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)); <XCH{Te1
} /*rMveT
for(int i=0;i<nEndPos.length-1;i++) xv4nYm9
{ yMX4 f
nEndPos = nStartPos[i+1]; nez5z:7F
} NmOQ7T
nEndPos[nEndPos.length-1] = nFileLength; (:-DuUt
} "TN}=^A\F
} ,!sAr;Rk`
P5] cEZ n
ag|d_;
//启动子线程 U?xl%qF`)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "UVV/&`o
for(int i=0;i<nStartPos.length;i++) BtU,1`El5
{ LoBKR c2t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !X[lNtO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q' _
nStartPos,nEndPos,i); :4(7W[r6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kq-y1h]7H
fileSplitterFetch.start(); *2;w;(-s
} W%vh7>.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W=F?+KgL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0Apvuf1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0FEb[+N
nEndPos = " + nFileLength); Y;-"Z
// fileSplitterFetch[nPos.length-1].start(); $t}L|"=8X
*dUnP{6g
7J$ ^R6rh
//等待子线程结束 j q1qj9KZ
//int count = 0; J fsCkS
//是否结束while循环 tb0s+rb
boolean breakWhile = false; L$7v;R3
Q?[k>fu0
&yVii^
while(!bStop) wond>m 3
{ /V&$SRdL*
write_nPos(); N;Hf7K
Utility.sleep(500); xwK<f6H!y
breakWhile = true; o^DiIoor
F_V~UX1D
U R@'J@V#:
for(int i=0;i<nStartPos.length;i++) v,p/r)E
{ vQBfT% &Q-
if(!fileSplitterFetch.bDownOver) WdIr3
{ hnE@+(d=qJ
breakWhile = false; Ev$?c9*>
break; o`G'E&
} {#Gr=iv~N
} `[o^w(l:5@
if(breakWhile) 8a-[Q
break; A!iV iX &y
C7qbofoV
of{wZU\J+9
//count++; 8?I(wn
//if(count>4) Q&n
// siteStop(); /!7m@P|&D
} #C!8a
{u9VHAXCf
}Qg9l|
System.err.println("文件下载结束！"); !>t|vgW
} ^dqyX(
catch(Exception e){e.printStackTrace ();} M-|4cd]6
} ,h>0k`J:a
N],A&}30
`n5|4yaG~
//获得文件长度 R<k4LHDy
public long getFileSize() dc%+f
{ npbNUKdz
int nFileLength = -1; WW==
try{ 8$3Tu"+;
URL url = new URL(siteInfoBean.getSSiteURL()); 5QMu=/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,v)@&1Wh:
httpConnection.setRequestProperty("User-Agent","NetFox"); Ij{{Z;o3
+J+]P\:
pD`7N<F 3
int responseCode=httpConnection.getResponseCode(); dwJ'hg
if(responseCode>=400) s*(Y<Ap7d
{ KvktC|~?
processErrorCode(responseCode); .c~;/@{
return -2; //-2 represent access is error c%i/ '<Afr
} Pi)`[\{
$IB@|n
R.>/%o
String sHeader; >JC.qjA
`iQyKZS/+
J/RUKhs/
for(int i=1;;i++) QD /| zi
{ pm<<!`w"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u4+)lvt
//Utility.log(in.readLine()); S>cT(q_&
sHeader=httpConnection.getHeaderFieldKey(i); fN t
if(sHeader!=null) D2?~03c
{ 1N:eM/a
if(sHeader.equals("Content-Length")) G7zfyw}W
{ "FG6R'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VWbgusxJ
break; % J+'7'g
} ^R K[-tVV
} 3H4p$\;C
else +J.^JXyp0
break; l2n>Wce9
} I>ofSaN
} 0]i#1Si~@
catch(IOException e){e.printStackTrace ();} a)`h*P5@
catch(Exception e){e.printStackTrace ();} NaAq^F U
|$6GpAq!
uQpV1o5iA
Utility.log(nFileLength); _Se>X=
Xo]FOJ5
d{9jd{ _#G
return nFileLength; 7J0PO}N
} (K0FWTmm
KOwEw~
,uDB]
//保存下载信息（文件指针位置） 64>Zr
private void write_nPos() bpKb<c
{ !f_Kq$.{
try{ ]lm9D@HMC
output = new DataOutputStream(new FileOutputStream(tmpFile)); z2nDD6N
output.writeInt(nStartPos.length); ?i9LqHL
for(int i=0;i<nStartPos.length;i++) zb:p,T@5
{ g($y4~#
// output.writeLong(nPos); N2q'$o
output.writeLong(fileSplitterFetch.nStartPos); ~-'nEATE
output.writeLong(fileSplitterFetch.nEndPos); MPM_/dn-
} UW)k]@L
output.close(); |A5]hL
} gqGl>=.m
catch(IOException e){e.printStackTrace ();} NV*t
catch(Exception e){e.printStackTrace ();} ,4EE9 ?J
} #[Ns\%Ri0
\kC/)d
]FsPlxk6
//读取保存的下载信息（文件指针位置） 1/j}VC
private void read_nPos() ~e'FPVDn
{ Eepy%-\
try{ -C.eXR{s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $yc&f(Tv
int nCount = input.readInt(); ^\Jg {9a
nStartPos = new long[nCount]; h9SS o0]F
nEndPos = new long[nCount]; z[CCgs&vqe
for(int i=0;i<nStartPos.length;i++) `[CXxp
{ /UM9g+Bb
nStartPos = input.readLong(); W}JJaZR*X
nEndPos = input.readLong(); ]TD]
} vW YN?"d
input.close(); wGb{O
} +F4xCz7f
catch(IOException e){e.printStackTrace ();} 9SMM%(3, r
catch(Exception e){e.printStackTrace ();} rS6iZp,
} MhJq~G p
]$KH78MTW
/5zzzaj{
private void processErrorCode(int nErrorCode) -u)06C*39
{ W\FKAvS
System.err.println("Error Code : " + nErrorCode); WS2TOAya)
} g[:5@fI#*
a Se.]_
T>W(Caelq
//停止文件下载 .>h|e_E
public void siteStop() ^VoQGP/cl
{ >;0z-;k6
bStop = true; 4[rD|
for(int i=0;i<nStartPos.length;i++) !"p,9
fileSplitterFetch.splitterStop(); #YhKAG@|
saYn\o"m
:t9(T?2
} H6e^"E
} <>2QDI6_
//负责部分文件的抓取 )3z.{.F
**FileSplitterFetch.java ?Yz.tg
*/ Fda<cS]
package NetFox; (Tc ~
1!BV]&,[
yh lZdF
import java.io.*; scN}eg:5
import java.net.*; Vv6xVX
4}#*M2wb
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public class FileSplitterFetch extends Thread { z?FZu,h}
)e]:T4*vo
q;Qpd]H
String sURL; //File URL r\_aux^z
long nStartPos; //File Snippet Start Position 'VR5>r
long nEndPos; //File Snippet End Position l.b
int nThreadID; //Thread's ID e`8z1r
boolean bDownOver = false; //Downing is over gY;N>Yq,C
boolean bStop = false; //Stop identical vjbot^W9
FileAccessI fileAccessI = null; //File Access interface 6U# C
;?%2dv2d
0.&gm@A~c$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yvNYYp2r
{ RwT.B+Onuy
this.sURL = sURL; d|DIqT~{W
this.nStartPos = nStart; p4(-
this.nEndPos = nEnd; r|rV1<d
nThreadID = id; cCWOGd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }{E//o:Ta
} [xM07%:
-7;RPHJs
~+^,o_hT
public void run() rA{h/T"
{ _czLKbcF
while(nStartPos < nEndPos && !bStop) 4#4kfGoT
{ OM2|c}]ZQ
v }P~g
;#f_e;
try{ OJkPlDym
URL url = new URL(sURL); ^!Bpev
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,gD30Pylz
httpConnection.setRequestProperty("User-Agent","NetFox"); (}]74Lc
String sProperty = "bytes="+nStartPos+"-"; "ZT=[&2
httpConnection.setRequestProperty("RANGE",sProperty); 1NJ*EzJ~?
Utility.log(sProperty); Ya\G/R
0fNWI
KGK8;Q,O
InputStream input = httpConnection.getInputStream(); 8v(Xr}q,r
//logResponseHead(httpConnection); '_(oa<g
QZQ@C#PR;
BAqu@F\):
byte[] b = new byte[1024]; '!IX;OSjH
int nRead; Fd|:7NRA<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B(b[Dbb
{ FKL}6W:
nStartPos += fileAccessI.write(b,0,nRead); M(oW;^B
//if(nThreadID == 1) <2|x]b8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5Ko"-
} REFisH-
f\/};a
7_q"%xH
Utility.log("Thread " + nThreadID + " is over!"); Uf_w o
bDownOver = true; V@cRJ3ZF
//nPos = fileAccessI.write (b,0,nRead); zXVQLz5
} @/|sOF;8W
catch(Exception e){e.printStackTrace ();} Z(U&0GH`
} LnR3C:NO k
} +wT,dUin_<
7 yF#G9,
S2j7(T;~YB
//打印回应的头信息 iAup',AZg
public void logResponseHead(HttpURLConnection con) [iL2c=_
{ jY ^ndr0;
for(int i=1;;i++) ]1D>3
{ 7W}~c/%
String header=con.getHeaderFieldKey(i); 6jF~zI^
if(header!=null) kv`x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r!Mr\
Utility.log(header+" : "+con.getHeaderField(header)); Q9W*)gBvn
else a$9UUH-|
break; h3O5DP6~
} i_gS!1Z2
} f_;3|i
Eb{TKz?
SOP= X-6f
public void splitterStop() }3)$aI_
{ KJ'MK~g
bStop = true; HJ_xg6.x
} ?A2EuvQH]
=X% D;2
;Oe6SNquT
} hM>xe8yE
vuw1ycy)
?\^u},HnE|
/* 4b7}Sr=`
**FileAccess.java n7{1m$/
*//文件访问(定位，写) !kmo%+
package NetFox; (v(_XlMK
import java.io.*; C-4I e
QRt(?96
rV2}> k
public class FileAccessI implements Serializable{ CGv(dE,G&]
[nG/>Z]W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iW |]-Ba\
RandomAccessFile oSavedFile; v SWqOv$
long nPos; {/B) YR
s'LG3YV-<
R`s /^0
public FileAccessI() throws IOException )NyGV!Zuu
{ t'[vN~I'
this("",0); i37W^9 R
} !pDS*{)E
D0"+E*
CsuSg*#X+
public FileAccessI(String sName,long nPos) throws IOException H<1C5-
{ :()4eK/\
oSavedFile = new RandomAccessFile(sName,"rw"); wBeOMA
this.nPos = nPos; &dOV0y_
oSavedFile.seek(nPos); Q[~O`Lz
} p&ow\AO
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1b_->_9
public synchronized int write(byte[] b,int nStart,int nLen) z|pH>R?:
{ hpAIIgn
int n = -1; gvsS:4N"Nq
try{ ZE}m\|$
oSavedFile.write(b,nStart,nLen); L6Ynid.k
n = nLen; pCpj#+|_)
} aIqNNR
catch(IOException e) dIM:U:c
{ 7&HP2r
e.printStackTrace (); HjV^6oP
} 1f}S:Z
jp[QA\
tP3H7Yl!g
return n; ?(g kkYI
} 4&`66\p;
I~q}M!v~
%*jpQOw
} %lV>Nc|iz=
Odbjl[>k
<GoE2a4Va
/* n.7 $*9)#
**SiteInfoBean.java QjQJ "
*/ sPd5f2'
package NetFox; gHox{*hb[
mZq*o<kTA
=8tduB
public class SiteInfoBean { W^yF5
L`"cu.l
f_z2d+
private String sSiteURL; //Site's URL czHO)uQ?d`
private String sFilePath; //Saved File's Path G~m(&,:Mu
private String sFileName; //Saved File's Name d628@~Ekn
private int nSplitter; //Count of Splited Downloading File *riGi
RmzK?muk
MN1|k
public SiteInfoBean() 9V"^F.>
{//nSplitter的缺省值为5 *b.>pY?2|
//default value of nSplitter is 5 ,eZ'pxt
this("","","",5); x,p|n
} | sQ5`lV?
px-*uh<
BwL:B\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 071wo7
{ FPcgQ v;p
sSiteURL= sURL; ?G8 D6
sFilePath = sPath; kdoE)C
sFileName = sName; wvUph[j}J
this.nSplitter = nSpiltter; <-lz_
`ZNjA},.
pwu5Fxn)
} g5T~%t5lo
u6%56 %^f
5Impv3qaZ
public String getSSiteURL() u |f h!-
{ !Noabt
return sSiteURL; 8fDnDA.e
} y"){?
3$y]#L
Z#oo8
public void setSSiteURL(String value) ~u3I=b
{ .t~I[J\<
sSiteURL = value; KUly"B
} =B?uNoe
@&2T0UB
!\"C<*5
public String getSFilePath() !CsoTW9C:
{ SJy?^
return sFilePath; f|b|\/.=
} \(;5YCCE
_`;6'}]s
QY{f=
public void setSFilePath(String value) b[u_r,b
{ ,:,c kul
sFilePath = value; ,q:6[~n
} : ;d&m
#s]]\
#}B~V3UD
public String getSFileName() KIuYWr7&
{ Q2Q`g`*O:
return sFileName; }>p)|YT"/
} 3g5i5 G\
;Y)?6^"
f[dwu39k
public void setSFileName(String value) p?dMa_g
{ v#nFPB=z
sFileName = value; [u-~<80
} g0ug:- R
o}NKqA3
;vd%=vR
public int getNSplitter() @9QHv
{ 0<o#;ZQ]
return nSplitter; 1`h`-dqr#
} OCRx|
KK7Y"~ 9&-
o+q5:vJt
public void setNSplitter(int nCount) ;f6G&>p
{ Y$'fds4P
nSplitter = nCount; 6}|/~n
} r3iNfY b
} blS*HKw
?EYF61? rw
K` U\+AE
/* 1{u;-pg
**Utility.java qOk4qbl[
*/ 2{&|%1Jg
package NetFox; IG#=}q
g\X"E>X
x.45!8Zb
public class Utility { ~){*XJw6
O>'o;0
RtF_p {s
public Utility() b@5bN\"x$
{ /#Ew{RvW'
!7}5"j ;A
Oys.8%+ P
} J.El&Dev
.4?M.Z4[
//线程睡眠 G19FSLrtA
public static void sleep(int nSecond) _c%~\LOk
{ q>H!?zi\Hy
try{ (}Gl'.>\M
Thread.sleep(nSecond); \8<bb<`
} W]rXt,{&
catch(Exception e) ef|Y2<P
{ -|V@zSKr3
e.printStackTrace (); EJL45R>
} iVmf/N@A|
} fzw6VGTf
b7"pm)6
//日志 SHhg&~B
public static void log(String sMsg) A #ZaXu/:X
{ "\> <UJ
System.err.println(sMsg); )Hw;{5p@
} [q_Yf!(m-
~6@~fhu
auS$B%
public static void log(int sMsg) AbfLV942
{ uwf3
System.err.println(sMsg); d~28!E+
} Hm4lR{A
} Tm`QZh3
(VC_vz-
mp@JsCU
/* LfF<wDvXf
**TestMethod.java Lmj?V1% V
*/ N}s[0s
package NetFox; %f, 9
^DIN(0u)
}g(aZ
public class TestMethod { ?#]c{Tlpz
>5]Xl*{H)
vA+RZ
public TestMethod() `W|2Xi=^5
{ ///xx/weblogic60b2_win.exe "7gS*v,r
try{ ;'cv?3Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A$|> Jt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >-oa`im+
SiteFileFetch fileFetch = new SiteFileFetch(bean); [[TB.'k
fileFetch.start(); xazh8X0P
} zwAuF%U
catch(Exception e){e.printStackTrace ();} YS~\Gls%
!y*V;J
e2Xx7*vS
} m#8KCZS
BNaZD<<
in B}ydk
public static void main(String[] args) KF7f<
{ QmgwIz_
new TestMethod(); l65'EO|
} ]4hXK!^Uu
} ,[~Ydth
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