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)); @4wN-T+1
} Ai~d
for(int i=0;i<nEndPos.length-1;i++) e@DVf
{ j34lPo `
nEndPos = nStartPos[i+1]; 7 V=%&+
} ,#.9^J
nEndPos[nEndPos.length-1] = nFileLength; m^;A]0h+
} D26A%[^O
} T#3`&[
`;Xwv)
K 5AArI
//启动子线程 YH3[Jvzf4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =k2"1f~e
for(int i=0;i<nStartPos.length;i++) s x)x7
{ `aM8L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a;v;%rs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gcF V$
nStartPos,nEndPos,i); .~%,eF;l$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *40Z}1ng
fileSplitterFetch.start(); 15cgmZsS
} `7Dj}vVu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +IM6 GeH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wV"C ,*V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `cqZ;(^
nEndPos = " + nFileLength); J1d|L|M
// fileSplitterFetch[nPos.length-1].start(); &Ui&2EW
9=G dj!L
{\5-b:#_
//等待子线程结束 Ip*[H#h
//int count = 0; :i]g+</
//是否结束while循环 Cgn@@P5ZC
boolean breakWhile = false; |dqvv
1A{iUddR
u`wT_?%w
while(!bStop) C44*qiG.
{ ^ =RSoR
write_nPos(); 7J$Yd976
Utility.sleep(500); '?b.t2
breakWhile = true; .GuZV'
g&L $5
}\d3
for(int i=0;i<nStartPos.length;i++) Nu6]R677Y
{ UY&DXIPM
if(!fileSplitterFetch.bDownOver) (=w ff5U
{ ,CjJO -
breakWhile = false; hJ0m;j&4y
break; fZt3cE\
} N0&#fXO
} K9Bi2/N
if(breakWhile) 5h>t4 [~
break; /[Sy;wn
vQL)I
#mbl4a
//count++; !' jXN82
//if(count>4) ybVdWOqv
// siteStop(); k?'PCV
} bn8?-
{#%;HqP
et :v4^*f
System.err.println("文件下载结束！"); 6T=zHFf~
} ai~JY[
catch(Exception e){e.printStackTrace ();} !GBGC|avE
} 8A|i$#.&
Mta;6<
0%5x&vx'S
//获得文件长度 jY5BVTWnV
public long getFileSize() \ /6m
{ l%9nA.M'
int nFileLength = -1; b}jLI_R{
try{ V39)[FH}
URL url = new URL(siteInfoBean.getSSiteURL()); ^1NtvQe@Y\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o!M*cyq
httpConnection.setRequestProperty("User-Agent","NetFox"); AZadNuL/
T#w *5Qf
s*W)BK|+?
int responseCode=httpConnection.getResponseCode(); ]<\; -i)
if(responseCode>=400) 7`6JK
{ IXmO1*o@
processErrorCode(responseCode); POvpaPAZ<
return -2; //-2 represent access is error !YEU<9
} G/C5o=cY
$;t#pN/`
=Pgu?WU@
String sHeader; @DYkWivLu
#L,5;R{`
YP vg(T
for(int i=1;;i++) 4C_-MJI
{ blA]z!FU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hX@.k|Yd
//Utility.log(in.readLine()); bNO/CD4
sHeader=httpConnection.getHeaderFieldKey(i); 6Bfu89
if(sHeader!=null) @X6|[r&Z
{ >SZ9,K4Gs
if(sHeader.equals("Content-Length")) #]5|Qhrr+
{ WS)u{ or
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yi/jZX
break; yD!V;?EnK
} J#y?^Qm$)<
} IRQ3>4hI
else u3H2\<
break; Ctxx.MM
} DeTZl+qm1E
} e/h7x\Z
catch(IOException e){e.printStackTrace ();} ^6 sT$set
catch(Exception e){e.printStackTrace ();} _[W`!#"
Epm=&6zf
3fJwj}wL
Utility.log(nFileLength); k6 f;A
|79!exVMBp
nNff~u)I
return nFileLength; K*Tvo`
} v#`Wf}G
{1 94u%'
x 1"ikp}
//保存下载信息（文件指针位置） {G%!M+n<
private void write_nPos() 'yM)>]u"
{ mckrR$>
try{ "@I"0OA
output = new DataOutputStream(new FileOutputStream(tmpFile)); :1wMGk
output.writeInt(nStartPos.length); ?y{C"w!
for(int i=0;i<nStartPos.length;i++) N{G+|WmQ
{ , eZL&n
// output.writeLong(nPos); @kKmkVhu*
output.writeLong(fileSplitterFetch.nStartPos); ]-aeoa#
output.writeLong(fileSplitterFetch.nEndPos); oa?eK
} $V)LGu2(m
output.close(); ]4>[y?k34
} bMD'teJ
catch(IOException e){e.printStackTrace ();} ^9UF Pij"
catch(Exception e){e.printStackTrace ();} HYPFe|t/
} pTK|u!fs
TPds)osZT
,&HZvU&
//读取保存的下载信息（文件指针位置） ^"%SHs
private void read_nPos() t=]&q.
{ r\"O8\
try{ RfwTqw4@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9Yowz]')
int nCount = input.readInt(); `8TM<az-L
nStartPos = new long[nCount]; $E4W{ad2jW
nEndPos = new long[nCount]; %6"b< MAO
for(int i=0;i<nStartPos.length;i++) 1a90S*M
{ R6Cm:4m}I
nStartPos = input.readLong(); ^F~e?^s
nEndPos = input.readLong(); [,a O*7N
} UG>OL2m>5
input.close(); |Tz4xTK
} ^[CD-#
catch(IOException e){e.printStackTrace ();} !DCJ2h%E[_
catch(Exception e){e.printStackTrace ();} morI'6N
} |pp@
?8(`tS(_?
S~F:%@,*
private void processErrorCode(int nErrorCode) T}[W')[s
{ ~]/X,Cf
System.err.println("Error Code : " + nErrorCode); Hk\+;'PrN
} #~.i\|VL
H+3I[`v
7Yxy2[
//停止文件下载 !o4xI?
public void siteStop() 8'B\%.+"8e
{ \sC0om,
bStop = true; 4T9hT~cT7
for(int i=0;i<nStartPos.length;i++) %~ecrQ;
fileSplitterFetch.splitterStop(); z>i D
%`}CbD6
uPV,-rm[F_
} Z=!*7@QY
} !r.}y|t?;
//负责部分文件的抓取 [NvEXTd
**FileSplitterFetch.java B:z-?u#B
*/ S/d})8~.
package NetFox; Xt=&
["Q8`vV0WO
J5Fg]O*
import java.io.*; 0 $e;#}
import java.net.*; z[v5hhI)4
%1VMwqC]E
;^DUtr ;
public class FileSplitterFetch extends Thread { W'XMC"
|-_5ouN.
45j+n.9=
String sURL; //File URL (4{49b
long nStartPos; //File Snippet Start Position U&3*c+B4
long nEndPos; //File Snippet End Position !icpfxOpjQ
int nThreadID; //Thread's ID OV8b~k4=
boolean bDownOver = false; //Downing is over Ti3BlWQH
boolean bStop = false; //Stop identical {u.V8%8
FileAccessI fileAccessI = null; //File Access interface bOck^1Hky
kM3BP& 3m1
MmWJYF=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g-p OO/|
{ SC2C%.%l`
this.sURL = sURL; 45MK|4\Y_
this.nStartPos = nStart; t48(GKF
this.nEndPos = nEnd; {C]M]b*F6(
nThreadID = id; iW"L!t#\|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1wc -v@E
} +zs6$OI]V
6eDIS|/
ZVp\5V*
public void run() 7Xad2wXn
{ iY|YEi8
while(nStartPos < nEndPos && !bStop) qfSoF|
{ fSqbGoIQ
dBlOU.B
U*&ZQw
try{ b=|&0B$E
URL url = new URL(sURL); GmL|76
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y6L+3*Qt
httpConnection.setRequestProperty("User-Agent","NetFox"); xD\Km>|i
String sProperty = "bytes="+nStartPos+"-"; Q"hI!PO+
httpConnection.setRequestProperty("RANGE",sProperty); [V)sCAW
Utility.log(sProperty); 5GJ0EZ'X
;2@sn+@
"]_|c\98
InputStream input = httpConnection.getInputStream(); -/gS s<"
//logResponseHead(httpConnection); "DlCvjc
.@6]_h;
+cV!=gDT
byte[] b = new byte[1024]; uPF yRWK
int nRead; u4<r$[]V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]R4)FH|><
{ HJJ^pk&
nStartPos += fileAccessI.write(b,0,nRead); Oq[E\8Wn
//if(nThreadID == 1) L|q<Bpz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #h3+T*5} 6
} `90v~OF
Eq8OAuN
?J~JQe42
Utility.log("Thread " + nThreadID + " is over!"); l#~FeD
bDownOver = true; 40#KcbMa|
//nPos = fileAccessI.write (b,0,nRead); T),:8/
} huF L [
catch(Exception e){e.printStackTrace ();} *}_/:\v
} @zJI0_Bp
} BL8\p_U
i`>X5Da5
k( g$_ ]X
//打印回应的头信息 7&At_l_
public void logResponseHead(HttpURLConnection con) sN C?o[9l!
{ EkL\~^
for(int i=1;;i++) nUd\4;J#
{ *b)b#p
String header=con.getHeaderFieldKey(i); '!.;(Jo
if(header!=null) 6#KI? 6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Dz50,*}J
Utility.log(header+" : "+con.getHeaderField(header)); 13QCM0#
else ^z^>]Qd
break; + kF[Oh#
} P+b^;+\1s
} Oq2H>eW`f
Iv<9})2K
*.*:(7`
public void splitterStop() DO\EB6xH>%
{ J7\q#]?
bStop = true; mNeW|3a
} $1?X%8V
~d8>#v=Q`
e6R"W9
} pMB=iS<E
@}?D<O8#"#
=N{eiJ.(p
/* &tgvE6/V
**FileAccess.java 2:N_c\Vi
*//文件访问(定位，写) 6g"<i}_|
package NetFox; qE{cCS
import java.io.*; jkP70Is
KNg5Ptk
"B}08C,?
public class FileAccessI implements Serializable{ 'sF563kE
d>`(.qvxR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 if}]8
RandomAccessFile oSavedFile; rl^LSz
long nPos; H n!vTB
h(8;7}K
o3yqG#dA
public FileAccessI() throws IOException (7b_g6>:
{ +lT]s#Fif
this("",0); wY.g-3
} i/J NG
%^l&fM*
u}1vn}F{
public FileAccessI(String sName,long nPos) throws IOException )/Xrhhx
{ \!QF9dP4
oSavedFile = new RandomAccessFile(sName,"rw"); E)hinH
this.nPos = nPos; +=h!?<*C8
oSavedFile.seek(nPos); >Y'yM4e*
} jp^WsHI3
FqsjuU@l
J3x7i8
public synchronized int write(byte[] b,int nStart,int nLen) na3kHx@
{ D&r8V;G[[
int n = -1; 8-5jr_*
try{ mG~y8nUtp
oSavedFile.write(b,nStart,nLen); qE72(#:R*
n = nLen; m[{&xF|_
} DP_Pqn8p&M
catch(IOException e) Hm*vKFhz
{ 9(F?|bfk
e.printStackTrace (); LQ@|M.$A
} 02^(z6K'&?
qX'a&~s)n
:UcS$M1LE
return n; OZ;E&IL
} >1U@NK)HfY
_A|\.(t
g$"eI/o
} S.)7u6/_!
N&ql(#r
,;P`Mf'YC
/* \u_v7g
**SiteInfoBean.java 4<g72| y
*/ >.hGoT!_k
package NetFox; HCIF9{o1j>
_O;~ }N4u
fJw=7t-t
public class SiteInfoBean { 56Y5kxmi
:J`!'{r
C)96/k
private String sSiteURL; //Site's URL i>Bi&azx
private String sFilePath; //Saved File's Path bus=LAJt=
private String sFileName; //Saved File's Name _ 1{5~
private int nSplitter; //Count of Splited Downloading File 0bxvM
,okJ eZ
.&x?`pER
public SiteInfoBean() -mHhB(Td'
{//nSplitter的缺省值为5 [a)~Dui0@\
//default value of nSplitter is 5 /Tf*d>Yh;
this("","","",5); ptcLJ]+)
} 8*#][wC2
]az} n(B,
,L{o,qzC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kw^Dp[8X
{ @!a]qAt
sSiteURL= sURL; T7,Gf({
sFilePath = sPath; v~2XGm
sFileName = sName; Df,VV+
this.nSplitter = nSpiltter; Px7g\[]
inv{dg/2
/9+A97{
} ;k&k#>L!K
Fl+tbF
ROt0<^<
public String getSSiteURL() vx5o k1UY
{ tbzvO<~
return sSiteURL; q\b ?o!#_
} ,o>pmaoLs
eN<pU%7
\m~\,em
public void setSSiteURL(String value) v6P~XK}G
{ R`C_CsXir
sSiteURL = value; "">fn(
} ;Q>3N(
W3V{Xk|
LYy:IBI7_
public String getSFilePath() T3t~=b>&L
{ Ul713Bjz
return sFilePath; {8Jk=)(md
} mf;^b.mKh
h[|zs>p
dI ZTLb"a
public void setSFilePath(String value) C3b0`|5
{ mf]( 3ZL
sFilePath = value; E2h;hr;W
} WQLHjGehe
t2-nCRXEP
k`7.p,;}U
public String getSFileName() Nzi/3r7m
{ R3{*v =ov
return sFileName; %AEK[W+0
} KB,~u*~!
tY$ty0y-e
]k`Fl,"
public void setSFileName(String value) 4'{hI;&a&
{ 3^A/`8R7K
sFileName = value; ,F?~'-K
} 28Ssb|
b?2X>QJ
{c\oOM<7
public int getNSplitter() ]~ #+b>
{ `^&15?Wk
return nSplitter; Bsu=^z
} ! F;<xgw
D=82$$
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public void setNSplitter(int nCount) \+?,c\x
{ S1az3VJI\
nSplitter = nCount; 8MeO U
} .i3lG( YG
} <(bCz>o|
R%)2(\
RlslF9f
/* j""y2c1
**Utility.java .,ppGc|*
*/ "doU.U&u
package NetFox; o! 2n}C
;vI*ThzdD
m[@%{
public class Utility { +Jo 3rX'`
Vyq#p9Q
0[2BY]`Z.
public Utility() (ifqwl62
{ FD XWFJ
E*r
@tE&<[e
} Rg8m4xw
s}[A4`EWH
//线程睡眠 38w.sceaT
public static void sleep(int nSecond) C)J_lI{^
{ s0\f9D
try{ n{.*El>{
Thread.sleep(nSecond); W?"2;](
} kyRh k\X
catch(Exception e) S6Xb*6
{ cXOje"5i
e.printStackTrace (); -40'[a9E
} }DDVGs[
} r sX$fU8
TXd5v#_vo
//日志 oeu|/\+HW
public static void log(String sMsg) daA47`+d
{ )]c]el@y
System.err.println(sMsg); LXh@o1
} KJ0xp hf
(^DLCP#*
WA]%,6
public static void log(int sMsg) JVUZ}#O
{ F_Z&-+,*3t
System.err.println(sMsg); `N|U"s;
} nJtEUVMt
} 7x[LF ^o
IFd )OZ5
Xq8uY/j
/* !fQJL
**TestMethod.java .6O52E
*/ [):{5hMA
package NetFox; 97qtJ(ESI
5"-una>D
} * ?n?'
public class TestMethod { h*;g0QBkl
V-D}U$fw
Sk6b`W7$
public TestMethod() ;mf4U85
{ ///xx/weblogic60b2_win.exe =_$XP
try{ dN$ 1$B^k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a"0B?3*r46
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4 [R8(U[g
SiteFileFetch fileFetch = new SiteFileFetch(bean); RLYU\@kK?
fileFetch.start(); 18DTv6?QG
} M>*0r<qn
catch(Exception e){e.printStackTrace ();} E;6Y? vJ
~-XOvKJb
YMc8Q\*B
} 0[n c7)sW
JCcN>DtP
Hv8SYQ|
public static void main(String[] args) ,s1&O`
{ $$haVY&
new TestMethod(); zAeGkP~K
} 9">zdFC'
} fOa6,
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