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)); #e=^[E-yE
} Yt'o#"R)
for(int i=0;i<nEndPos.length-1;i++) sg2C_]i,H
{ &ivIv[LV
nEndPos = nStartPos[i+1]; eC39C2q\
} =+L>^w#6=
nEndPos[nEndPos.length-1] = nFileLength; qprOxP r
} 8UcT?Zp
} |Wgab5D>V
?C{N0?[P-
ZM.g+-9
//启动子线程 # 0(\s@r.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }>:X|4]
for(int i=0;i<nStartPos.length;i++) TK>}$.c%+
{ ;v'Y'!-J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OY#_0p)i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z~5'p(|@f
nStartPos,nEndPos,i); pk4&-iu9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jp#cFUa t
fileSplitterFetch.start(); `QF|> N
} `!8Z"xD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mx4*zj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <i6MbCB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 19t*THgq
nEndPos = " + nFileLength); 3Cl9,Z"&6$
// fileSplitterFetch[nPos.length-1].start(); Uf<vw3
8(;i~f:bCW
9 JtG&^*
//等待子线程结束 OXB-.<
//int count = 0; !/zj7z !
//是否结束while循环 B" z5j
boolean breakWhile = false; hH/O2
g1|c?#fwo
UXJl;Mb
while(!bStop) MO/N*4U2
{ n}?G!ySg
write_nPos(); 7A6sSfPUy
Utility.sleep(500); }b(e
breakWhile = true; J5T#}!f
BxU1Q&
xTZ5q*Hqx
for(int i=0;i<nStartPos.length;i++) uSJP"Lw
{ [ _$$P*
if(!fileSplitterFetch.bDownOver) 1%`:8
{ k]iS3+nD
breakWhile = false; ~=ktFuEa
break; bYc qscW
} HWBom8u0
} O2dgdtm
if(breakWhile) :bDA<B6bb
break; S/;Y4o
4vS!99v)
>6 #\1/RP
//count++; ]Dg0@Y
//if(count>4) bn35f<+
// siteStop(); M(uB ;Te
} 9a%@j ]
nW_
v!xrUyN~m
System.err.println("文件下载结束！"); |Ze}bM=N
} BkfBFUDQ
catch(Exception e){e.printStackTrace ();} !e `=UZe1
} <GRf%zJ
9A(K_d-!H
+GU16+w~E
//获得文件长度 \k_3IP?o=
public long getFileSize() |/;5| z
{ 4?&a?*M
int nFileLength = -1; M3 u8NRd5|
try{ %U7f9
URL url = new URL(siteInfoBean.getSSiteURL()); 4/WCs$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QB,ad
httpConnection.setRequestProperty("User-Agent","NetFox"); 2v1&%x:y#
8-ssiiJ}gh
*XOKH+_u
int responseCode=httpConnection.getResponseCode(); MlE~gCD
if(responseCode>=400) h';v'"DoW`
{ e&4u^'+K
processErrorCode(responseCode); CD[=z)<z{
return -2; //-2 represent access is error G\ZRNb
} gDNW~?/
66^t[[
^)l@7XxD
String sHeader; @|Bp'`j%J
eE%yo3
_|:bac8pL
for(int i=1;;i++) H>iZVE
{ nV*sdSt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iQC&d_#
//Utility.log(in.readLine()); *8H;KGe=
sHeader=httpConnection.getHeaderFieldKey(i); 9z/_`Xd_
if(sHeader!=null) 3uG5b8?
{ ZMg9Qt
if(sHeader.equals("Content-Length")) 7`@?3?
{ 0\nhg5]?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5yi q#
break; .@-]A
} SkRQFm0a~
} RmV/wY
else d|+jCTKS
break; _hL4@C
} gr{Sh`Cm-
} 3|r!*+.
catch(IOException e){e.printStackTrace ();} pY>-N
catch(Exception e){e.printStackTrace ();} G0Tc}_o<Y
:vyf-K74M
b\m(0/x
Utility.log(nFileLength); %]$p ^m
@SG"t,5s
6FIoWG"x
return nFileLength; Rbc2g"]
} FXEfD"
DK_v{R
u!Nfoq&'u
//保存下载信息（文件指针位置） V?dK*8s
private void write_nPos() g] C3lf-
{ ^-*Tn
try{ ixHZX<6zYT
output = new DataOutputStream(new FileOutputStream(tmpFile)); GiO#1gA
output.writeInt(nStartPos.length); 9OT4jAm
for(int i=0;i<nStartPos.length;i++) )TG0m= *
{ LNxE-Dp
// output.writeLong(nPos); ]l7\Zq
output.writeLong(fileSplitterFetch.nStartPos); )u/ ^aK53^
output.writeLong(fileSplitterFetch.nEndPos); 02#Iip3t
} maEpT43f
output.close(); 3=|2Gs?ut
} b<V./rWIB
catch(IOException e){e.printStackTrace ();} jP.b oj_u*
catch(Exception e){e.printStackTrace ();} lF"(|n"R
} ~nc([%!=
)'dH}3Ba
[67E5rk-
//读取保存的下载信息（文件指针位置） 6 %k+0\d
private void read_nPos() :`^3MMLO
{ bKJ7vXC05
try{ yO,`"Dc_0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S<]a@9W
int nCount = input.readInt(); 4'hcHdL9
nStartPos = new long[nCount]; ig_<kj;Vd
nEndPos = new long[nCount]; OPt;G,$ta
for(int i=0;i<nStartPos.length;i++) IgR"euU
{ {AL9o2
nStartPos = input.readLong(); akCo+ @
nEndPos = input.readLong(); S{(p<%)[
} q(tGbhQ
input.close(); P(gVF|J?
} :htq%gPex9
catch(IOException e){e.printStackTrace ();} O:=|b]t
catch(Exception e){e.printStackTrace ();} J1Ki2I=
} S O:V|Tfj
^N2M/B|0
BS,5W]ervE
private void processErrorCode(int nErrorCode) dGD^op,6g
{ DEQE7.]3q
System.err.println("Error Code : " + nErrorCode); CL'Xip')T
} xgT~b9
hn\Q6f+
K_+;"G
//停止文件下载 oSA*~N:
public void siteStop() b801OF
{ LUDJPIk
bStop = true; |~bR.IA
for(int i=0;i<nStartPos.length;i++) DMcxa.Sd!
fileSplitterFetch.splitterStop(); dbuJ~?D,
6+B{4OY
"$IXZ
} =i^<a7M~
} 4,F3@m:<
//负责部分文件的抓取 Cq*}b4^;
**FileSplitterFetch.java 9kX=99kf[
*/ =e!l=d|/
package NetFox; )dIfr
g?[&0r1
Ph+X{|
import java.io.*; z(` }:t
import java.net.*; bA<AG*
\aVY>1`
z'oiyXEE3
public class FileSplitterFetch extends Thread { ){
}uI7\\S
#3Ej0"A@-B
String sURL; //File URL !H1tBg]5
long nStartPos; //File Snippet Start Position rx6-~0!eI=
long nEndPos; //File Snippet End Position A6NxM8ybn+
int nThreadID; //Thread's ID Ed^uA+D
boolean bDownOver = false; //Downing is over qQxA@kdd
boolean bStop = false; //Stop identical V@_-H gg
FileAccessI fileAccessI = null; //File Access interface (e8G (
]Q4PbW
WfDX"rA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M,t*nG
{ C3\E.u?
this.sURL = sURL; "7yNKO;W
this.nStartPos = nStart; &`yOIX-H_
this.nEndPos = nEnd; Gh2Q$w:
nThreadID = id; @<OO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H\| ]!8w5Z
} V'"I9R'1
K/2.1o;9
{;&B^uz ]
public void run() UIf ZPf=
{ JS/M~8+Et
while(nStartPos < nEndPos && !bStop) )Ab6!"'
{ q1f=&kGX~
.B'UQ|NR
7Y32p'
try{ 1@%B?
URL url = new URL(sURL); BeI;#m0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p`:*mf
httpConnection.setRequestProperty("User-Agent","NetFox"); gE@$~Q>M
String sProperty = "bytes="+nStartPos+"-"; p"[O#*p
httpConnection.setRequestProperty("RANGE",sProperty); kYxl1nv
Utility.log(sProperty); rps(Jos_~
a(@p0YpKT
=9pw uH
InputStream input = httpConnection.getInputStream(); Pknc[h},
//logResponseHead(httpConnection); |As2"1_f
bR`rT4.F
JAlU%n?R
byte[] b = new byte[1024]; U~*c#U"bh
int nRead; iUIy,Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @8=vFP'
{ ,M)k7t:
nStartPos += fileAccessI.write(b,0,nRead); _\dt?(m|
//if(nThreadID == 1) <Zp^lDxa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 20UqJM8Ot
} aXdf>2c{JD
#e.jY_
[IX*sr
Utility.log("Thread " + nThreadID + " is over!"); wfxOx$]zK
bDownOver = true; 4l&"]9D
//nPos = fileAccessI.write (b,0,nRead); gEv->pc
} !TP6=ks
catch(Exception e){e.printStackTrace ();} ohrw\<xsu
} g4:VR:o
} }iilzE4oH#
"v(G7*2
a`H\-G
//打印回应的头信息 FUaI2
public void logResponseHead(HttpURLConnection con) +7Yu^&
{ q*6q}s3n
for(int i=1;;i++) JbE?a[Eg?
{ E-~mOYea
String header=con.getHeaderFieldKey(i); iOT)0@f'
if(header!=null) [J0*+C9P*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^ <qrM
Utility.log(header+" : "+con.getHeaderField(header)); #B @X
else i`prv&
break; VpkD'<G
} aSOU#Csx
} J&M1t#UN
% f2<U;ff
iQt!PMF.
public void splitterStop() b5AGk
{ F:%^&%\
bStop = true; M h`CP
} ?75\>NiR
dQ:?<zZ
K7IyCcdB
} Kb}MF9?:e
K~c^*;F
6Wj@r!u
/* AD^X(rW
**FileAccess.java coDjL.u
*//文件访问(定位，写) 4d!S#zx
package NetFox; Nd`HB=ShJ
import java.io.*; R0%?:! F
P7z:3o.
VS?dvZ1cC
public class FileAccessI implements Serializable{ P: n#S%
D7)(D4S4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B4Q79gEh=
RandomAccessFile oSavedFile; KiQ(XNx
long nPos; q"S(7xWS
8QV t, 'I
< CDA"
public FileAccessI() throws IOException j"5Pe
{ xw?CMA
this("",0); e1Ob!N-
} ;4,'y
[*<.?9n)or
(vKI1^,
public FileAccessI(String sName,long nPos) throws IOException }mKwFVZ
{ Zvxp%dES
oSavedFile = new RandomAccessFile(sName,"rw"); dY8(nQG
this.nPos = nPos; _R)&k%i}
oSavedFile.seek(nPos); q0Xoj__c!A
} _zq)0\
1!!\+ c2*
RU6KIg{H
public synchronized int write(byte[] b,int nStart,int nLen) Jy9bY
{ !2z!8kI
int n = -1; R2l[Q){!
try{ rJDnuR
oSavedFile.write(b,nStart,nLen); [[w2p
n = nLen; *8PN!^
} i3\~Qj;1
catch(IOException e) tw=K&/@^O
{ a5a1'IVq
e.printStackTrace (); I:i<>kG
} L1wZU,o
ym\(PCa5`
l7z6i*R
return n; z>G;(F2
} SG:bM7*1'
ACb/ITu
lyyX<=E{)
} FPF6H puV
ZHCr2^w6
P/MM UmO
/* cx{T '1
**SiteInfoBean.java X"j>=DEX
*/ d8E,o7$m
package NetFox; |g<*Rk0
dv, C6t2
?g3 ]~;#
public class SiteInfoBean { fywvJ$HD]L
k9mi5Oc
*_1[[~Aw
private String sSiteURL; //Site's URL hL!QLiF:
private String sFilePath; //Saved File's Path zmiZ]uq
private String sFileName; //Saved File's Name tiYOMA
private int nSplitter; //Count of Splited Downloading File vZu~LW@1
-f?Ah
^,TTwLy-t
public SiteInfoBean() R-
{//nSplitter的缺省值为5 =1Z;Ma<;
//default value of nSplitter is 5 Z19m@vMsIP
this("","","",5); 2+.18"rvi
} "ZT.k5Z
_yvLuj
OR4!YVVQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,gMy@
{ (#|{%4g@>
sSiteURL= sURL; rk|a5-i
sFilePath = sPath; fxgU~'
sFileName = sName; \G>ZkgU
this.nSplitter = nSpiltter; iY~rne"l
g$FEEDF
5wT>N46UX
} }mZVL~|V
yfEb
W%o|0j\1GU
public String getSSiteURL() cSK&[>i)4
{ 0y~<%`~
return sSiteURL; .VM3D0aV
} ghAi{@s$)
Hx2En:^Gf
I%"'*7U
public void setSSiteURL(String value) eEl.. y
{ T5|c$doQ
sSiteURL = value; a}gkT]
} 8;8c"'Mn
q'G,!];qL
\NK-L."[
public String getSFilePath() uLk]LT
{ Qx)Jtb0`V
return sFilePath; fP[& a9l
} !%PWig-
|c2xy
<G~>~L.E
public void setSFilePath(String value) $bsH$N#6T
{ {G3i0r
sFilePath = value; rNlW7Y
} E4i0i!<z
u6Je@e_!
--fFpM3EvS
public String getSFileName() 1J}8sG2`
{ y(a!YicA?
return sFileName; eV7u*d?
} ;%!B[+ut"
DCQ^fZ/
*5VXyt2
public void setSFileName(String value) %gd(wzco
{ '91".c,3?
sFileName = value; F$MX,,4U
} @5VV|Wt=
<>Y?vC
&dR=?bz-A
public int getNSplitter() -#s [F S
{ j_cs;G: "
return nSplitter; U@F)2?
} "TS
H'=(`
VDbI-P&c
public void setNSplitter(int nCount) P"_$uO(5x
{ YB,t0%vTJw
nSplitter = nCount; Sw[{JB;y,
} ,Hn^z<f
} p'94SXO_
RA O`i>@
D@oCP =m<
/* {ZsdLF#
**Utility.java 0?0Jz
*/ 'CR)`G_'[
package NetFox; ve6w<3D@
!CUoHTmB
nBItO~l
public class Utility { XORk!m|
51BlM%
kAA>FI6
public Utility() w5=tlb
{ ^|MjJsn
[ ho(z30k
~b~2 >c9
} mLk(y*
|JF@6
//线程睡眠 ~lAKJs#{
public static void sleep(int nSecond) % ps$qB'
{ "=/ f$Xf
try{ 9=X)ung9
Thread.sleep(nSecond); c]-*P7W
} }J:+{4Yn
catch(Exception e) Hu3wdq
{ *J|(jdu7
e.printStackTrace (); ``VW;l{
} @=jWHS
} 7nq3S
1BHG'y
//日志 yifY%!@Xu
public static void log(String sMsg) 7JJ/D4uT
{ =3ioQZ^Vz
System.err.println(sMsg); #>=j79~
} NEt1[2X%
?<Wb@6kh`
9^FziM
public static void log(int sMsg) 0& >H^
{ (Rt7%{*
System.err.println(sMsg); HB+|WW t>
} 7\]E~/g
} Q\ /uKQ
ZF7IL
L(T12s
/* *]hBGr#6
**TestMethod.java qyC=(v
*/ WQyLf;!Lz
package NetFox; o8e?J\?
HK\~Qnq
8UC xnf#
public class TestMethod { _@S`5;4x
ljl^ GFo
lj+u@Z<xA
public TestMethod() .ERO|$fv
{ ///xx/weblogic60b2_win.exe F}Vr:~
try{ "-@[R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AJ#Nenmj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X7k.zlH7T
SiteFileFetch fileFetch = new SiteFileFetch(bean); hI9
fileFetch.start(); .bBdQpF-
} W9NX=gE4
catch(Exception e){e.printStackTrace ();} Q.K,%(^;a
%HrAzM.QBF
F:x [
} H"A7Zo
l;o1 d-n]
2-Y<4'>
public static void main(String[] args) x _c[B4Tw
{ jy-{~xdg[
new TestMethod(); oudxm[/U
} #g6.Glz3
} iY21Ql%
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