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)); To{G#QEgG
} 4\SBf\ c
for(int i=0;i<nEndPos.length-1;i++) 5J\|gZQF
{ !^bB/e
nEndPos = nStartPos[i+1]; )bXx9,VL
} bo!]
nEndPos[nEndPos.length-1] = nFileLength; 5QFXj)hR+4
} E(3+o\w
} \R>5F\ 0
o7a6 )2JK
q|$>H6H4b
//启动子线程 !0csNg!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q'Kik5I
for(int i=0;i<nStartPos.length;i++) &J/4J
{ H^PqYLjN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L8w76|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iraRB~
nStartPos,nEndPos,i); ~eV!!38 J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )\D40,p
fileSplitterFetch.start(); &;h~JS=
} BXK::M+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !k= 0X\5L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V3A>Ag+^~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", JGO$4DK-1
nEndPos = " + nFileLength); @FdCbPl$
// fileSplitterFetch[nPos.length-1].start(); q>|[JJ*6_N
:OQ:@Yk
YK?*7
//等待子线程结束 Gz[ymj)5
//int count = 0; q4.dLU,1
//是否结束while循环 FH`'1iVH
boolean breakWhile = false; o&XMgY~
Neo^C_[vN
[ 4Y `O
while(!bStop) D"x$^6`c}
{ nvs}r%1'5
write_nPos(); 0nD=|W\@{
Utility.sleep(500); X#kjt)W
breakWhile = true; oLqbR?
*e-ptgO
Q{l*62Bx
for(int i=0;i<nStartPos.length;i++) Z?~d']XD
{ R0hctT1j
if(!fileSplitterFetch.bDownOver) 3b?OW7H
{ |DFvZ6}
breakWhile = false; ]Ic?:lKN
break; -wfRR>)d
} 3?*M{Y|
} d(DX(xg
if(breakWhile) >: W-C{%
break; Vh#Mp!
/\-2l+y>J
7Js>!KR
//count++; NO+ 55n
//if(count>4) N7~)qqb
// siteStop(); .W@(nQ-<
} "'F;lzq
mP)3cc5T
KYkS6|A
System.err.println("文件下载结束！"); X@yr$3vC
} da00p-U
catch(Exception e){e.printStackTrace ();} 1~R$$P11[9
} @Ge>i5q
^)hAVf~E
4j=<p@
//获得文件长度 ;Y@!:p-H
public long getFileSize() $/, BJ/9
{ MS st
int nFileLength = -1; %su}Ru
try{ O/DAf|X|
URL url = new URL(siteInfoBean.getSSiteURL()); Y3P.|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `\/toddUh[
httpConnection.setRequestProperty("User-Agent","NetFox"); %K%^ ]{
$c@w$2
{ywXz|TP
int responseCode=httpConnection.getResponseCode(); [:nx);\
if(responseCode>=400) %_b^!FR
{ UK"}}nO@e
processErrorCode(responseCode); 2<[eD`u
return -2; //-2 represent access is error d`9W
} aJ5H3X}Y
X!7VyE+n
}xkLD!
String sHeader; CYPazOfj
<2)s<S.;
wovmy{K
for(int i=1;;i++) ^])e[RN7?n
{ ]DC;+;8Jc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XOysgX0g
//Utility.log(in.readLine()); 861i3OXVE>
sHeader=httpConnection.getHeaderFieldKey(i); 0^GbpSW{
if(sHeader!=null) -ajM5S=d*
{ XJx,9trH
if(sHeader.equals("Content-Length")) ~lzdbX
{ KqM!!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .O5LI35,
break; \4h>2y
} *2JH_Cj`
} tmO;:n<N
else kAZC"qM%i
break; CY*ngi&
} Xw7{R
} xn(+G$m
catch(IOException e){e.printStackTrace ();} X}oj_zsy;^
catch(Exception e){e.printStackTrace ();} Qs|OG
uy/y wm/?=
T)WZ_bR
Utility.log(nFileLength); X^zYQ6t
nK+lE0
az0cS*@
return nFileLength; &EAk z
} KxO/]
IFiTTIlT0
9pWi.J
//保存下载信息（文件指针位置） z^4KU\/JK
private void write_nPos() [RAj3Fr0
{ +yzcx3<
try{ jja{*PZ6H
output = new DataOutputStream(new FileOutputStream(tmpFile)); oi7 3YOB
output.writeInt(nStartPos.length); j((hqJr
for(int i=0;i<nStartPos.length;i++) m)s xotgXf
{ ^9&b+u=X
// output.writeLong(nPos); wA?@v|,dZ
output.writeLong(fileSplitterFetch.nStartPos); - #3{{
output.writeLong(fileSplitterFetch.nEndPos); TE3*ktB{N
} 2q)T y9
output.close(); yh S#&)O
} :3JCvrq
catch(IOException e){e.printStackTrace ();} |q3f]T&+>{
catch(Exception e){e.printStackTrace ();} xTW3UY
} G49Ng|qn
A#<vG1
"$GK.MP5
//读取保存的下载信息（文件指针位置） |<sf:#YzY&
private void read_nPos() vFTXTbt'h
{ \CcmePTN#x
try{ 2=>*O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XZ}de%U1
int nCount = input.readInt(); m7JPH7P@BM
nStartPos = new long[nCount]; 5v"Y\k+1
nEndPos = new long[nCount]; AlO,o[0
for(int i=0;i<nStartPos.length;i++) ^w>&?A'!
{ :]'q#$!
nStartPos = input.readLong(); $4=Ne3y
nEndPos = input.readLong(); aSUsyOe
} VsEGX@;tO
input.close(); ~%`EeJwT
} cn$5:%IK
catch(IOException e){e.printStackTrace ();} }d_<\
catch(Exception e){e.printStackTrace ();} z;J
} Y+FP
h-7A9:
^%;"[r
private void processErrorCode(int nErrorCode) u=%y
{ @8|Gh]\P
System.err.println("Error Code : " + nErrorCode); 2xDQ:=ec
} h0|[etaf
A^-iHm
`aIG;@Z
//停止文件下载 %*6RzJO6
public void siteStop() @: Z#E[N H
{ Vn'?3Eb<
bStop = true; F=srkw:*.
for(int i=0;i<nStartPos.length;i++) VUp. j
fileSplitterFetch.splitterStop(); GWgd8x*V
z=qWJQ
3Y`>6A=
} gt/!~f0r
} 6J\q`q(W(
//负责部分文件的抓取 %l,4=TQ[m
**FileSplitterFetch.java `$at9
*/ *6XRjq^#
package NetFox; Wm(:P
_%%yV
>60"p~t
import java.io.*; 45)D+
import java.net.*; PK+ x6]x
3w6&&R9
6}ftBmv
public class FileSplitterFetch extends Thread { UT4f (Xo
S6GMUaR
@ u+|=x];
String sURL; //File URL t@)my[!
long nStartPos; //File Snippet Start Position 2 5Q+1
long nEndPos; //File Snippet End Position Pu..NPl+
int nThreadID; //Thread's ID 088C|
boolean bDownOver = false; //Downing is over i j/o;_
boolean bStop = false; //Stop identical Jn*Nao_)
FileAccessI fileAccessI = null; //File Access interface !lhFKb;
&\k?xN
,E?4f @|X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y%g "Y
{ #EG?9T
this.sURL = sURL; 4[1k\
this.nStartPos = nStart; gLD{1-v
this.nEndPos = nEnd; A#35]V06
nThreadID = id; -2 xE#r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5mavcle{4r
} c|lU(Tf
j=W@P-
hM>*a!)U
public void run() O:JPJ"!
{ dF e4K"
while(nStartPos < nEndPos && !bStop) o8{<qn|
{ BC({ EE~R)
uoCGSXsi
zh%qS~8Yv
try{ JT)k
URL url = new URL(sURL); g\&2s,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E0YU[([G
httpConnection.setRequestProperty("User-Agent","NetFox"); 43L|QFo
String sProperty = "bytes="+nStartPos+"-"; 6e#wR/
httpConnection.setRequestProperty("RANGE",sProperty); -NzTqLBn
Utility.log(sProperty); 2r;GcjezH
;Iq5|rzDn
Dx3%KS
InputStream input = httpConnection.getInputStream(); l3p3tT3+
//logResponseHead(httpConnection); .S!-e$EJ
%ek"!A
.&iN(Bd
byte[] b = new byte[1024]; =/9<(Tt%m
int nRead; k 4B_W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dIJGB==
{ H&bh<KPMh
nStartPos += fileAccessI.write(b,0,nRead); ao$):,2*
//if(nThreadID == 1) J`<f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }9CrFTbx;
} tS<h8g_
s}(X]Gx1
e+@xsn3
Utility.log("Thread " + nThreadID + " is over!"); DA=1KaJ.
bDownOver = true; J3=BE2L
//nPos = fileAccessI.write (b,0,nRead); $<OhGk-
} e$|VG* d
catch(Exception e){e.printStackTrace ();} s;1e0n
} tD-gc''H
} "8HE^Po/pn
gS$A
J8;Okzb!L
//打印回应的头信息 [Oy >R
public void logResponseHead(HttpURLConnection con) fxtxu?A>
{ t`u!]DHv
for(int i=1;;i++) M#a&\cqC
{ :JlDi>B
String header=con.getHeaderFieldKey(i); &{W^W8,%
if(header!=null) rk,p!}FqL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >a=d;
Utility.log(header+" : "+con.getHeaderField(header)); +< KNY
else 5pJ*1pfeo
break; }bMWTT
} Df@/cT
} m r4b
<xlm K(
|C D}<r(N
public void splitterStop() r)b<{u=]
{ 3eKQ<$w
bStop = true; ^~l $&~
} }-p,iTm
Km*<Kfcz
><Uk*mwL
} io4aYB\
,4Y*:JU4
'qy#)F
/* 'msmXX@q
**FileAccess.java uvB1VV4
*//文件访问(定位，写) SRCOs1(EK9
package NetFox; 8i:[:Z
import java.io.*; >Z\BfH
5@P-g
gj+3y9
public class FileAccessI implements Serializable{ B*,?C]0{
)(bxpW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mP-2s;q
RandomAccessFile oSavedFile; Zq*eX\#C
long nPos; s, XM9h>P4
HC7JMj
p4>,Fwy2
public FileAccessI() throws IOException &iSD/W
{ ( v@jc8y
this("",0); m;/i<:`
} NHiq^ojk
onl>54M^
qI2'u%
public FileAccessI(String sName,long nPos) throws IOException 7>-yaL{
{ g-@h>$< 1
oSavedFile = new RandomAccessFile(sName,"rw"); J_ J+cRwq
this.nPos = nPos; >;nS8{2o
oSavedFile.seek(nPos); )}-$A-p#
} i&Kz*,pt
C5n?0I9
'[Gm8K5
public synchronized int write(byte[] b,int nStart,int nLen) /cY^]VLe
{ vv/J 5#^,\
int n = -1; (ZPXdr
try{ CV^c",b_
oSavedFile.write(b,nStart,nLen); n`L,]dco
n = nLen; J70D+
} ;V.vfar
catch(IOException e) oJY[{-qW
{ ("Dv>&w9
e.printStackTrace (); Sz0+<F#5
} .ECHxDp
nyhMnp#<
Q$=*aUU%G
return n; g%\L&}Jd
} ,{{SI
rsF:4G"%
OVswt
} -G b-^G
fk3kbdI
\G;CQV#{9
/* ^7u#30,}3~
**SiteInfoBean.java Lko`F$5X
*/ 8tQ|-l*
package NetFox; n33kb/q*
o3h-=t
|E|6=%^
public class SiteInfoBean { Q_4Zb
+d39f-[
PXEKV0y
private String sSiteURL; //Site's URL h<3p8eB
private String sFilePath; //Saved File's Path B\_[R'Pf&
private String sFileName; //Saved File's Name _#'9kx|)
private int nSplitter; //Count of Splited Downloading File ,w`~K:b.
y\[r(4h
)HVcG0H1
public SiteInfoBean() :ba/W&-d
{//nSplitter的缺省值为5 ./w{L"E
//default value of nSplitter is 5 ;KcFy@ 6q5
this("","","",5); lbkLyp2
} Q}P-$X+/ n
\P?A7vuhLs
"ahvNx;x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v0 ];W|
{ D4Sh9:\
sSiteURL= sURL; "!q?P" @C
sFilePath = sPath; \ 4gXY$`@
sFileName = sName; gq4 . d
this.nSplitter = nSpiltter; 7rIlTrG
Z"tQpJg
]!Zty[
} S< x:t(
POGw`:)A
.~`Y)PON
public String getSSiteURL() abWl ut
{ =kFuJ x)f
return sSiteURL; +X^4; &
} ;[Tyt[
#&siHHs \
yNva1I
public void setSSiteURL(String value) ~3=2=Uf
{ ~ hm`uP
sSiteURL = value; =Ahw%`/&}]
} [hU=mS8=^
O5-;I,)H
e@j8T gI)
public String getSFilePath() sXB+s
{ O5;-Om
return sFilePath; ~zyQ('
} 0w3b~RJ
Ae3,^
K-4tdC3
public void setSFilePath(String value) }m_t$aaUc1
{ j9xXKa5
sFilePath = value; fn1pa@P
} WQt5#m; W
!}q."%%J_%
F=i!d,S
public String getSFileName() z%};X$V`J
{ 2U%qCfh6|
return sFileName; BKA]G)G7u!
} p&5S|![\
z!CD6W1n
Jpx'W
public void setSFileName(String value) mP!N<K
{ 0N VI+Z$
sFileName = value; +/q0Y`v
} 0yTQ{'Cc
.Cr1,Po
D rTM$)
public int getNSplitter() K:w]>a
{ ('d{t:TsY
return nSplitter; C1 {ZW~"YI
} RbAt3k;y
<gcmsiB|
BD'NuI
public void setNSplitter(int nCount) .e$%[)D
{ sR!+d:LJ4
nSplitter = nCount; s3< F
} T6=-hA^A
} %EoH4LzT
3{pk5_c
^ LbGH<#J
/* ~04[KG
**Utility.java M.[wKGX(
*/ +2y&B,L_Wh
package NetFox; Nt,~b^9
TkT-$=i
C8MWIX}
public class Utility { i[_|%'p
i;]CL[#2e`
6eo4#/+%
public Utility() Bb_Q_<DTs
{ ' =}pxyg
l0#4Fma
%^!aB
} ucM.Ro=@
`EVg'?pl
//线程睡眠 G"C;A`6
public static void sleep(int nSecond) kp; &cQu!
{ @<5Tba>SC
try{ J{!'f| J
Thread.sleep(nSecond); >KHp-|0pv
} /f]/8b g>
catch(Exception e) HTN$ >QTI
{ [DhEh@
e.printStackTrace (); ifHU|0_=
} g8v[)o(qd
} raF] k0{
QQq/5r4O`q
//日志 QES^^PQe:
public static void log(String sMsg) ~4+8p9f
{ V" }*"P-%
System.err.println(sMsg); QE*%HR'
} _'lmCj8L
feN!_-
g@(4ujOT
public static void log(int sMsg) ,\}k~ U99
{ [%?hCc
System.err.println(sMsg); 369Zu4|u
} l_b_-p
} e3pnk =u
`Jqf**t
1~L\s}|2d
/* d QDLI
**TestMethod.java SlN"(nq
*/ sy=dY@W^
package NetFox; S%{lJYwXt
{yU0D*#6
u`+'lBE,
public class TestMethod { Fq4lXlSB
GqMB^Ad
?ff [$ab
public TestMethod() Ta^.$O=F
{ ///xx/weblogic60b2_win.exe }EP|Mb
try{ nAvs~J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hWm0$v1p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tStJ2-5*t
SiteFileFetch fileFetch = new SiteFileFetch(bean); V4Qz*z%
fileFetch.start(); :U8k|,~f
} $-e=tWkgv
catch(Exception e){e.printStackTrace ();} <irpmRQr
RB *P0
:S#i9# aB
} eZA6D\
:k\}Ik
yduuFK
public static void main(String[] args) 8,H~4Ce3
{ Gg}t-_M
new TestMethod(); sN=KRqe
} 1NW>wo
} A^t"MYX@
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