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)); LN2D
} <3okiV=ox
for(int i=0;i<nEndPos.length-1;i++) 17.x0gW,
{ zsXoBD\h
nEndPos = nStartPos[i+1]; J#2!ZQE 3
} ? 1*m,;Z
nEndPos[nEndPos.length-1] = nFileLength; N#C1-*[C
} Q@@v1G\
} KvPX=/&Zu
up'
BV`-=wRC
//启动子线程 wJ<Oo@snm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h*B|fy4K9U
for(int i=0;i<nStartPos.length;i++) !ZRs;UZ>o
{ sZ<9A Xk-E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CjIu[S1%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mTNVU@TY=
nStartPos,nEndPos,i); `Y=WMNy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &w8)* T
fileSplitterFetch.start(); cLY c6
} 1xE]6he4{T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Mg,:UC:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dq1:s1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #-% A[7Cdp
nEndPos = " + nFileLength); JPn$FQD
// fileSplitterFetch[nPos.length-1].start(); (b,[C\RBF
W5L iXM
$_H`
//等待子线程结束 I zbU)ud
//int count = 0; eM7Bc4V
//是否结束while循环 BvrB:%_:
boolean breakWhile = false; fFvF\
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OS|>t./U
while(!bStop) C[!MS5
{ Em 6Qe
write_nPos(); bI)u/
Utility.sleep(500); Wo~vhv$E
breakWhile = true; ig LMv+{
"1`Oh<={b
ph>7?3;t
for(int i=0;i<nStartPos.length;i++) JO<wK
{ "P-lSF?T
if(!fileSplitterFetch.bDownOver) 9+s.w25R
{ ml|W~-6l
breakWhile = false; Cv ejb+
break; ?Iyo9&1&
} W!!S!JF
} obrl#(\P
if(breakWhile) 54-#QIx|
break; Uo12gIX
dz [!-M
r0d35
//count++; m'\2:mDu0
//if(count>4) `LAR@a5i
// siteStop(); l {jmlT
} [.hyZ}B
h_1T,f(
8}X5o]Mv
System.err.println("文件下载结束！"); ae"]\a\&1o
} Ghl'nqPlm
catch(Exception e){e.printStackTrace ();} 6 5y+Z
} Y{v(p7pl
:l7U>~ o
~c)~015`
//获得文件长度 ^<e@uNGg
public long getFileSize() ~_s?k3cd
{ 'TH15r@
int nFileLength = -1; OouPj@r
try{ [gy*`@w
URL url = new URL(siteInfoBean.getSSiteURL()); P`s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -/{4Jf Wf
httpConnection.setRequestProperty("User-Agent","NetFox"); kr$b^"Ku
#P]#9Ty:
D`J6h,=2l/
int responseCode=httpConnection.getResponseCode(); g;$Xq)Dd
if(responseCode>=400) ?Kvl!F!`
{ ae:zWk'!
processErrorCode(responseCode); uZfnzd)c
return -2; //-2 represent access is error +dA,P\
} L-B<nl
M?&h~V1OI~
|#1(Z-}
String sHeader; pwwH<0[
Y6,Rj:8
(x^BKnZ
for(int i=1;;i++) FOq1>>a0
{ OpM(j&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I;VuW
//Utility.log(in.readLine()); yaq'Lt`
sHeader=httpConnection.getHeaderFieldKey(i); ) ri}nL.
if(sHeader!=null) p.+ho~sC,.
{ |#6QThK
if(sHeader.equals("Content-Length")) 3^s/bm$g
{ .h0b~nI>>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &>e-(4Xu
break; [mEql,x3
} U=hlu
} %IC73?
else =+t^f
break; E0`Lg c
} WTImRXK4
} K'K2X-E
catch(IOException e){e.printStackTrace ();} TuW%zF/
catch(Exception e){e.printStackTrace ();} rx(2yf
~QvqG{bFB
h?bb/T+'
Utility.log(nFileLength); p-1 3H0Kt
o9cM{ya/>
h3dsd
return nFileLength; &WNf M+
} /dv<qp
U|g:`v7
/-#I_>:8'
//保存下载信息（文件指针位置） Sz H"
private void write_nPos() &\apwD
{ F(t=!k,4\
try{ ?c0xRO%y
output = new DataOutputStream(new FileOutputStream(tmpFile)); _`64gS}^
output.writeInt(nStartPos.length); JK.ZdY%
for(int i=0;i<nStartPos.length;i++) 3;%5Yu
{ ^bEc6`eE
// output.writeLong(nPos); L%>n>w
output.writeLong(fileSplitterFetch.nStartPos); \GHiLs,!
output.writeLong(fileSplitterFetch.nEndPos); =gcM%=*'
} lFTF ,G
output.close(); >yY'7Ey
} 2h[85\4
catch(IOException e){e.printStackTrace ();} 0P\$2lk
catch(Exception e){e.printStackTrace ();} Z*-g[8FO
} S[7WW$lF
TDd{.8qf
6xD#?
//读取保存的下载信息（文件指针位置） hEh}PX:
private void read_nPos() * S=\l@EW
{ Ur*6Gi6
try{ =0;^(/1Mc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F<!)4>2@
int nCount = input.readInt(); /4xki_}
nStartPos = new long[nCount]; 'uq#ai[5I
nEndPos = new long[nCount]; 4.IU!.Uo
for(int i=0;i<nStartPos.length;i++) Bdj%hyW
{ Y(44pA&oN
nStartPos = input.readLong(); #!)n {h+
nEndPos = input.readLong(); >@"Oe
} ss5m/i7
input.close(); da (km+
} ?JL:CBvCp
catch(IOException e){e.printStackTrace ();} C-iK$/U
catch(Exception e){e.printStackTrace ();} yRo-EP
} e^ v.)
jg?x&'u\)
{J^lX/D
private void processErrorCode(int nErrorCode) byv[yGa`
{ !"eIV@7
System.err.println("Error Code : " + nErrorCode); WJ_IuX51'
} :]J Ye*
vap,y $C
`X3^fg
//停止文件下载 I_A@BnM{I
public void siteStop() .l@xsJn
{ =+AS/Jq
bStop = true; Vb9',a?#n
for(int i=0;i<nStartPos.length;i++) .nyfYa+
fileSplitterFetch.splitterStop(); 1&e} ms
h[PYP5{L
}fKSqB]T-
} =|9H
} D}vmwg@3
//负责部分文件的抓取 gB<3-J1R
**FileSplitterFetch.java 9Lr'YRl[W
*/ `3:.??7N
package NetFox; y K"kEA[;
%Qj;,#z
8stwg'
import java.io.*; =9j8cC5y
import java.net.*; F+@5C:<?
t*?0D\b 2
e[8LmuIZ
public class FileSplitterFetch extends Thread { u?9" jX
!%c'$f/
clk[/'1
String sURL; //File URL ,mj@sC>
long nStartPos; //File Snippet Start Position ~q~MoN<R
long nEndPos; //File Snippet End Position w+N> h;j
int nThreadID; //Thread's ID Uf,4
boolean bDownOver = false; //Downing is over c 9jGq
boolean bStop = false; //Stop identical $ibuWb"a
FileAccessI fileAccessI = null; //File Access interface Q9Q|lO
$]8h $
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DZ_lW
{ |_yYLYH'
this.sURL = sURL; O9r>E3-q
this.nStartPos = nStart; SCz(5[MZJ
this.nEndPos = nEnd; 2Y7)WPn
nThreadID = id; D&S26jrZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 # 0Lf<NZ
} ;s52{>&F]
9k6r_G"
^.>jGI%rB
public void run() i@4~.iZ8
{ ?2oHZ%G
while(nStartPos < nEndPos && !bStop) E<c9#I=
{ v;0|U:`]
5Lf{8UxI
AhNq/?Q Q~
try{ xe*aC
URL url = new URL(sURL); ak;*W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A]DTUdL
httpConnection.setRequestProperty("User-Agent","NetFox"); 4)("v-p
String sProperty = "bytes="+nStartPos+"-"; !=N"vD*
httpConnection.setRequestProperty("RANGE",sProperty); *guoWPA|Ij
Utility.log(sProperty); d20gf:@BM
ZfB" E
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InputStream input = httpConnection.getInputStream(); PP!SK2u"L
//logResponseHead(httpConnection); A$w4PVS
!U5Wr+83
}oNhl^JC
byte[] b = new byte[1024]; [h,QBz
int nRead; 0D&t!$Ibf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DS)RX.k_#
{ 3Oi nK['
nStartPos += fileAccessI.write(b,0,nRead); VhNz8)
//if(nThreadID == 1) ]GRWnif
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3.qTLga|}
} d,=r9.
q5#J~n8Wr
ma((2My'H
Utility.log("Thread " + nThreadID + " is over!"); B:+6~&,-
bDownOver = true; xQ@^$_
//nPos = fileAccessI.write (b,0,nRead); |JVk&8 ?8
} _~T!9
catch(Exception e){e.printStackTrace ();} 'CN|'W)g7
} *;fw%PW
} =|YxDas
QPfc(Z
^6_Cc
//打印回应的头信息 dX)GPC-D7
public void logResponseHead(HttpURLConnection con) sx`O8t
{ QV&D l_
for(int i=1;;i++) 67VT\f
{ uxzze~_+C
String header=con.getHeaderFieldKey(i); qk;{cfzHA
if(header!=null) xa pq*oj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1Tm^
Utility.log(header+" : "+con.getHeaderField(header)); dx+hhg\L
else $]/Zxd
break; jb^N|zb
} oDU ;E
} ruazOmnn~
mzf+Cu:`v
FG)$y[*
public void splitterStop() !H}vu]R
{ iV eC=^1
bStop = true; .3MIcj=p
} ,Y>Bex_v
<0PT"ij
,.qMEMm
} r9ww.PpNk#
"1HRLci
k+DR]icv
/* $O dCL
**FileAccess.java gR}35:$Z-
*//文件访问(定位，写) 1)[]x9]^q'
package NetFox; PgRDKygE
import java.io.*; &T}''
Y14W?|KOB
''Cay0h
public class FileAccessI implements Serializable{ ,qYJioWX
eR3$i)5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ryFxn|4
RandomAccessFile oSavedFile; DmOyBtj
long nPos; 'GL*u#h
^J\~XYg{7
PK4iuU`vh
public FileAccessI() throws IOException ]TyisaT
{ &JtV'@>v
this("",0); ^tCd L@$AS
} ]C:l,I
<&:=z?30"
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public FileAccessI(String sName,long nPos) throws IOException Y "VY%S^
{ PxfY&;4n!
oSavedFile = new RandomAccessFile(sName,"rw"); z$kenhFG/
this.nPos = nPos; {4-[r#R<M
oSavedFile.seek(nPos); Yp:KI7
} ($~RoQ=0S
Y)}Rb6qGW
w&x!,yd;
public synchronized int write(byte[] b,int nStart,int nLen) Bdu&V*0g
{ {je-I9%OK
int n = -1; ~O1&@xX
try{ pm9%%M$
oSavedFile.write(b,nStart,nLen); m,t|IgDh
n = nLen; p+Y>F\r&w
} -k7X:!>QHC
catch(IOException e) bHI<B)=`
{ jr`Ess
e.printStackTrace (); -c}, :G"
} 59Gk3frk(
B.L]Rk\4
b?j< BvQ
return n; 3yNU$.g
} -Fn}4M
(k|_J42[
? mhs$g>
} M_%B|S {
fks)+L'
>(snII
/* }YHX-e<Yx]
**SiteInfoBean.java lbuAE%
*/ EMc;^ d
package NetFox; DK oN}c
E.U_W
O/!bG~\Y
public class SiteInfoBean { ]7rj/l$u
8zBWIi
RTFZPq84
private String sSiteURL; //Site's URL V14B[|YM<
private String sFilePath; //Saved File's Path H`geS
private String sFileName; //Saved File's Name >|Cw\^
private int nSplitter; //Count of Splited Downloading File W mm4hkf
%.z,+Zz?
-> J_ ~
public SiteInfoBean() &EpAg@9!
{//nSplitter的缺省值为5 {N#KkYH{"
//default value of nSplitter is 5 DSj(]U~r
this("","","",5); YQS5P#
} i>joT><B
A=j0On
RAp=s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /P 2[:[w
{ )<xypDQ
sSiteURL= sURL; 3S&U!
sFilePath = sPath; }>[G5[\
sFileName = sName; TET`b7G
this.nSplitter = nSpiltter; _Um d
.%82P(
Kn?lHH*w7
} e*.b3z
VnT>K9&3
r lKlpl
public String getSSiteURL() U`]T~9I
{ G5FaYL.7
return sSiteURL; A%2:E^k(s
} Y1arX^Zb
?}B:
8L1ohj
public void setSSiteURL(String value) %xQ.7~
{ .WQ+AE8Q
sSiteURL = value; oQL59XOT4
} kZ=s'QRgL
2z@\R@F
1c@}C+F+
public String getSFilePath() >g;kJe
{ Ia'ZV7'
return sFilePath; )$Z=t-q
} wWXD\{Hk
2+Wzf)tB
`4 y]Z)
public void setSFilePath(String value) 8#&q$kE
{ s-ZI ^I2\
sFilePath = value; K2<~(78C
} e9E\% p
l)-Mq@V
@K:N,@yq
public String getSFileName() w;e(Gb%9
{ A4QcQ"
return sFileName; &,.Y9; b
} Ei2%DMN7)
U/NBFc:[y:
I_q~*/<h
public void setSFileName(String value) ')N{wSM9Ft
{ A$WZF/x
sFileName = value; ~xIjF1Z
} LA[g(i 7
jp+_@S>
d HJhFw
public int getNSplitter() 9*:gr#(5
{ (7DXRcr<
return nSplitter; 5ZY)nelc
} !SKV!xH9
nPUqMn'
UgN28YrW
public void setNSplitter(int nCount) j8K,jZ
{ #pHs@uvO
nSplitter = nCount; #*>E*#?t
} ! <WBCclX
} ,Os? f:Y6
CD0VfA>Z
)RsM!}
/* Xe+,wW3YF
**Utility.java LC0d/hM
*/ |*mL1#bB
package NetFox; Xes|[*Y!V
&5t :H 8b
-xD*tf*
public class Utility { aV1lJ;0
Hk7K`9
,pBh`av
public Utility() T$=4O9G
{ Q7bq
BN,>&1I
lHB) b}7E
} [ REf>_R
C}5M;|%3)
//线程睡眠 2ij# H ;
public static void sleep(int nSecond) w-$[>R[hw
{ 1=2^90
try{ u z\0cX_
Thread.sleep(nSecond); UMN*]_'+;b
} (.3'=n|kE
catch(Exception e) [4J6iF
{ De_CF8
e.printStackTrace (); V#q}Wysft
} MP>n)!R[`
} 8p1ziz`4>$
k8]O65t|
//日志 =iHiPvP0
public static void log(String sMsg) ug`NmIQP
{ ;PyZ?Z;
System.err.println(sMsg); >\A8#@1
} k#:2'!7G
(5$ZvXx?}
9tg)Mo%
public static void log(int sMsg) /( 6|{B
{ W >(vYU
System.err.println(sMsg); j*;N\;iL!*
} EN!?:RV
} !8tS|C#2
insY(.N
u2(eaP8d
/* W}'WA
**TestMethod.java ?nKF6f
*/ tK%c@gGU9
package NetFox; =wq;@'U
r(2R<A
'PWQnt_U
public class TestMethod { s4T}Bsr
=sOo:s
h?,\(KjP#
public TestMethod() hF&}lPVtv
{ ///xx/weblogic60b2_win.exe P(omfD4
try{ `xKFqx:e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _2vd`k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H'J|U|
SiteFileFetch fileFetch = new SiteFileFetch(bean); y:}sD_m0W
fileFetch.start(); {fSfq&o
} 1q.(69M
catch(Exception e){e.printStackTrace ();} p D=w>"
tu%[p 4
]qw0V
} bZipm(e
")lw9t`
.+K S`
public static void main(String[] args) #-cTc&$O;
{ *9gD*AnM,
new TestMethod(); gY9\o#)<
} sY;lt.b
} J7i+c];!<
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