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)); !Q(xA,p
} j8gw]V/B:
for(int i=0;i<nEndPos.length-1;i++) JAEn 72
{ Y.FqWJP=p
nEndPos = nStartPos[i+1]; oTS/z\C"<u
} phkfPvL{
nEndPos[nEndPos.length-1] = nFileLength; R)}ab{A
} ~\HGV+S!g}
} $646"1S
+Wgp~$o4
21k^MZ
//启动子线程 :g@H=W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,gYbi-E
for(int i=0;i<nStartPos.length;i++) NHI(}Ea|]
{ jNjm}8`t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y$-;6zk\]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0_\@!#-sml
nStartPos,nEndPos,i); x$p_mWC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M`m-@z
fileSplitterFetch.start(); DNYJR]>
} hzv4+1Wd[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "}/$xOl"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :<Z>?x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9UbD=}W
nEndPos = " + nFileLength); J9buf}C[
// fileSplitterFetch[nPos.length-1].start(); M^C|svm
4o|-v
.lbo\v}2W
//等待子线程结束 y+jOk6)W75
//int count = 0; T-.Q
//是否结束while循环 CSu}_$wC#
boolean breakWhile = false; Obj?,O
=H8 LBM
}fqz8'E9
while(!bStop) CGYZEPRR
{ hzR1O(
write_nPos(); 2^3N[pM;
Utility.sleep(500); (j>a?dKDS
breakWhile = true; XXwe/>J
mT:Z!sS
TAd~#jB9
for(int i=0;i<nStartPos.length;i++) %t.L;G
{ c}$C=s5 h}
if(!fileSplitterFetch.bDownOver) l:'\3-2a
{ a%FM)/oI|T
breakWhile = false; Wjf,AjL\
break; J/T$.*X
} |:[ [w&R
} JSf \ApX
if(breakWhile) B:?MMXB
break; u[Ij4h.
)c; YR}tC
}hoyjzv]L
//count++; PjxZ3O
//if(count>4) s28t'
// siteStop(); "bhF`,V
} B_ x?s
y'{*B(
8x,{rSqq
System.err.println("文件下载结束！"); _/\U
} agI"Kh]j?
catch(Exception e){e.printStackTrace ();} j o+-
} 655OL)|cD6
=#z8CFq[O
#?^%#"~4H
//获得文件长度 -G|?Kl
public long getFileSize() ZYMacTeJjg
{ q$ZmR]p
int nFileLength = -1; &N+i3l6`
try{ V]{^}AKc
URL url = new URL(siteInfoBean.getSSiteURL()); Zb? u'Vm=u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tjId?}\
httpConnection.setRequestProperty("User-Agent","NetFox"); jeu|9{iTVu
O~udlVn<6
LtK= nK
int responseCode=httpConnection.getResponseCode(); s%Y8;D,~+
if(responseCode>=400) 6\BZyry3*
{ l(~i>iQ 4
processErrorCode(responseCode); VnU/_#n
return -2; //-2 represent access is error Cu\6VnW_6
} ;1[a*z<l&s
$yoIz.?V
&%=]lP]
String sHeader; +m>)q4e
.,l4pA9v
J]-z7<j']
for(int i=1;;i++) B3';Tcs
{ U)sw IisE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %@,! (
//Utility.log(in.readLine()); 8aMmz!S
sHeader=httpConnection.getHeaderFieldKey(i); cxig<W
if(sHeader!=null) >;NiG)Z
{ @ =XJ<
if(sHeader.equals("Content-Length")) E&_q"jJRi
{ s`$YY_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mzGMYi*
break; <_8p6{=
} HB0DG<c-
} 7]}2`^9
else o"19{D^.
break; Q&?^eOI&#(
} N~)RR {$w
} UzKB"Q
catch(IOException e){e.printStackTrace ();} N'@E^ rYc
catch(Exception e){e.printStackTrace ();} ;x|LB>.
&e%eIz
x^XP<R{D
Utility.log(nFileLength); $E@U-=m
h(4&!x
zu!#
return nFileLength; l2h1CtAU
} \&,{N_G#L.
12TX_0
G^W'mV$xl
//保存下载信息（文件指针位置） t4H*&U
private void write_nPos() x1'4njTV$
{ K2@],E?e%|
try{ C(J+tbk
output = new DataOutputStream(new FileOutputStream(tmpFile)); n5z";:p
output.writeInt(nStartPos.length); b.#0{*/G
for(int i=0;i<nStartPos.length;i++) "">{8
{ d&owS+B{48
// output.writeLong(nPos); /V"6Q'D
output.writeLong(fileSplitterFetch.nStartPos); 0qSf7"3f
output.writeLong(fileSplitterFetch.nEndPos); &^hLFd7j/
} <KEVA?0>
output.close(); 1Pp2wpD4iC
} " Z2D@l
catch(IOException e){e.printStackTrace ();} fpA%:V
catch(Exception e){e.printStackTrace ();} .*~t2 :
} m.b}A'GT
\<kQ::o1y
u$Ty|NBjn
//读取保存的下载信息（文件指针位置） oHR@*2b
private void read_nPos() #DkdFy %`
{ s*9lYk0
try{ T/nG\WZbZn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^o-)y"GJ
int nCount = input.readInt(); ~LU$ no^
nStartPos = new long[nCount]; !S}d?8I6
nEndPos = new long[nCount]; MY>*F[~ 2
for(int i=0;i<nStartPos.length;i++) ~gA^tc3G
{ -& T.rsp
nStartPos = input.readLong(); bqcwZ6r<
nEndPos = input.readLong(); Fu\!'\6
} E(miQ
input.close(); #8CeTR23cw
} r=Od%
catch(IOException e){e.printStackTrace ();} '&<saqA
catch(Exception e){e.printStackTrace ();} _(J4
} &,%+rvo}
+8Q5[lh2]j
(4Ha'uqz
private void processErrorCode(int nErrorCode) .:9XpKbt
{ fI"OzIJV
System.err.println("Error Code : " + nErrorCode); VxqoE]Dh
} +&*Ybbhb
D^<5gRK?
I/k/5
//停止文件下载 |h%0)_
public void siteStop() D&|HS!
{ v:zKn[;o
bStop = true; `+]e}*7$f
for(int i=0;i<nStartPos.length;i++) XgPZcOzYB
fileSplitterFetch.splitterStop(); PE&$2(
d8N4@3CkL
,wB)hp
} L 4Sa,ZL
} [+(fN
//负责部分文件的抓取 c1}i|7/XSi
**FileSplitterFetch.java ewOe A|
*/ \o<&s{6L
package NetFox; #%{x*y:Ms
01">$
R&@NFin
import java.io.*; 8!|LJI
import java.net.*; LLU]KZhtY|
,#8H9<O9t
['DYP-1J
public class FileSplitterFetch extends Thread { x#jJ 0T
yGE)EBH
:S=!]la0h
String sURL; //File URL &2//\Qz
long nStartPos; //File Snippet Start Position }@<Ru
long nEndPos; //File Snippet End Position L',7@W
int nThreadID; //Thread's ID 5-.{RU=
boolean bDownOver = false; //Downing is over VmP5`):?b
boolean bStop = false; //Stop identical gI{56Z
FileAccessI fileAccessI = null; //File Access interface Ur,{ZGm
"VI2--%v3
p.RSH$]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aSH =|Jnc
{ @tVl8]y
this.sURL = sURL; miEf<<L#z
this.nStartPos = nStart; (&oT6Ji
this.nEndPos = nEnd; *zl-R*bM$
nThreadID = id; >fx/TSql:J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9HG"}CGZP
} nV>=n,+s"
?(E?oJ)(
s&D>'J
public void run() o!sHK9hvJ)
{ H5/w!y@
while(nStartPos < nEndPos && !bStop) N7#,x9+E
{ .Dt.7G
}ZkGH}K_}
)@E'yHYO>
try{ vg-'MG
URL url = new URL(sURL); <~P([5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KDu~,P]
httpConnection.setRequestProperty("User-Agent","NetFox"); TF-a1z
String sProperty = "bytes="+nStartPos+"-"; ^#&PTq>
httpConnection.setRequestProperty("RANGE",sProperty); #waK^B)<a
Utility.log(sProperty); T~)zgu%q_
Azag*M?
[WBU_
InputStream input = httpConnection.getInputStream(); -|( q9B
//logResponseHead(httpConnection); x4[ Fn3JL
]tc Cr;
~vstuRRST
byte[] b = new byte[1024]; O+PRP"$g"
int nRead; ?RU_SCp-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,Laz515
{ 2hFOwI
nStartPos += fileAccessI.write(b,0,nRead); 4S*7*ak{
//if(nThreadID == 1) <c]?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LhQidvCNJ
} 8rM1kOCf
@h)X3X
b*dEX%H8sf
Utility.log("Thread " + nThreadID + " is over!"); Lo uYY:Q
bDownOver = true; Qvm[2mb
//nPos = fileAccessI.write (b,0,nRead); &C.m*^`^
} ?oulQR6:
catch(Exception e){e.printStackTrace ();} 0&2eiMKG?n
} Q)ZbnR2Z8
} w02t9vz
_0!<iN L
vlx\hJ<I
//打印回应的头信息 d1hXzJs
public void logResponseHead(HttpURLConnection con) #b+>O+vx8
{ &d i=alvv1
for(int i=1;;i++) "-A@d&5.
{ `!7QegJa"
String header=con.getHeaderFieldKey(i); oxJ#NGD
if(header!=null) U_1N*XK6$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 02mu%|"
Utility.log(header+" : "+con.getHeaderField(header)); B+2Jea,N
else .MI 5?]_
break; am#(ms
} [*v-i%U}
} nCPIpw,]M
q a}=p
~)%DiGW&
public void splitterStop() t0+D~F(g
{ k{ibD5B
bStop = true; q-4#)EnW
} T8\%+3e.
15wwu} X
xqLIs:*
} '^~38=FA
mBWhC<kKs
<7yn:
/* I oFtfb[
**FileAccess.java vC_O!2E
*//文件访问(定位，写) i=j4Wg,{J
package NetFox; .p /VRlLU
import java.io.*; +e( (!
(*dJ
HQtUNtZ
public class FileAccessI implements Serializable{ o!}/& '(
{pM3f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o>oZh1/\T,
RandomAccessFile oSavedFile; .aE%z/@s=
long nPos; 2~q(?wY
R4Si{J*O
i*ji
public FileAccessI() throws IOException ?Qdp#K]WX
{ ]WZi+
this("",0); dX;G[\
} q<!KtI4
Z=CY6Zu7
C;.+ kE
public FileAccessI(String sName,long nPos) throws IOException S[L2vM)
{ OCYC Dn
oSavedFile = new RandomAccessFile(sName,"rw"); ybgAyJ{J<
this.nPos = nPos; AAld2"r
oSavedFile.seek(nPos); IX y $
} +)QA!g$
=[G)
5"8R|NU:\0
public synchronized int write(byte[] b,int nStart,int nLen) p:gM?2p1
{ @AAkEWo)_
int n = -1; 1PdxoRa4=
try{ o;M-M(EZQ6
oSavedFile.write(b,nStart,nLen); f+Da W
n = nLen; 8et.A
} TLiA>`r=
catch(IOException e) vV+>JM6<K
{ 'ktWKW$ D
e.printStackTrace (); O4w:BWVsn
} ; #^Jy#)
}^ G&n';J
_HkB+D0v
return n; B^sHFc""V
} Zfn390_
'P5|[du+
NK0hT,_
} >!|(n@
Hxzdxwz%$
hg=BXe4:
/* 1O]27"9
**SiteInfoBean.java uSi/|
*/ @C fxPA
package NetFox; l\Or.I7n
t?R=a-ZI
"7tEk<x
public class SiteInfoBean { 7Vxe]s
{|Pz9a-:
fG\]&LFBU
private String sSiteURL; //Site's URL hV4\#K[
private String sFilePath; //Saved File's Path Mb0cdK?hA
private String sFileName; //Saved File's Name 9Ucn 6[W
private int nSplitter; //Count of Splited Downloading File MOEB{~v`;
HJ,sZ4*]]
$S0eERga
public SiteInfoBean() pr(16P
{//nSplitter的缺省值为5 CF k^(V"
//default value of nSplitter is 5 \XXS;
this("","","",5); Z2dy|e(c
} RU^lR8;
[F<Tl =
|.zotEh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]Ak@!&hyak
{ -j 6U{l
sSiteURL= sURL; )!``P?3?
sFilePath = sPath; &]2z)&a
sFileName = sName; 4SqZV
this.nSplitter = nSpiltter; e!(0y)*
fC4D#
@|^2 +K/
} \Ow-o0
\4.U.pKY
ToHCS/J59
public String getSSiteURL() wGC)gW
{ "wPFQXU
return sSiteURL; "jUr[X2J
} K$..#]\TM
B R-(@
uUczD 8y
public void setSSiteURL(String value) &)p/cOiV
{ Y+#e| x
sSiteURL = value; M7(vI4V
} 0Up@+R2
G/Xa`4"_
\ l+RX*
public String getSFilePath() %#Vn?zr|~
{ i7[CqObzc
return sFilePath; Q\~4J1
} [k9aY$baT^
$z+iB;x
[z:bnS~yiD
public void setSFilePath(String value) 1;l&ck-Gg/
{ ZL`G<Mo;.
sFilePath = value; 2b]'KiX
} 6SMGXy*]^
Yp`6305f
Qj? G KO
public String getSFileName() IA|V^Wmt;
{ pX]*&[X?
return sFileName; {37DrSOa
} S< <xlW
.Jz$)R
"9-duDg
public void setSFileName(String value) Y'n TyH
{ HB4Hz0Fa
sFileName = value; [ed%"f
} HB$*xS1
! G%LYHx
8Us5Oi
public int getNSplitter() k})Ag7c
{ 9BGPq)#
return nSplitter; Jr18faEZw
} ~$f+]7
2FO.!m
C9/?B:
public void setNSplitter(int nCount) j$#pG
{ }}?L'Vby
nSplitter = nCount; 1{%EQhNd
} QJo)
} )}?'1ciHI
2F3IC
Y$EqBN
/* J?-"]s`J
**Utility.java Um\Nd#=:
*/ !>/U6h,_
package NetFox; 0z."6r
O@3EJkv
xkOyj`IS
public class Utility { KMznl=LF
:XF;v
@4h .?
public Utility() _"J-P={=
{ 'M+iVF6
> K,Q`sS
DJrE[wI
} SMgf(N3]
i}RxTmG<
//线程睡眠 D<}KTyG]
public static void sleep(int nSecond) ~LHG
{ ^MUtmzh
try{ ^o|igyS9
Thread.sleep(nSecond); DI**fywu[3
} R{@WlkG}
catch(Exception e) FgQd7p
{ ;04doub
e.printStackTrace (); eUVE8pZl
} eqs.zL
} fT/;TK>z>
'(kGc%
//日志 .5|wy<
public static void log(String sMsg) Gs.id^Sf
{ bKmR &
System.err.println(sMsg); 4'?kyTO~
} !iCY!:
!u~( \Rb;
Tw`^
public static void log(int sMsg) a~7`;Ar
{ (5;w^E9*n;
System.err.println(sMsg); 1Xt%O86
} [$]vi`c2
} d;9 X1`"
CG@ LYN
zOCru2/
/* d"Hh9O}6
**TestMethod.java jw5Bbyk
*/ zy8W8h(?
package NetFox; :|M0n%-X
F.?^ko9d
@ bPQhn#(g
public class TestMethod { 7<mY{!2iF?
7*M+bZ`x
60*2k
public TestMethod() |(*ReQ?=
{ ///xx/weblogic60b2_win.exe ]P<u^ `{*
try{ ^hq`dr|R=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZTVX5"#Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Im+<oZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); TPt<(-}W
fileFetch.start(); fl!8\4
} g[0b>r7
catch(Exception e){e.printStackTrace ();} D1;H,
0[7\p\Q
w [D9Q=
} ^9%G7J:vGO
B4r4PSB>!
.v9#|d d+
public static void main(String[] args) >93vMk~hU
{ vXAO#'4tm%
new TestMethod(); 6UG7lH!M
} 7MZBU~,r
} [DC8X P5<
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