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)); FdmoR;
} Vxim$'x!
for(int i=0;i<nEndPos.length-1;i++) M"z3F!-j
{ NSQf@o
nEndPos = nStartPos[i+1]; Su[f"2oR
} U9yR~pw
nEndPos[nEndPos.length-1] = nFileLength; x5!lnN,#
} J ?H|"
} zvh&o*\2<d
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(\$=+' hy
//启动子线程 F0+@FS0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bOdyrynh
for(int i=0;i<nStartPos.length;i++) %hb!1I
{ /PtmJ2[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <,(Ww
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yyuf
nStartPos,nEndPos,i); 8,&QY%8pX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z~ {[YsG
fileSplitterFetch.start(); R>`TV(W`9
} r!O4]j_3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;O *o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GZNfx8zsY+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dq~D4|
nEndPos = " + nFileLength); aZYs?b>Gm
// fileSplitterFetch[nPos.length-1].start(); "pkn
~(d#T|ez
>[TJ-%V>oR
//等待子线程结束 6R%NjEW:
//int count = 0; ~bSjZ1`
//是否结束while循环 <}^l MBa
boolean breakWhile = false; G:?l;+P1
V?+Y[Q
Z)H9D(Za
while(!bStop) Mj-B;r
{ tvvRHvL
write_nPos(); t[?O*>
Utility.sleep(500); u7ER
breakWhile = true; *61G<I
agxR V
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for(int i=0;i<nStartPos.length;i++) YNWAef4
{ BJ7m3[lz
if(!fileSplitterFetch.bDownOver) /,#&Htk
{ }e0)=*;l
breakWhile = false; Z\P&i#
break; 9x[|75}l
} <bxp/#6D
} tD !$!\`O
if(breakWhile) MbeO(Q
break; $Xr9<)?,
]{'lV~fc
E7UYJ)6]
//count++; Qg4g(0E@
//if(count>4) @+ U++
// siteStop(); yW)X asn
} Sej\Gt
)nJh) {4\
Fl&Z}&5p
System.err.println("文件下载结束！"); k->cqtG
} !^<%RT9@|
catch(Exception e){e.printStackTrace ();} }X[wWH
} h$eVhN&Vv
ia}V8i
|qTS{qQh{L
//获得文件长度 8q#Be1u<s2
public long getFileSize() - Ado-'aaS
{ 8st~ O
int nFileLength = -1; ~g[<A?0=y
try{ a)GT\1q
URL url = new URL(siteInfoBean.getSSiteURL()); .~Z@y#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M]$_>&"
httpConnection.setRequestProperty("User-Agent","NetFox"); `jyBF
pJ 7="n
7*&$-Hv
int responseCode=httpConnection.getResponseCode(); #GT4/Ej}W
if(responseCode>=400) Jv9yy~
{ W6[# q%o
processErrorCode(responseCode); EzDQoN7Em
return -2; //-2 represent access is error V[N4 {c
} V}UYr Va#9
!K$qh{n
JHZ`LWq
String sHeader; K<Qy1y~[
>*aqYNft
9F^rXY.
for(int i=1;;i++) UjI-<|
{ oDEvhNT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SYsbe 5j
//Utility.log(in.readLine()); !Cv:,q
sHeader=httpConnection.getHeaderFieldKey(i); I>L@P`d
if(sHeader!=null) Lw!Q*3c
{ 7-Yn8Gq
if(sHeader.equals("Content-Length")) f.&((z?rC
{ Pwh0Se5Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9:tn!<^=I
break; #fR~7KR
} XY1eeB-
} (jY -MF3
else ,:1_I`d>#X
break; E)=X8y
} bAa+MB#A
} ^E3i]Oem
catch(IOException e){e.printStackTrace ();} Y]R;>E5o|
catch(Exception e){e.printStackTrace ();} 3l8k O
z1u1%FwOfM
n!K<g.tjW
Utility.log(nFileLength); {v>orP?
D7"RZF\)
YzD6S*wb
return nFileLength; oTqv$IzqP
} )KPQ8y!d
)D1=jD(
x.OCE`
//保存下载信息（文件指针位置） t$W~X~//
private void write_nPos() R%Y#vUmBV{
{ ;.<0lnV
try{ $ }D9)&f;
output = new DataOutputStream(new FileOutputStream(tmpFile)); yxt`
output.writeInt(nStartPos.length); CkJ\v%JAW
for(int i=0;i<nStartPos.length;i++) @3:oo /;
{ _PR><L_
// output.writeLong(nPos); OAhCW*B
output.writeLong(fileSplitterFetch.nStartPos); bq<DW/
output.writeLong(fileSplitterFetch.nEndPos); >x$.mXX{
} f*}H4H EO
output.close(); jZ8#86/#{
} ,`ZIW
catch(IOException e){e.printStackTrace ();} +bbhm0f
catch(Exception e){e.printStackTrace ();} i!jR>+
} lrXi*u]
.^%!X!r
_Bh ^<D-
//读取保存的下载信息（文件指针位置） CQ+WBTiC
private void read_nPos() ZV;lr Vv
{ (t\ F>A
try{ n 7Bua
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3:;2Av2(X.
int nCount = input.readInt(); 6fOh *
nStartPos = new long[nCount]; )j[rm
nEndPos = new long[nCount]; PafsO,i-
for(int i=0;i<nStartPos.length;i++) !}gC0dJ
{ rg^
nStartPos = input.readLong(); B.-1wZl
nEndPos = input.readLong(); i!!1^DMrw
} ZKv^q%92
input.close(); @+3@Z?!SZ
} x3JX}yCX
catch(IOException e){e.printStackTrace ();} y~cDWD<h
catch(Exception e){e.printStackTrace ();} UaQR0,#0y
} D6KYkN(,v
Z,~EH
O#e'.n!rI
private void processErrorCode(int nErrorCode) n' \poB?
{ +H7lkbW
System.err.println("Error Code : " + nErrorCode); -|l^- Qf!
} _Co*"hl>2
qDQ$Zq[
fa7I6 i
//停止文件下载 Pa.D+
public void siteStop() U*.Wx0QM
{ c:SA#.
bStop = true; 6R%Ra
for(int i=0;i<nStartPos.length;i++) RJ ,a}w[9
fileSplitterFetch.splitterStop(); jt?937{
pXfg{2
=K6aiP$Ft
} [xF(t @p
} qRXb9c
//负责部分文件的抓取 ]-Z="YPY
**FileSplitterFetch.java |U*wMYC
*/ !2)$lM1@J
package NetFox; SjT8eH #
3d qj:4[f
,k*g`OTW
import java.io.*; l2))StEm
import java.net.*; WUQlAsme
YQyf:xJ
mHqw,28}
public class FileSplitterFetch extends Thread { PVGvjc
^-, aB
UN7>c0B
String sURL; //File URL "r6DZi(^K
long nStartPos; //File Snippet Start Position wI!>IV(5
long nEndPos; //File Snippet End Position ?U~9d"2=
int nThreadID; //Thread's ID ;(cqaB
boolean bDownOver = false; //Downing is over #$&!)13
boolean bStop = false; //Stop identical k_p4 f%9
FileAccessI fileAccessI = null; //File Access interface xef@-%mcoy
50:gk*hy
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nE!h&}(
{ (nWi9(}J
this.sURL = sURL; A.aUWh
this.nStartPos = nStart; E2M|b
this.nEndPos = nEnd; @Sxb}XI!f
nThreadID = id; i%m]<yElm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kW"6Gc&HUN
} ;++CMTza]
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public void run() Q`nsL)J
{ n>d@}hyv
while(nStartPos < nEndPos && !bStop) 39jnoT
{ FL}k0
6I0G.N
*Uvh;d{
try{ H1`}3}"
URL url = new URL(sURL); otQulL)T/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;A~efC^<
httpConnection.setRequestProperty("User-Agent","NetFox"); Tw|cgB
String sProperty = "bytes="+nStartPos+"-"; 3<ikMUq&
httpConnection.setRequestProperty("RANGE",sProperty); 7B@[`>5?%L
Utility.log(sProperty); 1'c
(1`z16
2!Ip!IQ:
InputStream input = httpConnection.getInputStream(); ZJCD)?]=3
//logResponseHead(httpConnection); ZP>KHiA
>7yOu!l
>syQDB
byte[] b = new byte[1024]; HmWU;9Vn+
int nRead; h,-8( S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tDF=Iqu)a
{ [42vO
nStartPos += fileAccessI.write(b,0,nRead); P`JO6O:&
//if(nThreadID == 1) kPt9(E]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yi7m!+D3
} Z x9oj
g3r4>SA
~NYy@l
Utility.log("Thread " + nThreadID + " is over!"); bo]xah|."j
bDownOver = true; u)]]9G _8
//nPos = fileAccessI.write (b,0,nRead); Z83A1`!.|
} RcQo1
catch(Exception e){e.printStackTrace ();} XUf]gQu3=
} ^T):\x(
} Y|eB;Dm1q
/s91[n(d
}pP<+U
//打印回应的头信息 9G7lPK
public void logResponseHead(HttpURLConnection con) +8tdAw
{ 86[/NTD<-
for(int i=1;;i++) ,2H@xji [
{ :JBvCyj4PE
String header=con.getHeaderFieldKey(i); Qqt<
if(header!=null) %nU8 Ca
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9.F+)y@
Utility.log(header+" : "+con.getHeaderField(header)); F$l]#G.@A
else K!|%mI8gk
break; "c[ D0{\{
} 9$-V/7@)
} DOi\DJV!
C_>dJYM
$vlc@]~d`&
public void splitterStop() xHs8']*\
{ eGZ{%\PH<
bStop = true; a@[y)xa$Z
} C]22 [v4
x.Sq2rw]V
SDY!!.
} R)s@2S
{1H3VSYq
QfI=
/* 8mM^wT
**FileAccess.java 1BQB8i-,
*//文件访问(定位，写) q&.SB`
package NetFox; 9(.P2yO
import java.io.*; < * )u\A
\}O'?)(1
39s%CcI`k
public class FileAccessI implements Serializable{ (A.%q1h
Gy*6I)l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hhu!'(j
RandomAccessFile oSavedFile; Isa]5>
long nPos; *ujn+0)[
a?]Ow J
_e/>CiN/
public FileAccessI() throws IOException 0QE2e'}}-
{ n@9*>DU
this("",0); E9=a+l9
} ZqaCe>
;x.xj/7
sxq'uF(K
public FileAccessI(String sName,long nPos) throws IOException $0[T=9q <+
{ MjIp~?*
oSavedFile = new RandomAccessFile(sName,"rw"); 9Ra_[1
this.nPos = nPos; y993uP
oSavedFile.seek(nPos); 16q"A$
} ]=5nC)|
,U_p6TV5
T\g%.
public synchronized int write(byte[] b,int nStart,int nLen) RIXUzKLO
{ FsrGI (x?
int n = -1; k@qn'Zi
try{ L&td4`2y
oSavedFile.write(b,nStart,nLen); ]|cL+|':y
n = nLen; !(=bH"P
} b[<Q_7~2
catch(IOException e) U0}]3a0
{ 4%#C _pE9
e.printStackTrace (); :cv_G;?
} C^]y iR-U
5;=,BWU
I2JE@?
return n; ?(Dk{-:T'
} RC5b'+E&#
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)M5:aSRz
} kFPZ$8e
9OYsI
@}&o(q1M0
/* >mzK96
**SiteInfoBean.java a%2r]:?^?
*/ K-VNU
package NetFox; MH{$"^K
D4?qw$"
m09 Bds
public class SiteInfoBean { {b4+ Yc
m S[Vl6
n,eO6X 4
private String sSiteURL; //Site's URL q7-Eu4w
private String sFilePath; //Saved File's Path yw'b^D/
private String sFileName; //Saved File's Name !2oe;q2X[G
private int nSplitter; //Count of Splited Downloading File !@E=\Sm8EV
RH+3x7l
7o?6Pv%HJC
public SiteInfoBean() ?YR/'Vq97
{//nSplitter的缺省值为5 L5C4#X
//default value of nSplitter is 5 \&6
this("","","",5); B6tp,Np5,
} 3rX5haD\
c!@g<<}[(
)ymd#?wq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U#v??Sl
{ [bH5UTA
sSiteURL= sURL; %h;~@-$
sFilePath = sPath; Bfw]#"N`
sFileName = sName; M|e Qds
this.nSplitter = nSpiltter; *RKYdwnb
A-:58Qau+
ZgCG'SU
} $Oa}U3
k?|l;6
;c"T#CH.
public String getSSiteURL() eaQ)r?M
{ Y2i:ZP
return sSiteURL; o@[yF<
} ;j]0GD,c$
F$Q(2:w
WlnmW(uahW
public void setSSiteURL(String value) 3P C'P2
{ )+2GF0%
sSiteURL = value; Y*iYr2?;
} F3/aq+<P[
$fSV8n;Y
-Y'Qa/:7
public String getSFilePath() mXnl-_
{ +rS}f N$L.
return sFilePath; lb3:#?
} L{xCsJ3d
}9[E+8L1
\4y7!
public void setSFilePath(String value) hR"j[
{ p(/PG+
sFilePath = value; F8S -H"
} ]v7f9MC'\
COJny/FT|
?<c)r~9]
public String getSFileName() ia!t~~f
{ nff&~lwhZ
return sFileName; F)KUup)gc
} 9u";%5 4
>h>X/a(=~
#|76dU
public void setSFileName(String value) xwG=&+66
{ uxF88$=!t
sFileName = value; /I|.^ Id|
} qh;ahX~
4PUSFZK?
fMRBGcg7Dc
public int getNSplitter() dD@k{5
{ *Q=ER
return nSplitter; U%3d_"{;
} [80jG+6
9dl\`zlA*
iD=VNf
public void setNSplitter(int nCount) v[VUX69
{ 7)sEW#d!
nSplitter = nCount; Gv(bD6Rz
} Gqvnc8V&
} |FS,Av
t?H.M
kBYZNjSz
/* UD6D![e
**Utility.java '3B`4W,
*/ F/z$jj)
package NetFox; cRBdIDIc
]O2ku^yM
)3g7dtq}
public class Utility { ZGrjb22M
?r"][<
sr%tEKba)
public Utility() =)}m4,LA
{ 'j>+eA>
BH _y0[y
>&V?1!N"
} FT'_{e!M
@cNBY7=
//线程睡眠 Cw1Jl5OVZ
public static void sleep(int nSecond) =/wAk0c^y
{ i1RU5IRy|j
try{ tX)l$oRPr
Thread.sleep(nSecond); tpw0j CVu
} iR j/Tm*T'
catch(Exception e) a86m?)-c
{ /rp.H'hC
e.printStackTrace (); Gxk=]5<7
} .U|e#t
} V {R<R2h1
g _fvbVX
//日志 OU+oS,
public static void log(String sMsg) _%#Q \D
{ WbZ{) i
System.err.println(sMsg); -kY7~yS7
} G!},jO*"
WS6pm6@A*!
z[:UPPbW
public static void log(int sMsg) ;n?72&h
{ W70J2
System.err.println(sMsg); Ql8E9~h
} Qp8.D4^@3
} bZ c&uq_
ZAe>MNtW
r:.5O F}
/* ='f<_FD
**TestMethod.java <4s$$Uw}6%
*/ m[&]#K6
package NetFox; G4g<PFx
m)4s4P57y
.m_yx{FZ=
public class TestMethod { 5Gm,lNQAv
)yp+!\
UEmNT9V
public TestMethod() S%n5,vwE
{ ///xx/weblogic60b2_win.exe (pXZ$R:
try{ Isv@V.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k]FP1\Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t6p}LNm(V
SiteFileFetch fileFetch = new SiteFileFetch(bean); pQr `$:ga
fileFetch.start(); xi=Z<G
} <-uE pF
catch(Exception e){e.printStackTrace ();} v|acKux=t
C$`z23E
l{wHu(1
} P1DYjm[+D
^yDCX
>QRpRHtb
public static void main(String[] args) 5_";EED
{ TA;
new TestMethod(); 8mTjf Br
} `?VtB!p@x=
} :Bc)1^I
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