http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !iKW1ks
} 1H-Y3G>jN
for(int i=0;i<nEndPos.length-1;i++) ]]PNYa
{ <E4(KE
nEndPos = nStartPos[i+1]; Ze~P6
} 7P+1W \
nEndPos[nEndPos.length-1] = nFileLength; ^)~Smj^d
} Xx{| [2`
} |@u2/U9
|CDM(g>%
D<6$@ZJ
//启动子线程 /e0B$UymFu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (Lgea
for(int i=0;i<nStartPos.length;i++) ?Fl}@EA#M
{ v1,#7sAW'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fWmc$r5n](
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H54RA6$>
nStartPos,nEndPos,i); o~~;I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6kH6"
fileSplitterFetch.start(); !FL"L 9
} o99ExQ.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zWC| Qe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1?Y>Xz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #"N60T@
nEndPos = " + nFileLength); yjjq&Cn
// fileSplitterFetch[nPos.length-1].start(); {$z54nvw$
5G`HJ6
:hZM$4
//等待子线程结束 IE`3I#v
//int count = 0; idYB.]Y(
//是否结束while循环 TmG);B}
boolean breakWhile = false; Hh1_zd|
V'&;r'#O
.yj@hpJM
while(!bStop) :*}Q/]N
{ ( V4Ppg
write_nPos(); Y"mFUW4
Utility.sleep(500); 5skN'*oG
breakWhile = true; kEDpF26!
lcdhOjz!N
;7P'>j1?U
for(int i=0;i<nStartPos.length;i++) |(.\J`_e
{ qdix@@
if(!fileSplitterFetch.bDownOver) /Q;wz!V$
{ 4H#-2LV`
breakWhile = false; j}^w:W76
break; [./FzlAs
} CPOHqK`k
} aJ+V]WmA
if(breakWhile) ~m6=s~Vn
break; =Wcvb?;*
B]X8KzLu
p3M!H2W
//count++; " @D
//if(count>4) ab6I*DbF
// siteStop(); 8FuxN2
} )=5&Q
\l59/ZFan
)pHtsd.eP
System.err.println("文件下载结束！"); &en. m>9,
} Wlc&QOfF
catch(Exception e){e.printStackTrace ();} O%EA,5U.
} wEjinP$2
4,)9@-|0R
I){4MoH.
//获得文件长度 \qG?'Iy
public long getFileSize() 9nG^_.}|
{ /7UvV60
int nFileLength = -1; ,#)d
try{ 9+@h2"|N4*
URL url = new URL(siteInfoBean.getSSiteURL()); ~+Gh{,f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &r1(1<
httpConnection.setRequestProperty("User-Agent","NetFox"); 1&MCS%UTL
[M\ an6h6O
3}|[<^$
int responseCode=httpConnection.getResponseCode(); :c/54Ss~
if(responseCode>=400) kq}byv}3I
{ G8av5zR
processErrorCode(responseCode); ?AyxRbk
return -2; //-2 represent access is error zZ%[SW&vC
} >. K
vJ&_-CX
~Gfytn9x.;
String sHeader; GLf!i1Z
?EFRf~7JP
_WEJ,0*#'
for(int i=1;;i++) ,6>3aD1w~q
{ `]KX`xGK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NxHUOPAJc
//Utility.log(in.readLine()); ~Zr}QO}G
sHeader=httpConnection.getHeaderFieldKey(i); aC,adNub
if(sHeader!=null) D;R~!3f./b
{ ,U\s89
if(sHeader.equals("Content-Length")) %/A>'p,~
{ +9Tc.3vQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u$d[&|`>_
break; aj5HtP-
} '-v:"%s|
} leC!Yj
else ^C'S-2nGH
break; n#">k%bD
} LSC[S:
} z x-[@G
catch(IOException e){e.printStackTrace ();} P*&[9)d6
catch(Exception e){e.printStackTrace ();} uyYV_Q0~;
nqy*>X`
:BPgDLL,
Utility.log(nFileLength); FSMM
0b{jox\!B
,iyy2
return nFileLength; 0f@+o}i=)
} :M"+
_WZx].|A=
9Vt ^q%DC
//保存下载信息（文件指针位置） )-4c@
private void write_nPos() Jinh#iar
{ 0Q{lyu
try{ .b";7}9{
output = new DataOutputStream(new FileOutputStream(tmpFile)); v[ iJ(C_
output.writeInt(nStartPos.length); AY52j
for(int i=0;i<nStartPos.length;i++) sx#O3*'>1
{ 8!2)=8|f
// output.writeLong(nPos); ;KQU% k$
output.writeLong(fileSplitterFetch.nStartPos); *HD(\;i-$
output.writeLong(fileSplitterFetch.nEndPos); ?g ,s<{
} 4~}NB%,
output.close(); (u 7Lh>6%
} Xe);LhDC
catch(IOException e){e.printStackTrace ();} 'UX^]
catch(Exception e){e.printStackTrace ();} D|zuj]
} ^&<M""Z
j6l1<3j
AOg'4
//读取保存的下载信息（文件指针位置） XCI
private void read_nPos() 2 ,nhs,FZ
{ Ar>B_*dr
try{ T:Cq}4k<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _#K|g#p5
int nCount = input.readInt(); WHC/'kvF
nStartPos = new long[nCount]; +<\LY(o
nEndPos = new long[nCount]; Tt~4'{Bc
for(int i=0;i<nStartPos.length;i++) ajycYk9<m
{ q?LOtN? o
nStartPos = input.readLong(); Zz} o t
nEndPos = input.readLong(); {qw'gJmX
} q_[y|ETJ]
input.close(); ;>7~@ K
} 5J`w8[;
catch(IOException e){e.printStackTrace ();} Q9cSrU[$
catch(Exception e){e.printStackTrace ();} zYaFbNi
} M %,\2!$
P.Tnq
N #v[YO`.
private void processErrorCode(int nErrorCode) ,It0brF
{ Kii@Z5R_?
System.err.println("Error Code : " + nErrorCode); )Cdw_Yx
} h>V6}(~;.
BZ\="N#f
ll5;09
//停止文件下载 ! #Pn_e
public void siteStop() pS8\B
{ x6K_!L*Fx]
bStop = true; ~Y43`@3H:
for(int i=0;i<nStartPos.length;i++) 3fLdceT
fileSplitterFetch.splitterStop(); E0qJ.v
k:n{AoUc
ds*gL ~k^
} xlZh(pf
} N]yT/8
//负责部分文件的抓取 7y^)n<'co
**FileSplitterFetch.java FTUfJIVN(
*/ 8T"L'{ggWB
package NetFox; ;ZB=@@l(
;r2DQg"#@
~d&&\EZ
import java.io.*; MY{Kq;FvRP
import java.net.*; zji9\
n$ByTmKxv
X,3"4 SK
public class FileSplitterFetch extends Thread { tV4yBe<``
P[aE3Felk
_9D]1f=&
String sURL; //File URL T.De1Q|
long nStartPos; //File Snippet Start Position )T '?"guh`
long nEndPos; //File Snippet End Position ]pNM~,
int nThreadID; //Thread's ID ],AtR1k
boolean bDownOver = false; //Downing is over Z3o HOy
boolean bStop = false; //Stop identical +Q"s!\5
FileAccessI fileAccessI = null; //File Access interface R;AcAJ;
8r}tf3xMCM
PUea`rE?R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [W$x5|Z}Q
{ =l2 @'YQ
this.sURL = sURL; 8Ud.t=2
this.nStartPos = nStart; Qv,ORm h5
this.nEndPos = nEnd; Lm$KR!z
nThreadID = id; c-zW 2;|61
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yo5-x"ze
} #U'}g *
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Z3zD4-p$_
public void run() + d>2'
{ Fu?_<G%Ynp
while(nStartPos < nEndPos && !bStop) ;t N@
{ ci%$So2#
W;Dik%^tg
R(> oyxA[F
try{ 0(5qVJ12
URL url = new URL(sURL); o7tlkSZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cooicKS7
httpConnection.setRequestProperty("User-Agent","NetFox"); EP4?+"Z
String sProperty = "bytes="+nStartPos+"-"; WO69Wo\C
httpConnection.setRequestProperty("RANGE",sProperty); /5KY6XxR
Utility.log(sProperty); ?/3{gOgI$`
rk+s[Qi~
|I]G=.*E
InputStream input = httpConnection.getInputStream(); ,o2x,I
//logResponseHead(httpConnection); {JQV~rfh`
SP=8v0
" u]X/ {L
byte[] b = new byte[1024]; $W;r S7b
int nRead; W)2k>cS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nKwOSGPQt
{ 22d>\u+c
nStartPos += fileAccessI.write(b,0,nRead); $*fEgU% c
//if(nThreadID == 1) w$qdV,s 7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dpdp0
} ]7,0}q.
9D5v0Qi
!9S!zRy@
Utility.log("Thread " + nThreadID + " is over!"); ,=u!hg
bDownOver = true; 2j^8{Agz
//nPos = fileAccessI.write (b,0,nRead); O8*yho
} _Pw5n mH c
catch(Exception e){e.printStackTrace ();} /GP:W6:6z6
} FYaBP;@J%
} #FGj)pu
:Mu]*N
0VgsV;
//打印回应的头信息 #9(iu S+BU
public void logResponseHead(HttpURLConnection con) mnYzn[d3U
{ pr\OjpvD
for(int i=1;;i++) ,7Q b24A
{ |3EKK:RE
String header=con.getHeaderFieldKey(i); e>HdJ"S`
if(header!=null) D<4cpH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =6,w~|W
Utility.log(header+" : "+con.getHeaderField(header)); XJ1<!tl
else VPDd*32HC
break; QlnI&o
} 5F5)Bh
} }@A{'q5y
KFHcHz
/kFw(l_.
public void splitterStop() yMe;
{ =.q8*7UY
bStop = true; *edhJUT
} 2$> <rB
Q[%+y.
d/I*$UC
} Cbr>\;sc2Z
KZsJ_t++!W
8|S}!P"
/* -]Q6Ril
**FileAccess.java }FAO.
*//文件访问(定位，写) -W"w
package NetFox; $mDlS
import java.io.*; X2C&q$8
tq8rG@-C
qa)Qf,`
public class FileAccessI implements Serializable{ k9oLJ<.k
Q\GSX RP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CW;=q[+w
RandomAccessFile oSavedFile; %@x.km3e2
long nPos; ^yVKW5x
{P $sQv
@6z]Xb
public FileAccessI() throws IOException 5(&'/U^
{ 0X4%Ccs
this("",0); L[.RV*sL
} }SBpc{ch
GMYfcZ/,K
qHra9yuSh
public FileAccessI(String sName,long nPos) throws IOException Qj',&b
{ zQyt1&!
oSavedFile = new RandomAccessFile(sName,"rw"); .Fn7yTQ%
this.nPos = nPos; m?pm)w
oSavedFile.seek(nPos); dG*2-v^G
} !p|d[
^|ln q.j
9w( Wtw'
public synchronized int write(byte[] b,int nStart,int nLen) hy{1Ea/T
{ ?*2Uw{~}
int n = -1; Jde@Th
try{ QcG-/_,'}
oSavedFile.write(b,nStart,nLen); Avn)%9
n = nLen; w{5v*SHl}`
} tw%z!u[a
catch(IOException e) Dt\rMSjZ9
{ a\?-uJ+
e.printStackTrace (); ! 4{T<s;q
} eg Zb)pP
LyA}Nd]pyq
/#xx,?~xx0
return n; ,"EgYd8-'
} &d/x1=
;<)<4N"
{m7>9{`
} bAZx*qE=
TIre,s)_
l.`f^K=8
/* U>=& 2Z2?
**SiteInfoBean.java K \_JG$(9
*/ q7ubRak
package NetFox; $~FnBD%|{
|v31weD8
@Rp#*{
public class SiteInfoBean { sbV {RSl
qxW^\u!<
Ir :y#
private String sSiteURL; //Site's URL iX\]-_D
private String sFilePath; //Saved File's Path }10ZPaHjl+
private String sFileName; //Saved File's Name vm Y*K
private int nSplitter; //Count of Splited Downloading File n+9rx]W,
#<EMG|&(
i]M:ntB"
public SiteInfoBean() 0G}]d17ho
{//nSplitter的缺省值为5 7t~12m8x
//default value of nSplitter is 5 ~rICPR
this("","","",5); t0-)\kXcA
} &h_do8R
7IUu] Fi
{]V+C=`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lbUUf}
{ FvVR \a
sSiteURL= sURL; y$6~&X
sFilePath = sPath; 3;Ztm$8
sFileName = sName; $zv&MD!&h
this.nSplitter = nSpiltter; ZxvBo4>tH
])3(@.
!bg2(2z
} tVFydN~
vE<z0l
W&`{3L
public String getSSiteURL() x}B_;&>&"_
{ (HD8Mm
return sSiteURL; 2=V~n)'a
} R7Z7o4jg
[ 30ta<-
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public void setSSiteURL(String value) A4
{ 6#za\[
sSiteURL = value; #[$zbZ(I>:
} q-|j =
i4s_:%+
h5^qo ^;g7
public String getSFilePath() :Cdqj0O3u
{ !)-)*T
return sFilePath; {#C)S&o)6
} jhF&
_ISaO C{2-
iPeW;=-2Wk
public void setSFilePath(String value) &V77WnOY
{ +]dh`8*8>1
sFilePath = value; 4Mck/i2
} CEHtr90P
,6AnuA
0Q4i<4 XW
public String getSFileName() $LOwuvu>
{ ##r9/`A
return sFileName; MR3\7D+9y
} 4];<` %
y)*W!]:7^>
&@[pJ2
public void setSFileName(String value) gUWW}*\ U
{ UVlh7wjg
sFileName = value; A!uO7".E
} Da-U@e!
{v>8Kp7_R
K'\Jnn
public int getNSplitter() !))!!{
{ [x8_ax}w
return nSplitter; x +]ek
} W87kE?,
Y?#aUQc
?A]/ M~3B
public void setNSplitter(int nCount) 0T2^$^g
{ FFq8LM8
nSplitter = nCount; :`B70D8ku
} 51gSbkVX
} @p%WFNR0
L}=t"y
>J) 9&?
/* BT^HlW<
**Utility.java q#PMQR"C
*/ }Uue}VOA
package NetFox; p1!-|Sqq
Av>xgfX
vlC$0P
public class Utility { ~?zu5,vb
utU;M*
^H`4BWc
public Utility() $EG9V++b3
{ ib%'{?Q.
GJIZu&C
}6"l`$=Ev
} +:3s f%0
V;d<S@$
//线程睡眠 vD76IG jm
public static void sleep(int nSecond) 3?Fe(!@
{ :"'*1S*
try{ `_e5pW=:>
Thread.sleep(nSecond); snP]&l+
} nQ@<[KNd
catch(Exception e) "Pl.G[Buc-
{ 0-:dzf
e.printStackTrace (); eCjyx|:J
} >Z>sR0s7
} nT9Hw~f<j
xg;vQKS6
//日志 bFVY&
public static void log(String sMsg) M>ntldV#g%
{ U>0bgL
System.err.println(sMsg); 3QCCX$,
} DfX~}km
VV"w{#XKw
G^:?)WRG
public static void log(int sMsg) mhI
{ 9^E!2CJ
System.err.println(sMsg); Mtc-
} =w7+Yt
} Fg0!2MKq*
yCwe:58
xy]oj
/* NH4T*R)Vz
**TestMethod.java ;Irn{O
*/ ]IH1_?HgP7
package NetFox; ?8FJMFv;4%
[U:P&)
N%9?8X[5
public class TestMethod { AWg'J
EFv^uve
:r7!HG_
public TestMethod() :mhO/Bx
{ ///xx/weblogic60b2_win.exe i,rX.K}X
try{ OHt^e7\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); thz[h5C?C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {s{+MbD
SiteFileFetch fileFetch = new SiteFileFetch(bean); GK[Hs1/
fileFetch.start(); T.W^L'L`
} tT+W>oA/M
catch(Exception e){e.printStackTrace ();} |Mgzb0_IiQ
qMw_`dC
;]k\F
} :KqSMuKR
! F<::fN
.>S1do+
public static void main(String[] args) mY]o_\`
{ 7~);,#[ky
new TestMethod(); Gd$!xN%O
} WWC&-Ni
} 5n1`$T.WG
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