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)); ?>y-5B[K/(
} K7.<,E"M.
for(int i=0;i<nEndPos.length-1;i++) 3DHm9n+/:
{ xAjQW=
nEndPos = nStartPos[i+1]; gAj)3T@
} wuk7mIJ
nEndPos[nEndPos.length-1] = nFileLength; q KM]wu0Et
} ?R(3O1,v^
} IebS~N E
5);#\&B
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//启动子线程 )ziQ=k6d6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nB5[]x'
for(int i=0;i<nStartPos.length;i++) *lK4yI*%o
{ 4BT`|(7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F^YIZ,=p!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %5G BMMn
nStartPos,nEndPos,i); m%[t&^b}T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FJLJ;]`7+
fileSplitterFetch.start(); kpH;D=;
} Q 8rtZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R`Lm"5w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p*0Ve21i,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #CPPdU$
nEndPos = " + nFileLength); ;}~=W!yz
// fileSplitterFetch[nPos.length-1].start(); $5b|@
#%9]Lq
'-IT@}
//等待子线程结束 r?!xL\C\
//int count = 0; J,O@T)S@
//是否结束while循环 j/<y
boolean breakWhile = false; J31M:<
tA-B3 ]
\.c )^QQ
while(!bStop) yj~"C$s
{ EaD@clJS
write_nPos(); =%\6}xPEl<
Utility.sleep(500); EKPTDKut
breakWhile = true; ;J(,F:N
rcZ SC3
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for(int i=0;i<nStartPos.length;i++) jw[BtRW
{ XKX,7
if(!fileSplitterFetch.bDownOver) 4Aew )
{ n^\;*1%$c@
breakWhile = false; Qcy`O m^2
break; 38rZ`O*D
} 5|CiwQg|,p
} ZZU8B?)
if(breakWhile) #( sNk,^Ax
break; =&pN8PEn\
&fW=5'
yCIgxPv|7
//count++; U"+ ry.3`
//if(count>4) ig}e@]
// siteStop(); A+*oT(`
} E`fssd~
r0deBRM
aT!9W'uY
System.err.println("文件下载结束！"); ?=!XhU .
} aNC,ccm
catch(Exception e){e.printStackTrace ();} :bRR(sP
} Kk>qgi$
5\0.[W{^
_IV@^v
//获得文件长度 6KCmswvE
public long getFileSize() `Kw"XGT
{ 4E-A@FR
int nFileLength = -1; *ZR@z80i
try{ AaYrVf 9!
URL url = new URL(siteInfoBean.getSSiteURL()); TucAs0-bF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8Wx@[!
httpConnection.setRequestProperty("User-Agent","NetFox"); Om2X>/V%C
_P<lG[V
KWJgW{{v
int responseCode=httpConnection.getResponseCode(); :6$4K"^1
if(responseCode>=400) bmVgTm&
{ W)!{U(X
processErrorCode(responseCode); 2nU NI U
return -2; //-2 represent access is error iW@Vw{|i I
} 1m`tqlFU9
7~ese+\smG
DRW.NL o
String sHeader; sV^h#g~Zb
S@xsAib0J
pLQSG}N
for(int i=1;;i++) )L<?g!j~
{ Z4AAg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); //M4Sq(
//Utility.log(in.readLine()); :aq>
sHeader=httpConnection.getHeaderFieldKey(i); /QXs-T}d
if(sHeader!=null) aE\BAbD7
{ '}+X,Usm
if(sHeader.equals("Content-Length")) LAY)">*49H
{ Flujwh@rg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k,R~oSA'n
break; z3Y)-
} id tQXwa
} te*Y]-&I|/
else <,pLW~2-"
break; C6'*/wq
} 8gtCY~m
} 3.<6;?
catch(IOException e){e.printStackTrace ();} G#n^@kc*,
catch(Exception e){e.printStackTrace ();} Sd\IGy{a
K-EI?6`xM
@yn^6cE
Utility.log(nFileLength); 4 ?@uF[
(L0hS'
_%Jl&0%q
return nFileLength; UI<PNQvo9
} nE,gQHw
9j?hF$L"
bj7MzlGFy
//保存下载信息（文件指针位置） ]EM)_:tRf
private void write_nPos() +:"6`um|
{ {1@4}R4
try{ 32 1={\X
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2Ph7qEBQ22
output.writeInt(nStartPos.length); a4jnu:e
for(int i=0;i<nStartPos.length;i++) ~6:LUM
{ '!fFI1s
// output.writeLong(nPos); LA+$_U"Jk
output.writeLong(fileSplitterFetch.nStartPos); 2rj/wakd
output.writeLong(fileSplitterFetch.nEndPos); `F2*o47|t
} $uUb$8Bu
output.close(); {"0TO|%x
} siRnH(^J
catch(IOException e){e.printStackTrace ();} BH#C<0="
catch(Exception e){e.printStackTrace ();} StyB"1y
} w{r(F`
l<aqiZSY
,dZ H$
//读取保存的下载信息（文件指针位置） (]}x[F9l
private void read_nPos() cPx~|,)l
{ \L9?69B~
try{ V8nz-DL{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g^z5fFLg/8
int nCount = input.readInt(); Tw}?(\ya
nStartPos = new long[nCount]; B15O,sL&W
nEndPos = new long[nCount]; @7Rt4}g
for(int i=0;i<nStartPos.length;i++) vzyNc'
{ urT/+deR
nStartPos = input.readLong(); oBRm\8 2|
nEndPos = input.readLong(); 8tV=fSHd
} EFRZ% Y
input.close(); B;z>Dd,Y_x
} #0?"J)
catch(IOException e){e.printStackTrace ();} 8g[(nxI~
catch(Exception e){e.printStackTrace ();} Ho)t=qn
} &N/|(<CB
~^rey
dThn?
private void processErrorCode(int nErrorCode) d^Zo35X
{ >?>ubM`,
System.err.println("Error Code : " + nErrorCode); +Q SxYV
} uv|eVT3jNs
%UUp=I
Ok}{jwJ%W;
//停止文件下载 o\@ A2r3
public void siteStop() agU%z:M{
{ P&[Ft)`
bStop = true; :jk)(=^
for(int i=0;i<nStartPos.length;i++) ~{7zm"jN
fileSplitterFetch.splitterStop(); L9{mYA]q
;L G %s
p|h.@do4
} GhG%>U#&a
} Sl. KLc@@
//负责部分文件的抓取 BaWQ<T8p8
**FileSplitterFetch.java 60hNCVq%
*/ P\q<d
package NetFox; R<n8M"B
L,C? gd@"
aPD?Bh>JU
import java.io.*; DA+A >5/
import java.net.*; s6uF5]M;2
}g>dn
HF&h
public class FileSplitterFetch extends Thread { KjFZ
ig{A[7qN
iUeV5cB
String sURL; //File URL qs6Nb'JvQR
long nStartPos; //File Snippet Start Position 935-{h@k
long nEndPos; //File Snippet End Position MB]#%g&
int nThreadID; //Thread's ID ~/j$TT"
boolean bDownOver = false; //Downing is over 4ss&'h
boolean bStop = false; //Stop identical &Pu+(~'Q
FileAccessI fileAccessI = null; //File Access interface b$dJ?%W
5nMkd/
h^o+E2<]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &K5C=]4
{ Y%78>-2L
this.sURL = sURL; B;xZ%M]
this.nStartPos = nStart; "XGD:>Q.
this.nEndPos = nEnd; W<\kf4Y
nThreadID = id; r+t ,J|V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |rr$U
} snXB`UC
5z1\#" B[
~A8qeaP
public void run() D ?Nd;[
{ - *:p.(c
while(nStartPos < nEndPos && !bStop) 5~@?>)TBv
{ %/UV_@x&
[3t0M5x w
Dh hG$
try{ '8s>rH5[V
URL url = new URL(sURL); +mJ :PAy4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =E&b=
httpConnection.setRequestProperty("User-Agent","NetFox"); zWy ,Om8P
String sProperty = "bytes="+nStartPos+"-"; If~95fy~c
httpConnection.setRequestProperty("RANGE",sProperty); XOu+&wOu
Utility.log(sProperty); c:=7lI
`%$8cZ-kr
_REqT
InputStream input = httpConnection.getInputStream(); `+roQX.p
//logResponseHead(httpConnection); C1h#x'k
y\^@p=e
O{PW
byte[] b = new byte[1024]; nAIH`L"X
int nRead; 5JS ZLC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xLA~1ZSVJw
{ nYOY"'z
nStartPos += fileAccessI.write(b,0,nRead); +J"' 'cZ
//if(nThreadID == 1) n4^~gT%b5]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L<bYRGz
} TG1P=g5h
sB?2*S"X)<
:~vxZ*a
Utility.log("Thread " + nThreadID + " is over!"); bAdiA2VF'
bDownOver = true; j3 6,w[Y:
//nPos = fileAccessI.write (b,0,nRead); <v]z6B@9!
} $[[?;g
catch(Exception e){e.printStackTrace ();} +C'XS{K,#
} t2"@Ps&1|
} qv *3A?uzr
/r276Q
-7k[Vg?
//打印回应的头信息 DeH0k[o
public void logResponseHead(HttpURLConnection con) ^uia`sOP4
{ a*D,*C5}
for(int i=1;;i++) v9u<F6
{ ERF,tLa!
String header=con.getHeaderFieldKey(i); w'A tf
if(header!=null) &B}Lo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >L^xlm%7o
Utility.log(header+" : "+con.getHeaderField(header)); |z:Q(d06
else @!e~G'j%VD
break; O]t\B*%}
} %Ys$@dB
} `AR"!X
#>=8w9]
VKy5=2&
public void splitterStop() Gu5~DyT`G
{ GMz8B-vk
bStop = true; PkTfJQP8
} [cDbaq,T
b\:~;
ZP-dW|<[x
} _mXs4
%4,xx'`
e8oKn&
/* fe|g3>/|
**FileAccess.java >:2}V]/;
*//文件访问(定位，写) $0#6"urG
package NetFox; h}h^L+4
import java.io.*; t)} \9^Uo
|=O1Hn
dByjcTPA
public class FileAccessI implements Serializable{ 5X0QxnnV
W"Z#Fs{n8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fp{G|.SA
RandomAccessFile oSavedFile; 8.yCA
long nPos; c_#*mA"+
Rv<L#!; t
^2EhlK^)
public FileAccessI() throws IOException }%$OU =T
{ *hF^fxLbl
this("",0); 09d9S`cS\
} <#y*h8IZ@t
wX0l?xdI
_8^0!,j
public FileAccessI(String sName,long nPos) throws IOException @.gPJMA
{ F}'wH-qp
oSavedFile = new RandomAccessFile(sName,"rw"); X'x3esw w
this.nPos = nPos; D,Lp|V
oSavedFile.seek(nPos); n?:2.S.8
} xIL#h@dz
0Gsu
i6Qb[\;
public synchronized int write(byte[] b,int nStart,int nLen) T#@{G,N
{ H@D;e
int n = -1; @r<b:?u
try{ =WK04\H
oSavedFile.write(b,nStart,nLen); e[{mVhg4E
n = nLen; 'w.}2(
} ,hWcytzEw
catch(IOException e) hm\\'_u
{ qfYG.~`5
e.printStackTrace (); w{`Acu
} PNpu*#Z`
?v4E<iXs
K(VW%hV1
return n; d2~l4IL)~
} _R^y\1Qu
ARF\fF|<2
T@P!L
} N*_"8LIfi_
>b48>@~bY
SE)nD@:
/* 514Z<omrK
**SiteInfoBean.java ;iU%Kt
*/ JoJukoy}F
package NetFox; g1{/ 5{XI
?#BV+#(
\|%E%Yc
public class SiteInfoBean { u,o1{%O
_ie.|4k
*5D3vB*S
private String sSiteURL; //Site's URL xE1'&!4O
private String sFilePath; //Saved File's Path /e1(? 20
private String sFileName; //Saved File's Name aQUGNa0+d
private int nSplitter; //Count of Splited Downloading File pOA!#Aj)
BpH%STEN
3vW4<:Lgy
public SiteInfoBean() :q (&$
{//nSplitter的缺省值为5 ',)7GY/n~
//default value of nSplitter is 5 fF;h V
this("","","",5); f%XJ;y\,9H
} W~ruN4q.
4h8*mMghs
bL`eiol6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ? ?[g}>
{ exZLj0kvF
sSiteURL= sURL; LZ<[ll#C
sFilePath = sPath; ~3CVxbB^<
sFileName = sName; IQnIaZ
this.nSplitter = nSpiltter; n]yEdL/1
ashar&'
x[i`S8D
} PeTA$Yl
e2w&&B-
EzpFOqJG
public String getSSiteURL() 5=L} \ankn
{ gXy-Mpzp
return sSiteURL; Ef@,hX
} ss iokLE
V.=lGhi
b>11h
public void setSSiteURL(String value) fS=hpL6]@
{ O{]9hm(tN
sSiteURL = value; JOD/Raq.1k
} Ig \#f
dRaOGm)
41Ve}%
public String getSFilePath() =\3Tv
{ mLyBm
return sFilePath; i9A~<
} [4Q"#[V&9
:O-1rD
+L%IG
public void setSFilePath(String value) Hd &{d+B
{ C6 "
sFilePath = value; ,6,]#R :J
} m3.sVI0I
Q(Gl{#b
nwmW.(R4
public String getSFileName() GF$`BGW
{ x#H 3=YD*
return sFileName; ;\{`Ci\
} f_=~H<j!
EWjgI_-
"%6/a7S
public void setSFileName(String value) V/%~F6e
{ V diJ>d[
sFileName = value; =L]Q2V}
} w$fJ4+
zpjqEEY;
{38bv.3'
public int getNSplitter() o{WyQ&2N
{ n<7q`tM#
return nSplitter; v)X\GmW7w
} SA"8!soY3
J'T=q/
;zH HIdQ>-
public void setNSplitter(int nCount) 'T8W!&$
{ #,NvO!j<4
nSplitter = nCount; L.'}e{ldW
} h2Bz F
} fV\]L4%
DN] v_u+}
)>a B
/* 5&!c7$K0
**Utility.java |> enp>
*/ ~d >W?A
package NetFox; v& $k9)]
[wnDHy6W
,5Vt]#F5@
public class Utility { jp2Q9Z
r'7LR
S<wj*"|.s
public Utility() j2 %^qL
{ \cJa;WM>
PkuTg";
(5Nv8H8|
} +0l`5."d
2?q(cpsN
//线程睡眠 "sUyHt-&
public static void sleep(int nSecond) h*i9m o
{ 5Wx~ZQZ
try{ aHzHvl
Thread.sleep(nSecond); b;cMl'
} E%N2k|%8d_
catch(Exception e) zZ-\a[F
{ r(A.<`\
e.printStackTrace (); \}0-^(9zd
} f58?5(Dc|
} 2{|$T2?e
{Qu"%h.Al
//日志 2}U!:bn(
public static void log(String sMsg) KzUlTl0
{ muON>^MbC
System.err.println(sMsg); <@v]H@E
} ]; $] G-
5*g]qJF
9LC&6Q5O&
public static void log(int sMsg) i5}4(sV
{ 5`D-
System.err.println(sMsg); t+uE
} (qMj-l
} ,M5}4E7L%s
wf.T3
JYb}Zw;
/* Z~
**TestMethod.java _l`e#XbG
*/ ,5 j"ruZ
package NetFox; B=f,QU
s"KJiQKGM
),:c+~@@kT
public class TestMethod { ~Heb1tl;
R\3VB NX.g
K$ }a8rH
public TestMethod() dq;|?ESP
{ ///xx/weblogic60b2_win.exe xgu `Q`~
try{ OHrY(I6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZD/jX_!t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g`^X#-!(
SiteFileFetch fileFetch = new SiteFileFetch(bean); bBcp9C)iY
fileFetch.start(); &C<yfRDu
} )j l8!O7
catch(Exception e){e.printStackTrace ();} VSX@e|Nj
K6JVg$
] ]U<UJ
} Z4K+ /<I
CBYX]
PQmq5N6
public static void main(String[] args) $lA V6I.
{ rf:XRJ<4
new TestMethod(); @oP_;G
} #65^w=Sp}
} ? 8aaD>OR$
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