Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 *YlV-C<}W"
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 p0pWzwTG3
@}kv-*
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 VcoOeAKL
*_ ?dVhxf
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 0:b2(^]bg
)Y)pmjZaG
。 xpOg8u5
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分页支持类: >a}f{\Q
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java代码: Onwp-!!.
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@'GGm#<
package com.javaeye.common.util; ]7e =fM9V;
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import java.util.List; !A%<#Gjt
MR}Agu#LG
publicclass PaginationSupport { ciMzf$+G$
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h
publicfinalstaticint PAGESIZE = 30; cH>%r^G\
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privateint pageSize = PAGESIZE; 5ls6t{Ci
-{ZWo:,r~q
privateList items; 4^URX>nx8
H<3I 5Kgt
privateint totalCount; 9V5-%Iv
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privateint[] indexes = newint[0]; NC38fiH_N
0'IBN}
privateint startIndex = 0; 73){K?R
v;)..X30
public PaginationSupport(List items, int "&3h2(#%
~
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totalCount){ KGg3 !jY
setPageSize(PAGESIZE); e;(0(rI
setTotalCount(totalCount); y99mC$"Ee`
setItems(items); )P+7PhE{J
setStartIndex(0); !50[z:
} IC7M$
[Vma^B$7Vj
public PaginationSupport(List items, int ,{mCf^
Ng_!zrx04
totalCount, int startIndex){ )Eo)t>
setPageSize(PAGESIZE); rvw)-=qR[
setTotalCount(totalCount); `*shF9.\C
setItems(items); :ijAqfX
setStartIndex(startIndex); "
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} X*\J_
#{\%rWnCm
public PaginationSupport(List items, int JeE;V![
6AhM=C
totalCount, int pageSize, int startIndex){ E@b(1@
setPageSize(pageSize);
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setTotalCount(totalCount); GN2Sn`;
setItems(items); lg&t8FHa;
setStartIndex(startIndex); &c,kQo+pA
} aca=yDs2
&Udb9
publicList getItems(){ }B1!gz$YNO
return items; ,l)^Ft`5
} Ct>GYk$
UNBH
publicvoid setItems(List items){ mrjswF27$o
this.items = items; g?ULWeZg5
} _D+J!f^
^cuc.g)c$?
publicint getPageSize(){ d}4Y(
return pageSize; ZEx}$<)_
} % S os
<q@a~'Ai?!
publicvoid setPageSize(int pageSize){ sL$:"=
this.pageSize = pageSize; 7K98#;a)5
} zld#qG6
c.e2 M/
publicint getTotalCount(){ 55fC~J<
return totalCount; #}y2)g
} BGX.U\uc
sdo[D
publicvoid setTotalCount(int totalCount){ k1D@fiz
if(totalCount > 0){ v
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this.totalCount = totalCount; U3dwI:cG
int count = totalCount / )z28=%g
Ptdpj)oi&Q
pageSize; e(<str>
if(totalCount % pageSize > 0) W@I|Q -
count++; N <Xq]!
K-
indexes = newint[count]; ?o|f':
for(int i = 0; i < count; i++){ e0,|Wm
indexes = pageSize * q}?4f*WC
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i; Fkd+pS\9g~
} %Da1(bBh
}else{ (O(}p~s
this.totalCount = 0; SR|`!
} @/ohg0
} P&^;656r
wLnf@&jQ%
publicint[] getIndexes(){ 9eQxit7
return indexes; dx@-/^.
} m()RU"WY
2HsLc*9{4
publicvoid setIndexes(int[] indexes){ ,tu.2VQc@
this.indexes = indexes; |$
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} @X;!92i
/k,-P
publicint getStartIndex(){ kZGRxp9
return startIndex; Tq[kl'_
} 0i\M,TNf*
8b;1FQ'
publicvoid setStartIndex(int startIndex){ fy@<&U5rg
if(totalCount <= 0) %2{%Obp'
this.startIndex = 0; |#cm`v
elseif(startIndex >= totalCount) =V-|#j
this.startIndex = indexes TI,&!E?;
FwkuC09tI
[indexes.length - 1]; HOJs[mqB%
elseif(startIndex < 0) `3WFjU5a
this.startIndex = 0; P"8~$ P#
else{ kr9*,E9cv
this.startIndex = indexes %|q>pin2
sl`s_$J
[startIndex / pageSize]; ~ls[Sl@
} 9CWezI+
} -7@/[9Gf`:
?!d&E?9\
publicint getNextIndex(){ '6cWS'9"
int nextIndex = getStartIndex() + Enn"hdI
1;Cyz)
pageSize; LcTt)rs
f
if(nextIndex >= totalCount) Ch|jtVeuyJ
return getStartIndex(); f$Fhf?'
else R5-@
return nextIndex; P"IPcT%Ob%
} %u5L!W&
H2jgO?l;!
publicint getPreviousIndex(){ nG'&ZjA
int previousIndex = getStartIndex() - Rnr(g;2
Q/(K$6]j
pageSize; lvBx\e;7P
if(previousIndex < 0) $Y/9SV,
return0; (
+Q&[E"87
else g4=pnK8
return previousIndex; /-_h1.!
} )f[
B6Y
= C8 ?M
} SwTL|+u
}J:U=HJ
:~tAUy":_*
#FCnA
抽象业务类 $0>60<J
java代码: %7IugHH9y
p93r'&Q
t\k$};qJ
/** @ hiCI.?X
* Created on 2005-7-12 7byK{{/z
*/ Cz\ew B
package com.javaeye.common.business; _/-jX
g(qJN<RC/
import java.io.Serializable; jHE}qE~>5
import java.util.List; S >X:ZYYC
=S+wCN
import org.hibernate.Criteria; ;o2$
Q
import org.hibernate.HibernateException; IEsEdw]aZE
import org.hibernate.Session; M/>7pZW
import org.hibernate.criterion.DetachedCriteria; hKLCJ#T
import org.hibernate.criterion.Projections; |,gc_G
import 2Mc3|T4)U
1PQ~jfGi
org.springframework.orm.hibernate3.HibernateCallback; nYR#
import Wz49i9e+d
[q)8N
org.springframework.orm.hibernate3.support.HibernateDaoS bMg(B-uF7
Ui_8)z _
upport; |ef7bKU8
eTI%^d|
import com.javaeye.common.util.PaginationSupport; aQ?/%\>
\r^qL^
public abstract class AbstractManager extends }Gz~nf%
DS.RURzd{r
HibernateDaoSupport { A}G7l?V&
dMf:h"7
privateboolean cacheQueries = false; 8<S~Z:JK
]@j*/IP
privateString queryCacheRegion; %Gz0^[+
)t0$qd ]
publicvoid setCacheQueries(boolean ZkRx1S"m
rzhWw-GY
cacheQueries){ J%v=yBC2
this.cacheQueries = cacheQueries; z;{iM/Xe
} TN!j13,
8=B|C'>
publicvoid setQueryCacheRegion(String M -cTRd-i
ww\CQ6/h
queryCacheRegion){ v5!d$Vctu
this.queryCacheRegion = 2&:f&"
h)ECf?r<
queryCacheRegion; Pk{_(ybaY
} =9y[1t
"CSsCA$/
publicvoid save(finalObject entity){ A-Sv;/yD_
getHibernateTemplate().save(entity); L-jJg,eY
} D.B.7-_8
,&]S(|2%>t
publicvoid persist(finalObject entity){ rdl;M>0@
getHibernateTemplate().save(entity); y I HXg#
} AK,J 7
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publicvoid update(finalObject entity){ #I{h\x><?
getHibernateTemplate().update(entity); :1cV;gJ
} gn8R[5:!V
8'r2D+Vwm
publicvoid delete(finalObject entity){ T6O::o6
getHibernateTemplate().delete(entity); |% F=po>w
} ~P*6ozSYpY
b3&zjjQ
publicObject load(finalClass entity, 9_L[w\P|4
|{BIHgMh
finalSerializable id){ 5gH1.7i b
return getHibernateTemplate().load @TLS<~
kw>v:F<M
(entity, id); /[a~3^Gs^
} q.KG^=10
6Z>FTz_
publicObject get(finalClass entity, A>vBQN
UldXYtGe
finalSerializable id){ ''q@>
return getHibernateTemplate().get O,+1<.;+
$?
m9")
(entity, id); rXmn7;B}g
} *]ly0nP
y?[ v=j*U
publicList findAll(finalClass entity){ Pu7_
v
return getHibernateTemplate().find("from F3N?Nk/
4,bv)Im+ `
" + entity.getName()); Ttu2 skcv
} p#ol*m5wE
A_XY'z 1
publicList findByNamedQuery(finalString mC4zactv
e}D3d=6`
namedQuery){ S@jQX
return getHibernateTemplate K,Ef9c/+K
hEA<o67
().findByNamedQuery(namedQuery); I?h)OvWd
} !^^?dRd*v
;;_,~pI?k
publicList findByNamedQuery(finalString query, eV2W{vuI
#+:9T/*>0
finalObject parameter){ %}SGl${-
return getHibernateTemplate 0ZT5bg_M
MuYk};f
().findByNamedQuery(query, parameter); ;+e}aER&9
} O!mvJD
5QW=&zI`=
publicList findByNamedQuery(finalString query, `_BNy=`s*
fL_4uC i\
finalObject[] parameters){ #^`4DhQ/
1
return getHibernateTemplate w,.+IV$Kk
"W=AB&
().findByNamedQuery(query, parameters); u8gS<\
} KK1gNC4R
bV(Y`g
publicList find(finalString query){ ujDd1Bxf?
return getHibernateTemplate().find C\S3Gs
_K`wG}YIE
(query); RTvqCp
} HTVuStM8
*i\Qo
publicList find(finalString query, finalObject D N'3QQn
na#CpS;pc
parameter){ qIVx9jNN
return getHibernateTemplate().find -l`f)0{
"oTHq]Ku
(query, parameter); WB?jRYp
} OP~HdocB
)T/0S$@
public PaginationSupport findPageByCriteria DNOueU
f1`gdQ)H
(final DetachedCriteria detachedCriteria){ !Z`j2
e}
return findPageByCriteria aUzBV\Yd}
w&$`cD
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 1_o],?Q
} fRrvNj0{V
w:%o?pKet1
public PaginationSupport findPageByCriteria h XfQ)$J
H(R1o~
(final DetachedCriteria detachedCriteria, finalint 6 )Hwt_b
'[U8}z3
startIndex){ {\S+#W\
return findPageByCriteria m`v2: S}
#Vl 0.l3
(detachedCriteria, PaginationSupport.PAGESIZE, *}]Nf
jq-p;-i
startIndex); DQNnNsP:M-
} 3
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public PaginationSupport findPageByCriteria R%Qf7Q
:H7D~ n
(final DetachedCriteria detachedCriteria, finalint "JVkVp[5D+
ks3`3q 7
pageSize, ;o^eC!:/%
finalint startIndex){ $56Z#'(D
return(PaginationSupport) V_C-P[2~
AjmVc])
getHibernateTemplate().execute(new HibernateCallback(){ ^@I
publicObject doInHibernate pM^9c7@!:
Y&[1`:-~-
(Session session)throws HibernateException { ~res V
Criteria criteria = <A<{,:5C
(hTCK8HK
detachedCriteria.getExecutableCriteria(session); !(mjyr
int totalCount =
:l~ I
O#x*iI%
((Integer) criteria.setProjection(Projections.rowCount 3 j!3E
}XZ'v_Ti
()).uniqueResult()).intValue(); uXI_M)
criteria.setProjection X'wE7=29M
|>27'#JC
(null); V_>\9m
List items = _,zA ^*b
_]04lGx27
criteria.setFirstResult(startIndex).setMaxResults Scp7X7{N
/,1D)0
(pageSize).list(); XOxr?NPQ^
PaginationSupport ps = vbkI^+=,YY
z3`-plE
new PaginationSupport(items, totalCount, pageSize, I'\kFjc
QZ4v/Ou
startIndex); n?A6u\sQ
return ps; +~'865 {
} ICuF %
}, true); P1zKsY,l$<
} R#xCkl -
UQ8M~x5$3%
public List findAllByCriteria(final `kOD[*
y]2qd35u_A
DetachedCriteria detachedCriteria){ 'HT7_$?*
return(List) getHibernateTemplate P.6nA^hXB
5 elw~u
().execute(new HibernateCallback(){ K2he4<
publicObject doInHibernate 6^%UU
o%
LL] zT H0
(Session session)throws HibernateException { qgE 73.!`6
Criteria criteria = wDcj,:h`
vK 7^*qr;j
detachedCriteria.getExecutableCriteria(session); ^cV;~&|.Xk
return criteria.list(); $>*3/H
} _Bj)r}~7#
}, true); `o<'
x.I
} |B.0TdF
_= +V/=
public int getCountByCriteria(final ,pqGX3
`%CtWJ(e
DetachedCriteria detachedCriteria){ '=[?~0(B
Integer count = (Integer) "nZ*{uv
wyp|qIS;
getHibernateTemplate().execute(new HibernateCallback(){ )u3 Zm
publicObject doInHibernate 0*%Z's\M"
iDMJicW!+F
(Session session)throws HibernateException { OH;b"]
Criteria criteria =
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~}F{vm
detachedCriteria.getExecutableCriteria(session); =Qh\D
return RD\
km)zMoE{c{
criteria.setProjection(Projections.rowCount zfI>qJ+Nqt
8'~[pMn`
()).uniqueResult(); k9)jjR*XxG
} 6Pnk5ps }h
}, true); < XP9@t&
return count.intValue(); ' pm2n0
} m6n?bEl6I
} wm]^3qI2
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Vm%1> '&
$P>`m$(8
${+ @gJ+S
_Xn qb+
用户在web层构造查询条件detachedCriteria,和可选的 Is]aj-#r
]GN7+8l
startIndex,调用业务bean的相应findByCriteria方法,返回一个 sW)Zi
ld3-C55
PaginationSupport的实例ps。 -M%_\;"de
[`p=(/I&L
ps.getItems()得到已分页好的结果集 MxWy*|J}
ps.getIndexes()得到分页索引的数组 bSsh^Z
ps.getTotalCount()得到总结果数 *\=.<|H Z
ps.getStartIndex()当前分页索引 ~GTz:nC*
ps.getNextIndex()下一页索引 u @~JiiC%
ps.getPreviousIndex()上一页索引 n9@ of
f~Fm4>\(
x\F,SEj
b|cyjDMAA
20vXSYa~
g) p,5BADm
SxdE?uCUS
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 (ohq0Y
J\d3N7_d
,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 /TZOJE(2j
Qi_>Mg`x
一下代码重构了。 U Z.=aQ}M
(rkyW z
我把原本我的做法也提供出来供大家讨论吧: O<96/a'
*:>"q ej
首先,为了实现分页查询,我封装了一个Page类: /DQc&.jK
java代码: 1"/He ` 4
XEn*?.e
Jj,U RD&0R
/*Created on 2005-4-14*/ G"X8}:}
package org.flyware.util.page; R<sJ^nx
t'BLVCu
/** (7XCA,KTGI
* @author Joa W5?yy>S6N
* Vy*:ne
*/ `kbSu}
publicclass Page { 6T+FH;h
NG
/** imply if the page has previous page */ 4AG\[f
8q
privateboolean hasPrePage; 43={Xy
T^T[$26
/** imply if the page has next page */ Y|8:;u'
privateboolean hasNextPage; BhM'@g*
T%6&PrQ7
/** the number of every page */ rFaF
Bd
privateint everyPage; 9so6WIWc
<Ard7UT
/** the total page number */ `D`sr[3n
privateint totalPage; [[>wB[w
I4i2+
*l}
/** the number of current page */ *g y{]
privateint currentPage; $ "E).j
8wVY0oRnU
/** the begin index of the records by the current uHAT#\m:
MS0Fl|YA
query */ dFH$l
privateint beginIndex; H|RT?Q
PZ{Dv'C
KN7^:cC
/** The default constructor */ K$ M^gh0
public Page(){ qw@puw@D
.pfP7weQ
} C0S^h<iSe*
w"OP8KA:^T
/** construct the page by everyPage L3G \
* @param everyPage M9y<t'
* */ d+X}cq=
public Page(int everyPage){ Kw8u`$Ad7
this.everyPage = everyPage; A|L 8P
} slg ]#Dy
HPb]Zj
/** The whole constructor */ ,$'])A?$
public Page(boolean hasPrePage, boolean hasNextPage, Ps%qfL\
Ga# :P F0
/e]'u&a
int everyPage, int totalPage, ,z;ky5Ct
int currentPage, int beginIndex){ .k
3'
this.hasPrePage = hasPrePage; 1Ab>4UhD
this.hasNextPage = hasNextPage; C8vOE`U,J
this.everyPage = everyPage; 4'-|UPhx
this.totalPage = totalPage; OE4+GI.r-
this.currentPage = currentPage; ]8icBneA~'
this.beginIndex = beginIndex; ,y+$cM(
} }0u8r`
$BFvF
,n
/** ?t+5s]
* @return % ]I ZLJ
* Returns the beginIndex. &^}6
9
*/ |1ST=O7.LH
publicint getBeginIndex(){ +)j1.X
return beginIndex; h$.:Uj8/
} 9lGOWRxR)
N\HQN0d9
/** tID%}Z v
* @param beginIndex &}?$i7x5
* The beginIndex to set. ;5tazBy&:C
*/ zo[[>MA
publicvoid setBeginIndex(int beginIndex){ ^|/](
this.beginIndex = beginIndex; W?eu!wL#p
} } ~"hC3w
x_c7R;C
/** ZTU&,1Y ;
* @return rAs,X
* Returns the currentPage. QHWBAGA
*/ Pb8^ b
publicint getCurrentPage(){ $<^u^q37u
return currentPage; "Kc>dJ@W
} ]S(%[|
/[ 6j)HIS
/** jS+AGE?5e
* @param currentPage s/7 A7![
* The currentPage to set. d3W0-INL
*/ K]j0_~3s
publicvoid setCurrentPage(int currentPage){ txcf=)@>V
this.currentPage = currentPage; g8w2Vz2/
} )ZBY* lk9
YKE46q;J
/** nK$X[KrV'
* @return B*~5)}1op
* Returns the everyPage. *;m5'}jsy
*/ :.?gHF.?
publicint getEveryPage(){ om |"S
return everyPage; 4<cz--g
} \mw(cM#:
-0_d/'d
/** IBQ@{QB
* @param everyPage +&Hr4@pgW
* The everyPage to set. \MK*by
*/ 6gT5O]]#o
publicvoid setEveryPage(int everyPage){ Pl<;[cB
this.everyPage = everyPage; u{FDdR9<
} E[O<S B
I
n @?4b8"
/** _:X|.W
* @return p|Q*5TO
* Returns the hasNextPage. !<UJ6t}
*/ b:R-mg.VT{
publicboolean getHasNextPage(){ k51Eyy50(
return hasNextPage; ZkIgL
} f)g7
3=
N gLU$/y;
/** _=q!
BW
* @param hasNextPage *dvDap|8W
* The hasNextPage to set. 8a_[B~
*/ v3GwD00
publicvoid setHasNextPage(boolean hasNextPage){ M@3"<[g
this.hasNextPage = hasNextPage; @ JvPx 0
} @h*fFiY&{
gqR)IVk>%
/** >@YtDl8R
* @return WWL4`s
* Returns the hasPrePage. jS;J:$>^
*/ /s-A?lw^2
publicboolean getHasPrePage(){ >yXN,5d[
return hasPrePage; 2P]L9'N{Y
} <H0R&l\
`'\t$nU
/** `xz<>g9e
* @param hasPrePage /
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* The hasPrePage to set. }lK3-2Pk
*/ gJ;_$`
publicvoid setHasPrePage(boolean hasPrePage){ L:(1ZS
this.hasPrePage = hasPrePage; .<z!3O&L
} dgDy5{_
xl"HotsX-x
/** Y=`
* @return Returns the totalPage. I+ es8
* J*l4|^i<
*/ oQv3GpO
publicint getTotalPage(){ \}~s2Y5j
return totalPage; ?88`fJ@tk?
} 0<PR+Iv*i
}<z_Q_b+e
/** q %0Cg=
* @param totalPage hky;CD~$
* The totalPage to set. S!PzLTc
*/ +dBz`WD
publicvoid setTotalPage(int totalPage){ c*`>9mv
this.totalPage = totalPage; 4lqH8l.
} RNPbH.
BS&;n
} Cda!Mk:
);*YQmdx'
`MEYd U1
8?*RIA.a
R.LL#u};
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 m%"uPv\
341?0%=
个PageUtil,负责对Page对象进行构造: 0wFH!s/B
java代码: 2Bk$ lx7
;Nr ]X
*WE1;msr
/*Created on 2005-4-14*/ -`f04_@>d
package org.flyware.util.page; _U{([M>;
#{9G sD
import org.apache.commons.logging.Log; |!q$_at
import org.apache.commons.logging.LogFactory;
@HBEt^!
+3i7D
/** 'a^{=+
* @author Joa pG^}Xf2a
* >K# ,cxY
*/ =`Y.=RL+'n
publicclass PageUtil { Y~)T
\@}#Gez
privatestaticfinal Log logger = LogFactory.getLog OG3/-K 8R
b dJ+@r
(PageUtil.class); E42eOGp9i
]APvp.Tw:
/** dr{y0`CCN
* Use the origin page to create a new page -[OXSaf6
* @param page Omi^>c4G
* @param totalRecords $|$e%
* @return |wox1Wt|E
*/ 8h<ehNX ^I
publicstatic Page createPage(Page page, int $6F)R|
xsjO)))f
totalRecords){ Pv<FLo%u<
return createPage(page.getEveryPage(), s cdtWA
1Uf*^WW4
page.getCurrentPage(), totalRecords); +Z!;P
Z6
} =2y8CgLj
\n9A^v`F/
/** F8e<}v&7R
* the basic page utils not including exception i#X!#vyc
^MD;"A<
handler 7n)&FXK`
* @param everyPage uhV0J97
* @param currentPage XYx6V
* @param totalRecords gPzL*6OSA
* @return page NZu)j["
*/ j<pw\k{i
publicstatic Page createPage(int everyPage, int AGYm';z3
,}xbAA#
currentPage, int totalRecords){ P6Bl
*@G
everyPage = getEveryPage(everyPage); 9Q W&$n^
currentPage = getCurrentPage(currentPage); kC$&:\Rh
int beginIndex = getBeginIndex(everyPage, u)Q;8$`
)a=/8ofe
currentPage); ^D@b;EyK
int totalPage = getTotalPage(everyPage, ig 0u^BC
Q36)7=at
totalRecords); V 'X;jC
boolean hasNextPage = hasNextPage(currentPage, :L0/V~D
Lc<eRVNd,
totalPage); %lr|xX
boolean hasPrePage = hasPrePage(currentPage); 'f/Lv@]a
+VEU:1Gt
returnnew Page(hasPrePage, hasNextPage, )[&_scSa
everyPage, totalPage, @\(v X ]
currentPage, ?IX!+>.H
OlxX.wP
beginIndex); Q\{x)|{$
} 1 7hTr
p4VqV6LwD
privatestaticint getEveryPage(int everyPage){ g"Qh]:
return everyPage == 0 ? 10 : everyPage; 5;)*T6Y
} |!d"*.Q@F
=A[5=
k>
privatestaticint getCurrentPage(int currentPage){ tPHS98y
return currentPage == 0 ? 1 : currentPage; 1'6cGpZY
} +c206.
6S?x
D5(
privatestaticint getBeginIndex(int everyPage, int OySy6IN]q
_-cK{
currentPage){ ,7|;k2
return(currentPage - 1) * everyPage; Gie@JX
} <64HveJ
tPuut\ee
privatestaticint getTotalPage(int everyPage, int }0=<6\+:`
~3WL)%
totalRecords){ Q
|i9aE
int totalPage = 0; `GQ{*_-
RE46k`44
if(totalRecords % everyPage == 0) 6R}j-1
<n
totalPage = totalRecords / everyPage; j?(!^ _!m
else 0?bA$y
totalPage = totalRecords / everyPage + 1 ; Zu<]bv
s[3fqdLP&
return totalPage; ,[48Mspp
} H!IDV}dn
%4>x!{jwV
privatestaticboolean hasPrePage(int currentPage){ >tRHNB_
return currentPage == 1 ? false : true; i6no;}j
} nl/UdgI
"c`xH@D
privatestaticboolean hasNextPage(int currentPage, xc'vS>&
1H4fJ3-
int totalPage){ y@vj;3:
return currentPage == totalPage || totalPage == 2%rLoL$Y2+
j033%p+Xc
0 ? false : true; p{;i& HNdp
}
&LQ%
>kY p%r6
G`]w?Di4
} 8KjRCm,I
)3?rXsSR
ysXx%k
B0mLI%B
gb-{2p>}
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。 AO0!liQ
@Gjny BJ
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 X,fu!
A[/I#Im7
做法如下: 2P~)I)3V
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 A! 6r/
)3E,D~1e%
的信息,和一个结果集List: cwtD@KC[B
java代码: g@nk.aRw
3(lVmfk
#n})X,ip2
/*Created on 2005-6-13*/ 66ohmP@04Z
package com.adt.bo; ^7XAw:
?
}Zl"9A#K
import java.util.List; ;[5r7
jHU
k
'zat3#f
import org.flyware.util.page.Page; ,-#GX{!
`<vxG4=62\
/** we]>(|
* @author Joa o42`z>~
*/ H7IW"UkBR
publicclass Result { {7#03 k
WfVMdwz=
private Page page; C|e+0aW
`1'5j "v
private List content; 9&jPp4qG
LdWc
X`K
/** >BiRk%x
* The default constructor 70iH0j)
*/ >!BFt$sd
public Result(){ TgaYt\"i[
super(); <f%/px%1
} 9Q[>.):
kojG-M
/** r,'O).7
* The constructor using fields /7p>7q9g
* *TnzkNN_,
* @param page nxRwWj57
* @param content !t-K<'
*/ YOw?'+8
public Result(Page page, List content){ :EB,{|m
this.page = page; dB)[O9K)
this.content = content; %,? vyY
} #<#%>Y^
ZgF/;8!~V-
/** 76MsrOv55
* @return Returns the content. 1_3?R}$Wl
*/ .uDM_ 34
publicList getContent(){ /yK"t<p
return content; 1P5LH5
} zh?4K*>.k
v ($L
/** BI/y<6#rR
* @return Returns the page. ~gt3Omh
*/ +qE']yzm!
public Page getPage(){ Bcaw~WD
return page; bF6gBM@*
} S:Xs'0K_
(Jpm
K O
/** lPS*-p#IZ
* @param content &7][@v
* The content to set. )F
E8D
*/ 0M\NS$u(Y
public void setContent(List content){ 3H'*?|Y(#
this.content = content; FfXZ|o$;
} `vEqj v
b`]M|C [5
/** *<dHqK`?C
* @param page u+DX$#-n!]
* The page to set. j |td,82.
*/ 5B|,S1b
publicvoid setPage(Page page){ 2FT-}w0;
this.page = page; AfE%a-;:
} ZYKd
} G+C}<S}
n_;S2KM
'z](xG<
DPeVKyjU
{rfte'4;=
2. 编写业务逻辑接口,并实现它(UserManager, Y- ~;E3(
?Ccw4]YO,=
UserManagerImpl) bX&e_Pd
java代码: T/Q==Q{W:
"G kI5!
NDW8~lkL
/*Created on 2005-7-15*/ Lupy:4AD
package com.adt.service; Xq%*#)M;
O\JD, w
import net.sf.hibernate.HibernateException;
{9;eH'e
>]?Jrs
import org.flyware.util.page.Page; U#"WrWj
:p$EiR
import com.adt.bo.Result; D"`[6EN[
NxB+?
/** vnVZJ}]w\
* @author Joa FK3Whe{KP{
*/ 4@/z
publicinterface UserManager { $owb3g(%4
%09*l%,;
public Result listUser(Page page)throws `{L{wJ:&a
Z fqQ{_
HibernateException; L6 kZ2-6
PC0HH
} O(Td:Zdp
'2xcce#
wzbz}P>
_f66>a<
a+'}XEhSC:
java代码: R(GmU4
O&= KlnI:
} bCK
/*Created on 2005-7-15*/ uDI}R]8~
package com.adt.service.impl; .xo_}Vw
59~FpjJ
import java.util.List; r
hZQQOQ
gE1|lY$NL
import net.sf.hibernate.HibernateException; r8F{A6i N
h-,?a_
import org.flyware.util.page.Page; *@~`d*d
import org.flyware.util.page.PageUtil; 0QMaM
<H-tZDh5
import com.adt.bo.Result; _r[r8MB
import com.adt.dao.UserDAO; ;9vIa7L&
import com.adt.exception.ObjectNotFoundException; qkiJH T
import com.adt.service.UserManager; k_BSY=$e*D
3Mxz_~
/** q>P[n z%
* @author Joa S_j1=6#^
*/ IY03"
publicclass UserManagerImpl implements UserManager { l_ZO^E~D_
>^;(c4C
private UserDAO userDAO; *afejjW[
PRZ8X{h
/** B3eNFS
* @param userDAO The userDAO to set. m}rh|x/?
*/ X;(oz]tr$
publicvoid setUserDAO(UserDAO userDAO){ 3]!h{_:u
this.userDAO = userDAO; YK7 \D:
} @OY1`EuO
V*>73I
/* (non-Javadoc) xl|ghjn
* @see com.adt.service.UserManager#listUser $\0TD7p
OCwW@OC +
(org.flyware.util.page.Page) qT"drgpi3
*/ R/Tj^lM
public Result listUser(Page page)throws cB_pyX9Z
:wSJ-\'$
HibernateException, ObjectNotFoundException { x<Iy<v7-
int totalRecords = userDAO.getUserCount(); uvR0TIF4
if(totalRecords == 0) gj[zka0_
throw new ObjectNotFoundException U{HyxZ|q<
WI0QLR'
("userNotExist"); tI"wVr
page = PageUtil.createPage(page, totalRecords); h)7v1,;w'
List users = userDAO.getUserByPage(page); $1b]xQ
returnnew Result(page, users); 7KeXWW/ d
}
!,Qm
SQKi2\8w
} %7iUlO}}V
aD?# ,
E7k-pquvE
5Ws5X_?d
AL(n*,
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 i[o&z$JO
sN"p5p
询,接下来编写UserDAO的代码: /4(Z`e;0
3. UserDAO 和 UserDAOImpl: 'lxLnX
java代码: }!eF
\moZ6J
!p-'t]
/*Created on 2005-7-15*/ 2;3x,<Cg
package com.adt.dao; M\9at\$
qK{|Q
import java.util.List; ?OdV1xB
UB5}i('L
import org.flyware.util.page.Page; 1 d=0q?nH
j~Xj
import net.sf.hibernate.HibernateException; 6.k^m&-A
qw6EP C
/** UIO6|*ka
* @author Joa ^xzE^"G6
*/ an-\k*w
publicinterface UserDAO extends BaseDAO {
n'! -Pv
O)Xd3w'
publicList getUserByName(String name)throws d]^\w'w$
!1D%-=dWX
HibernateException; "1_{c *ck
yW%&_s0
publicint getUserCount()throws HibernateException; >oVc5}
zC<'fT/rG
publicList getUserByPage(Page page)throws M|1eqR%x-?
N5[_a/
HibernateException; ~l;yr
@
zf M<x,XdY
} (K^YD K
nrxjN(9V%+
#&;m<%
E6,`Ld;c[
OJnPP>
java代码: -OHvK0~
pI'8>_o
;5&k/CB1
/*Created on 2005-7-15*/ $ijx#a&O
package com.adt.dao.impl; /&~nM
NvXj6U*%
import java.util.List; |U8>:DE l
6 lB{Ao?|
import org.flyware.util.page.Page; {KF 7j63
nL 1IS
import net.sf.hibernate.HibernateException; XMjI}SPG
import net.sf.hibernate.Query; >l7eoj
P&qy.0
import com.adt.dao.UserDAO; I@8+k&nXS
v]LFZI5
/** fs]#/* RR
* @author Joa .d<~a1k
*/ P58\+9d_
public class UserDAOImpl extends BaseDAOHibernateImpl jrDz7AfA
daaga}]d
implements UserDAO { U)&H.^@r$
$M:4\E5(
/* (non-Javadoc) uYG #c(lc
* @see com.adt.dao.UserDAO#getUserByName )_Z]=5Ds
BsoFQw4$9
(java.lang.String) + TPbIRA
*/ >WGX|"!"
publicList getUserByName(String name)throws m]+X}|
9'L1KQ
HibernateException { ^N*pIVLC
String querySentence = "FROM user in class |HKHN?)
8cYuzt]..
com.adt.po.User WHERE user.name=:name"; @c.11nfn`
Query query = getSession().createQuery $bF`PGR_
~$ cm9>
(querySentence); 5#9`ROT9
query.setParameter("name", name); o+)m}'T8
return query.list(); VZ9e~){xA
} (E2lv#[
}w|=c>'_}
/* (non-Javadoc) AxG?zBTFx
* @see com.adt.dao.UserDAO#getUserCount() Y/?DSo4G
*/ :epitpJ
publicint getUserCount()throws HibernateException { e8WPV
int count = 0; +lY\r + ;
String querySentence = "SELECT count(*) FROM :Su 5
OF<[Nh\.
user in class com.adt.po.User"; -y7l?N5F>
Query query = getSession().createQuery ex;Yn{4
s+OvS9et_
(querySentence); LaAgoarN
count = ((Integer)query.iterate().next .HH,l
S4@117z5
()).intValue(); ~|$) 1
return count; xc3Ov9`8%
} %j
9vX$Hj
W#oEF/G
/* (non-Javadoc) ;DT"S{"7
* @see com.adt.dao.UserDAO#getUserByPage >o=axZNa
(_s!,QUe
(org.flyware.util.page.Page) D9@<#2-
*/ Gc3PN
publicList getUserByPage(Page page)throws P~b%;*m}8
vl#V-UW$4P
HibernateException { 9fr&Yb=_o@
String querySentence = "FROM user in class <E(-QJ
o$qFa9|Ec?
com.adt.po.User"; Yp?a=R
Query query = getSession().createQuery qqO10~Xc
8&`T<ECq>
(querySentence); v]d?6g
query.setFirstResult(page.getBeginIndex()) I%VV4,I&pK
.setMaxResults(page.getEveryPage()); b{yH4)O
return query.list(); p!rGPyGC
} >E2WZHzd2
Hsux>+Q
} %Pt[3>
unbcz{&Hb[
Ay[9k=q]
[\w>{
`qYc#_ELv
至此,一个完整的分页程序完成。前台的只需要调用 xr1I8 5kM
6P/9Vh j'
userManager.listUser(page)即可得到一个Page对象和结果集对象 k^vmRe<lk
st1M.}
的综合体,而传入的参数page对象则可以由前台传入,如果用 r(/P||`l
:u|UVp5
webwork,甚至可以直接在配置文件中指定。 *SAcH_I2$>
2-B8>-
下面给出一个webwork调用示例: 37<GG)
java代码: 4=#QN
E!(`275s
'KN!m|
z
/*Created on 2005-6-17*/ Xf'
package com.adt.action.user; M#22Zfxq
%Tm'aY"
import java.util.List; X~/9Vd g
YRT}fd>R&
import org.apache.commons.logging.Log; [;kj,j
import org.apache.commons.logging.LogFactory; !UPAEA
import org.flyware.util.page.Page; aV0;WH_3
v2dSC(hRZ
import com.adt.bo.Result; H603L|4
import com.adt.service.UserService; -^SD6l$
import com.opensymphony.xwork.Action; )I0g&e^Tzy
b "AHw?5F
/** a}I z
* @author Joa `:^)"#z)
*/ H"Em|LX^
publicclass ListUser implementsAction{ #7E&16Fk
H6+st`{
privatestaticfinal Log logger = LogFactory.getLog BRQ5
)F9V=PJE
(ListUser.class); uma9yIk
t3h \.(mq
private UserService userService; !un"XI0`t<
rt4|GVa
private Page page; ^c:eXoU
~m"M#1,ln3
privateList users; ,1 9" [:WN
Y_ u7
0@`
/* ?\ i,JJO
* (non-Javadoc) 39^uLob
* ;kcFQed\w
* @see com.opensymphony.xwork.Action#execute() xdSj+507
*/ ZpP6Q
publicString execute()throwsException{ lVKF^-i
Result result = userService.listUser(page); {gq:sj>
page = result.getPage(); /)HEx&SQmZ
users = result.getContent(); ^SES')x
return SUCCESS; vN[m5)aT
} @x\gk5
(4/`@;[
/** P24
* @return Returns the page. 9H Bx[2&
*/ k@X
As
public Page getPage(){ [O =)FiY-
return page; Ql!6I (
} eXtF[0f
Zi '8~iEH
/** c[eGpZ]
* @return Returns the users. Tlv|To
*/ MZ#2WP)F
publicList getUsers(){ [@71
return users; OjL"0imN6
} _O'rZ5}&
CpJXLc3_d5
/** Sr-^faL
* @param page doUqUak
* The page to set. y#SD-#I-
*/ u K &_IE}
publicvoid setPage(Page page){ t`/RcAwA
this.page = page; 5L'@WB|{4u
} fxCPGj
5EZr"[8M
/** Pxuz {
* @param users N =}Z#
* The users to set. RyIaT
*/ ;Z0cD*Jb
publicvoid setUsers(List users){ "Kf~`0P
this.users = users; AZm)$@e)
} oA^
]x>
JL+[1=uE1L
/** )eVDp,.^
* @param userService "g&l~N1$
* The userService to set. S| ?--vai_
*/ /VOST^z!
publicvoid setUserService(UserService userService){ RAJ|#I1
this.userService = userService; Kwmo)|7uPU
} ;bu;t#
} '48|f`8$
eh#
(}v
eT
\Q
olW`.3f
_p^ "!
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, w\[*_wQp
sJ*U Fm{
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 vG=$UUh@~
*`/@[S2,cu
么只需要: g{.@|;d<p
java代码: <\Dl#DH
8c'-eT"
U\plt%2m>
<?xml version="1.0"?> s.Ic3ITd,
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 15yV4wHr
F973U
1.0//EN" "http://www.opensymphony.com/xwork/xwork- <qZ+U4@I)
"U~@o4u;
1.0.dtd"> JN|#
C)dYAq3,8
<xwork> WUQh[A41
Fd=`9N9
<package name="user" extends="webwork- @g` ,'r
`'t;BXedz/
interceptors"> JH,fg K+[
S~`AnX3!
<!-- The default interceptor stack name z:?
<aT
~ZIRCTQ"
--> P_Ja?)GT
<default-interceptor-ref Tm,L?Jh
Q>Q}/{8!
name="myDefaultWebStack"/> "uNxKLDB
^qy-el
<action name="listUser" 8?R_O}U
\r&@3a.>
class="com.adt.action.user.ListUser"> n Fn`>kQ
<param g#&##f
{N`<e>A]{
name="page.everyPage">10</param> +=xRr?F
<result 69w"$Vk
[wxI
X
name="success">/user/user_list.jsp</result> ;'+cT.cmH
</action> L*Cf&c`8r
qf {B
</package> Z-V%lRQ=b
LR.+CxQ
</xwork> u 9TlXn
#.xTAvD
~#Mx&mZ
U~c;W@T
xL"o)]a=
nlnJJM&J$
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 S}I=i>QB
hS/'b$#
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 !~kzxY
$S ("-3
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 =f|a?j,f~
<;"=ah7A
cC]1D*Bn
CR=MjmH
%P6!vx:&^b
我写的一个用于分页的类,用了泛型了,hoho N*-Z Jv
+5\\wGo<
java代码: ,_-*/- 7;8
d8I:F9
]jrxrUl
package com.intokr.util; fL:Fn"Nv
BS.6d}G4
import java.util.List; .`RC,R`C
%05a>Rf&
/** |
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* 用于分页的类<br> ZJm^znpw6
* 可以用于传递查询的结果也可以用于传送查询的参数<br> "xI[4~'`:
* ,6L>f.V^(U
* @version 0.01 |g!#
\
* @author cheng ~(S4/d5
*/ T`;M!-)2
public class Paginator<E> { V0(ABi:d
privateint count = 0; // 总记录数 1\kehCt
privateint p = 1; // 页编号 u'."E7o#
privateint num = 20; // 每页的记录数 GC3L2C0)k
privateList<E> results = null; // 结果 8B9zo&
#{1fb%L{i
/** .9QQ]fLs
* 结果总数 %q^]./3p
*/ v\FD~
publicint getCount(){ SsZzYj.d
return count; CxV%/ChJ#
} B.jYU
5w9<_W0d
publicvoid setCount(int count){ 'h=2_%l@Y
this.count = count; RMXj)~4.
} b5R*]
kMXl
{
/** s9>!^MzBK
* 本结果所在的页码,从1开始 S#dS5OX
* }IL@j A
* @return Returns the pageNo. Awh)@iTL
*/ mws.)
publicint getP(){ G.T1rUh=
return p; !HYqM(|{.
} xcA:Q`c.{
?CDq^)T[
/** q4oZJ -`
* if(p<=0) p=1 ,,gYU_V
* !NjE5USi
* @param p Y}Uw7\e
*/ Q!v[b{]8
publicvoid setP(int p){ H2vEFn V
if(p <= 0) o5uwa{v
p = 1; KMcP !N.I
this.p = p; |zKcL3*
} g~b'}^J
@dNbL}qQ
/** <5%We(3
* 每页记录数量 htaLOTO;A
*/ J;dFmZOk
publicint getNum(){ u!W00;`L
return num; iqeGy&F-
} Ok!{2$P8U9
&@+;]t
/** )3
* if(num<1) num=1 @T"385>
*/ bv "S(
publicvoid setNum(int num){ DP_ \%(A
if(num < 1) %<t/xAge
num = 1; 4y]*"(sQ;
this.num = num; tP-c>|cz
} =_Rd0,
e<K=Q$U.
/** }{J8U2])k
* 获得总页数 }: e9\r)
*/ l<+k[@Vox
publicint getPageNum(){ 3Daq5(fLP
return(count - 1) / num + 1; ~4 ab\hq
} :|Cf$2k7
9tO_hhEQ@
/** Ai;Pht9qi
* 获得本页的开始编号,为 (p-1)*num+1 _1ins;c52
*/ Qsa2iw{
publicint getStart(){ \z
'noc
return(p - 1) * num + 1; yr?\YKV)I
} $.Ni'U
Er)b( Kk
/** uvL|T48
* @return Returns the results. 0/$sr;
*/ n^K]R}S
publicList<E> getResults(){ %~~Q XH\
return results; "'Ik{wGc
} EZ4qhda
J7ln6 Y
public void setResults(List<E> results){ 7+"X^$
this.results = results; U N/.T
} Ad `IgZ
-SQYr
public String toString(){ A:f+x|[
StringBuilder buff = new StringBuilder eR
CGr?e4
P\JpE
(); f+&yc'[
buff.append("{"); |@RO&F
buff.append("count:").append(count); 2k_Bo~.
buff.append(",p:").append(p); sdLFBiR
buff.append(",nump:").append(num); {<@~;iq
buff.append(",results:").append /.r($Sg^
B}W^s;h
(results); 1K>4i. X
buff.append("}"); Rjf|
return buff.toString(); 8'y|cF%U
} 8Bhng;jX
u8*0r{kOH
} mN{$z<r
dn Xc- <
+] #>6/2q