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)); ta6WZu
} ;qk~>
for(int i=0;i<nEndPos.length-1;i++) FW.dHvNX
{ Q#r 0DWo\
nEndPos = nStartPos[i+1]; zXf+ieo
} =nL*/
nEndPos[nEndPos.length-1] = nFileLength; %Z5k8
} ?RzT0HRd
} X9gC2iSs]
Z "=(uwM
dO//
//启动子线程 yEqmB4^-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yaR;
for(int i=0;i<nStartPos.length;i++) V=*J9~K
{ -5 W0K}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <d5vVn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I!<v$
nStartPos,nEndPos,i); C[&&.w8Pm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v_@_J!s
fileSplitterFetch.start(); 6uXYZ.A
} ?-84_i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XP^6*}H.*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7~Ga>BK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yl ;'Ru:
nEndPos = " + nFileLength); ,"VQ0Z1
// fileSplitterFetch[nPos.length-1].start(); 9iy|=
jrl6):x
E\*",MGL
//等待子线程结束 9cmJD5OO
//int count = 0; +?:V\niQI
//是否结束while循环 \ +xIH
boolean breakWhile = false; l>(G3lIw
bv4cw#5z$9
zB$6e!fc
while(!bStop) 7Mv$.Z(
{ .nH /=
write_nPos(); 6qJB"_.
Utility.sleep(500); 66Xt=US
breakWhile = true; |\(/dXXP
%UJ4wm
)x7hhEk=^
for(int i=0;i<nStartPos.length;i++) *vO'Z &
{ oX4uRc7wR
if(!fileSplitterFetch.bDownOver) GKtQ>39B
{ ;2|H6IN"
breakWhile = false; k0IU~y%
break; RM+E
} KRZV9AJ
} U.F65KaKF
if(breakWhile) PK4UdT
break; NGY I%:
qi2dTB
r*wKYb
//count++; F]*-i 55S
//if(count>4) 7&)F;;H
// siteStop(); k9xKaJ%1
} cj<@~[uw
gAY2|/,
KxwLKaImI
System.err.println("文件下载结束！"); !gf3%!%
} UVJ(iNK"
catch(Exception e){e.printStackTrace ();} VC(|t} L4
} sEN@q
3Q}Y?rkJ5
*$$V,6O.
//获得文件长度 K-u/q6ufK
public long getFileSize() j2Y(Q/i
{ ;#i$0~lRl
int nFileLength = -1; @GtZK
try{ (d#Z-w-
URL url = new URL(siteInfoBean.getSSiteURL()); SXz([Z{)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TMCA?r%Y\
httpConnection.setRequestProperty("User-Agent","NetFox"); w0Y%}7
wS0bk<(
?&m]du#6
int responseCode=httpConnection.getResponseCode(); \Agg6tYr
if(responseCode>=400) \W^+vuD8
{ N=wy)+
processErrorCode(responseCode); y}HC\A77uD
return -2; //-2 represent access is error KgWT&^t
} ?|GxVOl
Dg+d=I?
V^+:U>$w
String sHeader; 'e64%t
oLMi vy4
CWQ2iu<_0
for(int i=1;;i++) m5aaY
{ ?\M6P?tpo&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u(Sz$eV
//Utility.log(in.readLine()); a?~csP^?}
sHeader=httpConnection.getHeaderFieldKey(i); ONiI:Z>%
if(sHeader!=null) z44~5J]
{ o~&!M_ED
if(sHeader.equals("Content-Length")) 3&fFIab9
{ /*^|5>-`i1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z;\"pP:
break; 6ya87H'e@
} <@2# VG
} f;H#TSJ
else oD@jtd>b%
break; ;w(1Ydo
} D])YP0|}
} >?eTbtP
catch(IOException e){e.printStackTrace ();} Pm(:M:a
catch(Exception e){e.printStackTrace ();} uE`|0
]GPJ(+5
TeCpT2!5j
Utility.log(nFileLength); p3FnYz-V
{WeXURp&nF
8Vhck-wF
return nFileLength; 2\B9o `Y
} */y]!<\v!k
lV6[d8P
jZT :-w
//保存下载信息（文件指针位置） CN~NyJL H
private void write_nPos() -Dxhq& }Y
{ A{x 7
try{ IKzRM|/
output = new DataOutputStream(new FileOutputStream(tmpFile)); v#]v,C-*
output.writeInt(nStartPos.length); g)?g7{&?>?
for(int i=0;i<nStartPos.length;i++) cgxFEv
{ 5vX8mPR_
// output.writeLong(nPos); _pko]F|()
output.writeLong(fileSplitterFetch.nStartPos); 6eYf2sZ;J
output.writeLong(fileSplitterFetch.nEndPos); #t2UPLO~
} ]ZzG!7
output.close(); q6JW@GT
} Xu94v{u3
catch(IOException e){e.printStackTrace ();} DwY<qNWT
catch(Exception e){e.printStackTrace ();} X0Z-1bs
} -F+P;S
=ch Af=
~K-*q{6Q
//读取保存的下载信息（文件指针位置） tG2OVRx8u
private void read_nPos() ' q<EZ{
{ \btR^;_\A
try{ #>m, Cm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;[KriW
int nCount = input.readInt(); `o8{qU,*]N
nStartPos = new long[nCount]; q X%vRf0
nEndPos = new long[nCount]; n~)HfY
for(int i=0;i<nStartPos.length;i++) rH&r6Xv[
{ s'aV qB
nStartPos = input.readLong(); q bZ,K@0
nEndPos = input.readLong(); ?(/j<,m^
} n^pZXb;Y
input.close(); A?IZ( Zx(`
} B(\r+"PB
catch(IOException e){e.printStackTrace ();} me:|!lI7YU
catch(Exception e){e.printStackTrace ();} &xBK\
} BnaU)E h
,> (bt%b
}x?H ~QQT
private void processErrorCode(int nErrorCode) 1KYbL8c
{ 8S1P&+iKs
System.err.println("Error Code : " + nErrorCode); ,]uX:h-EM
} )0U3w#,JQ
!<=%;+
EN-H4F
//停止文件下载 ..q63dr
public void siteStop() v=*Bb3dt
{ +-aU+7tu
bStop = true; \7t5U7v8U
for(int i=0;i<nStartPos.length;i++) `?]rr0.}hp
fileSplitterFetch.splitterStop(); yD[zzEuQ
! nCjA\$
7O+Ij9+{n
} vdH+>l
} jKj=#O
//负责部分文件的抓取 S0N2rU
**FileSplitterFetch.java (lN;xT`=
*/ p<HTJ0
package NetFox; NDRW
XatA8(_,5
Cgz&@@j,]
import java.io.*; Z\|u9DO
import java.net.*; h eE'S/
WjY{rM,K
[Y22Wi
public class FileSplitterFetch extends Thread { fwi};)K
1C0Y0{6,
3'[Rvy{
String sURL; //File URL vQKn=
long nStartPos; //File Snippet Start Position <o&o=Y8
long nEndPos; //File Snippet End Position DIG0:)4R.
int nThreadID; //Thread's ID Jtp>m?1Ve
boolean bDownOver = false; //Downing is over m%oGzx+
boolean bStop = false; //Stop identical llHc=&y#
FileAccessI fileAccessI = null; //File Access interface .Na&I)udX.
6.U"_%
R%b*EBZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /`+Hwdk
{ k<YtoV
this.sURL = sURL; 8ji^d1G,
this.nStartPos = nStart; v}F4R $
this.nEndPos = nEnd; &gGs) $f[
nThreadID = id; 7_Ba3+9jpa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (]3ERPn#y
} Hs"% S
NqJ<!q)
ptV4s=G2
public void run() L289'Gzg
{ U@.u-)oX
while(nStartPos < nEndPos && !bStop) ;RWW+x8IB
{ 8%o~4u3
lo+xo;Nd
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try{ p!+L
URL url = new URL(sURL); "_K}rI6(t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m<FF$pTT
httpConnection.setRequestProperty("User-Agent","NetFox"); ${hyNt
String sProperty = "bytes="+nStartPos+"-"; R9tckRG#
httpConnection.setRequestProperty("RANGE",sProperty); ]urK$
Utility.log(sProperty); @J-plJ4e
Qm.z@DwFM{
;W7hc!
InputStream input = httpConnection.getInputStream(); mi7sBA9L8
//logResponseHead(httpConnection); l^k+E-w\
Mjb 1
p`>AnfG
byte[] b = new byte[1024]; 3<c*v/L{C\
int nRead; [AXsnpa/C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |EF>Y9
{ b/}'Vf[
nStartPos += fileAccessI.write(b,0,nRead); a(8>n Z,V
//if(nThreadID == 1) $brKl8P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9v~1We;{$
} \s=QiPK
Bu7A{DRf
%6AYCN?Ih
Utility.log("Thread " + nThreadID + " is over!"); UhsO\9}qH
bDownOver = true; 7dSh3f!
//nPos = fileAccessI.write (b,0,nRead); (E!%v`_0
} |/@0~O(6
catch(Exception e){e.printStackTrace ();} A)8rk_92Q
} qE>i,|rP`
} {bN Y
[ZuVUOm
AK6=Ydu
//打印回应的头信息 B ,V(LTE
public void logResponseHead(HttpURLConnection con) +.w[6
{ aSRjFL^
for(int i=1;;i++) ^~^mR#<P$
{ %VzYqj_P"
String header=con.getHeaderFieldKey(i); /sy-;JDnsu
if(header!=null) Ll,I-BQ9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7g-Dfg.w
Utility.log(header+" : "+con.getHeaderField(header)); 4Mk8Cpz
else f,|QAj=a
break; I$n+DwKcN
} ^>-+@+( r
} <BSSa`N`
aZ$/<|y~:_
FIH@2zA
public void splitterStop() WPIZi[hBs
{ M3ZOk<O<R
bStop = true; Q\H_t)-
} v' C@jsxM
+a-D#^2;
vyE{WkZxR
} 5\WUoSgy
D>P;Izb
0}B?sNr
/* Q.yb4
**FileAccess.java k=e`*LB\
*//文件访问(定位，写) &1P(O\d
package NetFox; F"I*-!o
import java.io.*; )`^ /(YG
byafb+x
>E,Q
public class FileAccessI implements Serializable{ yX`#s]M
n[|6khOL-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y,'%7u
RandomAccessFile oSavedFile; E${J
long nPos; 6.[)`iF+#
?H`j>]%&
=LOk13l\"
public FileAccessI() throws IOException vHS2q >
{ guU=NQZ
this("",0); +s ULo
} #G[t X6gU
^+wk
m~;B:LN<
public FileAccessI(String sName,long nPos) throws IOException Apmw6cc
{ h(nj,X+
oSavedFile = new RandomAccessFile(sName,"rw"); d.p'pGL
this.nPos = nPos; c-5Ysg
oSavedFile.seek(nPos); ;=a_B1"9u
} B[CA 5Ry
44~hw:
zZ:xEc
public synchronized int write(byte[] b,int nStart,int nLen) w-ALCh8o
{ Fwb5u!_,
int n = -1; r_^)1w
try{ W2hA-1
oSavedFile.write(b,nStart,nLen); )&:L'N
n = nLen; Jld\8=
} tF^g<)S;t
catch(IOException e) t!jYu<P
{ "TNVD"RLY
e.printStackTrace (); P3!Atnv2
} z6I%wh
d*2u}1Jo8
0\Y1}C
return n; DHv2&zH
} ^^U%cuKg
pM9yOY
2e59Ez%k6
} ^&Q<tN7
E=]]b;u-n
et` 0Je
/* QD$Gw-U-l=
**SiteInfoBean.java FAw1o
*/ hO \/
package NetFox; Bd&`Xfebj
VO_dA4C}z
FqZgdmwR
public class SiteInfoBean { M?$ZJ-
oxzq!U
/P:EWUf'
private String sSiteURL; //Site's URL 2)9r'ai?a
private String sFilePath; //Saved File's Path cS(;Qs]Q
private String sFileName; //Saved File's Name k"0;D-lTZ>
private int nSplitter; //Count of Splited Downloading File A?A9`w
<^c3}
lL0M^Nv
public SiteInfoBean() m(_9<bc>
{//nSplitter的缺省值为5 Us=eq "eu
//default value of nSplitter is 5 `eR 7H>I
this("","","",5); Om9jtWk
} _{)9b24(
Ac`;st%l.
T<yb#ak
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^_W40/c3
{ >g}G}=R~3
sSiteURL= sURL; 6pp$-uS
sFilePath = sPath; S)7/0N79A
sFileName = sName; ix&'0IrX*
this.nSplitter = nSpiltter; lP3h<j
orqJ[!u)`
y' [LNp V
} cU8xUpq
<cj{Qk
Ryv_1gR!
public String getSSiteURL() 0` 5e
{ WbcS: !0
return sSiteURL; =wrP:wYF
} RB$ z]/=
[Y8S[YY
q7_+}"i
public void setSSiteURL(String value) 0BK5qz
{ ?\y%]1
sSiteURL = value; |<c WllN
} "HK/u(z)
B(,:haAr
ue\t,*KYd
public String getSFilePath() |`0n"x7
{ pW|u P8#
return sFilePath; tTuX\;G
} =J/FJb
[Y/:@t"2y
zk}{ dG^M:
public void setSFilePath(String value) L;/n!k.A
{ K0Tg|9
sFilePath = value; x?sI;kUw8
} ,H[SI0];
2*AG7
<[i}n55
public String getSFileName() f~ U.a.Fb
{ >5ChcefH
return sFileName; ,;jGJr
} m3 -9b"
*9D!A
N`$!p9r
public void setSFileName(String value) 3WUH~l{UJ
{ 27#5y_ `
sFileName = value; D$q'FZH
} RN9;kB)c
RUo9eQIPD
-LWK*q[J;*
public int getNSplitter() +B"0{>n}F
{ ;rR/5d1!
return nSplitter; %!|O.xxRR
} E^CiOTN
z]@6fM[
c$h9/H=~
public void setNSplitter(int nCount) h"W8N+e\
{ 5zB~4u
nSplitter = nCount; ^3~e/PKM
} ,D=fFpn
} [TTSA2
Nneo{j
&c%Y<1e`%
/* :dnJY%/q
**Utility.java KoBW}x9Jp
*/ }NCL>l;q
package NetFox; ~Xv=9@,h
,o#kRWRG
#wR;|pN
public class Utility { D4u%6R|F
57I}RMT"
l#qv 5f
public Utility() AkBMwV
{ QP(BZJC
I;MD>%[W,
egR-w[{
} =|U@
:d,^I@]
//线程睡眠 >U!*y4
public static void sleep(int nSecond) 5M_Wj*a}7
{ l=m(mf?QBg
try{ lB;FUck9
Thread.sleep(nSecond); &^.57]
} n"D ?I
catch(Exception e) #"*e+.j[;
{ L 3XB"A#
e.printStackTrace (); 9pSUIl9|j
} Ud(`V:d
} ~mp0B9L%
1KE:[YQ1
//日志 H)(jh
public static void log(String sMsg) Ey`h1Y
{ -ysn&d\rV
System.err.println(sMsg); [2c{k
} XNH4vG |
NL"G2[e
)A8v];.]3
public static void log(int sMsg) `BXS)xj
{ c-4STPNQi
System.err.println(sMsg); $'wq1u
} %Y nmuZ
} dA~ 3>f*b_
5K%Wa]W
{MBTP;{*~
/* }"s;\?a
**TestMethod.java #ToK$8
*/ au@a8MP
package NetFox; lCT{v@pp
/Lf6WMit
n# 7Pr/*0
public class TestMethod { |NFZ(6vNh
Ctu?o+^;z
~qP[eWe
public TestMethod() >{zk qvsQ&
{ ///xx/weblogic60b2_win.exe b1?xeG#
try{ =d`5f@'rl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t*S." q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r%]Qlt~K
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jh/ E@}'
fileFetch.start(); X` YwP/D
} ]+Ixi o
catch(Exception e){e.printStackTrace ();} \,G#<>S
o*S"KX$
X[$++p .
} t#E}NR
eVh-_
Sus;(3EX
public static void main(String[] args) bZwnaM4"F
{ ~l E _L1-c
new TestMethod(); kGYTl,A{
} 2[yBD-":
} N:5[,O<m_
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