Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ]|PTZ1?j
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 8x)i{>#i
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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 HfhI9f_ x
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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 ~GX
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分页支持类: P (7Q8i'
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java代码: r5UVBV8T
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package com.javaeye.common.util; ?B;7J7 T
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import java.util.List; ;92xSe"Ww
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publicclass PaginationSupport { M^8zqAA
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publicfinalstaticint PAGESIZE = 30;
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privateint pageSize = PAGESIZE; >g>r_0.
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privateList items; [t3 Kgjt
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privateint totalCount; r,.j^a
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privateint[] indexes = newint[0]; 0fBwy/:
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privateint startIndex = 0; UCmy$aW
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public PaginationSupport(List items, int QN$s%&O
<'$>&^!^
totalCount){ 7]1a3Jk
setPageSize(PAGESIZE); !*~QB4\2b
setTotalCount(totalCount); hx;kNcPbI
setItems(items); 5EVypw?]x
setStartIndex(0); -N^Ah_9ek
} t7u*j-YE
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public PaginationSupport(List items, int <EgJm`V
{_*G"A 9
totalCount, int startIndex){ "&f|<g5
setPageSize(PAGESIZE); \xggIW.^0
setTotalCount(totalCount); R!"|~OO
setItems(items); U`EOun,
setStartIndex(startIndex); dL+yd0b*
} '{.4~:
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public PaginationSupport(List items, int %5zIh[!1$
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totalCount, int pageSize, int startIndex){ Q<D_QJ
setPageSize(pageSize); 56c[$ q
setTotalCount(totalCount); oVZzvK(zR
setItems(items); Kn1;=k
setStartIndex(startIndex); L)\<7
} 'Z.C&6_
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publicList getItems(){ f1'X<VA
return items; C@:X9NU
} |4pl}:g/Z
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publicvoid setItems(List items){ fUY05OMZ
this.items = items; /%,aX[
} VK*`&D<P
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publicint getPageSize(){ tKe-Dk9
return pageSize; fa/o4S<
} ^{=UKf{
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publicvoid setPageSize(int pageSize){ =8`KGeP$
this.pageSize = pageSize; "62g!e}!c
} |XG&[TI- "
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publicint getTotalCount(){ pL[3,.@WA
return totalCount; $G)HU6hF*
} #W8?E_iu
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publicvoid setTotalCount(int totalCount){ u8>aO>(bVg
if(totalCount > 0){ MbInXv$q2/
this.totalCount = totalCount; l(_|CkcZ
int count = totalCount / F7b%
x7b
=X5w=(&
pageSize; >m;nt}f'+
if(totalCount % pageSize > 0) sm{0o$\Z
count++; A_E2v{*n
indexes = newint[count]; u tkdL4G}'
for(int i = 0; i < count; i++){ aj1,h)P
indexes = pageSize * dr&G>
6A.%)whI;
i; %vZHHBylu
} \*{Mg wF
}else{ &v;fK$=2C
this.totalCount = 0; .s4v*bng
} F Xr\
} D bi ^%
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publicint[] getIndexes(){ `'XN2-M8
return indexes; J;wBS w%1
} tl~ZuS/
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publicvoid setIndexes(int[] indexes){ n!8W@qhew
this.indexes = indexes; i4k [#x
} Btzes.
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publicint getStartIndex(){ 0`WFuFi^o
return startIndex; EHhc2^e
} j8 2w
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publicvoid setStartIndex(int startIndex){ _fY9u2Y
if(totalCount <= 0) 1##@'L|u
this.startIndex = 0; Ey U6^
elseif(startIndex >= totalCount) mP6}$D
this.startIndex = indexes 5+oY c-
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[indexes.length - 1]; .nVY" C&
elseif(startIndex < 0) c*zeO@AAn
this.startIndex = 0; 4t%Lo2v!X%
else{ I;wxgWOP
this.startIndex = indexes DQ/rx`BG
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[startIndex / pageSize]; 8Ara^Xh}q
} p8-$MF]]6
} K$}K2w
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publicint getNextIndex(){ <=6F=u3PtU
int nextIndex = getStartIndex() + 1oiSmW\
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pageSize; hPG@iX|V
if(nextIndex >= totalCount) yN `&oya
return getStartIndex(); t$VRNZ`dy
else "0 %fR"
return nextIndex; 8|\ -(:v
} VCnf`wZB"
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publicint getPreviousIndex(){ <zTz/Hk`
int previousIndex = getStartIndex() - G~u$BV'
nr&|
pageSize; wexX|B^u
if(previousIndex < 0) ~}ifwm'7 a
return0; >)*d/ ^
else >+;}"J
return previousIndex; XI$W
} `~lG5|
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} D'ZUbAh!
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抽象业务类 2g5 4<G*e
java代码: V,c^Vqy
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/** I
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* Created on 2005-7-12 .L1[Rv3
*/ KI*bW e
package com.javaeye.common.business; seAEv0YWz
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import java.io.Serializable; NW;_4g4qE
import java.util.List; >b0Bvx-
jjEu
import org.hibernate.Criteria; dG~U3\!
import org.hibernate.HibernateException; _PC<Td>nm
import org.hibernate.Session; $}S0LZ_H
import org.hibernate.criterion.DetachedCriteria; Yg&/^
import org.hibernate.criterion.Projections; VE/m|3%t
import |cuKC \
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org.springframework.orm.hibernate3.HibernateCallback; D8E^[w!
import sD?Ynpt
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org.springframework.orm.hibernate3.support.HibernateDaoS ume70ap}m
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upport; _^RN$4.R>
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import com.javaeye.common.util.PaginationSupport; %$)Sz[=
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public abstract class AbstractManager extends yD!GgnW
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HibernateDaoSupport { J%q)6&
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privateboolean cacheQueries = false; E;4d lL`*
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privateString queryCacheRegion; mrG#ox4$
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publicvoid setCacheQueries(boolean 4~oRcO8!Y
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cacheQueries){ wM;=^br
this.cacheQueries = cacheQueries; As^eL/m2L
} $5\sV4 8f
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publicvoid setQueryCacheRegion(String Y![i=/
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queryCacheRegion){ V5
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this.queryCacheRegion = apM)$
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queryCacheRegion; 4v5qK
} bng/v
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publicvoid save(finalObject entity){ d:]ZFk_*
getHibernateTemplate().save(entity); uz3 ?c6b
} CSWA/#&8>
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publicvoid persist(finalObject entity){ ^
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getHibernateTemplate().save(entity); :y{@=E=XSC
} &!'R'{/?X
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publicvoid update(finalObject entity){ C4dCaiX
getHibernateTemplate().update(entity); ^foCcO
} pA@R,O>zr
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publicvoid delete(finalObject entity){ *9F{+)A
getHibernateTemplate().delete(entity); CA$|3m9)NM
} v`7~#Avhz
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publicObject load(finalClass entity, Ne1W!0YLK
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finalSerializable id){ =gd~rk9
return getHibernateTemplate().load ,K&L/*
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(entity, id); ):L0{W{
} K\lu;
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publicObject get(finalClass entity, ^Vc(oa&;
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finalSerializable id){ H:16aaMn(
return getHibernateTemplate().get LTb#1JC
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(entity, id); V4,\vgGu
} /|v
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publicList findAll(finalClass entity){ 7$"5qJ{ s
return getHibernateTemplate().find("from zmFKd5
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" + entity.getName()); 7Mh!@Rd_V
} ]<_v;Q<t
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publicList findByNamedQuery(finalString _znn `_N:v
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namedQuery){ 97}l`z;Z
return getHibernateTemplate "Z-YZ>2
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().findByNamedQuery(namedQuery); 5~i}!n
} 'H1k
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publicList findByNamedQuery(finalString query, %e/L
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finalObject parameter){ RAxp2uif
return getHibernateTemplate "3Ckc"G@
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().findByNamedQuery(query, parameter); FJ|JXH*
} (Ii+}Mfp
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publicList findByNamedQuery(finalString query, <7MxI@\
q9$K.=_5
finalObject[] parameters){ zhI"++
return getHibernateTemplate 8;(3fSNC
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().findByNamedQuery(query, parameters); N8{
8 a
} ^^[A\'
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publicList find(finalString query){ VzuU0
return getHibernateTemplate().find >Qs{LEsLb
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(query); TA"gU8YQ
} FBA th
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publicList find(finalString query, finalObject #nS crs@
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parameter){ (ZD~Q_O-
return getHibernateTemplate().find )H*BTfmt
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(query, parameter); m]ALW0
} Rs "#gT
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public PaginationSupport findPageByCriteria '.t{\
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(final DetachedCriteria detachedCriteria){ cnU()pd
return findPageByCriteria =O~Y6|
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); a )M3t
} xc1-($Q,
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public PaginationSupport findPageByCriteria 'LLpP#(
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(final DetachedCriteria detachedCriteria, finalint cwI3ANV
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startIndex){ ~4`3p=$
return findPageByCriteria 'M%uw85
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(detachedCriteria, PaginationSupport.PAGESIZE, ?q}:ojrs1
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startIndex); mZL0<vU@^
} Gs(;&fw
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public PaginationSupport findPageByCriteria t^g+nguz
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(final DetachedCriteria detachedCriteria, finalint CWS]821;
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pageSize, +Al*MusS
finalint startIndex){ +Sg+% 8T
return(PaginationSupport) kwrM3nq
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getHibernateTemplate().execute(new HibernateCallback(){ Lv:;}
publicObject doInHibernate \kC'y9k
2 :&QBwr+;
(Session session)throws HibernateException { x3 01uf[
Criteria criteria = g ~>nT>6
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detachedCriteria.getExecutableCriteria(session); ]nm(V
int totalCount = :VlMszy}B3
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((Integer) criteria.setProjection(Projections.rowCount G-Zn-I
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()).uniqueResult()).intValue(); @{@)gE
criteria.setProjection 3PaMq6Ca
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(null); *!`bC@E
List items = ZKVM9ofXRi
/_tN&[
criteria.setFirstResult(startIndex).setMaxResults ])vqXjN6"
MO
*7:hI
(pageSize).list(); /F}dC/W
PaginationSupport ps = %Wt F\p
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new PaginationSupport(items, totalCount, pageSize, Fhs/<w-
__)"-\w-_(
startIndex); 14p{V}f3
return ps; oX?~
} J&;' gT
}, true); 0#/Pc`zC
} ePTN^#|W
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public List findAllByCriteria(final &a";jO
GB
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DetachedCriteria detachedCriteria){ (+;%zh-
return(List) getHibernateTemplate 5hp)Z7
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().execute(new HibernateCallback(){ wQ\bGBks
publicObject doInHibernate l1]'3]P(
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(Session session)throws HibernateException { 4_o+gG%HaM
Criteria criteria = DcEGIaW
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detachedCriteria.getExecutableCriteria(session); iayxN5,
return criteria.list(); W";Po)YC
} cDh\$7'b
}, true); <}1GYeP
} G/V0Yn""
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public int getCountByCriteria(final 0<]]q[pr
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DetachedCriteria detachedCriteria){ 3y-P-NI~=
Integer count = (Integer) &_$xMM,X
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getHibernateTemplate().execute(new HibernateCallback(){ P;p;o]
publicObject doInHibernate 4
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(Session session)throws HibernateException { Ms=11C
Criteria criteria = -A1:S'aN-
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detachedCriteria.getExecutableCriteria(session); k:CSH{ s5{
return seNH/pRb
qF4DX$$<
criteria.setProjection(Projections.rowCount _H$Z}2g<z
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()).uniqueResult(); 8iN@n8O
} RJLhR_t7n
}, true); #L xfE<^
return count.intValue(); <"x *ZT
} +!<{80w
} Ct}rj-L<i
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用户在web层构造查询条件detachedCriteria,和可选的 rvBKJ!b0
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 zl["}I(*n
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PaginationSupport的实例ps。 ??XtN.]7
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ps.getItems()得到已分页好的结果集 K${CHKFf
ps.getIndexes()得到分页索引的数组 l[{Ci|4
ps.getTotalCount()得到总结果数 o)Nm5g
ps.getStartIndex()当前分页索引 5C"A*Fg?;
ps.getNextIndex()下一页索引 B-aJn8>/
ps.getPreviousIndex()上一页索引 fFd"21>
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 8^"P'XQ
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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 3Tr}t.mt
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一下代码重构了。 KPs
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我把原本我的做法也提供出来供大家讨论吧: D[CEg2$y
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首先,为了实现分页查询,我封装了一个Page类: Gm'Ch}E
java代码: 9Q*zf@w
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/*Created on 2005-4-14*/ (1?k_!)T
package org.flyware.util.page; ({p@Ay
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/** ($:JI3e[;
* @author Joa =/F\_/Xw
* -xc'P,`
*/ Q4&<RWbT^
publicclass Page { ^W<uc :L7
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/** imply if the page has previous page */ ^tKJ}}
privateboolean hasPrePage; 0Kenyn4 ?
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/** imply if the page has next page */ "Kt[jV;6
privateboolean hasNextPage; &1,qC,:!
AJ-~F>gn
/** the number of every page */ <D{_q.`vA
privateint everyPage; SZ"^>}zl=
Q5qQ%cu
/** the total page number */ Y([vma>U]
privateint totalPage; sBD\;\I
pM7xnL4
/** the number of current page */ jRzQ`*KC#
privateint currentPage; E|
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/** the begin index of the records by the current
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|p{FSS
query */ \ .jT"Z~
privateint beginIndex; &li&P5!i
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/** The default constructor */ IEJp!P,E
public Page(){ IOi 6'
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} S)d_A
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/** construct the page by everyPage 2d Px s:8&
* @param everyPage "Crm\UI6
* */ dLI`\e<r&[
public Page(int everyPage){ ^YG.eT6iG
this.everyPage = everyPage; Ws(#ThA
} 3Q"4-pd
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/** The whole constructor */ 1ssEJ;#s
public Page(boolean hasPrePage, boolean hasNextPage, _jCjq
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int everyPage, int totalPage, 1p9+c~4l:
int currentPage, int beginIndex){ }];_ug*
"
this.hasPrePage = hasPrePage; ^ 04|tda
this.hasNextPage = hasNextPage; =!%+ sem
this.everyPage = everyPage; I7nZ9n|KU
this.totalPage = totalPage; Pkw` o #
this.currentPage = currentPage; U4@W{P02
this.beginIndex = beginIndex; 'F@#.Op`
} y}bE'Od
*T'>-nm]
/** s8<)lO<SV.
* @return
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* Returns the beginIndex. h^KLqPBt{
*/ 13nXvYo'
publicint getBeginIndex(){ "m:4e`_dz
return beginIndex; qSWnv`hL
} pZ4]oK\*
P$= Y 5
/** yy6?16@
* @param beginIndex ^l\^\>8
* The beginIndex to set. 8+<vumnw
*/ e.|_=Gd2/
publicvoid setBeginIndex(int beginIndex){ Sy<s/x^`
this.beginIndex = beginIndex; s) vHLf4 T
} 6M`N| %
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/** &zYo
* @return ,??%["R
* Returns the currentPage. Fhn=}7|4q
*/
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publicint getCurrentPage(){ I JAWG
return currentPage; e/;chMCq
} ^3L6mOoA
^^I3%6UY
/** 6DG:imGl
* @param currentPage 'B>%5'SdD
* The currentPage to set. p ft6
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*/ |[VtYV _{
publicvoid setCurrentPage(int currentPage){ {rG`Upp
this.currentPage = currentPage; [J|)DUjt
} THM\-abz
m18 If
/** xNh#= 6__9
* @return L@|W&N;%a
* Returns the everyPage. XKU+'Tz
*/ qi\!<clv
publicint getEveryPage(){ Sh=Px9'i
return everyPage; VzR(OB
} *$Df)iI6
*kXSl73 k
/** AqKl}8
* @param everyPage q1Si*?2W
* The everyPage to set. v^h
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*/ P/'~&*m-
publicvoid setEveryPage(int everyPage){ cia4!-#
this.everyPage = everyPage; /QsFeH
} ^ )Lh5
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/** zOpl#%"
* @return L$GhM!c
* Returns the hasNextPage. yVyh'd:Ik
*/ uLsGb=m%b
publicboolean getHasNextPage(){ `A)9
return hasNextPage; IwIk;pB O
} .Y%)&
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/** lGI5
* @param hasNextPage 6s833Tmb&r
* The hasNextPage to set. 7RmL#f`
*/ av( d0E}}b
publicvoid setHasNextPage(boolean hasNextPage){ D@yg)$;z
this.hasNextPage = hasNextPage; Vs~^r>
} eiJO;%fl>l
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/** Oph4&Ip[w
* @return 6EhRCl
* Returns the hasPrePage. Ek +L"7
*/ Rla4XN=mf
publicboolean getHasPrePage(){ dUtxG ~9
return hasPrePage; YWSo:)LY
} pCz;km
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/** k[l+~5ix
* @param hasPrePage h94SLj]
* The hasPrePage to set. ~ySmN}3~'
*/ r3l}I6
publicvoid setHasPrePage(boolean hasPrePage){ 8x
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this.hasPrePage = hasPrePage; fv!l {
} K h9 $
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/** 5#.uA_Fov
* @return Returns the totalPage. 2,O-/A;tW*
* Tv<iHHp
*/ AC=cz!3iB
publicint getTotalPage(){ \^kyC1
return totalPage; ^lT$D8
} aW7{T6.,
.*>LD
/** OE-$P
* @param totalPage X6~y+R
* The totalPage to set. mD:d,,~
*/ :4h4vp<
publicvoid setTotalPage(int totalPage){ i+yqsYKO
this.totalPage = totalPage; :b;2iBVB
} YNbs*i&
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} +vkqig
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lnW/T --
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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 lph3"a^
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个PageUtil,负责对Page对象进行构造: ](NSpU|*
java代码: :tM|$TZ
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/*Created on 2005-4-14*/ ;h_"5/#
package org.flyware.util.page; mSAuS)YD
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import org.apache.commons.logging.Log; ,JT|E~P?8
import org.apache.commons.logging.LogFactory; MQ2gzKw>
N10'./c K
/** geWis(#J
* @author Joa =/J4(#Xb
* z.eqOPW
*/ +DM+@F
publicclass PageUtil { ]y$D@/L@
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privatestaticfinal Log logger = LogFactory.getLog m^h"VH,
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(PageUtil.class); =2bW"gs
I
je.jui"
/** (`4^|_gw
* Use the origin page to create a new page -:m;ePK
* @param page 4QK([q
* @param totalRecords JiP]FJ;
* @return X#5dd.RR
*/ _< 69d
publicstatic Page createPage(Page page, int "*#$$e53A
ppVjFCv0<
totalRecords){ BgD;"GD*W
return createPage(page.getEveryPage(), b,7:=-D
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page.getCurrentPage(), totalRecords); 7*OO k"9
} 5?k_Q"~
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/** 8 +xLi4Pw
* the basic page utils not including exception WE4:Jy
{O#=%o[
handler K8{j oh
* @param everyPage .%3bXK+F
* @param currentPage X.xp'/d
* @param totalRecords W<yh{u&,
* @return page Q5r cPU>A
*/ W!I"rdo;V
publicstatic Page createPage(int everyPage, int o&g=Z4jj<
9+9}^B5@A
currentPage, int totalRecords){ '/b,3:
everyPage = getEveryPage(everyPage); dnNC
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currentPage = getCurrentPage(currentPage); d#I'9O0&
int beginIndex = getBeginIndex(everyPage,
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J7emoD[
currentPage); O~9
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int totalPage = getTotalPage(everyPage, 6YrkS;_HS
.Q?cNSWU
totalRecords); 5)V J
boolean hasNextPage = hasNextPage(currentPage, Pp:(PoH
?;+=bKw0
totalPage); sL~TV([6/
boolean hasPrePage = hasPrePage(currentPage); f`p`c*
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returnnew Page(hasPrePage, hasNextPage, R8Lp8!F'
everyPage, totalPage, iYHD:cg)~
currentPage, xx
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beginIndex); DM! vB+j+,
} aT(Pf7
O
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privatestaticint getEveryPage(int everyPage){ tn6\0_5n
return everyPage == 0 ? 10 : everyPage; kxhvy,t
} `HgT5}
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privatestaticint getCurrentPage(int currentPage){ /Y:_qsO1
return currentPage == 0 ? 1 : currentPage; rgB`<[:b
} fa/
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privatestaticint getBeginIndex(int everyPage, int 9X@y*;w<t
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currentPage){ Yj/S(4(h?
return(currentPage - 1) * everyPage; #_QvnQ?I
} engql;
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privatestaticint getTotalPage(int everyPage, int G#Nh)ff
. CLiv
totalRecords){ w%VHq z$
int totalPage = 0; 4B<D.i ;}
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if(totalRecords % everyPage == 0) 45edyQ
totalPage = totalRecords / everyPage; |`U^+Nf
else !?Z}b.%W
totalPage = totalRecords / everyPage + 1 ; ,78QLh9:
my[)/'
return totalPage; niFX8%<hP
} UALwr>+VJ
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privatestaticboolean hasPrePage(int currentPage){ 6WgGewn
return currentPage == 1 ? false : true; jkFS=eonK
} r{#od
7;
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privatestaticboolean hasNextPage(int currentPage, e~W35Y>A
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int totalPage){ X"y rA;,o
return currentPage == totalPage || totalPage == ,@khV
]3NH[&+
0 ? false : true; "|]'\4UdzQ
} u#\=g:
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} :upi2S_e
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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。 vZTX3c:,1
s)_7*DY
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 ]V<[W,*(5
:w#Zs)N
做法如下: ya5;C"
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 {|^9y]VFu
Um4
} `
的信息,和一个结果集List: tUGnD<P
java代码: s59v*
/
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AVOzx00U
/*Created on 2005-6-13*/ Ii?<Lz
package com.adt.bo; & *B@qQ
,`^B!U3m
import java.util.List; 8,a&i:C
9<.FwV>
import org.flyware.util.page.Page; F6}Pwz[c
DFwkd/3"
/** F8Rd#^9PD
* @author Joa )V!9&
*/ X'TQtI
publicclass Result { /wljbb/s
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private Page page; 7;5?2)+=6
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private List content; a^~T-;_V
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/** bVQLj}%
* The default constructor q+19EJ(
*/ [~W"$sT
public Result(){ #@;RJJZg
super(); mK%!9F
V
} V);{o>%.K
>e/;
/** Cj _Q9/
* The constructor using fields ZK27^oG
* `5r*4N<
* @param page - A
x$ Y
* @param content SJ6lI66OX
*/ E=Ah_zKU
public Result(Page page, List content){ 38L8AJqD
this.page = page; E&Pv:h,pV&
this.content = content; 1/jJ;}
} eZ[CqUJ&