Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 9j,g&G.K
.w2 ID
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .Mt3ec<
TktH28tK
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 R@vcS=m7
kBu{ bxL
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 FKa";f"
X\|!
。 {Cx5m
,^(]zZh
分页支持类: k:@DK9
"^
+a1x;
java代码: Cm}2 >eH
LFp "Waiv
+{J8,^z#
package com.javaeye.common.util; F@w; .e!
NTg@UT<
import java.util.List; Swi#^i
($[wCHU`!
publicclass PaginationSupport { bF'rK'',
-fR:W{u
publicfinalstaticint PAGESIZE = 30; }lJ;|kx$
hp\&g2_S0W
privateint pageSize = PAGESIZE; YGp+[|'
tK#R`AQ
privateList items; }U_
'7_JT
UX 1
)((
privateint totalCount; JfY*#({y
O7K.\
privateint[] indexes = newint[0]; {@Mr7*u
]MbPivM
privateint startIndex = 0; I=Y>z^4
_X6'uJ
public PaginationSupport(List items, int &p0e)o~Ux
K=g</@L6R
totalCount){ t}EMX9SQ
setPageSize(PAGESIZE); @mp`C}x"0&
setTotalCount(totalCount); je4l3Hl
setItems(items); bDI%}k9#
setStartIndex(0); "q@m6fs
} c OYDN[k
okNo-\Dh!
public PaginationSupport(List items, int ?1e{\XW
;JW_4;-
totalCount, int startIndex){ QTV*m>D
setPageSize(PAGESIZE); .n-#A
setTotalCount(totalCount); JKfG/z|
setItems(items); FL0uY0K
setStartIndex(startIndex); yV30x9i!2
}
QrZ#<{,J5
eL!41_QI
public PaginationSupport(List items, int sV^:u^
; *
[:~5Wc
totalCount, int pageSize, int startIndex){ ~/
%Xm<
setPageSize(pageSize); s\ IKSoE
setTotalCount(totalCount); JzHG5nmB
setItems(items); NW3c_]`=
setStartIndex(startIndex); 4zug9kFK
} my=f}%k=
RaZ>.5
D
publicList getItems(){ 2ZH+fV?.
return items; Cs,H#L
} +n3I\7G>
2_o#Gx'
publicvoid setItems(List items){ DL]tg[w{
this.items = items; pl[J!d.c
} eRauyL"Q+
@NHh-&;w
publicint getPageSize(){ <=uYfi 3,
return pageSize; x-^6U
} 8a)AuAi?!
/r}L_wI
publicvoid setPageSize(int pageSize){ FhE{khc#
this.pageSize = pageSize; Fe+
@;
} M[uWX=
s?SspuV
publicint getTotalCount(){ x 3@-E
return totalCount; oFY!NMq}:
} ~MpikBf
;"3B,Yj
publicvoid setTotalCount(int totalCount){ k3\N.@\
if(totalCount > 0){ D}-.<
this.totalCount = totalCount; XQ}Zr/f6
int count = totalCount / K%^n.
BHXi g~d
pageSize; OWd'z1Yl
if(totalCount % pageSize > 0) GkIE;7#2kX
count++; v
gN!9
indexes = newint[count]; !> UlvT-
for(int i = 0; i < count; i++){ {Gxe%gu6K
indexes = pageSize * 7
,Rg~L
t6+m` Kq
i; )?n'ZhsX
} \-<BUG]=
}else{ c:[k+_Zr
this.totalCount = 0; V+d_1]
l
} U"oNJ8&%|
} {(73*-~$
}5 o?7}?
publicint[] getIndexes(){ FLZ9pb[T
return indexes; ]rcF/uQJ<n
} '\Xkvi
EM,C
publicvoid setIndexes(int[] indexes){ _ k-_&PR
this.indexes = indexes; 8hRcB[F~S
} 1MelHW
v=`yfCX-qX
publicint getStartIndex(){ Iv`IJQH>
return startIndex; 8:cbr/F<
}
">A<%5F2
5&Oc`5QD
publicvoid setStartIndex(int startIndex){
4aayMS!#
if(totalCount <= 0) Hl*vS
this.startIndex = 0; ^xo<$zn
elseif(startIndex >= totalCount) .nV2n@SR
this.startIndex = indexes >J"IN I
5/H,UL
[indexes.length - 1]; ,'#TdLe
elseif(startIndex < 0) |dRVSVN
this.startIndex = 0; 3"fDFR
else{ A_9WSXR
this.startIndex = indexes qTO6I5u
Z\0Rw>#
[startIndex / pageSize]; xm'9n?
} @sXFu[!U
} _1"
ecaA
XTol|a=
publicint getNextIndex(){ UK`A:N2[
int nextIndex = getStartIndex() + L"_XWno
.RQra+up
pageSize; TS<d?:
if(nextIndex >= totalCount) /-=fWtA
return getStartIndex(); lFBdiIw
else <}a?<):S
return nextIndex; +X?ErQm
} ~ELY$G.xl
=w2 4(S
publicint getPreviousIndex(){ XN<SKW(H3
int previousIndex = getStartIndex() - K+g[E<x\=
Hq@+m!
pageSize; !oLn=
if(previousIndex < 0) :uL<UD,vu3
return0; ;m/e|_4;y
else nF3}wCe)
return previousIndex; O&%'j
} +ikSa8)*i
%L|fTndKH
} HR>Y?B{
p8Vqy-:
fHt \KP
'K[ml ?_
抽象业务类 oqrx7+0{
java代码: <'y<8gpM
}\4yU=JPK
AGhenDNV
/** *X5)9dq
* Created on 2005-7-12 Pz4#>tP
*/ 6F\ 6,E
package com.javaeye.common.business; V&mkS
I16FVdUun4
import java.io.Serializable; yR[6s#F/h
import java.util.List; ]4:QqdV
0cG'37[
import org.hibernate.Criteria; U S^% $Z:
import org.hibernate.HibernateException; *yq65yZi5
import org.hibernate.Session; {q>%Sr]9
import org.hibernate.criterion.DetachedCriteria;
F/Goq`
import org.hibernate.criterion.Projections; E0HqXd?
import Y&2FH/(M
Q3@ zUjq_Q
org.springframework.orm.hibernate3.HibernateCallback; -FeXG#{)
import <z Gh}.6v
R >x d*A
org.springframework.orm.hibernate3.support.HibernateDaoS 7Sdo*z
A U~DbU0O
upport; fRp]
\"P{8<h.3
import com.javaeye.common.util.PaginationSupport; n,I3\l9
.Rr^AGA4
public abstract class AbstractManager extends $b8[/],
emSq{A
HibernateDaoSupport { fk*(8@u>
mc{z
privateboolean cacheQueries = false; !Ko2yn}6l
x}G:n[B7_V
privateString queryCacheRegion; Hv6h7-
)f?I{
publicvoid setCacheQueries(boolean .7iRV
i_qY=*a?y
cacheQueries){ R%r
bysP
this.cacheQueries = cacheQueries; Tigw+2
} 6St=r)_
;zCUx*{
publicvoid setQueryCacheRegion(String Bdo{zv&A
%m&6'Rpfk
queryCacheRegion){ W"\~O"a
this.queryCacheRegion = s$Vl">9#
EJ:O 1
queryCacheRegion; $8^Hkxy
} ==Gc%
_p$/.~Xo9
publicvoid save(finalObject entity){ 3,PR6a,b'
getHibernateTemplate().save(entity); +n^M+ea;
} JCWTB`EB>
"@ >6<(Ki
publicvoid persist(finalObject entity){ qS?o22
getHibernateTemplate().save(entity); p
fc6;K:d
} W(q3m;n
<4r8H-(%
publicvoid update(finalObject entity){ _i_='dsyW/
getHibernateTemplate().update(entity); ljFq ;!I5
} PV68d; $:8
.}faWzRH9
publicvoid delete(finalObject entity){ b{0a/&&1O
getHibernateTemplate().delete(entity); ybaY+![*
} N'{[BA(eE
Ejug2q
publicObject load(finalClass entity, =\Q<TY
*-0s
`rC
finalSerializable id){ 9qx4F<
return getHibernateTemplate().load Q2
q~m8(
e5_Hmuk|
(entity, id); $;v! ,>
} ?(ORk|)kU
w8lrpbLh
publicObject get(finalClass entity, zx@!8Z
<Gpji5f2
finalSerializable id){ r]9-~1T
return getHibernateTemplate().get }M4dze
s|C[{n<_
(entity, id); O_QDjxj^rZ
} ,gV#x7IW
uFr12ZFgK
publicList findAll(finalClass entity){ 0/HFLz'
return getHibernateTemplate().find("from M9)4ihK
/@:X0}L
" + entity.getName()); ^ ` LqNG
} P2n8H Fi
7FH(C`uKi
publicList findByNamedQuery(finalString _k:8ib2TQ
}s,NM%oI
namedQuery){ #]h
X."b2
return getHibernateTemplate APu$t$dmm
TV{GHB!p"
().findByNamedQuery(namedQuery); ?G `m;S
} yaz6?,)
CL0lMZ
publicList findByNamedQuery(finalString query, -A#p22D,5
kcS7)"/ zC
finalObject parameter){ /2Izj/Q
return getHibernateTemplate ?LMQz=
bjVk9XvH6
().findByNamedQuery(query, parameter); @a9.s
} "Enb
4cQP+ n
publicList findByNamedQuery(finalString query, 're:_;lG
FJn-cR.n
finalObject[] parameters){ o~$O$
return getHibernateTemplate E{
/,
b)
/LFuf`bXV
().findByNamedQuery(query, parameters); vyZ&%?{*R
} ixA.b#!1
kk
fWiPO^
publicList find(finalString query){ AJyNlQ
return getHibernateTemplate().find |z)s9B;:#i
W.3b]zcV
(query); T0 K!Msz
} 2^[dy>[y0
{aAd (~YZ
publicList find(finalString query, finalObject 1ksFxpE
UZ<K'H,q
parameter){ b8d0]YS
return getHibernateTemplate().find q,Gymh;
puPI^6y%
(query, parameter); b8K]>yDAh
} ^J]&($-
*RkUF!)(
public PaginationSupport findPageByCriteria k`5I"-e
1(p:dqGS
(final DetachedCriteria detachedCriteria){ ^ ]9K>}
return findPageByCriteria _}R9!R0O
96w2qgc2
(detachedCriteria, PaginationSupport.PAGESIZE, 0); bK:U:vpYm
} 0?54 8yH
[9
MH"\
public PaginationSupport findPageByCriteria 2E }vuw=c
eN])qw{
(final DetachedCriteria detachedCriteria, finalint U:8[%a
t7by OMC
startIndex){ "$(+M t^
return findPageByCriteria 'K4FS(q
hywcj\[
(detachedCriteria, PaginationSupport.PAGESIZE, TuQGF$n@
xM%4/QE+
startIndex); h0<PQZJ
} ROFZ*@CH<
xhP~]akHN7
public PaginationSupport findPageByCriteria "3^tVX%$\[
9FDu{4:
(final DetachedCriteria detachedCriteria, finalint 6f +aGz
f<8Hvumw
pageSize, |aDBp
finalint startIndex){ ~N!HxQ
return(PaginationSupport) k6C XuU
'xH^ksb "
getHibernateTemplate().execute(new HibernateCallback(){ `X<B+:>v-
publicObject doInHibernate >Y>R1b%
JP8}+
(Session session)throws HibernateException { Et3I(X3
Criteria criteria = }JFTe
g
t5{P'v9J
detachedCriteria.getExecutableCriteria(session); +gd5&
int totalCount = Oc L7] b0
e|Ri
((Integer) criteria.setProjection(Projections.rowCount ;M?)-dpZ
]FCP|Jz
()).uniqueResult()).intValue(); u1/>)_U
criteria.setProjection b,Wm]N
=zFROB\
(null); AJ7w_'u=@
List items = %)j&/QdzF&
v@$N,g
criteria.setFirstResult(startIndex).setMaxResults 9JFN8Gf*)
m?kiGC&m
(pageSize).list(); AM-bs^
PaginationSupport ps = uG\~Hxqw7O
*I 1 H
new PaginationSupport(items, totalCount, pageSize, X%b1KG|#(
%mC@}
startIndex); ny{C,1QG
return ps; Om*QN]lGq
} CY o
m
}, true); ILm+o$o~
} f=^xU
P
NifQsy)*%
public List findAllByCriteria(final <IR#W$[
e(7#>O%1
DetachedCriteria detachedCriteria){ u+V*U5v
return(List) getHibernateTemplate *X.1b!
kGD_w
().execute(new HibernateCallback(){ "'CvB0>
publicObject doInHibernate {VAih-y
_^ENRk@
(Session session)throws HibernateException { c~hH
7/v
Criteria criteria = ]c>@RXY'
m[}P
detachedCriteria.getExecutableCriteria(session); v_XN).f;
return criteria.list(); P}4&J ^
} .HZ d.*
}, true); n%3!)/$
} | In{5Ek
l\Ozy
public int getCountByCriteria(final _*~F1% d
G!j 9D
DetachedCriteria detachedCriteria){ `4*I1WZW
Integer count = (Integer) :UdW4N-
'OnfU{Ai
getHibernateTemplate().execute(new HibernateCallback(){ S#]]h/
publicObject doInHibernate Xz4q^XJ
hF$`=hE,F~
(Session session)throws HibernateException { .{ v$;g
Criteria criteria = @JGmOwZ
+JErc)%
detachedCriteria.getExecutableCriteria(session); =7V4{|ESfy
return ehW [LRtq
qcs)
p
criteria.setProjection(Projections.rowCount _UVpQ5pN
8C{&i5kj\E
()).uniqueResult(); UPH#~D!
} ins(RWO
}, true); _%Z.Re
return count.intValue(); 5az%yS
} ]1++$Ej
} )|*Qs${tF
o^epXIrIPi
Nk9=A4=|
*5Zow 3
x;[ . ZzQ
n~629 &
用户在web层构造查询条件detachedCriteria,和可选的 d.+*o
PtkMzhX
startIndex,调用业务bean的相应findByCriteria方法,返回一个 :-{"9cgFR
CmB_g?K
PaginationSupport的实例ps。 O_;BZzT
*}vvS^ c0
ps.getItems()得到已分页好的结果集 o"JHB
ps.getIndexes()得到分页索引的数组 /[TOy2/;%b
ps.getTotalCount()得到总结果数 UIEvwQ
ps.getStartIndex()当前分页索引 c~U0&V_`j
ps.getNextIndex()下一页索引 GQt5GOt
ps.getPreviousIndex()上一页索引 0$|VkMq(
LtB5;ByeQ0
?d%)R*3IX
pwN2Nzski
Yh95W
d.f0OhQ
=b%f@x_U1
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 s:_hsmc"
b%lB&}uw}
,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 HwFg;r
TFkG"ev
一下代码重构了。 ) k/&,J3
437Wy+Q|e
我把原本我的做法也提供出来供大家讨论吧: + nR("Il
eP2Q2C8g
首先,为了实现分页查询,我封装了一个Page类: dSwfea_
java代码: \udB4O
P8c_GEna
QjLU@?&
/*Created on 2005-4-14*/ Z0&^(Fb
package org.flyware.util.page; Vs5 &X+k
[6TI_U~
/** $tu
* @author Joa ^X&`YXjuN
* |va@&;#wf
*/ )#AYb
publicclass Page { jN+`V)p
).kU7;0
/** imply if the page has previous page */ {APfSD_4
privateboolean hasPrePage; O
?T~>|
Gxd/t#;
/** imply if the page has next page */ `&NFl'l1C
privateboolean hasNextPage; v.W!
k$v7@|Aw
/** the number of every page */ 1le9YL1_g
privateint everyPage; ZTTA??}Y
q-t%spkl
/** the total page number */ @ fMlbJq
privateint totalPage; vE9"1M
b#I,Z+0ry
/** the number of current page */ '\{ OQH
privateint currentPage; HVvm3qu4
<uIPv
Zsx
/** the begin index of the records by the current v
Z10Rb8
Fe[6Y<x+:
query */ sA6Hk B.
privateint beginIndex; ?e-rwaW
SsX$l<t*
_,^f,WO~
/** The default constructor */ 5tv*uz|fv
public Page(){ GYw/KT~$
u|23M,
} 8!v|`Ky
`x=kb;
/** construct the page by everyPage DQhHU1
* @param everyPage n^QDMyC;I
* */ m@nGXl'!
public Page(int everyPage){ fyUW;dj
this.everyPage = everyPage; qF3S\
C
} :C;fEJN
=x w:@(]{
/** The whole constructor */ ;2h"YU-b
public Page(boolean hasPrePage, boolean hasNextPage, cV:Q(|QC
Tyb_'|?rW
T\wOGaCW
int everyPage, int totalPage, x75;-q
int currentPage, int beginIndex){ 3=]/+{B
this.hasPrePage = hasPrePage; <=uO*s>%
this.hasNextPage = hasNextPage; ruqE]Hx9(
this.everyPage = everyPage; JK)|a@BtOT
this.totalPage = totalPage; W{IP}mM
this.currentPage = currentPage; [
2@Lc3<
this.beginIndex = beginIndex; E2
'Al6^C
} yYOV:3!"
6AD&%v
/** VFV8ik)
* @return w8o?wx*
* Returns the beginIndex. I-.?qcy~
*/ VII`qbxT
publicint getBeginIndex(){ P9\y~W
return beginIndex; qjfv9sU
} ^ &KH|qRrO
R7Tl1!,h
/** fo}@B&=4
* @param beginIndex JBQ>"X^
* The beginIndex to set. 5YZ\@<|rH
*/ @W+8z#xr'
publicvoid setBeginIndex(int beginIndex){ ,,XHw;{
this.beginIndex = beginIndex; w;VUP@Wm
} m";8 nm
"~C\Z} ;
/** |RpZr!3V
* @return qyyLU@hd
* Returns the currentPage. i_6 wD
*/ M]\"]H?
publicint getCurrentPage(){ oQyMs> g
return currentPage; T5~Qfl?Y
} #oGvxc7
"6$+B/5
/** KJ?/]oLr0
* @param currentPage TuMZHB7h;
* The currentPage to set. yyR@kOGga
*/ Zf u" 8fX
publicvoid setCurrentPage(int currentPage){ W6B o\UK
this.currentPage = currentPage; w*SF Q_6YE
} #l2WRw_t
bVRxGn @l
/** h\-jqaq
* @return [-[|4|CnOm
* Returns the everyPage. fv3)#>Dgp>
*/ /7*qa G
publicint getEveryPage(){ [0+5 Gx
return everyPage; zJ0'KHF}o
} 8/34{2048
nDC5/xB
/** qmnCa&C9
* @param everyPage gvZLW!={
* The everyPage to set. qfY=!|O
*/ /|e"0;{
publicvoid setEveryPage(int everyPage){ ;LT#/t)}<
this.everyPage = everyPage; Q~*3Z4)j
} 9]8M {L
WY~}sE
/** kLY9#p=X
* @return qpc2;3*7
* Returns the hasNextPage. S4~;bsSx
*/ gk6j5 $Y"<
publicboolean getHasNextPage(){ ^?[^o\/@R
return hasNextPage; Z42v@?R.!W
} EZiGi[t7
&4MVk3SLx#
/** : [vp.vw}/
* @param hasNextPage h$zPQ""8
* The hasNextPage to set. [dL?N
*/ -p!KsU
publicvoid setHasNextPage(boolean hasNextPage){ Tf[-8H<
this.hasNextPage = hasNextPage; M/sqOhg
} d0Kg,HB
a( {`<F
/** &<i>)Ss
* @return U7fE6&g
* Returns the hasPrePage. l 0b=;^6
*/ >|I3h5\M
publicboolean getHasPrePage(){ ;/{Q4X{
return hasPrePage; I0jEhg%JZ
} VF==F_l
LRd,7P
/** XWy
iS\
* @param hasPrePage s_h<
* The hasPrePage to set. ow`c B
*/ ;1OTK6
publicvoid setHasPrePage(boolean hasPrePage){ 8QZk0O
this.hasPrePage = hasPrePage; z06pX$Q.<
} SS~Txt75m
yxQAO_C
/** \&qVr1|
* @return Returns the totalPage. ^lMnwqx<
* (U dDp"/
*/ f,a4LF
publicint getTotalPage(){ o_*|`E
return totalPage; WE~3(rs#X#
} N$,)vb<
O-2H!58$)
/** ^9b
`;}) .
* @param totalPage +`Bn]e8O
* The totalPage to set. n_ez6{
*/ GRV9s9^
publicvoid setTotalPage(int totalPage){ j1iC1=`ZM
this.totalPage = totalPage; Q6W)rJ[|
} /tv;W
80]TKf>
} ];2eIe
h+^T);h};|
n0i&P9@B1
&{=~)>h
0j/81Y}p
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 xNqQbkF
G =4 y!y
个PageUtil,负责对Page对象进行构造: Sf'5/9<DW+
java代码: w+$gY?%
q(p0#Mk,E
|uZ=S]V@
/*Created on 2005-4-14*/ tr/dd&(Y1
package org.flyware.util.page; y?@Y\ b
aC$g(>xFt
import org.apache.commons.logging.Log; 7VXeu+-P
import org.apache.commons.logging.LogFactory; 835Upj>
CGe'z
/** p+7BsW.l
* @author Joa !^fJAtCN]
* ;VFr5.*x
*/ lqCn5|S]
publicclass PageUtil { EXFxiw
rYS D-Kq
privatestaticfinal Log logger = LogFactory.getLog *f#4S_ws`
"AK3t'
jF*
(PageUtil.class); 0amz#VIB<u
@YB\PVhW
/** +e:ZN
tr9
* Use the origin page to create a new page 2!3&Ub#FO
* @param page q5W'P>
* @param totalRecords #rr-4$w+
* @return `pMI[pLZe
*/ 2*L/c-
publicstatic Page createPage(Page page, int fBOPd=
ge oN4
totalRecords){ r=Q5=(hn
return createPage(page.getEveryPage(), _Usg`ax-
*&0Hz{|
page.getCurrentPage(), totalRecords); `j<tI6[e
} ?^vZ{B)&0E
f,a %@WT
/** X[~CLKH(
* the basic page utils not including exception ZtLn*M
h^*{chm]
handler ] zY
* @param everyPage WO9/rF_
* @param currentPage bC{8yV=)
* @param totalRecords :Y3?,
* @return page m'B6qy!}6
*/ MX0B$yc$
publicstatic Page createPage(int everyPage, int T!a[@,)_
j1kc&(
currentPage, int totalRecords){ `x VA]GR4c
everyPage = getEveryPage(everyPage); Wd5t,8*8
currentPage = getCurrentPage(currentPage); y#DQOY+@^#
int beginIndex = getBeginIndex(everyPage, *]6dV'
NLGr=*dq
currentPage); ^e,RM_.
int totalPage = getTotalPage(everyPage, i?/?{p$#a-
$bosGG
totalRecords); ~&:R\
boolean hasNextPage = hasNextPage(currentPage, ECzNByP
vrv*k
totalPage); _64@zdL+
boolean hasPrePage = hasPrePage(currentPage); -JENY|6
@ 1A_eF
returnnew Page(hasPrePage, hasNextPage, #+PbcL
everyPage, totalPage, i|^6s87"N2
currentPage, EvmmQ
1W[(+TZ&s
beginIndex); Q9>]@DrAx
} 3@?YTez#
~Wm}M
privatestaticint getEveryPage(int everyPage){ 5,ahKB8
return everyPage == 0 ? 10 : everyPage; l7!)#^`2_
} 6{X>9hD
.A/H+.H;
privatestaticint getCurrentPage(int currentPage){ }2,#[mM
return currentPage == 0 ? 1 : currentPage; ItPK
} 3= zQ
U
*KH@u
privatestaticint getBeginIndex(int everyPage, int 8|NJ(D-$
"%t`I)
currentPage){ r_E)HL/A
return(currentPage - 1) * everyPage; U.'@S8
} 8Jj0-4]
3]es$ Jy
privatestaticint getTotalPage(int everyPage, int ]?`p_G3O
x 4</\o
totalRecords){ vqi$}=%n?W
int totalPage = 0; ]Hy PJ
)"uG*}\?b
if(totalRecords % everyPage == 0) <,4(3 >js
totalPage = totalRecords / everyPage; veg!mY2&
else /$,=>
totalPage = totalRecords / everyPage + 1 ; Z<<gz[$+p
f {Z%:H
return totalPage; ja- ~`
} AuipK*&g
i?dKmRp(@y
privatestaticboolean hasPrePage(int currentPage){ S)@vl^3ec
return currentPage == 1 ? false : true; >o#wP
} A i){,nh`0
>wO$Vu
`t
privatestaticboolean hasNextPage(int currentPage, ]GPJ(+5
otD?J= B
int totalPage){ *yq]
return currentPage == totalPage || totalPage == =L),V~b
qU*&49X
0 ? false : true; ]\,uF8gg)
} UH-uU~
{FY[|:Cp
2\B9o `Y
} A=d$ir
K[
6H,=S`V]EK
/JubiLEK
YQdX>k
$YY)g$
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。 X/K)kIi
'Sy *'&
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 -Dxhq&
}Y
#x@lZ! Y
做法如下: etMh=/NFV
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 2qMsa>~
ZWRRh^
的信息,和一个结果集List: 8{SU?MHQLE
java代码: G? gXK W
D *I;|.=u
355Sd;*
/*Created on 2005-6-13*/ cgxFEv
package com.adt.bo; auTTvJ
'Rd*X6dv
import java.util.List; @@3,+7%1
3u0<v%Qi
import org.flyware.util.page.Page; vF6*c
J2<
QAX
/** [7Lxt
* @author Joa tb?F}MEe
*/ 795Jwv
publicclass Result { .A7tq
R 4$Q3vcH
private Page page; Sja{$zL+W
5Sjr6l3Vq8
private List content; sC5uA
.?>9
4!~
.6cp3
/** Qj<{oZp&
* The default constructor YG 5Z8@kH
*/ 0SYf<$
public Result(){ Q|=
Q]$d
super(); G9n /S=R?
} =PFR{=F
LX\*4[0%K
/** xJ2O4ob
* The constructor using fields ,)rZAI
* ezr\T
* @param page 5u|=;Hz*)
* @param content 8\)U|/A7
*/ iQ|,&K0d]
public Result(Page page, List content){ Zp(=[n5
this.page = page; P A6KX5
this.content = content; CI!Eq&D,
} N`<4:v[P
Vvyrty
/** Bq~hV;9nf
* @return Returns the content. e@:P2(WWl
*/ ?l,
X!o6
publicList getContent(){ qH
h'l;.
return content; 0i*'N ch#i
} }>;ht5/i/
ewAH'H]o
/** ~S^X"8(U
* @return Returns the page. `o_fUOe8a
*/ c/=y*2,zo
public Page getPage(){ XnE
%$NJ
return page; 9jMC|oE
}
H\=LE
LGo2^Xx
/** cNuHXaWp
* @param content k~1j/VHv
* The content to set. oT|P1t.
*/ j(%gMVu
public void setContent(List content){ S?Bc~y
this.content = content; lP@)
} (~ ]g,*+
5"kx}f2$
/** S~k 0@
* @param page %9QMzz5
* The page to set. 9P7xoXJ@y
*/ "B9[cDM&
publicvoid setPage(Page page){ &N"'7bK6n
this.page = page; jB%"AvIX
} $AA~]'O>6:
} my\o P(e\
`y^zM/Ib
_oJ2]f6KX
Dh&:-
5@ bc(H
2. 编写业务逻辑接口,并实现它(UserManager, c{mKra
JFG",09]
UserManagerImpl) qukjS#>+
java代码: &0+x2e)7g
,pyQP^u-
QGH
h;
/*Created on 2005-7-15*/ - yC:?
package com.adt.service; |oe!P}u
?{
B[^
import net.sf.hibernate.HibernateException; TsaW5ho<p
-XBKOybHBO
import org.flyware.util.page.Page; |;A9A's
DO&+=o`"
import com.adt.bo.Result; Hs"%
S
NqJ<!q)
/** ptV4s=G2
* @author Joa L289'Gzg
*/ U@.u-)oX
publicinterface UserManager { ;RWW+x8IB
zBk_-'z
public Result listUser(Page page)throws .vv5t
FOCoiocPi
HibernateException; 4? m/*VV
5Noe/6
} L!;^#g
6P;o 6s
brg":V1a
j|VXC(6P,
81g9ZV(4
java代码: Ro'jM0(KE
Md8(`@`o
|Du,UY/
/*Created on 2005-7-15*/ wVgi+P
package com.adt.service.impl; / <JY:1|
5oz>1
import java.util.List; ow2M,KU6Z
6xQ"bFm
import net.sf.hibernate.HibernateException; sA/,+aM
B/jrYT$;m
import org.flyware.util.page.Page; )K{o<m~WAo
import org.flyware.util.page.PageUtil; ;#3ekl{-g
\s=QiPK
import com.adt.bo.Result; Bu7A{DRf
import com.adt.dao.UserDAO; %6AYCN?Ih
import com.adt.exception.ObjectNotFoundException; UhsO\ 9}qH
import com.adt.service.UserManager; \Y*!f|=of
9c#lLKrzG
/** RK?jtb=&A
* @author Joa xN6?yr
*/ U?8i'5)
publicclass UserManagerImpl implements UserManager { $ "Afy)Ir
fO*)LPen.z
private UserDAO userDAO; "
Wp
<O ;&qT*b
/** }dy9IH
* @param userDAO The userDAO to set. oG!6}5
*/ "?$L'!bM@
publicvoid setUserDAO(UserDAO userDAO){ A&N$tH
this.userDAO = userDAO; /sy-;JDnsu
} csYy7uzi
r+o_t2_b*
/* (non-Javadoc) X*0k>j
* @see com.adt.service.UserManager#listUser 4Mk8Cpz
Y|mW.
(org.flyware.util.page.Page) 1{^CfamF
*/ x'@W=P 7
public Result listUser(Page page)throws R;WW
f.#
Q-[3j
HibernateException, ObjectNotFoundException { a;%I\w;2
int totalRecords = userDAO.getUserCount(); 5)w4)K-%
if(totalRecords == 0) SGt5~Txj
throw new ObjectNotFoundException W:WQaF`2x
cI5N"U@yN
("userNotExist"); Tj=gRQ2v
page = PageUtil.createPage(page, totalRecords); UL&} s_
List users = userDAO.getUserByPage(page); > 84e`aGE
returnnew Result(page, users);
4bnt=5]
} *t^eNUA
NN^QUB
} \UOm]z
j(sLK
&
gt'*B5F(
47KNT7C
8+ov(B;(
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 22z1g(;@
DacN{r"3
询,接下来编写UserDAO的代码: yx2z%E
3. UserDAO 和 UserDAOImpl: YV-j/U{&
java代码: 1DUb
[W8
a~,Kz\Tt
F'1k<V?
/*Created on 2005-7-15*/ sMP:sCRC
package com.adt.dao; #00D?nC
^;+[8:Kb
import java.util.List; K!p,x;YX
R }1W
import org.flyware.util.page.Page; 0*/kGvw`i
+,z)#
import net.sf.hibernate.HibernateException; $%=G[/i'
/
$_M@>
/** JRXRi*@
* @author Joa Apmw6cc
*/ K U$`!h
publicinterface UserDAO extends BaseDAO { /HZv
E4=qh1d
publicList getUserByName(String name)throws n&$/Q$d&
Bhe{L?}0
HibernateException; 4Ac}(N5D@
)9B:Y;>)
publicint getUserCount()throws HibernateException; FNC[59
#ra*f~G
publicList getUserByPage(Page page)throws +Juh:1H
6|5H=*)DH
HibernateException; `^x9(i/NE
)&:L'N
} Jld\8=
BKay*!'PX
Kk=LXmL2
?_%u)S*g
ya.n'X14
java代码: xz8G}Ku
*}w+68eO
LL.x11o3
/*Created on 2005-7-15*/ pw\P<9e=
package com.adt.dao.impl; oR#Ob#&
>g]ON9CGH
import java.util.List; <UT>PCNG
N'QqJe7Z
import org.flyware.util.page.Page; 9,scH65x
_w>uI57U
import net.sf.hibernate.HibernateException;
]ENK8bW
import net.sf.hibernate.Query; s7l23*Czl
+Ofa#^5);K
import com.adt.dao.UserDAO; <bP#H
FqZgdmwR
/** M?$ZJ-
* @author Joa oxzq!U
*/ /P:EWUf'
public class UserDAOImpl extends BaseDAOHibernateImpl 6]n/+[ ks
o/^1Wm=
implements UserDAO { :^#vxdIC?
)c+k_;t'+
/* (non-Javadoc) ;|HL+je;Z
* @see com.adt.dao.UserDAO#getUserByName Z7z]2v3}c
8I.VJ3Q
(java.lang.String) ,F9nDF@)
*/ wXbsS)#/
publicList getUserByName(String name)throws ugLlI2 nJ
Gq1)1
HibernateException { r[pF^y0
String querySentence = "FROM user in class ;&S;%W>|
9->q| E4
com.adt.po.User WHERE user.name=:name"; y`So&:1
Query query = getSession().createQuery m*Cu-6&qd
nQ-mmY>#
(querySentence); R,,Qt
TGB
query.setParameter("name", name); (` c
G
return query.list(); :h*a
rT4{
} #K|9^4jt
50$W0L$
/* (non-Javadoc) +
>nr.,qo3
* @see com.adt.dao.UserDAO#getUserCount() Q4Q pn
*/ Ur3m[07H
publicint getUserCount()throws HibernateException { WbcS: !0
int count = 0; 4TZ cc|B5
String querySentence = "SELECT count(*) FROM J#
EP%
:c=.D;,
user in class com.adt.po.User"; cbYK5fj"T
Query query = getSession().createQuery (s&&>M]r_
?\y%]1
(querySentence); |<c
WllN
count = ((Integer)query.iterate().next "HK/u(z)
J'Sm0
()).intValue(); :mZYS4L~
return count; `]<`$71w
} Fe!9y2Mg
fzPZ|
/* (non-Javadoc) |]sx+NlNc
* @see com.adt.dao.UserDAO#getUserByPage {dzoEM[
1s
=;ICa~`C;
(org.flyware.util.page.Page)
3+U]?7t
*/ #{PmNx%M
publicList getUserByPage(Page page)throws E!mmLVa9
qZ+H5AG2
HibernateException { !Zjq9{t\"
String querySentence = "FROM user in class GBQn_(b9I
3CZS)
com.adt.po.User"; 6gU{(H
Query query = getSession().createQuery "#4dW 7E
k ;KdW P
(querySentence); r\qz5G *6
query.setFirstResult(page.getBeginIndex()) /.Q4~Hw%}
.setMaxResults(page.getEveryPage()); eR;!(Oy=A
return query.list(); 5/@UVY9_
} uQ3[Jz`y
orfp>B) 0
} H"Dn]$Q\Z
PJ\0JR7a
{_>em*V b
5o0Ch
kbI/4IRW
至此,一个完整的分页程序完成。前台的只需要调用 NX,-;v
qLK?%?.N<
userManager.listUser(page)即可得到一个Page对象和结果集对象 Jp~zX
lu
X.V[0$.;
的综合体,而传入的参数page对象则可以由前台传入,如果用 -t-tn22
5v
_P
Oq
webwork,甚至可以直接在配置文件中指定。 fZ{[]dn[
$>q@SJ1q
下面给出一个webwork调用示例: !#N\b
java代码: N#k61x
r{K;|'d%h
Im?LIgt$
/*Created on 2005-6-17*/ 'EhBRU%
package com.adt.action.user; L%h/OD
>I'%!E;
import java.util.List; eV};9VJ$F
.*5 Z"Q['G
import org.apache.commons.logging.Log; ~Xv=9@,h
import org.apache.commons.logging.LogFactory; `dW]4>`O
import org.flyware.util.page.Page; w0J|u'H
\".^K5Pm
import com.adt.bo.Result; Zv!{{XO2;
import com.adt.service.UserService; ,r^"#C0J}
import com.opensymphony.xwork.Action; 57I}RMT"
jNyoN1M
/** #&8rcu;/
* @author Joa 7Y( 5]A9=
*/ iK;opA"
publicclass ListUser implementsAction{ \RG!@$i
9A$m$
privatestaticfinal Log logger = LogFactory.getLog KZ:hKY@q
h<l1U'Bn7
(ListUser.class); NXk!qGV2
p,W_'?,9
private UserService userService; <48<86TP
\}"m'(\c
private Page page; >U!*y4
5M_Wj*a}7
privateList users; l=m(mf?QBg
rf
K8q'@
/* Ol/N}M|3
* (non-Javadoc) n"D ?I
* #"*e+.j[;
* @see com.opensymphony.xwork.Action#execute() #JW+~FU`
*/ 9pSUIl9|j
publicString execute()throwsException{ Ud(`V:d
Result result = userService.listUser(page); ~mp0B9L%
page = result.getPage(); svhI3"r
users = result.getContent(); kxB.,'
return SUCCESS; g P}+wbk
} IDFFc&
pPro }@@
/** 5/0j}_pP
* @return Returns the page. 1DJekiWf
*/ NL"G2[e
public Page getPage(){ )A8v];.]3
return page; `BXS)xj
} c-4STPNQi
dp5cDF}l
/** {MBTP;{*~
* @return Returns the users. ,. EBOUW^
*/ gFN9jM
publicList getUsers(){ uaPx"
return users; ^TdZ*($5
} ~N0sJ%
n# 7Pr/*0
/** |NFZ(6vNh
* @param page Ctu?o+^;z
* The page to set. ~qP[eWe
*/ >{zk
qvsQ&
publicvoid setPage(Page page){ 0y#Ih {L
this.page = page; nHXX\i
} \IM4Z|NN"
mEAXM1J|
/** @x&P9M0g
* @param users Sv[ 5NZn0&
* The users to set. &(pjqV
*/ Lxl_"kG
publicvoid setUsers(List users){ HL K@xKD<
this.users = users; _8?o'<!8?^
} =r.
>N\
/F/;G*n
/** S~OhtHwK
* @param userService ssQ BSbx
* The userService to set. 2\<.0
*/ ps|)cW3`
publicvoid setUserService(UserService userService){ kGYTl,A{
this.userService = userService; tln37vq
} .?W5{U
} @z`@f"l
R
W/z1
Fj
p.T;
WgQBGch,!
rSXzBi{
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, (8a#\Y[b
pbXi9|bI
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 1 jb/o5n;
F\JUx L@8
么只需要: K95;rd
java代码: %3Z/+uT@v]
kSncZ0K{
e&<yX
<?xml version="1.0"?> 0ezYd S~o
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork {Tp2H_EG
6=GZLpv
1.0//EN" "http://www.opensymphony.com/xwork/xwork- Q9F)
W&Y"K)`
1.0.dtd"> VyLH"cCv
eDKxn8+(H
<xwork> D@ek9ARAq
I27,mS+]
<package name="user" extends="webwork- F=a+z/xKT
&dB-r&4;+
interceptors"> kma?v B
coE&24,0
<!-- The default interceptor stack name .x83Ah`
Pt,ebL~
--> r),PtI0X
<default-interceptor-ref sN=6 gCau
jH;Du2w
name="myDefaultWebStack"/> `6=-WEo
&]6)LFm
<action name="listUser" gxNL_(A
<=K qcHb
class="com.adt.action.user.ListUser"> 6 ,ANNj
<param _u0$,Y?&