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)); gH G
} NOp609\^
for(int i=0;i<nEndPos.length-1;i++) ,u/aT5\_
{ xKFn.qFr
nEndPos = nStartPos[i+1]; 7PkJ-JBA
} ]niJGt
nEndPos[nEndPos.length-1] = nFileLength; yR4|S2D3xn
} u?+Kkkk
} lv]hTH 4T
N&M~0iw
Yh>]-SCw
//启动子线程 SI=yI-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P><o,s"v
for(int i=0;i<nStartPos.length;i++) +-G<c6 |
{ wR^RM(1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qkC/\![@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VH[hsj
nStartPos,nEndPos,i); >ss/D^YS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0)m(;>'70
fileSplitterFetch.start(); ?`4+cx}n
} *<J*S#]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), phgm0D7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aAB`G3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =Jym%m
nEndPos = " + nFileLength); q#8[
// fileSplitterFetch[nPos.length-1].start(); f{FDuIln
=XY\iV1J*
qBCK40
//等待子线程结束 zF`c8Tsx])
//int count = 0; rf$X>M=G
//是否结束while循环 rp0ZvEX
boolean breakWhile = false; +gLPhX:`
? 8LXP
4vwTs*eB`
while(!bStop) kP?KXT3y
{ et }T%~T
write_nPos(); [AW" D3
Utility.sleep(500); R[;zX(y
breakWhile = true; V#`fs|e;y
sxt-Vs7+6
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for(int i=0;i<nStartPos.length;i++) (e[}/hf6
{ 8:/e GM
if(!fileSplitterFetch.bDownOver) r3\cp0P;s
{ DuOG {
breakWhile = false; )'4k|@8|
break; D&/L:
} z5r$M
} o5Q{/
if(breakWhile) IzpZwx^3''
break; 8A+SjJ4$
GO^_=EMR[
?'<nx{!c
//count++; G 8V,
//if(count>4) Bn(W"=1
// siteStop(); Iwc{R8BV
} GPGm]Gt
4A2?Uhpy
o!!yd8~*r
System.err.println("文件下载结束！"); 0eS)&GdR
} n2fbp\I
catch(Exception e){e.printStackTrace ();} <Ce2r"U1e
} $]A/ o(
!OuWPH. :
&Y^WP?HS
//获得文件长度 -Q U^c2
public long getFileSize() $n^gmhp
{ NvvUSyk\;s
int nFileLength = -1; ]._LLSzWhg
try{ :.45u}[
URL url = new URL(siteInfoBean.getSSiteURL()); \ 5,MyB2/`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~PHB_cyth
httpConnection.setRequestProperty("User-Agent","NetFox"); B!\;/Vk
}eRD|1
WuZ/C_
int responseCode=httpConnection.getResponseCode(); w18y}mS"H
if(responseCode>=400) :"!9_p(,,
{ 14"J d\M8
processErrorCode(responseCode); ](^(=%
return -2; //-2 represent access is error %Pqf{*d8
} |H!9fZO
#2EI\E&$
!1G."fo
String sHeader; S!sqbLrBn
$VxA0 =ad
.({smN,B
for(int i=1;;i++) ?:L:EW8
{ mb!9&&2-t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U\sHx68
//Utility.log(in.readLine()); 8{Fsm;UsY
sHeader=httpConnection.getHeaderFieldKey(i); dH^<t,v
if(sHeader!=null) ,-OCc!7K
{ ;jipe3LU
if(sHeader.equals("Content-Length")) xQ'2BAEa
{ 4sP2g&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xu'yVt9RC
break; $]rj73p^tH
} -^ C=]Medl
} bpxeznz
else H Tz
break; `Ps:d^8*P
} gB4U*D0[e~
} +a*^{l}AST
catch(IOException e){e.printStackTrace ();} (S v~2
catch(Exception e){e.printStackTrace ();} <dvy"Dx
+ Q6l*:<|c
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Utility.log(nFileLength); wX*K]VMn
:,DM*zBVp
Q pmsOp|
return nFileLength; 5Fz.Y}
} Q"7Gy<
@_LN3zP
g=e71DXG2
//保存下载信息（文件指针位置） %:2+ o'
private void write_nPos() _{ZqO;[u
{ PClMQL#
try{ Zt3)]sB
output = new DataOutputStream(new FileOutputStream(tmpFile)); &RTX6%'KY
output.writeInt(nStartPos.length); 25&J7\P*
for(int i=0;i<nStartPos.length;i++) |eWjYGwJa
{ l#}.^71+
// output.writeLong(nPos); SC- $B
output.writeLong(fileSplitterFetch.nStartPos); UDL RCS8i
output.writeLong(fileSplitterFetch.nEndPos); !S_^94b@
} Q8_ d)t|
output.close(); cDI [PJ9
} \{EpduwZ
catch(IOException e){e.printStackTrace ();} &wB\ ~Ie-
catch(Exception e){e.printStackTrace ();} :(H>2xS,s
} @GvztVYo
Z*FrB58
fu9Cx
//读取保存的下载信息（文件指针位置） T =2=k&|
private void read_nPos() Vy|6E#U
{ U.@*`Fg
try{ ''kS*3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Hp(D);0+)
int nCount = input.readInt(); o^V(U~m]
nStartPos = new long[nCount]; E(i[o?
nEndPos = new long[nCount]; EFc-foN
for(int i=0;i<nStartPos.length;i++) O%ug@& S{
{ W\L`5CW
nStartPos = input.readLong(); "ax..Mh\y
nEndPos = input.readLong(); Tdc3_<1
} ^7.h%lSg
input.close(); \fjMc }'
} w`DW(hXJ
catch(IOException e){e.printStackTrace ();} bUY>st'
catch(Exception e){e.printStackTrace ();} `w.AQ?p@
} _H^^y$+1
SKW%X8
-D^}S"'
private void processErrorCode(int nErrorCode) ys#i@
{ >[1W:KQA
System.err.println("Error Code : " + nErrorCode); 2>l,no39t+
} ZoB{x*IH
\t|M-%&)4
NzW`B^p
//停止文件下载 NxLXm,
public void siteStop() :(_+7N[KA
{ X@|&c]]
bStop = true; 4Ua>Yw0
for(int i=0;i<nStartPos.length;i++) 1lpwZ"
fileSplitterFetch.splitterStop(); -&e92g&n
42\-~]
Nlj^Dm
} @EoZI~
} )aX2jSp
//负责部分文件的抓取 v<9&B94z
**FileSplitterFetch.java k'PQ} ,Vb
*/ 3.)b4T
package NetFox; o#[ KS:Y
Q_vW3xz
_aPh(qprc
import java.io.*; ]0r|_)s
import java.net.*; <vUVP\u~$
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public class FileSplitterFetch extends Thread { p\Lq}tk<
JO'>oFv_W
c)7j QA
String sURL; //File URL A$WZF/x
long nStartPos; //File Snippet Start Position ~xIjF1Z
long nEndPos; //File Snippet End Position LA[g(i 7
int nThreadID; //Thread's ID v~/~@jv
boolean bDownOver = false; //Downing is over |D.O6?v@
boolean bStop = false; //Stop identical 9RwawTM
FileAccessI fileAccessI = null; //File Access interface !SKV!xH9
++Ww88820
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x^*1gv $o
{ pN&c(=If
this.sURL = sURL; m~'? /!!
this.nStartPos = nStart; D.%B$Y;G
this.nEndPos = nEnd; Y[SU&LM
nThreadID = id; sFDG)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W~Z<1[
} a83g\c5
<*EZ@XoN>
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public void run() |*mL1#bB
{ Xes|[*Y!V
while(nStartPos < nEndPos && !bStop) &5t :H 8b
{ -xD*tf*
aV1lJ;0
%/.a]j!
try{ ,pBh`av
URL url = new URL(sURL); fj,m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KL'zXkS
httpConnection.setRequestProperty("User-Agent","NetFox"); 7P7b8]
String sProperty = "bytes="+nStartPos+"-"; g-vg6@6
httpConnection.setRequestProperty("RANGE",sProperty); !rhk $L
Utility.log(sProperty); eb|i3.
*xR 2)u
rNl.7O9b
InputStream input = httpConnection.getInputStream(); j'p1q
//logResponseHead(httpConnection); \/|)HElKR
*Ul*%!?D
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byte[] b = new byte[1024]; gf)t)-E
int nRead; j6ut}Uq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jKIc09H|
{ bqx0d=Z~[
nStartPos += fileAccessI.write(b,0,nRead); l?*r5[O>n
//if(nThreadID == 1) nIfCF,6,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~svO*o Wa
} Vc3mp;6"
gX5&d\y
]+H?@*b`
Utility.log("Thread " + nThreadID + " is over!"); Rb}KZ+o"Z
bDownOver = true; <ale$[
//nPos = fileAccessI.write (b,0,nRead); gBk5wk_j|
} sn{AwF%
catch(Exception e){e.printStackTrace ();} Zt E##p
} fMf&?`V
} kJ)gP2E
9TxyZL
as"N=\N
//打印回应的头信息 /\Q*MLwD
public void logResponseHead(HttpURLConnection con) nkeI60
{ B ?%L
for(int i=1;;i++) cyd~2\Kv~
{ !~-6wN"k
String header=con.getHeaderFieldKey(i); C0x"pO7
if(header!=null) /OGA$eP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9x`4RE
Utility.log(header+" : "+con.getHeaderField(header)); !Ngw\@f
else KbxR Lx]w
break; 4-v6=gz.
} 5 ZfP
} Me:{{-V4
?PPZp6A3L=
v@EQ^C2.&
public void splitterStop() yy(A(}
{ UmKX*T9
bStop = true; ?HR%bngK
} X21dX`eMN
$1*3!}_0
gH:ArfC
} Wf>^bFb"$
t0m*PJcF
x|~zHFm6
/* $GF]/;\m
**FileAccess.java 5@u~3jPd
*//文件访问(定位，写) #%S0PL"x U
package NetFox; $;D* n'8Fx
import java.io.*; ;8B.;%qkL
CHaE;olo
msk/p>{O
public class FileAccessI implements Serializable{ $->d!
Q1tpCT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 So4nJ><p
RandomAccessFile oSavedFile; b7h+?!H]R
long nPos; )fh0&Y; R
et$uP
.]76!(fWZ
public FileAccessI() throws IOException =ak7ldA=2
{ 9XV^z*E(J
this("",0); IjZ@U%g@;
} !Ua&0s%
0\a8}b||
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public FileAccessI(String sName,long nPos) throws IOException {0's~U+@
{ g*-2* \
oSavedFile = new RandomAccessFile(sName,"rw"); |pWaBh|r
this.nPos = nPos; # .q#OC
oSavedFile.seek(nPos); u.6P-yh
} u3dsQU
.2X2b<%)
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public synchronized int write(byte[] b,int nStart,int nLen) /)V4k:#b
{ fA8ozL T
int n = -1; WD?Jk9_F
try{ T{-2fp8r[
oSavedFile.write(b,nStart,nLen); 3eg5oAZ)G8
n = nLen; ^Omfe
} |f NMs
catch(IOException e) |Cf mcz(56
{ =,Ttw>
e.printStackTrace (); Y%IJ8P^Y
} G :4;y7
&(O06QL
Q\#UWsN(T/
return n; `fW{yb
} _+zVpZ
1!/-)1t
jp m#hH{R
} |NEd@
fS./y=j(X
6GKT yN
/* JE)J<9gf
**SiteInfoBean.java u7muaSy
*/ `-D$Fsl
package NetFox; VG#Q;Xd}
V.,bwPb{9
K+mU_+KRp
public class SiteInfoBean { R`Qpd3
(2%>jg0M
5\G)Q<A]*L
private String sSiteURL; //Site's URL ]_2yiKv&
private String sFilePath; //Saved File's Path t:9 ZCu ay
private String sFileName; //Saved File's Name },6*Y*?{
private int nSplitter; //Count of Splited Downloading File J~dTVBx
o>!JrH
N5\{yV21",
public SiteInfoBean() #Wx=v$"
{//nSplitter的缺省值为5 nW&$~d
//default value of nSplitter is 5 rv?!y8\
this("","","",5); 2nx9#B*/T
} vPsq<l}
X,Zd=
#{w5)|S#JD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g8Aj `O
{ gfVDqDF
sSiteURL= sURL; <|V'pim
sFilePath = sPath; 0pNo`Bm
sFileName = sName; #HDesen
this.nSplitter = nSpiltter; !Mil?^
_m7co :
{]M>Y%j48
} )G4rJ~#@
;KS`,<^-
;fx1!:;.
public String getSSiteURL() ]Wy.R6
{ _ _=s'
return sSiteURL; hfh.eL
} x3;jWg~'
s7|3zqi
R2Yl)2 D
public void setSSiteURL(String value) Jy`G]]?
{ \-G5l+!
sSiteURL = value; j]HE>
} uTw|Q{f
pe#*I/)b
Yhk6Uog{4
public String getSFilePath() 2+&R"#I
{ r./z,4A`
return sFilePath; 1g81S_T .
} gA"<MI'y
+{Gw9h"5g*
:f]!O@.~
public void setSFilePath(String value) 7%YYr^d
{ QqjTLuN
sFilePath = value; E- KK
} /KP_Vc:g2_
b.,$# D{p
L"9 Gc
public String getSFileName() 1)gv%_
{ +/}_%Cf8
return sFileName; !*8#jy
} PAr|1i)mB
.f+9 A>
RSFJu\0}N
public void setSFileName(String value) FSVS4mtiX\
{ ^ `E@/<w8
sFileName = value; aulaX/'-_
} [[&)cbv
WRY~fM
ny~W]1
public int getNSplitter() T7ki/hjRb
{ G ;jF9i
return nSplitter; rBS2>?
} fX""xTNPi
9yDFHz w
p/4S$ j#Tn
public void setNSplitter(int nCount) ,?fN#gc :
{ rQ &S<
nSplitter = nCount; FQQ@kP$.
} `TAcZl=8
} dJaEoF
=;g=GcVK
L[1d&d!p
/* OAY8,C=M
**Utility.java y 'mlee
*/ TXx'7[
package NetFox; v=j>^FZ
G u6[{u
>]^>gUmq
public class Utility { Io09W^
9ec0^T
E+:.IuXW$
public Utility() G~O" /WM
{ 2[XltjO
`|uoqKv
~DK F%}E
} }]tFz}E\
l~4_s/
//线程睡眠 rXlx?GV
public static void sleep(int nSecond) 5a8JVDLX^
{ '+tKvTU;
try{ p[_Yi0U
Thread.sleep(nSecond); i+U@\:=
} Ko@zk<~"[
catch(Exception e) +tPx0>p;
{ *ZX!EjICk
e.printStackTrace (); OA!R5sOz"
} vP-3j
} KU*`f{|
^P]?3U\nj
//日志 7:#
public static void log(String sMsg) O{Dm;@J-aM
{ 2B5A!?~>
System.err.println(sMsg); Jk%'mEGE
} (21']x
zUNH8=U
~v^%ze
public static void log(int sMsg) Ri9Kr
{ id3)6}
System.err.println(sMsg); 56"#Syj
} /*AJ+K._
} -*rHB&e
bkxk i@t
?rky6
/* ]Jja
**TestMethod.java vU?b"n
*/ GJ.kkTMT
package NetFox; Ng?apaIi@~
u,:CJ[3
j l}!T[5
public class TestMethod { Fecx';_1`
mx:J>SPA8
8e]z6:}'E
public TestMethod() >0kmRVd
{ ///xx/weblogic60b2_win.exe Czq1 kz
try{ xX[?L9RGz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <Z2(qZ^Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N[#iT&@T}/
SiteFileFetch fileFetch = new SiteFileFetch(bean); pk;ffq@
fileFetch.start(); lb-S0plw
} \8=e|a5`
catch(Exception e){e.printStackTrace ();} sM#!Xl;
&G0l&8pa
.WBI%ci
} ;Fx')
_)OA$
)GB3=@
public static void main(String[] args) ){+.8KI
{ zJz82jMm
new TestMethod(); :D<:N*9i
} Oqd"0Qt-
} HyZVr2
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