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)); BKE\SWu
} ~rgf{oGz
for(int i=0;i<nEndPos.length-1;i++) C<[d
{ Y|%anTP
nEndPos = nStartPos[i+1]; $i,6B9
} DO7-=74=
nEndPos[nEndPos.length-1] = nFileLength; G0I~&?nDa
} TJHN/Z/
} 8%;}LK
<Jwi~I=^
z>cIiprX
//启动子线程 F^.om2V|9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ki;!WhF~
for(int i=0;i<nStartPos.length;i++) B;xZ%M]
{ iEiu%T>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]$m#1Kj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bK?1MiXb
nStartPos,nEndPos,i); "bD+/\ z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @T<ad7g-2J
fileSplitterFetch.start(); A#v|@sul
} q%OcLZ<,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4t&gW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >EBZ$X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WW//heJe-
nEndPos = " + nFileLength); [3t0M5x w
// fileSplitterFetch[nPos.length-1].start(); Dh hG$
'8s>rH5[V
+mJ :PAy4
//等待子线程结束 XMt u"K
//int count = 0; bH'S.RWp=
//是否结束while循环 ?r{TOjn
boolean breakWhile = false; XOu+&wOu
CTl(_g
kcLj Kp
while(!bStop) 7]p>XAb
{ _^_5K(Uq
write_nPos(); E)C.eW /
Utility.sleep(500); ~'NX~<m
breakWhile = true; yOX&cZ[
%9t{Z1$
{I4%
for(int i=0;i<nStartPos.length;i++) @)o0GHNP
{ rpUy$qrRc
if(!fileSplitterFetch.bDownOver) mbF(tSy
{ +J"' 'cZ
breakWhile = false; n4^~gT%b5]
break; L<bYRGz
} J"diFz+20
} fx<FIj7
if(breakWhile) sB?2*S"X)<
break; 8$\Za,)g
6tOCZ'f
Dq?E\
//count++; fZ[kh{|
//if(count>4) y&1%1 #8F
// siteStop(); @'*eC}\E
} 'z)hG#{I
LyGUvi
yC W*fIaq
System.err.println("文件下载结束！"); ITVQLQ
} }x]&L/
catch(Exception e){e.printStackTrace ();} ypH8QfxLTr
} B9YsA?hg
BY3bpR
{1jpLdCbV^
//获得文件长度 vwVVBG;t
public long getFileSize() yB.G=90
{ IrJ+Jov
int nFileLength = -1; doBNghS
try{ Ski G2n]
URL url = new URL(siteInfoBean.getSSiteURL()); 0|ZVA+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {{32jU7<
httpConnection.setRequestProperty("User-Agent","NetFox"); uM<|@`&b
O#vn)+Y,*
q%>7L<r
int responseCode=httpConnection.getResponseCode(); @|BD|{k
if(responseCode>=400) uG;?vvg>
{ 4:D:|r
processErrorCode(responseCode); b6|Z"{TI _
return -2; //-2 represent access is error &M[MEO`t8
} )Nbc/nB$
_mXs4
|8bE9qt.P
String sHeader; lK*jhW?3:
fmFzW*,E
S.: 7k9
for(int i=1;;i++) \^9pW 2v
{ EJ`Q8uz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :/6()_>bO
//Utility.log(in.readLine()); COSTV>s;
sHeader=httpConnection.getHeaderFieldKey(i); JT04vm4
if(sHeader!=null) 3E,DipHg
{ dByjcTPA
if(sHeader.equals("Content-Length")) \QGa4_#
{ wFvT0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Cc!J1)
break; s O=4IBE
} HMV)U{
} :N2E}hxk
else W .U+.hR
break; T^]7R4Fg
} /YFa ;2 W
} Q/py qe G
catch(IOException e){e.printStackTrace ();} qEQAn/&
catch(Exception e){e.printStackTrace ();} \]8VwsP
qp>N^)>
K\(6rS}N
Utility.log(nFileLength); 7(Cx!Yb
lm$;:Roj*
P`EgA
return nFileLength; #-{N Ws\
} [(ygisqt
H-,TS^W
Iyyo3awc
//保存下载信息（文件指针位置） 0/Z !5-.
private void write_nPos() hsz^rZ
{ Qs l80~n_7
try{ |n`PESf_
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8}BS2C%P
output.writeInt(nStartPos.length); 2bLI%gg3
for(int i=0;i<nStartPos.length;i++) r+S;B[Vd
{ @}DFp`~5|
// output.writeLong(nPos); z]=8eV\
output.writeLong(fileSplitterFetch.nStartPos); v L}T~_=3
output.writeLong(fileSplitterFetch.nEndPos); vd (?$
} )3%@9
output.close(); T@P!L
} 'wvMH;}u
catch(IOException e){e.printStackTrace ();} >b48>@~bY
catch(Exception e){e.printStackTrace ();} SE)nD@:
} 514Z<omrK
!n<o)DsZR
E(4w5=8TI
//读取保存的下载信息（文件指针位置） uv]{1S{tb
private void read_nPos() s8vKKvs`9
{ _Yq@FOu
try{ u,o1{%O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BvK QlT
int nCount = input.readInt(); I9&lO/c0
nStartPos = new long[nCount]; Y:psZ
nEndPos = new long[nCount]; W`M6J}oG
for(int i=0;i<nStartPos.length;i++) :q (&$
{ {eQWO.C{
nStartPos = input.readLong(); /t5p-
nEndPos = input.readLong(); S^N{wZo
} opp!0:jS*
input.close(); VagT_D
} PeTA$Yl
catch(IOException e){e.printStackTrace ();} K_ke2{4Jm
catch(Exception e){e.printStackTrace ();} u =J&~
} q0./O|Dj
3t"4TjAy
S3Y2O x
private void processErrorCode(int nErrorCode) uMmXs%9T
{ QyGnDomQ
System.err.println("Error Code : " + nErrorCode); I7(?;MpI
} P^)q=A8Z#
7L3ik;>
Riry_
//停止文件下载 $yu?.b 9H#
public void siteStop() lAi2,bz"
{ 7%;_kFRV
bStop = true; v }\,o%t^
for(int i=0;i<nStartPos.length;i++) 9 OT,TpA
fileSplitterFetch.splitterStop(); ynwG\V
'V&Y[7Aeq
6b=q-0yj
} 0 n vSvk
} UE"GJt`I
//负责部分文件的抓取 ,wAz^cK|
**FileSplitterFetch.java o{WyQ&2N
*/ 1AD]v<M
package NetFox; \6!W05[ Q
hdma=KqZ(
Jn&7C
import java.io.*; }q[Bd
import java.net.*; h2Bz F
vbG]mMJ
~O6\6$3b5E
public class FileSplitterFetch extends Thread { {XCf-{a]~
7'lZg<z{~j
qxOi>v0\H
String sURL; //File URL N.do "
long nStartPos; //File Snippet Start Position PkuTg";
long nEndPos; //File Snippet End Position 3'`dFY,
int nThreadID; //Thread's ID !wz/cM;
boolean bDownOver = false; //Downing is over F7*wQ{~
boolean bStop = false; //Stop identical BMyzjteS+
FileAccessI fileAccessI = null; //File Access interface 3L5r*fa
4Y\wnwI
'@nbqM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j]rz]k
{ Cfu=u *u
this.sURL = sURL; s%4M$e
this.nStartPos = nStart; w?Ju5 5
this.nEndPos = nEnd; 5e8AmY8;
nThreadID = id; T1WWK'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5s{j=.O
} yR5XJ;Tct
ne}+E
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public void run() Dh4 6o|P
{ 8 .>/6M
while(nStartPos < nEndPos && !bStop) l`9t}
{ 0#o/^Ah
k(VB+k"3
,5 j"ruZ
try{ Q,T"ZdQ
URL url = new URL(sURL); O`1!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hh;:`;}
httpConnection.setRequestProperty("User-Agent","NetFox"); o`S?
String sProperty = "bytes="+nStartPos+"-"; OWq'[T4
httpConnection.setRequestProperty("RANGE",sProperty); k44Q):ncY7
Utility.log(sProperty); 5*%#o
"UFs~S|e
0pb'\lA
InputStream input = httpConnection.getInputStream(); m7c*)"^
//logResponseHead(httpConnection); QF2q^[>w6
CTa#Q,
igL<g
byte[] b = new byte[1024]; E>LkJSy=
int nRead; 5Z/7kU=I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T4/fdORS
{ SMr13%KN/
nStartPos += fileAccessI.write(b,0,nRead); n{0Ld -zH
//if(nThreadID == 1) qFX~[h8i+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U @v*0
} PXoz*)tk
:(|'S4z
E_z;s3AXQ
Utility.log("Thread " + nThreadID + " is over!"); uQ$^;Pr
bDownOver = true; :'L2J
//nPos = fileAccessI.write (b,0,nRead); CbBSFKM
} DB526O* [
catch(Exception e){e.printStackTrace ();} 6Q&r0>^{
} WS8+7O'1\
} r;>+)**@vl
Xr63?N
BAj-akc f
//打印回应的头信息 #hfuH=&oh
public void logResponseHead(HttpURLConnection con) POI.]1i
{ :,12")N
for(int i=1;;i++) @Hb'8F
{ gU^$Sx7'
String header=con.getHeaderFieldKey(i); Qp,DL@mp>8
if(header!=null) Y}*\[}l:&x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y/<lWbj*A
Utility.log(header+" : "+con.getHeaderField(header)); B5V_e!*5F*
else W1Lr_z6
break; l- pe4x
} `nXVE+E@
} <:FP4e "(
c !ZM
AUVgPXOwd
public void splitterStop() Pz#7h*;cw.
{ <:/&&@2
bStop = true; }eQRN<}P
} #PDf,^
)0vU k
AsS$C&^
} TC~Q G$NW
1(zsOeX
jc[_I&Oc_
/* =(a1+.O
**FileAccess.java .?p\n7
*//文件访问(定位，写) )D'^3)FF
package NetFox; J`q]6qf#
import java.io.*; \;-fi.Hrf$
[ xOzzp4
- K%,^6
public class FileAccessI implements Serializable{ tt?58dm|
v%k9M{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n?\ nn3
RandomAccessFile oSavedFile; I1X/Lj=
long nPos; scuHmY0
9YsR~SM
nVu&/
public FileAccessI() throws IOException ANIz,LS
{ HkV1sT
this("",0); -[= drj9I
} k4qp u=@U
[S.ZJUns
<PPNhf8
public FileAccessI(String sName,long nPos) throws IOException ^l^fD t
{ -U<Upn)2
oSavedFile = new RandomAccessFile(sName,"rw"); >@WX>0`ht
this.nPos = nPos; 87}&`
oSavedFile.seek(nPos); `c/*H29
} YY?a>j."a
uj%skOD6Z
,D\GGRw
public synchronized int write(byte[] b,int nStart,int nLen) h2ZkCML
{ hS[yNwD
int n = -1; =.y*_Ja
try{ *Nyev]8
oSavedFile.write(b,nStart,nLen); `X,yM-(
n = nLen; rC:?l(8ng3
} L,d LE-L
catch(IOException e) TI9UXa:V\
{ w ;daC(:
e.printStackTrace (); hYQ_45Z*?
} MYBx&]!\
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r]W
return n; 7nbB^2
} _#$*y
?JV|dM
6"c1;P!4
} 'Dvv?>=&
mh<=[J,%p
eI1GXQ%
/* Ca%g_B0t
**SiteInfoBean.java }SIGPVM
*/ oG$)UTzGc
package NetFox; \#68;)+=
T&86A\D\z
"x@='>:$
public class SiteInfoBean { p8s:g~ W
"<}&GcJbz
J5h+s-'
private String sSiteURL; //Site's URL &V|>dLT>A
private String sFilePath; //Saved File's Path 5Z4-Z
private String sFileName; //Saved File's Name Y(\T- bI
private int nSplitter; //Count of Splited Downloading File )BfT7{WN
^kST
.(J?a"
public SiteInfoBean() iHf-{[[Z
{//nSplitter的缺省值为5 {pb>$G:gfx
//default value of nSplitter is 5 64-#}3zL
this("","","",5); xEuN
} T#pk]c6Q
`%3/
DK0.R]&4(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7bxA]s{m
{ \A`hj~
sSiteURL= sURL; JT fd#g?I
sFilePath = sPath; <p;k)S2J
sFileName = sName; E7Cy(LO
this.nSplitter = nSpiltter; +UJuB
_C\[DR0n
z} '!eCl
} 2oJb)CB
1<ro7A4hK
65ly2gl
public String getSSiteURL() m]*Bx%-1c
{ 6Es? MW=
return sSiteURL; qyHZ M}/
} s:00yQ
iCP/P%
!ZDzEP*
public void setSSiteURL(String value) O4<g%.HC6
{ @|a>&~xX
sSiteURL = value; 8G>>i)Sbg
} 0J.dG/I%
CIjZG?A
8@NH%zWBp
public String getSFilePath() :|o<SZ
{ ::n;VY2&
return sFilePath; 4/X/>Y1
} WWT",gio
xf%4, JQ
Iqs+r?
public void setSFilePath(String value) 2cu#lMq
{ ]*O/+
sFilePath = value; DoC(Z)o
} :a:[.
A?G IBjs
?)'~~@NkH
public String getSFileName() Qr#1u
{ (]/9-\6(#
return sFileName; Cw5%\K$=
} c62=*] ,
2/,0iwj-
FZB~|3eq{
public void setSFileName(String value) \yrisp#`
{ 0oy-os
sFileName = value; ozsxXBh-`'
} &iN--~}!$
wV?,Z!\Z
`k\grr.J
public int getNSplitter() Li 2Zndp
{ \3Oij^l0
return nSplitter; -{h
} l0*Gb
K[ .JlIP
!gwjN_ZJ^
public void setNSplitter(int nCount) 3E}EBJLsZ
{ Dj\e@?Y
nSplitter = nCount; DjMf,wX-{
} (Lh#`L?x
} s!/TU{8J
I[o*RKT'"
y( r1I[W'
/* r%Rs0)$yj
**Utility.java &PcyKpyd
*/ ashcvn~z
package NetFox; fJjgq)9
iq?#rb P#I
9^P2I)aD
public class Utility { !BU)K'mj
'+<(;2Z vL
F?Ju??O
public Utility() \^*< y-jL
{ PXP`ZLF
')+0nPV
O?bK%P]ay
} m9M FwfZ
jc_\'Gr+[
//线程睡眠 HOt>}x
public static void sleep(int nSecond) '#\D]5
{ <<MjC5
try{ I 5ag6l
Thread.sleep(nSecond); ps1YQ3Ep&
} ;D ~L|
catch(Exception e) lfk9+)
{ n)8Yj/5
e.printStackTrace (); D-9\~gvh
} [n,?WwC
} EruP
,KW;2t*IQ@
//日志 Hv#q:R8
public static void log(String sMsg) 9-*NW0
{ ]kktoP|D
System.err.println(sMsg); B%<e FFV\
} "oJ(J{Jat
dOa!htx]
S_J :&9L
public static void log(int sMsg) "YFls#4H-
{ h?@G$%2
System.err.println(sMsg); )tZ`K |
} .M|>u_<Qd
} f<[jwhCWV
i~=s^8n`l
l52a\/
/* jStmS2n
**TestMethod.java kD~uGA
*/ !7H6i#g*
package NetFox; zLjgCS<7
g+q@i{Yn
E|Bd>G
public class TestMethod { $]d*0^J 6
^Uw[x\%#gD
p|6v~
public TestMethod() l_FGZ!7
{ ///xx/weblogic60b2_win.exe aP~gaSx
try{ ph30'"[Z}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xer@A;c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7-iIay1h"
SiteFileFetch fileFetch = new SiteFileFetch(bean); V:K;] h*!
fileFetch.start(); /dHs &SU,
} jThbeY[
catch(Exception e){e.printStackTrace ();} (;o*eFC F
irxz l3
mE$dO3
} ~P1_BD(
!oSLl.fQd
4-4?IwS
public static void main(String[] args) euRss#;
{ Z-Wfcnk
new TestMethod(); :Am-8
} a4GWuozl
} u?Hb(xZtg=
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