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)); @t,Y<)U
} YR0.m%U,
for(int i=0;i<nEndPos.length-1;i++) ]iH~1[
{ Ku]<$uo
nEndPos = nStartPos[i+1]; JO|xX<#:
} 2@$`xPg
nEndPos[nEndPos.length-1] = nFileLength; b:6e2|xf?
} ,V #r
} 9rM6kLD
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n~v*
//启动子线程 #w]@yL]|is
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [|oOP$u
for(int i=0;i<nStartPos.length;i++) JReJlDu
{ [X'u={
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `:;fc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), LE4P$%>H
nStartPos,nEndPos,i); ynG@/S6)K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aX(Y `g)|
fileSplitterFetch.start(); !1ZrS
} tJZ3P@ L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {t QZqqdn@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >iFi~)i_4y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DeRC_ [
nEndPos = " + nFileLength); CC{{@
// fileSplitterFetch[nPos.length-1].start(); Jnf@u
kU[#. y=%p
P)&qy .+E0
//等待子线程结束 SOo}}a0
//int count = 0; C(lGW,!
//是否结束while循环 s N|7
boolean breakWhile = false; zFeo8S
"gGv>]3
&{H LYxh
while(!bStop) h(3ko An
{ 8d*W7>rq
write_nPos(); ,lr\XhO
Utility.sleep(500); .3< sv
breakWhile = true; !O*uQB
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$z*Y:vFP
for(int i=0;i<nStartPos.length;i++) w2e9Ue~WH
{ Vo:Gp
if(!fileSplitterFetch.bDownOver) =hDFpb,mr
{ ZT%Q:]B+
breakWhile = false; f%5 s8)
break; ?_Y2'O
} VqK/GWg
} yUp"%_t0
if(breakWhile) S 0L"5B@
break; 2C_/T8
*Z C$DW!-
Hlye:.$
//count++; KJ;NcUq
//if(count>4) bO\E)%zp
// siteStop(); a>XlkkX
} $3Srr*
qJf=f3
bf1EMai"
System.err.println("文件下载结束！"); "fX9bh^
} m03]SF(#3
catch(Exception e){e.printStackTrace ();} 7z^\}&
} t~@~XI5
w*7BiZ{s<
x;p7n2_
//获得文件长度 -P7JaH/Q
public long getFileSize() 25CO_
{ F9 q9BH
int nFileLength = -1; F1UTj"<e
try{ RbGq$vYol/
URL url = new URL(siteInfoBean.getSSiteURL()); &['cZ/bM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Ap~Wok
httpConnection.setRequestProperty("User-Agent","NetFox"); [ bB
Dhy@!EOS
vgvJ6$#
int responseCode=httpConnection.getResponseCode(); K\a=bA}DG
if(responseCode>=400) 8KhE`C9z
{ `oUuAL
processErrorCode(responseCode); mhZ60RW
return -2; //-2 represent access is error {Mx3G*hr
} "<5su5]
60r4%>d
=& .KKr
String sHeader; [$[1|r *Q
^ H )nQ
p!]$!qHO(
for(int i=1;;i++) u#uT|a.
{ F1aI4H<(T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sGdlS&08(
//Utility.log(in.readLine()); Az"(I>VfD
sHeader=httpConnection.getHeaderFieldKey(i); }"CX`
if(sHeader!=null) S LSbEm
{ }HC6m{vH(
if(sHeader.equals("Content-Length")) 6 (@U+`
{ 6~_TXy/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FG[YH5
break; bQFMg41*w7
} I"1H]@"=
} mcB8xE
else /9..hEq^
break; NiCB.a
} drc]"6 k
} 7-u['nFJ
catch(IOException e){e.printStackTrace ();} q!+&|F
catch(Exception e){e.printStackTrace ();} L 2k?Pl
<5wk~|@t
<B%s9Zy
Utility.log(nFileLength); V<%eWT)x7C
9;*-y$@
&>]c"?C*
return nFileLength; ;5(ptXX1W
} 8vL2<VT;
/PuN+M
SlRQi:
//保存下载信息（文件指针位置） !QTfQ69Y0
private void write_nPos() ;@R=CQ6
{ 2GRdfX
try{ qB0F9[U
output = new DataOutputStream(new FileOutputStream(tmpFile)); B<p -.tv
output.writeInt(nStartPos.length); WzwH;!
for(int i=0;i<nStartPos.length;i++) 2a3RRP
{ WFTXSHcG
// output.writeLong(nPos); yaD_c;
output.writeLong(fileSplitterFetch.nStartPos); X/l{E4Ex
output.writeLong(fileSplitterFetch.nEndPos); 3r]:k)J
} XzBnj7E
output.close(); ,4&?`Q
} `f~\d.*U
catch(IOException e){e.printStackTrace ();} {hmC=j
catch(Exception e){e.printStackTrace ();} wG\ +C'&~
} --}5%6
" A}S92
6yN8(&`
//读取保存的下载信息（文件指针位置） #2~-I
private void read_nPos() `,O#r0m
{ +%%Ef]
try{ }+{? Ms
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); } qf=5v
int nCount = input.readInt(); f=L&>X
nStartPos = new long[nCount]; Q*J8`J:#^R
nEndPos = new long[nCount]; ~5Cid)Q}@o
for(int i=0;i<nStartPos.length;i++) :p@.aD5
{ &Oih#I
nStartPos = input.readLong(); VoTnm
nEndPos = input.readLong(); */7+pk(
} >Yf)]e-
input.close(); G'M;]R9EP
} K#e&yY
catch(IOException e){e.printStackTrace ();} k+D"LA%J
catch(Exception e){e.printStackTrace ();} ?b8 :
} KT>eE
oN\IQ7oI
BsJ d*-:X
private void processErrorCode(int nErrorCode) ,3As Ng
{ ]#fmih^
System.err.println("Error Code : " + nErrorCode); m/T3Um
} #BZ2%\
?E*;fDEC
oieJ7\h]m
//停止文件下载 3;hztCZj
public void siteStop() hN5?u:
{ m 3Y@p$i5
bStop = true; ~mR@L`"l
for(int i=0;i<nStartPos.length;i++) t6+c"=P#
fileSplitterFetch.splitterStop(); ]"2;x
C2[* $ 1U
XDtMFig
} 1[g -f,
} @ gv^
//负责部分文件的抓取 u3B[1Ae:K
**FileSplitterFetch.java YXi'^GU@
*/ UBm L:Qv
package NetFox; +'ZJ]
>OLKaghV.5
XjRk1~
import java.io.*; Biva{'[m
import java.net.*; RI[=N:C^
#aeKK7[
s.#%hPX{
public class FileSplitterFetch extends Thread { |}-bMQ|
_-M27^\vV
S#^2k!(|G
String sURL; //File URL 0'3f^Ajf
long nStartPos; //File Snippet Start Position &&daQg4Ha
long nEndPos; //File Snippet End Position nhu;e}[>
int nThreadID; //Thread's ID c&mLK1A6
boolean bDownOver = false; //Downing is over L/Ytkag
boolean bStop = false; //Stop identical WCdl 25L#
FileAccessI fileAccessI = null; //File Access interface w!j'k|b>
sMn)[k vX
AVnH|31dC~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C+m%_6<
{ zFba("E Z
this.sURL = sURL; $5]}]
this.nStartPos = nStart; 2I|`j^
this.nEndPos = nEnd; c;13V(Djy
nThreadID = id; ]VkM)< +
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dKk#j@[n"
} (^@rr[.o7
d:X@zUR*)
X"k:+
public void run() u{'|/g&
{ Km)VOX[ZZ
while(nStartPos < nEndPos && !bStop) L* 0$x
{ a7fFp9l!
@,:6wKMc
44x+2@&1
try{ lM|}K-2
URL url = new URL(sURL); @fc-[pv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \}n\cUy-
httpConnection.setRequestProperty("User-Agent","NetFox"); g!\H^d4
String sProperty = "bytes="+nStartPos+"-"; @BmI1
httpConnection.setRequestProperty("RANGE",sProperty); !S3^{l-
Utility.log(sProperty); "M!]t,?S
f'oO/0lx
sOyL
InputStream input = httpConnection.getInputStream(); ^cnTZzT#Q
//logResponseHead(httpConnection); z|$M,?r'
l"rX'g?
:u9OD` D
byte[] b = new byte[1024]; ~z kzuh
int nRead; JE*d-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bl3?C
{ $ o }
nStartPos += fileAccessI.write(b,0,nRead); MtD0e@
//if(nThreadID == 1) Mp7X+o/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }`~n$OVx
} ,6 IKkyD
@dyh:2!
&E+mXEve
Utility.log("Thread " + nThreadID + " is over!"); 6KRC_-
bDownOver = true; ogvB{R
//nPos = fileAccessI.write (b,0,nRead); QG=K^g
} II'"Nkxd
catch(Exception e){e.printStackTrace ();} 9Rm\@E [
} xjy(f~'
} 8-PHW,1@a3
,gdud[&|;
rQD^O4j R
//打印回应的头信息 q"e]\Tb=we
public void logResponseHead(HttpURLConnection con) YvG=P<_xw
{ 2oo/KndU
for(int i=1;;i++) `tPVNO,l
{ 6Qk[TL)t
String header=con.getHeaderFieldKey(i); l86gs6>
if(header!=null) DS1{~_>nFu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]SmN}Iq1
Utility.log(header+" : "+con.getHeaderField(header)); Miz?t*|{[
else ;O7Vl5R
break; i*((@:
} #M)+sK$H%f
} ]5r@`%9
!T#EkMM
1{AK=H')
public void splitterStop() jx{wOb~oO)
{ z*UgRLKZD
bStop = true; )*XD"-9
} v&qL r+_7
2e9.U/9
ifcp!l+8
} \iP5.3C
_CMNmmp`e
7Fx0#cS"\
/* Yi j^hs@eV
**FileAccess.java hXh nJ
*//文件访问(定位，写) Ae[fW97
package NetFox; SLW|)Q24
import java.io.*; {2)).g
h343$,))u
b_X&>^4Dkl
public class FileAccessI implements Serializable{ `W:z#uNG]
~1&WR`U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ew JNpecX
RandomAccessFile oSavedFile; TM5 Y(Q*
long nPos; N%F4ug@i
suS[P?4
@THa[|(S
public FileAccessI() throws IOException LS$zA>:
{ +s;>@j()V
this("",0); k<|}&<h
} 9:*[Q"v
6>]w1 H
;0U*N& f
public FileAccessI(String sName,long nPos) throws IOException HbRvU}C1
{ >6R3KJe
oSavedFile = new RandomAccessFile(sName,"rw"); r )HZaq
this.nPos = nPos; /9=r.Vxh
oSavedFile.seek(nPos); oY+p;&H
} N%?R(
_X|prIOb=
2EOx],(|
public synchronized int write(byte[] b,int nStart,int nLen) s"XwO8yhM
{ fy$?~Ji&
int n = -1; Eq%f`Qg+1E
try{ ^ L]e]<h(
oSavedFile.write(b,nStart,nLen); I~;w Q
n = nLen; { V)`6
} +0?1"2
catch(IOException e) D4\[D8pD
{ fDloL
e.printStackTrace (); H,c`=Ii3
} K9-9 c"cz
Cv@)tb
n.rn+nuwv
return n; nEUUD3a
} ps;dbY*s6
\%7fm#z6
Y]7503J
} ,kf.'N
^|SiqE
RRXp9{x`
/* 51u\am'T
**SiteInfoBean.java @dUN3,}
*/ ?;_*8Doq-a
package NetFox; 1BEs> Sm
'$c9S[
`yP`5a/
public class SiteInfoBean { g60k R7;\
+TyN;e
P@keg*5@
private String sSiteURL; //Site's URL h!ogH >S~
private String sFilePath; //Saved File's Path damG*-7Svx
private String sFileName; //Saved File's Name tS>^x
private int nSplitter; //Count of Splited Downloading File $_iE^zZaU^
4&=</ok6`0
JEk'2Htx
public SiteInfoBean() <:Mz2Rg
{//nSplitter的缺省值为5 aU~?&]
//default value of nSplitter is 5 E%DT;1
this("","","",5); 3%bhW9H%
} ] j8bv3
d!UxFY@
-pIz-*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }lDX3h
{ 7FJ4;HLQ
sSiteURL= sURL; c-PZG|<C[
sFilePath = sPath; TZ+ p6M8G
sFileName = sName; )|vy}Jf7
this.nSplitter = nSpiltter; s[sv4hq
14"57Jt8
J jm={+@+
} 3LT~-SvL
w|6/i/X
q" f65d4c
public String getSSiteURL() vc&v+5Y
{ pY@QR?F\
return sSiteURL; !6 L!%Oi
} Pmo<t6
:dh; @kp
&92/qRh7
public void setSSiteURL(String value) tsJR:~
{ oX8EY l
sSiteURL = value; mEbI\!}H0
} eb}P/
@lF?+/=$
t^KQ*8clG
public String getSFilePath() .}/8]
{ Ny^f'tsA
return sFilePath; }%8ZN :
} FGx)?
p<=Lh47 =
mf3,V|>[\
public void setSFilePath(String value) '9Z`y_~)G
{ cZQ8[I
sFilePath = value; W~0rSVD$<z
} 5h&sdzfG
aZ4?!JW.
9-/q-,
public String getSFileName() aTTkj\4
{ RARA_tii
return sFileName; 50QDqC-]XS
} k9f|R*LM
(0H=f6N
C@6:uiT$
public void setSFileName(String value) 7H5VzV
{ zQ|2D*W
sFileName = value; [9${4=Kq
} J?w_DQa
XZ~kXE;B(
YD'gyP4
public int getNSplitter() XQ]vJQYIR
{ Q $}#&
return nSplitter; \0x>#ygX
} XZb=;tYo
o6px1C:
6qHD&bv\%C
public void setNSplitter(int nCount) y\Aa;pL)RQ
{ Tc/^h4xH
nSplitter = nCount; u"=]cBRWL6
} oj - `G
} ?@9v+Am!
D,}bTwRb-
Ohk\P;}
/* LDc EjFK(
**Utility.java NgDhdOB
*/ 5[Vr {^)
package NetFox; SK\@w9#&$
@W>@6E
=|]h-[P'
public class Utility { |y U!d %
B18BwY
P|<V0 Vs.
public Utility() "00j]e.
{ P!W%KobZ7|
7P+1W \
i90X0b-A
} 'z;(Y*jb
`s}L3bR]
//线程睡眠 iz#R)EB/g
public static void sleep(int nSecond) N!(mM;1X)
{ ^A@f{g$KB+
try{ %xlpOR4
Thread.sleep(nSecond); ] #@:VR
} *'-4%7C`1
catch(Exception e) <=">2WP{
{ b!]O]dk#
e.printStackTrace (); (p[#[CI9
} ,Q-,#C"
} v1,#7sAW'
N.JR($N$
//日志 ?>h ~"D#
public static void log(String sMsg) ChTq!W
{ '#f<wfn
System.err.println(sMsg); Iw`tbN L[
} @KTuG ?.
<R]m(
9r].rzf9
public static void log(int sMsg) R'k`0
{ >J7slDRo
System.err.println(sMsg); FMVAXOO
} /yG34) aB
} =HCEUB9Fs
B-MS@<2
,a{85HLr]
/* .t_t)'L
**TestMethod.java 5G`HJ6
*/ hI:.Qp`r
package NetFox; ']1n?K=A
l;iU9<~
mH$tG $
public class TestMethod { <Q~N9W
r@4A%ql<
t(#9.b`W)
public TestMethod() ?XHQdN3e
{ ///xx/weblogic60b2_win.exe ^aSb~lce
try{ o pTXI*QA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^v;)6a2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `j>5W<5q\
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^cYB.oeu
fileFetch.start(); #hxYB
} 5skN'*oG
catch(Exception e){e.printStackTrace ();} L]kBY2c
4aS}b3=n
dEJqgp}\p
} {$^'oRk
^O_Z5NbC3
spV7\Gs.@
public static void main(String[] args) msmW2Zc
{ |T|m5V'l
new TestMethod(); mXRkR.zu+
} 4-yK!LR
} CVfV
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