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)); Luu.p<
} #sp8 !8|y
for(int i=0;i<nEndPos.length-1;i++) 2XGbqZj
{ $ACD6u6
nEndPos = nStartPos[i+1]; 0}y-DCuQ
} @jevY81)
nEndPos[nEndPos.length-1] = nFileLength; %oEvp{I
} aXO|%qX
} /0I=?+QSo
Di8;Tq
\mp5G&+/Q
//启动子线程 %G>V .d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u9R:2ah&K
for(int i=0;i<nStartPos.length;i++) U/I+A|S[
{ y153ax
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1$G'Kg/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X-=J7G`\h#
nStartPos,nEndPos,i); PFnq:G^L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qQ "O;_
fileSplitterFetch.start(); AilfeHG
} N:Zf4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gR:21*&cz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |Zrkk>GW:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0ge^pO\Z
nEndPos = " + nFileLength); d8Kxtg Y
// fileSplitterFetch[nPos.length-1].start(); =C.WM*='
a2N4Jg@
@ag*zl
//等待子线程结束 mrz@Y0mgL
//int count = 0; ngHPOI16
//是否结束while循环 LQrm/)4bF5
boolean breakWhile = false; Ghpk0ia%d
eEG]JH
$1$T2'C~+
while(!bStop) <"XDIvpc%L
{ F"M$ "rC]
write_nPos(); +O,h<*y
Utility.sleep(500); FI$#x%A
breakWhile = true; jB-)/8.qk
CD+2 w cy
+B0G[k7
for(int i=0;i<nStartPos.length;i++) v/B:n
{ K'zG[[P
if(!fileSplitterFetch.bDownOver) {l-V
{ v lsS
breakWhile = false; Z'I0e9Jw
break; !p~K;p,
} @)YQiE$
} XUyoZl?
if(breakWhile) ib%x&?||
break; \7Fkeo+
2i3& 3oz]O
pD>^Dfd
//count++; @j Y_^8#S
//if(count>4) W^^}-9
// siteStop(); WaRYrTDv64
} MjHjL~Tg
#)xg$9LQb
wzRIvm{
System.err.println("文件下载结束！"); Q5s?/r
} Xqac$%[3
catch(Exception e){e.printStackTrace ();} S(f V ,;Z
} C8 b%r|^#
Ag!#epi{0
!bHM:!6^
//获得文件长度 a~-^$Fzgy
public long getFileSize() S3k>34_%9
{ E|A,NPf%I
int nFileLength = -1; !7K-Kqn
try{ xf.2Ig
URL url = new URL(siteInfoBean.getSSiteURL()); >xt*(j&}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5E+k}S]M$
httpConnection.setRequestProperty("User-Agent","NetFox"); KQ x<{-G6
+i[w& P
:a4FO
int responseCode=httpConnection.getResponseCode(); Um$a9S8b&
if(responseCode>=400) UT9=S21
{ y=jTS
processErrorCode(responseCode); -~HlME*~f
return -2; //-2 represent access is error [[[QBplJ
} {:3XP<hqN
M\s^>7es
-0)So
String sHeader; ~"*;lT5KX
B43o_H|s
d.7Xvx0Yww
for(int i=1;;i++) p ?HODwZ
{ ibOXh U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 79^on8k}
//Utility.log(in.readLine()); swDSV1alMB
sHeader=httpConnection.getHeaderFieldKey(i); 6L6Lk
if(sHeader!=null) !!c.cv'
{ Ik#>6
if(sHeader.equals("Content-Length")) TLL.Ch|#Y
{ e< Ee2pGX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z6cG<,DQ
break; YSuwV)Y
} ^j2:fJOU#
} IpxFME%!
else 7<=7RPWmD
break; i#jCf3%+ h
} ^saJfr x
} y(RbW_ ?
catch(IOException e){e.printStackTrace ();} g"3h#SMb
catch(Exception e){e.printStackTrace ();} NRKAEf_#w
uREc9z`Q'
~P5!VNJ;r
Utility.log(nFileLength); omV.Qb'NS
Dz&4za+{
qvOBvUR}
return nFileLength; ``kKi3TWJ
} YV 9*B
qR_"aQ7s2
%;9eh'
//保存下载信息（文件指针位置） ZUyM:$
private void write_nPos() zYOPE 6E
{ |k'I?:'
try{ jkNZv. )p
output = new DataOutputStream(new FileOutputStream(tmpFile)); XEZ6%Q_
output.writeInt(nStartPos.length); $Mx.8FC +
for(int i=0;i<nStartPos.length;i++) kmW!0hm;e
{ \]J"e%
// output.writeLong(nPos); \Mlj 7.u]
output.writeLong(fileSplitterFetch.nStartPos); q_f v1U3
output.writeLong(fileSplitterFetch.nEndPos); tazBZ'\c
} y|KDh'Y
output.close(); #%e`OA(b
} )m[!HE`cZ
catch(IOException e){e.printStackTrace ();} ,`|KNw5
catch(Exception e){e.printStackTrace ();} d*3R0Q|#{
} ?=IbiT
qRB7I:m-Wi
vfhip"1
//读取保存的下载信息（文件指针位置） Qb# S)[6s+
private void read_nPos() V!KtF
{ y&__2t^u
try{ TF^]^XS'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3iWLo Qm
int nCount = input.readInt(); zMrZ[AU
nStartPos = new long[nCount]; Zt` ,DM
nEndPos = new long[nCount]; xs &vgel>
for(int i=0;i<nStartPos.length;i++) ,75,~
{ l!iB -?'u
nStartPos = input.readLong(); kd\yHI9A
nEndPos = input.readLong(); Mdwh-Cis/
} !s)2H/KM8
input.close(); $]81s`
} &8&WY1cU
catch(IOException e){e.printStackTrace ();} *pasI.2s#
catch(Exception e){e.printStackTrace ();} N=+Up\h
} 1*-58N*
n6o}$]H
71/6=aq>n
private void processErrorCode(int nErrorCode) OClY,@
{ Eun%uah6c
System.err.println("Error Code : " + nErrorCode); r9vC&pWZ
} |E7]69=P
~`N|sI,
G8oQSo;D
//停止文件下载 NM]6 o
public void siteStop() I3s}t$`y(
{ 8'cDK[L
bStop = true; 3YT _GW{
for(int i=0;i<nStartPos.length;i++) 'ZDa*9nkF
fileSplitterFetch.splitterStop(); 1g/mzC
AARhGx|L<
wOk:Q4OjL
} Yp ? 2<
} |R[m&uOib
//负责部分文件的抓取 H{GbOI.
**FileSplitterFetch.java cL WM]\Y
*/ 9Pb0Olh
package NetFox; uPp(l4(+
ohh 1DsB
fg1 zT~
import java.io.*; =q"3a9pb7
import java.net.*; yz+r@I5
uC;@Yi8
ss2:8up 99
public class FileSplitterFetch extends Thread { /n_HUY
Y.C*|p#
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String sURL; //File URL }M~AkJL
long nStartPos; //File Snippet Start Position ]jYl:41yI
long nEndPos; //File Snippet End Position dvj`%?=
int nThreadID; //Thread's ID <n`|zQ
boolean bDownOver = false; //Downing is over "M*\,IH
boolean bStop = false; //Stop identical '/p5tw8
FileAccessI fileAccessI = null; //File Access interface I%s/h4x^B[
E|fPI u
G37_ `C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException . }1!MK5
{ BW*zj=N%
this.sURL = sURL; 3~S~)quwP
this.nStartPos = nStart; O0I/^
this.nEndPos = nEnd; "{:*fI;!
nThreadID = id; _6[NYv$"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~gAx
} }z*p2)v`
[p(C:rH
[lJ[kr*7
public void run() N,1wfOE
{ Fq3;7Cq=hD
while(nStartPos < nEndPos && !bStop) =Vv{td
{ & 3a+6!L[
l%:_#1?isf
l{3utQH-=z
try{ /za,&7sf
URL url = new URL(sURL); oc?VAF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &KB{,:)?
httpConnection.setRequestProperty("User-Agent","NetFox"); \E30.>%,
String sProperty = "bytes="+nStartPos+"-"; qjFgy)qV
httpConnection.setRequestProperty("RANGE",sProperty); Yk5kC0B
Utility.log(sProperty); lV1|\~?4
MWuVV=rd8a
"N;|~S)w!
InputStream input = httpConnection.getInputStream(); S,v`rmI
//logResponseHead(httpConnection); BZBsE :(F
'F~u \m=E
B?4\IXek
byte[] b = new byte[1024]; I F@M
int nRead; )2A4vU-IR.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) oa4}GNH
{ | jkmh6
nStartPos += fileAccessI.write(b,0,nRead); nk{1z\D{
//if(nThreadID == 1) ZAP+jX;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1Li@O[%X<
} bM'AD[
Ob6vg^#
ibq@0CR
Utility.log("Thread " + nThreadID + " is over!"); ,yF)7fN
bDownOver = true; ~:@H6Ke[
//nPos = fileAccessI.write (b,0,nRead); w*}9;l
} l1??b
catch(Exception e){e.printStackTrace ();} :)z_q!$j
} B?M+`;
} y/FisX
)v9[/ ]*P
qq`RfZjL
//打印回应的头信息 \z{Y(dS
public void logResponseHead(HttpURLConnection con) M Q6Y^,B
{ ,y>Na{@Y
for(int i=1;;i++) @K/Ia!Lw
{ @.{
String header=con.getHeaderFieldKey(i); j.6kjQN
if(header!=null) 2*|]#W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UdGoPzN
Utility.log(header+" : "+con.getHeaderField(header)); \x!>5Z Y
else LWI~m2
break; gU?)
} a:fHTU=\p
} TU/J]'))C
aPC!M4#
Vo%d;>!G\;
public void splitterStop() H@zk8]_P
{ _x!pMj(A
bStop = true; w#e'K-=
} [a3 0iE
(Ka#6
d}ZHY[
} {ZcZ\Q;6
-db+Y:xUZ
z)%1i
/* lK4+8VZ
**FileAccess.java 4(R2V]
*//文件访问(定位，写) k mjm6
package NetFox; _a&|,ajy>
import java.io.*; .H"hRYPC?
FMVmH!E
T?Y\~.+99
public class FileAccessI implements Serializable{ pd#/;LT
b5DrwX{Ff
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L,6Y=?
RandomAccessFile oSavedFile; HhL%iy1
long nPos; 0U>Q<I}
V%ch'
4i,SiFKB
public FileAccessI() throws IOException lQ/XJw
{ `y}d)"!
this("",0); q8Dwu3D
} G)&'8W F5o
qx)k1QY
GcnY=%L?
public FileAccessI(String sName,long nPos) throws IOException ZkW@|v
{ ju]]|
oSavedFile = new RandomAccessFile(sName,"rw"); hptuTBD
this.nPos = nPos; PlZiTP
oSavedFile.seek(nPos); K_QCYS.
} [Ni4[\
Y9;Mey*oW
?_aR-[XRg
public synchronized int write(byte[] b,int nStart,int nLen) WM"^#=+$
{ I*}#nY0+
int n = -1; Ct)MvZ
try{ sh ;uKzQ
oSavedFile.write(b,nStart,nLen); 3ZlI$r(
n = nLen; >K :"[?
} "NU".q
catch(IOException e) ?N*0S'dY
{ c~xo@[NaS
e.printStackTrace (); !9, pX
} $VWzv4^:
0>iFXw:fn
3J T3;O
return n; U[b;#Y1X
} _m],(J=,z
bSf(DSqx
Zjg\jo
} "ILWIzf.]
@@IA35'tc
{yR)}r
/* 6[.Mx}h6
**SiteInfoBean.java X:lPWz!7{
*/ Net)l@IB]
package NetFox; W(h8!}
N}fUBX4k
N-`;\
public class SiteInfoBean { xXZKj
pFTlhj)1
n=? 0g;1!
private String sSiteURL; //Site's URL S |>$0P4W(
private String sFilePath; //Saved File's Path 7E`(8i
private String sFileName; //Saved File's Name 5L}>+js2
private int nSplitter; //Count of Splited Downloading File 5lnSa+_/f
ulf/C%t,R
<zuE=0P~%
public SiteInfoBean() ex\W]5
{//nSplitter的缺省值为5 H@E")@92
//default value of nSplitter is 5 T[-c|
this("","","",5); ]M;6o@hq
} q9Sz7_K
-Zg @D(pF
Reu{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TE%#$q
{ `t0f L\T
sSiteURL= sURL; i1I>RK
sFilePath = sPath; (YHvGGr
sFileName = sName; $-Pqs ^g
this.nSplitter = nSpiltter; >}b6J7_
IzdTXc f
tRnW%F5
} 3g[j%`k
p*`SGX
^Opy6Bqb
public String getSSiteURL() neh;`7~5@K
{ H:-A; f!Z
return sSiteURL; x$GsDV
} ?[VpN2*
8i;)|z7
yW^IN8fm
public void setSSiteURL(String value) {R-82%X
{ kt{C7qpD
sSiteURL = value; ZQ~myqx,+L
} [W$Z60?RR
Hp}
6_<s=nTX
public String getSFilePath() }l(m5
{ $i:||L^8p
return sFilePath; u'i%~(:$\)
} LkGf|yd_
s!ZW'`4!z
z8/xGQn
public void setSFilePath(String value) pp]_/46nN
{ <*"pra{3
sFilePath = value; OR\DTLIl
} pEVgJ/>
#[a"%byTR
) wY!/&
public String getSFileName() -~\.n
{ 6f?BltFaN
return sFileName; 7q!yCU
} 4b2mtLn_
Mf:M3H%YV+
BKQIo)g.G
public void setSFileName(String value) /Y[o=Uyl
{ -nk#d%a\
sFileName = value; d)0LVa(
} (+UmUx=
LR3`=Z9
~#"7,rQp
public int getNSplitter() aLKMDiT
{ v0`qMBr1y
return nSplitter; h zZ-$IX X
} cc41b*ci$
3X$Q,
iog # ,
public void setNSplitter(int nCount) 8jggc#.
{ e(~'pk"mZ
nSplitter = nCount; :YqQlr\
} 6!+X.+
} ^+*GbY$'
1GG>.RCP
y98JiNq
/* cXS;z.M\_
**Utility.java W""*hJ
*/ 4r1<,{gCS
package NetFox; NTm<6Is`
RQ^m6)BTo
CYtjY~
public class Utility { | "Jx
j?\$G.Y
gT(th9'+z
public Utility() jj!N39f
{ }UKgF.
WVS$O99Y
LBmM{Gu
} cX%:
(@)2PO/
//线程睡眠 q]"2hLq
public static void sleep(int nSecond) C}mYt/
{ eC6>yD6D
try{ \fK47oV
Thread.sleep(nSecond); |P~O15V*Q
} GS ;HtUQ
catch(Exception e) $A;7Em
{ C}b|2y
e.printStackTrace (); #y=ZP:{:t
} R2}kz.
} %n05Jitl
@up&q
//日志 7 9Qc`3a
public static void log(String sMsg) 2J;kD2"!
{ I %|@3=Yc
System.err.println(sMsg); %cH8;5U40
} |XKOXa3.
n1QEu"~Zj
fav5e'[$
public static void log(int sMsg) 7hB#x]oQo
{ 59{;VY81
System.err.println(sMsg); >u=%Lz"J
} h6u2j p(+
} q&zny2])
J>`v.8y
Mv.Ciyc
/* =X%!YZk p
**TestMethod.java I@n*[EC
*/ -xJX_6}A
package NetFox; iv:,fkwG
{(rf/:X!p
X*pZNz&E
public class TestMethod { T/[f5?p
lijB#1<8*
9s! 2 wwh
public TestMethod() /~40rXH2C
{ ///xx/weblogic60b2_win.exe Hm>-LOCcl
try{ 7\mDBG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8h2D+1,PZC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OmB TA=E<
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y[W6Sc
fileFetch.start(); i<%m Iq1L
} C<_Urnmn
catch(Exception e){e.printStackTrace ();} Da-u-_~
B@-|b
hZcmP"wgC1
} \B_i$<Sz
zhNQuK,L
l+%Fl=Q2em
public static void main(String[] args) 4~!Eje!
{ LU%#mY
new TestMethod(); R]Hz8 _X
} yahAD.Xuo@
} R.K?
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