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)); |SukiXJZF
} f<4q]HCa
for(int i=0;i<nEndPos.length-1;i++) )X!DCL:16
{ | 4oM+n;Y
nEndPos = nStartPos[i+1]; JX$NEq(
} (g2r\hI
nEndPos[nEndPos.length-1] = nFileLength; NF(IF.8G
} XAxI?y[c
} `m;"I
SY>,kwHO
@TPgA(5NR
//启动子线程 $0S#d@v}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vJAAAS
for(int i=0;i<nStartPos.length;i++) G[<[#$(
{ Sb9=$0%\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f(s3TLM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K-k.=6mS
nStartPos,nEndPos,i); ],}afa!A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5QFXj)hR+4
fileSplitterFetch.start(); h*%0@
} D)ne *},
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6O@ ^`T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m#'rI=}!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q1I_=fT
nEndPos = " + nFileLength); *5_8\7d
// fileSplitterFetch[nPos.length-1].start(); HZ<f(
~muIi#4
g6/N\[b%
//等待子线程结束 vWi.[]
//int count = 0; Z0 IxYEp
//是否结束while循环 8xpYQ<cax
boolean breakWhile = false; NRuG?^/}d
a.&#dxgW[
$X=D9h
while(!bStop) ctUF/[_w;
{ g=g.GpFt
write_nPos(); <AAZ8#^
Utility.sleep(500); r~G]2*3
breakWhile = true; h[ZN >T
A;WwS?fyQ
[T[9*6Kt
for(int i=0;i<nStartPos.length;i++) 6:@t=C
{ e(;`9T
if(!fileSplitterFetch.bDownOver) CX ]\Q-y
{ 2HK
breakWhile = false; kGuk -P
break; R4~zL!7;
} Wt)SdF=U/
} ZH$sMh<xg
if(breakWhile) 8}?Y;>s\
break; )lDIzLp
L^ #<HQ
kulQR>u
//count++; Y:"v=EhB
//if(count>4) ]D) 'I`
// siteStop(); o&XMgY~
} ss0'GfP
VmOFX:j!,
bDFCZH-:'O
System.err.println("文件下载结束！"); A{8K#@!
} 0nD=|W\@{
catch(Exception e){e.printStackTrace ();} qv0 DrL,3
} 'Elj"Iiu
`l gjw=
)_c=mT
//获得文件长度 EB29vHAt~
public long getFileSize() dp[w?AMhM9
{ B/sBYVU
int nFileLength = -1; Id.Z[owC`Y
try{ rxy{a
URL url = new URL(siteInfoBean.getSSiteURL()); |:e|~sism
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H?`)[#
httpConnection.setRequestProperty("User-Agent","NetFox"); +F7<5YW&(
3?*M{Y|
l\=-+'Y
int responseCode=httpConnection.getResponseCode(); NHFEr
if(responseCode>=400) Bd[L6J)
{ a:-)+sgHw
processErrorCode(responseCode); pg?i F1
return -2; //-2 represent access is error 7Js>!KR
} e\A(#l@g
2%{YYT
hM36QOdm
String sHeader; `z?KL(rI
=,AC%S_D~
gaw4NZd)0
for(int i=1;;i++) hLyTUt~\L
{ FV^4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =~\]3g
//Utility.log(in.readLine()); Xb<DpBrk
sHeader=httpConnection.getHeaderFieldKey(i); I NPYJ#%
if(sHeader!=null) ^)hAVf~E
{ }#ep}h
if(sHeader.equals("Content-Length")) #j^('K|
{ >9.5-5"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wiq{wxe
break; 4{*tn"y
} |ilv|UV
} XJ:>UNf5;
else OBI+<2`Oc
break; 0~Iu7mPY
} up3?$hUc.
} Gq0]m
catch(IOException e){e.printStackTrace ();} @@%i(>4Z
catch(Exception e){e.printStackTrace ();} jNe(w<',P
wUK7um
o9m
Utility.log(nFileLength); bSrRsgKvT
B=Zl&1
lJ:M^.Em0
return nFileLength; d`9W
} jF38kj3O7
c?!YFm
/lS+J(I
//保存下载信息（文件指针位置） kfqpI
private void write_nPos() e~+(7_2
{ f=:3!k,S
try{ E7X!cm/2<
output = new DataOutputStream(new FileOutputStream(tmpFile)); B]^>GH
output.writeInt(nStartPos.length); >:F,-cx<
for(int i=0;i<nStartPos.length;i++) VG<Hw{ c3r
{ @cuD8<\i
// output.writeLong(nPos); Ka]J^w;a
output.writeLong(fileSplitterFetch.nStartPos); $5TepH0D
output.writeLong(fileSplitterFetch.nEndPos); $=PWT-GIR
} Qy=HrL]x
output.close(); \Y!T>nWn)I
} kgbobolA
catch(IOException e){e.printStackTrace ();} Y{k>*: Ax_
catch(Exception e){e.printStackTrace ();} HYjMNj0
} b&lN%+%}
*'9)H0
gEr4zae
//读取保存的下载信息（文件指针位置） Si?$\H*:
private void read_nPos() >aEL;V=}P
{ x],8yR)R
try{ [!1)mR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Fw_ (q!
int nCount = input.readInt(); )p$\gwr=2
nStartPos = new long[nCount]; M11"<3]D
nEndPos = new long[nCount]; 4meidKw]
for(int i=0;i<nStartPos.length;i++) u(pdP"
{ \C]i|]tl
nStartPos = input.readLong(); H+4=|mkQ
nEndPos = input.readLong(); {8^Gs^c c
} <u/a`E?
input.close(); _4P;+Y
} Q7,EY /
catch(IOException e){e.printStackTrace ();} xn(+G$m
catch(Exception e){e.printStackTrace ();} b!i`o%Vb
} u.Mqj"o\
c%|vUAq*
cI*KRCU
private void processErrorCode(int nErrorCode) )Vwj9WD
{ UI!6aVL.
System.err.println("Error Code : " + nErrorCode); _Ry_K3K
} %&^Q(f
R<f#r03@|
rr|"r
//停止文件下载 j~M#Ss-H8
public void siteStop() OSp?okV
{ 9pWi.J
bStop = true; 6(>3P
for(int i=0;i<nStartPos.length;i++) Dn~Z SrJ
fileSplitterFetch.splitterStop(); f>.4-a?
`WH[DQ
F\>oxttS1
} oi7 3YOB
} K!3{M!B
//负责部分文件的抓取 Y)$52m5rM
**FileSplitterFetch.java blJIto'
*/ MV%Xhfk
package NetFox; )-=2w-ZX
mJ)tHv"7
"XCU'_k=
import java.io.*; }qer
import java.net.*; rmOQ{2}
C&=x3Cz
BjM+0[HC
public class FileSplitterFetch extends Thread { xTW3UY
+'-rTi\
bfFmTI$,
String sURL; //File URL 31WZJm^
long nStartPos; //File Snippet Start Position $Axng J c
long nEndPos; //File Snippet End Position {tPnj_|n<
int nThreadID; //Thread's ID m"n.Dz/S
boolean bDownOver = false; //Downing is over \CcmePTN#x
boolean bStop = false; //Stop identical (nGkZ}p
FileAccessI fileAccessI = null; //File Access interface F[5S(7M 7
)))2fskZ
#nKRTb+{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g^1r0.Sp{8
{ j5kA^MTG
this.sURL = sURL; ^w>&?A'!
this.nStartPos = nStart; Ig<}dM.Z[
this.nEndPos = nEnd; '<TD6jBs
nThreadID = id; 9oEpPL5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |Eb&}m:E$
} xJ-*%'(KZ
~%`EeJwT
|VK:2p^ u
public void run() VSh!4z1
{ `%|u!
while(nStartPos < nEndPos && !bStop) *xPB<v2N:P
{ ugno]5Ni
Qh^R Ax
/mc*Hc8R8
try{ dgXg kB'
URL url = new URL(sURL); ]GNh)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I-,>DLG
httpConnection.setRequestProperty("User-Agent","NetFox"); pDGT@qJ
String sProperty = "bytes="+nStartPos+"-"; Rfht\{N 7
httpConnection.setRequestProperty("RANGE",sProperty); <KtBv Ip]
Utility.log(sProperty); 5:c;RRn
+kM\ D~D1
`4LJ;KC(
InputStream input = httpConnection.getInputStream(); ;d4y{
//logResponseHead(httpConnection); 6z Ay)~
Jz0K}^Dj[
N r<9u$d9=
byte[] b = new byte[1024]; TFO74^
int nRead; i-b1d'?Rb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CJp-Y}fGEA
{ I:F <vE
nStartPos += fileAccessI.write(b,0,nRead); /u=aX
//if(nThreadID == 1) >5.zk1&H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `$at9
} )S2iIi;Bq
mf}\s]_c
>PIPp7C
Utility.log("Thread " + nThreadID + " is over!"); 8 }-7{
bDownOver = true; ABcBEv3
//nPos = fileAccessI.write (b,0,nRead); w,Q)@]_
} k{a)gFH O
catch(Exception e){e.printStackTrace ();} k d+l k:
} fWj@e"G
} X@!X6j
hfg O
,ijW(95{k
//打印回应的头信息 )A"jVQjI%w
public void logResponseHead(HttpURLConnection con) PK+ x6]x
{ &U&Zo@ot"x
for(int i=1;;i++) (xL :;
{ *Rq`*D>:U}
String header=con.getHeaderFieldKey(i); 3T1P$E" m
if(header!=null) +C_*Vs@4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2SciB*5
Utility.log(header+" : "+con.getHeaderField(header)); KY g3U
else ~T02._E
break; +`| mJa
} Ir27ZP
} _dr*`yXi
9`BEi(z
Z(HZB
public void splitterStop() Y%g "Y
{ b/nOdFO@
bStop = true; /'4Q{8.a
} Ff<)4`J
c;wA
)|RZa|`-G
} J)*8|E9P
4)^vMG&
=/Wu'gG)
/* #h N.=~
**FileAccess.java (@q3^)I4
*//文件访问(定位，写) JpK[&/Ct
package NetFox; SKR;wu
import java.io.*; q5p e~
hJ[UB
*S4aF*Qk
public class FileAccessI implements Serializable{ \XS]N_}8>
sJ~P:g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qlUzr.^-
RandomAccessFile oSavedFile; dE [Ol
long nPos; Ea]T>4
F7T E|LZ
QKccrAo
public FileAccessI() throws IOException -k{Jp/-D
{ RZh}:
this("",0); a#y{pT2 b
} XG&K32_fs
;SY.WfVA7
S+ebO/$>
public FileAccessI(String sName,long nPos) throws IOException GV8)Kor%
{ _|<BF
oSavedFile = new RandomAccessFile(sName,"rw"); "IwM:v
this.nPos = nPos; ,I`_F,
oSavedFile.seek(nPos); |>2:eH
} y|sma;D
_-%d9@x
Qq3fZ=
public synchronized int write(byte[] b,int nStart,int nLen) UX_I6_&
{ M<(u A'
int n = -1; T~J?AKx
try{ 5pJ*1pfeo
oSavedFile.write(b,nStart,nLen); hYb9`0G"2
n = nLen; u+2Lm*M
} ^>m^\MuZ
catch(IOException e) _M5Xk?e=
{ U3F3((EYJ
e.printStackTrace (); GuO`jz F
} yd>}wHt
7Fl-(Nv`
9=$!gC)
return n; bk3Unreh
} )N7n,_#T>
l~1AT%
KzVTkDn,
} /6U 4S>'(
};sMU6e
:3?|VE F
/* ~E*d G
**SiteInfoBean.java z+39ee
*/ R2LK.bTVn
package NetFox; Y&~M7TYb
s'L?;:)dyB
{oWsh)[x2
public class SiteInfoBean { sX:lE^)-z
Y {c5
<xn;bp[
private String sSiteURL; //Site's URL de YyaV
private String sFilePath; //Saved File's Path aws"3O% uW
private String sFileName; //Saved File's Name 8Rxc&`_X
private int nSplitter; //Count of Splited Downloading File #J$qa Ul
M!{'ED
>5Lexj
public SiteInfoBean() n )K6i7]xk
{//nSplitter的缺省值为5 \!H{Ks{#R.
//default value of nSplitter is 5 B*@6xS[IL
this("","","",5); Dg2uE8k
} 7>-yaL{
%j{.0H
:'*DMW~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EXpSh}
{ 1r571B*O
sSiteURL= sURL; cwynd=^nC
sFilePath = sPath; %EI<@Ps8c
sFileName = sName; DU{bonR`
this.nSplitter = nSpiltter; @ yxt($G
CBHc A'L
2P5_zND
} _e'Y3:
{4rQ7J4Ux
7ZFJexN]
public String getSSiteURL() o4)hxs
{ TnE+[.Qu
return sSiteURL; /F~X,lm*~
} +R[4\ hC0Y
J_xG}d
T:!MBWYe|
public void setSSiteURL(String value) 509Q0 [k
{ z[&s5"
sSiteURL = value; ]k+m=OR{/
} _;e\:7<m
@]'SeiNp
g%\L&}Jd
public String getSFilePath() qm(1:iK,0
{ 1^{`lK~2
return sFilePath; ._<ii2K'
} JSW&rn
=n0*{~r
-(;LQDG |
public void setSFilePath(String value) /EFq#+6
{ @@}`hii
sFilePath = value; zvf3b!}
} [7W(NeMk
77We;a
O&$0&dhc
public String getSFileName() Iql5T#K+
{ =! mJG
return sFileName; P5URvEnz:
} Q_4Zb
OE"<!oIs
((MLM3zJ
public void setSFileName(String value) PXEKV0y
{ V5MO}
sFileName = value; B\_[R'Pf&
} Y60"M4j
JTUNb'#RZ
~_PYNY`"
public int getNSplitter() r!K|E95oj9
{ K$-;;pUl
return nSplitter; y1C/v:;
} lbkLyp2
#T%zfcUj
gdi`x|0
public void setNSplitter(int nCount) xzk}[3P{
{ z="L4
nSplitter = nCount; $D_HZ"ytu
} JR1*|u
} H/jm f5
l{%a&/
Y';>O`
/* !_^g8^>2(
**Utility.java Y4To@TrN#\
*/ IZ~.{UQ
package NetFox; <lo`q<q
GqUSVQ
)%mAZk-*;^
public class Utility { 3{3/: 7
3k{ @.V?]
r/AHJU3&eY
public Utility() v2J0u:#,
{ D/s?i[lb
MsjnRX:c3u
#&siHHs \
} zilaP)5x6
4}-#mBV]/
//线程睡眠 wj%wp[KA$
public static void sleep(int nSecond) j=j+Nf$
{ 9#@Zz4Ww
try{ IVteF*8hU
Thread.sleep(nSecond); ,F:=(21
} (~#G'Hd
catch(Exception e) }1m_o@{3P
{ KXe ka
e.printStackTrace (); O5-;I,)H
} 3*WS"bt
} p@tp]u`7
re uYTH
//日志 ~zyQ('
public static void log(String sMsg) RWikJ
{ `d*b]2
System.err.println(sMsg); ,!>fmU`E4
} 6V;:+"BkJ
:6u~aT/
kF-TG3
public static void log(int sMsg) :`J>bHE
{ O71BM@2<
System.err.println(sMsg); s.y}U5Ty?P
} g1qi\axm
} 8]C1K Zs
7) 0q--B
2U%qCfh6|
/* }n95< {
**TestMethod.java [TCRB`nTQF
*/ _,Q[2gQ5N
package NetFox; !$r9C/k
3bts7<K=
^s*\Qw{Ii
public class TestMethod { 0N VI+Z$
:bv|Ah
q6&67u0
public TestMethod() -eL'KO5'
{ ///xx/weblogic60b2_win.exe /f&By p
try{ b *9-}g:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *?N<S$m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <E}N=J'uJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); t/ eo]
fileFetch.start(); PYieD}'
} RbAt3k;y
catch(Exception e){e.printStackTrace ();} J wFned#T
o?dR\cxj
la702)N{
} PP-kz;|
xt))]aH
kY!C_kFcn
public static void main(String[] args) i4VK{G~g"
{ $e1:Q#den2
new TestMethod(); V6+Zh>'S
} %MuaW(I o
} oCA(FQ6
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