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)); sute%6yM
} O%?TxzX;
for(int i=0;i<nEndPos.length-1;i++) .Rt_j
{ p;Ezmz
nEndPos = nStartPos[i+1]; v~^c-]4I
} .b] 32Ww
nEndPos[nEndPos.length-1] = nFileLength; W+k`^A|@
} PZ5BtDm
} w5*?P4P
P<P4*cOV
)zw}+z3st
//启动子线程 ,Q|[Yr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]~S,K}T
for(int i=0;i<nStartPos.length;i++) }p-<+sFo
{ mXZOkx{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C =fs[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y4*ezt:;Q
nStartPos,nEndPos,i); tI50z khaB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r,}U-S.w
fileSplitterFetch.start(); ! K? o H
} hKq <e%oVH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W\09hZ6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j" wX7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YrAaL"20
nEndPos = " + nFileLength); T' O5>e
// fileSplitterFetch[nPos.length-1].start(); OiPE,sv
8joJe>9VJ
zTi%j$o
//等待子线程结束 ;)Rvk&J5
//int count = 0; |k5uVhN
//是否结束while循环 AWlR" p2
boolean breakWhile = false; [@D+kL*>
WK7=z3mu
Qx,?v|Xg
while(!bStop) V0hC[Ilr
{ "0Xa?z8"
write_nPos(); Bi?.w5
Utility.sleep(500); fsc^8
breakWhile = true; ?DP]#9/4
;{b 1'
bA]/p%rZ8
for(int i=0;i<nStartPos.length;i++) :@LFNcWE
{ I"awvUP]a[
if(!fileSplitterFetch.bDownOver) KQsS)ju
{ 9( ;lcOz
breakWhile = false; a<+Qw'
break; $<^4G
} ]'Y vI!r
} y- S]\tu
if(breakWhile) ;)ffGg>
break; K{[ySB
dRg1I=|{_
n"B"Aysz
//count++; J;+AG^U<
//if(count>4) TbyQ'MbUv
// siteStop(); 5=CLR
} nA8]/r1k
cy=,Dr9O
dR2#n
System.err.println("文件下载结束！"); dtJaQ`
} <d$kGCz
catch(Exception e){e.printStackTrace ();} KA:>7-
} @W3fKF9*R
$I(2}u?1+d
#W<D~C[I _
//获得文件长度 ]>h2h?2te
public long getFileSize() S9X~<!]
{ $^R[t;
int nFileLength = -1; x9r5 ;5TI
try{ ,6rg00wGE
URL url = new URL(siteInfoBean.getSSiteURL()); kM>0>fkjE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I^ W
httpConnection.setRequestProperty("User-Agent","NetFox"); @DK,ka(
[.tqgU
@ ?y(\>
int responseCode=httpConnection.getResponseCode(); cWIX!tc8
if(responseCode>=400) kQlXcR
{ "dwx;E
processErrorCode(responseCode); =]x FHw8A
return -2; //-2 represent access is error |YjuaXd7N
} P\bW kp0
jYKs| J)[
LLOe
String sHeader; )_!t9gn*wr
fx|$(D@9
l= 5kd.{
for(int i=1;;i++) xy`aR< L
{ C/dqCUX:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lPm'>,}Y
//Utility.log(in.readLine()); _[h1SAJ
sHeader=httpConnection.getHeaderFieldKey(i); Cec!{]DL&
if(sHeader!=null) YBQO]3f
{ P(fTlrb
if(sHeader.equals("Content-Length")) -[OGZP`8
{ *1iJa
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); drTX
break; -Zfzl`r
} "^~f.N
} (PU0\bGA
else l'-dB
break; vvw6 GB,M
} w C]yE\P1
} j<!rc>)2+L
catch(IOException e){e.printStackTrace ();} 0}$",M!p
catch(Exception e){e.printStackTrace ();} gsufd{{
Uj}iMw,
' U{?"FP
Utility.log(nFileLength); Fc>W]1
:av6*&+
c_a*{L|c
return nFileLength; Bn*D<<{T
} `/ix[:}m^
Fs_V3i3|L
J!%Yy\G
//保存下载信息（文件指针位置） zllY$V&<!
private void write_nPos() l){l*~5zl2
{ 7~TE=t
try{ t6_6Bl:
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?m#X";^V
output.writeInt(nStartPos.length); uy{mSx?td
for(int i=0;i<nStartPos.length;i++) +#O?a`f
{ 69(z[opW
// output.writeLong(nPos); tDFN *#(
output.writeLong(fileSplitterFetch.nStartPos); 2Xk(3J!!'a
output.writeLong(fileSplitterFetch.nEndPos); F>&Q5Kl R
} Oa\!5Pw1
output.close(); Ac<V!v71
} ]hTYh^'e
catch(IOException e){e.printStackTrace ();} X<ZIeZBn
catch(Exception e){e.printStackTrace ();} )K>XLaG)
} u*`acmS>N
*>rpcS<l
rP,i,1Ar 4
//读取保存的下载信息（文件指针位置） /Q5pAn-u
private void read_nPos() -wlob`3
{ =UA-&x@
try{ \tLJ( <8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @5Q}o3.zA-
int nCount = input.readInt(); ^#e:q
nStartPos = new long[nCount]; .z7XYmv
nEndPos = new long[nCount]; wIuwq>
for(int i=0;i<nStartPos.length;i++) sxJKu
{ w(n&(5FzB<
nStartPos = input.readLong(); y.5mYQA4=[
nEndPos = input.readLong(); )zI<C=])"
} g*\u8fpRq
input.close(); "t~I;%$[
} h>$,97EU
catch(IOException e){e.printStackTrace ();} ' ^gF
catch(Exception e){e.printStackTrace ();} +SkD/"5ng
} ;Avd$&::
:^lyVQ%@
O:Bfbna
private void processErrorCode(int nErrorCode) qrO]t\
{ b,/fz6 {N
System.err.println("Error Code : " + nErrorCode); A_T-]YQ
} zMt"ST.
g"( vl-Uw
Y'Sxehx
//停止文件下载 ?mS798=f
public void siteStop() 4JFi|oK0H
{ Xj"/6|X
bStop = true; fG;)wQJ
for(int i=0;i<nStartPos.length;i++) o %A4wEye
fileSplitterFetch.splitterStop(); lYT}Nc4"="
CjORL'3
:2Qm*Y&_$V
} `23&vGk}
} )y'`C@ijI
//负责部分文件的抓取 r vVU5zA4H
**FileSplitterFetch.java e{U`^ao`F8
*/ IB /.i(
package NetFox; QkZT%!7
o1MI&}r
S20x
import java.io.*; $1.iMHb
import java.net.*; g$kK)z
IV;juFw}G
wKe^5|Rr
public class FileSplitterFetch extends Thread { j[m\;3Sp
!tv3.:eT
<<LmO-92
String sURL; //File URL n_AW0i.
long nStartPos; //File Snippet Start Position Y1+4ppZ
long nEndPos; //File Snippet End Position ygS*))7 r
int nThreadID; //Thread's ID $$<9tqA
boolean bDownOver = false; //Downing is over SG |!wH^
boolean bStop = false; //Stop identical t*zve,?}
FileAccessI fileAccessI = null; //File Access interface BqP:]
Hx2UDHF
y.JAtsxD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `r'q(M
{ XJ?|\=]
this.sURL = sURL; U}MU>kzb
this.nStartPos = nStart; |^C?~g
this.nEndPos = nEnd; M:6H%6eT
nThreadID = id; -]~U_J]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >pO[S[
} j\q1b:pE
wd~e3%JM
,!F'h:
public void run() TgJx%
{ %MU<S9k
while(nStartPos < nEndPos && !bStop) 1sYwFr5
{ HB{w:
(<s7X$(]e
R+P,kD?
try{ %Ub"V\1
URL url = new URL(sURL); C"k8M\RW?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k7>*fQ89@
httpConnection.setRequestProperty("User-Agent","NetFox"); JxiLjvIq
String sProperty = "bytes="+nStartPos+"-"; .hn{m9|U
httpConnection.setRequestProperty("RANGE",sProperty); pnca+d
Utility.log(sProperty); )"|'=
(k6=o';y
/],:sS7
InputStream input = httpConnection.getInputStream(); P9:7_Vc
//logResponseHead(httpConnection); !w]!\H
*y5d&4G2
&E.0!BuqV
byte[] b = new byte[1024]; *W y0hnr;]
int nRead; D(Zux8l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _D1bR7
{ ,[,+ _A
nStartPos += fileAccessI.write(b,0,nRead); yx3M0Qo
//if(nThreadID == 1) g~h`wv'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '`T.K<
} v+znKpE
^TVy:5Ag
<5@+:7Dv
Utility.log("Thread " + nThreadID + " is over!"); 50rCW)[#
bDownOver = true; =bded(3Z
//nPos = fileAccessI.write (b,0,nRead); W>K2d
} !-2nIY!
catch(Exception e){e.printStackTrace ();} r-^Ju6w{
} ggVB8QN{
} $n(?oyf
g}{Rk>k
bnUpH3
//打印回应的头信息 z[0L?~$
public void logResponseHead(HttpURLConnection con) 7SoxsT)
{ TmH#
for(int i=1;;i++) Lx8^V7X
{ L:%ek3SOz
String header=con.getHeaderFieldKey(i); PQWo<Uet
if(header!=null) u Y V=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %((F}9_6
Utility.log(header+" : "+con.getHeaderField(header)); ppR~e*rv-
else =\J^_g4-l
break; =:P9 $
} @Rig@
} ~PHAC@pU
W!4GL>9m}A
}(Nb]_H
public void splitterStop() <po.:c Ce
{ `XP]y=
bStop = true; _Z#yI/5r
} )6PZ.s/F6p
bnWIB+%_
^>.?kh9z
} t#&^ -;
"%D+_Yb'X
c;Hf+n
/* mc?5,oz;pz
**FileAccess.java A~\:}PN
*//文件访问(定位，写) 2fO ~%!.G
package NetFox; *1ekw#'
import java.io.*; /_xwHiA
mdypZ1f_
|n=m8X
public class FileAccessI implements Serializable{ 1'"o; a]k/
L/%3_,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~4=4Ks0
RandomAccessFile oSavedFile; <#7}'@
long nPos; ~YlbS-
AVOqW0Z+y
8 fVI33
public FileAccessI() throws IOException "6Nma)8
{ n/pM[gI
this("",0); UN`-;!
} >9esZA^';
',z'.t
&~6Z)}
public FileAccessI(String sName,long nPos) throws IOException 1e'-rm F
{ KOV^wSwS
oSavedFile = new RandomAccessFile(sName,"rw"); 6G/)q8'G
this.nPos = nPos; 8niQG']
oSavedFile.seek(nPos); }z,4IHNn
} 7xVI,\qV
bo$xonV@y
b}9K"GT
public synchronized int write(byte[] b,int nStart,int nLen) Xleoh2&M
{ :)q/8 0@
int n = -1; r*>XkM& M
try{ gA2Il8K
oSavedFile.write(b,nStart,nLen); .7g^w+W
n = nLen; j Z3N+_J1
} v8y77:
catch(IOException e) +'=^/!
{ ?T$i
e.printStackTrace (); |w>"oaLN|Q
} W`eYd|+C
5ii`!y
k^C;"awh
return n; .',ikez
} Fng":28o
*Mg=IEu-6[
jzI\Q{[m'
} ~~;fWM '
=5oFutg`
}dAb}0XK.
/* Zul]ekv
**SiteInfoBean.java EqUiC*u8{I
*/ :QUZ7^u
package NetFox; Dd!MG'%hlb
H6/@loO!Xy
*.Y!ZaK
public class SiteInfoBean { |B)e!#
nDiD7:e7=
Y_p
private String sSiteURL; //Site's URL M7eO5
private String sFilePath; //Saved File's Path kR-N9|>i
private String sFileName; //Saved File's Name WyA>OB<Zeq
private int nSplitter; //Count of Splited Downloading File mf,mKgfG
X~P0Q
6%U1%;
public SiteInfoBean() w{F8]N>0<
{//nSplitter的缺省值为5 cGsP0LkHC
//default value of nSplitter is 5 {h&*H[Z z
this("","","",5); yIXM}i:
} ^(N+s?
\r324Bw>2
q}ZZqYk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (FH4\'t)
{ F!|Z_6\tv:
sSiteURL= sURL; ^^jF*)DT@
sFilePath = sPath; @2CYv>
sFileName = sName; l"IBt:
this.nSplitter = nSpiltter; %Q1v8l.}
H^K(1
'RQZU*8
} &I:X[=;g
Gd%6lab
6\\B{%3R2
public String getSSiteURL() > :!faWX
{ lr+Kwve
return sSiteURL; yeE_1C .
} OJ@';ZyT=
}s}b]v
Lt@4F
public void setSSiteURL(String value) ]=WJ%p1l
{ QMy;?,
sSiteURL = value; *ErTDy(
} aZ*b"3
~<Gs<c}z
6M"J3\ x
public String getSFilePath() dvyE._/v
{ u\^<V)
return sFilePath; Yah3I@xGy
} @o9EX }
;l4rg!r(S
u5V<f;
public void setSFilePath(String value) *vJ1~SRV
{ "!p#8jR^
sFilePath = value; b1nw,(hLY
} r$k *:A$%
o$d; Y2K
F8_pwJUpf-
public String getSFileName() P%'bSx1
{ ~UK) p;|
return sFileName; fR6ot#b
} HQt=.#GW
Fdm7k){A
BxG0vJN|
public void setSFileName(String value) cX7xG U
{ L.U [eH
sFileName = value; FLEf(
} C.8]~MP
?.\CUVK
e<~uU9 lg1
public int getNSplitter() FxM`$n~K
{ HY5g>wv@
return nSplitter; [GhT.
} MyCX6+Ci)
~;UK/OZ
)uwpeq$j7l
public void setNSplitter(int nCount) {* >$aI
{ ^CZn<$
nSplitter = nCount; ;?=] ffa{
} iP|h];a+@
} Va(R*38k
Xa[gDdbL
nt "VH5
/* e`k 2g^
**Utility.java YXrTm[P
*/ +Y)rv6}m
package NetFox; J24UUZ9&$
c#u-E6
%pL ,A5M
public class Utility { J^n(WnM*F
J%j#gyTU
,_u8y&<|I
public Utility() ThJLaNS
{ 4xtbP\=
}k\a~<'X
U>:CX XHRt
} `U2Z(9le
^B?{X|U37
//线程睡眠 ,GVHwTZ0`
public static void sleep(int nSecond) kSB)}q6a
{ L)8;96
try{ ?*[t'D9f-
Thread.sleep(nSecond); ofcoNLX5c
} #`y7L4V*o
catch(Exception e) 6dC!&leNi
{ 9p2"5x
e.printStackTrace (); ,8+SQo#3
} p8Lb*7W
} )"t=sFxaB
^4B6IF*
//日志 yK"U:X
public static void log(String sMsg) c{|soc[#
{ #(ANyU(#e
System.err.println(sMsg); =ZzhH};aX
} r A0[y
a(d'iAU8^
r6PiZgR
public static void log(int sMsg) (tyo4Tz1
{ (V{bfDu&h@
System.err.println(sMsg); r{>tTJFD(:
} >/5D/}4
} ;`X-.45
kl3#&>e
qZ`@Ro
/* kj@#oLd%
**TestMethod.java Qs#v/r
*/ ^a<=@0|
package NetFox; WAqR70{KM
isWB)$q
'e;*V$+
public class TestMethod { [A*vl9=
Gxm+5q
P1Re7/
public TestMethod() 47`{ e_YP0
{ ///xx/weblogic60b2_win.exe t!D=oBCro
try{ fm&l0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [#3:CDT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dr,j~s
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3~s0ux[
fileFetch.start(); 6NJ La|&n
} cCyg&% zsT
catch(Exception e){e.printStackTrace ();} qLA
)ckx&e
^row=5]E
} W%0-SR
CEqfsKrsxE
kJJQcjAP:
public static void main(String[] args) P63z8^y
{ {n.g7S~
new TestMethod(); Td8'z'
} kC LeHH|K
} eaF5S'k 4$
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