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)); 3A9|{Vaz+6
} qjFgy)qV
for(int i=0;i<nEndPos.length-1;i++) aD:+,MZ
{ bd9c/>&
nEndPos = nStartPos[i+1]; 5Tu.2.)N
} n#R!`*[
nEndPos[nEndPos.length-1] = nFileLength; Ea !j-Lbo
} St3~Y{aI|
} G@;aqe[dB
p[$I{F*a
{J]|mxo
//启动子线程 8,=$>@u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~E\CAZ
for(int i=0;i<nStartPos.length;i++) ^q6~xC,/
{ x{- caOH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +1y#=iM{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *SW,pHYnLb
nStartPos,nEndPos,i); @PI\.y_w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (/Mc$V
fileSplitterFetch.start(); t>[r88v
} h Na<LZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wVVe L$28
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AjS5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oMVwIdf
nEndPos = " + nFileLength); j{PX ~/
// fileSplitterFetch[nPos.length-1].start(); )<|TEp4r-
Q&J,"Vxw
^/+sl-6/F
//等待子线程结束 ?-f>zx8O
//int count = 0; Cr` 0C
//是否结束while循环 `#]\Wnp~y
boolean breakWhile = false; fS~.K9
`4=b|N+b"
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while(!bStop) ymzm x$o=
{ S;NXOsSu
write_nPos(); ![ QQF|
Utility.sleep(500); zxh"@j$?
breakWhile = true; = `^jz}
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NR*SEbUU*
for(int i=0;i<nStartPos.length;i++) 7I|%GA_
{ gU?)
if(!fileSplitterFetch.bDownOver) *t_&im%E
{ 0D'Wr(U(
breakWhile = false; TU/J]'))C
break; eZ!k'bS=
} Vo%d;>!G\;
} $o/>wgQY-
if(breakWhile) @2mP
break; &0g,Xkr
]VvJ1Xn0
1@WGbORc*
//count++; c;^J!e
//if(count>4) ^Toi_
// siteStop(); ff#-USK^R
} cabN<a l
BUb(BzC
6"GpE5'*
System.err.println("文件下载结束！"); <-F"&LI{<
} `T70FsSJ
catch(Exception e){e.printStackTrace ();} FMVmH!E
} G DV-wPX
"" U_|JH-
:~(im_r
//获得文件长度 ju#63
public long getFileSize() RVfe}4Stm#
{ W%1S:2+Kl
int nFileLength = -1; }>0 Kc=
try{ Db=gS=Qm
URL url = new URL(siteInfoBean.getSSiteURL()); gnXjd}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +a/o)C{
httpConnection.setRequestProperty("User-Agent","NetFox"); W(aRO
))`Zv=y"
9^u?v`!
int responseCode=httpConnection.getResponseCode(); R~~rqvLm
if(responseCode>=400) =@2V#X]M*
{ #E9['JnZ
processErrorCode(responseCode); 'l|_$3
return -2; //-2 represent access is error [Ni4[\
} Y9;Mey*oW
"|%9xGX|D
WM"^#=+$
String sHeader; `dP+5u!
*K|aK p}
A ? M]5d
for(int i=1;;i++) tWnm{mF
{ 8-:k@W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zc+;VtP|8
//Utility.log(in.readLine()); %K"%Qm=Tl
sHeader=httpConnection.getHeaderFieldKey(i); u7?juI#Cl
if(sHeader!=null) 1c#'5~nB
{ g5Rm!T+@I<
if(sHeader.equals("Content-Length")) s{e(- 7'
{ %z~U@Mka
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^d80\PXz
break; #ja`+w}
} ]%|WE
} #-T.@a1X
else /BM1AV{s6
break; +ZKhmb!
} iwQ-(GjM[A
} cO,V8#H
catch(IOException e){e.printStackTrace ();} xV#a(>-4
catch(Exception e){e.printStackTrace ();} Hc]1mM
AxlFU~E4
GYC&P]
Utility.log(nFileLength); wkD:i2E7
(0W}e(D8
Eap/7U1Q
return nFileLength; y.p6%E_`
} -vHr1I<
SFk#bh
A Vm{#^p[(
//保存下载信息（文件指针位置） N?;o_^C
private void write_nPos() U@MP&sdL
{ k-V I9H!,
try{ ulf/C%t,R
output = new DataOutputStream(new FileOutputStream(tmpFile)); iIaT1i4t.
output.writeInt(nStartPos.length); 9T2A)a]0
for(int i=0;i<nStartPos.length;i++) _-]!;0EIV
{ *W12Rb2
// output.writeLong(nPos); o^Ysp&#p
output.writeLong(fileSplitterFetch.nStartPos); vQ"s
output.writeLong(fileSplitterFetch.nEndPos); -fJ@R1]
} ~AanU1U<
output.close(); i ,pN1_-
} O[)]dD&'
catch(IOException e){e.printStackTrace ();} tvT8UW'
catch(Exception e){e.printStackTrace ();} c%@~%IGF
} i1I>RK
&_d/ciq1f
QaWHz
//读取保存的下载信息（文件指针位置） k0_$M{@Y
private void read_nPos() qQOD
{ <m,yFk
try{ K;p<f{PE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xexe{h4t_>
int nCount = input.readInt(); Pzp+I}
nStartPos = new long[nCount]; f&}A!uLe4x
nEndPos = new long[nCount]; &3Z. #*
for(int i=0;i<nStartPos.length;i++) d-;9L56{P
{ fu<2t$Cn>
nStartPos = input.readLong(); `E5"Pmg
nEndPos = input.readLong(); P5>5ps"iU
} u=;nU(]M '
input.close(); !?o$-+a|
} g'ZMV6b?K
catch(IOException e){e.printStackTrace ();} Zknewv*sS4
catch(Exception e){e.printStackTrace ();} !I5~))E
} RP,:[}mPl
knOnUU
,p!B"# ot
private void processErrorCode(int nErrorCode) - SS r
{ ~sIGI?5f
System.err.println("Error Code : " + nErrorCode); B>Cs&}Y!
} xs'kO=
$tCcjBK\
{^2W>^
//停止文件下载 #)0Tt>d6
public void siteStop() y168K[p
{ -,Q$
bStop = true; w,Zx5bBg%
for(int i=0;i<nStartPos.length;i++) 0<@KDlF
fileSplitterFetch.splitterStop(); dA1 C)gLi
dHG Io
8b:clvh
} 6W;?8Z_1
} bugFl>
//负责部分文件的抓取 %,,`N I{
**FileSplitterFetch.java ;wXY3|@
*/ px|>v8
package NetFox; 1Vf78n
+K;Y+ K&;2
X#DL/#z k
import java.io.*; ')5L_$
import java.net.*; wfDp,T3w7
lMwk.#
+Cf0Y2*@hM
public class FileSplitterFetch extends Thread { YxEbg(Y
qsihQd
x(9;!4O>
String sURL; //File URL TTZ['HP oI
long nStartPos; //File Snippet Start Position 1a&/Zlr
long nEndPos; //File Snippet End Position t0e{|du
int nThreadID; //Thread's ID M_h8#7{G
boolean bDownOver = false; //Downing is over hB?,7-
boolean bStop = false; //Stop identical VJN/#
FileAccessI fileAccessI = null; //File Access interface x^)g'16`
^p 2.UW
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2"leUur~rO
{ 1Sg|3T8bGT
this.sURL = sURL; G;C8Kde
this.nStartPos = nStart; {jOzap|
this.nEndPos = nEnd; goDV2alC^
nThreadID = id; )C>}"#J>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dc.n-ipv$
} u3Usq=Ij{
+_ *eu
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public void run() N^h|h
{ '7Mep ]
while(nStartPos < nEndPos && !bStop) 0{?:FQ#
{ <E>7>ZL
q]"2hLq
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try{ ZT) !8
URL url = new URL(sURL); Cf0|Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;Y'8:ncDn
httpConnection.setRequestProperty("User-Agent","NetFox"); 6| *(dE2x(
String sProperty = "bytes="+nStartPos+"-"; d"B@c;dD
httpConnection.setRequestProperty("RANGE",sProperty); J}Qs"+x
Utility.log(sProperty); ]8$#qDS@
rH$eB/#F
|*^8~u3J"
InputStream input = httpConnection.getInputStream(); uW}Hvj;0a*
//logResponseHead(httpConnection); URYZV8=B~
=U4f}W;
&|Lh38s@$#
byte[] b = new byte[1024]; ^W Y8-6
int nRead; `FA)om
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >vWEUE[
{ nnt8 sf@\
nStartPos += fileAccessI.write(b,0,nRead); i`[#W(m
//if(nThreadID == 1) 5vD3K!\u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v:rD3=M-
} 6exI_3A4jh
lSH ZV Fd
XkPv*%Er8
Utility.log("Thread " + nThreadID + " is over!"); EKZA5J7kn
bDownOver = true; |',M_ e]
//nPos = fileAccessI.write (b,0,nRead); z,pNb%*O
} 6xH;:B)d
catch(Exception e){e.printStackTrace ();} X=v~^8M7%
} 5>k>L*5J
} )@}A r
}m6f^fs}
?gLR<d_
//打印回应的头信息 [IiwNqZ[~
public void logResponseHead(HttpURLConnection con) ,YjxCp3
{ ]SFWt/<
for(int i=1;;i++) a9[mZVMgUK
{ i=oTg
String header=con.getHeaderFieldKey(i); _ XE;-weE
if(header!=null) ,H>W:O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XZ.7c{B<
Utility.log(header+" : "+con.getHeaderField(header)); wJ6_I$>
else :qxm !P
break; oJ^C]E
} 1p8:.1)q
} kMM'[w
jcE Msc
'KH lrmnr
public void splitterStop() .iFViVZC
{ '%R<"
bStop = true; ~gP7s_qr{
} qQ^d9EK'?~
tcZa~3.
&=G)NeT_
} H#OYw#L"u
%/51o6a
>-!r9"8@
/* +A@m9
**FileAccess.java <mL%P`Jj
*//文件访问(定位，写) C 8N%X2R
package NetFox; @B?FE\
import java.io.*; _ w/_(k
Ua %UbAt
>w9sE8i
public class FileAccessI implements Serializable{ kP@HG<~
IXnb]q.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 TN5>"??"
RandomAccessFile oSavedFile; /iplU
long nPos; +jUgx;u,
RO.U(T
vQ1 v#Z
public FileAccessI() throws IOException )"|||\Iv
{ 2o4^
this("",0); 2}vNSQvG
} !X]8dyW
'1Y\[T*
-_em%o3XC
public FileAccessI(String sName,long nPos) throws IOException }gv8au<
{ vcv CD7MD
oSavedFile = new RandomAccessFile(sName,"rw"); BhkoSkr
this.nPos = nPos; q9]IIv
oSavedFile.seek(nPos); /&^W#U$4
} V kjuyK
9AQxNbs
T.ML$"f
public synchronized int write(byte[] b,int nStart,int nLen) .X'pq5
{ A%XX5*
int n = -1; rS7)6h7(7
try{ v-Qmx-N
oSavedFile.write(b,nStart,nLen); wNYg$d0M
n = nLen; X!>eiYK)
} S\*`lJzPM
catch(IOException e) E=$p^s
{ 2YlH}fnH
e.printStackTrace (); j.%K_h?V5
} H C0w;MG)
?6"{!s{v
.4-,_`T?
return n; >/=>B7
} ]rN#B-aAr
=a}b+(R
"N5!mpD"
} mbxbEqz
}D;WN@],
(V?:]
/* _zMgoc7
**SiteInfoBean.java =Vw 5q},3
*/ 69G`2_eKCp
package NetFox; Ba'LRz
Bd~1P/
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public class SiteInfoBean { k[kju%i4
._PzYE|m2
u0Nm.--;_3
private String sSiteURL; //Site's URL Wl-<HR!n
private String sFilePath; //Saved File's Path !EIjN
private String sFileName; //Saved File's Name 1P(&J
private int nSplitter; //Count of Splited Downloading File U;q];e:,=}
~xLJe`"JUx
t#i,1aHA
public SiteInfoBean() n6<V+G)T
{//nSplitter的缺省值为5 SUM4Di7
//default value of nSplitter is 5 #oni:]E!m
this("","","",5); {Ui=b+
} T~:|!`
4\M.6])_
EYX$pz(x;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $O)3q $|
{ p-SJ6Gg 9
sSiteURL= sURL; ]#2Y e7+
sFilePath = sPath; alq%H}FF
sFileName = sName; vVl; |
this.nSplitter = nSpiltter; tmUFT
kwpK1R4zs
BV#78,8(
} hC <O`|lF
v<Kmq-b
U}k9 Py
public String getSSiteURL() E&$yuW^z
{ Yz$3;
return sSiteURL; $%R$G`.KM
} jPZaD>!
67SV~L#%O
26vp1
public void setSSiteURL(String value) {gbn/{
{ j _L@U2i
sSiteURL = value; wV\gj~U;P
} d5 7i)=
$(e#aHB
X;v$5UKU
public String getSFilePath() '6y}ZE[
{ MY#
return sFilePath; G uQ=gN
} UFAL1c<V
Xce0~\_A
*jIqAhs0{
public void setSFilePath(String value) mE%$HZ}
{ RPd}Wf
sFilePath = value; 1K,1X(0rL8
} 91>fqe
U-/{0zB
K"j_>63)
public String getSFileName() VA*y|Q6
{ kVK/9dy-F
return sFileName; OCZaQ33
} Suk
8{`?=&%6
1$qh`<\
public void setSFileName(String value) ,1OyN]f3
{ c:Wze*vI;
sFileName = value; om?-WJI
} |sRipWh
)q7UxzE+
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public int getNSplitter() 8#!i[UFdj
{ 5%sE]Y#
return nSplitter; 2MZCw^s>
} {:@tQdM:i8
w2_bd7Wp<
b)(?qfXWP
public void setNSplitter(int nCount) ?v>ET2wD
{ M9zfT!-
nSplitter = nCount; {pM?5"MMJ
} hW!)w
} Z R/#V7Pj
b&1`NO
y6]vl=^L
/* z~`b\A,$
**Utility.java zg-2C>(6a
*/ jck}" N
package NetFox; ys 5&PZg*
Vz6Qxd{m3
a5a($D
public class Utility { Reatdh
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&gzCteS
public Utility() e[hcJz!D
{ `{qG1
[JF150zr
t%F0:SH
} )iFJz/n>
/cU<hApK
//线程睡眠 Um&(&?Xf
public static void sleep(int nSecond) =s<( P1|"
{ HRB<Y mP@
try{ " Hd|7F'u=
Thread.sleep(nSecond); YnLErJ
} \hCH>*x<
catch(Exception e) {%_L=2n6
{ "etPT@gF
e.printStackTrace (); M)SEn/T-
} 8#vc(04(
} / X1 x
_a1x\,R|DB
//日志 N<~ku<nAU
public static void log(String sMsg) O{#=d
{ F_CYYGZ
System.err.println(sMsg); 72'5%*1
} KEWTBBg
>,td(= :
hdrm!aBd
public static void log(int sMsg) z[Xd%mhjO
{ P#AW\d^"B
System.err.println(sMsg); TqnTS0fx
} >y,-v:Vy
} H)n9O/u
aA,!<^&}
K.0:C`C
/* Hw4%uS==V
**TestMethod.java 1YH+d0UGn
*/ MG.` r{5
package NetFox; w!D|]LoE
55z]&5N
9Q"'"b*?z
public class TestMethod { >3Eo@J,?d
I"GB<oB
(SvWvm
public TestMethod() {E@Lft-
{ ///xx/weblogic60b2_win.exe A,a.8!*}vd
try{ S_Wrw z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8SGo9[U2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &G-!qxe
SiteFileFetch fileFetch = new SiteFileFetch(bean); .X;3,D[w
fileFetch.start(); /{&tY:;m
} bD?VU<)3
catch(Exception e){e.printStackTrace ();} R~PA1wDZ
.hifsB~
Om5Y|v"*
} s=;uc]9g
u?}(P_9
n^g|Ja
public static void main(String[] args) ynQ: >tw
{ P09;ng67
new TestMethod(); Hg=";,J
} xU4 +|d
} z*!%g[3I
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