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)); g-bK|6?yz
} }B+C~@j
for(int i=0;i<nEndPos.length-1;i++) j{A y\n(
{ $k%2J9O
nEndPos = nStartPos[i+1]; 7(8;to6(
} BC.87Fji/
nEndPos[nEndPos.length-1] = nFileLength; X`>i&I]
} mR:uj2*
} HyZqUbHa
ZhaP2pC%4
v>)"HL"XG
//启动子线程 *)T^ChD,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #OD/$f_
for(int i=0;i<nStartPos.length;i++) ,m:.-iy?
{ & l&:`nsJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3yF,ak{Sl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i%]EEVmN
nStartPos,nEndPos,i); ,T$U'&;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +gtbcF@rx
fileSplitterFetch.start(); 'Aq{UGN
} 06Sceq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v%z=ysA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aP+X}r
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Be2DN5)
nEndPos = " + nFileLength); .}TZxla0Zr
// fileSplitterFetch[nPos.length-1].start(); )'#A$ Fj
WlC:l
k"iOB-@B+
//等待子线程结束 ?mxMk6w
//int count = 0; '8H4shYg
//是否结束while循环 X51:
boolean breakWhile = false; Fj3a.'
/]Md~=yNp
h2]P]@nW;W
while(!bStop) xj;H&swo
{ ~IBP|)WA-
write_nPos(); MaQqs=
Utility.sleep(500); :>f )g
breakWhile = true; @,7GaK\
Ai?*s%8v
,Uqs1#r
for(int i=0;i<nStartPos.length;i++) K;H&n1
{ f+)L#>Gl?
if(!fileSplitterFetch.bDownOver) C1n>M}b
{ 04P}-L,
breakWhile = false; ,j_i?Ff
break; !``,gExH
} u^I|T.w<r6
} j-}O0~Jz
if(breakWhile) 29] G^f>
break; e2oa($9
EUX\^c]n
O;jrCB
//count++; aSQ#k;T[
//if(count>4) $Sip$\+*
// siteStop(); 2-v%`fA
} !PQ<04jA!
y/7\?qfTk
8dIgjQX|
System.err.println("文件下载结束！"); )}Kf=
} Ie#Bkw'*
catch(Exception e){e.printStackTrace ();} vr6w^&[c^
} A]oV"`f
p]+Pkxz]'
>@_^fw)
//获得文件长度 uZKr
public long getFileSize() 6 V=9M:
{ rw JIx|(
int nFileLength = -1; SZ'R59Ee<
try{ flbd0NB
URL url = new URL(siteInfoBean.getSSiteURL()); $G@5qxcV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wt-GjxGi
httpConnection.setRequestProperty("User-Agent","NetFox"); 2uW; xfeY
iz PDd{[
z$. 88^
int responseCode=httpConnection.getResponseCode(); `dN@u@[\ks
if(responseCode>=400) P}^W)@+3k
{ c-6?2\]j@
processErrorCode(responseCode); =X:Y,?
return -2; //-2 represent access is error E*K;H8}s
} )F]]m#`
zHRplm+i
xfe+n$~ c
String sHeader; jm/`iXnMf
`1fY)d^ZS
>0TxUc_va
for(int i=1;;i++) Feq]U?
{ o3P${Rq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h3 }OX{k
//Utility.log(in.readLine()); ?%[@Qb=2
sHeader=httpConnection.getHeaderFieldKey(i); BW*rIn<?G
if(sHeader!=null) tg4pyW<
{ W[e$>yK
if(sHeader.equals("Content-Length")) /7^4O(iG
{ yN(%-u"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hhc,uJ">!
break; 7~.9=I'A
} y766; X:J
} S;#'M![8
else /@TF5]Ri
break; je=a/Y=%U{
} 'I6i,+D/q
} z<XtS[ki
catch(IOException e){e.printStackTrace ();} ,w4V?>l
catch(Exception e){e.printStackTrace ();} aj{Y\ 3L
m~0/&RA
$B5aje}i
Utility.log(nFileLength); r52gn(,
6mxfLlZ
-X2Buz8
return nFileLength; 9EibIOD^/
} I:1C8*/
`7V]y-
56kI 5:
//保存下载信息（文件指针位置） !wh8'X*
private void write_nPos() =MDysb&:
{ ],Do6 @M-
try{ ope^~+c~\
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~dTrf>R8M
output.writeInt(nStartPos.length); G3AesTT|
for(int i=0;i<nStartPos.length;i++) v;D~Pa
{ YO}<Ytx
// output.writeLong(nPos); M&9+6e'-F
output.writeLong(fileSplitterFetch.nStartPos); 60?%<oJ oH
output.writeLong(fileSplitterFetch.nEndPos); tW}'g:s
} \xw5JGm
output.close(); q(W3i^778
} FP4P|kl/9'
catch(IOException e){e.printStackTrace ();} 5D//*}b,
catch(Exception e){e.printStackTrace ();} *_\_'@1|J)
} oV78Hq6
Q K<"2p?
a~y'RyA
//读取保存的下载信息（文件指针位置） "b3"TPfK
private void read_nPos() ":QZy8f9%
{ aHK}sr,U
try{ CryBwm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |[b{)s?x
int nCount = input.readInt(); t!7-DF|N
nStartPos = new long[nCount]; ZyFjFHe+
nEndPos = new long[nCount]; ?)d~cJ
for(int i=0;i<nStartPos.length;i++) ^v7gIC
{ 5">Z'+8
nStartPos = input.readLong(); D_zZXbNc
nEndPos = input.readLong(); suDQ~\n
} R.yvjPwJ
input.close(); V+9 MoT?8
} CB}2j
catch(IOException e){e.printStackTrace ();} SSMHoJGm
catch(Exception e){e.printStackTrace ();} J)p l|I
} @_}P-h
r$s Qf&=
;vjOUn[E
private void processErrorCode(int nErrorCode) V1B5w_^>h'
{ p9{mS7R9T
System.err.println("Error Code : " + nErrorCode); )MTOU47U
} 89(Q1R ?:
&\*(Q*2N
d5:c^`
//停止文件下载 j*r{2f4Rt
public void siteStop() m^;f(IK5
{ nUOz\y
bStop = true; xMG~N`r
for(int i=0;i<nStartPos.length;i++) T{[=oH+
fileSplitterFetch.splitterStop(); WCixKYq
g{&ui.ml&
Yr[\|$H5
} D2~*&'4y
} XVZ
//负责部分文件的抓取 amY!qg0P*
**FileSplitterFetch.java {&1/V
*/ 6i3$CW
package NetFox; gp.^~p]x
?m"( Soh
JY(WK@
import java.io.*; 1#+S+g@#
import java.net.*; p H2Sbs:Tk
v):Or'$~M
WNrk}LFof
public class FileSplitterFetch extends Thread { nZYBE030
.eVG:tl\
t;\Y{`
String sURL; //File URL XU(eEnmom
long nStartPos; //File Snippet Start Position 4@ai6,<
long nEndPos; //File Snippet End Position {9q4)R}G
int nThreadID; //Thread's ID k~nBiV
boolean bDownOver = false; //Downing is over nb%6X82Q
boolean bStop = false; //Stop identical [MY|T<q
FileAccessI fileAccessI = null; //File Access interface V1M.JU
=Jb>x#Y
%n9aaoD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vUM4S26"NT
{ P+/e2Y
this.sURL = sURL; zIAD9mQex
this.nStartPos = nStart; l2Rb\4
this.nEndPos = nEnd; y?4BqgB
nThreadID = id; A2Gevj?F$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s!$7(Q86R
} #S"nF@
o&$A]ph8X
?.BC#S)q1
public void run() p0vVkdd
{ ?gGHj-HYJ
while(nStartPos < nEndPos && !bStop) :"/d|i`T
{ )\$|X}uny&
97!;.f-
dvUic-w<j
try{ (<C3Vts))
URL url = new URL(sURL); oNF6<A(@$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pFjK}JOF
httpConnection.setRequestProperty("User-Agent","NetFox"); *J`O"a
String sProperty = "bytes="+nStartPos+"-"; /9fR'EO{x
httpConnection.setRequestProperty("RANGE",sProperty); O:Tj"@h
Utility.log(sProperty); Xc&9Glf
Qzw;i8n{
/mzlH
InputStream input = httpConnection.getInputStream(); i=2N;sAl
//logResponseHead(httpConnection); P5ywhw-
3(80:@|
f4|rVP|x
byte[] b = new byte[1024]; qUb&
int nRead; t"oeQ*d%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I-l_TpM)
{ &{t,'[ u
nStartPos += fileAccessI.write(b,0,nRead); M9%$lCl
//if(nThreadID == 1) 5:_}zu|!u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e+fN6v5pU
} 1bwOmhkS
^^ixa1H<
CRy|kkT
Utility.log("Thread " + nThreadID + " is over!"); $ $mV d+
bDownOver = true; QoT;WM Z
//nPos = fileAccessI.write (b,0,nRead); uoh7Sz5!^
} ]:J$w]\
catch(Exception e){e.printStackTrace ();} }Jj}%XxKs
} nAlQ7'
} +mT_QsLEv
|+D!= :x
KoT%Mfu
//打印回应的头信息 FfT`;j
public void logResponseHead(HttpURLConnection con) Wmv#:U
{ SXP]%{@R/
for(int i=1;;i++) pOoEI+t
{ DZtsy!xA
String header=con.getHeaderFieldKey(i); ;Q`lNFa
if(header!=null) a0H+.W+]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 67FWa
Utility.log(header+" : "+con.getHeaderField(header)); 7WzxA=*#
else bW(0Ng
break; 4;2uW#dG"
} FGBbO\</
} dioGAai'
O5BYD=7
gw<q.XL
public void splitterStop() $VOFOc
{ kb!%-k
bStop = true; 3F^Q51:t
} SNk=b6`9
ysnx3(+|
('+d.F[109
} F#5~M<`.o
5'u<iSmBo
R[]Mdt<
/* EQSQFRk;
**FileAccess.java jq0O22 -R
*//文件访问(定位，写) &s!@29DXR
package NetFox; W=+ Y|R!
import java.io.*; +^F Zq$NP
"qy,*{~
/Z}}(6T
public class FileAccessI implements Serializable{ -"9
;*2Cm'8E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }4X0epPp;:
RandomAccessFile oSavedFile; rEz^
long nPos; <b*DQ:N
gf\oC> N
+R:(_:7
public FileAccessI() throws IOException 1s;Saq+
{ EU Fa5C:
this("",0); ]A_`0"m.U
} j3ls3H&
0jWVp-y
Bk{]g=DO
public FileAccessI(String sName,long nPos) throws IOException vtJJ#8a]
{ k4zZ7H
oSavedFile = new RandomAccessFile(sName,"rw"); gI|~|-'
this.nPos = nPos; =($xG#g`
oSavedFile.seek(nPos); ,|/f`Pl
} cPQiUU~W@
YtLt*Ig%
vW@=<aS Z
public synchronized int write(byte[] b,int nStart,int nLen) Y8t8!{ytg
{ j<e2d7oN
int n = -1; W\V.r$? v
try{ sNFlKQ8)Q
oSavedFile.write(b,nStart,nLen); #,'kXj
n = nLen; lH~[f
} *lJxH8\
catch(IOException e) J]r^W)O
{ bpa?C
e.printStackTrace (); <(!:$
} 'dc#F3
1Ai^cf:S
b%c9oR's^
return n; cso8xq|b7
} tfWS)y7
%\:Wi#w>
dqcL]e
} @>7%qS
`">=
V0Hj8}l;M
/* jSaU?ac
**SiteInfoBean.java ;qV>L=a
*/ iK;XZZ(
package NetFox; w&.aQGR#
M D#jj3y
AQ^u
public class SiteInfoBean { a$fnh3j[
#4;wjcGWw
qZZK#,Qb
private String sSiteURL; //Site's URL )QJUUn#
private String sFilePath; //Saved File's Path (**oRwr%
private String sFileName; //Saved File's Name ]eV8b*d6
private int nSplitter; //Count of Splited Downloading File K:WDl;8(d
'Z]w^<
b#o|6HkW
public SiteInfoBean() ]/{)bpu
{//nSplitter的缺省值为5 q1ma%eiN
//default value of nSplitter is 5 PZzMHK?hP
this("","","",5); iU:cW=W|M\
} !bP@n
{K!)Ss
o{[qZc_%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wa~=bH
{ o}{5iTg=
sSiteURL= sURL; !dT4
sFilePath = sPath; 5~S5F3
sFileName = sName; -tU'yKhn
this.nSplitter = nSpiltter; ?&uu[y
/zox$p$?h
1AFA=t:]p
} NCD04U5y
dgP3@`YS
#p{4^
public String getSSiteURL() c[s4EUG
{ (w zQ2Dk
return sSiteURL; 3iU=c&P
} Qv ?"b
#s9aI_
<{cQ2
public void setSSiteURL(String value) CNx8] _2
{ e~(5%CO>#j
sSiteURL = value; -7|H}!DFT
} $Z>'Jp
7PF%76TO
51.%;aY~z
public String getSFilePath() 5E <kwi
{ :fJN->wY^s
return sFilePath; /Gfw8g\}
} q0\6F^;M
Zgb!E]V[
L4l!96]a
public void setSFilePath(String value) nT)vNWT=
{ Ht&YC<X
sFilePath = value; wS3'?PRX
} -DAlRz#d,
9Gz=lc[!7
r@,2E6xn
public String getSFileName() ]]Ufas9
{ %N_%JK\{@
return sFileName; {fp[BF
} ^dxTm1Z
Wn}'bqp
wUM0M?_p[
public void setSFileName(String value) ,"0:3+(8;
{ Q=dy<kg']
sFileName = value; _Bj":rzY
} ijU*|8n{>
\lNN Msd&
M"To&?OI
public int getNSplitter() |e0`nn=
{ /_ajaz%
return nSplitter; A+?`?pOm&
} Uoix
BfiD9ka-z
~7Ux@Sx;
public void setNSplitter(int nCount) ;xn0;V'=
{ J4U1t2@)9
nSplitter = nCount; [opGZ`>)j"
} ;]:@n;c\
} caX< n>
h!9ei6
ygl0k \
/* dUdT7ixo
**Utility.java 5Jnlz@P9
*/ E&:,oG2M
package NetFox; <ZR9GlIr
\z} Ic%Tp
+8ZF"{y
public class Utility { q-d:TMkc
Y`wSv NU
8*a&Jl
public Utility() `~q<N
{ Yu2Bkq+
ht}wEvv
uFga~&#g
} #gw]'&{8D
/; 85i6
//线程睡眠 IV)j1
public static void sleep(int nSecond) 18:%~>.!
{ 0+b1vhQ
try{ #C@FYOf*
Thread.sleep(nSecond); ,5<Cd,`*
} cj5+NM"
catch(Exception e) ]5:8Z@
{ Pj%|\kbNs
e.printStackTrace (); %D "I
} aC)!T
} 8, >P
)whA<lC
//日志 "kqPmeI
public static void log(String sMsg) hP&Bt
{ q'MZ R'<@
System.err.println(sMsg); ;gr9/Vl
} IIx#2r
uY'HT|@:{
7. ;3e@s
public static void log(int sMsg) y"wShAR
{ Pk)1WK7E
System.err.println(sMsg); QP J4~
} \dQNLLg/
} geCM<]
K",N!koj
r]36zX v
/* k"w"hg&e
**TestMethod.java k|d+#u[Mj@
*/ $* Kvc$D
package NetFox; v|2T%y_ u
iAU@Yg`pt
=w0R$&b&
public class TestMethod { :*\Pn!r
bA->{OPkT
45>?o
public TestMethod() {Y9q[D'g.
{ ///xx/weblogic60b2_win.exe 7D5]G-}x.
try{ 6)Lk-D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tIgN$BHR>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kMd.h[X~
SiteFileFetch fileFetch = new SiteFileFetch(bean); f& '
fileFetch.start(); N]sAji*
} HyWCMK6b
catch(Exception e){e.printStackTrace ();} ?6Y?a2 |
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HHsmLo c4
} U4B(#2'
wD)XjX
~e@z;]CiY
public static void main(String[] args) TRq6NB
{ yz8jw:d^-
new TestMethod(); v_-dx
} c0u^zH<
} DR<9#RRD
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