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)); #`ZBA>FLaQ
} 7w<e^H?
for(int i=0;i<nEndPos.length-1;i++) i5,yrPF
{ HU/2P`DGP
nEndPos = nStartPos[i+1]; 8og8;#mnyr
} q@^^jlHP
nEndPos[nEndPos.length-1] = nFileLength; B'e@RhU;
} 9sN#l
} ;nx.:f
bt};Pn{3
TILH[r&Jg
//启动子线程 I 6'!b/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p/qu4[Mm
for(int i=0;i<nStartPos.length;i++) xi<yB0MoA
{ Yr*!T= z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S"t\LB*'Ls
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1=h5Z3/fj
nStartPos,nEndPos,i); iR!]&Oh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c{IL"B6>
fileSplitterFetch.start(); Ou4 `#7FR
} %>y`VN D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AtUtE#K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m5o$Dus+?'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o-o -'0l
nEndPos = " + nFileLength); sd"eu
// fileSplitterFetch[nPos.length-1].start(); `TYC]9
1bFGoLAEFl
#~m8zG
//等待子线程结束 |)C #
//int count = 0; e"%uOuIYX
//是否结束while循环 oj[~H}>
boolean breakWhile = false; =A*a9c2
N^M6*,F,J
8Vjv #pm
while(!bStop) {r~=mQ
{ A>8~deZ9
write_nPos(); H#uN&^+H
Utility.sleep(500); `fOp>S^Q4
breakWhile = true; {b'
WD_{bd)
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for(int i=0;i<nStartPos.length;i++) f62rm[
{ h;#046-7
if(!fileSplitterFetch.bDownOver) 5UJ ?1"J
{ zBK"k]rz
breakWhile = false; /1p5KVTKv
break; *fs[]q'Q
} L/E7xLz
} tDavp:M1v
if(breakWhile) 3:G$Y:#P
break; ,6X__Z#rGT
?6\N&MTF
mK/E1a)AG3
//count++; d'&OEGb<
//if(count>4) jhPbh5E
// siteStop(); 3d]~e
} xC9{hXg!
lU%oU&P/"S
TFm[sO0RZ
System.err.println("文件下载结束！"); =1k%T{>
} [y}h
catch(Exception e){e.printStackTrace ();} }]#z0'Aqsu
} en/h`h]h
g\?v 5
/CH]'u^j
//获得文件长度 a0+q^*\d\R
public long getFileSize() ?A3u2-
{ o>nw~_ H\
int nFileLength = -1; IN@o9pUjV
try{ h-|IZ}F7
URL url = new URL(siteInfoBean.getSSiteURL()); "]uPke@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .vctuy&
httpConnection.setRequestProperty("User-Agent","NetFox"); G'u[0>
U?d I
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int responseCode=httpConnection.getResponseCode(); P(FlU]q
if(responseCode>=400) 5|~nX8>
{ |x.^rx`
processErrorCode(responseCode); AE+BrN +"2
return -2; //-2 represent access is error ul~6zBKO
} =|``d-
V?'p E
M>|ZBEK
String sHeader; n$XEazUb0N
:4-,Ru1C"
S-}c_zbl;
for(int i=1;;i++) ,*dLE
{ ?hGE[.(eh]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =PQ4S2Q
//Utility.log(in.readLine()); 3[y$$qXI
sHeader=httpConnection.getHeaderFieldKey(i); _WvVF*Q"k
if(sHeader!=null) J}[[tl
{ $./aKJ1B
if(sHeader.equals("Content-Length")) *r[V[9+y-D
{ kX+9U"` C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k7Qs#L
break; (_!I2"Q*
} 9) ,|h
} {aq)Y>o5:T
else #R:&Irh
break; m<)`@6a/
} cfilH"EK
} 9Bw#VQ
catch(IOException e){e.printStackTrace ();} }eW<P079
catch(Exception e){e.printStackTrace ();} Bm,Vu 1]t
$OdBuJA
'tw ]jMD
Utility.log(nFileLength); GS=E6
qEXN}Pq<
SepwMB4@
return nFileLength; bEj}J_#
} #+p-
P`{$7ST'Hh
14,t
//保存下载信息（文件指针位置） J9!/C#Fm
private void write_nPos() $/C1s"C@O
{ q`/J2r+O
try{ ~v;+-*t
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~tt\^:\3~S
output.writeInt(nStartPos.length); .4R.$`z4
for(int i=0;i<nStartPos.length;i++) %Z<{CV
{ ZIa,pON
// output.writeLong(nPos); MTCfs~}m
output.writeLong(fileSplitterFetch.nStartPos); tB"9%4](
output.writeLong(fileSplitterFetch.nEndPos); {&>rKCi
} 2b"DkJj'
output.close(); Cs[d:T
} fn,hP_
catch(IOException e){e.printStackTrace ();} RC[Sa wA
catch(Exception e){e.printStackTrace ();} 'nGUm[vh
} *!$Z5Im
3m!tb)
iLZY6?_^
//读取保存的下载信息（文件指针位置） N10U&L'w
private void read_nPos() 18sc|t
{ 5]LWWjT
try{ 5 | ,b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I/tMFg
int nCount = input.readInt(); ap )B%9
nStartPos = new long[nCount]; Uzzm2OS`
nEndPos = new long[nCount]; D0xQXC3$`
for(int i=0;i<nStartPos.length;i++) qjhV/fsfb
{ F/BR#J1
nStartPos = input.readLong(); t!3N|`x
nEndPos = input.readLong(); u-,}ug|
} lTqlQ<`V
input.close(); DbH;DcV7
} [Cv./hEQi
catch(IOException e){e.printStackTrace ();} RYEZ'<
catch(Exception e){e.printStackTrace ();} I:iMRvp
} N4C7I1ihq
; $80}TY '
a24 AmoWx
private void processErrorCode(int nErrorCode) )S%t)}
{ iBAP,cR?`
System.err.println("Error Code : " + nErrorCode); z``wqK
} ) yMrET m
iO5g30l
aim\3y~
//停止文件下载 YPI)^ }
public void siteStop() c**&,aL
{ c#}K,joeU
bStop = true; Ql)hIf$Oo
for(int i=0;i<nStartPos.length;i++) i m;6$3
fileSplitterFetch.splitterStop(); B??07j
j8&NscK)
A)sYde(
} {m>ylE
} I* C~w
//负责部分文件的抓取 rMxIujx
**FileSplitterFetch.java ulIEx~qP
*/ A,DBq9Z+4R
package NetFox; D1xGUz2r
v>} +->f
b^d{$eoH?|
import java.io.*; H"l4b4)N\
import java.net.*; G$i)ELs
950N\Y@u
q%dG>!
public class FileSplitterFetch extends Thread { < v]
p 4>ThpX
"g^i%
String sURL; //File URL zk8)!Af
long nStartPos; //File Snippet Start Position {s0%XG1$
long nEndPos; //File Snippet End Position $C\ETQ@
int nThreadID; //Thread's ID qXW\/NT"p<
boolean bDownOver = false; //Downing is over pVy=rS-
boolean bStop = false; //Stop identical 0wv#AT
FileAccessI fileAccessI = null; //File Access interface TSP%5v;Dh
A%.mIc.
R}Lk$#S#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dyWp'vCQs\
{ (CxA5u1|l
this.sURL = sURL; 1^WGJ"1
this.nStartPos = nStart; f*XCWr
this.nEndPos = nEnd; R}=5:)%w
nThreadID = id; ?ZRF]\dP]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p5fr}#en
} :'Qiwf&
`sYFQ+D#O
M@A3+v%K
public void run() aDNB~CwZZ
{ ;yt6Yp.6e
while(nStartPos < nEndPos && !bStop) ?N<My&E
{ ;9T}h2^`B
%f1%9YH
h$l/wn
try{ }%jF!d
URL url = new URL(sURL); R#d~a;j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zok{ndO@|f
httpConnection.setRequestProperty("User-Agent","NetFox"); /YvXyi>^"%
String sProperty = "bytes="+nStartPos+"-"; Z;.-UXat
httpConnection.setRequestProperty("RANGE",sProperty); ]5Uuz?:e
Utility.log(sProperty); BkB>eE1)Ea
\#9LwC"8;
Q4"\k. ?
InputStream input = httpConnection.getInputStream(); +'?Qph6o,7
//logResponseHead(httpConnection); | ;tH?E
/sKL|]i=
l/X_CM8y~
byte[] b = new byte[1024]; &R72$H9C8i
int nRead; S:_Ms{S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YO7U}6wBt
{ EJkHPn
nStartPos += fileAccessI.write(b,0,nRead); ;?2)[a
//if(nThreadID == 1) hC:'L9Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4qOzjEQ
} ~$HB}/
Y_'ERqQ
n N<N~
Utility.log("Thread " + nThreadID + " is over!"); t/iI!}
bDownOver = true; I@'[>t
//nPos = fileAccessI.write (b,0,nRead); 6Xvpk1
} ]<f)Rf">:`
catch(Exception e){e.printStackTrace ();} >H;i#!9,
} FQ<-Wc
} 7]h%?W!
]ZY2\'
$xbC^ k
//打印回应的头信息 9pp+<c
public void logResponseHead(HttpURLConnection con) ;28d7e}
{ *r`=hNr
for(int i=1;;i++) v/`D0g-uX)
{ (u,)v_Oo]a
String header=con.getHeaderFieldKey(i); c?A$Y?|9
if(header!=null) v"bWVc~H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T`bYidA
Utility.log(header+" : "+con.getHeaderField(header)); ,"%C.9a
else Z,).)y#B
break; Ma^jy.
} }T?X6LA$I8
} 4era5=
) O0Cz n
8MJJ w;
public void splitterStop() AjVC{\Ik
{ m!V,W*RNr
bStop = true; k"N>pjgd$
} %~LY'cfPse
zKQ<Zr
HGQ</5Z
} sfM"!{7
FZe/3sY
=z.j{%
/* G]K1X"W?
**FileAccess.java #I/P9)4
*//文件访问(定位，写) oB:7R^a
package NetFox; 1V%tev9a
import java.io.*; jRK}H*uem
Y <6|z3
#dauXUKH
public class FileAccessI implements Serializable{ kuEXNi1l
`a83RX_\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n2U &}O
RandomAccessFile oSavedFile; ]>n{~4a
long nPos; 3<xE_ \DR
BhJ>G%
VE|:k:};
public FileAccessI() throws IOException ^h[6{F~J
{ 1WUSp;JMl
this("",0); ZbFD|~[ V
} 'oa.-g5
o=m5AUe?J
7)rQf{q7
public FileAccessI(String sName,long nPos) throws IOException {?qfH>oFA
{ }a]`"_i;[
oSavedFile = new RandomAccessFile(sName,"rw"); |Xso}Y{
this.nPos = nPos; NQdwj>_a
oSavedFile.seek(nPos); x93@[B*%
} |+cz\+
t~+M>Fjm?d
<y6`8J7:
public synchronized int write(byte[] b,int nStart,int nLen) PQHztS"
{ -)V0D,r$[
int n = -1; BZeEZ2"
try{ pzF_g-B
oSavedFile.write(b,nStart,nLen); T\6Qr$t
n = nLen; 2I.FSR_G?
} y1V}c,
catch(IOException e) PR{ubMn
{ d^v#x[1msZ
e.printStackTrace (); N63?4'_W
} Ia2WBs=
1c$pz:$vX
l)u%`Hcn
return n; |IAx!Z-P
} ndSu-8?L
mF6-f#t>H+
6uRE9h|
} xdSMYH{2A
8lF9LZ8
}QE.|.fA1
/* ;}B=g/C
**SiteInfoBean.java m$8siF{<q
*/ #qd!_oN
package NetFox; >tg)F|@
4H8r[
`m 5\
public class SiteInfoBean { Es=G' au
[@K'}\U^+
H1N@E}>|
private String sSiteURL; //Site's URL (kL"*y/"p
private String sFilePath; //Saved File's Path v`h>5#_[
private String sFileName; //Saved File's Name d?oXz|;H(
private int nSplitter; //Count of Splited Downloading File (B#FLoK
R@\fqNq
_S_,rTf&
public SiteInfoBean() |~9jO/&r
{//nSplitter的缺省值为5 eaRa+ <#u
//default value of nSplitter is 5 HNZ$CaJh
this("","","",5); iM .yen_vp
} VwR\"8r3
`I7s|9-=
a~KtH;7<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IADSWzQ@
{ B>u`%Ry&
sSiteURL= sURL; jOhAXe;~X{
sFilePath = sPath; ` nX,x-UM
sFileName = sName; )!(gS,
this.nSplitter = nSpiltter; <$A,|m
>MYxj}I4{z
FK BRJ5O
} p\zqZ=s
9/"&6,
A1zRzg4I
public String getSSiteURL() eC/{c1C
{ x8lBpr
return sSiteURL; ~&:-c v
} F=F84_+K
ww|fqx?
?>7\L'n=5I
public void setSSiteURL(String value) 0A}XhX
{ veDv14
sSiteURL = value; zlLZ8b+
} d.}65{F,x
sI\NX$M
C6ql,hR^h`
public String getSFilePath() Gs#9'3_U5
{ &>-'|(m+2
return sFilePath; k4#j l<R
} 8wWp+Hk
#19O5
#X]*kxQ<
public void setSFilePath(String value) xxGm T.&
{ R&1>\t
sFilePath = value; IB|!51H
} kR+}7G+
!>(uhuTBF
:V(C+bm *
public String getSFileName() fBX@ MedC
{ %:C6\4
return sFileName; a;$V;3C{b&
} 2IJniS=[>
Xau%v5r
1n8y4k)
public void setSFileName(String value) Q`i@['?p
{ A^lm0[3q
sFileName = value; 9>{ml&$
} @+;.W>^h
.i\FK@2
;)ay uS sQ
public int getNSplitter() QXj#Brp
{ $`OyGeq"T
return nSplitter; d/GSG%zB
} tnpEfi-
IV~)BW leT
C32*RNG?U
public void setNSplitter(int nCount) f)vnm*&-
{ B\D)21Ik}%
nSplitter = nCount; 8Z}%,G*n
} 3]S_w[Q4
} / 8O=3
)h ,v(Rxa
OGEe8Z9Jt
/* <uU<qO;6
**Utility.java @nqM#
*/ [<r.M<3
package NetFox; b4:{PD~Mh
K1YxF
jNbVp{%/S}
public class Utility { jhRr!
_G)A$6weU
;Q3[} ]su
public Utility() 62;xK-U
{ nK< v
(e_<~+E
=~s+<9c]
} _an0G?7
q4X(_t
//线程睡眠 Z|KDi `S
public static void sleep(int nSecond) Lapeh>1T
{ -[N9"Z,
try{ U8aVI
Thread.sleep(nSecond); /IcGJ&;
} Q~.t8g/
catch(Exception e) ~(*tcs]hY
{ +DQUL|\
e.printStackTrace (); 8@ f!,!Wn
} \v+>qY<q
} T!?tyW
XR VZU~ZV
//日志 ?(zCv9Pg
public static void log(String sMsg) z3[J sE%
{ 1tO96t^d%
System.err.println(sMsg); v?8i;[
} PcbhylKd
+*Wlj8
lA4-ZQ2Zp[
public static void log(int sMsg) 6 o
{ W.s8!KH:
System.err.println(sMsg); F6J]T6Y
} .[eC w
} ,^n&Q'p3
6?lAbW
-vm1xp$
/* E"[p_ALdC
**TestMethod.java wIAH,3!
*/ !m))Yp-"H
package NetFox; N,B!D~@
b IxH0=f
{o^tSEN!-
public class TestMethod { bD/ZKvg
#B <%
-Sh&x
public TestMethod() 2\&3x}@
{ ///xx/weblogic60b2_win.exe s[eSPSFZ
try{ Q%~BD@Io
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 67/\0mV:~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xC5Pv">
SiteFileFetch fileFetch = new SiteFileFetch(bean); (!b)<V*
fileFetch.start(); !\VEUF,K?
} s%rmfIp"
catch(Exception e){e.printStackTrace ();} MrUjqv6a[
u,:hT] ~+
GL>YJ%
} Yx,E5}-
_'G'>X>}WU
G3y8M|:
public static void main(String[] args) ]7TOA$Q
{ Q3hSWXq'
new TestMethod(); 5|jY
} H;<>uELie
} QoUdTIIL
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