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)); R0;c'W)
} a}a_&rf~Z
for(int i=0;i<nEndPos.length-1;i++) p#O#MN*
{ zh'TR$+\hO
nEndPos = nStartPos[i+1]; f)q\RJA)X
} =y8HOT}8
nEndPos[nEndPos.length-1] = nFileLength; ^>uzMR!q5
} +15j^ Az
} #lQbMuR
xTX\%s|
*eL%[B
//启动子线程 l/yLSGjM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EA2BN}
for(int i=0;i<nStartPos.length;i++) |H5){2V>K
{ rd\mFz-SB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), []0`>rVq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6hYv
nStartPos,nEndPos,i); 2](R}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !&TbE@Xk
fileSplitterFetch.start(); U KF/v
} :Tw3Oo_~S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gh}FZs5P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N{`-&8q;K
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?rWqFM:hb
nEndPos = " + nFileLength); !h7`W*::
// fileSplitterFetch[nPos.length-1].start(); :7IL|bA<
&by,uVb=|{
KO<fN,DR
//等待子线程结束 zzuDI_,/
//int count = 0; F8YD:
//是否结束while循环 uJMF\G=nb
boolean breakWhile = false; $Ha?:jSc
e%N\Pshgv
Z?[;Japg
while(!bStop) H|T:_*5
{ &qFdP'E;$
write_nPos(); kjN9(&D
Utility.sleep(500); @y->4`N
breakWhile = true; q^Lj)zmnK
^o"9f1s5
P6S^wjk
for(int i=0;i<nStartPos.length;i++) <(?ahO5
{ @\Sa)
if(!fileSplitterFetch.bDownOver) |A7Yv
{ :D-d`OyjG>
breakWhile = false; Ka2U@fK"
break; `8\pihww
} QY-P!JD
} >Fz_]z
if(breakWhile) NaG1j+LN
break; ZP*Hx %U
SS O$.rp
k\Oy\z@
//count++; 5wRDH1z@{
//if(count>4) >9F,=63A
// siteStop(); DyG3|5s1R
} b.h~QyI/W
kX\t0'=]
J7emoD[
System.err.println("文件下载结束！"); O~9 %!LAu
} 6YrkS;_HS
catch(Exception e){e.printStackTrace ();} =9y'6|>l
} 2#@S6zc
)& %X AW{
=]\,I'
//获得文件长度 DkA cT[
public long getFileSize() Q0,]Q ]_
{ -a]oN:ERb
int nFileLength = -1; +uKlg#wqc
try{ s}`ydwSg8
URL url = new URL(siteInfoBean.getSSiteURL()); w@nN3U+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;_of'
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Y j_@=
}Nl-3I.S^
E92dSLhs5
int responseCode=httpConnection.getResponseCode(); +kH*BhSj
if(responseCode>=400) ;QW6Tgt11
{ v(FO8*5DZ
processErrorCode(responseCode); Dq*>+1eW2
return -2; //-2 represent access is error !s?vj <
} '7 6}6G%
nBaY|
q*@7A6:FV>
String sHeader; 5IBe;o
xRP#}i:m
/t%IU
for(int i=1;;i++) TWEmW&Q
{ <QugV3e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !a~>;+
//Utility.log(in.readLine()); d'kQE_y2.
sHeader=httpConnection.getHeaderFieldKey(i); tu6c!o,@
if(sHeader!=null) 7}%3Aw6]S
{ ^g~Asz5]
if(sHeader.equals("Content-Length")) &y mfA{s
{ t}qoIxy)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %xyt4}-)m
break; aoco'BR F
} _z)G!_7.>\
} |`U^+Nf
else !?Z}b.%W
break; [}9R9G>"
} '>`?T}a,
} +T [0r
catch(IOException e){e.printStackTrace ();} 37a"<
catch(Exception e){e.printStackTrace ();} I^[R]Js
/o.wCy,J<
E[Tz%x=P
Utility.log(nFileLength); Z%N{Y x(
G!8O*4+A
IpoZ6DB$
return nFileLength; WsL*P.J
} d&wg\"E
O=MO M
aa.EtKl
//保存下载信息（文件指针位置） S$%T0~PR~
private void write_nPos() #v=hiL
{ ]"q)X{G(+
try{ Q68&CO(rE
output = new DataOutputStream(new FileOutputStream(tmpFile)); W~POS'1
output.writeInt(nStartPos.length); 1V+a;-?
for(int i=0;i<nStartPos.length;i++) +AtZltM i
{ IW Lv$bPZ/
// output.writeLong(nPos); tcwE.>5O
output.writeLong(fileSplitterFetch.nStartPos); %^p1ax
output.writeLong(fileSplitterFetch.nEndPos); &tj0Z:
} jLI(Z
output.close(); ?<#6=
} rfkk3oy
catch(IOException e){e.printStackTrace ();} dum! AO
catch(Exception e){e.printStackTrace ();} YCj"^RC^
} ?2 u_E "
>+7+ gSD#:
QSW03/_f
//读取保存的下载信息（文件指针位置） FdKp@&O+1
private void read_nPos() 245(ajxHC
{ bkceR>h%
try{ {K09U^JU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \d&j`UVY
int nCount = input.readInt(); bguhx3s
nStartPos = new long[nCount]; M9_ y>N[0
nEndPos = new long[nCount]; a,#f%#J\
for(int i=0;i<nStartPos.length;i++) I$n 0aR6
{ zob^z@2
nStartPos = input.readLong(); ^a[7qX_B
nEndPos = input.readLong(); %?<C ?.
} \%KJ+PJ
input.close(); KR^lmN
} r'7;:
catch(IOException e){e.printStackTrace ();} x9a*^l
catch(Exception e){e.printStackTrace ();} %Fa/82:- "
} RN5\,>+
]-bA{@tP.
PM=Q\0
private void processErrorCode(int nErrorCode) ,LSF@1|Fx
{ Agl5[{]E
System.err.println("Error Code : " + nErrorCode); (WVN*OR?
} " nq4!
TF}<,aR
rG:IS=
//停止文件下载 *%:p01&+
public void siteStop() ZC_b`q<
{ YKJk)%;+w
bStop = true; <dV|N$WV
for(int i=0;i<nStartPos.length;i++) VSx[{yn
fileSplitterFetch.splitterStop(); 1U;je,)
|[>`3p"&
\wCj$-;Jt
} MQ$[jOAqP
} H2BD5
//负责部分文件的抓取 K,&)\r kzD
**FileSplitterFetch.java qmdl:J|?
*/ }9/30
package NetFox; `l9Pk\X[
z\pT nteO
U?[a@Hj{
import java.io.*; }W#Gf.$6C
import java.net.*; 05gU~6AF
D(Pd?iQIO
MG*#-<OV.
public class FileSplitterFetch extends Thread { (*;b\h
we4e>)
8Focs p2
String sURL; //File URL X-|`|>3E
long nStartPos; //File Snippet Start Position )TP1i
long nEndPos; //File Snippet End Position -;a}'1HOE
int nThreadID; //Thread's ID Ett%Y*D+J
boolean bDownOver = false; //Downing is over x>A(016:C
boolean bStop = false; //Stop identical /1zi(z
FileAccessI fileAccessI = null; //File Access interface \L}Soe'
f>s3Q\+
2oXsPrtZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *TfXMN?w
{ 5n"b$hMF
this.sURL = sURL; $iUK, ?
this.nStartPos = nStart; "9!ln
this.nEndPos = nEnd; WogJ~N,d53
nThreadID = id; VE+Q Y9(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :XxsDD
} BKPXXR
+7U$qEG
E y1mlW
public void run() 1&ukKy,[
{ "a6[FqTs
while(nStartPos < nEndPos && !bStop) \sEq r)\k
{ %E}f7GT4
6%sX<)n%]
-%E+Yl{v
try{ <.HX_z3l
URL url = new URL(sURL); m=jxTZK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )[|TxXz d
httpConnection.setRequestProperty("User-Agent","NetFox"); kl4FVZof
String sProperty = "bytes="+nStartPos+"-"; @]uvpI!h
httpConnection.setRequestProperty("RANGE",sProperty); jAB~XaT,
Utility.log(sProperty); o9(:m
Wz)s#
_Jx.?8
InputStream input = httpConnection.getInputStream(); #f0J.)M
//logResponseHead(httpConnection); bX6eNk-L
:aI[ lZ
zlco?Rt
byte[] b = new byte[1024]; =3$JeNK9
int nRead; Qh<_/X?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,j>A[e&.
{ /oKa?iT
nStartPos += fileAccessI.write(b,0,nRead); @d:TAwOI'
//if(nThreadID == 1) #!wu}nDu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z$ZG`v>0
} ~2+J]8@I]
l tE`
JWoNP/v6
Utility.log("Thread " + nThreadID + " is over!"); u|&"l
bDownOver = true; as=Z_a:0N
//nPos = fileAccessI.write (b,0,nRead); 0"o%=i;
} w[}5qAI5*f
catch(Exception e){e.printStackTrace ();} tGDsZ;3Yr
} LG0+A}E=C
} 2kzm(K
s_S[iW`l=
Vr@I9W;D#
//打印回应的头信息 \B/+.\
public void logResponseHead(HttpURLConnection con) VRQ'sn@
{ [0<N[KZ)
for(int i=1;;i++) T}d%XMXq
{ P&@ 2DI3m
String header=con.getHeaderFieldKey(i); i}"Eu< P
if(header!=null) #\3(rzQVO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8;K'77h
Utility.log(header+" : "+con.getHeaderField(header)); A.vWGBR
else }c|)i,bL
break; 2XI%z4\)!
} *WdnP.'Y
} qIIc>By(\"
g\^7Q
`1k0wT(
public void splitterStop() ,7-@eZ
{ r#hA kOw
bStop = true; = i9|lU"Va
} (Qq;ySZ#
%ub\+~
x8 :
} bwN>E+
8WU_d`DF
p?F%a;V3
/* Xy/lsaVskX
**FileAccess.java ]yI~S(
*//文件访问(定位，写) +)YU/41W
package NetFox; tk=~b}8
import java.io.*; Af y\:&j
'b(V8x
U0>Uqk",
public class FileAccessI implements Serializable{ v3>jXf
$0+n0*fp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .rpKSf.
RandomAccessFile oSavedFile; is`O,Met
long nPos; N~Zcrt_D
r0jhIE#
rUgTJx&ds
public FileAccessI() throws IOException T7+_/ Qh
{ t$+[(}@+
this("",0); Z ,4G'[d
} 86+nFk
bz$)@gLc
N;N,5rxV
public FileAccessI(String sName,long nPos) throws IOException Eci,];S7
{ +'aG&^k4
oSavedFile = new RandomAccessFile(sName,"rw"); (b!`klQ
this.nPos = nPos; mtfEK3?2*
oSavedFile.seek(nPos); NABVU0}
} nz-( 8{ae
@px4[
wX?<o
public synchronized int write(byte[] b,int nStart,int nLen) QxUsdF?p
{ lO)-QE+
int n = -1; y*K]z
try{ hf#[Vns
oSavedFile.write(b,nStart,nLen); LYM(eK5V
n = nLen; &.D#OnRh9
} %#gHa
catch(IOException e) aG&ay3[&
{ Mzfuthq=@
e.printStackTrace (); N5m+r.<;
} 67,@*cK3?J
~# ~XDcc
(Qf"|3R4
return n; Fh[Gq
} #21t8
3/d`s0O
$K-od3h4=
} r*Iu6
@xu/&pbI
*21foBfqh
/* b&iJui"7k
**SiteInfoBean.java /U1&#"P
*/ .|d2s
package NetFox; Fqr}zR)
v7Q=
6xfG`7Az
public class SiteInfoBean { ;Nfd
fG{ 9doUD
d]bM,`K* 6
private String sSiteURL; //Site's URL +#$(>6Zu"{
private String sFilePath; //Saved File's Path !/]vt?v#^
private String sFileName; //Saved File's Name (j*1sk
private int nSplitter; //Count of Splited Downloading File .PAR
J|Af`HJ
=A yDVWpE
public SiteInfoBean() 335\0~;3
{//nSplitter的缺省值为5 aM2[<m}
//default value of nSplitter is 5 ZA;VA=)\8
this("","","",5); W'0(0;+G/j
} 8r|5l~`8
!}[cY76_
~sk{O%OI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O:^m#:[cE
{ YY? }/r
sSiteURL= sURL; W{JNNf6G
sFilePath = sPath; ;R#:? r;t
sFileName = sName; Q|3SYJf
this.nSplitter = nSpiltter; @-g'BvS
Hf^Tok^6@]
z'9Mg]&>
} cag9f?w@V
zc,kHO|
Td6Gu"
public String getSSiteURL() gp?|UMA9.
{ _mi(:s(
return sSiteURL; Xfq]vQ/{
} ]n/fB|tE
l>H G|ol
pN]$|#%q(
public void setSSiteURL(String value) Wd0$t
{ #!h +K"wX
sSiteURL = value; Y64B"J=P9
} pbM"tr_A{
P0/B!8x
*,Mg
public String getSFilePath() Xy;!Q`h(
{ .JJ^w!|>#
return sFilePath; NbDfD3 1GK
} G0u3*.
GNv5yWQ@
jNO8n)a&p
public void setSFilePath(String value) C6"bGA
{ 4Pm+0=E
sFilePath = value; O8J:Tw}M*
} UdSu:V|
6BPZ2EQ
|B0.*te6
public String getSFileName() e>oE{_e
{ fK$N|r
return sFileName; &dC #nw
} @3UVl^T
=XT'D@q~W
,;_D~7L
public void setSFileName(String value) N,><,7!q$,
{ E?& x5?
sFileName = value; bhFAt1h
} v{H3DgyG
.)wj{(>TJ
0M?nXHA[
public int getNSplitter() !Qg%d&q.Sx
{ ;[_w&"[6a
return nSplitter; yk5T"#'+
} }UzO_&Z#6
,u,]ab
$LPu_FJ
public void setNSplitter(int nCount) jaoGm$o>"F
{ iZ`1Dzxgk
nSplitter = nCount; us.+nnd
} ~YuRi#CTD:
} |sw&sfH[FD
; md{T'
9u'hCi(
/* u%#s_R
**Utility.java IXSCYqoK
*/ '9,14e6
package NetFox; V zx%N.
S*H :/Ip
KAg<s}gQJ
public class Utility { )-3!-1
\bh3&Z'.
u&=SZX&G k
public Utility() *5i~N}
{ $E^#DjhRQ3
t;DZ^Z"{
!d1}IU-h
} Q7y6</4f
-S=Zsr\
//线程睡眠 1%L* 9>e
public static void sleep(int nSecond) ]`D(/l'
{ ^}2 ie|
try{ zS:89y<
Thread.sleep(nSecond); lPS A
} 5JbPB!5;
catch(Exception e) 'DQp
{ t[6g9e$
e.printStackTrace (); Ne]/ sQ0
} ;y#6Nx,:
} 6TE RQ
yG0Wr=/<?
//日志 mI=^7'Mk
public static void log(String sMsg) b'$j* N
{ yaf&SR@7k{
System.err.println(sMsg); @1#$
} *JG?^G"l
6e@ O88=
^g,[#Rh
public static void log(int sMsg) cU25]V^{\
{ r\Wp\LfY&{
System.err.println(sMsg); j$*]'s&_hZ
} XM/P2=;
} +a&-'`7g
;G.m;5A
`07u}]d8
/* fB5Bh;K
**TestMethod.java /Q"nQSG
*/ M* W=v
package NetFox; o'Q)V
&7 }!U
SVp]}!jI
public class TestMethod { 0k5Zl?
xPh%?j?*v
yZ,k8TJ",
public TestMethod() `n:IXD5'
{ ///xx/weblogic60b2_win.exe A.vcE
try{ #VC^><)3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Ko}Pv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qy@gW@IU
SiteFileFetch fileFetch = new SiteFileFetch(bean); uNnwz%w
fileFetch.start(); Iz2K
} ewgcpV|spn
catch(Exception e){e.printStackTrace ();} @2 dp5
asR6,k
K0]'v>AWr
} w\;=3C`
?ZSG4La\
v,RLN`CID
public static void main(String[] args) 2 c'=^0:
{ @yaBtZUp3
new TestMethod(); +byw*Kk
} !23W=N}82
} ,ewg3mYHC&
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