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)); aKr4E3`
} [c )\?MWW
for(int i=0;i<nEndPos.length-1;i++) :8T@96]P
{ G=Bj1ss.
nEndPos = nStartPos[i+1]; Y%8QFM
} vG:,oB}
nEndPos[nEndPos.length-1] = nFileLength; v3#47F)
} vjS7nR"T
} g&5VorGx
tvCTC ey
8#-}3~l[
//启动子线程 ,W;8!n0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WLFzLW=PD
for(int i=0;i<nStartPos.length;i++) 'Q,<_L"
{ 1&nrZG9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nwH|Hs riU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wj~8KHan
nStartPos,nEndPos,i); f2f$aZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jZyh
fileSplitterFetch.start(); Z6pDQ^Ii
} /tP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 36UWoo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Yb/^Qk59
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^>uGbhBp
nEndPos = " + nFileLength); C.p*mO&N
// fileSplitterFetch[nPos.length-1].start(); w=2X[V}
Hb4rpAeP
(b!DJ;(O9
//等待子线程结束 BtZm_SeA
//int count = 0; -ZJ:<
//是否结束while循环 gRSG[GMV
boolean breakWhile = false; H-lRgJdc
\/zS@fz
B)*%d7=x
while(!bStop) NYRNop( N#
{ Os+=}
write_nPos(); 1-<Xi-=^{t
Utility.sleep(500); qILr+zH
breakWhile = true; #}?$mxME*
F@3,>~[%I
f}3bYF
for(int i=0;i<nStartPos.length;i++) (avaTUMOqy
{ GrIdQi^8
if(!fileSplitterFetch.bDownOver) FA,CBn5%
{ "WL
breakWhile = false; ),|bP`V
break; IC~D?c0H:
} ${3OQG
} hw2Hn
if(breakWhile) r?*?iw2g
break; -n-X/M
E ..[F<5
g`8|jg0]`I
//count++; SNFz#*
//if(count>4) beoMLHp
// siteStop(); so?1lG
} `dhK$jYD
h#9)M
dRmTE
System.err.println("文件下载结束！"); yKJp37R
} p6*D^-
catch(Exception e){e.printStackTrace ();} l71\II
} C:cu1Y9
t&]IgF
%yVZ|d*Q
//获得文件长度 = %m/
public long getFileSize() ;2}Gqh)Yr
{ 2"T&Fp<
int nFileLength = -1; L3\{{QOA
try{ n\4+xZr
URL url = new URL(siteInfoBean.getSSiteURL()); AS;{{^mM(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~XRr }z_Lq
httpConnection.setRequestProperty("User-Agent","NetFox"); d=XhOC$
|@nXlZE
#.RI9B
int responseCode=httpConnection.getResponseCode(); AF}HS8eYy
if(responseCode>=400) ~x+w@4)a>
{ (;3jmdJhK
processErrorCode(responseCode); 1GxYuTZ{
return -2; //-2 represent access is error 49D*U5o
} B~IOM
wv$=0zF
%;S5_K,
String sHeader; gg9W7%t/
}sZ]SE
-XBNtM_"
for(int i=1;;i++) l=yO]a\QZ
{ ADDpm-]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); as8<c4:v
//Utility.log(in.readLine()); 2},}R'aR
sHeader=httpConnection.getHeaderFieldKey(i); s_N!6$tS
if(sHeader!=null) 0=iJT4IEJ
{ W~4|Z=f
if(sHeader.equals("Content-Length")) sQvEUqy9
{ KqQrxi?f-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^B/{
break; rRW&29A
} &wfM:a/c
} \wd~Y
else .:0nK bW
break; Z3d&I]Tf
} f]4gDmn^
} h)rHf3:
catch(IOException e){e.printStackTrace ();} aw`mB,5U
catch(Exception e){e.printStackTrace ();} sC j3h
-T>`PJpJuL
K67x.PZ
Utility.log(nFileLength); Onl:eG;@
LYKepk
sfLBi~*j
return nFileLength; UcZ3v]$I
} 'D bHXS7N
LQe<mZ<
]=/f`
//保存下载信息（文件指针位置） Yr!3mU-Uvt
private void write_nPos() p0/I}n4<5n
{ 4%pvw;r
try{ *\>7@r[%5
output = new DataOutputStream(new FileOutputStream(tmpFile)); b4Z#]o
output.writeInt(nStartPos.length); 2yNlQP8%
for(int i=0;i<nStartPos.length;i++) Qk6FK]buV
{ x>Kem$z
// output.writeLong(nPos); ,SBL~JJ
output.writeLong(fileSplitterFetch.nStartPos); &lD4-_2J
output.writeLong(fileSplitterFetch.nEndPos); @`3)?J[w
} '=r.rW5
output.close(); !tVV +vT#
} 7]Z*]GRX
catch(IOException e){e.printStackTrace ();} 4-o$OI>
catch(Exception e){e.printStackTrace ();} rpd3Rp
} 22GtTENd1h
X*b0qJ Z
"371`!%
//读取保存的下载信息（文件指针位置） &EMm<(.]a
private void read_nPos() sU>*S$X8
{ i9\Pks#l%
try{ w/R^Vwq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2c}kiqi{
int nCount = input.readInt(); #M:W?&.
nStartPos = new long[nCount]; ^E9@L??
nEndPos = new long[nCount]; jN[Z mJz'
for(int i=0;i<nStartPos.length;i++) nQ mkDPjU
{ kn!J`"b
nStartPos = input.readLong(); OIN]u{S
nEndPos = input.readLong(); (GZm+?
} u3q!te
input.close(); 7>.^GD
} tW,<Pe
catch(IOException e){e.printStackTrace ();} TGg*(6'z
catch(Exception e){e.printStackTrace ();} ZnQnv@{8l
} 6Cibc.vt
dM QnN[d6
6ik6JL$AI
private void processErrorCode(int nErrorCode) 9TeDLp
{ &Z9b&P
System.err.println("Error Code : " + nErrorCode); iVFnt!
} 7|2:;5:U
$T1c{T6n}
#pf}q+A
//停止文件下载 hM;EUWv
public void siteStop() 0^;{b^!(
{ S>6APQ-
bStop = true; ohwQ%NDl
for(int i=0;i<nStartPos.length;i++) @x)z" )>
fileSplitterFetch.splitterStop(); :`_wy-}V
mCg5-E~;
'0[l'Dt'
} |/q*Fg[f
} ,7eN m>$
//负责部分文件的抓取 a+MC[aFr
**FileSplitterFetch.java }!2|*Y
*/ L,R9jMx?_
package NetFox; bO-8<IjC_3
==$Ox6.
_yU e2Gd
import java.io.*; l9n8v\8,o
import java.net.*; &We'omq
R(csJ4F
B-o"Y'iXs
public class FileSplitterFetch extends Thread { #x'C
xe 6x!
sO6+L #!
String sURL; //File URL pnf3YuB
long nStartPos; //File Snippet Start Position }=wSfr9g
long nEndPos; //File Snippet End Position :^l`m9
int nThreadID; //Thread's ID 0^hz1\g
boolean bDownOver = false; //Downing is over ?Hq`*I?b9
boolean bStop = false; //Stop identical 3B>!9:w~f
FileAccessI fileAccessI = null; //File Access interface 6MZfoR
[3j]r{0I
iE$0-Qe[3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $)kIYM&
{ J)*y1
this.sURL = sURL; w^dB1Y7c(W
this.nStartPos = nStart; x*(pr5k
this.nEndPos = nEnd; z]tvy).
nThreadID = id; K2NnA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .NZ_dz$c
} W(EU*~<UC
n}a# b%e
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public void run() YckexfL
{ N-lXC"{)
while(nStartPos < nEndPos && !bStop) 8^+Qn/b_%
{ {<&x9<f9
T?Gi;ld7
9erTb?@S
try{ jMgNi@
URL url = new URL(sURL); O75ioO0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D*heYh
httpConnection.setRequestProperty("User-Agent","NetFox"); {R&F_51)V
String sProperty = "bytes="+nStartPos+"-"; e-x{7
httpConnection.setRequestProperty("RANGE",sProperty); V[CS{Hy'
Utility.log(sProperty); he 9qWL&^G
{DAwkJvb]
Rg+V;C C~
InputStream input = httpConnection.getInputStream(); AM,@BnEcuT
//logResponseHead(httpConnection); &EZ28k"x
TqCzpf&&h/
CI ~+(+q
byte[] b = new byte[1024]; 7(ZI]<
int nRead; N9_9{M{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s}UPe)Vu
{ 2g|+*.*`
nStartPos += fileAccessI.write(b,0,nRead); 4_)@Nq
//if(nThreadID == 1) jwGd*8 /
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ws'3*HAce
} "c=\?
!i0:1{.
aZ- )w
Utility.log("Thread " + nThreadID + " is over!"); zPZy#7/A
bDownOver = true; _epi[zf@
//nPos = fileAccessI.write (b,0,nRead); -SZ^;t
} ^?w6
catch(Exception e){e.printStackTrace ();} yG{'hx6H
} >|mmJ4T
} .z)&#2E
^\J/l\n
E2 #XXc
//打印回应的头信息 XP~4jOL]
public void logResponseHead(HttpURLConnection con) s:,BcVLx^
{ ;IE|XR(
for(int i=1;;i++) NmVc2V]I
{ mam|aRzd
String header=con.getHeaderFieldKey(i); R8?Xz5
if(header!=null) NgQ {'H[Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OV^) N
Utility.log(header+" : "+con.getHeaderField(header)); t d-EB&i\
else V]<J^m8
break; @<r;>G
} L:j;;9Sp{
} E*i <P
AI/xOd!a
9Iy>oV
public void splitterStop() h{qB\aK
{ BPwFcT)i!(
bStop = true; 6xvyhg#B
} 44]/rP_m
9^x'x@6
&qF
} e%u1O-*
WR%x4\,d#
0Evq</
/* fMP$o3;
**FileAccess.java -}4<P}.5T
*//文件访问(定位，写) K9:I8E<
package NetFox; hZU@35~BN
import java.io.*; =T|Z[/fto
H<Ed"-n$I<
R6ca;
public class FileAccessI implements Serializable{ ~f;d3dJ]/
$x)C_WZj?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v=RQ"iv8
RandomAccessFile oSavedFile; ^dM,K p
long nPos; zkA"2dh
;n?H/(6X8>
|Rf4^vN
public FileAccessI() throws IOException $&OoxC
{ 2<y!3OeN
this("",0); ]KBzuz%
} (ylpH`
)u7y.o
OjcxD5"v9
public FileAccessI(String sName,long nPos) throws IOException ckHHD|
{ h}nceH0s3d
oSavedFile = new RandomAccessFile(sName,"rw"); VK5|w:
this.nPos = nPos; 9|jk=`4UK
oSavedFile.seek(nPos); Z^zUb
} 0sD"Hu
[yF>W$Bn%
ep>*]'
public synchronized int write(byte[] b,int nStart,int nLen) 7`9J.L&,;
{ WyF1Fw
int n = -1; /=).)<&|R
try{ }lvD 5
oSavedFile.write(b,nStart,nLen); G];5'd~C;d
n = nLen; xPl+ rsU
} =$`EB
catch(IOException e) :<=A1>&8
{ U ]Ek5p
e.printStackTrace (); eZ'J,;
} !yI , ~`Z
NifzZEX
]>M{Qn*
return n; tsaf|xe
} ^rO3B?_
5ztHar~f
'Y Bz?l9
} |gxT-ZM
Yw&{.<sL
,HO~NqmB4
/* Z/n\Ak sE
**SiteInfoBean.java 7O84R^!|2
*/ Q ;V `
package NetFox; v1*Lf/
Lf`LFPKb
35|F?Jx.r
public class SiteInfoBean { !$ItBn/_
}d?"i@[
yhhW4rz
private String sSiteURL; //Site's URL 4=^_ 4o2
private String sFilePath; //Saved File's Path zGjf7VV2a
private String sFileName; //Saved File's Name 3\j{*f$J
private int nSplitter; //Count of Splited Downloading File kGR5!8$z
>|1.Z'r/
mltG4R ?
public SiteInfoBean() 0n` 1GU)W
{//nSplitter的缺省值为5 )GhMM
//default value of nSplitter is 5 nG hFYQl
this("","","",5); vs]#?3+
} _1TSt%L
sq1Z;l31"
k<x %
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fbgq+f`\
{ c 4xh
sSiteURL= sURL; gb:)t}|
sFilePath = sPath; >T: Yp<
sFileName = sName; %P05k
this.nSplitter = nSpiltter; iU]py
s wgn( -
G$FNofQx
} i]oSVXx4WC
QbA+\
)xwWig.
public String getSSiteURL() ?|Y/&/;%I
{ f7NK0kuA
return sSiteURL; =23JE'^=
} unn2MP'
\@6PA
_o'_ z ]
public void setSSiteURL(String value) QhV!%}7
{ zfAHE{c
sSiteURL = value; 0`y;[qAG[
} yf5X=f.%@
)Nv$SH
B^`'2$3
public String getSFilePath() jF4h/((|EU
{ H]>b<Cs
return sFilePath; z@5t7e)!R
} woIcW
0=]RG
U6SgV 8
public void setSFilePath(String value) 57W4E{A
{ mqPV Eo
sFilePath = value; e}e|??'(\
} E07g^y"}i
V-rzn171Q)
'fB/6[bd
public String getSFileName() R?bF b|5t
{ GjF'03Z4
return sFileName; HivmKn`
} KFxy,Z$-4
v}w=I}<x
U-+%e:v
public void setSFileName(String value) haj\Dm
{ v"x{oD$R
sFileName = value; ;533;(d*o
} j(JUOief
D4jf%7X!Lu
PP{2{
public int getNSplitter() ~xz3- a/
{ O}VI8OB(&
return nSplitter; 5G-)>
} )'\pa2
%*4Gx +b
w783e
public void setNSplitter(int nCount) OG}auM4
{ cQj{[Wt4
nSplitter = nCount; '&~A
} sR%,l
} 8'c_&\kdv
-4:L[.2
=l%"Om*A
/* ZT@a2:&
**Utility.java "b6ZAgxv
*/ VeT\I.K[
package NetFox; 5$SO
iM'{,~8R5
{UX[SAQ
public class Utility { TMsEHd
r+X%0@K
5tyr$P! N
public Utility() :{pJ
{ i7^_y3dG
7=jeq|&kN
b.jxkx\nt
} ,XmTKOc
NNUm=g^
//线程睡眠 G[U'-a}I
public static void sleep(int nSecond) Vj.5b0/(
{ y~jKytq^@
try{ ((BuBu>
Thread.sleep(nSecond); Y)%CxaO`
} [[fhfV+H
catch(Exception e) K<`"Sr
{ FBfyW- 7
e.printStackTrace (); (+g!~MP
} ]@@3]
} 7.O1 ~-
qGS]2KY
//日志 | ?Js)i
public static void log(String sMsg) (^h47kY
{ B@wQ[
System.err.println(sMsg); ;D5B$ @W>
} J('p'SlI
muSQFIvt
R!7emc0T
public static void log(int sMsg) wg?:jK
{ V+A1O k)
System.err.println(sMsg); "Q*Z?6[Z
} hM*T{|y
} L@rKG~{Xy
aO@zeKg
)9@I7QG?
/* oh{!u!L`]
**TestMethod.java z_XI,u}
*/ !/0XoIf"
package NetFox; G6X
m9^?p
5" U8|
public class TestMethod { ^0t81,`
7QiJ1P.z
% ~%>3
public TestMethod() H9)$ #r6i
{ ///xx/weblogic60b2_win.exe +nKxSjqI
try{ A{hwT,zV:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Gq5)>'D?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >M7e'}0;
SiteFileFetch fileFetch = new SiteFileFetch(bean); u(KeS`
fileFetch.start(); i,/|H]Mzr
} KZV$rJ%G
catch(Exception e){e.printStackTrace ();} ZgO7W]Z4
-0| '{
;FYiXK%
} luZqW`?Bt
Yyl2J#$!
VHsNz WI
public static void main(String[] args) %^RlE@l9
{ ;8sEE?C$g
new TestMethod(); o?P(Fuf
} Fs:l"5~>1
} WU1I>i
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