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)); &<\4q
} IBn'iE[>
for(int i=0;i<nEndPos.length-1;i++) TyxU6<>4J4
{ !Qj)tS#Az
nEndPos = nStartPos[i+1]; &;SwLDF"1
} m70`{-O
nEndPos[nEndPos.length-1] = nFileLength; s{x*~M$vt
} yf0vR%,\
} 5i}CzA96
N>W;0u!
7C,<iY
//启动子线程 #`fi2K&]j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0:7v/S!:
for(int i=0;i<nStartPos.length;i++) `8$:F4%P
{ r&H=i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IG2`9rR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 60Xl.
nStartPos,nEndPos,i); [qO5~E`;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tal>b]B;
fileSplitterFetch.start(); $9LGdKZ_D
} B;Q`vKY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f}evw K[S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F:[Nw#gj/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %RfY`n
nEndPos = " + nFileLength); o>/uW8
// fileSplitterFetch[nPos.length-1].start(); s= -WB0E
1[fkXO{
1Ovx$*
//等待子线程结束 KNO*)\
//int count = 0; op.PS{_t
//是否结束while循环 sK""
boolean breakWhile = false; 'PmHBQvt&
tS_xa
bv:0EdVr
while(!bStop) Xy3g(x]
{ Y%n{`9=
write_nPos(); T6/$pJl
Utility.sleep(500); !>a&`j2:W
breakWhile = true; 8o%<.]
df21t^0/
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for(int i=0;i<nStartPos.length;i++) *Dd(+NI
{ y4)ZUv,}
if(!fileSplitterFetch.bDownOver) HlOAo:8'
{ =Ov;'MC
breakWhile = false; o}r!qL0c
break; l\A}lC0?J
} ".*a)
} !DY2{Wb
if(breakWhile) l"~h1xk~
break; vJ#rW8y
!"o1ve`{
N>F2 c)rm
//count++; +Zty}fe
//if(count>4) oJ4mxi@|#
// siteStop(); ';fU.uy
} "R\\\I7u
^Yf)lV&[
0IT20.~
System.err.println("文件下载结束！"); fmZzBZ_
} |2+F I<v4
catch(Exception e){e.printStackTrace ();} {=pP`HD0
} {3F}Slb
Muc*?wB`
]/<Qn-BbU
//获得文件长度 y$r?t0
public long getFileSize() G}9bCr,
{ a-UD_|!
int nFileLength = -1; )P(d66yq'u
try{ 6U,U[MWJ
URL url = new URL(siteInfoBean.getSSiteURL()); LzEE]i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fO^EMy\
httpConnection.setRequestProperty("User-Agent","NetFox"); .eDxIWW+ft
mXN1b!
6"rFfdns
int responseCode=httpConnection.getResponseCode(); gl(6m`a>
if(responseCode>=400) wZ\e3H z
{ n_!]B_Vd$
processErrorCode(responseCode); }ii]cY
return -2; //-2 represent access is error [w#x5Xsn
} &s6(3k
:+Z>nHe
=Y=^]ayO/
String sHeader; 46.q anh
[<3Q$*Ew
EiIFVP
for(int i=1;;i++) [&]YVn>kj
{ 0F;(_2V-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t6,M
//Utility.log(in.readLine()); m?kIa!GM=
sHeader=httpConnection.getHeaderFieldKey(i); 7Hr4yh[j&
if(sHeader!=null) Jz:W-o
{ gYH:EuY,
if(sHeader.equals("Content-Length")) vI:bl~
{ =-1^K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5sV/N] !
break; (>Q9jNW
} 6Kv}2M')+
} Q+%m+ /Zq
else ~1wdAq`'a
break; GO:1 Z?^
} J?,!1V=
} ,[K)E
catch(IOException e){e.printStackTrace ();} n9-q5X^e>
catch(Exception e){e.printStackTrace ();} zf!\wY"`
o"+&^
J!^~KN6[
Utility.log(nFileLength); OD@@O9
scPq\Qd?O
%&Q7;?
return nFileLength; DHujpZXQ
} E*!zJ,@8
*IO;`k q,;
C6=;(=?C
//保存下载信息（文件指针位置） 'mp{O
private void write_nPos() XtH_+W+O
{ +/_B/[e<>
try{ 8Q)mmkI\=
output = new DataOutputStream(new FileOutputStream(tmpFile)); da86Jj=k
output.writeInt(nStartPos.length); K&a]pL6D
for(int i=0;i<nStartPos.length;i++) {]_{BcK+
{ *mhw5Z=!
// output.writeLong(nPos); Uub%s`O
output.writeLong(fileSplitterFetch.nStartPos); gJ[q {b
output.writeLong(fileSplitterFetch.nEndPos); &fNE9peQFa
} lt(-,md
output.close(); p~zTRnm
} a518N*]j
catch(IOException e){e.printStackTrace ();} o!_; H}pq
catch(Exception e){e.printStackTrace ();} Qj~W-^/ -
} (9[C0eS
[{!j9E?(
$E@.G1T [
//读取保存的下载信息（文件指针位置） u{lDof>
private void read_nPos() z?) RF[
{ *$Wx*Jo
try{ $X\` 7`v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 63dtO{:4
int nCount = input.readInt(); #?|1~HC
nStartPos = new long[nCount]; @aPu}Hi
nEndPos = new long[nCount]; 2Q_{2(nQb
for(int i=0;i<nStartPos.length;i++) ws(}K+y_
{ +nyN+X34B
nStartPos = input.readLong(); ][K8\
nEndPos = input.readLong(); &8YI)G%
} U@t?jTMBkO
input.close(); VEYKrZA
} uB&I56
catch(IOException e){e.printStackTrace ();} SIBIh-L
catch(Exception e){e.printStackTrace ();} &/#Tk>:
} i^V4N4ux]
'*{Rn7B5
u9~V2>r\
private void processErrorCode(int nErrorCode) s1b\I6&:J
{ $8ww]}K
System.err.println("Error Code : " + nErrorCode); A5H8+gATK
} k49n9EX
xA1pDrfC/
g8qAJ4
//停止文件下载 &\D<n;3
public void siteStop() 1B]wSvP@
{ DdZ_2B2
bStop = true; i$<v*$.o
for(int i=0;i<nStartPos.length;i++) U,3K6AZA 7
fileSplitterFetch.splitterStop(); nsw8[pk
~322dG
i@?<]n
} (=/L#Yg_
} ScmzbDu
//负责部分文件的抓取 yW,#&>]# |
**FileSplitterFetch.java gl{PLLe[}
*/ +q?0A^C>
package NetFox; Nm :lC%>X
2o3k=hKS
GQAg ex)D
import java.io.*; ^|12~d_.T
import java.net.*; M]zNW{Xt
0+`*8G)
zgOwSg8
public class FileSplitterFetch extends Thread { b0CaoSWo
u^.k"46hn
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String sURL; //File URL RpXGgw
long nStartPos; //File Snippet Start Position &XTd[_VW!
long nEndPos; //File Snippet End Position EC\:uK
int nThreadID; //Thread's ID gK_[3FiKt
boolean bDownOver = false; //Downing is over (dnc7KrM
boolean bStop = false; //Stop identical K]Cs2IpI
FileAccessI fileAccessI = null; //File Access interface ;xC~{O
HQj4h]O#
JWjp<{Q;1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :v ~q
{ ~l(tl[
this.sURL = sURL; }(IDPaJ
this.nStartPos = nStart; BJ2W}R
this.nEndPos = nEnd; &IY_z0=
nThreadID = id; '"p*FN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 exU=!3Ji
} otVdx&%]
8pt<)Rs}
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public void run() MM$"6Jor
{ 0s[3:bZ\Ia
while(nStartPos < nEndPos && !bStop) Mp}NUQHE
{ d(tf:@
PS;*N8
dV*rnpN
try{ $ aBSr1
URL url = new URL(sURL); m8A1^ R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A{T@O5ucj
httpConnection.setRequestProperty("User-Agent","NetFox"); m|gd9m$,?
String sProperty = "bytes="+nStartPos+"-"; D??/=`|8
httpConnection.setRequestProperty("RANGE",sProperty); dp W%LXM_
Utility.log(sProperty); ;XuEMq,Di
n,LKkOG
AdW7 vn
InputStream input = httpConnection.getInputStream(); X.5LB!I)
//logResponseHead(httpConnection); |W];v@b\y
eV}Tx;1|}
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byte[] b = new byte[1024]; nECf2>Yp v
int nRead; ;P#*R3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tO;W?g
{ 8uW:_t]q
nStartPos += fileAccessI.write(b,0,nRead); PX/0 jv
//if(nThreadID == 1) ?2>v5p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5!p'n#_
} _ 9]3S>Rn
I"?&X4%e
e!'u{>u
Utility.log("Thread " + nThreadID + " is over!"); (19<8a9G
bDownOver = true; u6d~d\
//nPos = fileAccessI.write (b,0,nRead); }f*S 9V
} XmR5dLc8
catch(Exception e){e.printStackTrace ();} <Wq{ V;$
} /hR]aw
} Mc^7FWkw
ixpG[8s
mSeNM
//打印回应的头信息 '~a$f;: Dv
public void logResponseHead(HttpURLConnection con) fbkjK`_q
{ "b7C0NE
for(int i=1;;i++) IV*$U7~
{ >:|q J$J.
String header=con.getHeaderFieldKey(i); nP5fh_/
if(header!=null) 1OS3Gv8jc~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zjE4v-H:l
Utility.log(header+" : "+con.getHeaderField(header)); cNvcpv
else ( "z;Q?(
break; 3&:fS|L~c
} 3f8Z?[Bb@
} - mXr6R?
FQl|<l6
11+_OC2-
public void splitterStop() [)u{-
{ :E*U*#h/
bStop = true; NWj@iyi<
} C =U4|h~W
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} zf u78
(DAJ(r~
5)6%D
/* +06j+I
**FileAccess.java n3,wwymQ
*//文件访问(定位，写) gu&oCT
package NetFox; ij5YV3
import java.io.*; KR0 x[#.*
T667&@
(0f^Hh wF
public class FileAccessI implements Serializable{ LcF3P 4
:LG%8Z{R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A4h/oMis
RandomAccessFile oSavedFile; h65j,v6B
long nPos; rg.if"o
H)tDfk sq\
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public FileAccessI() throws IOException ~G:7*:[b
{ cw{[B%vw
this("",0); Y?cw9uYB
} v^'~-^s
iSHl_/I<
nrBitu,
public FileAccessI(String sName,long nPos) throws IOException <X*8Xzmv
{ -}o;Y)
oSavedFile = new RandomAccessFile(sName,"rw"); _#B/#^a
this.nPos = nPos; 5;Xrf=
oSavedFile.seek(nPos); ;"z>p25=T
} 9v0|lS!-
Nig-D>OS
FeLP!oS>
public synchronized int write(byte[] b,int nStart,int nLen) V;jz0B
{ /G;yxdb
int n = -1; Y2EN!{YU
try{ !)34tu2
oSavedFile.write(b,nStart,nLen); ZbUf|#GTB
n = nLen; p6'8l~W+
} b??1Up
catch(IOException e) (P-<9y@
{ K2 2Xo<3
e.printStackTrace (); g_U69 z
} X Rn=;gK%J
+&@0;zSga
UEUTu}4y
return n; eHR<(8c'f
} pJ[Q.QxU
iXFaQ
9K!='u`
} .2xkf@OP
2X_ef
ZI7<E
/* )RFeF!("
**SiteInfoBean.java Sqs`E[G*
*/ _rd{cvdR
package NetFox; -}@9lhS,
xTT>3Fj
xFZq6si?
public class SiteInfoBean { s?Kn,6Y
}T,uw8?f!
>YLm]7v}
private String sSiteURL; //Site's URL v&n&i?
private String sFilePath; //Saved File's Path oWmla*nCKL
private String sFileName; //Saved File's Name WmA578|l!
private int nSplitter; //Count of Splited Downloading File {Y Ymt!Ic
8*wI^*Q
e+wd>iiB
public SiteInfoBean() zu#o<6E{
{//nSplitter的缺省值为5 D3PF(Wx
//default value of nSplitter is 5 0N.*c
this("","","",5); jTnu! H2o
} /7^~*
'#PT C,0UJ
PW}.`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Cp%|Q.?
{ EeO{G*pq
sSiteURL= sURL; c'b,=SM
sFilePath = sPath; FWg7e3
sFileName = sName; cu-WY8n
this.nSplitter = nSpiltter; ]G:xTv8
m| Z)h{&
[C$ 0HW
} #_d%hr~d
}1V&(#H2
|($pXVLH`
public String getSSiteURL() XebCl{HHp
{ uT1x\Rt|e
return sSiteURL; _D~a4tgS
} k{~5pxd-t
Y*Pr
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public void setSSiteURL(String value) VI?[8@*Z
{ "q$M\jK#V
sSiteURL = value; X_lNnk
} nB.p}k
$IHa]9 {
b|NEU-oy
public String getSFilePath() ^N]*Zf~N?
{ oW6.c]Vo
return sFilePath; WCH>9Z>cj
} $Ix^Rm9c
}^H_|;e1p
*b&|
public void setSFilePath(String value) 7%hMf$KQ
{ sdb#K?l
sFilePath = value; 7$'ja
} 9;PtYdJ8
xRfX:3
PF.HYtZqK
public String getSFileName() "ggq7cJ}_
{ V|7 cdX#H
return sFileName; 8L:0Wp
} (f)QEho7
FEkx&9]
s[hD9$VB>
public void setSFileName(String value) S7bSR?~L[
{ 8:f(PN
sFileName = value; v[m>;Ubg&
} 4h|vd.t
[Y[|:_+5
fA8 ,wy|>
public int getNSplitter() ?g 3sv5\u
{ COap*
return nSplitter; 'G&w[8mqY
} d$!ibL#o
y=t -/*K
8W{R&Z7aL
public void setNSplitter(int nCount) &:rf80`z.
{ EB\\ F
nSplitter = nCount; F J)la9
} J&Ah52
} n}"MF>zDK
+p2)uXqW
hQ9VcS6=gD
/* j:0z/gHp$
**Utility.java `sSI;+
*/ k]Yd4CC2
package NetFox; E11"uWk`
*p"%cas
% 74}H8q_z
public class Utility { k3&Wv
;aSEv"iWX
K#>B'>A\
public Utility() gD-<^Q-
{ xu3qX"
>6c{CYuT
#<{sP0v*
} =7a9~&|
sPut@4[S
//线程睡眠 Lx.X#n.]T
public static void sleep(int nSecond) ~MOIrF
{ 0L'h5i>H)
try{ [l0>pHl@
Thread.sleep(nSecond); )gZ yW
} zFlW\wc
catch(Exception e) |1#*`2j\=9
{ sq_ f[!
e.printStackTrace (); OF}vY0oiw?
} zMtx>VI
} LKhUqW
y:mXv<g
//日志 V V<Zl
public static void log(String sMsg) Z\n nVM=
{ Gx!Y 4Q}-
System.err.println(sMsg); o<Q~pd#Ip,
} Wh,p$|vL
`rvS(p[s
KrB"2e+J
public static void log(int sMsg) uZCPxog
{ L+&$/1h]
System.err.println(sMsg); zpJQ7hym
} F&^u1RYz
} vLq_l4l
(<|,LagTuc
3:s!0ty"
/* G22u+ua
**TestMethod.java O.i.<VD7
*/ C1hp2CW$5/
package NetFox; n}EH{k9#
A\LMmg
!IcPO
public class TestMethod { af)L+%Q%R
.^eajb`:
EW]rD
public TestMethod() #V@[<S2
{ ///xx/weblogic60b2_win.exe xtyOG
try{ ^tI ,eZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `Ps&N^[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?|kwYA$4o
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ch>r.OfP
fileFetch.start(); )m|)cLT&
} f]Xh7m(Gh
catch(Exception e){e.printStackTrace ();} UZz/v#y~
1 Qln|b8<
zt6GJz1q
} Kqm2TMO]>V
y2KR^/LN|Y
7*.nd
public static void main(String[] args) :>f}rq
{ /@ m]@
new TestMethod(); -V7dSi
} /V0[Urc@
} Fsz;T;
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