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)); >x6)AH.
} 5tk7H2K^<
for(int i=0;i<nEndPos.length-1;i++) *!j!o%MB
{ J/3$I
nEndPos = nStartPos[i+1]; skU }BUK6
} ]u:_r)T
nEndPos[nEndPos.length-1] = nFileLength; 64vj6 &L
} Ktu~%)k%
} nPDoK!r'
-<sW`HpD'
yYP>3]z
//启动子线程 % [~0<uO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dn:\V?9
for(int i=0;i<nStartPos.length;i++) K=r~+4F
{ X\>/'fC$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x&"P^gh)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p/G9P +?
nStartPos,nEndPos,i); 5m;BL+>YE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KUpj.[5qo
fileSplitterFetch.start(); g9=_^^Tg
} \}X[0ct2!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), > 6=3y4tP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^8YBW<9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |>1#)cONW
nEndPos = " + nFileLength); Cs\jPh;"
// fileSplitterFetch[nPos.length-1].start(); dpX Fx"4A
Ypxp4B
=LgMG^@mu
//等待子线程结束 uy<<m"cA;
//int count = 0; @%YbptT}
//是否结束while循环 {;6a_L@q;|
boolean breakWhile = false; ;}M&fXFp"|
Z[0/x.pp$
4Xww(5?3
while(!bStop) ( uG;Q
{ m&z(2yb1
write_nPos(); '=eVem=
Utility.sleep(500); fJ6Q:7
breakWhile = true; REh\WgV!u
URt+MTU[
VF b
for(int i=0;i<nStartPos.length;i++) )eqF21\
{ 6urU[t1
if(!fileSplitterFetch.bDownOver) 6'.)z,ts
{ E25w^x2
breakWhile = false; P,(_y8
break; g++-v HD
} EEo I|
} (_6JQn
if(breakWhile) #k[Y(_
break; yk(r R
iXWB
Ix<!0! vk
//count++; UoUQ6Ij
//if(count>4) TtH!5{$s
// siteStop(); #sk~L21A
} 2E`mbT,v&
=''b`T$
{oR@'^N
System.err.println("文件下载结束！"); `M(st%@n
} !w@i,zqu
catch(Exception e){e.printStackTrace ();} h%NM%;"H/
} "@|rU4Y
t;-F]
ZHlHnUo
//获得文件长度 ~B?Wg!
public long getFileSize() 2$`Y 4b3t
{ zL3zvOhu}
int nFileLength = -1; SoHaGQox
try{ k*!iUz{]
URL url = new URL(siteInfoBean.getSSiteURL()); +@H{H2J4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I6gduvkXi4
httpConnection.setRequestProperty("User-Agent","NetFox"); YpRhl(|
GV28&!4sS
p)]x,F
int responseCode=httpConnection.getResponseCode(); pf+VYZ#)
if(responseCode>=400) tkkh<5{C
{ r. (}
processErrorCode(responseCode); 7$t['2j3
return -2; //-2 represent access is error wA)nryXV
} OVc)PMp
2-Wy@\
euW
String sHeader; ;t,v/(/3
3 TTQff
zSu,S4m_;
for(int i=1;;i++) wXKt)3dmu
{ E7_OI7C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '#eT
//Utility.log(in.readLine()); {E7STLQ_%
sHeader=httpConnection.getHeaderFieldKey(i); qmenj
if(sHeader!=null) LR\8M(rtvH
{ RCxwiZaf33
if(sHeader.equals("Content-Length")) OdNcuiLa
{ td23Z1Elk#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KmM:V2@A$
break; NV@$\<
} m6]6!_
} %DA`.Z9#
else 9sd}Z,l
break; l4(FM}0X5}
} rk@qcQR
} 8xG"hJR
catch(IOException e){e.printStackTrace ();} [Fv,`*/sm
catch(Exception e){e.printStackTrace ();} zMBGpqdP
I0=L_&`)
zr_L V_e
Utility.log(nFileLength); bR~5 :A^
o;#8=q
3K/'K[~
return nFileLength; b& -8/t
} bd% M.,
-5|el3%)
%6m' |(-
//保存下载信息（文件指针位置） ir>+p>s.
private void write_nPos() |F<%gJ
{ vts"
try{ c': 4e)
output = new DataOutputStream(new FileOutputStream(tmpFile)); SBf=d<j 1)
output.writeInt(nStartPos.length); mV)t
for(int i=0;i<nStartPos.length;i++) hY!>>
{ DUH_LnHw)
// output.writeLong(nPos); Q9B!0G.-bs
output.writeLong(fileSplitterFetch.nStartPos); V0&7MY*
output.writeLong(fileSplitterFetch.nEndPos); 6pfkv2.}
} &GvSgdttv
output.close(); ~l{Qz0&
} oDJ &{N|
catch(IOException e){e.printStackTrace ();} ! hEZV&y
catch(Exception e){e.printStackTrace ();} mFxt +\
} Msfxce
HDKY7Yr
VB T66kV
//读取保存的下载信息（文件指针位置） W tHJG5
private void read_nPos() 1$6 u
{ MpvGF7H
try{ _@gg,2 u-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _x#y
int nCount = input.readInt(); bAuiMw7!
nStartPos = new long[nCount]; ]` A*7
nEndPos = new long[nCount]; Wa.!eAe}
for(int i=0;i<nStartPos.length;i++) E|SmvIV-
{ %g3QE:(2@q
nStartPos = input.readLong(); ,:MUf]Ky
nEndPos = input.readLong(); NYs<`6P:Y
} o{n#f?EA
input.close(); B,%KvL&xMX
} OL:hNbw'~T
catch(IOException e){e.printStackTrace ();} !?Y71:_!
catch(Exception e){e.printStackTrace ();} B4+c3M\$V
} pv&iJ7RN
1/qD5 *`Y
8ph1xQ'
private void processErrorCode(int nErrorCode) jVN=_Y}\
{ d(R8^v/L
System.err.println("Error Code : " + nErrorCode); -vk/z+-^!
} GK6CnSV8d
UX.rzYM&T
KxeqQ@
//停止文件下载 a|[f%T<<
public void siteStop() 5J&Gc;[p
{ gm8JxhL
bStop = true; fQg^^ZXe"
for(int i=0;i<nStartPos.length;i++) /6yVbo"
fileSplitterFetch.splitterStop(); b&1hj[`)
"&^KnWk=
7^UY%t
} ;E5XH"L\
} T g3MPa#g
//负责部分文件的抓取 &TrL!9FtJ
**FileSplitterFetch.java M(C}2.20
*/ )`\Q/TMl5
package NetFox; j]5e$e{
0Q,Tcj
gSyBoY
import java.io.*; 0/fZDQH
import java.net.*; v$(Z}Hg
{TMng&
qs_cC3"=%=
public class FileSplitterFetch extends Thread { uGW#z_{(n
B>\q!dX3
0oBAJP
String sURL; //File URL F{.g05^y
long nStartPos; //File Snippet Start Position 6cbV[!BL
long nEndPos; //File Snippet End Position I69Z'}+qz
int nThreadID; //Thread's ID ]gv3|W
boolean bDownOver = false; //Downing is over O*,O]Q
boolean bStop = false; //Stop identical KZ^>_K&
FileAccessI fileAccessI = null; //File Access interface wc"~8Ah
qf<o"B|_9
'.S02=/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;:J"- p
{ /7,@q?v
this.sURL = sURL; `_ZbA#R,
this.nStartPos = nStart; 48G^$T{
this.nEndPos = nEnd; VsK8:[Al
nThreadID = id; $kMe8F_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m] p]J_6A
} w-v8P`V
REi"Aj=
2\+N<-(F5
public void run() 2.v`J=R
{ '}(Fj2P79
while(nStartPos < nEndPos && !bStop) 0R(['s:3`
{ M\IdQY-c
oblw!)
l^}5PHLd
try{ vMn$lT@
URL url = new URL(sURL); J#iuF'%Ds
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wq1s#ag<
httpConnection.setRequestProperty("User-Agent","NetFox"); `w@z Fc!"
String sProperty = "bytes="+nStartPos+"-"; p}wysVB
httpConnection.setRequestProperty("RANGE",sProperty); X(DP=C}v9
Utility.log(sProperty); "@5{=
4mX]JH`UTe
L5 Ai
InputStream input = httpConnection.getInputStream(); wGIRRM !b
//logResponseHead(httpConnection); ) R\";{`M
r8czDc),b
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byte[] b = new byte[1024]; YWV)C?5x&
int nRead; h2:TbQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Bqk+ne
{ <+b~E,
nStartPos += fileAccessI.write(b,0,nRead); ?hIDyM
//if(nThreadID == 1) s`.J!^u`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5N;xo??
} WUQa2$.
\X]I: 0^j
}20tdD ~
Utility.log("Thread " + nThreadID + " is over!"); 2@HmZ!|Q
bDownOver = true; f6Y-ss;'
//nPos = fileAccessI.write (b,0,nRead); F%%mcmHD#
} wZ`{ i
catch(Exception e){e.printStackTrace ();} Z7e"4wA
} AAB_Ytf
} Olt;^>MQ
j{=}?+M
7.n\a@I/
//打印回应的头信息 Zx6h%l,%
public void logResponseHead(HttpURLConnection con) gssEdJ
{ H{EZ} *{M4
for(int i=1;;i++) #Wb4*
{ ~52'iI)Mw
String header=con.getHeaderFieldKey(i); 0 EA3>$;
if(header!=null) v"Ryg]^_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \]\GDpu[
Utility.log(header+" : "+con.getHeaderField(header)); la$%%@0/
else Bw[IW[(~!
break; 8hyXHe
} XZ(<Mo\v
} jr-9KxE
37M,Os1(
']OT7)_
public void splitterStop() mfDt_Iq
{ *Id[6Z
bStop = true; RgM=g8}M
} ~rAcT6#
kKC] n
Sb)}
} 5pHv5e
V;~\+@
"#f5jH
/* -h8Z@r~a/
**FileAccess.java 6D{70onY+
*//文件访问(定位，写) *$1F|G
package NetFox; X>]<rEh
import java.io.*; yRQNmR;Uy
2:yXeSeA
KXWz(L!1
public class FileAccessI implements Serializable{ Wm)Id_
I:MrX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uOd1:\%*
RandomAccessFile oSavedFile; 0+w(cf~6
long nPos; a,fcR<
F2)KAIl
9u3P>a~b
public FileAccessI() throws IOException -|=)
{ -`t9@1P> =
this("",0); e?]HNy
} {q~N$"#
%S>6Q^B
mFd|JbW
public FileAccessI(String sName,long nPos) throws IOException KyqP@ {
{ AF{@lDa1h
oSavedFile = new RandomAccessFile(sName,"rw"); RyWfoLc
this.nPos = nPos; YnCuF0>
oSavedFile.seek(nPos); lfR}cx
} `sd H q
V*@&<x"E
ZHj7^y@P
public synchronized int write(byte[] b,int nStart,int nLen) 2xBh
{ 7p{uRSE4._
int n = -1; OO,%zwgt
try{ B.gEV*@
oSavedFile.write(b,nStart,nLen); CT<z1)#@^
n = nLen; " #U-*Z7
} 'P%&*%
catch(IOException e) wx2 z9Q
{ QG@Z%P~,E
e.printStackTrace (); lJS3*x#H
} m YhDi
%UV"@I+
FEV Ya#S
return n; G('UF1F
} v|3mbApv
C9>^!?>
!!~r1)zN
} G=kW4rAk
~ntDzF
4v#s!W
/* J*^ i=y
**SiteInfoBean.java pp >F)A0v
*/ v\}{eP'
package NetFox; B!)Tytm9u
Ffd;aZ4n
]XYD2fR2qA
public class SiteInfoBean { Emk:@$3{r
w`zS`+4
}L^PZS@Jf
private String sSiteURL; //Site's URL aHNn!9#1
private String sFilePath; //Saved File's Path E*+]Iq1u
private String sFileName; //Saved File's Name v,iq,p)&
private int nSplitter; //Count of Splited Downloading File o$}$Z&LK
zzT4+wy`
,V;HMF.
public SiteInfoBean() bGlr>@;-r
{//nSplitter的缺省值为5 (!Fu5m=<8
//default value of nSplitter is 5 ~P*{%=a
this("","","",5); Ve40H6Ox
} \GGyz{i
W!* P
;9vY5CxzC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i3$pqNe
{ @CC 6`D
sSiteURL= sURL; Y{X%C\
sFilePath = sPath; ]BmnE#n&
sFileName = sName; CUaL
this.nSplitter = nSpiltter; $vnx)#r3
#"[EVF0%1D
P|;f>*^Y
} J d,9<m$
shVEAT'`
5`::#[
public String getSSiteURL() }=u#,nDl>$
{ ?MvL}o\|
return sSiteURL; `?"r\Qo<
} !0v3Lu~j
g$qM}#s0}
uaha)W;'9
public void setSSiteURL(String value) nM99AW
{ ]qEg5:yY
sSiteURL = value; Bc<pD?uOK
} ?07}\N0~
0J;Qpi!u2v
9LOq*0L_:
public String getSFilePath() hF5(1s}e$
{ LK>;\BRe?
return sFilePath; &Cr4<V6-q
} Z55C4F5v
&=wvlI52`
}8`>n4
public void setSFilePath(String value) >g{b'Xx
{ /!*=*
sFilePath = value; 0sF|Y%N
} Qzv&
gYmO4/c,
-Q%Pg<Q-#
public String getSFileName() SES-a Mi3
{ ]y"=/Nu-Ja
return sFileName; ,!P}Y[|
} }gd'pgN"t
Z,8t!Y
ylQ9Su>o
public void setSFileName(String value) A}_pJH
{ pxW*kS
sFileName = value; R pT7Nr
} ao@CPB6N
| S'mF6Y
vr_Z0]4`C9
public int getNSplitter() ?R4%z2rcW
{ 6<f(Zv? I
return nSplitter; @\a~5CLN
} U+!&~C^y
WDt6{5T
*0<)PJ T
public void setNSplitter(int nCount) ff00s+
{ x_wWe>0
nSplitter = nCount; `dRqheX
} A!R'/m'VG
} c Ze59
XcL%0%`
mo&9=TaG
/* `^h:}V
**Utility.java q*cEosi'F?
*/ r^ABu_u(`I
package NetFox; T*'WS!z
wGxH
sFsf~|
public class Utility { Xx\,<8Xn
e-b>
GH`y-Ul'K
public Utility() 4^:$|\?]
{ ?MS!t6
{P)O#
YoWXHg!U
} /NxuNi;5
"|V}[ 2
//线程睡眠 8O[l[5u&
public static void sleep(int nSecond) be?Bf^O>
{ [*@ +
try{ eDvh3Y<D
Thread.sleep(nSecond); `oM'H+
} "+Sq}WR
catch(Exception e) _z9~\N/@[
{ 1X9J[5|ll
e.printStackTrace (); |f(*R_R
} "akAGa!V+
} d$Y_vX<
(;-_j/
//日志 3jHg9M23[^
public static void log(String sMsg) .bj:tmz
{ q4,/RZhzh
System.err.println(sMsg); dXsD%sG@
} OU!."r`9
-"?~By}<C
G#A6<e/
public static void log(int sMsg) 3{wuifS
{ 9mjJC
System.err.println(sMsg); m7i(0jd +
} }{Ra5-PY
} +[4y)y`
kO$n0y5e
ab]Q1kD
/* hFxT@I~
**TestMethod.java <`wOy[e
*/ @a,=ApS"
package NetFox; z#GSt ZT
;<"V}, C
0Gu?;]GSv
public class TestMethod { k"%sdYkb!
n~tb z"&
G\^<MR|
public TestMethod() O- LwX >
{ ///xx/weblogic60b2_win.exe M}q;\}
try{ Y/T-q<ag8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PWkSl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z'Pe%}3
SiteFileFetch fileFetch = new SiteFileFetch(bean); #rNc+
fileFetch.start(); UT[{NltH
} $xcZ{C
catch(Exception e){e.printStackTrace ();} {L [
{JF"PAS7
'yV*eG?^&
} 34nfL: y
VE}r'MBk
r3KNRr@
public static void main(String[] args) m9+?>/R
{ C%CgWO`Xj
new TestMethod(); %5nEyZOq
} %~,Fe7#p
} R.vOYzo
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