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)); :1Xz4wkWS*
} >0y'Rgfe
for(int i=0;i<nEndPos.length-1;i++) ;3coP{
{ _#E0g'3
nEndPos = nStartPos[i+1]; :wyno#8`-
} lWk>z; d
nEndPos[nEndPos.length-1] = nFileLength; \##zR_%
} .bl/*s
} |fJ};RLI"
Jl8H|<g~/
HXC ;Np
//启动子线程 #4NaL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; edq4D53
for(int i=0;i<nStartPos.length;i++) 7vKK%H_P
{ F@jZ ho
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VR8-&N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WF+99?75
nStartPos,nEndPos,i); ;W )Y OT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ij`w} V
fileSplitterFetch.start(); ea2ayT
} A0s ZOCky
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2eS~/Pq5=i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =!A_^;NQf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %g$o/A$
nEndPos = " + nFileLength); +4~_Ei[i
// fileSplitterFetch[nPos.length-1].start(); ./Zk`-OBT
Lnl(2xD
KhR81\
//等待子线程结束 nsC3
//int count = 0; Xf]d. :
//是否结束while循环 8U"v6S~A%Q
boolean breakWhile = false; )T2Caqs2
epe)a
;%9|kU
while(!bStop) |kg7LP3(8,
{ Y;M|D'y+
write_nPos(); SYJD?&C;
Utility.sleep(500); BsDn5\q
breakWhile = true; [-K&R
B)g[3gQ
h 0Q5-EA
for(int i=0;i<nStartPos.length;i++) !dnH7"
{ OU_gdp
if(!fileSplitterFetch.bDownOver) M#6W(|V/
{ 7hcYD!DS
breakWhile = false; Wq&if_
break; ;?iW%:_,
} zT]8KA
} Af2( 5]
if(breakWhile) e{K 215
break; ;7V%#-
nPl?K:(
`i*E~'
//count++; w+|L+h3L7
//if(count>4) n0 {i&[I~+
// siteStop(); 9wwqcx)3(
} '[:D$q;
~rKrpb]ow
L|xbR#v
System.err.println("文件下载结束！"); 0RLg:SV
} {rw|#Z>A
catch(Exception e){e.printStackTrace ();} :U%W%
} ;bib/
Y eo]]i{
'G4ICtHQ
//获得文件长度 ^"2J]&x`G
public long getFileSize() \V8PhO;j
{ xJ8M6O8
int nFileLength = -1; *vxk@`K~
try{ mxC;?s;~
URL url = new URL(siteInfoBean.getSSiteURL()); osAd1<EIC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *)T^ChD,
httpConnection.setRequestProperty("User-Agent","NetFox"); S`0(*A[W*
Jhhb7uU+
%T%sGDCV
int responseCode=httpConnection.getResponseCode(); IfAZn_
if(responseCode>=400) 9}<ile7^
{ <0&*9ZeD
processErrorCode(responseCode); 5x4yyb'
return -2; //-2 represent access is error Id .nu/
} pJ"qu,w
M`!H"R7
ChPmX+.i_
String sHeader; .}TZxla0Zr
)'#A$ Fj
WlC:l
for(int i=1;;i++) f+,qNvBY/
{ ?mxMk6w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '8H4shYg
//Utility.log(in.readLine()); m@v\(rT.
sHeader=httpConnection.getHeaderFieldKey(i); k"zv~`i'
if(sHeader!=null) )U:m:cr<
{ 97C]+2R%^
if(sHeader.equals("Content-Length")) u?(d gJ
{ c9 _rmz8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k2tF}
break; P* BmHz4KL
} )lqAD+9Q
} #a,PZDaE
else bJ {'<J
break; 9-a0:bP
} '$(^W@M#6
} #'szP\
catch(IOException e){e.printStackTrace ();} ~-Qw.EdC
catch(Exception e){e.printStackTrace ();} &Q#66ev
CXMLt
F/kWHVHU[
Utility.log(nFileLength); g@!V3V
29] G^f>
08\,<9
return nFileLength; eJX9_6m-
} fxHH;hRfv
0 ZKx<]!
$Sip$\+*
//保存下载信息（文件指针位置） LCKV>3+_#
private void write_nPos() i3mcx)d@H
{ SRDp*
try{ p%=u#QNi
output = new DataOutputStream(new FileOutputStream(tmpFile)); )}Kf=
output.writeInt(nStartPos.length); Js?]$V"
for(int i=0;i<nStartPos.length;i++) yq\K)g*=
{ Y)2,PES=
// output.writeLong(nPos); p]+Pkxz]'
output.writeLong(fileSplitterFetch.nStartPos); >@_^fw)
output.writeLong(fileSplitterFetch.nEndPos); pO3SUOP
} E4/Dr}4
output.close(); 2eY_%Y0
} bwMm#f
catch(IOException e){e.printStackTrace ();} w;amZgD>
catch(Exception e){e.printStackTrace ();} ~HsJUro
} N5 6g+,w%)
Z=o2H Bm7
3bH'H*2
//读取保存的下载信息（文件指针位置） SO'vpz{
private void read_nPos() N<VJ(20y
{ ?NsW|w_
try{ =X:Y,?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E*K;H8}s
int nCount = input.readInt(); )F]]m#`
nStartPos = new long[nCount]; zHRplm+i
nEndPos = new long[nCount]; +\ .Lp 5
for(int i=0;i<nStartPos.length;i++) jm/`iXnMf
{ `1fY)d^ZS
nStartPos = input.readLong(); >0TxUc_va
nEndPos = input.readLong(); Feq]U?
} o3P${Rq
input.close(); h3 }OX{k
} ?%[@Qb=2
catch(IOException e){e.printStackTrace ();} '7@zGk##(
catch(Exception e){e.printStackTrace ();} Lnl=.z`jK
} T:yE(OBf
Eo]xNn/g
2pa5U;u:+
private void processErrorCode(int nErrorCode) 4>e&f&y~
{ c<Tf 2]vZE
System.err.println("Error Code : " + nErrorCode); 7ZWgf"1j
} y766; X:J
lq;Pch
.}~_a76
//停止文件下载 v`Oc,
public void siteStop() c,+:i1IAy
{ 'I6i,+D/q
bStop = true; z<XtS[ki
for(int i=0;i<nStartPos.length;i++) ,w4V?>l
fileSplitterFetch.splitterStop(); y _k l:Ssa
#c.K/&Gc7j
E{P|)`,V
} w%jII{@,
} A#iV=76_
//负责部分文件的抓取 ]jp6k<KF
**FileSplitterFetch.java M!D3}JRm
*/ Y&Z.2>b
package NetFox; .|i.Cq8
f(y:G^V
S3Xl
import java.io.*; 'e'cb>GnA
import java.net.*; ?J~_R1Z
^o&. fQ*
Z o(rTCZX
public class FileSplitterFetch extends Thread { e1Hgw[l`
.Rs^YZF
H8}oIA"b
String sURL; //File URL X2~!(WxU F
long nStartPos; //File Snippet Start Position Ne1$ee.NE
long nEndPos; //File Snippet End Position Si;H0uPO
int nThreadID; //Thread's ID MeZf*' J
boolean bDownOver = false; //Downing is over K_Eux rPn
boolean bStop = false; //Stop identical 5MJS ~(
FileAccessI fileAccessI = null; //File Access interface #BH*Z(
`1IgzKL9
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $suzW;{#
{ v O_*yh1
this.sURL = sURL; :nOFR$W
this.nStartPos = nStart; ":QZy8f9%
this.nEndPos = nEnd; TJXT-\Vk
nThreadID = id; CryBwm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LsU9 .
} t!7-DF|N
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v_GUNRs
public void run() )|#sfHv7
{ gT6jYQ
while(nStartPos < nEndPos && !bStop) s&3Vg7B
{ )oPBa
bq0zxg%
UH"%N)[
try{ 'YSHi\z ](
URL url = new URL(sURL); z9Rp`z&`E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3eQ&F~S
httpConnection.setRequestProperty("User-Agent","NetFox"); `*1p0~cu
String sProperty = "bytes="+nStartPos+"-"; AFE~ v\Gz
httpConnection.setRequestProperty("RANGE",sProperty); d<P\&!R(
Utility.log(sProperty); hv>\gBe i
Qj3EXb
8&b,qQ~
InputStream input = httpConnection.getInputStream(); O)r4?<Q
//logResponseHead(httpConnection); %| Lfuz*
^SrJu:Q_
OYn}5RN
byte[] b = new byte[1024]; FXkM#}RgNm
int nRead; yEE*B:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zp=U W*g^
{ }b.%Im<3R
nStartPos += fileAccessI.write(b,0,nRead); v"Es*-{B
//if(nThreadID == 1) M[,@{u/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g{&ui.ml&
} k~1?VQ+?M
>}6%#CAf
draN0vf
Utility.log("Thread " + nThreadID + " is over!"); &6nWzF
bDownOver = true; ~oY^;/ j
//nPos = fileAccessI.write (b,0,nRead); \z(gqkc 6
} ?^\|-Gr
catch(Exception e){e.printStackTrace ();} sD#.Oq4&]y
} .U]-j\
} 49HZ2`Y
pIqeXY
c'yxWZEv
//打印回应的头信息 ~2-1 j
public void logResponseHead(HttpURLConnection con) *VT/
{ 1/J=uH
for(int i=1;;i++) 9~[Y-cpoi
{ I9ep`X6Y
String header=con.getHeaderFieldKey(i); &gx%b*;`L0
if(header!=null) Q>i^s@0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ['iPl/v0
Utility.log(header+" : "+con.getHeaderField(header)); Q hO!Ma]
else YT(AUS5n
break; BLD gt~h#
} A6(/;+n
} DEZveQr=
9q~s}='"
+ksVtG,
public void splitterStop() $yNS pNmT0
{ tK\~A,=
bStop = true; Ta\tYZj$
} '/s)%bc
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[Z$[rOF
} #S"nF@
*gWwALGo5
$-sHWYZ
/* Uz]|N6`
**FileAccess.java YNi.SXH
*//文件访问(定位，写) vyI!]p
package NetFox; }&D32\
import java.io.*; U-M>=3|N
+52{-a,>
~b8]H|<'Y
public class FileAccessI implements Serializable{ P/_['7
j&qub_j"xX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 brUF6rQ
RandomAccessFile oSavedFile; ?&1!vz
long nPos; II,8O
KPUV@eQ,
{bY%# m
public FileAccessI() throws IOException h@ryy\9
{ EXqE~afm2
this("",0); }0Ed]
} CzrC%xy
l,5+@i`5i
t*w/{|yO
public FileAccessI(String sName,long nPos) throws IOException 7-fb.V9
{ }@d@3
oSavedFile = new RandomAccessFile(sName,"rw"); \,0oX!<YY
this.nPos = nPos; 2<}%kQ`
oSavedFile.seek(nPos); L~N460
} h<<v^+m
?4T-@~~*`=
ysY*k`5
public synchronized int write(byte[] b,int nStart,int nLen) /N.U/MPL_
{ 5`p.#
int n = -1; ;;/{xvQ.1
try{ ;9QEK]@
oSavedFile.write(b,nStart,nLen); p9-K_dw3X@
n = nLen; @cXMG6:{
} `'7R,
catch(IOException e) 63IM]J
{ a9Zq{Ysj
e.printStackTrace (); FfT`;j
} .8JTe0
88$8d>-
f]srRYSR
return n; Uw<nxD/+
} U|R_OLWAg
a0H+.W+]
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} ,r_Gf5c
bW(0Ng
4;2uW#dG"
/* FGBbO\</
**SiteInfoBean.java dioGAai'
*/ (KZ{^X?a
package NetFox; a/xn'"eli
19%imf
?(_08O
public class SiteInfoBean { gL/9/b4
`C'H.g\>2Q
#&e-|81H
private String sSiteURL; //Site's URL QS;f\'1bb
private String sFilePath; //Saved File's Path +]{G@pn
private String sFileName; //Saved File's Name &s>Jb?_5Mx
private int nSplitter; //Count of Splited Downloading File S)"Jf?
)MT}+ai
@gK?\URoT
public SiteInfoBean() R2vlFx/
{//nSplitter的缺省值为5 -X6PRE5a2
//default value of nSplitter is 5 7D_=
this("","","",5); +G>\-tjSD
} uHRsFlw
!&@615Vtw
WcbiqxK7-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t\O16O7S
{ !^G\9"4A
sSiteURL= sURL; lNO;O}8
sFilePath = sPath; C~exi[3
sFileName = sName; rEz^
this.nSplitter = nSpiltter; AbW6x
+R75v)
gf\oC> N
} +R:(_:7
1s;Saq+
&=mtc%mL
public String getSSiteURL() 6j|{`Zd)G
{ )%fH(ns(
return sSiteURL; (S Yln>o
} 4E}Yt$|
-m#)B~)
HTTCTR
public void setSSiteURL(String value) lPAQ3t!,
{ SSzIih@u
sSiteURL = value; ,|/f`Pl
} X2'0PXv>!
&mM0AA'\?H
ti,d&c_7
public String getSFilePath() Q\0'lQJdy
{ E' uZA
return sFilePath; ;}p
} kD"{g#c
NvX[zqNP_R
E _|<jy$`
public void setSFilePath(String value) )D%~`,#pQ
{ @IZnFHN
sFilePath = value; ~pky@O#b
} uCB=u[]y4
;722\y(Y
;-Aa|aT!
public String getSFileName() +1!ia]
{ >+T)#.wo&
return sFileName; f* wx<
} fI|$K)K
+LJ73 !
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public void setSFileName(String value) "d}Gp9+$VY
{ GTxk%
sFileName = value; MiX43Pk]
} 4Wp=y
uhq8
,<X9Y2B
public int getNSplitter() |6y
{ Rf% a'b
return nSplitter; "$vRMpW:
} 0<*<$U
Vi|#@tC'
?Z}&EH
public void setNSplitter(int nCount) EKN~H$.
{ j5h-dK
nSplitter = nCount; uHNCSzH(
} #[[ en
} tO&^>&;5
N6TH}~62}
/g.U&oI]D
/* .fs3>@T"#
**Utility.java 7uk[Oy<_
*/ I( Mm?9F
package NetFox; K@%].:
z{r}~{{E
HK%7g
public class Utility { Pc]HP
^=*;X;7
]I6 J7A[
public Utility() &xExyz~`
{ A":T1s
@PIp*[7oC
8xMX
} {2gwk8
qxJ\ye+'*
//线程睡眠 #p{4^
public static void sleep(int nSecond) uEx-]F
{ YchH~m|
try{ #rg6,.I)<
Thread.sleep(nSecond); {\\Tgs
} U%/+B]6jP
catch(Exception e) -ze J#B)C
{ R^e'}+Z
e.printStackTrace (); K.yb ^dg5
} 23jwAsSo
} OcO3v'&
iJ|uvPCE
//日志 Y|/ 8up
public static void log(String sMsg) VS|2|n1<6
{ YHl;flv
System.err.println(sMsg); J,6yYIq
} T6kdS]4-
]K%!@O!
]JR +ayk7
public static void log(int sMsg) M'l ;:
{ OB}Ib]
System.err.println(sMsg); bQ5\ ]5M
} Ht&YC<X
} -%4,@ x`
@[v~y"tE}
,wPr"U+7
/* ~bpgSP"
**TestMethod.java r@,2E6xn
*/ ]]Ufas9
package NetFox; %N_%JK\{@
{fp[BF
^dxTm1Z
public class TestMethod { Wn}'bqp
wUM0M?_p[
,"0:3+(8;
public TestMethod() Q=dy<kg']
{ ///xx/weblogic60b2_win.exe _Bj":rzY
try{ wI "U7vr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \lNN Msd&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M"To&?OI
SiteFileFetch fileFetch = new SiteFileFetch(bean); |e0`nn=
fileFetch.start(); /_ajaz%
} A+?`?pOm&
catch(Exception e){e.printStackTrace ();} An/|+r\
>c}u>]D
AkiDL=;w
} H" 7u7l
k~z Iy;AZ
g#E-pdY
public static void main(String[] args) pI<f) r
{ l}M!8:UzU
new TestMethod(); 1yY0dOoLG)
} S`Rs82>
} [=`q>|;pOv
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