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)); ?Fx~_GT
} hhaiHi!$
for(int i=0;i<nEndPos.length-1;i++) jz_Y|"{`v
{ X PyDZk/m
nEndPos = nStartPos[i+1]; 'UhHcMh:
} Fn.JtIu
nEndPos[nEndPos.length-1] = nFileLength; _|["}M"?
} ss%,
} i*/i"W<
;ZUj2WxE
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//启动子线程 "7y,d%H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d^A]]Xg
for(int i=0;i<nStartPos.length;i++) T='uqKW\
{ '>t&fzD0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y[f]L4,V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), avq$aq(3&
nStartPos,nEndPos,i); `sqr>QD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0#OyT'~V%
fileSplitterFetch.start(); <~5O-.G]
} F:q4cfL6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D%]S>g5k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'Z~ZSu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U4=l`{5on
nEndPos = " + nFileLength); 3bWGWI
// fileSplitterFetch[nPos.length-1].start(); cZ_)'0
7ivo Q
^%,{R},s
//等待子线程结束 YA$YT8iMe
//int count = 0; rb-ao\
//是否结束while循环 y#B=9Ri=z
boolean breakWhile = false; ,:PMS8pS
@ &N
A]!0Z:{h%
while(!bStop) 9oJM?&i
{ <b H*f w
write_nPos(); nC p/.]Y*
Utility.sleep(500); k!x|oC0
breakWhile = true; $6mShp9(
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r\Y,*e
for(int i=0;i<nStartPos.length;i++) =F$?`q`
{ pFS@yHs
if(!fileSplitterFetch.bDownOver) Uo >aQk
{ $x'jf?zs!
breakWhile = false; pL1ABvBB
break; Rb:H3zh
} Q&:)D7m\)S
} rQ{|0+l
if(breakWhile) c ^ds|7i]a
break; C zJ-tEO
jKmjZz8L]%
# &.syD#
//count++; /al56n
//if(count>4) FTCIfW
// siteStop(); x9>$197
} */h(4Hz
3XlQ4
> pb}@\;:
System.err.println("文件下载结束！"); nrKAK^
} 1"Oe*@`pV
catch(Exception e){e.printStackTrace ();} V8 8u-
} -+@N/d5
n#x_da-m]
g7]S
//获得文件长度 pYQSn.`V~
public long getFileSize() x t-s"A
{ @/kI;8
int nFileLength = -1; ]:Ep1DIMl
try{ >`UqS`YQK
URL url = new URL(siteInfoBean.getSSiteURL()); dP_QkO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ag9GYm
httpConnection.setRequestProperty("User-Agent","NetFox"); 1ARtFR2C{b
6d]4 %QT
a%Q`R;W
int responseCode=httpConnection.getResponseCode(); =h4uN,
if(responseCode>=400) IW!x!~e
{ "<0!S~]
processErrorCode(responseCode); +h"i6`g
return -2; //-2 represent access is error O80Z7
} 3R<r[3WP
*d C|X
VYb,Hmm>kC
String sHeader; s?}qia\~m
DGGySO6=$e
5%2~/ "
for(int i=1;;i++) 4A@HR
{ nR,QG8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u;$qJjS N
//Utility.log(in.readLine()); ~$6` e:n
sHeader=httpConnection.getHeaderFieldKey(i); :epBd3f
if(sHeader!=null) esTL3 l{[
{ tZ[9qms^_
if(sHeader.equals("Content-Length")) vxPE=!|
{ t`Bk2Cc)+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ppIXS(
break; m#BXxS#B<_
} =)+^y}xb
} gH(#<f@ZI
else 12#yHsk
break; O:GPuVb\
} n>u_>2Ikkj
} 9<rs3 84
catch(IOException e){e.printStackTrace ();} ]vf_4QW=
catch(Exception e){e.printStackTrace ();} O<p=&=TD7
bJMsB|r
t }4
Utility.log(nFileLength); VE]TT><
#L!`n)J"
w%`S>+kX&
return nFileLength; vh.8m$,
} mxCneX
3L==p`
$A~aNI
//保存下载信息（文件指针位置） D,..gsg
private void write_nPos() W[I[Xg&
{ DC).p'0VL
try{ 2<UC^vZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9 D.wW
output.writeInt(nStartPos.length); jjH2!R]^>
for(int i=0;i<nStartPos.length;i++) '['%b
{ uM'n4oH
// output.writeLong(nPos); nL^7t7mp
output.writeLong(fileSplitterFetch.nStartPos); `%[m%Y9h
output.writeLong(fileSplitterFetch.nEndPos); c86?-u')
} <=|^\r !}&
output.close(); 1:<n(?5JI
} FP&Ykx~
catch(IOException e){e.printStackTrace ();} lGahwn:
catch(Exception e){e.printStackTrace ();} N>EMVUVS
} ,k.")
j{FRD8]V
u `ww
//读取保存的下载信息（文件指针位置） l$!ExXEZO;
private void read_nPos() K+/wJ9^B
{ fCu;n%
try{ U4dfO=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *?Wz/OJ0
int nCount = input.readInt(); ~h<T0Zc
nStartPos = new long[nCount]; 6miXaAA8
nEndPos = new long[nCount]; xr.;B`T0\'
for(int i=0;i<nStartPos.length;i++) ;C=d( pY
{ -}xK> ["
nStartPos = input.readLong(); y)|d`qC\
nEndPos = input.readLong(); 3BK 8{/
} x2fqfrr_]
input.close(); /Cwwz
} f8K0/z
catch(IOException e){e.printStackTrace ();} _t]Q*i0p
catch(Exception e){e.printStackTrace ();} z{BgAI,
} GNHXtu6
v" #8^q
Edc3YSg%;
private void processErrorCode(int nErrorCode) g3'dkS!
{ PfYeV/M|
System.err.println("Error Code : " + nErrorCode); ?2o+x D2
} DJdhOLx
roriNr/e
1k"t[^
//停止文件下载 dL'oIBp
public void siteStop() )]w&DNc
{ B:i$
bStop = true; ;L76V$&
for(int i=0;i<nStartPos.length;i++) A+Un(tU2(
fileSplitterFetch.splitterStop(); rvhMu}.
ZX-A}
x/]G"?Uix
} 6E^m*la%
} c'?EI EP
//负责部分文件的抓取 Q>X1 :Zn3
**FileSplitterFetch.java pdN8hJ
*/ zO9WqP_`iR
package NetFox; c<q33dZ!*
|R91|-H
!}mM"|<
import java.io.*; &<&eKq
import java.net.*; V?T&>s
m5J@kE%
7ko}X,aC
public class FileSplitterFetch extends Thread { oP7)
_W Hi<,-
+Y+fM
String sURL; //File URL 0%rE*h9+
long nStartPos; //File Snippet Start Position wmbG$T%k
long nEndPos; //File Snippet End Position :`BG/
int nThreadID; //Thread's ID kG4])qxC'
boolean bDownOver = false; //Downing is over j/wQ2"@a
boolean bStop = false; //Stop identical k;Qm%B
FileAccessI fileAccessI = null; //File Access interface 2GigeN|1N
:Eg4^,QX
C.u)2[(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Tsu\4 cL]
{ /i!/)]*-
this.sURL = sURL; ae0Mf0<#)
this.nStartPos = nStart; R-iWbLD
this.nEndPos = nEnd; }#Ji"e
nThreadID = id; $WW7,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bB/fU7<{)u
} R SWw4}
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public void run() q2Sc{E>[
{ 9O&MsTmg$
while(nStartPos < nEndPos && !bStop) E_D@7a
{ [BKTZQ@G@
DM)Re~*
Qdc#v\B
try{ h|z59h&X8G
URL url = new URL(sURL); 2xy{g&G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y,4?>:39J
httpConnection.setRequestProperty("User-Agent","NetFox"); K.?S,qg
String sProperty = "bytes="+nStartPos+"-"; %gqu7}'
httpConnection.setRequestProperty("RANGE",sProperty); A$zC$9{0I
Utility.log(sProperty); ?56;<%0
s<C66z
p)Ht =~
InputStream input = httpConnection.getInputStream(); Ba%b]vp
//logResponseHead(httpConnection); Y!u">M#@
dqt}:^L*0g
}p9#Bzc
byte[] b = new byte[1024]; ZD?LsD3
int nRead; n#P?JyGm1g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TuwSJS7
{ 7S_"h*Ud
nStartPos += fileAccessI.write(b,0,nRead); 5Yk|
//if(nThreadID == 1) o(i?_4E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @-1VN;N
} YpSK|(
a\MJh+K
Hs.5@l
Utility.log("Thread " + nThreadID + " is over!"); >O1u![9K|w
bDownOver = true; 9Pm|a~[m
//nPos = fileAccessI.write (b,0,nRead); =p8iYtI
} We"\nOP
catch(Exception e){e.printStackTrace ();} l2!ztK1^
} m0Uk*~Gz
} u69G #
?,Wm|xY
riglEA[^
//打印回应的头信息 FePWr7Ze
public void logResponseHead(HttpURLConnection con) RDqQ6(e"
{ :WSszak
for(int i=1;;i++) OOz;/kay
{ 2DBFY1[Pk
String header=con.getHeaderFieldKey(i); 5.Nc6$ N
if(header!=null) / Kj;%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6,p;8I
Utility.log(header+" : "+con.getHeaderField(header)); /-ewCCzZV
else Pz'Zn
break; F n*+uk
} =~$)Ieu
} U4y ?z
bXWodOSN
3)dtl!VMW[
public void splitterStop() 2ZMVYa2%(
{ u|ru$cIo
bStop = true; Eds{-x|10
} "SwM%j
d6e]aO=g
LaIH3!M3
} GmN~e*x>p
m&6I@S2
"4QD\k5
/* `uqsYY`V
**FileAccess.java HO8x:2m
*//文件访问(定位，写) kkV*#IZ
package NetFox; K./L'Me
import java.io.*; ozG!OiRW
M|'![]-
;u?H#\J,
public class FileAccessI implements Serializable{ ")GrQv a
J*f..:m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v<S?"# ]F=
RandomAccessFile oSavedFile; +JBYGYN&K
long nPos; b@N*W]
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HNL;s5gq
public FileAccessI() throws IOException naW!Mga
{ TSYe~)I
this("",0); a)M#O\i`
} OD1>s6uA7
\]p[DYBY#
vM/D7YS:
public FileAccessI(String sName,long nPos) throws IOException @I0[B<,:G
{ [yfi:|n1
oSavedFile = new RandomAccessFile(sName,"rw"); ^sZ,(sc{G
this.nPos = nPos; 3l''
oSavedFile.seek(nPos); T#G (&0J5
} IWAp
VTJ,;p_UH
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public synchronized int write(byte[] b,int nStart,int nLen) ! ^U!T\qDi
{ 92Df.xI}
int n = -1; Z<Ke/Xi
try{ 8G p%Q
oSavedFile.write(b,nStart,nLen); dI9u:-
n = nLen; dpcFS0
} 0RGSv!w
catch(IOException e) 7S]akcT/
{ ejPK-jxCa/
e.printStackTrace (); )3KQ QGi8
} "DNiVL.
3SWO_
[n;GP@A]R
return n; /N(Ol WEp
} .UJjB}4$f
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M8' GbF=1
} sAU!u
0hx EI
niP/i
/* Sg}]5Mn`
**SiteInfoBean.java aJ}Cqk
*/ FrBJv<
package NetFox; /\1MG>#K
V9i[dF
VWR6/,N^_
public class SiteInfoBean { =M+enSu
zkRL'-
QO%#.s
private String sSiteURL; //Site's URL 7|eD}=jy
private String sFilePath; //Saved File's Path Yv[j5\:x
private String sFileName; //Saved File's Name 3[O;HS3|
private int nSplitter; //Count of Splited Downloading File ~kAen
L[FNr&
%4rPkPAtrp
public SiteInfoBean() (VzabO
{//nSplitter的缺省值为5 `^7ARr/
//default value of nSplitter is 5 LlfD>cN
this("","","",5); DsP FBq
} KD5}Nk)t
}vLK-Vv
`CXAE0Fx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N [iv.B
{ *q.qO )X}3
sSiteURL= sURL; ?3 l4U
sFilePath = sPath; tv1Z%Mx?Cp
sFileName = sName; =8F]cW'1`
this.nSplitter = nSpiltter; SXx2
7VQk$im399
WhHnF*I
} z rV
zT5@wm
iB,Nqs3i*
public String getSSiteURL() u.s-/ g
{ AK*F,H9
return sSiteURL; U0kEhMIIf
} _jW}p-j
1Gojuey
b8@gv OB
public void setSSiteURL(String value) mnM!^[|z
{ C4jqT
sSiteURL = value; aI6fPQe
} P`K?k<
&91U(Go
k*8 ld-O
public String getSFilePath() pU|SUM
{ l}$Pv?T,2
return sFilePath; /J"U`/ {4
} Ox` +Z0)a
`E),G;I
.D`""up|{
public void setSFilePath(String value) G3&l|@5
{ q! +?
sFilePath = value; C?3?<FDL
} [o=v"s't)
^sNj[%I R
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public String getSFileName() /k(KA [bS
{ "c6(=FFq
return sFileName; OBY
} Y!6,ty'
]~SOGAFW
JPX5Jm()
public void setSFileName(String value) gt1W_C\
{ d+Vx:`tT
sFileName = value; :{d?B$
} nSL x1Q
4$=Dq$4z
wh\J)pA1
public int getNSplitter() $~V,.RD
{ 'ju{j`b
return nSplitter; 0!c^pOq6
} qe!\ oh
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0"~`U.k~M
public void setNSplitter(int nCount) g$\Z-!(
{ eJB !|
nSplitter = nCount; [4qx+ypT
} ?=%Q$|]-
} Q]Fm4
'Lw4jq
z@nJ-*'U8
/* |uT&`0T'e`
**Utility.java Kzw)Q
*/ H h4G3h0
package NetFox; F]hKi`@
s:j"8ZH
==[a7|q
public class Utility { i9.~cnk
h]rF2 B
Gu-*@C:^&
public Utility() &J)q_Z8
{ &VIX?UngE
vpy_piG|
gxX0$\8o7
} R0R Xw
w !N;Y0
//线程睡眠 Xj/U~
public static void sleep(int nSecond) u;xl}
{ f&w8o5=|I
try{ w7H.&7rF
Thread.sleep(nSecond); JCu3,O!q
} g.v)qB
catch(Exception e) nwk66o:|
{ >9o(84AxIH
e.printStackTrace (); /qW5M4.w
} 17Q1Xa
} :>U2yI
%z6.}4h
//日志 '1lr "}"Q+
public static void log(String sMsg) fX,L;Se"
{ 6B)3SC
System.err.println(sMsg); }E5oa\1u
} 2 0Xqs,
h*_h M1*;
"5]Fl8c?
public static void log(int sMsg) _`>F>aP
{ D}SYv})Ti
System.err.println(sMsg); EK^B=)q6:W
} V0Cz!YM_3
} b_&;i4[
o#KGENd
PQ`p:=~>:i
/* 7Vf2Qx1_
**TestMethod.java TO.71x|
*/ H+:SL $+<o
package NetFox; #On EQ:
_~aFzM
I$K?,
public class TestMethod { &TqY\l
$]4>;gTL'
}QszOi\fV1
public TestMethod() Yx21~:9}
{ ///xx/weblogic60b2_win.exe :"+/M{qz
try{ 'iM;e K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L lmdydC%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D];%Ey
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,6,sz]3-
fileFetch.start(); 3/P#2&jt
} EG<YxNX,
catch(Exception e){e.printStackTrace ();} KdT1Nb=
9o<}*L
cqzd9L6=
} `6KTQk'
OI3UC=G
L&wJ-}'l
public static void main(String[] args) gA)!1V+:
{ d\Xi1&&
new TestMethod(); rlEp&"+|M
} cPh U qET
} ,wJ#0?
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