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)); 3*</vo#`
} _" 9 q(1
for(int i=0;i<nEndPos.length-1;i++) b+qd' ,.Z
{ DehjV6t
nEndPos = nStartPos[i+1]; ^~V2xCu!
} Ds(Z.
nEndPos[nEndPos.length-1] = nFileLength; /.e7#-+?
} [+D]!&P
} u1X^#K$nu'
&qg6^&
yx|iZhK0:}
//启动子线程 y-E'Y=j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QO =5Q
for(int i=0;i<nStartPos.length;i++) ^ l#6Es
{ P{A})t7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :L@;.s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~o_JZ:
nStartPos,nEndPos,i); L-`V^{R]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &6s&nx
fileSplitterFetch.start(); )$S=iL8(
} -6DRX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `$> Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cS%dTrfo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <?B3^z$
nEndPos = " + nFileLength); _33b %
// fileSplitterFetch[nPos.length-1].start(); b_TI_
W2X`%Tx0
"Y<;R+z
//等待子线程结束 W|8VE,"7
//int count = 0; Q8`V0E\~
//是否结束while循环 )$TN%hV!
boolean breakWhile = false; \Vx^u}3O
FQO=}0Hl
nlB'@r
while(!bStop) v Z]j%c@
{ 4o}{3! m
write_nPos(); n}a`|Nbk
Utility.sleep(500); A4f"v)vM
breakWhile = true; @Pcgm"H<
ftRFG
+TqrvI.
for(int i=0;i<nStartPos.length;i++) nV8'QDQ:Al
{ K/*R}X
if(!fileSplitterFetch.bDownOver) >niv>+!N
{ t>"`rcg
breakWhile = false; LujLC&S
break; i FZGfar?
} _3%$E.Q
} ;7s^slVzF
if(breakWhile) HFP'b=?`]|
break; AI3x,rk#
15jQ87)
S'HA]
//count++; }Ecv6&G
//if(count>4) K*5gb^Ul
// siteStop(); f@;pN=PS
} g "Du]_,
RI8*'~ix]
VLm\PS
System.err.println("文件下载结束！"); yJ!26
} ~4+Y BN
catch(Exception e){e.printStackTrace ();} 'sIne>
} 8WV5'cX
w98M#GqV
GAY?F
//获得文件长度 9BZ B1oX
public long getFileSize() }i^M<A O
{ *~P| ? D'
int nFileLength = -1; ~OX\R"aZBW
try{ !k% PP
URL url = new URL(siteInfoBean.getSSiteURL()); o}r_+\n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !IR cv a
httpConnection.setRequestProperty("User-Agent","NetFox"); _}[WX[Le{
+/celp
k5K5OpY
int responseCode=httpConnection.getResponseCode(); 1f+A_k/@
if(responseCode>=400) ,X3D<wl
{ 3A^AEO
processErrorCode(responseCode); #"-_~
return -2; //-2 represent access is error KH#z=_
} JfkEJk<
~9o@1TO:v
_5S0A0
String sHeader; i45.2,
\\ItN
* ;sz/.
for(int i=1;;i++) g5+m]3#t
{ +i}H $.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a^LckHPI>
//Utility.log(in.readLine()); ZB1%Kn#zo4
sHeader=httpConnection.getHeaderFieldKey(i); (5] [L<L
if(sHeader!=null) Vf:.C|Z
{ 1p~ORQ
if(sHeader.equals("Content-Length")) ^@/wXj:
{ k'%yvlv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 873 bg|^hs
break; yg8=G vO
} @$kO7k0{g
} \2+ngq)
else CRCy)AS,t
break; uq[5 om"
} .Bkfe{^
} l4$ sku-
catch(IOException e){e.printStackTrace ();} Eg1TF oIWl
catch(Exception e){e.printStackTrace ();} ??e|ec2%
(&79}IEd
.*6NqX$
Utility.log(nFileLength); 'eBD/w5U
~roNe|P
)0E_Y@
return nFileLength; '%/=\Q`
} -cUbIbW
*2/qm:gB
tt-ci,X+
//保存下载信息（文件指针位置） MzB.Vvsy%9
private void write_nPos() <LH6my
{ \YJQN3^46>
try{ vbJdhaf
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]0<K^OIY
output.writeInt(nStartPos.length); Q[3hOFCX
for(int i=0;i<nStartPos.length;i++) ,5<AV K-#Q
{ `vzMuL;
// output.writeLong(nPos); x(sKkm`Q
output.writeLong(fileSplitterFetch.nStartPos); 00IW9B-
output.writeLong(fileSplitterFetch.nEndPos); PdVY tK%
} f%n ;Z}=
output.close(); Q1*_l
} }>AA[ba"'
catch(IOException e){e.printStackTrace ();} |8{ k,!P'K
catch(Exception e){e.printStackTrace ();} HABUf^~-
} LsI@_,XW<
+ R6X
CB9:53zK9
//读取保存的下载信息（文件指针位置） #\N8E-d
private void read_nPos() /zh:7N
{ Ie!">8."
try{ }BW&1*M{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .!^OmT,u
int nCount = input.readInt(); %n6<6t`$
nStartPos = new long[nCount]; @VHstjos^V
nEndPos = new long[nCount]; 0VQBm^$(
for(int i=0;i<nStartPos.length;i++) z2Wblh"_
{ +fM8
nStartPos = input.readLong(); G"3KYBN>
nEndPos = input.readLong(); \nyqW4nTm
} %I`'it2d
input.close(); m["e7>9G
} ;uc3_J]
catch(IOException e){e.printStackTrace ();} ?#<'w(^%#
catch(Exception e){e.printStackTrace ();} \H>Psv{
} MV3K'<Y
kz}Bc F
)$1j"mV
private void processErrorCode(int nErrorCode) s+_8U}R
{ J*K=tA
System.err.println("Error Code : " + nErrorCode); qYVeFSS
} euV!U}Xr
A`~?2LH,~F
4`o0?_.'
//停止文件下载 vq9O|E3
public void siteStop() IDpLf*vSG
{ @g`|ob]9
bStop = true; )(.g~Q:
for(int i=0;i<nStartPos.length;i++) 8cvSA&l(D
fileSplitterFetch.splitterStop(); 0iC5,
1,zc8>M
P()n=&XO6
} L$"x*2[A
} %&H^UxC
//负责部分文件的抓取 )mAD<y+
**FileSplitterFetch.java JgHYuLB
*/ dg*xo9Xi`
package NetFox; EJz!#f~
. WJ
Q~Nq5[
import java.io.*; R$IsP,Uw
import java.net.*; e\aW~zs2
;B2&#kot7
rFt+Y})
public class FileSplitterFetch extends Thread { %*<Wf4P"
K&{ _s
)#4(4 @R h
String sURL; //File URL ;D-k\kv
long nStartPos; //File Snippet Start Position UWqiA`,
long nEndPos; //File Snippet End Position Exv!!0Cd^
int nThreadID; //Thread's ID I)jAdd
boolean bDownOver = false; //Downing is over $z)egh(z
boolean bStop = false; //Stop identical QCDica `+*
FileAccessI fileAccessI = null; //File Access interface }h/7M
c>c4IQ&d
wj'fdrY5h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {Z!t:'x8
{ 45Zh8k
this.sURL = sURL; ./DlHS;
this.nStartPos = nStart; >}0H5Q8@
this.nEndPos = nEnd; 1W0[|Hf2v*
nThreadID = id; qKeR}&b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D>U(&n
} Ln+.$ C
S+eu3nMq
%0vsm+XQ0E
public void run() I:al[V2g
{ .bV^u
while(nStartPos < nEndPos && !bStop) *GhV1# <
{ Mw+ l>92
jC>mDnX
I3Z\]BI
try{ kDR5kDiS
URL url = new URL(sURL); (VCJn<@@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &01KHJY)/G
httpConnection.setRequestProperty("User-Agent","NetFox"); XdlA)0S)
String sProperty = "bytes="+nStartPos+"-"; c\szy&W
httpConnection.setRequestProperty("RANGE",sProperty); DtS7)/<T
Utility.log(sProperty); d}?KPJ{
- ? i
wJgH15oB
InputStream input = httpConnection.getInputStream(); 6"[,
//logResponseHead(httpConnection); m^RO*n.
{SZv#MrK
vkYiO]y
byte[] b = new byte[1024]; g^=Ruh+
int nRead; Ya<V@qd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,k@iNid
{ "ZNy*.G|[
nStartPos += fileAccessI.write(b,0,nRead); ?< Ma4yl</
//if(nThreadID == 1) |Zo36@s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &`]T#">
} RA+M.
X}QcXc.d
[oXr6M:
Utility.log("Thread " + nThreadID + " is over!"); @L607[!?
bDownOver = true; *|6vCR
//nPos = fileAccessI.write (b,0,nRead); JnQ@uZb`
} i_!$bk<yo
catch(Exception e){e.printStackTrace ();} 4] u\5K-
} 7coVl$_Zl
} ]-+l.gVFW
= ~*Vfx
GJ?J6@|
//打印回应的头信息 ~e]l
public void logResponseHead(HttpURLConnection con) Ak}`zIo
{ -\Z`+kY?p
for(int i=1;;i++) Qo(<>d
{ -Vmp6XY3q
String header=con.getHeaderFieldKey(i); FId,/la
if(header!=null) NJ$Qm.S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f&Sovuuh
Utility.log(header+" : "+con.getHeaderField(header)); xj]^<oi<
else Efpju(
break; anKflt3
} ?ZhBS3L
} "{bc2#F
!b$~Sm)
OzTR#`oey
public void splitterStop() EyV5FWb58
{ s,|v,,<+
bStop = true; W_ ;be
} 9D?JzTsyg
/p}pdXS
Y$ KR\ m
} =|c7#GaiF
(@*%moo
8&1xb@Nc7
/* x.I?)x!C'
**FileAccess.java @RdNAP_6
*//文件访问(定位，写) DoN]v
package NetFox; 5RF*c,cNq
import java.io.*; BISH34
( ~JtKSq%
2c*}1 _
public class FileAccessI implements Serializable{ Q} -YD.bx3
TTo?BVBK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M@pF[J/
RandomAccessFile oSavedFile; }h sR}
long nPos; IFtaoK
d]?fL&jr
(r1"!~d@
public FileAccessI() throws IOException zP$"6~.
{ w[^lxq
this("",0); D~2n8h"2ye
} |B2>}Y/
!G'wC0
Izfq`zS+\s
public FileAccessI(String sName,long nPos) throws IOException JFkx=![
{ gU@R
oSavedFile = new RandomAccessFile(sName,"rw"); R0q|{5S
this.nPos = nPos; 2H~E~6G
oSavedFile.seek(nPos); T!1XL7
} >GDf* ox[
5E${
NMN&mJsmh
public synchronized int write(byte[] b,int nStart,int nLen) 2Fbg"de3-
{ ~KxK+6[ :
int n = -1; 8&7zV:=
try{ WjvgDNk
oSavedFile.write(b,nStart,nLen); x*:"G'zT
n = nLen; :vE\r#hJ"
} ]-OF3+l4
catch(IOException e) TH~"y
{ WvcPOt8Bp>
e.printStackTrace (); IKp/xj[!
} aL8Z|*
7aHP;X~0
i\ )$
return n; b,#?LdQ%
} cfc=a
ypTH=]y
Rvj[Csgi
} f!B\X*|
}#Kl6x
=vb'T
/* VexQ ]
**SiteInfoBean.java bZgFea_>i
*/ FMl_I26]
package NetFox; Z:VT%-
$N4i)>&T2
TTSq}sb}
public class SiteInfoBean { ZP<OyX?
#\6k_toZ
yONX?cS
private String sSiteURL; //Site's URL GP=bp_L
private String sFilePath; //Saved File's Path l0%7u
private String sFileName; //Saved File's Name Tqx
private int nSplitter; //Count of Splited Downloading File <,&t}7M/:
2bOFH6g
_$T.N
public SiteInfoBean() D\z`+TyJ
{//nSplitter的缺省值为5 |_16IEJ
//default value of nSplitter is 5 or[!C%
this("","","",5); w#>CYP`0k6
} Htce<H-P
1HeE$
zoau5t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N{K[sXCW
{ &[[Hfs2:-]
sSiteURL= sURL; @KU^B_{i
sFilePath = sPath; 5&}p'6*K
sFileName = sName; JzkI!5c<j
this.nSplitter = nSpiltter; 'c$)}R I7
C=DC g
E~`<n]{G-C
} |N5|B Q(y$
H|<Zm:.%$
K^c%$n:}+
public String getSSiteURL() G@,XUP
{ Ym9~/'%]
return sSiteURL; 'CvV Ktk
} *YP;HL
^x}k1F3
$6/CTQ
public void setSSiteURL(String value) 'I@l$H
{ {br6*
sSiteURL = value; le~p2l#e
} OsgjSJrf
#9q ]jjH E
KH9D},
public String getSFilePath() yzyK$WN\[3
{ .\"8H1I\T
return sFilePath; Z (C0+A\
} m 8P`n
BSyS DM
70N Lv
public void setSFilePath(String value) q4Y7 HE|ym
{ /(DnMHn\
sFilePath = value; /vw$3,*z
} Lwkl*
:[ll$5E.
4.q^r]m*
public String getSFileName() noO#o+ Jg#
{ /2:s g1
return sFileName; e}TDo`q
} G)&S%R!i\N
C\}M_MD
`"y:/F"{
public void setSFileName(String value) N)
{ NPLJ*uHH
sFileName = value; wfQImCZ>l
} V6fJaZ
*)s^+F 0
yMJ(Sf
public int getNSplitter() > QG@P
{ & DhdB0Hjf
return nSplitter; {ukQBu#}<
} =&WH9IKz
m`Pk)c0
0t6DD
public void setNSplitter(int nCount) ;e6-*
{ 5>aK4: S/
nSplitter = nCount; -{NP3zy
} N,4hh?
} e;9x%kNs!
VI?kbqjo
XUTsW,WC
/* K7wU tg
**Utility.java 4++pK;I
*/ 3|bbJ6*.<
package NetFox; 0N_u6*@
#{@qC2!2/
D_ XOYzN}
public class Utility { $ J!PSF8PL
C0CJ;
~#7uNH2
public Utility() z&CBjlh
{ VXl|AA<OG
t\f[->f
v[O?7Np
} -@.FnFa
`bF4/iBW
//线程睡眠 0U?(EJ
public static void sleep(int nSecond) 5RyxVC0<
{ /ACau<U]t
try{ XHh*6Yt_ (
Thread.sleep(nSecond); A+(+PfU
} DSlO.)dHu
catch(Exception e) YmLpGqNv
{ S{N=9934_
e.printStackTrace (); WG +]
} u@t~*E5BpM
} Cng_*\=O
oj@=Cq':-
//日志 ?%$~Bb _
public static void log(String sMsg) 3!`_Q%
{ :KS"&h{SY
System.err.println(sMsg); v ,zD52
} 3 6t^iV*3
Xh}G=1}
uw(Ml=
public static void log(int sMsg) Gh352
{ 3gtKD9RL:
System.err.println(sMsg); -B#K}xL|x
} 1 ]ePU8
} m$7C{Mr'
HhwAzk/G~
/#zs
/* uZ'(fnZ$
**TestMethod.java k106fT]eX
*/ \\3 ?ij:v
package NetFox; 4RfBXVS
ZO>)GR2S
|XV`A)=f
public class TestMethod { w:x[kA
\"w+4}
wj5,_d)
public TestMethod() ;te( {u+
{ ///xx/weblogic60b2_win.exe s\p 1EL(
try{ _%#Uh#7P$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NMUF)ksjN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dA<_`GFR
SiteFileFetch fileFetch = new SiteFileFetch(bean); JL>DRIR%NV
fileFetch.start(); [I/ZzDMX
} _-2ntO<E
catch(Exception e){e.printStackTrace ();} {a15s6'd
N6> rU
`G%h=rr^c
} *X^C+F
HDaeJk
trB-(B%5
public static void main(String[] args) umCmxmr&
{ .[Qi4jm>`
new TestMethod(); \fp'=&tp~a
} cp0yr:~
} A4Q{(z-?
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