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)); _d5QbTe
} "wNJ
for(int i=0;i<nEndPos.length-1;i++) 9I}-[|`u
{ ,6-:VIHQ
nEndPos = nStartPos[i+1]; gIjh:_ Pz
} 7@D@ucL
nEndPos[nEndPos.length-1] = nFileLength; #"@|f
} *MKO I'
} OCNQvF~
G"h'_7
o,_?^'@
//启动子线程 < jJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OX\A|$GS
for(int i=0;i<nStartPos.length;i++) 3yVMXK
{ 59h)-^!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wB.&}p9p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C{U?0!^
nStartPos,nEndPos,i); &5yVxL:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H{Wu]C<@p
fileSplitterFetch.start(); A~)D[CV
} vSEuk}pk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y*qVc E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #d6)#:uss
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {\81i8b]
nEndPos = " + nFileLength); <0Xf9a8>
// fileSplitterFetch[nPos.length-1].start(); \W~N
E|iQc8gr&
gEy?s8_,
//等待子线程结束 [CQ+p!QZ
//int count = 0; h2G$@8t}I
//是否结束while循环 Q+[n91ey**
boolean breakWhile = false; :tV*7S=)
4K\G16'$v
8Vr%n2M
while(!bStop) AE[b},-[
{ nLXlU*ES
write_nPos(); fdFo#P
Utility.sleep(500); `sn^ysp
breakWhile = true; 4h|c<-`>t
pR=@S>!|
Z?h~{Mg
for(int i=0;i<nStartPos.length;i++) R!}H;[c
{ 6^]+[q}3
if(!fileSplitterFetch.bDownOver) !|^|,"A)
{ b3=rG(0f
breakWhile = false; 0XE4<U
break; eA2@Nkw~)
} %)1y AdG 8
} -|$@-fY;
if(breakWhile) bCRV\myd`
break; ,E S0NA
C5o#i*|
Y]'Z7<U}*E
//count++; Va"0>KX
//if(count>4) <^#,_o,!
// siteStop(); ;U/&I3dzV
} ag [ZW
*/`ki;\A
+r2+X:#~T
System.err.println("文件下载结束！"); ]d$8f
} ^aItoJq
catch(Exception e){e.printStackTrace ();} j()7_
} (ZUHvvL
oB(?_No7
,Vc6Gwm
//获得文件长度 Tp?7_}tRi
public long getFileSize() 6m}Ev95
{ =^M/{51j
int nFileLength = -1; J,'M4O\S
try{ 'j#*6xD
URL url = new URL(siteInfoBean.getSSiteURL()); A8muQuj]~~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); , qMzWa
httpConnection.setRequestProperty("User-Agent","NetFox"); fK>L!=Q
9+Np4i@
]C!gQq2'a
int responseCode=httpConnection.getResponseCode(); X_q\Sg
if(responseCode>=400) q+yQwX{
{ f\|w'
processErrorCode(responseCode); n@<YI
return -2; //-2 represent access is error }|h# \$w
} )1?y 8_B
f z'@_4hg
X8Bd3-B
String sHeader; Ytn9B}%o
KI"#f$2&
Z9v31)q(
for(int i=1;;i++) [_BP)e
{ d[iQ`YW5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g|o,uD
//Utility.log(in.readLine()); x]}^v#
sHeader=httpConnection.getHeaderFieldKey(i); S|Q@:r"
if(sHeader!=null) P_F30x(
{ lU8l}Ndz"
if(sHeader.equals("Content-Length")) }7b%HTF=
{ =x/X:;)>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ; 5*&xz
break; )3cAQ'w
} j`{?OYD
} ">\?&0
else 'g}!
break; <$D`Z-6
} sA+ }TNhq
} N=V==Dbu-
catch(IOException e){e.printStackTrace ();} P\E<9*V
catch(Exception e){e.printStackTrace ();} ]%;:7?5l
9)l$ aBa
hZm"t/aKc
Utility.log(nFileLength); tHU2/V:R
U7?;UCmX
#]\Uk,mhZB
return nFileLength; ^ gdaa>L
} ) ;EBz
'NWfBJm
&h}#HS>l
//保存下载信息（文件指针位置） iDpSj!x/_
private void write_nPos() mVj9,q0
{ bL0yuAwF2
try{ xVw9v6@`h
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2R[:]-b
output.writeInt(nStartPos.length); aS>u,=C
for(int i=0;i<nStartPos.length;i++) K%t*8 4j
{ Kew@&j~
// output.writeLong(nPos); j`EXlc~
output.writeLong(fileSplitterFetch.nStartPos); ))qy;Q,
output.writeLong(fileSplitterFetch.nEndPos); x`mG<Yt
} oh4E7yN
output.close(); p'Y^X
} })'B<vq
catch(IOException e){e.printStackTrace ();} ,V7nzhA2
catch(Exception e){e.printStackTrace ();} Ugr!"Q#M
} %aP!hy
0-B5`=yU
XgZD%7
//读取保存的下载信息（文件指针位置） 4j*
private void read_nPos() u2tfF
{ !hm]fh_j
try{ y#`tgJ:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qv-8)MSr
int nCount = input.readInt(); T;4NRC
nStartPos = new long[nCount]; P?%s #I:
nEndPos = new long[nCount]; F|`Hm
for(int i=0;i<nStartPos.length;i++) xw.A #Zb\_
{ (O\)_#-D
nStartPos = input.readLong(); ~?l | [
nEndPos = input.readLong(); zOJ%}
} )7hqJa-V
input.close(); \<bx[,?
} ."g`3tVK
catch(IOException e){e.printStackTrace ();} &w\{TZ{
catch(Exception e){e.printStackTrace ();} ::`HQ@^
} RTYvS5G
<3nMx^
)Om*@;r(
private void processErrorCode(int nErrorCode) Ao 'l"-
{ -oGdk|Yn
System.err.println("Error Code : " + nErrorCode); )705V|v
} Zj(AJ*r
X;$+,&M"
_YRFet[,m
//停止文件下载 z'Hw
public void siteStop() ;[ZEDF5H
{ Y_liA
bStop = true; xR~hwj
for(int i=0;i<nStartPos.length;i++) ibcRU y0%
fileSplitterFetch.splitterStop(); 0S"mVZ*P
hDDn,uzpd
J4hL_iCQ
} fuW\bo3
} 3<Lx&p~%T
//负责部分文件的抓取 {qk1_yP
**FileSplitterFetch.java sJKI!
*/ aj='b.2)
package NetFox; ,~U>'&M;
!|(-=2`
n9\TO9N
import java.io.*; G/E+L-N#`
import java.net.*; }:zE< bK
p T?}Kc
hE{K=Tz$
public class FileSplitterFetch extends Thread { <)Dj9' _J
X0HZH?V+
hPB9@hT$
String sURL; //File URL Q0sI(V#
long nStartPos; //File Snippet Start Position hgG9m[?K
long nEndPos; //File Snippet End Position : $1?i)
int nThreadID; //Thread's ID "nynl'Ryk
boolean bDownOver = false; //Downing is over 2k~l$p>CN!
boolean bStop = false; //Stop identical sI=xl
FileAccessI fileAccessI = null; //File Access interface AYBns]!
#^0R&) T
VD*6g%p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .^`{1%
{ ~12EQacOT
this.sURL = sURL; 9cbd~mM{
this.nStartPos = nStart; [(i
this.nEndPos = nEnd; ~ah~cwmpS
nThreadID = id; B`)BZ,#p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |d2SIyUc
} dFxIF;C>/
DeVv4D:}@
/8'NG6"H`
public void run() K8|r&`X0
{ c^xIm'eob
while(nStartPos < nEndPos && !bStop) I9A~Ye 5O&
{ P8:dU(nlW
|l^uEtG
7~h<$8Y(T
try{ C^Yb\N}S
URL url = new URL(sURL); ?FZ HrA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QT5TE: D
httpConnection.setRequestProperty("User-Agent","NetFox"); a=_g*OK}D
String sProperty = "bytes="+nStartPos+"-"; ?>:g?.+
httpConnection.setRequestProperty("RANGE",sProperty); QE+g j8
Utility.log(sProperty); e*kpdS~U&
e(&v"}Ef`
Pbn*_/H
InputStream input = httpConnection.getInputStream(); \!X8
//logResponseHead(httpConnection); VBlYvZ;$*
z|J_b"u4
HVCe;eI
byte[] b = new byte[1024]; eb\K "ec"
int nRead; }0*@fO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "S]0
{ 9<?M8_
nStartPos += fileAccessI.write(b,0,nRead); oSKXt}sh
//if(nThreadID == 1) EWhK0Vej=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9rX&uP)j^#
} $99n&t$Y
D/gw .XYL
.hb:s,0mP
Utility.log("Thread " + nThreadID + " is over!"); ?4}h&/
bDownOver = true; xIW3={b3
//nPos = fileAccessI.write (b,0,nRead); wU36sCo
} ~vhE|f
catch(Exception e){e.printStackTrace ();} Ml{,
} p`dU2gV
} 2a)xTA#
s\(k<Ks
|^I0dR/w:
//打印回应的头信息 _"yh.N&
public void logResponseHead(HttpURLConnection con) 76Cl\rV
{ :S83vE81WK
for(int i=1;;i++) Ta0|+IYk<
{ ?!:ha;n
String header=con.getHeaderFieldKey(i); iuW[`ouX
if(header!=null) {z5--TogJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B]wk+8SMY.
Utility.log(header+" : "+con.getHeaderField(header)); 2wg5#i
else |A~jsz6pI
break; I_#kgp
} ^/>(6>S^M
} x+:UN'"r
mDABH@R
#G|RnV%t$~
public void splitterStop() [b%D3-}'
{ N)|yu1S
bStop = true; {\"x3;3!6
} ^7cGq+t
\ZFGw&yN
,kGc]{'W
} `2WFk8) F
"Yv_B3p
.V/Rfq
/* .GXBc
**FileAccess.java =[{i{x|Qz
*//文件访问(定位，写) 33x{CY15
package NetFox; bHYy}weZ
import java.io.*; X/!o\yyT
6 7.+ .2
8 +/rlHp
public class FileAccessI implements Serializable{ [A~xy'T
]NY~2jmX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .t-4o<7 3
RandomAccessFile oSavedFile; VBGuC c/
long nPos; BLdvyVFx
]i)c{y
}O5i/#.lR
public FileAccessI() throws IOException PI)+Jr%L
{ -H@:*
this("",0); B\=8_z
} P>C~ i:4n
.Iw AK/QS
drP=A~?&:
public FileAccessI(String sName,long nPos) throws IOException %QGC8Tz
{ m+R[#GE8#
oSavedFile = new RandomAccessFile(sName,"rw"); .Wj;%|
this.nPos = nPos; B$ PP&/
oSavedFile.seek(nPos); "@@u3`#
} &< `NT D
?0?#U0(;u
QB uMJm
public synchronized int write(byte[] b,int nStart,int nLen) e0zq1XcZ
{ wLH>:yKUU
int n = -1; ~O0 $Suv
try{ y/{fX(aV
oSavedFile.write(b,nStart,nLen); cWaSn7p!X
n = nLen; I\{ 1u
} Y@vTaE^w3
catch(IOException e) QzVnL U)
{ a=9:[
e.printStackTrace (); W?R6ZAn
} 4<Utmr
w^|*m/h|@u
VcO0sa f`
return n; 61>.vT8P
} )e+>w=t
^z IW+:
R6.hA_ih
} ci.+pF
$?Hu#Kn,(
4#xDgxg\f
/* T|eu
**SiteInfoBean.java 9igiZmM
*/ 4y?n [/M/
package NetFox; u(>^3PJ+
L-WT]&n_
)._;~z!
public class SiteInfoBean { Fn;SF4KOm
Oi'5ytsES
_[c0)2h
private String sSiteURL; //Site's URL =JEv,ZGT3
private String sFilePath; //Saved File's Path 6:[dj*KGmT
private String sFileName; //Saved File's Name VU(v3^1"
private int nSplitter; //Count of Splited Downloading File >V?eog%~
-`kW&I0
iDp)FQ$
public SiteInfoBean() D9=KXo^
{//nSplitter的缺省值为5 JN-y)L/>
//default value of nSplitter is 5 (AaoCa[
this("","","",5); IqaT?+O\?r
} {yHCXFWlS
XK3tgaH
XkE`U5.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !}#8)?p
{ qs6]-
sSiteURL= sURL; 3tIVXtUCUk
sFilePath = sPath; 30#s aGV
sFileName = sName; _?m(V=z>
this.nSplitter = nSpiltter; }%ojw |
fP 1[[3i
[I,Z2G,Jb
} eCU:Q
#4Rx]zW^%
7Jyy z,!5
public String getSSiteURL() &ZlVWK~v
{ r[`9uVT/
return sSiteURL; ) <[XtK
} DZ'P@f)]
~?Qe?hB
T= y}y
public void setSSiteURL(String value) O~#!l"0 L+
{ 1y@i}<9F
sSiteURL = value; _lJ!R:*
} r"gJX
wtQ++l%{G
WTQ\PANAaR
public String getSFilePath() jP$a_hW
{ B:yGS*.tu
return sFilePath; In"ZIKaC
} hc(#{]].
Uou1mZz/
XSwl Tg
public void setSFilePath(String value) 7?!d^$B
{ #_ ;lf1x!
sFilePath = value; (?1y4M
} 4<w.8rR:A
{=9,n\85#
`t>l:<@%
public String getSFileName() YlJ@XpKM
{ CAig]=2'
return sFileName; j;+b0(53
} aB2FC$z
>W=,j)MA
[x=s(:qy
public void setSFileName(String value) g]l''7G
{ *k7+/bU~~
sFileName = value; <Uk}o8E
} n:I,PS0H<
B-Ll{k^
X&.ArXn*
public int getNSplitter() RtkEGxw*^
{ ?8H8O %Z8
return nSplitter; 8?B!2
} kf\PioD8
niMsQ
n$A9_cHF7
public void setNSplitter(int nCount) ^lnK$i
{ .Bl\Z
nSplitter = nCount; hIYNhZv
} \}yc`7T:L0
} nK1Slg#U
_b pP50Cu
y>8sZuH0
/* #ZUI)9My@
**Utility.java H`XUJh
*/ 7y'RFD9@{
package NetFox; NR$3%0 nC6
W 8<&gh+
Co9^OF-k
public class Utility { ;>%r9pz ~
rK8lBy:<
XW2b|%T
public Utility() |"q5sym8Y_
{ {LI=:xJJv
rm'SOJVA
]6k\)#%2
} ]? c B:}
Ye%~I`@?
//线程睡眠 ydEoC$?0
public static void sleep(int nSecond) xWH.^o,"
{ >>4qJ%bL
try{ +)AG*
Thread.sleep(nSecond); B9_X;c
} #H&|*lr
catch(Exception e) xJpA0_xfG
{ ?d\N(s9F
e.printStackTrace (); `{@8Vsmy:
} ''cInTCr
} d"1]4.c
3oj' ytxN
//日志 J/`<!$<c
public static void log(String sMsg) YsC>i`n9
{ ,C\i^>=
System.err.println(sMsg); (!u~CZ;
} ^cC,.Fdw
^'MT0j
93>jr<A
public static void log(int sMsg) *g"Nq+i@
{ LtO!umM
System.err.println(sMsg); +yG~T
} tn\yI!a
} /obfw^
a@K%06A;'
JJ-( Sl
/* UkwP
**TestMethod.java *}qWj_RT
*/ sPpH*,(
package NetFox; 98c(<
=`oCLsz=
)bL'[h
public class TestMethod { 0@0w+&*"@
4&lv6`G `
D(op)]8
public TestMethod() C\3rJy(VJ
{ ///xx/weblogic60b2_win.exe FW;?s+Uyx
try{ 'T;P;:!\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _IHV7*u{;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :1Xz4wkWS*
SiteFileFetch fileFetch = new SiteFileFetch(bean); aH(J,XY
fileFetch.start(); ,Q$q=E;X
} GTPHVp&y
catch(Exception e){e.printStackTrace ();} un"Gozmt5
& bm 1Fz
bTNgjc
} (62"8iD6
+zN-!5x
IJp-BTO{V
public static void main(String[] args) dh\'<|\K
{ G^|:N[>B
new TestMethod(); .[KrlfI
} F@jZ ho
} VR8-&N
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