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)); 8e)k5[\m
} [ivz/r(Rj
for(int i=0;i<nEndPos.length-1;i++) @^} % o-:
{ ,7SLc+
nEndPos = nStartPos[i+1]; d|]F^DDuI
} ukv _bw
nEndPos[nEndPos.length-1] = nFileLength; ,XCC#F(d1
} =PAvPj&}e
} 8dq{.B?
016l$K4
bP&o]?dN
//启动子线程 u-Ct-0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vlIet$k
for(int i=0;i<nStartPos.length;i++) rX%#Q\0h
{ Qbfm*JP~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P1=bbMk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6tI7vLmG
nStartPos,nEndPos,i); ~-lIOQ.v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tz+2g&+
fileSplitterFetch.start(); $&nF1HBI4
} o1MI&}r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S20x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $1.iMHb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g$kK)z
nEndPos = " + nFileLength); ~el#pf~
// fileSplitterFetch[nPos.length-1].start(); wKe^5|Rr
I:uxj%
F}<&@7kF
//等待子线程结束 D}px=?
//int count = 0; a+szA};
//是否结束while循环 $&EZVZ{r
boolean breakWhile = false; 's@v'u3
[nn/a?Z4S
,W5pe#n
while(!bStop) G{}E~jDi?
{ PV(bJ7&R
write_nPos(); 9fMg?
Utility.sleep(500); jpZX5_o
breakWhile = true; ;#78`x2
< Upn~tH
^v*ajy.>
for(int i=0;i<nStartPos.length;i++) 6Bmv1n[X^h
{ }lML..((1
if(!fileSplitterFetch.bDownOver) 7'7bIaJk
{ %>Z=#1h/a
breakWhile = false; 03J,NXs
break; pK1P-!c
} {z|0Y&>[=
} 2W|4
if(breakWhile) 71 hv~Nk/x
break; $@Zb]gavt?
,AGK O,w
=r3Yt9
//count++; !;pmql
//if(count>4) MA.1t
// siteStop(); 4otB1{
} a36n}R4Q
k^z)Vu|f.
d"Y9go"Z
System.err.println("文件下载结束！"); !sEI|47{
} fW!~*Q
catch(Exception e){e.printStackTrace ();} )"|'=
} (k6=o';y
/],:sS7
- 4'yp
//获得文件长度 G~a;q+7v'$
public long getFileSize() *y5d&4G2
{ Otj=vGr0
int nFileLength = -1; %bZ3^ ub}t
try{ ;H_yNrwA
URL url = new URL(siteInfoBean.getSSiteURL()); # Fw<R'c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5ap}(bO
httpConnection.setRequestProperty("User-Agent","NetFox"); Y~dRvt0_w
)M#~/~^f+
<d#9d.<
int responseCode=httpConnection.getResponseCode(); (3 8.s:-
if(responseCode>=400) ?(*KQ#d
{ @7 &rDZ
processErrorCode(responseCode); {F6hx9?
return -2; //-2 represent access is error TGdD7n&Ehh
} (NOAHV0H
(-(,~E
W:4]-i?2
String sHeader; +>KWYPH
U&C\5N]
8?W\kf$
for(int i=1;;i++) !9356) cV
{ 6aK'%K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }EE
//Utility.log(in.readLine()); #~I%qa"_pa
sHeader=httpConnection.getHeaderFieldKey(i); uKo)iB6D
if(sHeader!=null) _jy*`$"q(
{ !lm^(SSv
if(sHeader.equals("Content-Length")) q-/A_5>!;f
{ tQ5gmj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L7G':oA_`p
break; 8'Xpx+v
} ;Y?7|G97*S
} {(o\G"\<XY
else R)WvU4+U
break; %N|7<n<S
} }%| (G[
} yb*SD!
catch(IOException e){e.printStackTrace ();} $ n`<,;^l
catch(Exception e){e.printStackTrace ();} #lM!s
Mto3Ryic!
.r[DqC
Utility.log(nFileLength); szF[LRb
Q5;Km1(
r9%4q4D?>9
return nFileLength; VeA;zq
} _p?lRU8
tB&D~M6[
BEg%u)"([
//保存下载信息（文件指针位置） P}~6yX
private void write_nPos() qdCa]n!d
{ Rde#=>@V
try{ lD6hL8[
output = new DataOutputStream(new FileOutputStream(tmpFile)); oPk2ac
output.writeInt(nStartPos.length); <uU AAHi
for(int i=0;i<nStartPos.length;i++) !a[ voUS
{ 'dQ2"x?4
// output.writeLong(nPos); |bi"J;y
output.writeLong(fileSplitterFetch.nStartPos); Fb*^GH)J
output.writeLong(fileSplitterFetch.nEndPos); UB|Nx(V s
} y,DK@X
output.close(); @+syD
} j()_ VoB1
catch(IOException e){e.printStackTrace ();} M< *5Y43
catch(Exception e){e.printStackTrace ();} YMIDV-
} _;yp^^S
m qPWCFP
7{D+\i
//读取保存的下载信息（文件指针位置） ``1#^ `
private void read_nPos() P{)&#HXUVb
{ }z,4IHNn
try{ B:n9*<v(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $A7[?Ai ?
int nCount = input.readInt(); "}\z7^.W>
nStartPos = new long[nCount]; -[~{c]/c
nEndPos = new long[nCount]; pA!+;Y!ZB<
for(int i=0;i<nStartPos.length;i++) M98dQ%4I
{ [m|\N
nStartPos = input.readLong(); rD%(*|Y"c
nEndPos = input.readLong(); CP7Zin1S/w
} !z{bqPlFGG
input.close(); *;m5^i<,;S
} @>qzRo
catch(IOException e){e.printStackTrace ();} Pgr>qcbql
catch(Exception e){e.printStackTrace ();} \hc}xy 0
} y 8];MTl
'hVOK(o0
:?RooJ~#
private void processErrorCode(int nErrorCode) hK@1 s
{ ORv[Gkq_N)
System.err.println("Error Code : " + nErrorCode); lR{eO~'~V
} #|A @
~~;fWM '
GJy><'J,!>
//停止文件下载 00%$?Fyk
public void siteStop() ro}plK(<WQ
{ >J3N,f
bStop = true; w]"Y1J(i
for(int i=0;i<nStartPos.length;i++) >LgV[D#=&o
fileSplitterFetch.splitterStop(); s)375jCga
hs2f3;)
(vz)GrH>
} :?@d\c'
} y:iE'SRRK6
//负责部分文件的抓取 HzQ6KYAMq
**FileSplitterFetch.java @-qxNw
*/ kzLj1Ix2
package NetFox; n1y#gC
r7C m
GaSk&'n$Y
import java.io.*; T d4/3k
import java.net.*; KVtnz
uTbI\iq
^-4mZXAy1|
public class FileSplitterFetch extends Thread { AcrbR&cvG
m3F.-KPO
}-V .upl
String sURL; //File URL (4$lB{%
long nStartPos; //File Snippet Start Position 4D$$KSa
long nEndPos; //File Snippet End Position 9V.)=*0hp
int nThreadID; //Thread's ID k#JFDw\
boolean bDownOver = false; //Downing is over S?OK@UEJ
boolean bStop = false; //Stop identical s]5wzbFO
FileAccessI fileAccessI = null; //File Access interface 7T_g?!sdMh
@s/;y VVq
42Gr0+Mb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qoB
{ O*H:CW
this.sURL = sURL; MO9}Itg
this.nStartPos = nStart; xPQO}wKa
this.nEndPos = nEnd; 0Ny0#;P
nThreadID = id; #bsRL8@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yeE_1C .
} OZ![9l
mrqCW]#u
.3{S6#
public void run() d+fmVM?p
{ 70lb6A
while(nStartPos < nEndPos && !bStop) O7s0M?4
{ #T#&qo#
'3[Ecy#
dI>)4()
try{ ]AERi] B
URL url = new URL(sURL); $w[@L7'(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NvJu)gI%
httpConnection.setRequestProperty("User-Agent","NetFox"); _f|Au`7m
String sProperty = "bytes="+nStartPos+"-"; DcSL f4A
httpConnection.setRequestProperty("RANGE",sProperty); ]'~'V2Ey
Utility.log(sProperty); 1^!=J<`K;
kQ.atr`?e
EVgn^,
InputStream input = httpConnection.getInputStream(); T"kaOy
//logResponseHead(httpConnection); mRj-$:}L
jn]hqTy8
duXv [1
byte[] b = new byte[1024]; zi-zg Lx
int nRead; P:(,l,}F8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s3g$F23
{ w]tv<U={
nStartPos += fileAccessI.write(b,0,nRead); Eqp?cKrji
//if(nThreadID == 1) Mr2dhSQ!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LP@Q8{'
} XXuU@G6Z7$
v{Zh!mk* L
>p\IC
Utility.log("Thread " + nThreadID + " is over!"); 0z#+^
bDownOver = true; 75!IzJG
//nPos = fileAccessI.write (b,0,nRead); &m>`+uVBP
} CyzvQfpZr
catch(Exception e){e.printStackTrace ();} ?.\CUVK
} #q==GT7
} 4mNL;O
.A\9|sRZ5
T6OIb
//打印回应的头信息 Tud[VS?99
public void logResponseHead(HttpURLConnection con) &:akom8
{ 0eq>
for(int i=1;;i++) Yx(?KN7V?
{ YOGwQ
String header=con.getHeaderFieldKey(i); K+ufcct
if(header!=null) Y<w2_+(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yHr/i) c
Utility.log(header+" : "+con.getHeaderField(header)); / DeIs
else EZ1H0fm
break; SQ>.P
} ~S"G~a(&j
} #4%,09+
k-e_lSYk&c
/Wg$.<!5}
public void splitterStop() g@MTKqs
{ G A2S
bStop = true; egx(N <
} e_k1pox]l
E^A9u |x
+c}fDrr)
} T>vHZZiO
Nf-IDK
9y.C])(2
/* g3LAi#m
**FileAccess.java N=tyaS(YJ
*//文件访问(定位，写) +s1+;VUs3
package NetFox; /LuwPM
import java.io.*; W$?1" F.
ofcoNLX5c
ln9MVF'!&
public class FileAccessI implements Serializable{ .H7"nt^
OR1XQij
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +P}'2tE~'
RandomAccessFile oSavedFile; hkHMBsNi
long nPos; :V}8a!3h
,6i67!lb
.s7o$u~l
public FileAccessI() throws IOException (yc$W9
{ =ZzhH};aX
this("",0); r A0[y
} a(d'iAU8^
r6PiZgR
(tyo4Tz1
public FileAccessI(String sName,long nPos) throws IOException (V{bfDu&h@
{ r{>tTJFD(:
oSavedFile = new RandomAccessFile(sName,"rw"); >/5D/}4
this.nPos = nPos; ;`X-.45
oSavedFile.seek(nPos); kl3#&>e
} qZ`@Ro
kj@#oLd%
Qs#v/r
public synchronized int write(byte[] b,int nStart,int nLen) ^a<=@0|
{ WAqR70{KM
int n = -1; ;[gv-H
try{ +Nc|cj
oSavedFile.write(b,nStart,nLen); s8@fZ4
n = nLen; Be8Gx
} @8n0GCv
catch(IOException e) oo-^BG
{ cO)GiWE
e.printStackTrace (); ?o9l{4~g
} _f^q!tP&d
cl:*Q{(Cjk
9DKmXL
return n; C(e!cOG
} P*I\FV
aOWbIS[8
(:Bo'q S
} 2rPKZ|
<(3Uu()
r-4I{GPb
/* 0 I;>du
**SiteInfoBean.java "9kEqz4a
*/ J +<|8D
package NetFox; VR*5}Qp
7dV^35 KP
asPD>jc
public class SiteInfoBean { Lm-}W "7
OSfwA&
PCt&66F
private String sSiteURL; //Site's URL 8Q#&=]W$
private String sFilePath; //Saved File's Path 97F$$d54T
private String sFileName; //Saved File's Name iO<O2A.F
private int nSplitter; //Count of Splited Downloading File ^h^j:!76j
+n2x@ 0op
t m5>J)C
public SiteInfoBean() 9L!Vj J
{//nSplitter的缺省值为5 4.H!rkMM
//default value of nSplitter is 5 ``aoLQc`
this("","","",5); 47$JN}qI0
} >s[}f6*2@
c{||l+B
+1h^9Y'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bTHJbpt*-
{ GN=F-*2
sSiteURL= sURL; ~;bwfp_
sFilePath = sPath; w<\N-J|m
sFileName = sName; O}IS{/^7
this.nSplitter = nSpiltter; bsqoR8
Q6Jb]>g\H
G!0|ocE}
} f4!^0%l
#'$CC<*vy
Pvbw>k;
public String getSSiteURL() RoJ&dK
{ ;#rtV;
return sSiteURL; nU`vj`K
} "thfd"-
szmjp{g0
Br-y`s~cP
public void setSSiteURL(String value) 8 hWQ
{ A4(^I u
sSiteURL = value; %\:.rs^
} 2eyvY|:Q>
jWP(7}U
G@,qO#5&
public String getSFilePath() Lc<Gny^
{ F!zZIaB]
return sFilePath; ,aawtdt/
} Ix1ec^?f
pC#Z]_k
LNg[fF^:
public void setSFilePath(String value) }c&Zv#iO6
{ $5il]D`
sFilePath = value; }"q1B
} eYsO%y\I
W{Nhh3
'-W p|A
public String getSFileName() 4:6@9.VVT
{ IXd&$h]Lq
return sFileName; EWH'x$z_q
} 7J$ ^R6rh
3@6f%Dyj
@jwUH8g1
public void setSFileName(String value) E.6^~'/
{ { "$2
sFileName = value; Kpj0IfC,10
} d*q_DV
y}#bCRy~.A
D}b+#G(m[
public int getNSplitter() eN}FBX#'
{ zZ;tSKL
return nSplitter; 7(gQ6?KsZ
} U%w-/!p
wond>m 3
ce+\D'q[
public void setNSplitter(int nCount) 6pr}A
{ OaU$ [Z'8
nSplitter = nCount; &?zJ|7rh@|
} b%|%Rek8
} 0B3*\ H}5
$9Z8P_^.0(
Zu~ #d)l3N
/* puMpUY
**Utility.java ';b/D
*/ (qB$I\
package NetFox; QdDdrR^&
/l:3*u
PPE:@!u<
public class Utility { ,JVD ;u
}\l5|Ft[!
QD"V=}'?
public Utility() 3R4-MK
{ n%"s_W'E
,`-6!|:
~rn82an@G
} )G*Hl^Z;4
rBgLj,/`U/
//线程睡眠 o @&#*3<_e
public static void sleep(int nSecond) /i^b;?/1
{ )5yZSdA
try{ tQ=U22&7
Thread.sleep(nSecond); Gi;eDrgj~
} }Qg9l|
catch(Exception e) 4P2)fLmc
{ $:mCyP<y
e.printStackTrace (); }.`ycLW'
} . 1?AU6\
} WOgbz&S?J
v\\Z[,dK
//日志 9LCV"xgX
public static void log(String sMsg) ]^aece t
{ -V4@BKI8
System.err.println(sMsg); o*r\&!NIw
} v?d~H`L
JNX7]j\
$ n 7dIE
public static void log(int sMsg) $i~DUT(
{ Pf@8C{I
System.err.println(sMsg); k[G?22t
} Cww$ A %}
} _W?}%;
ze,HNFg@>
,|T
/* s(wbsRVP8
**TestMethod.java t;y>q
*/ . 6Bz48*
package NetFox; t^uX9yvx
7,Z%rqf\)
G}f.fRY
public class TestMethod { H!oP!rzEo
y4M<L. RO
)v ['p
public TestMethod() 2ht<"
{ ///xx/weblogic60b2_win.exe dwJ'hg
try{ {!6!z,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xg.\B1d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r7w&p.?
SiteFileFetch fileFetch = new SiteFileFetch(bean); >Qt#6X|
fileFetch.start(); mC J/gWDY
} =_Qt&B)
catch(Exception e){e.printStackTrace ();} - n11L
n%Nf\z
a.c2ScXG
} ]6$NU [
r=qb[4HiV
yuKfhg7
public static void main(String[] args) R.>/%o
{ "t4~xs`~X
new TestMethod(); 3-LO
} N:gS]OI*
} JUwP<C[
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