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)); t4h5R
} H<dm;cU
for(int i=0;i<nEndPos.length-1;i++) j @sd x)1+
{ ,odjL6u
nEndPos = nStartPos[i+1]; o{m$b2BW
} 2i8'*L+j
nEndPos[nEndPos.length-1] = nFileLength; Eo)n( Z9
} u]CW5snz
} hNSV}~h
qDOx5.d
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//启动子线程 >e"1a/2%>&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n(-XI&Kn
for(int i=0;i<nStartPos.length;i++) Va?wG3w
{ znX2W0V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L<5go\!bV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CQ6Z[hLWF
nStartPos,nEndPos,i); '0z@Jevd?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8M8=uw~#
fileSplitterFetch.start(); P7<~S8)Y
} 5=5~GX-kr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MhHygZT[}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wIL5-k,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^BSMlKyB
nEndPos = " + nFileLength); b[VP"KZ?
// fileSplitterFetch[nPos.length-1].start(); .,UpI|b
rEz=\yY^j'
B4_0+K H
//等待子线程结束 X|@|ZRN
//int count = 0; &nTB^MF
//是否结束while循环 tJ[Hcx*N
boolean breakWhile = false; KGzBK:
y~Sh|2x8v
.,<-lMC+
while(!bStop) 1/JgirVA
{ -.i1l/FzP
write_nPos(); \"5%w *vl
Utility.sleep(500); _D[vMr[
breakWhile = true; {BDp`uZ
d|w%F=
T'0Ot3m`
for(int i=0;i<nStartPos.length;i++) "~N#Jqzr:
{ @va)j
if(!fileSplitterFetch.bDownOver) [gQ*y~N
{ q/<.^X
breakWhile = false; hyVuZ\9B
break; f4CwyL6ur
} mf^(Tq[
} 2Pasmh
if(breakWhile) WwPfz<I
break; E;9SsA
aZ@Ke$jD
]7fqVOiOu
//count++; rW&8#&
//if(count>4) >& \QLo[5
// siteStop(); G}AfCd4
} 83Bp_K2\
e(,sFhR
r8}GiP0|
System.err.println("文件下载结束！"); (]0ZxWF
} [#$z.BoEo
catch(Exception e){e.printStackTrace ();} y!)Z ^u
} tAPqbi$a
lpj$\WI=
%koHTWT+
//获得文件长度 `` 6?;Y
public long getFileSize() C$b$)uI;
{ B}C"Xc
int nFileLength = -1; VD<W
try{ 0".pw; .}
URL url = new URL(siteInfoBean.getSSiteURL()); F]0O4p~fl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MX xRM~
httpConnection.setRequestProperty("User-Agent","NetFox"); xmT(yv,
Ud\Jc:DG
\:'=ccf
int responseCode=httpConnection.getResponseCode(); U;LbP-{B
if(responseCode>=400) m("! M~1
{ Jx[IHE
processErrorCode(responseCode); =k2In_
return -2; //-2 represent access is error yo#&>W
} ]b-Z;Nce
"P~07
6&`.C/"2
String sHeader; F]q pDv
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U(3{6^>Gc
for(int i=1;;i++) XA-DJ
{ ;SEH|_/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (sq4
//Utility.log(in.readLine()); CVyqr_n65/
sHeader=httpConnection.getHeaderFieldKey(i); {r#2X1
if(sHeader!=null) hp@giu7
{ NgaX&m`
if(sHeader.equals("Content-Length")) H B_si
{ f|cd_?|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qHt!)j9GKv
break; H$9--p
} NU-({dGK}
} ik=~`3Zp0
else S ])Ap'E
break; BHy#g>KUF
} xVao3+r
} #Wey)DI
catch(IOException e){e.printStackTrace ();} 3U!\5Nsby
catch(Exception e){e.printStackTrace ();} ?H#]+SpOcv
4/e-E^
Ec y|l;
Utility.log(nFileLength); ;X[mfg\
[k ZvBd
6'3@/.
return nFileLength; Qv,8tdx
} #(mm6dj
s/ibj@h
;\DXRKR
//保存下载信息（文件指针位置） <(TTYf8lS
private void write_nPos() (f,D$mX
{ 0Y,_ DU
try{ 0C#1/o)o
output = new DataOutputStream(new FileOutputStream(tmpFile)); GU8b_~Gk?
output.writeInt(nStartPos.length); 6kK\nZ$o$
for(int i=0;i<nStartPos.length;i++) E5w.wx
{ 0(iTnzx0
// output.writeLong(nPos); 6.kX~$K
output.writeLong(fileSplitterFetch.nStartPos); RMMx6L|-:
output.writeLong(fileSplitterFetch.nEndPos); {'4h.PB+r
} J@54B
output.close(); -ve{O-;
} gk>-h,>"
catch(IOException e){e.printStackTrace ();} 1a;Le8
catch(Exception e){e.printStackTrace ();} *z!!zRh3x
} ^a4y+!
XO~xbG7>gZ
]&`_5pS
//读取保存的下载信息（文件指针位置） j(F&*aH78
private void read_nPos() wrv-"%u)
{ M:z)uLDw
try{ m=b~Wf39
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rlqn39
int nCount = input.readInt(); D *RF._
nStartPos = new long[nCount]; |#q5#@,
nEndPos = new long[nCount]; .9_]8T
for(int i=0;i<nStartPos.length;i++) B<i)je!
{ )T/"QF}<T
nStartPos = input.readLong(); b&f;p}C24
nEndPos = input.readLong(); #80DM
} /.l8Jb4
input.close(); Pf5RlpL:p
} h~)oiT2v
catch(IOException e){e.printStackTrace ();} <GC<uB |p
catch(Exception e){e.printStackTrace ();} -} \g[|
} rC V&&09
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rT9<_<
private void processErrorCode(int nErrorCode) t<mT=(zt*
{ TkXD#%nFY
System.err.println("Error Code : " + nErrorCode); Ymkk"y.w
} -bJht
AD^9?Z
ESp)%
//停止文件下载 h$.y)v
public void siteStop() kKFmTo
{ ":EfR`A#
bStop = true; %m$TV@
for(int i=0;i<nStartPos.length;i++) ig:,:KN
fileSplitterFetch.splitterStop(); g N76
U?97yc\$
:c3}J<Z
} 3on]#/"1b
} u~FXO[b
//负责部分文件的抓取 jH#Tt;
**FileSplitterFetch.java aTF~rAne<
*/ t<s:ut)Q!
package NetFox; zBD ?O!
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L1ZhH3}X
import java.io.*; yo]!Zn
import java.net.*; %>Z;/j|#r
pi7Fd\A
(]7&][
public class FileSplitterFetch extends Thread { yk OJhd3
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]Tk3@jw+b
String sURL; //File URL #ky]@vyO
long nStartPos; //File Snippet Start Position I:l<t*
long nEndPos; //File Snippet End Position 2Pn
int nThreadID; //Thread's ID /T&z :st0
boolean bDownOver = false; //Downing is over TD:NL4dm
boolean bStop = false; //Stop identical l]D?S]{a
FileAccessI fileAccessI = null; //File Access interface Lh.?G#EM
?;Dh^mc
5>+>=)*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException COPH)Bdq.
{ |6/k2d{,(
this.sURL = sURL; }9yAYZ0q{b
this.nStartPos = nStart; #T:#!MKa
this.nEndPos = nEnd; Y^DS~CrM
nThreadID = id; d#E]>:w9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5VIc
} )jkX&7x
?,~B@Kx
#G2~#\
public void run() (#x<qi,T
{ .w=( G
while(nStartPos < nEndPos && !bStop) Y/cnj n
{ }pOL[$L
(3 xCW
;mH O#
try{ <>JN&#3?
URL url = new URL(sURL); l",JN.w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *6D0>F
httpConnection.setRequestProperty("User-Agent","NetFox"); _aa3;kT_
String sProperty = "bytes="+nStartPos+"-"; 1|$V
httpConnection.setRequestProperty("RANGE",sProperty); 5u +U^D
Utility.log(sProperty); 'q%56WAJ
pleLdGq
ArWMbT>Zqw
InputStream input = httpConnection.getInputStream(); 6[fpe
//logResponseHead(httpConnection); xG:eS:iT
eX7dyM
~/Gx~P]
byte[] b = new byte[1024]; /Y$UJt
int nRead; eF+:w:\h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g-`HKoKe
{ C "XvspJ
nStartPos += fileAccessI.write(b,0,nRead); bH4'j/3
//if(nThreadID == 1) hu}`,2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9qc<m'MZ
} G"w ?{W@
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"FA&Qm0
Utility.log("Thread " + nThreadID + " is over!"); [>+R|;ln
bDownOver = true; JGQlx-qv
//nPos = fileAccessI.write (b,0,nRead); M#o.$+Uh
} >i^8K U
catch(Exception e){e.printStackTrace ();} 4qMqAT
} b[&A,ZPh$@
} '&/ 35d9|*
qxS=8#-`(
egQB!%D
//打印回应的头信息 W4n;U-Hb
public void logResponseHead(HttpURLConnection con) {A2EGUmF2
{ Bk,:a,
for(int i=1;;i++) Zzy!D
{ `-a](0QU
String header=con.getHeaderFieldKey(i); 2d:<P!B
if(header!=null) B-Bgk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]D(!ua5|x`
Utility.log(header+" : "+con.getHeaderField(header)); \Tq !(]o^
else ~aKM+KmtPH
break; #OlU|I
} hx|Cam"
} reo
%04N"^mT'~
:`('lrq
public void splitterStop() MmUtBT
{ vv='.R, D
bStop = true; =!}n .
} Uedzt
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} nnr g^F
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Ky"]L~8$
/* * V;L|c
**FileAccess.java oU/CXz?H
*//文件访问(定位，写) Vl=!^T}l+
package NetFox; b4NUx)%ln
import java.io.*; b(^gv
`PML4P[
SN w3xO!;&
public class FileAccessI implements Serializable{ BET3tiHV
<}e2\x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fTQ_miAlP
RandomAccessFile oSavedFile; IQn|0$':Z
long nPos; 8MUY
+um Ua
L~x PIu
public FileAccessI() throws IOException pkWJb!
{ $ = uz
this("",0); b6KO_s:'g
} SvR:tyF
{+D 6o
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public FileAccessI(String sName,long nPos) throws IOException ]/byz_7]
{ _i@{:v
oSavedFile = new RandomAccessFile(sName,"rw"); e,j2#wjor
this.nPos = nPos; 5R^e
oSavedFile.seek(nPos); )ro3yq4??
} |Z\?nZ~
o}EipTL
>%qk2h>
public synchronized int write(byte[] b,int nStart,int nLen) -P I$SA,
{ ]IX6>p,
int n = -1; Ql~9a [8T~
try{ oW0A8_|9
oSavedFile.write(b,nStart,nLen); |>w>}w`~
n = nLen; cJb.@8^J
} 8:W,""
catch(IOException e) ;ZnSWIF2
{ ;Y/{q B!
e.printStackTrace (); um/2.Sn>
} $U3|.4
SZ/}2_;
Xr?(w(3
return n; 2oY.MQD7iW
} 4J#F;#iA
+y%"[6c|
lrn3yDkR?
} (~C_zG
c!,&]*h"k
R^_7B(
/* aQ@9(j> F
**SiteInfoBean.java l/=2P_8+Z
*/ x2-i1#j`;
package NetFox; G8]DK3#
j$2rU'
}>)e~\Tdzb
public class SiteInfoBean { _e2=BE`W)
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qG=?+em
private String sSiteURL; //Site's URL 977%9z<h
private String sFilePath; //Saved File's Path +Ce[OG.
private String sFileName; //Saved File's Name M84{u!>[
private int nSplitter; //Count of Splited Downloading File 1|]IWX|
Vjv~RNGF
1_AB;^
public SiteInfoBean() dv?ael^
{//nSplitter的缺省值为5 [73 \jT
//default value of nSplitter is 5 i=m5M]Ef
this("","","",5); tyEa5sy4
} (s:ihpI
cr}T ? $\K
v|\<N!g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (lNV\Za
{ (P(=6-0
sSiteURL= sURL; E5^P*6c(
sFilePath = sPath; O=,[u?
sFileName = sName; _J|TCm
this.nSplitter = nSpiltter; '7lHWqN<
QNH-b9u>8
nRP|Qt7>
} & XS2q0-x
}6Ut7J]a|
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public String getSSiteURL() O9+Dd%_KS#
{ h8nJt>h
return sSiteURL; *wH.]$
} I:~KF/q
goE \C
{B!LhvYAH
public void setSSiteURL(String value) H@+1I?l
{ *En29N#a{
sSiteURL = value; 7H$I9e
} [uJfmrEH
6MewQ{hi
fGeDygV^`
public String getSFilePath() y4@zi"G
{ >i6sJ)2?>
return sFilePath; l**gM
} k-:wM`C
q <, b
11'^JmKA
public void setSFilePath(String value) JAQ y
{ S.<aCN<@
sFilePath = value; a#huK~$~
} >yZe1CP
aUy!(Y
mJ_5Vt=
public String getSFileName() tzTnFV
{ \ oY/hT_
return sFileName; ~wtK(U
} }@)r\t4m
r<%ua6@
b7^Db6qu
public void setSFileName(String value) $dxk;V
{ Io(*_3V)B
sFileName = value; 2`|gnVw
} H%nA"-
D]?eRO9'
EJCf[#Sf
public int getNSplitter() Kl'u
{ 65HP9`5Tm
return nSplitter; Z!/!4(Fh
} yb-1zF|
7R4t%^F
<:n!qQS6
public void setNSplitter(int nCount) ]+"25V'L
{ 3}7`?$5
nSplitter = nCount; !J6;F}Pd/
} '%H\k5^
} zu,F 0;De
,+d\@:
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/* H|.cD)&eYy
**Utility.java /e:kBjysJ
*/ |]Eli%mNe
package NetFox; F3?PlH:Y
kS7`g A
QX`T-)T e
public class Utility { wv7XhY}
hZ[(Ik]*Zd
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public Utility() ^t$xR_
{ @^2?97i c
O x),jc[/
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} {vhP'!a6W
anzt;V.;Y
//线程睡眠 #Q]^9/;|4n
public static void sleep(int nSecond) NT0im%
{ nOCCOTf
try{ XkEJ_;:
Thread.sleep(nSecond); ^vY[d]R _\
} +%~/~1
catch(Exception e) q:/3uC7
{ pBxyq"z
e.printStackTrace (); W5^<4Ya!
} ${F4x"x
} +F4SU(T
q`0wG3
//日志 )Jaq5OMA/
public static void log(String sMsg) iLbf:DXK(
{ n/6qc3\5i
System.err.println(sMsg); |>~pA}
} }0oVIr
[S_qi,
iD${7 _
public static void log(int sMsg) X{u\|e{
{ -z~;f<+I`
System.err.println(sMsg); fEB&)mM
} "g%=FH3e
} ED;rp9(
_)U.5f<
$`&zIz
/* y2o~~te
**TestMethod.java A-&XgOL
*/ ^2a63_
package NetFox; 2X,`t%o
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t)l
public class TestMethod { IZs NMY
T^DJ/uhd
m#,AD,s
public TestMethod() E;bv;RUio
{ ///xx/weblogic60b2_win.exe u Wxl\+_i
try{ =v{Vl5&>?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,<t)aZL,A;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eUVhNg
SiteFileFetch fileFetch = new SiteFileFetch(bean); 63fgl+
fileFetch.start(); $.F.xYS9IJ
} aCF=Og
catch(Exception e){e.printStackTrace ();} g2%fla7r
:[J'B4>9
mv{bX|.
} G -V~6
va[r~
T&nIH[}v
public static void main(String[] args) ".7\>8A#a
{ 8)ykXx/f@
new TestMethod(); mlO\wn-F
} &e\UlM22
} \~> .NH-
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