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)); 0rCQz3gh1
} %abc-q
for(int i=0;i<nEndPos.length-1;i++) \"1%>O*
{ hkl9EVO)
nEndPos = nStartPos[i+1]; /|>?!;
} DAf0bh"
nEndPos[nEndPos.length-1] = nFileLength; =+w!fy
} PpezWo)9
} &.[I}KH|B
WYd9p;k
7[ZoUWx
//启动子线程 t_w2J=2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kc/"
for(int i=0;i<nStartPos.length;i++) V)A7q9Bum
{ i$lp8Y2ih
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U88gJ[$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K@tELYb
nStartPos,nEndPos,i); 9xaieR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !p!^[/9"c
fileSplitterFetch.start(); `wKd##v'@
} ti!kJ"q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $V,ZH* g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W#kd[Wi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~- eB
nEndPos = " + nFileLength); oaG;i51!
// fileSplitterFetch[nPos.length-1].start(); L [&|<<c
yb!/DaCd
B["jndyr
//等待子线程结束 epgAfx-_OH
//int count = 0; *yYeqm
//是否结束while循环 Vp&"[rC_z
boolean breakWhile = false; [@Mo3]#\
g[N3jt@
eI98J"h%?
while(!bStop) B*:W`}G]_c
{ ('Ha$O72
write_nPos(); iLQ;`/j
Utility.sleep(500); zMh`Uqid
breakWhile = true; NZz^*Ela
z}F^HQ1
)M*Sg?L
for(int i=0;i<nStartPos.length;i++) o:`^1
{ B]I*ymc#
if(!fileSplitterFetch.bDownOver) MavidkS
{ >Se-5QtLcf
breakWhile = false; ;gLOd5*0
break; wRg[Mu,Q5
} /9o6R:B
} d2fiPI7lg
if(breakWhile) .|@2Uf
break; <Ok7-:OxA
jT`u!CwdT
Tnas$=J
//count++; NfZC}
//if(count>4) ~( :$c3\
// siteStop(); 4kR;K!@k
} Zt}b}Bz
1n[wk'}qf4
,(f({l[J}
System.err.println("文件下载结束！"); G 2uM6
} f8-~&N/_R
catch(Exception e){e.printStackTrace ();} XB a^ A
} {vk%&{D0)
:s1.TQ;Y(
)5fly%-r)
//获得文件长度 "n{JH9sA:
public long getFileSize() y5XFJj
{ U+aiH U9
int nFileLength = -1; Jl|^^?
try{ _Td#C1g3
URL url = new URL(siteInfoBean.getSSiteURL()); c*i,z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T8^l}Y B
httpConnection.setRequestProperty("User-Agent","NetFox"); js!C`]1
}?MbU6"
HY;kV6g{P
int responseCode=httpConnection.getResponseCode(); FGeKhA 8jT
if(responseCode>=400) ru|*xNXKgC
{ ;zd.KaS
processErrorCode(responseCode); zjSHa'9*
return -2; //-2 represent access is error UzW]kY[A<
} ]W5p\(1g
!_oR/)
*;Cpz[N
String sHeader; ?!.J0q
_C19eW'
uo;m
for(int i=1;;i++) x$FcF8
{ nWhf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QZ[S, c^
//Utility.log(in.readLine()); `fl$ o6S/
sHeader=httpConnection.getHeaderFieldKey(i); X~/-,oV=A
if(sHeader!=null) 9W-1P}e,
{ /%)(Uz
if(sHeader.equals("Content-Length")) G<]@nP{P
{ Sggl*V/q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;P$ _:-C
break; _xBhMu2f
} [+="I &
} C0/G1\
else ux,eY
break; JIqg[Mao
} <9T,J"y
} %a:T9v
catch(IOException e){e.printStackTrace ();} 87m`K Str7
catch(Exception e){e.printStackTrace ();} JY,oXA6O
qEVpkvEq
w,_LC)9
Utility.log(nFileLength); :_`Yrx5
sbFIKq]
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return nFileLength; "z=~7g
} *SlWA)9Y
B\l0kiNT
^(@]5$^Z
//保存下载信息（文件指针位置） MXjN./
private void write_nPos() i6y=3k
{ A PrrUo
try{ l.Z+.<@
output = new DataOutputStream(new FileOutputStream(tmpFile)); qT&zg@m
output.writeInt(nStartPos.length); C~'.3Q6
for(int i=0;i<nStartPos.length;i++) P"Z1K5>2L
{ 8dJ+Ei~M
// output.writeLong(nPos); c?aOX/C'
output.writeLong(fileSplitterFetch.nStartPos); f9+6gY
output.writeLong(fileSplitterFetch.nEndPos); f zL5C2d
} r=p^~tuyxr
output.close(); sP~xe(
} NRspi_&4J
catch(IOException e){e.printStackTrace ();} /zr)9LQY0
catch(Exception e){e.printStackTrace ();} +}:2DXy@
} I|;C}lfp
JNP6qM
@X9T"
//读取保存的下载信息（文件指针位置） DJqJ6z:'
private void read_nPos() gA3f@7}d
{ =}Q|#C
try{ NS;LFeGD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +8"P*z,
int nCount = input.readInt(); ]86*k%A
nStartPos = new long[nCount]; U!E}(9 tb
nEndPos = new long[nCount]; ][YuJUK8
for(int i=0;i<nStartPos.length;i++) 2OqEyXh
{ 7) af
nStartPos = input.readLong(); WGyPyG#Fl
nEndPos = input.readLong(); Lf%}\0:
} -8dz`o}
input.close(); pd.unEWwF
} ZCMH?>
catch(IOException e){e.printStackTrace ();} 6z:/ma^
catch(Exception e){e.printStackTrace ();} P8;1,?ou
} `)MKCw$e
O`aNNy
8U7dd[
private void processErrorCode(int nErrorCode) nwqA\
{ bf2r8
System.err.println("Error Code : " + nErrorCode); ug;~dhe~
} {>XoE %
1TF S2R n
Z`zLrXPD)
//停止文件下载 <:mK&quf
public void siteStop() |ZXz&Xor
{ '$J M2 u
bStop = true; N[v=;&
for(int i=0;i<nStartPos.length;i++) mgM"u94-]
fileSplitterFetch.splitterStop(); 1KR4Wq@
:_=YH+bZ
2iO{*cB
} :uC9 #H"b
} "CREls,
//负责部分文件的抓取 VWzuV&;P
**FileSplitterFetch.java Sq:J'%/z
*/ */K]sQZa
package NetFox; pF8+< T3y
Z)@[N 6\?
Y]uVA`%"b
import java.io.*; Z+[W@5q
import java.net.*; s<aG
W"CG&.
f&RjvVP?s
public class FileSplitterFetch extends Thread { ,e'"SVQc
W/~q%\M {
XD_!5+\H1
String sURL; //File URL acQHqR
long nStartPos; //File Snippet Start Position T7O)
long nEndPos; //File Snippet End Position A4b+:MQ*OX
int nThreadID; //Thread's ID Dk8@x8
boolean bDownOver = false; //Downing is over jpoNTl'
boolean bStop = false; //Stop identical 6K=}n] n
FileAccessI fileAccessI = null; //File Access interface #uCfXJ-
>g@@ yR,
\ Z5160
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,q{~lf-
{ 6E^9>
this.sURL = sURL; j#Lj<jX!xR
this.nStartPos = nStart; { 9\/aXPS
this.nEndPos = nEnd; =En1?3?
nThreadID = id; wrK@1F9!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JeA_mtSQ|
} 2 &_>2"=<@
raU_Z[
8LXK3D}?3
public void run() I9`ZK2S
{ 9jNh%raG|
while(nStartPos < nEndPos && !bStop) sb?!U"v.'
{ ^),t=!;p
pr,1pqiAf
2k&Voa
try{ :C,}DyZy
URL url = new URL(sURL); r)Ml-r=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /WK1(B:
httpConnection.setRequestProperty("User-Agent","NetFox"); )a`kL,
String sProperty = "bytes="+nStartPos+"-"; %[azMlp<
httpConnection.setRequestProperty("RANGE",sProperty); KDA2 H>
Utility.log(sProperty); *Ue#Sade
NGO?K?
bMv[.Z@v(
InputStream input = httpConnection.getInputStream(); Re'3bs:+
//logResponseHead(httpConnection); S1C#5=
Z$6B}cz<
:()K2<E
byte[] b = new byte[1024]; !:tr\L {
int nRead; U:[CcN/~3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %afF%y
{ 7-\wr^ll3
nStartPos += fileAccessI.write(b,0,nRead); IH5^M74b
//if(nThreadID == 1) LCq1F(q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =@X?$>'
} uX&h~qE/
h,b_8g{!
5Kk}sxol
Utility.log("Thread " + nThreadID + " is over!"); (|3?wX'2U
bDownOver = true; F5M|QX@-
//nPos = fileAccessI.write (b,0,nRead); Ub4)x
} r/HG{XH`
catch(Exception e){e.printStackTrace ();} %/hokyx
} lEb H4 g
} J{Ld)Q,^
N.SV*G @
C+mPl+}w
//打印回应的头信息 G(t&(t`[
public void logResponseHead(HttpURLConnection con) |It{L0=U
{ .G"T;w6d
for(int i=1;;i++) `R lWhdE
{ -B-HZ_
String header=con.getHeaderFieldKey(i); 0}T56aD=!
if(header!=null) uv{*f)j/d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s!Iinc^p
Utility.log(header+" : "+con.getHeaderField(header)); dwiLu&]u
else 9C5F#(uY
break; _p9 _Pg8
} sAZL,w
} 0TiDQ4}i[
C/ ]Bx
JxM32?Rm*w
public void splitterStop() RtDTcaW/
{ (dV7N
bStop = true; 0$U\H>r
} A v;NQt8ut
!9j6l0
y'JJ#7O=
} !!Yf>0u#
4e?cW&
i=fhK~Jd
/* G,(Xz"`,
**FileAccess.java ?3v-ppw%
*//文件访问(定位，写) "ZmxHMf
package NetFox; x$S~>H<a
import java.io.*; M[_Ptqjb
yC!>7@m
yV&]i-ey
public class FileAccessI implements Serializable{ 4(,X.GVY/
a^VI)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bPl'?3
RandomAccessFile oSavedFile; XqcNFSo)
long nPos; u=(.}
SF[Z]|0gs
90H/Txq
public FileAccessI() throws IOException '6T *b
{ $u)#-X;x
this("",0); 'sk M$jr
} T%YN(f
5?E;YyA
oL9ELtb]s
public FileAccessI(String sName,long nPos) throws IOException \PmM856=ms
{ c&`]O\D-c
oSavedFile = new RandomAccessFile(sName,"rw"); t Q>/1
this.nPos = nPos; gM6o~ E
oSavedFile.seek(nPos); mt-t8~A
} LM!@LQAMY
7~H$p X
,JJ1sf2A
public synchronized int write(byte[] b,int nStart,int nLen) 3BB/u%N}
{ ^j?"0|
int n = -1; F}5skD=
try{ 2W63/kRbU
oSavedFile.write(b,nStart,nLen); o;pJjC]
n = nLen; ORfMp'uP=
} ~jC$C2A0
catch(IOException e) }jNVR#D:
{ *uF Iw}C/
e.printStackTrace (); .B6mvb\
} ^3Z~RK\}
c>#3{}X|x%
_wZr`E)
return n; <mQ9YO#
} ' KNg;
s 8lfW6
$rQi$w/
} _+&/P&
>i2WYT
v=YI%{tx)
/* 7t6TB*H
**SiteInfoBean.java 3+I"Dm,
*/ I"WmDC`1
package NetFox; NF_[q(k'
vVbS 4_
0}$R4<"{Y>
public class SiteInfoBean { j|y"Lcq
FF30VlJ
<T$rvS
private String sSiteURL; //Site's URL f5#VU7=1F2
private String sFilePath; //Saved File's Path ER<Z!*2
private String sFileName; //Saved File's Name stOD5yi
private int nSplitter; //Count of Splited Downloading File F^7qr
q&: t$tSS
C)ebZ3
public SiteInfoBean() XC[bEp$
{//nSplitter的缺省值为5 D(">bR)1
//default value of nSplitter is 5 G2FD'Sf
this("","","",5); ;QQ/bM&I
} EA<x$O
bHmn0fZ9
OJ)XJL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cb_nlG!
{ qmbhx9V
sSiteURL= sURL; (.9H1aO46|
sFilePath = sPath; TiSV`V q
sFileName = sName; zR }vw{
this.nSplitter = nSpiltter; Yr 1k\q
bU_P@GKB
V(6Ql j7
} A55F*d
^e1mK4`
}j|YX&`p
public String getSSiteURL() Zex`n:Wl?j
{ u!I=|1s
return sSiteURL; jxDA+7
} wRQMuFGY
ZgL]ex
=~{W;VZt'
public void setSSiteURL(String value) b@)nB
{ -!:h]
sSiteURL = value; MF4B 2d
} :.W</o~\s
jg=}l1M"
}wV/)Oy[
public String getSFilePath() fBct%M 3
{ hE}y/A[
return sFilePath; "$N 4S9U
} P<IZ%eS3B
EL1*@
0tP{K
public void setSFilePath(String value) j9$kaEf
{ 420yaw/":
sFilePath = value; ^h"F\vIpV
} ^uWj#
{#}?-X
/7yd&6`I
public String getSFileName() 1Et{lrgh f
{ ]gB:ht
return sFileName; YC d
} ? ]hS^&
km9@*@)
NIxtT>[+3
public void setSFileName(String value) 8Z(\iZ5Rgj
{ Ky6 d{|H
sFileName = value; iGsD!2
} qre(3,VE5
Yjp*T:6
"!_,N@\t
public int getNSplitter() t{Gc,S!]5
{ 6gJc?+
return nSplitter; m[6c{$A/w
} </)QCl'd
PW GNUNc
Z6_E/S
public void setNSplitter(int nCount) cg'z:_l
{ +"Mlj$O
nSplitter = nCount; be:=-B7!
} 2+qU9[kd|
} lxXIu8
glgXSOj
cK~VNzsz
/* 5WU?Km
**Utility.java f&L8<ASFo
*/ IltU6=]"l
package NetFox; x$/:%"E
_cD-E.E%
\4roM1&[
public class Utility { LQ.0"6oj
/^9yncG;>
R:t
public Utility() ~U`|+ 5
{ 73>Hzpv0
D|E,9|=v
&xMQ
} %][6TZ}
"|W``&pM
//线程睡眠 [gxH,=Pb
public static void sleep(int nSecond) EK<ly"S.
{ `beU2N
try{ |FxTP&8~
Thread.sleep(nSecond); oiNt'HQ2/
} [-'LJG Wb<
catch(Exception e) f,QBj{M,
{ YKG}4{T
e.printStackTrace (); 40R7@Vaf
} V[baGNe
} V{yk
GMQKR,6VM
//日志 I18<brZJ
public static void log(String sMsg) UZb!tO2
{ d+158qQOh]
System.err.println(sMsg); l F*x\AT
} El4SL'E@
_&|<(m&."
U((mOm6
public static void log(int sMsg) 8$C?j\J|*
{ fs6% M]u
System.err.println(sMsg); ;P!x/Ct
} NG?-dkD
} ooIA#u
W:* {7qJ
l"app]uVZ
/* !J-oGs\ u
**TestMethod.java qjI.Sr70
*/ ]q CCCI`
package NetFox; uhO-0H
]iE)8X
l~c# X3E
public class TestMethod { ^b@&O-&s
rw]7Lr_>
{&d )O
public TestMethod() ~fR-cXj"
{ ///xx/weblogic60b2_win.exe a?P$8NLr
try{ .U9A\$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p{S#>JTr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n06Jg+
SiteFileFetch fileFetch = new SiteFileFetch(bean); [|{m/`8C
fileFetch.start(); o=ULo &9
} [[gfR'79{
catch(Exception e){e.printStackTrace ();} #8;#)q_[u
MMS#Ci=Lj
.BjnV%l7Id
} T }^2IJ]
bc(b1u?
I4%25=0?
public static void main(String[] args) z)0%gd|
{ z;+LU6V
new TestMethod(); [y(AdZ0*
} jhkNi`E7
} )3A%Un#B
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