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)); jKZJ0`06q
} "tB"C6b
for(int i=0;i<nEndPos.length-1;i++) BB5(=n+
{ .t''(0_kC
nEndPos = nStartPos[i+1]; 9nlfb~F~P
} 08{0i,Fs
nEndPos[nEndPos.length-1] = nFileLength; K O"U5v
} =4uL1[0'
} *Hy-D</w%
tM]~^U
'9%72yG
//启动子线程 R)d1]k8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rvuskXdo
for(int i=0;i<nStartPos.length;i++) xal+buOiP
{ XRCiv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %4Cs c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c1M/:*?%
nStartPos,nEndPos,i); L5!aLv#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R9nW5f Nf
fileSplitterFetch.start(); -hw^3Af
} }YWLXxb;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?Z= %I$i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7J,j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I}Uj"m`>
nEndPos = " + nFileLength); ED&>~~k)
// fileSplitterFetch[nPos.length-1].start(); t7tX<|aN
|u8IQR'B
X&fM36o7
//等待子线程结束 Z`<S_PPz
//int count = 0; r$}M,! J
//是否结束while循环 z[X>>P3<n
boolean breakWhile = false; QNn\wz_)
<QFT>#@T
+<7~yZ[Z8
while(!bStop) %!I7tR#;
{ Gs;wx_k^
write_nPos(); m`gH5vQa
Utility.sleep(500); e/JbRbZX
breakWhile = true; 5xe}ljo
&?flH;
3ha^NjE
for(int i=0;i<nStartPos.length;i++) r18euB%
{ @S\!wjl]C
if(!fileSplitterFetch.bDownOver) Ya{$:90(4
{ bHRH2Ss
breakWhile = false; ,%7>%*nhk
break; 2%UzCK
} "C%<R
} G(W/.*
if(breakWhile) z ^t6VFM
break; T#kPn#|
0w9)#e+JS
TELN4*
//count++; <5(P4cm9
//if(count>4) ")m0{
// siteStop(); p&dpDJ?d:=
} VWf&F`^B(
9`
`~0)}K.F
System.err.println("文件下载结束！"); 5e=9~].7
} Hy=';Ccn}
catch(Exception e){e.printStackTrace ();} 7pf]h$2
} -L&r2RF/
K}7E;O5m"
koDIxj'%X
//获得文件长度 @-=0T!/
public long getFileSize() 1"tyxAo\
{ Pj(DlC7G,
int nFileLength = -1; ChzKwYDY
try{ C$?gt-tJ'
URL url = new URL(siteInfoBean.getSSiteURL()); Z$ q{!aY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `&y Qtj# '
httpConnection.setRequestProperty("User-Agent","NetFox"); 3NU{7,F
z6 T3vw
>tc#Ofgzd
int responseCode=httpConnection.getResponseCode(); f_v@.vnn.
if(responseCode>=400) T40&a(hXQ
{ EQ< qN<uW
processErrorCode(responseCode); Z./$}tVUG
return -2; //-2 represent access is error %;ST7
} MYNNeO
VwJA
DmzK* O{
String sHeader; mY6d+
0?c2=Y
WOBLgM,|
for(int i=1;;i++) ! Rrk
{ j#4 Iu&YJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5B6twn~[
//Utility.log(in.readLine()); \%&BK.t
sHeader=httpConnection.getHeaderFieldKey(i); ybk~m
if(sHeader!=null) t<=Ru*p
{ zv[$N,
if(sHeader.equals("Content-Length")) y2Eq-Ie
{ _mSDz=!Z3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /bm2v;
break; \tR](, /
} V+`gkWe/
} y,&'nk}
else 0xE37Ld,
break; 2IMU &
} |q|?y`X4/
} <46>v<
catch(IOException e){e.printStackTrace ();} GZ=7)eJ~<
catch(Exception e){e.printStackTrace ();} mQL8ec_c
WXq=FZ-
FTu6%~M/
Utility.log(nFileLength); &.W,Hh
>}~\*Y\8@
!fX&i6
return nFileLength; b$@vJ7V!
} /wAx#[c[
Nk JOD3>U
9t$#!2z
//保存下载信息（文件指针位置） *Wbs{>&No
private void write_nPos() hSAdD!
{ oVZI([O
try{ XotiKCk|Aq
output = new DataOutputStream(new FileOutputStream(tmpFile)); T'i^yd}*v
output.writeInt(nStartPos.length); GK6/S_l%D+
for(int i=0;i<nStartPos.length;i++) y5@#leM
{ -9PJ4"H
// output.writeLong(nPos); 5;v_?M!UCK
output.writeLong(fileSplitterFetch.nStartPos); nR%ey"
output.writeLong(fileSplitterFetch.nEndPos); J[|4`GT
} &,DZ0xA
output.close(); dw*PjIB9x
} L i g7Ac,
catch(IOException e){e.printStackTrace ();} zv%]j0 ?
catch(Exception e){e.printStackTrace ();} ]S
} gm^j8B
6DkFIkS
"FD`1
//读取保存的下载信息（文件指针位置） \p4>onGI
private void read_nPos() =Ff _)k
{ ZYS`M?Au
try{ bm>N~DC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bwR$910b
int nCount = input.readInt(); 7];AB;0"
nStartPos = new long[nCount]; 8n&Gn%DvX
nEndPos = new long[nCount]; !l6Ez_'
for(int i=0;i<nStartPos.length;i++) P^3`znq{
{ $Wy(Wtrx|
nStartPos = input.readLong(); %3%bRP
nEndPos = input.readLong(); o:wI{?%-3
} yf4I<v$y
input.close(); 9ZJn 8ki
} N4HIQ\p
catch(IOException e){e.printStackTrace ();} 6y+_x'
catch(Exception e){e.printStackTrace ();} hr@kU x
} $.+_f,tU
kuq&8f~!
2`'g 9R
private void processErrorCode(int nErrorCode) ~:krJ[=
{ qkbGM-H%U
System.err.println("Error Code : " + nErrorCode); zH5pe
} n2V $dF4m
#}p@+rkg2
N%f% U
//停止文件下载 n 9>**&5L
public void siteStop() C^IPddw>
{ W5*Kq^6Pd
bStop = true; \V(w=
for(int i=0;i<nStartPos.length;i++) ""f'L,`{.
fileSplitterFetch.splitterStop(); P:#KBF;a
:{LNr!I?I
\:BixBU7
} \; voBU
} eae`#>XP
//负责部分文件的抓取 $xU)t&Df
**FileSplitterFetch.java \<aR^Sj.
*/ <rihi:4K
package NetFox; {Mpx33
~dBx<
wi/qI(O!
import java.io.*; U-*`I?~=4
import java.net.*; 9oU1IT9
('~}$%C
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public class FileSplitterFetch extends Thread { V/&JArW
|1pDn7
BROn2aSx%
String sURL; //File URL rRvZG&k
long nStartPos; //File Snippet Start Position `Sx1?@8(
long nEndPos; //File Snippet End Position =OeLF
int nThreadID; //Thread's ID ;?G..,
boolean bDownOver = false; //Downing is over /:;"rnvq
boolean bStop = false; //Stop identical $5wf{iZY.Q
FileAccessI fileAccessI = null; //File Access interface ew.jsa`TrW
`N}aV Ns
@tIY%;Bgk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2C Fgit
{ V7"^.W*
this.sURL = sURL; F{G.dXZZ<
this.nStartPos = nStart; /UqIkc
this.nEndPos = nEnd; 4KX\'K
nThreadID = id; 4aiI&,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w{WEYS
} ,hOi5,|?L
ElA(1o|9I
9vckQCLM
public void run() P,rD{ 0~
{ *.6m,QqJ(
while(nStartPos < nEndPos && !bStop) n_{az{~
{ y 2C Jk~
+QEP:#qZw
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try{ R $@$
URL url = new URL(sURL); "-Yj~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ES\=MO5a7
httpConnection.setRequestProperty("User-Agent","NetFox"); [X 9zrGHt
String sProperty = "bytes="+nStartPos+"-"; (DkfLadB
httpConnection.setRequestProperty("RANGE",sProperty); LP'wL6#
Utility.log(sProperty); 0!b9%I=j
(h|E@gRa
^GS\(egt
InputStream input = httpConnection.getInputStream(); \<HY'[gr
//logResponseHead(httpConnection); 8shx7"
B|"-Ed
[pC2#_}
byte[] b = new byte[1024]; Vb)NWXmyu
int nRead; aL&nD1f=!-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,1B`Ve
{ ?IG[W+M8
nStartPos += fileAccessI.write(b,0,nRead); 8},:
//if(nThreadID == 1) t,u;"%go
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kk).KgR
} =gB8(1g8
N F,<^ u
F/cA tT.M?
Utility.log("Thread " + nThreadID + " is over!"); -wr_x<7
bDownOver = true; g`w46X
//nPos = fileAccessI.write (b,0,nRead); ?=im~
} B- D&1gO
catch(Exception e){e.printStackTrace ();} Oye6IT"
} $)eS Gslz
} 3lTnfc&
-\7_^8 am
1ozb tn
//打印回应的头信息 #5=W[+4eN
public void logResponseHead(HttpURLConnection con) CFUn1^?0
{ [1mEdtqf*
for(int i=1;;i++) NwVhJdo
{ ]=p^32
String header=con.getHeaderFieldKey(i); "yc|ng
if(header!=null) I+,CiJ|4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c^<~Y$i
Utility.log(header+" : "+con.getHeaderField(header)); ]_j={0%
else >Q=Q%~
break; P;eXUF+jn
} B1A:}#
} lL&U ioo}D
s!S_Bt):3
DYoGtks(
public void splitterStop() I_ AFHrj
{ (*_lLM@Cd
bStop = true; LJ K0WWch
} ,M~> t7+
_'4S1
}kF?9w
} s\< @v7A
FKPR;H8>
*I[tIO\
/* :H:Se
**FileAccess.java aU@1j;se@
*//文件访问(定位，写) E $P?%<o
package NetFox; ]V)*WP#a
import java.io.*; Sx8C<S5r<
"lrQC`?
^ FM
public class FileAccessI implements Serializable{ 7?D?s!%\
>=:^N-a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _Ie:!q
RandomAccessFile oSavedFile; sm;kg=
long nPos; dtE"1nR
NwxDxIIH/)
'\GU(j
public FileAccessI() throws IOException 1:r#m- \
{ _u'y7-
this("",0); &F:.OVzX
} 2C1NDrS;}
%P{3c~?DH
3/PvH E{R
public FileAccessI(String sName,long nPos) throws IOException Wffz&pR8
{ &E1m{gB(
oSavedFile = new RandomAccessFile(sName,"rw"); Y;'SD{On
this.nPos = nPos; xI.0m
oSavedFile.seek(nPos); ~4|Trz2T
} 'c_K[p$
5fMlOP_
Pf/8tXs}
public synchronized int write(byte[] b,int nStart,int nLen) 0yvp>{;p
{ :wN!E{0j
int n = -1; 1Vx5tOq
try{ D1$ER>
oSavedFile.write(b,nStart,nLen); ~L>86/hP,N
n = nLen; E[6:}z<
} +xgP&nw[-
catch(IOException e) a4gX@&it_k
{ AWE ab
e.printStackTrace (); awI{%u_(nA
} CUHT5J*sY
"Zx<hL*
nt+OaXe5D
return n; ~A1!!rJX
} aj,o<J
1;DRcVyS+
V#b=mp
} B^]PKjLNZ
;TS%e[lFhQ
#vhN$H:&q
/* N|Ag8/2A
**SiteInfoBean.java q3#+G:nh
*/ GKjtX?~1
package NetFox; /%s:aO
r/HCWs|
7(oA(l1V
public class SiteInfoBean { `R>z{-@=
KQvSeH>r
~**x_ v
private String sSiteURL; //Site's URL K[ [6A:
private String sFilePath; //Saved File's Path C\aHr!
private String sFileName; //Saved File's Name vf$IF|
private int nSplitter; //Count of Splited Downloading File +iFt)
| oK9o6m4
~;a\S3
public SiteInfoBean() HsUh5;
{//nSplitter的缺省值为5 @K+gh#
//default value of nSplitter is 5 uo J0wG.
this("","","",5); ~#jiX6<I
} 7Xu#|k
zA8@'`Id
wpN3-D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fISK3t/=C
{ _ilitwRN3
sSiteURL= sURL; fU?#^Lg
sFilePath = sPath; lgS7;
sFileName = sName; 1YJ?Y
this.nSplitter = nSpiltter; 5 7t.Ud
1kw*Q:
)dqNN tS
} 0 p?AL=
lux g1>
@fJsRWvGq
public String getSSiteURL() CoNaGb
{ -4sKB>b
return sSiteURL; ux)*B}/xh
} M?UUT8,
6%ofS8[
$Seh4
public void setSSiteURL(String value) @+H0D"
{ l EzN
sSiteURL = value; T'vI@i9
} c9fz x
~/9RSdv7
VOZxLyj^9
public String getSFilePath() kHylg{i{"
{ #IZh}*$
return sFilePath; r A(A$VR
} 0VSIyG_Z
"n`z`{<n
<<CWN(hQWO
public void setSFilePath(String value) j&_>_*.y
{ yDKH;o
sFilePath = value; 7/51_=%kR
} P1T{5u!T
pR93T+X
NWvIwt{
public String getSFileName() _<FUS'"
{ J sz=5`
return sFileName; 8K-P]]
} k]5tU\;Yw
$b1>,d'oz
S-88m/"]s
public void setSFileName(String value) f"P866@oWn
{ #jrlNg4(
sFileName = value; (C#0 ML
} >MN"87U6
;Vat\,45pg
JJ ?'<)EF
public int getNSplitter() e4SS'0|
{ 7=^}{
return nSplitter; k[ zyR
} o]Ne|PEpO
Y;_F,4H
rFpYlMct
public void setNSplitter(int nCount) @4T
{ ?x&}ammid
nSplitter = nCount; 5l1R")0`t_
} gM>?w{!LBx
} '~K]=JP
{qi#
_7Y-gy#\a
/* =3QhGFd
**Utility.java (b//YyqN
*/ >pLJ ,Z
package NetFox; FEu"b@v
SfC* ZM}<
\WFcb\..
public class Utility { XZARy:+bc
bRy(`
;9mRumLG"
public Utility() UTKyPCfj
{ zHZfp_I
[znN'Fg:"
V<S6a
} G6zFQ\&f
^C~Ryw7
//线程睡眠 U@y)x+:
public static void sleep(int nSecond) qzbW0AM[M
{ $.4A?,d
try{ \ opM}qZ
Thread.sleep(nSecond); e[u}Vf
} bKM*4M=k
catch(Exception e) C0N}B1-MU
{ iSezrN
e.printStackTrace (); d;YKw1
} Slg*[r#
} n({%|O<|
F<g&t|@
//日志 6c-3+,Y"#
public static void log(String sMsg) ?[zw5fUDS
{ AF"7 _
System.err.println(sMsg); InbB2l4G
} UzaAL9k
TU^ZvAO&
l1k&@1"
public static void log(int sMsg) tUxH6IS
{ \XV8t|*
System.err.println(sMsg); /Q(boY{
} Vsl,u
} uc@4fn
ZN$%\,<
b`D]L/}pr
/* (Q=o9o:b
**TestMethod.java SkmTW@v
*/ CYy=f-
package NetFox; -_t4A *
8bdO-LJ9
R&.&x'<
public class TestMethod { 0}NDi|o
4;Ucas6
E|c(#P{
public TestMethod() 1k4\zVgi
{ ///xx/weblogic60b2_win.exe 56<UxIa~
try{ tdxzs_V,-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1Y$%| `
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,Kj>F2{
SiteFileFetch fileFetch = new SiteFileFetch(bean); a)pc+w#
fileFetch.start(); mbkt7. ,P
} /Z:NoTGn
catch(Exception e){e.printStackTrace ();} }p*|8$#x"
x6R M)rr
E8r6P:5d`
} N Nk
*Igb3xK%
)m;*d7l~p
public static void main(String[] args) JK<[]>O
{ }wiyEVAh{
new TestMethod(); *w4#D:g
} @ !su7
} k*N!U[]
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