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)); VWG#v#o
} M#d_kDMw
for(int i=0;i<nEndPos.length-1;i++) x1$tS#lS
{ =1%3". "n@
nEndPos = nStartPos[i+1]; Y2w 9]:J
} '@Y@H,
nEndPos[nEndPos.length-1] = nFileLength; 2|#3rF
} UPPDs"
} a$FELlMv
t.>vLzrU
Y=4,d4uu
//启动子线程 OXzJ%&h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (6?pBdZ
for(int i=0;i<nStartPos.length;i++) "S^;X @#v
{ ]`y4n=L.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OlFls 8#>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >0i?}
nStartPos,nEndPos,i); (9$/r/-a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a)[XJLCQ
fileSplitterFetch.start(); r 06}@7
} t4UKG&[a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l<{]%=Qg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^gh/$my;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Lqbu]
nEndPos = " + nFileLength); 5 8p_b
// fileSplitterFetch[nPos.length-1].start(); "a6 wd
VA)3=82n
+*d,non6v
//等待子线程结束 sN7I~
//int count = 0; F1)Q#ThF\
//是否结束while循环 ^,b*.6t
boolean breakWhile = false; ev#d1s|<S
B.K"1o
dt) BMF8
while(!bStop) Lz=nJn
{ T2}I,{U
write_nPos(); $ah, $B
Utility.sleep(500); _$wWKJy9
breakWhile = true; #d*mG =
^QB/{9#
f3V&i)w(
for(int i=0;i<nStartPos.length;i++) #2I[F
{ RV^2[Gdi
if(!fileSplitterFetch.bDownOver) Q{H88g^=J
{ _1dG!!L_
breakWhile = false; jY:(Tv3~
break; @o44b!i
} Nt&}T
} x7l)i!/$
if(breakWhile) RXt`y62yK
break; S]9:3~
W&z.O
zScV 9,H1
//count++; A!<R?
//if(count>4) )(\5Wk9(
// siteStop(); d<V+;">2
} l8GziM{lp
1b;Aru~l
A]BG*
System.err.println("文件下载结束！"); v=i[s
} zEF3B
catch(Exception e){e.printStackTrace ();} (Y, @-V
} 2*Z~JM
QCa$<~c
]Vl*!,(i
//获得文件长度 i<bFF03*S
public long getFileSize() O<iE,PN)
{ 5p94b*l
int nFileLength = -1; 6N~~:Gt
try{ %nF6n:|:
URL url = new URL(siteInfoBean.getSSiteURL()); g}$]K!F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;r^8In@6
httpConnection.setRequestProperty("User-Agent","NetFox"); 3r+vpyu
2p@Rr7
vj[ .`fY
int responseCode=httpConnection.getResponseCode(); }v0oFY$u`H
if(responseCode>=400) He)v:AH
{ `"zX<
processErrorCode(responseCode); D>?%p"e
return -2; //-2 represent access is error +To{Tm-
} <z%zzc1s
lb{*,S
jp=^$rS6[
String sHeader; %OfaBv&
lY.FmF}k
yFl@z
for(int i=1;;i++) d@7 ]=P:
{ 1f~unb\Gg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E:&=A 4%
//Utility.log(in.readLine()); #XQEfa
sHeader=httpConnection.getHeaderFieldKey(i); k U*\Fa*E
if(sHeader!=null) 4FGcCE3
{ 4}W*,&_
if(sHeader.equals("Content-Length")) 35B0L.R
{ g>/,},jv[x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y''`73U"
break; 'r(}7>~fC
} $MfHA~^
} 1 c3gHc7{t
else Pqo"~&Y|~
break; *S:^3{.m=
} "sUL"i
} dF5EIPl;J
catch(IOException e){e.printStackTrace ();} >y(;k|-$
catch(Exception e){e.printStackTrace ();} ?\(E+6tpP
]6GdB3?UVM
zy
Utility.log(nFileLength); |@sUN:G4k
1bYc^(z0
+Z/*=;
return nFileLength; ?Z.p.v
} '.c[7zL
|k^'}n
F7Mf>."
//保存下载信息（文件指针位置） *_!nil3(i
private void write_nPos() }XX)U_x
{ pBL,kqYNA>
try{ O B_g:T
output = new DataOutputStream(new FileOutputStream(tmpFile)); Uk`ym
output.writeInt(nStartPos.length); )c^Rc9e/
for(int i=0;i<nStartPos.length;i++) l"W9uS;\T
{ QpBgG~h"
// output.writeLong(nPos); r.lH@}i%n
output.writeLong(fileSplitterFetch.nStartPos); Dwj!B;AZ_
output.writeLong(fileSplitterFetch.nEndPos); K9njD#/
} $.a<b^.Xi
output.close(); blpX_N
} s+#gH@c
catch(IOException e){e.printStackTrace ();} :"5i/Cx
catch(Exception e){e.printStackTrace ();} ='`z
} )^qM%k8
zq>pK_WG
=3]}87
//读取保存的下载信息（文件指针位置） 9E'fM
private void read_nPos() MCZTeYnx
{ E2 Q[
try{ 6}6;%{p"Gu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b|^g51v
int nCount = input.readInt(); B8F.}M-!
nStartPos = new long[nCount]; '-oS=OrZ
nEndPos = new long[nCount]; ~Z9Eb|B
for(int i=0;i<nStartPos.length;i++) ]P;uQ!
{ "1FPe63\*O
nStartPos = input.readLong(); P"Lk(gY
nEndPos = input.readLong(); ]v(8i3P84
} 4nK\gXz19
input.close(); x$Y44v'>
} UbNA|`H
catch(IOException e){e.printStackTrace ();} @<=xfs
catch(Exception e){e.printStackTrace ();} m\o<a|
} #tg,%*.s
d[E~}Dq3#
'3TwrY?-
private void processErrorCode(int nErrorCode) 4QC"|<9R
{ AFE6@/'
System.err.println("Error Code : " + nErrorCode); !~Gx@Ro
} J@sH(S
sU!h^N$
sL" h
//停止文件下载 me:~q#k
public void siteStop() t5t,(^;f
{ QK%Nt
bStop = true; GKT2x '(e
for(int i=0;i<nStartPos.length;i++) !~Vo'ykwx'
fileSplitterFetch.splitterStop(); 2;Vss<hR4A
8=QOp[w
Zk,` Iq
} ZByxC*Cz
} Tzr_K
//负责部分文件的抓取 \|e>(h!l;
**FileSplitterFetch.java aF*KY<w
*/ 8Na.H::cZ
package NetFox; <Qg).n>;z
Lzmdy0!'
4<V%7z_.B
import java.io.*; ?*DM|hzOi
import java.net.*; < z':_,
Y-2IAJHS8
{1?94rz
public class FileSplitterFetch extends Thread { mj{B_3b5
K[wny0 (
d*qb^C{'"
String sURL; //File URL (LiS9|J!
long nStartPos; //File Snippet Start Position e"}JHXs
long nEndPos; //File Snippet End Position +kA>^
int nThreadID; //Thread's ID NOY`1i
boolean bDownOver = false; //Downing is over *vy^=Yea
boolean bStop = false; //Stop identical MB7UI8
FileAccessI fileAccessI = null; //File Access interface L`'#}#O l
?'_Ty`vT
s;brs}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \r %y^G
{ HQp\0NC]
this.sURL = sURL; UY>[
this.nStartPos = nStart; @jL](Mq|]
this.nEndPos = nEnd; CdBpz/
nThreadID = id; (vX) <Z !
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1G}f83yR
} 6=cfr; BH2
vHJOpQmt~
LNz
public void run() @%lkRU)
{ fe!eZiE
while(nStartPos < nEndPos && !bStop) uzoI*aqk-s
{ rn$G.SMgz
2xLEB&
]I,(^Xq3a(
try{ =Bg $OX
URL url = new URL(sURL); Vc[aNpE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BGd# \2
httpConnection.setRequestProperty("User-Agent","NetFox"); SFu]*II;{
String sProperty = "bytes="+nStartPos+"-"; sX@}4[)<&
httpConnection.setRequestProperty("RANGE",sProperty); }SfS\b{|~
Utility.log(sProperty); o3"Nxq"U
c,2OICj
K`=9"v'f+
InputStream input = httpConnection.getInputStream(); bO i-QD
//logResponseHead(httpConnection); }/w]+f*
gt(^9t;
f+cN'jH E
byte[] b = new byte[1024]; (himx8Uml2
int nRead; 0OXl`V`w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YpOcLxFL
{ oF0DprP@
nStartPos += fileAccessI.write(b,0,nRead); M7[GwA[Z +
//if(nThreadID == 1) yk0tA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XS}-@5TI
} xfF;u9$;
"MvSF1
HA J[Y3d<
Utility.log("Thread " + nThreadID + " is over!"); jY2mn".N
bDownOver = true; 3'Hz,qP
//nPos = fileAccessI.write (b,0,nRead); UX2@eyejQ7
} zfD@/kU
catch(Exception e){e.printStackTrace ();} \#h{bnx
} mm9uhlV8
} qeW.~B!B
4Q!|fn0Sv
fikDpR
//打印回应的头信息 ~<.{z]*O
public void logResponseHead(HttpURLConnection con) HUAbq }
{ $bDaZGy
for(int i=1;;i++) Y(
{ uHsLlfTn
String header=con.getHeaderFieldKey(i); o}&{Y2!x
if(header!=null) eslvg#Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]K3bDU~
Utility.log(header+" : "+con.getHeaderField(header)); n0LNAhM
else A0>r]<y
break; V|hwT^h
} $dxA7 `L
} !{4'=+
ZC%;5O`
x=Aq5*A0
public void splitterStop() <-mhz`^
{ >=d 5Scix
bStop = true; 2FW"uYA;6
} ]WzeJ"r {3
\#PZZH%
diNAT`|?#
} z9:yt5ar
P:_bF>r ?
#sg*GK+|:R
/* aZ|?i }
**FileAccess.java E]v]fy"
*//文件访问(定位，写) !MrQ-B(
package NetFox; 734t
import java.io.*; >S-JAPuO
vsyg u
&qK:LHhj
public class FileAccessI implements Serializable{ 2~4&4
P^# 4m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f`KO#Wc
RandomAccessFile oSavedFile; +~BP~
long nPos; 6uv~.-T<l
J>k 6`gw
ZqdoYU'
public FileAccessI() throws IOException /\_n5XI1
{ i6A9|G$H
this("",0); 98)C 7N'
} K@JaN/OM
AAs&P+;
w[D]\>QHa
public FileAccessI(String sName,long nPos) throws IOException hkyO_ns
{ YF-A8gXS
oSavedFile = new RandomAccessFile(sName,"rw"); SB08-G2
this.nPos = nPos; /Wcx%P
oSavedFile.seek(nPos); *sZH3:
} O@ H.k<zn
K,JK9)T
n((A:b
public synchronized int write(byte[] b,int nStart,int nLen) %$kd`Rl}
{ #Q)r6V:
int n = -1; lz::6}
try{ >d=pl}-kOQ
oSavedFile.write(b,nStart,nLen); wPm
n = nLen; 83I 5n&)
} !4cY^4>o
catch(IOException e) rjiHP;-t1
{ ^H7xFd|>
e.printStackTrace (); W;cYg.W2
} <ShA_+Nd
4xq|
R|'W#"{@
return n; ,Pcg+^A
} m2"e ]I
<K<#)mcv
pqb`g@
} QK#wsw
fqY'Uq$=
OA=~i/n~
/* wBwTJCX
**SiteInfoBean.java !`RMXUV
*/ s2NBYDi$?
package NetFox; kE.4 #
"f_qG2A{
G"E_4YkJ
public class SiteInfoBean { 'sH_^{V2
T}=^D=
rIJPgF
private String sSiteURL; //Site's URL ;Su-Y!&%
private String sFilePath; //Saved File's Path e2NK7
private String sFileName; //Saved File's Name \.O&-oi
private int nSplitter; //Count of Splited Downloading File -,b+tC<V)0
pvsa?z;rP
;>jEeIlT
public SiteInfoBean() Q2- lHn^L:
{//nSplitter的缺省值为5 @-L]mLY
//default value of nSplitter is 5 oPr`SYB
this("","","",5); ;*<R~HJt
} 1S!}su,uH
{9}CU~R
5!fYTo|G>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?YS>_MN
{ @WS77d~S
sSiteURL= sURL; T\bP8D
sFilePath = sPath; -ycYQ~R
sFileName = sName; uf#h~;B
this.nSplitter = nSpiltter; QJ4$) Fr(
"QNQ00[T`>
O_a^|ln&
} (~zu4^9w
-wiQd@X
A| A#|D
public String getSSiteURL() =FhP$r*
{ yiC7)=
return sSiteURL; I ]ZZN6"
} IJGw<cB]+
4 O8ct,Y
4/`;(*]Fv
public void setSSiteURL(String value) (vZ-0Ep}
{ .waw=C
sSiteURL = value; ^wd@mWxx
} b-VygLN
+`k30-<P
=b:XL#VA
public String getSFilePath() W<prY
{ e7@ m i
return sFilePath; %5gdLm!p
} oc( '!c
D/."0 #q
H)D|lt5xy
public void setSFilePath(String value) fF0i^E<
{ Tt)z[^)%
sFilePath = value; {V QGfN
} 1$vGQ
}OAU5P!rp
b`#YJpA
public String getSFileName() `w:kY9
{ I!Z`'1"
return sFileName; F*PhV|XU
} CLaQE{
?lsK?>uU
|z=`Ur@)
public void setSFileName(String value) wg?}c ;
{ z.cDbkf}
sFileName = value; *XhlIQ
} ,w#lUgp
cWkg.ri-x
hD ~/ywS&
public int getNSplitter() bN. G%1
{ ;pW8a?
return nSplitter; ~rBFP)
} DPzW,aIgv
y 9]d{:9
h(/? 81:
public void setNSplitter(int nCount) f1_;da
{ M#'7hm6
nSplitter = nCount; 9<_hb1'
} A?lLK&*
} 3$!QP N
]AY 4bm
; CCg]hX
/* Zmyq6.1q~
**Utility.java ! *sXLlS
*/ @n)?=[p
package NetFox; lKejWT`;
uQO5GDuK>
v8f3B<kj
public class Utility { "mJo<i}
lm4A%4-db
B46:LQ9[
public Utility() ]vQa~}
{ S5hc@^|0Z
FAnz0p+t
n{4iW_/D
} %Y ZCdS
fYP,V0P
//线程睡眠 NRx 7S9W
public static void sleep(int nSecond) $Lstq_x+
{ 1!1JT;gG^9
try{ lu{ *]!
Thread.sleep(nSecond); V4Rs
} ,9ueHE
catch(Exception e) %6cr4}Zm}
{ D=a*Xu2zq
e.printStackTrace (); ,5c7jZ5H
} }SSg>.48w
} Wmd@%K
0e8
//日志 66?`7j X
public static void log(String sMsg) ^N<aHFF
{ c/K#W$ l
System.err.println(sMsg); Ja3#W K
} i`@cVYsL
{1)bLG|$
]#M"|iTR
public static void log(int sMsg) K;"H$0!9
{ ;b [>{Q;
System.err.println(sMsg); p_Xfj2E4c
} co\?SgE35
} %t&Lq}e
qY-aR;
$CB&>?~
/* bq7+l4CGTv
**TestMethod.java A/=cGE
*/ E4Q`)6]0
package NetFox; w-WAgAch
"-S!^h/v
'~b
public class TestMethod { Qf0P"s`
Z|@-=S(.
LeN }Q
public TestMethod() `{YOl\d_
{ ///xx/weblogic60b2_win.exe \_.'/<aQ
try{ bP$e1I3`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %GjG.11V,_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7vgRNzZoq
SiteFileFetch fileFetch = new SiteFileFetch(bean); s8(Z&pQ
fileFetch.start(); |u`YT;`!"-
} d >L8SL
catch(Exception e){e.printStackTrace ();} '(r?($s
&S.p%Qe"
N''xdz3Z
} 0 F8xS8vK+
WuVsW3@
u@D5SkT
public static void main(String[] args) L~+aD2E {
{ GAH<
new TestMethod(); VKXi*F9
} 7]u_
} 8u[.s`^
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