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)); <Q\KS
} vxj:Y'}
for(int i=0;i<nEndPos.length-1;i++) h_[{-WC
{ VMRfDaO9
nEndPos = nStartPos[i+1]; !>n!Q*\(Ov
} b4i=%]v8
nEndPos[nEndPos.length-1] = nFileLength; XPO-u]<W
} 6]Hwr_/tk
} {tUe(
TZ5TkE;1
j<*7p:L7_>
//启动子线程 }7[]d7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ={sjoMW
for(int i=0;i<nStartPos.length;i++) uR5+")r@S
{ 3NLn}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g"1V]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lo{wTYt:J
nStartPos,nEndPos,i); ,"(G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )>:~XA|?
fileSplitterFetch.start(); A}(]J!rc
} A-T-4I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _&hM6N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mi7?t/D1Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u9OY Jo
nEndPos = " + nFileLength); AX8~w(sv
// fileSplitterFetch[nPos.length-1].start(); <VKJ+
-je} PwT
L AasmQ
//等待子线程结束 b;UBvwY_
//int count = 0; tfGs|x
//是否结束while循环 j'z#V_S
boolean breakWhile = false; AAlc %d/9
|p&EP2?T
BZ?3=S1*
while(!bStop) S3ooG14Ls
{ eV|N@
write_nPos(); ]EX6Y
Utility.sleep(500); DOKe.k
breakWhile = true; {x_.QWe5
Y:ly x-lj
e=OHO,74z"
for(int i=0;i<nStartPos.length;i++) Hyy b0c^=
{ QIGUi,R
if(!fileSplitterFetch.bDownOver) eyDV911
{ OR+qi*)
breakWhile = false; TjTG+uQ
break; sip4,>,E
} G|rE\h 2w
} BqNeY<zB*
if(breakWhile) f47]gtB-
break; dgkS5Q$/
k56Qas+3=
n?EgC8b9
//count++; KUUA>'=
//if(count>4) =#V^t$
// siteStop(); &<BBPn@\
} 4@
\dtiv&x
-<s Gu9
System.err.println("文件下载结束！"); t^~vi'bB
} @./h$]6
catch(Exception e){e.printStackTrace ();} H~+A6g]T
} >o?v[:u*
4f[%Bb
u;_h%z5K
//获得文件长度 S\).0goOW
public long getFileSize() fZo#:"{/K
{ T?pS2I~
int nFileLength = -1; )y,^M3$?C
try{ 5)!g.8-!
URL url = new URL(siteInfoBean.getSSiteURL()); q,,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \0b}Z#'0
httpConnection.setRequestProperty("User-Agent","NetFox"); $9,&BW_*
LgNIb
GEWjQ;g
int responseCode=httpConnection.getResponseCode(); v745FIy<
if(responseCode>=400) {|?^@
{ ZZT #V%Q=u
processErrorCode(responseCode); ,0W^"f.g{m
return -2; //-2 represent access is error ^HC6v;K
} 6eV#x%z@v'
EnM
'E_~|C
String sHeader; N y'\Q"Y]
.T'@P7Hdx
@L3XBV2
for(int i=1;;i++) q Q\j
{ 'k,2*.A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p'K`K\X
//Utility.log(in.readLine()); jzbq{#
sHeader=httpConnection.getHeaderFieldKey(i); R@o&c%K"
if(sHeader!=null) (I>Ch)'
{ D@bGJc0
if(sHeader.equals("Content-Length")) ~lw9sm*2v2
{ *S.U8;*Xj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &zEQbHK6
break; Du+W7]yCl
} puC91
} ;,&cWz
else ==dKC;
break; YaC%69C'
} FH~:&;
} 4@PA+(kvS
catch(IOException e){e.printStackTrace ();} Xqf,_I=V
catch(Exception e){e.printStackTrace ();} N[e,){v
yajdRU
` =>}*GS
Utility.log(nFileLength); u:l-qD9=(
entU+Or
)E}v~GW.+
return nFileLength; =>$)F 4LW
} 3Qy@^"
CvoFt=c$jE
npdljLN
//保存下载信息（文件指针位置） 3z8i0
private void write_nPos() U)J5K
{ o:Fq|?/e
try{ FnO@\{M"A
output = new DataOutputStream(new FileOutputStream(tmpFile)); UkL1h7}a\
output.writeInt(nStartPos.length); f<YYo
for(int i=0;i<nStartPos.length;i++) Q\$3l'W
{ %2\Hj0JQQ
// output.writeLong(nPos); <3;p>4gN
output.writeLong(fileSplitterFetch.nStartPos); n Nt28n@
output.writeLong(fileSplitterFetch.nEndPos); .IeO+RDQ
} bKQho31a'
output.close(); 2e`}O
} jxog8E
catch(IOException e){e.printStackTrace ();} 23}` e
catch(Exception e){e.printStackTrace ();} jf9+H!?^N
} bv+u7B6,
k#].nQG
QZzamT)"
//读取保存的下载信息（文件指针位置） [l23b{
private void read_nPos() q(KjhM
{ 0fsVbC
try{ n4K!Wv&u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \Vyys[MMY8
int nCount = input.readInt(); l(t&<O(m9
nStartPos = new long[nCount]; ~t6q-P
nEndPos = new long[nCount]; 3!CUJs/W
for(int i=0;i<nStartPos.length;i++) I1Q!3P
{ XiW1X6
nStartPos = input.readLong(); <tr]bCu}
nEndPos = input.readLong(); 76nH)^%l<
} ~YYnn7)
input.close(); '75T2Ud
} i>m%hbAk
catch(IOException e){e.printStackTrace ();} SMN.AJ J
catch(Exception e){e.printStackTrace ();} KgL!~J
} q/i2o[f'n
QNNURf\[(
gEh/m.L7
private void processErrorCode(int nErrorCode) da$FY7
{ I3t5S;_8
System.err.println("Error Code : " + nErrorCode); #D`@G8~(
} +?_!8N8
>US*7m }
@62T:Vl
//停止文件下载 '}.Yf_
public void siteStop() 5ya9VZ5#
{ IG^@VQ%
bStop = true; iGyetFqKw
for(int i=0;i<nStartPos.length;i++) jP+yN|
fileSplitterFetch.splitterStop(); 28MMH Q
qN!oN*
t-\+t<;
} Q0U~s\<
} wI%M3XaBws
//负责部分文件的抓取 1h,iWHC
**FileSplitterFetch.java /5@YZ?|#2
*/ l1+l@r\
package NetFox; Uj!3MF
o@:"3s
cn'>dz3v
import java.io.*; m:H^m/g
import java.net.*; SQodk:1)
384n1?
QYH-"-)
public class FileSplitterFetch extends Thread { ].d2CJ'
@^,q/%;
vm [lMx
String sURL; //File URL `^M]|7
long nStartPos; //File Snippet Start Position 8U{D)KgS
long nEndPos; //File Snippet End Position 5zl+M`
int nThreadID; //Thread's ID ? x)^f+:9|
boolean bDownOver = false; //Downing is over !]4u"e
boolean bStop = false; //Stop identical M:+CW;||!
FileAccessI fileAccessI = null; //File Access interface ,-UF5U
,Z`}!%?
H/,KY/>i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ":]Xr!e
{ g3^s_*A
this.sURL = sURL; 6!<I'M'[e
this.nStartPos = nStart; "Y&I#&$b\
this.nEndPos = nEnd; [&lK.?V)
nThreadID = id; h@,ja
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sy&[Q{,4
} =KE7NXu]-
SuE~Wb5&
:qzg?\(
public void run() VPMu)1={:p
{ q<YM,%mgj
while(nStartPos < nEndPos && !bStop) B%F]K<
{ bLc5$U$!I
CoN[Yf3\
-]N2V'QB
try{ %>|FJ
URL url = new URL(sURL); 0z8(9DlTc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MB]E[&Q!
httpConnection.setRequestProperty("User-Agent","NetFox"); AWO)]rM
String sProperty = "bytes="+nStartPos+"-"; [txOh!sxD
httpConnection.setRequestProperty("RANGE",sProperty); 5y#,z`S
Utility.log(sProperty); E_,/)U8
*^?tr?e%I<
T7[@ lMa?
InputStream input = httpConnection.getInputStream(); O NabL.CV
//logResponseHead(httpConnection); N,~O+
{cK<iQJ
u0C:q`;z
byte[] b = new byte[1024]; 5KCQvv\
int nRead; s*uA3}j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yD9enYM
{ Liqo)m
nStartPos += fileAccessI.write(b,0,nRead); 3",gjXmBu
//if(nThreadID == 1) >* -IIo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ni;_Un~
} K~(RV4oF8B
DUOoTlp
~k*]Z8Z
Utility.log("Thread " + nThreadID + " is over!"); [ 8Ohg
bDownOver = true; /!6'K
//nPos = fileAccessI.write (b,0,nRead); 66=[6U9 *
} %4~"$kE
catch(Exception e){e.printStackTrace ();} Jqoo&T")
} Yh<F-WOo2
} )nm+_U
LU3pCM{
h&"9v~
//打印回应的头信息 V)$!WPL@
public void logResponseHead(HttpURLConnection con) EP>u%]#
{ t{k:H4
for(int i=1;;i++) !I7$e&Uz@
{ j\}.GM'8
String header=con.getHeaderFieldKey(i); Y\ [|k-6
if(header!=null) Aztrq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $|$@?H>K
Utility.log(header+" : "+con.getHeaderField(header)); J8'"vc}=
else z"@^'{.l
break; 4.9qB
} d4y#n=HnnV
} EC?5GNGT,
mWviWHK
VG5+u,U6>
public void splitterStop() ;,{_=n>
{ o/AG9|()4
bStop = true; ~j!n`#.\
} i"Jy>'
(4H\ho8+mp
T?3Q<[SmI
} J=A)]YE
[S6u:;7
fUw:jExz
/* }?[];FB
**FileAccess.java gM96RY
*//文件访问(定位，写) NaR} 0
package NetFox; |MNSIb&,W
import java.io.*; rto?*^N?
HUKrp*Hv
C[FHqo9M?H
public class FileAccessI implements Serializable{ 8h] TI_
f&-`+V}U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1]xmOx[mb
RandomAccessFile oSavedFile; n_kwtWX(
long nPos; \8CCa(H
>}SEU-7&\
pGie!2T E
public FileAccessI() throws IOException '54\!yQ<{
{ /-M:6
this("",0); Dk `&tr
} Ejk;(rxI
/&gg].&2?
~WA@YjQ]
public FileAccessI(String sName,long nPos) throws IOException tZ]gVgZg
{ rPk|2l,E,3
oSavedFile = new RandomAccessFile(sName,"rw"); }Rh\JDiQ
this.nPos = nPos; QK_5gD`$a,
oSavedFile.seek(nPos); VEps|d3,,
} |\(uO|)ju
a`wjZ"}'[
[ycX)iM
public synchronized int write(byte[] b,int nStart,int nLen) |/,SNE
{ "uH>S+%|b
int n = -1; (~~m8VJ>
try{ J|WE&5'
oSavedFile.write(b,nStart,nLen); n/9afIN
n = nLen; (T1< (YZ
} &2ED<%hH`
catch(IOException e) Jv}
{ .`D'eS6b
e.printStackTrace (); ItVN,sVJb
} mSYjc)z
M`Y^hDl6
Nj9A-*0g6N
return n; H-_gd.VD
} !Fl'?Kz
::Zo` vP
)+ <w>pc
} ztVTXI%Kz
5=o^/Vkc
2@S}x@^
/* (Yewd/T
**SiteInfoBean.java 1T|f<ChIF<
*/ eB0exPz%
package NetFox; <8WFaP3,
(3n "a'
snaAn?I4
public class SiteInfoBean { "0eX/rY%
oc1BOW z
|~Dl<#58
private String sSiteURL; //Site's URL 'i+L
private String sFilePath; //Saved File's Path tpWGmjfo>
private String sFileName; //Saved File's Name xQsxc
private int nSplitter; //Count of Splited Downloading File 3=enk0$
;!<}oZp{
OnTe_JML
public SiteInfoBean() 5dj" UxH
{//nSplitter的缺省值为5 ]\*^G@HA2
//default value of nSplitter is 5 3d}v?q78
this("","","",5); 7)2K6<q
} F`g(vD>
H07\z1?.K
#eW T-m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yGR{-YwU!
{ *OLqr/ yb
sSiteURL= sURL; 1Q@]b_"Xh
sFilePath = sPath; .UPh
sFileName = sName; /8GdCac
this.nSplitter = nSpiltter; /1OCK=
c~<;}ve^z
J&8KIOz14Z
} lu.]R>w
+a5F:3$
,AnD%#o
public String getSSiteURL() 6b|<$Je9
{ R`(2Fy%0\k
return sSiteURL; 9KVJk</:n
} C|ZPnm>f30
G)amng/
sS-dHa
public void setSSiteURL(String value) 9q"kM
{ 4l 67B]o
sSiteURL = value; x9YQd69
} $toTMah w
qFmw9\Fn
^_]ZZin
public String getSFilePath() J*;RL`
{ GD4S/fn3
return sFilePath; NW1Jr/
} Y-ao yoNS
UGAV"0
t6"%u3W8M
public void setSFilePath(String value) (%6fMVp
{ |nNcV~%~
sFilePath = value; Sf?;j{?G
} Vuz.b.,i`
=F+v+zP7P
v~mVf.j1
public String getSFileName() ?+]=|hN
{ ZDW9H6ux
return sFileName; i<Z%
} M@ U>@x;
OjGI !
:8`A
public void setSFileName(String value) KQr+VQdq>
{ 03~ ADj
sFileName = value; RqA>"[L
} W %*#rcdq
O,r;-t4vYU
g<Z :`00|
public int getNSplitter() R/=rNUe
{ Ll]5u~
return nSplitter; CXq[VYM&X
} 81Z;hO"~
>ai,6!
*L^W[o
public void setNSplitter(int nCount) L$5,RUy
{ 6q^$}eOt
nSplitter = nCount; A|ZT;\
} @1*^ttC
} 3L&:
3m>YR-n$
7${<u0((!
/* 7DAP_C
**Utility.java w5>[hQR\
*/ ||:>&
package NetFox; %0GwO%h},
\OW:-
8 W
public class Utility { gKh*q.
NsB]f{7>8+
W9?* ~!
public Utility() FOF@@C~aH
{ L"b&O<No
Bt<)1_
S)U*1t7[
} kp*v:*
I# tlaz#
//线程睡眠 -DkD*64wu
public static void sleep(int nSecond) ;+~5XLk
{ .`IhxE~mN
try{ Em!- W5*s
Thread.sleep(nSecond); E&8Nh J
} )Q=u[ p
catch(Exception e) _*AI1/>`
{ %Xh}{o$G
e.printStackTrace (); VukbvBWPN
} cy^=!EfA
} }2]|*?1,
e* [wF}))
//日志 w-Ph-L/
public static void log(String sMsg) xeF>"6\
{ Zv@qdY<:
System.err.println(sMsg); `PARZ|
} P&Keslk
Ll|-CY $
.?u<|4jE6
public static void log(int sMsg) iYr)Ao5X
{ "AagTFs(i
System.err.println(sMsg); =NY;#Jjn
} RiTL(Yx
} K$Bv4_|x
!Q>xVlPVu
{ {\oC$
/* $UzSPhv[
**TestMethod.java KPToyCyR1
*/ A}lxJ5h0
package NetFox; %mQ&pk
DWU=qD+
Ur+U#}
public class TestMethod { Ae7FtJO
]zYIblpde
<,:{Q75
public TestMethod() eay|>xa2
{ ///xx/weblogic60b2_win.exe y7+@ v'
try{ ! t!4CY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DQ8/]Z{H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0h1u W26^
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y*BmBRN
fileFetch.start(); Jh.~]\u
} k@7#8(3
catch(Exception e){e.printStackTrace ();} w>B}w
|YLja87
wS=vm}}u
} Gor9&aJ1
$2W#'_K+
;87PP7~
public static void main(String[] args) 6'r;6T *
{ -Mr_Ao`E
new TestMethod(); B=OzP+
} WD%(RC"Q
} &-*l{"7p+%
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