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)); luyU!
} Olg@ Ri
for(int i=0;i<nEndPos.length-1;i++) {/x["2a1
{ APgP*,
nEndPos = nStartPos[i+1]; qn+b*4
} <xm>_~,w
nEndPos[nEndPos.length-1] = nFileLength; tnbtfG;z#
} z#8d\X/
} ;Q;u^T`
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S1<mO-
//启动子线程 c8cV{}7Kb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]Hp o[IF
for(int i=0;i<nStartPos.length;i++) HrUQ X4
{ e7<//~W7W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =U6%Wdth
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f*VBSg[`
nStartPos,nEndPos,i); pr2b<(Pm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p=Nord
fileSplitterFetch.start(); ubn`w=w$
} >4A~?=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,1"w2,=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '[ZRWwhr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cC.=,n
nEndPos = " + nFileLength); LCrE1Q%VP
// fileSplitterFetch[nPos.length-1].start(); vxxa,KR/y
y;+5cn C
f#RI&I\
//等待子线程结束 AZ7
//int count = 0; Nj2f?',;U
//是否结束while循环 8:%=@p>$
boolean breakWhile = false; qV%t[>
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while(!bStop) *RQkL'tRf
{ "JLKO${ Y
write_nPos(); .!ThqYo
Utility.sleep(500); R6ynL([xh
breakWhile = true; }U=|{@%
q$$:<*Uy
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for(int i=0;i<nStartPos.length;i++) fX,L;Se"
{ 6B)3SC
if(!fileSplitterFetch.bDownOver) }E5oa\1u
{ 2 0Xqs,
breakWhile = false; 'E2\e!U/
break; e Ir|%
} W|K"0ab
} :/N/u5.]
if(breakWhile) &C eG4_Mi
break; 7q&//*%yF
j +j2_\
*t{$GBP
//count++; i,Yq oe`
//if(count>4) _c=[P@
// siteStop(); h&3*O[`
} <_HK@E<_HO
gO*:<B g
v$R+5_@[l
System.err.println("文件下载结束！"); FhZ^/= As
} i<N[sO
catch(Exception e){e.printStackTrace ();} _~aFzM
} I$K?,
&TqY\l
$]4>;gTL'
//获得文件长度 &UhI1mi]h
public long getFileSize() @J~n$^ke
{ o2 =UUD&
int nFileLength = -1; 'iM;e K
try{ L lmdydC%
URL url = new URL(siteInfoBean.getSSiteURL()); gU7@}P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^goa$uxU
httpConnection.setRequestProperty("User-Agent","NetFox"); >E;-asD
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int responseCode=httpConnection.getResponseCode(); j rX.e
if(responseCode>=400) MP|J 0=H5
{ (9_~R^='y
processErrorCode(responseCode); &uwj&-u?
return -2; //-2 represent access is error ~f&lQN'1
} OI3UC=G
L&wJ-}'l
gA)!1V+:
String sHeader; d\Xi1&&
rlEp&"+|M
" gB.
for(int i=1;;i++) xtef18i>
{ p`// *gl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SST1vzm!
//Utility.log(in.readLine()); jd9GueV*(
sHeader=httpConnection.getHeaderFieldKey(i); Oj<.3U[C
if(sHeader!=null) 8+no>%L
{ GE`:bC3
if(sHeader.equals("Content-Length")) ,f`435R
{ @SREyqC4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VvuwgJX
break; +.N3kH
} 0MK|spc
} G1 ?."
else rixP[`!]x
break; h+e Oe}
} si.A"\bm
} i)nb^
catch(IOException e){e.printStackTrace ();} 3,~M`~B
catch(Exception e){e.printStackTrace ();} Si,[7um
N zY}-:{
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Utility.log(nFileLength); S Rs~p
X {,OP/
PI>PEge!&
return nFileLength; ?CB*MWjd
} mzufl:-=
*')g}2iB
%Z@+K_X9x
//保存下载信息（文件指针位置） /+\m7IS
private void write_nPos() Ha l,%W~e
{ mQmn&:R
try{ !8q+W`{
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^,L vQW4
output.writeInt(nStartPos.length); =M"H~;f]
for(int i=0;i<nStartPos.length;i++) v,Lv4)
{ P-9[,3Zd
// output.writeLong(nPos); 7cx~?xk <m
output.writeLong(fileSplitterFetch.nStartPos); "(y",!U@
output.writeLong(fileSplitterFetch.nEndPos); -TKS`,#
} 70p1&Y7or
output.close(); 8X=cGYC#
} TRwlUC3hQ
catch(IOException e){e.printStackTrace ();} rrK&XP&
catch(Exception e){e.printStackTrace ();} f,9jK9/$
} (~F{c0\C
O5HK2Xg,C
V5y8VT=I
//读取保存的下载信息（文件指针位置） hC ^|
private void read_nPos() 1iq,Gd-G.
{ <7HVkAa
try{ J&4QI( b.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S pxkB!
int nCount = input.readInt(); c$),/0td|
nStartPos = new long[nCount]; {6%vmMbJ
nEndPos = new long[nCount]; Fj\}&H*+
for(int i=0;i<nStartPos.length;i++) %,$Ms?,n`
{ 7a_pO1MBL
nStartPos = input.readLong(); |;2Y|>=
nEndPos = input.readLong(); $mvcqn;
} ]]lgCac_U9
input.close(); (4_7ICFI
} )3<|<jwcx
catch(IOException e){e.printStackTrace ();} EL!V\J`S_
catch(Exception e){e.printStackTrace ();} DA)+)PhY7K
} Q3MG+@)S
D"o}XTH
y=i_:d0M
private void processErrorCode(int nErrorCode) ?!>B}e&,
{ T'9I&h%\
System.err.println("Error Code : " + nErrorCode); yX%T-/XJ
} .<zW(PW
KK;3<kX
y6.}h9~
//停止文件下载 K;jV"R<9
public void siteStop() WF0%zxg]
{ CZB!vh0
bStop = true; BrYU*aPW;
for(int i=0;i<nStartPos.length;i++) ,4oYKJ$+h
fileSplitterFetch.splitterStop(); x2p}0N
E"!I[
7'wt/9
} ~=hM y`Ml
} CJB
//负责部分文件的抓取 V4cCu~(3;~
**FileSplitterFetch.java S,Q!Xb@
*/ K#bdb
package NetFox; T^LpoN/T
}gL:"C"~
(.Hiee43
import java.io.*; bJc<FL<E
import java.net.*; Ed[ tmaEuV
Q!DH8'|4?L
L/Cp\|~ O
public class FileSplitterFetch extends Thread { g_lj/u]P
"?Dov/+Q.
4|Z;EAFx
String sURL; //File URL @UCI^a~w
long nStartPos; //File Snippet Start Position YXE?b@W"
long nEndPos; //File Snippet End Position X`km\\*
int nThreadID; //Thread's ID lz>YjK:
boolean bDownOver = false; //Downing is over f49pIcAq
boolean bStop = false; //Stop identical 6?y<F4
FileAccessI fileAccessI = null; //File Access interface qzk/P1{-
A4RA5N/}
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Il(p!l<Xz#
{ om%L>zfB
this.sURL = sURL; );T0n
this.nStartPos = nStart; C^ngdba\
this.nEndPos = nEnd; \l^L?69
nThreadID = id; :^7P. lhK
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z3!j>X_w
} UObI&*2
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public void run() #clOpyT*
{ Jt79M(Hp!
while(nStartPos < nEndPos && !bStop) ; MU8@?yN
{ 0zrgK;9
DG& ({vy
(XtN3FTY
try{ eQh@.U*S)
URL url = new URL(sURL); ]IbX<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [JAHPy=+w
httpConnection.setRequestProperty("User-Agent","NetFox"); @c&}\#;
String sProperty = "bytes="+nStartPos+"-"; ovv<7`
httpConnection.setRequestProperty("RANGE",sProperty); .FUws
Utility.log(sProperty); VO#x+u]/
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3vx5dUgl,
InputStream input = httpConnection.getInputStream(); NQQ+l0txI
//logResponseHead(httpConnection); V+#Sb
zTtn`j$
p<b//^
byte[] b = new byte[1024]; &L3OP@;
int nRead; BJGL &N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5,/rh,?
{ N ]KS\
nStartPos += fileAccessI.write(b,0,nRead); I'&#pOB
//if(nThreadID == 1) 7.7aHt0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~>C@n'\lv
} hY$gzls4
L?~>eT
12 y=Eh
Utility.log("Thread " + nThreadID + " is over!"); Dq=&K,5;
bDownOver = true; -$W#bqvz^
//nPos = fileAccessI.write (b,0,nRead); Co|3k:I 8
} 0=N,y
catch(Exception e){e.printStackTrace ();} >eX&HSoy
} }yQ&[Mt
} P2y`d9,Q
l=EnK"aU
K%NNw7\A
//打印回应的头信息 ZL!,s#
public void logResponseHead(HttpURLConnection con) Ze `=n
{ bf1Tky=/
for(int i=1;;i++) w>-@h>Ln
{ [ .]xy
String header=con.getHeaderFieldKey(i); 5%H(AaG*q
if(header!=null) !,D7L6N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a%\6L
Utility.log(header+" : "+con.getHeaderField(header)); UC3&:aQ!
else 7Mx F? I
break; Gn*cphb
} ]=X6* E*/E
} [bE-Uu7q5P
Y j[M>v
_~q!<-Z
public void splitterStop() .3xpDVW^e
{ &BF97%E2
bStop = true; :bBLP7eyV
} Ew`(x30E
r~mZ?dI
t:MeSO
} R/!lDv!
g]kM7,/M
e6?iQ0
/* ~_l@ _P5yz
**FileAccess.java -PfBL8
*//文件访问(定位，写) 54[#&T$S
package NetFox; z1dSZ0NoA
import java.io.*; e}@VR<h
"LwLTPC2
i}&&rr
public class FileAccessI implements Serializable{ P{T\zT
}kJfTsFS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n~c<[
RandomAccessFile oSavedFile; ;Dh\2! sr
long nPos; z@bq*':~J
++9?LH4S4
DIsK+1
public FileAccessI() throws IOException -DVoO2|Dv
{ u{| Q[hf[
this("",0); X`/GiYTu
} @wvgMu
aPU.fER
>(EC.ke
public FileAccessI(String sName,long nPos) throws IOException ?<F=*eS
{ .[8! E_
oSavedFile = new RandomAccessFile(sName,"rw"); Ux[2 +Cf
this.nPos = nPos; KjWF;VN*[3
oSavedFile.seek(nPos); ,=_)tX^
} e>$d*~mwn
Y"{L&H `
-FOn%7r#Y
public synchronized int write(byte[] b,int nStart,int nLen) RB\ Hl
{ K#"J8h;x
int n = -1; uez"{_I
try{ XAb%V'
oSavedFile.write(b,nStart,nLen); Oy}^|MFfA
n = nLen; ddTsR
} V8w7U:K
catch(IOException e) 8+f{ /
{ rt rPRR\:"
e.printStackTrace (); [c^!;YBp)
} N F$k~r
QJ i5H
(6}[y\a+
return n; enC/@){~
} -1_WE/Ps
O'Mo/ u1-
n%faD
} lr*p\vH
gg0rkg
-gQtw% `x
/* T}}T`Ce
**SiteInfoBean.java TS_5R>R3
*/ f:9bq}vH
package NetFox; `w6*(t:T
(HEi;
3 as~yF0
public class SiteInfoBean { cp:U@Nh(
40e(p/Qka
bmOK8
private String sSiteURL; //Site's URL \DiAfx<Ub
private String sFilePath; //Saved File's Path 8t;vZ&
private String sFileName; //Saved File's Name _ez*dE%
private int nSplitter; //Count of Splited Downloading File @Ojbu@A
t!8(IR
+TZVx(Z&A
public SiteInfoBean() > `1K0?_
{//nSplitter的缺省值为5 &%UZ"CcA
//default value of nSplitter is 5 <~ Dq8If
this("","","",5); ?v z[Zi
} BS.5g<E2q
`<3%`4z/
uIy$|N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~GLWhe-
{ =dT #x
sSiteURL= sURL; }6'%p Bd
sFilePath = sPath; _4f=\
sFileName = sName; UVd ^tg
this.nSplitter = nSpiltter; HJi FlL3
WaPuJ5;e
&ggOm
} lt{Df~c
\wKnX]xGf
$$ 9!4
public String getSSiteURL() p uZY4}b_
{ @+6cKP
return sSiteURL; .rwa=IW
} o5E5s9n
GI<3L K\
aD&4C-,1
public void setSSiteURL(String value) /;5/7Bvj
{ 2@6Qifxd@
sSiteURL = value; p)qM{`]G\
} 1`sTGNo
,bxGd!&{Q
4Uk\hgT0
public String getSFilePath() z j F'CY
{ ZBkbr
return sFilePath; U>i}C_7g
} /u&7!>,
0;L.h|R T(
6J]8BHJn+
public void setSFilePath(String value) ?$Dc>
{ jK]An;l{Z
sFilePath = value; p[K!.vOt+
} rw$ =!iyO
N}ugI`:
?{;7\1[4
public String getSFileName() IkuE|
{ v@d]*TG
return sFileName; <^w4+5sT/
} C"0vMUZ
K8JshFIe
5^97#;Q;J"
public void setSFileName(String value) ,_UTeW6M
{ 1{<r~
sFileName = value; +w2 `
} l*z+<c6$_
KJ7-Vl>
`)tIXMn
public int getNSplitter() Fr_6pEH]}
{ q`|rS6
return nSplitter; P9o=G=i
} T<%%f.x[s
p=[SDk`
m@W>ku
public void setNSplitter(int nCount) Eq=j+ch7
{ 2@!B;6*8q
nSplitter = nCount; r+usMF<'
} #0:rBKm,
} xC9?Wt'
Nwg?(h#
=PjxMC._
/* h-]c
**Utility.java `n"PHur
*/ i~LY
package NetFox; $=5kn>[_Z%
e0M'\'J
@Hl+]arUh
public class Utility { ZUakW3f
oL7F^34;
h2y<vO
public Utility() FY)US>
{ X4JSI%E
3$9V4v@2
2v<O}
} :W9a t
Ri>ZupQ6
//线程睡眠 Dqc2;>
public static void sleep(int nSecond) 0_N.s5~N
{ /bF>cpM
try{ _`.Q7
Thread.sleep(nSecond); !tSh9L;<O
} ^vJy<
catch(Exception e) A: O"N
{ zJ_y"bt
e.printStackTrace (); SPp|/ [i7
} _h I81Lzq
} LvMA('4
pV`/6 }
//日志 '?6j.ms M
public static void log(String sMsg) ZA\;9M=
{ (3Z;c_N
System.err.println(sMsg); !xU[BCbfYV
} lV9
Svdmg D!
}1 j'
public static void log(int sMsg) =&)R2pLs*
{ 7M~/[f7Z{
System.err.println(sMsg); pM~-o?
} PU4-}!K
} LKA/s ~G
pjma<^|F
wlEK"kKU
/* >[ g=G
**TestMethod.java Os*s{2OvO
*/ qYQ vjp
package NetFox; pq:[`
rl x6a@MiD
WtC&Qyuq
public class TestMethod { ]_`ICS
tNQACM8F;
R7A:K]iJ5
public TestMethod() 5n[''#D
{ ///xx/weblogic60b2_win.exe k\r^GB
try{ 5z:#Bl-,L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S~>R}=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iz0:
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8~F?%!X
fileFetch.start(); x.sC015Id
} MpTOC&NG%s
catch(Exception e){e.printStackTrace ();} tns4e\
G_M8? G0
0lOR.}]q
} >uDC!0)R
&}t8O?!
OuKRaZ
public static void main(String[] args) @)wsHW%cjz
{ q8HnPXV
new TestMethod(); d5`D[,]d
} X|aD>CT
} >I',%v\?@
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