Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 3:lp"C51
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ]bb}[#AY
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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 <z2mNq
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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 vp-7>Wj
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分页支持类: I?Fa
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java代码: 5C1Rub)
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package com.javaeye.common.util; &> .1%x@R
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import java.util.List; MmH_gR
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publicclass PaginationSupport { fMPq
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publicfinalstaticint PAGESIZE = 30; j%jd@z ]@
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privateint pageSize = PAGESIZE; G D{fXhgk
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privateList items; `yX+NRi(s
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privateint totalCount; zN/~a)
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privateint[] indexes = newint[0]; % 3-\3qx*
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privateint startIndex = 0; Sx9:$"3.X
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public PaginationSupport(List items, int :;q_f+U
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totalCount){
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setPageSize(PAGESIZE); 0nq}SH
setTotalCount(totalCount); p6Dv;@)Yn
setItems(items); wx%nTf/Oa
setStartIndex(0); ^@lg5d3F
} m:fouMS
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public PaginationSupport(List items, int &Z;8J @
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totalCount, int startIndex){ vs)I pV(
setPageSize(PAGESIZE); 3J~kiy.nfW
setTotalCount(totalCount); C=aj&
setItems(items); "Xk%3\{P
setStartIndex(startIndex); dN\P&"`
} @*O{*2
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public PaginationSupport(List items, int k-cIb@+"
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totalCount, int pageSize, int startIndex){ |k
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setPageSize(pageSize); ]VG84bFm
setTotalCount(totalCount); ciGpluQF
setItems(items); gLSG:7m@
setStartIndex(startIndex); ^Ii \vk
} {_toh/8)r
pG F5aF7T
publicList getItems(){ xe gL!
return items; JdUz!=I
} PMN2VzE4{
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publicvoid setItems(List items){ akvwApn5
this.items = items; W^d4/]
} c."bTq4tJ
2VV[*QI
publicint getPageSize(){ ,KhMzE8_a
return pageSize; B==a
} ;;w6b:}-c
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publicvoid setPageSize(int pageSize){ 3aE[F f[
this.pageSize = pageSize; ^M(`/1 :
} R2Rstk
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publicint getTotalCount(){ o(d_uJOB
return totalCount; zJuRth)(,
} 4)odFq:
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publicvoid setTotalCount(int totalCount){ N5f0|U&
if(totalCount > 0){ tf7v5iG e
this.totalCount = totalCount; <5ft6a2fQ
int count = totalCount / %eJ\d?nw
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pageSize; [}p
if(totalCount % pageSize > 0) _/jUs_W
count++; Ku0H?qft(
indexes = newint[count]; .kbr?N,'
for(int i = 0; i < count; i++){ 0/SC
indexes = pageSize * L*
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} {8{t]LK<
}else{ lRv#1'Y
this.totalCount = 0; X"TUe>cM
} Sqdc1zC
} z{`6#
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publicint[] getIndexes(){ $#G6m`V
return indexes; 'Vm5Cs$
} z)&naw.
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publicvoid setIndexes(int[] indexes){ D%;wVnUw
this.indexes = indexes; %
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} A#Q0{z@H
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publicint getStartIndex(){ --
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return startIndex; 9raHSzK@d
} ^sT+5M^
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publicvoid setStartIndex(int startIndex){ YeRcf`
if(totalCount <= 0) }>{ L#JW
this.startIndex = 0; om".j
elseif(startIndex >= totalCount) ` $.X [\*U
this.startIndex = indexes `z3|M#r\;
VMxYZkMNd_
[indexes.length - 1]; C!ZI&cD9
elseif(startIndex < 0) x1m8~F
this.startIndex = 0; u}-d7-=
else{ FylWbQU9
this.startIndex = indexes aQ!9#d_D
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[startIndex / pageSize]; X"hOHx5P
} M>?aa6@0
} 7y>Tn`V8G
I" 8d5a}
publicint getNextIndex(){ 6P%<[Z
int nextIndex = getStartIndex() + j<l#qho{h
k
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pageSize; :S QDqG
if(nextIndex >= totalCount) -O~C m}e
return getStartIndex(); A$9q!Ui#d
else |u^)RB
return nextIndex; <S\;k@f
} wUru1_zjO
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publicint getPreviousIndex(){ 6?%]odI#
int previousIndex = getStartIndex() - o5N]((9
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pageSize; YH<$ +U
if(previousIndex < 0) X+`ddX
return0; -@%t"8
else U9<_6Bsd
return previousIndex; ZhGh{D[,
} ojN`#%X
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} Ff[H>Lp~
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抽象业务类 9Tzc(yCY
java代码: PzIy">plm
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/** NlA*\vco
* Created on 2005-7-12 Z -pyFK\
*/ :6 Uk)
package com.javaeye.common.business; !(B_EM
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import java.io.Serializable; S8*^ss>?^R
import java.util.List; lP}o[Rd
8BHL
import org.hibernate.Criteria; F`fGz)Mk
import org.hibernate.HibernateException; ,"@w>WL<9
import org.hibernate.Session; Vn)%C_-]A
import org.hibernate.criterion.DetachedCriteria; |tG05 +M
import org.hibernate.criterion.Projections; D4AEZgC F,
import IgLVn<5n
nped
org.springframework.orm.hibernate3.HibernateCallback; 'GrRuT<
import ?$<SCN=
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org.springframework.orm.hibernate3.support.HibernateDaoS W=~id"XtJ
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upport; 40 Au9o
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import com.javaeye.common.util.PaginationSupport; ktN%!Mh\
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public abstract class AbstractManager extends XlRw Z/Wc
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HibernateDaoSupport { zs4>/9O
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privateboolean cacheQueries = false; u06tDJ[
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privateString queryCacheRegion; /CIx$G
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publicvoid setCacheQueries(boolean ,r@xPZPz:e
)r=9]0=
cacheQueries){ b([:,T7
this.cacheQueries = cacheQueries; y^9bfMA
} I9;xz ES
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publicvoid setQueryCacheRegion(String yU *u
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queryCacheRegion){ =ntftSH
this.queryCacheRegion = FU[*8^Z
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queryCacheRegion; S3ErH,XB.
} yXkt:O,i
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publicvoid save(finalObject entity){ H4W1\u
getHibernateTemplate().save(entity); V>6QPA^
} Jl\'V
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publicvoid persist(finalObject entity){ X)8e4~(?
getHibernateTemplate().save(entity); |ribWCv0
} L,#^&9bHa#
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publicvoid update(finalObject entity){ >#INEO
getHibernateTemplate().update(entity); ;r3}g"D@
} &0s*PG
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publicvoid delete(finalObject entity){ X2LV&oi
getHibernateTemplate().delete(entity); >$Fp}?xX
} UnP|]]o:I
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publicObject load(finalClass entity, /\d(c/, 4
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finalSerializable id){ AH|Y<\
return getHibernateTemplate().load '|_/lz$h
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(entity, id); 5lGQ#r
} 7"#f!.E
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publicObject get(finalClass entity, ,'u *ZB;
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finalSerializable id){ 0JK2%%
return getHibernateTemplate().get +N7"EROc
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(entity, id); vf[&7n
} ![
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publicList findAll(finalClass entity){ pp<E))&R
return getHibernateTemplate().find("from o OQ'*7_
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" + entity.getName()); vmLpmxS
} fa4=h;>a+
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publicList findByNamedQuery(finalString &f"T,4Oh
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namedQuery){ P<vo;96JT
return getHibernateTemplate W+K.r?G<j
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().findByNamedQuery(namedQuery); ';Nu&D#Ph
} d+0^u(gc!8
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publicList findByNamedQuery(finalString query, zSKKr?{
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finalObject parameter){ yyjw?#\8
return getHibernateTemplate $~G@
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().findByNamedQuery(query, parameter); 57<Di!rt
} x}|+sS,g
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publicList findByNamedQuery(finalString query, z+
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finalObject[] parameters){ hl<y4y&|
return getHibernateTemplate W+\?~L.
8ljuc5,J
().findByNamedQuery(query, parameters); uFo/s&6K
} kM;o0wi
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publicList find(finalString query){ zqf[Z3
return getHibernateTemplate().find o,*=$/or
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(query); toIYE*ocv=
} ceG&,a$\
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publicList find(finalString query, finalObject *gDl~qNRoS
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parameter){ G,|KL" H6
return getHibernateTemplate().find CdL.?^
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(query, parameter); #q;z8 @
} |z*>ixK
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public PaginationSupport findPageByCriteria +`Pmq}ey
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(final DetachedCriteria detachedCriteria){ E30Z`$cz:
return findPageByCriteria iD714+N(
#ouE r-=
(detachedCriteria, PaginationSupport.PAGESIZE, 0); n}OU Y
} |vz9Hs$@l
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public PaginationSupport findPageByCriteria `[Sl1saZ$S
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(final DetachedCriteria detachedCriteria, finalint 0>FE%
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startIndex){ G "brT 5:
return findPageByCriteria >f@ G>H)+
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(detachedCriteria, PaginationSupport.PAGESIZE, " #v%36U
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startIndex); ;7j,MbU
} `HyF_m>\
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public PaginationSupport findPageByCriteria M4:s;@qZ.
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(final DetachedCriteria detachedCriteria, finalint #U"1 9@|}
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pageSize, hZU1O
finalint startIndex){ :tbd,Uo
return(PaginationSupport) Dr+ Ps
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getHibernateTemplate().execute(new HibernateCallback(){ 30d#Lq
publicObject doInHibernate Mk5RHDh
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(Session session)throws HibernateException { YlKFw|=
Criteria criteria = Y.-S=Y
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detachedCriteria.getExecutableCriteria(session); W;TJenv
int totalCount = H1&RI4XC
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((Integer) criteria.setProjection(Projections.rowCount u"Y]P*[k
0OWL
()).uniqueResult()).intValue(); [K:29N9~4
criteria.setProjection =:~(m
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(null); DFy1 bg
List items = !_x*m@/
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criteria.setFirstResult(startIndex).setMaxResults Nog(VN4I&
zPE$
(pageSize).list(); x{hn2]6+eB
PaginationSupport ps = l1r_b68
9/3;{`+[a
new PaginationSupport(items, totalCount, pageSize, d.r Y-k
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startIndex); a+
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return ps; doLNz4W
} wW5Yw
i
}, true); i/$SN-5}1
} B*79qq
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public List findAllByCriteria(final 5[R?iSGL1
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DetachedCriteria detachedCriteria){ gtYRV*^q
return(List) getHibernateTemplate "8/dD]=f^a
m~>@BCn;
().execute(new HibernateCallback(){ [W;[v<E;
publicObject doInHibernate 1;&T^Gdj
e U;jP]FA
(Session session)throws HibernateException { (/?R9T[V&^
Criteria criteria = hY=I5[*
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detachedCriteria.getExecutableCriteria(session); Dbz]{_Y;
return criteria.list(); vr4S9`,
} Ac\W\=QvB
}, true); c0[k T
} }0{B
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public int getCountByCriteria(final k
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DetachedCriteria detachedCriteria){ H(> M
Integer count = (Integer) (oYW]c}G,
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getHibernateTemplate().execute(new HibernateCallback(){ KyLp?!|>
publicObject doInHibernate
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(Session session)throws HibernateException { d+5:Qrr
Criteria criteria = Kz[BB@[
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detachedCriteria.getExecutableCriteria(session); KY+]RxX
return o0`q#>7!_b
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criteria.setProjection(Projections.rowCount x+:zq<0|
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()).uniqueResult(); @a(oB.i
} 784;]wdy\
}, true); RGp'b
return count.intValue(); 2 ~-( A
} ikHOqJ-,m
} p(?3
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* nCx[
用户在web层构造查询条件detachedCriteria,和可选的 I?M@5u
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 x+^Vg3 q
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PaginationSupport的实例ps。 $?f]ZyZr.
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ps.getItems()得到已分页好的结果集 e/94y6*>
ps.getIndexes()得到分页索引的数组 [z+x"9l0!
ps.getTotalCount()得到总结果数 >EIrw$V$
ps.getStartIndex()当前分页索引 x'i0KF
ps.getNextIndex()下一页索引 #LWg" i
ps.getPreviousIndex()上一页索引 a))*F!}c
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 o4~kX
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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 "L@g3g?|`
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一下代码重构了。 OX3Xy7
ke6n/ h5`
我把原本我的做法也提供出来供大家讨论吧: g;G5 r&T
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首先,为了实现分页查询,我封装了一个Page类: s<VJ`Ur
java代码: jL_5]pzJ
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/*Created on 2005-4-14*/ @C_ =*
package org.flyware.util.page; 2sun=3qb
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/** la`"$f
* @author Joa Hirr=a3
* wY`#$)O0*
*/ ZIW7_Y>_
publicclass Page { K~@`o-Z[
ccMd/
/** imply if the page has previous page */ :rmauKR
privateboolean hasPrePage; 4(|yD;
0BDS_Rx
/** imply if the page has next page */ 8A4TAT4,
privateboolean hasNextPage; 3#mE(
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[gn[nP9
/** the number of every page */ vHc#m@4o
privateint everyPage; 3+zzi
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/** the total page number */ b9#m m
privateint totalPage; t=
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/** the number of current page */ Bac| ;+L~L
privateint currentPage; T 9MzUV&
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/** the begin index of the records by the current JZw^W{
Da CblX
query */ [yF^IlSs
privateint beginIndex; :`5;nl63
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/** The default constructor */ $eMK{:$O
public Page(){ eI?HwP{m
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} #G~wE*VR$
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/** construct the page by everyPage Gym#b{#":
* @param everyPage ZQ|gt*
* */ `#p< rfe
public Page(int everyPage){ 9C=~1>S
this.everyPage = everyPage; b~9`]+
} mF~ys{"t
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/** The whole constructor */ v^\JWPR/
public Page(boolean hasPrePage, boolean hasNextPage, DZ2Fl>7
f-&ATTx`J
t)!V+Qcb
int everyPage, int totalPage, 4znH$M>bU
int currentPage, int beginIndex){ jm+blB^%K
this.hasPrePage = hasPrePage; Bs@:rhDi
this.hasNextPage = hasNextPage; 8W@dtZ,d
this.everyPage = everyPage; X98#QR#m
this.totalPage = totalPage; lJlhl7
this.currentPage = currentPage; $':JI#
this.beginIndex = beginIndex; sX!3_'-
} Z,SY
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/** GI?PGAT
* @return EoKo
* Returns the beginIndex. LS{bg.e
*/ 0W_mCV
publicint getBeginIndex(){ X*)?LxTj
return beginIndex; "R8.P/ 3
}
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/** l[Tt[n
* @param beginIndex /Bh>
* The beginIndex to set. 6UO$z- e
*/ OelU
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publicvoid setBeginIndex(int beginIndex){ G"{4'LlA
this.beginIndex = beginIndex; 3Qk/ Ll
} nPcxknl(pd
a^(2q{*
/** n
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* @return <8*A\&
* Returns the currentPage. <5M_EJp
*/ CuIqh BW!
publicint getCurrentPage(){ f&f`J/(
return currentPage; 9QC< E|
} .(JE-upJ"
hRa\1Jt>a
/** *^uGvJXF
* @param currentPage :Jm!=U%'Z
* The currentPage to set. 3Fgz)*Gu]
*/ )U]:9)
publicvoid setCurrentPage(int currentPage){ qg|Ox*_od"
this.currentPage = currentPage;
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} vUqe.?5
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/** D/e&7^iK
* @return iQu^|,tHEM
* Returns the everyPage. |^?`Q.|c$
*/ gji*Wq
publicint getEveryPage(){ Qg[heND
return everyPage; b$dBV}0 L
} 8>ESD}(
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/** t?KUK>>w
* @param everyPage ::v;)VdX+*
* The everyPage to set. Z>X9J(=
*/ uW )
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publicvoid setEveryPage(int everyPage){ 4{Q$!O>
this.everyPage = everyPage; U7jhV,gO4
} kp'b>&9r
EG%I1F%
/** E1#H{)G
* @return Wa(W&]
* Returns the hasNextPage. Rq"VB.ef&{
*/ dJloH)uJZ>
publicboolean getHasNextPage(){ 04P.p6
return hasNextPage; [+y&HNf
} fBf]4@{
C?8PT/
/** I; ^xAd3G
* @param hasNextPage ?Y%}(3y
* The hasNextPage to set. @ <|6{N<
*/ sf
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publicvoid setHasNextPage(boolean hasNextPage){ "v@);\-V
this.hasNextPage = hasNextPage; 6euR'd^Qi
} 1]"D%U=
"tfn?n0
/** 4tbw*H5!5
* @return [|y`y%
* Returns the hasPrePage. W&HF?w}s
*/ 8b-7]%
publicboolean getHasPrePage(){ T:be 9 5!,
return hasPrePage; )gr}<}X)B
} ,;9ak-$8p
m"5{D*|
/** ~u};XhZ
* @param hasPrePage sq6>DuBZz
* The hasPrePage to set. AU3auBol
^
*/ ixIh
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publicvoid setHasPrePage(boolean hasPrePage){ rH[5~U
this.hasPrePage = hasPrePage; dz{#"No0
} `Q:de~+AM{
H~~7~1"x
/** >/(i3)
* @return Returns the totalPage. F(J\ctha
*
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*/ Cw6>^
publicint getTotalPage(){ n>u.3wL
return totalPage; wYZy e^7
} V+Y|4Y&
R
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/** >_rzT9gX&
* @param totalPage ` 52%XI
* The totalPage to set. =9kj?
u~
*/ ]\[m=0K
publicvoid setTotalPage(int totalPage){ jn.R.}TT
this.totalPage = totalPage; @<hF.4,]
} ;gZwQ6)i
oxUE79
} &r&;<Q
V*~1,6N[
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jVLY!7Z4
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 ='7er.~\
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个PageUtil,负责对Page对象进行构造: ]ev *m&O
java代码: D-'i G%)kA
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/*Created on 2005-4-14*/ $Sp*)A]E`
package org.flyware.util.page; I8%d;G~
N!tpzHXw
import org.apache.commons.logging.Log; h`z2!F4
import org.apache.commons.logging.LogFactory; @WhZx*1
*jYHd#UZx4
/** |^YzFrc
* @author Joa C!oS=qK?]
* .}IK}A/-
*/ >+yqjXRzm
publicclass PageUtil { F% F
c+?
lt@
privatestaticfinal Log logger = LogFactory.getLog m-:8jA?
5}vRo;-
(PageUtil.class); vF5wA-3&t
8
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/** 3r,1^h
* Use the origin page to create a new page v_y!Oh?EG
* @param page 6a "VCE]
* @param totalRecords z7OZ4R:
* @return 0!9?H1>
*/ W,QnU d'N
publicstatic Page createPage(Page page, int -9=M9}eDF
L9E;Uii0
totalRecords){ + ")qi=
return createPage(page.getEveryPage(), k98< s
8[6ny=S`
page.getCurrentPage(), totalRecords); 7Vz[ji
} bBkm]
>
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/** qZT 4+&y
* the basic page utils not including exception
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'Qm` A=
handler '5|Q<5!o
* @param everyPage CL)1Q
* @param currentPage vjexx_fq
* @param totalRecords dzjB UD
* @return page
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*/ 2ApDpH`fiJ
publicstatic Page createPage(int everyPage, int 8m#}S\m
3v8V*48B$
currentPage, int totalRecords){ }-REBrb-
everyPage = getEveryPage(everyPage); r;&]?9)W0
currentPage = getCurrentPage(currentPage); -mev%lV
int beginIndex = getBeginIndex(everyPage, c!'A)JD@
Ze[g0"
currentPage); Y9IJ
int totalPage = getTotalPage(everyPage, C m,*bgX
ltCwns
totalRecords); ;n( #b8r9
boolean hasNextPage = hasNextPage(currentPage, ua]\xBWx
(SgEt
totalPage); %JP&ox|^&
boolean hasPrePage = hasPrePage(currentPage); (cOND/S
`c qH}2s#
returnnew Page(hasPrePage, hasNextPage, wx]+*Lzz
everyPage, totalPage, Ns+)Y^(5
currentPage, =yk Rki
t*Z .e.q+
beginIndex); kPx]u\
} @+0@BO12
fZka%[B
privatestaticint getEveryPage(int everyPage){ Wo:zU
return everyPage == 0 ? 10 : everyPage; otmIu` h
} b
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^@|<'g.R-
privatestaticint getCurrentPage(int currentPage){ >< <$
return currentPage == 0 ? 1 : currentPage; <GL}1W"Ay
} ql#{=oGDnA
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privatestaticint getBeginIndex(int everyPage, int ?6gDbE%
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currentPage){ Z^/z
return(currentPage - 1) * everyPage; VYl_U?D
} bqw/O`*wfN
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privatestaticint getTotalPage(int everyPage, int
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totalRecords){ J)7,&Gc6
int totalPage = 0; p=8M0k
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if(totalRecords % everyPage == 0) cM> G>Yzo
totalPage = totalRecords / everyPage; ! /|0:QQi
else #hy5c,}>
totalPage = totalRecords / everyPage + 1 ; ugIm:bg&
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return totalPage; _Ep{|]:gw
} ~>}dse
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privatestaticboolean hasPrePage(int currentPage){ c t2_N
return currentPage == 1 ? false : true; "v\ bMuS
} x[GFX8h(k6
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privatestaticboolean hasNextPage(int currentPage, ()JYN5
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int totalPage){ 3X-{2R/ 3
return currentPage == totalPage || totalPage == %KabyvOl)
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0 ? false : true; .-C+0L1j
} E>l#0Zw
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} G<">/_jn
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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。 )M&Azbu
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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 WL)_8!
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做法如下: W G3mQ\k
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 /H\^l.|vk
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的信息,和一个结果集List: O)$N}V0
java代码: 9:CVN@E
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/*Created on 2005-6-13*/ h|c:!VN@
package com.adt.bo; @mQ/WYs
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import java.util.List; Y-neD?V N
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import org.flyware.util.page.Page; m 1'&{O:
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/** &|'Kut?8
* @author Joa 32iWYN
*/ #cp$ltY
publicclass Result { ;4S
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private Page page; $X.'W\o|
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private List content; 43}&w