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)); 3>Yec6Hs
} 3OTSLF/
for(int i=0;i<nEndPos.length-1;i++) #'8E%4
{ 6<2 7}S
nEndPos = nStartPos[i+1]; -LF^u;s8&S
} Tg[+K+b
nEndPos[nEndPos.length-1] = nFileLength; qzXch["So
} Gg/K
} zKR_P{W>^
m]85F^R0
aX~7NslR
//启动子线程 ^ `!6Yax?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5 gE
for(int i=0;i<nStartPos.length;i++) oY &r76
{ Wn|w~{d{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v vFX\j3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h4]yIM`8d
nStartPos,nEndPos,i); nlKWZYv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l+@NjZGm<
fileSplitterFetch.start(); 3SDw-k
} {epsiHK@tK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3AWg43L7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *9G;n!t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |[0|j/V%O
nEndPos = " + nFileLength); 0nC%tCV'
// fileSplitterFetch[nPos.length-1].start(); cxVnlgq1
,+0_kndR
jZ)1]Q2
//等待子线程结束 {'JoVJKv
//int count = 0; 0q81H./3
//是否结束while循环 &<4Jyhm:o
boolean breakWhile = false; V^"5cW
/Ue~W,|
2x0[@cTi?
while(!bStop) V5m4dQ>t
{ S?&ntUah
write_nPos(); %1S;y
Utility.sleep(500); (JOge~U
breakWhile = true; 1aKY+4/G
-(dc1?COi
[W` _`
for(int i=0;i<nStartPos.length;i++) 2\_}81hM
{ /K1YDq<=
if(!fileSplitterFetch.bDownOver) v. !L:1@I.
{ H_Vf_p?
breakWhile = false; v#F.FK
break; JpN+'/
} 0P z"[
} N,L$+wm
if(breakWhile) C/!kMMh>vV
break; nF]lSg&]X
so1% MV
.,I^)8c
//count++; Bf.@B0\
//if(count>4) Ft'?43J
// siteStop(); Y'wQ(6ok
} yi PMJ
aVEg%8
;BsyN[bF
System.err.println("文件下载结束！"); w!7Hl9BW
} ZJ1%
catch(Exception e){e.printStackTrace ();} !A qSG-
} R]H/Jv\'
}9=VhC%J
z^bv)u
//获得文件长度 *Mk5*_
public long getFileSize() It&$R`k
{ mGb,oj7l
int nFileLength = -1; g,*LP
try{ @uApm~}
URL url = new URL(siteInfoBean.getSSiteURL()); 63 F@Ft
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Eu2@%2}P
httpConnection.setRequestProperty("User-Agent","NetFox"); ;.+sz(:hm
I'm.+(1m,
f!AcBfaLr
int responseCode=httpConnection.getResponseCode(); =c:K(N qL
if(responseCode>=400) 1$H*E~
{ N$i!25F`
processErrorCode(responseCode); yP.,Dh s
return -2; //-2 represent access is error jt=%oa
} \b6H4aQii
M|xd9kA^
1%g%I8W%
String sHeader; 4CCtLHb
MF69n,(o
j&~`H:=E
for(int i=1;;i++) =f4>vo}@k
{ [,JUC<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VXX7Y?!
//Utility.log(in.readLine()); P :zZ
sHeader=httpConnection.getHeaderFieldKey(i); nB>C3e
if(sHeader!=null) j#6@cO'`
{ 2[zFKK
if(sHeader.equals("Content-Length")) =wEU+R_#o
{ _9*3Mr)2N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^VabXGzo#
break; [M?'Nw/[S
} :@K1pAh4
} r2"B"%;
else UaG })
break; d.>Zn?u4L
} G*`Y~SJp
} a*/%EP3
catch(IOException e){e.printStackTrace ();} u4hC/!
catch(Exception e){e.printStackTrace ();} ;d5d$Np@m&
ufq9+}
Q6%dM'fR
Utility.log(nFileLength); s1~&PH^
{{N*/E^
@~1}n/
return nFileLength; 3M~*4
} J?DJA2o
JlaT -j
H+lBb$
//保存下载信息（文件指针位置） o>~xrV`E
private void write_nPos() m}`!FaB #
{ nz+k ,
try{ U}hQVpP#
output = new DataOutputStream(new FileOutputStream(tmpFile)); )a99@`L\P
output.writeInt(nStartPos.length); T3H\KRe6
for(int i=0;i<nStartPos.length;i++) {_[\k^98>
{ t:$^iUrx
// output.writeLong(nPos); z"D'rHxy
output.writeLong(fileSplitterFetch.nStartPos); Lgr(j60s
output.writeLong(fileSplitterFetch.nEndPos); ;fiH=_{us
} 2":{3=oW~
output.close(); %OT}r
} {&3{_Ml
catch(IOException e){e.printStackTrace ();} :9?y-X
catch(Exception e){e.printStackTrace ();} u?xXZ]_u-
} 4 s&9A/&pC
$OGTHJA
$<DcbJW
//读取保存的下载信息（文件指针位置） m6wrG`-di
private void read_nPos() {@E(p4W
{ ^&8FwV]
try{ >tGl7Ov
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )+L.$h
int nCount = input.readInt(); 1>)q5D
nStartPos = new long[nCount]; ZlEQzL~
nEndPos = new long[nCount]; _4^#VD#f
for(int i=0;i<nStartPos.length;i++) .0=VQU
{ mssCnr;
nStartPos = input.readLong(); 4C]>{osv
nEndPos = input.readLong(); V;@kWE>3
} qE:/~Q0
input.close(); wg.TCT2
} "fH"U1Bw
catch(IOException e){e.printStackTrace ();} lJ>OuSd
catch(Exception e){e.printStackTrace ();} n=_jmR1
} `bAOhaB,/
25R6>CXsi
#]SiS2lM#
private void processErrorCode(int nErrorCode) J!+)v
{ T#OrsJdu
System.err.println("Error Code : " + nErrorCode); 4s_|6{ANS
} QtSJ9;eP
ZkA05wPZ#
(,P6cWt}"
//停止文件下载 _-6IB>
public void siteStop() /l6r4aO2=
{ J n~t>?
bStop = true; zLt7jxx
for(int i=0;i<nStartPos.length;i++) B QxU~s
fileSplitterFetch.splitterStop(); .=`r?#0
))NiX^)8^
SJ0IEPk
} P,RdYM06
} #^i.[7p
//负责部分文件的抓取 (6g;FD:"6
**FileSplitterFetch.java ,RXfJh
*/ F4X0DRC,G
package NetFox; D #Ku5~j
N0mP EF2
#0uD&95<
import java.io.*; +-$Hx5
import java.net.*; ~[*\YN);
42B_8SK
6R=dg2tKT
public class FileSplitterFetch extends Thread { V!&O5T(~
MGbl-,]
+!6dsnr8
String sURL; //File URL #Y>os3]
long nStartPos; //File Snippet Start Position I7C*P~32{n
long nEndPos; //File Snippet End Position RX\l4H5;
int nThreadID; //Thread's ID IN!,|)8s
boolean bDownOver = false; //Downing is over %pd-{KR
boolean bStop = false; //Stop identical hW Va4
FileAccessI fileAccessI = null; //File Access interface t^')ST
!Zi_4 .(4
UB9n7L(@c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }.S4;#|hw
{ Xg^9k00C
this.sURL = sURL; Tm) (?y
this.nStartPos = nStart; -ufO,tJRLL
this.nEndPos = nEnd; tqYwPSr
nThreadID = id; &i{>Li
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3*<?'O7I0
} 5vSJjhS
&:@)roCR
|G(9mnZ1
public void run() iD"9,1@~n
{ 0 v>*P*
while(nStartPos < nEndPos && !bStop) ~jOn)jBRZ
{ 9snc *<
kKlcK_b;
DnI31!+y
try{ p*ic@n*G
URL url = new URL(sURL); yE{(Ebm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hT DFIYV
httpConnection.setRequestProperty("User-Agent","NetFox"); ;&$Nn'~a
String sProperty = "bytes="+nStartPos+"-"; a 9H^e<g
httpConnection.setRequestProperty("RANGE",sProperty); [G#PK5C
Utility.log(sProperty); !M*$pQi}
1[U`,(C1
sCrOdJ6|
InputStream input = httpConnection.getInputStream(); %xuJQuCqf
//logResponseHead(httpConnection); .KeZZLH
i"Z
z7$,m#tw
byte[] b = new byte[1024]; PYhRP00}M
int nRead; qW"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JIH6!
{ u301xc,N<z
nStartPos += fileAccessI.write(b,0,nRead); fFiFS\''V
//if(nThreadID == 1) |Ym3.hz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); umJ!j&(
} 41oXOB
ymo].
)Bo]+\2
Utility.log("Thread " + nThreadID + " is over!"); :41Ch^\E
bDownOver = true; zxhE9 [`*e
//nPos = fileAccessI.write (b,0,nRead); /Y_)dz^@
} ~A-Y%P
catch(Exception e){e.printStackTrace ();} yR'%UpaE
} kl+^0i
} !=SBeq
(_.0g}2
E#A%aLp0E
//打印回应的头信息 D.:6X'hp
public void logResponseHead(HttpURLConnection con) aEvW<jHh
{ kh5VuXpe
for(int i=1;;i++) )/mBq#ZS
{ d")TH3pG
String header=con.getHeaderFieldKey(i); A.wuB
if(header!=null) yc:y}"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k[<Uxh%
Utility.log(header+" : "+con.getHeaderField(header)); @q/E)M?
else "x~su?KiA
break; >Y8\I
} ]mZN18#
} \&#IK9x{
:rzq[J^
5'%nLW7;O
public void splitterStop() Nay&cOz
{ S:YQVj
bStop = true; dHO8 bYBH
} .sBwJZ
W^8MsdM
^=.QQo||B
} =,w(D~ps
bZf}m=C!
W^"C|4G}
/* 1wTPT,k
**FileAccess.java @{LD_>R
*//文件访问(定位，写) NR9=V
package NetFox; l)K8.(2
import java.io.*; Ef2i#BoZ
sn-P&"q
/O{iL:`
public class FileAccessI implements Serializable{ 'J1!P:tJ
)1iqM]~;B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rjWn>M
RandomAccessFile oSavedFile; IDn$w^"
long nPos; +JlPQ~5
SDHJX8Hq
u?%FD~l:uU
public FileAccessI() throws IOException /+JHnedK
{ ,We'AR3X
this("",0); -.t/c}a#
} ]X\p\n'@j
'MK"*W8QRM
?&_u$Nn
public FileAccessI(String sName,long nPos) throws IOException }[mLtv%&
{ Zp qb0ro
oSavedFile = new RandomAccessFile(sName,"rw"); ~pWV[oUD
this.nPos = nPos; :N#8|;J1Fl
oSavedFile.seek(nPos); ["N_t:9I
} kR/Etm5_
3;Y9<
@|6#]&v`
public synchronized int write(byte[] b,int nStart,int nLen) $az9Fmta
{ +"GBuNh
int n = -1; bx._,G
try{ |y.^F3PE
oSavedFile.write(b,nStart,nLen); U-:"Wx%G
n = nLen; wY xk[)&Y
} *&O4b3R
catch(IOException e) 5KgAY;|
{ @O9wit.
e.printStackTrace (); Qr9@e Q1Pp
} q5#6PYIq
tFvXVfml
PUbfQg
return n; U%V4@iz~\m
} cTa$t :K@
6R#.AD\
PTP0 _|K
} ##5e:<c&[
G}LOQ7
_ZHDr[
/* sa w
**SiteInfoBean.java c@|f'V4
*/ )zAATBb4.
package NetFox; &hu3A)%
,R[<+!RS
vB Vg/
public class SiteInfoBean { n=A}X4^
d A>6
',m!L@7M5
private String sSiteURL; //Site's URL bR*} s/
private String sFilePath; //Saved File's Path RXw }Tb/D8
private String sFileName; //Saved File's Name &|I{ju_
private int nSplitter; //Count of Splited Downloading File -58Sb"f
S5/p3;O\c
qlm7eS"sy
public SiteInfoBean() o7kQ&w
{//nSplitter的缺省值为5 #ja6nt8GC
//default value of nSplitter is 5 J*D3=5&
this("","","",5); s)~Wcp'+M:
} $J9/AFzO"
Pj^O8
->rudRQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mt\pndTy7!
{ fRK=y+gl@
sSiteURL= sURL; ~u-_DOA
sFilePath = sPath; 7;@o]9W
sFileName = sName; <tgfbY^nL
this.nSplitter = nSpiltter; nj=nSD
v9MliD'
XM~eocn
} iLk"lcX
gQ$0 |0O
6QePrf
public String getSSiteURL() FV\$M6 _
{ oD3Q{e
return sSiteURL; ZmaGp* Wj
} yC\!6pg
C:ntr=3J
so_^%) gdJ
public void setSSiteURL(String value) &I7T?
{ 1xjw=
sSiteURL = value; nJR(lXWO
} GsiT!OP]y
U.c~l,5%"
6ANAoWg*
public String getSFilePath() ZO&F15$P
{ PMZ*ECIJU
return sFilePath; qDPl( WXb
} 8I<LZ{a10
% |G"ZPO?
LX</xI08W
public void setSFilePath(String value) |vY|jaV}
{ :u|F>e
sFilePath = value; q8H9au&/
} hx hs>eY
>o5eyi
^w*&7.Z
public String getSFileName() Y@MFH>*
{ AH|'{
return sFileName; J5SOPG
} d=/a{lP\
>x8~?)7z
VWW(=j
public void setSFileName(String value) O#`y;%
{ ,B$e'KQ
sFileName = value; 1i}p?sU
} pykRi#[UrX
nmoC(| r
t'*2)U
public int getNSplitter() /_i]bM7W
{ S#l)|c_~
return nSplitter; -~_;9[uV
} $: qrh66
O4T_p=Xc
Idr|-s%l6'
public void setNSplitter(int nCount) ;fB!/u
{ w"AO~LF
nSplitter = nCount; v<E_n;@9k
} ZmZ7E]c
} r?}L^bK
ew1bb K>
&?M'(` ~
/* =' &TqiIv"
**Utility.java l-M .C8N
*/ 7%yP5c B
package NetFox; QA#Jx
)]{&
Q#}c5TjVr
public class Utility { $}.#0c8I
' eH Fa
M4K>/-9X+V
public Utility() a]=j
{ 85#+_}#
?}<Wmy2A
&NK6U
} j,v2(e5:
m-R`(
//线程睡眠 yD(v_J*
public static void sleep(int nSecond) _Sult;y"u
{ ^i6`w_/
try{ XT\Q"=FD
Thread.sleep(nSecond); \"l/D?+Q
} 2$1D+(5;
catch(Exception e) 0]2@T=*kTY
{ l%v2O'h
e.printStackTrace (); vR'rYDtU@
} 0ae}!LO
} \g:Bg%43h
e`;U9Z
//日志 &I?d(Z=:\
public static void log(String sMsg) kRB2J3Nt.
{ %-3wR@
System.err.println(sMsg); no8FSqLUS~
} B8 R&Q8Q
ci`N,&:R
^spASG-o
public static void log(int sMsg) CxJH)H$
{ -](3iPy}
System.err.println(sMsg); NXdT"O=P
} b0[H{q-z{X
} yA^+<uz}
|=#uzp7*
eG%Q 3h
/* =R0#WMf$@
**TestMethod.java %$zX a%A
*/ dwmZ_m.
package NetFox; |"k+j_/+
o'!WW
5+Hw @CY3
public class TestMethod { c8M'/{4rH
TbR!u:J
ui1h M
public TestMethod() fC!+"g55
{ ///xx/weblogic60b2_win.exe R2dCp|6A
try{ -+&sPrQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xv?'*2J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !KmSLr7xU
SiteFileFetch fileFetch = new SiteFileFetch(bean); g:fzf>oQ>p
fileFetch.start(); !z?;L_Lb
} =l1O9/\9
catch(Exception e){e.printStackTrace ();} O"f|gc)GLz
THz=_L6
IW- BY =C
} ,B$m8wlI|
L=<{tzTc
;p/$9b.0:
public static void main(String[] args) $qfNEAmDf\
{ PVX23y;
new TestMethod(); eC*-/$D
} Gcd'-1
} 2JLXDkZ
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