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)); `_]UlI_h
} jz>b>;
for(int i=0;i<nEndPos.length-1;i++) vfc,{F=Q
{ +=nWB=iCb
nEndPos = nStartPos[i+1]; `7?EE1o
} S/l6c P
nEndPos[nEndPos.length-1] = nFileLength; #>sIXY
} g;7u-nP
} tDMNpl
5dbj{r)s6i
ov >5+"q)
//启动子线程 K(P.i^k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w02C1oGfx
for(int i=0;i<nStartPos.length;i++) 5v=e(Ph+
{ @Q&k6.{4Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H7meI9L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g+(Y)9h&
nStartPos,nEndPos,i); &^Gp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C<w&mFozL
fileSplitterFetch.start(); cJM.Q_I}Y
} mHH>qW{`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .*J /F$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PR,8c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a(G}<
nEndPos = " + nFileLength); `lt[Q>Z
// fileSplitterFetch[nPos.length-1].start(); : JSuC
4[Wwm
,pVe@d'
//等待子线程结束 $H&:R&Us
//int count = 0; Pa$"c?QUy
//是否结束while循环 ::-*~CH)
boolean breakWhile = false; gyT0h?xDt
;Sp/N4+
Z.s0ddMs
while(!bStop) (CJx Y(1K
{ +%K~HYN
write_nPos(); o*oFCR]j
Utility.sleep(500); rfr]bq5
breakWhile = true; 9w=[}<E
_g'x=VJF
A\13*4:;l
for(int i=0;i<nStartPos.length;i++) ,3!4 D^
{ o,@(]e~
if(!fileSplitterFetch.bDownOver) yW"[}Lh4
{ |.-Muv
breakWhile = false; %7?Z|'\
break; 8`90a\t'Z
} D#^euNiWd
} u*rHKZ9i
if(breakWhile) BKgCuz:y
break; D6C h6i5$
BPVOBL@
.nEiYS|T
//count++; k)W&ZY
//if(count>4) [X>f;;h
// siteStop(); POX{;[SV
} xLgZtLt9
\5Y<UJKi
da@W6Ovx
System.err.println("文件下载结束！"); }02(Y!Gh
} P?zaut
catch(Exception e){e.printStackTrace ();} agQDd8oX
} %36@1l-N
#qxo1uV(c
ud"Kko Rt
//获得文件长度 =1<v1s|)q
public long getFileSize() wxT(ktE
{ ;82?ACCP
int nFileLength = -1; wzBI<0]z
try{ QGE0pWL-a
URL url = new URL(siteInfoBean.getSSiteURL()); 8# x7q>?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \0&F'V
httpConnection.setRequestProperty("User-Agent","NetFox"); Sl@Ucc31
O=^/58(m
)lq+Gv[%F
int responseCode=httpConnection.getResponseCode(); q1m{G1W n
if(responseCode>=400) "b%FkD
{ kv;P2:"|
processErrorCode(responseCode); 77ztDQDtM
return -2; //-2 represent access is error RdNLf
} |IS$Om
(%"9LYv
IFhS(3YK[
String sHeader; M+:9U&>
)ybF@emc
2. v<pqn
for(int i=1;;i++) >`0mn|+
{ ?/myG{E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8pZOgh
//Utility.log(in.readLine()); ;|:R*(2
sHeader=httpConnection.getHeaderFieldKey(i); *%E\mu,,c
if(sHeader!=null) c]/S<w<
{ s'$2 }K
if(sHeader.equals("Content-Length")) R'" c
{ (L(n%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'g3T'2"`5
break; +(^HL3
} 8IE^u<H(:
} %Y>E
else &So1;RR,_M
break; j0s$}FPUI
} o^m?w0 \
} 3xiDt?&H
catch(IOException e){e.printStackTrace ();} g(,^';j
catch(Exception e){e.printStackTrace ();} T k@~w
4S[UJ%
d`~~Ww1
Utility.log(nFileLength); 5}c8v2R:B
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c] t@3m
return nFileLength; h_SkX@"/-
} Lw%_xRn)
[^^Pl:+
$48Z>ij?f
//保存下载信息（文件指针位置） D3%2O`9
private void write_nPos() q'TIN{\.{
{ &HtTh {
try{ BRM!g9
output = new DataOutputStream(new FileOutputStream(tmpFile)); W|y;Kxy
output.writeInt(nStartPos.length); D2=zrU3Y64
for(int i=0;i<nStartPos.length;i++) b};o:
{ +T8MQ[(4
// output.writeLong(nPos); EdkIT|c{
output.writeLong(fileSplitterFetch.nStartPos); 8@RtL,[d
output.writeLong(fileSplitterFetch.nEndPos); (.VS&Kv#U
} ou-uZ"$,c
output.close(); SvrUXf
} e`OQ6|.k8
catch(IOException e){e.printStackTrace ();} }W&9}9p"
catch(Exception e){e.printStackTrace ();} {8oGWQgrj
} +C[g>c}d
1ANb=X|hig
w~ON861
//读取保存的下载信息（文件指针位置） $2RSYI`py
private void read_nPos() lW|v_oP9
{ SD<a#S\o
try{ ,>8w|951'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]vP}K
int nCount = input.readInt(); ~"NuYM#@
nStartPos = new long[nCount]; To5hVL<Ex"
nEndPos = new long[nCount]; Z*Gf`d:
for(int i=0;i<nStartPos.length;i++) z?( b|v
{ | L1+7
nStartPos = input.readLong(); 5t"FNL <(M
nEndPos = input.readLong(); PB?2{Cj
} c&FOt
input.close(); C+[)^2M{
} aB?usVoS
catch(IOException e){e.printStackTrace ();} -;J6S
catch(Exception e){e.printStackTrace ();} #sDb611}#
} #V%98|"
v(!:HK0oeT
YRFz]
private void processErrorCode(int nErrorCode) B?- poB&
{ - l^3>!MAM
System.err.println("Error Code : " + nErrorCode); )%3T1 D/
} R&a$w8
{]Hv*{ ]
9dBxCdpu
//停止文件下载 ,&qC R sw
public void siteStop() t(9q6x3|e
{ }m~MN4 l
bStop = true; x!\q69ndv
for(int i=0;i<nStartPos.length;i++) Q2uV/M1?
fileSplitterFetch.splitterStop(); 5j6`W?|q
e}S+1G6r)
f'H|K+bO
} ^gZ,A]
} d7 H*F
//负责部分文件的抓取 TlRc8r|
**FileSplitterFetch.java ^|]Dg &N.
*/ rp{|{>'`.q
package NetFox; x3Y)l1gh
g\ vT7x
tiHR&v
import java.io.*; q$mc{F($D
import java.net.*; upL3M`
I "~.p='
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public class FileSplitterFetch extends Thread { sA77*T
v{fcQb
ii-AE L
String sURL; //File URL y& 1@d+Lf
long nStartPos; //File Snippet Start Position ?1a9k@[t
long nEndPos; //File Snippet End Position ne/JC(
int nThreadID; //Thread's ID Jk6}hUH,
boolean bDownOver = false; //Downing is over \m GY'0
boolean bStop = false; //Stop identical T9H*]LxK
FileAccessI fileAccessI = null; //File Access interface L/V^#$
qS FtQ4
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Np/\}J&IF
{ oSC'b%
this.sURL = sURL; -4& i t:
this.nStartPos = nStart; =@?[.`
this.nEndPos = nEnd; %&| uT
nThreadID = id; %kjG[C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !W9:)5^X
} `+"(GaZ
+ovK~K$A
*^~ =/:
public void run() (Y@T5-!D
{ $?G@ijk,
while(nStartPos < nEndPos && !bStop) ElV!C}g
{ 5;UIz@BJ
"8{A4N1B5
}: HG)V
try{ .'gm2
URL url = new URL(sURL); '=n?^EPE3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4^F%bXJ)
httpConnection.setRequestProperty("User-Agent","NetFox"); Oo}h:3?
String sProperty = "bytes="+nStartPos+"-"; pB8D
httpConnection.setRequestProperty("RANGE",sProperty); /uj^w&l#
Utility.log(sProperty); *}d N.IL,
J-5>+E,nZ
8Auek#[
InputStream input = httpConnection.getInputStream(); ,0.kg
//logResponseHead(httpConnection); yJq<&g
y]m: {
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byte[] b = new byte[1024]; ExS5RV@v'
int nRead; JfIXv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MK=oGzK
{ 0lg$zi x(
nStartPos += fileAccessI.write(b,0,nRead); Y \-W`
//if(nThreadID == 1) C,Nf|L((6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1 _?8OU
} Pc`d]*BYi
|'nQvn:{
<$0is:]
Utility.log("Thread " + nThreadID + " is over!"); 4a+gM._+O
bDownOver = true; 'bi;Y1:
//nPos = fileAccessI.write (b,0,nRead); dm4Q'u
} ?K>)bA&l'
catch(Exception e){e.printStackTrace ();} 2@<_,'
} J**(7d
} ~v.mbh
vSH,fS-n
:ZV|8xI
//打印回应的头信息 <\~v$=G
public void logResponseHead(HttpURLConnection con) _SAM8!q4,
{ ,X4+i8Yc
for(int i=1;;i++) &*=!B9OBI
{ U]=yCEb8p
String header=con.getHeaderFieldKey(i); oAQQ OtpZN
if(header!=null) hul,Yd) Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AafS6]y
Utility.log(header+" : "+con.getHeaderField(header)); S\g9@g.
else ayy\7b
break; 4,I,f>V
} H9/!oI1P?
} )S g6B;CJ
D_DwP$wSo
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public void splitterStop() &zdS9e-fF
{ u}[ a
bStop = true; q!y.cyL
} aDF@AS
@:C)^f"
:>0ywg
} Lq2Q:w'
'[ t.
,a?)O6?/
/* gjDNl/r/
**FileAccess.java MA`nFkVK
*//文件访问(定位，写) eiKY az
package NetFox; 'Qy6m'esW
import java.io.*; j=l2\W#}
|nefg0`rk
MJXnAIG?2
public class FileAccessI implements Serializable{ 6]brL.eGj
MXaFqK<Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fEHFlgN3Ap
RandomAccessFile oSavedFile; &B{zS K$N
long nPos; SGWb*grt
]<;7ZNG"Y5
_z@/~M(
public FileAccessI() throws IOException NfV|c~?d
{ MzIDeZ
this("",0); EN!C5/M{&
} g,Ob/g8uc
.q9Sg8G
3ZXAAV
public FileAccessI(String sName,long nPos) throws IOException LZV-E=`
{ pU7;!u:c4%
oSavedFile = new RandomAccessFile(sName,"rw"); lL)f-8DX
this.nPos = nPos; \sNgs#{7E7
oSavedFile.seek(nPos); /ox7$|Jyr
} Hd~g\
/mkT7,]
a{kJ`fK
public synchronized int write(byte[] b,int nStart,int nLen) wpK1nA+7N
{ {A0jkU
int n = -1; J!uG/Us
try{ "ko*-FrQ
oSavedFile.write(b,nStart,nLen); [bhKL5l
n = nLen; @+b$43^
} f24W*#IX
catch(IOException e) q/EX`%U
{ *9\j1Nd
e.printStackTrace (); ?b]zsku8
} xMjhC;i{
<_YdN)x
u7< +)6-
return n; D$}hoM1
} gi!_Nz
m_)-
wN[lC|1c
} QX=TuyO
dn 6]qW5
g *Js4
/* Cbff:IP
**SiteInfoBean.java "\o#YC
*/ w6vbYPCN
package NetFox; KuJ)alD;1
}4C_r'd6
1-y8Hy_a2
public class SiteInfoBean { 6>]_H(z7
<2pp6je\0s
rfwJLl/
private String sSiteURL; //Site's URL a|t~&\@
private String sFilePath; //Saved File's Path /a1uG]Mt
private String sFileName; //Saved File's Name w%])
private int nSplitter; //Count of Splited Downloading File (<Cq_Kw
t\Vng0
%~Yo{4mHs
public SiteInfoBean() ;Nn(
{//nSplitter的缺省值为5 v9f+ {Y%-
//default value of nSplitter is 5 jEBn"]\D
this("","","",5); oMbd1uus
} :s *
#/YS
kLgkUck8]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #*iUZo
{ ~0PzRS^o
sSiteURL= sURL; >$m<R&
sFilePath = sPath; ;%n'k
sFileName = sName; u"0{) ,
this.nSplitter = nSpiltter; /|v4]t-
-}6ew@GE
'yiv.<4
} EE"8s7ZF
9lq5\ tL-
h.Qk{v
public String getSSiteURL() 7!J-/#!
{ Jqxd92 bI
return sSiteURL; "1a;);S=*)
} |ke0G
gv67+Mf
`3\aX|4@
public void setSSiteURL(String value) 2K:A4)jZ
{ AS;Sz/YP
sSiteURL = value; N@|<3R!N*e
} [<XYU,{R
6{)pF
'l'3&.{Yfk
public String getSFilePath() :ts3_-cr
{ O\<zQ2m
return sFilePath; )BJkHED{
} %"{P?V<-V
mqZK1<r
hV@ N-u^
public void setSFilePath(String value) ZUI6VM
{ ZxtO.U2
sFilePath = value; 9^/Y7Wp/@
} 0Md>-H;ZY
,V1"Typ#<
_<AkM"
public String getSFileName() b+~_/;Y9
{ 6Q:Wo)^!
return sFileName; q(n"r0)=
} `NtW+v
kP`#zwp'Ci
Zu"qTJE/1
public void setSFileName(String value) uw3vYYFX
{ .))g]CH
sFileName = value; znrO~OK
} {F<0e^*
2Hd\>{*
/l<(i+0
public int getNSplitter() sywuS
{ y`oj\
return nSplitter; (utP@d^
} z|Y54o3
1{N+B#*<[X
.2%t3ul[
public void setNSplitter(int nCount) =AO (
{ ]njNSn
nSplitter = nCount; mh8fJ6j29N
} u[**,.Ecg
} D?dBm
!H\;X`W|~D
1 iox0
/* 3@":&
**Utility.java M-t9M~
*/ ,P9F*;Dj
package NetFox; lrJV"H
Pm%xX~H
fnq 3ic"V
public class Utility { ZiZ@3O6
3t<a3"{9
]$ d ;P
public Utility() ~HIj+kN
{ 1Le8W)J
gnH{_
VzXVy)d
} 4FzTf7h^
Ue \A ,
//线程睡眠 JtO}i{A
public static void sleep(int nSecond) },d^y:m
{ K~d'*J-
try{ ymm]+v5S.]
Thread.sleep(nSecond); dU9;sx
} _&]7
catch(Exception e) 6rnFXZ\
{ Md4Q.8
e.printStackTrace (); GTLS0l)
} '1D$ ;
} 1 3]e< '
*IOrv)
//日志 X|\`\[
public static void log(String sMsg) :;_}Gxx
{ B& @ pZYl
System.err.println(sMsg); )n)AmNpq
} X{x(p
;h1hz^Wq
Tz)Ku
public static void log(int sMsg) |mKohV qr
{ :,l16{^
System.err.println(sMsg); VEy]vr}
} =6U5^+|d
} x1Gx9z9
2OUx@Vj
dm}1"BU<
/* lW5Lwyt8
**TestMethod.java {> ,M
*/ )jXKPLj
package NetFox; :h(RS;
D9TjjA|zS
Ja~8ZrcY
public class TestMethod { ;=n}61
ho$}#o
HWV A5E[`Y
public TestMethod() 'o)Y!VYnJF
{ ///xx/weblogic60b2_win.exe 1?BLL;[a8
try{ c1E{J<pZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yeg<MrS4D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?;oJ=.T
SiteFileFetch fileFetch = new SiteFileFetch(bean); `xx.,;S
fileFetch.start(); pnuo;rs
} ~qZ6I)?
catch(Exception e){e.printStackTrace ();} $e+4Kt ,
:4AIYk=q
CmXLD} L_x
} VWzQXo
^.:&ZsqV
>>$L vQ
public static void main(String[] args) &jY| :Fe
{ PESvx>:
new TestMethod(); Je|:\Qk
} ?GH/W#{o)
} x%s1)\^A
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