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)); u5glKE
} h !R=t
for(int i=0;i<nEndPos.length-1;i++) dpNERc5
{ p@4GI[4
nEndPos = nStartPos[i+1]; zhFm2
} fbOqxF"?we
nEndPos[nEndPos.length-1] = nFileLength; 25{_x3t^
} 2@GizT*mA
} nR*' 3
Km%L1Cd]
.#|?-5q/iN
//启动子线程 Q!U}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PS[ C!s&KE
for(int i=0;i<nStartPos.length;i++) }58MDpOF1
{ 8j3Y&m4^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NM![WvtjW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zB`woI28
nStartPos,nEndPos,i); s:"Sbml
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xSK#ovH2
fileSplitterFetch.start(); W [K.|8ho
} d,JDfG)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y-YuY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g""GQeR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \'*M }G
nEndPos = " + nFileLength); K SOD(
// fileSplitterFetch[nPos.length-1].start(); y5m2u8+
l&qCgw
[{BY$"b#:
//等待子线程结束 bD:0k.`
//int count = 0; g]2L[4
//是否结束while循环 l$/lbwi%
boolean breakWhile = false; Q^rR}Ws
Hy[: _E
M%!;5
while(!bStop) ~S\L(B(
{ %|D)%|Z
write_nPos(); oYStf5
Utility.sleep(500); BU/A\4xQ,Y
breakWhile = true; `;;l {8
%g.cE}^
uy3<2L#.
for(int i=0;i<nStartPos.length;i++) Ws@'2i\;
{ SNH 3C1
if(!fileSplitterFetch.bDownOver) #Q^".#
{ }a6t<m`V
breakWhile = false; ~!r;?38V`
break; NSB6 2
} SXOAa<u5
} ^1bslCe
if(breakWhile) Kx]SiejJ
break; M[YFyM(
A:r?#7 Ma
+C{-s
//count++; eNAxVF0
//if(count>4) ?s^3o{!<W
// siteStop(); ~dRstH7u
} cA q3Gh
SE]5cJ'>
4F~^RR"
System.err.println("文件下载结束！"); EaO@I.[
} DdgiY9a.
catch(Exception e){e.printStackTrace ();} 6&eXQl
} #lLUBJ#:
]zSFX =~(S
g8%O^)d=>
//获得文件长度 &P|[YP37_
public long getFileSize() -o6rY9\_!
{ :BF? r
int nFileLength = -1; [fa4
try{ 'cXdc
URL url = new URL(siteInfoBean.getSSiteURL()); UUJQc~=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !=,4tg`
httpConnection.setRequestProperty("User-Agent","NetFox"); "S%t\
EX`P(=zD
sV
int responseCode=httpConnection.getResponseCode(); .9qK88fUR
if(responseCode>=400) tUJRNEg
{ uPA (1
processErrorCode(responseCode); |/*Pimk
return -2; //-2 represent access is error F`nQS&y
} ;[sW\Ou
S }`sp[6
J/?Nf2L4
String sHeader; // o.+?S
"n!yK
)S)L9('IxT
for(int i=1;;i++) tF0jH+7J-
{ `@h|+`h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +tqErh?Al
//Utility.log(in.readLine()); aKbmj
sHeader=httpConnection.getHeaderFieldKey(i); %T{]l;5
if(sHeader!=null) HB/V4ki
{ WVbrbs4
if(sHeader.equals("Content-Length")) Z.6dL
{ hi0HEm\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ' [ 4;QYw
break; G21o@38e
} F1t(P 8
} z*eBjHbF
else FM@iIlY"
break; K T}
} 1PkCWRpR
} @^W`Yg)C
catch(IOException e){e.printStackTrace ();} bV_nYpo
catch(Exception e){e.printStackTrace ();} |@Tga_0p
'-;[8:y.
e<L@QNX
Utility.log(nFileLength); Ma[EgG
{3tzr;c?
e`D}[G#
return nFileLength; g>@JGzMLP
} 1sQIfX#2f
$<^t][{
Dm>"c;2
//保存下载信息（文件指针位置） zH8E,)
private void write_nPos() fd\RS1[
{ %z><)7
try{ iQwQ5m!d &
output = new DataOutputStream(new FileOutputStream(tmpFile)); Eah6"j!B8n
output.writeInt(nStartPos.length); OU[<\d
for(int i=0;i<nStartPos.length;i++) *U?O4E9
{ wHc my
// output.writeLong(nPos); HGDrH
output.writeLong(fileSplitterFetch.nStartPos); gb ga"WO
output.writeLong(fileSplitterFetch.nEndPos); :]^e-p!z
} ~&?bU]F
output.close(); x*Lt]]A
} +&Ld`d!n
catch(IOException e){e.printStackTrace ();} tgK I
catch(Exception e){e.printStackTrace ();} }htjT/Nm
} dj0; tQ=C
>H2`4]4]
vT'Bs;QR
//读取保存的下载信息（文件指针位置） Aw o)a8e
private void read_nPos() (yOkf-e2y
{ ~C.*Vc?|
try{ 0+1wi4wy/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rl*O-S/
int nCount = input.readInt(); O !L`0 =%c
nStartPos = new long[nCount]; '|C3t!H`
nEndPos = new long[nCount]; ly[LF1t
for(int i=0;i<nStartPos.length;i++) )D)5 `n)
{ ^QB[;g.O
nStartPos = input.readLong(); D6sw"V#
nEndPos = input.readLong(); |?`5~f
} ;?-AFd\i
input.close(); hvd}l8
} Y::0v@&(
catch(IOException e){e.printStackTrace ();} H"C'<(4*\
catch(Exception e){e.printStackTrace ();} ]n22+]D
} `BPTcL<W
%`vzQt`>
<qCa9@Ea
private void processErrorCode(int nErrorCode) <AHpk5Sn{
{ uy'ghF
System.err.println("Error Code : " + nErrorCode); 5Wt){rG0Z
} 5gszAvOO
Ac7^JXh%
kX 1}/l
//停止文件下载 iTVe8eI
public void siteStop() I$n=>s
{ Y Y:BwW:
bStop = true; Zo9<96I&
for(int i=0;i<nStartPos.length;i++) JE?p'77C
fileSplitterFetch.splitterStop(); V|7YRa@
j]a$RC#
vh9* >[i
} \INH[X#>
} )*|/5wW1
//负责部分文件的抓取 j=_rUc'Me
**FileSplitterFetch.java K~x,so
*/ &K)8
package NetFox; weitDr6
)Nv1_en<!
VSj!Gm0LB
import java.io.*; ~xH&"1
import java.net.*; !XA3G`}p6s
x%P|T3Qy5
"(koR Q
public class FileSplitterFetch extends Thread { fn#8=TIDf
}kbSbRH43
[\uR3$j#
String sURL; //File URL g|=_@ pL
long nStartPos; //File Snippet Start Position 73WSW/^F
long nEndPos; //File Snippet End Position H#-3
int nThreadID; //Thread's ID +>w]T\[1~
boolean bDownOver = false; //Downing is over ]6&NIz`:,
boolean bStop = false; //Stop identical W+nu=iQ!
FileAccessI fileAccessI = null; //File Access interface r );R/)&
e5=d Ev
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wN2+3LY{
{ (z?HyxRT
this.sURL = sURL; gwZ<$6
this.nStartPos = nStart; &4'<{
this.nEndPos = nEnd; 'nJF:+30ZH
nThreadID = id; Ae)xFnuq3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4 23zX6
} CU$khz"
aM^iDJ$>
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public void run() )fH Q7
{ :fRXLe1=
while(nStartPos < nEndPos && !bStop) qZoDeN-CC
{ UNI< r
I Mgd2qIC
`h}eP[jA
try{ yu?5t?vf
URL url = new URL(sURL); XGlt^<`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fc[KIG3@
httpConnection.setRequestProperty("User-Agent","NetFox"); Iw1Y?Qia
String sProperty = "bytes="+nStartPos+"-"; x^eu[olN
httpConnection.setRequestProperty("RANGE",sProperty); B.<SC
Utility.log(sProperty); a(Y'C`x
NGra/s,9|
~{c ?-qb
InputStream input = httpConnection.getInputStream(); ]5W$EvZ9)
//logResponseHead(httpConnection); lwnO
WSThhI
+,Dc0VC?
byte[] b = new byte[1024]; x_PO;
int nRead; t@RYJmW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) St=nf\P&F
{ ;%|im?
nStartPos += fileAccessI.write(b,0,nRead); e r" w{
//if(nThreadID == 1) +qxPUfN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (5a73%>@
} MsB>3
fV:15!S[
tobE3Od4
Utility.log("Thread " + nThreadID + " is over!"); LvG.ocCG
bDownOver = true; [f6uwp
//nPos = fileAccessI.write (b,0,nRead); #mH@ /6,#[
} vwR_2u
catch(Exception e){e.printStackTrace ();} B6XO&I1c
} tMr7d
} k(Yz2
xh6(~'$
=;Id["+
//打印回应的头信息 0SpB2>_
public void logResponseHead(HttpURLConnection con) h!"2Ux3!x
{ 8K8u|]i
for(int i=1;;i++) 3qYGEhxv
{ Z[vx0[av&
String header=con.getHeaderFieldKey(i); EIi<g2pM(
if(header!=null) %lKw+D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %zavSm"
Utility.log(header+" : "+con.getHeaderField(header)); S :HOlJze
else :]"5UY?oF
break; {1GJ,['qL
} ;qx#]Z0 <
} 8&QST!JGSX
C|{Sj`,XG
R!VfTAv
public void splitterStop() :cpj{v;s
{ $+eeE
bStop = true; 37bMe@W
} Iil2R}1
WR+j?Fcf
Wzq W1<*`
} 5C w( 4.
p^l#Wq5
uH_KOiF
/* dg D-"-O
**FileAccess.java mY|c7}>V;
*//文件访问(定位，写) sA0Ho6
package NetFox; zI88IM7/
import java.io.*; ! FcGa
^0,}y]5p
glAS$<
public class FileAccessI implements Serializable{ T2{e1 =Z7
V:0IBbh)w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0 _!0\d#c
RandomAccessFile oSavedFile; 7KtU\u
long nPos; "+DA)K
/4{WT?j
ITPE2x
public FileAccessI() throws IOException ?o<vmIge
{ z$^d_)
this("",0); $-_" SWG.
} J%bNt)K}
\%-<O
BRFsw`c
public FileAccessI(String sName,long nPos) throws IOException I=`?4%
{ &9jJ\+:7
oSavedFile = new RandomAccessFile(sName,"rw"); -:}vf?
this.nPos = nPos; VPCI5mS_
oSavedFile.seek(nPos); IRW0.'Dn
} b1xE;0uR
Y;af|?U*6:
KFM[caKeJO
public synchronized int write(byte[] b,int nStart,int nLen) q4BXrEOw
{ &+9 ;
int n = -1; &oL"AJU
try{ xvGYd,dlK
oSavedFile.write(b,nStart,nLen); z/Lb1ND8
n = nLen; * :"*'
} YznL+TD
catch(IOException e) _/[qBe
{ +|?a7qM
e.printStackTrace (); &BVUK"}P
} e\)%<G5
ui]iOp
q NGR6i
return n; 4S(G366
} T! }G51
/N0mF< P
+o+f\!
} K#FD$,c~
L1IF$eC
1$Up7=Dr=
/* eDd&vf
**SiteInfoBean.java #y\O+\4e
*/ &Vj@){
package NetFox; $.,PteYK
Uo3
qw+7.h#V
public class SiteInfoBean { ft"-
@Y~gdK
y)r`<B
private String sSiteURL; //Site's URL o*T?f)_[p
private String sFilePath; //Saved File's Path .M6.]H
private String sFileName; //Saved File's Name GTs,?t16/
private int nSplitter; //Count of Splited Downloading File tmGhJZ2j
GEPWb[Oa
`n+uA~
public SiteInfoBean() !&%KJS6p4
{//nSplitter的缺省值为5 c<13r=+
//default value of nSplitter is 5 kn#?+Q
this("","","",5); 9WHE4'Sa
} l4gH]!/@
q\tr&@4iC
/OKp(u;)z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VnuG^)S
{ %+r(*Q+0$f
sSiteURL= sURL; ^;II@n i
sFilePath = sPath; hC-uz _/3
sFileName = sName; hu-]SGb6
this.nSplitter = nSpiltter; hl]d99Lc
Dw=L]i :0v
#kQ! GMZH
} TjpyU:R,&|
IO7z}![V;
DzC`yWstP
public String getSSiteURL() q~>!_q]FE
{ FC 8<D
return sSiteURL; zBm~J%
} Vc\g"1x
uVYn,DB`
:b9#e g
public void setSSiteURL(String value) <B%wq>4S
{ b'(AVA
sSiteURL = value; Ioe.[&o6B
} ]xf89[;0
\m`IgP*
ErN[maix#
public String getSFilePath() (R=ZI
{ #h ud_
return sFilePath; ,):aU
} _Q:ot'(~0-
P]"@3Z&w
=Vh]{y~$
public void setSFilePath(String value) OL1xxzo
{ $7X;FmlG&
sFilePath = value; *Y1s4FXu2
} do`'K3a"
Ov"wcJ
Wz^;:6F
public String getSFileName() oD%n}
{ D~inR3(}
return sFileName; ~N/%R>(v
} Sh;`<Ggi~
%X\J%Fj
QM!UMqdj
public void setSFileName(String value) yS)k"XNb
{ wgDAb#Zuk
sFileName = value; 9X[378f+(
} !yg &zzP*
VI3fvGHat{
f$</BND
public int getNSplitter() &tkPZ*}#1
{ s"7FmJ\7rw
return nSplitter; *K>2B99TXu
} 2U%t
D~qi6@Ga
nUY)LnI
public void setNSplitter(int nCount) ]Vfp,"op
{ ym p*:lH(
nSplitter = nCount; Bl)D/
} '>OEQU5-
} )1 @v<I
$_%
+VIEDV+
/* [p\xk{7Y
**Utility.java %AV3eqghCg
*/ UB] tKn
package NetFox; ,>g(%3C
daY0;,>
HJr*\%D}1
public class Utility { MPp:EH
FpttH?^
6 y"r'
public Utility() h*4wi.-
{ "% i1zQo&
$sL+k 'dY
3b?-83a
} .&=\ *cZc
xR'd}>`
//线程睡眠 -Hi_g@i*XW
public static void sleep(int nSecond) KJn 3&7
{ aSm</@tO&
try{ yokZ>+jb
Thread.sleep(nSecond); AzGbvBI&V
} rI)&.5^
catch(Exception e) hAi'|;g
{ fk#Ggp<
e.printStackTrace (); 4P2p|Gc3
} ),<h6$
} nP=/XiCj
a$"Z\F:x
//日志 4/o9K*M+
public static void log(String sMsg) 54JI/!a
{ p<VW;1bt5
System.err.println(sMsg); $ z+ =lF
} Z\-Gr 2k
7|m{hSc
8Z@O%\1x6
public static void log(int sMsg) X7aj/:fXe
{ Yv*i69"
System.err.println(sMsg); "| oW6@
} (yu0iXZY
} p8y<:8I
+'e3YF+'
?s0")R&
/* n[-d~Ce2{
**TestMethod.java QK~>KgVi
*/ I#yd/d5^
package NetFox; wS2N,X/Y
u<@ 55k
V6<Ki
public class TestMethod { !OH'pC5
BD ,3JDqT
51%<N\>/4
public TestMethod() D@mqfi(x
{ ///xx/weblogic60b2_win.exe t/"9LMKs?
try{ ht)KS9Xu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <RkJ7Z^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); is-{U?-
SiteFileFetch fileFetch = new SiteFileFetch(bean); v2#qs*sW8
fileFetch.start(); Zfr?(y+3
} * 8D(Lp1
catch(Exception e){e.printStackTrace ();} vCR\lR+
TwE&5F*
Lj3q?>D*^6
} [h :FJ
I'cM\^/h
BgG+
public static void main(String[] args) HQ|{!P\/?U
{ LZ9IE>sj
new TestMethod(); 6~+?DIc
} *Oe;JqQkK
} 7w"YCRKh
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