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)); 3u4:l
} dxntGH< O
for(int i=0;i<nEndPos.length-1;i++) V $>"f(
{ ~hzEKvs
nEndPos = nStartPos[i+1]; q^%5HeV 2
} q#|r
nEndPos[nEndPos.length-1] = nFileLength; %:%MUdl6
} cPJ7E
} pW7kj&a_.
(Wn "3 ]
?l>e75V%w
//启动子线程 wM0E%6 P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bqp&2zg)@
for(int i=0;i<nStartPos.length;i++) boIVU`F-!
{ g*28L[Q~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BPqwDjW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I0(8Z]x
nStartPos,nEndPos,i); C?S~L5a#oC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (c<f<D|
fileSplitterFetch.start(); HI z9s4Y_
} M",];h(I6(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y6+k9$h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PJ}[D.elO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tfsh!)u?
nEndPos = " + nFileLength); tgc@7
// fileSplitterFetch[nPos.length-1].start(); wD}EW
4sI3(z)9H
L+uOBW_
//等待子线程结束 5vYsA1Z
//int count = 0; +B](5z4
//是否结束while循环 jzQ9zy_
boolean breakWhile = false; KzIt
$,g 3*A
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while(!bStop) F>TYVxQ
{ 7L1\1E:!
write_nPos(); 2Qw)-EB
Utility.sleep(500); xcsFODx~
breakWhile = true; H7y&N5.V
:jl u
5f/@:~
for(int i=0;i<nStartPos.length;i++) |:dCVd<du
{ 3x,Aczb
if(!fileSplitterFetch.bDownOver) "9TxK6
{ =%:JjgKc*t
breakWhile = false; :v|r=#OI
break; $:xF)E
} XB6N[E
} XCKY xv&
if(breakWhile) *pDXcURw
break; V]+o)A$
^A:!ni@3
GZxglU,3T
//count++; Sn_z
//if(count>4) ~ra#UG\Y8
// siteStop(); e);bF>.~
} zpBBnlq
2&zn^\%"
=1V>Vd?8.
System.err.println("文件下载结束！"); uzat."`d'
} Lf$Q %eM0
catch(Exception e){e.printStackTrace ();} R^mu%dw)(%
} ,%"\\#3S
BH.:_Qrbh[
k~'?"'
//获得文件长度 z7NGpA(
public long getFileSize() PV5TG39qQ
{ *K0j5dx
int nFileLength = -1; #QJ4o_
try{ X_^_r{
URL url = new URL(siteInfoBean.getSSiteURL()); F&nMI:h7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FJ3:}r6 "
httpConnection.setRequestProperty("User-Agent","NetFox"); #`YxoY`
[[.&,6
KxgR5#:i"
int responseCode=httpConnection.getResponseCode(); 6T} CPDRq
if(responseCode>=400) Y_|K,T6Zj@
{ A~yw8v5UF
processErrorCode(responseCode); TnMVHO-
return -2; //-2 represent access is error s)`1Rf
} #%}u8\q
]HZa:aPY
f:JYG]E&
String sHeader; g-{<v4NGI
.zSimEOF
%BKR}
for(int i=1;;i++) K{r1&O>W
{ l9ch
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ztpm_P6
//Utility.log(in.readLine()); {C,1w
sHeader=httpConnection.getHeaderFieldKey(i); U{za m
if(sHeader!=null) twJ|Jmd
{ [M8qU$&?]
if(sHeader.equals("Content-Length")) e{rHO,#A>
{ y9re17{ X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wr;|\<c
break; Ep,0Z*j
} x":Bw;~
} GqK&'c
else ,N@Icl
break; e$xv[9
} wEHrer
} }:c,SO!
catch(IOException e){e.printStackTrace ();} ;]#4p8lh+
catch(Exception e){e.printStackTrace ();} .KwuhmR
lo]B5_en
p?`|CE@h7
Utility.log(nFileLength); $=QGua V
uI:3$
2Ws/0c
return nFileLength; s2' :&5(
} |uBot#K|
KHs{/
~bWWu`h
//保存下载信息（文件指针位置） \qd)l
private void write_nPos() Tdmo'"m8z_
{ (.nJT"&
try{ +Tc(z{;
output = new DataOutputStream(new FileOutputStream(tmpFile)); rgvc5p
output.writeInt(nStartPos.length); ?[4khQt
for(int i=0;i<nStartPos.length;i++) vJjj+:
{ #O974f8
// output.writeLong(nPos); ^{sI'l~
output.writeLong(fileSplitterFetch.nStartPos); fdEj#Ux<H
output.writeLong(fileSplitterFetch.nEndPos); K|J#/
} &7kSLat+9{
output.close(); rJ~(Xu>,s
} HE<%d
catch(IOException e){e.printStackTrace ();} :tDGNz*zG
catch(Exception e){e.printStackTrace ();} )mZy>45
} bDh(;%=
cXEy>U|/
!I+u/f?TO7
//读取保存的下载信息（文件指针位置） g$+O<a@n
private void read_nPos() cFNtY~(b
{ (8X8<>w~
try{ S5 oHe4#89
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l:C0:m%
int nCount = input.readInt(); !-o||rt
nStartPos = new long[nCount]; R =c
nEndPos = new long[nCount]; +fR`@HI
for(int i=0;i<nStartPos.length;i++) ]vyF&`phb
{ 8jx1W9=`9[
nStartPos = input.readLong(); 6%y: hLT
nEndPos = input.readLong(); 6>A8#VT
} ];]EK6dzG
input.close(); iB_j*mX]
} m1;jS|
catch(IOException e){e.printStackTrace ();} }7v2GfEkM
catch(Exception e){e.printStackTrace ();} a5&j=3)|
} E6)mBAE
Sw)ftC~d
FZ/&[;E!
private void processErrorCode(int nErrorCode) @/iLC6QF
{ ylJlICK
System.err.println("Error Code : " + nErrorCode); |7fBiVo
} u'>CU
t,6=EK*3T
giq`L1<
//停止文件下载 K.7gd1I
public void siteStop() jm"xf7
{ "de:plMofy
bStop = true; O}V2>W$
for(int i=0;i<nStartPos.length;i++) B~rK3BS
fileSplitterFetch.splitterStop(); P&;I]2#
Hua8/:![+
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} M}u2aW2]X
} <^paRKEa+#
//负责部分文件的抓取 tA.C"
**FileSplitterFetch.java t!GY>u>`
*/ #oI`j q
package NetFox; |zE7W
*XuzTGa"
cW\7yZh
import java.io.*; *:(t.iL
import java.net.*; lk|/N^8M
L<n_}ucA
uJizR F
public class FileSplitterFetch extends Thread { j#,O,\
e_SlM=_u
l_WY];a
String sURL; //File URL $8)/4P?OL
long nStartPos; //File Snippet Start Position }V{, kK
long nEndPos; //File Snippet End Position 'J}lnt[V
int nThreadID; //Thread's ID `{%*DHa
boolean bDownOver = false; //Downing is over We|*s2!
boolean bStop = false; //Stop identical yd k
FileAccessI fileAccessI = null; //File Access interface PNq#o%q
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1EN5ZN,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I`|>'$E[r
{ zI(Pti
this.sURL = sURL; T!n<ya!
this.nStartPos = nStart; `&o|=
this.nEndPos = nEnd; =vWnqF:
nThreadID = id; 2 UgjH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *+G K?Ga
} qQb8K+t
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uo0(W3Q *
public void run() +CACs7tV
{ Y9Pb
while(nStartPos < nEndPos && !bStop) |D\ ukml
{ 4P.ry|2
(mzyA%;W
2iUF%>
try{ ,yC~{H
URL url = new URL(sURL); wL{Qni3A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pG (8VteH
httpConnection.setRequestProperty("User-Agent","NetFox"); FIuKX"XR
String sProperty = "bytes="+nStartPos+"-"; V; ChrmE
httpConnection.setRequestProperty("RANGE",sProperty); ^t| %!r G
Utility.log(sProperty); 9O|m#&wa]
b_B4
v>,XJ7P
InputStream input = httpConnection.getInputStream(); \d6A<(!=v
//logResponseHead(httpConnection); u}pLO9V"`
A;%fAI2Vr
F:n7yey
byte[] b = new byte[1024]; 2nf{2edC
int nRead; $(GXlhA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B${Q Y)t
{ a{y;Ub
nStartPos += fileAccessI.write(b,0,nRead); gG#M-2P
//if(nThreadID == 1) ?O28Q DUI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FvRog<3X
} Cjw|.c`
wE'~Qj
EayZ*e]
Utility.log("Thread " + nThreadID + " is over!"); IF<jq\M
bDownOver = true; Wu:evaZ:i
//nPos = fileAccessI.write (b,0,nRead); %kF6y_h`
} 0PZpE "$X
catch(Exception e){e.printStackTrace ();} Nl0*"}`I_
} Z/O5Dear/h
} T$SGf.-
`Os@/S
-_B*~M/vV`
//打印回应的头信息 <"6}C)G
public void logResponseHead(HttpURLConnection con) K1jE_]@Z
{ GP1b/n3F1
for(int i=1;;i++) ^`ny]3JA
{ 1a`dB ~>
String header=con.getHeaderFieldKey(i); n%A)#AGGc
if(header!=null) wgY:W:y'N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ym^
Utility.log(header+" : "+con.getHeaderField(header)); L2+~I<|>
else i,ga2{GnM
break; Re-4y5f
} 'V/+v#V+>
} xO{yr[x"L
]U82A**n
T:dV[3
public void splitterStop() cJ=0zEv
{ F@UbUm2o
bStop = true; D&#wn.0|E
} OF-$*
yJNQO'wcv
@#rF8;
} Y'H|Tk^`
G*^4+^Vz?
H85JMPZ7
/* NSI$uS6
**FileAccess.java n 'gU
*//文件访问(定位，写) 4d-f6iiFV
package NetFox; (l}W\iB'd
import java.io.*; 7Ji|x{``
8#L V oR
m9M#)<@*
public class FileAccessI implements Serializable{ d;@"Naw
?h\fwF3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =S#9\W&6Q
RandomAccessFile oSavedFile; P.aN4 9`=
long nPos; maTQ0GX
"lLwgh;
x18(}4
public FileAccessI() throws IOException Gu@n1/m@o
{ LT[g +zGB
this("",0); [3D*DyQt
} z;iNfs0i$
!:baG]Y
_TntZv.?
public FileAccessI(String sName,long nPos) throws IOException '9u(9S
{ z_f^L %J0
oSavedFile = new RandomAccessFile(sName,"rw"); hU'h78bt(
this.nPos = nPos; uo9FLm
oSavedFile.seek(nPos); Zz/ z7~{
} {^":^N)
>)^Q p-
T{:8,CiW
public synchronized int write(byte[] b,int nStart,int nLen) #?"^:,Y
{ []:&WA9N
int n = -1; LIE5of
try{ 7y4jk
oSavedFile.write(b,nStart,nLen); l=UXikx
n = nLen; nD.K*#u
} 8'qq!WR~
catch(IOException e) y**YFQ*sc
{ %/oeV;D
e.printStackTrace (); IFsh"i
} p(>D5uN_}5
fG zx;<0P!
qC6@
return n; jP#I](\eG
} ^P|Zze zwU
BD- c<K"
V3Ep&<=/
} 4&AGVplgF
9zl-C*9vj
bgeJVI
/* O{x-9p
**SiteInfoBean.java ~p?D[]h
*/ L8J] X7
package NetFox; ;#L]7ZY9:-
D@%!|:
QtA@p
public class SiteInfoBean { &z05h<]
Q!5W x
_ h/:r1
private String sSiteURL; //Site's URL 87F]a3
private String sFilePath; //Saved File's Path G\R6=K:f7
private String sFileName; //Saved File's Name T|p%4hH
private int nSplitter; //Count of Splited Downloading File @=OX7zq\h-
dVMLn4[,MA
+7{8T{
public SiteInfoBean() @~&|BvK% \
{//nSplitter的缺省值为5 'U,\5jj'Y
//default value of nSplitter is 5 /IlO
this("","","",5); Y.q$"lm7k
} OepQ Z|2
PZY6 I
K#Xl)h}y7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .e4upTGU
{ ,Iru_=Wk~
sSiteURL= sURL; ^A=2#j~H\
sFilePath = sPath; 9rIv-&7'm
sFileName = sName; /i
this.nSplitter = nSpiltter; PzT@q\O
MwX8FYF D
V+zn` \a
} _;R#B`9Iu
Q3'P<"u
8K@e8p( y
public String getSSiteURL() 3[@:I^q
{ E B! ,t
return sSiteURL; TEbIU8{Y
} YV'B*arIA
b~{nS,_Rn
-c{Y+M`
public void setSSiteURL(String value) [+ : zlA
{ >QPCYo<E
sSiteURL = value; X5(oL
} (=j/"Mb
,Xg^rV~]
-0I&dG-
public String getSFilePath() Y5P9z{X=
{ ItVVI"-
return sFilePath; f%JM a]yV
} ~fs} J
6W~JM^F
:;IZ|hU
public void setSFilePath(String value) 1(Z+n,Hh
{ _n4_;0
sFilePath = value; C' WX$!$d
} MwL!2r
-=n!k^?lK
Rl_1g`84
public String getSFileName() "`mG_qHI[
{ P)~olrf
return sFileName; O&#>i]*V
} QWWI
N/1xc1$SB
V2:S 9vO'
public void setSFileName(String value) fo<nk|i
{ jw/@]f;N
sFileName = value; KM[&WT
} DcC|oU[
#Fgybokm
gt=@v())
public int getNSplitter() 5A%Uv*
{ FTzc,6
return nSplitter; F^lau f
} Zrew}0
\5a;_N[Ed
"|N0oEG&
public void setNSplitter(int nCount) i3)7Qa[
{ bU}l*"
nSplitter = nCount; S2 P9C"
} bn=7$Ax
} X|4Kdi.r@
J/rF4=j%xy
B-|C%~fe
/* g>a% gVly
**Utility.java ACI.{`SrQ=
*/ zs'Jgm.v
package NetFox; 6I|9@~!y[
d_&~^*>
$dKo}
public class Utility { gRw? <U^
[t*-s1cq
Wi*HLP!lNC
public Utility() Sg(\+j=
{ {>Qs+]
vCtnjWGX}/
1R]h>'
} "rrE_
I@1VX5
//线程睡眠 !$Arc^7r
public static void sleep(int nSecond) T+:GYab/
{ /~g.j1g
try{ +('=RyoT
Thread.sleep(nSecond); g{hbq[>X]
} #* 8^ar<
catch(Exception e) .|y{1?f_
{ NRs%q}lX
e.printStackTrace (); cdg&)
} =05jjR1
} Nu><r
\~T&C5
//日志 f/Q/[2t
public static void log(String sMsg) p0pA|
{ KPa@~rU
System.err.println(sMsg); raZ0B,;eFu
} T6=~vOzTJ
GJBMaT
>NA{**$0
public static void log(int sMsg) WAVEwA`r
{ ASr3P5/
System.err.println(sMsg); %;O# y3,
} {<2q
} w)}@svv"
-M-y*P)
rU7t~DKS
/* B(pHo&ox
**TestMethod.java I!~3xZ
*/ XK yW
package NetFox; :;o?d&C
w)Y}hlcq
L$; gf_L
public class TestMethod { WZ ,t~TN
wM#q [m;
Xgo`XsA
public TestMethod() C,5Erb/
{ ///xx/weblogic60b2_win.exe jq+:&8!8(e
try{ l4q7,%G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w%f51Ex
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6X$iTJ[\x
SiteFileFetch fileFetch = new SiteFileFetch(bean); '59l.
fileFetch.start(); 3$kElq[
} ~;nW+S$o
catch(Exception e){e.printStackTrace ();} 9S)A6]
E=~Ahkg
SrXuiiK
} 9!Vp-bo
~Nl`Zmn(A|
@#| R{5=+
public static void main(String[] args) Rj,M|9Y)o
{ n`7n5M*
new TestMethod(); Mer\W6e"e
} /4u:5G
} w7h=vy n?
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