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)); (De>k8
} JL7;l0#
for(int i=0;i<nEndPos.length-1;i++) wEU=R>j.
{ T#&X7!4
nEndPos = nStartPos[i+1]; X7*fmD=Uy
} NjO_Y t
nEndPos[nEndPos.length-1] = nFileLength; 2r@9|}La
} /1xBZfrN
} ZT<VDcP{
\ #la8,+9
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//启动子线程 CsjrQ-#9yn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zNg[%{mz
for(int i=0;i<nStartPos.length;i++) Q5Epq sKyC
{ Ieh<|O,-C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |z0% q2(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KC8
nStartPos,nEndPos,i); Dnd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RW<4",
fileSplitterFetch.start(); Zlrbd
} V \/Qik{h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7ab'q&Y[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AN)r(86L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "1UpoF'w
nEndPos = " + nFileLength); [i_evsUj?
// fileSplitterFetch[nPos.length-1].start(); 27}0
.S]*A b
E,Xl8rC
//等待子线程结束 VeOM `jy
//int count = 0; t~":'le`zr
//是否结束while循环 0#~k)>(7lR
boolean breakWhile = false; _\{/#J;lN
C* 0ZF
wZ=@0al
while(!bStop) .fS{j$
{ 7JBr{3;eS
write_nPos(); Ve<f}
Utility.sleep(500); u~~ ~@p
breakWhile = true; .9UrWBW\I
Oc5f8uv
01NP
for(int i=0;i<nStartPos.length;i++) UUF]45t>
{ t[MM=6|Wb
if(!fileSplitterFetch.bDownOver) [&(~1C|C
{ KDj/S-S
breakWhile = false; #c~-8=
break; "Jdi>{o8
} nQ{~D5y,,
} q#\B}'I{
if(breakWhile) b1%w+*d<z
break; i(V
'}-QZ$|*
ubc k{\.
//count++; qggRS)a
//if(count>4) FtlJ3fB@
// siteStop(); z0F55<i
} {aUv>T"c
9#kk5)J
$x#qv1
System.err.println("文件下载结束！"); :z6?
} *:`fgaIDa
catch(Exception e){e.printStackTrace ();} .')^4\
} GB,ub*|
{\|XuCF#
a>+m_]*JZ
//获得文件长度 9E|QPT
public long getFileSize() ~RZN+N
{ %/ :&L+q
int nFileLength = -1; v?n# C
try{ 2X(2O':Uc
URL url = new URL(siteInfoBean.getSSiteURL()); @X=sfygk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZZc^~
httpConnection.setRequestProperty("User-Agent","NetFox"); f lt'~fe
}iLi5Qkx
=\\rk,F
int responseCode=httpConnection.getResponseCode(); *z_`$Y
if(responseCode>=400) Yq:/dpA_
{ b{X.lz0
processErrorCode(responseCode); uzLm TmM+
return -2; //-2 represent access is error jaMpi^C
} v "[<pFj^
A5[kYD,_
Lmw)Ts>
String sHeader; 6F%6]n
% 3fpIzm
^9YS dFH/
for(int i=1;;i++) !~j9Oc^
{ 0rif,{"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j J54<.D
//Utility.log(in.readLine()); r]kks_!Z
sHeader=httpConnection.getHeaderFieldKey(i); brLu~]I
if(sHeader!=null) FRQkD%k
{ 0/cgOP!^
if(sHeader.equals("Content-Length")) )ub!tm
{ E^~ {thf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &]anRT#
break; (X (:h\^
} ]eTp?q%0
} d[E= HN
else ZY;g)`E1
break; KCqz]
} Z$35`:x&h
} ur]WNk8bN
catch(IOException e){e.printStackTrace ();} ':utU1dL
catch(Exception e){e.printStackTrace ();} O_5;?$[m
'SIc2H
vv
Utility.log(nFileLength); 2"o<>d
=sS=
D^{jXNDNO
return nFileLength; Gr3 q
} n9 Jev_!A
&((04<@e
4dh>B>Q
//保存下载信息（文件指针位置） 9g$fFO
private void write_nPos() `"$9L[>
{ D9n+eZ
try{ J,=^'K(
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^q<EnsY
output.writeInt(nStartPos.length); \;"S>dg
for(int i=0;i<nStartPos.length;i++) 0bGQO&s [
{ foI:`]2"*
// output.writeLong(nPos); cr^R9dv
output.writeLong(fileSplitterFetch.nStartPos); V{rQ@7SE
output.writeLong(fileSplitterFetch.nEndPos); *Ym+xu_5
} 7 S%`]M4;
output.close(); O:dUzZR['
} ^;Yjs.bI`F
catch(IOException e){e.printStackTrace ();} **ls 4CE<
catch(Exception e){e.printStackTrace ();} ;uuBX0B
} Q%t _Epe
==bT0-M.~
E7]a#
//读取保存的下载信息（文件指针位置） G2J4N2hu
private void read_nPos() fl*49-d
{ L_IvR 4:j~
try{ >lugHF$G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X`I=Z ysB
int nCount = input.readInt(); &2W`dEv]?
nStartPos = new long[nCount]; }BCxAwD4
nEndPos = new long[nCount]; n$"BF\eM
for(int i=0;i<nStartPos.length;i++) !,*Uvs@b
{ 2}ywNVS
nStartPos = input.readLong(); L_>LxF43
nEndPos = input.readLong(); McvLU+
} iyMoLZ5
input.close(); ;i3C
} <Oj'0NK-
catch(IOException e){e.printStackTrace ();} ?j} Fxr
catch(Exception e){e.printStackTrace ();} oMN Qv%U
} e#?rK=C?9
4{" v
"+BuFhSLf
private void processErrorCode(int nErrorCode) hrbeTtqi
{ Z0Qh7xWve
System.err.println("Error Code : " + nErrorCode); "K*^%{
} c*)PS`]t
:NWrbfz
#YLI"/Kn
//停止文件下载 QFEc?sEe
public void siteStop() T{ /\q 5
{ PMiG:bM
bStop = true; (DTkK5/%
for(int i=0;i<nStartPos.length;i++) ;B"S*wYMN
fileSplitterFetch.splitterStop(); 4rNuAK`2
BCr*GtR)W
p2m`pT
} &>hln<a>
} )"^ )Nk
//负责部分文件的抓取 b"~Ct}6f
**FileSplitterFetch.java NW?h~2
*/ 6;}FZ
package NetFox; g0RfvR
>zv}59M
Bj\oo+L/
import java.io.*; /909ED+)>9
import java.net.*; ~ponYc.Y
a]R1Fi0n
0S>U_#-
public class FileSplitterFetch extends Thread { T@DT|lTI
\H.1I=<
xA"7a
String sURL; //File URL ZN(@M@}
long nStartPos; //File Snippet Start Position `z`"0;,7S
long nEndPos; //File Snippet End Position gz"I=9
int nThreadID; //Thread's ID n6 AP6PK7
boolean bDownOver = false; //Downing is over }9(:W</}
boolean bStop = false; //Stop identical U~{sJwB
FileAccessI fileAccessI = null; //File Access interface nsV;6^>
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0p ZX_L'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HVcd< :g0
{ /'>#1J|TlK
this.sURL = sURL; dK?vg@|'
this.nStartPos = nStart; $~2qEe.h
this.nEndPos = nEnd; o_ SR
nThreadID = id; x-ShY&k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C<\O;-nHH
} (8OaXif
\^rAH@
GOhGSV#
public void run() rz3!0P!"K
{ 06S-3bis
while(nStartPos < nEndPos && !bStop) &5F@u IA
{ 2x&mJ}o#k
m>@ *-*8k
m\xE8D(,
try{ ~T<o?98
URL url = new URL(sURL); Td>Lp=0rU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q!+m, !M
httpConnection.setRequestProperty("User-Agent","NetFox"); 5//.q;z
String sProperty = "bytes="+nStartPos+"-"; wWR9dsB.;
httpConnection.setRequestProperty("RANGE",sProperty); OTe0[p6v
Utility.log(sProperty); Iz<}>J B
bC@9 */i
tMWsgK.B
InputStream input = httpConnection.getInputStream(); S+EC!;@Xg
//logResponseHead(httpConnection); Dk XB
NbtNu$%t
+TnRuehtk
byte[] b = new byte[1024]; 4^mpQ.]lO
int nRead; 2nGQD{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2|n~5\K|t
{ $pm5G} .
nStartPos += fileAccessI.write(b,0,nRead); k6vY/)-S
//if(nThreadID == 1) 8s_'tw/{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3tlA!e
} b{o%`B*
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Gmi$Nl!~
Utility.log("Thread " + nThreadID + " is over!"); j7|r^
bDownOver = true; :3# t;
//nPos = fileAccessI.write (b,0,nRead); _ ecKX</Q
} ^Fr82rJs
catch(Exception e){e.printStackTrace ();} )J"Lne*"
} p Rn vd|
} v]tbs)x;h
C=6Vd
@,RrAL}|
//打印回应的头信息 `4'['x
public void logResponseHead(HttpURLConnection con) TrHz(no
{ 4epE!`z_&
for(int i=1;;i++) ?>V4pgGCE
{ gZ*8F|sg
String header=con.getHeaderFieldKey(i); lth t'|
if(header!=null) }-:s9Lt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n 4:Yc@,
Utility.log(header+" : "+con.getHeaderField(header)); (0Xgv3wd
else _[8BAm
break; xA-O?s"CY
} ~7tG%{t%
} at@B>Rb
9WaKsdf
(#WE9~Sru
public void splitterStop() tc%?{W\
{ _N5$>2
bStop = true; cCd2f>EHw
} ^h z4IZ^
ceDe!Iu
`gIlS^Q
} H[ DrG6GA
oGi;S="I
H1H+TTZr
/* &}P{w
**FileAccess.java E4^zW_|xE
*//文件访问(定位，写) R&13P&:g
package NetFox; fdIk{o
import java.io.*; 1>$fLbmkI
0s"g%gq|
^1rw\Zp
public class FileAccessI implements Serializable{ }VlX!/42
IG?044Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Fh u(u
RandomAccessFile oSavedFile; .`z](s
long nPos; x?0ZzB),
uUXvBA?l
+@wa?"
public FileAccessI() throws IOException I4kN4*d!N,
{ `}/&}Sp
this("",0); 9*gD;)!
} {umdW x.*
JHpaDy*
<S'5`-&
public FileAccessI(String sName,long nPos) throws IOException >r] bfN,
{ Z `FqC
oSavedFile = new RandomAccessFile(sName,"rw"); `<>Emc8Z
this.nPos = nPos; './j<2|;U
oSavedFile.seek(nPos); Gma)8X#
} VU7x w
|A".Mo_5
?ic7M
public synchronized int write(byte[] b,int nStart,int nLen) &K@2kq,
{ &DC o;Ij;
int n = -1; XJl2_#
try{ @[M5$,"
oSavedFile.write(b,nStart,nLen); Ay'2!K,I
n = nLen; V:*QK,
} "f|\":\
catch(IOException e) ^a~^$PUqI
{ tmF->~|
e.printStackTrace (); D&q-L[tA@
} _ F&BSu
J_A+)_
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return n; ,"!t[4p=f
} hO3>Gl5<
`N%q^f~
f8um.Xnp6
} }ie\-V
swv1>52{
)8Defuxk
/* "*O(3L.c-
**SiteInfoBean.java sFaboI
*/ =ja(;uC
package NetFox; D6 B(6 5Y
k^-HY[Q9
,B]kX/W
public class SiteInfoBean { B.nq3;Y
j}NGyS" =
{?c`0C
private String sSiteURL; //Site's URL K@u\^6419
private String sFilePath; //Saved File's Path A7!!kR":
private String sFileName; //Saved File's Name uY+N163i
private int nSplitter; //Count of Splited Downloading File ydFZ$W_}w
i,jPULzyjk
)*_4=-8H
public SiteInfoBean() z7X[$T$V
{//nSplitter的缺省值为5 yZJR7+
//default value of nSplitter is 5 zb/w^~J_i
this("","","",5); .\1{>A
} A%S6&!I:(
g:bw;6^u
/I@nPH<y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,<]X0;~oB
{ }lzUl mRTe
sSiteURL= sURL; GrWzgO
sFilePath = sPath; k[3J5 4`g1
sFileName = sName; oW]~\vp^0
this.nSplitter = nSpiltter; .0$$H"t
-' 7I|r
595P04
} gKK*` L~
-DgJkyt+<
w+<`>
public String getSSiteURL() @?,iy?BSG
{ IN2FO/Y@
return sSiteURL; 9(`d h
} nRKh|B)
G?\\k[#,&
\ UCOe
public void setSSiteURL(String value) Ms8&$
{ QAiont ,!
sSiteURL = value; `4V_I%lJ&
} y#-mj,e
v6B}ov[Y2
3LKL,z
public String getSFilePath() e)I-|Q4^%
{ $J8?!Xg
return sFilePath; fz H$`X'M
} S+LE ASOr
XI#1)
=m{]Xep
public void setSFilePath(String value) P9j[ NEV
{ 8.9TWsZ
sFilePath = value; A1`y_ Aj
} Q9v OY8
w#EP`aM2$=
|y+<|fb,a
public String getSFileName() `/en&l
{ -X#Zn>#
return sFileName; =bt/2nPV
} {ir8n731p
'xO5Le(=M
>U/m/H'
public void setSFileName(String value) #sLyU4QV
{ )%D2JC
sFileName = value; @SH%l]
} x^_(gve:
JVO,@~~
7`,A]":;
public int getNSplitter() 7}+U;0,)
{ xE+Nz5F
return nSplitter; 3R!?r^h
} UOTM>d1P
d^5OB8t
kaBP&6|Z
public void setNSplitter(int nCount) "o+E9'Dm
{ I"/p^@IX
nSplitter = nCount; Er; @nOyD
} h*J=F0KM
} hdZ{8 rP
D,FX&{TYU
p-d2HXo
/* CF|c4oY82
**Utility.java 6|q\ M
*/ Qs24b
package NetFox; NYS|fa
{Vy2uow0
}cDw9;~D
public class Utility { laVqI|0q
[v7)xV@c
5&}~W)"9
public Utility() Y](kMNUSg
{ kjWY{7b!
PGTi-o}
}A@op+0E
} .L;M-`^
l;TWs_N
//线程睡眠 ^HpUbZpat)
public static void sleep(int nSecond) 2)O-EAn
{ mj\]oWS7d
try{ a`]Dmw8@
Thread.sleep(nSecond); "AH1)skB:
} oqu; D'8
catch(Exception e) S.,om;`
{ N_AAhD
e.printStackTrace (); `~${fs{-`/
} Tk(ciwB
} "P4#Q_
fTn
//日志 mJjd2a"vi
public static void log(String sMsg) LQy`,-&
{ OMaG*fb=
System.err.println(sMsg); h_O6Z2J1
} p[kEFE,%
1: cD\
@.JhL[f
public static void log(int sMsg) 9~AAdD
{ $+#Lq.3,
System.err.println(sMsg); mGf@J6wGz
} _0Mt*]L }
} Q&p'\6~
XYeuYLut
VK7lm|J+
/* Q]9g
**TestMethod.java xp+Z%0D
*/ Tyc`U&
package NetFox; 9rO,h|L
eVDO]5?
#;l~Y}7'
public class TestMethod { u ##.t
s@Q, wa(
+YS0yTWeX
public TestMethod() ^ +e5 M1U=
{ ///xx/weblogic60b2_win.exe l$j/Ye]
try{ \YV`M3O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Vn4y^_H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); })zYo 7
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3bMQ[G
fileFetch.start(); D_n(T')
} S"*M9*8
catch(Exception e){e.printStackTrace ();} /hx|KC&:e
!KYX\HRW
4T]n64Yid
} fT:a{
p>GTFXEi6
:E$<!q
public static void main(String[] args) 9DAk|K
{ STfcx]L
new TestMethod(); @' V=Vr
} Klw\
} 4 w$f-
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