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)); &p5^Cjy L
} w6|l ~.$=
for(int i=0;i<nEndPos.length-1;i++) Jn"ya^~
{ 6Tsi^((Li
nEndPos = nStartPos[i+1]; \%QA)T%
} FA1h!Vit
nEndPos[nEndPos.length-1] = nFileLength; 9ZI^R/*Kc
} 2j=HxE
} @Wa,
8p PQ
4f'!,Q ;
//启动子线程 YtA<4XHU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c6tH'oV
for(int i=0;i<nStartPos.length;i++) K/z2.Npn
{ 8JU{]Z!G<;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CB`GiH/j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :]9CdkaU
nStartPos,nEndPos,i); x57O.WdN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S+GW}?!
fileSplitterFetch.start(); /hAy1V6
} 3 V$ \s8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,e;_ Vb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DtkOb,wY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hpo*5Va
nEndPos = " + nFileLength); lA n^)EL
// fileSplitterFetch[nPos.length-1].start(); ;OSEMgB1
TbgIr
U+:Mu]97
//等待子线程结束 VMw[M^
//int count = 0; fwv.^kx
//是否结束while循环 *|6*jU
boolean breakWhile = false; x$.0:jP/s
UVgDm&FF
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while(!bStop) \ \gAa-}:
{ *.!5327
write_nPos(); o&Y R\BI/
Utility.sleep(500); 34 I Cn~
breakWhile = true; C5~ +"#B
)p[Qj58
n7hjYNJ
for(int i=0;i<nStartPos.length;i++) (/A 6kp?
{ `_(N(dm
if(!fileSplitterFetch.bDownOver) gQuU_dbXSB
{ (8Te{Kh'
breakWhile = false; Gk!CU"`sP
break; pd.5
} bpdluWS+)
} rN`-ak
if(breakWhile) !r4B1fX
break; =4K:l}}
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M\r=i>(cu
//count++; <=@6UPsn2
//if(count>4) Xw&vi\*m
// siteStop(); QsyM[;\j:
} $>hH{
ORFi0gFbA
jm,:jkr
System.err.println("文件下载结束！"); :b<<
} tD> qHR
catch(Exception e){e.printStackTrace ();} 6o~g3{Ow
} dm"|\7
B*n_ VBd
ja^
//获得文件长度 6<No_x |_
public long getFileSize() 5E}!TL$
{ PKYm{wO-
int nFileLength = -1; U%KsD 4B
try{ fDwqu.K
URL url = new URL(siteInfoBean.getSSiteURL()); |v:fP;zc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Q~++PKBe
httpConnection.setRequestProperty("User-Agent","NetFox"); 4v.i!U# {
+HoCG;C{
bM"d$tl$?'
int responseCode=httpConnection.getResponseCode(); ;Ngu(es6
if(responseCode>=400) L<p.2[3
{ >z k6{kC
processErrorCode(responseCode); A#nSK#wS61
return -2; //-2 represent access is error NUX$)c
} QPKY9.Rvv
*OHaqe(*
u>[hLXuB
String sHeader; '[Bok=$B)
h&x;#.SYK
VF g"AJf
for(int i=1;;i++) 3<}r+,j
{ _A6e|(.ll
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GW0e=Y=LR
//Utility.log(in.readLine()); K'b #}N\
sHeader=httpConnection.getHeaderFieldKey(i); QaSRD/,M
if(sHeader!=null) bH.f4-.u>)
{ fn Pej?f:
if(sHeader.equals("Content-Length")) 5wbR}`8
{ i?6#>;f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #fq&yjl#A
break; 6d;RtCENo
} '@WS7`@-y
} Je=k.pO1
else _p0G8
break; \6vr)1~N>
} -8z@FLUK-
} W.?EjEx
catch(IOException e){e.printStackTrace ();} pW-aX)\DR
catch(Exception e){e.printStackTrace ();} ~Q+J1S]Fs
@%I-15Jz
j0A9;AP;;C
Utility.log(nFileLength); CMU\DO
j "e]Ui
'nfdOX.d
return nFileLength; B }
} =A<a9@N}N
DVw 04ay%
=|IY[2^
//保存下载信息（文件指针位置） 4Vv$bbu+
private void write_nPos() T:S[[#f{5
{ R'h.lX
try{ b21@iW
output = new DataOutputStream(new FileOutputStream(tmpFile)); iV.j!H7o
output.writeInt(nStartPos.length); 'J_6SD
for(int i=0;i<nStartPos.length;i++) :F pt>g
{ ah15,<j
// output.writeLong(nPos); 1U8/.x|
output.writeLong(fileSplitterFetch.nStartPos); 1a'0cSH
output.writeLong(fileSplitterFetch.nEndPos); 2I0Zr;\f
} 3W55m@w
output.close(); a+P^?N
} M`,`2I A
catch(IOException e){e.printStackTrace ();} Pk)H(,
catch(Exception e){e.printStackTrace ();} 077wk
} YeVkX{y
>?r8D48`
$uYfy<
//读取保存的下载信息（文件指针位置） 0[7tJbN
private void read_nPos() !^qpV7./l
{ lnt}l
try{ #BhcW"@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z;PF%F
int nCount = input.readInt(); T;{"lp.
nStartPos = new long[nCount]; G>S3?jGk
nEndPos = new long[nCount]; )\QPUdOvx
for(int i=0;i<nStartPos.length;i++) 5k`Df/
{ [*d<LAnuWP
nStartPos = input.readLong(); P5oYv
nEndPos = input.readLong(); ?pkGejcQ
} xQ>T.nP}1
input.close(); XWBTBL
} UI74RP
catch(IOException e){e.printStackTrace ();} U9x6\Iy
catch(Exception e){e.printStackTrace ();} ;#ElJXS
} R;H>#caJ
.12H/F
vec4R )S
private void processErrorCode(int nErrorCode) }cERCS\t
{ !]=S A &
System.err.println("Error Code : " + nErrorCode); k;!}nQ&
} 6U%F mE@
+lw*/\7
ETrL3W<
//停止文件下载 GUUd(xS{
public void siteStop() N`NW*~
{ v6O5n(5,,
bStop = true; 'rSJ9Mw"x
for(int i=0;i<nStartPos.length;i++) F 8 gw3
fileSplitterFetch.splitterStop(); h:{^&d a
e6_`
]s}9-!{O
} K'S\$
} r<EwtO+x
//负责部分文件的抓取 :djbZ><
**FileSplitterFetch.java :;N2hnHoG
*/ V7$-4%NL
package NetFox; c!J|vRA5
->5[C0: ]
f- ~]
import java.io.*; k5eTfaxl
import java.net.*; -5<G^AS
?T_bjALW
}Ih5`$
public class FileSplitterFetch extends Thread { RwDXOdgu
MsjC4(Xla.
l`?4O
String sURL; //File URL A\QrawBp0l
long nStartPos; //File Snippet Start Position M`QK{$1p
long nEndPos; //File Snippet End Position ?xb2jZ/0X
int nThreadID; //Thread's ID tW"s^r=95
boolean bDownOver = false; //Downing is over @+; cFj
boolean bStop = false; //Stop identical w! ':Ws
FileAccessI fileAccessI = null; //File Access interface TZw['o
lCJ/@)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gv/yfiA?
{ RKwuvVI
this.sURL = sURL; e/F+Tf
this.nStartPos = nStart; zd?uMq;w
this.nEndPos = nEnd; )KcY<K
nThreadID = id; la89>pF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h3z9}'
} *M+CA_I(
A5%cgr% 6
xZ>@wBQ
public void run() 0<42\ya
{ CAbT9Wz&
while(nStartPos < nEndPos && !bStop) P B"nf|pm
{ $QJ,V~
f(.t0{Etq
,Zb_Pu
try{ 1JF>0ijU@
URL url = new URL(sURL); %oiA'hz;*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SaiYdJ
httpConnection.setRequestProperty("User-Agent","NetFox"); s^ K:cz
String sProperty = "bytes="+nStartPos+"-"; n-:n.JX
httpConnection.setRequestProperty("RANGE",sProperty); mZ4I}_\,
Utility.log(sProperty); yvV]|B@sO
?D=t:=
)/uCdSDIc
InputStream input = httpConnection.getInputStream(); 2[5z6oG
//logResponseHead(httpConnection); a'B 5m]%
./Wi(p{F
<*5`TE0J
byte[] b = new byte[1024]; [OQ+&\
int nRead; 7hfa?Mcz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R1C2d+L
{ bVYsPS
nStartPos += fileAccessI.write(b,0,nRead); I8LoXY
//if(nThreadID == 1) x}H%NzR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m9Hdg^L
} <x\I*%(
?CZ*MMV
#4ii!ev
Utility.log("Thread " + nThreadID + " is over!"); QS2~}{v
bDownOver = true; #5mnSky+s
//nPos = fileAccessI.write (b,0,nRead); A?Gk8
} Mx=L lC)
catch(Exception e){e.printStackTrace ();} ,=y8[(h
} UjH+BC+9`b
} }7Y@u@R
lBfG#\rdW~
J]qx4c
//打印回应的头信息 $jL+15^N0+
public void logResponseHead(HttpURLConnection con) ~A-VgBbU>_
{ ~+Ows
for(int i=1;;i++) x).`nZ1
{ _`q ei0
String header=con.getHeaderFieldKey(i); Nj;G%KAP
if(header!=null) `zMR?F`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3k5F$wf
Utility.log(header+" : "+con.getHeaderField(header)); $/;<~Pzi
else @4%x7%+[c
break; I)}T4OOc/
} i0*6o3h
} Nzel^~
iT&Y9
eHHqm^1z
public void splitterStop() _:.'\d(
{ (S k+nD
bStop = true; _-bEnF+/0
} jGKasI`
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ulxy 4] h
} s14;\
XyE%<]
qjVhBu7A
/* b5d;_-~d
**FileAccess.java p_l.a
*//文件访问(定位，写) -MT.qhx
package NetFox; 3(R]QO`%'
import java.io.*; lv0}d
Ikj_ 0/%F
y/yg-\/XF
public class FileAccessI implements Serializable{ {B+{2;Zk
"ba>.h,#'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xw{Qktn
RandomAccessFile oSavedFile; %[7<GcWl
long nPos; WbDD9ZS
c;1Xu1
)Qx&m}
public FileAccessI() throws IOException X1;ljX
{ ?&GV~DYxA
this("",0); f1}b;JJTsv
} #\r5Q>
XoqmT/P
?^W`7HF%0
public FileAccessI(String sName,long nPos) throws IOException yZDS>7H
{ pG9qD2Cf
oSavedFile = new RandomAccessFile(sName,"rw"); \,G7nT
this.nPos = nPos; #Yr/GNN
oSavedFile.seek(nPos); 3rQ;}<*M
} k4Ub+F
6qzyeli
6I,4 6 XZ-
public synchronized int write(byte[] b,int nStart,int nLen) {[Vkht}
{ )#_:5^1
int n = -1; W! q-WU
try{ 8.R~Ys*
oSavedFile.write(b,nStart,nLen); u+/1ryp
n = nLen; sFWH*kdP?
} ,I|TjC5
catch(IOException e) YsXf+_._
{ r>gU*bs(
e.printStackTrace (); @&LtIN#
} %44Z7
WjsE#9D!of
A~7q=-
return n; 0-a[[hL?
} 3a\.s9A"
zQhc V
h`:f
} I&Y9
li Hz5<|
p^ojhrr
/* '}eA2Q>BV
**SiteInfoBean.java S((\KL,
*/ U>jLh57
package NetFox; \:D'u<8E
2or!v^^u
lf%Ju$H
public class SiteInfoBean { /6Vn WrN_
pswEIa
n.\|NR'v
private String sSiteURL; //Site's URL ?g\SF}2
private String sFilePath; //Saved File's Path 7o5~J)qIC
private String sFileName; //Saved File's Name x9{&rldC
private int nSplitter; //Count of Splited Downloading File (D5.NB%@
_pS!sY~d
7y2-8eL
public SiteInfoBean() (<:mCPk(~
{//nSplitter的缺省值为5 k%S;N{Qh@
//default value of nSplitter is 5 K4>nBvZ?v
this("","","",5); >4N=P0=
} o$FYCz n
E5U{.45
)@OKL0t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'z.: e+Q_
{ =$t
sSiteURL= sURL; :i>/aRNh1
sFilePath = sPath; .*>pD/
sFileName = sName; #(KE9h%
this.nSplitter = nSpiltter; ek3,ss3
!tL&Ktoj
ehCZhi~
} uk)6%
=u^{Jvl[
Sd0y=!Pj=
public String getSSiteURL() v%6mH6V
{ :n t\uwh
return sSiteURL; g9$P J:
} hy?e?^
kbF+aS
NDv_@V(D
public void setSSiteURL(String value) )Ap0" ?q
{ sF=8E8qa
sSiteURL = value; D+:}D*_&
} t/HUG#W{
%ymM#5A
j%y)%4F8
public String getSFilePath() yA#-}Y|]b
{ > l@o\
return sFilePath; wK[Xm'QTPJ
} xf?6_=
t:h~p-&QB
B1C"F-2d
public void setSFilePath(String value) $sX X6K),
{ 82bOiN15
sFilePath = value; `mfN3Q*[c
} %G%D[ i]
$_P*Bk)
pd1V8PZSG
public String getSFileName() #g6*s+Gm
{ VP<_~OLc
return sFileName; }N6r/ VtOQ
} d^Jf(NE0Yo
Xw2tCRzD
,n&e,I
public void setSFileName(String value) B- VhUS
{ qAF.i^
sFileName = value; 9J!@,Zsh
} 5U3b&0
QNzx(IV@
-#ta/*TT:
public int getNSplitter() 8eVQnp*
{ HAi'0%"
return nSplitter; C"We>!
} Ehv*E
'n)]"G|
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public void setNSplitter(int nCount) [H!8m7i;
{ zU7/P|Dw+
nSplitter = nCount; b2Jgg&?G
} z^q ~|7
} ]5=C3Y
#el i_Cxe
?z2k74&M^
/* Rf~? u)h1
**Utility.java oq>8
*/ xqua>!mqS
package NetFox; {{\ d5CkX
pM^r8kIH
zeZ}P>C
public class Utility { }8W5m(Zq9n
t*&O*T+fgy
C6XZZ
public Utility() |Ir&C[QS{y
{ )^C w
laQM*FLg
X8Xw'
} 5V^+;eO
\Q5Jg
//线程睡眠 }4; \sY
public static void sleep(int nSecond) 7:h8b/9
{ : Nf-}"
try{ ?1f(@
Thread.sleep(nSecond); NG2@.hP:uU
} 2 P=c1;
catch(Exception e) "[*W=6m0
{ z}" Xt=G?
e.printStackTrace (); &mM[q'V
} 2[Ja|W\If
} km]RrjRp
k3/V$*i,1b
//日志 z8ox#+l
public static void log(String sMsg) GV5hmDzRs
{ KV!!D{VS`@
System.err.println(sMsg); 5DHFxym'
} /kAu&}
P7||d@VW,
AvN\^ &G
public static void log(int sMsg) FE`:1
{ jG0o-x=X
System.err.println(sMsg); rdFeDZo&Z)
} jtMN)TM
} Qo!/n`19
wuv2bd )+
%Q}T9%Mtj
/* <Q4yN!6
**TestMethod.java -qPYm?$
*/ d@:4se-q+
package NetFox; s5s'$|h"
Z"# /,?|3@
6+MZ39xC
public class TestMethod { gZFtV
H^N@fG<*dh
=]OG5b_-Y
public TestMethod() !Ol>![
{ ///xx/weblogic60b2_win.exe 9K>$
try{ bUW`MH7yJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `[.':"~2N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wm5/>Cu,
SiteFileFetch fileFetch = new SiteFileFetch(bean); H!D?;X
fileFetch.start(); vsjl8L
} RaS7IL:e
catch(Exception e){e.printStackTrace ();} | 'SqG}h
-N')LY
l>i<J1
} QsaaA MGY
*EZ'S+wR
H$ !78/f
public static void main(String[] args) fNVNx~E
{ .}}w@NO
new TestMethod(); FM c9oyU~
} USKa6<:{W
} -!dL <
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