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)); a'W-&j
} Y[@$1{YS
for(int i=0;i<nEndPos.length-1;i++) nTp?
{ Tj@s\@hv
nEndPos = nStartPos[i+1]; XoL9:s(m~
} n*hHqZl
nEndPos[nEndPos.length-1] = nFileLength; (hs[B4nV
} ' !ZFK}
} 89?AcZ.D
$D<LND=o=
5o'V}
//启动子线程 !Zlvz%X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t@.M;b8
for(int i=0;i<nStartPos.length;i++) ]t(;bD hT
{ UcKpid
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ks7DoXCvE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CZuV{Oh}?
nStartPos,nEndPos,i); =T|Z[/fto
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); grp1nWAs
fileSplitterFetch.start(); T\NvN&h-
} 2a3i]e5Kt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), now\-XrS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |Rf4^vN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %D:Mt|
nEndPos = " + nFileLength); &>XIK8*
// fileSplitterFetch[nPos.length-1].start(); ~kj1L@gy
%lF}!
ckHHD|
//等待子线程结束 YQ:FBj
//int count = 0; c!d>6:\
//是否结束while循环 Hw-,sze j"
boolean breakWhile = false; E%FCOKw_
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{R5Q{]dK3
while(!bStop) TO ^}z
{ A(S=
write_nPos(); 0O5(\8jM
Utility.sleep(500); }\!&3^I
breakWhile = true; \#?n'qyj
NifzZEX
X~(%Y#6
for(int i=0;i<nStartPos.length;i++) iaPrkMhd
{ eo.y,Uh
if(!fileSplitterFetch.bDownOver) T:p,!?kc7
{ =87.6Ai
breakWhile = false; (,z0V+!
break; Hpo7diBE
} 65X$k]x
} X458%)G!(K
if(breakWhile) yqi=9NB
break; +nU"P
'mx_]b^O
^LO=&Cq
//count++; mF7T=pl
//if(count>4) $Hh3*reSg-
// siteStop(); zX*+J"x
} MLf,5f;e
!|}(tqt
gBBS}HF
System.err.println("文件下载结束！"); DlIy'@ .
} Pp.qDkT
catch(Exception e){e.printStackTrace ();} YaI8hj@}
} Ry2rQM`
#!!Ea'3Iq
7UM!<@9\
//获得文件长度 aMI\gCB/
public long getFileSize() WB~ ^R<g
{ S,A\%:Va
int nFileLength = -1; :j2G0vHIl(
try{ zOO:`^ m
URL url = new URL(siteInfoBean.getSSiteURL()); ]"?+R+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2@ 4^ 81
httpConnection.setRequestProperty("User-Agent","NetFox"); lrQ +G@#
PO9<g%qTf
c@iP^;D
int responseCode=httpConnection.getResponseCode(); ^,F8 ha
if(responseCode>=400) AWSe!\b
{ E{_$C!.
processErrorCode(responseCode); wa/ :JE
return -2; //-2 represent access is error 3%c{eZxG=
} 9nIBs{`/Ac
O :P%gz4
eF)vx{s
String sHeader; DSiI%_[Ud
<tp\+v!u
=fy~-FN_
for(int i=1;;i++) ,#;%ILF4%
{ s+m,ASj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G;r-f63N
//Utility.log(in.readLine()); uEp v l
sHeader=httpConnection.getHeaderFieldKey(i); DxX333vC
if(sHeader!=null) NKae~ 1b
{ eLC}h %
if(sHeader.equals("Content-Length")) Sg$14B
{ |/LCwq%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @H'pvFLK?
break; Ga o(3Y
} X[pk9mha
} sR%,l
else K.CwtUt`54
break; T/8*c0mU
} "b6ZAgxv
} NUiNn 7C
catch(IOException e){e.printStackTrace ();} _Se~bkw?v
catch(Exception e){e.printStackTrace ();} TMsEHd
$O|J8;"v
fG;(&Dx
Utility.log(nFileLength); bY6y)l
j\t"4=,n
[3":7bB 'E
return nFileLength; G(piq4D
} ((BuBu>
n~/#~VTVe
|BysSJ
//保存下载信息（文件指针位置） ~;aSE
private void write_nPos() (+g!~MP
{ S9Kay'.aJ(
try{ qGS]2KY
output = new DataOutputStream(new FileOutputStream(tmpFile)); <{\UE~
output.writeInt(nStartPos.length); @C),-TM
for(int i=0;i<nStartPos.length;i++) =\IcUY,4
{ E%L]ifA9!
// output.writeLong(nPos); =d_@k[8<0
output.writeLong(fileSplitterFetch.nStartPos); BS}uv3
output.writeLong(fileSplitterFetch.nEndPos); ?&Y3Fr)%
} sePOW#|
output.close(); @Bfwb?&
} maANxSzi
catch(IOException e){e.printStackTrace ();} h%kB>E~
catch(Exception e){e.printStackTrace ();} _"`wUMee
} % ~%>3
6"Tr$E
b2;Weu3WN
//读取保存的下载信息（文件指针位置） GiBq1U-Q
private void read_nPos() GXaCH))TO
{ "HR &Rf k
try{ ["N>Po
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _\ n'uW$
int nCount = input.readInt(); p\e*eV1dxx
nStartPos = new long[nCount]; Rs;,_
nEndPos = new long[nCount]; h+$1+Es
for(int i=0;i<nStartPos.length;i++) _:om(gL
{ Py 8o8*H
nStartPos = input.readLong(); {pUOu8`Z
nEndPos = input.readLong(); cXcn}gKV
} [_j.pMH/P
input.close(); n15c1=gs
} WPyd ^Y<
catch(IOException e){e.printStackTrace ();} /B!"\0G/,
catch(Exception e){e.printStackTrace ();} "z^Ysvw&~
} ^sH1YE}0
*n?6x!A
NVFAmX.Z:
private void processErrorCode(int nErrorCode) iZ[o2Tre
{ ?AY596
System.err.println("Error Code : " + nErrorCode); w`1qx;/!
} > ^3xBI:Q
fE)+9!
h bj^!0m
//停止文件下载 ' 7>}I{Lq
public void siteStop() ]@ETQ8QN
{ ^f!d8 V
bStop = true; wSIt"g,%
for(int i=0;i<nStartPos.length;i++) #:Cr'U
fileSplitterFetch.splitterStop(); C bG"8F|4
@]*z!>1
& A9psc(,&
} *GuCv3|
} bz H5Lc{%
//负责部分文件的抓取 +cy(}Vp
**FileSplitterFetch.java !l6B_[!@
*/ \ox:/-[c\<
package NetFox; lW&glU(
xNxIqq<k
1[3"|
import java.io.*; +}4vdi"
import java.net.*; :CHCVoh@95
`-ENKr]
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public class FileSplitterFetch extends Thread { [4xN:i
~n"V0!:'4
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String sURL; //File URL J+DuQ;k;
long nStartPos; //File Snippet Start Position L1)?5D
long nEndPos; //File Snippet End Position 'zT/x`V
int nThreadID; //Thread's ID |7%$+g
boolean bDownOver = false; //Downing is over S2jo@bp!
boolean bStop = false; //Stop identical Hg(\EEe
FileAccessI fileAccessI = null; //File Access interface E? F @
{AIZ,
<\zb*e&vr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z eIBB
{ W97Ka}Y
this.sURL = sURL; )J#@L*
this.nStartPos = nStart; B u4N~0
this.nEndPos = nEnd; 8-8= \
nThreadID = id; f"Iv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 } A#C
} }3[ [ONA
8CEy#%7]}
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public void run() TS3 00F
{ 2? !b!
while(nStartPos < nEndPos && !bStop) Pi*,&D>{7
{ 1YnDho;~
kt;X|`V{5z
Ld`~^<B
try{ k7W8$8v
URL url = new URL(sURL); n}MG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j<L!ONvJ1
httpConnection.setRequestProperty("User-Agent","NetFox"); M>I}^Zp!
String sProperty = "bytes="+nStartPos+"-"; r&ToUU 5
httpConnection.setRequestProperty("RANGE",sProperty); qVM]$V#e
Utility.log(sProperty); o)-Qd3d%S
;UPw;'
l_f"}l
InputStream input = httpConnection.getInputStream(); UJ6WrO5#kB
//logResponseHead(httpConnection); 'mmyzsQ\6
*Li;:b"t
<,cDEN7
byte[] b = new byte[1024]; 9U;) [R Mb
int nRead; u8[X\f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n7{c0;)$
{ 45-pJf8F
nStartPos += fileAccessI.write(b,0,nRead); yr;oq(&N
//if(nThreadID == 1) +p43d:[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z3#3xG5pl
} 7x1jpQ-
~sA}.7
\j K?R 6
Utility.log("Thread " + nThreadID + " is over!"); t~bjDV^`
bDownOver = true; 8o4 vA,
//nPos = fileAccessI.write (b,0,nRead); j4NS5
} ?SQT;C3j(
catch(Exception e){e.printStackTrace ();} =CqLZ$10
} s'K0C8'U
} (,<?Pg7v:f
-i;#4@^t
p6ZKyi
//打印回应的头信息 *~-~kv4-
public void logResponseHead(HttpURLConnection con) 12rr:(#%s
{ kU#$
for(int i=1;;i++) -EL"Sv?
{ Z~P5SEg
String header=con.getHeaderFieldKey(i); KD#ip3
if(header!=null) s=KA(4p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gWJLWL2
Utility.log(header+" : "+con.getHeaderField(header)); 4ci @$nL1
else +i K.+B
break; $aVcWz%
} K@?S0KMK
} KWd]?e)
&{7%VsTB
G2em>W_n
public void splitterStop() WMYvE\"
{ LdRLKE<'e
bStop = true; R2r0'Yx
} rVZkG,Q
1 "4AS_Q
.+ _x|?'
} EpPKo
`+i<:,z-gs
$e0sa=/
/* HPu nNsA
**FileAccess.java SVeL c
*//文件访问(定位，写) MF>?! !
package NetFox; M<Eg<*
import java.io.*; 'S&5zwrH
XFH7jHnL+U
;B!&( 50e
public class FileAccessI implements Serializable{ _W&.{ 7
"-\I?k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a^|mF# z
RandomAccessFile oSavedFile; f`vB$r>
long nPos; \vpUl
$1/yc#w u
5Vf#(r f
public FileAccessI() throws IOException {QJJw}!#
{ vr2tMD
this("",0); ~#OnA1)
} yA=#Ji
b$%W<D
_@SC R%
public FileAccessI(String sName,long nPos) throws IOException Un@dWf6'
{ Me2%X>;
oSavedFile = new RandomAccessFile(sName,"rw"); kwWDGA?zFB
this.nPos = nPos; V+-%$-w>
oSavedFile.seek(nPos); t 8|i>(O
} FL9Dz4
=J<3B H^m
h 5<46!P
public synchronized int write(byte[] b,int nStart,int nLen) 7S}NV7
{ F7x]BeTM
int n = -1; Z`T]jm-3
try{ K>N\U@@8i
oSavedFile.write(b,nStart,nLen); EWrIDZi
n = nLen; !%?O`+r
} $mgW|TBXCQ
catch(IOException e) YZMSiDv[e
{ @j=:V!g2O
e.printStackTrace (); P XKEqcQR
} +Hgil
oIrO%v:'!
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return n; )[+82~F
} _(l?gj
nm Y_)s
lE'3UqK
} J2adG+=
]l>LU2 sx
VddHK
/* HCfme<'
**SiteInfoBean.java xsu9DzPf&{
*/ 0Un?[O
package NetFox; eu={6/O
G%iTL"6
=HMa<"-8
public class SiteInfoBean { 2[j(C
u}3D'h
J?{@pA
private String sSiteURL; //Site's URL aKjP{Z0k$
private String sFilePath; //Saved File's Path jaw&[f 7
private String sFileName; //Saved File's Name @@JyCUd
private int nSplitter; //Count of Splited Downloading File @,Z0u2WLl6
50_[n$tqE
p<1y$=zS
public SiteInfoBean() 5`Q j<
{//nSplitter的缺省值为5 0vETg'r
//default value of nSplitter is 5 m<H{@ZgN(
this("","","",5); WP2=1"X63
} $Nd,6w*`
(\0 <|pW
H2H`7 +I,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 28k=@k^q
{ )fHr]#v
sSiteURL= sURL; &rGB58
sFilePath = sPath; p^CTHk_|
sFileName = sName; z',Fa4@z
this.nSplitter = nSpiltter; ;z.L^V0
fuzB;Ea
rtS' 90`
} ,jOJ\WXP
Z:dp/M}
1W\E`)Z}]
public String getSSiteURL() >))CXGE
{ Jy5sZ}t[
return sSiteURL; d2V X\
} %Yj%0
f. "\~
.4p3~r?=S
public void setSSiteURL(String value) ;h\T7pwwb
{ /M_$4O;*@
sSiteURL = value; |RFBhB/u
} C,An\lsT
g:>'+(H;
PVsKI<
public String getSFilePath() TWzLJ63*
{ h:nybLw?
return sFilePath; &^r>Q`u
} gxN>q4z
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P.}d@qD{)
public void setSFilePath(String value) LWyr
{ |'q%9#
sFilePath = value; F!]Sr'UA
} ;f=m+QXU
Snx!^4+MF
_!nsEG VV
public String getSFileName() x@t?7 o\&
{ flsejj$
return sFileName; E5w;75,
} $KK~KEZ2
wY8:j
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public void setSFileName(String value) ?13qDD:
{ p49]{2GXb
sFileName = value; zxbfh/=
} /ad9Q~nJ
w&q[%(G_
=~B"8@B
public int getNSplitter() }yz>(Pq
{ g8W,Xq+
return nSplitter; 8]ZzO(=@{
} .Q{RTp
0cd_l 2f#g
`*C=R _
public void setNSplitter(int nCount) c0oHE8@
{ LQ jbEYp
nSplitter = nCount; e$# *t
} fpD$%.y'J
} xN1P#
CSO'``16
9iA rBL"
/* ?sf<cFF
**Utility.java WYw#mSp
*/ c3$T3Lu1
package NetFox; g7\=
a=iupXre9
Zf'*pp T&q
public class Utility { apvcWF%
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h>-P/
public Utility() 5E]t4"
{ L:z0cvn"
#z\ub5um
;]{ee?Q^ld
} #9vC]Gm
4&/CES
//线程睡眠 sV\_DP/l
public static void sleep(int nSecond) vgz`+Zj*S
{ )t6]F6!_
try{ YH&=cI@
Thread.sleep(nSecond); JJ?{V:
} RBX<>*
catch(Exception e) h9vcN#22D
{ )!T~l(g
e.printStackTrace (); -%nD'qy,.
} SQKhht`M
} f6Qr0Op
$3-vW{<
//日志 nxLuzf4U5
public static void log(String sMsg) ;nY#/%f
{ $|K d<wv
System.err.println(sMsg); $.G 7Vt
} A1WUK=P
55[ 4)*
K,b M9>}
public static void log(int sMsg) LQ+/|_(.
{ y<)TYr
System.err.println(sMsg); }X(&QZ7i`
} HU3:6R&
} ;b~ S/
qd`e:s*%
_fAgp_)
/* jHLs 5%
**TestMethod.java P7x;G5'.
*/ 0[;2dc
package NetFox; 60D36b(
D3pz69W
Y.:R-|W
public class TestMethod { &|yLTx
^X#y'odtbS
#&3,T1i`
public TestMethod() &|v)
{ ///xx/weblogic60b2_win.exe N& _~y|
try{ Q*ITs!~Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bIQ,=EA1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m[DQ;`Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); rb*|0ST
fileFetch.start(); ((y|?Z$
} [Nyt0l "z
catch(Exception e){e.printStackTrace ();} H]TdW;ZbZ
}nmlN
%sa?/pjK
} UwN Vvo
FD=% 4#|
(?FH`<
public static void main(String[] args) [W[{ 4 Xu
{ Psb !Z(
new TestMethod(); bcIae0LZ
} z^Hc'oVXj:
} hmy%X`%j
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