Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 212
F#l!LER^1g
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 wgKM6?
0F[+rh"x
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 U 0dhr; l
X}]g;|~SN
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 FzQ6UO~'
m^1'aO_;q
。 9Qc=D"'
' "o2;J)7
分页支持类: 24d{ol)
2PVQSwW:
java代码: esHcE{GNOS
TZE;$:1vx>
I!g+K
package com.javaeye.common.util; Vs&Ul6@N
4]ETF+
import java.util.List; q<Wz9lDMNR
2!6-+]tC
publicclass PaginationSupport { Q|W~6
RjG=RfB'V
publicfinalstaticint PAGESIZE = 30; Wg=4`&F^
0/b3]{skK
privateint pageSize = PAGESIZE; LhtA]z,m
G\H |\i
privateList items; U$6(@&P!
>Te h ?P
privateint totalCount; W0N*c*k
2[Bw+<YA`
privateint[] indexes = newint[0]; d/` d:g
T2MXwd&l
privateint startIndex = 0; TM`6:5ONv
w?A6S-z
public PaginationSupport(List items, int rPoq~p[Y
tD3v`Ke
totalCount){ sFonc
setPageSize(PAGESIZE); <FU1|
setTotalCount(totalCount); (p}N
cn.
setItems(items); N/eFwv.Er
setStartIndex(0); n~v*
} Q`(h
#TG.weTC
public PaginationSupport(List items, int "P8cgj C
!l#n.Fx&3
totalCount, int startIndex){ iea7*]vW
setPageSize(PAGESIZE); (&-!l2
setTotalCount(totalCount); ]s^Pw>/`
setItems(items); t,R4q*
setStartIndex(startIndex); iKe68kx
} CJ[^Fi?CH
|C.[eHe&D
public PaginationSupport(List items, int APL #-`XC
TWo.c _l
totalCount, int pageSize, int startIndex){ DzG$\%G2R}
setPageSize(pageSize); \kVi&X=q:
setTotalCount(totalCount); mpDQhD[n
setItems(items); aA&}=lm
setStartIndex(startIndex); =F90SyzTy
} g,""j`
:,FI 6`
publicList getItems(){ 5vqh09-FB
return items; jmh$6 N%
F
} z)]Br1
8z'_dfP=5
publicvoid setItems(List items){ Ox}a\B8
this.items = items; dpI! {'"M
} !ZTBiC5R
)w&k&TY4H
publicint getPageSize(){ jij-pDQnv
return pageSize; C(lGW,!
} XXZ <r
j+QE~L
publicvoid setPageSize(int pageSize){ iP+3)
this.pageSize = pageSize; V75P@jv5J
} n~G-X
04QY
x}a
publicint getTotalCount(){ &{H LYxh
return totalCount; <&p0:S7
} s2iL5N|"Q
KeE)9e
publicvoid setTotalCount(int totalCount){ i[a1ij=
if(totalCount > 0){ CxJkT2
this.totalCount = totalCount; =/L;}m)7
int count = totalCount / cuo'V*nWQ
":,J<|Oy
pageSize; Y SD|#0
if(totalCount % pageSize > 0) ''~#tK
f
count++; L&h90Az1W
indexes = newint[count]; @6:J$B~)u
for(int i = 0; i < count; i++){ )0p7d:%mV
indexes = pageSize * dSw%Qv*y
qQx5n
i; ^%~ux0%^T
} ZT%Q:]B+
}else{ f%5 s8)
this.totalCount = 0; rk .tLk
} 6F4OISy%3
} VLs%;|`5D
[nG@
3n
publicint[] getIndexes(){ %SlF7$
return indexes; kMY1Xb
} [ _wenlkm
Mg76v<mv<
publicvoid setIndexes(int[] indexes){ ?PST.+l
this.indexes = indexes; eIY![..J/N
} -x0VvkHu
sDzlNMr?P+
publicint getStartIndex(){ :ZP`Y%dt'
return startIndex; 55]E<2't
} %_%/ym
a.!|A(zw
publicvoid setStartIndex(int startIndex){ %$H~
if(totalCount <= 0) ~AbTbQ3
this.startIndex = 0; O[/l';i
elseif(startIndex >= totalCount) |>L|7>J{<d
this.startIndex = indexes QvjOOc@k~n
/$,~|X;&
[indexes.length - 1]; |$aTJ9 Iq:
elseif(startIndex < 0) F1UTj"<e
this.startIndex = 0; #>@~3kGg
else{ &['cZ/bM
this.startIndex = indexes -cW'g
dpWBY3(7a
[startIndex / pageSize]; [W{WfJ-HwG
} !<I3^q
} S@PAtB5
t;e+WZkV
publicint getNextIndex(){ VQ((c:+!
int nextIndex = getStartIndex() + /WWD;keP5
:Mq-4U.e
pageSize; ?,0 5!]
if(nextIndex >= totalCount) An0Zg'o!G
return getStartIndex(); 9XSZD93L
else 3'D<'S}[
return nextIndex; HHU0Nku@ho
} FqT2+VO~
2N$yn
publicint getPreviousIndex(){ g(Dr/D
int previousIndex = getStartIndex() - DEcsFC/SK
vsL)E:0
pageSize; EA+}Rf6}
if(previousIndex < 0) slWO\AYiO
return0; ~KF>Jow?Y
else 7xr@$-U
return previousIndex; w;Jby
} N akSIGm
FJl_2
} }uaRS9d
8kwe ._&)
ohPCYt
q V+gQ
抽象业务类 /degBL+
java代码: UZ` <D/
+^\TG>le
1ehl=WN
/** t'pY~a9F
* Created on 2005-7-12 ]&mN~$+C
*/ Fw!TTH6l0
package com.javaeye.common.business; 6*]g~)7`Q~
/PuN+M
import java.io.Serializable; SlRQi:
import java.util.List; !QTfQ69Y0
;@R=CQ6
import org.hibernate.Criteria; =T0;F0@#4
import org.hibernate.HibernateException; 6bXR?0$*M.
import org.hibernate.Session; ToVi;
import org.hibernate.criterion.DetachedCriteria; WzwH;!
import org.hibernate.criterion.Projections; 2a3RRP
import
RZg8y+jM
5!pof\/a
org.springframework.orm.hibernate3.HibernateCallback; $V0G[!4
import 3r]:k)J
~Os1ir.
org.springframework.orm.hibernate3.support.HibernateDaoS ,4&?`Q
`f~\d.*U
upport; >m-VBo
{hmC=j
import com.javaeye.common.util.PaginationSupport; (ndTEnpp
L~u@n24
public abstract class AbstractManager extends hhU:
nw
s.p4+KJ
HibernateDaoSupport {
nGqD{!i<
O^+H:Y|
privateboolean cacheQueries = false; x]=s/+Y
{#,eD
privateString queryCacheRegion;
RrG5`2
p]-\\o}
publicvoid setCacheQueries(boolean } qf=5v
C=6.~&(
cacheQueries){ X*^^W_LH.
this.cacheQueries = cacheQueries; ~5Cid)Q}@o
} &Is}<Ew
&Oih#I
publicvoid setQueryCacheRegion(String jrKRXS
-xXz}2S4
queryCacheRegion){ m@Vz42g~+
this.queryCacheRegion = @*VfG CQ(
;;#_[Zl
queryCacheRegion; `pfZJ+
} R;]z/|8
?b8 :
publicvoid save(finalObject entity){ KT>eE
getHibernateTemplate().save(entity); *@zh
} +[R,wsG
,3As
Ng
publicvoid persist(finalObject entity){ DN GXp5I
getHibernateTemplate().save(entity); qz@k-Jqq
d
} |*T3TsP u
pp2,d`01[L
publicvoid update(finalObject entity){ N-9Vx#i
getHibernateTemplate().update(entity); Sl!#!FGI
} Ddr.kXIpo
,_$}>MY;
publicvoid delete(finalObject entity){ 7^2
getHibernateTemplate().delete(entity); O_kBAC-|R(
} fy6<KEea
NZTG)<
publicObject load(finalClass entity, k"z ~>
I+4#LR3;
finalSerializable id){ 5(+PIKCjC
return getHibernateTemplate().load U_8 Z&
/qd5{%:
(entity, id); o^!_S5zKe.
} >OLKaghV.5
6VsgZ"Il
publicObject get(finalClass entity, x/B1\U
I
.T63:
finalSerializable id){ Vx<`6uv
return getHibernateTemplate().get =1vl-*uYh
WEnI[JGe
(entity, id); U{JD\G8m
} 5OR2\h!XZt
&&daQg4Ha
publicList findAll(finalClass entity){ nhu;e}[>
return getHibernateTemplate().find("from +}.~"
R_7[7/a
" + entity.getName()); wi gs1
} QCD
MRh n
g5OKhL0u
publicList findByNamedQuery(finalString x%!Ea{s
<?>1eU%
namedQuery){ 2d# 3LnO
return getHibernateTemplate /TndB7l"3
bih%hqny
().findByNamedQuery(namedQuery); xk:=.Qqh
} yZ:AJNb
kF@Z4MB}yr
publicList findByNamedQuery(finalString query, Km)VOX[ZZ
d$H
finalObject parameter){ hb. ^&
return getHibernateTemplate k Xg&}n7
sP'U9l
().findByNamedQuery(query, parameter); %A$5mi^
} fFNscY<4w
n6xJ
publicList findByNamedQuery(finalString query, ]<xzCPB
vH?rln
finalObject[] parameters){ j&Trvw<t
return getHibernateTemplate VRs|";
zzH^xxg
().findByNamedQuery(query, parameters); Z^[
]s1iP}
} w!eY)p<
D^Gs_z$['
publicList find(finalString query){ */6lyODf
return getHibernateTemplate().find \GD\N=?~
.}c&"L;W
(query); nf0]<x2
} DuMzK%
)
w1`<7L
publicList find(finalString query, finalObject L+X:M/)
Tpd|+60g
parameter){ jl"su:y
return getHibernateTemplate().find xjy(f~'
KSAE!+
(query, parameter); ;I/ A8<C
} i,B<k 0W9
dJjkH6%}
public PaginationSupport findPageByCriteria M-8`zA2
#I"s{*
(final DetachedCriteria detachedCriteria){ _M)
G
return findPageByCriteria 2j;9USZ
p
%#<MCiaK
(detachedCriteria, PaginationSupport.PAGESIZE, 0); |Zk2]eUO+
} b]b+PK*h
~JS BZ@
public PaginationSupport findPageByCriteria h5Ee*De
>i_ #q$o
(final DetachedCriteria detachedCriteria, finalint l86gs6>
DS1{~_>nFu
startIndex){ ]SmN}Iq1
return findPageByCriteria Miz?t*|{[
;O7Vl5R
(detachedCriteria, PaginationSupport.PAGESIZE, QnA~,z/.w
}n( ?|
startIndex); ;Rljx3!N
} ntntB{t
,
.E>
public PaginationSupport findPageByCriteria E1`TQA
:>y;*x0w
(final DetachedCriteria detachedCriteria, finalint X`fb\}~R(
ka_(8
pageSize, Y$5uoq%p3A
finalint startIndex){ L++qMRk9
return(PaginationSupport) a*&(cn
TI|h
getHibernateTemplate().execute(new HibernateCallback(){ v1rTl5H
publicObject doInHibernate fKW)h?.Kd
=NmW}x|n
(Session session)throws HibernateException { mxE<
Criteria criteria = cgi:"y F
b_X&>^4Dkl
detachedCriteria.getExecutableCriteria(session); +#Wwah$
int totalCount = [w90gp1O[
9:P\)'y?
((Integer) criteria.setProjection(Projections.rowCount A5T&i]
MD^,"!A
()).uniqueResult()).intValue(); 5eiKMKW[
criteria.setProjection M@z_tR'3\
N8iLI`
(null); "~mY4WVG
List items = a4[t3U
nTl2F1(sV7
criteria.setFirstResult(startIndex).setMaxResults e%lxRN"b
;0U*N &
f
(pageSize).list(); HbRvU}C1
PaginationSupport ps = iB|htH'T
nV`U{}x
new PaginationSupport(items, totalCount, pageSize, Ci4;e
U&ytZ7iB
startIndex); @^Rl{p
return ps; UM/!dt}DnF
} {;N2 &S o
}, true); 6e8 gFQ"w2
} .DI?-=p|_#
TlowEh8r
public List findAllByCriteria(final &1Cs'
R nwFxFIQ
DetachedCriteria detachedCriteria){ &f}w&k2yj
return(List) getHibernateTemplate F{4v[WP)
$A`m8?bY
().execute(new HibernateCallback(){ fD lo L
publicObject doInHibernate inFS99DKx
Gr 4v&Mz:
(Session session)throws HibernateException { Ze[,0Y!u&
Criteria criteria = !1=*"H%t
0'HQ=pP
detachedCriteria.getExecutableCriteria(session); tY>Zy1hlI
return criteria.list(); K iEmvC
} wTD}c1J(
}, true); 1_b*j-j
} @dUN3,}
Vm[F~2+HX
public int getCountByCriteria(final ;?k<L\zaw
e=l:!E10
DetachedCriteria detachedCriteria){ l2kGFgc
Integer count = (Integer) x5CMP%}d
damG*-7Svx
getHibernateTemplate().execute(new HibernateCallback(){ "X^<g{]
publicObject doInHibernate fZj,Q#}D
L$i:~6
(Session session)throws HibernateException { *:Rs\QH
Criteria criteria = [}M!ez
$C sE[+k1
detachedCriteria.getExecutableCriteria(session); $4^SWT.
return 5.*,IedY
? 3OfiGX?
criteria.setProjection(Projections.rowCount l^d' 8n
>[Wjzg
()).uniqueResult(); lm
96:S
} =@0J:"c
}, true); YVwpqOE.=
return count.intValue(); ]'"Sa<->
} 641P)
} bU}v@Uk
l -xc*lC
x1?mE)n]
t,Ka]
/I
.1q}mw
hHhDs>tB
用户在web层构造查询条件detachedCriteria,和可选的 p #{y9s4h
J8!2Tt
startIndex,调用业务bean的相应findByCriteria方法,返回一个 {x?qz~W
e6>G8d
PaginationSupport的实例ps。 J_h.7V
I8YUq
ps.getItems()得到已分页好的结果集 &
Wod
ps.getIndexes()得到分页索引的数组 *g,ls(r\[
ps.getTotalCount()得到总结果数 +8C}%6aX
ps.getStartIndex()当前分页索引 Z[OX{_2]K
ps.getNextIndex()下一页索引 n."n?C'{
ps.getPreviousIndex()上一页索引 v\5O\ I ^
W} i6{Vh
w;gk=<_
tc0;Ake-&
q~b# ml2QS
":8\2Qp
2
4+
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^8;MY5Wbs
#|ts1lD#ah
,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 ",.f
D>[Sib/@
一下代码重构了。 "qNFDr(WM
K<wFr-z
我把原本我的做法也提供出来供大家讨论吧: |~e"i<G#
4hy-M>!D|
首先,为了实现分页查询,我封装了一个Page类: ;_vhKU)%J#
java代码: %+=;4tHJ
-R]0cefC<f
Bd <0}
/*Created on 2005-4-14*/ P*A+k"DU1
package org.flyware.util.page; zXx/\B$&d*
fJ[ ^_,O
/** m~5 unB9
* @author Joa s`_EkFw>Gl
* h/t;ZLUAZP
*/ (<r)xkn
publicclass Page { tg@61V?>
. s9E
+1
/** imply if the page has previous page */ A{
~D_q
privateboolean hasPrePage; -n&&d8G^s
:31_WJ^
/** imply if the page has next page */ wKLYyetM!
privateboolean hasNextPage; e{@RBYX@+c
J`U]Ux/L
/** the number of every page */ !:!(=(4$P
privateint everyPage; pE&G]ZC
7h}gIm7e"
/** the total page number */ >)u;X
privateint totalPage; D{6y^@/
h(HpeN%`#
/** the number of current page */ <Z:FY|'s
privateint currentPage; B=TUZ)
%-!%n=P
/** the begin index of the records by the current XnZ$%?$
x<gmDy*
query */ yws'}{8
privateint beginIndex; SG)Fk *1
C '(
Y
<#h,_WP*
/** The default constructor */ z3uR1vF'
public Page(){ #QoWneZ
QQS*r}>
} YWK0.F,8a
=U3S"W %
/** construct the page by everyPage ;[}OZt
* @param everyPage f%,S::%Ea
* */ D<6$@ZJ
public Page(int everyPage){ reN\|?0{
this.everyPage = everyPage; Xe%J{
} |O_JUl
]ub"OsXC
/** The whole constructor */ C8|V?bL
public Page(boolean hasPrePage, boolean hasNextPage, X\h.@+f=
YCD|lL#
%]_: \!
int everyPage, int totalPage, 7HDc]&z
int currentPage, int beginIndex){ HLW_Y|QaFo
this.hasPrePage = hasPrePage; + +}!Gfc?s
this.hasNextPage = hasNextPage; $Y|OGZH8E
this.everyPage = everyPage; |reA`&<q
this.totalPage = totalPage; !FL"L
9
this.currentPage = currentPage; ;#85 _/
this.beginIndex = beginIndex; ojy^A
} R'k`0
>J7slDRo
/** FMVAXOO
* @return lV$JCNe
* Returns the beginIndex. =HCEUB9Fs
*/ B-MS@<2
publicint getBeginIndex(){ ,a{85HLr]
return beginIndex; rkjnw@x\
} 5G`HJ6
hI:.Qp`r
/** ~S/oW89
* @param beginIndex bFG~08Z ,d
* The beginIndex to set. XPX?+W=mv
*/ (SyD)G\rj
publicvoid setBeginIndex(int beginIndex){ W#F9Qw
this.beginIndex = beginIndex; Hh1_zd|
} ?}KRAtJ8
=wh[D$n$~
/** e_=K0fFz
* @return eM<N?9 s
* Returns the currentPage. kkq1:\pZ]a
*/ ab2FK
publicint getCurrentPage(){ ]bY|>q
return currentPage; GOc
} MT-Tt
F@u7Oel@m
/** iwK.*07+
* @param currentPage <gF]9%2E
* The currentPage to set. k_7m[o
*/ ;7P'>j1?U
publicvoid setCurrentPage(int currentPage){ E{orezP
this.currentPage = currentPage; 'dKfXYY1`N
} +l7)7qKx
.g8*K "
/** u"HGT=Nl
* @return b(0<,r8
* Returns the everyPage. .$&^yp
*/ -!PJHCLd
publicint getEveryPage(){ ai_ve[A
return everyPage; o]<Z3)
} ~!$"J}d}<
,&_H
/** axnlI*!
* @param everyPage aJ+V]WmA
* The everyPage to set. (Mk7"FC7
*/ ~m6=s~Vn
publicvoid setEveryPage(int everyPage){ 0vv~G\yM
this.everyPage = everyPage; QOB^U-cW
} w5%Yi{
]>X_E%`G<b
/** KnG7w^
* @return wo@ T@Ve~
* Returns the hasNextPage. v6*0@/L
M
*/ MNu0t\`p4
publicboolean getHasNextPage(){ -uYxc=4Lh
return hasNextPage; :*Wq%Y=
} sM-,95H
VhO%4[Jl
/** }X)vktE+|
* @param hasNextPage 296}LW
* The hasNextPage to set. sycAAmH<
*/ yqx5_}
publicvoid setHasNextPage(boolean hasNextPage){ `;UWq{"
this.hasNextPage = hasNextPage; u9!
?
} ]DVr-f
~
\qG?'Iy
/** bIU.C|h@
* @return (7R?T}
* Returns the hasPrePage. y#GHmHeh
*/ Cy;UyZ
publicboolean getHasPrePage(){ q}LDFsU
return hasPrePage; lbHgxZ
} >bW=oTFz
T-] {gc
/** ?Lg(,-:
* @param hasPrePage joe)b
* The hasPrePage to set. d/; tq
*/ cw<IL
publicvoid setHasPrePage(boolean hasPrePage){ *z~,|DQ(A
this.hasPrePage = hasPrePage; Cab.a)o
} \BnU?z
:c/54Ss~
/** K0gQr.J53
* @return Returns the totalPage. 2z-Nw <bA
* w/6X9d
*/ {'IO
publicint getTotalPage(){ Bv<g Vt
return totalPage; %,@pV%2
} _*o<<C\E
Xz^nm\
/** ^^b'tP1>
* @param totalPage 7a"06Et^
* The totalPage to set. V%8(zt
*/ mUg :<.^
publicvoid setTotalPage(int totalPage){ ^%7(
this.totalPage = totalPage; ]rv\sD`[
} =.3#l@E!C
gcA:Q4
} `]KX`xGK
"9caoPI0~
AT&K> NG
eAlOMSL\
@62,.\F
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 GAj%o]}u
Blxa0&3
个PageUtil,负责对Page对象进行构造: MJGT|u8O&
java代码: _LaG%* R6
3x;UAi+&
WoTeIkM9
/*Created on 2005-4-14*/ gv`_+E{P
package org.flyware.util.page; 9S%5Z>
;\pVc)\4"
import org.apache.commons.logging.Log; aj5HtP-
import org.apache.commons.logging.LogFactory; 'gf[Wjb,%
g#$ C8k
/** a`'>VCg
* @author Joa ozRO:*51
* +YvF+E
*/ gy.UTAs
N
publicclass PageUtil { LSC[S:
On*I.~
privatestaticfinal Log logger = LogFactory.getLog ga
+,
P
<wSJK
(PageUtil.class); 95,]86
!8G)`'
/** &Gt{9#
* Use the origin page to create a new page B'yjMY![
* @param page M@.l#
[@U
* @param totalRecords Q5ASN"_
* @return kPX+n+$
*/ B/4M;G~
publicstatic Page createPage(Page page, int ~0p8joOH
`]5qIKopL
totalRecords){ $)#orZtzr
return createPage(page.getEveryPage(), Al^tM0T^
hju^x8
,=m
page.getCurrentPage(), totalRecords); Fe!MA
} 8$}<4 `39
> Z+*tq
/** Y+"1'W
* the basic page utils not including exception C!+D]7\j
@7nZjrH
handler 63oe0T&
* @param everyPage PLz{EQ[cV
* @param currentPage {?`rGJ{f
* @param totalRecords j#//U2VdN
* @return page A]bQUWt2
*/ %tVU Rj
publicstatic Page createPage(int everyPage, int (,I:m[0
21v--wZ
currentPage, int totalRecords){ sx#O3*'>1
everyPage = getEveryPage(everyPage); 76w[X=Fv
currentPage = getCurrentPage(currentPage); TDo)8+.2z
int beginIndex = getBeginIndex(everyPage, )h]+cGM
7z;2J;u`n
currentPage); k{+cFG\C&
int totalPage = getTotalPage(everyPage, q9vND[BQ
ClKWf\(ii6
totalRecords); Jq0sZ0j
boolean hasNextPage = hasNextPage(currentPage, #f#6u2nF\
3
`_/h' ~
totalPage); Xe);LhDC
boolean hasPrePage = hasPrePage(currentPage); 1J!v;Y\\
LLgw1 @-D
returnnew Page(hasPrePage, hasNextPage, No7-fX1B
everyPage, totalPage, ;{I9S'
currentPage, 8ae`V!5
li%@HdA!
beginIndex); 7rdmj[vu
} Nr*l3Z>LD
LgF?1?
privatestaticint getEveryPage(int everyPage){ "pDU v^ie
return everyPage == 0 ? 10 : everyPage; 2 ,nhs,FZ
} Ic&~iqQ
i*|HN"!
privatestaticint getCurrentPage(int currentPage){ @|:fm()
<
return currentPage == 0 ? 1 : currentPage; 8|Tqk,/pD
} :gsRJy1
WXxnOLJr
privatestaticint getBeginIndex(int everyPage, int 2Z{?3mAb;
,WE2.MWR
currentPage){ `/WxEu3
return(currentPage - 1) * everyPage; C|]c#X2t3
} ajycYk9<m
}uDpf0;^
privatestaticint getTotalPage(int everyPage, int F$8:9eL,T
bhUE!h<
totalRecords){ }Q`+hJ0
int totalPage = 0; [x)T2sA
5J`w8[;
if(totalRecords % everyPage == 0) %X_A# 9
totalPage = totalRecords / everyPage; XuP%/\
else "w"a0nv
totalPage = totalRecords / everyPage + 1 ; W"%n5)
. gy:Pl]w
return totalPage; {mU%.5
} @]Vcl"t
jga;q
privatestaticboolean hasPrePage(int currentPage){ |}d^lQ9
return currentPage == 1 ? false : true; B*G]Dr)e
} QuS=^,]
9po=[{Bp
privatestaticboolean hasNextPage(int currentPage, ;jgf,fbM
wp~}1]g
int totalPage){ DQ0S]:tC
return currentPage == totalPage || totalPage == [lIX&!T"
)y]Dmm
0 ? false : true; <7y/)b@
} o+x%q<e;c
pS8\ B
?J$k
5;
} .J -k^+-
1V`-D8-?
">7xSWR*4
LHtO|Utn(
UG.:D';3,
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。 vs8[352
jW&*?6<
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 oJM;CN
=RUy4+0>F
做法如下: F+Kju2
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 HxK'u4I
7s%D(;W_Mo
的信息,和一个结果集List: 3z0Bg
java代码: QV."ZhL5 =
KF&8l/f
npeL1zO-$
/*Created on 2005-6-13*/ h HHR]e5:
package com.adt.bo; 9L7z<ntn
X(Af`KOg[
import java.util.List; ?n<F?~
"6]oi*_8
import org.flyware.util.page.Page; {#+K+!SvDX
C+\z$/q
/** MY{Kq;FvRP
* @author Joa ->qRGUW
*/ JRBz/ j
publicclass Result { Hva!6vwO%O
JAHmmNlW
private Page page; hg12NzbK
y:\<FLR}j
private List content; (f"Qz~R|6_
!l dE9 .
/** '[6]W)f
* The default constructor h<3bv&oI .
*/ Rm3W&hQ
public Result(){ iM!V4Wih6
super(); 7r,GdP .
} !_Y%+Rkp0
;nh_L(
/** ],AtR1k
* The constructor using fields {31X
* )[Rwc#PA;
* @param page u9:sj
* @param content oG22;
*/ @}jg5}
public Result(Page page, List content){ yq, qS0Fo
this.page = page; <.g)?nj1
this.content = content; <Y /3U
} 5<X"+`=9
>l}v
_k*~B
/** 8Ud.t=2
* @return Returns the content. 3q'nO-KJ
*/ ,6y.wNb :F
publicList getContent(){ FXk*zXn6
return content; [*K9V/
} %dw0\:P?Q
8F\'?7
/** B$c'^
)
* @return Returns the page. %A
5s?J?
*/ L?N:4/0;!
public Page getPage(){ <> HI(6\@Z
return page; D0\*WK$
} DFfh!KKR$
lx$Z/f
/** 1_&W1o
* @param content ci%$So2#
* The content to set. Q_/UC#I8
*/ JWu0VLo
public void setContent(List content){ .4 NcaMj
this.content = content; b7'A5]X
} Lz9|"F"V
r
'ioH"=
/** r"L:Mu
* @param page *` -
* The page to set. s Wj:m )
*/ `j2|aX
%Z*
publicvoid setPage(Page page){ v*y,PY1*
this.page = page; ZdhA:}~^E
} \Pfm>$Ib=
} ^~B#r#
&mJm'Ks
<@>icDFEHn
Zz|et206
?S)Pv53>}
2. 编写业务逻辑接口,并实现它(UserManager, 4fL>Ou[YuX
TD ;u"
UserManagerImpl) OS~Z@'Eg
java代码: Fyz1LOH[X
FLumI-se!
m2%
/*Created on 2005-7-15*/ Q9X+H4`}y
package com.adt.service; it j&L <e
0 4ceDe
import net.sf.hibernate.HibernateException; !9S!zRy@
R-Tf9?)
import org.flyware.util.page.Page; fn//j7 j
F{&0(6^p!
import com.adt.bo.Result; BC%V<6JBu(
2Zq_zvKUt
/** %B>>J%
* @author Joa z4[8*}
*/ /GP:W6:6z6
publicinterface UserManager { K?S5C8
/u'V>=D;f
public Result listUser(Page page)throws 6
#jpA.;
Y4Jaw2b
HibernateException; sVS),9\}
p?s[I)e
} 7?Twhs.O
GKXd"8z]
od/Q"5t[p
mnYzn[d3U
c=B!\J<1
java代码: 0$R}_Ok
Nk\/lK\
xCU
pMB7
/*Created on 2005-7-15*/ ?Ql<s8
package com.adt.service.impl; |dqAT .
gr>>]C$
import java.util.List; C%P"\>5@
)k 6z
import net.sf.hibernate.HibernateException; NW*$+u%/R
R5cpmCs@R
import org.flyware.util.page.Page; ynq^ztBVe
import org.flyware.util.page.PageUtil; $.Qq:(O:6
VPDd*32HC
import com.adt.bo.Result; G/Yqvu,2!
import com.adt.dao.UserDAO; -
[vH4~
import com.adt.exception.ObjectNotFoundException; F`f8q\Fc
import com.adt.service.UserManager; rV/! VJ6x
}@A{'q5y
/** >@|XY<
* @author Joa sc# q03
*/ 'oM&Ar$
publicclass UserManagerImpl implements UserManager { )K0rPnYV
8{%[|Ye
private UserDAO userDAO; I|P#|0< 2
0e~4(2xK
/** Q$S|L C
* @param userDAO The userDAO to set. RZ9chTX/
*/ \avgXndI
publicvoid setUserDAO(UserDAO userDAO){ Qvhy9Cr;
this.userDAO = userDAO; &Y8S! W@4
} LeXkl=CC
WaDdZIz4
/* (non-Javadoc) V53iWWaFe
* @see com.adt.service.UserManager#listUser D"s
]dQ$r
68a
(org.flyware.util.page.Page) -]Q6Ril
*/ :8Ql(I
public Result listUser(Page page)throws I#:4H2H6
Z'\{hL S
HibernateException, ObjectNotFoundException { `< cn
int totalRecords = userDAO.getUserCount(); Cq%1j[
if(totalRecords == 0) $tca:
b}Mk
throw new ObjectNotFoundException _Dg|Iz,Uh
iJEKLv
("userNotExist"); MryY<s
page = PageUtil.createPage(page, totalRecords); "D/\&1.&
List users = userDAO.getUserByPage(page); sxn^1|O;m
returnnew Result(page, users); /c52w"WW
} 4wx_@8
V%'+ ob6
} e_t""h4D
<.c#l':
8s<t*
pI2
y(Ck j"
`Ct fe8
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 +J(@.
t8z=R6zX
询,接下来编写UserDAO的代码: (Q][d+} /
3. UserDAO 和 UserDAOImpl: wD`jks
java代码: *gL-v]V
UZ 6:vmcT
Ab)X/g-I@
/*Created on 2005-7-15*/ L3^+`e
package com.adt.dao; A{KF<Omu
i| OG#PsY-
import java.util.List; UNKr
FYl
A@#D_[~
import org.flyware.util.page.Page; nG !6[^D
Jhr3[A
import net.sf.hibernate.HibernateException; ;=E!xfp5U
ycSC'R
/** .KzU7
* @author Joa |$.`4h?
*/ GUdVsZjz(
publicinterface UserDAO extends BaseDAO { vvcA-k?
zQyt 1&!
publicList getUserByName(String name)throws j21nh >d
Pa\"l'!>^
HibernateException; VF] ~J=>i
^,N=GZRWW
publicint getUserCount()throws HibernateException; dG*2-v^G
~jn~M_}K
publicList getUserByPage(Page page)throws 4ROuy+Ms'
;*409P
HibernateException; $Z{Xt*
2<8JY4]!]
} 3YOYlb %j
T9O3$1eqfo
L<MH:
5Uha,Q9SA
Jde@Th
java代码: K&>+<bJ_
a+ lGN
_h8|shyP
/*Created on 2005-7-15*/ %cFqD
& 6
package com.adt.dao.impl; 7c
aV-8:
ntt:>j$
import java.util.List;
Oa/# 2C~
sAfNu~d
import org.flyware.util.page.Page; hNF.
7,&M6<~
import net.sf.hibernate.HibernateException; { x/~gp
import net.sf.hibernate.Query; UKBaGX:v
] B3\IT
import com.adt.dao.UserDAO; `hE@S |4
W"*~1$vf
/** tunjV1 ,]
* @author Joa Z@{e\sZ)
*/ P\2UIAPa\b
public class UserDAOImpl extends BaseDAOHibernateImpl LyWgaf#/d
2qxede
implements UserDAO { hqVxvS"
;@l5kdZx`
/* (non-Javadoc) pu?D^h9/
* @see com.adt.dao.UserDAO#getUserByName nN$aZSb`
'\I!RAZ
(java.lang.String) l.`f^K=8
*/ A~MIFr /8
publicList getUserByName(String name)throws v3/l=e?u
TG@ W:>N(
HibernateException { y=spD^tM8
String querySentence = "FROM user in class ~Ddlr9Ej
pGdo:L?
com.adt.po.User WHERE user.name=:name"; ( !=^ (Nd
Query query = getSession().createQuery z}&JapJ
GFppcL@a
(querySentence); $PE{}`#g
query.setParameter("name", name); o"-*,:Qe
return query.list(); C3>`e3v
} =#|K-X0d=
-N~eb^3[c
/* (non-Javadoc) 3C7}V{?
* @see com.adt.dao.UserDAO#getUserCount() _@:O&G2nB
*/ P!K;`4Ika
publicint getUserCount()throws HibernateException { 8ZPjzN>c6
int count = 0; 1NQstmd{
String querySentence = "SELECT count(*) FROM JuTIP6
/G
Hm*?<o9mxC
user in class com.adt.po.User"; O[O[E}8#
Query query = getSession().createQuery i]M:ntB"
0; BX
(querySentence); X[r\ Qa
count = ((Integer)query.iterate().next .T|1l$Jn
5`H.{4@
()).intValue(); !H/5Ud9
return count; _q<Ke/
} 1'Y7h;\~\
mO(A'p "b
/* (non-Javadoc) ^I]A@YNni
* @see com.adt.dao.UserDAO#getUserByPage eUeOyC
)$oboAv#
(org.flyware.util.page.Page) a15kFun
*/ ,J)wn;@
publicList getUserByPage(Page page)throws .\:{6_
B(B77SOb
HibernateException { t],5{UF
String querySentence = "FROM user in class jNu`umS
cH>3|B*y
com.adt.po.User"; yON";|*\m
Query query = getSession().createQuery T>qI,BEY
}G53"
(querySentence); 8^>qzaf
8
query.setFirstResult(page.getBeginIndex()) C^8n;i9
.setMaxResults(page.getEveryPage()); "yA=Tw
return query.list(); I@jXW>$
} oW\kJ>!
xR`M#d5"
} R-lpsvDDL2
uEX+j
?&rt)/DV,
O/1:2G/`
: 7Jpt3
至此,一个完整的分页程序完成。前台的只需要调用 %=EN 3>,
kK&M>)&o#
userManager.listUser(page)即可得到一个Page对象和结果集对象 "nQ&~KQ
0P7sMCYu
的综合体,而传入的参数page对象则可以由前台传入,如果用 )E>nr
Z
<yxy ;o
webwork,甚至可以直接在配置文件中指定。 K 0Gm ?(
a7YzX5n
下面给出一个webwork调用示例: 09L"~:rg
java代码: Q$XNs%7w5,
{sb2r%U!+
b"7L
;J5|
/*Created on 2005-6-17*/ PRQEk.C
package com.adt.action.user; !Pf6UNN'
`y0u(m5
import java.util.List; 8k|&&3_[?
[,86||^
import org.apache.commons.logging.Log; dDxb}dx8
import org.apache.commons.logging.LogFactory; i4s_:%+
import org.flyware.util.page.Page; eb#p-=^KP
+u\kTn
import com.adt.bo.Result; yh:Wg$qx
import com.adt.service.UserService; SQ0?M\D7
import com.opensymphony.xwork.Action; vn(ji=
}Md5a%s<
/** A8oTcX_
* @author Joa f<;w1sM\
*/ -lqsFaW
publicclass ListUser implementsAction{ c[<>e#s+;
8o%g2 P9.
privatestaticfinal Log logger = LogFactory.getLog xixdv{M<FF
c]1\88
(ListUser.class); YQ$EN>.eO
8K@>BFk1.
private UserService userService; 9^<Y~rkm
5zi}OGtXv
private Page page; CEHtr90P
]21`x
privateList users; x*7Q
r~q3nIe/,
/* 2PTAIm Rq
* (non-Javadoc) ##r9/`A
* TnXx;v
* @see com.opensymphony.xwork.Action#execute() 7GG:1:2+>
*/ >O$JS,
publicString execute()throwsException{ zz**HwRt
Result result = userService.listUser(page); [
@ASAhV^+
page = result.getPage(); Sk7sxy<F'
users = result.getContent(); /C\tJs
return SUCCESS; 2m{d>
} UVlh7w jg
%yPjPUHy
/** Jk>!I\
* @return Returns the page. )&vuT
q'7'
*/ e<+$E%"7hS
public Page getPage(){ 6tZ ak1=V
return page; GJ Takhj3
} `W9~u: F
cyTBp58
/** $eiW2@
* @return Returns the users. p>9|JMk
*/ 20Z=_},
publicList getUsers(){ .NSV%I
return users; G(;R+%pu
} u8r<B4k
B]#^&89wG)
/** GFTOP%Tgl
* @param page 8Ao-m38
* The page to set. ^d@ME<mb
*/ ifI0s)Pn
publicvoid setPage(Page page){ Jt(RF*i
this.page = page; S8k<}5
} d.xT8l}sS
Y.
Uca<{.[
/** @p%WFNR0
* @param users Zdy{e|-Zn
* The users to set. -Dy":/Bk
*/ +F]=Z
publicvoid setUsers(List users){ BT^HlW<
this.users = users; y&L Lx[8^
} 8e"MP\0V
6Wk9"?+1
/** noZ!j>f{@l
* @param userService wJF(&P
* The userService to set. e:+[}I)
*/ !uW;Ea?
publicvoid setUserService(UserService userService){ I_5[-9
this.userService = userService; M4)Y%EPc
} h!J|4Qa
} P!u0_6
g&r3;
5Zuk`%O
h@CP
aIo%~w
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, Xmw%f[Xl
UK5u"@T
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 aNUMF
h{ T{3
么只需要: R5N~%Dg)3
java代码: ^Eif~v
dR!x)oO=
SZD7"m4
<?xml version="1.0"?> e/b
|
sl
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork
xV"~?vD
8lFYk`|g
1.0//EN" "http://www.opensymphony.com/xwork/xwork- s1bb2R
-,q
qQf
1.0.dtd"> i
hcSS Um
`_e5pW=:>
<xwork> 2$b JMx>
[L=M=;{4
<package name="user" extends="webwork- @k9n 0Qe|F
/BwG\GhM
interceptors"> 1h3`y
lUIh0%O
<!-- The default interceptor stack name sspGB>h8l
zNM*xPgS
--> L, 2;-b|
<default-interceptor-ref zmFS]IOv$
!@>q^_Gez
name="myDefaultWebStack"/> nCDG PzJ
2oo\ SmO]
<action name="listUser" J\hqK*/8
C:.>*;?7
class="com.adt.action.user.ListUser"> M>ntldV#g%
<param PkcvUJV
QYps5zcn
name="page.everyPage">10</param> Z5eM
<result z\-/R9E/5-
1L%$\0B4hm
name="success">/user/user_list.jsp</result> :cKdl[E4z
</action> M_h8{
+z<GycIc?K
</package> D*'sO B(
B\tm
</xwork> iL|5}x5\
ujf7r`;u.
l[^0Ik-G
0:$pJtx"
O~|Y#T
:xk+`` T
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 r-No\u_
X/h|;C*9
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。 Z|xgZG{
kAs=5_?I
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 ]IH1_?HgP7
qfqL"G
n7.85p@ua
vs@u*4.Ut<
q+
`QiPj
我写的一个用于分页的类,用了泛型了,hoho N%9?8X[5
#'y&M t
java代码: {a]u
4'"WD0
|>b;M,`OO
package com.intokr.util; Cx&l0ZXHEX
EY0,Q {
import java.util.List; K/_"ybR7
/vpwpVHIpG
/** a7aj:.wi
* 用于分页的类<br> "JE->iD
* 可以用于传递查询的结果也可以用于传送查询的参数<br> %~[@5<p
* ^ywDa^;-
* @version 0.01 uSv]1m_-]
* @author cheng zm3$)*p1
*/ [x'D+!
public class Paginator<E> { =t
%;mi,M
privateint count = 0; // 总记录数 gHFQs](G.
privateint p = 1; // 页编号 3R%yKa#
privateint num = 20; // 每页的记录数 JAy-N bb\
privateList<E> results = null; // 结果 o.V
JnrJ
n<1*cL:8B
/** D^6Q`o
* 结果总数 jp|*kBDq\
*/ _w2%!+'
publicint getCount(){ $,0EV9+af
return count; $xis4/2
} .)<l69ZD Z
$4Dr +Z
H
publicvoid setCount(int count){ Z29LtKr
this.count = count; jhJ<JDJ?`
} '(-H#D.oy'
O;|jLf_If
/** a:;7'w'
* 本结果所在的页码,从1开始 'K\H$<CJ
* 7~);,#[ky
* @return Returns the pageNo. Eqi;m,)
*/ 'F3@Xh
publicint getP(){ sFHqLG{/
return p; KwgFh#e
} 5n1`$T.WG
L`(\ud
/** VQ8Fs/Zt!
* if(p<=0) p=1 xVRxKM5 {
* 8#[2]1X^8
* @param p f4VdH#eng`
*/ /PbMt
publicvoid setP(int p){ @$nh6l>i
if(p <= 0) z]D/Qr
p = 1; ZQn>+c2%!
this.p = p; BAi`{?z$<
} +S'm<}"1
8_pyfb
/** '}:(y$9.`
* 每页记录数量 ].sD#~L_
*/ pfw`<*e'
publicint getNum(){ /1_O5'5+v
return num; f:6F5G
} ^]Q.V
%<8r`BMo
/** ev4_}!
* if(num<1) num=1 *9|p}q9n
*/ 9_8\xLk
publicvoid setNum(int num){ 85$ WH
if(num < 1) ZXXJ!9-&+J
num = 1; ]Inu'p\
this.num = num; ryqu2>(
} ;j
qF:Wl@
nM *}VI
/** bYqv)_8
* 获得总页数 ?zfm"o
*/ 4iZg2"[D
publicint getPageNum(){ Uy*d@vU9c
return(count - 1) / num + 1; mg" _3].j
} .jiJgUa7
] ^?w0A
/** C6Cr+TScH
* 获得本页的开始编号,为 (p-1)*num+1 /F46Ac}I
*/ <H{K&,Z(ZM
publicint getStart(){ :*^aSPlV
return(p - 1) * num + 1; A%x0'?GU
} X|D-[|P
7SNdC8GZ~
/** lBm`W]3T
* @return Returns the results. FM(EOsWk
*/ 4S4gK
publicList<E> getResults(){ L=fy!R
return results; 1yqsE`4f
} q*tGlM@R?
bZ:xH48MY
public void setResults(List<E> results){ Bs|Xq'1M!;
this.results = results; %yd(=%)fMB
} A&M(a
78 ]Kv^l^_
public String toString(){ ;?q}98-2
StringBuilder buff = new StringBuilder g4YlG"O[~
!aKu9SR^e
(); 2-jXj9kp`
buff.append("{"); oE6`]^^
buff.append("count:").append(count); 7WY~v2SDF
buff.append(",p:").append(p); B#+n$5#FK
buff.append(",nump:").append(num); +-9-%O.(;
buff.append(",results:").append wm Ie x
:U/]*0b
(results); #Ma:Av/
)
buff.append("}"); =F}qT|K
return buff.toString(); o!U(=:*b
} UFu0{rY_
u&[L!w
} 9
W|'~r
bfm+!9=9S
cB36w$n8