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)); a7G2C oM8
} Ui!|!V-
for(int i=0;i<nEndPos.length-1;i++) @/L. BfTz
{ )6^xIh
nEndPos = nStartPos[i+1]; c&-$?f r
} <v k$eB8EC
nEndPos[nEndPos.length-1] = nFileLength; ^6>|!
} g"S+V#R
} ZF(=^.gc
C/Bx_j((
|LE++t*X~
//启动子线程 T l(uqY?9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oH0F9*+W
for(int i=0;i<nStartPos.length;i++) ^\jX5)2{
{ 4 GW[GT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JSK5x(GlH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Cpv%s 1M
nStartPos,nEndPos,i); Tk&9Klo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "IJMvTmj
fileSplitterFetch.start(); >[4|6k|\x
} &W// Ox )f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z3>3&|&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); os^SD&hL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }AZx/[k |z
nEndPos = " + nFileLength); 6F/ OlK<
// fileSplitterFetch[nPos.length-1].start(); [Vp2!"
@]wem
p+UHJ&
//等待子线程结束 b:cK>fh0_
//int count = 0; Prz+kPP
//是否结束while循环 Ds,"E#?
boolean breakWhile = false; PFgjWp"Y
_|wY[YJ[
Tc5OI'-V
while(!bStop) _XNR um4
{ UH&1c8y}
write_nPos(); @^6OV)
Utility.sleep(500); ieRBD6_
breakWhile = true; |SukiXJZF
3nC#$L-
um2s^G
for(int i=0;i<nStartPos.length;i++) ?WtG|w
{ `=$jc4@J
if(!fileSplitterFetch.bDownOver) c$<O0dI
{ 7a]Zws
breakWhile = false; 5J\|gZQF
break; :Z]hI+7
} FoD/Q
} wt=>{JM
if(breakWhile) 4[CBW
break; DEp%\sj?
mImbS)V
+6M+hO]
//count++; #JR,C -w
//if(count>4) 'Kzr-)JS
// siteStop(); ivUsMhx>S,
} -,fa{yt-
FDd>(!>
t6g)3F7T
System.err.println("文件下载结束！"); {F6dSF`
} nL(%&z \4
catch(Exception e){e.printStackTrace ();} 6n6VEwYj
} _QMHPRELk
90h1e7ZcC
&kjwIg{
//获得文件长度 Rp`_Grcd
public long getFileSize() !ga(L3vf
{ 4>"cc@8&~
int nFileLength = -1; jPYe_y
try{ NzeI/f3K5
URL url = new URL(siteInfoBean.getSSiteURL()); T^%n!t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m!#)JFe67
httpConnection.setRequestProperty("User-Agent","NetFox"); {Sr=SE
[ 4Y `O
'=Kof1
int responseCode=httpConnection.getResponseCode(); SC $`
if(responseCode>=400) <`p75B
{ (XG[_
processErrorCode(responseCode); ULNAH`{D
return -2; //-2 represent access is error Y7:Y{7E7
} 4`UL1)A]
Mi/ &$"=
ZH;y>Z
String sHeader; @( n^S?(
+i`Q 7+d
jqX@&}3@
for(int i=1;;i++) [C+Gmu
{ yA?ENAM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y3KcM#[
//Utility.log(in.readLine()); .W@(nQ-<
sHeader=httpConnection.getHeaderFieldKey(i); m,@1LwBH
if(sHeader!=null) gP%|:"
{ |,1bkJt
if(sHeader.equals("Content-Length")) }l}yn@hYC
{ @Ge>i5q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |YE,) kiF
break; V{T{0b"\U
} +w k]iH
} 62MRI
else F%PwIB~cy
break; `\/toddUh[
} dcl.wD0~V
} X/E7o92\
catch(IOException e){e.printStackTrace ();} M q^|M~
catch(Exception e){e.printStackTrace ();} ^zaKO'KcV
Zp7yaz3y
N;Z`%&
Utility.log(nFileLength); c7+Djqs
d1~_?V'r]
4-7kS85
return nFileLength; uq!;
} I #M%%5e
\);.0
Ka]J^w;a
//保存下载信息（文件指针位置） E\]OySC%C$
private void write_nPos() XMN?;Hj>
{ kgbobolA
try{ NI5]Nz<?
output = new DataOutputStream(new FileOutputStream(tmpFile)); )%iRZ\`f
output.writeInt(nStartPos.length); LbJtpwz>z
for(int i=0;i<nStartPos.length;i++) c Ndw9?Z
{ x],8yR)R
// output.writeLong(nPos); y4xT:G/M
output.writeLong(fileSplitterFetch.nStartPos); KqM!!
output.writeLong(fileSplitterFetch.nEndPos); QU^/[75Ea0
} w=f0*$ue+w
output.close(); hD nM+4D
} eecw]P_?
catch(IOException e){e.printStackTrace ();} Qw24/DJK
catch(Exception e){e.printStackTrace ();} xT9Yes&
} hq/J6 M
,M\j%3
)Vwj9WD
//读取保存的下载信息（文件指针位置） JN9^fR09G
private void read_nPos() 1s#yWQ
{ 1&"-*)
try{ B0f_kH~p~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H4M{_2DO
int nCount = input.readInt(); ETU-]R3
nStartPos = new long[nCount]; %x&F4U
nEndPos = new long[nCount]; 2HcsQ*H]G
for(int i=0;i<nStartPos.length;i++) K!3{M!B
{ _h0-
nStartPos = input.readLong(); JXpoCCe
nEndPos = input.readLong(); hVMYB_<~
} !8.En8Z<D-
input.close(); 2q)T y9
} C&=x3Cz
catch(IOException e){e.printStackTrace ();} n vm^k
catch(Exception e){e.printStackTrace ();} B;VH`*+X
} hlX>K
./$ <J6-J
@u,+F0Yd
private void processErrorCode(int nErrorCode) A2Q[%A
{ fD'/#sA#'
System.err.println("Error Code : " + nErrorCode); nz^nptw
} f%c06Un=
A:/}`
$4=Ne3y
//停止文件下载 |Eb&}m:E$
public void siteStop() 4<u;a46Z#M
{ NdZ)[f:2
bStop = true; 8=:A/47=J
for(int i=0;i<nStartPos.length;i++) JfMJF[Mb
fileSplitterFetch.splitterStop(); XM$GQn]B
9qEOgJ
@8|Gh]\P
} >;,gGH
} V{!lk]p}a
//负责部分文件的抓取 B22b&0
**FileSplitterFetch.java V"O9n[|
*/ !}ilN 1>
package NetFox; cv= \g Z
D3y>iQd
o5P&JBX<
import java.io.*; r&SO:#rOSM
import java.net.*; 6J\q`q(W(
pw=F' Y@N
y`rL=N#
public class FileSplitterFetch extends Thread { V{0%xz #
g92dw<$>
y1iX!m~)
String sURL; //File URL VgA48qZ
long nStartPos; //File Snippet Start Position ilv_D~|
long nEndPos; //File Snippet End Position e8{^f]5
int nThreadID; //Thread's ID FuuS"G,S
boolean bDownOver = false; //Downing is over Ir/:d]N*
boolean bStop = false; //Stop identical 9\AS@SH{^T
FileAccessI fileAccessI = null; //File Access interface jn^fgH?
3T1P$E" m
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J?IC~5*2
{ ENq"mwV|
this.sURL = sURL; 088C|
this.nStartPos = nStart; T%kKVr
this.nEndPos = nEnd; 9:-T@u
nThreadID = id; E5gl^Q?Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &:No}6
} cz#_<8'N
K_>/lirE?
f*<ps o
public void run() .E$q&7@/j
{ BSKEh"f
while(nStartPos < nEndPos && !bStop) 59i]
{ Fg=v6j4W
=Z`0>R`
[D[D`gpjA
try{ Cw#V`70a
URL url = new URL(sURL); Pbe7SRdr^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \Yq0 zVol
httpConnection.setRequestProperty("User-Agent","NetFox"); &$#99\/
String sProperty = "bytes="+nStartPos+"-"; h$Tr sO
httpConnection.setRequestProperty("RANGE",sProperty); .&iN(Bd
Utility.log(sProperty); AS|Rd+.
x: ~d@
U5<@<j(@
InputStream input = httpConnection.getInputStream(); yp+F<5o
//logResponseHead(httpConnection); wyw<jH
0`n 5x0R
7Z0/(V.-
byte[] b = new byte[1024]; WNF9#oN|oT
int nRead; "w&/m}E,[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M&yqfb[
{ gz61FW
nStartPos += fileAccessI.write(b,0,nRead); W:O0}
//if(nThreadID == 1) tD-gc''H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CH;;V3
} 4AHL3@x
C:GvP>
/{X_ .fv<v
Utility.log("Thread " + nThreadID + " is over!"); d>!p=O`>{q
bDownOver = true; YPszk5hn
//nPos = fileAccessI.write (b,0,nRead); /U*yw5
} WZ?!!
catch(Exception e){e.printStackTrace ();} 2B` 8eb
} >nry0 ;z0,
} J]fS({(\I
GwQn;gkF
2EfflZL3
//打印回应的头信息 |C D}<r(N
public void logResponseHead(HttpURLConnection con) % {Q-8w!
{ D{C:d\ e)$
for(int i=1;;i++) D9-Lg%
{ kCA5|u
String header=con.getHeaderFieldKey(i); <AUWby,"
if(header!=null) Ei~f`{i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $bGD%9 z
Utility.log(header+" : "+con.getHeaderField(header)); uvB1VV4
else bx>i6 R2
break; |+NuYz?
} g$3>~D
} Bq!cY Wj
0{R/<N
n93zD*;5
public void splitterStop() NHkL24ve
{ Zq*eX\#C
bStop = true; FT/amCRyT
} aws"3O% uW
G$5m$\K
-3hCiKq
} 6vp0*ww
m mw-a0
DJP6TFT&G
/* =!,Gst_
**FileAccess.java )^ <3\e
*//文件访问(定位，写) *^h_z;{,
package NetFox; @J vZ[T/
import java.io.*; $(q8y/,R*-
ZnXejpj)D
ax@H"d&
public class FileAccessI implements Serializable{ ^ vbWRG~
o4)hxs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J70D+
RandomAccessFile oSavedFile; +t]Xj1Q
long nPos; 6^YJ]w
LfX0Z=<
rt b*n~
public FileAccessI() throws IOException tWD|qg_
{ m0( E kK
this("",0); 1^{`lK~2
} i_U}{|j
2QayM?k8
PZM42"[&
public FileAccessI(String sName,long nPos) throws IOException 7+XM3
{ fLB1)kTS
oSavedFile = new RandomAccessFile(sName,"rw"); vJCf~'
this.nPos = nPos; Iql5T#K+
oSavedFile.seek(nPos); =!<G!^
} SS8ocGX
T1NH eH>
nl@E[yA9[
public synchronized int write(byte[] b,int nStart,int nLen) I/s.xk_i
{ r nBOj#N
int n = -1; oR %agvc^^
try{ Rd! 2\|
oSavedFile.write(b,nStart,nLen); Ew4g'A:H
n = nLen; ./w{L"E
} @"8R3BN
catch(IOException e) uO'/|[`8
{ 6?SFNDQ"C
e.printStackTrace (); }kPVtSQ
} a[C&e,)}
=`p&h}h-L
gq4 . d
return n; %f!iHo+Z
} UqtHxEI%R~
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1xTTJyoq
} tWk{1IL
MY F#A
WK;(P4Z
/* 4<}A]BQVkJ
**SiteInfoBean.java \"d?=uFe
*/ CEqZ:c
package NetFox; SE!L :
2 sSwDF
E1W:hGI
public class SiteInfoBean { o}~3JBnT
I,j3bC
I:t^S.,
private String sSiteURL; //Site's URL ;0j*>fb\q7
private String sFilePath; //Saved File's Path |s|/]aD}o
private String sFileName; //Saved File's Name a:u}d7T3e
private int nSplitter; //Count of Splited Downloading File N!m%~kS9k<
,qy&|4Jz
0j$OE
public SiteInfoBean() F=i!d,S
{//nSplitter的缺省值为5 kCp)!hVQ
//default value of nSplitter is 5 b1=pO]3u
this("","","",5); \n0gTwiO%
} bp%S62Dj
mP!N<K
M(5D'4.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yW>RRE;
{ e\.HWV]I
sSiteURL= sURL; GP]TnQ<*;
sFilePath = sPath; !!+Da>
sFileName = sName; 1S*P"8N}0h
this.nSplitter = nSpiltter; wOcg4HlW
o?dR\cxj
owMmCR
} ;[~^(. f
q{@P+2<wF
sVoR?peQ
public String getSSiteURL() \HG$V>2
{ f0FP9t3k
return sSiteURL; cY~M4:vgT
} ,'_(DJX
2 `&<bt[g
w, 7Cr
public void setSSiteURL(String value) _BwKY#09Zp
{ ^j iE9k)
sSiteURL = value; 4:`[qE3
} ai^t= s
LE|<O
4d-q!lRpa
public String getSFilePath() GLcd9|H
{ GBr,LN
return sFilePath; w"6aha*%7
} zn^v!:[
9A<0zt
J{!'f| J
public void setSFilePath(String value) X~zRZ0
{ P57GqT
sFilePath = value; [DhEh@
} 4Pf+]R
!l"tI#?6W%
QQq/5r4O`q
public String getSFileName() {\Ys@FF
{ ^(g_.>
return sFileName; UEN56@eCNf
} oX*b<d{\N
%HVD^. V
369Zu4|u
public void setSFileName(String value) !"%S#nrL$
{ ]*GnmG:D*
sFileName = value; \H[Yyp4
} N5ci};?
,@479ZvvR3
7P c(<Ui+
public int getNSplitter() V:8@)Hc=
{ v!KJ|c@m
return nSplitter; j^{b^!4~}
} =tHD 4I
c l9$g7
c`pYc
public void setNSplitter(int nCount) pSXEJ 2k
{ EFD?di)s
nSplitter = nCount; I[%M!_+
} ]h0Y8kpd
} IOS^|2:,
#:Xa'D+
<ipWMZae0F
/* r\B"?oqC
**Utility.java +2El
*/ lZBv\JE
package NetFox; C,(j$Id
vU7&'ca
4NJVW+:2
public class Utility { @??u})^EL
z41D^}b
fmBkB8
public Utility() k}#@8n|b
{ !@A|L#*
m+p4Mc%u
t={poQC~
} Ls(&HOK[p
KjC[q
//线程睡眠 ?S8$5gA
public static void sleep(int nSecond) KoFv0~8Q
{ /8:gVXZi
try{ sFCf\y
Thread.sleep(nSecond); 75<el.'H
} } mgVC
catch(Exception e) G}Gb|sD Zq
{ $vz_%Y
e.printStackTrace (); 2UQN*_
} Cy]"
} V,E9Uds
`Y0fst<,
//日志 Q:kwQg:~
public static void log(String sMsg) .iN-4"_j1
{ kja4!_d
System.err.println(sMsg); 2m|Eoc&M_
} ^kc>m$HY
JATS6-Lz`
D\@e{.$MZ|
public static void log(int sMsg) ' l|41wxk
{ eog\pMv
System.err.println(sMsg); {_rZRyr
} tWcizj;?wK
} u<$S>
K<D`(voL
tX+0 GLz
/* ]6jHIk|
**TestMethod.java <WO&$&
*/ ]r"31.w(
package NetFox; IvY,9D
=PI^X\if88
dl7Riw-J
public class TestMethod { (N)r#"FV
#(m`2Z`H
A9NOeE
public TestMethod() Tnzco
{ ///xx/weblogic60b2_win.exe w:~nw;.T
try{ er&uC4Y]a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aS c#&{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =x|##7
SiteFileFetch fileFetch = new SiteFileFetch(bean); aeN}hG
fileFetch.start(); p~,a=
} sURUQ H
catch(Exception e){e.printStackTrace ();} x.jYip
Zm"!E6`69
Zkwy.Hq^
} AAIyr703cQ
7j9D;_(.^$
s!8J.hD'I
public static void main(String[] args) dSA [3V
{ pko!{,c
new TestMethod(); D#vn {^c8O
} ae9k[=-
} Im0+`9Jw
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