Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 )\=xPfs
+q'1P}e
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 5EcVW|(
[i/!ovcY
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 gK`w|kh`
'v~'NWfd
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 7>__ fQu
#%\0][Xf
。 0H}tb}4
3WJk04r
分页支持类: `a4&_`E,p
3X`9&0:j%
java代码: ]`|$nU}v
0bDc
4m
[3G{NC|'
package com.javaeye.common.util; >8"Svt$
Oh*~+/u}q
import java.util.List; M`H#Qo5/
BsIF3sS#9
publicclass PaginationSupport { 1N8] ~j
@@Ybg6.+*
publicfinalstaticint PAGESIZE = 30; D4!;*2t
FOsd{Fw
privateint pageSize = PAGESIZE; nc k/Dw
sv%X8
privateList items; `Npa/Q
_xaum
privateint totalCount; {Ya$Q#l
Swhz\/u9
privateint[] indexes = newint[0];
0Idek
vPNbV
privateint startIndex = 0; +?{"Q#.>;
5wx_ol}2
public PaginationSupport(List items, int rUb{iU;~m
1'E=R0`pA
totalCount){ E(r_mF7:
setPageSize(PAGESIZE); |q*yuK/
setTotalCount(totalCount); NZvgkci_(u
setItems(items); Trv}YT.
setStartIndex(0); Ay?<~)H
} O2{["c
e
?'MkaG0g
public PaginationSupport(List items, int "[_j8,t`
f CU]
totalCount, int startIndex){ ;'n%\*+fHH
setPageSize(PAGESIZE); t{]Ew4Y4%O
setTotalCount(totalCount); kXwAw]ogN
setItems(items); f8:nKb>nq$
setStartIndex(startIndex); S;% &X
} I`V<Sh^Qd
|2j,
public PaginationSupport(List items, int 90Ki.K 0
m)tu~neM
totalCount, int pageSize, int startIndex){ ~S8:xG+s
setPageSize(pageSize); "]S
setTotalCount(totalCount); + `|A/w
setItems(items); 9&Jf4lC94
setStartIndex(startIndex); &>JP.//spi
} mJUM#ry
*:n~j9V-
publicList getItems(){ Z3S+")^
return items; Nm?^cR5r
} zZ=SAjT QP
A(FnU:
publicvoid setItems(List items){ #f2Ot<#-
this.items = items; L
kK
*.
} MGR:IOTa
kUd]8Ff!
publicint getPageSize(){ cRT'?w`}
return pageSize; &i5@4,p y9
} tMxde+$y
S<0 &V
publicvoid setPageSize(int pageSize){ @_+aX.,
this.pageSize = pageSize; r2=@1=?8
} Nz
dN4+
Z`S#> o
publicint getTotalCount(){ lfgJQzi
G
return totalCount; Hl$W+e|tj
} 28!C#.(h
b>uD-CSA
publicvoid setTotalCount(int totalCount){ C"I
jr=w
if(totalCount > 0){ E4X6f
this.totalCount = totalCount; gm9*z.S\'
int count = totalCount / kXz~ez 7
Nr4}x7
pageSize; F1Z'tjj+
if(totalCount % pageSize > 0) 'PF>#X''
count++; FZi@h
indexes = newint[count]; ER"69zQg|2
for(int i = 0; i < count; i++){ ,Z{\YAh1
indexes = pageSize * U=n7RPw
sYKx3[ V/
i; 2k.VTGak
} }Ng P`m
}else{ zgb$@JC
this.totalCount = 0; 6K.2VY#
} <`nShP>vl
} rpow@@ad<
~q`!928Gu
publicint[] getIndexes(){ dNe!X0[
return indexes; (?4%Xtul1
} &S >{9y%
n>'(d*[e&
publicvoid setIndexes(int[] indexes){ j`_S%E% X
this.indexes = indexes; uxfh?gsL
} [q9B"@X
B;9,Qbb
publicint getStartIndex(){ OUBGbld
return startIndex; +x%u?ZR
} qb"S
|*bUcS<S
publicvoid setStartIndex(int startIndex){ C$w%!
jE
if(totalCount <= 0) ^'X
I%fEf
this.startIndex = 0; ('&lAn
elseif(startIndex >= totalCount) {ZeY:\G~
this.startIndex = indexes 65LtCQ}
't<iB&wgF
[indexes.length - 1]; [:X@|,1V!L
elseif(startIndex < 0) I*rUe#$
this.startIndex = 0; b31$i 5{
else{ ^to*ET{0
this.startIndex = indexes u]*7",R
uU
2C
S9v
[startIndex / pageSize]; @ m`C%7<
} 7@c!4hmrU
} iYXD }l;r
;$D,w
publicint getNextIndex(){ opa/+V3E4
int nextIndex = getStartIndex() + wv\X
zhJeTctRz
pageSize; Gk:fw#R
if(nextIndex >= totalCount) 1Yb &E7j
return getStartIndex(); k{*EoV[.$
else 4%0s p
return nextIndex; 0,hs%x>v
} {~apY,3
m
H:Un{,
publicint getPreviousIndex(){ S1=P-Ao
int previousIndex = getStartIndex() - S#ryEgc]
,M.C]6YMr
pageSize; 2}^=NUM\NX
if(previousIndex < 0) k^7!iOK2
return0; *R6lK&
else 0AM_D >fH
return previousIndex; lT[,w9 $
} ,:Px(=d4
u|<?mA!
} H;`F}qQ3
czRBuo+k+
SK}jhm"y
<EC"E #p
抽象业务类 j~'.XD={
java代码: G2`YZ\
H&s`Xr
ykQb;ZP8jh
/** ?8
}pZ_ j
* Created on 2005-7-12 +s#%\:Y M
*/ I[E 6N2
package com.javaeye.common.business; {t;o^pUF
~&~4{
import java.io.Serializable; Y1cL dQn
import java.util.List; :'DX
M{
0Y oKSo
import org.hibernate.Criteria; E$%v);u
import org.hibernate.HibernateException; 7~2_'YX>:
import org.hibernate.Session; K+Him]
b
import org.hibernate.criterion.DetachedCriteria; +"84.PZ
import org.hibernate.criterion.Projections; A^aY-V
import /3)\^Pof
F
w{:shC
org.springframework.orm.hibernate3.HibernateCallback; 7#JnQ|
]
import }hy4EJ
[60y.qE
org.springframework.orm.hibernate3.support.HibernateDaoS 5 =;cN9M@
8YZ9
upport; -gGw_w?)(
]O;*Y{:Y
import com.javaeye.common.util.PaginationSupport; =*fq5v
\zU<o~gs
public abstract class AbstractManager extends }wo:1v8J
0^*,E/}P&
HibernateDaoSupport { ,|c;x1|O
&/m^}x/_W
privateboolean cacheQueries = false; u""26k51
^m7y=CJM
privateString queryCacheRegion; TJYhgna
i>S@C@~
publicvoid setCacheQueries(boolean 8`S1E0s
3^KR{N p
cacheQueries){ <IWg]AJT:
this.cacheQueries = cacheQueries; 1{/Cr K/o
} .]E"w9~
ta95]|z"j
publicvoid setQueryCacheRegion(String ,~7~ S"
g]j&F65D
queryCacheRegion){ 6}Y==GPt
this.queryCacheRegion = >}wFePl
~> )>hy)
queryCacheRegion; tRPIvq/
} ZeG4z({af
0J?443AY
publicvoid save(finalObject entity){ }alq~jY
getHibernateTemplate().save(entity); >Ec;6V
e
} xw{K,;WeO
(6/aHSXI
publicvoid persist(finalObject entity){ F
u5zj\0J
getHibernateTemplate().save(entity); S?Cd,WxT
} XRV~yBIS
<:AA R2=
publicvoid update(finalObject entity){ h}|.#!C3
getHibernateTemplate().update(entity); N5W!(h)
} ?6"U('y>n
'hu'}F{
publicvoid delete(finalObject entity){ 7
2i&-`&4
getHibernateTemplate().delete(entity); S*n5d >;
} 3 }sy{Mx%9
x
[vbi
publicObject load(finalClass entity, qYoU\y7
HjzAFXRG
finalSerializable id){ W)Mz1v #s
return getHibernateTemplate().load J>+\a1{
zk1]?
(entity, id); 8 # BR\
} 63'%+
]w,|WZm
publicObject get(finalClass entity, `
>>]$ZJ
cSv;HN:
finalSerializable id){ Zqf
ovG
return getHibernateTemplate().get 'b" 7Lzp2
!yi*Zt~
(entity, id); KXz7l\1Gb
} mYfHBW:
-1hCi!
publicList findAll(finalClass entity){ OZz/ip-!lc
return getHibernateTemplate().find("from 9]T61Z{OW1
OK-*TPrc
" + entity.getName()); /?j
kVy*"
} *Cp:<Mnd
j"Ew)6j
publicList findByNamedQuery(finalString `c^">L
4KHIUW$
namedQuery){ (QojIdHt
return getHibernateTemplate 6)ysiAH?
;P}007;
().findByNamedQuery(namedQuery); S&&QU#
} FWp ?l
xEq? [M
publicList findByNamedQuery(finalString query, ?b}e0C-a
9:3`LY3wW
finalObject parameter){ gw">xt5
return getHibernateTemplate Kv:.bHN}
jUZ$vyT
().findByNamedQuery(query, parameter); ![4_K':=
} uT=5zu
-glGOTk
publicList findByNamedQuery(finalString query, "E4CQL'U
MLiaCG;
finalObject[] parameters){ u] G
return getHibernateTemplate BW3Q03SW6
!?J-Y
().findByNamedQuery(query, parameters); 8df| 9E$
} A5\ Hq
<gFisc/#r
publicList find(finalString query){ P;K3T![
return getHibernateTemplate().find cdGBo4
GJU9[
(query); Yi[MoYe/K
} >o3R~ [
{61Y;
publicList find(finalString query, finalObject f<oU"WM
3 _!MVT
parameter){ 9@mvG^
return getHibernateTemplate().find @A`j Wao
/C<p^#g9.
(query, parameter); OZz!8-|wE
} l&kZ6lZ
Q Wc^}#!!
public PaginationSupport findPageByCriteria $Xu/P5
a2]ZYY`R7
(final DetachedCriteria detachedCriteria){ Wi,)a{
return findPageByCriteria JvP>[vb
-eD]gm
(detachedCriteria, PaginationSupport.PAGESIZE, 0); paMK]-
} *(5T?p[7
x&+&)d
public PaginationSupport findPageByCriteria se]&)%p[
darbL_1
(final DetachedCriteria detachedCriteria, finalint oSjYp(h:
3Of!Ykf=
startIndex){ <9:~u]ixt
return findPageByCriteria `ueOb
]n"U])pJd
(detachedCriteria, PaginationSupport.PAGESIZE, kkMChe};5
M)Z!W3
startIndex); >#gDk K
} q"S,<I<f
nqTOAL9FF
public PaginationSupport findPageByCriteria Tdz#,]Q
nZ#u#V
(final DetachedCriteria detachedCriteria, finalint ""_G4{
*DZ7,$LQ~D
pageSize, iTT%_-X-
finalint startIndex){ |;d#k+/;
return(PaginationSupport) -yBj7F|
JR&yaOws
getHibernateTemplate().execute(new HibernateCallback(){ :)T*:51{#
publicObject doInHibernate ;mGPX~38
/EegP@[
(Session session)throws HibernateException { YTTij|(
Criteria criteria = `
vFD O$K
\d]Y#j<
detachedCriteria.getExecutableCriteria(session); )^"V}z
t
int totalCount = D@ !r?E`
M&gi$Qs[E
((Integer) criteria.setProjection(Projections.rowCount KK6z3"tk5
^K_FGE0ec
()).uniqueResult()).intValue(); Br42Qo2"T>
criteria.setProjection >LN*3&W
:O,r3O6
(null); )l!`k
List items = #Q-#7|0&
:xbj&
l
criteria.setFirstResult(startIndex).setMaxResults qdmAkYUC
| WTWj
(pageSize).list(); Yo=$@~vN]
PaginationSupport ps = EA9.?F
Tr|PR t
new PaginationSupport(items, totalCount, pageSize, ^e;9_(
K=}Eupn=
startIndex); ~{-Ka>A
return ps; r ?<kWR?w
} v ;Q*0%~
}, true); v,z~#$T&
} #n15_cd
Dv`"3
public List findAllByCriteria(final 4sRg+mMI
6BEpnw>p(
DetachedCriteria detachedCriteria){ ~-uf%=
return(List) getHibernateTemplate yHlQKI
7 b(
().execute(new HibernateCallback(){ *QIYq
publicObject doInHibernate #h
U4gX,
J7aYi]vI
(Session session)throws HibernateException { kumo%TXB&
Criteria criteria = |cp_V
9V&+xbR&
detachedCriteria.getExecutableCriteria(session); iQT0%WaHl
return criteria.list(); `kv7Rr}Q
} <sM_zoprc
}, true); j6$@vA)
} BYHyqpP9
e8oAGh"
public int getCountByCriteria(final Nh/i'q/
!b4AeiL>w
DetachedCriteria detachedCriteria){ S')DAx
Integer count = (Integer) :hW(2=%
j8bA"r1
getHibernateTemplate().execute(new HibernateCallback(){ (: kn)
publicObject doInHibernate L:mE)Xq2
T /IX(b'<
(Session session)throws HibernateException { ,aBy1K
Criteria criteria = Q=vo5)t
.f. tPm
detachedCriteria.getExecutableCriteria(session); &m[}%e%~0
return M5d EZ
YGs'[On8
criteria.setProjection(Projections.rowCount 0T#z"l<L
x?u@
j7[
()).uniqueResult(); >SziRm>Y7
} s|c}9/Xe)
}, true); H.C*IL9
return count.intValue(); *=v%($~PK6
} kTT%<
e
} :pz@'J
ips)-1
Y}s6__
qdKqc,R1{
KLVYWZib
c+T`X?.j
用户在web层构造查询条件detachedCriteria,和可选的 Uam%u
x>BFK@#
startIndex,调用业务bean的相应findByCriteria方法,返回一个 ,O-_Pv
)p> p3b g
PaginationSupport的实例ps。 &b*v7c=o
q
_K@KB
ps.getItems()得到已分页好的结果集 h"Wpb}FT
ps.getIndexes()得到分页索引的数组 #Z
`Tk)u/
ps.getTotalCount()得到总结果数 (18ZEKk
ps.getStartIndex()当前分页索引 0pW;H|h
ps.getNextIndex()下一页索引 @|">j#0
ps.getPreviousIndex()上一页索引 ot!m=s
TvT>UBqj=
sKR%YK
"A
_LfbEv<,T
ZF#n(Y?
0:4>rYBC
kRb JK
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 )^4Ljb1
L\c3D|
,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 /uDcJ1u66
Knb(MI6
一下代码重构了。 oTXIs4+G
PvjZoF["
我把原本我的做法也提供出来供大家讨论吧: Y$c7uA:4
F:jtzy"
首先,为了实现分页查询,我封装了一个Page类: 8f)pf$v`
java代码: Le bc@,
c~OPH
0,
T@#?{eA
/*Created on 2005-4-14*/ _nxu8g]
package org.flyware.util.page; F]>+pU
0o6o<ggi
/** gae=+@z
* @author Joa O<,\tZ'N
* l7VTuVGUJ
*/ EK0~3HSZ
publicclass Page { Xppb|$qp4H
$MNJsc^n
/** imply if the page has previous page */ !?+0O]`}
privateboolean hasPrePage; Lpkx$QZ
~Jw84U{$
/** imply if the page has next page */ gYk5}E-
privateboolean hasNextPage; }opMf6`w
KQ81Oxu*C
/** the number of every page */ ]F>#0Rdc
privateint everyPage; ru`U/6n
9h)8Mq+M
/** the total page number */ $ #GuV'
privateint totalPage; 7j&EQm5\9
RF'nwzM3
/** the number of current page */ 9b,0_IMHH
privateint currentPage; Ct~j/.
_j0xL{&&
/** the begin index of the records by the current xFM^-`7
jAy2C&aP
query */ p$jAq~C
privateint beginIndex; shy[>\w
&N6[*7
1=,2i)
/** The default constructor */ :2
:VMIa
public Page(){ Zz/p'3?#
#G`K<%{?f
} @H~oOf
_~C1M&b(X3
/** construct the page by everyPage 5/h-Hr
* @param everyPage zks7wt]A
* */ JXq!v:w6
public Page(int everyPage){ 7l=Tl[n
this.everyPage = everyPage; |s(Ih_Zn
} `#8k Jt
6vps`k$,~
/** The whole constructor */ *jPd=+d
public Page(boolean hasPrePage, boolean hasNextPage, =_m3~=Z
]o0]i<:
j&Xx{ 4v
int everyPage, int totalPage, .j^BWr
int currentPage, int beginIndex){ /^\E:(RH
this.hasPrePage = hasPrePage; 74:~F)BP
this.hasNextPage = hasNextPage; p8@&(+z
this.everyPage = everyPage; ']I!1>v$[
this.totalPage = totalPage; o,c}L9nvt
this.currentPage = currentPage; d6JW"
this.beginIndex = beginIndex; yE,qLiH
} |K{d5\_
AJ&j|/
/** qq<T~^
* @return p8)R#QWz9
* Returns the beginIndex. kN{$-v=K
*/ !!V1#?0jw
publicint getBeginIndex(){ 2Vf242z_
return beginIndex; G `!A#As
} /J/V1dC}]D
|o9`h 9i
/** G8%VL^;O*5
* @param beginIndex 8zlvzp
* The beginIndex to set. <DR!AR)
*/ "M[&4'OM
publicvoid setBeginIndex(int beginIndex){ .s,04xW\
this.beginIndex = beginIndex; tvFe_*Ck
} +L.D3
6S_mfWsi
/** dhnX\/
* @return 9s[
* Returns the currentPage. m;>G]Sbe
*/ Ert={"Q
publicint getCurrentPage(){ Eri007? D
return currentPage; ^--R#$X
} 6D2ot&5WW
.[1 f$
/** js Z"T
* @param currentPage ;]m;p,$
* The currentPage to set. r4K9W90
*/ F!u)8>s+z{
publicvoid setCurrentPage(int currentPage){ |nnFjGC`~
this.currentPage = currentPage; !z4I-a
} 9{j`eAUZl
Jj=N+,km
/** Wex2Fd?DO
* @return 3%GsTq2o
* Returns the everyPage. cNmAr8^}
*/ 41Q)w=hoN
publicint getEveryPage(){ 26k~Z}
return everyPage; V?"U)Y@Y
} *C+[I
a.gMH
uL
/** RHNAHw9
* @param everyPage er-0i L@
* The everyPage to set. YzM/?enK}T
*/ /.!&d^
publicvoid setEveryPage(int everyPage){ &-Wt!X 3
this.everyPage = everyPage; >#;;g2UV
} (2L,m
dJnKa]X
/** j#P4&
* @return .|07IH/Di{
* Returns the hasNextPage. c U(z5th
*/ .B2e$`s$
publicboolean getHasNextPage(){ {fl[BX]kZ
return hasNextPage; V(0Y
} |IzL4>m:;
Ax~
i`
/** Hmhsb2`\
* @param hasNextPage R[v<mo[s
* The hasNextPage to set. o~9*J)X5i
*/ $E^sA|KcT
publicvoid setHasNextPage(boolean hasNextPage){ W1xPK*
this.hasNextPage = hasNextPage; y $uq`FW
} Oe@w$?
noa+h<vGb
/** H\<0{#F
* @return %P<fz1
* Returns the hasPrePage. %'e$N9zd
*/ #Y-_kQV*
publicboolean getHasPrePage(){ AT3HHQD
return hasPrePage; <_eEpG}9
} V3VTbgF
AU%Yr6
/** m
zoH$@
* @param hasPrePage o(l%k},a
* The hasPrePage to set. upk_;ae
*/ $J)`Ru6.
publicvoid setHasPrePage(boolean hasPrePage){ yW7>5r
this.hasPrePage = hasPrePage; ,d_rK\J
} \vV]fX
4Jc~I
/** eUCBQK
* @return Returns the totalPage. z%+rI
* #sjGju"#_
*/ 09Eg ti.
publicint getTotalPage(){ Lp|n)29+du
return totalPage; DQV9=
} N:+EGmp
8
Elhcs
/** "ixea- 2
* @param totalPage ~/aCzx~
* The totalPage to set. '4~I%Z7L
*/ Tl-%;X<X
publicvoid setTotalPage(int totalPage){ R! X+-
this.totalPage = totalPage; wnXU=
} e F}KOOfC
FrLv%tK|
} d>zC[]1
8$iHd
*nHMQ/uf
E|_8#xvb
yn(bW\
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 7u:kR;wk
eBmHb\
个PageUtil,负责对Page对象进行构造: .s41Tc5u
java代码: Rm$( X5x>o
Lrr(7cH,
yqtHlz%
/*Created on 2005-4-14*/ Jx`7W1%T
package org.flyware.util.page; Z:x`][vg
K g.O2F77
import org.apache.commons.logging.Log; ,->5 sJ{U
import org.apache.commons.logging.LogFactory; -w)v38iX!
^x^(Rk}|
/** 4,Uqcw?!F'
* @author Joa #(+V&<K
* H`q[!5~8
*/ swJQwY
publicclass PageUtil { 4_'B oU4
-GB,g=Dk
privatestaticfinal Log logger = LogFactory.getLog ty%,T.@e
Ja/
(PageUtil.class); A
=&`TfXu
Vr%ef:uVV
/** eC6wrpZO
* Use the origin page to create a new page 7<B-2g
* @param page %AWc`D
* @param totalRecords 3QdCu<eBZ
* @return _nX8f
&
*/ EUV8H}d5
publicstatic Page createPage(Page page, int "*MF=VB1
44YKS>Cq
totalRecords){ Wfc~"GQq4
return createPage(page.getEveryPage(), BD^1V(
I/
}*qj,8-9
page.getCurrentPage(), totalRecords); "oF)u1_?
} YGc:84S
[U"/A1p
/** /J&DYxl":
* the basic page utils not including exception kh#fUAt
%p&y/^=0I
handler wg\p&avvb
* @param everyPage Mk+G(4p
* @param currentPage yg~@}_C2_
* @param totalRecords z%lJWvaA7
* @return page M#m;jJqON
*/ *BF[thB:a
publicstatic Page createPage(int everyPage, int 0?gHRdU"
27$,D XD
currentPage, int totalRecords){ HXZ,"S
everyPage = getEveryPage(everyPage); \ a(ce?C
currentPage = getCurrentPage(currentPage); iXvrZofE
int beginIndex = getBeginIndex(everyPage, ;G3?Sa7+
Y}<%~z#.4
currentPage); 1Ax;|.KQH
int totalPage = getTotalPage(everyPage, n5IQKYrg
<dr2 bz
totalRecords); u3pFH(
boolean hasNextPage = hasNextPage(currentPage, ha 2=O
{B6ywTK\`
totalPage); rK:cUW0]X
boolean hasPrePage = hasPrePage(currentPage); YgS,5::SU
"h7Dye
returnnew Page(hasPrePage, hasNextPage, K,%CE
].
everyPage, totalPage, f:J-X~T_f
currentPage, ~<s =yjTu+
Ude?[6
beginIndex); "dvo@n|
} 1KBGML-K3
W7!iYxO
privatestaticint getEveryPage(int everyPage){ n+YUG
return everyPage == 0 ? 10 : everyPage; `<M>"~W
} /!MKijI
PiCGZybCA
privatestaticint getCurrentPage(int currentPage){ ;DR5?N/a
return currentPage == 0 ? 1 : currentPage; 1<_/Qu>V
} }^p<Y5{b
aW{5m@p{"
privatestaticint getBeginIndex(int everyPage, int cY kb3(
~a&VsC#
currentPage){ a_?b<
return(currentPage - 1) * everyPage; gTU5r4xm~
} ~dp f1fP
N2duhI6
privatestaticint getTotalPage(int everyPage, int h,]VWG
Qr4 D
totalRecords){ Z[ (d7
int totalPage = 0; [A"=!e$<
TB+k[UxB
if(totalRecords % everyPage == 0) !jSgpIp
totalPage = totalRecords / everyPage; AovBKB
$
else 72yJv=G
totalPage = totalRecords / everyPage + 1 ; [0]A-#J
cBZEyy&
return totalPage; 0`-b57lF&
} ]W`?0VwF
q#8yU\J|,
privatestaticboolean hasPrePage(int currentPage){ J@6j^U
return currentPage == 1 ? false : true; #vga
qe9
} 9q_{_%G%
Y68A+
B.
privatestaticboolean hasNextPage(int currentPage, Sp:w _;{#
5rdB>8W
int totalPage){ 7*KUM6z
return currentPage == totalPage || totalPage == rqqd} kA
s-PS]l@
0 ? false : true; [xr^t1
} <<A#4!f
f pq|mY
-n"wXOx3
} 4_U"M@
%'2.9dB
H${L F.8
Mh5>
hD
s_VcC_A
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 p$'S\W|
2tpu v(H;
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 Hxgc9Fis
/3~L#jS
做法如下: xn503,5G*7
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 8{2
TaBya0-
的信息,和一个结果集List: d9;&Y?fp
java代码: %gAT\R_f
nk%v|ZxoFv
7KhS{w6
/*Created on 2005-6-13*/ fPUr O
package com.adt.bo; &TQ~!ZMOR"
zHX\h[0f
import java.util.List; ,mp<<%{u
"}*D,[C5e
import org.flyware.util.page.Page; /u4RZ|&as
g}D)MlXRq
/** NF6xKwRU]_
* @author Joa ZxwrlaA
*/ bN zb#P#hP
publicclass Result { goIvm:?
bAZoi0LR
private Page page; uo]xC+^
@`4T6eL5
private List content; /)Cfm1$ic
b3E1S+\=~
/** aX;>XL4
* The default constructor
w_Slg&S
*/ BA2"GJvfIA
public Result(){ BKg8p]`+
super(); P|$n
} l1DJ<I2
M8X6!"B$Y
/** OVi<d
* The constructor using fields 8O'bCBhv
* s;OGb{H7
* @param page E .Xp\Dm71
* @param content c#{lXS^
*/ j*?8w(!
public Result(Page page, List content){ SZ9Oz-?
this.page = page;
|gO7`F2
this.content = content; {S{ %KkAV
} 72OqXa*
A[+)PkR
/** 0>BxS9?w
* @return Returns the content. M\m:H3[
*/ Lxp}o7>K
publicList getContent(){ f%o[eW#
return content; R QQ'Wg
} zX_F+"]THt
=SLG N`m3
/** 0* F` h
* @return Returns the page. aKriO
*/ ),p0V
public Page getPage(){ `&D#P%
return page; >k\pSV[
} 940:NOgm
U=~?ca
/** (Ut8pa+yX
* @param content T$D(Y`zdn
* The content to set. #]jl{K\f#X
*/ ^H.B6h?
public void setContent(List content){ TxPFl7,r
this.content = content; x8@ 4lxj
} T&'Jc
Sxq@W8W
/** n/5T{ NfG
* @param page %JE>Z]
* The page to set. RlL]p`g
*/ JI.=y5I
publicvoid setPage(Page page){ Q<V(#)*
this.page = page; ^_ch%3}Im
} X=whZ\EZ
} $.Tn\4z&
L=#NUNiXr
(Y)2[j
T<0 r,
nnj<k5
2. 编写业务逻辑接口,并实现它(UserManager, L6_%SGY_iE
wvq4 P
UserManagerImpl) i6KfH\{N
java代码: I0zx'x)F
Qa_V
33DP?nI}
/*Created on 2005-7-15*/ %N-aLw\
package com.adt.service; ?{ExBZNa
Bn]=T
import net.sf.hibernate.HibernateException; ^ 4<