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)); 0$P/jt
} buMqF-j
for(int i=0;i<nEndPos.length-1;i++) Q^_/By@
{ C"w {\ &R
nEndPos = nStartPos[i+1]; Ru\_dr2yI}
} kQv*eZ~
nEndPos[nEndPos.length-1] = nFileLength; U4,2br>
} TMVryb
} lmCZ8 j(FF
$u9]yiY.{
g:#dl\k
//启动子线程 !<\Br
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; my.`k'
for(int i=0;i<nStartPos.length;i++) W WG /k17
{ pW?&J>\6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }_OM$nzj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fI|[Z+"
nStartPos,nEndPos,i); f4('gl9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^U q
fileSplitterFetch.start(); oFC)
} \5><3*\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8v92Ng7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &tI#T)SSs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k|E]YvnfG
nEndPos = " + nFileLength); 0ZI(/r
// fileSplitterFetch[nPos.length-1].start(); !~iGu\y
7C,T&g 1:
IB5BO7J
//等待子线程结束 -X1X)0v$
//int count = 0; n!ok?=(kQ
//是否结束while循环 9w4sSj`
boolean breakWhile = false; I9y.e++/
<vc`^Q&4B
3I=kr
while(!bStop) XhW %,/<
{ Ob<W/-%5tH
write_nPos(); W{"XJt_
Utility.sleep(500); )g1a'G
breakWhile = true; _}Ps(_5D
oQ2KW..q
<:;^'x>!
for(int i=0;i<nStartPos.length;i++) -w6 "?
{ mDMt5(.
if(!fileSplitterFetch.bDownOver) h{iEZ#
{ g /+oZU
breakWhile = false; WE!vSZ3R
break; 'c`jyn
} vK'?:}~
} LXfCmc9|Z
if(breakWhile) 5\4g>5PD
break; =hH.zrI6e
nKh&-E
}At{'8*n
//count++; ~6[*q~B
//if(count>4) DPDe>3Mi[
// siteStop(); u\e\'\
} zA+@FR?
2%UBwSiqR
i u]&;
System.err.println("文件下载结束！"); tpf7_YP_!-
} 6vy7l(%
catch(Exception e){e.printStackTrace ();} z01>'
} x5si70BKC/
tbDoP Y
/Wj,1WX~
//获得文件长度 m6n!rRQ^U
public long getFileSize() K\.5h4k
{ ?pGkk=,KB
int nFileLength = -1; 3`V1XE.;
try{ #;tT8[Ewuw
URL url = new URL(siteInfoBean.getSSiteURL()); woOy*)@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ubz"rCjq
httpConnection.setRequestProperty("User-Agent","NetFox"); viaJblYj(f
M#jN-ix
udqS'g&
int responseCode=httpConnection.getResponseCode(); Q=cQLf;/'
if(responseCode>=400) fQLax
{ C;B}3g&
processErrorCode(responseCode); Xa9TS"
return -2; //-2 represent access is error d+L#t
} x;E2~&E
Cpl;vQ
]`=X'fED
String sHeader; ?/#}ZZK^
c'fSu;1
1&)_(|p[C
for(int i=1;;i++) .m4;^S2cO
{ [w\?j,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f|7u_f
//Utility.log(in.readLine()); `iShJz96
sHeader=httpConnection.getHeaderFieldKey(i); JC;^--0(z
if(sHeader!=null) u' Qd,
{ # '|'r+
if(sHeader.equals("Content-Length")) B5am1y{P#
{ .V'V:;BE%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C'mL&
break; H}0dd"
} Oxx^[ju~
} ,w)p"[^b
else ,d,\-x-+/
break; $a;]_Y
} 'Pltn{iq[
} $ItF])Bj5N
catch(IOException e){e.printStackTrace ();} HL{$ ^l#v
catch(Exception e){e.printStackTrace ();} r4 dOK] 0
%'Xk)-+y
&~DTZgY
Utility.log(nFileLength); k!XhFWb
[THG4582oB
l95<QI
return nFileLength; &~sfYW
} tx7~SUr
V`hu,Y;%
e_3CSx8Cc
//保存下载信息（文件指针位置） xl4=++pu)
private void write_nPos() jdqj=Yc
{ ctmQWrk|B
try{ 7Hw<ojkt
output = new DataOutputStream(new FileOutputStream(tmpFile)); }odV_WT
output.writeInt(nStartPos.length); |01?w|
for(int i=0;i<nStartPos.length;i++) ,Fqz e/
{ pb;")Q'
// output.writeLong(nPos); (zo^Nn9VJ
output.writeLong(fileSplitterFetch.nStartPos); =d;Vk
output.writeLong(fileSplitterFetch.nEndPos); !cEG}(|h
} y>VcgLIB
output.close(); F_;tT%ywfx
} :K.4n
catch(IOException e){e.printStackTrace ();} Tp%(I"H'_;
catch(Exception e){e.printStackTrace ();} pa .K-e)Mu
} sYbH|}
nY?
}k$4/7ri
//读取保存的下载信息（文件指针位置） g<*jlM1r
private void read_nPos() S4NL "m
{ eo]#sf@\0
try{ e,1u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @)YY\l#
int nCount = input.readInt(); &R-H"kK?
nStartPos = new long[nCount]; *=F(KZ
nEndPos = new long[nCount]; B33$ u3d
for(int i=0;i<nStartPos.length;i++) *tQk;'/A]
{ WPuz]Ty
nStartPos = input.readLong(); wNCCH55Pt
nEndPos = input.readLong(); /ci]}`'ws
} 7()?C}Ni-
input.close(); gz#4{iT~
} L-i>R:N4
catch(IOException e){e.printStackTrace ();} ]5CNk+`'
catch(Exception e){e.printStackTrace ();} @ CsV]97`
} SqPtWEq@P
Sq]pQ8
jB$SUO`*
private void processErrorCode(int nErrorCode) `\$8`Zb;
{ pNaiXu3
System.err.println("Error Code : " + nErrorCode); Y0uvT7+[hi
} ~.tvrxg
`d]Z)*9
\y Hen|%
//停止文件下载 Q%=YM4;
public void siteStop() $+= <(*
{ P~CrtTss
bStop = true; pJpNO$$w
for(int i=0;i<nStartPos.length;i++) Gy29MUF
fileSplitterFetch.splitterStop(); $r.U
[2Mbk~
1hQN8!:<
} oW}!vf3z
} T`YwJ6N
//负责部分文件的抓取 GUp;AoQ
**FileSplitterFetch.java HZJL/=;
*/ =C7 khE
package NetFox; hXL|22>w<
gvavs+H%
wGKo.lt
import java.io.*; +=@^i'
import java.net.*; R'K/t|MC
eBr4O i
c=p=-j=.J
public class FileSplitterFetch extends Thread { T.&7sbE_
`x8Bn"
8QgA@y"
String sURL; //File URL xh9qg0d
long nStartPos; //File Snippet Start Position I+?hG6NM
long nEndPos; //File Snippet End Position rs8\)\z
int nThreadID; //Thread's ID B&KL2&Z~Pq
boolean bDownOver = false; //Downing is over %HuyK
boolean bStop = false; //Stop identical f4t.f*#
FileAccessI fileAccessI = null; //File Access interface Un=a fX?j
+Ghi}v
Q s(Bnb;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y=N"=Z
{ Q4'C;<\@(Q
this.sURL = sURL; dDcZ!rRaL@
this.nStartPos = nStart; kEN#u
this.nEndPos = nEnd; %CH6lY=lI
nThreadID = id; $^%N U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0%C^8%(x
} C0C0GqN,
8v_C5d\
x1[?5n6
public void run() wrv5V M}
{ W:s@L#-
while(nStartPos < nEndPos && !bStop) **;p(CI
{ Y*YFB|f?
eD#XDK
Lubrn"128
try{ 19u =W(
URL url = new URL(sURL); UPh=+s #Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4iX-(ir,
httpConnection.setRequestProperty("User-Agent","NetFox"); +++pI.>(*Q
String sProperty = "bytes="+nStartPos+"-"; 649 !=
httpConnection.setRequestProperty("RANGE",sProperty); 7k8n@39?
Utility.log(sProperty); Di(9]:+
:b#%C pR
Cnh|D^{s
InputStream input = httpConnection.getInputStream(); ,Qc.;4s-
//logResponseHead(httpConnection); 7XAvd-
IM(u<c$
F9o6V|v
byte[] b = new byte[1024]; |m>}%{
int nRead; mV\$q@sII
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e-6w8*!i
{ #6> 6S;Ib
nStartPos += fileAccessI.write(b,0,nRead); FvImX
//if(nThreadID == 1) a-0cN 9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C8b''9t.
} [1Dm<G u@
MWwJzVL8
3(_!`0#F%
Utility.log("Thread " + nThreadID + " is over!"); _n O.-
bDownOver = true; 2<W&\D o@
//nPos = fileAccessI.write (b,0,nRead); oN,s.Of
} .XH8YT42
catch(Exception e){e.printStackTrace ();} \_ow9vU
} ]|oJ)5P
} pdz'!I
%efGt6&
" ~Q*XN2
//打印回应的头信息 d0UZ+ RR#
public void logResponseHead(HttpURLConnection con) knHv?#
{ [#b2%G1
for(int i=1;;i++) #uvJH8)D
{ "dCzWFet
String header=con.getHeaderFieldKey(i); L]bVN)JU
if(header!=null) <0j{ $.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ol+Kp!ocY
Utility.log(header+" : "+con.getHeaderField(header)); 4<gJ2a3
else YMB~[]$V<
break; /&s}<BMHU
} Y`li> .\
} MOZu.NmO
otriif@+Z
Jq1 n0O
public void splitterStop() >{&A%b4JF
{ mnQ'X-q3iO
bStop = true; 4F#%f#"
} `iYc<N`
5P+YK\~
G}Z4g
} K8Zt:yP
3N%{B
qo;)X0N
/* !#}>Hv^N
**FileAccess.java P;U@y"s
*//文件访问(定位，写) RaNeZhF>M
package NetFox; [MmM9J["
import java.io.*; g9V.13k
5' \)`
L|67f4
public class FileAccessI implements Serializable{ ?!S GiARW?
Yn<)k_kp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [b1hC ~I;
RandomAccessFile oSavedFile; [thboP.?
long nPos; uWc:jP
$KQ,}I
Auac>')&Q
public FileAccessI() throws IOException #93}E Y
{ 9k`~x1Y)
this("",0); "$@,n7k
} \y~)jq:d"
42@a(#z(U
fValSQc!U
public FileAccessI(String sName,long nPos) throws IOException $ I<|-]u
{ uPU#c\
oSavedFile = new RandomAccessFile(sName,"rw"); d]7*mzw^j
this.nPos = nPos; >d%VDjk .
oSavedFile.seek(nPos); M,..Kw/ }~
} `]>on`n?
o;;,iHu*
=J3`@9;
public synchronized int write(byte[] b,int nStart,int nLen) ,cQA*;6
{ yQ-hnlzn~
int n = -1; K%2I
try{ NsmVddj
oSavedFile.write(b,nStart,nLen); ,"H?hFQ
n = nLen; <!!nI%NC
} )%#?3X^sI
catch(IOException e) I#c(J
{ iS05YW
e.printStackTrace (); A2_Ls;]
} EXHR(t}e
C'<'7g4
_3&/(B%H
return n; A$m<@%Sz
} m/?h2McS
~XQ$aRl&
NcM3P G
} LUul7y'"
FV8\+ep
,;3:pr
/* vU9ek:.l
**SiteInfoBean.java uu@<&.r\C
*/ s01$fFJgO
package NetFox; p">WK<N
ZbyG*5iq
>w2f8tW`PP
public class SiteInfoBean { 3_U\VGm
enPYj.*/0
sD2Qm
private String sSiteURL; //Site's URL sH@ &*
private String sFilePath; //Saved File's Path U,HS;wo;t
private String sFileName; //Saved File's Name 6vWii)O.D
private int nSplitter; //Count of Splited Downloading File JD-Becz
">,K1:(D
Ou!)1UFI
public SiteInfoBean() eoL0^cZj
{//nSplitter的缺省值为5 ?\d5;%YSr
//default value of nSplitter is 5 FvA|1c
this("","","",5); @7X\tV.Z
} K*:Im#Q
1:5P%$?b
]:!8 s\#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k!vHO
{ X&,N}9>B
sSiteURL= sURL; 5iv@@1c
sFilePath = sPath; `.`FgaJ |
sFileName = sName; APOea
this.nSplitter = nSpiltter; .S(^roM;+
ku-cn2M/
VLx T"]f
} iz(m3k:w
%|bN@@
7_7xL(F/
public String getSSiteURL() pKYLAt+^>
{ BArJ"t*/z
return sSiteURL; wRj~Qv~E
} *Ji9%IA
=xoBC&u
HFv?s
public void setSSiteURL(String value) u{pTva
{ YpiRF+G
sSiteURL = value; Uv'uqt
} rr>IKyI'
Sn0Xl3yr
V"BVvSNu
public String getSFilePath() uiuTv)pwF
{ -$b?rt]h1g
return sFilePath; I,w^?o
} dkETM,
i >J:W"W
DWdLA~'t
public void setSFilePath(String value) ym[+Rw
{ ,A^L=+
sFilePath = value; &'NQ)Dn
} %qONJP
2-PI JO
@_(nd57oSs
public String getSFileName() EI<"DB
{ Dn: Yi8=
return sFileName; VDPxue
} Fr<Pe&dn
2-p8rGI_F
pDP33`OFh
public void setSFileName(String value) ?DJuQFv
{ +<H !3sW
sFileName = value; YdPlN];[
} ADTU{6UPS
W;5N04ko
TjT](?'o
public int getNSplitter() I8:"h
{ "[Yip5
return nSplitter; 1o(+rR<h9
} ,I("x2
bL+sN"Km
NuHL5C?To
public void setNSplitter(int nCount) LZbRQ"!!o
{ gq=0L:
nSplitter = nCount; Ni&,g
} So0`c,D
} _Wq7U1v`
4;08n|C
zf}rfn
/* bn5"dxV
**Utility.java -=@K%\\~5
*/ ><MGZ?-N
package NetFox; "pR $cS
<<i=+ed8eP
>qr=l,Hi
public class Utility { F>p%2II/
hU |LFjc
7&#'c8]/qh
public Utility() Ty)gPh6O
{ no eb f
0m qSA
jY1^+y{
} rD_Ss.\^g
7$;c6_se
//线程睡眠 JiG8jB7%}
public static void sleep(int nSecond) c"6Kd$?M
{ $XU-[OF%:9
try{ ^!N;F"
Thread.sleep(nSecond); Vx0MG{vG1
} 7MR:X#2v>
catch(Exception e) :k Rv
{ pIk4V/fy
e.printStackTrace (); ,q{lYX83S
} 0%vixR52
} L2:oZ&:u`J
e,PQ)1
//日志 %w;1*~bH
public static void log(String sMsg) m~b#:4D3
{ r9U[-CX:"
System.err.println(sMsg); <6~/sa4GN
} `PXoJl
!.x=r
O%rS;o
public static void log(int sMsg) :==UDVP
{ lsTe*Od
System.err.println(sMsg); 7N&3FER
} EuhF$L1
} 2n<qAl$t
!&W"f#_Z
Yqq$kln
/* QSlf=VK*y
**TestMethod.java K*hf(w9="%
*/ "a2H8x
package NetFox; vLVSZX
mE)x7
M$DwQ}Z
public class TestMethod { $6qR/#74
>EPaZp6
i[V,IP +
public TestMethod() BbXmT"@
{ ///xx/weblogic60b2_win.exe CJ37:w{%*Y
try{ r-Xjy*T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'dd<<E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 74</6T]^
SiteFileFetch fileFetch = new SiteFileFetch(bean); |qFN~!
fileFetch.start(); 476M` gA
} 5cv, >{~5
catch(Exception e){e.printStackTrace ();} ePFC$kMn
qCv}+d)
|wl")|b%
} C 6:pY-
<ZN) /,4PS
x %!OP\
public static void main(String[] args) &QHA_+88W
{ m"ki*9]
new TestMethod(); 2g`uC}
} ?L.p9o-S0
} #oS
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