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)); R/kF,}^F
} *mkL>v &
for(int i=0;i<nEndPos.length-1;i++) gaR~K
{ y)b=7sU
nEndPos = nStartPos[i+1]; v_,'NA0
} ._6e#=
nEndPos[nEndPos.length-1] = nFileLength; 7%5EBH &
} HAAU2A9B2
} Wo~;h(6
g1&q6wCg|
> mEB,
//启动子线程 z)%]#QO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pQk@ +r
for(int i=0;i<nStartPos.length;i++) {GG;/Ns{f-
{ ]\*_}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SzyaVBD3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0lS=-am
nStartPos,nEndPos,i); Nq#B4Zx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ITfz/d8
fileSplitterFetch.start(); ?cB26Zrcb
} {=9"WN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (1Klj+"p%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dg4q+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FBS]U$1
nEndPos = " + nFileLength); 9/dADJe0b
// fileSplitterFetch[nPos.length-1].start(); e,T^8_>
qD{~QHDa
_c,{}sn
//等待子线程结束 wpcqgc
//int count = 0; QZFH>,d
//是否结束while循环 4}Yn!"jW&
boolean breakWhile = false; I[bWd{i:
af|x(:!H
41I2t(H @z
while(!bStop) $8>II0C.
{ [m(n-MuF
write_nPos(); FLLfTkXdI
Utility.sleep(500); b ; U
breakWhile = true; ?4#wVzuzA
63c\1]YB.
=*KY)X
for(int i=0;i<nStartPos.length;i++) ^a=V.
{ 4c@_u8
if(!fileSplitterFetch.bDownOver) 'LC0hoV
{ 9ZI^R/*Kc
breakWhile = false; K?*p|&Fi?8
break; mLDuizWI
} :*eJ*(M
} oVY_|UujG
if(breakWhile) _eUd RL>
break; r;GAQH}j_
eJE!\ucS2W
6yd?xeD
//count++; nf,Ez
//if(count>4) - @tL]]
// siteStop(); 0Z jE(3i
} c=33O,_
t(xe*xS
x$.0:jP/s
System.err.println("文件下载结束！"); I$*LMzve
} jfpbD /
catch(Exception e){e.printStackTrace ();} p$a+?5'Q
} lf_q6y
p%IVWeZnx
zA8Tp8(
//获得文件长度 *kt%.wPJ
public long getFileSize() F{laA YE
{ lKV7IoJ&;
int nFileLength = -1; rN`-ak
try{ <%S[6*6U
URL url = new URL(siteInfoBean.getSSiteURL()); ;$FMOMR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @*iT%p_L
httpConnection.setRequestProperty("User-Agent","NetFox"); LXm@h
UH#S |o4
ww)ow\
int responseCode=httpConnection.getResponseCode(); 6NGQU%Hd
if(responseCode>=400) sn8r`59C
{ W/u_<\
processErrorCode(responseCode); f!J?n]
return -2; //-2 represent access is error oWBjPsQ
} U|v@v@IBA
!}=#h8fv
`/9&o;qM
String sHeader; 51`*VR]`K
GP_%.fO\M
4q\gFFV4
for(int i=1;;i++) 9Rb tFwbn
{ .cs4AWml<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O[z-K K<
//Utility.log(in.readLine()); Gg6<4T1
sHeader=httpConnection.getHeaderFieldKey(i); h&x;#.SYK
if(sHeader!=null) +d=8/3O%
{ hlFvm$P`M
if(sHeader.equals("Content-Length")) MsP`w3b
{ pI}6AAs}Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E|x t\*
break; y(Tb=:
} TCK<IZKLqK
} qjf9ZD&
else <UbLds{+Uo
break; 8HL8)G6
} :@^T^
} HlXEU$e
catch(IOException e){e.printStackTrace ();} dQ_yb+<
catch(Exception e){e.printStackTrace ();} }nMp.7b
~[:Cl
hh<ryuZ
Utility.log(nFileLength); Vs, &
:F?L,I,K
no7Q%O9
return nFileLength; "\rR0V!wA
} NH!x6p]n
@c;:D`\p1C
0E/16@6=
//保存下载信息（文件指针位置） Jv59zI
private void write_nPos() A8j$c~
{ EOG&Xa
try{ SD]rYIu+
output = new DataOutputStream(new FileOutputStream(tmpFile)); C |P(,Xp
output.writeInt(nStartPos.length); (RI+4V1
for(int i=0;i<nStartPos.length;i++) *iXaQuT
{ ;f9a0Vs
// output.writeLong(nPos); SH;:bLk_
output.writeLong(fileSplitterFetch.nStartPos); [*d<LAnuWP
output.writeLong(fileSplitterFetch.nEndPos); Z6_fI
} aThvq%;
output.close(); %VwkYAgA
} Z1R{'@Y0Z
catch(IOException e){e.printStackTrace ();} R;H>#caJ
catch(Exception e){e.printStackTrace ();} aU%QJ#j
} }cERCS\t
UUqA^yJ
Lo5CVlK
//读取保存的下载信息（文件指针位置） YI+o:fGC5
private void read_nPos() DQ%(X&k
{ uX~YDy
try{ F 8 gw3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mLH,6rO9
int nCount = input.readInt(); k1Sr7|
nStartPos = new long[nCount]; r<EwtO+x
nEndPos = new long[nCount]; eD0|6P;Ei
for(int i=0;i<nStartPos.length;i++) TS@U0Ror
{ (\CH;c-@
nStartPos = input.readLong(); F3&:KZ!V&m
nEndPos = input.readLong(); "hLmwz|a
} H<ZXe!q(nx
input.close(); Hzojv<c
} R|R3Ob.e
catch(IOException e){e.printStackTrace ();} &-p!Lg&D
catch(Exception e){e.printStackTrace ();} V(3rTDg
} x(y=.4Yf+
YL9Tsw
u^+ (5|
private void processErrorCode(int nErrorCode) o5<w2(
{ `k~w 14~w
System.err.println("Error Code : " + nErrorCode); qWb8"
} {|R +|ow
YbP}d&L
8o[+>W
//停止文件下载 F{FSmUxzK
public void siteStop() xZ>@wBQ
{ zN7Ou .
bStop = true; CAbT9Wz&
for(int i=0;i<nStartPos.length;i++) [G7S
fileSplitterFetch.splitterStop(); BaOPtBYA:
#An_RU6h
-59;Zn/
} 89a`WV@}
} z-;yDB:~t
//负责部分文件的抓取 )/uCdSDIc
**FileSplitterFetch.java G|)fZQ1nS
*/ j$=MJN0
package NetFox; ^LAdN8Cbb
<k7q9"\4
hSU|rVi
import java.io.*; *sq+ Vc(
import java.net.*; P*9L3R*=N
y\}<N6
H263<^
public class FileSplitterFetch extends Thread { 0j2M< W#
m'5rzZP
l8By2{pN
String sURL; //File URL f<P>IE
long nStartPos; //File Snippet Start Position q{RT~,%
long nEndPos; //File Snippet End Position x).`nZ1
int nThreadID; //Thread's ID z|sR `]K
boolean bDownOver = false; //Downing is over zq4)Uab*
boolean bStop = false; //Stop identical 7A46?kfu
FileAccessI fileAccessI = null; //File Access interface J)_IfbY
99&PY[f:{
MI*@^{G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T.iVY5^<
{ BxHfL8$1[$
this.sURL = sURL; mY/x|)MmM
this.nStartPos = nStart; #GA6vJ4^s
this.nEndPos = nEnd; Ar1X mHq
nThreadID = id; ~6Df~uN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vAo|o*
} @BS7Gyw
h}<Ie <
'EsdYx5C
public void run() +u'y!@VV
{ oSB0P
while(nStartPos < nEndPos && !bStop) #;Z+X)
{ _:.'\d(
(S k+nD
_-bEnF+/0
try{ jGKasI`
URL url = new URL(sURL); 6'QlC+E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j[\aGS7u
httpConnection.setRequestProperty("User-Agent","NetFox"); s14;\
String sProperty = "bytes="+nStartPos+"-"; XyE%<]
httpConnection.setRequestProperty("RANGE",sProperty); qjVhBu7A
Utility.log(sProperty); iV8O<en&i
<[<]+r&*
\z)` pno
InputStream input = httpConnection.getInputStream(); ~h6aTN
//logResponseHead(httpConnection); $sBje*;
yZ57uz
lO5*n|Ic,
byte[] b = new byte[1024]; D-4\AzIb
int nRead; e8$OV4X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D}7G|gX1
{ +hKH\]
nStartPos += fileAccessI.write(b,0,nRead); l?swW+x\
//if(nThreadID == 1) O5?3nYHa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !:w&eFC6
} PR*qyELu
_4MT,kN
:h60
Utility.log("Thread " + nThreadID + " is over!"); Z*Jp?[##
bDownOver = true; +q@g
//nPos = fileAccessI.write (b,0,nRead); |_`wC
} NlV,] $L1T
catch(Exception e){e.printStackTrace ();} F~${L+^
} \)mV2r!%
} agMI$
;,F:.<P
CXfPC[o
//打印回应的头信息 6qzyeli
public void logResponseHead(HttpURLConnection con) 6I,4 6 XZ-
{ iH[ .u{h
for(int i=1;;i++) BA cnFO
{ $Hbd:1%i {
String header=con.getHeaderFieldKey(i); VA0p1AD
if(header!=null) [^GXHE=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MuCnBx
Utility.log(header+" : "+con.getHeaderField(header)); ums*EKjs97
else ;L.RfP"5<
break; NgPY/R>
} NY!"?Zko
} FW7@7cVoF
?v$kq}Rg
~G*eJc0S:
public void splitterStop() lH8e?zJ
{ q&N1| f7
bStop = true; qz2j55j
} 0?d}Oj
}|!9aojr
Da8{==
} o\7q!
|37y ="
js<}>wD7<
/* 4+j:]poYG{
**FileAccess.java q"sD>Yh&
*//文件访问(定位，写) R" '=^
package NetFox; E A8>{}Z*
import java.io.*; l9up?opq
x%\m/_5w%
KeiPo KhZi
public class FileAccessI implements Serializable{ :VEy\ R>W
]&l%L4Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C-6m[W8S
RandomAccessFile oSavedFile; 4RXF.kJ3=
long nPos; 5? rR'0
:P1/kYg
>u)DuZXj
public FileAccessI() throws IOException AJ`R2 $
{ |?KdQeL
this("",0); h-`*S&mZ
} WOaj_o
!WD~zZ|
e}Xmb$
public FileAccessI(String sName,long nPos) throws IOException ID1/N)56
{ f/Q7WXl0
oSavedFile = new RandomAccessFile(sName,"rw"); IR<`OA
this.nPos = nPos; 3S_H hvB
oSavedFile.seek(nPos); 5QoU&Hv
} b=-LQkcZhK
.oR_r1\y
BDCFToSf|
public synchronized int write(byte[] b,int nStart,int nLen) 3+v+_I>%k
{ =*Ad
int n = -1; z8"(Yy7m
try{ 9?xc3F2EBD
oSavedFile.write(b,nStart,nLen); \X?GzQkr
n = nLen; ^.f`6 6/
} mI$3[ #+
catch(IOException e) Q[M?LNE`
{ ~ [4oA$[a|
e.printStackTrace (); !U2Wiks
} $_P*Bk)
"ccP,#Y
7P2?SW^
return n; +UTs2*H/^
} u3>Dvl@
s{]2~Z^2od
w[V71Iej
} Pd[&&!+gV
5yhfCe m|
N))G/m3
/* &74*CO9B9
**SiteInfoBean.java Ehv*E
*/ WF.y"{6>
package NetFox; v'QmuMWF
@9wug!,
;1&7v
public class SiteInfoBean { Gpauy=4f
FojsI<
# [0>wEq
private String sSiteURL; //Site's URL nd 5w|83
private String sFilePath; //Saved File's Path !AGjiP$
private String sFileName; //Saved File's Name E2D}F@<]
private int nSplitter; //Count of Splited Downloading File h 'F\9t
d&'}~C`~k
#<\A[Po
public SiteInfoBean() dt efDsK
{//nSplitter的缺省值为5 kZsat4r
//default value of nSplitter is 5 }8W5m(Zq9n
this("","","",5); S1R:/9 z
} nDhD"rc
/4R|QD
?5>Ep:{+/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {'QA0K
{ 9Xu O\+z
sSiteURL= sURL; 5V^+;eO
sFilePath = sPath; TZ]D6.mD
sFileName = sName; i8tH0w/(M
this.nSplitter = nSpiltter; Ba9le|c5
F^v <z)x
Zu$30&U
} 2 P=c1;
"[*W=6m0
2JV,AZf
public String getSSiteURL() 6S~lgH:
{ U#jbii6e
return sSiteURL; h zh%ML3L
} %:P&!F\?
d4h, +OU
t&r-;sH^[
public void setSSiteURL(String value) tyH*epanw
{ {=Y.Z1E:
sSiteURL = value; Ny.s u?E
} 22|a~"Z
.!\NM&E
Lb'HM-d
public String getSFilePath() zdwr5k
{ nI-^
return sFilePath; ;JK!dzi}
} <oE(I)r4,
7%-+7O3ud
l~/g^lN
public void setSFilePath(String value) k_2W*2'S
{ FK$?8Jp
sFilePath = value; &s|&cT
} .[Z<r>
c&+p{hH+
X\I"%6$
public String getSFileName() drJ<&1O
{ bGl5=`
return sFileName; IXmtjRv5
} H'L~8>
)<D(Mb2p|
v\Y362Xv
public void setSFileName(String value) 6%K,3R-d
{ !;YmLJk;hN
sFileName = value; @q?zh'@;
} O>=D1no*
)V}u}5
uKI2KWU?2
public int getNSplitter() `XwFH#_
{ i#@3\&{J>
return nSplitter; H$ !78/f
} ;+dB-g[
=]pcC
^_5Nh^
public void setNSplitter(int nCount) .,C8ASfh
{ }}";)}C`
nSplitter = nCount; 9`/\|t|V
} ^<0azza/(
} Lh%>> Ht{
Z2yZz:.'
p&nIUx"
/* +v 9@du
**Utility.java *Ge2P3
*/ Y5}<7s\UDO
package NetFox; tFvc~zz9
Zhl}X!:c?\
\\F@_nB,b
public class Utility { !H`! KBW
UIUCj8QJg
rUX1Iu7
public Utility() AXV+8$ :R
{ H!y%FaTi
zCdQI
3[RbVT
} cO,ELu
j5*W[M9W
//线程睡眠 NR8YVO)5$
public static void sleep(int nSecond) TSQ/{=r
{ `TM[7'
try{ :nuMakZZ
Thread.sleep(nSecond); kKV`9&dZe
} hw?'aXK{
catch(Exception e) ('/5#^%R
{ Fm@G@W7,m
e.printStackTrace (); -r9G5Z!|n
} x0ZEVa0`4
} p{knQ],
E\5cb[Y
//日志 ':kj\$U
public static void log(String sMsg) 5B[kZ?>
{ a'f0Wv0%"
System.err.println(sMsg); @za X\
} "o +" Jd
rBv
S!0ocS!t
public static void log(int sMsg) {wWh;
{ H7 acT
System.err.println(sMsg); .JNU3%s
} fmDU
} fqaysy
5>J{JW|
#GBe=tm\K
/* 8~QEJW$
**TestMethod.java #P,mZ}G\
*/ *R17 KMS
package NetFox; 2QUZAV\ Y
eGrC0[SH
0*66m:C2
public class TestMethod { <Z^t^ O
f n9[Li
q' };.tv
public TestMethod() |Uz?i7z
{ ///xx/weblogic60b2_win.exe |k~\E|^
try{ \29a@6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =]h5RC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =W1`FbR
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3lc'(ts%
fileFetch.start(); R v61*F4
} YYFJJ,7?
catch(Exception e){e.printStackTrace ();} tcYbM+4e
zmf`}j[
5}3Q}o#
} 9QaEUy*,
,Mf@I5?
!br0s(|
public static void main(String[] args) ?MevPy`H
{ i]{M G'tg
new TestMethod(); 41y}n{4n8
} vpOn0([hS
} 4&IBNc,sn
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