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)); pqr"x2=.
} a&[nVu+
for(int i=0;i<nEndPos.length-1;i++) BY d3rI
{ ={Hbx>p
nEndPos = nStartPos[i+1]; Sce9R?II
} Zk[#BUA
nEndPos[nEndPos.length-1] = nFileLength; o&O!Ur
} `2oi~^.
} `WT7w']NT
i*tj@5MY-
QM]^@2rK2
//启动子线程 ^v'Lu!\f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {8MF!CG]
for(int i=0;i<nStartPos.length;i++) 9e5UTJ
{ PA/6l"-`3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b1OB'P8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YH>n{o;- ?
nStartPos,nEndPos,i); tc',c},h~,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k);!H+
fileSplitterFetch.start(); 3YRzBf:h
} r__M1 !3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %Fv)$ :b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #?*jdN:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d0^2<
nEndPos = " + nFileLength); 'yNp J'
// fileSplitterFetch[nPos.length-1].start(); GND[f}
g;h&Xkp
<gy'@w?
//等待子线程结束 0d2%CsMS"D
//int count = 0; t|m3b~Oyv
//是否结束while循环 $3ILVT
boolean breakWhile = false; 1:t>}[Y
m+=!Z|K
S`G\Cd;5
while(!bStop) [ZbK)L+_
{ &)l:m.
write_nPos(); i&$uG[&P
Utility.sleep(500); 7`}z7nk
breakWhile = true; 2$91+N*w9
1rEP)66N
Xwi&uyvU&
for(int i=0;i<nStartPos.length;i++) 9PAp*`J@kr
{ UPYM~c+}
if(!fileSplitterFetch.bDownOver) bqO"k t
{ 1#(1Bs6X
breakWhile = false; "J#:PfJ%
break; -ZB"Yg$l
} Exr7vL
} 7E95"B&w
if(breakWhile) R;o_*
break; ||V:',#,W
-eMRxa>
qAS^5|(b[
//count++; Nt8(
//if(count>4) "x)DE,
// siteStop(); [XXN0+ /
} W<Lrfo&=Y]
g$b*#
.IXwa,
System.err.println("文件下载结束！"); y#+o*(=fRE
} 4_<Uk
catch(Exception e){e.printStackTrace ();} * 5n:+Tw(
} J%)2,szn0
w%;'uN_
5[_8N{QC;
//获得文件长度 o1Ln7r.
public long getFileSize() zTLn*?
{ Sg-xm+iSDt
int nFileLength = -1; |BW,pT
try{ lND[anB!
URL url = new URL(siteInfoBean.getSSiteURL()); 3p4?-Dd|_$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %j@FZ )a[
httpConnection.setRequestProperty("User-Agent","NetFox"); ^&iV%vQ[
u*{ _WL[(
.a*$WGb
int responseCode=httpConnection.getResponseCode(); 1' m $_
if(responseCode>=400) 9f\8oJQ
{ ^v-'=1ub?
processErrorCode(responseCode); 919g5f`
return -2; //-2 represent access is error QGd- 9UEA]
} p0K;m%
iC]lO
w>uZ$/
String sHeader; >{a,]q*
p( *3U[1
Q8?D}h
for(int i=1;;i++) EcIQ20Z_-
{ \]xYV}(FO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W1Qc1T8
//Utility.log(in.readLine()); F/sBr7I
sHeader=httpConnection.getHeaderFieldKey(i); mx~sxYa
if(sHeader!=null) d&`j8O
{ jm\#($gl=
if(sHeader.equals("Content-Length")) #Uh5tc
{ "ux]kfoT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AvZ)1(
break; Wg^cj:&`u
} )/"7$2Aoy
} &F_rg,q&_
else 31& .Lnq
break; u9w&q^0dqG
} Kdu\`c-lB
} 8F`
catch(IOException e){e.printStackTrace ();} *K'ej4"u
catch(Exception e){e.printStackTrace ();} P*`xiTA
/Ph&:n\4
.E#Sm?gK
Utility.log(nFileLength); 5Q`n6x|
(JW?azU
-P>=WZu
return nFileLength; :-La $I>
} fhKiG%i'l
.To:tN#
<C;>$kX
//保存下载信息（文件指针位置） sdYj'e:N
private void write_nPos() e oSM@Isu
{ |SKG4_wGe
try{ SzX~;pFM0
output = new DataOutputStream(new FileOutputStream(tmpFile)); R Sz[6
output.writeInt(nStartPos.length); t<F]%8S
for(int i=0;i<nStartPos.length;i++) #J724`
{ ^G&D4uZ
// output.writeLong(nPos); ?K {1S
output.writeLong(fileSplitterFetch.nStartPos); JZ/O0PW
output.writeLong(fileSplitterFetch.nEndPos); ii y3
} Y>Hl0$:=
output.close(); ><Z3<7K9
} Fx5d@WNa>
catch(IOException e){e.printStackTrace ();} 6L9[U^`@
catch(Exception e){e.printStackTrace ();} d`uO7jlm
} v9m;vWp
+\GZ(!~
lk1Gs{(qhH
//读取保存的下载信息（文件指针位置） @B[Cc`IN"
private void read_nPos() l/zC##1+.
{ P<!$A
try{ (%yc5+f!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !]+Z%ed`%
int nCount = input.readInt(); 5!jNL~M
nStartPos = new long[nCount]; > ' 0 ][~
nEndPos = new long[nCount]; 6h6?BQSE
for(int i=0;i<nStartPos.length;i++) wZ8 MhE
{ kN|5 J
nStartPos = input.readLong(); ]/Yy-T#@
nEndPos = input.readLong(); dyiEK)$h
} "C.7;Rvkp>
input.close(); [Am`5&J
} |( 9#vt#
catch(IOException e){e.printStackTrace ();} [Cj)@OC
catch(Exception e){e.printStackTrace ();} ?7MwTi8{F
} tQ/ #t<4D
HJaw\zbL
kEhm'
private void processErrorCode(int nErrorCode) ct4 [b|
{ i4zV(
System.err.println("Error Code : " + nErrorCode); }?]yxa~
} [~c'|E8Q
<o!&Kk9
_b_?9b-)D
//停止文件下载 ``|RO[+2
public void siteStop() dMs||&|&
{ {{*]bGko
bStop = true; AXP`,H
for(int i=0;i<nStartPos.length;i++) 7X{bB
fileSplitterFetch.splitterStop(); bLEATT[
_gm?FxV:
n<<=sj$\!
} )w2K&Zr0
} J4v0O="
//负责部分文件的抓取 ct}%Mdg
**FileSplitterFetch.java qJ+52U|z
*/ (;pi"/x[
package NetFox; M?xpwqu\
zf3:<CRX5
Va@6=U7c
import java.io.*; QhXC>)PW
import java.net.*; H8$<HhuZM
S1^nC tSF
/ggkb8<3
public class FileSplitterFetch extends Thread { Bug}^t{M
YYE8/\+B.
Z@,PZ
String sURL; //File URL WVWS7N\
long nStartPos; //File Snippet Start Position n(1wdlEp
long nEndPos; //File Snippet End Position 3p3WDL7
int nThreadID; //Thread's ID 6`qr:.
boolean bDownOver = false; //Downing is over Q:kVCm/;
boolean bStop = false; //Stop identical i&pJg1
FileAccessI fileAccessI = null; //File Access interface 6b]1d04hT
ZEj!jWP2m
/MKNv'5&!%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _+\:OB[Y
{ ,9Z2cgXwJ
this.sURL = sURL; nx-1*
this.nStartPos = nStart; O~h94 B`
this.nEndPos = nEnd; (D>y6r>r
nThreadID = id; XpgV09.EE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 | 7 m5P@X
} dv'E:R(a
=@JS88+
n</k/Mk}
public void run() qcTmsMpj
{ c.(Ud`jc
while(nStartPos < nEndPos && !bStop) ZD)0P=%
{ 6Q2orn[
,2,SG/BB
XLZ j
try{ F)/~p&H
URL url = new URL(sURL); \f/#<|Hm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U=F-]lD
httpConnection.setRequestProperty("User-Agent","NetFox"); 4|6&59?pnc
String sProperty = "bytes="+nStartPos+"-"; tE]5@b,R
httpConnection.setRequestProperty("RANGE",sProperty); uNe}"hs
Utility.log(sProperty); qDRNtFa
-@ZzG uS(
)X~Pr?52?
InputStream input = httpConnection.getInputStream(); =a)iVXSB]
//logResponseHead(httpConnection); Iz}2 ^
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g\o{}Q%X
byte[] b = new byte[1024]; .-SF$U_P*a
int nRead; N7*CP|?E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]*2EK9<
{ L\b]k,Ksf
nStartPos += fileAccessI.write(b,0,nRead); _%wK}eH+sy
//if(nThreadID == 1) -G],H)M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gX@nPZjg
} psIkG0 &
pbDw Lo]
xH<'GB)
Utility.log("Thread " + nThreadID + " is over!"); +{xMIl_
bDownOver = true; G{kj}>kS_
//nPos = fileAccessI.write (b,0,nRead); ^:4L6
} (Sth:{;
catch(Exception e){e.printStackTrace ();} uxa=KM1H
} Q[J [=
} _0,"vFdj
\6 \hnP
S3uyn78hI
//打印回应的头信息 >|a\>UgC
public void logResponseHead(HttpURLConnection con) 3ppuQQ
{ yS[z2:!
for(int i=1;;i++) ;/@?6T"
{ J3;Tm~KJ_
String header=con.getHeaderFieldKey(i); h/I@_?k+
if(header!=null) 3`58ah
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uR#'lb`3
Utility.log(header+" : "+con.getHeaderField(header)); IQ3n@
else @Ex;9F,Q
break; })@tA<+
} n{dP@_>WS
} >0PUWr$8
f.||PH
LthGZ|>
public void splitterStop() Dd| "iA
{ +0]'| tF>
bStop = true; g<fDY6jt
} [ njx7d
XtCoX\da
%_R$K#T^,
} *(k%MTG
i"L}!5
QU:EY'2
/* pT4qPta,2
**FileAccess.java Ptx,2e&Hq
*//文件访问(定位，写) 1g1?zk8zO
package NetFox; 4P|$LkI
import java.io.*; G%a] j
XVw-G }5
|~SE"
public class FileAccessI implements Serializable{ %=V"CJ$|
R N@^j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bRNK.[|
RandomAccessFile oSavedFile; @]f3|>I
long nPos; DU;[btK>
I*Vt,JYx
%N)e91wC
public FileAccessI() throws IOException VCjq3/[_
{ cVp[ Z#B
this("",0); *4t-e0]j@w
} wW-Ab
*=Doe2(!C
"Y7+{
public FileAccessI(String sName,long nPos) throws IOException {AOG"T&<
{ UP\C"\
oSavedFile = new RandomAccessFile(sName,"rw"); OU!nN>ln
this.nPos = nPos; f`9JE8
oSavedFile.seek(nPos); ,jy<o+!
} M;*$gV<x
D?^540,b
wa!zv^;N*
public synchronized int write(byte[] b,int nStart,int nLen) P+h6!=nD7
{ ^|#>zCt^
int n = -1; S?L#N
try{ Go1(@
oSavedFile.write(b,nStart,nLen); eJ)1K
n = nLen; 6mCq/$
} :G-1YA
catch(IOException e) F;u7A]H^
{ &y70
e.printStackTrace (); L\YKdUL
} G$C}?"l
;7rd;zJ
4QE=f(u;h
return n; 7{pIPmJ
} 7rcA[)<'
Pp+~Cir
f])M04<
} NPm;
9JPEj-3`g
ocF>LR%P
/* _.{zpF=j
**SiteInfoBean.java `FZF2.N
*/ %zzYleJ!]
package NetFox; ca(U!T68
`?|Rc
l-}KmZ]
public class SiteInfoBean { +Q)ULnie e
x? N.WABr;
C/G]v*MBQ
private String sSiteURL; //Site's URL aG(hs J)
private String sFilePath; //Saved File's Path ZqQ*}l5
private String sFileName; //Saved File's Name wK ?@.l)u
private int nSplitter; //Count of Splited Downloading File 2ev*CX6.
@4drjT
Z\Z,,g+WL
public SiteInfoBean() *YtB )6j
{//nSplitter的缺省值为5 Q(Gyq:L=>
//default value of nSplitter is 5 ([R")~`(l2
this("","","",5); _({@B`N}
} $W&:(&
y<uAp
X&a:g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M+poB+K.
{ <~{du ?4n
sSiteURL= sURL; *%\mZ,s"
sFilePath = sPath; fW(/Loh
sFileName = sName; *KJB>W%@uM
this.nSplitter = nSpiltter; E9+HS
sWHyL(C@
Izn T|l^
} ~~nqU pK?v
JJ?I>S N!
F_=1;,K%
public String getSSiteURL() I{ ryD -!
{ 6Ps.E
return sSiteURL; ?59'dGnz_
} Zw{MgoJ0Z
M0L&~p_F
%2"J:0j
public void setSSiteURL(String value) |sIr?RL{C
{ c~imE%
sSiteURL = value; ,%[4j9#!_
} "R[l ZJ@
pu9^e4B9
7Xg?U'X
public String getSFilePath() WC*=rWRxF
{ ;3"@g]e
return sFilePath; 6L9,'Bg
} q.Jsf+
m#e*c[*G
V`#.7uUP
public void setSFilePath(String value) C\}/"
{ lpgd#vr
sFilePath = value; y('k`>C
} RWKH%C[Yd
FhkkWWL
3mO;JXd
public String getSFileName() m$wlflt
{ ]~0}=,H$N
return sFileName; 5~'IKcW<
} jlqv2V7=/
/,s[#J
}Fa%%}
public void setSFileName(String value) J?&l*_m;t
{ V'G Ju
sFileName = value; CMW,slC_3
} ,.tfWN%t\
9Uf j
+f|BiW
public int getNSplitter() a.2L*>p
{ ;H'gT+t<c
return nSplitter; z6*<V5<7
} 3jZ6kfj
Y32 "N[yw
R=]d%L8
public void setNSplitter(int nCount) xQ4%e[/
{ u92^(|
nSplitter = nCount; y<:<$22O
} z>m=h)9d~
} P7.'kX9
i-" p)2d=#
*\G)z|^yx
/* LWfqEL -
**Utility.java ~" i0x
*/ 1}%B%*N
package NetFox; T{+Z(L
B<?wh0
3Ot~!AlR
public class Utility { bBc[bc>R
O+vS|
;30nd=
public Utility() XH}'w9VynR
{ PG~$D];
CW&.NT
2`GOJ,$
} eE GfM0
vy9 w$ls
//线程睡眠 jszK7$]^
public static void sleep(int nSecond) -n80&
{ m908jI_So
try{ v'!a\b`9
Thread.sleep(nSecond); N$>^g"6o
} 'o_:^'c
catch(Exception e) p5r]J+1
{ 06q(aI^Ch@
e.printStackTrace (); @#g<IBG=*
} v59dh (:`Z
} @.Icz
1KM`i
//日志 ^(HUGl_
public static void log(String sMsg) }7E^ZZ]f
{ G` XC
System.err.println(sMsg); o1cErI&q"
} c2t=_aAIPQ
j>-gO,v, y
4%nE*H%
public static void log(int sMsg) q@t0NvNSu
{ )G^ KDj"
System.err.println(sMsg); ="wzq+U
} y*pUlts<
} w-wV3Q6X
:L44]K5FL
ZOCDA2e(j
/* li~d?>
**TestMethod.java /DQaGq/Ld
*/ /+Lfrt
package NetFox; Qham^
n!p<A.O7@
+_XzmjnDd
public class TestMethod { 6f')6X'x
s<qe,'Y
EkgE_8
public TestMethod() -gSUjP
{ ///xx/weblogic60b2_win.exe e/0<[s*#Q
try{ 1$M@]7e+!+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MrZh09y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <B9C*M"4%
SiteFileFetch fileFetch = new SiteFileFetch(bean); Og,$ sH}`
fileFetch.start(); J5^'HU3
} oE#d,Z
catch(Exception e){e.printStackTrace ();} 0 stc9_O
ZovW0Q)m
*h}XWBC1q
} \"X!2
E_vq
]IoUwgpI)
public static void main(String[] args) (p2K36,9m
{ !%"8|)CAr
new TestMethod(); j#cYS*^H
} c-B cA
} .zi_[
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