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)); =X9fn
} m/"([Y_
for(int i=0;i<nEndPos.length-1;i++) -y>~ :.
{ u=tp80_
nEndPos = nStartPos[i+1]; aIDv~#l
} sF>O=F-7
nEndPos[nEndPos.length-1] = nFileLength; w{t]^w:
} mFeR~Bi>!
} zdw* ?C
5KP\#Y
OADW;fj
//启动子线程 ':3[?d1Es
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G<* Iw>ep
for(int i=0;i<nStartPos.length;i++) C1+f\A|9FP
{ .9N7`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >bd@2au9!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~sZ$`t
nStartPos,nEndPos,i); y+Hz(}4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D(OJr5Gg
fileSplitterFetch.start(); 1$+8wDVwad
} R$+p4@?S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }LeS3\+UHl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :t<S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Bgn%d4W;G
nEndPos = " + nFileLength); lXZ*Pb<j
// fileSplitterFetch[nPos.length-1].start(); ^Ua6.RH8
4$WR8
?O3d Sxi
//等待子线程结束 `lQ;M?D
//int count = 0; \Z,{De%
//是否结束while循环 <&#MX
boolean breakWhile = false; k'k}/Hxub
Rj4C-X4=
M9""(`U
while(!bStop) T9XUNR{&
{ H\qZu%F'
write_nPos(); 9K#3JyW*
Utility.sleep(500); oR,6esA+6n
breakWhile = true; TQmrL
M9afg$;.xe
DIw_"$'At
for(int i=0;i<nStartPos.length;i++) nmts% u
{ %<x!mE x
if(!fileSplitterFetch.bDownOver) %1$#fxR
{ P%H Dz
breakWhile = false; Fe4>G8uuwn
break; Mm(#N/
} %1:caa@_p
} UfPHV%Wd
if(breakWhile) 1]eRragm"
break; k|\M(Z*(P
A*wf: mW0c
&^#u=w?^x
//count++; RgA"`p7{
//if(count>4) 8Y.9%@
// siteStop(); $XTtDUP@
} jz![#-G
WubV?NX;EF
KN[;z2i
System.err.println("文件下载结束！"); !yxqOT-
} ZZ!">AN`^
catch(Exception e){e.printStackTrace ();} 8I*N
} *m^\&
&b`W<PAc?4
D4,>g )B
//获得文件长度 #CaPj:>[
public long getFileSize() :)D7_[i
{ DJ@n$G`^^
int nFileLength = -1; q[C?1Kc.z
try{ 6[4VbIBSI
URL url = new URL(siteInfoBean.getSSiteURL()); #XA`n@2Uoo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g27'il
httpConnection.setRequestProperty("User-Agent","NetFox"); Qj;{Z*l%+
{x.0Yh7
nvT@'y+
int responseCode=httpConnection.getResponseCode(); )t"-#$,@
if(responseCode>=400) 1kKfFpN
{ g+4y^x(X@1
processErrorCode(responseCode); P3: t 4^
return -2; //-2 represent access is error Hj|&P/jY]*
} ?KOw~-u
jT=|!,Pn
l"%80"zO
String sHeader; 3,Yr%`/5'
Uu5(/vw]
eF22 ~P
for(int i=1;;i++) j&oRj6;Ha+
{ #}FUau$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V(F9=r<X
//Utility.log(in.readLine()); _OTVQo Ap
sHeader=httpConnection.getHeaderFieldKey(i); U]~@_j
if(sHeader!=null) Tk4>Jb
{ |DJ8 "T]E
if(sHeader.equals("Content-Length")) Leb|YX
{ ro\oL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~cCMLK em
break; @)uV Fw"\
} twq~.:<o
} jh)@3c
else "H).2{3(x
break; fDf[:A,8
} DJL.P6-W
} <cp9+P <
catch(IOException e){e.printStackTrace ();} 'v~'NWfd
catch(Exception e){e.printStackTrace ();} PnA{@n\
JRo/ HY+
`.@sux!lu
Utility.log(nFileLength); 0DmA3
xBVOIc[4(
BZ?Ck[E]Z
return nFileLength; |cf-S8pwY
} `a4&_`E,p
5b7(^T^K
kFWwz^x
//保存下载信息（文件指针位置） 'UIFP#GtFO
private void write_nPos() *G> x07S)~
{ MhD'
try{ fw jo?
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,UMr_ e{|
output.writeInt(nStartPos.length); igfQ,LWe!
for(int i=0;i<nStartPos.length;i++) |(z{)yWbC[
{ _TOWqV^
// output.writeLong(nPos); J8alqs7
output.writeLong(fileSplitterFetch.nStartPos); + U5Q/g
output.writeLong(fileSplitterFetch.nEndPos); wW@e#:
} 5]N0p,f
output.close(); B2ln8NF#Q
} MO8}i?u=z
catch(IOException e){e.printStackTrace ();} FOsd{Fw
catch(Exception e){e.printStackTrace ();} U`ttT5;
} !H\oQv-I
sv%X8
hpF_@n
//读取保存的下载信息（文件指针位置） FfJp::|ddr
private void read_nPos() Qh1pX}X
{ FBNLszT{L
try{ 9{jMO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +Y sGH~jX
int nCount = input.readInt(); #&}- q RA
nStartPos = new long[nCount]; CUI3^;&S
nEndPos = new long[nCount]; m4hkV>$d
for(int i=0;i<nStartPos.length;i++) @kFZN6
{ [Y .8C$0
nStartPos = input.readLong(); K$,Zg
nEndPos = input.readLong(); 5wx_ol}2
} JY#vq'dl|
input.close(); X3:z=X&Zd
} _-_iw&F
catch(IOException e){e.printStackTrace ();} $*#^C;7O
catch(Exception e){e.printStackTrace ();} )4 4Y`v
} *OG<+#*\_?
NZB*;U~t
]!B0= XP
private void processErrorCode(int nErrorCode) !E 5FU *s
{ 4^L;]v,|7
System.err.println("Error Code : " + nErrorCode); [Km{6L&
} Dt: Q$
pux IJ
rFg$7
//停止文件下载 o72r `2
public void siteStop() -qIi.]/f"9
{ f CU]
bStop = true; *#Cx-J
for(int i=0;i<nStartPos.length;i++) oe|#!SM(
fileSplitterFetch.splitterStop(); `q*[fd1u.
=OHX5:Z
5~[7|Y
} _nMd
} I@cw=_EQL
//负责部分文件的抓取 .uJ J<
**FileSplitterFetch.java D;pI!S<#
*/ <a6pjx>y
package NetFox; d?*]/ZiR
PEf yHf7`
}HoCfiE=X
import java.io.*; e'3V4iU]
import java.net.*; ="voJgvw
Tz @=N]D
J?8Mo=UZz
public class FileSplitterFetch extends Thread { BIWe Hx
d+q],\"R
duY?LJ@g
String sURL; //File URL i/9iM\2
long nStartPos; //File Snippet Start Position kW/G=_6
long nEndPos; //File Snippet End Position RpivO,
int nThreadID; //Thread's ID lx:$EJ
boolean bDownOver = false; //Downing is over *:n~j9V-
boolean bStop = false; //Stop identical {rKC4:
FileAccessI fileAccessI = null; //File Access interface h3?>jE=H
SOOVUMj
u<edO+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &u>dKf)5
{ 3a?-UT!
this.sURL = sURL; QHR,p/p
this.nStartPos = nStart; d0:LJ'<Q
this.nEndPos = nEnd; !O_G%+>5W
nThreadID = id; U]cXE1c>F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $tmdE)"&
} 7iP+!e}$.
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h9)S&Sk{s
public void run() ybBmg'198
{ {18hzhs
while(nStartPos < nEndPos && !bStop) tMxde+$y
{ ZxF`i>/h
;4rhhh&
@_+aX.,
try{ q+L'h8
URL url = new URL(sURL); k1wIb']m]z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,s[%,ep`
httpConnection.setRequestProperty("User-Agent","NetFox"); >rd#,r
String sProperty = "bytes="+nStartPos+"-"; /$c87\
httpConnection.setRequestProperty("RANGE",sProperty); ix!xLm9\
Utility.log(sProperty); RA0;f'"`
oYqHl1cs
B>53+GyMV
InputStream input = httpConnection.getInputStream(); m+(Cl#+
//logResponseHead(httpConnection); uM2@&)u
~lj[> |\Oj
v;]rFc#Px[
byte[] b = new byte[1024]; $mQ0w~:@
int nRead; sA2-3V<t8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V 0Bl6
{ &hYgu3O
nStartPos += fileAccessI.write(b,0,nRead); P[3i!"O>
//if(nThreadID == 1) =~1EpZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r:H]`Uo'r
} .&^p@A~
>#]A2,
bU=Utniq
Utility.log("Thread " + nThreadID + " is over!"); !d72f8@9
bDownOver = true; enQ*uMKd^
//nPos = fileAccessI.write (b,0,nRead); =QqH`.3
} &A0OYV3i.
catch(Exception e){e.printStackTrace ();} CHgip&(.F
} U{2xgNJ
} i~';1 .g
f'*-<sSr
!&:=sA
//打印回应的头信息 m}"Hm(,6
public void logResponseHead(HttpURLConnection con) eEZgG=s
{ f$lb.fy5
for(int i=1;;i++) ?bZH Aed
{ ?NMk|+
String header=con.getHeaderFieldKey(i); 0m_yW$w
if(header!=null) )3h\QE!z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sYKx3[V/
Utility.log(header+" : "+con.getHeaderField(header)); AQ,lLn+
else X*2W4udF
break; Rc1j^S;>
} $+4DpqJ
} -UhpPw6
QH'*MY
9j2t|D4uT
public void splitterStop() @c|=onx5
{ 2) X#&IE
bStop = true; .6wPpLG?{
} \g}]u(zg%
U6.aoqb%
&4?&tGi
} ]C \+b<
)?rq8VO
B>2R-pa4~
/* *'Yy@T8M
**FileAccess.java F^%w%E\
*//文件访问(定位，写) _b&|0j:Ud
package NetFox; $)M3fZ$#
import java.io.*; )iN;1>
f}-'67*Y
B;9,Qbb
public class FileAccessI implements Serializable{ NUsxMhP
;.}L#'0j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +x%u?ZR
RandomAccessFile oSavedFile; &_L@hsm
long nPos; Ju+3}
|*bUcS<S
tq L(H25z
public FileAccessI() throws IOException "to!&@I| 4
{ !*#9b
this("",0); ^'X I%fEf
} MLDzWZ~}ef
=KPmZ,/w
w"R<8e=
public FileAccessI(String sName,long nPos) throws IOException %-n)L
{ Xh"9Bcjf
oSavedFile = new RandomAccessFile(sName,"rw"); o#qdgZ
this.nPos = nPos; <F9-$_m
oSavedFile.seek(nPos); x{R440"
} "| nXR8t.r
Wdd}y`lS
f{9+,z
public synchronized int write(byte[] b,int nStart,int nLen) #T)Gkc"{
{ Wb}-H-O
int n = -1; T@W:@,34
try{ yT^2;/Z
oSavedFile.write(b,nStart,nLen); #49l\>1z
n = nLen; +#IUn
} $LXa]
catch(IOException e) XCM!8x?K
{ Jm4uj&}3
e.printStackTrace (); Y'/6T]a
} \[G'cE
E1QJ^]MG.
SdH=1zBc
return n; +5y^c|L0
} ";/]rwHa)
}c,b]!:
TEV DES
} #0AyC.\
)\+Imn
fJ}e
/* ucl001EK
**SiteInfoBean.java x;vfmgty
*/ $0Y`>3
package NetFox; Z %pc"
vobC/m
%FjUtB
public class SiteInfoBean { *BKD5EwS
{K|?i9K
N'b GL%
private String sSiteURL; //Site's URL 1H-Wk
private String sFilePath; //Saved File's Path hDXTC_^s
private String sFileName; //Saved File's Name *;Kp"j
private int nSplitter; //Count of Splited Downloading File k^7!iOK2
W?Z>g"
ILuQ.VhBVN
public SiteInfoBean() (;fJXgj.
{//nSplitter的缺省值为5 Pe:)zt0
//default value of nSplitter is 5 !8@yi"n
this("","","",5); P>_O :xD
} ANm@$xO*
u|<?mA!
tw4,gW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _9BL7W $;
{ czRBuo+k+
sSiteURL= sURL; 9B~&d(Bm
sFilePath = sPath; \S h/<z
sFileName = sName; Tg)F.):
this.nSplitter = nSpiltter; 2|k$Vfz
{\>4)TA
-VohU-6 |
} YdD; Qx#O
$:u*)&"t|
YKe&Ph.
public String getSSiteURL() KR.;X3S}
{ a 4?A 5
return sSiteURL; kF1$
} SS/vw%
SkDr4kds
@!iS`u
public void setSSiteURL(String value) [#KY.n
{ Jxl'!8t
sSiteURL = value; WsbVO|C
} u(zgKoF9A
<0';2yP"
nf pO
public String getSFilePath() ,!> ~izB
{ 4Uny.C]
return sFilePath; Yo%U{/e
} 7~2_'YX>:
th{J;a
U)dcemQY
public void setSFilePath(String value) Lv+{@)
{ + }"+
sFilePath = value; 2*snMA
} V_3oAu54s{
[FhYQI
+c8`N'~
public String getSFileName() |k~AGc
{ [>NMuwtG
return sFileName; %Za}q]?
} IYn`&jS{
4`?PtRX
5=;cN9M@
public void setSFileName(String value) |ts0j/A]Pi
{ ]{=y8]7
sFileName = value; -gGw_w?)(
} 2>jk@~Z1:u
+xuv+mo
X&[Zk5DU*
public int getNSplitter() /J^dzvH
{ 23CvfP
return nSplitter; @*rMMy 4
} pnu?=.O
_HM?p(H@
dg.1{6HM
public void setNSplitter(int nCount) R\cx-h*
{ pbKmFweq
nSplitter = nCount; +1#oVl!
} W(s5mX,Kv
} Ep-bx&w+
FW[|Zq;}
~j{c9EDT|
/* zsQ]U!*rD
**Utility.java L%H\|>k`
*/ MO0t
package NetFox; ((Av3{05H&
ta95]|z"j
_L=-z*a\
public class Utility { >4@w|7lS
g]j&F65D
~AWn 1vFc
public Utility() 1Z0Qkd(
{ << =cZ.HP
9O &]!ga
1E$\&*(
} vcW(?4e
In4VS:dD
//线程睡眠 7zzFM
public static void sleep(int nSecond) pcv\|)&}
{ b7hICO-w
try{ pIR_2Eq
Thread.sleep(nSecond); 2r2:
} %V;*E]
catch(Exception e) !>'A2V~F
{ 8nZ_.
e.printStackTrace (); nt"\FZ*;3
} Fr50hrtkU
} mfj%-)l9
m>Z3p7!N}
//日志 O-.G("
public static void log(String sMsg) )09ltr0@"
{ ?h1g$SBxk
System.err.println(sMsg); w3i74C&0
} h>>~Bi
-5v{p
kJ%a;p`O
public static void log(int sMsg) 4,@jSr|I3i
{ pj7al;
System.err.println(sMsg); +PBl3
} p+ReQ.5|
} HJb^l 4Q
!d 4DTo
Tcv/EST
/* {li Q&AZ
**TestMethod.java AaU!a
*/ |L89yjhWBs
package NetFox; pFs/ipZX^*
,2 xD>+=
t"9r`0>
public class TestMethod { mph9/ %]S
s/t,6-~EH
zk1]?
public TestMethod() ZUj1vf6I
{ ///xx/weblogic60b2_win.exe \0Xq&CG=E
try{ #'@@P6o5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2f{p$YIt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <k3KCt
SiteFileFetch fileFetch = new SiteFileFetch(bean); >;"%Db
fileFetch.start(); ;TC]<N.YJT
} [ Y{
catch(Exception e){e.printStackTrace ();} hVyeHbx
``]NB=N}{1
ltrti.&
} w_"-rGV
uzb|yV'B
} PL{i
public static void main(String[] args) [xb'73
{ t%,:L.?J#
new TestMethod(); yD$d^/:
} N,8.W"fV
} fHwS12SB
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