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)); ?+d`_/IB
} GkJcd;
for(int i=0;i<nEndPos.length-1;i++) Ax=HDW}
{ k3#'g'>yh
nEndPos = nStartPos[i+1]; ls@]%pz.1d
} p +i1sY
nEndPos[nEndPos.length-1] = nFileLength; 27eG8
} kMQ /9~
} -)}s{[]d6m
+Dy^4p?o
5Ml=<^
//启动子线程 '{d@Gc6.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )]1hN;Nz
for(int i=0;i<nStartPos.length;i++) y>a?<*Y+e
{ _B^zm-}8|B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {.:$F3T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C{}_Rb'x
nStartPos,nEndPos,i); E^i]eK*"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >c,s}HJ
fileSplitterFetch.start(); 6TW7E}a.
} <>3)S`C`p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A0DGDr PD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "bo0O7InOV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *|AQV:
nEndPos = " + nFileLength); PE%$g\#?
// fileSplitterFetch[nPos.length-1].start(); !a@)6or
Y2 @8B6
D4=*yP
//等待子线程结束 USBQEt
//int count = 0; ]Ox5F@
//是否结束while循环 q\Y4vWg
boolean breakWhile = false; I^?tF'E
)j_El ]?
c2npma]DZ
while(!bStop) &3Zq1o
{ C ^Y\?2h1
write_nPos(); Gnkar[oa&
Utility.sleep(500); THYw_]K
breakWhile = true; i>F=XE
YT\@fgBt
TekUY m!G
for(int i=0;i<nStartPos.length;i++) jm^.E\_
{ ~e{ @5.g
if(!fileSplitterFetch.bDownOver) qLN\%}69/
{ -#|D>
breakWhile = false; Wc3z7xK1@
break; ?%,NOX
} "j^i6RS
} C?<pD+]b_
if(breakWhile) 6}4})B2
break; tb3VqFx
*pKTJP
PMzPj,
//count++; d ]P~
//if(count>4) aLO^>",
// siteStop(); aB]0?C y9(
} JB_fS/I
`Fy-"Uf
y~SVD@
System.err.println("文件下载结束！"); t^rw@$"}
} _P;D.>?
catch(Exception e){e.printStackTrace ();} ~4~`bT9
} "/W[gP[y%
.Mt3ec<
{0zn~+
//获得文件长度 \(o"/*
public long getFileSize() V`V\/sgj
{ u^80NR
int nFileLength = -1; FfoOJzf~o
try{ V>Wk\'h
URL url = new URL(siteInfoBean.getSSiteURL()); a)qan
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r~4uIUE{
httpConnection.setRequestProperty("User-Agent","NetFox"); 0'QWa{dS\
3*b5V<}'|
_fGTTw(
int responseCode=httpConnection.getResponseCode(); D&@]
if(responseCode>=400) :GHv3hn5
{ ._mep\#.:
processErrorCode(responseCode); _VtQMg|u
return -2; //-2 represent access is error JfY*#({y
} rqdwQ
<xOv8IQ|
uV/5f#)
String sHeader; vF$i"^;tJ;
xmW~R*^
Vz{+3vfra6
for(int i=1;;i++) c OYDN[k
{ IK~&`n](>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TkbaoD
//Utility.log(in.readLine()); c8RJOc4X
sHeader=httpConnection.getHeaderFieldKey(i); eI #Gx_mg
if(sHeader!=null) x0*{oP
{ G#M)5'Q]U
if(sHeader.equals("Content-Length")) FR&`R
{ jG5HW*>k0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $o^Z$VmL
break; k9|5TLXq?
} 4zug9kFK
} <g4}7l8
else Hvl n>x@
break; ]S|FK>U[
} D:)Wr, 26
} 7*/{mK)
catch(IOException e){e.printStackTrace ();} IgT`on3Y
catch(Exception e){e.printStackTrace ();} {|;a?]?
.8hI ad
/r}L_wI
Utility.log(nFileLength); 1I+9?fa
En5oi
'6KvB
return nFileLength; *Ak.KBg
} I7f ^2
1GY2aZ@
~5 ^Jv m
//保存下载信息（文件指针位置） |s|}u`(@9
private void write_nPos() 9g92eKS
{ |(7}0]BP0
try{ <v"o+
output = new DataOutputStream(new FileOutputStream(tmpFile)); rS8a/d~;0
output.writeInt(nStartPos.length); DE?v'7cmA
for(int i=0;i<nStartPos.length;i++) 4<s.|W`
{ n|`3d~9$&
// output.writeLong(nPos); \-<BUG]=
output.writeLong(fileSplitterFetch.nStartPos); GK?ual1
output.writeLong(fileSplitterFetch.nEndPos); "fFSZ@,r
} [oWkd_dK
output.close(); FLZ9pb[T
} }d$-:l,w
catch(IOException e){e.printStackTrace ();} EM,C
catch(Exception e){e.printStackTrace ();} BD g]M/{
} Zg;$vIhn
gN&i&%*!
8:cbr/F<
//读取保存的下载信息（文件指针位置） T U%@_vYR
private void read_nPos() 18g_v"6o
{ K}*ets1s}
try{ n:j'0WW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5*0zI\
int nCount = input.readInt(); tDByOml8Ix
nStartPos = new long[nCount]; 3"fDFR
nEndPos = new long[nCount]; \1EuHQ?
for(int i=0;i<nStartPos.length;i++) 37AVk`a
{ j;x()iZ<
nStartPos = input.readLong(); qHtQ4_Zn;
nEndPos = input.readLong(); A|A~$v("R
} OG\i?N
input.close(); $-4](br|
} @SQsEq+A?\
catch(IOException e){e.printStackTrace ();} 'uPAG;)m
catch(Exception e){e.printStackTrace ();} tjdPia
} $:ush"=f8^
A=|XlP$6
j50vPV8m
private void processErrorCode(int nErrorCode) ,GbmL8P7Y
{ O&%'j
System.err.println("Error Code : " + nErrorCode); c{#2;k Q,
} \Lx=iKs<
HB07 n4 |
>7U/TVd&
//停止文件下载 f@*69a8
public void siteStop() q?,PFvs"
{ *X5)9dq
bStop = true; -YoL.`s1
for(int i=0;i<nStartPos.length;i++) *D5 xbkH=.
fileSplitterFetch.splitterStop(); &OR(]Wt0
U?[ (
xJq|,":gj
} ]xC56se
} N:j7J
//负责部分文件的抓取 {q>%Sr]9
**FileSplitterFetch.java 2D\pt
*/ o|$D|E
package NetFox; FW]tDGJOw
wO??"${OH
*A-_*A
import java.io.*; A U~DbU0O
import java.net.*; ^F^g(|(K
[6GYYu\
~Xi@#s~
public class FileSplitterFetch extends Thread { y6(PG:L
1NYR8W]2
?Uql30A
String sURL; //File URL 7FX4|]
long nStartPos; //File Snippet Start Position dX(JV' 18A
long nEndPos; //File Snippet End Position *ug~LK5Y.
int nThreadID; //Thread's ID 1U\ap{z@
boolean bDownOver = false; //Downing is over /t5)&
boolean bStop = false; //Stop identical 1tuvJ+`{
FileAccessI fileAccessI = null; //File Access interface S-t#d7'B
n 0!8)Sth
{C |R@S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IjI'Hx
{ *s6x
this.sURL = sURL; wt($trJ
this.nStartPos = nStart; bY_'B5$.^2
this.nEndPos = nEnd; ;i@S}LwL
nThreadID = id; 3,PR6a,b'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I}f`iBG
} 9QQ XB-
;m7V]h? R
PD#,KqL:
public void run() J4bP(=w!
{ Emlj,c<?j
while(nStartPos < nEndPos && !bStop) ;"dX]":
{ Dka,v
sXVl4!=l6
jY6GWsh:9
try{ 9r%fBiSk
URL url = new URL(sURL); N{J 1C6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }:8}i;#M
httpConnection.setRequestProperty("User-Agent","NetFox"); #GM^:rF
String sProperty = "bytes="+nStartPos+"-"; ?(ORk|)kU
httpConnection.setRequestProperty("RANGE",sProperty); (MGgr
Utility.log(sProperty); Ow0>qzTg
@*%3+9`yq
$6Ma{rC|
InputStream input = httpConnection.getInputStream(); 0ix(1`Z
//logResponseHead(httpConnection); }`=7%b`-?
M9)4ihK
6_mi9_w
byte[] b = new byte[1024]; HT<p=o'$Z
int nRead; *\ii+f-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "ESc^28
{ l";Yw]:^
nStartPos += fileAccessI.write(b,0,nRead); i(~DhXz*T
//if(nThreadID == 1) sL@\,]Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =.`\V]
} ns~]a:1yh
N~/'EaO
8Lgt
Utility.log("Thread " + nThreadID + " is over!"); =l(euBb
bDownOver = true; I\*6 >
//nPos = fileAccessI.write (b,0,nRead); 4cQP+n
} 1!uBzO6/$
catch(Exception e){e.printStackTrace ();} o~$O$
} x3n9|Uud
} bM?gAY]mB8
)N 3^r>(e<
;nSF\X(;{
//打印回应的头信息 /3s&??{tv
public void logResponseHead(HttpURLConnection con) kN=&"
{ tz;3
for(int i=1;;i++) |_?e.}K
{ sVx}(J
String header=con.getHeaderFieldKey(i); gnJ8tuS
if(header!=null) \'~ E%=Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9#9 UzKX#
Utility.log(header+" : "+con.getHeaderField(header)); Pd7\Q]of
else ^ ]9K>}
break; q|*^{(tWs
} bK:U:vpYm
} G&S2U=KdV%
ZR1U&<0c@
@43psq1
public void splitterStop() j(%N.f6
{ z&;8pZr
bStop = true; g}MUfl-L
} a``|sn9
QIiy\E%
~,/@]6S&Y
} .D@J\<,+l
R;DU68R
'=0}2sF>
/* \Th<7WbR6#
**FileAccess.java mB-,\{)
*//文件访问(定位，写) m!7%5=Fc
package NetFox; -,bnj^L
import java.io.*; zT>!xGTu7~
2.3_FXSt
s|p I`
public class FileAccessI implements Serializable{ ?=&; A
:|;@FkQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $z=%e#(!I
RandomAccessFile oSavedFile; Uxjc&o
long nPos; krfXvQJwJ
?4':~;~
`<9>X9.+
public FileAccessI() throws IOException !AwMD
{ 6U{A6hH]
this("",0); `n$Ak5f
} AYnPxiW|
r,;ca6>5H
`=Ip>7T&
public FileAccessI(String sName,long nPos) throws IOException -+"#G?g
{ LwB1~fF
oSavedFile = new RandomAccessFile(sName,"rw"); f30J8n"k
this.nPos = nPos; G[KjK$.Ts?
oSavedFile.seek(nPos); kGD_w
} HJ&P[zV^
8R*;8y_
`O6#-<>
public synchronized int write(byte[] b,int nStart,int nLen) ]c>@RXY'
{ MtJ-pa~n
int n = -1; kk78*s {6
try{ mn@1&#c4y
oSavedFile.write(b,nStart,nLen); ?L }>9$"
n = nLen; ZN8j})lE
} y`RzcXblIZ
catch(IOException e) /V,xSK9.&
{ +@ChZ
e.printStackTrace (); ^$Y9.IH"
} 1h@qcom9K_
u[)X="-e#
=7V4{|ESfy
return n; ?"@Fq2xgB4
} TKnWhB/J
kx&JY9(&#
SRfh{u
} eu5te0{G
CtY-Gs
<)ZQRE@
/* llZU: bs
**SiteInfoBean.java h8(#\E
*/ ]+:yfDtZd
package NetFox; D|OGlP
CmB_g?K
-`'|z+V
public class SiteInfoBean { o"JHB
UIEvwQ
2_pF#M9
private String sSiteURL; //Site's URL OH@"]Nc~
private String sFilePath; //Saved File's Path Vq3NjN!+5
private String sFileName; //Saved File's Name Iynks,ikA
private int nSplitter; //Count of Splited Downloading File nWsRauY
~DD _n
yepRJ%mp
public SiteInfoBean() \oPe"k=
{//nSplitter的缺省值为5 PzPNvV/o
//default value of nSplitter is 5 %<kfW&_>w
this("","","",5); eP2Q2C8g
} >Cr"q*
04U|Frc
@_`r*Tb)dM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l-w4E"n3
{ |&@q$d
sSiteURL= sURL; ]L~z9)
sFilePath = sPath; }#1.$a
sFileName = sName; 4PVg?
this.nSplitter = nSpiltter; ZJ{DW4#t
3@=<4$
b]]k\b
} 7Q/H+)
.Vt|;P}
Mzg'$]N
public String getSSiteURL() ZTTA??}Y
{ l]|&j`'O
return sSiteURL; p+P@I7V
} Lx-%y'P
E{6ku=2F
N,w6
public void setSSiteURL(String value) NATi)A"TZ
{ |!K&h(J|
sSiteURL = value; iY>xx~V
} ]/!*^;cY(
f #h0O3
@16y%]Q-E#
public String getSFilePath() Oi?Q^ISxP
{ 26~rEOgJ
return sFilePath; xFUD9TM
} d '2JMdbc
x/1FQ>n:9
'tTlBf7#
public void setSFilePath(String value) NH/jkt&F[
{ fXevr `
sFilePath = value; ,dba:D=l
} NTJ,U2
\nOV2(FAT
_`Kh8G {e
public String getSFileName() %/zHL?RqJ
{ |\B\IPs{%'
return sFileName; VFV8ik)
} \yymp70w
gu3)HCZ
_6FDuCVD-
public void setSFileName(String value) ^ &KH|qRrO
{ ,hK =x
sFileName = value; N0fE*xo
} ,,XHw;{
JKmd'ZGw
|RpZr!3V
public int getNSplitter() ^R\5'9K!
{ M]\"]H?
return nSplitter; ,[m4+6G5
} 5NSXSR9c
j@JY-^~K5
EI9Yv>7d{
public void setNSplitter(int nCount) i\36 s$\
{ K6<1&
nSplitter = nCount; [t^%d9@t
} bv[*jr;45
} <.7W:s,f=
fv3)#>Dgp>
Y!E|X 3
/* e ]>{?Z
**Utility.java '.&,.E&{$
*/ gp'n'K]
package NetFox; GLl@ 6S>v
,@gDY9Q3r/
\No22Je6d
public class Utility { 9]8M{L
Q!%CU8!`&
7L:R&W6
public Utility() Y@'1}=`J
{ sEfGf.
;Wr,VU]
1/qiE{NW
} ]*;+ U6/?
kqAQrg]n
//线程睡眠 ]O&A:Us
public static void sleep(int nSecond) aEZn6k1
{ s?K4::@Fv
try{ <Q-ufF85)
Thread.sleep(nSecond); WU,72g=
} tbv6-)Hs
catch(Exception e) 2|w.A!
{ Zk;;~ESOU
e.printStackTrace (); CM's6qhQnn
} vrW9<{
} KF-gcRh
kAk,:a;P
//日志 U14dQ=~b/
public static void log(String sMsg) t_VHw'~"
{ 7iJk0L$]x
System.err.println(sMsg); :~)Q]G1Nj
} M[*:=C)H
izWl5}+'B
$BBfsaJPT
public static void log(int sMsg) o-'i)pp
{ UZX)1?U
System.err.println(sMsg); &Y=NUDt_
} Iq}h}Wd
} S@"=,Xj M
tw3d>H`
hA\8&pI;
/* =<_5gR
**TestMethod.java /eMZTh*1P
*/ -MEz`7c~
package NetFox; Pd;ClMa%
q(p0#Mk,E
n*6s]iG V
public class TestMethod { }Voh5*$E`
TgB;R5
Qy/bzO
public TestMethod() /[IQ:':^
{ ///xx/weblogic60b2_win.exe EH "g`r
try{ XP^6*}H.*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d$,i?d,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,"VQ0Z1
SiteFileFetch fileFetch = new SiteFileFetch(bean); .M{[J]H`t
fileFetch.start(); @YB\PVhW
} pOYtN1uN|
catch(Exception e){e.printStackTrace ();} jgo@~,5R
E$>e< T
2*L/c-
} (Sv%-8?gs
>oNk(. %
`k|nf9_
public static void main(String[] args) U ^9oc&
{ a*[\edcHU
new TestMethod(); F`Y<(]+
} UQcmHZ+lf
} (*x"6)`
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