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)); ;;<[_gp,E
} "= >8UR
for(int i=0;i<nEndPos.length-1;i++) Z8q*XpUH
{ Xf*}V+&WN
nEndPos = nStartPos[i+1]; p0@l581
} Yy4l -}"
nEndPos[nEndPos.length-1] = nFileLength; 0JX/@LNg0
} 7^n{BsN
} &OP =O*B
"-A@d&5.
U?(+ {4l
//启动子线程 EV|L~^Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a 8.Xy])!
for(int i=0;i<nStartPos.length;i++) ( Y)a`[B
{ ^9 {r2d&c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k{ibD5B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .R{+Pz D
nStartPos,nEndPos,i); n%I9l]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C5&+1VrP
fileSplitterFetch.start(); *D;VZs0O
} hnnPi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VDC"tSQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n8 e4`-cY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b@yFqgJ_
nEndPos = " + nFileLength); ]-tAgNzl%
// fileSplitterFetch[nPos.length-1].start(); V SUz+W
8,YxCm ie
@d_;p<\l
//等待子线程结束 {uji7TB
//int count = 0; C 8qVYrw
//是否结束while循环 q<!KtI4
boolean breakWhile = false; jG~UyzWH;
~#V1Gunq
O!.mc=Gx7
while(!bStop) jN^09T49
{ qD/FxR-!
write_nPos(); NZ?|#53
Utility.sleep(500); B(U0 ~{7a
breakWhile = true; +Y|HO[
:z}
c0W4<(
for(int i=0;i<nStartPos.length;i++) rkC6-9V
{ &yQM8J~
if(!fileSplitterFetch.bDownOver) >m&r,z
{ 4E.K6=k|=a
breakWhile = false; y6!Zt}m
break; XG_Iq ,
} NK0hT,_
} (8/Qt\3jv
if(breakWhile) k7ODQ(*v
break; Pw_[{LL
l\Or.I7n
:i_kA'dl&
//count++; {|Pz9a-:
//if(count>4) smt6).o
// siteStop(); 9Ucn 6[W
} Q&Ox\*sMK
m+/-SG
$6]7>:8mz
System.err.println("文件下载结束！"); C5jR||
} YOHYXhc{S
catch(Exception e){e.printStackTrace ();} KU}HVM{
} 1@Zjv>jy[
)!``P?3?
\PB~6
//获得文件长度 'ehJr/0&g
public long getFileSize() #e:*]A'I
{ $&|*v1rH
int nFileLength = -1; ?>p<!:E!r
try{ ZP&"[_
URL url = new URL(siteInfoBean.getSSiteURL()); $N#f)8v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Pc]qu
httpConnection.setRequestProperty("User-Agent","NetFox"); \KaWR
O/(qi8En
K"sfN~@rT[
int responseCode=httpConnection.getResponseCode(); `[;b#.
if(responseCode>=400) r4~Bn7j2
{ ?wR;"
processErrorCode(responseCode); d&p]O
return -2; //-2 represent access is error &!{wbm@
} m$xyUv1
:fr2K
|Aw(v6
String sHeader; OT9\K_
Yp`6305f
_ID2yJ
for(int i=1;;i++) $+<X 1
{ 9Osjh G
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A`7uw|uO$
//Utility.log(in.readLine()); MO:##C
sHeader=httpConnection.getHeaderFieldKey(i); QY2!.a^q
if(sHeader!=null) ~$f+]7
{ \>j._#t$h
if(sHeader.equals("Content-Length")) '?5=j1
{ j$#pG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }}?L'Vby
break; 1{%EQhNd
} r6Z&i^cMe
} &G@*/2A
else r+;C}[E
break; M"K$81
} 0gVylQ
} :x97^.eW~
catch(IOException e){e.printStackTrace ();} 0K,*FdA
catch(Exception e){e.printStackTrace ();} $.(>Sj1
pN&Dpz^
Nora<
Utility.log(nFileLength); :XF;v
.*D~ .!
_"J-P={=
return nFileLength; -) $$4<L
} K(Otgp+zb
!5 %c`4
r M'snW)
//保存下载信息（文件指针位置） K|Std)6
private void write_nPos() Cdiu*#f
{ ro6peUL*2`
try{ Gy 'l;2
output = new DataOutputStream(new FileOutputStream(tmpFile)); Hbx=vLQ6
output.writeInt(nStartPos.length); J}KATpHs
for(int i=0;i<nStartPos.length;i++) bR49(K$~
{ A;w,m{9<
// output.writeLong(nPos); >t?;*K\x"
output.writeLong(fileSplitterFetch.nStartPos); tp_*U,
output.writeLong(fileSplitterFetch.nEndPos); uFb&WIo1
} 9pStArF?F0
output.close(); {DBgW},
} WU{G_Fqaz
catch(IOException e){e.printStackTrace ();} HlPf
catch(Exception e){e.printStackTrace ();} bKmR &
} I8`@Srw8
znFa4
!u~( \Rb;
//读取保存的下载信息（文件指针位置） zhKb|SV
private void read_nPos() 1>4'YMdZi
{ : UD<1fh
try{ CP'?Om2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jUZ84Gm{
int nCount = input.readInt(); ?H0 #{!s
nStartPos = new long[nCount]; `K~300-hOb
nEndPos = new long[nCount]; m/JpYv~
for(int i=0;i<nStartPos.length;i++) %gJf&A
{ 3rTYe6q$U
nStartPos = input.readLong(); eL#pS=
nEndPos = input.readLong(); ;a XcGa
} d5\w'@Di
input.close(); W'-B)li
} BE:HO^-.1
catch(IOException e){e.printStackTrace ();} d11~mU\
catch(Exception e){e.printStackTrace ();} C\j|+s
} :7<spd(%"
votv rZ=
=" #O1$
private void processErrorCode(int nErrorCode) YbND2i
{ 8{8J(~
System.err.println("Error Code : " + nErrorCode); BYyR-m
} sikG}p0mx<
>pbO\=j]X
^0R.'XL
//停止文件下载 vtKQvQ
public void siteStop() i!LEA/"V
{ vXAO#'4tm%
bStop = true; 8Sd<!
for(int i=0;i<nStartPos.length;i++) (g`G(K_
fileSplitterFetch.splitterStop(); HbX>::J8
c]v$C&FX
>_jT.d
} h<f_Eoz-a
} $5jQm,V$K
//负责部分文件的抓取 |`1lCyV\tE
**FileSplitterFetch.java <xKer<D %
*/ a"EX<6"
package NetFox; 7;jwKA;k
NGOc:>}k>
<La$'lG4J
import java.io.*; 0D+[W5TB
import java.net.*; 3s<~}&"
R?b3G4~
Z,^`R] 9
public class FileSplitterFetch extends Thread { {Iy<iV
7xTgG!>v
?n)d: )Ud"
String sURL; //File URL ~1]4 J(+
long nStartPos; //File Snippet Start Position ijEMS1$=7
long nEndPos; //File Snippet End Position _CO?HX5ek
int nThreadID; //Thread's ID hCVe05
boolean bDownOver = false; //Downing is over %4|*
boolean bStop = false; //Stop identical gHpA@jdC*
FileAccessI fileAccessI = null; //File Access interface 0}C> e`<'
[nZf4KN
S<#>g s4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tgSl(.
{ Anr''J&9`H
this.sURL = sURL; 1O]'iS"
this.nStartPos = nStart; epuN~T
this.nEndPos = nEnd; +:k Iq
nThreadID = id; @/FE!6 |O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?f f!(U
} n}/?nP\%
:,Z'/e0&
bnHQvCO3$
public void run() `2-6Qv
{ wCw-EGLR
while(nStartPos < nEndPos && !bStop) tj$&89
{ {9:[nqX
;,2i1m0"
v;m`d{(i2
try{ o81RD#>E)
URL url = new URL(sURL); 1W3+ng
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )r2$!(NQ
httpConnection.setRequestProperty("User-Agent","NetFox"); /e5' YVP
String sProperty = "bytes="+nStartPos+"-"; cq:<,Ke
httpConnection.setRequestProperty("RANGE",sProperty); #gn{X!;-;
Utility.log(sProperty); ;e Iqxe>
&O8vI,M
r9MS,KG8
InputStream input = httpConnection.getInputStream(); do,ZCn
//logResponseHead(httpConnection); H4RqOI
qLC_p)
&!i'Q;q
byte[] b = new byte[1024]; [bM$n m
int nRead; ,w-=8>5lrj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^u2unZ9BK!
{ pRR1k?
nStartPos += fileAccessI.write(b,0,nRead); m8M2ka
//if(nThreadID == 1) =VIU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); stGk*\>U'
} ?R-4uG[(
bd|ZhRsL
N;Hoi8W
Utility.log("Thread " + nThreadID + " is over!"); >A&D/kMO
bDownOver = true; @}9*rWJIE
//nPos = fileAccessI.write (b,0,nRead); 3DjlX*
} W5i{W'
catch(Exception e){e.printStackTrace ();} RJ}%pA4I
} hA=.${uIO
} ul(pp+%S
/Ne;Kdp
wFbw3>'a9
//打印回应的头信息 iA.:{^_)09
public void logResponseHead(HttpURLConnection con) C2e.RTxc
{ z`]sWi F0
for(int i=1;;i++) T-MC|>pv
{ \B/!}Tn;
String header=con.getHeaderFieldKey(i); q,;8Ka )
if(header!=null) hW<TP'Zm*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uuaoBf
Utility.log(header+" : "+con.getHeaderField(header)); jJ.isr|`
else 7a0T]
break; 3M^s EaUI
} \9t/*%:
} xg(*j[ff3
=w!>/#U
P>U7RX e
public void splitterStop() \wR;N/tg
{ JnE\z*NB
bStop = true; (e"\%p`
} \d)HwO
>mAi/TZC
!8Y$}
} *lo0T93B
6N\f>c
99GK6}~TGm
/* }'`iJb\
**FileAccess.java 2#81oz&K
*//文件访问(定位，写) Au10]b
package NetFox; a&z$4!wQB
import java.io.*; mXwDB)O{)
2}uSrA7n]
Ir6(EIwx0
public class FileAccessI implements Serializable{ 'ZFbyt Q2
P. Kfoos
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d_1uv_P
RandomAccessFile oSavedFile; d-{1>\-_
long nPos; dy.U;
!sVW0JSh
bQgtZHO
public FileAccessI() throws IOException 3D-VePM=`
{ *{!E`),FX
this("",0); 4^GIQEjx
} bLsN?_jy
(`"87Xomnn
GL-Pir
public FileAccessI(String sName,long nPos) throws IOException WRqpQEY
{ =m-nvXD
oSavedFile = new RandomAccessFile(sName,"rw"); yvCX is
this.nPos = nPos; h$)4%Fy
oSavedFile.seek(nPos); "Z]z9(
} :h8-y&;
T@R2H&L
LI9 Uc\
public synchronized int write(byte[] b,int nStart,int nLen) |wM<n
{ a}g<<{
int n = -1; :Aa5,{v_
try{ R4%}IT^%P
oSavedFile.write(b,nStart,nLen); av"dJm
n = nLen; LMRq.wxbbB
} UT%?3}*u"
catch(IOException e) x31Jl{x8\?
{ |xFSGrC
e.printStackTrace (); avb'dx*q>
} rm%MQmF
a8 .x=j<
\:jJ{bl^A
return n; 4W<8u(
} ~\OZEEI
oAF#bj_f
om{aws;
} RG6U~o1
UIo jXR<
8Z>=sUMQ
/* O4oI&i 7
**SiteInfoBean.java 9+!"[
*/ $ S]l%
package NetFox; +:&|]$8<
&Fh#otH_
C/ENJ&
public class SiteInfoBean { <_#a%+5d
H|z:j35\
m`xzvg
private String sSiteURL; //Site's URL !Q=xIS
private String sFilePath; //Saved File's Path UF;iw
private String sFileName; //Saved File's Name 2`pg0ciX (
private int nSplitter; //Count of Splited Downloading File [&+5E1%L
wZb77
)|B3TjHC
public SiteInfoBean() cIg+^Tl
{//nSplitter的缺省值为5 lr9s`>9
//default value of nSplitter is 5 bj_oA i
this("","","",5); -5GRit1q?
} Z`x*Igf8
wY*tq{7
<CN+VXF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C/YjMYwKgv
{ c52S2f7
sSiteURL= sURL; li&&[=6A
sFilePath = sPath; x%%OgO+>
sFileName = sName; tjbI*Pw7(
this.nSplitter = nSpiltter; _e$T'*q
nZ/pi$7
.NT9dX
} F~x>\?iN
E&>=
f~{4hVA
public String getSSiteURL() M5c~-}Ay
{ 2-_d~~O1N
return sSiteURL; ,Kwtp)EX
} h.)o4(bO
'L8B"5|>
ok(dCAKP
public void setSSiteURL(String value) Mc<O ~
{ A3Oe=rB
sSiteURL = value; ~JG\b?s
} %>EM ^Z
L(DDyA{bA
!+T29QYK8
public String getSFilePath() OpFm:j3
{ @h!nVf%fe
return sFilePath; #GOL%2X
} L<Q>:U.@\
zaG1
MhZ\]CAs9
public void setSFilePath(String value) %IK[d#HO
{ cCO2w2A[*
sFilePath = value; ##BfI`FJ
} Q<T+t0G\O-
`}S;_g!
h Nx#x
public String getSFileName() WnL7 A:sZ
{ =_Ip0FfK!
return sFileName; ;%!]C0?
} 2JL\1=k;
tFu"h1
6D/K=-
public void setSFileName(String value) Cnv?0to2l
{ ]?lUe5F
sFileName = value; _:~I(c6
} dzs(sM=
{P'^X+B0*
[^0 S#,L
public int getNSplitter() &*#Obv
{ bE6bx6=u
return nSplitter; U o[\1)
} v/x~L$[
D+"+m%^>C
|OBh:d_B]
public void setNSplitter(int nCount) uYCWsw/
{ 7& 'p"hF
nSplitter = nCount; xl ,(=L]
} 1C+d&U
} >>%E?'9A
`l0"4[?
A.cNOous|
/* JS^!XB'!
**Utility.java PnZY%+[I
*/ 8c%_R23
package NetFox; 7'.]fs:
#:s*Hy=
*AJYSa,z
public class Utility { IsiBn(1Z
>hO9b;F}
$7*@TMX
public Utility() c' Q4Fzj0'
{ eS/Au[wS
ffR<G&"n~b
e#!p6+#"
} @1s 2#)l(
t&Jrchk
//线程睡眠 LC})aV|
public static void sleep(int nSecond) O96%U$W
{ s9,Z}]Th
try{ ',]^Qu`a
Thread.sleep(nSecond); p4vX3?&1W
} <Yn-sH
catch(Exception e) GDYFhH7H
{ 5xhYOwQBo
e.printStackTrace (); R5=M{
} 6"yIk4u:
} Y2$xlqQd"
EbnV"]1
//日志 ),XDY_9K
public static void log(String sMsg) rmeGk&*R8
{ v9"03=h
System.err.println(sMsg); +LF`ZXe8l
} @T%8EiV
xwojjiV
oZ>2Tt%
public static void log(int sMsg) Rw^X5ByJE
{ (} wMU]!_
System.err.println(sMsg); X*t2h3"}
} -nqq;|%
} <3laNk
]/7#[
> 1=].
/* t'[`"pp=
**TestMethod.java ~z'Y(qG
*/ H` h]y
package NetFox; S|]\q-qA&
gP`CQ0t
d "25e"(~F
public class TestMethod { S5[}kfe
7A^L$TY
w d6+,B
public TestMethod() 4e?MthJ>
{ ///xx/weblogic60b2_win.exe Qn}M
try{ ?hKpJA'%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^*b11/7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5=Il2
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7`tJ/xtMy;
fileFetch.start(); EzU3'x
} vf-8DB
catch(Exception e){e.printStackTrace ();} 4wPP/`
{J-Ojw|Y b
H^+Znmo
} e17]{6y
3x)jab
D!mx&O9
public static void main(String[] args) f1q0*)fk
{ \7G.anY
new TestMethod(); 5%w08
} E.G]T#wt0
} |a=7P
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