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)); Li]bU
} b"WF]x|^
for(int i=0;i<nEndPos.length-1;i++) b"uO BB
{ ckMG4 3i\j
nEndPos = nStartPos[i+1]; f`:GjA,J$
} -w*fS,O
nEndPos[nEndPos.length-1] = nFileLength; PChew3
} hw,nA2w\
} Vm|KL3}NRv
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hs[x\:})/
//启动子线程 y_X jY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aX`uF<c9
for(int i=0;i<nStartPos.length;i++) V:w%5'^3
{ ?TeozhUY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b3EGtC}^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vof8bQ{&
nStartPos,nEndPos,i); 23P&n(.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +l^tT&s;f
fileSplitterFetch.start(); 5CZyA`3V^5
} vP x/&x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~v%6*9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?V,q&=9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K fD.J)
nEndPos = " + nFileLength); Ly&+m+Gwu
// fileSplitterFetch[nPos.length-1].start(); X8VBs#tLE
/i3JP}
)O"E#%
//等待子线程结束 =B9-}]DDO
//int count = 0; PQDLbSe)\
//是否结束while循环 +=jS!
boolean breakWhile = false; Bhxs(NO
yI 2UmhA
3l%Qd<
while(!bStop) KEtV
{ Sp492W+
write_nPos(); Xd=KBB[r?
Utility.sleep(500); gzIx!sc
breakWhile = true; 9T;4aP>6j#
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/kY9z~l
for(int i=0;i<nStartPos.length;i++) `*Yw-HL
{ UB.1xcI
if(!fileSplitterFetch.bDownOver) UxL*I[z5
{ 5X20/+aT
breakWhile = false; HwHF8#D*l
break; O;~e^ <*
} }3^m>i*8
} -T,?'J0 2
if(breakWhile) lFGuQLuqA{
break; &1$d`>fn
=..Bh8P71!
aOH|[
//count++; ^K;k4oK
//if(count>4) EY)2,
// siteStop(); . :Skc
} j:h}ka/!p
\IE![=p\w
HohCb4do
System.err.println("文件下载结束！"); rS{}[$Zpl
} iX$G($[l(
catch(Exception e){e.printStackTrace ();} D`T;j[SsS#
} !BsQJ_H
~Jk&!IE2
P9/ (f$=
//获得文件长度 ^+SE_-+]
public long getFileSize() 7q+D}+ Xf
{ fZ$b8
int nFileLength = -1; T&lgWOls
try{ TI'v /=;)
URL url = new URL(siteInfoBean.getSSiteURL()); 9B!Sv/)y!r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mux/\TII
httpConnection.setRequestProperty("User-Agent","NetFox"); QWk3y"5n<
YIg(^>sq
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int responseCode=httpConnection.getResponseCode(); XVqOiv)
if(responseCode>=400) :~otzI4%!
{ KLyRb0V
processErrorCode(responseCode); {V6&((E8
return -2; //-2 represent access is error 3>KEl^1DB
} V`y^m@U!
wXKtQ#o}
hq 3n&/
String sHeader; Nap[=[rv
vN Bg&m
|NuMDVd+s
for(int i=1;;i++) ~[HzGm%
{ CRK%^3g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;Z]Wj9iY
//Utility.log(in.readLine()); ij ?7MP
sHeader=httpConnection.getHeaderFieldKey(i); 'XK 'T\m
if(sHeader!=null) g&s. 0+
{ PMfW;%I.
if(sHeader.equals("Content-Length")) 4yyw:"
{ ib=)N)l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dh8ECy5k<*
break; gQ_<;'m)2
} )2&3D"V
} tm+*ik=x|
else hzo> :U
break; G?s9c0f
} o;$xN3f,
} 'JOUx_@z
catch(IOException e){e.printStackTrace ();} Q;]JVT1
catch(Exception e){e.printStackTrace ();} KqK]R6>
Ymz/:
gJQ#j~'
Utility.log(nFileLength); pF{jIXu
[Fl_R[o
)9hqd
return nFileLength; NoiB98g
} EhxpMTS
}u_D{bz
1Gsh%0r3
//保存下载信息（文件指针位置） 2_q/<8t
private void write_nPos() %e~xO x
{ {<42PJtPY
try{ L7$f01*
output = new DataOutputStream(new FileOutputStream(tmpFile)); g-eJan&]N
output.writeInt(nStartPos.length); 5W&L6.J}+
for(int i=0;i<nStartPos.length;i++) 2][9Wp
{ ]SQ+r*a
// output.writeLong(nPos); fx;rMGa
output.writeLong(fileSplitterFetch.nStartPos); )x6&Y
output.writeLong(fileSplitterFetch.nEndPos); t7f(%/] H0
} M~A#_%2U
output.close(); S%iK);
} T#ls2UL*xh
catch(IOException e){e.printStackTrace ();} Xq?>a+B
catch(Exception e){e.printStackTrace ();} B!wN%>U
} l77 -I:
=A'>1N
$e\s8$EO
//读取保存的下载信息（文件指针位置） bo\ bs1
private void read_nPos() 76l. {TXF
{ EpS/"adI-!
try{ c,a8#Og
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o(hUC$vW
int nCount = input.readInt(); JP>EW&M
nStartPos = new long[nCount]; 2P"643tz
nEndPos = new long[nCount]; LKM018H>
for(int i=0;i<nStartPos.length;i++) \lbH
{ 74([~Qs _M
nStartPos = input.readLong(); |5^ iqW
nEndPos = input.readLong(); C~&E7w
} //&3{B
input.close(); c8&3IzZ
} W`[VLi}fe
catch(IOException e){e.printStackTrace ();} `i`P}W!F
catch(Exception e){e.printStackTrace ();} w|f+OlPXq
} "S;4hO
f)Qln[/
\@@G\\)er
private void processErrorCode(int nErrorCode) "yu{b]AU
{ A[l )>:
System.err.println("Error Code : " + nErrorCode); ?/.])'&b
} 2+&;jgBP
x{pj`'J)
Ichg,d-M-K
//停止文件下载 JLd%rM\m
public void siteStop() nE]rPRU}[
{ YuhfPa
bStop = true; n*\o. :f
for(int i=0;i<nStartPos.length;i++) sPNm.W$_
fileSplitterFetch.splitterStop(); 1UMEbb
\'2rs152
y6$a:6
} JG;}UuHYM
} uH89oA/H
//负责部分文件的抓取 gt8dFcm|s
**FileSplitterFetch.java #w;"s*
*/ n*[ZS[I
package NetFox; !j$cBf4
~>@~U]
-8)Hulo/{U
import java.io.*; &b (*
import java.net.*; /`M#
e#oK% {A
]WMzWt:L
public class FileSplitterFetch extends Thread { KH2]:&6:Q
}XUL\6U
z?DCQ
String sURL; //File URL yy5|8L
long nStartPos; //File Snippet Start Position ]y#'U
long nEndPos; //File Snippet End Position g[~{iu_$d
int nThreadID; //Thread's ID y(DT^>0
boolean bDownOver = false; //Downing is over x_3B) &9
boolean bStop = false; //Stop identical Tf#Op v)
FileAccessI fileAccessI = null; //File Access interface ./I?|ih
:Quep-:fy<
eBa#Z1Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )xVf3l pQ
{ jGouwta
this.sURL = sURL; Jj)J5S /
this.nStartPos = nStart; VP!4Nob
this.nEndPos = nEnd; ;gL{*gR]S
nThreadID = id; f}yRTR GJv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @G;9eh0$
} +s<6eHpm
{>km]CG
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public void run() @v`.^L{P
{ ViW2q"4=
while(nStartPos < nEndPos && !bStop) ]U#of O
{ )"?'~5A
w<~[ad}
<zpxodM@T
try{ +o@:8!IM1
URL url = new URL(sURL); r0nnmy]{d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bGwOhd<.
httpConnection.setRequestProperty("User-Agent","NetFox"); BvvjaC
String sProperty = "bytes="+nStartPos+"-"; {_!,T%>+1
httpConnection.setRequestProperty("RANGE",sProperty); p"P+8"`
Utility.log(sProperty); Lv@WI6DM
UIU Pi gd
m=n79]b:N
InputStream input = httpConnection.getInputStream(); 0to`=;JI
//logResponseHead(httpConnection); </'n={+q
0xZ^ f}@L
V]Te_ >E;w
byte[] b = new byte[1024]; J#Q>dC7
int nRead; :^W}$7$T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <cZ/_+H%C
{ yR~$i3Z*
nStartPos += fileAccessI.write(b,0,nRead); ~0+<-T
//if(nThreadID == 1) zf8SpQ2~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CA|l| t^
} vJs6nVbK
'Ev[G6vo
+\["HS7+'0
Utility.log("Thread " + nThreadID + " is over!"); ,8zJD&HMx
bDownOver = true; i%!<9D~n
//nPos = fileAccessI.write (b,0,nRead); [PN2^
} ];CIo> b_(
catch(Exception e){e.printStackTrace ();} eV%{XR?y
} auGK2i
} BEax[=&W
|(l]Xr&O
r<kgYU`
//打印回应的头信息 *A`ZcO=
public void logResponseHead(HttpURLConnection con) UU(Pg{DA6
{ db_Qt'>
for(int i=1;;i++) }Tk:?U{
{ :YRHO|
String header=con.getHeaderFieldKey(i); NL:dyV}
if(header!=null) &*o4~6pQ#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,FP0n
Utility.log(header+" : "+con.getHeaderField(header)); i+5Qs-dHA
else b5MU$}:
break; N?t*4Y
} pq]z%\$u
} W\-`}{B_/
2ZV; GS#
3~R,)fO;
public void splitterStop() /$clk=
{ :' 5J[]J
bStop = true; _R|_1xa=
} M._E$y,5
G0m$bi=z
v6DjNyg<x
} >l8?B L
qi/k`T
74N_>1!j
/* $aEv*{$y
**FileAccess.java I*j~5fsS'
*//文件访问(定位，写) }fk3a9j9u
package NetFox; T}z? i
import java.io.*; x]`F#5j
R|}4H*N
Y,L[0%
public class FileAccessI implements Serializable{ ,<!*@xy7v
{/)i}V#RE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vN v'%;L
RandomAccessFile oSavedFile; H!0m8LCnb
long nPos; Z&?4<-@6\p
U/PNEGuQ
}|/A &c
public FileAccessI() throws IOException Z #
{ L|<j/bP
this("",0); b 1.S21
} sqpo5~
.fqy[qrM
L'a+1O1q&i
public FileAccessI(String sName,long nPos) throws IOException oCE'@}s.i
{ |5`ecjb.
oSavedFile = new RandomAccessFile(sName,"rw"); q2F`q. j
this.nPos = nPos; Lp"OXJ*es
oSavedFile.seek(nPos); IO&U=-pn&
} $?!]?{K
?7)v:$(G}
4~A$u^scn
public synchronized int write(byte[] b,int nStart,int nLen) "oiN8#Hf
{ _vb'3~'S
int n = -1; ?fP3R':s
try{ Y|b,pC|,
oSavedFile.write(b,nStart,nLen); ^ )"Il
n = nLen; CG@Fn\J
} ,]ySBAO
catch(IOException e) \"RCJadK
{ XXX y*/P
e.printStackTrace (); ld#x'/
} {[:C_Up)f
raOuD3
N LQ".mM+
return n; f U=P$s
} AfhJ6cSIE
1yz%ud-l
V:j^!*
} E<tR8='F
Eo^m; p5
"(W;rl
/* ha;fxM]
**SiteInfoBean.java +1yi{!j1
*/ LKI\(%ba#
package NetFox; ,<K+.7,)E
ZY7-.
%E#Ubm!
public class SiteInfoBean { b==jlYa=
qov<@FvE0
T=~d.&J
private String sSiteURL; //Site's URL un!v1g9O
private String sFilePath; //Saved File's Path 3O4lGe#u
private String sFileName; //Saved File's Name V;RgO}
private int nSplitter; //Count of Splited Downloading File MYb^G\K
S?`0,F
r)-{~JA!
public SiteInfoBean() 6W1+@ q
{//nSplitter的缺省值为5 aY,Bt
//default value of nSplitter is 5 jyF*JQjK4
this("","","",5); B_[I/ ?
} $ S3b<]B
tboQn~&4
q,#s m'S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G Wa6FX:/
{ "1a!]45+
sSiteURL= sURL; Hc<@T_h+2
sFilePath = sPath; - |DWPU!"
sFileName = sName; 5tkKd4VfL
this.nSplitter = nSpiltter; h]~FYY
aqqo>O3 s
%X\A|V&
} mX.mX70|J
Xl2g Hh
3'6 UvAXFH
public String getSSiteURL() w[l#0ZZ
{ rxMo7px@}I
return sSiteURL; d>I)_05t
} NTZ3Np`
kq(><T
F~E)w5?\O
public void setSSiteURL(String value) 1Zp/EYWa{
{ E <j=5|0t
sSiteURL = value; 6J JA"] `
} S}h d,"I
3 ;F
F[O147&C
public String getSFilePath() ,)d`_AD+5
{ ,KM%/;1Dm
return sFilePath; ` W);+s
} OMmfTlM%
; \co{_&D
?-Of\fNu
public void setSFilePath(String value) =,ax"C?pR
{ u=s,bt,"5
sFilePath = value; a""9%./B
} t1 9f%d
e~)4v
D5Sbs(
public String getSFileName() WdS1v%
{ wTR?8$
return sFileName; I*o6Bn |D
} H'k~;
Jpp-3i.F#
'>1M~B
public void setSFileName(String value) Z)~?foe'
{ OOIp)=4
sFileName = value; ,Js_d
} .WN&]yr,
&-^*D%9
@VOegf+N
public int getNSplitter() ^J^~5q8
{ WwnBe"7M
return nSplitter; *]<=04v]R
} BHgs,
N#-.[9!
)$f?v22
public void setNSplitter(int nCount) O,^s)>c
{ Yyd}>+|<,
nSplitter = nCount; v_%6Ly
} ("}Hs[
} ^fd*KM
Ho/tCU|w
O\;Lb[`lb
/* IRk)u`
**Utility.java j?$B@Zk
*/ DH_~,tK9
package NetFox; zCA8}](C^
txnH~;(
1#"wfiW
public class Utility { &u[F)|
!E00I0W-h
/>9`Mbg[G
public Utility() |8k^jq
{ I;_T_m4.q
\j)c?1*$
$$4flfx
} BIx*(
8,+T[S
//线程睡眠 hB\BFVUSn/
public static void sleep(int nSecond) d72 yu3
{ O3slYd&V
try{ hr'?#K
Thread.sleep(nSecond); 9dszn^]T
} mqJD+ K
catch(Exception e) `'r]Oe
{ JF}i=}
e.printStackTrace (); ?Y\WSI?i
} BSSehe*
} a8[%-eW,
n 78!]O
//日志 \?e2qu/ C
public static void log(String sMsg) 3bC-B!{;g
{ d@JavcR
System.err.println(sMsg); UDJ#P9uy
} PPpaH!(D
k"BM1-f
5)k/4l '
public static void log(int sMsg) ~/SLGyu
{ d1^5r 31
System.err.println(sMsg); 1+M !EW
} $[cB6
} UDcr5u eKn
3~WI3ZIR
@*op5qVw
/* A9DFZZ0
**TestMethod.java at*DYZBjDB
*/ +dq2}gM
package NetFox; R"t2=3K
+ZE"pA^C
y\iECdPU
public class TestMethod { zKYN5|17
5>1c4u`x
F)'_,.?0
public TestMethod() Bgsi$2hI
{ ///xx/weblogic60b2_win.exe !VG ]~lc
try{ xQ?$H?5B<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d--6<_q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u,72Mm>
SiteFileFetch fileFetch = new SiteFileFetch(bean); r`)'Kd
fileFetch.start(); DBvozTsF~
} ep48 r>
catch(Exception e){e.printStackTrace ();} |z}VP-L
.bh7
UY.o,I>s
} |P9)*~\5
@frV:%
I7f:TN
public static void main(String[] args) )&)tX.
{ W Kd:O)J
new TestMethod(); jM{5nRQ
} 4|eI_u{_
} @Y9tkJIt
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