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)); YqkA&qL]#;
} @RQ+JYQi
for(int i=0;i<nEndPos.length-1;i++) :E}6S
{ "hz>{oe
nEndPos = nStartPos[i+1]; i^~sn `o
} 5NFq7&rJ6
nEndPos[nEndPos.length-1] = nFileLength; e-1;dX HL
} n2H&t>N
} t% <pbZO
5BZ+b_A>VV
_8Pmv$
//启动子线程 s-fKh`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PZ~`O
for(int i=0;i<nStartPos.length;i++) EC0zH#N
{ 5X#i65_-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7ucx6J]c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g521Wdtnn
nStartPos,nEndPos,i); 1fmSk$ y.9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T %$2k>
fileSplitterFetch.start(); @<0h"i x
} $HP/cKu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5^bh.uF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <d3PDO@w/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4,o %e,z
nEndPos = " + nFileLength); :LU"5g
// fileSplitterFetch[nPos.length-1].start(); !>?4[|?n<
-Cg`x=G;z
@263)`9G
//等待子线程结束 9@JlaY)0
//int count = 0; "K/[[wX\b
//是否结束while循环 )j$b9ZBk
boolean breakWhile = false; p|xs|O6{
wV7@D[8
>B@i E
while(!bStop) R994R@gz
{ f6@^Mg
write_nPos(); +qE,<c}}
Utility.sleep(500); ))8Emk^Q{
breakWhile = true; )zo#1$C-
h2im sjf
Vf@S8H
for(int i=0;i<nStartPos.length;i++) 3Pw%[q=g
{ 9;}L{yve
if(!fileSplitterFetch.bDownOver) ~5x4?2
{ ~NTDG
breakWhile = false; g/fp45s
break; ly9x1`?$
} .~FKyP>[$
} #JHy[!4
if(breakWhile) 3U :YA&K(
break; cg>!<T*
7Y$4MMNQ
u<BHf@AI
//count++; ^p{A!I!
//if(count>4) =ip~J<sw&
// siteStop(); u?LW+o
} "H wVK
Lg\8NtP
#RCZA4>
System.err.println("文件下载结束！"); >eYU$/80
} U^vUdM"
catch(Exception e){e.printStackTrace ();} PT 0Qzg
} !y[}|
z(8)1#(n7
U}mL,kj"
//获得文件长度 FY_avW
public long getFileSize() (MF+/fi
{ @S/g,;7"
int nFileLength = -1; W)G2Cs?p
try{ }Rf}NWU)|
URL url = new URL(siteInfoBean.getSSiteURL()); xkk@{}J\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qivf|H619
httpConnection.setRequestProperty("User-Agent","NetFox"); <DA{\'jJ
w!=_
nsM>%+o
int responseCode=httpConnection.getResponseCode(); ze#rYNvo/
if(responseCode>=400) 'Qp&,xK
{ \}]=?}(
processErrorCode(responseCode); (:</R$I
return -2; //-2 represent access is error Y3 Pz00x
} duZ|mT8Q==
y\r^\ S9%
wR5\^[GN
String sHeader; .b!OZ
`2 %eDFZ
ox i a}
for(int i=1;;i++) F)[XIY&2/
{ s0X/1Cq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %8rr*l5
//Utility.log(in.readLine()); Zpn*XG
sHeader=httpConnection.getHeaderFieldKey(i); Y&1!Z*OL;
if(sHeader!=null) sK""
{ 'PmHBQvt&
if(sHeader.equals("Content-Length")) i{1)=_$Vt`
{ Xy3g(x]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y%n{`9=
break; T6/$pJl
} S\yu%=h
} 8o%<.]
else df21t^0/
break; ~:ub
} *Dd(+NI
} ]*kP>
catch(IOException e){e.printStackTrace ();} HlOAo:8'
catch(Exception e){e.printStackTrace ();} k=ior
o}r!qL0c
~x+:44*
Utility.log(nFileLength); eE#81]'6a
!DY2{Wb
gnKU\>2k
return nFileLength; vJ#rW8y
} 5~ *'>y
N>F2 c)rm
On2Vf*G@|
//保存下载信息（文件指针位置） kG|>_5
private void write_nPos() )|59FOWg
{ dcrJ,>i}
try{ C[J`x>-K
output = new DataOutputStream(new FileOutputStream(tmpFile)); b}EYNCw_7S
output.writeInt(nStartPos.length); ~,M;+T}[r
for(int i=0;i<nStartPos.length;i++) Kc-A-P &Ry
{ MZ|c7f&`
// output.writeLong(nPos); jiw`i
output.writeLong(fileSplitterFetch.nStartPos); N~Sue
output.writeLong(fileSplitterFetch.nEndPos); ~,`\D7Z3
} YDZ1@N}^B
output.close(); w'5dk3$"
} CwH)6uA
catch(IOException e){e.printStackTrace ();} .LGkr@P
catch(Exception e){e.printStackTrace ();} fd,}YAiX
} |aOnV,}
nCSd:1DY
+i q+
//读取保存的下载信息（文件指针位置） ~NxoF
private void read_nPos() h!t2H6eyF
{ p[k9C$@e}
try{ mXN1b!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nfd?@34"A2
int nCount = input.readInt(); wZ\e3H z
nStartPos = new long[nCount]; u1pYlu9IW
nEndPos = new long[nCount]; B9;,A;E};
for(int i=0;i<nStartPos.length;i++) 4o)\DB?!
{ 46.q anh
nStartPos = input.readLong(); e) /u>I
nEndPos = input.readLong(); y!{/'{?P
} D.oS8'
input.close(); [jtj~]&mO
} fi-&[llg
catch(IOException e){e.printStackTrace ();} d= T9mj.@
catch(Exception e){e.printStackTrace ();} f'zFg["aZS
} \PtC
Ph7(JV{
U%B]N@
private void processErrorCode(int nErrorCode) );/5#b@<Y
{ RGPU~L
System.err.println("Error Code : " + nErrorCode); e&a[k
} xzGsfd
48"Y-TV
U~zN*2-
//停止文件下载 [0,q7d?"
public void siteStop() t2-zJJf8
{ GWkJ/EX
bStop = true; (j"~]T!)1
for(int i=0;i<nStartPos.length;i++) y8(?:#ZC
fileSplitterFetch.splitterStop(); fb=$<0Ocj
rxK[CDM,
'N,NG$G2
} {4jSj0W
} {c EKz\RX
//负责部分文件的抓取 wk <~Y 3u
**FileSplitterFetch.java ^VYZ%
*/ 9C'+~<l
package NetFox; r L|BkN
Q\>SF
cW|Zgz8vv
import java.io.*; #Uk6Fmu]
import java.net.*; lJQl$Wx^
7)It1i-
\U =>
public class FileSplitterFetch extends Thread { 28qWC~/9
8P y_Y>
uXW. (x7"f
String sURL; //File URL i$<v*$.o
long nStartPos; //File Snippet Start Position hD.wKX?oO
long nEndPos; //File Snippet End Position ?j$8Uy$$
int nThreadID; //Thread's ID MKYE]D;
boolean bDownOver = false; //Downing is over 8\t7}8f
boolean bStop = false; //Stop identical XK9*,WA9r
FileAccessI fileAccessI = null; //File Access interface VqT[ca\
52R.L9Ai
,7$uh):
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kk./-G
{ 3:gO7Uv
this.sURL = sURL; ^>}[[:(6/
this.nStartPos = nStart; -+2xdLa63
this.nEndPos = nEnd; 2X|jq4
nThreadID = id; .B-,GD}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0+`*8G)
} #UnO~IE.m$
GM56xZ!2T
b0CaoSWo
public void run() u^.k"46hn
{ <T~fh>a
while(nStartPos < nEndPos && !bStop) jl%eO.
{ ?BZ`mrH^
X1QZEl
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try{ TZ_'nB~
URL url = new URL(sURL); H4",r5qw:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y/*Tvb #TJ
httpConnection.setRequestProperty("User-Agent","NetFox"); =@/^1.`
String sProperty = "bytes="+nStartPos+"-"; T7nX8{l[RG
httpConnection.setRequestProperty("RANGE",sProperty); 0 9'o
Utility.log(sProperty); v8(u9V%?6
|y=F (6Z
jsht2]iq3K
InputStream input = httpConnection.getInputStream(); %SFR.U0}yK
//logResponseHead(httpConnection); N28?JQha
D_kzR
mP+yjRw
byte[] b = new byte[1024]; d'nuk#r
int nRead; n&&U9sf?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kF~e3A7C
{ :rc[j@|pH
nStartPos += fileAccessI.write(b,0,nRead); ~a,'
//if(nThreadID == 1) W 9MZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m&c(N
} 4gt "dfy+
ON!G{=7
e[o ;l
Utility.log("Thread " + nThreadID + " is over!"); &8L\FAY0%9
bDownOver = true; UC$+&&rO
//nPos = fileAccessI.write (b,0,nRead); ITPpT
} [:'?}p
catch(Exception e){e.printStackTrace ();} \`5u@Nzx
} ,B>b9,~3a
} $F$R4?_
UeeV+xU
YQsc(6
//打印回应的头信息 Y|jesa {x
public void logResponseHead(HttpURLConnection con) YhR"_
{ 6MQ:C'8T&=
for(int i=1;;i++) QP0X8%+p
{ HaUo+,=
String header=con.getHeaderFieldKey(i); 5ml}TSMu'
if(header!=null) n:] 1^wX#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |H@p^.;
Utility.log(header+" : "+con.getHeaderField(header)); glIIJ5d|,
else 4u7>NQUDu
break; nL~ b
} ?saVk7Z[|5
} Ka2tr]+s
SXF_)1QO\W
aBLb i
public void splitterStop() L#bQ`t
{ qE=OQs9
bStop = true; Lwk-
} izo $0
S*:w\nXP~
=LA@E&,j
} _@76eZd
g+*[CKO{
3f8Z?[Bb@
/* sRnMBW.
**FileAccess.java X.|0E87
*//文件访问(定位，写) KK|Jach
package NetFox; OUMr}~/
import java.io.*; 1ki"UF/
x*V<afLY[
mr.DP~O:9p
public class FileAccessI implements Serializable{ !%9I%Ak^
DJUtuex
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \(L^ /]}G)
RandomAccessFile oSavedFile; LXl! !i%
long nPos; yK3z3"1M?
EV$n>.
"KwKO8f
public FileAccessI() throws IOException GrC")Z|3u
{ 7C^ nk z
this("",0); OSk9Eb4ld
} h (2k;M^s
`;@4f|N9
INpub5
public FileAccessI(String sName,long nPos) throws IOException 49GCj`As
{ m"]ys#
oSavedFile = new RandomAccessFile(sName,"rw"); M+:wa@Kl
this.nPos = nPos; t68RWzqiG[
oSavedFile.seek(nPos); TaG-^bX8B
} HskN(Ho
eRbO Hj1
k*^W lCZ3
public synchronized int write(byte[] b,int nStart,int nLen) X.<R['U&\
{ l[k$O$jo
int n = -1; :B~c>:
try{ '"^JNb^I
oSavedFile.write(b,nStart,nLen); CXZeL 1+
n = nLen; !f6
} YvX I
catch(IOException e) [*t EHW
{ v(~m!8!TI
e.printStackTrace (); *E'K{?-K
} wt;aO_l
xkovoTzV
FeLP!oS>
return n; B?Skw{&
} (%}C
Y2EN!{YU
!)34tu2
} ZbUf|#GTB
,jmG!qJb
ri ~2t3gg
/* y rk#)@/m
**SiteInfoBean.java flqTx)xE
*/ #C^m>o~R
package NetFox; Q #gHD
X$f%Ss
.EO1{2=
public class SiteInfoBean { )VC) }
PQ>JoRs
T^_9R;
private String sSiteURL; //Site's URL D2bUSRrb
private String sFilePath; //Saved File's Path .&y1gh!=
private String sFileName; //Saved File's Name jLSZ#H
private int nSplitter; //Count of Splited Downloading File 0J~4
~@JC1+
& j43DYw4
public SiteInfoBean() L%FL{G
{//nSplitter的缺省值为5 hr5)$qZW
//default value of nSplitter is 5 43XuQg4
this("","","",5); wG O)!u 4
} c3##:"wr
.E&~]<
kns]P<g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |+;"^<T)l
{ 2B7&Ll\>
sSiteURL= sURL; )Yml'?V"
sFilePath = sPath; ?}[keSEh>
sFileName = sName; F*f)Dv$p
this.nSplitter = nSpiltter; *rLs!/[Z_
sXu]k#I^"
lS^0*(Y
} @zbXG_J
}8HLyK,4
i7FEjjGtG
public String getSSiteURL() JFZ p^{
{ P*>V6SK>b
return sSiteURL; ioggD
} fvDwg
D6w0Y:A{.
7nmo p7
public void setSSiteURL(String value) z( wXs&z;
{ Lmb<)YY
sSiteURL = value; \IKr+wlN8
} ]NCOi?Odx
F~1R.r_Lu
scdT/|(U$
public String getSFilePath() E_K7.c4M
{ :R)IaJ6)
return sFilePath; DI_mF#5q
} amRtFrc|
W4<}w-AoEp
a|.u;
public void setSFilePath(String value) )-(NL!?`
{ o0 Ae*Y0
sFilePath = value; (rJvE*
} {8' 5
5 F-Q&
x?3p3[y
public String getSFileName() L" o6)N
{ ]9' \<uR
return sFileName; rhrlEf@
} ]Uu/1TTf
+~-|( y
DcOLK\
public void setSFileName(String value) hXCDlCO
{ D)Zv
sFileName = value; .qZ<ROZ
} b|NEU-oy
Y3[@(
+ '`RJ,K+[
public int getNSplitter() 5GKz@as8
{ R:Lu)d>=
return nSplitter; 9cLKb
} M0|z^2
6R25Xfm_|
'Gk|&^
public void setNSplitter(int nCount) W;=ZQ5Lw
{ \21!NPXH2
nSplitter = nCount; bu]bfnYi9
} jzQgDed ]
} 1n^xVk-G
~L2Fo~fw
`6zoZM7?Y
/* SC#
**Utility.java Vh&uSi1V
*/ 99`xY$
package NetFox; @c.pOX[]m,
}{$@|6)R
Q8_d]V=X:
public class Utility { Q-\: u~
#u~8Txt
R#0UwRjeF
public Utility() %n^]1R#
{ #r\uh\Cy
=#W6+=YN8
v"j7},P@
} L(.5:&Y=`
rB4]TQ`c
//线程睡眠 G]{)yZ'}
public static void sleep(int nSecond) y0xte&
{ >">-4L17m
try{ 139_\=5|U/
Thread.sleep(nSecond); Y9ru~&/o$
} qg_=5s
catch(Exception e) ujaaO6oZ7
{ o!Y7y1$
e.printStackTrace (); MD+Q_
} +7=3[K
} B9]KC i
(uSfr]89'
//日志 S;Vj5
public static void log(String sMsg) [ACa<U/
{ um/iK}O
System.err.println(sMsg); 8"+Kz
} L!\I>a5C0G
cG.4%Va@s_
#jQITS7
public static void log(int sMsg) lyP<&<Y5
{ RJ`F2b sYN
System.err.println(sMsg); 0L'h5i>H)
} O[!]/qP+.
} 7v{Dwg
biQDupTz
jVr:O`
/* =m UtBD.;
**TestMethod.java /)j:Y:5
*/ {a(TT)d
package NetFox; {<V{0 s%
U<zOR=_
PAJt M
public class TestMethod { rAgb<D@,H
6]M(ElV1H
X4gs{kx}|
public TestMethod() +5voAx!
{ ///xx/weblogic60b2_win.exe hDCR>G
try{ opd^|xx0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MFRM M%`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); alyWp
SiteFileFetch fileFetch = new SiteFileFetch(bean); ol-U%J
fileFetch.start(); +ps(9O/B>
} -GH>12YP
catch(Exception e){e.printStackTrace ();} :U=*@p4?
dW6sA65<Y
MGK%F#PM
} t~3!| @3i
`$05+UU
H+` Zp
public static void main(String[] args) jx J5F3d
{ {;q zz9 |
new TestMethod(); "d%o%
} w~Aw?75t
} v#TU7v?~
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