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)); I\FBf&~
} "-U`E)]w*[
for(int i=0;i<nEndPos.length-1;i++) <hA1[S}
{ Qv`Lc]'
nEndPos = nStartPos[i+1]; 1q Jz;\wU
} aGRD`ra
nEndPos[nEndPos.length-1] = nFileLength; 8qi6>}A
} 6bXP{,}Gp
} =OUms@xcE
n(}zq
XX:?7:j}[8
//启动子线程 f'>270pH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8M DX()Bm
for(int i=0;i<nStartPos.length;i++) ~s[St0
{ Ld?-Ik~fF>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \W',g[Y:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `1T?\
nStartPos,nEndPos,i); -? |-ux
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U/|;u;H=
fileSplitterFetch.start(); %JsCw8C6?
} MS~|F^g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %9qG|A,cA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F6$QEiDu@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A3Lfh6O
nEndPos = " + nFileLength); jZ5 mpYUO
// fileSplitterFetch[nPos.length-1].start(); K\2UwX
;:/<XfZ
!pMp n%r<]
//等待子线程结束 k ='c*`IE
//int count = 0; 2Kg+SLU[~
//是否结束while循环 [!k#au+#c
boolean breakWhile = false; 4-wCk=I
l^$8;$Rq
PI5a'k0F
while(!bStop) Y4 <
{ XC D&Im
write_nPos(); :{YOJDtR
Utility.sleep(500); a1 I"Sh
breakWhile = true; wACx}'+M
av.L%l&d
c@]_V
for(int i=0;i<nStartPos.length;i++) sr*3uI-)L
{ m/`"~@}&
if(!fileSplitterFetch.bDownOver) Y9K$6lz
{ -S7y1 )7
breakWhile = false; NdlJdq
break; F*bmV>Qq
} :*`5|'G}
} }z$_=v
if(breakWhile) [It E+{U
break; 1syI%I1
:k"VR,riF
3ZF-n`
//count++; =WYI|3~Cz
//if(count>4) *u|bmt
// siteStop(); ?<l,a!V'6
} z'(][SB
J!5>8I(_wX
)0Lno|l
System.err.println("文件下载结束！"); ^Iz(V2
} V\ 7O)g
catch(Exception e){e.printStackTrace ();} C]xKdPQj%
} ZMI!Sl
9AxeA2/X
KqE5{ q
//获得文件长度 BJ]4j-^o
public long getFileSize() :JEzfI1
{ b&i0)/;
int nFileLength = -1; BM@:=>ypQ
try{ NFEF{|}BM
URL url = new URL(siteInfoBean.getSSiteURL()); -S ASn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |K H&,
httpConnection.setRequestProperty("User-Agent","NetFox"); is2OJ,
n&51_.@Q
JS&=V67[
int responseCode=httpConnection.getResponseCode(); _"Bh 3 7
if(responseCode>=400) :ziV3jRM
{ O=9mLI6
processErrorCode(responseCode); =Z($n:m=*
return -2; //-2 represent access is error + \DGS
} CfSpwkg
{5$.:Y
U1Z.#ETnM
String sHeader; RO]Vn]qb
h]DS$WZ
3%g\)Cs
for(int i=1;;i++) R43yr+p
{ ^hpdre"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ncGg@$E
//Utility.log(in.readLine()); L*rND15
sHeader=httpConnection.getHeaderFieldKey(i); *gJ:irah
if(sHeader!=null) #-0}r
{ 0&YW#L|J
if(sHeader.equals("Content-Length")) ^Ia:e ?)W
{ ~BSIp .
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;~2RWj=-
break; w=UFj
} sn4wd:b7%
} d^0vaX6e}
else &<s[(w!%%
break; x/UmpJD+
} F@76V$U.
} B``)
catch(IOException e){e.printStackTrace ();} :$>Co\D
catch(Exception e){e.printStackTrace ();} .??[qBOTE
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!c;Z<@
Utility.log(nFileLength); #LGAvFA*_F
fO;#;p.
7kQZ$sLc
return nFileLength; Ic%c%U=i
} 2=&4@c|cn
Stzv
Z|8oD*,
//保存下载信息（文件指针位置） P|>pm]>C
private void write_nPos() 4H<@da}
{ .ykCmznf*
try{ vS!%!-F
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7_HJ|QB
output.writeInt(nStartPos.length); Y5 BWg
for(int i=0;i<nStartPos.length;i++) gJkk0wokC
{ W'>"E/Tx#O
// output.writeLong(nPos); yJ\K\\]
output.writeLong(fileSplitterFetch.nStartPos); *?'^Rc
output.writeLong(fileSplitterFetch.nEndPos); V<ZohB?y
} K,!"5WrX*
output.close(); W+F^(SC\
} u9TiEEof3
catch(IOException e){e.printStackTrace ();} 6 J&_H(^
catch(Exception e){e.printStackTrace ();} ^""Ss
} r+4<Lon~
3kTOWIX
HF2w?:
//读取保存的下载信息（文件指针位置） vZDM}u
private void read_nPos() <B }4}-}
{ rF/k$_bFt
try{ Rl. YF+YH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6AM-^S@
int nCount = input.readInt(); =B0#z]qu
nStartPos = new long[nCount]; Gu3# y"a>
nEndPos = new long[nCount]; &YSjwRr
for(int i=0;i<nStartPos.length;i++) (?G?9M#7_
{ -3z$~ {
nStartPos = input.readLong(); ,)S(SnCF
nEndPos = input.readLong(); Kx-s95t
} C EzTErn
input.close(); #J=@} S)
} 8PR1RCJ
catch(IOException e){e.printStackTrace ();} 7Fg-}lJAC
catch(Exception e){e.printStackTrace ();} :o)4Y
} l,I[r$TCf
8&g`Uy/b
lg9`Z>?
private void processErrorCode(int nErrorCode) 9S.J%*F7
{ ;tBc&LJ?
System.err.println("Error Code : " + nErrorCode); j>OuNeo@4
} i`FskEoijq
4Ou|4WjnL
0R#T3K}
//停止文件下载 I;Sg9`k=
public void siteStop() pb\W7G
{ >=T\=y
bStop = true; &Z.zem?n
for(int i=0;i<nStartPos.length;i++) l8$7N=Y
fileSplitterFetch.splitterStop(); bv%A;
%,Pwo{SH
ySS kw7
} "_g3{[es!
} 9d\B*OU
//负责部分文件的抓取 U2lDTRt
**FileSplitterFetch.java Vb _W&Nwd
*/ L.%N
package NetFox; $aY*1UVq
*/T.]^
L\CufAN
import java.io.*; myR}~Cj;q
import java.net.*; K&\3j-8^
=b{!p|
W=[..d
public class FileSplitterFetch extends Thread { /C'dW
e>OYJd0s
z_A:MoYfo
String sURL; //File URL g9rsw7
long nStartPos; //File Snippet Start Position Po~u-5
long nEndPos; //File Snippet End Position RPXkf71iM
int nThreadID; //Thread's ID q h+c}"4m
boolean bDownOver = false; //Downing is over gz,x6mnQ
boolean bStop = false; //Stop identical ~> xVhd
FileAccessI fileAccessI = null; //File Access interface =:4vRq [
jkN-(v(T
C6!P8qX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -C>q,mDJZ
{ }Q=@$YIesD
this.sURL = sURL; MFHc>O DA
this.nStartPos = nStart; SWrt4G
this.nEndPos = nEnd; ,X&(BQj h
nThreadID = id; .y)Y20=o!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XDot3)2`
} "!fvEE
Qd{h3K^hlu
TB8a#bK4
public void run() Q9[$8
{ bnm3 cR:h"
while(nStartPos < nEndPos && !bStop) lrE|>R
{ _YT9zG
1]yjhw9g
K4H U9!
try{ "F$0NYb]I
URL url = new URL(sURL); WgV'T#*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ftw@nQNU
httpConnection.setRequestProperty("User-Agent","NetFox"); #?V7kds]
String sProperty = "bytes="+nStartPos+"-"; `H^?jX>7
httpConnection.setRequestProperty("RANGE",sProperty); -kv'C6gB
Utility.log(sProperty); Me.t_)
Xv5|j/<~p
T VuDK
InputStream input = httpConnection.getInputStream(); x'uxSeH$
//logResponseHead(httpConnection); M.[A%_|P
r N.<S[
PXH"%vVF
byte[] b = new byte[1024]; MV~-']2u
int nRead; ^EG@tB $<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7p!w(N?s
{ I1TzPe
nStartPos += fileAccessI.write(b,0,nRead); =` %iv|>r0
//if(nThreadID == 1) _F"o0K!u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'u%;5;%2
} {e3XmVAI
]t23qA@^2
2&k5X-Y
Utility.log("Thread " + nThreadID + " is over!"); ~I_v {
bDownOver = true; _i-(`5
//nPos = fileAccessI.write (b,0,nRead); IIrXI8'}
} Z6`oGFq
catch(Exception e){e.printStackTrace ();} n*HRGJ
} .QaHE`e{
} gk*Md+
DH5]Kzb/
jDaWmy<ha
//打印回应的头信息 m V U(b,
public void logResponseHead(HttpURLConnection con) W8/8V,
{ jW?siQO^
for(int i=1;;i++) L'*P;z7<
{ l$:.bwXXO
String header=con.getHeaderFieldKey(i); h /.^iT
if(header!=null) B!#F!Wk"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X`,]@c%C`
Utility.log(header+" : "+con.getHeaderField(header)); !GNLq.rQ
else neHozmm|
break; ub#>kCL9
} il)LkZ@
} .\W6XRw
RgPY,\_9+
Vd'KN2Jm
public void splitterStop() _;M46o%h
{ c<(LXf+61
bStop = true; )/:r$n7
} XHN`f#(w
w(y#{!%+
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} |<YoH$.
X~H~k1
77:s=)
/* TC2gl[
**FileAccess.java v7L}I[f
*//文件访问(定位，写) K~?M?sa
package NetFox; \w]c<gM K
import java.io.*; 1o;*`
c04"d"$ x
<IX)D `mf
public class FileAccessI implements Serializable{ *@C4~Zo
!Gphs`YI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P@u&~RN9f+
RandomAccessFile oSavedFile; Rilr)$
long nPos; 9O%4x"*PO
)ny,vcU]
Rj/9\F3H
public FileAccessI() throws IOException &SzLEbU!
{ 5&uS700
this("",0); C&\vVNV;9
} D-/aS5wM
OfR\8hAY
""dX4^gtU
public FileAccessI(String sName,long nPos) throws IOException PR&D67:Jy
{ l<](8oc. w
oSavedFile = new RandomAccessFile(sName,"rw"); R/yOy^<
this.nPos = nPos; CQq'x+{F
oSavedFile.seek(nPos); Tz=YSQy$9
} "/EE$eU
s1[_Pk;!
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public synchronized int write(byte[] b,int nStart,int nLen) Wgh4DhAW
{ 0P5!fXs*
int n = -1; 9}4EW4
try{ )6S;w7
oSavedFile.write(b,nStart,nLen); `VT0wAe2;
n = nLen; !`BK%m\8
} pvz*(u
catch(IOException e) yrDWIU(8;6
{ yqg&dq
e.printStackTrace (); [N|/d#
} 5X7kZ!r
5 i1T?
!~'\Ey
return n; JJvf!]
} s$ONht
/12D >OK
I6]|dA3G
} g5EdW=Dt,
0d-w<lg9
b}G4eXkuj
/* 5-277?
**SiteInfoBean.java seFug
*/ 5(/ 5$u
package NetFox; ;%1ob f 89
[;c'o5M&
a0"gt"qA
public class SiteInfoBean { C?n3J
1MtvnPY
W#<&(s4
private String sSiteURL; //Site's URL `ag7xd!
private String sFilePath; //Saved File's Path $jYwV0
private String sFileName; //Saved File's Name Y$^x.^dT,
private int nSplitter; //Count of Splited Downloading File kT(}>=]g
Nk-biD/J
mx#H+:}&r
public SiteInfoBean() qAH@)}
{//nSplitter的缺省值为5 HQ%-e5Q
//default value of nSplitter is 5 Z\=].[,w4
this("","","",5); ~P*t_cpZ
} lN,8(n?g
E"Z9 NDgl#
wHW";3w2~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {cF7h)j
{ \?,'i/c-
sSiteURL= sURL; \C3ir&
sFilePath = sPath; ?VMj;+'tr
sFileName = sName; U~8.uldnF
this.nSplitter = nSpiltter; S9Fg0E+J
v+Vpak9|
[aF?1KxNMt
} x@+m_y
,L+tm>I
]E66'
public String getSSiteURL() 8Ek<J+&|I
{ #e.2m5T
return sSiteURL; Na^1dn
} o~ .[sn5l-
W{Cc wq
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public void setSSiteURL(String value) k]<
{ V1KWi^
sSiteURL = value; \s2hep
} -ob_]CKtJ~
ZdEeY|j
a1p:~;f}[
public String getSFilePath() DBl.bgf
{ 0fvQPs!O
return sFilePath; h<.G^c)
} 'sJ=h0d_[V
<^,w,A
2}u hPW+
public void setSFilePath(String value) y D.S"
{ w,NK]<dU@
sFilePath = value; bz_Zk
} lgZ3=h
)5lo^Qb
B&0^3iKFi
public String getSFileName() w:Fi 2aJ
{ KQ3]'2q
return sFileName; FxSBxz<N-A
} (Q !4\Gy
<@n/[ +3
E|D~:M%~
public void setSFileName(String value) *=L3bBu?
{ E%\iNU!
sFileName = value; 0SV#M6`GX
} Wy%q9x]}
QP|Ou*Qm)
=+q9R`!L]
public int getNSplitter() BVxg=7%St
{ }cyHR1K
return nSplitter; #Nxk3He]8
} @FL?,_,Y{
~=HN30
w[z^B&
public void setNSplitter(int nCount) !v|j C
{ /-<S FT`
nSplitter = nCount; ^_JD 7-g
} ;Jt*s
} d$s1l
X'Q$v~/
\_FX}1Wc2.
/* In|:6YDL&
**Utility.java ~#iRh6^98
*/ l?~SH[V
package NetFox; D;)Tm|XizW
^~(vP:
K1Nhz'^=D
public class Utility { eX9{wb(
T[s_w-<7$
@(PYeXdV6&
public Utility() ^jb55X}
{ J_R54Y~vu
$b\`N2J-_
`CW8Wj
} !<]%V]5[_
ys:1%D,,_
//线程睡眠 `pzp(\lc
public static void sleep(int nSecond) e0"R7a
{ tfj6#{M5
try{ i$)bZr\
Thread.sleep(nSecond); =,KRZqz
} ~%_$e/T
catch(Exception e) h@FDP#H
{ xh[Mmq/R
e.printStackTrace (); HDYr?t~V
} CfQOG7e@
} 9H?er_6Yf
?hvPPEJf
//日志 j$^3
public static void log(String sMsg) K+xiov-r?
{ a ^<W ?Z
System.err.println(sMsg); #gi0FXL
} -WwFUm
< i*v
O5{!CT$
public static void log(int sMsg) p*F&G=ZE
{ Adgh:'h
System.err.println(sMsg); 33|>u+
} OBi9aFoQ
} _)Q)tOW
ed4:r/Dpo
MhNzmI&`
/* %5RY Ea
**TestMethod.java Bv \ihUg/
*/ ,K .P,z~*
package NetFox; xn1
G!k&'{2
vGO-a2Z
public class TestMethod { Y8`4K*58%
B:)9hF?o@
-EFtk\/
public TestMethod() 64>E|w
{ ///xx/weblogic60b2_win.exe jDIO,XuF
try{ |Y"q. n77
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7}>j [
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :}TT1@
SiteFileFetch fileFetch = new SiteFileFetch(bean); ej>8$^y
fileFetch.start(); ]p:x,%nm
} IBb3A
catch(Exception e){e.printStackTrace ();} (%"M% Qko
P0S;aE
UvRa7[<y%%
} 7kO5hlKeo
-}1S6dzr
;$l!mv7
public static void main(String[] args) k'}}eu/ q
{ sXOGIv
new TestMethod(); 7g_:Gv~v
} ?JDZDPVJ)
} ct=|y(_
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