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)); 85r)>aCMn
} <qbZG}u
for(int i=0;i<nEndPos.length-1;i++) M^j<J0(O
{ F!OOrW]p0
nEndPos = nStartPos[i+1]; h1^9tz{
} ,+ns {ppn
nEndPos[nEndPos.length-1] = nFileLength; ;[{:'^n
} z:Xj_ `p
} N,j>;x3xT
!lQ#sL`
Z?~gQ $
//启动子线程 [{S;%Jj*X/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?%cn'=>ZI
for(int i=0;i<nStartPos.length;i++) -yX.Jv
{ CRZi;7`*1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -`zG_]=-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0Jm]f/iZ
nStartPos,nEndPos,i); Tjnt(5g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c;c:Ea5
fileSplitterFetch.start(); )u39}dpeu
} +(;8@"u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jd ["eI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o"'iXUJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", abM84EU
nEndPos = " + nFileLength); 5Y(r\Dd
// fileSplitterFetch[nPos.length-1].start(); 'RDWU7c9]
y#b;uDY
xGKfej9
//等待子线程结束 b%Wd<N2
//int count = 0; jZXVsd
//是否结束while循环 -M"IVyy@
boolean breakWhile = false; t{_!Z(Rt5)
"DVt3E
g~~m'^
while(!bStop) N=>- Q)
{ Dz[566UD
write_nPos(); yB-.sGu
Utility.sleep(500); n=f`AmF;
breakWhile = true; >$2E1HW.
|'ZN!2u
_ymJ~MK
for(int i=0;i<nStartPos.length;i++) IYuyj(/!
{ &g*klt'B
if(!fileSplitterFetch.bDownOver) |.1qy,|!X
{ 98BYtxa
breakWhile = false; V3## B}2[Y
break; .W!tveX8-
} E;9Z\?P
} >HE,'
if(breakWhile) 4Z*|Dsw
break; riID,aut
@Ppo &>
N g58/}zO
//count++; y&7YJx
//if(count>4) |kId8WtA
// siteStop(); q#;BhPc
} m'd^?Qc
1+R:3(AC
GA.BI"l
System.err.println("文件下载结束！"); SV&kWbS
} /Z:N8e
catch(Exception e){e.printStackTrace ();} >Cvjs
} \0D$Mie
1XG$ z@NN
/v5qyR7an
//获得文件长度 GOGt?iw*<
public long getFileSize() >&BrCu[u
{ !~kEtC
int nFileLength = -1; ?RDO] I>
try{ _Aa[?2 O
URL url = new URL(siteInfoBean.getSSiteURL()); mn.`qfMh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3a'q`.L
httpConnection.setRequestProperty("User-Agent","NetFox"); a~WqUL
G OpjRA@
sN-oEqS
int responseCode=httpConnection.getResponseCode(); ]5N zK=2{
if(responseCode>=400) Z #EvRC
{ T0r<O_ubOA
processErrorCode(responseCode); ; VBpp<
return -2; //-2 represent access is error m`'=)x|
} VO9XkA7
V7P6zAJy
=:4?>2)
String sHeader; ;J'OakeVO
c)03Ms4 D
z4g+2f7h-X
for(int i=1;;i++) eO'xkm
{ Ee8--
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }S,-uggz
//Utility.log(in.readLine()); #'C/Gya
sHeader=httpConnection.getHeaderFieldKey(i); c -w0
if(sHeader!=null) 2\5cjdy
{ n? ]f@OR
if(sHeader.equals("Content-Length")) !Vb,zQ
{ 3EmcYC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D{R/#vM jk
break; @m?{80;uQ
} A';n6ne%i
} ' X}7]y
else @LcT-3u
break; i *B:El1
} WKxm9y V
} ` VwN!B:
catch(IOException e){e.printStackTrace ();} q@%h^9.
catch(Exception e){e.printStackTrace ();} QhCY}Q?X
_-/x;C
M\dO({o
Utility.log(nFileLength); Q&gPa]z]}
@HvScg*Y
QNb>rLj52
return nFileLength; dhW<p5
} !_dR'
\dTQQ
Ra0=q4vdk
//保存下载信息（文件指针位置） @89I#t6A.
private void write_nPos() !y%+GwoW
{ jXWNHIl)@
try{ pisB,wP$2
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7 W{~f?Sh
output.writeInt(nStartPos.length); 9^!wUwB
for(int i=0;i<nStartPos.length;i++) x<s|vgl|
{ n8$=f'Hgb
// output.writeLong(nPos); n$YE !D'
output.writeLong(fileSplitterFetch.nStartPos); 2m\m/O
output.writeLong(fileSplitterFetch.nEndPos); F@1d%c
} "<x&pQZ%
output.close(); U. (Tl>K|0
} $3 4j6;oN
catch(IOException e){e.printStackTrace ();} UWw}!1
catch(Exception e){e.printStackTrace ();} HlPG3LD!
} yb?{LL-uy
]\BUoQ7I/
a.DX%C/5
//读取保存的下载信息（文件指针位置） 69/?7r
private void read_nPos() (zC
{ H_Os4}
try{ {i>Jfl]G}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $/paEn"
int nCount = input.readInt(); xs%LRF#u
nStartPos = new long[nCount]; U` hfvTi
nEndPos = new long[nCount]; 8R}K?+]
for(int i=0;i<nStartPos.length;i++) @!<d0_dnC
{ bDWeU}
nStartPos = input.readLong(); f05=Mc&)
nEndPos = input.readLong(); x'qWM/
} ?'wsIH]m
input.close(); Vho0eV=
} 30_ckMG"g
catch(IOException e){e.printStackTrace ();} |sf*hlrJ
catch(Exception e){e.printStackTrace ();} |l7%l&!
} 4P%m>[
8*s7m
%iJ|H(P
private void processErrorCode(int nErrorCode) *,lh:
{ ax_YKJ5#P
System.err.println("Error Code : " + nErrorCode); \QT9HAdd@
} 8;#AO8+U7)
6IP$n($2
!5UfWk\G
//停止文件下载 }lP5GT2
public void siteStop() /C$ xH@bb
{ `?9T~,
bStop = true; ZPyM>XK$4
for(int i=0;i<nStartPos.length;i++) =VSkl;(O
fileSplitterFetch.splitterStop(); O R #7"
V7C1FV2
:6lwO%=F
} yU7I;]YP
} sx5r(0Z
//负责部分文件的抓取 6*l^1;U
**FileSplitterFetch.java %xlqF<
*/ kVI#(uO
package NetFox; E$a ?LFa6
(3[z%@I
Tj~IaU
import java.io.*; S1_6C:^k
import java.net.*; Nf3.\eR
Bb&^{7
#QvMVy
public class FileSplitterFetch extends Thread { ,U*)2`[
4>^K:/y
?Y:x[pOe
String sURL; //File URL ;)Kh;;e
long nStartPos; //File Snippet Start Position &`Y!;@K9W#
long nEndPos; //File Snippet End Position xX0-]Y h:
int nThreadID; //Thread's ID Cp^@zw*/
boolean bDownOver = false; //Downing is over <)g8yA
boolean bStop = false; //Stop identical <J(sR
FileAccessI fileAccessI = null; //File Access interface h0?2j)X_
jNwjK0?
/$n ~lf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c[}(OH
{ C ]Si|D
this.sURL = sURL; .%'(9E
this.nStartPos = nStart; ES<1tG
this.nEndPos = nEnd; GN#<yv$av
nThreadID = id; "I;C;}!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o01kYBD
} 9/SXs0
ej&<GM|
sDgXU@
public void run() IYWjHE+)d
{ *BD=O@
while(nStartPos < nEndPos && !bStop) 1\RGM<q$f
{ M:Er_,E
n}A\2bO
. .QB~
try{ sUl6hX4
URL url = new URL(sURL); s6 ( z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?#0snlah|
httpConnection.setRequestProperty("User-Agent","NetFox"); DPrBFmHF
String sProperty = "bytes="+nStartPos+"-"; N_4eM,7t
httpConnection.setRequestProperty("RANGE",sProperty); 6,1b=2G
Utility.log(sProperty); *KK+X07
rI5Foh6
_!xD8Di#
InputStream input = httpConnection.getInputStream(); gB\T[RV
//logResponseHead(httpConnection); 2)?(R;$,
EG'[`<*h
-]Cc
byte[] b = new byte[1024]; gw+9x<e
int nRead; e73^#O&Xt
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d{et8N
{ nmlPX7!{$
nStartPos += fileAccessI.write(b,0,nRead); E{=2\Wkcp
//if(nThreadID == 1) _2fkb=2@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _ 7oV<
} k<w(i k1bi
89{HJ9}
=U OLT>!
Utility.log("Thread " + nThreadID + " is over!"); @vgG1w
bDownOver = true; uBg 8h{>
//nPos = fileAccessI.write (b,0,nRead); /)N@M
} ^/wfXm
catch(Exception e){e.printStackTrace ();} s)voII&
} aI zv
} c_{z(W"
pDPxl?S
d lH$yub
//打印回应的头信息 iK;dU2h
public void logResponseHead(HttpURLConnection con) +&tgJ07A
{ Q8p&Ki;i
for(int i=1;;i++) U]qav,^[
{ PYB+FcR6?n
String header=con.getHeaderFieldKey(i); Uts"aQ
if(header!=null) "wH)mQnd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R7oj#
Utility.log(header+" : "+con.getHeaderField(header)); %v5R#14[n
else jD){I
break; e"-X U@`k1
} ?wMHS4
} K*K1(_x=
5_K5?N
F}Mhs17!|
public void splitterStop() N;F)jO xsl
{ 'f8(#n=6qP
bStop = true; -0o[f53}p
} y;" n9
7>o.0
9D@$i<D:
} PDx)S7+w[
fLN!EDq
VeiElU3
/* &zL#hBE
**FileAccess.java Zr$d20M2A;
*//文件访问(定位，写) '/0#lF
package NetFox; W:&R~R
import java.io.*; k!jNOqbb
~CRSL1?
z^* '@
public class FileAccessI implements Serializable{ FHy76^h>e
pvWau1ArNq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |YJCWFbs8
RandomAccessFile oSavedFile; ;SwC&.I
long nPos; >Dm8m[76
?9j{V7h
&'|B =7
public FileAccessI() throws IOException 78#!Q.##
{ ;'T{li2
this("",0); v|Jlf$>
} hSqY$P
&Y|Xd4:
x!S;SU
public FileAccessI(String sName,long nPos) throws IOException Ftb%{[0}u3
{ O/AE}]
oSavedFile = new RandomAccessFile(sName,"rw"); Df07y<>7Q
this.nPos = nPos; 1N`vCt]w
oSavedFile.seek(nPos); @`u?bnx]e
} KHiFJ_3
\jW)Xy
`T*U]/zQ
public synchronized int write(byte[] b,int nStart,int nLen) 9G?ldp8
{ V+MK'<#B
int n = -1; t *6loS0+
try{ S^RUw
oSavedFile.write(b,nStart,nLen); A Ayv
n = nLen; <T,A&`/
} `ue[q!Qq
catch(IOException e) ~d>%,?zz
{ _fTwmnA
e.printStackTrace (); ";3*?/uM
} '3tw<k!1{.
H!r &aP
;uI~BV*3
return n; $Ptk|qFe
} W+>wu%[L
BW[5o3 i
,#u\l>&$
} i`U:gw
cH`^D?#se
sOFa!bdPW
/* JXQPT
**SiteInfoBean.java }amU[U,
*/ -mNQ;zI1
package NetFox; dZ2%S''\
7 &)]) {Q
>O{7/)gS^
public class SiteInfoBean { {5:Zl<0
I %_MV
=6%|?5G
private String sSiteURL; //Site's URL AMlV%U#
private String sFilePath; //Saved File's Path 1IH[g*f
private String sFileName; //Saved File's Name uF(k[[qaiN
private int nSplitter; //Count of Splited Downloading File /9ZcM]X B
B:oF;~d/,
7|YrdK<
public SiteInfoBean() r((Tavn
{//nSplitter的缺省值为5 _j#SpL'P
//default value of nSplitter is 5 wvc>0?t'
this("","","",5); '8Wv.X0`
} _."E%|5
*$,+`+
i s"vekC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "ORzWnE4U
{ QEJGnl676
sSiteURL= sURL; Rq)BssdF
sFilePath = sPath; R"xp%:li
sFileName = sName; H3FW52pjX
this.nSplitter = nSpiltter; Z[#IfbYt
Ueyw;Y
:iCM=k
} &~~s6
-e>|kPfv!
Agy <j
public String getSSiteURL() +cg {[f,J;
{ aO1IVESr$
return sSiteURL; sOC&Q&eg
} x'`"iZO.t
4,1oU|fz
NrJzVGeS
public void setSSiteURL(String value) iyM^[/-R6
{ hw,^G5m
sSiteURL = value; }C6@c1myq-
} YB!!/ SX4
(!zM\sF
Z!\@%`0$
public String getSFilePath() (aKZ5>>cN
{ `F1dyf!p<
return sFilePath; oh\,OW
} -CBD|fo[h
!oMt_k X
uEd,rEB>
public void setSFilePath(String value) MV936
{ b~Z=:'m8
sFilePath = value; D s-`
} y4F^|kS) [
gg]~2f
aWvd`qA9r
public String getSFileName() moO_-@i
{ kL7^$
return sFileName; ?SX_gYe9
} 1r4,XSk
*BOBH;s
~mH+DV3
public void setSFileName(String value) Jp]T9W\
{ 1D1b"o
sFileName = value; $L{7%]7QC
} ^ }#f()
j[DIz@^
a-PGW2G
public int getNSplitter() h([0,:\
{ ]h@{6N'oNS
return nSplitter; KOSyh<&
} 0|C[-ppr
7%CIt?Z%
`"Dy%&U
public void setNSplitter(int nCount) Ak=UtDN[
{ 5-'vB
nSplitter = nCount; L>nO:`>h
} #v8Cy|I
} 79tJV
yiT{+;g^
|R~;&x:
/* ryEvmWYu
**Utility.java t<lyg0f
*/ ,OB&nN t>
package NetFox; Nmf#`+7gCI
<nA3Sd"QfV
AQ}l%
public class Utility { 3wNN<R
\{>eOD_
f[@#7,2~M
public Utility() :&$Xe1)i]
{ "jGe^+9uT
? ).(fP
MZ^Ch
} Mf7E72{D
>sV Bj(f
//线程睡眠 ngqUH
public static void sleep(int nSecond) liG~y|
{ LW?2}`+
try{ /nM*ljfB\
Thread.sleep(nSecond); UCF[oO>v
} rqC1
catch(Exception e) lt%-m@#/
{ yS"0/Rm}
e.printStackTrace (); '%O\E{h
} & =sayP
} m){&:Hs
}rxFS <j
//日志 M=Is9)y
public static void log(String sMsg) ddMM74
{ p;ZDpR
System.err.println(sMsg); f[M"EMy
} 2$Y3[$
%0(>!SY
6cZ C
public static void log(int sMsg) HjPH
{ <Am^z~[
System.err.println(sMsg); 9oD#t~+F4
} g[<uwknf
} ke</x+\F
|vN$"mp^a
"j;!_v>=f`
/* 73#9NZR
**TestMethod.java {lKEZirO
*/ -9i+@%{/
package NetFox; sp,(&Y]US
| &\^n2`>
-CZ-l;5
public class TestMethod { C9+Dw#-fV
Xa\]ua_
?/L1tX)
public TestMethod() h!;MBn`8
{ ///xx/weblogic60b2_win.exe ceI [hM
try{ 0Cv4/Ar(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :if5z2PE/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !j'guT&9]
SiteFileFetch fileFetch = new SiteFileFetch(bean); m"1 ?
fileFetch.start(); -*5yY#fw}
} ;WPI+`-
catch(Exception e){e.printStackTrace ();} 1 pYsjo~
th;]Vo
0MhxFoFO
} J2x$uO{Bn
q .)^B@}_
-hm9sNox
public static void main(String[] args) t"FRLC
{ }8X:?S %
new TestMethod(); +0)5H>h
} {S# 5g2
} OQ 0b$qw
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