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)); ZUAWSJ,s
} 7b:oz3?PI
for(int i=0;i<nEndPos.length-1;i++) =u${2=
{ JS}W4 N
nEndPos = nStartPos[i+1]; |@Q(~[It
} .I {X
nEndPos[nEndPos.length-1] = nFileLength; ' OdZ[AN
} /=,^fCCN
} N;Hrc6nin^
V{ra,a*
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//启动子线程 w v9s{I{P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~;wSe[
for(int i=0;i<nStartPos.length;i++) Q:>;d-D|1
{ NTs< ;ED
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V\!FD5%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %jqBYn0q'
nStartPos,nEndPos,i); 0wAZ9AxA{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %zb7M%dC6`
fileSplitterFetch.start(); "&Q-'L!M'/
} 3vQ?vS|2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ItC*[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iWGgt]RJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u?Iop/b
nEndPos = " + nFileLength); (gl CTF9v
// fileSplitterFetch[nPos.length-1].start(); K34ca-~
j3Cpo x
$J=9$.4"
//等待子线程结束 { tim{nV
//int count = 0; \eI )(,A
//是否结束while循环 f.V0uBDN
boolean breakWhile = false; #wx0xQ~,J
I;uZ/cZ|/
8kH'ai
while(!bStop) >pG]#Z g
{ Itj|0PGd
write_nPos(); \P&'4y~PL
Utility.sleep(500); g3e\'B'
breakWhile = true; \>23_d0
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:9_K@f?n
for(int i=0;i<nStartPos.length;i++) =QRLKo#_
{ $-5iwZ
if(!fileSplitterFetch.bDownOver) 04WKAP'c N
{ frc>0\
breakWhile = false; e9k}n\t3
break; {LR?#.
} DK*2d_
} O`OntYwa>
if(breakWhile) ,5t.0XqS
break; H.O7Y
_S2QY7/
W*`2lf
//count++; fVb&=%e
//if(count>4) :g+R}TR[i
// siteStop(); UZmzk
} 2ai \("?
]c[80F-
c.KpXY
System.err.println("文件下载结束！"); aR*z5p2-w
} 1wE~dpnx
catch(Exception e){e.printStackTrace ();} )h2wwq0]
} gPQ2i])"Q
eu^z&R!um
-.ha\t0J
//获得文件长度 5<,}^4wWZ
public long getFileSize() Maf!,/U4
{ c<pr1g
int nFileLength = -1; 'JKFEUzM
try{ !;zacw
URL url = new URL(siteInfoBean.getSSiteURL()); w<-CKM3qe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t}_qtO7>
httpConnection.setRequestProperty("User-Agent","NetFox"); v)okVyv
RUYwDtC
B07(15y]
int responseCode=httpConnection.getResponseCode(); |DwI%%0(F
if(responseCode>=400) 0)yvyQ5
{ k3}ymhUf
processErrorCode(responseCode); iN<&
return -2; //-2 represent access is error yZUB8erb.
} 8iqx*8}
6$9n_AS
`fY~Lv{4d_
String sHeader; ?9OiF-:n
1i$9x$4~E
y9pQ1H<F;
for(int i=1;;i++) M-T&K%/lW
{ .!l#z|/x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wu/]M~XwI
//Utility.log(in.readLine()); }yK_2zak5i
sHeader=httpConnection.getHeaderFieldKey(i); UccnQZ7/I
if(sHeader!=null) b H?dyS6Bx
{ 'fy1'^VPAV
if(sHeader.equals("Content-Length")) u"?cmg<.1
{ .FXq4who
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )$#ov-]
break; e~i ?E
} mxGa\{D#y
} `k a!`nfo
else j42U|CuK
break; a%Q.8
} PfF7*}P
} 5d*k[fZ
catch(IOException e){e.printStackTrace ();} Uj(,6K8W
catch(Exception e){e.printStackTrace ();} )?K3nr
#J\ 2/~
bJx{mq
Utility.log(nFileLength); \2L%%M
t(\d;ybyx
K0g<11}(Yg
return nFileLength; 5A>W;Q\4
} PHyS^J`
v,KH2 (N
?Q]&d!UCs
//保存下载信息（文件指针位置） '2WYbcU
private void write_nPos() >C*q
{ QG4#E$c
try{ uV#/Lgw{M
output = new DataOutputStream(new FileOutputStream(tmpFile)); (9*=d_=
output.writeInt(nStartPos.length); qg 4:Vq
for(int i=0;i<nStartPos.length;i++) f]h99T
{ 0"ZB|^c=
// output.writeLong(nPos); B=(m;A#G
output.writeLong(fileSplitterFetch.nStartPos); 53=VIN]
output.writeLong(fileSplitterFetch.nEndPos); "o*F$7D!
} "c\ZUx_i6
output.close(); QukLsl]U
} /E2/3z
catch(IOException e){e.printStackTrace ();} E@}t1!E<
catch(Exception e){e.printStackTrace ();} erdWGUfQOe
} `|8)A)ZVT
^}ngbDn
%i]q} M
//读取保存的下载信息（文件指针位置） HH&`f3
private void read_nPos() R.Ao%VT
{ 1Yo9Wf;vP
try{ -|~6Zf"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _SJ#k|vcq
int nCount = input.readInt(); J)6RXt*!
nStartPos = new long[nCount]; +#"CgZ]
nEndPos = new long[nCount]; /VgA}[%y
for(int i=0;i<nStartPos.length;i++) JpvE c!cli
{ W~$YKBW
nStartPos = input.readLong(); 1 xm8w$%
nEndPos = input.readLong(); po}Jwx!
} 5%mc|
input.close(); /[#<@o
} n-be8p)-
catch(IOException e){e.printStackTrace ();} |bk.gh
catch(Exception e){e.printStackTrace ();} oP$NTy[
} *[]7l]XK.
ZZL.&Ho
-fI-d1@
private void processErrorCode(int nErrorCode) Z!0D97^
{ (|(#~o]40t
System.err.println("Error Code : " + nErrorCode); ,]gYy00w0s
} Vahfz8~w/
X-|Lg.s
`PXSQf
//停止文件下载 R3`!Xj#&M
public void siteStop() (]n^_G#-$
{ tY-{uHW&h
bStop = true; .E-)R
for(int i=0;i<nStartPos.length;i++) (, Il>cR4
fileSplitterFetch.splitterStop(); +@ga
2 1.;lj
HP}d`C5<R
} GD<xmuo
} n dgG1v%
//负责部分文件的抓取 $TyV< G
**FileSplitterFetch.java 5(R ./
*/ vY&[=2=
package NetFox; AP&mr1_
AC;ja$A#
;^za/h>r
import java.io.*; 6,"86
import java.net.*; ^"WrE(3
pbM~T(Y8
9(g?{6v|
public class FileSplitterFetch extends Thread { [LDsn]{
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zRSIJ!A~
String sURL; //File URL V+j58Wuf
long nStartPos; //File Snippet Start Position BO)K=gl;8
long nEndPos; //File Snippet End Position Q^}6GS$
int nThreadID; //Thread's ID Goa0OC,
boolean bDownOver = false; //Downing is over [(Ss^?AJW
boolean bStop = false; //Stop identical ^EY^.?Mg
FileAccessI fileAccessI = null; //File Access interface \6~(#y
y,e#e`
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qP=4D 9 ]
{ YTP6m9hA+
this.sURL = sURL; Wm_:1~
this.nStartPos = nStart; s @\UZC
this.nEndPos = nEnd; Q'xZ\t
nThreadID = id; oRmz'F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Al&)8x{p
} d(!W
>S/m(98
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public void run() w$%d"Jm#X
{ gbF^m`A>%+
while(nStartPos < nEndPos && !bStop) X.TsOoy
{ hn]><kaA
GR6BpV7
/sHWJ?`&/,
try{ zE$KU$
URL url = new URL(sURL); zq\YZ:JC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7S+_eL^
httpConnection.setRequestProperty("User-Agent","NetFox"); \H <k
String sProperty = "bytes="+nStartPos+"-"; <Sw>5M!j
httpConnection.setRequestProperty("RANGE",sProperty); 6%'bo`S#
Utility.log(sProperty); P")duv
2 VgFP3
n *Y+y
InputStream input = httpConnection.getInputStream(); ;#c=0*.
//logResponseHead(httpConnection); |cKo#nfzZ
;oL`fQyr
Z:51Q
byte[] b = new byte[1024]; s'/b&Idf8
int nRead; (vL-Z[M!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Cbw@:+%J{
{ yc ize2>q
nStartPos += fileAccessI.write(b,0,nRead); Hqsj5j2i
//if(nThreadID == 1) @&H Tt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yffg_^fR
} B5FRe'UC
^eu={0k
Qv~KGd9
Utility.log("Thread " + nThreadID + " is over!"); 0A$x'pU)
bDownOver = true; {{'GR"D
//nPos = fileAccessI.write (b,0,nRead); aE]/w1a
} ZcT%H*Ib]9
catch(Exception e){e.printStackTrace ();} BT[jD}?
} CVo2?ZQ
} 7;]n+QRfm
>\J({/ #O
j A/xe
//打印回应的头信息 $_bhZnYp7
public void logResponseHead(HttpURLConnection con) ^P)W/2
{ 70sb{)
for(int i=1;;i++) jS_fwuM
{ h?cf)L
String header=con.getHeaderFieldKey(i); g>g]qQ
if(header!=null) }ZPO^4H;-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }a=<Gl|I;w
Utility.log(header+" : "+con.getHeaderField(header)); Ab| tE5%
else `TugtzRU
break; -)='htiU
} H);O.m
} ~3,>TV
rUg<(/c
v$H=~m
public void splitterStop() iR_j h=2{
{ d<x7* OW)
bStop = true; l+%2kR
} $ NNd4d*
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j=&]=0F
} % ~!A,
!&8nwOG
WAd5,RZ?
/* UG@9X/l}
**FileAccess.java _zuaImJ0o
*//文件访问(定位，写) ]j=Eof%Rc
package NetFox; yJyovfJz.
import java.io.*; {>x6SVF
*y6zwe !M
q?&Ap*
public class FileAccessI implements Serializable{ Z%rMX}
@ PboT1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @ )bCh(u
RandomAccessFile oSavedFile; fu=GgD*
long nPos; IjshxNk
,b b/ $
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public FileAccessI() throws IOException YI877T9>
{ *h <_gn
this("",0); E}YJGFB7"
} t\GoUeH]
j3W)
\/wbk`2
public FileAccessI(String sName,long nPos) throws IOException 26e.Hu
{ zp4aiMn1F
oSavedFile = new RandomAccessFile(sName,"rw"); ls;!Og9
this.nPos = nPos; >e'Hz(~'/
oSavedFile.seek(nPos); pW y+oZ
} r bfIH":
Ro2Ab^rQ|
XCN^>ToD
public synchronized int write(byte[] b,int nStart,int nLen) {E 'go]
{ =%i~HDiy
int n = -1; C>MEgGP
try{ y E;n.L
oSavedFile.write(b,nStart,nLen); g"KH~bN
n = nLen; N=vb*3ECg
} 7NFRCCXHQ
catch(IOException e) ?q*,,+'0
{ :j<ij]rsI
e.printStackTrace (); _aaQ1A`p
} 4#MPD
j#f7-nHyz8
+";<Kd-
return n; [(O*W
} *LZB.84
2[V9`r8*
C/JFb zVx
} ;_nV*G.y#^
Fr|Ts>Kx
SK]"JSY`
/* \F; S
**SiteInfoBean.java Vlf=gP
*/ R'z -#*[
package NetFox; &*\-4)Tf
V,?BVt
{L#+v~d^'n
public class SiteInfoBean { G@(ukt`0}
Kqn{q4L
HX`>" ?{
private String sSiteURL; //Site's URL e.n*IJ_fz
private String sFilePath; //Saved File's Path k@Q>(`
private String sFileName; //Saved File's Name Iq% 0fX
private int nSplitter; //Count of Splited Downloading File o_#F,gze)S
qrLE1b 1$
hLo>jE
public SiteInfoBean() Ir4M5OR\
{//nSplitter的缺省值为5 T!ik"YZ@i
//default value of nSplitter is 5 66Tx>c"H
this("","","",5); 713)D4y}
} W*!u_]K>
YsBOh{Ml
&f"kWOe$X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OGGuVY
{ 0Vwl\,7z9
sSiteURL= sURL; 0,M1Q~u%.
sFilePath = sPath; 6?uo6 I
sFileName = sName; ?,AWXiif
this.nSplitter = nSpiltter; ;p] f5R^
(q+EP(Q
H vezi>M
} J.g4I|{
]ff5MY 36
O@)D%*;v
public String getSSiteURL() 7zWr5U.
{ w"/RI#7.
return sSiteURL; ,nnVHBN
} o8h1
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p J#<e
public void setSSiteURL(String value) w.0:#4
{ n^+rxG6L
sSiteURL = value; cfrvx^,2&
} A{(<#yRfg
@`S8d%6P
mvV5Xal
public String getSFilePath() z&W5@6")`
{ YjTA+1}
return sFilePath; +^tw@b
} XL2iK)A
etD8S KD
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public void setSFilePath(String value) ??g`c=R!V
{ u''~nSR3&
sFilePath = value; )<8f3;qd
} *j/[5J0'M
O9Fg_qfuT_
^N2N>^'&1.
public String getSFileName() yw{;Qm2\7
{ <-%OXEG
return sFileName; s"g"wh',
} xZpGSlA
l;'#!hC)
A\S1{JrR
public void setSFileName(String value) /'uFX,
{ du0]LiHV
sFileName = value; q(YFt*(;w
} @b,&b6V
'D1Sm&M2%e
$Afw]F$
public int getNSplitter() w\f>.N
{ WUesTA>
return nSplitter; f:6%DT~a&C
} XDM~H
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ujMics(
public void setNSplitter(int nCount) .)Af&+KT
{ fj,]dQT
nSplitter = nCount; 7\e96+j|f
} IQ3]fLb
} RxZ#`$F
1E'/!|
~~D =Z#
/* 60`4 _Uy]_
**Utility.java E 02l=M
*/ |'bRVqJ
package NetFox; rDvz2p"R
v!b 8_0~u6
P O{1u%P
public class Utility { N)rf/E0
#Lq{_Y
Uq8=R)1<|d
public Utility() >*"6zR2 o
{ 1G6MO
i8Y$cac!
XA%a7Xtni
} Q'mLwD3>
EE<^q?[3^
//线程睡眠 ~.,h12
public static void sleep(int nSecond) ZO!
{ l*+5WrOS
try{ <P"4Mk7`s
Thread.sleep(nSecond); $^1L|KgXp
} 4\6-sL?rW
catch(Exception e) *xl930y
{ X%>Sio
e.printStackTrace (); I )LO@
} 3nJd0E
} C<?Huw4R0
-#nfO*H}
//日志 jW G=k#WN
public static void log(String sMsg) Y^(Sc4 W
{ MGmUgc
System.err.println(sMsg); K[XFJ9
} ?5oeyBA@
F$QAWs
EpO5_T_
public static void log(int sMsg) bBFdr
{ gtBnP~zT\B
System.err.println(sMsg); b(Ev:
} u*<G20~A
} CX8tTbuFl
%qM3IVPK)q
nv9kl Q@
/* =eXJZPR
**TestMethod.java ~alC5|wCUQ
*/ Z!qHL$
package NetFox; ZN:~etd
&$vW
UBUZ}ZIbN
public class TestMethod { Dw@0P
]/p)XHKo
t1)~J
public TestMethod() Y68T&swD
{ ///xx/weblogic60b2_win.exe ^r7-|
try{ l9J]<gG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0wzq{~\{=_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I#]$H#}Av
SiteFileFetch fileFetch = new SiteFileFetch(bean); QX*HvT
fileFetch.start(); ;(kU:b|j
} ZjE!? '(ef
catch(Exception e){e.printStackTrace ();} K,>D%mJ
X:*Ut3"
DO!?]"
} .Jt&6N
7DU"QeLeb
rf%E+bh4
public static void main(String[] args) );^] is~
{ w/KCuW<
new TestMethod(); %C]K`=vI-
} 0Wf,SYx`s
} {-sy,EYcw
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