Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Xhq7)/jp
RA!q)/+
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 /5<= m:
PY;tu#W!%
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 Khb Ku0Z
AhD C5ue=
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 dU#-;/}o
CLTkyS)C
。 ;=7K*npT
V)5K/ U{
分页支持类: *a\6X(
~
9O- 2
java代码: QgI[#d{
y^"@$
p- a{6<h
package com.javaeye.common.util; kU+|QBA@
L
R\LC6kM
import java.util.List; drMMf[
gW,hI>
publicclass PaginationSupport { {#:31)P
n1JtY75#,/
publicfinalstaticint PAGESIZE = 30; j*5IRzK1%0
{l)$9!
privateint pageSize = PAGESIZE; EJ>&\Iq
*f3S tX
privateList items; +J|H~`
pB4Uc<e
privateint totalCount; )S
7+y6f&*
r\d(*q3B
privateint[] indexes = newint[0]; S3:AitGJ
zs~Tu
privateint startIndex = 0; ^$50[
F#>00b{Q
public PaginationSupport(List items, int \"1>NJn&k)
i84!x%|P
totalCount){ <:V~_j6P0
setPageSize(PAGESIZE); 4Wp5[(bg
setTotalCount(totalCount); 4 sax
setItems(items); *68 TTBq(
setStartIndex(0); :{2~s
} +i!5<nn
wS);KLe3
public PaginationSupport(List items, int CVWT>M<
+rJ6DZ
totalCount, int startIndex){ ~W [I
setPageSize(PAGESIZE); ~L"$(^/
setTotalCount(totalCount); $'%GB $.
setItems(items); QXZyiJX}
setStartIndex(startIndex); `XhH{*Q"X
} qx'0(q2Ii(
"bIb?e2h9G
public PaginationSupport(List items, int J\r\_P@;c
eD?&D_l~6
totalCount, int pageSize, int startIndex){ cf88Fd6l/
setPageSize(pageSize); Oj;*Gi9E
setTotalCount(totalCount); H;
NV?CD
setItems(items); FDQ=$w}'>
setStartIndex(startIndex); U\p`YZ
} Wk<fNHg
755,=U8'wi
publicList getItems(){ ?id)
2V0s
return items; VD$5 Djq
} RkE)2q[5
Ln4]uqMG.
publicvoid setItems(List items){ Z^:_,aJ?
this.items = items; 16zRe I(
} V9,<>
8i154#l+\
publicint getPageSize(){ dMH_:jb
return pageSize; >[AmIYg
} Tb$))O}
3)y1q>CQf
publicvoid setPageSize(int pageSize){ 1o`1W4Q
this.pageSize = pageSize; E ?Mgbd3
} I&{T 4.B:U
[zx|3wWAX-
publicint getTotalCount(){ l S)^8
return totalCount; '9zW#b
}
E.h
x
;|HT
publicvoid setTotalCount(int totalCount){ gS5REC4I/
if(totalCount > 0){ dS ojq6M
this.totalCount = totalCount; y#j7vO
int count = totalCount / o]q~sJVk6
Jh3
pageSize; m ol,iM*l
if(totalCount % pageSize > 0) Y"H`+UV
count++; |%C2 cx
indexes = newint[count]; ]SCHni_
for(int i = 0; i < count; i++){ 0f6o0@
indexes = pageSize * -G.N
:)~l3:O
i; <D/K[mz-
} V: D;?$Jl
}else{ pi?/]}:
this.totalCount = 0; e*2^
} e,JBz~CK*w
} mD'nF1o
Ly
#<xFO^TB
publicint[] getIndexes(){ c["1t1G
return indexes; ^I!Z)/
}
UjI./"]O
p(n0(}eVC'
publicvoid setIndexes(int[] indexes){ <[k3x8H'
this.indexes = indexes; C}h(WOcr`X
} ESCN/ocV
AkQ(V
publicint getStartIndex(){ }_nBegv
return startIndex; q-(~w!e
} 6\.g,>
e3ZRL91c
publicvoid setStartIndex(int startIndex){ AwZ@)0Wy
if(totalCount <= 0) 1Vy8eI`4
this.startIndex = 0; l ms^|?
elseif(startIndex >= totalCount) nX (bVT4i
this.startIndex = indexes -s0SQe{!_
`,V&@}&"n
[indexes.length - 1]; !
v![K
elseif(startIndex < 0) b$'%)\('g
this.startIndex = 0; ^UvL1+
else{ 0XA\Ag\`G
this.startIndex = indexes 8WytvwB}
2U[/"JL
[startIndex / pageSize]; >)WE3PT/O"
} ~T@E")uR
} Yb5U^OjyJ
e8`d<U
publicint getNextIndex(){ 4BMu0["6|s
int nextIndex = getStartIndex() + f/sz/KC]~
2!6hB sEr
pageSize; (f&V 7n
if(nextIndex >= totalCount) +PYV-@q
return getStartIndex(); /(~
HHN nh
else zu}uW,XH-
return nextIndex; Vx!ZF+
} < dE7+w
ck;:84
publicint getPreviousIndex(){ 1O Ft}>1
int previousIndex = getStartIndex() - lz`\Q6rZ
#X)DFAtb
pageSize; 9BakxmAc
if(previousIndex < 0) &3iI\s[
return0; W>' DQB
else L"YQji!
return previousIndex; <W!T+sMQj
} >7WT4l)7!b
vVB WhY]
} O.dZ3!!+
gX!K%qJBg
bmHj)^v5]
H2],auBY
抽象业务类 `m'RvU c
java代码: QHv]7&^rlj
qg j;E=7
S8v,'Cc
/** ^X#)'\T
* Created on 2005-7-12 Zdrniae
ah
*/ e[fld,s
package com.javaeye.common.business; i`i`Hu>
`&=%p|
import java.io.Serializable; D Z~036
import java.util.List; 9vi+[3s/=;
_&HFKpHQ
import org.hibernate.Criteria; HxR5&o
import org.hibernate.HibernateException; 6<z#*`U1
import org.hibernate.Session; Ne9VRM
P
import org.hibernate.criterion.DetachedCriteria; T7qp ({v?Q
import org.hibernate.criterion.Projections; &kf \[|y
import |3k r*#
VnN(lJ
org.springframework.orm.hibernate3.HibernateCallback; Y3|_&\v6
import G$)q% b;Lz
}Q[U4G
org.springframework.orm.hibernate3.support.HibernateDaoS 5#z7Hj&w
c
CjN8<
upport; =8vwaJ
O4nA?bA
import com.javaeye.common.util.PaginationSupport; fm#7}Y
D8k >f ]
public abstract class AbstractManager extends "vYjL&4h
N8T.Ye N
HibernateDaoSupport { s|WcJV
QfjoHeG7
privateboolean cacheQueries = false; ]@_|A, ]
hAgrs[OFj
privateString queryCacheRegion; Z{u]qI{l
`m V(:
publicvoid setCacheQueries(boolean bz:En'2>F
Eb,M+c?
cacheQueries){ r{~b4~kAf5
this.cacheQueries = cacheQueries; uGC%3!f!
} 2x gk$E$ 7
5> 81Vhc,
publicvoid setQueryCacheRegion(String Z%sTj6Th
P{RGW.Ci@
queryCacheRegion){ k(`> (w
this.queryCacheRegion = e0C_ NFS+
\]FPv7!
queryCacheRegion; af[dkuv
}
ndyIsR
./tZ*sP:
publicvoid save(finalObject entity){ JrxQ.,*i
getHibernateTemplate().save(entity); :MYLap&L&
} g6gwNC:aF
U4"&T,'lTL
publicvoid persist(finalObject entity){ a'q&[08
getHibernateTemplate().save(entity); {h|kx/4{m
} CT\rx>[J.6
RSeav
publicvoid update(finalObject entity){ n1x3q/~
getHibernateTemplate().update(entity); Vf(..8
} OHY|< &*
\"I418T K
publicvoid delete(finalObject entity){ 9qq6P!
getHibernateTemplate().delete(entity); 0W
1bZPM
} ,-n_(U
=q[+e(,3
publicObject load(finalClass entity, Qp@}v7Due
^c}kVQ\g3
finalSerializable id){ >YdLB@
return getHibernateTemplate().load [pt U}
[$]-W$j+
(entity, id); ocS}4.a@
} RdjoVCf
\+
Ese-la
publicObject get(finalClass entity, 7OPRf9+o
xyV7MW\?w
finalSerializable id){ xNJ*TA[+
return getHibernateTemplate().get Ea[SS@'R
.*?-j?U.
(entity, id); 1vh[sKv9%
} VYK%0S9yH[
{p$X*2ReB
publicList findAll(finalClass entity){ &[|Z2}
return getHibernateTemplate().find("from 16ip:/5
{\h:k\k
" + entity.getName()); ErQGVE;zk
}
u7&5t
7 /"Z/^
publicList findByNamedQuery(finalString *I9O63
nWd;XR6|
namedQuery){ z@<jZM
return getHibernateTemplate F$s:\N
OJFWmZ(X
().findByNamedQuery(namedQuery); $7O3+R/=
} ;t/KF"
$F/xv&t
publicList findByNamedQuery(finalString query, @E> rqI;`
}?CKE<#%
finalObject parameter){ YvUV9qps~
return getHibernateTemplate DRVvC~M-,
n482?Wp
().findByNamedQuery(query, parameter); Rd@?2)Xm
} &jrc]
7a4Z~r27/
publicList findByNamedQuery(finalString query, 8qUNh#
b.
:2x4
finalObject[] parameters){ >+%0|6VSb
return getHibernateTemplate GG4FS
Jg&f.
().findByNamedQuery(query, parameters); 5z.Y}
} Xag#ZT
Eh *u6K)Z
publicList find(finalString query){ R,l*@3Q
return getHibernateTemplate().find ?%T]V+40
E]pDp
/D
(query); ,W$&OD
} Ih5CtcE1'd
;Yt'$D*CP
publicList find(finalString query, finalObject
S O`b+B
GCrsf
parameter){ F_iZ|B
return getHibernateTemplate().find ,H/BW`rL]#
N.V5>2
(query, parameter); $%1oZ{&M
} ] `;Fc8$
OFZo"XtF
public PaginationSupport findPageByCriteria *b`1+~p_2
[1e/@eC5
(final DetachedCriteria detachedCriteria){ 5hDm[*83
return findPageByCriteria b:x~Jz#%2
8wCB}q C
(detachedCriteria, PaginationSupport.PAGESIZE, 0); Om8Sgy?
} 3[R[`l]v?
Ibv`/8xh
public PaginationSupport findPageByCriteria p3IhK>
qjN*oM,
(final DetachedCriteria detachedCriteria, finalint ;YrmT9Jx6
|-]'~@~
startIndex){ !3ji]q;uF
return findPageByCriteria fTGVG
]_m(q`_
(detachedCriteria, PaginationSupport.PAGESIZE, Dyj>dh-
+@+*sVb
startIndex); o}L\b,])
} Vo(bro4ZQi
rL/H{.@$`
public PaginationSupport findPageByCriteria `Js"*[z
b}ODc]3
(final DetachedCriteria detachedCriteria, finalint (I#3![q
R E9`T
pageSize, %d0BQ|
finalint startIndex){ Ee{Y1W
return(PaginationSupport) rDLgQ{Sea
@,q <CF@Y
getHibernateTemplate().execute(new HibernateCallback(){ >%c>R'~h
publicObject doInHibernate ' $"RQ=
Md*.q^:
(Session session)throws HibernateException { 1(WBvAPS
Criteria criteria = 5?>ES*
C|S~>4`
detachedCriteria.getExecutableCriteria(session); `>HrO}x^
int totalCount = N}'2GBqfU4
I$ ?.9&.&
((Integer) criteria.setProjection(Projections.rowCount m :2A[H+
p|w0
i[hc
()).uniqueResult()).intValue(); D1wONss
criteria.setProjection 0>ce~KU
-]Aqt/w"l
(null); -T>i5'2)
List items = +DYsBCVbag
Eu[/* t+l
criteria.setFirstResult(startIndex).setMaxResults T@ zV
8M7Bw[Q1
(pageSize).list(); Wfsd$kN6{
PaginationSupport ps = |u#7@&N1
d_Z?i#r0l
new PaginationSupport(items, totalCount, pageSize, =F46v{la
lB
startIndex); RVh{wg
return ps; Lwo9s)j<e
} AK&=/[U>
}, true); 6P02=
} PeJIa
%iE
CrYPcvd6
public List findAllByCriteria(final ?DKY;:dZF
^]?juL
DetachedCriteria detachedCriteria){ R|]n;*y
return(List) getHibernateTemplate z6 .^a-sU5
m-<m[ 49
().execute(new HibernateCallback(){ T1(*dVU?
publicObject doInHibernate CEBa,hp@
/1b7f'
(Session session)throws HibernateException { /sdZf|Zl
Criteria criteria = sE[
Yg8yAt
KESM5p"f
detachedCriteria.getExecutableCriteria(session); bv}e[yH
return criteria.list(); E^m;Ab=
} *eMMfxFl
}, true); C40o_1g
} c6VyF=2q
)D&xyC}
public int getCountByCriteria(final 8;x0U`}Ez(
T _fM\jdI
DetachedCriteria detachedCriteria){ +.QJZo_
Integer count = (Integer) _[/#t|I}
H'&[kgnQ@
getHibernateTemplate().execute(new HibernateCallback(){ /25Ay
publicObject doInHibernate s133N?
0x fF
(Session session)throws HibernateException { 7\yh<?`V8
Criteria criteria = k +Cwnp
&"^U=f@v
detachedCriteria.getExecutableCriteria(session); sEi9<$~R@0
return ZKai*q4?
sGc.;":
criteria.setProjection(Projections.rowCount I5ZM U
U+&Eps&NI
()).uniqueResult(); xL"O~jTS
} t$rla_rbY
}, true); "6Z(0 iu:{
return count.intValue(); \t)`Cp6,[b
} ]AX3ov6z9;
} \;JZt[
9T0g%&
`yO'-(@"gY
BO.Db``
q`UaJ_7
0e1-ZP CDj
用户在web层构造查询条件detachedCriteria,和可选的 G"h}6Za;DO
Nt/hF>"7
startIndex,调用业务bean的相应findByCriteria方法,返回一个 S q{@4F}d
<(i5hmuVd
PaginationSupport的实例ps。 w1eFm:'
HEw&'
ps.getItems()得到已分页好的结果集 ~ 7<M6F
ps.getIndexes()得到分页索引的数组 I+
Y{_yw"f
ps.getTotalCount()得到总结果数 BAtjYPX'w
ps.getStartIndex()当前分页索引 K|I<kA~!H
ps.getNextIndex()下一页索引 |qBcE
ps.getPreviousIndex()上一页索引 JX{_,2*$
<>)N$$Rx&
YLuf2ja}X
w"C,oo3
M{4XNE]m
l z-I[*bA
4issj$
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 8e1Z:axn0
}_5 R9w]"
,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 hw(\3h()
B<0Kl.V
一下代码重构了。 Sb(OG 6
n#@ Qd!uzM
我把原本我的做法也提供出来供大家讨论吧: ;%;||?'v
F~eY'~&H}
首先,为了实现分页查询,我封装了一个Page类: '.k'*=cq0
java代码: ^b.#4i(v
6[SIDOp*^
"lSh4X
/*Created on 2005-4-14*/ bc3`x1)\^
package org.flyware.util.page; Ej1<T,w_
dFyGI?
/** [bRE=Zr$Ry
* @author Joa Kxg@( Q
* J_?v=dW`
*/ u1=K#5^
publicclass Page { 7*"Jx}eM
5JHEBw5W%
/** imply if the page has previous page */ MdmN7>
privateboolean hasPrePage; !#=3>\np+X
P^tTg
/** imply if the page has next page */ (|NC xey
privateboolean hasNextPage; l qKj;'
#'0Yzh]qc
/** the number of every page */ 6q6xqr:W
privateint everyPage; 72 |O&`O
e~d=e3mBp
/** the total page number */ h9/fD5
privateint totalPage; "%p7ft
%D5F7wB
/** the number of current page */ e[s}tjx
privateint currentPage; P-3f51 Q
=1@LMIi5x
/** the begin index of the records by the current EC 1|$Co
Pc2!OQC'""
query */ UtP|<]{
privateint beginIndex; -Jw4z#/-
,[)l>!0\H
~?FhQd\Q
/** The default constructor */ =4l @A>
public Page(){ )BvMFwQG
Hf\sF(, (
} v?Utz~lQ
gu+zfvkcY
/** construct the page by everyPage
6su~SPh
* @param everyPage |<5F08]v
* */ 6uT*Fg-G
public Page(int everyPage){ `j(._`8%a
this.everyPage = everyPage; /R&h#;l
} O1S7t)ag
zRou~Kxi
/** The whole constructor */ o+7)cI
public Page(boolean hasPrePage, boolean hasNextPage, w jD<"p;P
QXN_ ?E,g/
_DH^ K9,9
int everyPage, int totalPage, 40pz <-B
int currentPage, int beginIndex){ D>-r `
this.hasPrePage = hasPrePage;
-0x Q'1I
this.hasNextPage = hasNextPage; x7U=1y(
this.everyPage = everyPage; XbB(<\0+
this.totalPage = totalPage; iER@_?
this.currentPage = currentPage; tH44\~
this.beginIndex = beginIndex; >6HGh#0(p
} ;RRw-|/Wm
p6R+t]oH
/** mO;QT
* @return I<ohh`.
* Returns the beginIndex. %^L{K[}
*/ w.a9}GC
publicint getBeginIndex(){ bWAa:
r
return beginIndex; .Zv~a&GE
} }`g-eF>p
4P k%+l
/** XFvl
* @param beginIndex t`+A;%=K]
* The beginIndex to set. 6UuN-7z!"
*/ ]LUcOR
publicvoid setBeginIndex(int beginIndex){ tVEe) QX
this.beginIndex = beginIndex; {0Y6jk>I
} $_E.D>5^%7
k#Sr; "
/** &hI!mo
* @return IBo
* Returns the currentPage. <D ~hhGb
*/ T\uIXL?3
publicint getCurrentPage(){ 7I
XWv-
return currentPage; _huJ*W7lR
} wW1VOj=6V"
{zvaZY|K"
/** m^}|LB:5
* @param currentPage Cl<!S`
* The currentPage to set. 3HpqMz
*/ M7cD!s@'I
publicvoid setCurrentPage(int currentPage){ 8qg%>ZU4d
this.currentPage = currentPage; C$TU
TS
} ou <3}g
XGR2L
DR
/** s@ @Km1w
* @return b>OB}Is
* Returns the everyPage. w\o6G7
*/ W~;Jsd=f
publicint getEveryPage(){ u9OY
Jo
return everyPage; AX8~w(sv
} <VKJ+
-je} PwT
/** L
AasmQ
* @param everyPage @6>Q&GYqt
* The everyPage to set. gGL}FNH
*/ Ne1Oz}
publicvoid setEveryPage(int everyPage){ 0BlEt1e2T
this.everyPage = everyPage; f?Zjd&|Ch
} .EL3}6"A
.iRKuBM/
/** +ig%_QED[\
* @return Lc{arhN
* Returns the hasNextPage. r6Yd"~ n
*/ ly17FLJ].
publicboolean getHasNextPage(){ k8+J7(_c
return hasNextPage; hhy+bA}
} id1cZig
|VWT4*K
/** m6ge
%
* @param hasNextPage C!*!n^qA
* The hasNextPage to set. G|rE\h 2w
*/ >0{}tRm-P&
publicvoid setHasNextPage(boolean hasNextPage){ F tIcA"^N
this.hasNextPage = hasNextPage; "kyCY9)%
} iAu/ t
O@T,!_Zf
/** q>2bkc GY#
* @return Z)`)9]*
* Returns the hasPrePage. Kq3c Kp4
*/ \dtiv& x
publicboolean getHasPrePage(){ -<s Gu9
return hasPrePage; ^el+ej/=
} \N*([{X
H~+A6g]T
/** ~i5YqH0
* @param hasPrePage 6e+'Y"v
* The hasPrePage to set. 3Tl<ST\
*/ \9VF)Y.ke
publicvoid setHasPrePage(boolean hasPrePage){ Q6qW?*Y
this.hasPrePage = hasPrePage; (4+P7Z,Nc
} E{|B&6$[}
H`CID*Ji
/** lI=<lmM0|/
* @return Returns the totalPage. (SBhU:^h
* 90<g=B
*/ {-\U)&6#v
publicint getTotalPage(){ MNd\)nX
return totalPage; '[{<aEo
} N; g@lyo
F}nwTras
/** H#SQ>vyAV
* @param totalPage @(,1}3s
* The totalPage to set. !{lH*
*/ XDemdMy$
publicvoid setTotalPage(int totalPage){ l*1|B3#m!
this.totalPage = totalPage; e3p|g]
} |"gL{De
y@3p5o9lv-
} =8\.fp
?R)]D:`
Z>9@)wo
,dIev<
xqG<R5k>>
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 bE _8NA"2
qiNVaV\wr|
个PageUtil,负责对Page对象进行构造: g_Z
tDxz
java代码: L.HeBeO
puC91
;,&cWz
/*Created on 2005-4-14*/ ==dKC;
package org.flyware.util.page; MET9rT
Y MX9Z||
import org.apache.commons.logging.Log; e}UQN:1
import org.apache.commons.logging.LogFactory; RuPnWx!
.Kb3VNgwvm
/** HuevDy4
* @author Joa 3Z
b]@n
* dvB=Zk]m
*/ /|0-O''
publicclass PageUtil { \R#SoOd
)'djqpM.
privatestaticfinal Log logger = LogFactory.getLog %k!CjW3
a`!Jq'
(PageUtil.class); "n%s>@$
Oidf\%!mvR
/** +hyOc|5
* Use the origin page to create a new page ^m qEKy<
* @param page JusU5 e|
* @param totalRecords EwP2,$;
* @return 'UX.Q7W
*/ OIcXelS:@k
publicstatic Page createPage(Page page, int `z|0O
#a8kA"X
totalRecords){ .IeO+RDQ
return createPage(page.getEveryPage(), bKQho31a'
2e`}O
page.getCurrentPage(), totalRecords);
jxog8E
} |toP86
yb`PMj j15
/** FZHA19Kb
* the basic page utils not including exception !jj`Ht)
N,(!
handler :X0L6y)u
* @param everyPage p`"k=tZ{
* @param currentPage aB,-E>+
* @param totalRecords 5'zXCHt
* @return page }Le]qR9Y]
*/ U$OZkHA[
publicstatic Page createPage(int everyPage, int +,76|oMsQ%
`b?uQ\#-M
currentPage, int totalRecords){ qe0 D[L
everyPage = getEveryPage(everyPage); `/8@Fj
currentPage = getCurrentPage(currentPage); u^Q`xd1
int beginIndex = getBeginIndex(everyPage, '75T2Ud
SMN.AJ
J
currentPage); KgL!~J
int totalPage = getTotalPage(everyPage, q/i2o[f'n
b($hp%+yJ
totalRecords); -#v~;Ci
boolean hasNextPage = hasNextPage(currentPage, Vb0T)C
y9:4n1fg
totalPage); (S[z
boolean hasPrePage = hasPrePage(currentPage); aO' #!k*R
)^j_O^T5
returnnew Page(hasPrePage, hasNextPage, um2a#6uo
everyPage, totalPage, p+d-7'?I
currentPage, x?h/e;
9K+>;`
beginIndex); 2\xw2VQ@P
} ~7]V^tG
*8}b&4O~
privatestaticint getEveryPage(int everyPage){ t-\+t<;
return everyPage == 0 ? 10 : everyPage; 4V+bE$Wu
} Itl8#LpLM
&.)=>2
privatestaticint getCurrentPage(int currentPage){ nS+Rbhs
return currentPage == 0 ? 1 : currentPage; <:S qMf
} tB_le>rhl
RZa/la*
privatestaticint getBeginIndex(int everyPage, int [|(|"dh@^H
mQ[$U
currentPage){ xTHD_?d
return(currentPage - 1) * everyPage; /3b*dsYsl
} SDnl^a
2b"*~O;
privatestaticint getTotalPage(int everyPage, int qE)FQeN
E7 Cobpm
totalRecords){ 8U{D)KgS
int totalPage = 0; ? x)^f+:9|
! ]4u"e
if(totalRecords % everyPage == 0) zoq;3a5cqB
totalPage = totalRecords / everyPage; ,Z`}!%?
else z*.AuEK?
totalPage = totalRecords / everyPage + 1 ; ]Ry9{:
NRRJlY
S
return totalPage; _7c3=f83
} s(,S~
=ZgueUz,
privatestaticboolean hasPrePage(int currentPage){ PxkV[nbS
return currentPage == 1 ? false : true; JF=R$! 5
} [|]J8o@u^
{[y6qQm
privatestaticboolean hasNextPage(int currentPage, 5!c/J:z
v">?`8V
int totalPage){ xR+vu>f
return currentPage == totalPage || totalPage == N`8K1{>BH
9CDei~
0 ? false : true; I Xc `Ec
} 0z8(9DlTc
MB]E[&Q!
8lyIL^
} [txOh!sxD
#CS>_qe.{
77RZ<u9/`
xT*'p&ap
vq$6e*A
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。 `PWKA;W$0
u0C:q`;z
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 EC+t-:a]
CK_dEh2c
做法如下: j7I=2xnTWu
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 R7::f\I
)_#V>cvNG
的信息,和一个结果集List: 4_#$k{
java代码: 4I4m4^
Ob0sB@
M.}9)ho
/*Created on 2005-6-13*/ =G-OIu+H!U
package com.adt.bo; .:S/x{~
fc#9e9R
import java.util.List; {lI}a8DP
x9lA';})
import org.flyware.util.page.Page; +){^HC\7h
JE.$]){
/** G ek?+|m
* @author Joa PGTEIptX7
*/ 7oZ:/6_>
publicclass Result { \u[x<-\/6
&V38)83a
private Page page; H<Snp)
SmXoNiM"y
private List content; F`D$bE;|
h:Pfiw]
/** *C*J1JYp+
* The default constructor DB}Uzw|
*/ 6-U_TV
public Result(){ 9q;O`&
super(); !BQt+4G7
} $QJ3~mG2
*i"9D:
/** m6Dm1'+
* The constructor using fields Tmg C {_
* r)<A YX]J
* @param page OUv )`K
* @param content P\"kr?jZP
*/ ] \yIHdcDi
public Result(Page page, List content){ is;g`m
this.page = page; }?[];FB
this.content = content; gM96RY
} NaR} 0
+d,
~h_7!
/** ieyK$q
* @return Returns the content. ^t0!Dbx3SE
*/ .6y+van
publicList getContent(){ E\iK_'#
return content; ?P9aXwc
} f)sy-o!
.; MS78BR
/** yfl?\X{
* @return Returns the page. #Xg;E3BM
*/ ^ :VH?I=
public Page getPage(){ CHnclT
return page; K V5
'-Sv1
} &h:4TaD
Bii'^^I;?
/** !vz'zy)7
* @param content hFV,FBsAO
* The content to set. r S@/@jKZE
*/ [6VB&
public void setContent(List content){ Z`TfS+O6
this.content = content; 1/$PxQ
} MlV(XG>'
.n\JY;"
/** xe@e#9N$
* @param page @eYpARF
* The page to set. lZk
z\
*/ CE"/&I
publicvoid setPage(Page page){ .s{"NqRA
this.page = page; x`6MAZ
} s&73g0$$
} !2t7s96
CCTU-Xz/
+\=g&G,
1l-5H7^w2?
-Y_,
.'ex
2. 编写业务逻辑接口,并实现它(UserManager, >a8iY|QY
[8QK @5[
UserManagerImpl) # ~<]z
java代码: :qm\FsO
\[9VeqMU
)^:H{1'
/*Created on 2005-7-15*/ &d6@SQ
package com.adt.service; =-sTV\
f-~Y
import net.sf.hibernate.HibernateException; ~[CFs'`(2
;L-=z]IR,
import org.flyware.util.page.Page; 7|}4UXr7y
P@N+jS`Vf
import com.adt.bo.Result; e!VtDJDS
<+QdBp'd;
/** GDLw_usV
* @author Joa xvl$,\iqE
*/ P<pv@l9)
publicinterface UserManager { ~b_DFj
UytMnJ88
public Result listUser(Page page)throws :FAPH8]
,z&S;f.f
HibernateException; <rzP
Lc!2'Do;
} }nrjA0WN
+&.zwniSS
PVb[E 03
>)M{^
Z],j|rWy6
java代码: ;21D ^e
xsa`R^5/c
FWbp;v{
/*Created on 2005-7-15*/ Z6I|Y5#H
package com.adt.service.impl; $zP5Hzx
)Do 0
import java.util.List; Pb&tWv\ql
bq/Aopfr
import net.sf.hibernate.HibernateException; kj6:P$tH
"2mPWRItO
import org.flyware.util.page.Page; =E9\fRGU
import org.flyware.util.page.PageUtil; YTTyMn
ggDT5hb
import com.adt.bo.Result; bRvGetX
import com.adt.dao.UserDAO; @&\Y:aRO%i
import com.adt.exception.ObjectNotFoundException; K<P d.:
import com.adt.service.UserManager; o/N!l]r
h'*v$lt
/** gPd
K%"B@
* @author Joa wI@87&
*/ 5Zq
hyv=
publicclass UserManagerImpl implements UserManager { ]BO:*&O
fZiAl7b!
private UserDAO userDAO; 9q"kM
4l 67B]o
/** Ty g>Xv
* @param userDAO The userDAO to set. <YvXyIs
*/ E+]}KX:
publicvoid setUserDAO(UserDAO userDAO){ zud_BOq{f
this.userDAO = userDAO; 8w5}9}xF
} X%yG{\6:
:[CV_ME.;
/* (non-Javadoc) }$_@yt<{W@
* @see com.adt.service.UserManager#listUser 8?Zhh.
a7g;8t-&
(org.flyware.util.page.Page) $INB_/RE
*/ 9nR\7!_
public Result listUser(Page page)throws <- \|>r Q
;wwc;wQ'
HibernateException, ObjectNotFoundException { c!IZLaVAr9
int totalRecords = userDAO.getUserCount(); A-!e$yz>
if(totalRecords == 0) {s8c@-'
throw new ObjectNotFoundException >pF* unC;
zj7ta[<tr
("userNotExist"); ~nA k-toJ
page = PageUtil.createPage(page, totalRecords); x3y+=aj
List users = userDAO.getUserByPage(page); Tz1^"tx9
returnnew Result(page, users); i(4<MB1a
} }Ulxt:}
r `PJb5^\|
} wtS*-;W
@:>]jp}uq
0:V/z3?
\V-N~_-H
l5D)UO
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 5f*_K6 ,v
D40 vCax^J
询,接下来编写UserDAO的代码: 4p"' ox#
3. UserDAO 和 UserDAOImpl: Bve|+c6W
java代码: iVFOOsJ@
Cx TAd[az
ep6+YK:cn
/*Created on 2005-7-15*/ flCT]ZR
package com.adt.dao; _/1/{
$yx\2
import java.util.List; 6ld4'oM
YPGM||
import org.flyware.util.page.Page; ji ?Hw
%n|
import net.sf.hibernate.HibernateException; :9hGL
(4FVemgy
/** PK+sGV
* @author Joa <{#_;7h"
*/ QP\9#D~
publicinterface UserDAO extends BaseDAO { gWr7^u&q@|
/"X_{3dq?
publicList getUserByName(String name)throws x0# Bc7y
0=>$J
WF
HibernateException; `vBBJ@f4)
Wj.t4XG!
publicint getUserCount()throws HibernateException; QXb2jWz
L"b&O<No
publicList getUserByPage(Page page)throws bB$f=W!m%
SA<\n+>q^
HibernateException; ^+yz}YFM
JVoC2Z<
} ^5X?WA,Z99
1ui)Hv=h*
x17:~[c']
HTL6;87w+]
':n`0+Eh
java代码: e0(/(E:
ov+{<0Q
Wep^He\:
/*Created on 2005-7-15*/ |u>V>
PN
package com.adt.dao.impl; $M}"u[Qq
-_ 9k+AV
import java.util.List; ]W3_]N 3
*H/>96
import org.flyware.util.page.Page; s*PKr6X+
M86"J:\u]
import net.sf.hibernate.HibernateException; p)SW(pS
import net.sf.hibernate.Query; mOJdx-q?r
BeUyt
import com.adt.dao.UserDAO; ~9]vd|
}#m9Q[
/** 5|rBb[
* @author Joa n.@HT"
*/ &@6xu{o
public class UserDAOImpl extends BaseDAOHibernateImpl jG1(Oe;#
hNXZL>6
implements UserDAO { KtaoOe
{dF@Vg_n
/* (non-Javadoc) L -Q8iFW'
* @see com.adt.dao.UserDAO#getUserByName Sqa9+'
[
5qM$ahN3wH
(java.lang.String) $+80V{J#
*/ 7{<v$g$
publicList getUserByName(String name)throws 0)|Z7c&
,8384'
HibernateException { RL` jaS?V
String querySentence = "FROM user in class Un]wP`
! t!4CY
com.adt.po.User WHERE user.name=:name"; 2/+~h(Cc
Query query = getSession().createQuery {<{VJGY7T
p<r^{y
(querySentence); ^t3>Z|DiB^
query.setParameter("name", name); '@Uu/~;h
return query.list(); w>B}w
} 2q[pOT'k
wS=vm}}u
/* (non-Javadoc) Gor9&aJ1
* @see com.adt.dao.UserDAO#getUserCount() $2W#'_K+
*/ ;87PP7~
publicint getUserCount()throws HibernateException { 6'r;6T *
int count = 0; {]6-,/3UR
String querySentence = "SELECT count(*) FROM -Mr_Ao`E
eQi^d/yi
user in class com.adt.po.User"; !\#Wq{p>W*
Query query = getSession().createQuery DCp8rvUI
$]LS!@ Rm
(querySentence); V<
F&\
count = ((Integer)query.iterate().next Zv}F?4T~:
brTNwRze
()).intValue(); H|aFs.S EQ
return count; b"$?(Y
} -. *E<%
CWeQv9h]X
/* (non-Javadoc) .'=S1|_(
* @see com.adt.dao.UserDAO#getUserByPage \HB
fM&
F%V|Aa
(org.flyware.util.page.Page) Il&FC
*/ N~]qQoj,
publicList getUserByPage(Page page)throws +Kgl/Wg%
62ru%<x=
HibernateException { lZAGoR;0Ra
String querySentence = "FROM user in class v(;yy{>8"
]?]M5rP
com.adt.po.User"; ,LwinjHA*
Query query = getSession().createQuery ,<Cl^ ^a,
-,/7u3
(querySentence); >8/Otg+h
query.setFirstResult(page.getBeginIndex()) M.Q
HE2
.setMaxResults(page.getEveryPage()); h
8$.mQr
return query.list(); 8`L]<Dm
} B!mHO*g
3PkZXeH/
} fYuSfB+<
$Z;8@O3
;>2-
+7%?p"gEY\
o<A-ETx<
至此,一个完整的分页程序完成。前台的只需要调用 _
uOi:Ti
(87wWhH
userManager.listUser(page)即可得到一个Page对象和结果集对象 "iEnsP@'Wg
Aq(cgTNW
的综合体,而传入的参数page对象则可以由前台传入,如果用 I'IFBVhaYn
GDCp@%xW
webwork,甚至可以直接在配置文件中指定。 ;#zteqn
%( OP
[
下面给出一个webwork调用示例: n=j)M
java代码: K^o$uUBe
X[Iy6qt
zx<t{e7
/*Created on 2005-6-17*/ gH7 +#/
package com.adt.action.user; \j!/l
f)
@MibKj>o
import java.util.List; _v#puFy
egs P\ '
import org.apache.commons.logging.Log; \
C:Gx4K
import org.apache.commons.logging.LogFactory; I+Fy)=DO9
import org.flyware.util.page.Page; k% \;$u=%
:sw5@JdJ
import com.adt.bo.Result; :g$"Xc8Zn
import com.adt.service.UserService; wxBHlgK4z
import com.opensymphony.xwork.Action; s:'>G;p
3]1 !g6
/** '?$@hqQn
* @author Joa |?jgjn&RQ
*/ ~H#c-B
publicclass ListUser implementsAction{
gwIR3u
N^B7<~ bD
privatestaticfinal Log logger = LogFactory.getLog ;S^"Y:7)
$G <r2lPy
(ListUser.class); [<i3l'V/[
5 `TMqrk
private UserService userService; N'{Yhx u
~I N g9|
private Page page; :kcqf,7
g:RS7od=,
privateList users; <`-sS]=d}
o.Ww.F
/* QN;5+p[N
* (non-Javadoc) #O_%!7M{4
* M5RN Z%
* @see com.opensymphony.xwork.Action#execute() M
p<r`PM2
*/ r1q'+i
publicString execute()throwsException{ =~D[M)UO|
Result result = userService.listUser(page); A ___|
#R
page = result.getPage(); hTO5*5]0zP
users = result.getContent(); m^BXLG:b
return SUCCESS; 5vD\?,f E
} -`ljKp
EyR/
/** vg?(0Gasm*
* @return Returns the page. G "+[@|
*/ f\?Rhyz
public Page getPage(){ 1d!s8um;
return page; FLJ&ZU=s
} ~c&sr5E
[ {"x{;
/** y)LX?d
* @return Returns the users. _GY2|x2c
*/ cb'Ya_
publicList getUsers(){ s8:epcL`A
return users; Msvs98LvW
} ai/]E6r
~:,}?9
/** _Cf:\Xs
m
* @param page U`N?<zm<oO
* The page to set. e`a4Gr
*/ CUdpT$ $x3
publicvoid setPage(Page page){ kqZRg>1A
this.page = page; f3,LX]zKA
} D;2V|CkU
3qGz(6w6E
/** 3,Z;J5VL4!
* @param users )y:M8((%
* The users to set. C3.]dsv:
*/ :xmj42w>^
publicvoid setUsers(List users){ oGZuYpa9
this.users = users; <%^WZ:c
} <% mD#S
6;~V@t
/** B.?F^m@zS
* @param userService b!MN QGs
* The userService to set. <Ed; tq
*/ 9pi{)PDJ
publicvoid setUserService(UserService userService){ {B#w9>'b
this.userService = userService; =MJRQV67
} k5%)
} s hq
+
^^k9Acd~p
LdOqV'&r
\N0wf-qa=
|0p@'X1
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, e|SNb*_
o=7e8l
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 .|DrXJ\c
eo;MFd%;
么只需要: AD!w:jT9
java代码: f"\klfrRI_
xIc||o$
DHjfd+E=s
<?xml version="1.0"?> ORqqzy +
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork (!m6>m2
< j
1.0//EN" "http://www.opensymphony.com/xwork/xwork- g<DXJ7o
v:!TqfI
1.0.dtd"> 3GL?&(eU;
Y$,++wx
<xwork> ~c+=$SL-=
7r3CO<fb
<package name="user" extends="webwork- *\+oe+ 3
V_^pPBa
interceptors"> [T'[7Z
n}9<7e~/
<!-- The default interceptor stack name 9I5AYa?
^v5]Aq~X
--> ON{a'H
<default-interceptor-ref $B9?>a|{A
usK P9[T$
name="myDefaultWebStack"/> DIP%*b#l$\
,QA=)~;D
<action name="listUser" KDf#e3
v0!(&g3Sd
class="com.adt.action.user.ListUser"> |
h "$
<param *Vb#@O!
eMEKR5*-O
name="page.everyPage">10</param> 1f"}]MbLR
<result jL)Y'
5Uhxl^c
name="success">/user/user_list.jsp</result> GaJE(N
</action> VqD_FS;E
f]sR4mhO
</package> iz [IK%K
U![$7k>,pr
</xwork> Dbx zqd
WcXNc`x
]m&Ss
?|`n&HrP
PxWH)4
gDw(_KC
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 &_@M
6[-
U0|bKU
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 #PC*l\
)
EKw)\T1
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 aWvC-vZk
zLxuxf~4@
[P6A$HC<
BTOl`U
>pol'=
我写的一个用于分页的类,用了泛型了,hoho cN2Pl%7
n Jz* }=
java代码: uHZjpMoM
~U ]%>Zf
(Xzq(QV
package com.intokr.util; Gw6Odj
SEu:31k{o
import java.util.List; SN}3
Xrc{wDn
/** wT3D9N.
* 用于分页的类<br> S,'ekWVD
* 可以用于传递查询的结果也可以用于传送查询的参数<br> c8_,S[W
* :YLYCVi|
* @version 0.01 GsD?Z%t~%
* @author cheng @QYCoEU8J
*/ P3a]*> .,
public class Paginator<E> { z)eNM}cF
privateint count = 0; // 总记录数 VY|UB7,C
privateint p = 1; // 页编号 n~jW
privateint num = 20; // 每页的记录数
D4@(_6^
privateList<E> results = null; // 结果 uVX,[%*P
_S*QIbO
/** uTl"4;&j
* 结果总数 ,Cy&tRjR B
*/ ignOF
publicint getCount(){ ^4[QX
-_2
return count; $j!:ET'V
} 2]x,joB
<h~uGBS"
publicvoid setCount(int count){ Q/HEWk
this.count = count; !af;5F
} E3x<o<v
:a=]<_*x
/** Ir-
1@_1Q
* 本结果所在的页码,从1开始 sP9{tk2K
* fkk9&QB%(
* @return Returns the pageNo. iP9Dr<P
*/ Y{t}sO%A
publicint getP(){ Xz/aytp~A
return p; R$it`0D4o
} t`Xx\
6@d/k.3p
/** Y'}c$*OkI
* if(p<=0) p=1 :4\_upRE
* ]N1,"W}
* @param p hbx+*KM
*/ B>"-8#B[4
publicvoid setP(int p){ :^x,>(a
if(p <= 0) K)\D,5X^
p = 1; f?@M"p@T
this.p = p; ?f5||^7
} .Rb4zLYL*w
'&]6(+I>
/** d%!yFix;<
* 每页记录数量 ,yfJjV*I
*/ S!iDPl~
publicint getNum(){
ILHn~d IC
return num; +\vN#xDz
} [H2su|rBI`
#m'+1 s L
/** \ov]Rn
* if(num<1) num=1 SS;'g4h\6
*/ 1bCS4fs^>
publicvoid setNum(int num){ eI-FJ/CJ
if(num < 1) Xi=4S[.4
num = 1; k6;pi=sYNW
this.num = num; $7Tj<;TV
}
@3I?T
Q1
9q^7%b,
/** 3 "|A5>Vo
* 获得总页数 +:J:S"G
*/ 0.wN&:I8t
publicint getPageNum(){ L_=3`xE
_
return(count - 1) / num + 1; ^<aj~0v
} a
uve&y"R
BK.RYSN
/** "(a}}q 9-
* 获得本页的开始编号,为 (p-1)*num+1 )9!J
$q
*/ You~
6d6Om
publicint getStart(){ L[:M[,?=`
return(p - 1) * num + 1; L$ju~0jl)%
} DVBsRV)/
s6oIj$
/** 368H6 Jj
* @return Returns the results.
Bf,}mCq
*/ gdqED}v
publicList<E> getResults(){ k{\a_e`
return results; $bk_%R}s
} A&Q!W)=
Ez>!%Hpn\
public void setResults(List<E> results){ &{x`K4N
this.results = results; u3PM 7z!~
} ZgzYXh2
,^T0!k$
public String toString(){ ^P*+0?aFr
StringBuilder buff = new StringBuilder <yKyM#4X
m&Y?]nbq
(); w`Rt "d_B
buff.append("{"); tQ2S*]"f
buff.append("count:").append(count); \@7 4I7
buff.append(",p:").append(p); &KeD{M%
buff.append(",nump:").append(num); ZD8E+]+
buff.append(",results:").append g^k=z:n3,
B=i%Z_r]w
(results); ^Ov+n1,)
buff.append("}"); +AOpB L'
return buff.toString(); <)gTi759h)
}
&y7~
e/IVZmUn^
} 2-wgbC5
Uetna!ABB
Sr6?^>A@t