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)); a?MtY EK2
} 1G;Ns] u
for(int i=0;i<nEndPos.length-1;i++) Iq=B]oE
{ Tz-cN
nEndPos = nStartPos[i+1]; k$ M4NF~$
} V<pqc&f.
nEndPos[nEndPos.length-1] = nFileLength; ~.lH)
} ;X6y.1N~
} H7=z%Y9y
|K-lgrA
rQm
//启动子线程 7tpZE+OX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D` X6'PP
for(int i=0;i<nStartPos.length;i++) fYjsSUnf
{ B3t>M) 9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >[: 2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kf!/9
nStartPos,nEndPos,i); -c?wEqa~2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zn!
fileSplitterFetch.start(); $:N "*
} \KXEw2S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z+W&C@Uw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5O W(] y|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", TkoXzG8yE<
nEndPos = " + nFileLength); 05 Q8`
// fileSplitterFetch[nPos.length-1].start(); JW[\"`x!
gVJ#LJ
U3K<@r
//等待子线程结束 :+Ax3
//int count = 0; I<K/d
//是否结束while循环 [5*-V^m2
boolean breakWhile = false; si_HN{
D>e\OfTR:
}t3FAy(%
while(!bStop) SvP\JQ<c
{ U hhmG+
write_nPos(); z8 ;#H tr
Utility.sleep(500); cloSJmUlQ
breakWhile = true; F'$S!K58
u=}bq{
H8]^f=
for(int i=0;i<nStartPos.length;i++) <?{}Bo0xG
{ AE4~M`6D
if(!fileSplitterFetch.bDownOver) -yQ\3wli`
{ L(n/uQ :
breakWhile = false; %=4ak]As
break; >[fVl8G_0
} kF,\bM
} `s>=Sn&UP
if(breakWhile) ]z=Vc#+!
break; i;hc]fYb=K
UnWGMo?JEi
k-pEBhOH
//count++; B%J%TR_
//if(count>4) km\ld&d]$
// siteStop(); :sVHY2x
} mHEf-6|C`
%^5@z1d,
j"IM,=
System.err.println("文件下载结束！"); %L13Jsw
} %FyygTb;S
catch(Exception e){e.printStackTrace ();} )ClMw!ZrU
} U\Ar*b)/T
6=,#9C9
^'[@M'`~L
//获得文件长度 4iv]N 4
public long getFileSize() Hg9.<|+yo
{ [+l
int nFileLength = -1; _rMT{q3
try{ %]<RRH.w
URL url = new URL(siteInfoBean.getSSiteURL()); }PFt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -H4+ur JJ
httpConnection.setRequestProperty("User-Agent","NetFox"); Sc/`=h]T
iTLW<wG
'8l yj&
int responseCode=httpConnection.getResponseCode(); nQ642i%RQ
if(responseCode>=400) [X }@Ct6
{ ~y)bYG!G
processErrorCode(responseCode); %K^gUd>,R
return -2; //-2 represent access is error \oB'
} 8jjFC9Cbn0
Vm~qk
SH vaV[C
String sHeader; z+k=|RMau
$7UoL,N>
6QII&Fg
for(int i=1;;i++) +mc[S
{ hD_5~d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `*NO_K
//Utility.log(in.readLine()); Y$`eg|$
sHeader=httpConnection.getHeaderFieldKey(i); q]eFd6
if(sHeader!=null) VT% KN`l
{ #v4LoNm
if(sHeader.equals("Content-Length")) PFS;/
{ X>Al:?`}N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hIuMHq7h
break; S9G+#[.|
} BTTLy^
} p^1zIC>F
else +Qh[sGDdY
break; bmOqeUgB
} N0Efw$u
} , 3X: )
catch(IOException e){e.printStackTrace ();} J7BFk ?=
catch(Exception e){e.printStackTrace ();} /gz:zThf{
bauA}3
@Od^k#
Utility.log(nFileLength); A8pj~I/*-
KD% TxK
FR x6c
return nFileLength; l|YT[LR7
} 5@P%iBA4(3
VF)uu[ f9
Hm%g_Mt
//保存下载信息（文件指针位置） gmh5 %2M
private void write_nPos() mxQR4"]jY
{ 6M ^IwE
try{ (1CJw:
output = new DataOutputStream(new FileOutputStream(tmpFile)); egm)a
output.writeInt(nStartPos.length); 55.;+B5L*
for(int i=0;i<nStartPos.length;i++) RMoJz6^>
{ g"wxC@IR
// output.writeLong(nPos); zZ%DtxUoU.
output.writeLong(fileSplitterFetch.nStartPos); 2-++i:, g
output.writeLong(fileSplitterFetch.nEndPos); 4j>fI)FUW
} ^[k0k(_
output.close(); b"``D ?
} V vu(`9u]
catch(IOException e){e.printStackTrace ();} ?O??cjiA@
catch(Exception e){e.printStackTrace ();} gv#4#]
} `)32&\
x?"#gK`3;
e,HMwD
//读取保存的下载信息（文件指针位置） \m4T3fy
private void read_nPos() ,CciTXf
{ 1,,|MW
try{ lWWP03er!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MIq"Wy|Zs
int nCount = input.readInt(); hSB?@I4s<\
nStartPos = new long[nCount]; -gS"pE^1
nEndPos = new long[nCount]; k=[pm5ZvT~
for(int i=0;i<nStartPos.length;i++) )RN<GW'
{ ;+ azeW^
nStartPos = input.readLong(); XphE loL
nEndPos = input.readLong(); xRum*}|4
} F8<"AI
input.close(); 5t\HJ`C1Z
} =E(#YCx
catch(IOException e){e.printStackTrace ();} ?CP2AK
catch(Exception e){e.printStackTrace ();} ;o0#(xVz
} ?]#OM_,8
.2W"w)$nuq
7]Em,
private void processErrorCode(int nErrorCode) +m)q%I>
{ 1@>$ Gcc
System.err.println("Error Code : " + nErrorCode); Y9Z]i$qS&k
} l30Y8t~d
:@eHX&
|A\a4f'G
//停止文件下载 =Mj0:rW
public void siteStop() kJ{+M]pW
{ kGHQ`h
bStop = true; *nC(-(r:J`
for(int i=0;i<nStartPos.length;i++) os4{0Mxu
fileSplitterFetch.splitterStop(); wi_'iv
:"Y*<=x#2
DY\J[l<<
} -]srp;=i
} IgIYguQ
//负责部分文件的抓取 !4(zp;WY^
**FileSplitterFetch.java CrC=A=e
*/ v+G=E2Lhv
package NetFox; QA3/
r)^vO+3u
S<`I Jpkv
import java.io.*; W3H+.E
import java.net.*; 5T@aCC@$h
[sF(#Y:I
aNxAZMg
public class FileSplitterFetch extends Thread { <\ `$Jx#
pav'1d%
PPkx4S_>
String sURL; //File URL rG}\Zjn{
long nStartPos; //File Snippet Start Position Hnk:K9u.B:
long nEndPos; //File Snippet End Position CVNj-&vj
int nThreadID; //Thread's ID y5r4+2B
boolean bDownOver = false; //Downing is over 7aV%=_
boolean bStop = false; //Stop identical A@hppaP!
FileAccessI fileAccessI = null; //File Access interface 8[vc?+>&
nKa$1RMO
":a\z(*t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $+p?Y)h .
{ ryB}b1`D
this.sURL = sURL; AN!s{7V3
this.nStartPos = nStart; 21hv%CF\9
this.nEndPos = nEnd; \K`L3*cBKK
nThreadID = id; >/[GTqi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I/Jb!R ~
} ~5FW[_
g0R~&AN!g
h/?l4iR*
public void run() wE+${B03
{ (hiyNMC
while(nStartPos < nEndPos && !bStop) '5&s=M_
{ ^nbnbU4'
T,aW8|
y@0E[/O
try{ /1Ue?)g
URL url = new URL(sURL); Cj~'Lhmv'T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FEVEp
httpConnection.setRequestProperty("User-Agent","NetFox"); }gJ(DbnV
String sProperty = "bytes="+nStartPos+"-"; (L^]Lk x)
httpConnection.setRequestProperty("RANGE",sProperty); Ym3\pRFiD
Utility.log(sProperty); Fu!RhsW5j
th;{V%:LW
/p8dZ+X
InputStream input = httpConnection.getInputStream(); 0$,SF3K
//logResponseHead(httpConnection); w!fE;H8w6
ZYC<Wb)I
8F._9U-EN
byte[] b = new byte[1024]; ;q*e=[_DF
int nRead; On?p 9^9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8F'x=lIO
{ %i5M77#Z
nStartPos += fileAccessI.write(b,0,nRead); ."9];)2rx
//if(nThreadID == 1) ~]QHk?[wc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y&V@^"`
} yU9DSY\m{
-3Hy*1A.
E{|W(z,
Utility.log("Thread " + nThreadID + " is over!"); 1fpQLaT
bDownOver = true; ZzSz%z_sE
//nPos = fileAccessI.write (b,0,nRead); Ft&]7dT{W
} 'IwNTM
catch(Exception e){e.printStackTrace ();} C#Na&m
} [Al&
} !qWH`[:
"vOwd.(?N
Fvbh\m ~
//打印回应的头信息 [k/@E+;
public void logResponseHead(HttpURLConnection con) R=QZgpR
{ {0WHn.,2Y
for(int i=1;;i++) :51/29}
{ ++`0rY%
String header=con.getHeaderFieldKey(i); bcE._9@@
if(header!=null) OG>}M$Ora
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }f6HYU
Utility.log(header+" : "+con.getHeaderField(header)); ZZzMO6US0
else ~v|>xqWV
break; \D*KGd]M0
} D=-SO +
} :%,:"
huh6t !
lww!-(<ww
public void splitterStop() 7o#I,d~
{ w"Gm;B4
bStop = true; Y[}>CYO
} -"'j7t:
)<h*eS{
[\v}Ul
} i@"@9n~
<7/R,\Wg~
EyJJ0
/* su{poQ}K
**FileAccess.java @#T|Y&
*//文件访问(定位，写) jCOIuw
package NetFox; < $lCkSx<Q
import java.io.*; lrlgz[
<Tzrj1"Q3
v&DI`xn~
public class FileAccessI implements Serializable{ .WA-&b_
`T@i.'X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mHdA2
RandomAccessFile oSavedFile; {Aw#?#GPW
long nPos; . qO@Q=
Z'`<5A%;
1"MhGNynB>
public FileAccessI() throws IOException O_oPh]x)
{ 4&<oFW\r
this("",0); IA8f*]?
} il4^zj82
UZ\u;/}
5Dm.K?l;
public FileAccessI(String sName,long nPos) throws IOException #L=x%8B
{ y-'$(x
oSavedFile = new RandomAccessFile(sName,"rw"); @vC4[:"pD}
this.nPos = nPos; %(3|R@G.
oSavedFile.seek(nPos); 1H? u Qy
} ?uzRhC_)!
dk[!V1x4\
i1ixi\P{0
public synchronized int write(byte[] b,int nStart,int nLen) 2b}t,&bv?
{ a!6{:8Zi0
int n = -1; !JHL\M>A5
try{ V\ZGd+?
oSavedFile.write(b,nStart,nLen); u^@f&BIG]:
n = nLen; W,V:R
} !"?#6-,Xn
catch(IOException e) eBZXI)pPh
{ @'#,D!U
e.printStackTrace (); \FQRNj?'_
} ZQ4p(6a
!`Fxa4i>
|7'df&CA
return n; %<\vGqsM
} Qf~vZtJ+J
yr)G]K[/
1-8mFIK
} I:R[;TB?y
yZ0-wI
5kc/Y/4o
/* }^ApJS(FQ
**SiteInfoBean.java dN$0OS`s[
*/ ne>pOK<vZ
package NetFox; Go5J%&E9
Q- cFtu-w
%f&/E"M
public class SiteInfoBean { -o^7r@6
l.67++_
8zZvht*
private String sSiteURL; //Site's URL du<tGsy
private String sFilePath; //Saved File's Path MU`1LHg
private String sFileName; //Saved File's Name kKaE=H-x
private int nSplitter; //Count of Splited Downloading File |U:k,YH
hi_NOx
1T"`vtR
public SiteInfoBean() Ot4 Z{mA
{//nSplitter的缺省值为5 AHD=<7Rs
//default value of nSplitter is 5 "M<8UE\n
this("","","",5); Eq%}
} /Wi[OT14
I,E?h?6Y
DwM)r7<Ex
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4X!/hI=jq
{ @CpfP;*{w`
sSiteURL= sURL; UE8kpa)cQ
sFilePath = sPath; .T}Wdng
sFileName = sName; Y4J3-wK5
this.nSplitter = nSpiltter; _zR+i]9
${<%" hR$
]Z>}6!
} sfpZc7
mUNn%E:7@{
'F/~o1\.
public String getSSiteURL() MU($|hwiL
{ &agWaf1%a
return sSiteURL; i[O& )N,c
} g?c xp+
aHV;N#Lx3
Jf{*PgP
public void setSSiteURL(String value) '*Z1tDFS
{ ?j'7l=94A
sSiteURL = value; 6]&OrS[
} BnX0G1|#
6O7'!@@
9>=;FY
public String getSFilePath() j5(Z_dm'
{ |hKDvH
return sFilePath; =T3<gGM
} B?OFe'*
7LfAaj
N+9VYH"*
public void setSFilePath(String value) u0}vWkn\4
{ J-[,KME_^
sFilePath = value; 2A']yD
} /Y/UM3/
=%BSKSG.
d8DV[{^
public String getSFileName() jSJqE_1
{ \Q {m9fE
return sFileName; %p Ynnfr
} tl[Uw[
n"h`5p5'
N&.H|5
public void setSFileName(String value) nyX2|m&
{ cF\;_0u
sFileName = value; +UCG0D
} <!&[4-;fU
J9..P&c\
^dI424
public int getNSplitter() aKJwofD
{ {IjF+@I
return nSplitter; hE &xE;
} =R^%(Py
D+#E-8
H!@kO]?n
public void setNSplitter(int nCount) # ncRb
{ x/%aM1"X^
nSplitter = nCount; ;RH;OE,A
} ?'IP4z;y
} R$EW4]j
mJ<=n?{Z
N(O9&L*4fm
/* |e=,oV"
**Utility.java pXtl 6K%
*/ seba9y
package NetFox; c|f<u{'
W=ig.-
C2.HMgL
public class Utility { M+-*QyCFK
36.Z0Z1'F>
Dxtp2wu%t
public Utility() oph}5Krd)
{ !d'GE`w T
f<GhkDPm>?
1}"++Z73P
} E!;SL|lj.
Qo>b*Ku;
//线程睡眠 pD(j'[
public static void sleep(int nSecond) bkRLC_/d
{ |Yx~;q:
try{ ~cWAl,(B<F
Thread.sleep(nSecond); 1v#%Ei$6`t
} \TIT:1
catch(Exception e) ^0Zf,40
{ ag;Q F
e.printStackTrace (); a,Sw4yJ!Q
} 85>05?
} Yy5h"r
'-QwssE
//日志 8."]//V
public static void log(String sMsg) ,y1PbA0m
{ +\x,HsUc"
System.err.println(sMsg); v/@^Q1G/:
} 4Xgg%@C
7Sf bx~48
-M~8{buxv
public static void log(int sMsg) ~3^ 8>d/
{ WJ$bf(X*
System.err.println(sMsg); svsqg{9z
} ^/)^7\@
} dW)B1iUo!
<qtr
B#exHf8
/* ~Uu4=
**TestMethod.java ,%6P0#-
*/ &]g}u5J!=
package NetFox; :uP,f<=)K
i=ea ?eT`
YA''2Ii
public class TestMethod { \?w2a$?6w
iyA'#bE-
>i_2OV
public TestMethod() &@G:G(
{ ///xx/weblogic60b2_win.exe v;BV@E0}x
try{ 6q*9[<8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W~6EEyD%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UGD2
SiteFileFetch fileFetch = new SiteFileFetch(bean); @>u]4Jn
fileFetch.start(); YO#M/%^j
} Q8C_9r/:N>
catch(Exception e){e.printStackTrace ();} c*(bO3 b
&?W0mW(
IW>T}@ |
} -1 FPkp
pN!}UqfI-
#~#R-
public static void main(String[] args) vY4\59]P
{ wi;Br[d
new TestMethod(); nePfuG]Q
} Vdtry@Q
} ?QsQnQ
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