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)); \nQEvcH
} o%Qn%gaX
for(int i=0;i<nEndPos.length-1;i++) a1weTn*
{ o`}8ZtD
nEndPos = nStartPos[i+1]; _)#~D*3
} O}7aX '
nEndPos[nEndPos.length-1] = nFileLength; ACgWT
} TR{dNO!q
} 27H4en; o=
6M8(KN^
m(WVxVB
//启动子线程 %,)Xi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j7HOh|q
for(int i=0;i<nStartPos.length;i++) )/tdiRpn
{ Szlww
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WF<*rl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *P[N.5{
nStartPos,nEndPos,i); rX&?Xi1JeV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JhB$s
fileSplitterFetch.start(); I~c}&'V
} %M05& <
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^EKf_w-v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5{8,+ Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .ZH5^Sv$vp
nEndPos = " + nFileLength); Xc]Q_70O
// fileSplitterFetch[nPos.length-1].start(); 9M-/{D^+<
.s@[-! p
k8"[)lDc.
//等待子线程结束 )$I"LyK)
//int count = 0; !^A t{[U
//是否结束while循环 pJwy~ L
boolean breakWhile = false; cNqw(\rr
g/soop\:
BH=CoD.
while(!bStop) 8f|+045E@
{ Z7R+'OC
write_nPos(); fBt7#Tc=U
Utility.sleep(500); %|3UWN
breakWhile = true; vweD{\b
jl4rEzVu
6T~xjAuJ3T
for(int i=0;i<nStartPos.length;i++) r7p>`>_Q\
{ sQe>LNp,G
if(!fileSplitterFetch.bDownOver) _qqJ>E<0
{ S b3@7^
breakWhile = false; Z@`HFZJ
break; Ok~\
} D<cHa |
} n-_-;TYH
if(breakWhile) V|fs"HY
break; 2]*2b{gF,
%@FTg$
JEes'H}Y
//count++; /P|jHK|{
//if(count>4) Ws`P(WHm
// siteStop(); ]={{$}8.
} 8~|PZ,oZ
$Mp#tH28
R#Bdfmldq
System.err.println("文件下载结束！"); oFV>b
} 5q?ZuAAA
catch(Exception e){e.printStackTrace ();} !(Y23w*
} ~dK)U*Q
FiqcM-Af4
U{o0Posg
//获得文件长度 9YpD\H`
public long getFileSize() ( Qw"^lE3
{ x*[\$E`v
int nFileLength = -1; X@)5F 9
try{ BUcze\+
URL url = new URL(siteInfoBean.getSSiteURL()); FXOA1VEg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yggQ4y6
httpConnection.setRequestProperty("User-Agent","NetFox"); 6nRD:CH)X
;Z"6ve4
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int responseCode=httpConnection.getResponseCode(); Hs8c%C
if(responseCode>=400) MDS;qZx=
{ eUA6X ,I
processErrorCode(responseCode); kfBVF%90
return -2; //-2 represent access is error 70L{u+wIy
} P-VK=Y1q
;X!sTs
cSBYC_LU
String sHeader; `|;R}"R;
2mbZ6'p {
ucyz>TL0
for(int i=1;;i++) 1 {dhGX
{ ]dc^@}1bN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #!KbqRt
//Utility.log(in.readLine()); [|\~-6"7N|
sHeader=httpConnection.getHeaderFieldKey(i); RJ1Q.o
if(sHeader!=null) x(7K=K']
{ DGTSk9iK(
if(sHeader.equals("Content-Length")) o64&BpCK
{ pUWj,&t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T"XP`gk
break; :grJ}i-D
} DQd~!21\|
} TDdFuO'}
else i3*S`/]p
break; 'QjX2ytgX
} ?C6iJnm
} =usx' #rb
catch(IOException e){e.printStackTrace ();} 2![.Kbqa%
catch(Exception e){e.printStackTrace ();} AW4N#gt8',
'c\zWmAZ
JB a:))lw
Utility.log(nFileLength); h&||Ql1
impzqQlZ,
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return nFileLength; Q d]5e
} 16[>af0<g
Jeyy Z=
ig]*Z
//保存下载信息（文件指针位置） P'GX-H
private void write_nPos() TGGeTtk=
{ j8!fzJG
try{ [L8Bgw1
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3HC aZ?Ry'
output.writeInt(nStartPos.length); qCn(~:
for(int i=0;i<nStartPos.length;i++) DF/p{s1Y3
{ ;=Jj{FoG%
// output.writeLong(nPos); eXWiTi@
output.writeLong(fileSplitterFetch.nStartPos); Z}TuVE
output.writeLong(fileSplitterFetch.nEndPos); ]L%qfy4
} Q2iS0#
output.close(); aHe/MucK
} 6$w)"Rq
catch(IOException e){e.printStackTrace ();} oorit
catch(Exception e){e.printStackTrace ();} PmO utYV
} "d>{hP
IY?[0S
"?hEGJ;m"
//读取保存的下载信息（文件指针位置） F`3c uL[N
private void read_nPos() dX: (%_Mn
{ at${^,&
try{ z@^[.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); meT~b
int nCount = input.readInt(); R3<>]/1p|P
nStartPos = new long[nCount]; f@T/^|`mh
nEndPos = new long[nCount]; snOd 3Bw
for(int i=0;i<nStartPos.length;i++) ;(fDR8
{ <Vm+Lt9
nStartPos = input.readLong(); ?2_Oa%M
nEndPos = input.readLong(); \B8tGog
} 3:X3n\z
input.close(); c_<m8b{AEF
} mS5'q q;t
catch(IOException e){e.printStackTrace ();} \:]Clvc
catch(Exception e){e.printStackTrace ();} ,J"6(nk
} N_lQz(nG/2
+',[q
jt?4raNW
private void processErrorCode(int nErrorCode) kB{
{ W'u6F-$2
System.err.println("Error Code : " + nErrorCode); u~7mH
} j+"i$ln+s
9&fS<Hk
X@|'#%
//停止文件下载 m.e+S,i
public void siteStop() 3 HOJCgit
{ x7)j?2
bStop = true; '=K [3%U
for(int i=0;i<nStartPos.length;i++) [Hw
fileSplitterFetch.splitterStop(); je@F:5
iZ %KHqG
Xptb4]
} +>h}Uz
} A&X(\c M
//负责部分文件的抓取 a~E@scD
**FileSplitterFetch.java Jn3cU
*/ b9Jah
package NetFox; gcDo o2RE
@q:v?AO
?,uTH 4
import java.io.*; qpzzk9ba[
import java.net.*; 07 [%RG
r8>(ayJ,
I,;@\
public class FileSplitterFetch extends Thread { VWDXEa9
81Ixs Qt
^f*}]`S
String sURL; //File URL l3kYfq{";"
long nStartPos; //File Snippet Start Position vM )2F
long nEndPos; //File Snippet End Position [P~6O>a5p
int nThreadID; //Thread's ID ZI.;7G@|
boolean bDownOver = false; //Downing is over XJJdCv^
boolean bStop = false; //Stop identical ZslH2#
FileAccessI fileAccessI = null; //File Access interface >Y,3EI\
?4>uGaU\
Z9Prw/8P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [MLJs-*
{ :sO^b*e /
this.sURL = sURL; $7M/rF;N5X
this.nStartPos = nStart; qkQ_#
this.nEndPos = nEnd; nADt8
nThreadID = id; YbCqZqk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %f??O|O3
} r*$$82s
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"p]Fq,
public void run() 2K >tI9);
{ ! C}t)R]^
while(nStartPos < nEndPos && !bStop) Bfh[C]yy
{ V[E7mhqy
$BIQ#T>qK
[HEqMBX=;
try{ 6AS'MD%&
URL url = new URL(sURL); dFdll3bC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /WIO@c
httpConnection.setRequestProperty("User-Agent","NetFox"); oL?[9aww
String sProperty = "bytes="+nStartPos+"-"; #$\cRLPg
httpConnection.setRequestProperty("RANGE",sProperty); ;=rMIi
Utility.log(sProperty); [>`[1;aX
mX@Un9k
*7`N^e
InputStream input = httpConnection.getInputStream(); O_}ZSB8"
//logResponseHead(httpConnection); @\~qXz{6J
Rg:3}T`~n
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byte[] b = new byte[1024]; TF\<`}akX
int nRead; #3uBq(-Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iU)-YFO
{ = mnjIp
nStartPos += fileAccessI.write(b,0,nRead); 3F%Qq7v
//if(nThreadID == 1) $}[Tj0+:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $Cu/!GA4.>
} ^RN1?dXA
0 O{Y Vk`
3YY<2<
Utility.log("Thread " + nThreadID + " is over!"); id^U%4J
bDownOver = true; Kd_WN;l
//nPos = fileAccessI.write (b,0,nRead); nMU#g])y)
} a S- rng
catch(Exception e){e.printStackTrace ();} <`dF~
} V/5hEoDt
} tVx.J'"Y
'-jKv=D+
Xco$ yF%
//打印回应的头信息 FswMEf-|
public void logResponseHead(HttpURLConnection con) ^qpa[6D6x
{ ArkFC
for(int i=1;;i++) ,5\:\e0H
{ >l$vu-k)~4
String header=con.getHeaderFieldKey(i); @LY 5]og
if(header!=null) $Z;HE/3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A!v-[AI[
Utility.log(header+" : "+con.getHeaderField(header)); #( nheL
else T0_9:I`&
break; /,v:!*
} z(< E %
} ErC~,5dj;n
TGLkwXOkT
]P0DPea
public void splitterStop() }\u~He%
{ 1at$_\{.(
bStop = true; ?xf59mY7
} /3%]Ggwe
ZLvw]N&R
AW'tZF"
} c: *wev
~4}m'#!
)<.S3
/* }jd[>zk
**FileAccess.java u2<:mu[|P
*//文件访问(定位，写) #py7emu
package NetFox; p!'wOThO`
import java.io.*; _|8"&*T^
_0F6mg n
^ +{ ~ ^y7
public class FileAccessI implements Serializable{ K=sQ_j.&Z
"4"\tM(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %8o(x 0
RandomAccessFile oSavedFile; Cu;X{F'H
long nPos; J=K3S9:n]g
|0f\>X I
wX 41R]pF
public FileAccessI() throws IOException 4BEVG&Ks
{ k9 *0xukJ
this("",0); .M>u:,v
} 0nie>
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`ss]\46>
public FileAccessI(String sName,long nPos) throws IOException *7*g! km
{ bT{P1nUu
oSavedFile = new RandomAccessFile(sName,"rw"); SgXXitg9+
this.nPos = nPos; ?7&VT1
oSavedFile.seek(nPos); !y] Y'j
} OD1ns
95]%j\
s?Q`#qD
public synchronized int write(byte[] b,int nStart,int nLen) L0&!Qct
{ B8s|VI
int n = -1; =D[h0U
try{ }= <!j5:
oSavedFile.write(b,nStart,nLen); |e< U%v
n = nLen; 0_]aF8j
} %!.rP
catch(IOException e) SbI,9<
{ A`N;vq,
e.printStackTrace (); _^'k_a
} =kc{Q@Dk
*E. 2R{
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return n; 41uSr 1
} 9MYt4
8c/Ii"1
LAwS8t',
} v'@LuF'e8
?,8b-U#A1
WI~%n
/* ud#8`/!mq
**SiteInfoBean.java fzio8mKVX
*/ /6.b>|zF
package NetFox; Z\7bp&&
sO6t8)$b
h n]6he
public class SiteInfoBean { 0,3 ':Df
@"EX%v.
>5gzo6j/
private String sSiteURL; //Site's URL v}mmY>M%
private String sFilePath; //Saved File's Path $ta#]>{
private String sFileName; //Saved File's Name d!X?R}
private int nSplitter; //Count of Splited Downloading File Z"^@B2v
h ,n!x:zy@
#3$|PM7,_
public SiteInfoBean() puyL(ohem
{//nSplitter的缺省值为5 W P&zF$
//default value of nSplitter is 5 "O 'I
this("","","",5); _t[%@G>P
} bDNd m-
'ng/A4
!Ch ya
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xd.C&Dx5
{ qprOxP r
sSiteURL= sURL; M:$nL
sFilePath = sPath; Dw[Q,SE
sFileName = sName; `ouzeu9}
this.nSplitter = nSpiltter; lq5E?B
,m8*uCf
t*#&y:RG
} iy"Kg]
Ei<:=6EX?8
mTgn}rXk
public String getSSiteURL() gk#rA/x
{ \nWpV7TSN
return sSiteURL; w1b <>A?87
} hH/O2
k#&SWp=
t} M3F-NZ
public void setSSiteURL(String value) 9R[','x
{ nSiNSLv
sSiteURL = value; J;`~ !g
} NZ5~\k
A'8K^,<
'7R'fhiO/3
public String getSFilePath() m~eWQ_a]C@
{ W|e>
return sFilePath; *% *^a\2
} r|@?v,
zY+Et.lg]^
6%#'X
public void setSFilePath(String value) ?g4|EV-56
{ E=NY{|>
sFilePath = value; PEIr-qs%D
} {eEWfMKIn
]:s|.C%qI
Q8oo5vqQ#C
public String getSFileName() |/;5| z
{ T}[vfIJD
return sFileName; ""^BW Re D
} x?'%
Qu_T&
-RQQ|:O$
public void setSFileName(String value) =_J<thp
{ Yj\yO(o/
sFileName = value; )`7+o9&
} T+h{Aeg
Gx_e\fe-/
;_5 =g
public int getNSplitter() b'5pQ2Mq
{ ix@rq#
return nSplitter; /exl9Ilt]
} r.^X>?
5yi q#
>%dAqYi $
public void setNSplitter(int nCount) ldvxYq<:
{ M~F2cXW
nSplitter = nCount; vXQmEIm
} wg_CI,Kq
} =e-aZ0P
,nRwwFd.
Atq2pL"
/* [<a%\:c m4
**Utility.java !>Y\&zA
*/ -0WCwv
package NetFox; T8TsKjqOZ
^GaPpm
qgsE7 ]
public class Utility { Y6?mY!
Mv`LF
=1OAy`8
public Utility() UA4d|^ev
{ FK >8kC
wK`ieHmp
=&:f+!1$
} maEpT43f
7oLf5V1~
//线程睡眠 8Pr7aT:,
public static void sleep(int nSecond) cPaWJ+c
{ ?[1qC=[Z<
try{ S@zkoj@
Thread.sleep(nSecond); v:Z4z6M-
} nC.2./OwMf
catch(Exception e) SLjf<.S
{ RHl=$Hm.%
e.printStackTrace (); _AB9BQm
} %x8`fm
} KPd C9H
/j69NEl
//日志 [gns8F#H\
public static void log(String sMsg) bb/?02*)H
{ O:=|b]t
System.err.println(sMsg); N|O]z
} ?-::{2O)
]v\egfW,W
R~5*#r@f
public static void log(int sMsg) 1mVVPt^6
{ L8]{B
System.err.println(sMsg); i$^B-
} V>jhGf
} =6:L+V
d O46~
MjXE|3&
/* !MJe+.
**TestMethod.java KA-/k@1&
*/ 1S(\2{Ylo
package NetFox; %V(N U_o
"ryk\}*<
lHKf#|
public class TestMethod { \9(- /rE
yB4H3Q )
,c%K)KuPK.
public TestMethod() BF@5&>E
{ ///xx/weblogic60b2_win.exe Gl8&FrR
try{ Y%0d\{@a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WfDX"rA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); { 8f+h
SiteFileFetch fileFetch = new SiteFileFetch(bean); phgexAq
fileFetch.start(); Gh2Q$w:
} 45+%K@@x
catch(Exception e){e.printStackTrace ();} hH1lgc
4g7ja
sCF40AoY&
} @1qdd~B}
1X::0;3
-.{oqs$
public static void main(String[] args) wMz-U- z
{ ss`P QN
new TestMethod(); \6lh `U
} x*h?%egB!p
} /}w#Jk4pD
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