Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 vnk"0d.
9V zk:zOT
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 }n6BI}n
dmP*2
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 zN].W\("\
P{(m: `N
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 qw%4j9}
NxNR;wz>l
。 @MtF^y
^>GL<1
1
分页支持类: <^R\N#
;Bcf~[ErM
java代码: $7TYix8=
uP|AP
GK95=?f~8;
package com.javaeye.common.util; &BG^:4b
~#I1!y~`
import java.util.List; O~{Zs\u9
4E4o=Z|K
publicclass PaginationSupport { >m}.}g8
7Yk6C5C
publicfinalstaticint PAGESIZE = 30;
[+{ ot
/Ia=/Jj7N
privateint pageSize = PAGESIZE; ~l CG37
v6s8 p
privateList items; +/\.%S/
=!U{vT
privateint totalCount; V QPq+78
/nb(F h|{T
privateint[] indexes = newint[0]; 4mshB
+;Cq>1x,
privateint startIndex = 0; PwF}yxkI
Ng'f u|
public PaginationSupport(List items, int b44H2A.
>P\Tnb"Q\
totalCount){ FX}<F0([?
setPageSize(PAGESIZE); }xLwv=Ia
setTotalCount(totalCount);
*}ay
setItems(items); AKa{C
f
setStartIndex(0); ]a_;*Xq8d
} xd(AUl4qY
k]R O=/ ?M
public PaginationSupport(List items, int L4Nk+R;
JB+pd_>5
totalCount, int startIndex){ bn<&Xe
setPageSize(PAGESIZE); RF6(n8["MW
setTotalCount(totalCount); J'@I!Jc
setItems(items); <+_OgF1G
setStartIndex(startIndex); B'yN &3
} U%gP2]t%cs
y::KjB 0
public PaginationSupport(List items, int %=#&\ldPS
hJFQ/(
totalCount, int pageSize, int startIndex){ @sfV hWG
setPageSize(pageSize); \VtCkb
setTotalCount(totalCount); bI]1!bi]i
setItems(items); Q=e?G300#L
setStartIndex(startIndex); 71K6] ~<
} ]PUyX8'~
T]CvfvO5
publicList getItems(){ @|-ydm0
return items; ^o,@9GTs
} /DbwqBx
@Z3b^G[
publicvoid setItems(List items){ 6K`frt
this.items = items; 7acAU{Rr
} ,wX/cUyZ
mXhr: e
publicint getPageSize(){ E8%O+x}
return pageSize; _$cQAH0 E
} ,j&o H$mW
#7Qn\C2
publicvoid setPageSize(int pageSize){ ]t(g7lc}U
this.pageSize = pageSize; 4RTEXoXs
} 4`Fbl]Q
~0/=5 dC
publicint getTotalCount(){ _;'}P2&Q
return totalCount; `awk@
} Lg Bs<2
dR$P-V\y`%
publicvoid setTotalCount(int totalCount){ o"[qPZd>
if(totalCount > 0){ OY[N%wr!
this.totalCount = totalCount; /3Se*"u
int count = totalCount / xg3G
$#t&W&
pageSize; /eIwv31
if(totalCount % pageSize > 0) l l&iMj]
count++;
>St
indexes = newint[count]; c:=Z<0S;
for(int i = 0; i < count; i++){ _e`b^_
indexes = pageSize * bE0S)b)
:$P <e~z'
i; r43dnwX
} |nm,5gPNC
}else{ Yq1 ~"he8
this.totalCount = 0; jRgv
8n
} M.|hnGXN
} o^7NZ]m
VLQfuh;
publicint[] getIndexes(){ 'BUdySng
return indexes; ^]aDLjD
} (q
+Q.Q
Qz<v. _
publicvoid setIndexes(int[] indexes){ oO= 6Kd+T
this.indexes = indexes; f3yZx!K_Br
} {{2ZWK 6|
A`OU}'v?L
publicint getStartIndex(){ Dhef|E<
return startIndex; #}k^g:l1
} _Z8zD[l
N|7._AR2
publicvoid setStartIndex(int startIndex){ }]g>PY
if(totalCount <= 0) t5 5k#`Z
this.startIndex = 0; E"u>&uPH
elseif(startIndex >= totalCount) 0D.YO<PU
this.startIndex = indexes ->93.sge
snj+-'4T
[indexes.length - 1]; \f
elseif(startIndex < 0) bZtjg
this.startIndex = 0; Mb$&~!
else{ "]JS,g {m
this.startIndex = indexes )0UQy#r
I}?fy\1A&
[startIndex / pageSize]; p&ZD1qa
} :T'"%_d5
} ,Hj=]e2?
lW>bXC
publicint getNextIndex(){ a
nIdCOh
int nextIndex = getStartIndex() + |@d7o]eM|
L#NPt4Sz+
pageSize; YpNTq_S1,
if(nextIndex >= totalCount) 4;&(
return getStartIndex(); 8c~b7F
\
else ~G"6^C:x
return nextIndex; \&W~nYXq"
} RJd55+h
[kC-g @
publicint getPreviousIndex(){ g{a_{P
int previousIndex = getStartIndex() - (?J&Ar0
FQ O6w'
pageSize; 53l9s<bOQ
if(previousIndex < 0) jUjQ{eT
return0; B-eYWt8s
else 5ue{&z
@T
return previousIndex; 81aY*\
} X0
%k`3
iL5+Uf)E3
} seq
S*^7
nk6xavQji
r[~Km5
NCl={O9<j
抽象业务类 .O lq_wuH
java代码: ^iTjr$hQ;
>gVR5o
KeXQ'.x5O
/** 0!!pNK%(
* Created on 2005-7-12 JO1c9NyKr
*/ .\1XR
package com.javaeye.common.business; NFc<%#H
neOR/]
import java.io.Serializable; [g<6i.<I
import java.util.List; 0~^opNR
[nflQW6
import org.hibernate.Criteria; =zI
eZ7
import org.hibernate.HibernateException; #x"pG
import org.hibernate.Session; c: #1Aym
import org.hibernate.criterion.DetachedCriteria; 9~u1fk{
import org.hibernate.criterion.Projections; tJg
import yQCfn1a)
=DF7l<&km
org.springframework.orm.hibernate3.HibernateCallback; [n66ZY#U]
import +KD~/}C%-
u^V`Ucd"R
org.springframework.orm.hibernate3.support.HibernateDaoS vp-)$f&
Pk*EnA)
upport; sFB; /*C
zf2]|]*xz
import com.javaeye.common.util.PaginationSupport; $7PFos%@
f3*u_LO
public abstract class AbstractManager extends *S{%+1F
i}M&1E
HibernateDaoSupport { [Ma&=2h
i' N
privateboolean cacheQueries = false; z!t&zkAK
n; !t?jnf.
privateString queryCacheRegion; #nn2odR
|4wVWJ7
publicvoid setCacheQueries(boolean }4ta#T Ea
| F:?
cacheQueries){ )S>~ h;
this.cacheQueries = cacheQueries; B4&x?-0ZC
} _RjM .
[}d
3u!
publicvoid setQueryCacheRegion(String I_Oa<J\+
3LX<&."z
queryCacheRegion){ A^o
this.queryCacheRegion = L42C<
2rD`]neA
queryCacheRegion; o),i2
} [O(78n$$
U2+CL)al^
publicvoid save(finalObject entity){ QJ pUk%Wj
getHibernateTemplate().save(entity); .$S`J2Y
} DhkzVp_
d<: VoQM6M
publicvoid persist(finalObject entity){ {v~&.|
getHibernateTemplate().save(entity);
:E'38~
} \+S~N:@><k
}%_x T
publicvoid update(finalObject entity){ nG{jx_{`
getHibernateTemplate().update(entity); J&Le*R'
}
voV=}.(p
;>|:I(l;
publicvoid delete(finalObject entity){ ILTd*f
getHibernateTemplate().delete(entity); UZ&bT'>;9g
} O,: en t|
mKWA-h+f
publicObject load(finalClass entity, g8}/Ln*W'
vZ$uD,@;.
finalSerializable id){ TZPWMCN4
return getHibernateTemplate().load 8|V6Rg A%
[#uX{!q'
(entity, id); 3]<$;[Q
} 0(-'L\<>x
Qh)@-r3
publicObject get(finalClass entity, Wc03Sv&FZ
jlzqa7
finalSerializable id){ Q)H Vh[4
return getHibernateTemplate().get Alh%Z\
3vmLftZE}
(entity, id); ;c<:"ad(
} JTl
37j
,Ea.ts>
publicList findAll(finalClass entity){
0qZ{:}`3
return getHibernateTemplate().find("from 0Q%'vBX\`
j[) i>Qw
" + entity.getName()); z`5+BL,|ND
} j:$2,?|5
xzIs,i}U
publicList findByNamedQuery(finalString -Qqb/y
op&,&
namedQuery){ Y( D d7`c
return getHibernateTemplate LK/gG6n5M0
tSE6m -
().findByNamedQuery(namedQuery); ]#))#-&1
} 'Ys"yY@
b"x;i\Z0%
publicList findByNamedQuery(finalString query, "t`r_Aw
"uqa~R{
finalObject parameter){ u.8vXc
return getHibernateTemplate )d0&iE`@
u ldea)
().findByNamedQuery(query, parameter); w0tlF:Eg
} tkV:kh< L~
HC}D<FX|
publicList findByNamedQuery(finalString query, D@5&xd_@4
:
bT*cgD{
finalObject[] parameters){ [,|KVc=&H
return getHibernateTemplate Rm)vY}v
:#I8Cf
().findByNamedQuery(query, parameters); Wky~ hm
} Vg6?a
#=Q/<r.~G
publicList find(finalString query){
QH9(l
return getHibernateTemplate().find 2P@>H_JFF
mkrvWZjZX
(query); BAg*zYV7
} <w.V !"!
cV)fe`Gg
publicList find(finalString query, finalObject ,t61IU3"
]Fl+^aLS
parameter){ 1:q55!b
return getHibernateTemplate().find j\!zz
dFo9O!YX[f
(query, parameter); -!(3fO:
} \9@*Jgpd6*
KW^s~j
public PaginationSupport findPageByCriteria #B)/d?aa'
m{(D*Vuqd
(final DetachedCriteria detachedCriteria){ ldanM>5
return findPageByCriteria >sPu*8D40a
G\Toi98d*
(detachedCriteria, PaginationSupport.PAGESIZE, 0); B58H7NH ;G
} hH )jX`Ta
Q gDjc'
public PaginationSupport findPageByCriteria PFUb\AY
=@gH$Q_1
(final DetachedCriteria detachedCriteria, finalint ?VS {,"X
.'5yFBS
startIndex){ 2~ Gcoda
return findPageByCriteria 8X5;)h
dGP*bMCT
(detachedCriteria, PaginationSupport.PAGESIZE, Q3wD6!'&m
C<6u}czA
startIndex); >:Xzv
} /$&~0pk
u)R>ozER
public PaginationSupport findPageByCriteria 2frJSV ?
7+#^:;19`
(final DetachedCriteria detachedCriteria, finalint </:f-J%U/
RyIr_:&-~
pageSize, .eK1xwhJ
finalint startIndex){ i
"62+
return(PaginationSupport) 4h:Oo
G/2@Mn-
getHibernateTemplate().execute(new HibernateCallback(){ L>xcgV7
publicObject doInHibernate [UR+G8X21m
5}e-\:J>B
(Session session)throws HibernateException { !ny;YV
Criteria criteria = A}OV>y M
%w/o#*j<;
detachedCriteria.getExecutableCriteria(session); >^D"% Oj y
int totalCount = [M@i,d-;A
>`'#4!}G5j
((Integer) criteria.setProjection(Projections.rowCount OA4NXl'
RvYew!n
()).uniqueResult()).intValue(); 0wAZ9AxA{
criteria.setProjection ruB&&C6)v
dH#S69>
(null); =qCVy:RL4
List items = (U/ 6~r'.L
^dYFFKQ
criteria.setFirstResult(startIndex).setMaxResults ZJ=-cE2n
QRgWzaI
(pageSize).list(); C&zgt
:q6}
PaginationSupport ps = z})H$]: $
1g2%f9G
new PaginationSupport(items, totalCount, pageSize, (gl CTF9v
C.%iQx`
startIndex); j05ahquI
return ps; im*QaO%a4
} L.l"'=M
}, true); V<:kS
} HR.S.(t[_
*~prI1e(
public List findAllByCriteria(final hk}M'
K
,f 1c}
DetachedCriteria detachedCriteria){ #s(B,`?N
return(List) getHibernateTemplate r_FW)F u^
9]1-J5iO
().execute(new HibernateCallback(){ wb"Jj
publicObject doInHibernate 8kH'ai
T>kJB.V:oQ
(Session session)throws HibernateException { W_O,Kao
Criteria criteria = f^:9gRt
.fUqsq
detachedCriteria.getExecutableCriteria(session); [~f%z(vI
return criteria.list(); g3e\'B'
} ^^3
>R`
}, true); tG^Oj:
} Ds&)0Iwf
HEht^/pJ
public int getCountByCriteria(final Fm*n>^P@Y
7:mM`0g!
DetachedCriteria detachedCriteria){ W{=>c/
Integer count = (Integer) Gv?3}8Wp
d3 fE[/oU
getHibernateTemplate().execute(new HibernateCallback(){ wvx
N6
publicObject doInHibernate &>i+2c~
3/}=x<ui
(Session session)throws HibernateException { GB^Ch YOb
Criteria criteria = goIn7ei92
7I(Sa?D:
detachedCriteria.getExecutableCriteria(session); ]1abz:
return 31Zl"-<#-
+%UXI$v
criteria.setProjection(Projections.rowCount -t:yy:4
JAmv 7GL'6
()).uniqueResult(); 76zi)f1f
} >6r&VZu*n
}, true); .IYOtS
return count.intValue(); Z&JW}''n|F
} hh
<=D.u
} Yt0
l'B%[u
9p>3k&S
*2=:(OK
vRRi"bo
S>*i^If
i?4vdL8M
用户在web层构造查询条件detachedCriteria,和可选的
c.KpXY
VSms hld
startIndex,调用业务bean的相应findByCriteria方法,返回一个 d[-w&[iy
1wE~dpnx
PaginationSupport的实例ps。 @~QW~{y
uH65DI<
ps.getItems()得到已分页好的结果集 gPQ2i])"Q
ps.getIndexes()得到分页索引的数组 rguC#Xt!4
ps.getTotalCount()得到总结果数 #x':qBv#
ps.getStartIndex()当前分页索引 -.ha\ t0J
ps.getNextIndex()下一页索引 HQQc<7c",
ps.getPreviousIndex()上一页索引 j9x}D;?n
Maf!,/U4
pYceMZ$
bYgrKz@uK
'JKFEUzM
\qNj?;B
,F6i5128{
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 l')?w]|
kX+y2v(2++
,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 &0Wv+2l@
&"K74
一下代码重构了。 Z3~$"V*ZB{
J3S@1"
我把原本我的做法也提供出来供大家讨论吧: 2@uo2]o)
|1T2<ZT
首先,为了实现分页查询,我封装了一个Page类: #^yw!~:{
java代码: 0&2TeqsLh)
i7mT<w>?
`<b 3e(A
/*Created on 2005-4-14*/ q`"gT;3S
package org.flyware.util.page; qD7#q]
`[VoW2CLH+
/** 3xp%o5K
* @author Joa 1ncY"S/VO
* % ]r@vjeyd
*/ 6$9n_AS
publicclass Page { oizD:|
EoIP#Cnd1
/** imply if the page has previous page */ "Z& {
privateboolean hasPrePage; 0Evmq3,9
{-7];e
/** imply if the page has next page */ +>44'M^Z|(
privateboolean hasNextPage; T%
Kj >-
@m1v B!
/** the number of every page */ x AkM_<
privateint everyPage; R`!x<J
^r}^-
/** the total page number */ ~ NKw}6
privateint totalPage; 2\CFt;fk
~
9^1m
/** the number of current page */ !@W1d|{lu
privateint currentPage; ~BD VmQa
'fy1'^VPAV
/** the begin index of the records by the current ;oH%d;H
u6awcn
query */ |Y0BnyGK
privateint beginIndex; kbM 4v G
{%N*AxkvId
bF|j%If%
/** The default constructor */ ncu
&<j }U
public Page(){ M_Z*F!al<
7'J}|m{7
} 1Xu\Tm\Ux
Y3mATw 3Wh
/** construct the page by everyPage ~Q0jz/#c
* @param everyPage 6f\0YU<C&
* */ CJ
{?9z@$.
public Page(int everyPage){ 5d*k[fZ
this.everyPage = everyPage; Y \& 4`v'
} Uj(,6K8W
R`:Y&)c_$
/** The whole constructor */ ]uWx<aDB
public Page(boolean hasPrePage, boolean hasNextPage, 6wqq"6w
b U-Cd
&t+03c8g!
int everyPage, int totalPage, M})2y+
int currentPage, int beginIndex){ <&t^&6k
this.hasPrePage = hasPrePage; }ytc oIuLf
this.hasNextPage = hasNextPage; m!$"-nh9
this.everyPage = everyPage; ]9l=geZd%;
this.totalPage = totalPage; c03A_2%
this.currentPage = currentPage; 4 "@BbVYR
this.beginIndex = beginIndex; .%M=dL>
} % )i?\(/
p*-o33Ve
/** T,TKt%
* @return r[Qk-}@vp
* Returns the beginIndex. DSM,dO'
*/ kK16+`\+
publicint getBeginIndex(){ n-#?6`>a
return beginIndex; gk>A
} ALiA+k N
"F7g8vu
/** (9*=d_=
* @param beginIndex T]Vh]|_s
* The beginIndex to set. xD8x1-
*/ g%4-QCZ,
publicvoid setBeginIndex(int beginIndex){ K9mL1 [B
this.beginIndex = beginIndex; V2^(qpM!
} {I@@i8)]
yCf*ts1
/** 53=VIN]
* @return #?@k=e\
* Returns the currentPage. ZcYxH|Gn
*/ i
jg'X#E
publicint getCurrentPage(){ $83TA><a
return currentPage; ']Nw{}eS`
} v< xe(dC
j;=+5PY
/** MV-fDqA(
* @param currentPage 5$`i)}:s
* The currentPage to set. @-NdgM<
*/
|4\.",Bg
publicvoid setCurrentPage(int currentPage){ G;Q)A$-
this.currentPage = currentPage; 9} :n
} zF>|
9JU
Zh)Qq?H
/** W=M]1hy
* @return CKNC"Y*X
* Returns the everyPage. )|x)KY
*/ &y;('w
publicint getEveryPage(){ '{5|[
return everyPage; _SJ#k|vcq
} u `1cXL['
y"<nx3
/** CSN]k)\N(
* @param everyPage 'ZgrN14
* The everyPage to set. +Tf ,2?O
*/ :tu6'X\k
publicvoid setEveryPage(int everyPage){ 63#Sf$p{v
this.everyPage = everyPage; t,]r%
} x\]%TTps
w`bojM@e1
/** nAZuA]p}S]
* @return 21O!CvX
* Returns the hasNextPage. ? DWF7{1
*/ ;[R{oW
Nw
publicboolean getHasNextPage(){ k#_B^J&d
return hasNextPage; jqPQ=X
} ]E .+)>
8`EzvEm
/** $VvL
* @param hasNextPage *[]7l]XK.
* The hasNextPage to set. ?\L@Pr|=Dr
*/ ~c%H3e>Jcq
publicvoid setHasNextPage(boolean hasNextPage){ -fI-d1@
this.hasNextPage = hasNextPage; L~%@pf>
} zqh.U@
6D_3Hwrs
/** [8EzyB>fH
* @return P3jDx{F
* Returns the hasPrePage. 4yW9}=N!
*/ h.gj4/g
publicboolean getHasPrePage(){ `f,SY
return hasPrePage; Ob$|IH8.
} ng(STvSh:
(]n^_G#-$
/** 8_US.52V
* @param hasPrePage dE=4tqv-r
* The hasPrePage to set. ]R~K-cN`
*/ 9XImgeAs
publicvoid setHasPrePage(boolean hasPrePage){ v}XMFC !
this.hasPrePage = hasPrePage; nsQx\Tnhx
} ~5<-&Dyp7
I,OEor6%R(
/** h[b;_>7
* @return Returns the totalPage. O~N0JK_>
* MKq:=^ w
*/ 7dhip
publicint getTotalPage(){ PJA%aRP,:
return totalPage; d#9
\]Ul&
} g]PmmK_L
`bw>.Ay
/** Squ'd
* @param totalPage ' te4mY}
* The totalPage to set. AP&mr1_
*/ ~1jSz-s
publicvoid setTotalPage(int totalPage){ 8XZS BR(Z
this.totalPage = totalPage; 59A@~;.F
} 0l=g$G
\%
Pb4%"9`
} tu8n1W
[LDsn]{
ys`"-o[*
99j^<)
T~@$WM(
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 }wJ-*By{+
'yd<<BM`
个PageUtil,负责对Page对象进行构造: 4+qoq$F</
java代码: >_bH,/D'
T{-<G13
kXK D>."E*
/*Created on 2005-4-14*/ qT7E"|.$
package org.flyware.util.page; [(Ss^?AJW
W'WZ@!!
import org.apache.commons.logging.Log; ^t,sehpR:l
import org.apache.commons.logging.LogFactory; ANh7`AUuO
wPdp!h7B~N
/** I/:M~ b
* @author Joa 0IO#h{t
* OP>rEUtj
*/ 4d~Sn81xW
publicclass PageUtil { </~!5x62Oy
VL4ErOoZ
privatestaticfinal Log logger = LogFactory.getLog Wm_:1~
!cS
A|C
(PageUtil.class); C{AVV<
WfYu-TK*
/** *F7ksLH|q
* Use the origin page to create a new page AG/?LPJ
* @param page l>p S23
* @param totalRecords |t](4
* @return /sVy"48-
*/ 1 XsB
publicstatic Page createPage(Page page, int 1Z-f@PoM
J<J_yRg2
totalRecords){ !;EG<ji,gj
return createPage(page.getEveryPage(), N6yPuH
]@YBa4}w
page.getCurrentPage(), totalRecords); 5R"My^G
}
2w6y
~Iw7Xq E2
/** &+]x
* the basic page utils not including exception rBR,lS$4
eaSf[!24"
handler rik-C7
* @param everyPage zE$KU$
* @param currentPage VE3,k'^v
* @param totalRecords :rr;9nMR[
* @return page )"SP >2}
*/ _4H
9rPhf
publicstatic Page createPage(int everyPage, int Reci:T(_
,.Xqb~
currentPage, int totalRecords){ (`%$Aa9J
everyPage = getEveryPage(everyPage); Wc]L43u
currentPage = getCurrentPage(currentPage); lxsBXX Zg
int beginIndex = getBeginIndex(everyPage, mFoE2?Y
=^
currentPage); c~j")o
int totalPage = getTotalPage(everyPage, <i}lP/U
8bl&-F`
totalRecords); Y [8~M8QX
boolean hasNextPage = hasNextPage(currentPage, Lckb*/jV&
|j3fS[.$
totalPage); k4WUfL d
boolean hasPrePage = hasPrePage(currentPage); L{XNOf3
u17e
returnnew Page(hasPrePage, hasNextPage, zW[fHa$m
everyPage, totalPage, ~%)ug3%e
currentPage, MBlhlMyI
y"5>O|`
beginIndex); c*iZ6j"iI
} w, uyN
.7lDJ2
privatestaticint getEveryPage(int everyPage){ "zpc)'$L=
return everyPage == 0 ? 10 : everyPage; .v<Q-P\8/
} eRV4XB :
cPQUR^!5
privatestaticint getCurrentPage(int currentPage){ DK-V3}`q}
return currentPage == 0 ? 1 : currentPage; e}V3dC^pU
} dw6U}
aE]/w1a
privatestaticint getBeginIndex(int everyPage, int kTJz .
GJ1ap^k
currentPage){ l]:nncpns
return(currentPage - 1) * everyPage; 2|2'?
} kY e3A&J
fyb:eO}
privatestaticint getTotalPage(int everyPage, int h?UUd\RU)
T&@xgj|!)
totalRecords){ 3RSiu}
int totalPage = 0; PWU8 9YXp
Rn] `_[)*~
if(totalRecords % everyPage == 0) Na6z1&wS
totalPage = totalRecords / everyPage; <K6:"
else iv3=J
totalPage = totalRecords / everyPage + 1 ; Rwu
y!F
}V@ *
:3w8
return totalPage; 1^F
!X=
} LI`L!6^l
x}acxu 2H7
privatestaticboolean hasPrePage(int currentPage){ }ZPO^4H;-
return currentPage == 1 ? false : true; HfQZRDH
} >b6!*Lrhs
T~=r*4
privatestaticboolean hasNextPage(int currentPage, SEf:u
"Q{)H8,E)x
int totalPage){ {\HEUIa]w
return currentPage == totalPage || totalPage == x d9+P
-1~-uE.~4d
0 ? false : true; CC8M1iW3
} Nd5G-eYI
rUg<(/c
nDiy[Y-4Wp
} "t[9EbFL
>gQJ6q
}@+3QHwYU
N*vBu`
'{e9Vh<x
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。 pb>TUKvT&
6oh\#v3zV
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 cM'\u~m{
{xW HKsI>,
做法如下: `,-w+3?Al
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 BYhF?
O/Q7{5n
的信息,和一个结果集List: wNNInS6
java代码: 0[/GEY@
R&lJ& SgC
UG@9X/l}
/*Created on 2005-6-13*/ olHT* mr
package com.adt.bo; 2hD(zUSy
c/K:`XP~
import java.util.List; )qyJwN
.D
nU^ -D1s{
import org.flyware.util.page.Page; Jf#Ika&px
7EI5w37
/** %9^^X6yLM
* @author Joa >
T$M0&<
*/ wW.V>$q
publicclass Result { >#9f{
mNc?`G_R
private Page page; [2WJ];FJ
{~L{FG)O
private List content; XBvJc'(s
8Uv2p{ <#
/** @ )bCh(u
* The default constructor D90.z"N\i9
*/ {c(@u6l28
public Result(){ xZMQ+OW2i
super(); b8QQS#q)V
} 7?1[sPM
d*}dM"
/** n8FmIoZ&`
* The constructor using fields L6>;"]:f`
* "7G>
* @param page QsXy(w#F
* @param content 4@qHS0$
*/ j=q*b Qr
public Result(Page page, List content){ t\GoUeH]
this.page = page; &1!T@^56
this.content = content; BXzn-S
} Bv=
Qru
iQ/t
/** %>)HAx `
* @return Returns the content. CXAW>VdK_
*/ uPbGQ :%}
publicList getContent(){ t9QnEP'
return content; fV "gL(7
} ' F,.y6QU
88]4GVi
/** NZ|(#` X
* @return Returns the page. bXiOf#:''
*/ k}0Y&cT!rU
public Page getPage(){ 3QD+&9{D
return page; qcmf*Yl:v
} [.
rULQl
6d# 7
/**
spX*e1
* @param content .kl.awT
* The content to set. e>6NO
*/ E"/r*C+T
public void setContent(List content){ dE_d.[!
this.content = content; EF8~rKO3
} qV7F=1k]
VfV|fuW
/** cFV)zFu
* @param page ;Xr|['\'
* The page to set. o/J2BZ<_<
*/ K6z)&<
publicvoid setPage(Page page){ WDF;`o*3
this.page = page; ~zd+M/8
} 4#MPD
} ='[J.
\nzaF4+$
Gg,&~
jHib
mw!EDJ;'
c}-WK*v
2. 编写业务逻辑接口,并实现它(UserManager, EqYBT
KAFx^JLo
UserManagerImpl) :TZ</3Sw
java代码: dlf nhf
m4m,-}KNi
J
,s9,("
/*Created on 2005-7-15*/ ; *ZiH%q,
package com.adt.service; n N_Ylw
9w:F_gr
import net.sf.hibernate.HibernateException; ]lgI Q;r
A8zh27[w%
import org.flyware.util.page.Page; N E/ _
,zP.ch0K
import com.adt.bo.Result; {0~xv@ U
&*\-4)Tf
/** 'CfM'f3uu
* @author Joa `pJWZ:3
*/ B/^1uPTZ71
publicinterface UserManager { 4iPxtVT
X }""=
S<
public Result listUser(Page page)throws ;+Sc Vz
d%(4s~y
HibernateException; 9*ek5vPB
c_N'S_)~7Q
} ;;]^d_
QcN$TxU >
QqdVN3#1z
2@jlF!zC
M&h`uO/[
java代码: DxvD 1u
{0IC2jE
xE"QX
N
/*Created on 2005-7-15*/ uJ:SN;
package com.adt.service.impl; },& =r= B
B s {n
import java.util.List; Be4n\c.
p+y2w{{
import net.sf.hibernate.HibernateException; D&]dlY@*
D:I6nSoC
import org.flyware.util.page.Page; `9vCl@"IV
import org.flyware.util.page.PageUtil; "b6ew2\
RLE6=#4
import com.adt.bo.Result; (RM;T @`
import com.adt.dao.UserDAO; 2+'4 m#@)
import com.adt.exception.ObjectNotFoundException; >$/PfyY7@#
import com.adt.service.UserManager; |WUm;o4E`U
ln&9WF\I
/** 3x6@::s~
* @author Joa Z&MfE0F/B
*/ <],~V\m
publicclass UserManagerImpl implements UserManager { bmd3fJb`r
:OC(93d)0
private UserDAO userDAO; 2`V[Nb
`U6bI`l
/** H vezi>M
* @param userDAO The userDAO to set. '"4S3Fysm
*/ ^1jZwP;5eW
publicvoid setUserDAO(UserDAO userDAO){ [+_0y[~,tB
this.userDAO = userDAO; 8EC$p} S
} O@)D%*;v
e<E]8GAF
/* (non-Javadoc) t$k$Hd';
* @see com.adt.service.UserManager#listUser v0uA]6:
7jtDhsVz
(org.flyware.util.page.Page) .0ExHcr
*/ hL(zVkYI
public Result listUser(Page page)throws IuOY.c2.u
qs
0'}>
HibernateException, ObjectNotFoundException { w`a(285s)i
int totalRecords = userDAO.getUserCount(); ZL^
svGy
if(totalRecords == 0) 0%OV3`
throw new ObjectNotFoundException vN8Xq+
>6\rhx>
("userNotExist"); 7w8I6
page = PageUtil.createPage(page, totalRecords); F =Zc_
List users = userDAO.getUserByPage(page); d:%!)s
returnnew Result(page, users); 3B6"T;_
} laX67Vjv
)m4O7'2G
} o?]g
\4FKZ>1+R
W4V
!7_
1(*Pa
SGA!%=Lp
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 ^Ss4<
ry[NR$L/m
询,接下来编写UserDAO的代码: P+s-{vv{0
3. UserDAO 和 UserDAOImpl: r_?i l]l
java代码: f83Tl~
??g `c=R!V
hrZ=8SrW
/*Created on 2005-7-15*/ se, 0Rvkt
package com.adt.dao; 7$/%c{o
idLCq^jnJ
import java.util.List; *5Aq\g,n
~K-_]*[x
import org.flyware.util.page.Page; 4Px
Q?7:XbN
import net.sf.hibernate.HibernateException; +~] :oj
0oU;Cmw.
/** LI/;`Y=
* @author Joa gZ&' J\
*/ C?47v4n-'
publicinterface UserDAO extends BaseDAO { 0{'%j~"
X GhV?
tA
publicList getUserByName(String name)throws I6B4S"Q5<
Rb=8(#
HibernateException; qL1d-nH
cN]]J
publicint getUserCount()throws HibernateException; *]]C.t-cd
;+W9EbY2
publicList getUserByPage(Page page)throws :Tu%0="ye
^V5g[XL2
HibernateException; D/7hVwMw:
JAA{5@ST
} Ei&
Z
&8^ch,+pD
Dw-i!dq
6*Y>Y&sea
^+)q@{\8Y
java代码: @cT= t0*
ZUiInO
X&+*?Q^
/*Created on 2005-7-15*/
wn-{Vkpm
package com.adt.dao.impl; <xpHlLc
xO nW~Z
import java.util.List; ulzQ[?OMl
(RtjD`e}
import org.flyware.util.page.Page; D3i`ehh
5lp};
import net.sf.hibernate.HibernateException; IQ3]fLb
import net.sf.hibernate.Query; ^>H+#@R
xM6v0U a
import com.adt.dao.UserDAO; SF#Rc>v
K,o@~fj
/** 'CkN
* @author Joa -'jPue2\
*/ WI+ 5x
public class UserDAOImpl extends BaseDAOHibernateImpl 2-#:Y
<Z6tRf;B
implements UserDAO { Pu-/*Fx
qV`JZ\n
/* (non-Javadoc) `OP?[
f d
* @see com.adt.dao.UserDAO#getUserByName ?*ni5\y5o
sKLH.@
(java.lang.String) S7_^E
*/ `4N{x.N
publicList getUserByName(String name)throws 3jG
#<4;J
yk<$XNc
HibernateException { PiTe/
String querySentence = "FROM user in class _o-lNt+
:a#pzEK
com.adt.po.User WHERE user.name=:name"; u|'}a3
Query query = getSession().createQuery *w[\(d'T
J|D$
(querySentence); ZKT~\l
query.setParameter("name", name); yavoGk
return query.list(); 5?()o}VjAO
} 3{;W!/&>
Es~|:$(N]|
/* (non-Javadoc) `T \"B%
* @see com.adt.dao.UserDAO#getUserCount() 1; "t8.*%e
*/ +#|):aF
publicint getUserCount()throws HibernateException { v1E=P7}\{s
int count = 0; djxM/"xo
String querySentence = "SELECT count(*) FROM |0jmOcZF
!^/Mn
user in class com.adt.po.User"; ZX
Sl+k.
Query query = getSession().createQuery p>c` GDU
8!c#XMHV
(querySentence); W6>SYa
count = ((Integer)query.iterate().next .;'3Roi
t=;84lA
()).intValue(); X%>Sio
return count; ~il{6Z+#n
} 1p[Z`m*9
@^)aUOe
/* (non-Javadoc) +z2+z
* @see com.adt.dao.UserDAO#getUserByPage ;Q0WCm\5
^ld?v
(org.flyware.util.page.Page) VZJ[h{ 6
*/ ^S'#)H-8C3
publicList getUserByPage(Page page)throws C;3>q*Am4
=CE(M},d
HibernateException { fzVU9BU
String querySentence = "FROM user in class ZPISclSA+
\\WIu?
com.adt.po.User"; 27NhYDo
Query query = getSession().createQuery F$QAWs
g+-=/Ge
(querySentence); ,VM)ZK=Tr
query.setFirstResult(page.getBeginIndex()) c&o|I4|Y,
.setMaxResults(page.getEveryPage()); 3N]
return query.list(); :Gdfpz-{?
} FrXh\4C
aB(6yBBoxj
} K^_Mt!%
1YklPMx6
/<Doe SDJ|
TyCMZsvM,
d/57;6I_
至此,一个完整的分页程序完成。前台的只需要调用 tv+H4/
N~%F/`Z<+
userManager.listUser(page)即可得到一个Page对象和结果集对象 ~alC5|wCUQ
V0Z\e
_I
的综合体,而传入的参数page对象则可以由前台传入,如果用 {Y%X
Z{|U!tn
webwork,甚至可以直接在配置文件中指定。 XU}|Ud562
~x>?1K
下面给出一个webwork调用示例: ;'B\l@U\
java代码: &m'ttUG?
?d -$lI
dtdz!'q)Y
/*Created on 2005-6-17*/ |^ao,3h#
package com.adt.action.user; .i7bI2^
^r7-|
import java.util.List; J:YFy-[w(
\y-Lt!}
import org.apache.commons.logging.Log; H@uCbT
import org.apache.commons.logging.LogFactory; u,d@oF(=
import org.flyware.util.page.Page; r] +V:l3
<V3N!H_d
import com.adt.bo.Result; Z]I[?$y
import com.adt.service.UserService; jZm57{C#*?
import com.opensymphony.xwork.Action; %mhnd):
GYD`
/** N|,6<|
* @author Joa 0$n0fu
*/ B@,L83
publicclass ListUser implementsAction{ &DMKZMj<Q*
DO!?]"
privatestaticfinal Log logger = LogFactory.getLog 31n5n
S=^a''bg
(ListUser.class); S)@95pb
M.Fu>Xi
private UserService userService; ?Afx{H7
:>Gm&w
(n
private Page page; ?s<'3I{F`
dnby &-+T
privateList users; g2=5IU<
LDJ=<c!
/* fR>(b?C
* (non-Javadoc) 0YsC@r47wL
* B}.G(-u?7
* @see com.opensymphony.xwork.Action#execute() w%no6 ;
*/ {=AK|
publicString execute()throwsException{ iB Ld*B|#K
Result result = userService.listUser(page); GRanR'xG
page = result.getPage(); J^@0Ff;=5^
users = result.getContent(); EV:y}
return SUCCESS; ("t;
2Mw
} c1IK9X*
])=k";76
/** o9!DK
* @return Returns the page. UQwLAXs
*/ acWm+
public Page getPage(){ <}c`jN!z.
return page; <y(uu(c
} Fejs9'cB
lO-: [@
/** ^X%{]b K
* @return Returns the users. [~;#]az
*/ lc%2Pi[X
publicList getUsers(){ 1*eWo~G
return users; _MZqH8
} Xj;nh?\u
7Q<xC
/** 3*G7H
* @param page z G
{1;
* The page to set. llbj-9OZL
*/ 93|u.
@lEy
publicvoid setPage(Page page){ ; 4E0%@R
this.page = page; q%=`PCty
} 3A_7R-sQ
u-zl- ?Ne
/** 2\ /(!n
* @param users =N,Mmz%
* The users to set. So*Q8`"-.
*/ klG]PUzd
publicvoid setUsers(List users){ 3S-n sMs.
this.users = users; .c'EXuI7),
} ~y+QL{P4~
%C%~f{4
/** T`{W$4XS
* @param userService uj$b/I>.'
* The userService to set. f1;Pzr
*/ ,z1X{
publicvoid setUserService(UserService userService){ @|xcrEnP}B
this.userService = userService; 8CxC`*L(
} (5%OAjW
} d%Zt]1$
7d?'~}j
?]}1FP
xBhfC!AK}
e2Sudd=' G
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, Akf?BB3bC
zE +)oQ,
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 (!Q^.C_m
~A+DH
么只需要: m!s/L,iJJ
java代码: bWK}oYB*
Pew-6u"
p]uwGWDI
<?xml version="1.0"?> ir<HC 'D[
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork ]<mXf~zg
dm1WC:b
1.0//EN" "http://www.opensymphony.com/xwork/xwork- _eAZ_@
~xqRCf{8
1.0.dtd"> le?hCPHkp
xI}h{AF7
<xwork> n%I%O7
i{w<4E3
<package name="user" extends="webwork- KTd,^h
yZbO{PMr
interceptors"> <U=:N~L
+Sk ;
<!-- The default interceptor stack name \+mc
|s
:b9sfA
--> m M!H}|
<default-interceptor-ref ba^cw}5
[G^ir
name="myDefaultWebStack"/> $VYMAk&\
/GNLZm^
<action name="listUser" zFh
JLH*C
lL~T@+J~
class="com.adt.action.user.ListUser"> 0t<]Uf
<param +]/_gz
5An|#^]
name="page.everyPage">10</param> MzRURH,
<result @2-Eky
PZ~uHX_d>
name="success">/user/user_list.jsp</result> *Z=K9y,IC
</action> 4flyV -
]Kb
</package> 3!^5a%u
O:3pp8
</xwork> Z[
}0K3,5
2xH9O{
Ob2H7!
Af5O;v\
zlIXia5
Tm@d;O'E1
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 IB:Wh;_x
pb_+_(/c
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。 TOV531
{~ ZSqd
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 FLJdnL
k6-Q3W[+a
vRYQ4B4o
-J4?Km
^EE3E'
我写的一个用于分页的类,用了泛型了,hoho Y[9x\6
_E
7Xm7{`jH
java代码: .asHFT7]9
\"c;MK{
$:w4_X5T
package com.intokr.util; S/& _
0f/=C9L
import java.util.List; ,/{mRw%
a?K=
/** )s(J8J[b*L
* 用于分页的类<br> ,Khhu%$
* 可以用于传递查询的结果也可以用于传送查询的参数<br> N7k<q=r-
* *xXa4HB
* @version 0.01 mV0F^5
* @author cheng g
PogV(V
*/ ~hPp)-A
public class Paginator<E> { 9*2A}dH
privateint count = 0; // 总记录数 .Y[sQO~%
privateint p = 1; // 页编号 x F7C1g(
privateint num = 20; // 每页的记录数 :-7`Lfi@%
privateList<E> results = null; // 结果 H[ocIw
di}YHMTx
/** 7(lR$,bE;=
* 结果总数 *;. l/
*/ LF?83P,UJ#
publicint getCount(){ Zso&.IATng
return count; /rN%y
} 1iEZ9J?
nJ |O,*`O
publicvoid setCount(int count){ T;X8T
this.count = count; X64OX9:YF
} ]0.? 1s e
n!~mdI&
/** S/v+7oT
* 本结果所在的页码,从1开始 JyWBLi;Z
* r 11:T3
* @return Returns the pageNo. aN{C86wx
*/ y-O#
+{7
publicint getP(){ 1[o] u:m9U
return p; (nfra,'
} \9dSI
+J30OT8
/** ZvEcExA-
* if(p<=0) p=1 P|YBCH
* z|[#6X6tT
* @param p x&7%U
*/ LS@[O])$'
publicvoid setP(int p){ 9B")/Hz_
if(p <= 0) qN}kDT
p = 1; ~>zml1aJ6
this.p = p; &-W5T?Sl
} 2f ]CnD0$
tmiRv.Mhn<
/** "I?sz)pxG
* 每页记录数量 1XQJ#J1/
*/ ]8KAat~J
publicint getNum(){ xnWCio>M
return num; Xm&L@2V
} ~fB}v
_,(]T&j #2
/** Y ::\;s
* if(num<1) num=1 XbdoTriE
*/ |9ro&KA
publicvoid setNum(int num){ YJ_`[LnL
if(num < 1) j|!.K|9B
num = 1; JCZ"#8M3
this.num = num; &x19]?D"+
} '{WYho!
5"xZ'M~=
/** j>X;a39|
* 获得总页数 4a]m=]Hm
*/ 4&;.>{:;
publicint getPageNum(){ B8-v!4b0`
return(count - 1) / num + 1; =SPuOy8
} b{qeu$G R
g=.~_&O
/** 'gd3 w~
* 获得本页的开始编号,为 (p-1)*num+1 R[ p. )F7
*/ itb0dF1G
publicint getStart(){ MJ'|$b}
return(p - 1) * num + 1;
E;\XZ<E
} aZ^P*|_K3
K}ACZT)Wp
/** Dv?'(.z
* @return Returns the results. jV)!9+H#
*/ B~oSKM%8R
publicList<E> getResults(){ HVaWv ].
return results; 9k =-8@G9
} ;V]EF
bUbM }
public void setResults(List<E> results){ D ODo
!
this.results = results; MVHj?
} &RP!9{F<
<y1V2Np
public String toString(){ LcCb[r
StringBuilder buff = new StringBuilder +cv7]
;Vc@]6Ck
(); 6J0HaL
buff.append("{"); u38FY@U$
buff.append("count:").append(count); JmdXh/X
buff.append(",p:").append(p); rhY>aj
buff.append(",nump:").append(num); .b>1u3
buff.append(",results:").append \7z&iGe!
Zy^mSI4i
(results); *A}QBZ
buff.append("}"); 2Cn^<(F^4I
return buff.toString(); -dbD&8
} [tDUR
%
INRds
}
b<v \
)
?rJKr[`
Ao)hb4ex