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)); Z[9f8/6<b
} seA=7c5E
for(int i=0;i<nEndPos.length-1;i++) /OeOL3Y
{ tx]!|x" F
nEndPos = nStartPos[i+1]; YQaL)t$0
} %kL]-Z
nEndPos[nEndPos.length-1] = nFileLength; 9`G}GU]@}
} w C-x'
} T^H`$;\
*wV`7\@
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//启动子线程 I ka V g L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >:P-3#e*
for(int i=0;i<nStartPos.length;i++) CM 8Ub%
{ Jqqt@5Ni
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g&O!w!T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +A<7:`sO
nStartPos,nEndPos,i); p"QV| `
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '/@i} digf
fileSplitterFetch.start(); 7F8>w 7Y]
} iQz c$y^,9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 54%h)dLDy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /igbn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v,Yz\onB^
nEndPos = " + nFileLength); gF&HJF 0x
// fileSplitterFetch[nPos.length-1].start(); ju(QSZ|;
*.zC9Y,
y])z,#%ED
//等待子线程结束 U_AmRiy
//int count = 0; :{x
//是否结束while循环 MXynv";<H
boolean breakWhile = false; z5 :53,`D'
B8 R&Q8Q
ci`N,&:R
while(!bStop) ^spASG-o
{ ;{ESo?$*
write_nPos(); -](3iPy}
Utility.sleep(500); WxS$yUu
breakWhile = true; N>',[4pJ|
$GX9-^og=T
B2)SNhF2Y
for(int i=0;i<nStartPos.length;i++) ?#VkzT
{ tkf^sGgNO
if(!fileSplitterFetch.bDownOver) *Zz hN]1
{ LAv!s/O$=
breakWhile = false; |oTA$bln
break; FoGSCg%
} z>O=. Ku6
} #<gD@Jybu
if(breakWhile) nHIW_+<Mf
break; crRYgr
v9l|MI15V
l5l#LsaQb
//count++; jfsbvak
//if(count>4) >UBozmF=\
// siteStop(); !T1)tGrH
} !z?;L_Lb
~19&s~
QxeK-x^
System.err.println("文件下载结束！"); mY!&*nYn|
} ,B$m8wlI|
catch(Exception e){e.printStackTrace ();} 8?&!@3n
} h}f l:J1C
h0Ilxa
PVX23y;
//获得文件长度 eC*-/$D
public long getFileSize() 5)<}a&;{
{ {%XDr,myd
int nFileLength = -1; dnstm@0k
try{ ~ A4_
URL url = new URL(siteInfoBean.getSSiteURL()); #~:@H&f790
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o :_'R5
httpConnection.setRequestProperty("User-Agent","NetFox"); d/&~IR
SMbhJ}\O
<wO8=bem
int responseCode=httpConnection.getResponseCode(); Fq#;
if(responseCode>=400) c_)lTI4
{ w$z]Z-
processErrorCode(responseCode); L(\o66a-rV
return -2; //-2 represent access is error bs\7 juHt
} OjBg$f~0F
E~'QC
>e9xM Gv
String sHeader; gukKa
4: S-
3NxwQ,~
for(int i=1;;i++) +G[N lb
{ Nm,9xq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 88M$mjx
//Utility.log(in.readLine()); Yb Dz{m
sHeader=httpConnection.getHeaderFieldKey(i); Zh3hCxXa
if(sHeader!=null) }pL#C
{ Sz'JOBp
if(sHeader.equals("Content-Length")) ad'C&^o5
{ dEWI8Q]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I-o|~
break; ylBjuD+
} i9quP"<9
} 3Fl!pq]
else <hM`]/J55
break; I+_u?R)$
} } 2P,Z6L
} Z{spo=
catch(IOException e){e.printStackTrace ();} [{cMEV&
catch(Exception e){e.printStackTrace ();} OAd}#R\U
Uh8c!CA8:\
"[p-Iy1
Utility.log(nFileLength); \1cJ?/$_Of
DW.vu%j^[
{G(N vf,K]
return nFileLength; LFT)_DG7(
} vILq5iR
3v7*@(y
H3qM8_GUA
//保存下载信息（文件指针位置） |%xgob
private void write_nPos() CJ#1j>
{ ^E`SR6_cmj
try{ |XoW Z,K
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ph|\%P`>%
output.writeInt(nStartPos.length); PcQqdU^!
for(int i=0;i<nStartPos.length;i++) nK;c@!~pS
{ EG3?C
// output.writeLong(nPos); 92)e/t iP
output.writeLong(fileSplitterFetch.nStartPos); @?\[M9yK
output.writeLong(fileSplitterFetch.nEndPos); =}7[ypQM`]
} mu# a
output.close(); (_$'e%G0
} E4dN,^_ F!
catch(IOException e){e.printStackTrace ();} '+*{u]\
catch(Exception e){e.printStackTrace ();} FCMV1,
} +4*jO5EZ
:{ Q[kYj
";$rcg"%X
//读取保存的下载信息（文件指针位置） qZ|>{^a*
private void read_nPos() @ob4y
{ (zL(
try{ }[m,HA<j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tNbZ{=I>
int nCount = input.readInt(); f hS4Gb_
nStartPos = new long[nCount]; ^P !}"
nEndPos = new long[nCount]; K|g+Wt^tQ
for(int i=0;i<nStartPos.length;i++) qKL mL2O
{ 3T7,Y(<V
nStartPos = input.readLong(); ;R8pVj!1f
nEndPos = input.readLong(); ,ThN/GkSC
} ;u "BCW
input.close(); G>yTv`-
} :Lze8oY(D}
catch(IOException e){e.printStackTrace ();} 0281"aO
catch(Exception e){e.printStackTrace ();} c-gpO|4>
} POtwT">z
6o!Y^^/U
HbXYinG%
private void processErrorCode(int nErrorCode) smTPca)7s
{ hxQx$
System.err.println("Error Code : " + nErrorCode); EvQMt0[?EW
} zUCtH*
<W<>=vDzyE
9C2DW,?
//停止文件下载 k-N` h
public void siteStop() N|53|H
{ [c_o.`S_\
bStop = true; d"Aer
for(int i=0;i<nStartPos.length;i++) 27q=~R}
fileSplitterFetch.splitterStop(); "Gh5 ^$w?j
ql_GN[c/
uiQRRT
} (h3f$
} ?z$^4u3
//负责部分文件的抓取 IGC:zZ~z
**FileSplitterFetch.java Gl@}b\TB
*/ JNZ O7s
package NetFox; mM6X0aM
f7_EqS=(
E+$%88
import java.io.*; M!j: 2dT"
import java.net.*; B(TE?[ #
#2qDn^s
,q|;`?R;
public class FileSplitterFetch extends Thread { CV )v6f
SZ'2/#R>
[@LA<Z_
String sURL; //File URL U3UDA
long nStartPos; //File Snippet Start Position \2Atm,#4
long nEndPos; //File Snippet End Position xYUC|c1Q9
int nThreadID; //Thread's ID XzF-g*e
boolean bDownOver = false; //Downing is over OPtFz6
boolean bStop = false; //Stop identical ,KyG^;Riy
FileAccessI fileAccessI = null; //File Access interface :G\X
>.X& v
?\7$63gBH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i,z^#b7JQ
{ $63_*9
this.sURL = sURL; VwKo)zH
this.nStartPos = nStart; ljw(cUM
this.nEndPos = nEnd; N&]GPl0
nThreadID = id; 6b6rM%B.oD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EFqYEDXW
} 7I0[Ii
S(\<@S&
w#Di
public void run() MJDW-KL-
{ 44p?x8(z*
while(nStartPos < nEndPos && !bStop) 8,^2'dK34
{ V^[B=|56
Q]v><
n |e=7?H8
try{ 9J $"Qt5;6
URL url = new URL(sURL); Q6lC:cB<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aHR&6zj4
httpConnection.setRequestProperty("User-Agent","NetFox"); rOyKugHe
String sProperty = "bytes="+nStartPos+"-"; T}55ZpSC&
httpConnection.setRequestProperty("RANGE",sProperty); h.%)RW?
Utility.log(sProperty); ^^FqN;
@cC@(M~Ru
9H6%\#rw
InputStream input = httpConnection.getInputStream(); 6hX[5?}
//logResponseHead(httpConnection); {/E_l
lCAD $Ia~
~p* \|YC
byte[] b = new byte[1024]; s=BJ7iU_68
int nRead; zZ*\v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^0fe:ac;
{ Y$\c_#/]
nStartPos += fileAccessI.write(b,0,nRead); RP1sQ6$
//if(nThreadID == 1) r]<?,xx[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )'3V4Z&
} % r>v^1Vo
n&N>$c,T27
!x@3U^${
Utility.log("Thread " + nThreadID + " is over!"); V[RsSZx =
bDownOver = true; dtDT^~
//nPos = fileAccessI.write (b,0,nRead); zHu w[
} \zMx~-2oN
catch(Exception e){e.printStackTrace ();} _Q=h3(ZI
} w$1B|7tX;2
} ];63QJU
.FWi$B';
5%K(tRc|
//打印回应的头信息 ucwUeRw,
public void logResponseHead(HttpURLConnection con) JMVh\($,x
{ Sz'H{?"
for(int i=1;;i++) )ld`2) 4
{ 1[k.apn
String header=con.getHeaderFieldKey(i); *MM8\p_PuT
if(header!=null) OS]FGD3a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N6thbH@
Utility.log(header+" : "+con.getHeaderField(header)); z1vSt[s
else i~sW_f+
break; 7~ =r9-&G
} sG K7Uy
} WTX!)H6Zv
d"U'\ID2y
! a!^'2
public void splitterStop() 3:ELYn
{ V|`w/P9g4
bStop = true; g3Z"ri~!G
} eX3|<Bf
3@8Zy:[8<
kl[Jt)"4@
} oa q!<lI
dm`:']?
U0fr\kM
/* z5q(
**FileAccess.java c)B <d#
*//文件访问(定位，写) 9JBVG~m+
package NetFox; 25wvB@0&
import java.io.*; >uy(N
;/s##7qf
3"HX':8x
public class FileAccessI implements Serializable{ $dkkgsw7
^w6~?'}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GEbm$\
RandomAccessFile oSavedFile; m&{%6
long nPos; A=bBI>GEYP
{O"N2W
oF {u
public FileAccessI() throws IOException &T&>4I!'M
{ g),t
this("",0); OkfnxknZ|
} |:)ARH6l#
{T'M4y=)i
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public FileAccessI(String sName,long nPos) throws IOException yDmx)^En
{ \l71Q/y6u`
oSavedFile = new RandomAccessFile(sName,"rw"); H*R4AE0
this.nPos = nPos; XZH\HK)K-]
oSavedFile.seek(nPos); k?VH4yA
} .z}*!
Uxb>)36I
W0;MGBfb
public synchronized int write(byte[] b,int nStart,int nLen) (_Ky'.
{ 1!p7N$QR
int n = -1; 4KnrQ-D
try{ $-p#4^dg
oSavedFile.write(b,nStart,nLen); kpLx?zW--q
n = nLen; TJ+,G4z
} >^TcO
catch(IOException e) {}DoRpq=
{ :{'%I#k2
e.printStackTrace (); .X;DI<K
} Qoom[@$
6u[ B}%l
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return n; r";;Fk#5
} y|2y!&o,!
@l %x;`E
y\@INA^
} 1T/ 72+R0
r"bV{v
4ztU) 1
/* \Jm^XXgS
**SiteInfoBean.java >})W5Y+
*/ z 8y.@<6
package NetFox; y41,T&ja
5Zy%Nam'gN
AZf$XHP2
public class SiteInfoBean { +XoY@|Djd
TS49{^d$
HtAO9
private String sSiteURL; //Site's URL `g^bQx
private String sFilePath; //Saved File's Path .Hm1ispq
private String sFileName; //Saved File's Name b<\aJb{2
private int nSplitter; //Count of Splited Downloading File tr@)zM GB
@s7wKk
j:P(,M[
public SiteInfoBean() @G?R(
{//nSplitter的缺省值为5 DTo P|P
//default value of nSplitter is 5 2 i97
this("","","",5); <}('w/
} b/6!>qMMk%
#iVr @|,
ePscSMx&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v0u, :eZ4
{ UJ7{FN=@t
sSiteURL= sURL; cllnYvr3
sFilePath = sPath; :7[4wQDt4
sFileName = sName; f <pJ_
this.nSplitter = nSpiltter; r O-=):2
u`Abko<D
':#DROe!
} :)DvZxHE@
ZIs=%6""&
Apbgm[m|{
public String getSSiteURL() RhD
{ z#Db~
return sSiteURL; P&5kO;ia
} Yx':~
nNpXkI:
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public void setSSiteURL(String value) UoOxGo
{ <RJ+f-
sSiteURL = value; (,;4f7\
} /j"aOLL|
x9i^_3Z
q"Th\? }%
public String getSFilePath() 6L,"gF<n
{ s7"5NU-
return sFilePath; s}g3*_"
} tf4clzSTa
]:}x 4O#
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public void setSFilePath(String value) /0(c-Dv
{ BNq6dz$J
sFilePath = value; ;X%8I$Ba,
} C8AR^FW
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*^i"q\n5(
public String getSFileName() 1HBWOV7z.?
{ bEB9J- Q
return sFileName; +O!4~k^
} 8Az|SJ<
{Y1&GO;
9"cyZO
public void setSFileName(String value) Ws;X;7tS
{ vpz l{
sFileName = value; e`bP=7`0
} D8\9nHUD`
7g-{<d
;YYnIb(
public int getNSplitter() sfzDE&>'
{ 0`$fs.4c
return nSplitter; Z=9gok\
} &}!AjA)
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2U&+K2
public void setNSplitter(int nCount) x<1t/o
{ yM# %UeZ\
nSplitter = nCount; OPJ(ub
} 6[\1Nzy>
} \JDxN
$%.,=~W7
j026CVL
/* [ @9a
**Utility.java @BMuov
*/ =F/EzS
package NetFox; /5y _ <
V>& 1;n
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public class Utility { a^7QHYJ6
b]g#mQ
ccwz:7r
public Utility() `Ln1g@
{ 6 jU?~
8f>v[SQ"
iM M s3
} ?\_vqW
lY[\eQ 1:
//线程睡眠 Qb8Z+7
public static void sleep(int nSecond) o]@'R<F(u
{ K)GpQ|4:<
try{ 58t~? 2E
Thread.sleep(nSecond); tY%T
} p<c1$O*
catch(Exception e) &"d :+!4h
{ vDCbD#.6
e.printStackTrace (); JfRqOEP4Y
} iz3Hoj
} uLr-!T
=Y*zF>#lP
//日志 5h6-aQU[
public static void log(String sMsg) i4lB]k
{ &n]]OPo
System.err.println(sMsg); g=jB'h?
} <vd}oiB@
85BB{T;
}c=YiH,o
public static void log(int sMsg) EpK7VW
{ m O"Rq5
System.err.println(sMsg); =yZ6$ hK
} R0e!b+MZ.
} C:z7R" yj
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B$MHn?
/* p~OX1RBI
**TestMethod.java \_MWZRMc5
*/ n^` `)"
package NetFox; #rQT)n
\jr-^n]
#g~]2x
public class TestMethod { zz #IY'dwT
&?# YjU"
#>2cfZ`6'J
public TestMethod() JPpNCC.b
{ ///xx/weblogic60b2_win.exe \`W8#fob
try{ _ME?o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rh T!8dTk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 74a k|(!
SiteFileFetch fileFetch = new SiteFileFetch(bean); * yGlX[
fileFetch.start(); WnhH]WY
} RmQ>.?
catch(Exception e){e.printStackTrace ();} ge#P(Itz
7-mo\jw<
{BZ0x2
} rBZ00}
vy5I#q(k
g{JH5IZ~
public static void main(String[] args) [6)vD@
{ V o%GO9b;
new TestMethod(); = Q"(9[Az
} O^IS:\JX&
} 3 <Zo{;
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