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)); ch2m Ei(
} +DG-MM%\
for(int i=0;i<nEndPos.length-1;i++) `_f&T}]
{ mGDy3R90
nEndPos = nStartPos[i+1]; 8.G<+.
} `$Um
nEndPos[nEndPos.length-1] = nFileLength; [+d~He
} 4{Q$^wD+.
} ;m7~!m)
?0'e_s
*LMzq9n3o
//启动子线程 \2!.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k`#E#1niN
for(int i=0;i<nStartPos.length;i++) |$;4/cKfy
{ _&(L{cFx6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T6b~uE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F Uz1P
nStartPos,nEndPos,i); 6.9C4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d~MY z6"
fileSplitterFetch.start(); |"PS e~ u
} GSs?!BIC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q:nUn?zB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3ZC@q #R A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,Ne9x\F
nEndPos = " + nFileLength); (t){o>l
// fileSplitterFetch[nPos.length-1].start(); !rs }83w!
_M&n~ r
M,W-,l ]
//等待子线程结束 rizjH+
//int count = 0; ]#[4eaCg
//是否结束while循环 |)xWQ KzA
boolean breakWhile = false; E2 FnC}#W
o~9sO=-O
7IFZK\V
while(!bStop) Y}xM&%
{ 7NT0]j(w-
write_nPos(); MLlvsa0
Utility.sleep(500); VFM!K$_
breakWhile = true; |Eh2#K0x4G
~Ad2L*5S
!4`:(G59
for(int i=0;i<nStartPos.length;i++) }z#M!~
{ @-L\c>rqT
if(!fileSplitterFetch.bDownOver) q sUBvq
{ w#hg_RK(Jr
breakWhile = false; Niu |M@
break; N p*T[J
} vz#-uw,O:
} .%dGSDru
if(breakWhile) pacD7'1{
break; Pr>05lg
5Ok3y|cEx
x4PzP
//count++; ]%I\FefT
//if(count>4) #?+[|RS|
// siteStop(); FZ}^)u}o
} N34-z|"q
4DDBf j
u Fw1%
System.err.println("文件下载结束！"); XZ{rKf2
} ev0>j4Q
catch(Exception e){e.printStackTrace ();} 8ki3>"!A
} mR|5$1[b
0Gc:+c7{
YM#MfL#
//获得文件长度 qou\4YZ
public long getFileSize() ]'?Ue7
{ #AP;GoIf"j
int nFileLength = -1; Z m%,L$F*L
try{ OiXO<1'$
URL url = new URL(siteInfoBean.getSSiteURL()); .gGO+8[N*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7QnWw0
httpConnection.setRequestProperty("User-Agent","NetFox"); oH&@F@r:+
eub}+~_?[
[mQ1r*[j
int responseCode=httpConnection.getResponseCode(); aeI0;u
if(responseCode>=400) \2=I//YF
{ 0:71Xm
processErrorCode(responseCode); 0:n"A,-p
return -2; //-2 represent access is error &;pM<h
} ?%8%1d
*U6+b
;du},>T$n
String sHeader; {$Uj&/IC
F-b]>3r
&o7PB`(l
for(int i=1;;i++) Q\}-MiI/
{ SrB>_0**
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s3m\
//Utility.log(in.readLine()); |c8\alw
sHeader=httpConnection.getHeaderFieldKey(i); us~cIGm
if(sHeader!=null) rM,f7hm[S*
{ '(C+qwdRv
if(sHeader.equals("Content-Length")) AX%}ip[PC
{ Y>/_A%vQU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x7<NaMK\
break; AG}j'
} oJ*,a
} `L 1+j
else ! [1aP,
break; R&6@*Nn
} /O.Ql,6[
} )+'=Zvgej=
catch(IOException e){e.printStackTrace ();} [<{r~YFjWW
catch(Exception e){e.printStackTrace ();} JFO,Q -y\
1fsNQ!vQP
#]5KWXC'~
Utility.log(nFileLength); q2J|koT
N>YSXh`W`y
/n(0w`
return nFileLength; `p9N| V
} #:N#i
[;7zg@Sa
C|Y[T{g?t
//保存下载信息（文件指针位置） nA_'jl
private void write_nPos() X<.l(9$
{ %XeN_ V
try{ .)+c01
output = new DataOutputStream(new FileOutputStream(tmpFile)); {4A,&pR
output.writeInt(nStartPos.length); gED|2%BXb
for(int i=0;i<nStartPos.length;i++) G/FDD{y
{ uq-`1m}
// output.writeLong(nPos); CJCxL\
output.writeLong(fileSplitterFetch.nStartPos); `JDZR:bMaT
output.writeLong(fileSplitterFetch.nEndPos); ZiQ<SSo:
} ?!jJxhK<h
output.close(); Yq51+\d
} IO9|o!&>
catch(IOException e){e.printStackTrace ();} :L+xEL
catch(Exception e){e.printStackTrace ();} Rc{R^5B
} DiOd!8Y
GVA%iE.
z9OpMA
//读取保存的下载信息（文件指针位置） w' J`$=
private void read_nPos() &n_f.oUc
{ p&V64L:V
try{ 4G' E<ab
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \b$pH
int nCount = input.readInt(); Ssz;d&93
nStartPos = new long[nCount]; "P@ SR`v#
nEndPos = new long[nCount]; YaSBIq{z
for(int i=0;i<nStartPos.length;i++) bo90;7EK8
{ xR%NiYNQz
nStartPos = input.readLong(); 2[3t7C
nEndPos = input.readLong(); ps:`rVQ7
} 13Z,;YW
input.close(); d7G@Z|R3p
} #k)z5vZ$h
catch(IOException e){e.printStackTrace ();} P2f^]z
catch(Exception e){e.printStackTrace ();} hp/pm6
} pO7OP"q1
Z}0xK6
gsEcvkj*
private void processErrorCode(int nErrorCode) LFxk.-{=
{ \+sa[jK
System.err.println("Error Code : " + nErrorCode); ;A@DE@^5w
} F.aG7
M_UmnqN1C
bri8o"
//停止文件下载 *A8*FX>\F
public void siteStop() &}Wi@;G]2
{ 9M7P|Q
bStop = true; 7- LjBlH
for(int i=0;i<nStartPos.length;i++) MG.c`t/w
fileSplitterFetch.splitterStop(); R!"|~OO
,9jk<)m]L
fVY I
} 6pS}\aD
} Q<D_QJ
//负责部分文件的抓取 wGT>Xh!
**FileSplitterFetch.java gt.F[q3
*/ ;>6~}lMgJ
package NetFox; O.QR1
`W@jo~y<
L-}Uj^yF
import java.io.*; pGR3
import java.net.*; 3b0|7@_E
ohx$;j
|4pl}:g/Z
public class FileSplitterFetch extends Thread { ?qSwV.l]d
2bw), W
xSM1b5=Pu
String sURL; //File URL nj;3U^
long nStartPos; //File Snippet Start Position 'a JE+
long nEndPos; //File Snippet End Position c;"e&tW
int nThreadID; //Thread's ID KFO K%vbM
boolean bDownOver = false; //Downing is over <Fx%P:d
boolean bStop = false; //Stop identical W<#!He
FileAccessI fileAccessI = null; //File Access interface <XDnAv0t
:NWIUN
/*BU5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GT]>
{ oxeu%wj_
this.sURL = sURL; AhA&=l i;
this.nStartPos = nStart; +HUy,@^Pa
this.nEndPos = nEnd; B/@LE{qUn
nThreadID = id; KGc.YUoE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u1UCe
} >jmHe^rH
-R]~kGa6m<
H? z~V-8
public void run() 1twpOZ>
{ ']\SX*z?
while(nStartPos < nEndPos && !bStop) 0',buJncV
{ "?aI
4\|Q;@f
d(V4;8a0
try{ Bnk<e
URL url = new URL(sURL); <Rn-B).3bs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V0 Z8VqV
httpConnection.setRequestProperty("User-Agent","NetFox"); (j@c946z""
String sProperty = "bytes="+nStartPos+"-"; Z+6WG
httpConnection.setRequestProperty("RANGE",sProperty); 5HHf3E [
Utility.log(sProperty); (=WYi~2v
F|m &n&
YCb|eS^u
InputStream input = httpConnection.getInputStream(); =Gzs+6A8
//logResponseHead(httpConnection); S~fP$L5
[tt{wl"E
??.aLeF&
byte[] b = new byte[1024]; 8`)* ?Q9~
int nRead; k+"7hf=C|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wnQy
{ W,yLGz\
nStartPos += fileAccessI.write(b,0,nRead); C<T6l'S{?
//if(nThreadID == 1) LdOme[C1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *! :j$n;
} jwLZC
zx]r.V
9a]o?>`E
Utility.log("Thread " + nThreadID + " is over!"); ,aS+RJNM
bDownOver = true; 1c]{rO=taN
//nPos = fileAccessI.write (b,0,nRead); u]O}Ub`
} GKF!GbGR@
catch(Exception e){e.printStackTrace ();} 8O{V#aop
} 9__Q-J
} p8-$MF]]6
K$}K2w
$?z}yx$
//打印回应的头信息 +'93%/:
public void logResponseHead(HttpURLConnection con) YG=:lf
{ ZWS:-]P.
for(int i=1;;i++) - uO(qUa#
{ *6AqRE
String header=con.getHeaderFieldKey(i); L..
if(header!=null) ~J~R.r/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?F$#t6Q
Utility.log(header+" : "+con.getHeaderField(header)); Ho*B<#&(A|
else -Q<OSa='
break; -!5l4
} MxX)&327
} kiyKL:6D|
#Q["[}flVv
"O$WfpKX
public void splitterStop() OIw[sum2
{ bw/mF5AsW
bStop = true; a[j]fv*6
} gn.)_
9$9aBW
c'VCCXe
} $>_`.*I/
BT0;I
Uj 4HVd
/* 1uKIO{d@
**FileAccess.java FwB xag:u
*//文件访问(定位，写) <v_Wh@m
package NetFox; CXz9bhn<4
import java.io.*; FcZ)^RQ4G
reYIF*
@C[p?ak
public class FileAccessI implements Serializable{ OKau3T]
d^tY?*n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ' i5}`\
RandomAccessFile oSavedFile; bcuUej:
long nPos; VFnxj52<
C{t}q*fG 5
Oi~Dio_?
public FileAccessI() throws IOException G[>CBh5
{ (yuOY/~k/
this("",0); |cuKC \
} @~7au9.V=X
L_:~{jV
$Fc}K+
public FileAccessI(String sName,long nPos) throws IOException G#NbLj`h
{ Q (gA:aQ
oSavedFile = new RandomAccessFile(sName,"rw"); 7iv g3*
this.nPos = nPos; ER&\2,fZ
oSavedFile.seek(nPos); Ji=`XsV
} mrKIiaU<J
${ DSH
k'e1ZAn
public synchronized int write(byte[] b,int nStart,int nLen) #^|2PFh5
{ 8~.8"gQ
int n = -1; |7Z}#eP//
try{ IvQuxs&a
oSavedFile.write(b,nStart,nLen); qyy.&+
n = nLen; {A ,w%
} -cn`D2RP
catch(IOException e) {H9g&pfv
{ '?NMQ
e.printStackTrace (); ,.=7{y~
} 2p 7;v7)y
f`-vnh^+
e iH&<AH
return n; '< >Q20
} I'n}6D.M
U_Mag(^-
vGJw/ij'X
} E"/k"1@
ZtGkMd$
B 'd@ms
/* bng/v
**SiteInfoBean.java &:g1*+
*/ l;aO"_E1m
package NetFox; )N3/;U;
rt)[}+ox
sUxEm}z
public class SiteInfoBean { 0oi.k;
QJx<1#
#!yX2lR
private String sSiteURL; //Site's URL .p'McCV=
private String sFilePath; //Saved File's Path [;D1O;c'W.
private String sFileName; //Saved File's Name W_/$H_04+
private int nSplitter; //Count of Splited Downloading File hQL@q7tUr
+zo\#8*0MF
4@ny%_/
public SiteInfoBean() J=O_nup6C
{//nSplitter的缺省值为5 `tKs|GQf
//default value of nSplitter is 5 ^foCcO
this("","","",5); DI-CC[
} I>-1kFma;
.ubZ
pf yJL?_%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 81I9xqvSd~
{ Ib/e\+H\
sSiteURL= sURL; *'{9(Oj
sFilePath = sPath; aqi]5,
sFileName = sName; 3_i29ghv
this.nSplitter = nSpiltter; &wkbr2P
(Nf!E[}Z
wYv++< z
} %(\et%[]
K}whqe]j
Rp_}_hL0
public String getSSiteURL() 0Uk;&a0s
{ l u{6
return sSiteURL; M4d4b
} :V)=/mR
):L0{W{
(J(SwL|
public void setSSiteURL(String value) K[9P{0hA
{ }^odUIj
sSiteURL = value; ^Vc(oa&;
} /kO%aN
RWJyd=
1dy"
public String getSFilePath() l?^}n(_.
{ )g U#[}6H
return sFilePath; g+4x
} ~qA\u5sB9@
o6:]Hvqjr
~sWXd~\
public void setSFilePath(String value) zrC1/%T
{ $TAsb>W!(
sFilePath = value; /}d)g4\j
} a72L%oJ
m'ZxmsFo
`w"ooK
public String getSFileName() {~Q}{ha
{ QbWeQ[V{
return sFileName; j4#S/:Q<7
} 9m%+6#|
]qk`Yi
a5`9mR)Y$'
public void setSFileName(String value) p%\&M bA
{ X#MC|Fzy@
sFileName = value; uxW<Eh4H*
} )@.0ai
OeQ~g-n
j#H&~f
public int getNSplitter() O&dh<
{ W#x~x|(c
return nSplitter; HJe6h. P
} Fa X3@Sd!
0v3 8LBH)
v/Xz.?a\jF
public void setNSplitter(int nCount) }ol<DV
{ G98fBw
nSplitter = nCount; IfCa6g<&(
} 0A75)T=lQ
} I$fm"N
=u5( zaBe
5J6~]J
/* fQ2U|
**Utility.java S^5Qhv
*/ M(Yt9}Z%Y
package NetFox; vH"^a/95|
x^YsXzu
M&rbXi.
public class Utility { lBG"COu
CG!9{&F
@@6c{r^P
public Utility() |q\Rvt$d
{ yV)9KGV+:
1#vi]CX
!~}@Eoii4
} r{Z4ifSl(
mr XmM<
//线程睡眠 i%r+/D)KvG
public static void sleep(int nSecond) p,mKgL63
{ L5]uT`Twa
try{ qI2&a$Zb$
Thread.sleep(nSecond); WG5)-;>q|
} .DhB4v&
catch(Exception e) Xc G
{ R)]+>M-.
e.printStackTrace (); e1R<+`]
} {"*gX&;~
} (S63:q&g
:CXm@yF~4=
//日志 f(c#1AJE53
public static void log(String sMsg) mqQC`Aqx:
{ @dhnpR:L
System.err.println(sMsg); N >];xb>
} qoC<qn{.a
,mE}#cyY
6dqI{T-i?
public static void log(int sMsg) *XG.?%x*|
{ K'U=);W
System.err.println(sMsg); L\t?^u
} AK$i0Rn;pm
} }Y3*X:i7
JuRx>F4
di~ [Ivw
/* AZbFj-^4
**TestMethod.java %07vH&<C.
*/ E qt\It9
package NetFox; 3s,a%GOk
Q\*zF,ek
" 8g\UR"[
public class TestMethod { ] N7(<EV/
eeOG(@@o(
%VO>6iVn
public TestMethod() 9G{#a#Z.
{ ///xx/weblogic60b2_win.exe '.t{\
try{ FND+Ok&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tr%VYc|}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "0?" E\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 207h$a,
fileFetch.start(); 6oq/\D$6~
} >u?a#5R:m
catch(Exception e){e.printStackTrace ();} b}m@2DR'|m
L&Pj0K-HT3
)bB Va^
} H:`H4S}
?H21Ru>:*
0@}:`OynX
public static void main(String[] args) F Xp_`9.zH
{ idY Xv)R
new TestMethod(); J!5&Nc
} cwI3ANV
} bMN]co
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