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)); h.tj8O1
} eY3:Nl^
for(int i=0;i<nEndPos.length-1;i++) ]L~z9)
{ }4>u_)nt
nEndPos = nStartPos[i+1]; ^x&x|ckR!
} wwl,F=| Y
nEndPos[nEndPos.length-1] = nFileLength; u[qy1M0
} U,2OofLM
} "22./vWV|i
R"OT&:0/
d_ =K (}eR
//启动子线程 v.W!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "5eD >!
for(int i=0;i<nStartPos.length;i++) lB27Z}
{ ?`TJ0("z"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &m5^ YN$b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L@\t] ~
nStartPos,nEndPos,i); #N`'hPD}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]MYbx)v)
fileSplitterFetch.start(); ;d<XcpK}
} TU?n;h#TZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lx-%y'P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8nI~iN?"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [g}^{ $`
nEndPos = " + nFileLength); N,w6
// fileSplitterFetch[nPos.length-1].start(); VQ!4( <XD
9]3l'
r5&c!b\
//等待子线程结束 ScJ:F-@>
//int count = 0; ]yKwH 9sl
//是否结束while循环 L^e*_q2d:>
boolean breakWhile = false; 2>"{El|PbN
u0R[TA3
.:H'9QJg
while(!bStop) %;4#?.W8
{ _3 [E$Lg
write_nPos(); "|i1AR:I
Utility.sleep(500); 5S? "<+J'
breakWhile = true; UP-2{zb |?
9>+>s ?IgK
x/1FQ>n:9
for(int i=0;i<nStartPos.length;i++) zpT{!V
{ |g7)A?2J~
if(!fileSplitterFetch.bDownOver) [vtDtwL
{ ?bd!JW bg`
breakWhile = false; <;i&-,
break; Z2{$FN
} 5%S5*c6BD
} NZ`6iK-V_
if(breakWhile) {;bec%pq0
break; w+rw<,u%
'_g&!zi8~
W=2.0QmW
//count++; IF>v -Z
//if(count>4) ?Zv5iI
// siteStop(); &/EZn xl
} akw:3+`
\yymp70w
%|@?)[;
System.err.println("文件下载结束！"); R(Vd[EGY
} CWs;1`aP
catch(Exception e){e.printStackTrace ();} yq3"VFh3d
} ?_pd#W=!
,S(_YS^m
jM*wm~4>@
//获得文件长度 IAd^$9
public long getFileSize() .*k!Zl*
{ ;2 o{6
int nFileLength = -1; Y\!:/h]E&
try{ ~l+~MB
URL url = new URL(siteInfoBean.getSSiteURL()); ^umHuAAE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ahd{f!
httpConnection.setRequestProperty("User-Agent","NetFox"); M]\"]H?
oQyMs>g
T5~Qfl?Y
int responseCode=httpConnection.getResponseCode(); #oGvxc7
if(responseCode>=400) ziW[qH {
{ KJ?/]oLr0
processErrorCode(responseCode); TuMZHB7h;
return -2; //-2 represent access is error yyR@kOGga
} Zfu" 8fX
K6<1&
w*SFQ_6YE
String sHeader; tORDtMM9+
,38bT#p:,r
/9y'UKl7[
for(int i=1;;i++) !x:w2
{ RAyR&p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0txSF^x
//Utility.log(in.readLine()); lSId<v?C>
sHeader=httpConnection.getHeaderFieldKey(i); x^F2Ywp%
if(sHeader!=null) '.&,.E&{$
{ Q[O U`
if(sHeader.equals("Content-Length")) BcGQpv&x
{ /`x|-9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D/{Spw@
break; _ )^n[_E
} Qzk/oHs
} b!37:V\#}
else X>jwjRK $
break; q33!X!br
} r52,f%nlm
} uP ?gGo
catch(IOException e){e.printStackTrace ();} [/t/694
catch(Exception e){e.printStackTrace ();} !as<UH"\
S4~;bsSx
gk6j5 $Y"<
Utility.log(nFileLength); ^?[^o\/@R
Z42v@?R.!W
EZiGi[t7
return nFileLength; &4MVk3SLx#
} : [vp.vw}/
;lWy?53=@
[dL?N
//保存下载信息（文件指针位置） 1[`l`Truz
private void write_nPos() nBiA=+'v
{ s.dn~|a
try{ d0Kg,HB
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?t.?f`(|
output.writeInt(nStartPos.length); Hp> J,m(*
for(int i=0;i<nStartPos.length;i++) L{CHAVkV
{ zck |jhJ6
// output.writeLong(nPos); f<'&_*7,|t
output.writeLong(fileSplitterFetch.nStartPos); N<Q}4%^c
output.writeLong(fileSplitterFetch.nEndPos); 4_I,wG@
} VF==F_l
output.close(); "Lpt@g[HF
} ZCJ8I
catch(IOException e){e.printStackTrace ();} v:T` D
catch(Exception e){e.printStackTrace ();} 7erao-
} .}y Lz
#WpO9[b>
Z*e7W O.
//读取保存的下载信息（文件指针位置） t@19a6:Co
private void read_nPos() nt[0krG
{ .r*b+rc;]
try{ U ._1'pW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =yNHJHRA#
int nCount = input.readInt(); 't_=%^q
nStartPos = new long[nCount]; c!\y\r
nEndPos = new long[nCount]; $BBfsaJPT
for(int i=0;i<nStartPos.length;i++) ptq{$Y{_
{ u]MF r2
nStartPos = input.readLong(); G7/LYTT)
nEndPos = input.readLong(); Z/RUrYeb
} Tx_(^K
input.close(); ]R>k0X.V
} b~1p.J4
catch(IOException e){e.printStackTrace ();} YL=k&QG
catch(Exception e){e.printStackTrace ();} !<6wrOMaO
} +m7x>ie)
6$dm-BI
$xZk{ rK
private void processErrorCode(int nErrorCode) f"0H9
{ Y@\5gZ&T
System.err.println("Error Code : " + nErrorCode); o%9>elOju
} -MEz`7c~
Gf]s?J^a
IFTW,9hh
//停止文件下载 #"yf^*wX
public void siteStop() =K>Z{%i
{ I2DmM"-|
bStop = true; aQmL=9
for(int i=0;i<nStartPos.length;i++) B+DRe 8
fileSplitterFetch.splitterStop(); \j;uN#)28
cnPXvD^kY
(MIw$)#^
} R39R$\
} 5)oIPHXw
//负责部分文件的抓取 B:r-')!0$#
**FileSplitterFetch.java g^4FzJ
*/ =U2Te
package NetFox; .}<B*e=y
"AK3t' jF*
jrl6):x
import java.io.*; E\*",MGL
import java.net.*; 9cmJD5OO
2!3&Ub#FO
q5W'P>
public class FileSplitterFetch extends Thread { l>(G3lIw
`pMI[pLZe
2*L/c-
String sURL; //File URL fBOPd=
long nStartPos; //File Snippet Start Position >C}RZdO~
long nEndPos; //File Snippet End Position r=Q5=(hn
int nThreadID; //Thread's ID _Usg`ax-
boolean bDownOver = false; //Downing is over *&0Hz{|
boolean bStop = false; //Stop identical `j<tI6[e
FileAccessI fileAccessI = null; //File Access interface ?^vZ{B)&0E
f,a %@WT
yrs3`/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U[D<%7f
{ ZtLn*M
this.sURL = sURL; ggTjd"|)
this.nStartPos = nStart; ncdr/(`
this.nEndPos = nEnd; .am*d|&+G
nThreadID = id; {|E7N"Qzg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,h._iO)I^
} y4L9Cxvs
NFc8"7Mz}
A,e^bM
public void run() _MEv*Q@o
{ 'X,V
while(nStartPos < nEndPos && !bStop) \veL5
{ EG.C2]Fi
R7{hoqI2
4"{wga~%/
try{ .Cus t
URL url = new URL(sURL); \8D~,$,``|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UG_0Y8$
httpConnection.setRequestProperty("User-Agent","NetFox"); k>CtWV5B
String sProperty = "bytes="+nStartPos+"-"; Z :+#3.4$3
httpConnection.setRequestProperty("RANGE",sProperty); 8!SiTOzR?
Utility.log(sProperty); >[@d&28b%
pb Ie)nK
o?FUVK
InputStream input = httpConnection.getInputStream(); (`+Z'Y
//logResponseHead(httpConnection); (d#Z-w-
SXz([Z{)
}aM`Jp-O
byte[] b = new byte[1024]; w0Y%}7
int nRead; wS0bk<(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?&m]du#6
{ \Agg6tYr
nStartPos += fileAccessI.write(b,0,nRead); vB*oI~<
//if(nThreadID == 1) 8!6*|!,:?n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Ab_PAw
} 3raA^d3!?
^b %8_?2m
J"%}t\Q
Utility.log("Thread " + nThreadID + " is over!"); T_[\(K`w!
bDownOver = true; oLMi vy4
//nPos = fileAccessI.write (b,0,nRead); CWQ2iu<_0
} m5aaY
catch(Exception e){e.printStackTrace ();} ?\M6P?tpo&
} zpqNmxmF
} # :w2Hf6Q
J6ShIPc
A_~5|
//打印回应的头信息 MjC%6%HI
public void logResponseHead(HttpURLConnection con) %:?QE ;
{ xN8JrZE&
for(int i=1;;i++) Jk`)`94I
{ ok2~B._+;
String header=con.getHeaderFieldKey(i); 2] G$6H
if(header!=null) X$iJ|=vW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i%4k5[f.:
Utility.log(header+" : "+con.getHeaderField(header)); H<}eoU.
else :&)/vq
break; >o#wP
} 'a^tL[rLP1
} ]UT|BE4v
TeCpT2!5j
.<^YE%
public void splitterStop() /'fDXSdP
{ {WeXURp&nF
bStop = true; `lezJ(Xm
} {FY[|:Cp
=e8L7_;
n o+tVm|
} )2Ru!l#
YQdX>k
$YY)g$
/* .]s(c!{y
**FileAccess.java 9XqAjez\
*//文件访问(定位，写) \Fg6b6
package NetFox; #x@lZ!Y
import java.io.*; etMh=/NFV
2qMsa>~
{a8^6dm*E
public class FileAccessI implements Serializable{ ]j2v"n
Pph8"`mv.m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i6#]$B
RandomAccessFile oSavedFile; T) tZU?
long nPos; ;GFB@I@
s[2ZxCrCw
)1nCw
public FileAccessI() throws IOException #3yw
{ 83ic@[
this("",0); "=\_++
} 6eYf2sZ;J
_c ]3nzIr
66@3$P%1p
public FileAccessI(String sName,long nPos) throws IOException s7nX\:Bw:
{ 9me}&Fdr
oSavedFile = new RandomAccessFile(sName,"rw"); W({TC
this.nPos = nPos; j-`X_8W
oSavedFile.seek(nPos); ~J>gVg%66
} =Cy>$/H64
tK|9qs<%
4!~ .6cp3
public synchronized int write(byte[] b,int nStart,int nLen) Qj<{oZp&
{ YG 5Z8@kH
int n = -1; 0SYf<$
try{ Jhsv2,8 {
oSavedFile.write(b,nStart,nLen); q X%vRf0
n = nLen; n~)HfY
} rH&r6Xv[
catch(IOException e) s'aV qB
{ q bZ,K@0
e.printStackTrace (); ?(/j<,m^
} s|gD
u2-@?yt
nz(q)"A
return n; me:|!lI7YU
} &xBK\
3_\{[_W
2@3.xG
} $TA6S+
gJ3OK!/
jxnQG A
/* En,)}yI
**SiteInfoBean.java ^\[LrPqe
*/ 12tJrS*Z
package NetFox; ? %+VG
y^!E "
cF_;hD|YZ
public class SiteInfoBean { FS`vK`'
Dpdn%8+Z
<cDKGd
private String sSiteURL; //Site's URL C](z#c~c
private String sFilePath; //Saved File's Path i'Y'HI
private String sFileName; //Saved File's Name 6i]Nr@1C
private int nSplitter; //Count of Splited Downloading File Z[k#AgC)
[EmOA.6
"s>fV9YyZ
public SiteInfoBean() 2fzKdkJhe
{//nSplitter的缺省值为5 %R5Com
//default value of nSplitter is 5 fys5-1@-p
this("","","",5); xz"Z3B
} ke}Y2sB
,ykPQzO
"B9[cDM&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,l$NJt
{ $AA~]'O>6:
sSiteURL= sURL; my\o P(e\
sFilePath = sPath; :T7?
sFileName = sName; H~[LJ5x
this.nSplitter = nSpiltter; `!nJS|
9U|<q
y8w0eq94
} msc 1^2
's>#8;X
,C{^`Bk-W
public String getSSiteURL() 6wb^*dD92
{ b8N[."~:
return sSiteURL; ).NcLJw_
} W&+y(Z-t
%XJQ0CE<(
w.J%qWJq
public void setSSiteURL(String value) GSz @rDGY
{ k-WHHoU>o
sSiteURL = value; Qj 6gg
} cc|CC Zl
a[1sA12
:cc[Jco@w
public String getSFilePath() }rzdm9
{ xdd:yrC
return sFilePath; ~~C6)N~1
} GA|/7[I}
i>Z|65
Lw>-7)
public void setSFilePath(String value) [1z{T(dh
{ brg":V1a
sFilePath = value; j|VXC(6P,
} 81g9ZV(4
Ro'jM0(KE
gB]C&Q
public String getSFileName() 6Xdtr
{ d?:`n9`
return sFileName; r0F_;
} 5oz>1
[AXsnpa/C
6xQ"bFm
public void setSFileName(String value) sA/,+aM
{ <9ma(PFa
sFileName = value; )K{o<m~WAo
} ;#3ekl{-g
\s=QiPK
IWAj Mwo
public int getNSplitter() X_D6eYF
{ >9-Dd)<
return nSplitter; 0jBKCu
} MWBXs75I
W`#gpi)7N
xME(B@j
public void setNSplitter(int nCount) mR"uhm}q
{ $"Afy)Ir
nSplitter = nCount; fO*)LPen.z
} " Wp
} }%eDEM
&oA~ Tx
k_]\(myq
/* 5B%w]n
**Utility.java GGCqtA^@7d
*/ Js/N()X
package NetFox; 6hZ.{8e0
YVoao#!
z~F37]W3[
public class Utility { {3_Gjb5\\4
}A-{6Qe
f[x~)=
public Utility() V {p*z
{ x@htx?
J;S-+
rB,ldy,f
} >gr<^$
C?,*U
//线程睡眠 M3ZOk<O<R
public static void sleep(int nSecond) A*hZv|$0
{ T-^0:@5o9
try{ sr\cVv")
Thread.sleep(nSecond); UanEzx%
} W/sY#"
catch(Exception e) RF:04d
{ \UOm]z
e.printStackTrace (); j(sLK &
} 47KNT7C
} GSP?X$E
YNI;h%w
//日志 yx2z%E
public static void log(String sMsg) YV-j/U{&
{ 1DUb [W8
System.err.println(sMsg); a~,Kz\Tt
} F'1k<V?
sMP:sCRC
#00D?nC
public static void log(int sMsg) ^ESUMXb
{ `g--QR
System.err.println(sMsg); \6{LR&
} +s ULo
} $%Z3;:<Uf-
*#zS^b n
m~;B:LN<
/* CI^[I\$&
**TestMethod.java \0nlPXk?G
*/ })PO7:
package NetFox; d.p'pGL
c-5Ysg
;=a_B1"9u
public class TestMethod { B[CA 5Ry
44~hw:
zZ:xEc
public TestMethod() U9 bWU'
{ ///xx/weblogic60b2_win.exe 33 :@*
try{ yplG18
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D*QYKW=)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0'`S,
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6lsEGe
fileFetch.start(); `"c'z;
} $Zxt&a
catch(Exception e){e.printStackTrace ();} t!jYu<P
"TNVD"RLY
QXs8:;T
} q6REh;$
CcY7$D
NO2(vE
public static void main(String[] args) Vc _:*
{ WqE '(
new TestMethod(); !>3LGu,
} ;}K62LSR
} -%,"iaO
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