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)); hm"i\JZ3N
} Z<6XB{Nh\
for(int i=0;i<nEndPos.length-1;i++) [m3[plwe
{ 1'wwwxe7
nEndPos = nStartPos[i+1]; rcUXYJCh-
} 5(0f"zY
nEndPos[nEndPos.length-1] = nFileLength; (he cvJ
} zyyt`
} $Cw> z^}u
!e?g"5r{Bv
dGf:0xE"
//启动子线程 x#ub % t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iq_y80g`8h
for(int i=0;i<nStartPos.length;i++) EY=`/~|c
{ @giJ&3S,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .:?X<=!S&t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V3j1M?>
nStartPos,nEndPos,i); ns|)VX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )&R^J;W$M1
fileSplitterFetch.start(); ;Z%PBMa
} \~|+*^e)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qP6YnJWl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q 65mR!)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "L'0"
nEndPos = " + nFileLength); ,f ..46G
// fileSplitterFetch[nPos.length-1].start(); /,v>w,
0Q^ -d+!
YY~BNQn6d
//等待子线程结束 V7}5Zw1
//int count = 0; 34ij5bko_)
//是否结束while循环 Ve,h]/G
boolean breakWhile = false; +L(0R&C
i;4|UeUl
/[Oo*}Dc=F
while(!bStop) "iFA&$\
{ jiS|ara"
write_nPos(); Vsh7>|@
Utility.sleep(500); s ~'><ioh
breakWhile = true; H'N$Vv2q
6[g~p< 8n}
XRi/O)98o
for(int i=0;i<nStartPos.length;i++) X2>qx^jT
{ ?;1^8 c0
if(!fileSplitterFetch.bDownOver) ;Ml??B]C
{ l AF/O5b
breakWhile = false; !Z+4FwF
break; {k.Dy92
} >iefEv\
} 1T(:bM_t`7
if(breakWhile) 3QlV,)}
break; xlQl1lOX
bo^d!/;
}1<_
//count++; 2,.%]U
//if(count>4) '\yp}r'u
// siteStop(); gY'w=(/`
} VO"f=gFg
WR'm<u
r?Y+TtF\e
System.err.println("文件下载结束！"); uYW9kw>$
} tEEeek(!
catch(Exception e){e.printStackTrace ();} 99Jk<x k
} 4j9
uMW5F-~-+
M XB fX
//获得文件长度 q^nSYp#
public long getFileSize() 3fC|}<Wzt
{ xi5/Wc6
int nFileLength = -1; WU oGIT'
try{ /9/svPc]
URL url = new URL(siteInfoBean.getSSiteURL()); ;DWtCtD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yv0;UKd
httpConnection.setRequestProperty("User-Agent","NetFox"); qkX}pQkG)h
DtBIDU]
}q0lbwYlb
int responseCode=httpConnection.getResponseCode(); f@@2@# 5B
if(responseCode>=400) B-63IN
{ n7UZ&ab
processErrorCode(responseCode); UPtWj8h
return -2; //-2 represent access is error xgl~4
} wFr}]<=Mi
,>-Q#
Zkn$D:
String sHeader; ]KX _a1e
<a>\.d9#)7
/rRQ*m_
for(int i=1;;i++) b}P5*}$:9"
{ -OLXRc=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5fGUJ[F=
//Utility.log(in.readLine()); \VW&z:/*pZ
sHeader=httpConnection.getHeaderFieldKey(i); 1iOQ8hD
if(sHeader!=null) Mp;yvatO
{ j!c[$;
if(sHeader.equals("Content-Length")) {4\hxyw
{ N_jCx*.G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r Ntc{{3_
break; ~i)O^CKq
} m#[tY>Q[b
} UloZo? e`
else ;bJ2miO"e
break; l@}BWSx&ms
} !6:q#B*
} F">>,Oc)U"
catch(IOException e){e.printStackTrace ();} !A>VzW
catch(Exception e){e.printStackTrace ();} Y~=]RCg
[oOA@
#A|~s;s>N
Utility.log(nFileLength); j\w>}Pc
)3i}(h0
>-0b@ +j
return nFileLength; I+ipTeB^
} ,z}wR::%
o6e6Jw
$"Oy }
//保存下载信息（文件指针位置） \R&4Nu2F
private void write_nPos() ns.[PJ"8
{ "P:kZ=M Q
try{ s^_E'j$
output = new DataOutputStream(new FileOutputStream(tmpFile)); }`/wj
output.writeInt(nStartPos.length); A[juzOn\
for(int i=0;i<nStartPos.length;i++) h3^&,U
{ Gmcx#?|Tx
// output.writeLong(nPos); Is6<3eQ\x
output.writeLong(fileSplitterFetch.nStartPos); l6.#s3I['
output.writeLong(fileSplitterFetch.nEndPos); Zp|LCE"
} f[)_=T+
output.close(); }vOUf#^k
} _q([k_4h
catch(IOException e){e.printStackTrace ();} )Qve[O
catch(Exception e){e.printStackTrace ();} md[FtcY\
} CL(,Q8yG
EXz5Rue LV
I>b-w;cC
//读取保存的下载信息（文件指针位置） +NRn>1]
private void read_nPos() W%]sI n
{ 6p/gvpZ
try{ x{io*sY-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x>Ah4ad
int nCount = input.readInt(); \K 01F
nStartPos = new long[nCount]; 4+mawyM
nEndPos = new long[nCount]; n3{m "h3
for(int i=0;i<nStartPos.length;i++) fM]McZ9)D
{ 2aUz.k8o
nStartPos = input.readLong(); xh>/bU!>
nEndPos = input.readLong(); "m]"%MU78
} WG 9f>kE
input.close(); eafy5vN[zX
} &/lJ7=Nq
catch(IOException e){e.printStackTrace ();} G)l[\6Dn
catch(Exception e){e.printStackTrace ();} qx5X2@-;:
} JH!qGV1
_C?<re3*
)@Yp;=l
private void processErrorCode(int nErrorCode) f}bUuQrH-!
{ ]>@; 2%YvY
System.err.println("Error Code : " + nErrorCode); `$`:PT\Zv4
} {+[~;ISL
Yt*M|0bL
RIX0AE
//停止文件下载 xJ9_#$ngeM
public void siteStop() 96F:%|yG
{ S=lA^#'UdX
bStop = true; xM%E;
for(int i=0;i<nStartPos.length;i++) (5d~0
fileSplitterFetch.splitterStop(); yy?|q0
] K7>R0
?Gl'-tV
} my")/e
} ,TU!W|($
//负责部分文件的抓取 CGg:e:4
**FileSplitterFetch.java |6B:tw/.
*/ bl\44VK2'
package NetFox; $X5~9s1Wl
-mZo`
MAR kTxzi
import java.io.*; l1c&a[M)
import java.net.*; kETA3(h'
)iy>sa{
<Q=ES,M
public class FileSplitterFetch extends Thread { ^e8R43w:!
5h[u2&;G
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String sURL; //File URL ZP?k|sEH
long nStartPos; //File Snippet Start Position c}mJ6Pt
long nEndPos; //File Snippet End Position #s1M>M)
int nThreadID; //Thread's ID ;JFE7\-mC
boolean bDownOver = false; //Downing is over ?9X#{p>q
boolean bStop = false; //Stop identical c i7;v9
FileAccessI fileAccessI = null; //File Access interface >4\V/ I
l{#m"S7J^
<E@7CG.=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GMU<$x8o
{ *cp|lW!ag
this.sURL = sURL; -/
this.nStartPos = nStart; @.*[CC;&
this.nEndPos = nEnd; ~<, \=;b/
nThreadID = id; vFb{(gIJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [CPZj*|b
} }p t5.'l
_DC/`_'
g)$Pvfc
public void run() OJ UM Y<5
{ =&"Vf!7YR7
while(nStartPos < nEndPos && !bStop) D0i84I`Z%
{ :G^`LyOM
ENC_#-1x
R)cns7oW
try{ F.A<e #e?
URL url = new URL(sURL); A&9l|b-"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~J<bwF
httpConnection.setRequestProperty("User-Agent","NetFox"); /N%f78 Z
String sProperty = "bytes="+nStartPos+"-"; o9wg<LP
httpConnection.setRequestProperty("RANGE",sProperty); @+1E|4L1vf
Utility.log(sProperty); .ET;wK
JIb<>X,
Pms3X
InputStream input = httpConnection.getInputStream(); }C*o;'o5G
//logResponseHead(httpConnection); K- }k-S
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q'(WIv@
byte[] b = new byte[1024]; !+uMH!
int nRead; -(cm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #]lUJ &M}e
{ 8.pz?{**T
nStartPos += fileAccessI.write(b,0,nRead); Wlg(z%
//if(nThreadID == 1) 1AE/ILGo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +{hxEDz
} y^@%Xrs
%\~;I73
)lw7W9
Utility.log("Thread " + nThreadID + " is over!"); MruWt*
bDownOver = true; $+Pv fQ
//nPos = fileAccessI.write (b,0,nRead); a m<R!(
} Z$zUy|s[
catch(Exception e){e.printStackTrace ();} \)M5o
} Z~?:r
} ys#M* {?
eaX`S.!jR
X3W)c&Pr
//打印回应的头信息 @1]<LQ\\
public void logResponseHead(HttpURLConnection con) +ypG<VBx%
{ \=N tbBL$[
for(int i=1;;i++) SOK2{xCG
{ {6%uNT>|
String header=con.getHeaderFieldKey(i); >t D-kzN
if(header!=null) ik$wS#1+L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $,aU"'D
Utility.log(header+" : "+con.getHeaderField(header)); =R>Sxaq
else yQi|^X~?$
break; l*v([@A\
} =rBFMTllM
} 7Ck;LF}>0
}2NH>qvY
=fsaJ@q,R
public void splitterStop() d:pp,N~2o
{ *<Ddn&_
bStop = true; zl: u@!'
} c<DYk f
k oHY AF
@\"*Z&]8z0
} chd${ j
}MIH{CMH
6\TstY3
/* :.35pp,0
**FileAccess.java [CUJA
*//文件访问(定位，写) ?1N0+OW
package NetFox; y:42H tS
import java.io.*; '^/E2+
p9s~WD/K
z!3Z^d`
public class FileAccessI implements Serializable{ cw5YjQ8 9
jSG jv>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :%>8\q>UX
RandomAccessFile oSavedFile; M`>W'<
long nPos; KbUX(9+B
@wFm])}0
Cfi2N V
public FileAccessI() throws IOException z9'0&G L
{ d|o"QYX
this("",0); jSVO$AW~C
} ?s?uoZ /2
L3GJq{t
'D/AL\1{p(
public FileAccessI(String sName,long nPos) throws IOException +.N;h-'
{ 4z*_,@OA
oSavedFile = new RandomAccessFile(sName,"rw"); @[FFYVru
this.nPos = nPos; UpIf t=@P
oSavedFile.seek(nPos); A0]o/IBz
} Tb)x8-0
{30<Vc=
CYn}wkz
public synchronized int write(byte[] b,int nStart,int nLen) c|.:J]
{ PaDT)RrEM
int n = -1; 0iL8i#y*
try{ <+$S{Z.
oSavedFile.write(b,nStart,nLen); )F$Stg3e
n = nLen; 41zeN++
} .lFSFJ??
catch(IOException e) IRU2/Ycg
{ R/wSGP`W
e.printStackTrace (); s{,e^T
} /,>.${,;u
X<QE]RZ
z<fEJN
return n; 2"MI8EK
} 0K2[E^.WN
:RQ[(zD]
MMAC,4
} (s3%1OC[
BdKtpje
FO5SXwx
/* 5`uS<[vA
**SiteInfoBean.java i3"sArP"|
*/ ^0&] .m
package NetFox; C49 G&
sXa8(xc
64vSJx>u
public class SiteInfoBean { [>:gwl _\
8$vH&HdI
C5M-MZaS
private String sSiteURL; //Site's URL H<xC%/8
private String sFilePath; //Saved File's Path %OtW\T=u
private String sFileName; //Saved File's Name =z/F=1^<
private int nSplitter; //Count of Splited Downloading File D1n2Z:9
2|=_kN8;
kwL)&@
public SiteInfoBean() :acQK=fe
{//nSplitter的缺省值为5 d0=nAZZ
//default value of nSplitter is 5 a82mC r
this("","","",5); q"Md)?5N
} 0/6&2
]]Z,Qu#<-
8bGq"!w-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8<kme"%s
{ #~+#72+x7
sSiteURL= sURL; >gZz`CH
sFilePath = sPath; J:u|8>;
sFileName = sName; uJ`&hX
this.nSplitter = nSpiltter; S8=4C`>jf
m?j!0>
SRTpE,
} #{M -3
5a ~tp'
:#/bA&
public String getSSiteURL() LasH[:QQQ
{ )^\='(s
return sSiteURL; !{Y#<tG]
} 4BT`|(7
F^YIZ,=p!
%5G BMMn
public void setSSiteURL(String value) m%[t&^b}T
{ FJLJ;]`7+
sSiteURL = value; kpH;D=;
} MuobMD}jqe
R`Lm"5w
p*0Ve21i,
public String getSFilePath() #CPPdU$
{ E(tBN]W.
return sFilePath; )sf~l6
} 'y?|shV{]
Uot-@|l
.=yus[,~
public void setSFilePath(String value) 8zC k9&
{ Q:gn>/
sFilePath = value; }$U[5wL,_
} 'j_H{kQy
>bN~p
<L~xR5
public String getSFileName() sAoM=n}!
{ zy[=OX+
return sFileName; 9i}D6te
} .$0Ob<.
m0Syxb
u-{l,p_H
public void setSFileName(String value) ql~{`qoD~
{ Z0eBx
sFileName = value; ;g:bn5G
} :BX{*P
)$B+3f
n\-_i2yy
public int getNSplitter() ^\&g^T%
{ ;a&:r7]=
return nSplitter; oKi1=d+T
} el?V2v[
r^t{Ii~
1N!g`=}
public void setNSplitter(int nCount) cN7z(I0[
{ Z9&D'n)
nSplitter = nCount; 8-a6Q|
} uX +<`3O
} 1Wk EPj,
\83A|+k
^|GtO.
/* oqba:y;AR
**Utility.java ms7 7{A3
*/ %^=!s
package NetFox; 5TneuG[OD
1[BvHOI2
g>xUS_d>
public class Utility { '$XHRS/q]
J,G9m4Z7
{7Avba
public Utility() P! Ed
{ /iy*3P,`
h+3Z.WKhwP
`4.sy +2
} Ig3(|{R
g]<Z]R`
//线程睡眠 ` G=L07
public static void sleep(int nSecond) )H9*NB8%
{ (oitCIV
try{ bmVgTm&
Thread.sleep(nSecond); W)!{U(X
} 5@D7/$bLp
catch(Exception e) $xtE+EV.p
{ 1m`tqlFU9
e.printStackTrace (); 7~ese+\smG
} DRW.NL o
} i!W8Q$V
S@xsAib0J
//日志 pLQSG}N
public static void log(String sMsg) )L<?g!j~
{ Z4AAg
System.err.println(sMsg); G0QXf
} ]jVSsSv
zrU$SWU
tOM3Gs~o6z
public static void log(int sMsg) 4@]xn
{ #* gU[9U~
System.err.println(sMsg); _'hCUXeY'
} abaQJ|
} DV[ Jbl:)
@`;Y/',
2Z`$
/* Ac!&j=ZE
**TestMethod.java +%#MrNM'
*/ l?JO8^Nn
package NetFox; 4 ?@uF[
aT1CpY=T|.
ah/6;,T
public class TestMethod { Hx2j=Q_dw
vYSetAdv
(: TGev
public TestMethod() UiK+c30FU
{ ///xx/weblogic60b2_win.exe *lerPY3 q
try{ y/}VtD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k~jKJb-_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8q~FUJhU
SiteFileFetch fileFetch = new SiteFileFetch(bean); {{]=zt|69
fileFetch.start(); /y](mu"!
} QK?2E
catch(Exception e){e.printStackTrace ();} ?St=7a(D
5{ 4"JO3
$uUb$8Bu
} moVa'1ul
g;-+7ViIr
BH#C<0="
public static void main(String[] args) StyB"1y
{ w{r(F`
new TestMethod(); l<aqiZSY
} ,dZ H$
} 8XYD L]I'
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