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)); E>k!d'+tb
} *[b22a4H(
for(int i=0;i<nEndPos.length-1;i++) .@3bz
{ 9AHxa
nEndPos = nStartPos[i+1]; Ae>:i7.V
} x^/453Lk
nEndPos[nEndPos.length-1] = nFileLength; ?m dGMf)
} 5ii:93Hlj
} '*n2<y
)jed@?
3Jw}MFFV
//启动子线程 mI-9=6T_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n@y*~sG]
for(int i=0;i<nStartPos.length;i++) }TwSSF|}3
{ vs(x;zpJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hjc *WTu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cUc:^wvLS
nStartPos,nEndPos,i); QZamf lk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .?*TU~S
fileSplitterFetch.start(); s?_H<u
} Z,5B(Xj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jn)DZv8?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6G]hsgro
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c^`(5}39v
nEndPos = " + nFileLength); w4j,t
// fileSplitterFetch[nPos.length-1].start(); NLF6O9
g\=e86
PR~9*#"v..
//等待子线程结束 {}N=pL8MS
//int count = 0; n_@cjO
//是否结束while循环 pEX|zee
boolean breakWhile = false; ><"0GPxrx
J|:Zs1.<d
{Q AV
while(!bStop) SX@zDuM
{ Y@Ti2bI`v
write_nPos(); _q3|Ddm2LN
Utility.sleep(500); SB=%(]S
breakWhile = true; *#Hw6N0#
;B6m;[M+
Pm!/#PtX
for(int i=0;i<nStartPos.length;i++) p _q]Rt
{ [?nM)4d
if(!fileSplitterFetch.bDownOver) s[#ww =T\
{ =SLCG.
breakWhile = false; hO0g3^
break; G~KYFNHr
} S F&EVRv
} Kzrt%DA
if(breakWhile) )m.U"giG++
break; x$=""?dd
pDM95.6
IJv+si:k
//count++; gkL{]*9&%
//if(count>4) 1cY,)Z%l #
// siteStop(); <^fvTb&*
} sH /08Z
*W$bhC'w
NAh^2X
System.err.println("文件下载结束！"); ZCz#B2Sf8
} _Sn45h@"
catch(Exception e){e.printStackTrace ();} &@/25Y2
} "*Gp@
~dlpoT
z 3N'Xk
//获得文件长度 E% d3}@
public long getFileSize() pW1(1M)[%Z
{ L1YiXJ,T,
int nFileLength = -1; x5 ?>y{6D
try{ d.t$VRO
URL url = new URL(siteInfoBean.getSSiteURL()); J3,m{%EtNM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &~sirxR p
httpConnection.setRequestProperty("User-Agent","NetFox"); 5;q{9wvqO
22FHD4
/L*JHNu"_
int responseCode=httpConnection.getResponseCode(); mk]8}+^.
if(responseCode>=400) BSHtoD@e7
{ [LDY;k~5+
processErrorCode(responseCode); !FHm.E_>
return -2; //-2 represent access is error c!dc`R
} 0*XCAnJ^_
D2MWrX
nV3I6
String sHeader; a+PVi
-&JQdrs
j6DI$tV~
for(int i=1;;i++) QI*<MF,1
{ 6gTc)rhRT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nD\H$5>5
//Utility.log(in.readLine()); ky=h7#wdv-
sHeader=httpConnection.getHeaderFieldKey(i); vfloha p
if(sHeader!=null) pgEDh^[MW
{ #9CLIYJAd
if(sHeader.equals("Content-Length")) {W$K@vuV;?
{ (fcJp)D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /[+%<5s
break; y{Vh?Z<E
} SmVL?wf
} Q%n$IQr4gM
else LZ<^b6Dxk
break; 12HE=
} <P.'r,"[
} (Fs{~4T
catch(IOException e){e.printStackTrace ();} J+r:7NvZ
catch(Exception e){e.printStackTrace ();} s"B+),Jod
)%vnl~i!
jj6yf.r6c
Utility.log(nFileLength); ch]{=61
jH?!\F2)+
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return nFileLength; OU'm0Jlk
} ;bRyk#
>p 9~'
Nx=rw h
//保存下载信息（文件指针位置） ]_43U` [#
private void write_nPos() =Hx]K8N)
{ f[wxt n'r
try{ 52t6_!y+V
output = new DataOutputStream(new FileOutputStream(tmpFile)); *cAI gO7
output.writeInt(nStartPos.length); aM YtWj
for(int i=0;i<nStartPos.length;i++) /_</m?&.U&
{ ()e|BFL.
// output.writeLong(nPos); #eIFRNRb)
output.writeLong(fileSplitterFetch.nStartPos); bk:mk[
output.writeLong(fileSplitterFetch.nEndPos); KvXFzx|A
} ip!-~HNwJ
output.close(); +F+M[ef<ws
} UX%J?;g
catch(IOException e){e.printStackTrace ();} 45;ey }8
catch(Exception e){e.printStackTrace ();} % Ou'+A
} xQkvK=~$
a!B"WNb+
bXk(wXX
//读取保存的下载信息（文件指针位置） Dvm[W),(k
private void read_nPos() |dhKeg_
{ :f~qt%%/
try{ }/2M?W0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (9Q@I8}Iy
int nCount = input.readInt(); *" +u^
nStartPos = new long[nCount]; ZQ{-6VCjl
nEndPos = new long[nCount]; 1P?|.W_^1
for(int i=0;i<nStartPos.length;i++) Z}S7%m
{ J?C:@Q
nStartPos = input.readLong(); u=t.1eS5
nEndPos = input.readLong(); S?#6{rx
} ZlP+t>
input.close(); MI)v@_1d
} U=PTn(2
catch(IOException e){e.printStackTrace ();} ^@^K <SVc
catch(Exception e){e.printStackTrace ();} `T{'ufI4B
} $4q$!jB5
G`RQl@W>)(
><I{R|bC
private void processErrorCode(int nErrorCode) "3/&<0k
{ wKKQAM6P1
System.err.println("Error Code : " + nErrorCode); P1ak>T*#2
} B>g(i=E
wSi$.C2
y/+IPR
//停止文件下载 qP]1}-
public void siteStop() Z)md]Twt
{ \/ipYc
bStop = true; }$i/4?dYsQ
for(int i=0;i<nStartPos.length;i++) 9}5o> iR
fileSplitterFetch.splitterStop(); VS>xvF
1!NrndJI
}=Ul8 <
} .wB'"z8L
} c(aykIVOo
//负责部分文件的抓取 6V*,nocL_+
**FileSplitterFetch.java ,Oe:SZJ>
*/ { &Vt]9
package NetFox; ~;#sj&~
1)5$,+~lL
tAsap}(
import java.io.*; 8OiCldw:HN
import java.net.*; S%aup(wu6
51Vqbtj^
"6 ~5RCZ
public class FileSplitterFetch extends Thread { -iKoQkHt
_s*p$/V\
.><-XJ
String sURL; //File URL S=\cF,Zs
long nStartPos; //File Snippet Start Position D -d
long nEndPos; //File Snippet End Position x#gZC1$Y
int nThreadID; //Thread's ID fUr%@&~l^
boolean bDownOver = false; //Downing is over <@P. 'rE
boolean bStop = false; //Stop identical LosRjvQ:
FileAccessI fileAccessI = null; //File Access interface xkv%4H>
XJ5@/BW
'6; {DX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [S1 b\f#
{ \*[DR R0
this.sURL = sURL; vn!5@""T
this.nStartPos = nStart; hQ'W7EF
this.nEndPos = nEnd; YmOj.Q&
nThreadID = id; +abb[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $JUkwsc
} .+kg1=s
S`$%C=a.
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public void run() V0BT./ B\<
{ D|ra ;d
while(nStartPos < nEndPos && !bStop) )K$YL='kX
{ ;dPaWS1D
U!NuiKaQ26
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try{ U8J9 #+:
URL url = new URL(sURL); D<|$ZuB4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XRO(p`OE-
httpConnection.setRequestProperty("User-Agent","NetFox"); < Sgc6>)
String sProperty = "bytes="+nStartPos+"-"; &>]U c%JK
httpConnection.setRequestProperty("RANGE",sProperty); m2"wMt"*V
Utility.log(sProperty); *V7mM?
_QEw=*.<
;|0P\3
InputStream input = httpConnection.getInputStream(); {Wi*B(
//logResponseHead(httpConnection); 7'"qW"<
ptrwZ8'
FvY=!U06
byte[] b = new byte[1024]; k1oJ<$Q
int nRead; DP0@x+`k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) = pn;b1=
{ ~M8|r!_
nStartPos += fileAccessI.write(b,0,nRead); zjh:jrv~
//if(nThreadID == 1) `a83bF35
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E*`PD<:)H
} ;i\N!T{>
/(*Ucv2i}T
Wy}^5]R0E
Utility.log("Thread " + nThreadID + " is over!"); L9N}lH
bDownOver = true; n}_}#(a
//nPos = fileAccessI.write (b,0,nRead); 2Z%n "z68
} -gm5Eqi
catch(Exception e){e.printStackTrace ();} qdn_ZE
} xT]t3'y|-
} yo/;@}g}
g'b|[ q
^C1LQZ
//打印回应的头信息 ge(,>xB
public void logResponseHead(HttpURLConnection con) 1G7l+6w5~^
{ Kei0>hBi
for(int i=1;;i++) e5 L_<V^Jo
{ WG3!M/4r H
String header=con.getHeaderFieldKey(i); \pfa\,rW
if(header!=null) w;yzgj:n&f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3]GMQA{L)
Utility.log(header+" : "+con.getHeaderField(header)); FR[I~unqD
else vi *A5
break; G{]RC^Zo
} Jx~H4y=z
} jLM([t
l)*(UZ"
|Q%P4S"B?
public void splitterStop() l cHf\~
{ ZnRT$ l O
bStop = true; *Z^`H!&
} A&)2m
}oA>0Nw$K
)WbWp4
} C1e@{>
]95VMyN
`BKb60
/* ;cvMNU$fN
**FileAccess.java | bRU=dg
*//文件访问(定位，写) [K$5Rm5
package NetFox; $8rnf
import java.io.*; IHdA2d?.]
z4Zm%
%jy$4qAf%
public class FileAccessI implements Serializable{ ^h$*7u"^y
]t~.?)Ad+2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tiE|%jOzt
RandomAccessFile oSavedFile; 5{k,/Z[L
long nPos; 'E9{qPLk(
x<M::")5!V
wpuK?fP
public FileAccessI() throws IOException Qy0w'L/@
{ 'mbLK#q
this("",0); T>'O[=UWh
} ,wes*
#55:qc>m
4qp|g'uXT
public FileAccessI(String sName,long nPos) throws IOException G(.G>8pf
{ Ba8=nGa4KY
oSavedFile = new RandomAccessFile(sName,"rw"); oG1zPspL
this.nPos = nPos; WM?-BIlT=
oSavedFile.seek(nPos); W/bW=.d Jd
} - [h[
F0p=|W
X':FFD4h
public synchronized int write(byte[] b,int nStart,int nLen) Ajm!;LA[jO
{ }LS8q
int n = -1; 4h@,hY1#
try{ }n4 T!N
oSavedFile.write(b,nStart,nLen); lbda/Zx
n = nLen; UjQz
} M%`CzCL u
catch(IOException e) /HLI9
{ sFz0:SqhE
e.printStackTrace (); 3?a`@C&x
} Zh;wQCDj
wDh]vH[
0>Snps3*Z
return n; .)b<cH~%
} (cOe*>L;
|Q3d7y
&L$9Ii
} ZI!:
1*u]v{JJ(
7Dbm s(:(
/* ]|tg`*l!>
**SiteInfoBean.java Cjr]l!
*/ }x`Cnn
package NetFox; @@H_3!B%4v
B4RrUA32
PM[_0b
public class SiteInfoBean { ?h&XIM(
\)No?fB
H%@f ^
private String sSiteURL; //Site's URL XqmB%g(
private String sFilePath; //Saved File's Path !vAmjjB
private String sFileName; //Saved File's Name /S"jO[n9b
private int nSplitter; //Count of Splited Downloading File bPxL+ +
%US&`BT!
;yomaAr
public SiteInfoBean() )~wKRyQff
{//nSplitter的缺省值为5 S4_/%~?
//default value of nSplitter is 5 Pj <U|\-?
this("","","",5); d j\Z}[
} c EYHB1*cT
Gn8sB
_GG\SWm
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AhN3~/u%7
{ V'j+)!w5
sSiteURL= sURL; xKSQz
sFilePath = sPath; %m |I=P
sFileName = sName; +_7a/3kh
this.nSplitter = nSpiltter; f"FFgQMkv
ad: qOm
.g*N+T6O
} jXE:aWQht
B>L7UQ6_[
gUru=p
public String getSSiteURL() "5V;~}=S
{ 60!%^O =
return sSiteURL; jG[Vp b
} 6/8K2_UeoW
(NvjX})eh
PK2;Ywk`
public void setSSiteURL(String value) 6h>#;M
{ ;bB#Pg
sSiteURL = value; }CBQdH&g;
} '|SO7}`;Q
:Ph>\aG
"V>}-G&
public String getSFilePath() %i9 e<.Ot
{ |MZ1j(_
return sFilePath; T ?[28|
} QgqJ #
8D )nM|
C>+n>bH]L
public void setSFilePath(String value) ,~d0R4)
{ jjV'`Vy)
sFilePath = value; \s*M5oN]]
} d.vNiq,`
e3;&
G*9>TavE
public String getSFileName() }#ZRi}f2VJ
{ ]#]Z]9w
return sFileName; &|k=mxox\
} $os]$5(
;Sivu-%
%1Q:{m
public void setSFileName(String value) 0A)0Zw
{ V8M()7uJ
sFileName = value; Gw<D'b)!
} !l $d^y345
w{W+WJ
P5<9;PPbZ
public int getNSplitter() A O:F*%Q u
{ L\2"1%8Wj
return nSplitter; H[~ D]RG}'
} "#O9ij
d&NnpjH}c
MQ!4"E5"j
public void setNSplitter(int nCount) epiviCYC
{ B"&-) (
nSplitter = nCount; :8)Jnh\5
} K<J,n!zc
} #BLHHK/[
i=Qy?aU?
J 4gtm"2)
/* uy hh"[
**Utility.java U4!KO;Jc
*/ xfb .Z(
package NetFox; >.Gmu
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_c>ww<*3
public class Utility { B r#{
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0/su`
public Utility() yI: ;+K
{ ' 4FH9J
sGu.G
xT+_JT65
} iM<$ n2t
B5z'Tq1
//线程睡眠 ?sk>Mzr
public static void sleep(int nSecond) f`hZb
{ "A}sD7xy9
try{ 6'^E ],:b
Thread.sleep(nSecond); ;TJpD0
} n*7^lAa2
catch(Exception e) +c~&o83[
{ ]:gW+6w"C
e.printStackTrace (); Ok_}d&A
} 9w=7A>.U
} +7gd1^|$e
KmNnW1T
//日志 |HmY`w6*z
public static void log(String sMsg) PMytk`<`zw
{ cHvm
System.err.println(sMsg); JUr t%2
} c7XBZ%D
&+#5gii1i
Yg8*)u0
public static void log(int sMsg) -P;0<j@6k5
{ ,MXU]{
System.err.println(sMsg); 'SXHq>#gA
} o.ZR5`.
} !_W/p`Tc
s/7Z.\
=%m{|HQ`
/* J#$U<`j*G
**TestMethod.java ^bv^&V&IB
*/ q-`&C
package NetFox; SZKYq8ZA)V
~,}|~
M(a%Qk?]/
public class TestMethod { Vc9rc}
%V>%AP
e-rlk5k%f
public TestMethod() MZV$YD^S
{ ///xx/weblogic60b2_win.exe x4* bhiu
try{ +.!D>U$)}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a$=~1@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @s1T|}AJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6M >@DRZ'|
fileFetch.start(); |6Q5bV
} 8* A%k1+
catch(Exception e){e.printStackTrace ();} v@=qVwX
@-sWXz*W
,>-jZtm
} !h.hJt
HV~Fe!J_
9O 'j+?(`@
public static void main(String[] args) ;eYG\uKC{
{ iN&oSpQ
new TestMethod(); vaB ql(?'2
} 4 . 7X*1
} F@?-^ E@
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