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)); @sZ' --Y
} T:K}mLSg
for(int i=0;i<nEndPos.length-1;i++) 99'c\[fd'
{ [K4k7$
nEndPos = nStartPos[i+1]; .)%,R
} ~^'t70 :D
nEndPos[nEndPos.length-1] = nFileLength; ,+v(?5[6
} x@O)QaBN!
} (Lj*FXmz
^jpQfDe6
iDgc$'%?
//启动子线程 -R];tpddR5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y!S:d
for(int i=0;i<nStartPos.length;i++) = 4|"<8'
{ 4/3w *
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \f Kn} ]kG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5oB#{h
nStartPos,nEndPos,i); +5R8mbD!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n) HV:8j~
fileSplitterFetch.start(); 4XiQ8"C
} %Y#W#G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q`z1ht nf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fU%Mz\t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N;}X$b5Y @
nEndPos = " + nFileLength); ~K|ha26W
// fileSplitterFetch[nPos.length-1].start(); bYhG`1,$-a
Y![i=/
N 5{w
//等待子线程结束 \>.[QQVI"l
//int count = 0; V5 9Vf[i|
//是否结束while循环 `s=Z{bw
boolean breakWhile = false; MX!N?k#KhP
;<0~^,Xm
"9*MSsU
while(!bStop) `W1TqA
{ c;yp}k]\
write_nPos(); $6r> Tc](
Utility.sleep(500); &:g1*+
breakWhile = true; e&[~}f?
w_QWTD0
^K~=2^sh
for(int i=0;i<nStartPos.length;i++) `@6y Wb:X
{ +>u 8r&Jw.
if(!fileSplitterFetch.bDownOver) QJx<1#
{ #!yX2lR
breakWhile = false; .p'McCV=
break; [;D1O;c'W.
} W_/$H_04+
} 37tJ6R6[
if(breakWhile) YF;2jl Nm
break; 4@ny%_/
J=O_nup6C
`tKs|GQf
//count++; ^foCcO
//if(count>4) DI-CC[
// siteStop(); I>-1kFma;
} .ubZ
pf yJL?_%
81I9xqvSd~
System.err.println("文件下载结束！"); Ib/e\+H\
} z<yqQ[
catch(Exception e){e.printStackTrace ();} 7o*~zDh@fH
} 3_i29ghv
&wkbr2P
k#V\O2lb
//获得文件长度 "1DlusmCCB
public long getFileSize() r=RiuxxTq
{ (v}l#M7w
int nFileLength = -1; Rp_}_hL0
try{ 0Uk;&a0s
URL url = new URL(siteInfoBean.getSSiteURL()); 8f'r_,"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v.,D,6qZ
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^WkW\9kO
LiGECqWBa'
(J(SwL|
int responseCode=httpConnection.getResponseCode(); YXU2UIY<~
if(responseCode>=400) ]yFO~4Nu
{ ] J|#WtS
processErrorCode(responseCode); !\Xrl) $j{
return -2; //-2 represent access is error $c+:dO|Fb
} wwa)VgoS[
tjne[p
ojIGfQV
String sHeader; "%rU1/@#
~qA\u5sB9@
o6:]Hvqjr
for(int i=1;;i++) ~sWXd~\
{ zrC1/%T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $TAsb>W!(
//Utility.log(in.readLine()); /|v b)J
sHeader=httpConnection.getHeaderFieldKey(i); a72L%oJ
if(sHeader!=null) m'ZxmsFo
{ ehMpo BL
if(sHeader.equals("Content-Length")) b0N7[M1Xl
{ h?->A#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G*zhy!P
break; 2jP(D%n
} IG:CWPU
} qUQP.4Z95
else '|&?$g(\h
break; r|953e
} SmAF+d
} _2}/rwVg
catch(IOException e){e.printStackTrace ();} _znn`_N:v
catch(Exception e){e.printStackTrace ();} ,LU|WXRB
k/Ao?R=@gI
Y5mk*Q#q
Utility.log(nFileLength); WBD"d<>'
>IZ$ .-
`n`HwDo;i
return nFileLength; 2kFP;7FO
} E@Yq2FBpnn
ZYTBc#f
]^QO^{Sz
//保存下载信息（文件指针位置） mw\Pv|
private void write_nPos() 4%SA%]a L1
{ }$3pS:_N~
try{ \LM{.gzT
output = new DataOutputStream(new FileOutputStream(tmpFile)); 07,&weQ
output.writeInt(nStartPos.length); "haJwV6-
for(int i=0;i<nStartPos.length;i++) a{kLAx[>
{ Z?."cuTt
// output.writeLong(nPos); +OOmy
output.writeLong(fileSplitterFetch.nStartPos); U)('}u=b
output.writeLong(fileSplitterFetch.nEndPos); vC^n_
} (~#-J7
output.close(); _J_QB]t
} L^ U.h
catch(IOException e){e.printStackTrace ();} W)odaab7
catch(Exception e){e.printStackTrace ();} m9$lOk4/
} YE-}1&8
{>X2\.Rl
v 5&8C
//读取保存的下载信息（文件指针位置） ,e*WJh8k[
private void read_nPos() AIM<mU
{ 'W p~8}i@
try{ mbIHzzW>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (+bt{Ma
int nCount = input.readInt(); hx}X=7w
nStartPos = new long[nCount]; ,#(k|Zztc
nEndPos = new long[nCount]; 9%?a\#C
for(int i=0;i<nStartPos.length;i++) ,Q+.kAh !G
{ s`dUie}y<
nStartPos = input.readLong(); l+^4y_
nEndPos = input.readLong(); Qf@ha
} !<0 `c
input.close(); ,GF(pCZzG
} fvV5G,lD3h
catch(IOException e){e.printStackTrace ();} =$< .:b
catch(Exception e){e.printStackTrace ();} }I~)o!N%7
} R'B-$:u
BIjkW.uf
$< .wQ8:Q
private void processErrorCode(int nErrorCode) Mg\8m-L^
{ rJCu6
System.err.println("Error Code : " + nErrorCode); /+?eSgM/
} kclZ+E
iGIry^D
Rw`64L_
//停止文件下载 wG&rkg";#
public void siteStop() <im<0;i&e
{ 3'tq`t:SQ
bStop = true; e,@5`aYHM@
for(int i=0;i<nStartPos.length;i++) O|&SL03Z8
fileSplitterFetch.splitterStop(); W@vCMy!
>q1rdq
|k/;1.b!9(
} rCdTn+O2
} h"ATRr^
//负责部分文件的抓取 "lBYn2W
**FileSplitterFetch.java 6oq/\D$6~
*/ Xcci)",!
package NetFox; b}m@2DR'|m
VP6_}9:9
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import java.io.*; ?s9f}>
import java.net.*; n wO5<b;
TA!6|)BUW
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public class FileSplitterFetch extends Thread { /wJocx]vQ
c/-PEsk_TP
m=D9V-P
String sURL; //File URL BVxk}#d
long nStartPos; //File Snippet Start Position cbv%1DT3
long nEndPos; //File Snippet End Position }?,Eb~q
int nThreadID; //Thread's ID XGDJCN
boolean bDownOver = false; //Downing is over 1 o\COnt
boolean bStop = false; //Stop identical ~4`3p=$
FileAccessI fileAccessI = null; //File Access interface +}^^]J$Nh
lN[#+n
L=kETJ:g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $`"$ZI6[
{ 8:"s3xaO3
this.sURL = sURL; md/NMC \
this.nStartPos = nStart; x UTlM
this.nEndPos = nEnd; r<_qU3Eaj
nThreadID = id; l#3jJn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #}C6}};
} ME'LZ"VT
5DVSaI$ =
zB#.EW
public void run() ePiZHqIsv/
{ c^}DBvG,
while(nStartPos < nEndPos && !bStop) 4siq
{ ryt`yO
_*u$U
$NwPGy?%
try{ z v:o$2Z
URL url = new URL(sURL); )W!\D/C+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7G 3e
httpConnection.setRequestProperty("User-Agent","NetFox"); |:LklpdYe
String sProperty = "bytes="+nStartPos+"-"; m/ngPeZ
httpConnection.setRequestProperty("RANGE",sProperty); [yDOvQ[
Utility.log(sProperty); He LW*
Ap!i-E,"J
!w:pb7+G
InputStream input = httpConnection.getInputStream(); E#c9n%E\sz
//logResponseHead(httpConnection); D]+@pKb
rVDOco+w
2mfG:^^c
byte[] b = new byte[1024]; x3 01uf[
int nRead; T&]IPOH9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9PJnKzQ4
{ muIJeQ.C
nStartPos += fileAccessI.write(b,0,nRead); Rh{`#dI~=
//if(nThreadID == 1) 5O:4-}hz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]nm(V
} lrK?&a9AB
7O'u5N
9K=K,6 b
Utility.log("Thread " + nThreadID + " is over!"); /Ca M(^W
bDownOver = true; 4'H)h'#C
//nPos = fileAccessI.write (b,0,nRead); C@9K`N[*
} "Q;Vy t
catch(Exception e){e.printStackTrace ();} ;H"OZRQ
} !+n'0{
} >,c'Z<TM
OZ2faf
6Q}>=R^h
//打印回应的头信息 ;rt\
public void logResponseHead(HttpURLConnection con) Y|-:z@n6C
{ `6pz9j]
for(int i=1;;i++) K,Hxe;-
{ ,gIeQ!+vy
String header=con.getHeaderFieldKey(i); OwLJS5r@<-
if(header!=null) f:ep~5] G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e J:#vX86
Utility.log(header+" : "+con.getHeaderField(header)); {5JYu
else ){4$oXQ
break; jN!sLW
} ``Rg0o
} ^2"w5F
%WtF\p
x=V3_HI/}
public void splitterStop() >*]B4Q
{ ,-1d2y
bStop = true; M0woJt[&
} q`HK4~i,
__)"-\w-_(
,~XAV ;+
} G+K`FUNA
'o1lJ?~kH
z"V`8D
/* M&0U@ r-
**FileAccess.java [m9=e-KS$Q
*//文件访问(定位，写) 4&H&zST//m
package NetFox; |i- S}M
import java.io.*; 1N+ju"2R
fP{IW`t}]
?7w7Y;FuR
public class FileAccessI implements Serializable{ HVNX"`]"
HUx-8<ws
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L%/atl!
RandomAccessFile oSavedFile; aa\?k\h'7X
long nPos; CjLiLB
6' 9zpe@`
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public FileAccessI() throws IOException }\vw>iHPX@
{ Gvquv\
this("",0); %`]fZr A]#
} 8!7`F.BX
>%85S>e
U6~79Hnt
public FileAccessI(String sName,long nPos) throws IOException (o1o);AO
{ D^A#C<Gs
oSavedFile = new RandomAccessFile(sName,"rw"); GX%r-
this.nPos = nPos; &M2fcw?
oSavedFile.seek(nPos); $K_-I8e|
} VQn]"G(`
j15t8du&O
36yIfC,
public synchronized int write(byte[] b,int nStart,int nLen) FK;2u$:
{ !FeNx*31i
int n = -1; y@dTdR2Wc
try{ HLl"=m1/>
oSavedFile.write(b,nStart,nLen); =_`cY^ib+
n = nLen; 8lF:70wia
} ^\3z$ntF
catch(IOException e) 5>rjL;
{ 'UB"z{w%
e.printStackTrace (); [<VyH.
} g HKA:j`c
Fj1'z5$
R3E|seR
return n; 10r9sR
} $H1igYc
A"~Oi
BV]$= e'
} wQ\bGBks
=[`gfw
;>jOB>b{h
/* XF99h&;9
**SiteInfoBean.java UsdUMt!u
*/ l"9$lF}
package NetFox; uar[D|DcD"
-FQS5Zb.!
poXT)2^)
public class SiteInfoBean { MMf_
Io<L! =>
9D51@b6k
private String sSiteURL; //Site's URL ~lH2#u>g
private String sFilePath; //Saved File's Path =p#:v
private String sFileName; //Saved File's Name ie<m)
private int nSplitter; //Count of Splited Downloading File Vet<,;Te
Lq{/r+tt/
DO ,7vMO
public SiteInfoBean() tDNo; f
{//nSplitter的缺省值为5 (0zYS_mA
//default value of nSplitter is 5 l#|M.V6G
this("","","",5); TJkWL2r0c
} [P%'p-Hg_
910N1E
\$2zF8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Xvn \~Vr
{ 3y-P-NI~=
sSiteURL= sURL; }62Q{>`
sFilePath = sPath; $"`e^J9!!
sFileName = sName; c.h_&~0qf
this.nSplitter = nSpiltter; .,gVquqMY
:/i13FQ
~{!,ZnO*
} j4Y] 8
s7:w>,v/
]VK9d;0D
public String getSSiteURL() xO;Qr.3PX
{ N#7_)S[@0l
return sSiteURL; PsI{y&.
} wbh^ZMQ
seNH/pRb
qF4DX$$<
public void setSSiteURL(String value) <u2iXH5w
{ j9 &0/ ~/
sSiteURL = value; mv1|oFVW
} Cj#?Z7}z
*jo1?
)iCg,?SSw=
public String getSFilePath() a}7P:e*u
{ r8[Ywn<u
return sFilePath; eHH9#Vrhc$
} gOm%?sg
\`WAG>'l5
n|!O .+\b
public void setSFilePath(String value) No(S#,vJ;
{ 5 OF*PBZ
sFilePath = value; q??N,
} Ox+}JB [
( ALsc@K
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public String getSFileName() P%Wl`NA P
{ t}Kzh`
return sFileName; h]?[}&
} ((tWgSZ3
X$ 76#x
)LE#SGJP
public void setSFileName(String value) _<l9j;6
{ @wW)#!Mou
sFileName = value; I}1<epd ,
} }3y Q*<
Ui;PmwQc&
,\E5et4
public int getNSplitter() WvHy}1W
{ IR<*OnKn
return nSplitter; nF{>RD
} pqxBu
DP4l %2m0
0/?=FM>
public void setNSplitter(int nCount) k{pn~)xg
{ nokMS
nSplitter = nCount; %{^kmlO
} d15E$?ZLH
} BG2Z'WOH
@!s(Zkpev
BZ@v8y _TA
/* Wx-rW
**Utility.java ,ikn%l#cm
*/ /BfCh(B
package NetFox; B,RHFlp{
~n!7 ?4%U
C~:!WRCz
public class Utility { iVb#X#
wq`\p['Q,
p?eQN Y
public Utility() HZzdelo
{ ,Y2){8#l
+0FmeM&`h_
8:4`q9
} h_ J|uu
j=TG&#e
//线程睡眠 XX'Rv]T
public static void sleep(int nSecond) KiG/XnS
{ [[d@P%X&
try{ qVmG"et'J
Thread.sleep(nSecond); iC\t@BVS
} )ia$pes
catch(Exception e) d#wK
{ 8sxH)"S
e.printStackTrace (); ?u /i8
} vxx7aPjC
} 'C|yUsBC
h5R5FzY0&
//日志 H1g"09?h6o
public static void log(String sMsg) U0%m*i
{ gSu3\keF
System.err.println(sMsg); vt-53fa|
} b-,]21
F6\r"63
'aW<C>
public static void log(int sMsg) E>6:59+
{ e8<[2J)P&
System.err.println(sMsg); zhFk84
} BFyVq
} $2\k| @)s
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*FEY"W+bY
/* 9Fm><,0'u
**TestMethod.java 'HDbU#vD
*/ .]W A/}
package NetFox; k!6wVJ|_Y
nFfwVqV
J#'+&DH
public class TestMethod { b?FTwjV+#
'^Ce9r}
{,rVA(I@
public TestMethod() Nm]\0m0p-
{ ///xx/weblogic60b2_win.exe fr<, LC.
try{ 9K F`9Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a7UfRG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )q+9_KUq
SiteFileFetch fileFetch = new SiteFileFetch(bean); xkzC+ _A
fileFetch.start(); bbO1`b-
} N/fH%AtM
catch(Exception e){e.printStackTrace ();} t'0dyQ%u
`[5QouPV
sj?7}(s
} &Kgl\;}
+e%U6&l{
q^hL[:ms#
public static void main(String[] args) <e&*Tx<8
{ !xxu~j^T
new TestMethod(); v/yt C/WH"
} R83Me#&
} i@M^9|Gh
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