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)); 8z&7wO
} b e[KNrO
for(int i=0;i<nEndPos.length-1;i++) ~_C[~-
{ 90OSe{
nEndPos = nStartPos[i+1]; t,#9i#q#
} 2O\p`,.
nEndPos[nEndPos.length-1] = nFileLength; # Vz9j
} $_s"16s
} l \~w(8g<A
k(|D0%#b7
C.I.f9s?R
//启动子线程 JjarMJr|D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #$p&J1
for(int i=0;i<nStartPos.length;i++) p9w<|ZQ]:
{ y/t{*a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PLDg'4DMg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nO^aZmSu
nStartPos,nEndPos,i); >?iL_YTX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "N'tmzifh
fileSplitterFetch.start(); f\CJ |tKX
} a4HUP*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H^ _[IkuA%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4QbDDvRQ^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L&3Ak}sh
nEndPos = " + nFileLength); &Rw4ub3
// fileSplitterFetch[nPos.length-1].start(); p/jC}[$v
!yAlb#yu
H8d%_jCr
//等待子线程结束 *FoH'\=
//int count = 0; 5o;M
//是否结束while循环 "~~Js~
boolean breakWhile = false; A:$Qt%c
5Ug.J{d
5~&9/ALk5
while(!bStop) X yi[z tN
{ JvFd2@
write_nPos(); g?,\bmHE
Utility.sleep(500); 7b7~D +b
breakWhile = true; J})G l
f7B)iI!
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for(int i=0;i<nStartPos.length;i++) v'`VyXetl
{ hM~9p{O
if(!fileSplitterFetch.bDownOver) 2pR+2p`
{ :o$k(X7a
breakWhile = false; eSvS<\p
break; 7x8/Vz@\
} oujg( ^E
} Cf@~W)K
if(breakWhile) Le#>uWM
break; ,CiN@T \&
m$^Wyk}
?wzE+p-
//count++; )}QtK+Rq
//if(count>4) x6Q,$B
// siteStop(); +"1@6,M
} YlfzHeN1
Jq0aDf f
H4C]%Q
System.err.println("文件下载结束！"); ziUEA>m*/
} S<Z]gY @c
catch(Exception e){e.printStackTrace ();} y;zp*(}f$h
} 9[yW&t;#
~DYUI#x
N!R>L{H>
//获得文件长度 f' |JLhs
public long getFileSize() TEQs\d
{ lYz{#UX}
int nFileLength = -1; VF8pH<
try{ {%g]Ym=
URL url = new URL(siteInfoBean.getSSiteURL()); tkT:5O6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zN2CI6
httpConnection.setRequestProperty("User-Agent","NetFox"); ~qFuS933
gaFOm9y.e
+T]/4"^M
int responseCode=httpConnection.getResponseCode(); M7U:UV)
if(responseCode>=400) [n%=2*1p
{ J~.8.]gXW
processErrorCode(responseCode); Q<4Sd:P`"
return -2; //-2 represent access is error ^0oOiZs
} %K0 H?^.
;2Aqztp
$oF0[}S
String sHeader; {8b6M
(jj=CLe
sfb)iH|sW
for(int i=1;;i++) WI@l2`X
{ }N@8zB~X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R@ksYC3 F
//Utility.log(in.readLine()); l/WQqT
sHeader=httpConnection.getHeaderFieldKey(i); u7Z-kZ
if(sHeader!=null) ^FO&GM2a
{ Er@'X0n
if(sHeader.equals("Content-Length")) TsiI5'tx
{ BO5\rRa0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); | ]#PF*
break; IIj :\?r
} 2G=prS`s
} ySkz5K+|g
else v#/k`x\
break; l1_hD,4
} 6uNWL `v
} ]7+9>V
catch(IOException e){e.printStackTrace ();} L!/Zw~
catch(Exception e){e.printStackTrace ();} c, IAz
@\ udaZc
X*'i1)_h
Utility.log(nFileLength); 10?+6*d
-jXO9Q
Epo/}y
return nFileLength; ks3ydHe`
} B!J~ t8
3^!Y9$y1
zDakl*
//保存下载信息（文件指针位置） 6*W7I-A
private void write_nPos() $,I%g<
{ 4%refqWK
try{ @Z}TF/Rx4
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'ozu4y
output.writeInt(nStartPos.length); ^T>P
for(int i=0;i<nStartPos.length;i++) %s&"gWi
{ 0j\} @
// output.writeLong(nPos); nF"NXYa
output.writeLong(fileSplitterFetch.nStartPos); qcVmt1"
output.writeLong(fileSplitterFetch.nEndPos); ;RR\ Hwix
} t%S2D
output.close(); 7XM:4whw
} 3UR'*5|'
catch(IOException e){e.printStackTrace ();} Bp:PAy
catch(Exception e){e.printStackTrace ();} lE=&hba
} NuEcTww
f;{K+\T
4:zyZu3fm
//读取保存的下载信息（文件指针位置） {TOz}=R"3h
private void read_nPos() @~ 6,8nQ
{ ro}WBv
try{ /#Fz K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K=K]R01/o
int nCount = input.readInt(); (&o|}"kRq
nStartPos = new long[nCount]; w ]%EJ|'
nEndPos = new long[nCount]; h/s8".\
for(int i=0;i<nStartPos.length;i++) td!YwN*
{ b)(si/]\
nStartPos = input.readLong(); u.yjk/jF
nEndPos = input.readLong(); xwhS[d
} dy"7Wl]hi7
input.close(); 9EFQo^ E
} O\X=vh/D
catch(IOException e){e.printStackTrace ();} Pl/B#Sbf'
catch(Exception e){e.printStackTrace ();} ]H-5
} P*!~Z*"
9O4\DRe5c
zkm#w
private void processErrorCode(int nErrorCode) -`cNRd0n
{ Z,_EhEm
System.err.println("Error Code : " + nErrorCode); rnSrkn"j{
} 7W.z8>p
4R}$P1 E
k*u4N
//停止文件下载 M+l~^E0Wj
public void siteStop() 1lLXu
{ -IE=?23Do?
bStop = true; werTwe2Q
for(int i=0;i<nStartPos.length;i++) E0t%]?1
fileSplitterFetch.splitterStop(); 8+mu'RZ X
W.sH
|_\q5?S
} oAt{#v
} {>h,@
//负责部分文件的抓取 ],|;
**FileSplitterFetch.java f\u5=!kjN
*/ 19]O;
package NetFox; `st^i$A
D6fGr$(N%
l\6.f_
import java.io.*; dTVh{~/
import java.net.*; (.~,I+Cz'
tSX,*cz
CyKupJ.Fq
public class FileSplitterFetch extends Thread { z{(c-7*
M?v`C>j
fO{'$?K
String sURL; //File URL s*tzU.E(
long nStartPos; //File Snippet Start Position OrRU$5Lo
long nEndPos; //File Snippet End Position -Gj."ks
int nThreadID; //Thread's ID $h|8z
boolean bDownOver = false; //Downing is over v$~ZT_"(9
boolean bStop = false; //Stop identical )U+Pt98"
FileAccessI fileAccessI = null; //File Access interface *@E&O^%cO
2>F`H7W
#9/S2m2\YG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #XeEpdE
{ F*_ytL
this.sURL = sURL; 7hAc6M$h;
this.nStartPos = nStart; A 6j>KTU
this.nEndPos = nEnd; oV;I8;#\J
nThreadID = id; rrrn8b6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yv(\5)XF
} '/GZ/$a_l
0czEA
ia*Bcx_RW+
public void run() h,x'-]q
{ =SK{|fBB
while(nStartPos < nEndPos && !bStop) *kq>Z 06'i
{ ' p!\[*e
W@WKdaJ
Ey]P >J
try{ "%dok@v
URL url = new URL(sURL); pIgjo>K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +8 }p-<a
httpConnection.setRequestProperty("User-Agent","NetFox"); aMO+y91Y(
String sProperty = "bytes="+nStartPos+"-"; - -ZSl
httpConnection.setRequestProperty("RANGE",sProperty); %&&;06GU}
Utility.log(sProperty); MuP&m{
ZJ'FZ8Sx
_8s1Wh G
InputStream input = httpConnection.getInputStream(); 8?[#\KgH1
//logResponseHead(httpConnection); 6B&ERdoX
G0Wv=tX|
%R-KkK<S
byte[] b = new byte[1024]; FQO>%=&4
int nRead; HyJ&;4rf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q/3 )yG6s
{ - %`iLu
nStartPos += fileAccessI.write(b,0,nRead); *:,y`!F=y
//if(nThreadID == 1) 8+8P{_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D`@*udn=
} lk%W2N5
"a]Ff&T-
1J[|Ow
Utility.log("Thread " + nThreadID + " is over!"); TUO*w
bDownOver = true; ]oE:p
//nPos = fileAccessI.write (b,0,nRead); *v0}S5^/"
} 89l{h8R
catch(Exception e){e.printStackTrace ();} T]y^PT<8?
} C^9bur/
} `t Zw(Z=h
}Oe9Zq
!~a1xI~s
//打印回应的头信息 {f[X)
public void logResponseHead(HttpURLConnection con) O;SD90
{ V"W)u#4,
for(int i=1;;i++) *S\/l-D
{ :'K%&e?7s
String header=con.getHeaderFieldKey(i); t_{rKb,
if(header!=null) B$&&'i%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z)dE#A_X
Utility.log(header+" : "+con.getHeaderField(header)); hgI;^ia
else 0|OmQ\SQ
break; _?~)B\@~0
} @>Ul0&Mf?
} tjt#2i8/
{aYCrk1
/+{1;}AT
public void splitterStop() O>Ao#_*hOb
{ U=>4=gsG
bStop = true; 4kdQ h]
} SAtK 'Jx[
@Yzc?+x
:yE7jXB
} }@NT#hD
5d5q0bb
;(~H(]D
/* P'p5-l UK
**FileAccess.java #hP&;HZ2>"
*//文件访问(定位，写) _%6Vcy
package NetFox; d ~3GEK
import java.io.*; N Uq'96{Y
_do(
Y|y X]\,
public class FileAccessI implements Serializable{ <O30X !QuK
n;0x\Q|S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qFg"!w
RandomAccessFile oSavedFile; (d$ksf_[%f
long nPos; Kk<MS$Ov
4xnM7t\
4Q5c'
public FileAccessI() throws IOException rhvTV(Bz
{ u<a =TPAU
this("",0); sN9 SuQ
} .qG*$W2f
)1 =|\
#vBS7ba
public FileAccessI(String sName,long nPos) throws IOException UJ1Ecob
{ _.G p}0a
oSavedFile = new RandomAccessFile(sName,"rw"); 1)N{!w`
this.nPos = nPos; k{d)'\FM
oSavedFile.seek(nPos); BuIly&qbm<
} +Rb0:r>kU
aIW W[xZ
v#o<. Ig
public synchronized int write(byte[] b,int nStart,int nLen) $H2HVJ
{ _ ZC[h~9H
int n = -1; a~"<lzu|$
try{ _M9-n
oSavedFile.write(b,nStart,nLen); 7l|D!`BS
n = nLen; v|K<3@J
} 2[Q/|D}}|
catch(IOException e) /ng+IC3
{ Q^z&;%q1
e.printStackTrace (); "8YXFg
} ]eD5It\
L#X!.
V=DT.u
return n; )3RbD#?
} >Vvjs
L fx$M
|"XxM(Dm
} E2a00i/9Y
1X$hwkof
KD)+&69
/* N0 F|r8xS
**SiteInfoBean.java !JE=QG"
*/ qD?-&>dBWi
package NetFox; =Zc Vywz;+
QwL'5ws{q
sU}.2k
public class SiteInfoBean { qH-':|h7
H<bK9k)E
q*B(ZG
private String sSiteURL; //Site's URL h.D*Y3=<
private String sFilePath; //Saved File's Path .ECT
private String sFileName; //Saved File's Name ?Pw(
private int nSplitter; //Count of Splited Downloading File -yH8bm'0"
M4m90C;dq
1=.+!Tg
public SiteInfoBean() b3RCsIz
{//nSplitter的缺省值为5 Z UCz-53
//default value of nSplitter is 5 +~L26T\8
this("","","",5); >!7\Rx
} JSOgq/\
/>E:}1}{
Wu9))Ir
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3Az7urIY
{ !1s^TB>N
sSiteURL= sURL; _Bhm\|t
sFilePath = sPath; qe\JO'g#e
sFileName = sName; {f kP|d
this.nSplitter = nSpiltter; @p}"B9h*^
;[>g(W+
hRWRXC9
} DRUvQf
Ar:ezA
2UGnRZ8:1Y
public String getSSiteURL() j/<z[qr
{ PWw2;3`-6w
return sSiteURL; E0Neo _7
} !Hp H
!^EdB}@yS
]@D#<[5\
public void setSSiteURL(String value) %Z#s9QC
{ |#6))Dh
sSiteURL = value; $<N!2[I L
} _jr'A-M
^Td_B03)
#=* y7w
public String getSFilePath() JM?X]l
{ K V-}:u(
return sFilePath; _:Jra
} ?\D=DIN-r
8A3pYW-
R^*h|7)E
public void setSFilePath(String value) Z1t?+v+Ro*
{ dY'mY~Tv
sFilePath = value; t@(`24
} `0qBuE_^h
Pb(XR+
UD@u hL
public String getSFileName() c+^#(OB
{ _CDl9pP36#
return sFileName; @Pt,N qj:
} =oPc\VYW
IV5B5Q'D
jbU=D:|
public void setSFileName(String value) >P/Nb]C
{ 1 ynjDin<
sFileName = value; T1&^IO-F7$
} 3Wl,T5}{
]$VYzE2e
j.FW*iX1C
public int getNSplitter() ?tJyQT
{ 2W_p)8t>b
return nSplitter; DG!H8^
} S|pMX87R
\~:Uj~
AUk,sCxd
public void setNSplitter(int nCount) 3i c6!T#t"
{ EGKj1_ml
nSplitter = nCount; )t-Jc+*A>
} wf= s-C
} ^^-uq)A
W_ =
WjrUns
/* CfWtCA
**Utility.java %bp8VR sY
*/ 7K|: 7e(
package NetFox; F{g^4
tL;!!vg#V
LXm5f;
public class Utility { d\R]>
fW,,@2P
b&l/)DU
public Utility() &%ZiI@O-
{ TC=djC4$/
o?Wp[{K
h5:>o
} m\}8N u
EP|OKXRltA
//线程睡眠 %L\buwjy$
public static void sleep(int nSecond) jBTXs5q
{ J9kmIMq-C
try{ FHu -';
Thread.sleep(nSecond); c~1X/,biA
} nS53mLU)
catch(Exception e) *,UD&N_)*6
{ Dj~]]
e.printStackTrace (); Y~</vz+H
} y$]gmg
} 4a&*?=GG
TaZw_)4c
//日志 XYOPX>$T
public static void log(String sMsg) @Y~R*^n"}
{ yJheni
System.err.println(sMsg); fn1G^a=
} `o.DuvQ E
\1AtBc&
epWO}@ b a
public static void log(int sMsg) x*EzX4$x
{ sUfYEVjr
System.err.println(sMsg); >|"mhNF
} 7.r}98V
} cPemrNxydN
;}tEU'&
v[aFSXGj)
/* :DxCjv
**TestMethod.java hr+,-j
*/ x}`]9XQ
package NetFox; qm.30 2
+EmT+$>J
0u?{"xH{+}
public class TestMethod { yC]xYn)
GAZw4dz
C^o9::ER
public TestMethod() ;Jn"^zT
{ ///xx/weblogic60b2_win.exe 7# /c7
try{ jL|y4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?HP54G<{xz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5&y;r
SiteFileFetch fileFetch = new SiteFileFetch(bean); \,w*K'B_Y
fileFetch.start(); zH1pW(
} 5kK:1hH7
catch(Exception e){e.printStackTrace ();} gbf-3KSp^
Myl!tXawe8
]kN<N0;\d
} ?y] q\>
62R94
{M7`z,,[
public static void main(String[] args) JH%^FF2
{ [|=#~(yYQ
new TestMethod(); -`iXAyr)m
} Y7vTseq
} Nn"[GB
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