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)); l h/&__
} 9+Nw/eszO
for(int i=0;i<nEndPos.length-1;i++) irMd jG
{ %MJ;Q?KB
nEndPos = nStartPos[i+1]; c_1/W{
} mP-2s;q
nEndPos[nEndPos.length-1] = nFileLength; s, XM9h>P4
} wFL3&*
} 84M3c
70Ka!
3ATjsOL
//启动子线程 `|<+ ?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >&Fa(o;*
for(int i=0;i<nStartPos.length;i++) NHiq^ojk
{ m mw-a0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6c<ezEJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q6^x8
nStartPos,nEndPos,i); 6fwY$K\X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >n!ni(
fileSplitterFetch.start(); ~HDdO3
} Np)aS[9W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7&6Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _/ Os^>R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %EI<@Ps8c
nEndPos = " + nFileLength); DU{bonR`
// fileSplitterFetch[nPos.length-1].start(); @ yxt($G
ZnXejpj)D
N[k<@Q?*a
//等待子线程结束 vv/J 5#^,\
//int count = 0; 7co`Zw4}g
//是否结束while循环 d^84jf.U
boolean breakWhile = false; <k]qH-v4
8(xw?|D7
i2`0|8mw'
while(!bStop) >o[|"oLO
{ L2|aHI1'l
write_nPos(); U:lv^QPG
Utility.sleep(500); }*kJ-q&0
breakWhile = true; _V@P-Ye
#WufZ18#
qY(:8yC36
for(int i=0;i<nStartPos.length;i++) T9)wj][ .
{ X\sm[_I
if(!fileSplitterFetch.bDownOver) g%\L&}Jd
{ qm(1:iK,0
breakWhile = false; HDS"F.l5
break; \*"`L3
} xl] ;*&
} =B(mIx;m
if(breakWhile) ?~F. /
break; 9L)L|4A.l
fp&Got!pB
h~miP7,c<u
//count++; gfo}I2"
//if(count>4) 'sU)|W(3U
// siteStop(); )5yj/0oT
} 4}yE+dRUK:
G)7)]yBL
=! mJG
System.err.println("文件下载结束！"); vA-PR&
} 3] 76fF\^[
catch(Exception e){e.printStackTrace ();} {XnPx?V
} Lk.h.ST
p`>d7S>"
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//获得文件长度 I/s.xk_i
public long getFileSize() J22rv(
{ '29WscU
int nFileLength = -1; R&So4},B
try{ (9GbG"
URL url = new URL(siteInfoBean.getSSiteURL()); Lq04T0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #T%zfcUj
httpConnection.setRequestProperty("User-Agent","NetFox"); gdi`x|0
yQ[u3tI
w0Ij'=:
int responseCode=httpConnection.getResponseCode(); _D-Riu>#J
if(responseCode>=400) m6U8)!)T
{ 5"=:#zN
processErrorCode(responseCode); 7rIlTrG
return -2; //-2 represent access is error (cs~@
} K`4GU[ul
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GS%b=kc
String sHeader; dVGbe07
#nEL~&
/77z\[CeYH
for(int i=1;;i++) 2k+16/T
{ -e*BqH2t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v2J0u:#,
//Utility.log(in.readLine()); :s*>W$Wp4
sHeader=httpConnection.getHeaderFieldKey(i); _4R,Ej}
if(sHeader!=null) C1QWU5c v
{ ZvH{wt
if(sHeader.equals("Content-Length")) {tt$w>X
{ ~ hm`uP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JEHK:1^
break; qG9qN.|dC
} KO,_6>8]U
} treXOC9^B8
else V^En8
break; cU+>|'f&
} d8:C3R
} kZ[mM'u#
catch(IOException e){e.printStackTrace ();} ]^@0+!
catch(Exception e){e.printStackTrace ();} {A3m+_8
I,j3bC
2Xgx*'t\
Utility.log(nFileLength); NG9vml
d@g2k> >
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return nFileLength; 0&$xX!]
} xIgql}.
c]v +
:6u~aT/
//保存下载信息（文件指针位置） kF-TG3
private void write_nPos() lzfDH=&
{ ORH93`
try{ oT->^4WY
output = new DataOutputStream(new FileOutputStream(tmpFile)); Wc;+2Hl[@
output.writeInt(nStartPos.length); Cef7+fa
for(int i=0;i<nStartPos.length;i++) NI\H \#bJ
{ h{/ve`F>@
// output.writeLong(nPos); x,1=D~L}
output.writeLong(fileSplitterFetch.nStartPos); (C`@a/q
output.writeLong(fileSplitterFetch.nEndPos); RVP18ub.S
} 1+^n!$
output.close(); $L&BT 0
} F+*Q <a4
catch(IOException e){e.printStackTrace ();} %6]\^
catch(Exception e){e.printStackTrace ();} 4oJ$dN
} +/q0Y`v
yW>RRE;
J3&Sj{ o
//读取保存的下载信息（文件指针位置） k7T alR
private void read_nPos() `a'`$'j
{ a#QByP
try{ }+DDJ6Jzs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b42QBTeg
int nCount = input.readInt(); XRa#21pQ
nStartPos = new long[nCount]; @1.9PR$x
nEndPos = new long[nCount]; ]fC7%"nB
for(int i=0;i<nStartPos.length;i++) ][t6VA
{ $8@+j[>
nStartPos = input.readLong(); W5I=X]&
nEndPos = input.readLong(); \`gEu{
} iGa}3pF
input.close(); CB]l[hM$
} T*\$<-^
catch(IOException e){e.printStackTrace ();} M=+M8M`Iy
catch(Exception e){e.printStackTrace ();} A^g>fv
} hVZo"XUb
JUU&Z[6J
6 [ _fD
private void processErrorCode(int nErrorCode) ITc`]K
{ (H-cDsh;c
System.err.println("Error Code : " + nErrorCode); {]["6V6W
} R&!]Rl9hf
+-P<CCvWz
WRM$DA
//停止文件下载 o=mo/N4
public void siteStop() wA",SBGX
{ y.ql#eQ,
bStop = true; .C?GW1[c~@
for(int i=0;i<nStartPos.length;i++) >)y$mc6
fileSplitterFetch.splitterStop(); :<UtHf<=k
5Hy3\_ +
ucM.Ro=@
} os_WYQ4>j
} dyl 0]Z
//负责部分文件的抓取 O+vcs4
**FileSplitterFetch.java ['t8C
*/ 6KB^w0oA
package NetFox; [Q:f-<nH
to51hjV
hiIyaWU
import java.io.*; ,`"K
import java.net.*; 9'X@@6b*'
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public class FileSplitterFetch extends Thread { @it/$>R^)
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{\Ys@FF
String sURL; //File URL @E(P9zQ/zy
long nStartPos; //File Snippet Start Position V" }*"P-%
long nEndPos; //File Snippet End Position _<2RYXBC
int nThreadID; //Thread's ID }Az'Zu4 =
boolean bDownOver = false; //Downing is over z \^
boolean bStop = false; //Stop identical gi 5XP]z
FileAccessI fileAccessI = null; //File Access interface Iy.mVtcsZ
^Rk^XQCh
%HVD^. V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2_.CX(kI
{ L?Tu)<Mn
this.sURL = sURL; S[sr'ZW
this.nStartPos = nStart; }{t3SGsJ
this.nEndPos = nEnd; <K,[sy&Qy
nThreadID = id; d QDLI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >qn+iI2U
} RY9.n
L,W:,i/C
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public void run() gtMw3D`FL
{ cTy'JT7
while(nStartPos < nEndPos && !bStop) =G*z 53
{ u9,=po=+7f
aC}p^Nkr"k
s"N\82z)
try{ -`g J
URL url = new URL(sURL); 2;h+;G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1Df,a#,y"
httpConnection.setRequestProperty("User-Agent","NetFox"); %2,/jhHL
String sProperty = "bytes="+nStartPos+"-"; :-U53}Iy
httpConnection.setRequestProperty("RANGE",sProperty); FF jRf
Utility.log(sProperty); p$XnOh
G4O3h Y.`
lm!FM`m
InputStream input = httpConnection.getInputStream(); ]h0Y8kpd
//logResponseHead(httpConnection); <irpmRQr
_trpXkQp
;8uHRcdQ
byte[] b = new byte[1024]; A`g.[7
int nRead; -FaaFw:Z;A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :k\}Ik
{ <oQ6ZX
nStartPos += fileAccessI.write(b,0,nRead); !x6IV25
//if(nThreadID == 1) }\EL;sT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lZBv\JE
} Gg}t-_M
xmOM<0T
1j+eD:d'
Utility.log("Thread " + nThreadID + " is over!"); C&e8a9*,(a
bDownOver = true; ?o8a_9+
//nPos = fileAccessI.write (b,0,nRead); PQi }Evxa
} -GFwFkWm
catch(Exception e){e.printStackTrace ();} l-XnB
} ZDfS0]0F
} 0xLkyt0
d0TgqO{
*0lt$F$~b
//打印回应的头信息 K1<k+t/V
public void logResponseHead(HttpURLConnection con) !%X>rGkc
{ g4i #1V=
for(int i=1;;i++) b13nE.
{ o16d`}/<
String header=con.getHeaderFieldKey(i); 0:jsV|5B8
if(header!=null) =I7[L{+~Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L-j/R1fTvl
Utility.log(header+" : "+con.getHeaderField(header)); y>4p~
else s *K:IgJ/
break; MV9r5|3-
} aE}=^%D
} V@Ax}<$A
@kS|Jz$iY
w~ijD ^g
public void splitterStop() $f9 ,##/
{ <Nvlk\LQ
bStop = true; dWMccn;-m
} 3Nc'3NPQ'
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} p1C_`f N,
Q:kwQg:~
g^qz&;R]
/* .iN-4"_j1
**FileAccess.java vs*>onCf
*//文件访问(定位，写) *13g<#$
package NetFox; w' .'Yu6
import java.io.*; y(V&z"wk[
{ 576+:*
gfV]^v
public class FileAccessI implements Serializable{ D\@e{.$MZ|
y|$vtD%c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m9 ^m
RandomAccessFile oSavedFile; SlR7h$r'
long nPos; ?56~yQF/2
|C^ c0
tWcizj;?wK
public FileAccessI() throws IOException ^ sS>Mts
{ @T9m}+fR
this("",0); A{G5Plrh
} &~z+R="=
tX+0 GLz
cAYa=}~<
public FileAccessI(String sName,long nPos) throws IOException ;OQ#@|D
{ nZ"{y
oSavedFile = new RandomAccessFile(sName,"rw"); y?[5jL|Ue
this.nPos = nPos; pM1=UF
oSavedFile.seek(nPos); od;Bb
} d&O'r[S
#($k 3OA
oXnC"y}0P
public synchronized int write(byte[] b,int nStart,int nLen) 3| GNi~
{ >fW+AEt\JB
int n = -1; JHnk%h0
try{ #(m`2Z`H
oSavedFile.write(b,nStart,nLen); [lmHXf@1C
n = nLen; PWADbu{+
} ^vYVl{$bT
catch(IOException e) 3WQRN_
{ w:~nw;.T
e.printStackTrace (); 6 Xzk;p
} d;;>4}XJ]
}qG?Vmq*R[
em f0sL
return n; ;D%$Eh&oma
} LsuAOB 8
!l sy&6
Oz"@yL}
} e-L5=B
67Af} >Q
)->-~E}p9
/* j<`I\Pmv
**SiteInfoBean.java p.6$w:eV
*/ Y\ #.EVz
package NetFox; ;u4@iN}p
)^*9oqQ
?$>u!V<'
public class SiteInfoBean { .=.yZ
{hkM*:U
s!8J.hD'I
private String sSiteURL; //Site's URL W}#QKZ)MB
private String sFilePath; //Saved File's Path G%V=idU*"
private String sFileName; //Saved File's Name EuR!yD
private int nSplitter; //Count of Splited Downloading File X ,V= od>
GC5#1+fQ
U89]?^|bb
public SiteInfoBean() :F!dTD$
{//nSplitter的缺省值为5 EM>c%BH<N
//default value of nSplitter is 5 eONeWY9
this("","","",5); .y/NudD
} rCnV5Yb0O
d/ 'A\"o+
D=5t=4^H(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7Va#{Y;Zy
{ UUdu;3E=5
sSiteURL= sURL; ~:P8g<w
sFilePath = sPath; a}[=_vb}K
sFileName = sName; ?3B t;<^
this.nSplitter = nSpiltter; %x cM_|AyR
?<>,XyY
Egjk^:@
} [9YlLL@
thlpj*|
L.I}-n
public String getSSiteURL() Pq[0vZ_}dN
{ ,J`lr U0
return sSiteURL; 110>p
} 84hi, S5P
>[E|p6jgT
ei|*s+OZu
public void setSSiteURL(String value) "c!oOaA
{ kMJQeo79
sSiteURL = value; 3[|:sa8?s
} ' q=NTP
x3Dg%=R
Pi"tQyw39$
public String getSFilePath() \@ WsF$
{ NbQMWU~7
return sFilePath; rH2tC=%
} C>k;MvqO
BRSgB-Rr7
XEgx#F ;F
public void setSFilePath(String value) Im' :sJ31
{ *$4A|EA V
sFilePath = value; k_En_\c?p2
} >H=Q$gI
%1 VNP(E
5 vu_D^Q
public String getSFileName() [#P`_hx
{ =?`y(k4a
return sFileName; cc2oFn
} H>X\C;X[
Jegx[*O>b
yG4LQE
public void setSFileName(String value) +qSr=Y:+
{ #0YzPMV
sFileName = value; Ck/_UY|
} &)"7am(S`
nM(=bEX
cV=_GE
public int getNSplitter() '7O{*=`oj
{ v,!Y=8~9
return nSplitter; s:m<(8WRw
} tsSS31cv
&=6cz$]z
UVoLHd
public void setNSplitter(int nCount) kb}]sj
{ 2XecP'+m
nSplitter = nCount; #by9D&QP]
} jt10gVC
} ^b `>/>
ZimMjZ%4
[ilv/V<
/* Z9 q{r s
**Utility.java d'x<F[`O
*/ "e7$q&R |
package NetFox; F)<G]i8n~
h2/1S{/n]
hOrk^iYN=
public class Utility { +k(3+b$S-
)R a/
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public Utility() 5S-o 2a
{ YL&b9e4
1UA~J|&gi^
/nD0hb
} 8a$jO+UvN
lA Ck$E
//线程睡眠 7L~ zI>2
public static void sleep(int nSecond) h7W%}6Cqkw
{ f'i8Mm4IL
try{ =Q=&Ucf_
Thread.sleep(nSecond); (h@yA8>n
} ,C@hTOT
catch(Exception e) l]klV+9t
{ Bg+]_:<U
e.printStackTrace (); D-+)M8bt
} @|UIV
} ^* /v,+01f
3W0E6H"
//日志 GT\s!D;<
public static void log(String sMsg) 3RH#e1Y
{ eS@!\Hx
System.err.println(sMsg); '*LN)E>d
} 7s fuju(
9bcyPN
cmGj0YUQ1
public static void log(int sMsg) ga1gd~a
{ %_@5_S
System.err.println(sMsg); DneSzqO"o
} SeJFZ0p
} k4AE`[UE
I}W-5%
KutgW#+40
/* ':R3._tw\
**TestMethod.java +8vzkfr3It
*/ 7Ae,|k
package NetFox; >~wk
3f2Hjk7,d
Z"%O&O
public class TestMethod { ;R|#ae@
Nj@?}`C 4
\F+o=
public TestMethod() >LaL!PnZ
{ ///xx/weblogic60b2_win.exe 3ws(uF9$
try{ wyA(}iSq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~G^}2#5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 53+rpU_
SiteFileFetch fileFetch = new SiteFileFetch(bean); d_7Xlp@
fileFetch.start(); gjN!_^_
} .]ZuG
catch(Exception e){e.printStackTrace ();} lbuW*)
=UKR<@QrK
.gkPG'm[
} Md?bAMnG+}
_kY[8e5
't%%hw-m}
public static void main(String[] args) %WT:RT_
{ $J0~2TV<
new TestMethod(); Gx*0$4xJ3
} >0+|0ba
} v7OV;ea$
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