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)); cq>J]35
} z#G\D5yX[*
for(int i=0;i<nEndPos.length-1;i++) ~AD>@;8fG
{ YnnK]N;\x
nEndPos = nStartPos[i+1]; -`8@
} }Rz,}^B
nEndPos[nEndPos.length-1] = nFileLength; G9XkimQ'
} !{*yWpZ:
} 8^EWD3N`
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qJF'KHyU{l
//启动子线程 H, 3Bf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X.{xHD&_
for(int i=0;i<nStartPos.length;i++) 2XL^A[?
{ ^0"^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `IlhLv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +76'(@(1Y
nStartPos,nEndPos,i); { 1~]}K2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1D[V{)#
fileSplitterFetch.start(); K 'I6iCrD
} DI)"FOM6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 64b AWHv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1PxRj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [;hkT
nEndPos = " + nFileLength); rXmrT%7k
// fileSplitterFetch[nPos.length-1].start(); 0#GnmH
b)a5LFt|
Q.9,W=<6
//等待子线程结束 L+ew/I>:
//int count = 0; q5Zu'-Cx@
//是否结束while循环 }WJXQ@
boolean breakWhile = false; T$mT;k
N@_y<7#C
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while(!bStop) *CGHp8
{ xj33g6S
write_nPos(); d_(;sW"I
Utility.sleep(500); <zY#qFQ2
breakWhile = true; V|A.M-XLv4
-J!n7
c|:EMYS
for(int i=0;i<nStartPos.length;i++) Q0`@=5?-
{ fFVQu\
if(!fileSplitterFetch.bDownOver) hQ>$"0K
{ B t3++ Mj
breakWhile = false; JK,^:tgm
break; IM6n\EZ^
} f4\F:YT
} Q(x=;wf5r
if(breakWhile) i.^UkN{
break; [qxpu{
[jNVk3
p-"wY?q
//count++; "r;cH53
//if(count>4) E_30)"]
// siteStop(); qm#?DSLap
} j/O9LygB
^{J^oZ'%~
tag)IWAiE
System.err.println("文件下载结束！"); %1cxZxGT
} U1 3Lsky%
catch(Exception e){e.printStackTrace ();} A"DGn
} -mO<(wfV>
x-@?:P*
n9 bp0#K
//获得文件长度 G~_eBy
public long getFileSize() ;[lLFI
{ >g+Y//Z
int nFileLength = -1; |CQjgI|;
try{ +R$;LtR
URL url = new URL(siteInfoBean.getSSiteURL()); AvIheR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G@e;ms1
httpConnection.setRequestProperty("User-Agent","NetFox"); r.@UH-2c
q~18JB4WPJ
=|O]X|y-lZ
int responseCode=httpConnection.getResponseCode(); >yenuqIKQv
if(responseCode>=400) b* n#XTV
{ H9_>a-> )~
processErrorCode(responseCode); LkafB2y
return -2; //-2 represent access is error IN;!s#cl:
} UC`sq-n
?3LV$S)U
,: z]15fX
String sHeader; VAheus
_;BNWH
%26HB w=JF
for(int i=1;;i++) / E!6]b/
{ _;x`6LM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aFnyhu&W'
//Utility.log(in.readLine()); ?=?*W7
sHeader=httpConnection.getHeaderFieldKey(i); \2f?)id~
if(sHeader!=null) dhg($m
{ zb~;<:<
if(sHeader.equals("Content-Length")) Tz:,l$
{ .1h\r, #
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4y.'O
break; Z5wDf+
} Vl(id_~_
} b*Hk} !qH
else [$>@f{:
break; ,DWq
} Rc@lGq9
} BD.l5~:
catch(IOException e){e.printStackTrace ();} :hB6-CZkqN
catch(Exception e){e.printStackTrace ();} A[Ce3m
&RS)U72
ndBqXS
Utility.log(nFileLength); :1UOT'_
K^/.v<w
fP;I{AiN~
return nFileLength; >Ir?)h
} (t"|XSF
Vw.4;Zy(
t=fAG,k5
//保存下载信息（文件指针位置） n68qxD-X
private void write_nPos() O#^qd0e'P!
{ 8SiWAOQAL
try{ 5M>SrZH
output = new DataOutputStream(new FileOutputStream(tmpFile)); oY\;KPz
output.writeInt(nStartPos.length); -G1R><8[
for(int i=0;i<nStartPos.length;i++) Uu`}| &@i
{ ]]u_Mdk
// output.writeLong(nPos); rJp9ut'FEz
output.writeLong(fileSplitterFetch.nStartPos); o9{1_7K
output.writeLong(fileSplitterFetch.nEndPos); s}^W2
} j)mS3#cH
output.close(); #5{lOeN
} Q\^BOdX^`
catch(IOException e){e.printStackTrace ();} 4/x.qoj
catch(Exception e){e.printStackTrace ();} wqE2n
} =xH>,-8}
ZTGsZ}{5
> JTf0/
//读取保存的下载信息（文件指针位置） vMXn#eR
private void read_nPos() 2{hG",JL
{ d)%l-jj9,
try{ Me+)2S 9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /PBK:B
int nCount = input.readInt(); o}D7 $6
nStartPos = new long[nCount]; Ko0T[TNkh
nEndPos = new long[nCount]; Ej@N}r>X
for(int i=0;i<nStartPos.length;i++) C0>)WVCK
{ 5tVg++I
nStartPos = input.readLong(); :'!_PN
nEndPos = input.readLong(); IxWX2yJ]
} o:%;AOcl
input.close(); PB:r+[91
} p:!FB8
catch(IOException e){e.printStackTrace ();} (/P-9<"U
catch(Exception e){e.printStackTrace ();} MA mjoH
} V2 }.X+u&<
_2})URU<S
;[,#VtD
private void processErrorCode(int nErrorCode) 2Aq+:ud)P
{ 1(VskFtZF
System.err.println("Error Code : " + nErrorCode); z)&&Ym#
} 0NSCeq%;6q
rsK b9G
lb)i0`AN+
//停止文件下载 ',Oc+jLR
public void siteStop() pAtxEaXh
{ %8"Aq
bStop = true; i?F~]8
for(int i=0;i<nStartPos.length;i++) y=1(o3(
fileSplitterFetch.splitterStop(); ,ce$y4%(
(jh0cy}|]
K+U0YMRmz
} cn ;2&
} ns[h_g!j;
//负责部分文件的抓取 *^%ohCUi
**FileSplitterFetch.java T,4REbm^
*/ I"jub kI=Z
package NetFox; WODgG@w
~HX'8\5
G7HvA46
import java.io.*; pmDFmES
import java.net.*; oPA m*
}Do$oyAV$G
IkLcL8P^
public class FileSplitterFetch extends Thread { E-#}.}i5
qEPC]es|T
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String sURL; //File URL U$IB_a2
long nStartPos; //File Snippet Start Position i~*#z&4A+
long nEndPos; //File Snippet End Position #|}EPD9$
int nThreadID; //Thread's ID s9?H#^Y5u
boolean bDownOver = false; //Downing is over \z=!It]f.
boolean bStop = false; //Stop identical k?Iq 6
FileAccessI fileAccessI = null; //File Access interface z`y^o*qc]
yLvU@V@~
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s !HOrhV
{ L q;=UE
this.sURL = sURL; kAk+Sq^n
this.nStartPos = nStart; cfW;gFf
this.nEndPos = nEnd; ^pvnUODW[
nThreadID = id; ^{+_PWn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?w"zW6U
} k Rp$[^ma
}$'T=ay&
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public void run() .u9,w
{ 0qo:M3
while(nStartPos < nEndPos && !bStop) D +9l$**a
{ ~jOk?^6
HS 1zA
+@yTcz
try{ ~0gHh
URL url = new URL(sURL); e:WKb9nT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ne2eBmY}(
httpConnection.setRequestProperty("User-Agent","NetFox"); s ` +cQ
String sProperty = "bytes="+nStartPos+"-"; Q2xzux~T
httpConnection.setRequestProperty("RANGE",sProperty); E$E#c8I:
Utility.log(sProperty); fUS1`
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H}}C>p"!,
InputStream input = httpConnection.getInputStream(); 7a<:\F}E0
//logResponseHead(httpConnection); w:[\G%yQ
FO xZkU\e=
l>jNBxB|/A
byte[] b = new byte[1024]; -f8iq[F5
int nRead; V5HK6-T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;Z{jol
{ @7,k0H9Moa
nStartPos += fileAccessI.write(b,0,nRead); rW0-XLbL5H
//if(nThreadID == 1) |jTRIMj%,_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `KmM*_a
} ~~3 BV,
xEqr3(
:PDyc(s{
Utility.log("Thread " + nThreadID + " is over!"); E(Y}*.\]#s
bDownOver = true; XlU`jv+
//nPos = fileAccessI.write (b,0,nRead); W v!%'IB
} ]*vv=@"`e
catch(Exception e){e.printStackTrace ();} /X97dF)zt
} 59M\uVWR
} a}/A]mu
8{4jlL;"`?
}:hN}*H
//打印回应的头信息 /}$D&KwYg
public void logResponseHead(HttpURLConnection con) 7y'2
{ aqN6.t
for(int i=1;;i++) c R6:AGr
{ 1gDsL
String header=con.getHeaderFieldKey(i); +I r
if(header!=null) C7T}:V](q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F'9#dR?
Utility.log(header+" : "+con.getHeaderField(header)); L~>~a1p!
else @j=Q$k.GF
break; jS| 9jg:
} %*Lv
} k^*S3#"
3/0E9'
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public void splitterStop() 4S3uzy%
{ )V?:qCuY>
bStop = true; N)^` 15w
} {E$smX
6k*,Yei
Ni-@El99
} g.T:72"
swLrp 74
8XdgtYm
/* S!+}\*
**FileAccess.java \*5${[
*//文件访问(定位，写) 8t >nL
package NetFox; bE>"DPq
import java.io.*; :pvJpu$]
9B?-&t
:SvgXMY@
public class FileAccessI implements Serializable{ z6;6 o!ej
'nSo0cyQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g=]VQ;{
RandomAccessFile oSavedFile; VH7nyqEM
long nPos; ![9umsx
V3<H8pL
CWw#0
public FileAccessI() throws IOException b ]u01T-
{ %+HZ4M+hV
this("",0); yU'<b.]
} <S68UN(Ke
}YCpd)@
2$s2u;
public FileAccessI(String sName,long nPos) throws IOException GYwU3`{
{ jcL%_of
oSavedFile = new RandomAccessFile(sName,"rw"); +Fa!<txn
this.nPos = nPos; ^c|_%/
oSavedFile.seek(nPos); &r)[6a$fW
} 1V:I}~\
iqr/MB,W
omzG/)M:O
public synchronized int write(byte[] b,int nStart,int nLen) K26`wt
{ Zi=/w
int n = -1; y$[:Kh,
try{ ;9$71E
oSavedFile.write(b,nStart,nLen); @jY=b<
n = nLen; h'ik19
} v8f1o$R
catch(IOException e) _=-B%m
{ Cd2A&RB
e.printStackTrace (); -+{<a!Nb
} U'k 0;
fs\A(]`$
M`)/^S9
return n; a]nK!;>$
} ?/|KM8
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} )9i$ 1"a(
MUn(ZnQy|
|ya.c\}q
/* J"~!jrzBh(
**SiteInfoBean.java ->L>`<7(
*/ LR#BP}\b'
package NetFox; %%FzBbWAO
D9h
yQ0:M/r;0
public class SiteInfoBean { G& m~W
je85G`{DC
s>*xAIx
private String sSiteURL; //Site's URL 5Ky(C6E$s
private String sFilePath; //Saved File's Path * o{7 a$V
private String sFileName; //Saved File's Name /]oQqZHv
private int nSplitter; //Count of Splited Downloading File e2^TQv2(=e
LyH1tF
!|Wf mU
public SiteInfoBean() %2y5a`b
{//nSplitter的缺省值为5 KX J7\}
//default value of nSplitter is 5 2F :8=_sA
this("","","",5); gCq'#G\Z
} T>68 ,; p
,&.$r/x|?
>#VNA^+t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LwYWgT\e
{ Z+=M_{`{
sSiteURL= sURL; 1Li*n6tLX`
sFilePath = sPath; slzB#
sFileName = sName; y9b%P]i
this.nSplitter = nSpiltter; <*(^QOM
l];/,J^
6n^@Ps
} RdBIbm
"+E\os72|
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public String getSSiteURL() -Xx4:S
{ pX+4B=*
return sSiteURL; S$ffTdRz
} :V1j*)
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_n1[(I
public void setSSiteURL(String value) 'o~gT ;T#
{ (x fN=Te,-
sSiteURL = value; ``%yVVg}
} -9::M}^2
k/(]1QnW
NfUt\ p*
public String getSFilePath() ,u>[cRqw
{ Ec2;?pvd%J
return sFilePath; 4*&k~0#t
} Yt?]0i+
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F$bV}>-1k
public void setSFilePath(String value) 7[PEiAI
{ A=3L_ #nO
sFilePath = value; :bm%f%gg
} &d0sv5&s
4jt(tZS
mRa\ wEg%
public String getSFileName() 0<O()NMv
{ )2_[Ww|.
return sFileName; -n8d#Qm)
} 3{fg3?
W.NZ%~|+e/
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public void setSFileName(String value) uFhaN\S
{ [dAQrou6P
sFileName = value; QFMAy>Gdn
} =3 Vug2*wd
YZ`SF"Bd(
tj$[szo
public int getNSplitter() s&Y"a,|Z
{ kg 8Dn
return nSplitter; BM'!odRv
} 2?SbkU/3|P
hGkJ$QT
kRc+OsY9
public void setNSplitter(int nCount) xx(C$wCJ
{ R<U]"4CBx
nSplitter = nCount; $dF3@(p
} G:p85k`
} 0Ni{UV? k
8xg^="OJ
1)MDnODJ
/* &a;?o~%*]i
**Utility.java /-,\$@J5)
*/ M(zZ8#
package NetFox; Z`u$#<ukX
xP!QV~$>
r*]pL<
public class Utility { eIfQ TV
U8AH,?]#
Q2D!Agq=D
public Utility() N@L{9ak1
{ e"52'zAV-
~7U~
r4fHD~#l{
} c(e>Rmh
p |1u,N
//线程睡眠 h='F,r5#2
public static void sleep(int nSecond) t`&x.o
{ 8lL|j
try{ U!`iKy-
Thread.sleep(nSecond); B+snHabS6
} !TJ,:c]4{!
catch(Exception e) C!a1.&HHZ7
{ 9&5<ZC-D
e.printStackTrace (); ".tL+A[
} Ff%V1BH[
} -X~mW
Cf3!Ud
//日志 qS2Nk.e]o
public static void log(String sMsg) Z sTtSM\Ac
{ dw3Hk$"h
System.err.println(sMsg); z8'1R6nq
} M{Z ;7n'
`}$o<CJ
lOk8VlH<h
public static void log(int sMsg) 9MYk5q.X:
{ =y4dR#R(\
System.err.println(sMsg); QCF'/G
} ^w.hI5ua)
} &J*M
1XMR7liE
8&)v%TX
/* 1(Ta*"(0Ip
**TestMethod.java :t{~Mi=T
*/ ]MV8rC[\
package NetFox; LWN{
jb-kg</A
67YC;J]n=z
public class TestMethod { o^\Pt<~W
0(D^NtB7
/v8Q17O?e
public TestMethod() IB/3=4n^|
{ ///xx/weblogic60b2_win.exe *iEtXv
try{ a+E&{pV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ki2!sADd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3/@z4:p0R
SiteFileFetch fileFetch = new SiteFileFetch(bean); -f)fiQ-<
fileFetch.start(); FT@uZWgQ=
} M 9t7y
catch(Exception e){e.printStackTrace ();} b.&WW
rtRbr_
S3E,0%yo+)
} xi=ApwNj
pn gto
TZAd{EZa
public static void main(String[] args) G @..?>
{ $/++afim
new TestMethod(); _`|1B$@x
} d]pb1ECuu
} '7-Yo Q
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