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)); 1^tSn#j
} 'tut4SwC
for(int i=0;i<nEndPos.length-1;i++) :r-.r"[m-
{ {70Ou}*
nEndPos = nStartPos[i+1]; ~K%k 0kT
} ik1XGFy?
nEndPos[nEndPos.length-1] = nFileLength; ?4MSgu
} HoV{Uzm
} Vp\80D&
*f?S5.
o[n<M>@
//启动子线程 qr9Imr0w<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^+URv
for(int i=0;i<nStartPos.length;i++) b.@H1L
{ F/xCG nP-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u(8~4P0w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F6DxvyANr
nStartPos,nEndPos,i); YV4 :8At1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MN\i-vAL8
fileSplitterFetch.start(); PRZ8X{h
} Dl&PL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xg{VP7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f~U#z7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K:uQ#W.&
nEndPos = " + nFileLength); f%L:<4
// fileSplitterFetch[nPos.length-1].start(); C)U #T)
A3<^ U
XnPJC'
//等待子线程结束 e"lD`*U8R
//int count = 0; yr%yy+(.k
//是否结束while循环 2c"/QT
boolean breakWhile = false; A0UV+ -PP
5d%_Wb'
8F\~Wz7K
while(!bStop) m'3OGvd
{ ZRX^^yN
write_nPos(); f!mE1,eBEe
Utility.sleep(500); BB0g}6M
breakWhile = true; /G{&[X<4U
\ hrBq^I
I7A7X*
for(int i=0;i<nStartPos.length;i++) u/;_?zI
{ cl@kRX<7'
if(!fileSplitterFetch.bDownOver) FoQ?U=er
{ 2.!1kije
breakWhile = false; F9v)R#u~
break; ~d&'Lp[3
} u"*J[M~
} aD?# ,
if(breakWhile) ;,mBT[_ZO
break; %Fs*#S
K?$9N}+
AL(n*,
//count++; i[o&z$JO
//if(count>4) sN"p5p
// siteStop(); gHp'3SnS
} >c}:
q|R+x7x
^8b~ZX
System.err.println("文件下载结束！"); ! Zno[R
} 4u@yJ?U
catch(Exception e){e.printStackTrace ();} (6e!09P&
} =VCi8jDkP
/]pX8 d
Dp%5$wF)8
//获得文件长度 W]} #\\$z
public long getFileSize() u):X>??
{ jG =(w4+
int nFileLength = -1; A J<iM)l|
try{ X77A; US
URL url = new URL(siteInfoBean.getSSiteURL()); @gs26jX~2}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 37J\i ]
httpConnection.setRequestProperty("User-Agent","NetFox"); <GSQ2bX[
ww-XMz h
|*lH9lWJ
int responseCode=httpConnection.getResponseCode(); A$%@fO.b
if(responseCode>=400) Q~x*bMb.
{ j@%K*Gb`
processErrorCode(responseCode); >|v=Ba6R0
return -2; //-2 represent access is error p Z0=
} t^`<*H
Z'voCWCd
5Xp$yX =
String sHeader; 8W(<q|t
w g$D@E7
ac2}3$u
for(int i=1;;i++) N;e;4,_ n
{ OJnPP>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -OHvK0~
//Utility.log(in.readLine()); pI'8>_o
sHeader=httpConnection.getHeaderFieldKey(i); _K 4eD.
if(sHeader!=null) $ijx#a&O
{ 8yY"x ['
if(sHeader.equals("Content-Length")) ;:v]NZtc
{ Q,[rrG;?@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oc!biE`u
break; j4.Qvj >:4
} L-^# 02
} Bq~AU#
else \W3+VG2cA
break; N{?Tm`""
} 43UJ#rF
} v]LFZI5
catch(IOException e){e.printStackTrace ();} fs]#/*RR
catch(Exception e){e.printStackTrace ();} .d<~a1k
P58\+9d_
jrDz7AfA
Utility.log(nFileLength); rU/-Wq`B
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v1`bDS?*Q
return nFileLength; tXssejiE%
} zv$=*
$#6Fnhh}
/ig^7+#
//保存下载信息（文件指针位置） @t{{Q1
private void write_nPos() yVbg,q'?
{ @ef//G+Z"
try{ {jj]K.&
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;`X`c
output.writeInt(nStartPos.length); Y?"v2~;3
for(int i=0;i<nStartPos.length;i++) fY|@{]rx
{ KUl Zk^a
// output.writeLong(nPos); , V0iMq
output.writeLong(fileSplitterFetch.nStartPos); $ioaunQKP
output.writeLong(fileSplitterFetch.nEndPos); TMnT#ypf<5
} umq$4}T'$
output.close(); &4ug3
} !?tu! M<1?
catch(IOException e){e.printStackTrace ();} }w|=c>'_}
catch(Exception e){e.printStackTrace ();} AxG?zBTFx
} Y/?DSo4G
:epitpJ
e8WPV
//读取保存的下载信息（文件指针位置） jgZX~D
private void read_nPos() I1eb31<
{ E 6>1Fm8%V
try{ g4BwKENM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B1 jH.(
int nCount = input.readInt(); C9"f6>i
nStartPos = new long[nCount]; UgOGBj,&5W
nEndPos = new long[nCount]; FvtM~[Q
for(int i=0;i<nStartPos.length;i++) jk WBw.(
{ K-g=td/@
nStartPos = input.readLong(); &;uGIk>s
nEndPos = input.readLong(); A;/Xt
} ;iwD/=Y
input.close(); LN,$P
} }RC.Q`b
catch(IOException e){e.printStackTrace ();} m\R@.jkZ
catch(Exception e){e.printStackTrace ();} (o6A?37i
} _BeX7
gn;nS{A
f"}0j|Gg
private void processErrorCode(int nErrorCode) ;I0yQlx|U
{ @n~ND).
System.err.println("Error Code : " + nErrorCode); RN cI]oJ
} <E(-QJ
o$qFa9|Ec?
9I^H)~S
//停止文件下载 S%a}ip&
public void siteStop() L@^!(
{ ]9~#;M%1
bStop = true; <+mO$0h"r
for(int i=0;i<nStartPos.length;i++) gvwCoCbb
fileSplitterFetch.splitterStop(); 9e :d2
MO(5-R`
;1(qGy4
} |?pYJkrYO
} <7RkM
//负责部分文件的抓取 \a~;8):q=i
**FileSplitterFetch.java XH_qA[=c]
*/ Cbf,X[u
package NetFox; +wPvQKVfI
+@<^i?ale
SbQ{ >
import java.io.*; ni02N3R
import java.net.*; OM.(g%2
,rvZW}=
MZhJ,km)
public class FileSplitterFetch extends Thread { Z)Xq!]~/g
pqNoL* H
2-B8>-
String sURL; //File URL 37<GG)
long nStartPos; //File Snippet Start Position /fcwz5~
long nEndPos; //File Snippet End Position E!(`275s
int nThreadID; //Thread's ID 'KN!m| z
boolean bDownOver = false; //Downing is over _#\5]D~""
boolean bStop = false; //Stop identical z;@S_0M,Z
FileAccessI fileAccessI = null; //File Access interface #f jX|b
z<C~DH
!UPAEA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aV0;WH_3
{ v2dSC(hRZ
this.sURL = sURL; $(<*pU
this.nStartPos = nStart; -^SD6l$
this.nEndPos = nEnd; s$=B~l
nThreadID = id; fjeE.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B+e~k?O]1
} xX67bswG
l<+,(E=
<P Z\qE*+y
public void run() _|2";.1E
{ g]hn@{[
while(nStartPos < nEndPos && !bStop) rO2PbF3
{ fe]T9EDA
^dp[Z,[1z
jl?y}
try{ =K&q;;h
URL url = new URL(sURL); M. UUA?d<'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vA $BBXX
httpConnection.setRequestProperty("User-Agent","NetFox"); D\i8rqU/l
String sProperty = "bytes="+nStartPos+"-"; s13 d*
httpConnection.setRequestProperty("RANGE",sProperty); rH9|JEz
Utility.log(sProperty); ,19"[:WN
Q!$kUcky9
q?b)zeJ
InputStream input = httpConnection.getInputStream(); 39^uLob
//logResponseHead(httpConnection); ;kcFQed\w
^gVbVz[17
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byte[] b = new byte[1024]; 9R<J$e
int nRead; ,HjHt\!~<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Xwn|.
{ N6 Cc%,
nStartPos += fileAccessI.write(b,0,nRead); m]b.P,~v
//if(nThreadID == 1) +r34\mAO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i_Q4bhVj
} Z_TbM^N
@eD2<e
W71#NjM2Z
Utility.log("Thread " + nThreadID + " is over!"); EC&19
bDownOver = true; 8CHf.SXh
//nPos = fileAccessI.write (b,0,nRead); 'J<zVD}0
} "\P~Re"EH
catch(Exception e){e.printStackTrace ();} Hwi7oXP
} :Y&W)V-
} ?F:C!_
6(RqR
)}Mt'd
//打印回应的头信息 gj(l&F *@
public void logResponseHead(HttpURLConnection con) 8*X L19N
{ d(cYtM,P
for(int i=1;;i++) 2LK*Cv[
{ jZgnt{
String header=con.getHeaderFieldKey(i); `[R:L.H1
if(header!=null) pl? J<48
//responseHeaders.put(header,httpConnection.getHeaderField(header)); SF}L3/C&h
Utility.log(header+" : "+con.getHeaderField(header)); kA$;vbm
else '[M2Q"X
break; gbi~!S-
} w[7HY@[
} X([n>w
a}8>(jtSt
n@8{FoF
public void splitterStop() qv >(
{ XT;IEZQZ
bStop = true; 7UnO/K7oB.
} v?iH}7zb%Q
CX(yrP6;
`E%d$
} 2tTV5,(1
yvnrZ&x:
Ib<+m%Ac
/* <UHf7:0V
**FileAccess.java kT3;%D^
*//文件访问(定位，写) uTFEI.N
package NetFox; vVRCM
import java.io.*; K>E!W!-PJ
%.}
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public class FileAccessI implements Serializable{ st^N QL
UVi/Be#|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9(\N+
RandomAccessFile oSavedFile; I;PO$T
long nPos; <.]&FPJ
GoGgw]h>x
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public FileAccessI() throws IOException LWR&(p.%
{ -|UX}t*
this("",0); $zH0$aOx
} 2G*#Czr"
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public FileAccessI(String sName,long nPos) throws IOException Wam?(!{mOf
{ C)dYAq3,8
oSavedFile = new RandomAccessFile(sName,"rw"); WUQh[A41
this.nPos = nPos; Fd=`9N9
oSavedFile.seek(nPos); @g` ,'r
} JaN_[ou
`'t;BXedz/
I ywx1ac
public synchronized int write(byte[] b,int nStart,int nLen) 23?0'AU
{ PW\FcT
int n = -1; V)?g4M3}
try{ i(#c Yb
oSavedFile.write(b,nStart,nLen); rm;"98~zJ?
n = nLen; , X+(wp
} 4E94W,1%,Y
catch(IOException e) LPgI"6cP
{ .EELR]`y7I
e.printStackTrace (); M/I d\~
} X64I~*
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[~0q )
return n; uw&,pq
} #GJh:#tt^
ooxzM `
_^A NJ7
} _Pm}]Y:_
F#R\Ot,hv
K8we*
/* soCHwiE
**SiteInfoBean.java _ o3}Ly}
*/ c.> (/
package NetFox; fXQRsL8 ]
"C|l3X'
CzbNG^+
public class SiteInfoBean { +u)$o
PA[Rhoit,
s&hP^tKT
private String sSiteURL; //Site's URL `h]f(
private String sFilePath; //Saved File's Path JQ4>S<ttJ
private String sFileName; //Saved File's Name F'Vl\qPt
private int nSplitter; //Count of Splited Downloading File sM_e_e
oVgNG!/c0
}# ^PbM
public SiteInfoBean() y=`(`|YW}`
{//nSplitter的缺省值为5 2C&%UZim;P
//default value of nSplitter is 5 a VMFjkW
this("","","",5); \5_^P{p7<
} (LPc\\Vv
4(gf!U
p-Btbhv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K Hc+
{ e4LNnJU\|
sSiteURL= sURL; tfQq3#
sFilePath = sPath; (HxF\#r?
sFileName = sName; ^%^0x'"
this.nSplitter = nSpiltter; 9jO+ew
N$b;8F
I'YotV7
} (`xnA~BN
dkC/ ?R
B\yq%m
public String getSSiteURL() pP&M]'
{ ^a5>`W
return sSiteURL; a"4 6_>
} {P+[CO
c^k. <EA
-qF|Y f
public void setSSiteURL(String value) rpWy 6oD
{ #+\G- =-
sSiteURL = value; 9mm(?O~'p
} /ep~/#Ia
?8/h3xV;
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public String getSFilePath() ,oil}N(
{ 1>{(dd?L
return sFilePath; 2N]s}/l
} 8m0sEV>
>S]')O$c
V|`|CVFo]
public void setSFilePath(String value) Zv93cv
{ VV0$L=mo
sFilePath = value; :Yqa[._AF
} mws.)
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`Mg "!n`
public String getSFileName() z(qz(`eGC&
{ e+TNG &_
return sFileName; IF1}}[Ht
} f6)H!SI
cO9Aw!
yW 3h_08
public void setSFileName(String value) `314.a6S
{ <Vb{QOgc;
sFileName = value; J;dFmZOk
} *Q?HaG|S
yM@cml6Ox
rv:O|wZ
public int getNSplitter() $)!Z"2T
{ r^)<Jy0|r
return nSplitter; =B1!em|
} ;Lu|fQ#u*
\BW(c)Q
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public void setNSplitter(int nCount) /_\4(vvf
{ /Y:Zqk3
nSplitter = nCount; HFOp4
} ^Tx1y[hw$
} ;f Gi5=-
4tjRju?
Hw? J1#1IE
/* >B0S5:S$W
**Utility.java ??PpHBJ')
*/ ,U}8(D~:
package NetFox; Qsa2iw{
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4.TG&IQ nN
public class Utility { U' Cp3>
DNPK1e3a{
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public Utility() ;<\*(rUe
{ v]v f(]""
trLs4o,
N<x5:f#+
} dq2v[?*R
c1[;a>
//线程睡眠 novZ<?7 5;
public static void sleep(int nSecond) 6c:$[owC
{ X9R-GT
try{ W2RS G~|
Thread.sleep(nSecond); |dK-r
} H UjmJu6f{
catch(Exception e) "<n{/x(
{ tyh%s"
e.printStackTrace (); B}W^s;h
} _~!,x.Dbp
} i!NGX
4J s>yP
//日志 JsV#:
public static void log(String sMsg) #!2gxm;g
{ $aG'.0HW
System.err.println(sMsg); !E%!,
} Xp'KQ1w)
a <3oyY'
^P[*yf
public static void log(int sMsg) UxW~yk
{ bWqGypq4
System.err.println(sMsg); QO8/?^d
} [7bY(
} W6pS.}
jV(ISD
\vI_%su1N
/* |l9AgwDg
**TestMethod.java %UmE=V
*/ bnlL-]]9z
package NetFox; R~`Y6>o~9:
(/%}a`2#o
<^=k~7m
public class TestMethod { ZrTq)BZ
_Qv4;a
)YZ41K5N
public TestMethod() _u>+H#
{ ///xx/weblogic60b2_win.exe Z1Ms~tch
try{ :!%oQQO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X**wRF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _?{2{^v
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6c2fqAF>i
fileFetch.start(); q+K`+& @\
} nP}/#Wy
catch(Exception e){e.printStackTrace ();} RKe19l_V
zmdOL9"a
,yB-jk?
} +/ #J]v-
cJt#8P
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public static void main(String[] args) ^#G>P0mG%
{ (vY10W{
new TestMethod(); L9x,G!
} F*a+&% Q
} t<e?f{Q5
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