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)); NT;cTa=;
} rtC:3fDy
for(int i=0;i<nEndPos.length-1;i++) O*udVE>
{ 6~tj"34_
nEndPos = nStartPos[i+1]; BXa.XZ<n(
} v%E~sX&CG
nEndPos[nEndPos.length-1] = nFileLength; ykD-L^}
} 4`'V%)M
} s4vj
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//启动子线程 "] [u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pz ~REsx
for(int i=0;i<nStartPos.length;i++) Hd89./v`:
{ Mt\.?V:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e {805^X}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *^i"q\n5(
nStartPos,nEndPos,i); h{VdW}g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W-<`Vo'
fileSplitterFetch.start(); 8Az|SJ<
} {Y1&GO;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I]6,hygs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $ 9 k5a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3"LT''
nEndPos = " + nFileLength); +@qIDUiF3
// fileSplitterFetch[nPos.length-1].start(); m_h$fT8 _
U$Od)
o(eh.
//等待子线程结束 _|wnmeL*
//int count = 0; Eu2(#z 6eW
//是否结束while循环 GxS!Lk
boolean breakWhile = false; jQ3&4>gj
BDT"wy8
iH>IV0 <
while(!bStop) =?[:Nj636
{ (CrP6]=
write_nPos(); BY>]6SrP
Utility.sleep(500); hUe\sv!x?
breakWhile = true; n*rXj{Kt
BE)&.}l
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for(int i=0;i<nStartPos.length;i++) =F/EzS
{ /5y _ <
if(!fileSplitterFetch.bDownOver) V>& 1;n
{ Yd]
breakWhile = false; a^7QHYJ6
break; b]g#mQ
} V0!kvIv
} `Ln1g@
if(breakWhile) 6 jU?~
break; 8f>v[SQ"
iM M s3
cS(=wC
//count++; ?D['>Rzu
//if(count>4) @nOuFX4
// siteStop(); 2[i(XG{/
} 3 EOuJ
FZtT2Z4&i
L b-xc]
System.err.println("文件下载结束！"); wo9`-o6
} ;^cMP1SH
catch(Exception e){e.printStackTrace ();} tY%T
} -%TwtO<$']
-q&7q
X/FRe[R
//获得文件长度 G6pR?K+
public long getFileSize() V)]lca
{ +do*C=z
int nFileLength = -1; RmJ|g<
try{ J~)JsAXAI
URL url = new URL(siteInfoBean.getSSiteURL()); uvJmEBL:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V\=%u<f
httpConnection.setRequestProperty("User-Agent","NetFox"); py$i{v%
emIF{oP
6\USeZh
int responseCode=httpConnection.getResponseCode(); @?5pY^>DK
if(responseCode>=400) @./@"mR<
{ *0Wkz'=U
processErrorCode(responseCode); J3hhh(
return -2; //-2 represent access is error V$bq|r
} \-D[C+1(
jJAr #|
CEJqo8ds
String sHeader; F%$lcQ04%
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Sobp;OZ5
for(int i=1;;i++) 3:bP>l!
{ Kl]l[!c7$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \qJ cs'D
//Utility.log(in.readLine()); r=#v@]zB
sHeader=httpConnection.getHeaderFieldKey(i); `$ pJ2S
if(sHeader!=null) @ 1FWBH~
{ jQ['f\R
if(sHeader.equals("Content-Length")) [nLd>2P
{ _ygdv\^Tet
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,15$$3z/E
break; zS'{F>w
} ! q+>'Mt
} ]CX^!n
else zC`ediyu
break; e#@u&+K/f
} irMBd8WG
} Ct]? /
catch(IOException e){e.printStackTrace ();} /w2NO9Q
catch(Exception e){e.printStackTrace ();} F41gMg
4%7Oaf>9
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Utility.log(nFileLength); 0yxwsBLy
@B9#Hrc
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return nFileLength; ]W7&ZpF
} O@>{%u
at(gem
(I;lE*>
//保存下载信息（文件指针位置） A_+*b [P
private void write_nPos() R)Dh;XA
{ [ZD`t,x(
try{ X/H2c"!t
output = new DataOutputStream(new FileOutputStream(tmpFile)); )2J#pz?.
output.writeInt(nStartPos.length); EUS^Gtc
for(int i=0;i<nStartPos.length;i++) 1-Q>[Uz,
{ ceAefKdb
// output.writeLong(nPos); Ryn@">sVI
output.writeLong(fileSplitterFetch.nStartPos); u?KG%
output.writeLong(fileSplitterFetch.nEndPos); +f,I$&d.V
} r@ba1*y0
output.close(); Qm4cuV-0{
} 5Zl7crA[
catch(IOException e){e.printStackTrace ();} }DQ[C&
catch(Exception e){e.printStackTrace ();} 9`!#5i)VU8
} /Q'O]h0a
W3&~[DS@~
Ox6^=D"
//读取保存的下载信息（文件指针位置） TSj)XU {W
private void read_nPos() \b?O+;5Cj
{ XlJ+:st
try{ 1~[GGl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~e=KBYDBu
int nCount = input.readInt(); S9 @*g3
nStartPos = new long[nCount]; 5K00z?kD2V
nEndPos = new long[nCount]; M] W5%3do
for(int i=0;i<nStartPos.length;i++) LP) IL~
{ QY$4D;M`g6
nStartPos = input.readLong(); =<U'Jtu6'
nEndPos = input.readLong(); sNJ?Z"5k1h
} PcvA/W
input.close(); u43-\=1$T
} ihIRB9
catch(IOException e){e.printStackTrace ();} \{1Vjo
catch(Exception e){e.printStackTrace ();} xt8@l [Z
} Co`:D
~HXZ-*
)T@+"Pw8t
private void processErrorCode(int nErrorCode) M B,Z4 ^
{ %Gm4,+8P3o
System.err.println("Error Code : " + nErrorCode); J=ot&%
} fw0Z- 9*
N~B'gJJDx
N}q*(r!q<
//停止文件下载 r8!M8Sc
public void siteStop() /P*ph0S-
{ #M92=IH
bStop = true; D$SO 6X~
for(int i=0;i<nStartPos.length;i++) o Hrx$>W]
fileSplitterFetch.splitterStop(); 4<U6jB5
@fd{5 >\
a!:R_P}7
} LsNJ3oy
} /7C%m:
//负责部分文件的抓取 cQ/T:E7$`
**FileSplitterFetch.java s=n_(}{ q
*/ l%7^'nDn
package NetFox; w4Ku1G#jC
_2WIi/6K
M:w]g`LKl
import java.io.*; ~T&X#i
import java.net.*; u!cA_,
T\L LOx\
e{d$OzT) V
public class FileSplitterFetch extends Thread { ;\t(c
ni3A+Y0
V,:~FufM^
String sURL; //File URL 8C2!Wwz`J8
long nStartPos; //File Snippet Start Position .vXe}%
long nEndPos; //File Snippet End Position 2|LkCu)~,"
int nThreadID; //Thread's ID y#5;wb<1
boolean bDownOver = false; //Downing is over t8-LPq
boolean bStop = false; //Stop identical eXMl3Lxf
FileAccessI fileAccessI = null; //File Access interface C-ipxL"r
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}pv<<7}|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U KdCG.E9^
{ jI807g+
this.sURL = sURL; vC5y]1QDd
this.nStartPos = nStart; eh$T 3_#q
this.nEndPos = nEnd; q.PXO3T
nThreadID = id; L!kbDbqn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ib$?[
} ;EfREfk
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public void run() p\M\mK
{ c(0Ez@
while(nStartPos < nEndPos && !bStop) 1 *$-.
{ 5[$jrG\!
>]WQ1E[=
z=VL|Du1OT
try{ h:'wtn@l(
URL url = new URL(sURL); o^~KAB7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Le}-F{~`^
httpConnection.setRequestProperty("User-Agent","NetFox"); X3rvM8
String sProperty = "bytes="+nStartPos+"-"; O.+X,CQG*
httpConnection.setRequestProperty("RANGE",sProperty); +jX.::UPm
Utility.log(sProperty); l%$co07cX
(Y]G6> Oa
PQ[x A*
InputStream input = httpConnection.getInputStream(); w\ 7aAf3O
//logResponseHead(httpConnection); )NS&1$
=k22f`8ew
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byte[] b = new byte[1024]; OPVcT
int nRead; \}mn"y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #me'1/z
{ p*(]8pDC
nStartPos += fileAccessI.write(b,0,nRead); V .VV:`S
//if(nThreadID == 1) Fs)m;C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .=4k'99,
} v"G)G)*z
d/`Q,Vl
UI.>BZ6}
Utility.log("Thread " + nThreadID + " is over!"); uSK<{UT~3
bDownOver = true; |#-GH$.v
//nPos = fileAccessI.write (b,0,nRead); ~gvw6e*[
} {F+iL&e)
catch(Exception e){e.printStackTrace ();} n:[GK_
} 9dD;Z$x&Xk
} zAdZXa[MRY
;?0r,0l2$
En/EQ\T@F
//打印回应的头信息 "+:IA|1wD
public void logResponseHead(HttpURLConnection con) ar|!iU
{ E`>u*D$un~
for(int i=1;;i++) 5A=FEg
{ ]QAMCu(>
String header=con.getHeaderFieldKey(i); 9~$'?
if(header!=null) Gfn?1Kt{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?_7^MP>
Utility.log(header+" : "+con.getHeaderField(header)); lGtTZcg
else " )_-L8
break; [boB4>.
} kI>PaZ`i)
} eC41PQ3=1'
+=A53V[C
EAM2t|MG.
public void splitterStop() YX:[],FP
{ Kwa$5qZI
bStop = true; -Lbi eS%
} B7!dp`rPp
w>ap8><4
!*l5%H
} Sx3R2-!Z
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G;3N"az
/* OwM.N+z#T
**FileAccess.java {y k0Zef_
*//文件访问(定位，写) jh&WL
package NetFox; 4w5mn6MxR
import java.io.*; u$?t |Ll
R3=]Av46
THbV],RhJ
public class FileAccessI implements Serializable{ Iib39?D W
O}IRM|r"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V,CVMbn/%N
RandomAccessFile oSavedFile; IDpW5Dc
long nPos; mlD 1 o
d=_Wgz,d
+sc--e?
public FileAccessI() throws IOException wO {-qrN
{ &p2fMVWJ7
this("",0); !Yan}{A,
} =fr_` "?k
_<i*{;kR6
#U j~F
public FileAccessI(String sName,long nPos) throws IOException 12,,gwh
{ <>FpvdB
oSavedFile = new RandomAccessFile(sName,"rw"); ;,yjkD[mWE
this.nPos = nPos; _ X* A
oSavedFile.seek(nPos); L'?0*t
} !:^lTvYWZH
q|+`ihut
T[YGQT|B
public synchronized int write(byte[] b,int nStart,int nLen) wJQ"|
{ otgU6S7F
int n = -1; y.:Z:w6$
try{ b0_Ih6
oSavedFile.write(b,nStart,nLen); $h( B2
n = nLen; "2'pS<|
} PV_q=70%T
catch(IOException e) w_hGWpm
{ 7FiQTS B:
e.printStackTrace (); Tp7slKc0p
} 41[1_p(
xrPC
qg+bh
return n; p7pJ90~E
} (wRJ"Nwu
&gL &@';,
lp;=f
} D!oELZ3
+w]KK6
9 ZD4Gv
/* Lh(`9(tX
**SiteInfoBean.java cj!Ew}o40D
*/ g}B|ZRz+{
package NetFox; @m=xCg.Z
b&V}&9'[M;
I;<aJo6Yl
public class SiteInfoBean { EhOy<f[4W
sX~ `Vn&
m%bw$hr
private String sSiteURL; //Site's URL 7:D@6<J?
private String sFilePath; //Saved File's Path >;A7mi/
private String sFileName; //Saved File's Name _K?{DnTb
private int nSplitter; //Count of Splited Downloading File 2/c^3[ccR
oe8sixZ[
L/VlmN_v>s
public SiteInfoBean() $C;)Tlh
{//nSplitter的缺省值为5 dSkW[r9Z%l
//default value of nSplitter is 5 E?z~)0z2`
this("","","",5); ^atX/
} cN5,\I.
9y~5@/32R
nKzS2u=:Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @,Iyn<v{B
{ `bJ+r)+5
sSiteURL= sURL; 8a^E{x@HT
sFilePath = sPath; fgW>U*.ar
sFileName = sName; X7*i-v@
this.nSplitter = nSpiltter; R4V~+tnbG&
v?U;o&L(
g(i_di
} ugwZAC
XRMYR97
FKOTv2
public String getSSiteURL() 12yr_
{ SGd[cA Ko
return sSiteURL; _^2rRz
} hw@ `Q@
e7(iMe
OUd&fUmH
public void setSSiteURL(String value) QD6in>+B@
{ t@`w}o[#
sSiteURL = value; _i=431Z40
} 7$l!f
._uXK[c7P
"lFS{7
public String getSFilePath() ^11y8[[
{ }J~ d6m
return sFilePath; %q~YJ*\
} e-Xr^@M*Q
fr\"MP
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public void setSFilePath(String value) fq@r6\TI
{ :/c40:[
sFilePath = value; ZB)`*z>*
} k_E Jg;(
pQGlg[i2/
f(^? PGO
public String getSFileName() 4pin\ZS:C
{ 29xm66
return sFileName; x.+r.cAXH
} tJ{3Z}K
F ka^0
(9#$za>
public void setSFileName(String value) *?2aIz"
{ &DX&*Xq2
sFileName = value; /Ria"lLv
} % Rv;e
/E/Z0<l7
qSg#:;(O
public int getNSplitter() J<"=c z$
{ y_>l'{w3^
return nSplitter; +[JvpDv%
} ^~3u|u
@B@`V F
"Cj{Z@n
public void setNSplitter(int nCount) &tNnW
{ <6 HrHw_
nSplitter = nCount; KI@OEy
} 4jOq.j
} X 5.%e&`
1Mftq4nq
A#yZh\#
/* "Je*70LG#
**Utility.java fEdp^oVg
*/ eSqKXmH[m
package NetFox; +b =X~>vZ
3Kx&+
=bx;TV
public class Utility { TpB4VNi/<
#2/2Xv
zS9HR1
public Utility() `b11,lg
{ !mjrI "_
-`I&hzl6E
^\ N@qL
} #~_ZG% u
|61W-9;
//线程睡眠 5f~49(v]
public static void sleep(int nSecond) }{R?i,j(
{ I"=a:q
try{ c#ahFpsnlw
Thread.sleep(nSecond); 6njwrqo
} %nRz~3X|+v
catch(Exception e) 9JDdOjqo
{ c'wxCqnE
e.printStackTrace (); Y<]A5cm
} w$aiVOjgT
} X6T*?t3!9[
\>DMN #
//日志 dR9[K4`p/
public static void log(String sMsg) m]7oTmS
{ n$*e(
System.err.println(sMsg); L@|xpq
} #OQT@uF!
T5AoBUw
KW&vX%i(.
public static void log(int sMsg) Z[,A>tJ
{ kBRy(?Mft&
System.err.println(sMsg); j>}<FW-N
} qg`8f?
} 6>X9|w
5DI&pR1eZ
<>Nq]WqA
/* ?oD]J
**TestMethod.java 5x2m]u
*/ 6EX_IDb
package NetFox; ;8~tt I
<Z>p1S
nNEIwlj;
public class TestMethod { J7RO*.O&Iq
'm4v)w<y#
JZUf-0q
public TestMethod() !4/s|b9K
{ ///xx/weblogic60b2_win.exe f\|R<3 L
try{ \FL`b{!+ N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4Odf6v,*@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6^+T_{gl
SiteFileFetch fileFetch = new SiteFileFetch(bean); >Oz~j>jL
fileFetch.start(); xoYaL
} G@N-+
catch(Exception e){e.printStackTrace ();} >.76<fni
smJ#.I6/L
O$K?2-
} L'@@ewA
C-TATH%f^
K:JM*4W
public static void main(String[] args) A7hWAq
{ a3Fe42G2c|
new TestMethod(); '",+2=JJ
} 0sR+@\
} |EjMpRNE
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