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)); T-en|.
} ^viabkf C
for(int i=0;i<nEndPos.length-1;i++) _p-e)J$7
{ &J>e;X
nEndPos = nStartPos[i+1]; N*o{BboK;
} UZyg_G6
nEndPos[nEndPos.length-1] = nFileLength; @AEH?gOX
} LjI`$r.B
} X8$i*#D
`x[Is$
6O7s^d&K
//启动子线程 Wo1xZZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4dX{an]Cz
for(int i=0;i<nStartPos.length;i++) X7},|cmD_
{ 8=`L#FkRp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ).SJ*Re*^I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k QuEG5n.-
nStartPos,nEndPos,i); R~\R>\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =yf)Z^
fileSplitterFetch.start(); s@F&N9oh
} r)*23&Ojs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fMUcVTFe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lG7PM^Eb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =,6H2ew
nEndPos = " + nFileLength); MiT0!6Pg
// fileSplitterFetch[nPos.length-1].start(); SYCL\b
-&1(~7
nkW})LyB\
//等待子线程结束 \MP~}t}c
//int count = 0; W[ l
//是否结束while循环 .XJ'2yKof
boolean breakWhile = false; 1<YoGm&
)+G"57p
vMTf^V
while(!bStop) Q(bOar5
{ {R}F4k
write_nPos(); DB/~Z
Utility.sleep(500); q/#e6;x
breakWhile = true; 4q}+8F`0F
@J[@Pu O
:@(('X(".
for(int i=0;i<nStartPos.length;i++) gP2zDI
{ tT}b_r7h(1
if(!fileSplitterFetch.bDownOver) jn<?,UABD
{ uX_H;,n
breakWhile = false; w% %q/![uy
break; ~g{j)"1
} *~vB6V|1
} Er;/zxg9p
if(breakWhile) l0qaTpn
break; 1Bj.MQ^
/8x';hQ
azPH~'E'
//count++; {^N,=m\
//if(count>4) u8Ys2KLpL
// siteStop(); ;TAj;Tf]H
} (dy(.4W\
${f<}
h `Lr5)B'
System.err.println("文件下载结束！"); Y^fw37b
} \ruQx)5M
catch(Exception e){e.printStackTrace ();} Aa ~W,
} m5K?oV@n
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r48|C{je-
//获得文件长度 f3K-X1`]'U
public long getFileSize() 7(Fas(j3
{ 586P~C[ic
int nFileLength = -1; >8f~2dH2%
try{ Ku(YTXtK
URL url = new URL(siteInfoBean.getSSiteURL()); 1d5%(:@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /2tA n
httpConnection.setRequestProperty("User-Agent","NetFox"); %*R, ceuI
EF0v!XW
giakEPl
int responseCode=httpConnection.getResponseCode(); YYWD\Y`8
if(responseCode>=400) k@4N7}
{ }y(t')=9
processErrorCode(responseCode); U=Ps#
return -2; //-2 represent access is error .j]tzX
} j4$nr=d.6
PLCm\Oh$l
GA^hev
String sHeader; +kL7"
aI=p_+.h
'S`l[L:.8
for(int i=1;;i++) uNyU]@R<W
{ AdDX_\V,*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c!EA>:;(<
//Utility.log(in.readLine()); V*vQNPey
sHeader=httpConnection.getHeaderFieldKey(i); -SsgW
if(sHeader!=null) r h*F
{ Qi18q|l8v
if(sHeader.equals("Content-Length")) ] K$YtM^
{ f:>y'#P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 69c4bT:b"
break; ?;XO1cs
} Rl?1|$%
} .9J^\%JD
else -CvmZ:n
break; dbf<k%i6
} c8uaZvfW
} wWl?c
catch(IOException e){e.printStackTrace ();} ;s+/'(*
catch(Exception e){e.printStackTrace ();} iLy^U*yK
s= Fp[>qA
F9%_@n
Utility.log(nFileLength); `B%%2p&
;K<VT\
wm5&5F4:
return nFileLength; I}`pY3
} )N.3Q1g-
0L}`fYf
kckRHbeU
//保存下载信息（文件指针位置） ,GSiSn
private void write_nPos() +( LH!\{^
{ #-L0.z(
try{ &~:EmLgv
output = new DataOutputStream(new FileOutputStream(tmpFile)); de:@/-|
output.writeInt(nStartPos.length); f"Sp.'@
for(int i=0;i<nStartPos.length;i++) KuR]X``2
{ Y@FYo>0O
// output.writeLong(nPos); l2F#^=tp
output.writeLong(fileSplitterFetch.nStartPos); E !kN h
output.writeLong(fileSplitterFetch.nEndPos); '2^}de!E
} Phn^0 iF
output.close(); GfONm6A
} L3eF BF/
catch(IOException e){e.printStackTrace ();} ,DFN:uf=l
catch(Exception e){e.printStackTrace ();} J!C \R5\
} UC`h o%OBF
KL$.E!d
>|3Y+X
//读取保存的下载信息（文件指针位置） ?!RbS#QV}
private void read_nPos() M5I`i{Gw
{ '\bokwsP
try{ mERkC,$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Cy-p1s
int nCount = input.readInt(); )1At/mr
nStartPos = new long[nCount]; a6Vfd&
nEndPos = new long[nCount]; a*p|Ij
for(int i=0;i<nStartPos.length;i++) 13?:a[~=Y
{ *7AB0y0k
nStartPos = input.readLong(); Ii0\Skb
nEndPos = input.readLong(); B^2r4 9vC
} 5{=+S]
input.close(); /\1'.GR
} )Jt. Z^J<
catch(IOException e){e.printStackTrace ();} @qNY"c%HV
catch(Exception e){e.printStackTrace ();} WJ8i=MO67
} $%EX~$=m]-
h0F=5| B
@Ou H=<YN
private void processErrorCode(int nErrorCode) Cu@q*:'
{ , Q0Y} )
System.err.println("Error Code : " + nErrorCode); I~l qg
} sc*R:"
rWr'+v?
`l45T~`]$
//停止文件下载 -r*|N.5c
public void siteStop() [8'?G5/n
{ -mO#HZIq
bStop = true; q^xG%YdPz+
for(int i=0;i<nStartPos.length;i++) "M/c0`>C!i
fileSplitterFetch.splitterStop(); ';R]`vWFe
QGN+f)
2TGND-(j
} -;cF)C--12
} 0MRWx%CR
//负责部分文件的抓取 !/G}vu
**FileSplitterFetch.java V7WL Gy.,
*/ M6wH$!zRa
package NetFox; 4q.;\n
t?9J'.p
?)9L($VVD
import java.io.*; )f3A\^
import java.net.*; >vD}gGBe
2S7BzZ/
G@P;#l`(D
public class FileSplitterFetch extends Thread { (1x8DVXNN
j&Hui>~
}[leUYi`
String sURL; //File URL {XU!p: x
long nStartPos; //File Snippet Start Position l2;$qNAo
long nEndPos; //File Snippet End Position b@J"b(
int nThreadID; //Thread's ID ((gI OTV
boolean bDownOver = false; //Downing is over T.cTL.}
boolean bStop = false; //Stop identical )2c]Z|
FileAccessI fileAccessI = null; //File Access interface /)[-5n{
Z"c-Ly{vEj
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |mMsU,*gB
{ R+.4|1p
this.sURL = sURL; k2Cq9kQq
this.nStartPos = nStart; e!J5h<:
this.nEndPos = nEnd; >r`O@`^U
nThreadID = id; 2#NnA3l]x%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ObM/~{rKx
} {aA6b
<,$*(dX)(
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public void run() OcUj_Zd
{ T^!Q(`*
while(nStartPos < nEndPos && !bStop) SE*;6&yL
{ cq>J]35
z#G\D5yX[*
~AD>@;8fG
try{ YnnK]N;\x
URL url = new URL(sURL); ;40Z/#FI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f\5w@nX
httpConnection.setRequestProperty("User-Agent","NetFox"); 2<*"@Vj
String sProperty = "bytes="+nStartPos+"-"; od#Lad@p
httpConnection.setRequestProperty("RANGE",sProperty); XOX$uLm
Utility.log(sProperty); 4x ?NCD=k
], Bafz)4
2{RRaUoRb
InputStream input = httpConnection.getInputStream(); bbq`gEV
//logResponseHead(httpConnection); uKzx >\}?1
e!0xh
2MB>NM<xO
byte[] b = new byte[1024]; ajkV"~w',|
int nRead; 'T^MaLK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [? "hmSJ
{ !Gnm<|.
nStartPos += fileAccessI.write(b,0,nRead); $m ;p@#n
//if(nThreadID == 1) l`~$cK!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t>quY$}4
} .oM- A\!
'{0O!y[H6
P'iX?+*
Utility.log("Thread " + nThreadID + " is over!"); g@x72$j
bDownOver = true; vE`;1UA}
//nPos = fileAccessI.write (b,0,nRead); cFie;k
} j)G%I y[`
catch(Exception e){e.printStackTrace ();} m\*ca3$
} N@_y<7#C
} Y->sJm
(]sm9PO
G8]{pbX
//打印回应的头信息 POm;lM$
public void logResponseHead(HttpURLConnection con) 2FdwX,O.
{ aNM*=y`
for(int i=1;;i++) !0^4D=dO
{ CD`6R.
String header=con.getHeaderFieldKey(i); c\[&IlM
if(header!=null) 2.JrLBhN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %@(+`CCA
Utility.log(header+" : "+con.getHeaderField(header)); KUPQ6v }
else |H=5Am
break; Xgh%2;:
} .+Q1h61$T
} Q,9KLi3
T-n>+G{
~YNzSkz
public void splitterStop() %;]/Z%!
{ rc:UG "[
bStop = true; zt]8F)l@
} 9'Z{uHi%
!M}-N
_`C|K>:
} 3\{acm
Z 9cb
*fd:(dN|
/* ?r]0%W^
**FileAccess.java xP9R d/xa|
*//文件访问(定位，写) IecD41%
package NetFox; o;9H~E
import java.io.*; dC4`xUv
3#""`]9H
RKMF?:
public class FileAccessI implements Serializable{ 41B.ZE+*qd
VwBw!,%Ab
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7^)yo#i4
RandomAccessFile oSavedFile; f7 ew<c\
long nPos; 6V9r[,n
IY~I=}
}|-8-;
public FileAccessI() throws IOException B~Z61
{ j AoI`J
this("",0); "AqLR
} WSF$xC/~
= ?/6hB=7<
.2P3 !KCL
public FileAccessI(String sName,long nPos) throws IOException 7"eIZ
{ kVeY} 8
oSavedFile = new RandomAccessFile(sName,"rw"); %;_EWs/z8
this.nPos = nPos; i5WO)9Us
oSavedFile.seek(nPos); oN83`Z
} Ir` l*:j$
CyVi{"aF3
hYFi"ck
public synchronized int write(byte[] b,int nStart,int nLen) =JTwH>fD
{ $Y$s*h_-/<
int n = -1; nJgN2Z
try{ Pr1OQbg]8
oSavedFile.write(b,nStart,nLen); cjLA7I.O
n = nLen; \ z*<^ONq
} 0jXDjk5'<
catch(IOException e) qbD_
{ 4 q % Gc
e.printStackTrace (); u3 +]3!BQ
} ok-q9dM
_M>S=3w
2c,w 4rK
return n; Q^Vch(`&P
} 2nFr?Y3g,
%0u5d$bq
bLggh]Fh
} Mu" vj*F
X)TZ S
_s=<Y^l%x
/* /K,@{__JP
**SiteInfoBean.java |e+r~).4B
*/ T/%k1Hsa4H
package NetFox; kDiR2K&
vl`St$$|
s}^W2
public class SiteInfoBean { "|WKK}
ldKLTO*&
B(wi+;
private String sSiteURL; //Site's URL hR>`I0|p&
private String sFilePath; //Saved File's Path vXSpn71Jb
private String sFileName; //Saved File's Name Y}\3PaUa
private int nSplitter; //Count of Splited Downloading File 527u d^:
93.L887
OtZtl*5
public SiteInfoBean() Tz(Dhb,
{//nSplitter的缺省值为5 lP(<4mdP
//default value of nSplitter is 5 M;z )c|Z
this("","","",5); .D=#HEshk
} b3=XWzK5
v9D[|4
e7Sg-NWV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'F1<m^
{ Hc0V4NHCaL
sSiteURL= sURL; x;7p75Wm
sFilePath = sPath; <Lle1=qQ
sFileName = sName; @a]`C $6
this.nSplitter = nSpiltter; }V+&o\4
M7gqoJM'Q
m}m|(;T
} {X\FS
%CrpUx
61b<6r0o
public String getSSiteURL() 'Te'wh=Y
{ |L)qH"Eo
return sSiteURL; @<1T&X{Z!
} ?`SBGN;
y0t-e
x}7Xd P.2$
public void setSSiteURL(String value) 0w$1Yx~C
{ aTLr%D:Ka
sSiteURL = value; %A@U7gqc
} %8"Aq
i?F~]8
mndNkK5o
public String getSFilePath() H//,qxDc
{ 4d-"kx3X
return sFilePath; ;p(Doy)i
} BLo=@C%w5
"L)?dlb6T
W$R@Klz
public void setSFilePath(String value) {f>e~o
{ ]"vpCL
sFilePath = value; nlx~yUXL4
} d:n.Vp
)5U7w
; JHf0
public String getSFileName() `$VnB
{ kPp7;U2A
return sFileName; 6)3pnhG9
} |=Pw-uk
^+dL7g?+
o l+*Oe
public void setSFileName(String value) Oyjhc<6
{ eKqo6P:#f
sFileName = value; f:A1j\A?
} YR~)07
_ Av_jw`m
4p(\2?B%f
public int getNSplitter() u,Cf4H*xS
{ yLvU@V@~
return nSplitter; Z1+1>|-iW
} S?(/~Vb%
DIc -"5~
cfW;gFf
public void setNSplitter(int nCount) k`,>52
{ flU?6\_UC
nSplitter = nCount; wb-_CQ
} Cy\! H&0wg
} &o)eRcwH`
WS ^%< h#
ohB@ijC!
/* ncij)7c)u
**Utility.java p w`YMk
*/ K!SFS
package NetFox; y$HV;%G{26
NB)22 %
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public class Utility { ,S=ur%
Md1ePp]
a"X9cU[
public Utility() BP0*`TY
{ "?{=|%mf
YZ^;xV
lyyRyFfQ
} )Es|EPCx!
sxU 0Fg
//线程睡眠 XXPpj< c
public static void sleep(int nSecond) V3>JZH`
{ 4#wZ#}
try{ i(n BXV{
Thread.sleep(nSecond); &\M<>>IB
} QetyuhS~
catch(Exception e) _{YUWV50}
{ Vqxxm&^P
e.printStackTrace (); 7,Q>>%/0P
} :^992]EBEj
} GA"zO,
p6W|4_a?
//日志 lH1gWe
public static void log(String sMsg) _air'XQ&!
{ 7,EdJ[CR$
System.err.println(sMsg); /~;om\7r
} D1f}g
w|8T6W|w
jB%aHUF;
public static void log(int sMsg) (<xl _L:*.
{ xr1,D5
System.err.println(sMsg); TKZ[H$Z
} W(,3j{d2i
} _T.k/a
5}"9)LT@@w
EHX/XM
/* @PyZ u7'
**TestMethod.java 4,qhWe`/
*/ jq12,R2+)
package NetFox; JY6^pC}*
:c`Gh< u
vAjvW&'g
public class TestMethod { (E]q>'X
|tuh/e@dx
|'N)HH>;
public TestMethod() [^2c9K^NK
{ ///xx/weblogic60b2_win.exe 0hM!#BU5K
try{ o0:RsODl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L/2,r*LNx$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $irF
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ud'/ 9:P
fileFetch.start(); gX!-s*{E
} \d}>@@U&
catch(Exception e){e.printStackTrace ();} .h[yw$z6
LF\HmKM,
NNP ut$.
} /K\]zPq
EK$3T5e
nv/'C=+L
public static void main(String[] args) )@[##F2
{ ?_nbaFQK3
new TestMethod(); :SvgXMY@
} ^n&_JQIXb
} B'8/`0^n5
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