalPage; h~t]WN
} #kEdf0
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} 6 h):o
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9G9lSj5>
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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 %yVZ|d*Q
^&%?Q_]
个PageUtil,负责对Page对象进行构造: M"V@>E\L
java代码: !j@ 8:j0WY
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/*Created on 2005-4-14*/ *lSIT]1
package org.flyware.util.page; xPv&(XZR
}, H,ky
import org.apache.commons.logging.Log; ] $*cmk(Y
import org.apache.commons.logging.LogFactory; fA^ O
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/** /k,p]/e
* @author Joa A(B2XBS!?
* F=H=[pSe
*/ E {MSi"
publicclass PageUtil {
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privatestaticfinal Log logger = LogFactory.getLog y[vjqfdmU
_)Ms9RN
(PageUtil.class); RK0IkRXQd
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/** 4 ET
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* Use the origin page to create a new page C~B^sG@;
* @param page ;Baf&xK
* @param totalRecords LYKepk
* @return %K%z<R8
*/ P~&X$H%e
publicstatic Page createPage(Page page, int .Qaqkb-Ty
l"Css~^
totalRecords){ g8C+j6uR0
return createPage(page.getEveryPage(), zy.Ok 49
#q-t!C%E
page.getCurrentPage(), totalRecords); p`It=16trT
} '=r.rW5
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/** 3,GSBiK3}
* the basic page utils not including exception n V<YwqK
qdOS=7]W
handler 607#d):Y
* @param everyPage 0-@waK
* @param currentPage eI@O9<.&
* @param totalRecords (C!fIRY
* @return page ? in&/ZrB
*/ PW}Yts7p
publicstatic Page createPage(int everyPage, int 7>.^GD
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currentPage, int totalRecords){ Y$N|p{Z
everyPage = getEveryPage(everyPage); twJck~l~n
currentPage = getCurrentPage(currentPage); A2B&X}K|U
int beginIndex = getBeginIndex(everyPage, Dv$xP)./
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currentPage); 1$c*/Tc:E
int totalPage = getTotalPage(everyPage, fx*Swv%r
S"lcePN
totalRecords); w ^r*qi"
boolean hasNextPage = hasNextPage(currentPage, mCg 5-E~;
9AS,-5;XQ
totalPage); R (6Jvub"I
boolean hasPrePage = hasPrePage(currentPage); FrB19
sR5dC_
returnnew Page(hasPrePage, hasNextPage, *FO']D
everyPage, totalPage, Jg7IGU(dct
currentPage, ek.L(n,J|
-2f0CAh~
beginIndex); 0\.y0
K8
} 0evG
F7mzBrz
privatestaticint getEveryPage(int everyPage){ 3B>!9:w~f
return everyPage == 0 ? 10 : everyPage; H>M0GL
} ym-212wl
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privatestaticint getCurrentPage(int currentPage){ o8bVz2E
return currentPage == 0 ? 1 : currentPage; N!hp^V<7
} ww=< =
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privatestaticint getBeginIndex(int everyPage, int +-5CM0*&
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currentPage){ SdN|-'qf
return(currentPage - 1) * everyPage; $lUZm\R|k
} >:8GU f*
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privatestaticint getTotalPage(int everyPage, int b>G!K)MS3
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totalRecords){ }&ZO
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int totalPage = 0; .{~ygHQ`f
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if(totalRecords % everyPage == 0) .,-t}5(VSq
totalPage = totalRecords / everyPage; /Eu[7
else ZCV&v47\p_
totalPage = totalRecords / everyPage + 1 ; "c=\?
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return totalPage; e>X&[\T
} k'EP->r
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privatestaticboolean hasPrePage(int currentPage){ 9tqX77UK
return currentPage == 1 ? false : true; {'EQ%H$q
} vxY7/ _]
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privatestaticboolean hasNextPage(int currentPage, ]#KZ
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int totalPage){ l. !5/\
return currentPage == totalPage || totalPage == 7l%O:M(\
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0 ? false : true; 9Iy>oV
} _L<IxOZh+
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} Z[[@O
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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。 R=_
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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 ix [aS
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做法如下: 3T+#d-\
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ag+$qU
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的信息,和一个结果集List: 049E#[<Q"
java代码: t6W$t
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/*Created on 2005-6-13*/ 6av]LY K
package com.adt.bo; )`, Bt
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import java.util.List; WyF1Fw
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import org.flyware.util.page.Page; )S]4
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/** $<xa "aN!
* @author Joa B{hP#bYK
*/ ]>M{Qn*
publicclass Result { {9S=:
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private Page page; ?j6?KR@#
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private List content; z%Pbs[*C
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/** ;'CWAJK
* The default constructor 65X$k]x
*/ J$JXY@mBSC
public Result(){ G$kspN*"A
super(); ~"6/OJA
} 0.7*2s-
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/** nK=-SQ
* The constructor using fields + o^b ,!
* zX*+J"x
* @param page a7KP_[_(
* @param content Z\Qa6f!
*/ iU]py
public Result(Page page, List content){ %<8@NbF
this.page = page; MDI[TNYG
this.content = content; v,qK=]ty
} 'Pyeb`AXE9
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/** s2s}5b3
* @return Returns the content. =gL~E9\
*/ 1xAZ0X#
publicList getContent(){ N&ZIsaK,j
return content; M8j%bmd(,
} ~Mu=,OT
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/** a:nMW '!
* @return Returns the page. l'h[wwEXm{
*/ d9@!se9&Z
public Page getPage(){ R?bF
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return page; N#<h/
} ra#s!m1
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/** 4'L%Wz[6
* @param content v"x{oD$R
* The content to set. #IH7WaN
*/ K5(:UIWx
public void setContent(List content){ Sg$14B
this.content = content; erG@8CG
} ,":l >0P[
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/** '&