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)); "s!7dKXI"
} kr$b^"Ku
for(int i=0;i<nEndPos.length-1;i++) jdE5~a+
{ D`J6h,=2l/
nEndPos = nStartPos[i+1]; J_Ltuso
} ;S0Kh"A
nEndPos[nEndPos.length-1] = nFileLength; LK6; ?m
} }ENR{vz$A
} 8Og_W8
P=3RLL<l
W^3uEm&l!)
//启动子线程 322jR4QGr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E9?phD
for(int i=0;i<nStartPos.length;i++) r]3'74j:
{ JpsPNa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <E\$3Ym9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H$G0`LP0/a
nStartPos,nEndPos,i); Mu'8;9_6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pdJ/&ufh
fileSplitterFetch.start(); iyj+:t/
} ?4H i-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), it]E-^2>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p!k7C&]E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b'6-dU%
nEndPos = " + nFileLength); 5_XV%-wM
// fileSplitterFetch[nPos.length-1].start(); xss`Y,5?
!mWiYpbU+
yG Wnod'
//等待子线程结束 ` PYJ^I0
//int count = 0; /Uo y/}!
//是否结束while循环 =K{\p`?
boolean breakWhile = false; Dfq(Iv
Hwo$tVa:=
Y"OG@1V;8
while(!bStop) tmqY2.
{ 1x,[6H
write_nPos(); aK`@6F,]j
Utility.sleep(500); c@v{`d
breakWhile = true; cZ)}LX
%tG*C,l]
22f`LoM
for(int i=0;i<nStartPos.length;i++) b~nAPY6
{ \:'%9 x
if(!fileSplitterFetch.bDownOver) dCj,b$
{ Q{B}ef
breakWhile = false; |9~GM
break; 6N)!aT9eo
} 3O7!`Nm@
} $Of0n` e
if(breakWhile) NPFpq,P>
break; vN3Zr34
wdUBg*X8
,t\* ZTt$
//count++; S"Zp D.XX
//if(count>4) pp7$J2s+j
// siteStop(); 5]M>8ll
} i1S>yV^l
hWH:wB
:1Q!$ m
System.err.println("文件下载结束！"); a{{g<<H
} 0ez(A
catch(Exception e){e.printStackTrace ();} UQB"v3Z
} a33TPoj
_/wV;h~R
< yC
//获得文件长度 u|4$+QiD
public long getFileSize() SPp#f~%m
{ XS$OyW_Q
int nFileLength = -1; -?(E_^ng
try{ r#xg#uoj
URL url = new URL(siteInfoBean.getSSiteURL()); 0_CN/5F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i\W/C
httpConnection.setRequestProperty("User-Agent","NetFox"); Z!U)I-x&
M`ip~7"
Yv:55+e!|
int responseCode=httpConnection.getResponseCode(); y#XbJuN/
if(responseCode>=400) ~#kT_*sw)
{ _x!7}O#k
processErrorCode(responseCode); A^p[52`
return -2; //-2 represent access is error d>{nQF;c
} qL,tYJ<m%
wC5ee:u C%
1UKg=A-q
String sHeader; C`5
OK\A</8r
w: >5=mfk
for(int i=1;;i++) cK 06]-Y
{ =b/L?dR.-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -&<Whhs.@
//Utility.log(in.readLine()); A<W6=5h
sHeader=httpConnection.getHeaderFieldKey(i); ?2>FdtH
if(sHeader!=null) B, 9w0
{ \?jeWyo
if(sHeader.equals("Content-Length")) NMA}Q$o s
{ jAud {m*T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /PLn+-
break; 1AU#%wIEP
} cq$i
} L:9F:/G
else &LbJT$}V
break; ?:w1je7
} E8-P"`Qba
} K# Jk _"W
catch(IOException e){e.printStackTrace ();} Sv &[f}S
catch(Exception e){e.printStackTrace ();} J9=m]R8T
3;a<_cE*@
5< ja3
Utility.log(nFileLength); zL\OB?)5J
*6} N =Z
VO"("7L
return nFileLength; Ntbg`LGf'!
} -=(!g&0
vBog0KD);s
s M+WkN}{
//保存下载信息（文件指针位置） U4cY_p?
private void write_nPos() z@wMc EH
{ {c (!;U
try{ og0*Nt+
output = new DataOutputStream(new FileOutputStream(tmpFile)); *W kIq>
output.writeInt(nStartPos.length); f"St&q>[s
for(int i=0;i<nStartPos.length;i++) V =-WYu
{ aJcf`<p
// output.writeLong(nPos); 95z]9UL
output.writeLong(fileSplitterFetch.nStartPos); ca>Z7qT!
output.writeLong(fileSplitterFetch.nEndPos); 2z|*xS'G
} &o<F7U'R
output.close(); /r=tI)'$
} <A# l 35
catch(IOException e){e.printStackTrace ();} KG=h&
catch(Exception e){e.printStackTrace ();} -Y='_4s
} Q_t`.jus
!tp1:'KG
FHC\?Cg
//读取保存的下载信息（文件指针位置） $H-!j%hV
private void read_nPos() (`:O~>[N
{ AhNq/?Q Q~
try{ xe*aC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ak;*W
int nCount = input.readInt(); A]DTUdL
nStartPos = new long[nCount]; 0$-xw
nEndPos = new long[nCount]; !=N"vD*
for(int i=0;i<nStartPos.length;i++) fXcm|U,ho
{ Lliqj1&
nStartPos = input.readLong(); k70|'*Kh
nEndPos = input.readLong(); B` k\EL'
} HB7;0yt`:
input.close(); X_7UJ jFw"
} 3}/&w\$
catch(IOException e){e.printStackTrace ();} D#o}cC.
catch(Exception e){e.printStackTrace ();} &cu lbcz
} )4&cph';
-UD\;D?$
qv@$ZLR
private void processErrorCode(int nErrorCode) u&n' ITH
{ uh?>- ]r`
System.err.println("Error Code : " + nErrorCode); BN4_:
} Rb{U+/gq
X#e1KZ
MzL1Bh!M
//停止文件下载 ]Ei0d8Uo
public void siteStop() @U2qD J6
{ B4mR9HMh
bStop = true; *;Ed*ibf
for(int i=0;i<nStartPos.length;i++) DrO2y
fileSplitterFetch.splitterStop(); ?!`=X>5
/IM#.v
sx`O8t
} L\#<JxY$p
} 3l#IPRn9AO
//负责部分文件的抓取 uxzze~_+C
**FileSplitterFetch.java P<f5*L#HD
*/ 6C+"`(u%V
package NetFox; )lZp9O
?G-e](]^<
:at$HCaK
import java.io.*; zNIsf"
import java.net.*; 1SR+m>pL
r}jGUe}d
k0Uyf~p~
public class FileSplitterFetch extends Thread { >b]S3[Q(
t>[KVVg W
(4Zts0O\
String sURL; //File URL /\WQxe
long nStartPos; //File Snippet Start Position <0PT"ij
long nEndPos; //File Snippet End Position ,.qMEMm
int nThreadID; //Thread's ID r9ww.PpNk#
boolean bDownOver = false; //Downing is over f?'JAC*
boolean bStop = false; //Stop identical wV^V]c?U
FileAccessI fileAccessI = null; //File Access interface m2v'WY5u
|\g5+fv9
a!u rew#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j<)9dEM'
{ INyk3`FT
this.sURL = sURL; sn?]n~z
this.nStartPos = nStart; _`pD`7:aI^
this.nEndPos = nEnd; H[='~%D
nThreadID = id; I;1lX L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?A )hN8
} &[;HYgp
MKWyP+6`
[/BE8]M~
public void run() Y>&Ew*Y
{ Z"uY}P3
while(nStartPos < nEndPos && !bStop) (1NA
{ _X'"w|0
PfZ+PqS
?:L:EW8
try{ mb!9&&2-t
URL url = new URL(sURL); U\sHx68
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); = hN !;7G
httpConnection.setRequestProperty("User-Agent","NetFox"); }ga@/>Sl&
String sProperty = "bytes="+nStartPos+"-"; S*,rGCt'T
httpConnection.setRequestProperty("RANGE",sProperty); w#g#8o>'
Utility.log(sProperty); P';?YV0
@, Wvvh
%3$*K\Ai
InputStream input = httpConnection.getInputStream(); Vb'7>
//logResponseHead(httpConnection); Q;D0<Bv
U_{Ux2
<!pvqNApg
byte[] b = new byte[1024]; <bD>m[8,
int nRead; EVNY*&p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L^{|uP15N
{ PtTHPAKj
nStartPos += fileAccessI.write(b,0,nRead); 5=1^T@~#&
//if(nThreadID == 1) D2,z)O%VK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wWp(yvz
} =lVK IW
+|ycvHd
_BDK`D
Utility.log("Thread " + nThreadID + " is over!"); +tD[9b! m
bDownOver = true; wW%4d
//nPos = fileAccessI.write (b,0,nRead); *tAg*$
} gc?#pP
catch(Exception e){e.printStackTrace ();} 3dDX8M?
} kn/Ao}J74z
} YXI'gn2b#
l3IWoa&sh
>(snII
//打印回应的头信息 bl'z<S, '
public void logResponseHead(HttpURLConnection con) <~)kwq'
{ nYJTKU
for(int i=1;;i++) l#}.^71+
{ SC- $B
String header=con.getHeaderFieldKey(i); UDL RCS8i
if(header!=null) fhCc! \
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &wB\ ~Ie-
Utility.log(header+" : "+con.getHeaderField(header)); 1\r|g2Z :
else 9Fr3pRIJ
break; po}F6m8bX
} 6AWKLFMV
} {N#KkYH{"
DSj(]U~r
UYz0PSV=.
public void splitterStop() #-GJ&m8
{ o^V(U~m]
bStop = true; LB.co4
} "hQ_sgz[Z
o'$jNciOW
yA3wtm/?
} 8Y#\xzod
DU=dLE6-P;
Tc+gdo>G
/* 2"-S<zM
**FileAccess.java ~%2pp~1K
*//文件访问(定位，写) sIv)'
package NetFox; `~W-Xx
import java.io.*; wm+})SOX9
84{Q\c
A%2:E^k(s
public class FileAccessI implements Serializable{ mB0l "# F
1U,1)<z~u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QL$S4 J"
RandomAccessFile oSavedFile; %xQ.7~
long nPos; .WQ+AE8Q
oQL59XOT4
8+Td-\IMk
public FileAccessI() throws IOException {vE(l'
{ aceZ3U>W
this("",0); B7Tk4q\;Q
} . ]8E7
n\ Hs@.
sk|=% }y
public FileAccessI(String sName,long nPos) throws IOException |0,vQv
{ dCFlM&(i
oSavedFile = new RandomAccessFile(sName,"rw"); ZY56\qcY
this.nPos = nPos; d;+[i
oSavedFile.seek(nPos); Zx$ol;Yd
} NOS>8sy
EbZdas!l
5p +ZD7jK
public synchronized int write(byte[] b,int nStart,int nLen) 3or\:
{ #YSF&*
int n = -1; &ciN@nJ|$z
try{ S{K0.<,E
oSavedFile.write(b,nStart,nLen); 8/"fWm/
n = nLen; q-Qxbg[>e
} P6Mhbmt9*
catch(IOException e) 7FF-*2@
{ Eaqca{%/^
e.printStackTrace (); ?J,AB #+
} j.:h5Y^N
x3zj?-
D\H/
return n; ayBRWT0
} AE@NOM7u
"Y=+Ls(3o(
>5 b/or
} 5IKL#V`3a
5#E |R
wJlX4cT4YV
/* pN&c(=If
**SiteInfoBean.java m~'? /!!
*/ D.%B$Y;G
package NetFox; :L 3&FA
sFDG)
W~Z<1[
public class SiteInfoBean { a83g\c5
<*EZ@XoN>
n$(p-po
private String sSiteURL; //Site's URL b|5w]<?'
private String sFilePath; //Saved File's Path auWXgkwZs/
private String sFileName; //Saved File's Name t]-uw-E
private int nSplitter; //Count of Splited Downloading File _u}4j9T
Yif*"oO
*U#m+@\0
public SiteInfoBean() ~3RC>8*Qw
{//nSplitter的缺省值为5 ]Zf6Yw.Y
//default value of nSplitter is 5 mNYl@+:psj
this("","","",5); 0L^u2HZYL
} _#_ E^!
>ulY7~wUv
#?B%Ja% ;W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~}DQT>7$
{ /VHi>
sSiteURL= sURL; T5O _LCIws
sFilePath = sPath; NcM>{{8
sFileName = sName; bY~@}gC**@
this.nSplitter = nSpiltter; rx:z#"?I
bqx0d=Z~[
l?*r5[O>n
} ZlKw_Sq:
9PUes3"v
W@\ (nfD2
public String getSSiteURL() MK}-<&v
{ NV r0M?`4
return sSiteURL; +{53a_q
} "gW7<ilw
8%RI7Mg
D,ly#Nn
public void setSSiteURL(String value) OVk~N)
{ uENdI2EY8y
sSiteURL = value; H g5++.Bp
} e1q"AOV6
R\s!*)
nF)uTk
public String getSFilePath() [XlB<P=|>
{ DW(~Qdk
return sFilePath; 0F;,O3Q
} 1f(DU4h
#:ns64|
G"y.Z2$
public void setSFilePath(String value) PKq-@F%X
{ 8X&Ya =
sFilePath = value; @oe\"vz
} <1~^C
%"A_!<n@*`
[{&jr]w`|
public String getSFileName() \0FT!} L
{ ~9$X3.+
return sFileName; o'%eI
} }PeZO!K
1q.(69M
p D=w>"
public void setSFileName(String value) tu%[p 4
{ >adV(V<
sFileName = value; ")lw9t`
} .+K S`
B>TSdn={>
D!TZI
public int getNSplitter() l*7?Y7FK
{ /owO@~G
return nSplitter; g.Hio.fVd
} ]y1fM0
tjv\)Nn'
Q*O<@
public void setNSplitter(int nCount) v@u<Ww;=@
{ O%1/r*
nSplitter = nCount; q'(z #h,cv
} {)K](S ~
} FEm=w2
{8NwFN.
eXy"^xp^
/* XrN- 2HTV
**Utility.java B/eaqJ
*/ PCfo
package NetFox; :mv`\
_dU P7H (
Nf?\AK!
public class Utility { LAZVW</
[>w%CY<Fd
5 d ;|=K
public Utility() z \?UGxu}
{ t%+$"nP
G?V"SU.
QD<eQsvV
} KAb(NZK
,{<p
//线程睡眠 d\]O'U)s
public static void sleep(int nSecond) Bh`IXu
{ v:d9o.h
try{ Q~ 0Dfow?
Thread.sleep(nSecond); 68x}w Ae
} MTmO>V&O
catch(Exception e) qa!RH]B3
{ dbO#
e.printStackTrace (); YBSl-G'
} d\Jji 6W
} (@]tG?I=
+8^_D?*\n
//日志 HZ\k-!2
public static void log(String sMsg) zk>h u<_
{ |< N frz
System.err.println(sMsg); NfF~dK|
} koH4~m{
%D^bahf
&`@M8-m#F
public static void log(int sMsg) /4C`k=>
{ %ejeyc
System.err.println(sMsg); 3Xdn62[&
} R [9w
} exphe+b
Kpg:yrc['
QHQj/)J8
/* %3,xaVN
**TestMethod.java ?~)Ak`=
*/ 0>Fqx{!heq
package NetFox; /2h][zrZ[.
G?[-cNdk
BW71 s
public class TestMethod { .Z5[_'T
$Sb@zLi)
@)z*BmP
public TestMethod() ;E's4jWq
{ ///xx/weblogic60b2_win.exe _0]QS4a][c
try{ uL>:tb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @"8~Y|L93
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8_iHVc;<
SiteFileFetch fileFetch = new SiteFileFetch(bean); t F/nah
fileFetch.start(); .&(8(C
} 4e/cqN6
catch(Exception e){e.printStackTrace ();} sV'v* 1|
|#cAsf_{
9cOx@c+/
} E$T(Qu<-
A\C'dZ <N
KnFQ)sX^
public static void main(String[] args) 73pC
{ yfq>,
new TestMethod(); yjeL9:jH[
} 6J;i,/ky
} 6!RikEAh
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