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)); "Ue.@>
} 5]NqRI^0
for(int i=0;i<nEndPos.length-1;i++) ?ATOXy
{ k`So -e-
nEndPos = nStartPos[i+1]; UYk/v]ZA
} 5~r33L%
nEndPos[nEndPos.length-1] = nFileLength; J#w J4!
} kw#;w=\>R{
} qs1 ?IYD
mtJ9nC
fa++MNf}3
//启动子线程 Sx708`/Ep
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?j40} B]]d
for(int i=0;i<nStartPos.length;i++) "Om=N@?
{ >OL3H$F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;1:Js0=;H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [Yo,*,y31
nStartPos,nEndPos,i); V,mw[Hw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C69q&S,
fileSplitterFetch.start(); ! ='rc-E
} Hc>m;[M)l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :ctu5{"UJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tZ'|DCT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "/3 db[
nEndPos = " + nFileLength); |_] Q$q[[%
// fileSplitterFetch[nPos.length-1].start(); X#*JWQO=
jE}33"
4(|cG7>9-
//等待子线程结束 -n=^U
//int count = 0; nSW=LjrO~<
//是否结束while循环 $ {O#
boolean breakWhile = false; lBK}VU^
'^No)n\`
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while(!bStop) _JHd9)[
{ [3(74
write_nPos(); n@C[@?D
Utility.sleep(500); y0#u9t"Z;
breakWhile = true; EK;YiJ
x[$z({Yf
+3BBQ+x!
for(int i=0;i<nStartPos.length;i++) JT-J#Ag
{ PmKeF}
if(!fileSplitterFetch.bDownOver) P(H8[,
{ YL]Z<%aKt
breakWhile = false; `8AR_7i
break; %k;|\%B`
} yzerOL
} JT3-AAi[Z
if(breakWhile) ,q}MLTSi
break; X~lVVBO
^>jwh
y~q8pH1
//count++; 3~uW I%I`
//if(count>4) NYrQ$N"
// siteStop(); fA+,TEB~d
} FFu9&8Y
SKkUU^\#R`
y%%}k
System.err.println("文件下载结束！"); nQ5n-A&["
} aX5 z&r:{
catch(Exception e){e.printStackTrace ();} m9.{[K"
} aqj@Cjk4Z
0:9.;x9_
S7/eS)SQR
//获得文件长度 [_1G@S6Ex
public long getFileSize() w8U&ls1b
{ 7ccO93Mz
int nFileLength = -1; !,6c ~ w
try{ FB{KH .
URL url = new URL(siteInfoBean.getSSiteURL()); AlAYiUw{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e[&L9U6GW-
httpConnection.setRequestProperty("User-Agent","NetFox"); TU:7Df
m^ tFi7c
(Iaf?J5{
int responseCode=httpConnection.getResponseCode(); A Q'J9
if(responseCode>=400) {<R2UI5m5
{ 56zL"TF`
processErrorCode(responseCode); Z -W(l<
return -2; //-2 represent access is error \=:~ki=@B
} {^\+iK4bS
M%2+y5
E5I"%9X0H
String sHeader; /v-6WSN
925|bX6I
glM$R&/
for(int i=1;;i++) nxWY7hU
{ WtG~('g>&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bN]+_ mF
//Utility.log(in.readLine()); |=`~-i2W
sHeader=httpConnection.getHeaderFieldKey(i); 1(I6.BHW
if(sHeader!=null) =5/9%P8j9
{ ;<Ar=?
if(sHeader.equals("Content-Length")) bdC8zDD
{ 6p?,(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d1AioQ9
break; /& Jan:
} 8ZM&(Lz7u
} }1Gv)l7
else &cxRD
break; gtk7)Uh
} 9 7GV2]-M
} UTH*bL5/J2
catch(IOException e){e.printStackTrace ();} /?@3.3sl_
catch(Exception e){e.printStackTrace ();} O_wEcJPE
#gz M|
CG0 M
Utility.log(nFileLength); QZ6D7tUc8
`Aw^H!
[x+FcXb
return nFileLength; gp>3I!bo[K
} {1UQ/_
1_9<3,7
}=<
//保存下载信息（文件指针位置） ZCmgs4W!
private void write_nPos() OGK}EI
{ WI-&x '
try{ |TS>hwkI
output = new DataOutputStream(new FileOutputStream(tmpFile)); n^Hm;BiE#
output.writeInt(nStartPos.length); jrr EAp
for(int i=0;i<nStartPos.length;i++) K2TcOFQ
{ y0sR6TY)f
// output.writeLong(nPos); +R3k-' >
output.writeLong(fileSplitterFetch.nStartPos); RRmz"j>
output.writeLong(fileSplitterFetch.nEndPos); -ws? "_w
} ojaws+(& y
output.close(); A)bWcB}U
} Q# ~Q=T'<
catch(IOException e){e.printStackTrace ();} ur)9x^y
catch(Exception e){e.printStackTrace ();} ~IYUuWF(
} \UPjf]&
s'!Cp=xQF"
A,JmX
//读取保存的下载信息（文件指针位置） wjHzE
private void read_nPos() L-ET<'u
{ @:+8?qcP
try{ {m4b(t`xw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h;p>o75O
int nCount = input.readInt(); &5\iM^
nStartPos = new long[nCount]; %Qmn-uZ
nEndPos = new long[nCount]; 5x5@t :
for(int i=0;i<nStartPos.length;i++) 2L3)#22m*
{ 2^r<{0@n
nStartPos = input.readLong(); v[ .cd*b
nEndPos = input.readLong(); N-G1h?e4
} SWH2
input.close(); <^VJy5>
} Kz~ps 5
catch(IOException e){e.printStackTrace ();} WffQ:L?
catch(Exception e){e.printStackTrace ();} p*< 0"0
} +9M^7/}H
Njxv4cc
m4**~xfC
private void processErrorCode(int nErrorCode) Z/W:97M
{ v&9y4\j
System.err.println("Error Code : " + nErrorCode); QX!-B
} CNih6R
J1,9kCO
/kE6@
//停止文件下载 fa-IhB1!K
public void siteStop() >tYm+coS
{ /$i.0$L
bStop = true; tRs [ YK
for(int i=0;i<nStartPos.length;i++) 'H3^e}
fileSplitterFetch.splitterStop(); MDnKX?Y
N nRD|A
^hG-~z<
} \9cbI3rGz
} };mA^xO]j
//负责部分文件的抓取 Ok|*!!T
**FileSplitterFetch.java 6hw=
*/ Ghu#XJB?
package NetFox; u__9Z:+
Q!o'}nA
O@tU.5*$5
import java.io.*; o\[~.";Z
import java.net.*; o15-ZzE-
; ^*}#Xd
:nh_k4S@v
public class FileSplitterFetch extends Thread { Pj[PIz
GD&uQ`Y5
US+Q~GTA
String sURL; //File URL f~t:L,\,
long nStartPos; //File Snippet Start Position ~d o9;8v
long nEndPos; //File Snippet End Position o@r7 n>G
int nThreadID; //Thread's ID HD@$t)mn
boolean bDownOver = false; //Downing is over tnV/xk#!
boolean bStop = false; //Stop identical ++bf#qS<8D
FileAccessI fileAccessI = null; //File Access interface Hu^1[#
uX"H4lO~
!SC`D])l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xj<Rp|7&
{ fWCo;4<5?
this.sURL = sURL; qPWP&k
this.nStartPos = nStart; Bz_^~b7
this.nEndPos = nEnd; <>n0arAn
nThreadID = id; dl.N.P7}4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2;[D;Y}
} $Ad{Z
A;G;^s
0v6)t.]s
public void run() hv)x=e<
{ a:+{f&
while(nStartPos < nEndPos && !bStop) efSM`!%j
{ #c!*</
WKQ^NEqr3
LnFdhrB@x
try{ JHW"-b
URL url = new URL(sURL); Qf58ig-vCY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `^91%f
httpConnection.setRequestProperty("User-Agent","NetFox"); "MxnFeLM#
String sProperty = "bytes="+nStartPos+"-"; 9lTv
httpConnection.setRequestProperty("RANGE",sProperty); R7]l{2V#^
Utility.log(sProperty); h~A/y!s
<i<J^-W
*EI6dD"
InputStream input = httpConnection.getInputStream(); DDvh4<Hk
//logResponseHead(httpConnection); 2^XGGB0
3yANv?$a
BK*x] zG$
byte[] b = new byte[1024]; @<<<C?CTv
int nRead; -)s qc P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c@YI;HS_g
{ D>|H 2
nStartPos += fileAccessI.write(b,0,nRead); }L &^xe
//if(nThreadID == 1) 2C2fGYu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )js)2L~
} w|3z;-#Q;
1m+p;T$
kSC}aN'
Utility.log("Thread " + nThreadID + " is over!"); {2qFY5H
bDownOver = true; "BD~xP(
//nPos = fileAccessI.write (b,0,nRead); |\w=u6jX
} 9s_vL9u
catch(Exception e){e.printStackTrace ();} Ok{*fa.PK
} + r!1<AAE$
} @HT% n
k $M]3}$U
!GOM5z,
//打印回应的头信息 .#wqXRd
public void logResponseHead(HttpURLConnection con) nJbtS#`G4
{ gHhh>FFAq
for(int i=1;;i++) -g)9R%>-
{ c?P?yIz6p
String header=con.getHeaderFieldKey(i); iM2W]
if(header!=null) dG@"!!,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t'9*R7=
Utility.log(header+" : "+con.getHeaderField(header)); %509\;el
else l6(-I Tb
break; 6cpw~
} @vpf[j
} CQwL|$)]Y
AGH|"EWG
GRMiQa
public void splitterStop() "nm FzN
{ .R)PJc5^
bStop = true; jlp:lX
} /V=24\1Ky
fKp#\tCc y
^BUYjq%(`
} qZ]pq2G
;WgJ<&33
RbCPmiZcH
/* DvPlV q~
**FileAccess.java f}Np/
*//文件访问(定位，写) ;GVV~.7/
package NetFox; "oWwc zzO
import java.io.*; 1mfs4
\(VTt|}By$
.w> 4
public class FileAccessI implements Serializable{ /R~1Zj2&
fq5_G~c=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BJgW,huLy
RandomAccessFile oSavedFile; ikSF)r;*t
long nPos; N+LL@[
W3Dc r@Dy
I#m-g-J
public FileAccessI() throws IOException u\LiSGePN
{ |fxA|/s[<
this("",0); @o#!EfZyE
} _$wmI/_JM
%)[+%57{
fGw^:,B
public FileAccessI(String sName,long nPos) throws IOException s7g(3<(
{ bV edFm
oSavedFile = new RandomAccessFile(sName,"rw"); %STliJ
this.nPos = nPos; _<=S_<$2
oSavedFile.seek(nPos); j<2m,~k`V
} Dfps gY)/?
YLwnhy>dD
K TsgJ\W
public synchronized int write(byte[] b,int nStart,int nLen) Z|_K6v/c
{ >w-;Z>3Q@
int n = -1; %9k!A]KD
try{ 'fcMuBc+4
oSavedFile.write(b,nStart,nLen); j [rB"N`0
n = nLen; neXeAU
} 5DXR8mLoaJ
catch(IOException e) :(a]V"(&Eq
{ 7_.11$E=H
e.printStackTrace (); +2K:qvzZ
} 1G0fp:\w
4q'B<7{Q
d~/q"r1"
return n; HQUeWCN
} !@x+q)2
S#-wl2z
uQ=^~K:Z~
} `%E8-]{uS
uGwJK`!~
L4b:F0
/* :U d
**SiteInfoBean.java QJ F=UB
*/ /^$UhX9v
package NetFox; j,t#B"hOnp
-*~CV:2iq-
4\pWB90V
public class SiteInfoBean { WpS1a440
QDTBWM%
kW`r=u
private String sSiteURL; //Site's URL X*g(q0N<S
private String sFilePath; //Saved File's Path rrnNn'
private String sFileName; //Saved File's Name ]Ni;w]KE
private int nSplitter; //Count of Splited Downloading File c(U
cO\-
/w8"=6Vv~
public SiteInfoBean() < AI;6/
{//nSplitter的缺省值为5 O<jPGU
//default value of nSplitter is 5 WKrX,GF
this("","","",5); K7e4_ZGI
} QN>7~=`
uNHdpni
4Hb $0l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >sD4R}\})
{ `p0ypi3hn
sSiteURL= sURL; ?( =p<TUw
sFilePath = sPath; Jz:r7w{4eB
sFileName = sName; /ahNnCtu?1
this.nSplitter = nSpiltter; :Pq.,s
`W `0Fwu9
Sd))vS^g
} T#!lPH :&h
dQgk.k
m7=1%6FN3
public String getSSiteURL() >p])it[q&$
{ mxFn7.|r~
return sSiteURL; kax\h
} _M,lQ~
9 L?;FY)_
RGD]8mw
public void setSSiteURL(String value) b8BD8~;
{ }:z5t,u6
sSiteURL = value; cPn+<M#
} yPu4T6Vv
g):]'
K(T\9J.
public String getSFilePath() Ep~wWQh
{ x`Fjf/1T*m
return sFilePath; 1;| LI?
} uH\kQ9f
{SG>'KXZ
pKJK9@Ad
public void setSFilePath(String value) .~=HgOJ
{ 8v yG*UK
sFilePath = value; uD>z@J-v
} S{p}ux[}=
80ZnM%/}
xi'<y
public String getSFileName() ; !$m1
{ )QY![&k}1z
return sFileName; u/AT-er;
} zW4O4b$T
ua 8m;>R
Jp;k+"<q
public void setSFileName(String value) BIWD/|LQ
{ }uX|5&=~f
sFileName = value; tLX,+P2|
} "S(X[Y'
A['uD<4b
,9ml>ji`=
public int getNSplitter() R]b! $6Lt
{ #*%fu
return nSplitter; [}""@?
} izt^Wi|
EI`vVI
gOE_ ]
public void setNSplitter(int nCount) w@N{@tG
{ !p%@Deu
nSplitter = nCount; yMIT(
} ]G1R0 Q
} *q"G }
5~\Kj#PBx
]Ti$ztJ
/* &X w`T9<
**Utility.java {'(ej5,6
*/ _'*DT=H'U
package NetFox; u 2lXd'
|(%AM*n
E*4t8
public class Utility { sQ(1/"gb
8*k oxS
>)%#V<{<
public Utility() U+!UL5k
{ ib Ue*Z["1
`V~LV<v5
CveWl$T12
} oQBiPN+v.3
x(yX0 ,P/7
//线程睡眠 =|#w.(3y
public static void sleep(int nSecond) le2/Zs$
{ H:E5xz3VQ
try{ w&+\Wo;([b
Thread.sleep(nSecond); LI:?Y_r
} $nc, ?)i!
catch(Exception e) hwZ6.
{ 0Ts!(b]B
e.printStackTrace (); T"A^[r*
} wV %8v\
} g(aNyn
$*aE$O6l
//日志 WxDb3l~
public static void log(String sMsg) IPkA7VhFF
{ rkP4<E-M
System.err.println(sMsg); ){jqfkL
} dRM5urR6,
l92!2$]b
"sSjVu
public static void log(int sMsg) (,d/JnP
{ SkriX\p
System.err.println(sMsg); f^ywW[dF
} o9~h%&
} ;4R=eI
hq]xmM?&
u% r!?-z
/* L F8Pb;I
**TestMethod.java 5_PWGaQa
*/ KuU3DTS85Z
package NetFox; K:Mujx:
/kAwe *)
`X3Xz!
public class TestMethod { ;K>{_kf
Bmi:2} j
DBLA% {05
public TestMethod() A8#.1uEgNb
{ ///xx/weblogic60b2_win.exe r94j+$7
try{ |R[v@c`pn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d'x<-l9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h85(N
SiteFileFetch fileFetch = new SiteFileFetch(bean); t5I^1u6
fileFetch.start(); s$js5 ou
} 97['VOh0
catch(Exception e){e.printStackTrace ();} L`<T'3G
%kFTnXHK
" whO}
} BUcaj.S
;,Of\Efc|
g5lmUKlQ$0
public static void main(String[] args) bEVO<x+
{ ?|%\<h@;
new TestMethod(); yS1b,cxz
} [Ihp\!xqI
} xn%l
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