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)); EI1W .V>@
} Nfv="t9e
for(int i=0;i<nEndPos.length-1;i++) onnI !
{ Z+Yeg
nEndPos = nStartPos[i+1]; n1QEu"~Zj
} [D3+cDph
nEndPos[nEndPos.length-1] = nFileLength; c ]>DI&$;J
} 3ty4D2y
} XkPv*%Er8
8P,l>HA
rO/a,vV
//启动子线程 -#LjI.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Hf VHI1f
for(int i=0;i<nStartPos.length;i++) iv:,fkwG
{ izMYVI?0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P+Wm9xR2d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lijB#1<8*
nStartPos,nEndPos,i); 3A-*vaySV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DH5bpg&T
fileSplitterFetch.start(); a9[mZVMgUK
} gUl1CH&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,H>W:O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i<%m Iq1L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bqSMDK
nEndPos = " + nFileLength); HHz;0V4w?
// fileSplitterFetch[nPos.length-1].start(); }@d>,1DU
{!L=u/qs"
?-e7e%
//等待子线程结束 ^6Yd}
//int count = 0; 8tU>DJ}0
//是否结束while循环 R7lYu\mA
boolean breakWhile = false; M~uMY+>
:-z&Y492
FJ{=2]x|
while(!bStop) /vHYMS
{ C 8N%X2R
write_nPos(); |2O')3p"9
Utility.sleep(500); j(j#0dXLh
breakWhile = true; S+r^B?a<oM
".gNeY6)x
W!t{rI72
for(int i=0;i<nStartPos.length;i++) ;AKwx|I$g
{ alFNSRY
if(!fileSplitterFetch.bDownOver) !x>,N%~
{ $!f!,fw+
breakWhile = false; xk& NAB
break; GQb i$kl
} x|8^i6xB
} u^t$cLIZ
if(breakWhile) g0PT8]8
break; ;`DD}j`
9TC) w|
'r\ 4}Ik
//count++; P1MvtI4gm
//if(count>4) =NadAyv
// siteStop(); 6ZcXS
} msiu8E
Vz{>cSz#
`{[RjM`
System.err.println("文件下载结束！"); SrFx_n
} e?b)p5g
catch(Exception e){e.printStackTrace ();} !scD|ti
} >TY6O.]
V C-d0E0
l-<`m#/v
//获得文件长度 M%I@<~wl
public long getFileSize() 2VA!&`I
{ KFU%DU G
int nFileLength = -1; ^*0'\/N&
try{ QOH<]~3J
URL url = new URL(siteInfoBean.getSSiteURL()); A (okv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8#w)X/
httpConnection.setRequestProperty("User-Agent","NetFox"); #Y2i*:<
9gy(IRGq/
s3:9$.tiR[
int responseCode=httpConnection.getResponseCode(); 7CGyC[[T~
if(responseCode>=400) s9@Sd
{ iG#}`
processErrorCode(responseCode); &l m#
return -2; //-2 represent access is error 5!(?m~jJ
} 2z\e\I
BEUK}T K4
,$N#Us(Wa
String sHeader; Z+4D.bA
X:|8vS+0gU
$=)gpPT
for(int i=1;;i++) Su7bm1
{ ((bTwx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '#.#$8l
//Utility.log(in.readLine()); 9AQxNbs
sHeader=httpConnection.getHeaderFieldKey(i); Rko M~`CT
if(sHeader!=null) g<wRN#B
{ pr&=n;_ n
if(sHeader.equals("Content-Length")) IeP WOpj3
{ __Nv0Ru
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w!&~??&=}
break; %S \8.
} 9t$]X>}
} M'L;N!1A
else %\Wf^6Y^
break; Mxl]"?z
} =5x&8i
} fuMJdAuY7d
catch(IOException e){e.printStackTrace ();} /.1.MssQM
catch(Exception e){e.printStackTrace ();} }t%W1UJ
4a''Mi`u
69G`2_eKCp
Utility.log(nFileLength); =0
CU)|-*uiK
A/}W&bnluD
return nFileLength; VIJ<``9[
} k{I01
1:M@&1LYp
U;q];e:,=}
//保存下载信息（文件指针位置） T~4N+fK
private void write_nPos() OLC{iD#
{ .@F]Pht
try{ ,|kDsR!
output = new DataOutputStream(new FileOutputStream(tmpFile)); =]C]=
output.writeInt(nStartPos.length); 7U|mu~$.!
for(int i=0;i<nStartPos.length;i++) bm% $86
{ _zWfI.o
// output.writeLong(nPos); [U/(<?F{(
output.writeLong(fileSplitterFetch.nStartPos); .iD*>M:W
output.writeLong(fileSplitterFetch.nEndPos); w= P9FxB
} JW.=T)
output.close(); {0"YOS`3AX
} 'T<iHV&
catch(IOException e){e.printStackTrace ();} A:l@_*C..
catch(Exception e){e.printStackTrace ();} 5L,}e<S$
} P [Uy
\</b4iR)LT
:GpDg
//读取保存的下载信息（文件指针位置） L|@y&di
private void read_nPos() $37 g]ZD
{ !V2/A1?
try{ Q6'x\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GVHV =E
int nCount = input.readInt(); /,=@8k!t?
nStartPos = new long[nCount]; ' Z0r>.
nEndPos = new long[nCount]; )B,|@ynu
for(int i=0;i<nStartPos.length;i++) @f]{>OS
{ y\dEk:\)
nStartPos = input.readLong(); . \
nEndPos = input.readLong(); R218(8S
} *}k;L74|
input.close(); YW u cvw&
} $Iv2j">3)
catch(IOException e){e.printStackTrace ();} ,1OyN]f3
catch(Exception e){e.printStackTrace ();} X3'H `/
} +6wiOHB`
Wjhvxk
< -W*$?^
private void processErrorCode(int nErrorCode) <\kr1qHH
{ `\Hf]b
System.err.println("Error Code : " + nErrorCode); >SPh2[f
} Z87_#5
M9zfT!-
sBrI}[oyx
//停止文件下载 /|6;Z}2
public void siteStop() 3bnS W5
{ ^&y$Wd]6
bStop = true; M%jPH
for(int i=0;i<nStartPos.length;i++) F 8B#}%JE
fileSplitterFetch.splitterStop(); |$5[(6T|
S[WG$
P#=`2a#G
} |2{wG4
} ~ vqa7~}m
//负责部分文件的抓取 vWGwVH/K
**FileSplitterFetch.java _h}kp\sps
*/ M Y|w
package NetFox; yj^+G
M(/r%-D
Q-1vw6d
import java.io.*; 8#vc(04(
import java.net.*; RjN{%YkXe
O{#=d
nqLA}u4IM
public class FileSplitterFetch extends Thread { "I(xgx*
5LOo8xN
*QH28%^
String sURL; //File URL i>(e}<i
long nStartPos; //File Snippet Start Position 6i}iAP|0
long nEndPos; //File Snippet End Position K.0:C`C
int nThreadID; //Thread's ID ~c\e'&sc;
boolean bDownOver = false; //Downing is over z*-2.}&U<
boolean bStop = false; //Stop identical SJHr_bawd
FileAccessI fileAccessI = null; //File Access interface )rC6*eR
AJ=qna
j:VbrR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t2)rUWg
{ 8SGo9[U2
this.sURL = sURL; >Z5gSs0
this.nStartPos = nStart; %\:[ o
this.nEndPos = nEnd; o,)?!{k}
nThreadID = id; RNe^; B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sfNE68I2
} t;}:waZD
-X"p:=;j
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public void run() Sn|BlXrey
{ V{!J-nO
while(nStartPos < nEndPos && !bStop) h%uZYsK
{ qHrc9fB
oaIi2=Tf
W>j!Q^?
try{ z62;cv
URL url = new URL(sURL); IhVO@KJI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l`f/4vy
httpConnection.setRequestProperty("User-Agent","NetFox"); 6V7B;tB
String sProperty = "bytes="+nStartPos+"-"; a m|F?|1
httpConnection.setRequestProperty("RANGE",sProperty); UdpF@Q
Utility.log(sProperty); q!|*oUW
f,kZ\Ia'r
PoxK{Y
InputStream input = httpConnection.getInputStream(); !1$])VQWI
//logResponseHead(httpConnection); 7+\+DujE$
8@MV%MVy$
}&wUr>=
byte[] b = new byte[1024]; d?A 0MKnl
int nRead; t.xxSU5~%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e&&53?
{ BRgXr
nStartPos += fileAccessI.write(b,0,nRead); JvVWG'Z"
//if(nThreadID == 1) cj$[E]B3V*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UG+d-&~Ll
} 5kCUaPu
v|dBSX9k0
wea-zN
Utility.log("Thread " + nThreadID + " is over!"); b4[bL2J$h1
bDownOver = true; H9YW
//nPos = fileAccessI.write (b,0,nRead); Y^$X*U/q%U
} Y 0d<~*
catch(Exception e){e.printStackTrace ();} t gI{`jS%
} TFlet"ge=
} j+$rj
;:\<gVi:
#49kjv@
//打印回应的头信息 g?z/2zKR
public void logResponseHead(HttpURLConnection con) 3G}x;Cp\D
{ (nf~x
for(int i=1;;i++) Z2qW\E^_r
{ =8AO:
String header=con.getHeaderFieldKey(i); K,+LG7ec
if(header!=null) ~A'!2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,!#*GZ.ix
Utility.log(header+" : "+con.getHeaderField(header)); C~2F9Pg
else haK3?A,"_A
break; gG<~-8uQ
} 6-$jkto
} VVac:
E8$20Ue
(^TF%(H
public void splitterStop() /:~\5}tW
{ HK,cJahq
bStop = true; ?XrQ53
} 8']M^|1
#U! _U+K
X[]m _@v
} &"f";
*|%@6I(
*W,]>v0%T
/* R!\_rc1/
**FileAccess.java ^1iSn)&
*//文件访问(定位，写) ~zCEpU|@N
package NetFox; {.?ZHy\Rk
import java.io.*; Uc7mOa}4
n0r+A^]
JjPKR?[>
public class FileAccessI implements Serializable{ Uzz'.K(Mv|
0b+Wc43}K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @L<*9sLWh
RandomAccessFile oSavedFile; *SU\ABcov
long nPos; ]zj9A]i:a
_4"mAPt
8ja$g,
public FileAccessI() throws IOException :o0JY= 5
{ HePUWL'
this("",0); 2D75:@JL}|
} qkt0**\
o3Yb7h9
O@u?h9?cf>
public FileAccessI(String sName,long nPos) throws IOException 6h|q'.Y
{ sD{Wxv
oSavedFile = new RandomAccessFile(sName,"rw"); :[wsKFaV+
this.nPos = nPos; R<\F:9
oSavedFile.seek(nPos); G,?hp>lj
} En~5"yW5>]
'n{Nvt.c
tjIl-IQ
public synchronized int write(byte[] b,int nStart,int nLen) oe%}?u
{ AqWUwK9T
int n = -1; Huy5-[)15
try{ [$qyF|/K`n
oSavedFile.write(b,nStart,nLen); AJh w
n = nLen; U &C!}
} 9!6f-K
catch(IOException e) 'Q|M'5'
{ DgUT5t1
e.printStackTrace (); r[2ILe
} }Ga\wV
GR&z,
.:@Ykdm4I
return n; fKeT,U`W
} 'C`U"I
kh {p%<r{
_"E%xM*r
} >pU$wq|i
wP6Fl L
i*|\KM?P
/* Z'4./
**SiteInfoBean.java Wi*.TWz3
*/ Gr7=:+0n|P
package NetFox; e5*ni/P
LgKaPg$
_Tf4WFu2
public class SiteInfoBean { /M|262%
kjg~n9#T
48:>NW
private String sSiteURL; //Site's URL wLi4G@jJ
private String sFilePath; //Saved File's Path 3jGWkby0
private String sFileName; //Saved File's Name )k\H@Dy%$
private int nSplitter; //Count of Splited Downloading File +1uF !G&l
KV}FZ3jY
qs1 ?IYD
public SiteInfoBean() 4A8;tU$&
{//nSplitter的缺省值为5 G'oG</A
//default value of nSplitter is 5 N/Z2hn/m
this("","","",5); YUx.BZf7
} 419x+3>}
]^Qn
?j40} B]]d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R@/"B8H
{ 5 xppKt
sSiteURL= sURL; 6N",-c
sFilePath = sPath; 43|XSyS
sFileName = sName; 4[.oPK=i
this.nSplitter = nSpiltter; 4[;X{ !
F<L EQ7T
brW :C?}
} 3?c3<`TW
5k`l$mW{
%6t2ohO"
public String getSSiteURL() \Pj
{ !zkZQ2{Wn
return sSiteURL; u -;_y='m
} eIz<)-7:
:ctu5{"UJ
_oHNkKQ
public void setSSiteURL(String value) [#l*_0
{ MXw hxk#E
sSiteURL = value; 3 ^>l\,
} <QA6/Ef7
Jl5c [F
XWUWY
public String getSFilePath() /LvRP yj@
{ N"" BCh"
return sFilePath; N.\- 8?>
} {>R:vH8
&X|#R1\
e7m*rh%5>
public void setSFilePath(String value) JTr vnA
{ S'4(0j
sFilePath = value; rf?qdd(~cH
} yUZb#%n
"Q!(52_@J
~Lm$i6E<
public String getSFileName() U&Wt%U{
{ p^Ak1qm~e
return sFileName; r~/
} rf>0H^r
?$*SjZt
g'H$R~ag
public void setSFileName(String value) G_0( |%
{ n;@bLJ$W
sFileName = value; fDT%!
} tKuVQH~D
yKa{08X:
4Uphfzv3D
public int getNSplitter() l|/ep:x8
{ P!H_1RwXKC
return nSplitter; *1v[kWa?
} q=%RDG+
9;r)#3Q[^
hEBY8=gK
public void setNSplitter(int nCount) ]^lw*724'>
{ $oj:e?8N
nSplitter = nCount; PmKeF}
} %>~sJ0
} 4kBaB
2 lj'"nm
MRb-H1+Xf
/* OR%'K2C6S
**Utility.java U%<koD[,
*/ d/[; `ZD+
package NetFox; BQ=PW|[
g;2?F[8Th
-o!$tI&
public class Utility { |N%fMPKa
In18_bc
U.DDaT1
public Utility() M%ICdIc'
{ ` :o4'CG
9QDFEYG
&3bx`C
} jN[`L%Qm
<eQj`HL
//线程睡眠 \Ta"}TF8
public static void sleep(int nSecond) &Xf^Iu
{ 3BtaH#ZY
try{ D|e uX7b
Thread.sleep(nSecond); k@/sn(x
} fh](K'P#^
catch(Exception e) p-Kz-+A[
{ / c AUl
e.printStackTrace (); DNr@u/>vB
} wB!Nc Y\p
} gj*+\3KO@a
j!U-'zJ
//日志 Dpl A?
public static void log(String sMsg) .P[ _<8
{ thifRd$4
System.err.println(sMsg); :_g$.h%%
} 4lKq{X5<
?QFpv#4
wVEm:/;z&
public static void log(int sMsg) AaWs}M
{ ioYGZ%RG#
System.err.println(sMsg); 5@+,Xh,H|t
} ,N!o
} 2E}*v5b,
P_*" dza
_V7r1fY:
/* umt.Um.m2
**TestMethod.java YVHm{A1b0
*/ FB{KH .
package NetFox; -OapVac
;#vKi0V7
whi`Z:~
public class TestMethod { %M7` Hwu
k'Sp.
|wH5sjT
public TestMethod() ,*7 (%k^`
{ ///xx/weblogic60b2_win.exe :lf+W
try{ rA%usaW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -"=U?>(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D-5VC9{
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0w&27wW
fileFetch.start(); {q`jDDM
} t!r A%*
catch(Exception e){e.printStackTrace ();} $5ak_@AC
P)Rh=U
j g8fU
} A v2 08}Y
"1L$|
G(p`1~xm
public static void main(String[] args) Wu[&Wv~
{ { g/0x,-Z
new TestMethod(); _kU:Z
} o<COm9)i
} 0K`#>}W#X
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