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)); Ub(zwR;
} a}eM ny
for(int i=0;i<nEndPos.length-1;i++) 5#/"0:2
{ 9Y&,dBj+
nEndPos = nStartPos[i+1]; a.QF`J4"'
} zbn0)JO
nEndPos[nEndPos.length-1] = nFileLength; !^BXai/
} L9[? qFp
} 95jJ"4a+
kuq3QW<
o!EPF-:
//启动子线程 Qa~dd{?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3lYM(DT
for(int i=0;i<nStartPos.length;i++) N}Ozm6Mc
{ +~mBo+ ,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l}B,SkP^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2ijw g~_@
nStartPos,nEndPos,i); H~x,\|l#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'zV/4iE=
fileSplitterFetch.start(); j;@7V4'
} l<0BMwS8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LQ pUyqR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *+TIF"|1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U&#1qRm\h
nEndPos = " + nFileLength); +*-u_L\'
// fileSplitterFetch[nPos.length-1].start(); Q?rb(u(
x"0*U9f
wQiRj.
//等待子线程结束 Z[:fqvXQ
//int count = 0; s8iJl+Jm
//是否结束while循环 L>Bf}^
boolean breakWhile = false; r2H_)Oi
~$} `R=
:{<( )gfk
while(!bStop) W_(
{ -~T?xs0_
write_nPos(); v`8dRVN
Utility.sleep(500); y)_T!&ze
breakWhile = true; Pda(O;aNU
&A>Hq/Y
&z;F'>"
for(int i=0;i<nStartPos.length;i++) I4 dS,h
{ bJ8G5QU
if(!fileSplitterFetch.bDownOver) O.4ty)*
{ (m|w&oA/
breakWhile = false; SAswP
break; H@Dj$U
} ;,GE!9HW
} \2,7fy'
if(breakWhile) |NFX"wv:c<
break; >AIkkQT
]v96Q/a
@4dB$QF`&
//count++; DP`$gd
//if(count>4) rQgRD)_%w
// siteStop(); 6+HpN"?e
} X]d["
mf]1mG})
513{oM:
System.err.println("文件下载结束！"); |KFRC)g
} >en,MT|
catch(Exception e){e.printStackTrace ();} fnV^&`BB
} xe5|pBT
}WXO[ +l
g|_-O"l
//获得文件长度 qXmkeidb&W
public long getFileSize() $8#zPJR&
{ z;`o>Ja2
int nFileLength = -1; X,d`-aKO\y
try{ xFcJyjo^z
URL url = new URL(siteInfoBean.getSSiteURL()); vB >7W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i_8q!CL@{
httpConnection.setRequestProperty("User-Agent","NetFox"); A9^t$Ii
8*yhx
_:F0>=$
int responseCode=httpConnection.getResponseCode(); ]F kLtq
if(responseCode>=400) Ym IVtQ
{ J{c-'Of2yi
processErrorCode(responseCode); `[x`#irD
return -2; //-2 represent access is error NFpR jC?
} ~*R"WiDtI
iW\cLp "
<}x_F)E[t
String sHeader; cSy{*K{B
d;UP|c>2
KO/Z|I
for(int i=1;;i++) _IiTB
{ {p&M(W]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d>@&[C!28
//Utility.log(in.readLine()); !ckmNE0
sHeader=httpConnection.getHeaderFieldKey(i); dbF?#s~u
if(sHeader!=null) p<IMWe'tP
{ Om`VQ?
if(sHeader.equals("Content-Length")) ?:F#WDD
{ Iqe=)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U6V+jD}L]
break; ``bIqY
} #`R`!4
} )=6|G^
else $OMTk
break; k fS44NV
} 0 =#)-n
} /Zs;dam
catch(IOException e){e.printStackTrace ();} 4L}i`)CmB
catch(Exception e){e.printStackTrace ();} meQ>mW
}& ;49k
(izGF;N+
Utility.log(nFileLength); tVJ}NI #
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{,z$*nf
return nFileLength; 3dm lP2
} 1"k"<{%
y7J2:/@[x
|E:q!4?0
//保存下载信息（文件指针位置） #;ezMRKM"
private void write_nPos() a?#v,4t^
{ 04{*iS95J
try{ L|hsGm\
output = new DataOutputStream(new FileOutputStream(tmpFile)); [:Kl0m7
output.writeInt(nStartPos.length); Q; DN*
for(int i=0;i<nStartPos.length;i++) (dZu&
{ %\OG#36
// output.writeLong(nPos); }c/p+Wo
output.writeLong(fileSplitterFetch.nStartPos); Uz(Sv:G
output.writeLong(fileSplitterFetch.nEndPos); wxw3t@%mNm
} hxcRFqX"
output.close(); {=n-S2%
} O3,IR1
catch(IOException e){e.printStackTrace ();} k@QU<cvI
catch(Exception e){e.printStackTrace ();} V2-fJ!
} Hrb67a%b
LRNgpjE}
7P!<c/ E
//读取保存的下载信息（文件指针位置） {OHaI ;
private void read_nPos() YCJcDab
{ {s^vAD<~x3
try{ \va'>?#o1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ('yBIb\ue
int nCount = input.readInt(); p'PHBb8I
nStartPos = new long[nCount]; aH6{_eY
nEndPos = new long[nCount]; ]ADj9
for(int i=0;i<nStartPos.length;i++) 9I3vW]0x[
{ ,S.<qmf
nStartPos = input.readLong(); @uru4>1_dy
nEndPos = input.readLong(); J'99
} YK(I'
input.close(); ]PlDe8
} ~dkN`1$v
catch(IOException e){e.printStackTrace ();} %mLQ'$
catch(Exception e){e.printStackTrace ();} bvVEV
} -"m4 A0
l)@Zuh
alu3CE
private void processErrorCode(int nErrorCode) Q4;eN w
{ r3.A!*!
System.err.println("Error Code : " + nErrorCode); M[aF3bbN
} )3h%2C1uM
M'Fa[n*b?!
~loJYq'y
//停止文件下载 JIeKp7;^
public void siteStop() >,JLYz|</
{ xqV>m
bStop = true; 7S"W7O1>
for(int i=0;i<nStartPos.length;i++) HR0t[*
fileSplitterFetch.splitterStop(); !YJfP@"e6r
=*K~U# uoC
|^z?(?w
} <G d?,}\
} WO=X*One
//负责部分文件的抓取 VKzY6
**FileSplitterFetch.java z D&5R/I
*/ !nX}\lw
package NetFox; z@WuKRsi
'rWu}#Nb
Mlr]-Gu5Z
import java.io.*; >cVEr+r9t
import java.net.*; |g o jb
P3[!-sv
.m',*s<CMQ
public class FileSplitterFetch extends Thread { qIm?F>>@
(?luV#{5
vAeh#V~#
String sURL; //File URL wD(1Sr5n
long nStartPos; //File Snippet Start Position <Uz~V;
long nEndPos; //File Snippet End Position *Ru@F:
int nThreadID; //Thread's ID ED9uKp<Wbv
boolean bDownOver = false; //Downing is over rgth2y]
boolean bStop = false; //Stop identical O3U6"{yJ)
FileAccessI fileAccessI = null; //File Access interface :z=C
/$]#L%
a(|YLN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U%E6"Hg
{ Dm=d
this.sURL = sURL; DyZe+,g;S
this.nStartPos = nStart; =_(i#}"A
this.nEndPos = nEnd; j,7NLb9M
nThreadID = id; Rg4'9I%B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qx#k()E.U
} g[Tl#X7F
sY @S
N#C"@,}Y
public void run() eVRFb#EU0e
{ \tL9`RKpg
while(nStartPos < nEndPos && !bStop) Z_%9LxZlyj
{ }zA kUt
K6vF}A|
k-o(Q"[ '
try{ x2@Q5|a
URL url = new URL(sURL); ;4E.Yr*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M$|r8%z1
httpConnection.setRequestProperty("User-Agent","NetFox"); 1h.Ypzu
String sProperty = "bytes="+nStartPos+"-"; ho5mH{"OV
httpConnection.setRequestProperty("RANGE",sProperty); `R}q&|o7<
Utility.log(sProperty); nveHLHvC7
.=y-T=}
e1*<9&S
InputStream input = httpConnection.getInputStream(); {Ac5(li_
//logResponseHead(httpConnection); desrKnY
:o!bz>T
C~C}b
byte[] b = new byte[1024]; ]QB<N|ps
int nRead; (eTe`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VBHDI{HzRv
{ v%mAU3M
nStartPos += fileAccessI.write(b,0,nRead); *3,GQ%~/z
//if(nThreadID == 1) x3X^\Ig
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FlWgTn>
} z(-j%?
[&6VI?
*}yOL [
Utility.log("Thread " + nThreadID + " is over!"); H;#3S<
bDownOver = true; =(!&8U9
//nPos = fileAccessI.write (b,0,nRead); XYBvM]
} jzRfD3_s
catch(Exception e){e.printStackTrace ();} zF+NS]XK
} w Pk\dyP
} Equj[yw%@
/h)_Q;35S;
<"Ox)XG3]W
//打印回应的头信息 -\Y"MwIED
public void logResponseHead(HttpURLConnection con) DK!QGATh
{ j3<|X
for(int i=1;;i++) (}$pf6s
{ ;0)|c}n+.5
String header=con.getHeaderFieldKey(i); *aE/\b
if(header!=null) Y)X 'hk)5|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vr/O%mDp
Utility.log(header+" : "+con.getHeaderField(header)); )qgcz<p?W
else ^qn,b/>L
break; 3~Qvp )~
} ?Cg",k'
} ~/R,oQ1!g}
O'<5PwhG
{km~,]N
public void splitterStop() wi7a_^{
{ 3^ct;gz
bStop = true; %kod31X3<
} xJ/<G$LNJ0
5xHP5+&
WtT* 1Z
} z>\vYR$
9Ai e$=
3ID1>
/* R)p+#F(s
**FileAccess.java pzkl;"gK
*//文件访问(定位，写) >";I3S-t
package NetFox; o09)esy
import java.io.*; ?Ek 3<7d
3Kv~lo^
NU>'$s
public class FileAccessI implements Serializable{ av}Giz
In[!g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;zMZ+GZ?;+
RandomAccessFile oSavedFile; vG`;2laY
long nPos; /7s^OkQ
H$M#+EfL
*.4VO+^
public FileAccessI() throws IOException &, =Z
{ COV8=E~
this("",0); |)"`v'8>
} bO)voJ<
/-in:gX8
T^"-;
public FileAccessI(String sName,long nPos) throws IOException 6c[&[L%
{ ~,*=j~#h
oSavedFile = new RandomAccessFile(sName,"rw"); gpIq4Q<
this.nPos = nPos; .u+ZrA#
oSavedFile.seek(nPos); :A~6Gk92A
} 4,nUCT
rA=iBb3`
nUp, %z[
public synchronized int write(byte[] b,int nStart,int nLen) ~\UH`_83[
{ 1 P0)La#
int n = -1; E< 57d,3l
try{ P(n_eIF-f
oSavedFile.write(b,nStart,nLen); OMl<=;^:|
n = nLen; yvQRr75
} NCid`a$
catch(IOException e) il=:T\'U9
{ 5<Lal^c D
e.printStackTrace (); 2 Nr*
} HDV@d^]-
iSiez'
_4Ciai2Ql
return n; c.<bz
} #it)
K!L0|WH%!
_LYI#D
} X,ES=J0
rw9m+q
bu}N{cW
/* X(YR).a~
**SiteInfoBean.java cft'%IEs
*/ JB}jt)ol%
package NetFox; =>y%Aj&4
;5ANw"Dq
vVA)x~^
public class SiteInfoBean { :n%KHen3\
'}F=U(!
j9voeV|7
private String sSiteURL; //Site's URL >EVY,
private String sFilePath; //Saved File's Path pA~eGar_J
private String sFileName; //Saved File's Name +\Zr\fOe|%
private int nSplitter; //Count of Splited Downloading File 4s <|8
p7Q}xx
qm!&(8NfK
public SiteInfoBean() ZQ MK1
{//nSplitter的缺省值为5 p+ki1!Ed
//default value of nSplitter is 5 eG\|E3Cb9
this("","","",5); OYbgt4
} h)~i?bq!/
H N )@sLPc
eHIsTL@Fp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y}.?`/Q#
{ zfm-vU
sSiteURL= sURL; t,v=~LE
sFilePath = sPath; x%$as;
sFileName = sName; @hz~9AII9
this.nSplitter = nSpiltter; /'g/yBY
`P(Otr[6
40M/Gu:
} +|iJQF
P {8d.
'1f:8
public String getSSiteURL() ~T'!.^/
{ S.E'fc1
return sSiteURL; l ;fO]{
} r;~2NxMF/
pOmHxFOOK
=Zt7}V
public void setSSiteURL(String value) 2B!Bogs
{ ;oT!\$Mu
sSiteURL = value; +eIX{J\s
} $Fr>'H+i
sX,."@[
}zE Qrfl
public String getSFilePath() S0zk<S
{ v ?OIK=Xm
return sFilePath; p10i_<J]=
} ]Av)N6$&-Z
C8oAl3d+h
5(qc_~p^
public void setSFilePath(String value) B=,j$uH
{ b-Uy&+:X*d
sFilePath = value; |s}7<A
} `%5~>vPS
/W @k:
o4l=oY:'
public String getSFileName() |PY*"Ul
{ BQ /0z^A
return sFileName; Y \oz9tf8
} e5HHsR6
'(.vB~m7*+
{i!@C(M3
public void setSFileName(String value) %aHQIoxg
{ 9NPOdt:@
sFileName = value; ^5,B6
} VW%eB
&1(PS)s
E$?:^ausu
public int getNSplitter() N Dg*8i
{ \ld{Z;e
return nSplitter; C3#mmiL-
} qe@ctHpn
7G 3*@cl
y wf@G; fK
public void setNSplitter(int nCount) .~L^h/)Gjy
{ ~4t7Q
nSplitter = nCount; ?A\[EI^
} O.+02C_*
} |."thTO
YS|Ve*t(L=
wFHz<i!jr&
/* ta)'z@V@g
**Utility.java !}$,) ~<+H
*/ oDvE0"Sz
package NetFox; /OaW4 b$Tz
N:]Ud(VRM
8<w8"B.i
public class Utility { A@HCd&h
]"DsZI-glW
7z@Jw
public Utility() E#I^D/0
{ <lxE^M
dh.vZ0v=7
~UhTy~jya
} ^XbN&'^,HL
l^"HcP6
//线程睡眠 zK@DQ5
public static void sleep(int nSecond) s+jL BY
{ -NgL4?p=
try{ <:gNx%R
Thread.sleep(nSecond); m-h+UKt
} }X;LR\^u[f
catch(Exception e) YlP8fxS
{ }0(.HMiGj
e.printStackTrace (); h,u?3}Knnb
} zwEZ?m!
} \A'tV/YAd
D$OUy}[2`.
//日志 8E:d!?<^&I
public static void log(String sMsg) {YoK63b$
{ q=+AN</
System.err.println(sMsg); \as^z!<
} 'GJ'Vli
p~!UE/V
fSL'+l3
public static void log(int sMsg) 7yDWcm_y
{ G$HXc$OY
System.err.println(sMsg); /GQN34RD
} JXa5snh{h
} LaolAqU
pMy];9SvW
U<"@@``+N
/* +LEU|#
**TestMethod.java @|hn@!YK
*/ f(r=S Xa*
package NetFox; )t#v55M
ja_.{Zv
ha -KfkPFE
public class TestMethod { TTSyDl
;I5u"MDHGI
F#S)))#
public TestMethod() W? ^ ?Kx
{ ///xx/weblogic60b2_win.exe 2U Q&n`A
try{ i;GF/pi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %Uz 5Ve
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c'gV
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z<2j#rd
fileFetch.start(); 3{j&J-
} "dN4EA&QJ
catch(Exception e){e.printStackTrace ();} ys#V_ysb
R3`h$`G
-{tB&V~+v
} rbEUq.Yk]~
>Y\$9W=t
1m5=Nu
public static void main(String[] args) P nxxW?
{ R | &+g\{;
new TestMethod(); zx7g5;J
} #XaTUT
} w '<8lw
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