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)); \HIBnkj)3n
} 1c{m rsB
for(int i=0;i<nEndPos.length-1;i++) }N}Js*
{ p+8o'dl8=
nEndPos = nStartPos[i+1]; IG{lr
} :%z#s
nEndPos[nEndPos.length-1] = nFileLength; zYP6m3n
} \FUMfo^
} 6J\ 2=c`
P-a8S*RRa
\WBO(,]V
//启动子线程 >|z:CX$]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tz8fZ*n
for(int i=0;i<nStartPos.length;i++) 8k3y"239t
{ z#Fel/L`O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q 'd]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]ag{sU@#
nStartPos,nEndPos,i); |{Ex)hkw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x|yJCs>
fileSplitterFetch.start(); EjFn\|VK
} }`2a>N: &
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z;V(YK(WO.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {_-T!yb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w\MWr+4
nEndPos = " + nFileLength); 4/%fpU2
// fileSplitterFetch[nPos.length-1].start(); t V( WhP
I eJI-lo
>|c?ZqW
//等待子线程结束 2*<Zc|uNW
//int count = 0; 8h0CG]
//是否结束while循环 ilde<!?
boolean breakWhile = false; ImG8v[Q E
hsQDRx%H}
;<q2
while(!bStop) !d<R=L
{ =%<, ^2o
write_nPos(); uJCp
Utility.sleep(500); "AZ|u#0P
breakWhile = true; bZ1*:k2
7)]boW~Q
\I:27:iAL
for(int i=0;i<nStartPos.length;i++) P JATRJ1.
{ nShXY6bA
if(!fileSplitterFetch.bDownOver) pbEWnx_
{ g<(!>:h
breakWhile = false; 0VcHz$ 6
break; "b~C/-W I
} umWs8-'Uw
} p:TE##
if(breakWhile) c+&Kq.~K
break; ?$K-f:?c
V]; i$
ZT@=d$Z&t
//count++; ?IYu"UO<)|
//if(count>4) zzhZ1;\
// siteStop(); E& .^|<n
} D h;5hu2"
R;!@ xy
\HbZ~I-
System.err.println("文件下载结束！"); U+qyS|i
} {ibu0
catch(Exception e){e.printStackTrace ();} vRH^en
} r}&&e BY f
FJDC^@Ne
J{^md0l
//获得文件长度 Mib.,J~
public long getFileSize() eM_;rMCr}
{ [:.wCG5
int nFileLength = -1; !p/SX>NJ
try{ i_Hm?Bi!F
URL url = new URL(siteInfoBean.getSSiteURL()); {PX&#,_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J/'Fj?
httpConnection.setRequestProperty("User-Agent","NetFox"); gkO^J{_@q
&n;*'M
Bkd$'7UT
int responseCode=httpConnection.getResponseCode(); )-_^vB
if(responseCode>=400) ~;3#MAG
{ IK\~0L;ozE
processErrorCode(responseCode); =X?fA,
return -2; //-2 represent access is error O_8 SlW0e
} ",3v%$>
6w7;
Nna.NU1
String sHeader; /^AH/,p
B;eka[xU
]CF-#q}'
for(int i=1;;i++) ppRmC,0f^
{ :c~SH/qS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TL2E|@k1]
//Utility.log(in.readLine()); @>Yd6C
sHeader=httpConnection.getHeaderFieldKey(i); y62f{ks_/
if(sHeader!=null) sJ|pR=g)!
{ <4LJ#Fx
if(sHeader.equals("Content-Length")) z )'9[t
{ h40;Q<D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 84QOW|1
break; a$|U4Eqo
} EW*sTI3
} v1 8<~
else #vBrRHuA#"
break; n#g_)\
} ;.uYWP|9
} #+1|O;PB#
catch(IOException e){e.printStackTrace ();} 3/`BK{
catch(Exception e){e.printStackTrace ();} (p{%]M
).;{'8Q
e&;e<6l&{
Utility.log(nFileLength); ]0."{^ksL
UsyNn39
Ob/)f)!!
return nFileLength; y017 B<Ou
} -*' ?D@l
4>=M"DhB
BQ0?B*yqd
//保存下载信息（文件指针位置） >8_y-74
private void write_nPos() 7A\`
{ ?YW~7zG
try{ 3W7^,ir
output = new DataOutputStream(new FileOutputStream(tmpFile)); QMBT8x/+_'
output.writeInt(nStartPos.length); bFX{|&tHU
for(int i=0;i<nStartPos.length;i++) KAClV%jP
{ M YF ^zheD
// output.writeLong(nPos); /eQAGFG
output.writeLong(fileSplitterFetch.nStartPos); p75o1RU
output.writeLong(fileSplitterFetch.nEndPos); S/XU4i:aV
} aDdGhB
output.close(); @}Hu)HO
} ;stuTj@vH
catch(IOException e){e.printStackTrace ();} k`m7j[A]l
catch(Exception e){e.printStackTrace ();} +r3)\L{U
} Bib<ySCre
mcV<)UA}
)$:1e)d
//读取保存的下载信息（文件指针位置） eLSzGbKf
private void read_nPos() -x+3nb|.
{ <2U@O` gC
try{ A4tk</A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tLy:F*1i
int nCount = input.readInt(); ^xa, r#N:V
nStartPos = new long[nCount]; R'v~:wNTNs
nEndPos = new long[nCount]; &IQ=M.!r
for(int i=0;i<nStartPos.length;i++) uI-T]N:W8x
{ P+j=]Yg
nStartPos = input.readLong(); 9~Dg<wQ
nEndPos = input.readLong(); z?\it(
} KQPu9f9
input.close(); lAU99(GXV
} .rtA sbp.!
catch(IOException e){e.printStackTrace ();} L~6%Fi&n4
catch(Exception e){e.printStackTrace ();} BTkx}KK
} (zo7h
G]=z ![$
_Q5mPBO
private void processErrorCode(int nErrorCode) ~</FF'Xz
{ !1)aie+p6
System.err.println("Error Code : " + nErrorCode); ",b:rgpRp
} 5*%Gh&)
m8fj\,X
bp?5GU&Uy
//停止文件下载 ln82pQD2Y~
public void siteStop() gyvrQ, u
{ ,0! 2x"Q=
bStop = true; a!$kKOK
for(int i=0;i<nStartPos.length;i++) >B{NxL3->
fileSplitterFetch.splitterStop(); cj[b^Wv:
Ks%0!X?3q
`*8}q!.
} [7@g*!+d
} G}pFy0W\S
//负责部分文件的抓取 TwkT|Piw S
**FileSplitterFetch.java &!8 WRJ
*/ Rml'{S
package NetFox; (A~7>\r +
kG>jb!e@(
;MS.ag#
import java.io.*; a#j,0FKv
import java.net.*; IIR+qJ__|
[e+Y7M7
#|b*l/t8
public class FileSplitterFetch extends Thread { wm`<+K
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e"04jd/
String sURL; //File URL <VxA&bb7c
long nStartPos; //File Snippet Start Position P-\f-FS
long nEndPos; //File Snippet End Position -+WAaJ(b
int nThreadID; //Thread's ID a4,V(Hlm
boolean bDownOver = false; //Downing is over i|^Q{3?o#
boolean bStop = false; //Stop identical !UT'4Fs
FileAccessI fileAccessI = null; //File Access interface Q>{$Aqc,e
c|?(>
~tp]a]yV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t$!zgUJ
{ nONuw;K
this.sURL = sURL; rt+4-WuK>
this.nStartPos = nStart; ,sL'T[tuiU
this.nEndPos = nEnd; Z Ts*Y,
nThreadID = id; 8Rj5~+5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^@^8iZ
} [bh?p+V
40kAGs>_
?6:qAFw
public void run() sq'm)g
{ u} mj)Nk
while(nStartPos < nEndPos && !bStop) k+h}HCzE
{ ZE=sw}=
+KTfGwKt
(]#^q8)]\9
try{ /I7V\
URL url = new URL(sURL); Ugri _
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /z-rBfdy^
httpConnection.setRequestProperty("User-Agent","NetFox"); S8#0Vo$)a
String sProperty = "bytes="+nStartPos+"-"; 9\_s&p=:.
httpConnection.setRequestProperty("RANGE",sProperty); W[&nQW$E
Utility.log(sProperty); <&E}db
=2p?_.|'
(kxS0 ]=
InputStream input = httpConnection.getInputStream(); oYu xkG
//logResponseHead(httpConnection); O=o}uB-*6
(K[{X0T
T)zk2\u
byte[] b = new byte[1024]; l?m"o-Gp3
int nRead; =!\Nh,\eQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xTAfVN
{ %%NoXW
nStartPos += fileAccessI.write(b,0,nRead); eQ>Ur2H8n
//if(nThreadID == 1) p'h'Cz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _5p$#U`
} R (f:UC
}QI \K
e/D{^*~S
Utility.log("Thread " + nThreadID + " is over!"); <,~OcJG(
bDownOver = true; x/s:/YN'
//nPos = fileAccessI.write (b,0,nRead); | 1B0
} #*.!J zOg
catch(Exception e){e.printStackTrace ();} ^OY$ W
} &hWELZe0vv
} b-&rMML
iE'_x$i
I*-\u
//打印回应的头信息 8&@=Anc&q
public void logResponseHead(HttpURLConnection con) m^ xTV-#l@
{ e)e(f"t6Q
for(int i=1;;i++) qR@ESJ_
{ Lvf<g}?4
String header=con.getHeaderFieldKey(i); Z[@ i/. I
if(header!=null) "uBnK!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \tgY2:
Utility.log(header+" : "+con.getHeaderField(header)); e4YfJd
else @D9O<x
break; zB%~=@Q^6
} 0!\gK<,z
} \lK?f]qJq
L~&S<5?
fJLl-H
public void splitterStop() g}+|0FTV
{ %j&vV>2
bStop = true; +-!3ruwSn
} d*6f,z2=
:BxO6@>Xc
H1-DK+Q:
} 2U./ Yfk\
=zn'0g,J4
dy6zrgxygP
/* 2? E;(]dQ
**FileAccess.java 1|sem(t
*//文件访问(定位，写) n{QyqI
package NetFox; 08ZvRy(Je<
import java.io.*; V[.{cY?6
C@qWour
':4ny]F
public class FileAccessI implements Serializable{ (U'n1s/X
12^uu)6Xm,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <Y)14w%
RandomAccessFile oSavedFile; oywPPVxj
long nPos; v/ry" W
7@{%S~TN
^JY {<
public FileAccessI() throws IOException DGJ:#UE
{ U.TZd"
this("",0); f,ro1Nke
} VESvCei
xC< )]
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public FileAccessI(String sName,long nPos) throws IOException @ 51!3jeu
{ Oem1=QpaC
oSavedFile = new RandomAccessFile(sName,"rw"); ~|KqG
this.nPos = nPos; R6<'J?k
oSavedFile.seek(nPos); 8$-MUF,
} 6Jgl"Jw8
j"jssbu}
0Px Hf*
public synchronized int write(byte[] b,int nStart,int nLen) JlSqTfA
{ yD<#Q\,
int n = -1; t3$cX_
try{ $@VJ@JAe
oSavedFile.write(b,nStart,nLen); OXLB{|hH80
n = nLen; ~;(\a@ _
} cEHpa%_5
catch(IOException e) IEm?'o:
{ u/W{JPlL
e.printStackTrace (); ~T}D#}
} E zcch1
"*zDb|v
}zA|M9%E
return n; ?Z|y-4 &>
} _CNXyFw.7
%>K(IRpMW
Rc)]A&J
} UW":&`i
H'S~GP4D
m&AbH&;
/* Cnpl0rV~5
**SiteInfoBean.java K14.!m
*/ zDYJe_m ~
package NetFox; =F[M>o
*effDNE!
v_5O*F7)
public class SiteInfoBean { )-+tN>Bb
7'+`vt#E
kYS#P(1
private String sSiteURL; //Site's URL /;_$:`|/
private String sFilePath; //Saved File's Path gB#!g@
private String sFileName; //Saved File's Name ${Lrj}93
private int nSplitter; //Count of Splited Downloading File ~/4j&IG
>%"TrAt
pYCMJK-H
public SiteInfoBean() {X,-T&
{//nSplitter的缺省值为5 Rq15AR
//default value of nSplitter is 5 z .lb(xQ
this("","","",5); >$}Mr%49
} #p"F$@N
'5$: #|-
Il/`#b@h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fCa lR7!
{ wOUCe#P|r
sSiteURL= sURL; '!X`X=
sFilePath = sPath; pz2E+o
sFileName = sName; '\H & EJ'
this.nSplitter = nSpiltter; >a@1y8B
uYTyR;a
=2Ju)!%wr
} -X EK[
>CCy2W^W
s,J\nbj0h
public String getSSiteURL() f[zKA{R
{ ,9|7{j|u
return sSiteURL; v'L"sgW6I
} d;%~\+)x4
(|W6p%(
lS;S:- -F
public void setSSiteURL(String value) !OV+2suu1
{ fpNq
sSiteURL = value; 2wU,k(F_
} }`whg8 fZ
'o]}vyz;
l7ES*==&@0
public String getSFilePath() cmf*BkS
{ O,@QGUoA
return sFilePath; F[ ^ p~u{
} *[nS*D\:
<c`,fd8
L-W*h
public void setSFilePath(String value) _58&^:/^
{ Z1H
sFilePath = value; C1HNcfa7
} >taT V_,
$v{sb,
wj$3L3
public String getSFileName() g[2[ zIB=
{ C/"Wh=h6
return sFileName; ORo +]9)Yv
} tchpO3u,
MoC/xF&
NnZ_x>R
public void setSFileName(String value) a;7gy419<p
{ blV'-Al
sFileName = value; d#,
} TGPdi5Eq
iaJN~m\ M
;f3))x
public int getNSplitter() #"-w;T%b
{ 1eqFMf
return nSplitter; '\7&Iz:%
} +Y~,1ai 5^
9LEUj
$<wU>X
public void setNSplitter(int nCount) K0^+2lx
{ %]DJ-7 xE
nSplitter = nCount; UJX5}36
} tIX|oWC$q
} =WOYZ7
,J-YfL^x6*
cRPy5['E
/* JENq?$S
**Utility.java `Oi6o[a
*/ n@e|PWu
package NetFox; $/i;UUd
doe u`
( (mNB]sy
public class Utility { ;#D:S6 L
M\9p-%"L
{u7_<G7
public Utility() [\i1I`7pE
{ 9%Ftln6
rFv=j:8
@h\u}Ee
} zI>,A|yy
CI?M2\<g
//线程睡眠 9%uJ:c?
public static void sleep(int nSecond) u-Ip*1/wp
{ 5E|/n(
try{ +Y^/0=6h
Thread.sleep(nSecond); eYjr/`>O
} UD r@
catch(Exception e) Jqi^Z*PuX
{ ?<$DQ%bf
e.printStackTrace (); 0jwex
} i%_nH"h
} n47v5.Wn
b{d@:"
//日志 t?kbN\,
public static void log(String sMsg) n|iO)L\9aB
{ ^RS`q+g
System.err.println(sMsg); |N>TPK&Xt
} ?G!DYUK
q:v&wb%
of:xj$dQ_
public static void log(int sMsg) xBcE>^{1.
{ X6@G)68
System.err.println(sMsg); Ik|nL#JH]
} D7x"P-ie
} HTCn=MZm ?
>'lte&
-5yEd>Z
/* "Tm`V9
**TestMethod.java /v:+ vh*mS
*/ X8b= z9
package NetFox; -d 6B;I<'
gg%OOvaj5
O}#h^AU-BS
public class TestMethod { ] Vbv64M3
F.JvMy3
S2fBZ=V8
public TestMethod() 5eWGX
{ ///xx/weblogic60b2_win.exe A|d(5{:N
try{ ;HeUD5Nt6F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +Te;LJP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sk_Q\0a
SiteFileFetch fileFetch = new SiteFileFetch(bean); EWg\\90
fileFetch.start(); wGf SVA-q\
} _6 |lw&o07
catch(Exception e){e.printStackTrace ();} }A%Sx!7~
*G#W],~0
3Ga!)
} anTS8b
C2</.jeLa
Wf=D'6w
public static void main(String[] args) .qCD(XZ+
{ Ytnk^/Z1L
new TestMethod(); AA um1xl
} Rx 4 ;X
} *1KrI9i
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