Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 :+%Zh@u\
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 d vOJW".
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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 rxO2js
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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 [Qdq}FYr
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分页支持类: sLcFt1
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java代码: +jqj6O@Tjr
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package com.javaeye.common.util; 6S.~s6o,
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import java.util.List; p\bFdxv#
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publicclass PaginationSupport { cE{ =(OQ
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publicfinalstaticint PAGESIZE = 30; Fvxu>BK
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privateint pageSize = PAGESIZE; ~SjZk|
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privateList items; pGIe=Um0W
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privateint totalCount; h7;bclU
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privateint[] indexes = newint[0]; cUK\x2
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privateint startIndex = 0; S^cH}-+
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public PaginationSupport(List items, int HhkN^S,
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totalCount){ {BO|u{C
setPageSize(PAGESIZE); W3Ulewa
setTotalCount(totalCount); b>~RSO*
setItems(items); 2D([Z -<i
setStartIndex(0); BN@,/m9OQ%
} mEQ!-p
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public PaginationSupport(List items, int !Zbesp KZ
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totalCount, int startIndex){ U&y`-@A4
setPageSize(PAGESIZE); "L3Xd][
setTotalCount(totalCount); TRKgBK$,
setItems(items); %HSl)zEo>C
setStartIndex(startIndex); vN{-?
} `ycU-m==
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public PaginationSupport(List items, int i~& c|
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totalCount, int pageSize, int startIndex){ -{9Gagy2&
setPageSize(pageSize); zfjTQMaxh
setTotalCount(totalCount); (:Cc3
setItems(items);
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setStartIndex(startIndex); `W[+%b
} XLTD;[jO
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publicList getItems(){ B50 [O!
return items; (BERY
} k_3j
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publicvoid setItems(List items){ Dw |3Z
this.items = items; \]Z&P,}w
} 7nz!0I^
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publicint getPageSize(){ 64D%_8#m
return pageSize; NygI67
} >IR$e=5$
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publicvoid setPageSize(int pageSize){ fQQ|gwVki
this.pageSize = pageSize; e`sw*m5
} }f}IA\8]
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publicint getTotalCount(){ '; /84j-3F
return totalCount; n9fk,3
} "g
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publicvoid setTotalCount(int totalCount){ _=6 OP8
if(totalCount > 0){ 3 C"_$?y"
this.totalCount = totalCount; vF>gU_gz.
int count = totalCount / s#lto0b"8
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pageSize; m.V,I}J.q
if(totalCount % pageSize > 0) a{_ KSg
count++; \n@V-b
indexes = newint[count]; !"! ii$@
for(int i = 0; i < count; i++){ /S/aUvN
indexes = pageSize * "2mFC!
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} +v[O
}else{ ?`A9(#ySM
this.totalCount = 0; :^G%57NX
} ,#aS/+;[)
} 6+8mV8{-8
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publicint[] getIndexes(){ 1D$::{h
return indexes; l^,qO3ES
} aRKv+{K
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publicvoid setIndexes(int[] indexes){ Wy(pLBmb
this.indexes = indexes; 6_U|(f
} ?f@ 9n ph
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publicint getStartIndex(){ (b|#n|~?YL
return startIndex; qG^_c;l6a
} k6J\Kkk(
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publicvoid setStartIndex(int startIndex){ S$K}v,8.sr
if(totalCount <= 0) 6To:T[ z#
this.startIndex = 0; M;qb7Mu
elseif(startIndex >= totalCount) q5?L1
this.startIndex = indexes 966<I56+
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[indexes.length - 1]; \ 522,n`
elseif(startIndex < 0) h^d\xn9GT#
this.startIndex = 0; ;>C9@S+
else{ S*rO0s:
this.startIndex = indexes `r]TA]DR
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[startIndex / pageSize]; >i`8R
} !a4cjc(
} gV.f*E1C
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publicint getNextIndex(){ 1$OVe4H1
int nextIndex = getStartIndex() + jnDQ{D
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pageSize; }Eb]9c\
if(nextIndex >= totalCount) ^vn\4
return getStartIndex(); `x4E;Wjv
else |1i]L @&
return nextIndex; Q,n4i@E
} d|3o/@k
@% H8"A
publicint getPreviousIndex(){ (s Jq;Z
int previousIndex = getStartIndex() - YnD#p[Wo^
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pageSize; =
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if(previousIndex < 0) WCoF{*
return0; r!~(R+,c
else ,,}sK
return previousIndex; rd|crD3
} }
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} }z?xGW/k
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抽象业务类 33,;iE
java代码: y 3IA '
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/** ?-d
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* Created on 2005-7-12 QQT G9s
*/ fPOEVmj<
package com.javaeye.common.business; ||`qIElAW,
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import java.io.Serializable; | yS5[?.`
import java.util.List; }U(\~
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import org.hibernate.Criteria; 2q/nAQ+
import org.hibernate.HibernateException; XN4oL[pO
import org.hibernate.Session; Et)920
import org.hibernate.criterion.DetachedCriteria; _ r~+p
import org.hibernate.criterion.Projections; [4ee <J
import *$JB`=Q
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org.springframework.orm.hibernate3.HibernateCallback; ^t`f1rGR
import %8a=mQl1^
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org.springframework.orm.hibernate3.support.HibernateDaoS M q76]I%
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upport; jzMhJ
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import com.javaeye.common.util.PaginationSupport; ([[)Ub$U
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public abstract class AbstractManager extends .r7D)xNa@
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HibernateDaoSupport { <sO?ev[
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privateboolean cacheQueries = false; c%jsu"
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privateString queryCacheRegion; g&q]@m
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publicvoid setCacheQueries(boolean &|s+KP|d
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cacheQueries){ ^@ M [t<
this.cacheQueries = cacheQueries; O<4Q$|=&?
} 2wGF-V
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publicvoid setQueryCacheRegion(String tF<^9stM
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queryCacheRegion){ 7[4_+Q:}
this.queryCacheRegion = ^GE^Q\&D&
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queryCacheRegion; _yiRh:
} 1% asx'^
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publicvoid save(finalObject entity){ 7t ZW^dF
getHibernateTemplate().save(entity); %)BwE
} #-}kG"
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publicvoid persist(finalObject entity){ eVZa6la"
getHibernateTemplate().save(entity); .4H_Zt[2
} f3/SO+Me}
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publicvoid update(finalObject entity){ <9ePi9D(
getHibernateTemplate().update(entity); hU 9\y
} N 9c8c
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publicvoid delete(finalObject entity){ umZlIH[7
getHibernateTemplate().delete(entity); P4hZB_.=
} fL(':W&n-
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publicObject load(finalClass entity, I/mvQxp
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finalSerializable id){ VV?]U$
return getHibernateTemplate().load Y0 @'za^y
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(entity, id); #.<*; rB
}
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publicObject get(finalClass entity, f0/jwfL
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finalSerializable id){ 17WNJ
return getHibernateTemplate().get ;3 G~["DA
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(entity, id); _= o1?R
} "L9C
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publicList findAll(finalClass entity){ 0q:(-z\S4
return getHibernateTemplate().find("from t9?R/:B%
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" + entity.getName()); hO^&0?
} hZp=BM"bJ
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publicList findByNamedQuery(finalString `%FIgE^
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namedQuery){ di8W2cwz
return getHibernateTemplate
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().findByNamedQuery(namedQuery); ^^n+
} =#OHxM
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publicList findByNamedQuery(finalString query, xP8iz?6"V
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finalObject parameter){ [ED!J~lg8
return getHibernateTemplate g,00'z_D
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().findByNamedQuery(query, parameter); g2+l@$W
} XD;15a
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publicList findByNamedQuery(finalString query, e*Uz#w:
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finalObject[] parameters){ a9yIV5_N
return getHibernateTemplate ArNur~
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().findByNamedQuery(query, parameters); 4a(g<5wfI
} JK@izI
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publicList find(finalString query){ yf
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return getHibernateTemplate().find 3S[w'
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(query); 8vz_~p9%j
} z1Bj_u{
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publicList find(finalString query, finalObject 4q\.I+r^
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parameter){ %00k1*$
return getHibernateTemplate().find Jo6~r-
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(query, parameter); n.2E8m/
} 3v9gb,)y\
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public PaginationSupport findPageByCriteria 1$='`@8I
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(final DetachedCriteria detachedCriteria){ o~i]W.SI(
return findPageByCriteria 8gVxiFjo
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); tx:rj6-z
} jw:4fb
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public PaginationSupport findPageByCriteria 3e!3.$4M
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(final DetachedCriteria detachedCriteria, finalint ,omp F$%
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startIndex){ ka?IX9t\
return findPageByCriteria L Q I: ]d
)
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(detachedCriteria, PaginationSupport.PAGESIZE, Bq$e|t)'
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startIndex); f_i"/xC-/
} u^#4G7<
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public PaginationSupport findPageByCriteria gFWEodx,9
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(final DetachedCriteria detachedCriteria, finalint XEf&Yd
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pageSize, l5\B2 +}7
finalint startIndex){ mV:RmA
return(PaginationSupport) Q|j@#@O 1
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getHibernateTemplate().execute(new HibernateCallback(){ O?C-nw6kP
publicObject doInHibernate <FUqD0sQ
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(Session session)throws HibernateException { Y{Y;EY4
Criteria criteria = ps!5HZ2:
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detachedCriteria.getExecutableCriteria(session); U}RS*7`
int totalCount = Q.pEUDq/
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((Integer) criteria.setProjection(Projections.rowCount !LHzY(
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()).uniqueResult()).intValue(); V7B=+(xK
criteria.setProjection fG8}= xH_&
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(null); [p( #WM:
List items = c-s`>m
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criteria.setFirstResult(startIndex).setMaxResults 1c<CEq:?e%
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(pageSize).list(); c:h.J4mv
PaginationSupport ps = Ac5o K
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new PaginationSupport(items, totalCount, pageSize, &J6o$i
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startIndex); Q
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return ps; !
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} (l3UNP
}, true); rB.=f[aX[
} I9:G9
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public List findAllByCriteria(final e\d5SKY
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DetachedCriteria detachedCriteria){ we:5gK&
return(List) getHibernateTemplate 4P O%qO
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().execute(new HibernateCallback(){ TzevC$m;z
publicObject doInHibernate X5L(_0?F1
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(Session session)throws HibernateException { 8zCGMhd
Criteria criteria = yNLa3mW
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detachedCriteria.getExecutableCriteria(session); MuFU?3ovG*
return criteria.list(); Ew?/@KAV\
} |L.~Amd
}, true); 9h3~;Q
} Cdt,//xrz
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public int getCountByCriteria(final aV?}+Y{#
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DetachedCriteria detachedCriteria){ j?f,~Y<k
Integer count = (Integer) ^O$[Y9~*
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getHibernateTemplate().execute(new HibernateCallback(){ H4y1Hpa,
publicObject doInHibernate I7G\X#,iz
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(Session session)throws HibernateException { <D;H}ef
Criteria criteria =
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detachedCriteria.getExecutableCriteria(session); l|ZzG4]+l
return 9?}rpA`P
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criteria.setProjection(Projections.rowCount $@u^Jt, ?
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()).uniqueResult(); t5X^(@q4N
} M|Dwk3#
}, true);
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return count.intValue(); U3_yEvZ
} }<\65 B$1
} d,oOn.n&
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用户在web层构造查询条件detachedCriteria,和可选的 <SC|A|
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 Yyo9{4v+p{
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PaginationSupport的实例ps。 o.
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ps.getItems()得到已分页好的结果集 ,a]~hNR*X
ps.getIndexes()得到分页索引的数组 g]iy-,e
ps.getTotalCount()得到总结果数 Y%CL@G60
ps.getStartIndex()当前分页索引 5>1Y="B
ps.getNextIndex()下一页索引 %B {D
ps.getPreviousIndex()上一页索引 L
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 +{Jf]"KD
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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 "PX3%II
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一下代码重构了。 .f92^lu9
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我把原本我的做法也提供出来供大家讨论吧: 5k%N<e``
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首先,为了实现分页查询,我封装了一个Page类: 6rN5Xf cS
java代码: }'.Sn{OWf
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/*Created on 2005-4-14*/ X_s G6Q@
package org.flyware.util.page; h&k^l,
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/** #g`cih=QL
* @author Joa F{H0
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* $Z7|t
*/ 6m{$rBR
publicclass Page { Lq
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/** imply if the page has previous page */ }b]y
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privateboolean hasPrePage; kJ<Xq
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/** imply if the page has next page */ ;AL@<,8
privateboolean hasNextPage; tCCi|*P
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/** the number of every page */ Ye=7Y57Nr
privateint everyPage; hzPB~obC
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/** the total page number */ zS"zb
privateint totalPage; .McoW7|Y
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/** the number of current page */ p:Ld)U *
privateint currentPage; =|5bhwU]
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/** the begin index of the records by the current <#x%A0
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query */ d>"$^${
privateint beginIndex; X @jYQ.
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/** The default constructor */ >
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public Page(){ 9@z|2z2\G
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} dZiWVa
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/** construct the page by everyPage ;!Z7-OZX
* @param everyPage o`1V
* */ CT:eV7<>s
public Page(int everyPage){ KjfKo;T
this.everyPage = everyPage; H"RF[bX(
} `:BQ&T%UQR
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/** The whole constructor */ ; 7v7V
public Page(boolean hasPrePage, boolean hasNextPage, ,;e-37^0l
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int everyPage, int totalPage, p$o&dQ=n[
int currentPage, int beginIndex){ [qD<U %Hi
this.hasPrePage = hasPrePage; "T1#*"{j
this.hasNextPage = hasNextPage; >Hzb0N!VJ
this.everyPage = everyPage; t?H;iBrpxd
this.totalPage = totalPage; nTy,Jml
this.currentPage = currentPage; Qbt>}?-
this.beginIndex = beginIndex; ~Ow23N
} rKs WS~U
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/** U W)&Eky
* @return FjLv*K[#d
* Returns the beginIndex. . N} }cJq
*/ @NwM+^
publicint getBeginIndex(){ f{5|}PL
return beginIndex; SU}oKii
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} V #\ZS{'J
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/** F t8h=
* @param beginIndex f5qHBQ
* The beginIndex to set. D&6Qk&>
*/ Eno2<<
publicvoid setBeginIndex(int beginIndex){ DoB3_=yJ+
this.beginIndex = beginIndex; QDT{Xg*I
} =? *"V-l
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/** qkG;YGio
* @return /?-p^6U
* Returns the currentPage. ~0r.3KTl"Y
*/ KY34 'Di
publicint getCurrentPage(){ wOkJ:k
return currentPage; -j=&