Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @;_xFL;{g
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 8C7$8x]mM
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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 % 3d59O
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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 i2j_=X-
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。 \2KwF}[m
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分页支持类: S+
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java代码: BF{v0Z0/}k
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package com.javaeye.common.util; -L%tiz`_
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import java.util.List; w/BaaF.0
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publicclass PaginationSupport { -7,xjn
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publicfinalstaticint PAGESIZE = 30; EVZuwbO)|
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privateint pageSize = PAGESIZE; 2L Kpwz?
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privateList items; P>n}\"z4
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privateint totalCount; -XBD WV
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privateint[] indexes = newint[0]; `d]D=DtH
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privateint startIndex = 0; P7np
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public PaginationSupport(List items, int bwN>E+
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totalCount){ p?F%a;V3
setPageSize(PAGESIZE); Xy/lsaVskX
setTotalCount(totalCount); ]yI~S(
setItems(items); :Rl*64}
setStartIndex(0); zt,pV\|
} hDBVL"
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public PaginationSupport(List items, int 6?8x[l*5M
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totalCount, int startIndex){ s[6y|{&ze
setPageSize(PAGESIZE); v3>jXf
setTotalCount(totalCount); $0+n0*fp
setItems(items); 1?+%*uoPX
setStartIndex(startIndex); #fdQ\)#q>
} o^HzE;L}
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public PaginationSupport(List items, int ,xmL[Yk,
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totalCount, int pageSize, int startIndex){ H|@R+
setPageSize(pageSize); $}_a`~u
setTotalCount(totalCount); vk;]9o j*
setItems(items); qcpAjjK
setStartIndex(startIndex); a2Q_K2t
} 4FLL*LCNX
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publicList getItems(){ 3>O=d>
return items; (.[HE
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} U&x)Q
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publicvoid setItems(List items){ KlOL5"3
this.items = items; V% -wZL/
} =VXxQ\{
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publicint getPageSize(){ HYqDaRn
return pageSize; lO)-QE+
} [@K#BFA
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publicvoid setPageSize(int pageSize){ ";vP77|m7R
this.pageSize = pageSize; )S~ySiJ<U
} oW7\T!f
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publicint getTotalCount(){ #i6ZY^+ee
return totalCount; Iq/V[v
} *Y"j 0Yob
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publicvoid setTotalCount(int totalCount){ v>ygr8+C,
if(totalCount > 0){ fT$Fv
this.totalCount = totalCount; FH Hi/yh
int count = totalCount / (c3%rM m]
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pageSize; w&U>w@H^
if(totalCount % pageSize > 0) 4<c#3]
count++; #@qd.,]2
indexes = newint[count]; ~m0l_:SF
for(int i = 0; i < count; i++){ pXL@&]U+
indexes = pageSize * b Ag>;e(
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i; ;~nz%LJ
} svT1b'=\$I
}else{ Gh.@l\|tf
this.totalCount = 0; ItLP&S=
} LA\)B"{J
} .LQvjK[N
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publicint[] getIndexes(){ @)hrj2Jw
return indexes; RlW7l1h&
} A~Uqw8n$\
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publicvoid setIndexes(int[] indexes){ |~V`Es +j
this.indexes = indexes; '5V#sq;Z
} m`3Mev
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publicint getStartIndex(){ (=de#wh2]
return startIndex; 6<%W8m\
} e
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publicvoid setStartIndex(int startIndex){ wfE%` 1
if(totalCount <= 0) Z{#;my*X|
this.startIndex = 0; B%~D`[~?
elseif(startIndex >= totalCount) 3jaY\(`%h
this.startIndex = indexes W{JNNf6G
>%PPp.R
[indexes.length - 1]; b0vbE8wa
elseif(startIndex < 0) OvFWX%uY
this.startIndex = 0; hp:8e@
else{ h~F`[G/'
this.startIndex = indexes "@h 5
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[startIndex / pageSize]; ~wX4j
} v<2B^(i}VB
} "?[7oI}c&
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publicint getNextIndex(){ >WKlR` J%
int nextIndex = getStartIndex() + (l~3~n
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pageSize; @['4 X1pqt
if(nextIndex >= totalCount) q/|WkV `m
return getStartIndex(); .*0`}H+_
else \K,piCVViN
return nextIndex; ZJ|@^^GcL
} tOu:j [
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publicint getPreviousIndex(){ e.Y*=P}D
int previousIndex = getStartIndex() - nV$ctdusQ
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pageSize; 9Ytd E*,k
if(previousIndex < 0) K% Gbl#
return0; y
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else TNvE26.(
return previousIndex; 1|PmZPKq9n
} #h#Bcv0 Z
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} ;~Em,M"o
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抽象业务类 f%1Dn }6
java代码: FyZ iiH4|
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/** 1f.xZgO/2
* Created on 2005-7-12 o4Bl!7U
*/ BhMHT:m
package com.javaeye.common.business;
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import java.io.Serializable; fC$~3v
import java.util.List; 4cO||OsMU
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import org.hibernate.Criteria; &M,"%w!
import org.hibernate.HibernateException; BBg&ZIYEh
import org.hibernate.Session; F[
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import org.hibernate.criterion.DetachedCriteria; P'nbyF
import org.hibernate.criterion.Projections; 9t$%Tc#Z
import =&-hU|ur
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org.springframework.orm.hibernate3.HibernateCallback; ^z[-pTY
import LX
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org.springframework.orm.hibernate3.support.HibernateDaoS JMMsOA_]
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upport; zn |=Q$81
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import com.javaeye.common.util.PaginationSupport; 6$'6x2,
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public abstract class AbstractManager extends u%#s_R
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HibernateDaoSupport { '9,14e6
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privateboolean cacheQueries = false; P80z@!
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privateString queryCacheRegion; n9zS'VU
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publicvoid setCacheQueries(boolean !(!BW9Zt+
6]|NB &
cacheQueries){ tk^1Ga3
this.cacheQueries = cacheQueries; VD\pQ.=
} h>Z$
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publicvoid setQueryCacheRegion(String y\
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C { }s
queryCacheRegion){ 4*UoTE-g$
this.queryCacheRegion = {PM)D [$i
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queryCacheRegion; X7sWu{n
} tPS.r.0#^
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publicvoid save(finalObject entity){ `p&ko$i2
getHibernateTemplate().save(entity); >#@1
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} -(n[^48K
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publicvoid persist(finalObject entity){ cJ&e^$:Er
getHibernateTemplate().save(entity); HrA6wn\O
} ou44vKzS
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publicvoid update(finalObject entity){ `d=$9Pi
getHibernateTemplate().update(entity); cU25]V^{\
} F}Bc +i#]
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publicvoid delete(finalObject entity){ N0c+V["s
getHibernateTemplate().delete(entity); B{ NKDkDH
} FhB^E$r%
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publicObject load(finalClass entity, JF*JFOb
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finalSerializable id){ W%09.bF
return getHibernateTemplate().load ]lF'o&v]
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(entity, id); :^SpKe(7
} ->}K- n ),
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publicObject get(finalClass entity, z9$x9u
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finalSerializable id){ O0"i>}g4
return getHibernateTemplate().get 1h\: Lj
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(entity, id); {e2 (
} uNnwz%w
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publicList findAll(finalClass entity){ 3V`K^X3
return getHibernateTemplate().find("from @2
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" + entity.getName()); XJ]MPiXj
} >b-rAO\{}
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publicList findByNamedQuery(finalString lN+NhPF
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namedQuery){
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return getHibernateTemplate )dLESk
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().findByNamedQuery(namedQuery); >qx~m>2|8]
} g\
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publicList findByNamedQuery(finalString query, *6Rl[eXS
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finalObject parameter){ O6;>]/`
return getHibernateTemplate m7kDxs(KO
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().findByNamedQuery(query, parameter); g_]
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} )?pin|_x
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publicList findByNamedQuery(finalString query, X3]E8)645N
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finalObject[] parameters){ )1j~(C)E8
return getHibernateTemplate ;ijJ%/
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().findByNamedQuery(query, parameters); svyC(m)'
} K4n1#]8i
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publicList find(finalString query){ ;k7` `
return getHibernateTemplate().find ]Vl5v5_
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(query); g$dL5N7
} Ph]e\
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publicList find(finalString query, finalObject $EviGZFAaR
~<v.WP<:
parameter){ ]-%ZN+
return getHibernateTemplate().find ]rn!+z
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(query, parameter); w}NgFrL
} A
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public PaginationSupport findPageByCriteria #Opfc8pm'
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(final DetachedCriteria detachedCriteria){ AXPUJ?V
return findPageByCriteria qvYYKu
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ~uC4>+dk
} um#;S;
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public PaginationSupport findPageByCriteria
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(final DetachedCriteria detachedCriteria, finalint $'9r=#EH
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startIndex){
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return findPageByCriteria W%Rh2l
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(detachedCriteria, PaginationSupport.PAGESIZE, f,M$>!$V
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startIndex); {K3\S
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} dN |w;|M
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public PaginationSupport findPageByCriteria tx5_e[
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(final DetachedCriteria detachedCriteria, finalint nZ\,ZqV
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pageSize, Q(]-\L'
finalint startIndex){ &1Cq+YpI
return(PaginationSupport) K/\#FJno
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getHibernateTemplate().execute(new HibernateCallback(){ :R_{tQ-WG
publicObject doInHibernate K:y q^T7
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(Session session)throws HibernateException { ~BS*x+M
Criteria criteria = ~iwEhF
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detachedCriteria.getExecutableCriteria(session); M8cLh!!
int totalCount = _"0n.JQg
y\0^c5}
((Integer) criteria.setProjection(Projections.rowCount t_]UseP$RF
|!!E5osXq
()).uniqueResult()).intValue(); /mD KQ<
criteria.setProjection (sqS(xIY
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(null); 3:Z(tM&-O
List items = m]"YR_
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criteria.setFirstResult(startIndex).setMaxResults ?sS'T7r
v
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(pageSize).list(); ]LSa(7>EU
PaginationSupport ps = 29qQ3M?
uqQMS&;+,|
new PaginationSupport(items, totalCount, pageSize, JyB>,t)
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startIndex); 4uftx1o
return ps; t&P5Zw*B
} _)_XO92~
}, true); p\-.DRwT`
} oC7#6W:@w
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public List findAllByCriteria(final t9`NCng
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DetachedCriteria detachedCriteria){ E?9_i
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return(List) getHibernateTemplate 1MahFeQ[
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().execute(new HibernateCallback(){ ZcWl{e4
publicObject doInHibernate Y}?@Pm drz
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(Session session)throws HibernateException { epG;=\f}m`
Criteria criteria = R3@iN&
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detachedCriteria.getExecutableCriteria(session); <=7)t.
return criteria.list(); ~IqT>
} njq-iU
}, true); X4k/7EA
} F_r eBPx
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public int getCountByCriteria(final ix#
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DetachedCriteria detachedCriteria){ l:|Fs=\
Integer count = (Integer) H~~(v52wD
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getHibernateTemplate().execute(new HibernateCallback(){ @<6-uk3S
publicObject doInHibernate X_YD[
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(Session session)throws HibernateException { EV(/@kN2
Criteria criteria = A!Yqj~
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detachedCriteria.getExecutableCriteria(session); +nZG!nP
return #-f^;=7
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criteria.setProjection(Projections.rowCount ^7''x,I
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()).uniqueResult(); ?#[K&$}
} b
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}, true); 3AL.UBj&}
return count.intValue(); $I/p 6
} Y$Ke{6 4
} /vV 0$vg
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用户在web层构造查询条件detachedCriteria,和可选的 T*ic?!
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 -)Vj08aP
[<`+9R
PaginationSupport的实例ps。 G`P+J
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ps.getItems()得到已分页好的结果集 Wm,,OioK
ps.getIndexes()得到分页索引的数组 evR= Z\
_
ps.getTotalCount()得到总结果数 W6iIL:sp
ps.getStartIndex()当前分页索引 GkC88l9z
ps.getNextIndex()下一页索引 S- H3UND"
ps.getPreviousIndex()上一页索引 W!(Q_B
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 :h3JDQe:.
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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 CP'-CQ\Q
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一下代码重构了。 "osYw\unI
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我把原本我的做法也提供出来供大家讨论吧: Uoe?5Of(*
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首先,为了实现分页查询,我封装了一个Page类: b2Hpuej
java代码: d]^i1
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/*Created on 2005-4-14*/ EGt)tI&
package org.flyware.util.page; )?WoLEjq
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/** f,#xicSB*
* @author Joa 4kM<L}J#
* )'g vaT
*/ >xjy
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publicclass Page { <b\urtoJ
MI }D%n*
/** imply if the page has previous page */ qSd
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privateboolean hasPrePage; fm*Hk57
'nno)kQ"
/** imply if the page has next page */ x,%&[6(
privateboolean hasNextPage; S@#L!sT`u
-*A'6%`
/** the number of every page */ |3LMVN
privateint everyPage; Q'VS]n
8\9EDgT
/** the total page number */ 8f.La
privateint totalPage; ?1uAY.~ZZB
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/** the number of current page */ y)}aySQK^
privateint currentPage; :]s] =q&]
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/** the begin index of the records by the current OOCeZ3yF(
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query */ DbN'b(+
privateint beginIndex; Q [{vU
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/** The default constructor */ NP8TF*5V
public Page(){ /HRaX!|E#
x_K%
} ~ #CCRUhM
)YFs
/** construct the page by everyPage 1%,Z&@^j
* @param everyPage l_c?q"X
* */ lu_Gr=#O
public Page(int everyPage){ CkU=0mcY
this.everyPage = everyPage; : [y(<TLw
} m"R(_E5
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/** The whole constructor */ Eg*3**gTO
public Page(boolean hasPrePage, boolean hasNextPage, ^U}0D^jDeE
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>gl.(b25C
int everyPage, int totalPage, (zBQ^97]
int currentPage, int beginIndex){ Z3dd9m#.]
this.hasPrePage = hasPrePage; B/OO$=>(
this.hasNextPage = hasNextPage; tOw
0(-:iq
this.everyPage = everyPage; x8Sq+BY
this.totalPage = totalPage; G$ FBx
this.currentPage = currentPage; 7;NV
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this.beginIndex = beginIndex; 2#3R]zIO
} y`\Mhnj
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/** 1'
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* @return 9f\8oJQ
* Returns the beginIndex. ^v-'=1ub?
*/ 8:xo ~Vc
publicint getBeginIndex(){ pC-OZ0
return beginIndex; __j8jEV
} nY)Pxahm 7
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/** jhv1 D'>6
* @param beginIndex cqx1NWlY
* The beginIndex to set. }=a4uCE
*/ `Ny8u")=
publicvoid setBeginIndex(int beginIndex){ 1 1CJT
this.beginIndex = beginIndex; s? k[_|)!
} / JB4 #i7
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/** 9#ft;c
* @return $x;h[,y
* Returns the currentPage. K*$#D1hG
*/ <q\)
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publicint getCurrentPage(){ $0T"YC%
return currentPage; 4- _lf(#i
} P-[K*/bPw
sv"mba.J
/** M%xL K7
* @param currentPage s2~dmZ_B|_
* The currentPage to set. *GP_ut%
*/ S:/RYT"
publicvoid setCurrentPage(int currentPage){ 1i:g
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this.currentPage = currentPage; OL5HofgNm
} )H)Udhz
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/** /T[ICd2J
* @return |+-i'N9
* Returns the everyPage. RWCS
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*/ &pjV4m|j<
publicint getEveryPage(){ bK\WdG\;
return everyPage; b6&NzUt34V
} !"%sp6Wc
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/** JWHt|zBg
* @param everyPage 3^>a TU<Z
* The everyPage to set. od*Z$Hb>'
*/ vN:[
publicvoid setEveryPage(int everyPage){ uz3pc;0LPY
this.everyPage = everyPage; xY2_*#{.
} ROS"VV<
g ypq`F
/** [P=[hj;
* @return o!`O
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* Returns the hasNextPage. ><Z3<7K9
*/ n~u3
publicboolean getHasNextPage(){ {$YD-bqY
return hasNextPage; ih |Ky+ !
} e=sJMzm~
p''"E$B/(
/**
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* @param hasNextPage
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* The hasNextPage to set. |qcFmy
*/ l/zC##1+.
publicvoid setHasNextPage(boolean hasNextPage){ P<!$A
this.hasNextPage = hasNextPage; (%y c5+f!
} 7G(f1Y
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/** > '
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* @return AAq=,=:R<
* Returns the hasPrePage. F(9
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*/ .*-w UBr
publicboolean getHasPrePage(){ _iJXp0g
return hasPrePage; :dIQV(iW
} 'z}M[h
K]
e ]o'i;I
/** =yX&p:-&
* @param hasPrePage r>~d[,^$m4
* The hasPrePage to set. o 7W Kh=
*/ 4:&qTY)H
publicvoid setHasPrePage(boolean hasPrePage){ in#]3QGV
this.hasPrePage = hasPrePage; I9un
} )|y2Q
L'XdX\5
/** |F@xwfgb
* @return Returns the totalPage. xX/s1(P
* IAF;mv}'
*/ Secq^#]8
publicint getTotalPage(){ xVkTRCh
return totalPage; {XD/8m(hN|
} 2FIR]@MQd
FaE #\Q
/** DwmU fZp
* @param totalPage HXfXb^~
* The totalPage to set. $dh4T";
*/ *Ht*)l?
publicvoid setTotalPage(int totalPage){ D"XX920$~
this.totalPage = totalPage; \!JS7!+
} EEs-&
WAB0e~e:|Q
} }PQSCl^I
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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 /ggkb8<3
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个PageUtil,负责对Page对象进行构造: qwF*(pTHq
java代码: S2&9#6
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/*Created on 2005-4-14*/ ^{*f3m/
package org.flyware.util.page; 2Za,4'
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import org.apache.commons.logging.Log; 2zKo
import org.apache.commons.logging.LogFactory; 1<a@ p}
y=9Dxst"V
/** p2x1xv
* @author Joa $xA J9_2P
* ~llMrl7
*/ ~|'y+h89
publicclass PageUtil { @q+cmJKv
j&dx[4|m:h
privatestaticfinal Log logger = LogFactory.getLog d]CviQUq
p:JRQT"A
(PageUtil.class); NFY|^*bll
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/** 7Ai o`&^
* Use the origin page to create a new page @)vy'qP d
* @param page f2 ydL/M,
* @param totalRecords 9^PRX
* @return 22GnbA7O
*/ =! N _^cb
publicstatic Page createPage(Page page, int <AMb!?Obh
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totalRecords){ %6A-OF
return createPage(page.getEveryPage(), [A"H/Qztk
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page.getCurrentPage(), totalRecords); #9$V
08
} +ze}0lrEL
CF|moc:;
/** m<4s*q0\i
* the basic page utils not including exception V$dJmKg
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handler g\o{}Q%X
* @param everyPage ~V2ajM1Z&O
* @param currentPage 4=Tpi`
* @param totalRecords .pM
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* @return page Z
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*/ -9OMn}w/*
publicstatic Page createPage(int everyPage, int (Qk&g"I
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currentPage, int totalRecords){ Fn86E dFM
everyPage = getEveryPage(everyPage); d7"U WY^
currentPage = getCurrentPage(currentPage); bQwdgc),s{
int beginIndex = getBeginIndex(everyPage, {sC@N![
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currentPage); |N:MZ#};
int totalPage = getTotalPage(everyPage, YH[XRUa
{*QvC
g?
totalRecords); T?X^0UdJj
boolean hasNextPage = hasNextPage(currentPage, cQT1Xi
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totalPage); pi`;I*f/
boolean hasPrePage = hasPrePage(currentPage); H\^VqNK"
k> b&xM!
returnnew Page(hasPrePage, hasNextPage, -3.UE^W2
everyPage, totalPage, 61/)l0<;
currentPage, ybZ}
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beginIndex); g1ZV&X=2
} Abj97S
Z-(} l2\
privatestaticint getEveryPage(int everyPage){ b fp,zs
return everyPage == 0 ? 10 : everyPage; \ Y*h
} },DyU
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privatestaticint getCurrentPage(int currentPage){ >0PUWr$8
return currentPage == 0 ? 1 : currentPage; 8f?rEI\0GD
} m@ i2#
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privatestaticint getBeginIndex(int everyPage, int S8O)/Sg=
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currentPage){ u4:\UC'
return(currentPage - 1) * everyPage; $
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} m!<X8d[bD
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privatestaticint getTotalPage(int everyPage, int EdEoXY-2
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totalRecords){ 1g1? zk8zO
int totalPage = 0; |*:tyP%m^
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if(totalRecords % everyPage == 0) RCI4~q
totalPage = totalRecords / everyPage; pd d|n2q
else 1Gsw-a;a
totalPage = totalRecords / everyPage + 1 ; !:(C"}5wM
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return totalPage; "YJ[$TG
} eGLO!DdxZ
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privatestaticboolean hasPrePage(int currentPage){ \a"i7Caa
return currentPage == 1 ? false : true; oEJaH
} *p=fi
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privatestaticboolean hasNextPage(int currentPage, }2lO _i}L
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int totalPage){ i;c'P}[K
return currentPage == totalPage || totalPage == Pg/T^n&
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0 ? false : true; q]px(
} lR:?uZ$
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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。 S?L#N
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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 +'|{1gB
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做法如下: SBTPTb
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 6
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的信息,和一个结果集List: , 9mgYp2
java代码: e8,{|a
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/*Created on 2005-6-13*/ !tU'J"Zy
package com.adt.bo; A:eFd]E{(
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import java.util.List; iU5P$7.p
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import org.flyware.util.page.Page; +{.780|
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/** Kq&qE>Ju
* @author Joa Pt)S;6j
*/ ,h^r:g
publicclass Result { %:3'4;jh%
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private Page page; 9@ndi u[
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private List content; %x2uP9
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/** |O-`5_z$r
* The default constructor w9f
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*/ hGI+:Js6
public Result(){ ,}0$Tv\1
super(); sw$2d
} H\E7o"m
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/** gO='A(Y
* The constructor using fields f#$|t>
*
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* @param page ~U$":~H[
* @param content +@ MPQv
*/ s\gp5MT
public Result(Page page, List content){ nO{ x^b <
this.page = page; nA_%2F'W}
this.content = content; {,?ss$L
} 7?J3ci\
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