Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 YaJ[39V
~:r:?PwWG
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 q/,>UtRr
53d8AJ_@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 Qvh: hkR
y^:!]-+
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 WpE\N0Yg
(J8(_MF
。 Tj}H3/2
J[rpMQ
分页支持类: <zE,T@c
>K$9(
java代码: +^n [B
~=~|@K
Sw<@u+Z;%
package com.javaeye.common.util; ftB-gItV
XTpYf
import java.util.List; F@Qzh
RnV
)*
publicclass PaginationSupport { E7-il;`cKn
g$<Sh.4A
publicfinalstaticint PAGESIZE = 30; Md_S};!QN6
v'(p."g
privateint pageSize = PAGESIZE; n>?o=_|uR
I!?-lI@(
privateList items; UU')V
5Jd(&k8%
privateint totalCount; To1 .U)do
B2QttcJ
privateint[] indexes = newint[0]; LIYj__4=|
r9<OB`)3+
privateint startIndex = 0; rf_(pp)
fB+4mEG@
public PaginationSupport(List items, int $8gj}0}eH
x5_V5A/@LU
totalCount){ #?8dInu>
setPageSize(PAGESIZE); _]btsv\)f
setTotalCount(totalCount); `,|"rn#S
setItems(items); [%'yHb~<
setStartIndex(0); {/SUfXq
} o.IJ4'}aN
e E:J
public PaginationSupport(List items, int WPT0=Hqp7
'E FP/(2J
totalCount, int startIndex){ mOG;[CB
setPageSize(PAGESIZE); D+G?:mR
setTotalCount(totalCount); K
TJm[44
setItems(items); U^iNOMs?
setStartIndex(startIndex); K*^3FO}JG
} (D5 dN\
8."B
public PaginationSupport(List items, int ha+)ZF
D?ojxHe
totalCount, int pageSize, int startIndex){ +VxzWNs*JP
setPageSize(pageSize); EM9K^l`
setTotalCount(totalCount); wp7<0PP
setItems(items); [@YeQ{
setStartIndex(startIndex); Q!7il<S
} .}
al s
+?r,Nn
publicList getItems(){ PhTMXv<cE
return items; #[$^M:X.
} 5Fa.X|R~
Fq\vFt|m<
publicvoid setItems(List items){ o9I=zAGjy
this.items = items; Yxik.S+G
} 2wR?ON=Q
BZHba8c(
publicint getPageSize(){ )5n*4A
return pageSize; V0 70oZ
} yOHVL~F
s6=jHrdvv
publicvoid setPageSize(int pageSize){ GH ]c
this.pageSize = pageSize; oPP`)b$x
} G`1!SEae
~jcdnm]
publicint getTotalCount(){ M&au A
return totalCount; fCC^hB]'
} H,8HGL[l
X0a)6HZ{
publicvoid setTotalCount(int totalCount){ "m2g"xa\7
if(totalCount > 0){ ?r
P'PUB
this.totalCount = totalCount; +d/V^ <#
int count = totalCount / r"HQ>Wn
ZSWKVTi
pageSize; 'x/pV5[hQ
if(totalCount % pageSize > 0) 'Lm\ r+$F
count++; W}^X;f
indexes = newint[count]; zsM3
[2E*
for(int i = 0; i < count; i++){ t5t!-w\M$+
indexes = pageSize * g~ubivl2
T$w`=7
i; ))M!"*
} 8NP|>uaj
}else{ i`k{}!F
this.totalCount = 0; E~]37!,\\9
} mO#62e4C
} ,%Go.3i[
M/<>'%sj
publicint[] getIndexes(){ Zw@=WW[Q`p
return indexes; H5MO3DJ
} z[vHMJ
0
+"P!es\q
publicvoid setIndexes(int[] indexes){ LR`]C]
this.indexes = indexes; MKiP3kt8
} qXF#qS-28
M%{,?a0V
publicint getStartIndex(){ U+[ p>iP
return startIndex; Go;fQ yG
} wlC7;u
8&q[jxI@8
publicvoid setStartIndex(int startIndex){ GpwoS1#)0|
if(totalCount <= 0) /Py1Q
this.startIndex = 0; /7[U J'
elseif(startIndex >= totalCount) 7&O0
this.startIndex = indexes YB`1S
]7|Zs]6
[indexes.length - 1]; )\O;Rt(
elseif(startIndex < 0) kg/<<RO
this.startIndex = 0; n,Gvgf
else{ 8%\0v?a5
this.startIndex = indexes p)&Yr
U 7_1R0h
[startIndex / pageSize]; vyS8yJUY
} .#Vup{.
} Al}D~6MD
S:=
_o
publicint getNextIndex(){ !_i;6UVG
int nextIndex = getStartIndex() + QZZt9rA;
V'iT>
pageSize; Y%zYO
if(nextIndex >= totalCount) nyl[d|pVa
return getStartIndex(); B!j7vXM2
else .X.,.vHx
return nextIndex; $R&K-;D/8
} v?O6|0#x
k`(Cwp{Oc
publicint getPreviousIndex(){ tS[@3h
int previousIndex = getStartIndex() - |#i|BVnoE
<>71;%e;'
pageSize; +eUWf{(_
if(previousIndex < 0) Bx" eX>A8
return0; BbCaIt
else +{b3A@f|F
return previousIndex; ]yAOKmS
} )&px[Dbx
3'jH,17lWV
} YJm64H,[
!5^&?plC@
4NK{RN3
]8o[&50y
抽象业务类 \c(Z?`p]R1
java代码: qGkD] L
U32&"&";c
9er0Ww.d
/** Of gmJ(%
* Created on 2005-7-12 x\K9|_!
*/ 5fDp"-
package com.javaeye.common.business; 'UFPQ
sZh| <2
import java.io.Serializable; lHI?GiB@
import java.util.List; Y'U]!c9
#+ai G52+
import org.hibernate.Criteria; /RBIZ_
import org.hibernate.HibernateException; E``\Jre@
import org.hibernate.Session; GOU>j"5}2
import org.hibernate.criterion.DetachedCriteria; qBDhCE
import org.hibernate.criterion.Projections; .~Gt=F+`s
import V jqs\
|T+YC[T#v
org.springframework.orm.hibernate3.HibernateCallback; W6&mXJ^3L
import fN_Ilg)t?5
ozUsp[W>
org.springframework.orm.hibernate3.support.HibernateDaoS f=cj5T:[
\N a
upport; S2PPwCU
%G>
import com.javaeye.common.util.PaginationSupport;
:zK\t5
LUKt!I0l
public abstract class AbstractManager extends L43]0k
`)n/J+g
HibernateDaoSupport { aS/ MlMf
;=lQMKx0
privateboolean cacheQueries = false; @!KG;d:l
UZ-[vD1n
privateString queryCacheRegion; Wagb|B\
/I~(*X
publicvoid setCacheQueries(boolean $,8}3R5}
8;<3Tyjzu
cacheQueries){ "NvB@>S
this.cacheQueries = cacheQueries; G_v^IM#B=
} HLb`'TC3r+
|_u|Td(n
publicvoid setQueryCacheRegion(String \H{UJ
$Ma*q EB
queryCacheRegion){ z;lWr(-x
this.queryCacheRegion = A|<i7QVY
/#Lm)-%G
queryCacheRegion; Sej(jJX1
} ^X|Bzz)
&'"dYZj{
publicvoid save(finalObject entity){ $TY1'#1U;
getHibernateTemplate().save(entity); PL*1-t?#
} i:n1Di1~E
I*EHZctH
publicvoid persist(finalObject entity){ u!TMt8+c
getHibernateTemplate().save(entity); P*g:rg
} lnWscb3t
=y]FcxF
publicvoid update(finalObject entity){ !f01.Tq8
getHibernateTemplate().update(entity); +L-(Lz[p
} !)HB+yr
W.7XShwd*2
publicvoid delete(finalObject entity){ il~A(`+YO
getHibernateTemplate().delete(entity); Jl-:@[;
} 2@>#?c7
LB/1To
publicObject load(finalClass entity, )~C+nb '6/
It8s#o q8
finalSerializable id){ ,jJbQIu#
return getHibernateTemplate().load 19*D*dkBR
@XN*H- |
(entity, id); (dHil#l
}
4Ixu%
6g 5Lf) yG
publicObject get(finalClass entity, v{O(}@
m/p:W/0L
finalSerializable id){ AkA2/7<[
return getHibernateTemplate().get KOit7+Q
_Eus7
(entity, id); xi}3)5
} OY,iz
|*JMCI@Mz
publicList findAll(finalClass entity){ wj-z;YCV
return getHibernateTemplate().find("from d6zfP1lQ
G%XjDxo$I
" + entity.getName()); _KAg1Ww
} ~!#2s'
<]'1Y DA
publicList findByNamedQuery(finalString u69fYoB'
gh<2i\})'
namedQuery){ jPmp=qg"q
return getHibernateTemplate ]^v*2!_(
t$(<9
().findByNamedQuery(namedQuery); QRz5eGpW
} w3K>IDWI7
+OfHa\Nz
publicList findByNamedQuery(finalString query, !w{(}n2Wq
YjzGF=g#
finalObject parameter){ C~c|};&%
return getHibernateTemplate O =\`q6l
A9kn\U92
().findByNamedQuery(query, parameter); {"hyr/SK d
} PGJkQsp0
FSHC\8siS
publicList findByNamedQuery(finalString query, a
n|bzG
N6w!V]b
finalObject[] parameters){ 8=WX`*-uH
return getHibernateTemplate (dQsR sA
]<:qMLg
().findByNamedQuery(query, parameters); M:R|hR{=*
} 68nBc~iAm
hs?cV)hDS
publicList find(finalString query){ ITf4PxF
return getHibernateTemplate().find %^}|HG*i??
^-dhz88wV
(query); /5j]laYK)
} a4x(lx&
MBO>.M$B
publicList find(finalString query, finalObject xMD]b
>/9on.
parameter){ +a74] H"
return getHibernateTemplate().find *s (L!+
DUWSY?^c
(query, parameter); aSQvtv)91
} |s, Add:S
j[Oh>yG
public PaginationSupport findPageByCriteria FSA"U9 w<
aJSBG|IC
(final DetachedCriteria detachedCriteria){ 9
M!U@>
return findPageByCriteria K%3{a=1
<iNxtD0
(detachedCriteria, PaginationSupport.PAGESIZE, 0); \) vI-
} ;)'
}J(o!2.
public PaginationSupport findPageByCriteria 9y`Vg
CkEbSa<)hK
(final DetachedCriteria detachedCriteria, finalint r"=6s/q7
;Ff5ooL{
startIndex){ nPj
&a
return findPageByCriteria &0JCZ/e
nx|b9W<
(detachedCriteria, PaginationSupport.PAGESIZE, G\/7V L
MRa
|<yK
startIndex); *Fm#Qek
} T )"Uq
eWU@@$9
public PaginationSupport findPageByCriteria 7cly{U"
<BhNmEo)2
(final DetachedCriteria detachedCriteria, finalint E2yL9]K2
=6< Am
pageSize, t[HA86X
finalint startIndex){ %C~LKs5oH
return(PaginationSupport) k/.a
yLq
R d>PE=u
getHibernateTemplate().execute(new HibernateCallback(){ V^qkHm e
publicObject doInHibernate .;jp2^
m$80D,3
(Session session)throws HibernateException { 5<mGG;F
Criteria criteria = z-`-0@/A$
GCv*a[8?n
detachedCriteria.getExecutableCriteria(session); *."a>?D~
int totalCount = TY*uK
@Xl/<S&
((Integer) criteria.setProjection(Projections.rowCount V8+8?5'l
wfrSI:+>
()).uniqueResult()).intValue(); y4`uU1=
criteria.setProjection )~ =g}&
q
!Nb-O{
(null); GcCMCR3
List items = Wv-nRDNG
#*x8)6Ct
criteria.setFirstResult(startIndex).setMaxResults jZP~!q
DY?;Z98P?
(pageSize).list(); Q4QF_um
PaginationSupport ps = YLFM3IaP
[FN4 _
new PaginationSupport(items, totalCount, pageSize, ))eQZ3ap9
:JfT&YYi"
startIndex); l_0/g^(
return ps; _p,1m[&M
} Oj0,Urs7
}, true); m1,yf*U
} y5$AAas
]n (:X
public List findAllByCriteria(final $}z%}v
RAi]9` *7
DetachedCriteria detachedCriteria){ w5R?9"d@
return(List) getHibernateTemplate bZd)4
z<z\)
().execute(new HibernateCallback(){ kbKGGn4u
publicObject doInHibernate X}RQ&k
8w L%(p
(Session session)throws HibernateException { m5KAKpCR,
Criteria criteria = O
cJ(i#Q~<
oC >l|?h,
detachedCriteria.getExecutableCriteria(session); ;vLg4k
return criteria.list(); 4j VFzO%.
} PYJ8\XZ1_N
}, true); 5`Oaf\S
} >TB Rp,;r
/Lt Lu
public int getCountByCriteria(final 1-:{&!
ZDt|g^
DetachedCriteria detachedCriteria){ o}VW%G"
Integer count = (Integer) IPEJ7n49
O\ph!?L
getHibernateTemplate().execute(new HibernateCallback(){ SVj4K\F
publicObject doInHibernate @o4n!Ip2x/
VKb'!Ystl
(Session session)throws HibernateException { 8V(-S,
Criteria criteria = $<v{$UOh
$zYo~5M?i-
detachedCriteria.getExecutableCriteria(session); SED_^
return D?6ah=:&R
z57|9$h}w
criteria.setProjection(Projections.rowCount >4x~US[VB
,V{Cy`bi
()).uniqueResult(); ;+Uc}=
} #Ss lH
}, true); *hZ{>
return count.intValue(); R@Bnrk
} V/CZcMY_
} v''F\V )
5"o)^8!>
usz H1@g'
siK:?A@4D
fkWTO"f-
JtGBNz!"
用户在web层构造查询条件detachedCriteria,和可选的 z4iZE*ZS
FNB4YZ6
startIndex,调用业务bean的相应findByCriteria方法,返回一个 VT~jgsY
~LufHbr
PaginationSupport的实例ps。 , \
6*fXc
KQv97#n1
ps.getItems()得到已分页好的结果集 Ub9p&=]h
ps.getIndexes()得到分页索引的数组 `zBQ:_3J_
ps.getTotalCount()得到总结果数 >cM}M =4s
ps.getStartIndex()当前分页索引 ewD=(y r
ps.getNextIndex()下一页索引 W^Z#_{
ps.getPreviousIndex()上一页索引 @A;Ouu(
Bgy?k K2[
,)](h+zl_6
l
d@ B
]5`Y^hS_g
.W1i3Z 6g
-/z #?J\
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 "[M k5tM
Y*q_>kps"
,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 HMrl!;:
f{j(H?5
一下代码重构了。 :jUu_s}
_q/UDf1
我把原本我的做法也提供出来供大家讨论吧: 6nP-IKL
NNM+Z:
首先,为了实现分页查询,我封装了一个Page类: "? t@Y
java代码: * M,'F^E2
2,.;Mdl
e~iPN.'1
/*Created on 2005-4-14*/ PShluhY
package org.flyware.util.page; _8eN^oc%
ZclZD{%8J
/** 6y
d/3k
* @author Joa XEvDtDR
* 0 CFON2I
*/ syR
+;
publicclass Page {
#:st>V_h
/UAcN1K!B
/** imply if the page has previous page */ dB%q`7O
privateboolean hasPrePage; "Nlw&+
c7
x;L.j7lzA;
/** imply if the page has next page */ 'hn=X7
privateboolean hasNextPage; @+ee0
CLT
NiPa-yRh
/** the number of every page */ z=/xv},
privateint everyPage; '<eeCe-
$Z!7@_Ys
/** the total page number */ L4?)N&V
privateint totalPage; C^W9=OH
P6
& _q
/** the number of current page */ &hri4p/
privateint currentPage; uBXl ltU
pk5W!K
/** the begin index of the records by the current tH\ aHU[
;4]
s P^+
query */ k~+(X|!5w
privateint beginIndex; }'.k
pcl'!8&7
nm.~~h+8M
/** The default constructor */ h..D1(M
public Page(){ @%}4R`S0
1deNrmp%
} ?}D|]i34
1y)|m63&
/** construct the page by everyPage >nA6w$
* @param everyPage @+(TM5Ub
* */ Dd:;8Xo
public Page(int everyPage){ SC6cFyp2
this.everyPage = everyPage; FsdxLMwk1
} *'&mcEpg
Rz_fNlA
/** The whole constructor */ JDA :)[;
public Page(boolean hasPrePage, boolean hasNextPage, L@t}UC
n fU\l<
%/r}_V(UN
int everyPage, int totalPage, (ev(~Wc
int currentPage, int beginIndex){ alB[/.1
this.hasPrePage = hasPrePage; O?I~XM'S
this.hasNextPage = hasNextPage; ">V.nao
this.everyPage = everyPage; TtZ
'~cGR
this.totalPage = totalPage; bw\a\/Dw
this.currentPage = currentPage; eJv_`#R&Of
this.beginIndex = beginIndex; Q\ AM]
U
} D3BNA]P\2@
f6d:5
X_
/** n,+/%IZ
* @return w?LDaSz\t
* Returns the beginIndex. Np?%pB!Q
*/ [LHx9(,NM
publicint getBeginIndex(){ A^9RGz4=
return beginIndex; %1Pn;bUU!
} !L)~*!+Gf
as%ab[ fX
/** E"|LA[o
* @param beginIndex k Up[b~
* The beginIndex to set. | ]DJz
*/ ^3B&E^R
publicvoid setBeginIndex(int beginIndex){ 1dg y-$H~
this.beginIndex = beginIndex; 6zfi\(fop
} )`sEdVxbr
L9Gxqw
/** 4Sq[I
* @return &1:_+
* Returns the currentPage. 4)i(`/U
*/ >%o\Ue
publicint getCurrentPage(){ et$VR:
return currentPage; 9ne13qVm+
} /I>o6 CI
v[O }~E7'
/** k{ru<cf
* @param currentPage +oT/ v3,
* The currentPage to set. `qnNEJL,
*/ tf5h/:
publicvoid setCurrentPage(int currentPage){ #J,?oe=<4
this.currentPage = currentPage; (<"uV%1
} S3G9/
jM'kY|<g;
/** c9 c_7g'q-
* @return >)&]Ss5J
* Returns the everyPage. TI9]v(
*/ Hlr[x
publicint getEveryPage(){ Id/-u[-yo
return everyPage; s?irT;=
} ?C[W~m P
g{_wMf
/** ]&dU%9S
* @param everyPage (zO)J`z>
* The everyPage to set. &`RD5uml
*/ Y$%z]i5
publicvoid setEveryPage(int everyPage){ Br,^4w[Hq
this.everyPage = everyPage; e;kH,fHUI3
} :&{:$-h!
4zRz U
/** i`Tp +e@a>
* @return w'/Mn+
* Returns the hasNextPage. ][jW2;A
*/ l=*60Ag\J~
publicboolean getHasNextPage(){ x2m*0D~
return hasNextPage; Hj>(kL9H
} W@vt6v
^Pq4 n%x
/** o<Esh;;*nm
* @param hasNextPage d=q&%gqN
* The hasNextPage to set. M_+"RKp
*/ w
B i'KS
publicvoid setHasNextPage(boolean hasNextPage){ r?w^#V
this.hasNextPage = hasNextPage; N'8u}WO
} Y M<8>d
vH^6O:V
/** 'K L"i
* @return n I63Ns
* Returns the hasPrePage. N}j]S{j}'
*/ -8r';zR
publicboolean getHasPrePage(){ &7i o/d\/
return hasPrePage; s?:&#
} c,K)*HB
Zt;dPYq>
/** Q(3Na 6
* @param hasPrePage %a_ rYrL
* The hasPrePage to set. w=ib@_:f
*/ 8,0WHivg
publicvoid setHasPrePage(boolean hasPrePage){ Ly7|:IbC
this.hasPrePage = hasPrePage; YPV@/n[N
} /Vg=+FEO
eNwF<0}
/** ~6)A/]6
* @return Returns the totalPage. Mx3MNX/
* .d JX,^
*/ GV+K]
KDI
publicint getTotalPage(){ -|"[S"e
return totalPage; y.O%
} m>H+noc^
?)_?YLi
/** fbG+.'
* @param totalPage g[NmVY-o
* The totalPage to set. 8zMt&5jD
*/ ]f3[I3;K
publicvoid setTotalPage(int totalPage){ W7F1o[
this.totalPage = totalPage; i1(}E#
} mM[!g'*
BrHw02G
} ,m`>
r~q(m>Ct6
0bR)]"K
<Va7XX%>
bvxol\7 ;
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 rwJCVkF
,EE,W0/zzM
个PageUtil,负责对Page对象进行构造: YR 5C`o
java代码: 6D=9J%;
u%o]r9xl'
d;4LHQ0yU
/*Created on 2005-4-14*/ K4G43P5q`
package org.flyware.util.page; kE8\\}B7
isG8S(}IW&
import org.apache.commons.logging.Log; Q1b<=,
import org.apache.commons.logging.LogFactory; t-;zgW5mwF
iFJ1}0<(x
/** R/_bk7o]H
* @author Joa ;*H@E(g
* q)m0n237P
*/ /:+f5\"-b
publicclass PageUtil { fLtN-w6t
j$<sq
privatestaticfinal Log logger = LogFactory.getLog Z7="on4
\Nvu[P
(PageUtil.class); }MCh$
D('
w<9.
/** i40'U?eG~6
* Use the origin page to create a new page +nz6+{li\
* @param page 61[ 8I},V
* @param totalRecords +.EP_2f9
* @return dbE]&w`?d
*/ K1gZ>FEY|N
publicstatic Page createPage(Page page, int M2$.Yom[
\~(scz$
totalRecords){ mSg{0_:
return createPage(page.getEveryPage(), "CX@a"
uZg[PS=@!X
page.getCurrentPage(), totalRecords); ~l^Q~W-+
} mB.j?@Y%
MXsCm(
/** mBrH`!
* the basic page utils not including exception @U 6jd4?)
MR?5p8S#g
handler 5Al1u|;HB
* @param everyPage N4xCZb
* @param currentPage SqF `xw
* @param totalRecords H;~Lv;,g,
* @return page |#Gug('
*/ F=B[%4q`%
publicstatic Page createPage(int everyPage, int pGsk[.
k6}M7&nY
currentPage, int totalRecords){ *K57($F
everyPage = getEveryPage(everyPage); TI<?h(*R_
currentPage = getCurrentPage(currentPage); Q|6lp
int beginIndex = getBeginIndex(everyPage, ]U,c`?[7#
X%Lhu6F
currentPage);
4eRV?tE9
int totalPage = getTotalPage(everyPage, 2m*g,J?ql
(\I9eBm
totalRecords); pef)c,U$
boolean hasNextPage = hasNextPage(currentPage, _<8~CWo:
qDVt
totalPage); #B^A"?*S
boolean hasPrePage = hasPrePage(currentPage); "KiTjl`M,
fHLt{ !O
returnnew Page(hasPrePage, hasNextPage, r=J+
everyPage, totalPage, R/O>^s!Co
currentPage, !bq3c(d
;h-W&i7
beginIndex); ,(@J Ntx
} M SnRx*-
g0Ff$-#7
privatestaticint getEveryPage(int everyPage){ w Avnj
return everyPage == 0 ? 10 : everyPage; *6`};ASK
} BKV,V/*p
(*K=&e0O
privatestaticint getCurrentPage(int currentPage){ ?=dp]E{
return currentPage == 0 ? 1 : currentPage; \ ";^nk*
} n9w(Z=D\
na4^>:r~
privatestaticint getBeginIndex(int everyPage, int u^ 3,~:E
JQ~[$OGH
currentPage){ SJJ[y"GvD
return(currentPage - 1) * everyPage; "C/X#y
} 7:S4 Ur
hHsN(v
privatestaticint getTotalPage(int everyPage, int X1C
&;5
]_EJ "'x
totalRecords){ mH,L,3R;R
int totalPage = 0; JS^QfT,zE
ceUhCb
if(totalRecords % everyPage == 0) qk
*b,`;
totalPage = totalRecords / everyPage; ,8`CsY^1
else ;S5J"1)O~
totalPage = totalRecords / everyPage + 1 ; MV?#g-5
SqosJ}K
return totalPage; %S$+3q%F
} I;g>r8N-Bu
(oxMBd+n1
privatestaticboolean hasPrePage(int currentPage){ 0zHMtC1,
return currentPage == 1 ? false : true; *De}3-e1b
} \+T U{vr
_pN:p7l(
privatestaticboolean hasNextPage(int currentPage, *I6W6y;E=
wxc24y
int totalPage){ ;]PP+h
return currentPage == totalPage || totalPage == v(`9+*
}I3m8A
0 ? false : true; [X7KlS9x2
} gy*c$[NS$
%jErLg
]=Dzr<*v
} ?glK~G!i
hR+\,P#G[
Re<@.d
|6O7_U#q
NE)Yd7m-
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。 /Pyj|!C3`q
!zZ3F|+HB
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 NW4tQ;ad
t[4V1:
做法如下: $l=&
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 C)?tf[!_6
g@ 2f&m
的信息,和一个结果集List: 'o]kOp@q
java代码: @9e}kiW
ak"W/"2:
U0ZPY )7k
/*Created on 2005-6-13*/ sJ{J@/5
package com.adt.bo; \n>7T*iM&
F^Y%Q(Dd7w
import java.util.List; @QO^3%b8
hQ@E2 Xsv
import org.flyware.util.page.Page; .gclE~h.
gski:C
/** M 3&GO5<
* @author Joa QF4)@ r{2x
*/ 9q ]n&5
publicclass Result { %
4Gt^:J"
7SJbrOL4Q-
private Page page; ;u*I#)7
%:!ILN
private List content; <;lwvO
ey@{Ng#
/** E;rS"'D:
* The default constructor `V2doV)
*/ HJ+Q7)
public Result(){ v83@J~
super(); Eyq4w
} ~$jRn(2
H{4_,2h=m
/**
:SD#>eD0
* The constructor using fields =eyPo(B
* mfx-Ja_a
* @param page JI[{n~bhGD
* @param content z)ndj
1,#)
*/ Sfa;;7W@R
public Result(Page page, List content){ p|>m 2(|
this.page = page; ;Sl%I+?
this.content = content; .G-L/*&%
} <)a7Nrc\T
SajasjE!^1
/** +n>p"+c
* @return Returns the content. QmC#1%@a
*/ c+upoM
publicList getContent(){ f7b6!R;z_
return content; :X}fXgeL
} qH4+iSTnV
t"nxny9&
/** 7nPjeh
* @return Returns the page. O>eg_K,c
*/ S1o[)q
public Page getPage(){ }z F,dst
return page; :?j]W2+kR
} Jb6)U]
wv
/** 1 T}jK^"
* @param content NpH9},1i
* The content to set. |pZ:5ta#
*/ ny}_^3
public void setContent(List content){ :7?n)=Tx
this.content = content; H5(:1
} ](^FGz
Z# %s/TL
/** +`7!4gxwK!
* @param page E>N [
* The page to set. >mj WC) U
*/ d*dPi^JjC
publicvoid setPage(Page page){ 7l4}b^>/`
this.page = page; n )PqA*
} q)3QmA~
} T>|Y_3YO_a
OHv4Yy]$B
Ln8r~[tVE<
\c1>15
bPIo9clq
2. 编写业务逻辑接口,并实现它(UserManager, 9
^=kt 2[
QJSi|&Rx&?
UserManagerImpl) K{9
java代码: +k V$ @qH
)"J1ET,z
uFuP%f!yY
/*Created on 2005-7-15*/ ?CldcxM#
package com.adt.service; (
6ucA
|-TxX:O-
import net.sf.hibernate.HibernateException; |S]T,`7u
IdCE<Oj\
import org.flyware.util.page.Page; R[l~E![!j
`neo.]
import com.adt.bo.Result; 0J6* U[
X o[GD`t
/** -EE}HUP)
* @author Joa P('bnDU
*/ vDyGxU!#\
publicinterface UserManager { fg/hUUl
4KR$s Kq$q
public Result listUser(Page page)throws Rm}G4Pq
[Wxf,rW i
HibernateException; U#%+FLX@w
r::0\{{r"p
} [OS&eK 8
T%A"E,#
==S^IBG
8gG;A8
0./Rdf=-1j
java代码: iI;np+uYk
hW` o-'
_p?s[r*
/*Created on 2005-7-15*/ ;M"[dy`dY
package com.adt.service.impl; wEw;],ur
yH9&HFDp
import java.util.List; e-nwR
@k\,XV`T~t
import net.sf.hibernate.HibernateException; wRZS+^hx
'wWuR@e#&
import org.flyware.util.page.Page; hxt;sQAo{
import org.flyware.util.page.PageUtil; q3`~uTzk
q.j$]?PQ
import com.adt.bo.Result; C=bQ2t=Z
import com.adt.dao.UserDAO; U;M! jj
import com.adt.exception.ObjectNotFoundException; Tfx-h)oP3
import com.adt.service.UserManager; 6n;? :./
4 %4Yqx )
/** 4y!GFhMh
* @author Joa rxj#
*/ `XM0Mm%
publicclass UserManagerImpl implements UserManager { cYBjsN(!A|
6!8uZ>u%Vg
private UserDAO userDAO; )@<HG$#
|{RCvm
/** 9v1 Snr
* @param userDAO The userDAO to set. !%B-y9\
*/ oi8M6l
publicvoid setUserDAO(UserDAO userDAO){ ge1U1o
this.userDAO = userDAO; (hh^?
} AmQsay#I_
P<;Puww/
/* (non-Javadoc) EKS?3z%!
* @see com.adt.service.UserManager#listUser -J0OtrZ
B5+$VQ
(org.flyware.util.page.Page) 9i
D&y)$"
*/ v^;vH$B
public Result listUser(Page page)throws ..w$p-1
"
t?44[
HibernateException, ObjectNotFoundException { Hz=s)6$ey
int totalRecords = userDAO.getUserCount(); *?VB/yO=0
if(totalRecords == 0) ~6+Um_A_L
throw new ObjectNotFoundException c:+UC
H%Z;Yt8^gt
("userNotExist"); -:~z,F
page = PageUtil.createPage(page, totalRecords); hLVgP&/E
List users = userDAO.getUserByPage(page); shO4>Ha
returnnew Result(page, users); D[6wMep^n
} *1T~ruNqa
'v=BAY=Ef
} ap,zC)[
MZqHL4<|
,XI=e=
G_5w5dbG
T!Lv%i*|Y
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 xk3)#*
er2;1TW3E
询,接下来编写UserDAO的代码: EfkBo5@ Qi
3. UserDAO 和 UserDAOImpl: d,Oe3?][0p
java代码: ~M1T
@Mv
HGi%b5:<=M
AS0mMHJk
/*Created on 2005-7-15*/ rB|4
package com.adt.dao; jo<Gf 5
%IDl+_j
import java.util.List; (`u+(M!^
.4[M-@4+]
import org.flyware.util.page.Page; 6j!a*u:}"
;iJ}[HUo
import net.sf.hibernate.HibernateException; ywB0
D`s'
E^m)&.+'M
/** /<dl"PWkJv
* @author Joa vE)d0l"
*/ t{ `-G*^
publicinterface UserDAO extends BaseDAO { BqdGU-Q
9;rZ )QD
publicList getUserByName(String name)throws 6zi
Mf
Zu>CR_C
HibernateException; v[R_6
5HTY ~&C
publicint getUserCount()throws HibernateException; F=f9##Y?7M
)i\foSbB`V
publicList getUserByPage(Page page)throws ldc`Y/:{
(a~V<v"
HibernateException; Yp8XZ3
,mK UCG
} gKgdu($NJ
R;uP^
Q8]S6,pt
~q}]/0-m
pW>.3pj
java代码: :5jor Vu
23opaX5V=
@V@<j)3P
/*Created on 2005-7-15*/ 6;Mv)|FJF
package com.adt.dao.impl; 3E>]6
[|YJg]i-
import java.util.List; &ha<pj~
T( k:\z/
import org.flyware.util.page.Page; L Z3=K`gj
>feeVk
import net.sf.hibernate.HibernateException; 8^R~qpg%
import net.sf.hibernate.Query; `_"?$ v2F
C\|HN=2eh
import com.adt.dao.UserDAO; 2d<`dQY{l3
Xob(4
/** D2io3Lo$ov
* @author Joa }/g1
*/ v[a4d&P
public class UserDAOImpl extends BaseDAOHibernateImpl ZB5NTNf>
u!b0<E
implements UserDAO { 3ZvQUH/{W
v{8r46Y~Z)
/* (non-Javadoc) /)rv Ndn
* @see com.adt.dao.UserDAO#getUserByName #jg3Ku;Y
-cUw}
(java.lang.String) t 1G2A`
*/ #rp)Gc
publicList getUserByName(String name)throws 2#'"<n,G
q\~D:z$+CO
HibernateException { 'o7V6KG
String querySentence = "FROM user in class SV^[)p)
P%<MQg|k`
com.adt.po.User WHERE user.name=:name"; Ac/LNqIs
Query query = getSession().createQuery 1z@ ncqe
5rJ7CfVq
(querySentence); _$oE'lat
query.setParameter("name", name); ~Q=^YZgn8
return query.list(); lO}I>yo}\
} (&/~q:a>
2 ,.8oa(
/* (non-Javadoc) 3v)``
n@
* @see com.adt.dao.UserDAO#getUserCount() q-e3;$
*/ CZ(fP86e
publicint getUserCount()throws HibernateException { =CaSd|
int count = 0; 2F ~SH
String querySentence = "SELECT count(*) FROM ,rhNXx
%B| Ca&
user in class com.adt.po.User"; u#3Cst8Y
Query query = getSession().createQuery vQ{mEaH
)xTu|V
(querySentence); WTZuf9:
count = ((Integer)query.iterate().next i^rHZmT
!ed0
()).intValue();
x![ut
return count; f6#1sO4"
} S^~
lQ|D
4>]B8ZxH
/* (non-Javadoc) Qaiqx"x3
* @see com.adt.dao.UserDAO#getUserByPage =DI/|^j{;
;]2d%Qt
(org.flyware.util.page.Page) 2JHV*/Q
*/ !'=<uU-
publicList getUserByPage(Page page)throws i"{znKz vD
>}86#^F
HibernateException { j 2e|
String querySentence = "FROM user in class P>7PO~E.
U^OR\=G^
com.adt.po.User"; )N&95\u
Query query = getSession().createQuery ; VQ:\fG
L0ZAF2O
(querySentence); &=lhKt
query.setFirstResult(page.getBeginIndex()) =8DS~J{
.setMaxResults(page.getEveryPage()); Oq95zo
return query.list(); r<"k
/
} pAcu{5#7
~B`H5#
} 1*B'o<?P1
.L_ Hk
$XFFNE`%
p{w;y6e
,){WK|_
至此,一个完整的分页程序完成。前台的只需要调用 &GI'-i
RP6hw|
userManager.listUser(page)即可得到一个Page对象和结果集对象 w.Go]dpK
bWMb@zm
的综合体,而传入的参数page对象则可以由前台传入,如果用 4& 9V
et`rPK~m
webwork,甚至可以直接在配置文件中指定。 r#^uY:T%
gE6{R+sp
下面给出一个webwork调用示例: B)Dsen
java代码: (KT+7j0^
=5g|7grQ:`
tU>4?`)E
/*Created on 2005-6-17*/
=#vU$~a
package com.adt.action.user; N gOc2I
Vc
"+|^
import java.util.List; - 4S4I
zHvW@A'F
import org.apache.commons.logging.Log; .H5^ N\V|
import org.apache.commons.logging.LogFactory; 0Y*Ag,S
import org.flyware.util.page.Page; v0+$d\mP4<
[<#`@Kr
import com.adt.bo.Result; <rNz&;m}
import com.adt.service.UserService; OF`:);
import com.opensymphony.xwork.Action; aOW$H:b
5K$d4KT
/** sH Hu<[psM
* @author Joa vNAQ/Q
*/ MNKY J
publicclass ListUser implementsAction{ Qr[".>+
]DI%7kw'
privatestaticfinal Log logger = LogFactory.getLog ;vgaFc]
\B8[UZA.&
(ListUser.class); 2!}rHw
.IORvP-M&
private UserService userService; f_> lz
c)17[9"
private Page page; f`p"uLNo<
HO39>:c
privateList users; $eh>.c'&]
@Y+9")?
/* *g 2N&U
* (non-Javadoc) {7 nz:f
* R,W
w/D
* @see com.opensymphony.xwork.Action#execute() 1zY"Uxp
*/ q]m$%>
publicString execute()throwsException{ Iyt.`z
Result result = userService.listUser(page); !Bb^M3iA
page = result.getPage(); ngH_p>
users = result.getContent(); S{qsq\X
return SUCCESS; r1|;V~a$~
} bcFZ ~B
THnZbh4#)
/** P64<O5l/
* @return Returns the page. (Bu-o((N@0
*/ i8`0-
public Page getPage(){ stlkt>9
return page; DX8pd5U
} -&r A<j
XE :JL_
/** 6Y}Bza
* @return Returns the users. <z-+{-?z~
*/ >66v+
publicList getUsers(){ @Yh%.#\i%
return users; &, WQr
} }%k3
|(rTz!!-
/** -{S:sK.o
* @param page Y kcN-
* The page to set. =BBDh`$R
*/
8=j_~&*
publicvoid setPage(Page page){ |kkg1M#
this.page = page; A$o ?_
} &13#/
O `a4
")R
/** 5U%a$.yr
* @param users 9Zpd=m8dU
* The users to set. F]^ZdJ2
*/ #
,27,#
publicvoid setUsers(List users){ (T2\
this.users = users; @#&y
} mdukl!_x
f#zm}+,`
/** DbvKpM H
* @param userService K1^x+I7%U[
* The userService to set. Py-}tFr
*/ _tpqo>
publicvoid setUserService(UserService userService){ Y'2 |GJc2
this.userService = userService; Fs;_z9ej-u
}
.'^Pg
} L:RMZp*bK
G,h=5y9_J
^`oyf{w@
.wz.Jr`{
S(h+,+289
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, \>r<z46x
%v 1NDhaXz
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 53X5&Bwh
':_1z5
么只需要: hha^:,
java代码: w&^_2<a2
0|@*`-:VO
TClgywL
<?xml version="1.0"?> o<8=@ ^T
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork TSAVXng
1<d|@9?9`
1.0//EN" "http://www.opensymphony.com/xwork/xwork- 7.`:Z_
a 9f%p
1.0.dtd"> }o MY
Dg2=;)"L
<xwork> khtYn.eaL
\t\ZyPxn
<package name="user" extends="webwork- V.Ki$0>
O%?d0K
interceptors"> W4o$J4IX{
0*}%v:uN9
<!-- The default interceptor stack name k874t D
x6={)tj
--> !`?*zf
<default-interceptor-ref 6l-V%3-
*T{P^q.s~[
name="myDefaultWebStack"/> a}MSA/K(
^+zhzfJ
<action name="listUser" 6+Wkcrh
]Sgc42hk
class="com.adt.action.user.ListUser"> Foc) u~
<param _0(Bx?[h
Pf?y!dK<
name="page.everyPage">10</param> ^&6'FE
<result \<K@t=/
6
UN6Du\)]d
name="success">/user/user_list.jsp</result> ]Uee!-dZ
</action> r^|AiYI)
?go+oS^
</package> yDW$v/j.|
^+20e3 ~Y
</xwork> 1JXa/f+
Q]d3a+dK
J}UG{RttI
,/>hWAx
;.4A,7w#
(( D*kd"
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 T,eP&IN
x O~t
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 4#^?-6
\E3evU
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 !9knFt43
O>j_x W]V
o|?bvFC
ZW0gd7Wh
8V$ :th('
我写的一个用于分页的类,用了泛型了,hoho ,AO]4Ec
42wa9UL<Ka
java代码: EgT2a
bijE]:<AE7
#}Qzu~
package com.intokr.util; mOkf
DlWnz-
import java.util.List; P:gN"f6
;P#c!
/** uYv"5U]MFv
* 用于分页的类<br> ?-`G0 (
* 可以用于传递查询的结果也可以用于传送查询的参数<br> v9qgfdBS5
* @GpM4>:
* @version 0.01 dE[nPtstb
* @author cheng &eHhj9
*/ W%xg;uzp
public class Paginator<E> { MWxv\o
privateint count = 0; // 总记录数 Mr3;B+S
privateint p = 1; // 页编号 ,#FK3;U
privateint num = 20; // 每页的记录数 }bxW@(bs
privateList<E> results = null; // 结果 8;C_@
x!08FL)
/** F.0CJ7s
* 结果总数 30fsVwE2
*/ 23AMrDF=N
publicint getCount(){ dMnJ)R
return count; V{j>09u
} ?!:$Z4G
'9Hah
publicvoid setCount(int count){ IP]"D"
this.count = count; 8 N5ga
} Q8kdX6NMd&
^gK8
u]>
/** ^/<0r]=
* 本结果所在的页码,从1开始 3k J8Wn
* dDAIfe2y
* @return Returns the pageNo. VQQtxHTC3
*/ $]Vvu{
publicint getP(){ 5zqlK-$
return p; X(Wd
} vIi#M0@N
5ZRO{rf
/** MifPZQ
* if(p<=0) p=1 \[Dxg`;4
* IU8/B+hM~
* @param p $H9+>Z0(
*/ b`=\<u8
publicvoid setP(int p){ %ifq4'?Z
if(p <= 0) '<A:`V9M}v
p = 1; I}#_Jt3R
this.p = p; 5gPcsn"D
} fJb<<6C
Nl3@i`;
/** ~ "^]\3#
* 每页记录数量 5f:Mb|.?
*/ }CiB+
publicint getNum(){ me+F0:L
return num; y3]7^+k
} )L*6xTa~
/a?*Ap5"
/** \m3;<A/3n
* if(num<1) num=1 L@"1d.k_
*/ 4+Sq[Rv0
publicvoid setNum(int num){ :+9KNyA
if(num < 1) uz(3ml^S
num = 1; :jol
Nl|a
this.num = num; /$
-^k[%
} vakAl;
$\0%"S
/** PfaBzi9?f
* 获得总页数 N6"b
OxJ(
*/ f
xWW"B*A
publicint getPageNum(){ 0'giAA
return(count - 1) / num + 1; %V>Ss9;/8
} NDJIaX:]
iBq|]
/** PhHBmMGL
* 获得本页的开始编号,为 (p-1)*num+1 =
h
_>OA
*/ {R2gz]v4
publicint getStart(){ TV~<1vj
return(p - 1) * num + 1; s)=fs#%
} (8(7:aE$
Hl,.6>F?
/** 'w?*4H
* @return Returns the results. zHI_U\"8D
*/ BI'}
publicList<E> getResults(){ `uO(#au,U
return results; IA\CBwiLj
} Mpfdl65
^^u{W|'CaH
public void setResults(List<E> results){ _B@=fY(g!
this.results = results; g:l5,j.K
} )%4%Uo_Xm
6*] g)m
public String toString(){ -R^OYgF
StringBuilder buff = new StringBuilder u~|D;e
x<m{B@3T
(); =*VKp{5=
buff.append("{"); p[Pa(a,B7
buff.append("count:").append(count); {bxTODt@
buff.append(",p:").append(p); }klET
buff.append(",nump:").append(num); J YA
buff.append(",results:").append k3[%pS
+1Qa7\
(results); *o}LI6_u
buff.append("}"); [jPUAr}
return buff.toString(); `D0>L'
} jE
/pba4R
"f/Su(6{0
} '[E|3K5d
(]JZ1s|
or?@Ti;