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)); !oH{=.w
} }83 8F&
for(int i=0;i<nEndPos.length-1;i++) .$\-{)
{ ip?]&5s
nEndPos = nStartPos[i+1]; qJG;`Ugl:
} Zh8\B)0unn
nEndPos[nEndPos.length-1] = nFileLength; H9WYt#
} lWRl
} U$2Em0HO}
;1&"]N%
! $JX3mP
//启动子线程 L&6^(Bn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ULK]' Rn
for(int i=0;i<nStartPos.length;i++) i*$+>3Q-
{ &4OOW;,?<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L} R"1O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >/-H!jUF]
nStartPos,nEndPos,i); $}vk+.!*1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4q.;\n
fileSplitterFetch.start(); 3I 0pHP5
} )f3A\^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >vD}gGBe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2S7BzZ/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x<I[?GT=
nEndPos = " + nFileLength); 3$"V,_TBZ
// fileSplitterFetch[nPos.length-1].start(); G$,s.MSf
ZV{C9S&
C]b:#S${
//等待子线程结束 k (AE%eA
//int count = 0; N[eLQe]q
//是否结束while循环 w6Gez~8
boolean breakWhile = false; /T6bc^nOW
KTYjC\\G
X>$Wf3
while(!bStop) y],opG6
{ "6C a{n1hk
write_nPos(); {N]WVp*R
Utility.sleep(500); :?~)P!/xl5
breakWhile = true; &en2t=a
|kZ!-?9Z
gq?O}gVD
for(int i=0;i<nStartPos.length;i++) )VQ[}iT
{ g7323m1=
if(!fileSplitterFetch.bDownOver) 0j8fU7~6S
{ GyL9}
breakWhile = false; qG,h 1
break; zuNm!$
} E^J &?-
} 4Pr^>m
if(breakWhile) #_^p~:
break; }Bv1fbD4U
xD*Zcw(vj~
6n/=n%US
//count++; %3dc_YPS
//if(count>4) $-/-%=
// siteStop(); 2<*"@Vj
} od#Lad@p
Q>Ct]JW&
9]N{8
System.err.println("文件下载结束！"); qJF'KHyU{l
} wdj?T`4
catch(Exception e){e.printStackTrace ();} X.{xHD&_
} 2XL^A[?
^0"^
W'"hjQ_
//获得文件长度 uPl7u1c
public long getFileSize() ^6# yL6E,~
{ R@grY:h
int nFileLength = -1; r1F5'?NZ(0
try{ G\tN(%.f
URL url = new URL(siteInfoBean.getSSiteURL()); mNC?kp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @5&57R3>
httpConnection.setRequestProperty("User-Agent","NetFox"); gK~Z Ch
n3?P8m$
2Bi]t%<{
int responseCode=httpConnection.getResponseCode(); Pg.JI:>2Ku
if(responseCode>=400) lZ5-lf4
{ V}TPt6C2
processErrorCode(responseCode); Ur 1k3
return -2; //-2 represent access is error j)G%I y[`
} m\*ca3$
ax5n}
H,<CR9@(5d
String sHeader; w}6~t\9D
\>4>sCC
'`k
for(int i=1;;i++) M &-p
{ K?M~x&Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !^Ay!
//Utility.log(in.readLine()); oeKl\cgFx
sHeader=httpConnection.getHeaderFieldKey(i); u gRyUny
if(sHeader!=null) Q~"Lyy8
{ /Q W^v;^
if(sHeader.equals("Content-Length")) DNj<:Pdd)
{ $'}|/D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q65M(x+oy
break; xBc$qjV
} 2.JrLBhN
} O<wH+k[
else xK0;saG#
break; ~tTa[_a!
} o1 27? ^
} 8yYag[m8
catch(IOException e){e.printStackTrace ();} mx1Bk9h%Xe
catch(Exception e){e.printStackTrace ();} &:C[ nq
L$a{%]I
u`B/9-K)y
Utility.log(nFileLength); E_30)"]
A##Q>|>)
j/O9LygB
return nFileLength; ^{J^oZ'%~
} <NDV 5P
us5Zi#}
K HNU=k
//保存下载信息（文件指针位置） sMAH;'`!Eu
private void write_nPos() StR)O))I
{ T__@hfT
try{ {|%^'lS
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y:CqQ
output.writeInt(nStartPos.length); o;9H~E
for(int i=0;i<nStartPos.length;i++) dC4`xUv
{ UCmJQJc
// output.writeLong(nPos); B4*,]lS?
output.writeLong(fileSplitterFetch.nStartPos); Ts, U T L
output.writeLong(fileSplitterFetch.nEndPos); )y!gApNs"
} 3bLOT#t
output.close(); s(5(zcBK
} ?N+pWdi
catch(IOException e){e.printStackTrace ();} b+RU <qR
catch(Exception e){e.printStackTrace ();} eJ[+3Wh
} X`Lv}6}xT
?st}rJ_
%/U'Wu{*
//读取保存的下载信息（文件指针位置） |]:6IuslJ
private void read_nPos() Pvv7|AV
{ mGwJ>'+d
try{ ^eoW+OxH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R/B/|x
int nCount = input.readInt(); }#g &l*P
nStartPos = new long[nCount]; V/\`:
nEndPos = new long[nCount]; l YdATM(h
for(int i=0;i<nStartPos.length;i++) \2f?)id~
{ dhg($m
nStartPos = input.readLong(); zb~;<:<
nEndPos = input.readLong(); Tz:,l$
} .1h\r, #
input.close(); ELG{xN=o
} MjBI1|*
catch(IOException e){e.printStackTrace ();} Vl(id_~_
catch(Exception e){e.printStackTrace ();} 6P9#6mZ
} [$>@f{:
),o=~,v:
\/wk!mWV@
private void processErrorCode(int nErrorCode) S=L#8CID
{ BB/c5?V
System.err.println("Error Code : " + nErrorCode); o{2B^@+Vb
} x `%x f
/ml+b8@
K)Ya%%6[U#
//停止文件下载 55y}t%5
public void siteStop() RU.MJ kYQ5
{ 2 =>3B
bStop = true; 0ikA@SAq
for(int i=0;i<nStartPos.length;i++) : @gW3'
fileSplitterFetch.splitterStop(); e=tM=i"
Z0~,cO8~
ev7A;;
} H11@ DQ6
} fA V.Mj-
//负责部分文件的抓取 VK%ExMSqEh
**FileSplitterFetch.java Zic:d-Q47
*/ {poTA+i
package NetFox; j9%vw.3b
H?=[9?1wI5
mCI5^%*0jQ
import java.io.*; 'w;J)_Yc2
import java.net.*; {j[*:l0Ui
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z`J-J*R>d
public class FileSplitterFetch extends Thread { g]b%<DJ
21?>rezJ
rd(-2,$4
String sURL; //File URL $0M7P5]N*G
long nStartPos; //File Snippet Start Position |f}`uF
long nEndPos; //File Snippet End Position H!y-o'Z
int nThreadID; //Thread's ID }6__E;h#J
boolean bDownOver = false; //Downing is over 6il+hz2&lH
boolean bStop = false; //Stop identical !cO<N~0*5x
FileAccessI fileAccessI = null; //File Access interface )Ps<u-V
grd fR`3
.D=#HEshk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b3=XWzK5
{ Pl|*+g
this.sURL = sURL; e7Sg-NWV
this.nStartPos = nStart; naY#`xig
this.nEndPos = nEnd; nrTCq~LO(
nThreadID = id; WK SWOSJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mL@7,GD
} 4%>tk 8 [
!?B2OE
@nj`T{*.
public void run() r_V^sX
{ Ys5Iqj=mp
while(nStartPos < nEndPos && !bStop) 1x0)mt3
{ {mHxlG)
57N<OQWf
gi/W3q3c6
try{ -,"eN}P^
URL url = new URL(sURL); 8?o{{ay
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8L))@SA+uJ
httpConnection.setRequestProperty("User-Agent","NetFox"); w (,x{Bg\
String sProperty = "bytes="+nStartPos+"-"; NCx)zJ\S
httpConnection.setRequestProperty("RANGE",sProperty); ^X*l&R_=R
Utility.log(sProperty); p!(]`N
K!G/iz9SB
Kku@!lv
InputStream input = httpConnection.getInputStream(); xAf?E%_pi
//logResponseHead(httpConnection); %(1y
Z3 na.>Z
erV&N,cI
byte[] b = new byte[1024]; $O9#4A;
int nRead; M[Jy?b)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i:^ 8zW
{ *pGbcBQ
nStartPos += fileAccessI.write(b,0,nRead); Js,.$t
//if(nThreadID == 1) `b5pa`\4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {'zs4)vw
} pmDFmES
oPA m*
s.!gsCQme
Utility.log("Thread " + nThreadID + " is over!"); VC NQ}h[D
bDownOver = true; 3_Re>i
//nPos = fileAccessI.write (b,0,nRead); 'p,54<e
} `9VRT`e
catch(Exception e){e.printStackTrace ();} wIQt f|ZI>
} M0MvOO*ad
} DB+.<
yu'@gg(
5lm>~J!/^
//打印回应的头信息 qP[jtRIN
public void logResponseHead(HttpURLConnection con) L8KMMYh[
{ ){i 9,u")
for(int i=1;;i++) u+]8Sq
{ s !HOrhV
String header=con.getHeaderFieldKey(i); L q;=UE
if(header!=null) kAk+Sq^n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cfW;gFf
Utility.log(header+" : "+con.getHeaderField(header)); k`,>52
else flU?6\_UC
break; wb-_CQ
} Cy\! H&0wg
} &o)eRcwH`
WS ^%< h#
ohB@ijC!
public void splitterStop() ncij)7c)u
{ p w`YMk
bStop = true; 3gba~}c)
} +C[%^G-:
O>2i)M-h9x
<SNu`,/I
} ,S=ur%
Md1ePp]
a"X9cU[
/* BP0*`TY
**FileAccess.java /:aY)0F0<&
*//文件访问(定位，写) YZ^;xV
package NetFox; HY7#z2L
import java.io.*; b(:U]>J
WQYw@M~4Q!
agPTY{;
public class FileAccessI implements Serializable{ !&vPG>V
(%iCP/E3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Wr\A ->+
RandomAccessFile oSavedFile; i(n BXV{
long nPos; &\M<>>IB
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Gmh6|Dsg
public FileAccessI() throws IOException 2lRE+_qz
{ IX 2 dic'
this("",0); =$Sd2UD
} Q)\4 .d
p6W|4_a?
`-82u :"
public FileAccessI(String sName,long nPos) throws IOException J0x)NnWJ
{ Meo. V|1
oSavedFile = new RandomAccessFile(sName,"rw"); /~;om\7r
this.nPos = nPos; pK@8=+
oSavedFile.seek(nPos); i}r|Zo
} ORo,.#<
(<xl _L:*.
xr1,D5
public synchronized int write(byte[] b,int nStart,int nLen) TKZ[H$Z
{ 5}"9)LT@@w
int n = -1; NuC+iC$_/
try{ 4,qhWe`/
oSavedFile.write(b,nStart,nLen); me&'BQ
n = nLen; {Z(kzJwN
} :c`Gh< u
catch(IOException e) vAjvW&'g
{ (E]q>'X
e.printStackTrace (); ~~X-$rtU
} i5jsM\1j
2N[/Cc2Tg/
0hM!#BU5K
return n; R>n=_C
} ($r-&]y
$irF
m>ApN@n
} gX!-s*{E
\d}>@@U&
`0Bk@B[>
/* Vo8gLX]a
**SiteInfoBean.java NNP ut$.
*/ /K\]zPq
package NetFox; EK$3T5e
.*Ylj2nM
)@[##F2
public class SiteInfoBean { ?_nbaFQK3
:SvgXMY@
z6;6 o!ej
private String sSiteURL; //Site's URL ^n&_JQIXb
private String sFilePath; //Saved File's Path B'8/`0^n5
private String sFileName; //Saved File's Name 5l4YYwd>v
private int nSplitter; //Count of Splited Downloading File jPa"|9A
mL]a_S{H
&Na,D7A:3I
public SiteInfoBean() r: M>/Z/
{//nSplitter的缺省值为5 2nkymEPu
//default value of nSplitter is 5 $u P'>
this("","","",5); db`L0JB
} XsbYWJdds
`A ^
:.aMhyh#*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \2!1fN
{ ;Bwg'ThT
sSiteURL= sURL; 6tF_u D
sFilePath = sPath; (rm*KD"]
sFileName = sName; M2lvD&
this.nSplitter = nSpiltter; FE,BvNBZ
kmT5g gy
]-"G:r
} f O,5 u;
2rPmu
P+bA>lJd
public String getSSiteURL() !!?TkVyEyM
{ ~EtwX YkRZ
return sSiteURL; a|eHo%Qt
} VMIX=gTZ
7-#
#Ic)]0L
public void setSSiteURL(String value) +o-jMvK9
{ o&ETs)n|
sSiteURL = value; +^|_vq^XR
} Lv UQ&NmY
T7~H|%
@L?KcGD
public String getSFilePath() 7BkY0_KK
{ RG_.0'5=hc
return sFilePath; I>JBGR`j
} F<TIZ^gFP
#ADm^UT^
ohna1a^
public void setSFilePath(String value) qsWy <yL+
{ 75^AO>gt
sFilePath = value; 5Deo}(3
} ez<V
0TWd.+
g5:?O,?
public String getSFileName() U*4r<y9R
{ sm"s2Ci=}
return sFileName; ,0a\Ka{^
} ( 4(,"
7!Qu+R
Z0%:j\W4c
public void setSFileName(String value) 4i7+'F
{ 49.B!DqQW&
sFileName = value; 5Mz:$5Tm
} 1]69S(
Kf1NMin7
+\]Gu(z<
public int getNSplitter() )M><09
{ /mXxj93UA
return nSplitter; Qk72ra)
} >#VNA^+t
2Gh&h(
lg +>.^7k
public void setNSplitter(int nCount) R*/s#*gmL
{ < 1[K1'7h
nSplitter = nCount; sGa}Cf;H@g
} Ad&VOh+0
} $[UUf}7L
CEW1T_1U<\
LXqPNVp#
/* EF6h>"']/
**Utility.java Cxeam"-HTt
*/ H*e+ 2
package NetFox; ALj~e#{;z
BP}@E$
F3hG8YX
public class Utility { E!_3?:[S_
#a9O3C/MP
5;+KMM:zb
public Utility() ,x$^^
{ M|NQoQ8q
.$@+ /@4
dIfy!B"
} )k;;O7Ck
m*jTvn
//线程睡眠 Ol~M BQs
public static void sleep(int nSecond) c?N,Cd~q
{ #_{Q&QUk
try{ }R11G9N.
Thread.sleep(nSecond); Z&O6<=bg!
} tzthc*-<
catch(Exception e) K)U[xS;<
{ inip/&P?V
e.printStackTrace (); `/^ _W <
} M*f]d`B
} P?S]Q19Q4
s VHk;:e>x
//日志 sn"z'=ch
public static void log(String sMsg) xv&h>GOg
{ oC-v>&bW
System.err.println(sMsg); |c^?tR<
} 1jej7p>K
`nKN|6o#x
^=5x1<a9$
public static void log(int sMsg) +IO>%
{ Ek1c>s,t
System.err.println(sMsg); AgZ?Ry
} GC:q6}
} @$~IPg[J
em'ADRxG+
-]+pwZ4g
/* "F%JZO51
**TestMethod.java [q Uv|l1
*/ SnR2o3r-Of
package NetFox; U(#JC(E-#
iGkysU<wcp
le]~Cy0
public class TestMethod { x x4GP2
uKXNzz
nwh@F1|
public TestMethod() ^sB0$|DU
{ ///xx/weblogic60b2_win.exe 3H`{ A/r
try{ /-,\$@J5)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mf)+ 5On
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pQKSPr
SiteFileFetch fileFetch = new SiteFileFetch(bean); QW$p{ zo
fileFetch.start(); l<BV{Gl
} !1fZ7a
catch(Exception e){e.printStackTrace ();} ),-gy~
)Qd x
ddyX+.LMk
} HC/z3b;
!3Pbu=(cte
!Av9?Q:
public static void main(String[] args) r4fHD~#l{
{ c(e>Rmh
new TestMethod(); p |1u,N
} a5GLbanF
} # )y/aA
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