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)); ~m6b6Aj@6
} ttd ^jT
for(int i=0;i<nEndPos.length-1;i++) TJ_pMU
{ qx f8f
nEndPos = nStartPos[i+1]; VXP@)\!
} @aC9O9|~
nEndPos[nEndPos.length-1] = nFileLength; |E?,hTRe5
} 4r tNvf5`
} y"T(Unvc
KJYcP72P
,p)Qu%'
//启动子线程 12o6KVV^x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <X"_S'O
for(int i=0;i<nStartPos.length;i++) 4d63+iM+}
{ ]9lR:V sw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oXFo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), epGC Ta
nStartPos,nEndPos,i); IcJQC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PdqyNn=
fileSplitterFetch.start(); ZE:!>VXa87
} QruclNW{Bv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /I48jO^2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {JlSfJw!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qtlcY8!
nEndPos = " + nFileLength); sIzy/W0iV
// fileSplitterFetch[nPos.length-1].start(); M{4U%lk
{v,NNKQ4x
3Q!)bMv \
//等待子线程结束 3XSfXS{lwP
//int count = 0; oYAHyCkVq
//是否结束while循环 r?2J
boolean breakWhile = false; ` #; "
3,^.
ngOGo =
while(!bStop) KXT9Wt=
{ ni?5h5-
write_nPos(); C17$qdV/
Utility.sleep(500); RMs+pN<5
breakWhile = true; Ny5$IIFe
%V|n2/O Y
/2>.*H_2
for(int i=0;i<nStartPos.length;i++) NnRX0]
{ ~s2la~gu
if(!fileSplitterFetch.bDownOver) &cZl2ynPi
{ a\B'Qe+
breakWhile = false; -8Q}*Z
break; !rTkH4!_
} })umg8s
} Vb,'VN%
if(breakWhile) x(7Q5Uk\
break; XsGc!o
C;I:?4
8k )i-&R
//count++; #+8G`
//if(count>4) i\dd
// siteStop(); ']U<R=5T$
} s<{) X$
V/]o':
&3f^]n!@
System.err.println("文件下载结束！"); _sK{qQxvM=
} $1Qcz,4B|
catch(Exception e){e.printStackTrace ();} in7h^6?I
} 2" u,f
,t +sw4
gX]ewbPDQ
//获得文件长度 Gz:ell$
public long getFileSize() Slv91c&md,
{ ]([^(&2
int nFileLength = -1; c0Yc~&RF
try{ 9`td_qh
URL url = new URL(siteInfoBean.getSSiteURL()); )Wy:I_F351
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ttA'RJ
httpConnection.setRequestProperty("User-Agent","NetFox"); rUg|5EN^)d
tE<'*o'
(W |;gQ
int responseCode=httpConnection.getResponseCode(); b6!7j
if(responseCode>=400) J1Run0
{ @_0tq{
processErrorCode(responseCode); Hm'aD2k
return -2; //-2 represent access is error +!mEP>
} uj@d {AQ
K(#O@Wmjq
6 IRa$h>H
String sHeader; @plh'f}
M{g.x4M@W
O>d [;Q
for(int i=1;;i++) sAS[wcOQ
{ RT<HiVr`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (qzBy \\p
//Utility.log(in.readLine()); hv*XuT/
sHeader=httpConnection.getHeaderFieldKey(i); r7FpR!
if(sHeader!=null) 3.6Gh|7
{ JPM~tp?;<
if(sHeader.equals("Content-Length")) nd }Z[)
{ `L%<3/hF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W<:x4gBa
break; <"yL(s^u"
} .'b|pd
} U(2=fKK;
else o~M=o:^nH
break; sh*/wM
} kS4YxtvB
} r@EHn[w
catch(IOException e){e.printStackTrace ();} x/ix%!8J
catch(Exception e){e.printStackTrace ();} .Nk5W%7]=
wz>[CXpi_
#^{%jlmHxJ
Utility.log(nFileLength); m qwJya
P=.~LZZ]89
LfN,aW
return nFileLength; VniU:A
} mrBK{@n
)Em`kle
u.Tknw-X
//保存下载信息（文件指针位置） s8dP=_ `
private void write_nPos() [qU`}S2
{ Dt\rrN:v
try{ CA5T3J@vAQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); a n0n8l
output.writeInt(nStartPos.length); $'<FPbUtD}
for(int i=0;i<nStartPos.length;i++) *U-:2uf
{ T+oOlug
// output.writeLong(nPos); \h?6/@3ob
output.writeLong(fileSplitterFetch.nStartPos); @VQ<X4Za
output.writeLong(fileSplitterFetch.nEndPos); *T~b ox
} 1024L;
output.close(); "^)GnK +-
} ^!z(IE'
catch(IOException e){e.printStackTrace ();} MT6"b
catch(Exception e){e.printStackTrace ();} -Jt36|O
} Oh%p1$H
b!r%4Ah
qkqtPbQ 7
//读取保存的下载信息（文件指针位置） [Sj"gLj
private void read_nPos() A4(k<<xjE
{ w c
try{ b,X+*hRt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "]|7%]
int nCount = input.readInt(); 7Ah
nStartPos = new long[nCount]; p`EgMzVO,
nEndPos = new long[nCount]; xQl}~G]!
for(int i=0;i<nStartPos.length;i++) Bo\~PV[
{ YFDOp*
nStartPos = input.readLong(); DTa!vg
nEndPos = input.readLong(); <s%Ft
} >!Xj%RW
input.close(); _-rC]iQJ55
} 6s'n r7'0
catch(IOException e){e.printStackTrace ();} YRMe<upo
catch(Exception e){e.printStackTrace ();} j{D tjV8
} m&s>Sn+
)+ 'r-AF*
7 IJn9b
private void processErrorCode(int nErrorCode) 4sW'pH
{ u%lUi2P2E
System.err.println("Error Code : " + nErrorCode); kP'm$+1or
} p:W{c/tV
5nTcd@lX
":q+"*fy
//停止文件下载 T8&eaAoo
public void siteStop() 97~>gFU77#
{ TZGk[u^*
bStop = true; jFip-=T{4
for(int i=0;i<nStartPos.length;i++) e<(6x[_
fileSplitterFetch.splitterStop(); jGT|Xo>t
hA;Ai:8
%hlgLM
} sVGQSJJ5
} y0-UO+;
//负责部分文件的抓取 }Q@~_3,UJ
**FileSplitterFetch.java RAnF=1[v
*/ 1;'-$K`}
package NetFox; }h1eB~6M
R.DUfU"gp
\98N8p;,I
import java.io.*; *?$M=tH
import java.net.*; n`@dk_%yI
&SNH1b#>E
'sNiJ>
public class FileSplitterFetch extends Thread { .Z#/%y3S
,fqM>Q
L62%s[
String sURL; //File URL }"SqB{5e(
long nStartPos; //File Snippet Start Position wX_~H*m?
long nEndPos; //File Snippet End Position :H&G}T(#
int nThreadID; //Thread's ID :KR KD
boolean bDownOver = false; //Downing is over &W c$VDC
boolean bStop = false; //Stop identical !|j|rYi-
FileAccessI fileAccessI = null; //File Access interface 74N3wi5B
s~bi#U;dF
~I9o*cq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p&5>j\uJ1&
{ wOCAGEg
this.sURL = sURL; gFrNk Uqp
this.nStartPos = nStart; 0TSB<,9a[
this.nEndPos = nEnd; #ti%hm
nThreadID = id; !dU$1:7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t%J1(H
} }}ic{931
7!h> < sx
IF-y/]
public void run() TIt\
{ HTz`$9
while(nStartPos < nEndPos && !bStop) m(d|TwG{
{ ez.a
;<thEWH;Y
&%GAPs%
try{ iK+Vla`}
URL url = new URL(sURL); Jp%5qBS^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F3]VSI6^E,
httpConnection.setRequestProperty("User-Agent","NetFox"); Lq1?Y
String sProperty = "bytes="+nStartPos+"-"; MB $aN':
httpConnection.setRequestProperty("RANGE",sProperty); <VQ)}HW;k
Utility.log(sProperty); 1r_V$o$
-%gEND-AP
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InputStream input = httpConnection.getInputStream(); f$n5$hJlQ
//logResponseHead(httpConnection); Pqw<nyC.
("r:L<xe&
Ir5|H|b<
byte[] b = new byte[1024]; Jj\lF*B
int nRead; q mv0LU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $COjC!M
{ T:Ee6I 3l
nStartPos += fileAccessI.write(b,0,nRead); H0sTL#/L\
//if(nThreadID == 1) E`V\/`5D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^]'_Qbi]}
} esQ$.L
NdSuOkwwt
m{?f,Q=u@
Utility.log("Thread " + nThreadID + " is over!"); #.[eZ[
bDownOver = true; KX7fgC
//nPos = fileAccessI.write (b,0,nRead); 3fB]uq+eD%
} ZTz07Jt
catch(Exception e){e.printStackTrace ();} |FM*1Q[1
} <Z<meB[g
} a'/i/@h
u%+k\/Scp.
k4hk* 0Jq
//打印回应的头信息 +xU({/
public void logResponseHead(HttpURLConnection con) l"1D'Hk
{ rUmP_
for(int i=1;;i++) FMI1[|:;
{ lw[c+F7
String header=con.getHeaderFieldKey(i); FKu8R%9xn%
if(header!=null) {jmy:e2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3l41"5Fy&
Utility.log(header+" : "+con.getHeaderField(header)); GGr82)E
else 2 \}J*0
break; 6]d]0TW_
} qP<D9k>
} SY[3O
KR%WBvv
Qni`k)4
public void splitterStop() `>`b;A4
{ |:JT+a1
bStop = true; :?BK A0E
} S\<i`q
^.\O)K {h
M}#DX=NZc
} uf9&o#
QDV+(
{?IbbT
/* 9A} *
**FileAccess.java h_S>Q
*//文件访问(定位，写) i!e8-gVMP&
package NetFox; -~lq <M
import java.io.*; xk% 62W
gCC7L(1
htR.p7&Tn
public class FileAccessI implements Serializable{ p/VVb%
&0qpgl|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )Hmf=eoc
RandomAccessFile oSavedFile; vno/V#e$WX
long nPos; e]1Zey
^N|8 B?Vg
/OzoeIt
public FileAccessI() throws IOException =3w;<1 ?'
{ 9 %4:eTcp
this("",0); ;tZQ9#S
} ^PezV5(
PC<_1!M]
@r/~Y]0Ye5
public FileAccessI(String sName,long nPos) throws IOException qJrKt=CE
{ $=N?[h&4
oSavedFile = new RandomAccessFile(sName,"rw"); ceJi|`F
this.nPos = nPos; ?X6}+
oSavedFile.seek(nPos); ]4en|Aq
} X(*O$B{ R
l[ $bn!_e
& rab,I"
public synchronized int write(byte[] b,int nStart,int nLen) &4S2fWx
{ L}Y.xi
int n = -1; jJNCNH*0
try{ /}m*|cG/
oSavedFile.write(b,nStart,nLen); o!":mJy
n = nLen; y7fy9jQ 8.
} SnmUh~`L~
catch(IOException e) a~$Y;C_#<
{ bC1G5`v_D
e.printStackTrace (); !LwHKCj
} ~Q]5g7k=&
,Q7;(&x~
)B0%"0?`8
return n; >!xyA;
} /0XMQy
mA+:)?e5~
()l3X.t,$
} 3EICdC
yW=+6@A4
C$1W+(
/* ]>VG}e~b
**SiteInfoBean.java >- \bLr
*/ ")STB8kQ
package NetFox; @ gWd
ngl +`|u
Pa{
public class SiteInfoBean { f(Of+>
'1gfXC
Wq1 jTIQ
private String sSiteURL; //Site's URL Pp tuXq%U
private String sFilePath; //Saved File's Path ;: 2U}p^-
private String sFileName; //Saved File's Name 1d<Uwb>
private int nSplitter; //Count of Splited Downloading File aY>v
R;c9)>8L
'6 F-%
public SiteInfoBean() =x\`yxsG
{//nSplitter的缺省值为5 7*{f*({
//default value of nSplitter is 5 QH9t |l
this("","","",5); l\*9rs:!
} @5S'5)4pB
Q7$o&N{
SscB&{f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /D3{EjUE=
{ zTw"5N
sSiteURL= sURL; _V-KyK
sFilePath = sPath; p/HDG ^T:u
sFileName = sName; 2H)4}5H
this.nSplitter = nSpiltter; k~"Eh]38
$ItjVc@U
73D<wMgZF
} 6`e7|ilh6
=Nxkr0])!
WQ.0}n}d
public String getSSiteURL() 1*TbgxS~W
{ WK>|IgK
return sSiteURL; L>h8>JvQ
} nTEN&8Y>R
Gs,:$Im
-SrZ^
public void setSSiteURL(String value) F^75y?
{ 0 Uropam
sSiteURL = value; &xQM!f
} Go)$LC0Mi
kO}&Oi,?
xV)[C )6
public String getSFilePath() }oRBQP^&K
{ dz] 5s
return sFilePath; m0"K^p
} TmQIpeych
pa[/6(
~P1~:AT
public void setSFilePath(String value) P2-&Im`+
{ {_O!mI*
sFilePath = value; _5jT}I<k
} E^axLp>(I
8Y?M:^f~
>1Z"5F7=
public String getSFileName() ?BnU0R_r]
{ (j&:
return sFileName; \!-BR0+y;
} N]A# ecm
(jM0YtrD
[>O!~
public void setSFileName(String value) ?l0Qi
{ YA4D?'
sFileName = value; *j%x
} '+PKGmRW
`<C<[JP:o
9{toPED
public int getNSplitter() 6Yj{% G
{ lM6pYYEq=
return nSplitter; Gmz^vpQ]t
} 0@ Y#P|QF
l#'V SFm&
to'7o8Z
public void setNSplitter(int nCount) #Vq9 =Q2
{ :aesG7=O
nSplitter = nCount; E#B-JLMGl
} ?l0eU@rwQ
} Lnr9*dm6q
Iux3f+H
@Jzk2,rI
/* +xFn~b/
**Utility.java *;o%*:
*/ 6p9fq3~7Y
package NetFox; \#{PV\x:Nn
*;Jb=
/T w{JO#Q
public class Utility { ANM#Kx+
2%W;#oi?
*GT=U(d
public Utility() 8h=t%zMSb
{ f!9i6
4<y
8QrpNSj4
} j[G`p^ul
}aZuCe_
//线程睡眠 >HP `B2Q H
public static void sleep(int nSecond) b(iF0U>&
{ )kpEcMlR
try{ j/O~8o&
Thread.sleep(nSecond); i5VZ,E^E
} c|&3e84U
catch(Exception e) 7n8nJTU{4j
{ ^3;B4tj[
e.printStackTrace (); -*C WF|<G
} {M]_]L{&7
} D}_.D=)
5R7x%3@L
//日志 s2;~FK#/
public static void log(String sMsg) `JySuP2~/
{ 36"n7
System.err.println(sMsg); cb}"giXQTB
} (Xd8'-G$m
NAGM3{\5v$
|N.2iN:
public static void log(int sMsg) _f1o!4ocx
{ QL?_FwZL
System.err.println(sMsg); z 6:Wh
} 0HzqU31%l@
} AkhG~L
77P\:xc
9LDv?kYr
/* k9Pvh,_wp
**TestMethod.java hbw(o
*/ 5 ~Wg=u<6
package NetFox; Z>hTL_|]a{
;*A'2ymXUT
#-/W?kD
public class TestMethod { nBh+UT}
E9:@H;Gc
#[+# bw_6
public TestMethod() ]I?.1X5d0
{ ///xx/weblogic60b2_win.exe uO%0rKW
try{ 2|nm> 4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u,^CFws_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OM86C
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y t(D
fileFetch.start(); 9]4Q@%
} 0U '"@A \
catch(Exception e){e.printStackTrace ();} lSxb:$g
Br1R++]
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} pSs*Z6c)@
pgU[di
V;M_Y$`Lh
public static void main(String[] args) ]PXM;w
{ GEBSUvM7
new TestMethod(); UcRP/LR%C
} ['d9sEv.
} {v?Q9
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