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)); -fILXu
} iF#|Z$g-(
for(int i=0;i<nEndPos.length-1;i++) 2V6kCy@V
{ q*E<~!jL
nEndPos = nStartPos[i+1]; xq<3*Bcw
} d$}z,~sN
nEndPos[nEndPos.length-1] = nFileLength; ~ WO
} ccPTJ/%$
} jqeR{yo&0b
*fj5$T-Z
t5"g9`AL
//启动子线程 !um~P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T1YCld
for(int i=0;i<nStartPos.length;i++) *@1(!A
{ 5zf bI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yJRqX]MLA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !Yi2g-(
nStartPos,nEndPos,i); NZW)$c'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pn|;VCh
fileSplitterFetch.start(); 2^;zj0]Rt
} )4tOTi[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L)qDtXd4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'K7m!y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \Hs*46@TC
nEndPos = " + nFileLength); P]mJ01@'
// fileSplitterFetch[nPos.length-1].start(); P1u(0t
49?wEm#
rY,zZR+@
//等待子线程结束 ]I<w;.z
//int count = 0; `$oy4lDKQ
//是否结束while循环 5ca!JLs
boolean breakWhile = false; LyuA("xB#
Qt+i0xd
V7}]39m(s
while(!bStop) 089 <B& <
{ z55g'+Kab
write_nPos(); W Yo>Md 8
Utility.sleep(500); ~4V-{-=0a7
breakWhile = true; gCL?{oVU
3o^~6A
;#XF.l,u
for(int i=0;i<nStartPos.length;i++) $No^\.mV
{ e,DRQ2AU
if(!fileSplitterFetch.bDownOver) O/b1^ Y
{ k((kx:
breakWhile = false; 0 H0U%x8
break; i*jnC>
} Min{&?a
} I1 +A$<Fa
if(breakWhile) #\l#f8(l
break; &\iMIJ-
C1w6[f1+
me YSW
//count++; U_C[9Z'P
//if(count>4) O[j$n
// siteStop(); H.]p\UY9
} 044Q>Qz,
:2*0Jh3_
@>q4hYF
System.err.println("文件下载结束！"); -_^#7]
} Y;1s=B9
catch(Exception e){e.printStackTrace ();} u-u:7VtH0=
} U7xKu75G1
|<2<`3
J;S Z"I'
//获得文件长度 t3<HE_B|
public long getFileSize() kk$D:UQX
{ ?Ll1B3f
int nFileLength = -1; '>:%n
try{ k[a5D/b
URL url = new URL(siteInfoBean.getSSiteURL()); sp7#e%R\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -#`tS
httpConnection.setRequestProperty("User-Agent","NetFox"); 3U9leY'2N
L~!Lq4]V\g
0 } |21YED
int responseCode=httpConnection.getResponseCode(); (YY!e2
if(responseCode>=400) MZ%S3'
{ %4x,^ K]
processErrorCode(responseCode); Ij?Qs{V
return -2; //-2 represent access is error d;g]OeF
} S9E<)L
p>1Klh:8.'
xMA2S*%ca
String sHeader; *t bgIW+h
7b*9 Th*a
IN=l|Q$8f
for(int i=1;;i++) IXU~&5&J
{ }+fBJ$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,T8fo\a4
//Utility.log(in.readLine()); ow7*HN*
sHeader=httpConnection.getHeaderFieldKey(i); c8oE,-~
if(sHeader!=null) +:3p*x%1H
{ )VeeAu)p
if(sHeader.equals("Content-Length")) X<uH [
{ NC%)SG \
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OyATb{`'
break; yJ2A!id
} ,ik\MSS
} s@K #M
else RJE<1!{
break; [(iJj3s!
} jTN!\RH9NF
} Z9UNp[0
catch(IOException e){e.printStackTrace ();} eo<=Q|nI&
catch(Exception e){e.printStackTrace ();} GC)xQZU)s
P`y 0FKS
I{7Hz{
Utility.log(nFileLength); `r+`vJ$
]64?S0p1c!
Q@- h
return nFileLength; H1e^/JD)
} k-8$43
WO+_|*&
4p]hY!7
//保存下载信息（文件指针位置） x<>In"QV
private void write_nPos() q&@q/9kz
{ .xg, j{%(
try{ {3G2-$yb
output = new DataOutputStream(new FileOutputStream(tmpFile)); }O8#4-E_Ji
output.writeInt(nStartPos.length); Os)}kkja
for(int i=0;i<nStartPos.length;i++) D1~3 3;
{ a*?,wmzl
// output.writeLong(nPos); =aRE
output.writeLong(fileSplitterFetch.nStartPos); F17nWvF
output.writeLong(fileSplitterFetch.nEndPos); ^:]~6p#
} cp5
output.close(); Am)XbN')1
} gg QI
catch(IOException e){e.printStackTrace ();} q6zKyOE
catch(Exception e){e.printStackTrace ();} h9j/mUwV
} oT[8Iu
z/t+t_y
ym6gj#2m
//读取保存的下载信息（文件指针位置） QE~#eo
private void read_nPos() wIK&EGQ
{ [ FNA:
try{ `YPNVm<3)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =xPBolxm5U
int nCount = input.readInt(); Y 9~z7
nStartPos = new long[nCount]; usOIbrQ
nEndPos = new long[nCount]; S<DS|qOo
for(int i=0;i<nStartPos.length;i++) >TwL&la
{ P*6&0\af|
nStartPos = input.readLong(); MUqV$#4@I
nEndPos = input.readLong(); (C!33s1
} /@f3|L<1@V
input.close(); ]z5gC`E0
} Hv<jf38
catch(IOException e){e.printStackTrace ();} 5Y(f7,JX
catch(Exception e){e.printStackTrace ();} qY%{c-aMA
} TkV*^j5
e"6!0Py#*
\&5t@sC
private void processErrorCode(int nErrorCode) CDgu`jj%]
{ %yP*Vp,W
System.err.println("Error Code : " + nErrorCode); ^FN(wvqb8
} \F8*HPM=*
$K*&Wdo
tJ@5E^'4
//停止文件下载 exL<cN
public void siteStop() yXL]uh#b
{ PH3#\ v.
bStop = true; PV/SzfvIq
for(int i=0;i<nStartPos.length;i++) Mwd(?o
fileSplitterFetch.splitterStop(); o;2QZ"v
M}BqSzd*
\hFIg3
} >$p|W~x
} cQldBc
//负责部分文件的抓取 l]v>PIh~N
**FileSplitterFetch.java Rjz~n38.
*/ :Vx5%4J
package NetFox; -A17tC20J1
\t 04-
H}B%OFI\+
import java.io.*; Ye) F{WqZ#
import java.net.*; B&RgUIrFoY
uQlQ%n%
0N19R5NN8
public class FileSplitterFetch extends Thread { nnPY8pdjSD
T?'Vb
o$-!E(p
String sURL; //File URL XB'PEvh8
long nStartPos; //File Snippet Start Position by8~'?
long nEndPos; //File Snippet End Position oN6X]T<
int nThreadID; //Thread's ID M;K%=l$NG
boolean bDownOver = false; //Downing is over fG*366W
boolean bStop = false; //Stop identical \%+5p"Z<
FileAccessI fileAccessI = null; //File Access interface uRfFPOYH
dy^zOqc
BR [3i}Ud
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c})f&Z@<
{ wA;Cj
this.sURL = sURL; (5(TbyWwD
this.nStartPos = nStart; 9akIu.H
this.nEndPos = nEnd; _r&,n\ T
nThreadID = id; 'lD"{^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L\Y4$e9bF8
} ;}k9YlQrN
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HRxA0y=
public void run() YB1uudW9
{ R:t>PFwo
while(nStartPos < nEndPos && !bStop) }{.0mu9
{ a2'f#[as
b qNM
;5 JzrbtL
try{ _wKaFf
URL url = new URL(sURL); oe{K0.`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nVt,= ?_ U
httpConnection.setRequestProperty("User-Agent","NetFox"); U4*Q;A#
String sProperty = "bytes="+nStartPos+"-"; ^*=.Vuqy
httpConnection.setRequestProperty("RANGE",sProperty); 08TeGUjJ
Utility.log(sProperty); yMoV|U6
_pS|bqF
@ =M:RA
InputStream input = httpConnection.getInputStream(); swh8-_[c/
//logResponseHead(httpConnection); OEFALt
H<`<5M8
;9rS[$^$O
byte[] b = new byte[1024]; "bC1dl<
int nRead; k6?;D_dm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [R~`6
{ nPU=n[t8O
nStartPos += fileAccessI.write(b,0,nRead); J*} warf&
//if(nThreadID == 1) s}3`%?,6y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m=hUHA,p4
} <)dHe:
;mAlF>6]\
{5, ]7=]
Utility.log("Thread " + nThreadID + " is over!"); _^5OoE"}!
bDownOver = true; gx',~
//nPos = fileAccessI.write (b,0,nRead); j aEUz5
} TC+L\7
catch(Exception e){e.printStackTrace ();} ZcLW8L
} WQ1~9#
} muJR~4
88l\8k4r
RMvq\J}w!
//打印回应的头信息 2`;&Uwt
public void logResponseHead(HttpURLConnection con) C@3`n;yZ=
{ _vV3A3|Ec,
for(int i=1;;i++) v{[:7]b_=
{ t) :'XGk@
String header=con.getHeaderFieldKey(i); il5Qo
if(header!=null) DQy<!Wb+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bk}'wcX<+]
Utility.log(header+" : "+con.getHeaderField(header)); %qYiE!%&
else t3// U#
break; ;n~-z5)
} [ u.r]\[J
} x[_SNX"
O;dtz\
'fIoN%
public void splitterStop() f~0CpB*X
{ # zbAA<f
bStop = true; z?DI4O#Up
} ^.HvuG},O
:+qd>;yf#
3Hd~mfO\
} &{uj3s&C
nign"r
45aUz@
/* \QvoL
**FileAccess.java wJ%;\06
*//文件访问(定位，写) {)?:d6"
package NetFox; 9k.5'#
import java.io.*; };Oyv7D+b
V*<`!w
("r\3Mvs
public class FileAccessI implements Serializable{ .V
3HEm-pok
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LGdM40
RandomAccessFile oSavedFile; B8~JUGD
long nPos; X;&Iu{&=
<c77GimD?
QB.QG!@
public FileAccessI() throws IOException JJZu%9~[
{ >2t.7UhDI
this("",0); d2a*xDkv
} YLsOA`5X
2if7|o$=
MfA@)v
public FileAccessI(String sName,long nPos) throws IOException /Bw <?:
{ q)j_QbW)
oSavedFile = new RandomAccessFile(sName,"rw"); TKe\Bi
this.nPos = nPos; D>fg
oSavedFile.seek(nPos); [p+-]V
} C==yl"w
v8} vk]b
.sCj3sX*
public synchronized int write(byte[] b,int nStart,int nLen) VtN1 [}
{ \'Q rJ ?D
int n = -1; { )-8P
try{ !sG#3sUe[
oSavedFile.write(b,nStart,nLen); (hJ&`Tt
n = nLen; 4OaU1Y[
} tiGBjTPt
catch(IOException e) jP{&U&!i
{ yiw4<]{IX
e.printStackTrace (); gHo sPY[
} lz7?Z
}6_*i!68"U
%b[>eIJU#
return n; Xwo%DZKN
} ;=p3L<~c`K
![i)_XO
$*Kr4vh
} Yu$QL@
`y|_hb
jNvDE}'
/* w*M&@+3I
**SiteInfoBean.java %E\zR/
*/ X- ZZLl#
package NetFox; V,h}l"
(^NYC$ZxM=
SK*z4p
public class SiteInfoBean { 3;RQ\{eM
R4y]<8}
M$48}q+
private String sSiteURL; //Site's URL ZZn$N-
private String sFilePath; //Saved File's Path j'k <
private String sFileName; //Saved File's Name `/O AgV"`
private int nSplitter; //Count of Splited Downloading File a$j ~YUG_
)qRH?Hsb7
Vel}lQD
public SiteInfoBean() %s! |,Cu
{//nSplitter的缺省值为5 H76iBJ66
//default value of nSplitter is 5 s IFE:/1,
this("","","",5); g<N;31:c\
} ^)(-7H
B<Q)z5KK
.P <3+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) byFO^pce
{ l*?_@
sSiteURL= sURL; Z]e`bfNnI
sFilePath = sPath; +Bf?35LP
sFileName = sName; s&hr$`V4
this.nSplitter = nSpiltter; lA pZC6Iwk
P8(hHuO
^Z-oO#)h#
} uzI=.j
u"uL,w 1-
[!De|,u(^
public String getSSiteURL() 57~y 7/0
{ Ptc+ypTu
return sSiteURL; ny cn
} <iA\ZS:
%q}[ZD/HD
/w1M%10
public void setSSiteURL(String value) E.Q]X]q
{ |AH>EXhv
sSiteURL = value; :KgH7s}
} DXo]O}VF
S,j. ?u*!
f S[-K?K
public String getSFilePath() &s(J:P$!
{ =W &Mt
return sFilePath; V2!0),]B
} !~&&&85
xeL"FzF:V
S=0DQ19
public void setSFilePath(String value) *s,[Uy![
{ lLp,sNAj
sFilePath = value; :r@t'
} `% QvCAR
-72EXO=|
1~'jC8&J
public String getSFileName() 9vz\R-un
{ cGiL9|k
return sFileName; *f3StX
} +J|H~`
|{&M#qXe
@)BO`;*$fF
public void setSFileName(String value) WR3,woo
{ `sCn4-$8
sFileName = value; ,sIC=V +
} .[}G{%M~[
"(3u)o9
0'Si ^>bW
public int getNSplitter() Z,/K$;YWo
{ <n4`#d
return nSplitter; e{7\pQK
} Bb:C^CHIQm
qa-FLUkIk!
r=&,2meo
public void setNSplitter(int nCount) qXg&E}]:=
{ 'S1u@p,q
nSplitter = nCount; G[\TbPh
} J09jBQ]R
} kDE-GX"Y
~\mh\a&
i1|>JM[V
/* .G8>UXX
**Utility.java K J\kR
*/ 6q\*{_CPB
package NetFox; 8f/KNh7#s
z7ik/>d?
_Z Sp$>)/
public class Utility { Bl*}*SPU
~%8P0AP
%\v8FCb
public Utility() aknIrblS\
{ &yvvea]
F)(^c
gLB(A\yG
} |ZL?Pqki
{2h*NFp
//线程睡眠 b!P,+!<
public static void sleep(int nSecond) CtXbAcN2B
{ V6X )L>!xx
try{ '< U&8?S
Thread.sleep(nSecond); -BH/)$-$
} O|V0WiY<
catch(Exception e) A<ds+0
{ uYMn VE"
e.printStackTrace (); Xj 1Oxm42
} :YI5O/gsk?
} =3.dgtH
wX0D^)NtF
//日志 kU[hB1D5
public static void log(String sMsg) F#gA2VCm
{ l!f_ +lv
System.err.println(sMsg); Qds<j{2
} rXi&8R[
s`jlE|jtN
n.&7lg^X
public static void log(int sMsg) SO=gG 2E
{ xgcxA:
System.err.println(sMsg); Cgx:6TRS
} k1<^Ept
} gS5REC4I/
!?nO0Ao-$
KClkPL!jP
/* %dzt'uz
**TestMethod.java TP rq:"K
*/ NX&dJ 6a
package NetFox; He(65ciT<O
XgC^-A w
f6%k;R.Wz
public class TestMethod { 9j:]<?D,A
kk /#&b2
XM`GK>*aC(
public TestMethod() ?$|tT\SFV
{ ///xx/weblogic60b2_win.exe 0f6o0@
try{ d}\]!x3t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ryL1<u ~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); S=_u3OH0
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9wYm(7M6
fileFetch.start(); ~_fc=^o
} wa8jr5/k"
catch(Exception e){e.printStackTrace ();} a9-Mc5^'n
NPK;
M0w Uis:`
} = LNU%0m
qWhW4$7x
Y~vk>ZC
public static void main(String[] args) H?=W]<!W{y
{ :1A:g^n
new TestMethod(); W3,r@mi^s7
} Ddr.6`VJ
} gADf9x"b
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