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)); q\,H9/.0k
} Ov9.qNT
for(int i=0;i<nEndPos.length-1;i++) NF.SGga
{ l^_X?L@
nEndPos = nStartPos[i+1]; g41LpplX
} Gc'HF"w
nEndPos[nEndPos.length-1] = nFileLength; !cpBX>{w
} x83XJFPWL
} (ZnA#%
5&>(|Y~I
82<L07fB
//启动子线程 hYV{N7$U|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -K0tK~%q
for(int i=0;i<nStartPos.length;i++) ?`vb\K<5H;
{ wFvilF V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4k#6)e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }vi%pfrB
nStartPos,nEndPos,i); C@[:}ZGMV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); __9673y
fileSplitterFetch.start(); NOx| #
} TwH(47|?Nt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uC3$iY:_e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6/z}-;,W'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'L,rJ =M3
nEndPos = " + nFileLength); ReRRFkO"2
// fileSplitterFetch[nPos.length-1].start(); }PXWRv.gW
f|`{PP`\
H [v~
//等待子线程结束 Cn"N5(i
//int count = 0; `DwlS!0
//是否结束while循环 iTX.?*
boolean breakWhile = false; w+}dm^X
'i,<j s3\f
uYl ?Q
while(!bStop) P.wINo
{ e\h:==f
write_nPos(); O<Kr6+ -
Utility.sleep(500); gW, ET
breakWhile = true; #RSxo 4
XBc+_=)$
}bHpFe
for(int i=0;i<nStartPos.length;i++) uJWX7UGuz
{ HGKm?'['
if(!fileSplitterFetch.bDownOver) =19]a
{ "P|G^*"~2
breakWhile = false; d0xV<{,-
break; }QI*Ns
} `A'*x]l
} X#o:-FKf
if(breakWhile) ABSeX
break; A=])pYE1
RBb@@k[v
saZ;ixV
//count++; Y7p#K<y]9
//if(count>4) ?G{fF H
// siteStop(); b,'./{c0
} ?SpI^Wn)[
VcP#/&B|
l9Vim9R5T
System.err.println("文件下载结束！"); Ax\Fg 5
} N@VD-}E
catch(Exception e){e.printStackTrace ();} jzV#%O{`
} Oe#k|
m/ukH{H1%
"~;jFB8
//获得文件长度 QXrK-&fju
public long getFileSize() C]`Y PM5
{ qN)cB?+
int nFileLength = -1; J]N}8 0
try{ qdm!]w.G5
URL url = new URL(siteInfoBean.getSSiteURL()); r=k}EP&<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .UDZW*
httpConnection.setRequestProperty("User-Agent","NetFox"); b:JOR@O
*dTw$T#
qm '$R3g
int responseCode=httpConnection.getResponseCode(); p?`N<ykF<
if(responseCode>=400) ,Q:dAe[ZsX
{ @@$ _TaI
processErrorCode(responseCode); EZHEJW'JnE
return -2; //-2 represent access is error =FKB)#N
} -(2-zznZ
)CB?gW
zqeU>V~<F
String sHeader; 51&T`i
HaSH0eTw
UOY1^wY
for(int i=1;;i++) 3S9~rLrn?
{ T;%SB&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ygPZkvZ
//Utility.log(in.readLine()); -Av/L>TxlI
sHeader=httpConnection.getHeaderFieldKey(i); :Y'nye3:
if(sHeader!=null) p[wjHfIq
{ 3ty){#:
if(sHeader.equals("Content-Length")) y5#_@
{ w.3R1}R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \<8!b{F
break; XC$~!
} ^T[#rNkeL
} }dxdxnVt
else uqnZ
break; 0eLK9u3<
} ^\I$tnY`
} p<jr&zVEc>
catch(IOException e){e.printStackTrace ();} UOu&sg*o2B
catch(Exception e){e.printStackTrace ();} '71btd1
J0K"WmW
o#Y1Uamkf
Utility.log(nFileLength); 1Y`MJ\9
Ob+&!XTp?0
-K!-a'J
return nFileLength; vuAjAeKm
} e,BJD>N ?
G pd:k
bcYz?o6
//保存下载信息（文件指针位置） 3)ip@29F
private void write_nPos() -bE|FFU
{ >"[u.1J_'I
try{ n>Ei1
output = new DataOutputStream(new FileOutputStream(tmpFile)); fP|\1Y?CS
output.writeInt(nStartPos.length); dO@iq^9-
for(int i=0;i<nStartPos.length;i++) 9~_6mR<
{ r:IU+3
// output.writeLong(nPos); OTm`i>rB
output.writeLong(fileSplitterFetch.nStartPos); a$GKrc,z
output.writeLong(fileSplitterFetch.nEndPos); cwroG#jGT
} %Xl@o
output.close(); 7Av]f3Zr
} 4Y2>w
catch(IOException e){e.printStackTrace ();} 4L0LT>'M\
catch(Exception e){e.printStackTrace ();} c"xaN
} pIXQ/(h31
ox6rR
.DQ]q o]OG
//读取保存的下载信息（文件指针位置） ^#o.WL%4/B
private void read_nPos() u *< (B
{ e=_hfOUC
try{ %9lxE[/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l0_V-|x
int nCount = input.readInt(); q mB@kbt
nStartPos = new long[nCount]; :wZZ 1qa
nEndPos = new long[nCount]; .EcMn
for(int i=0;i<nStartPos.length;i++) |2# Ro*
{ [=Z{y8#:J
nStartPos = input.readLong(); .>YJ95&\
nEndPos = input.readLong(); ~I<y^]2{
} |`nVr>QF&
input.close(); h2>0#Vp3j
} ,&-[$,
catch(IOException e){e.printStackTrace ();} kD>vQ?
catch(Exception e){e.printStackTrace ();} [wR8q,2
} @oEDtN
S%oGBY*Z
F\I^d]#,[
private void processErrorCode(int nErrorCode) k-U/x"Pl
{ NEk [0
System.err.println("Error Code : " + nErrorCode); ~iWSc8-
} 93\,m+-
>MT)=4 9q
g6V*wjC
//停止文件下载 AMdS+(J
public void siteStop() hs4r5[
{ wOOPWwk
bStop = true; |>4{4
for(int i=0;i<nStartPos.length;i++) \K6J{;#L
fileSplitterFetch.splitterStop(); F'I6aE%
kQ8WO|bA
DFonK{
} Zux2VepT
} U~m.I
//负责部分文件的抓取 zMKL: Um"
**FileSplitterFetch.java #7=LI\
*/ St`m52V(5X
package NetFox; YLGLr@:q
Q)>'fZ)
EMG*8HRI>r
import java.io.*; ;j=1 oW
import java.net.*; -+>am?
>y[S?M
jq)|Uq'6
public class FileSplitterFetch extends Thread { keOW{:^i
;Y\,2b, xh
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String sURL; //File URL mxGN[%ve
long nStartPos; //File Snippet Start Position V*}zwms6
long nEndPos; //File Snippet End Position m##=iB|;
int nThreadID; //Thread's ID 6qlr+f
boolean bDownOver = false; //Downing is over `t6L'%\
boolean bStop = false; //Stop identical H[ q{R
FileAccessI fileAccessI = null; //File Access interface mQd?Tyvn
@ni~ij
B5G$o{WM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }^7V^W
{ SfUUo9R(sm
this.sURL = sURL; h.0K PF]O
this.nStartPos = nStart; j&.BbcE45
this.nEndPos = nEnd; 7krA+/Qr(
nThreadID = id; <Tf;p8#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z7C1&bGe
} =*jcO119L
4)I#[&f
v=VmiBq[
public void run() V-jL`(JF%
{ 7p6J
while(nStartPos < nEndPos && !bStop) JuSS5_&
{ vuBA&j0C
*\", qMp
8BDL{?Mu
try{ GwBQ pNjy
URL url = new URL(sURL); |T*qAJ8c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Phu| hx<
httpConnection.setRequestProperty("User-Agent","NetFox"); n bk(FD6
String sProperty = "bytes="+nStartPos+"-"; [[Z>(d$8
httpConnection.setRequestProperty("RANGE",sProperty); `x)bw
Utility.log(sProperty); |m- `, we
g/p }r.
4a!7|}W
InputStream input = httpConnection.getInputStream(); (+dRD]|T
//logResponseHead(httpConnection); ,~(}lvqVH
kB#vh
bl_WN|SQ
byte[] b = new byte[1024]; ^ {f^WL=
int nRead; VhgEG(Ud
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WmUW i{
{ A#&qoZ(C
nStartPos += fileAccessI.write(b,0,nRead); Ir #V2]$
//if(nThreadID == 1) R"`{E,yj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :'~ gLW>j
} "b4iOp&:=
(L%q/$
yXg1N N
Utility.log("Thread " + nThreadID + " is over!"); u^%')Ncp
bDownOver = true; /}_c7+//
//nPos = fileAccessI.write (b,0,nRead); :n9~H+!
} bK9~C" k
catch(Exception e){e.printStackTrace ();} C)s1' =TZ
} GK?R76d
} pIiED9
+z0}{,HX
: "te-
//打印回应的头信息 9PK-r;2
public void logResponseHead(HttpURLConnection con) \/'n[3x
{ DAHf&/JK
for(int i=1;;i++) vqMk)htIz
{ H^;S}<pxW
String header=con.getHeaderFieldKey(i); :b*`hWnQ
if(header!=null) Z[u,1l.T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K/v-P <g
Utility.log(header+" : "+con.getHeaderField(header)); 1Z8Oh_DC
else O'|P|
break; Ks2%F&\cE
} %C0O?q
} 3}{5 X'
IA#*T`
e uHu}
public void splitterStop() ,9wenr
{ R(N(@KC
bStop = true; %W',cu
} R+VLoz*J6
\Rqh|T<D
N3p 7 0
} ."Ix#\|x
IPi<sE
ugCS &
/* h?3l
**FileAccess.java Ny,A#-?
*//文件访问(定位，写) MI'l4<>u
package NetFox; W<|K
import java.io.*; Bi:wP/>v
H9Q7({v
m:fouMS
public class FileAccessI implements Serializable{ 124L3AG
ivz9R'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {-N90Oe
RandomAccessFile oSavedFile; pkfOM"5'
long nPos; A2:){`Mw
.4re0:V
i~B@(,
public FileAccessI() throws IOException 8Gl5)=2
{ ZQ' z
this("",0); W$Q)aA7
} ,9tbu!Pvq
%_R|@cyD
^Xy$is3
public FileAccessI(String sName,long nPos) throws IOException <C"N X
{ ,x"yZ
oSavedFile = new RandomAccessFile(sName,"rw"); R5&$h$[/
this.nPos = nPos; ->2wrOH|H
oSavedFile.seek(nPos); %^?3s5PXD
} uj9tr`Zh
<Z:8~:@
pebx#}]p-
public synchronized int write(byte[] b,int nStart,int nLen) -C-OG}XjI
{ 9#T%bB"J
int n = -1; ?V)C9@bp
try{ 1;:t~Y
oSavedFile.write(b,nStart,nLen); nR@,ouB-$
n = nLen; gLSG:7m@
} `TD%M`a
catch(IOException e) ?I2k6%a
{ ?WQd
e.printStackTrace (); Fr3d#kVR
} pG F5aF7T
UG"6RW @
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return n; :7Z\3_D/
} opcR~tg@r
DPS1GO*
J"Y
} iPY vePQ
<m/b]|
yg-FJ/
/* MpIw^a3(r
**SiteInfoBean.java Pm#x?1rAj
*/ (o6[4( G
package NetFox; AJ?}Hel[0
E/8u'
2^^'t6@
public class SiteInfoBean { [[?[? V ,
: >wQwf
T7lj39pJq
private String sSiteURL; //Site's URL o(d_uJOB
private String sFilePath; //Saved File's Path zJuRth)(,
private String sFileName; //Saved File's Name 4)odFq:
private int nSplitter; //Count of Splited Downloading File *pb:9JKi
N5f0|U&
tf7v5iGe
public SiteInfoBean() >1a\%G
{//nSplitter的缺省值为5 @W1WReK]f
//default value of nSplitter is 5 tFvgvx\:
this("","","",5); }}``~
} PJK]t7vp
jW1YTQ
*qO]v9 j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h8#5vO2
{ YV1a3
sSiteURL= sURL; gY>;|),
sFilePath = sPath; 65waq~#
sFileName = sName; uP(B<NfL:'
this.nSplitter = nSpiltter; zr3q>]oma
cZaF f?]k
A{4G@k+#d
} Mm5U`mB
~}$\B^z+
q?;*g@t
public String getSSiteURL() 4/HY[FT
{ |6sT,/6
return sSiteURL; dXhCyr%"6
} @~$F;M=.*
c_qcb7<~.
-- i&"
public void setSSiteURL(String value) \'; t*
{ ;# R3k
sSiteURL = value; nIV.9#~&
} ;w+:8<mM}a
W>}Qer4
#aitESbT
public String getSFilePath() WyBQ{H{So
{ `jb0+{08
return sFilePath; ^o $W
} [j:}=:feQ
ZRXI?Jr%
MfXt+c`r
public void setSFilePath(String value) ~A[YnJYA#
{ f.b8ZBNj>
sFilePath = value; IOsXPf9@
} uQ:ut(
VD9 q5tt7
vx\nr8'k
public String getSFileName() y3={NB+
{ eW%L$I
return sFileName; %;pD8WgJA
} C 'B4 mmC
j<l#qho{h
k Zk .]b
public void setSFileName(String value) :SQDqG
{ < 72s7*Rv
sFileName = value; Yl)eh(\&J
} ERp:EZ'
0(Y%,q
A+0T"2
public int getNSplitter() )3]83:lD2
{ @@xO+$6
return nSplitter; FasI'Ulk
} U;';"9C2>
jo,6Aog|u
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public void setNSplitter(int nCount) :kWZSN8.D
{ Wk/fB0
nSplitter = nCount; Jj=yG"$!
} V~'k1P4
} Y)'!'J
gq H`GI
l9_m>X~
/* ?)!SmN/
**Utility.java F1 <489
*/ I$aXnd6)
package NetFox; yD"]{
s~'9Hv9
f*{M3"$E
public class Utility { <)_:NRjBF&
X!U]`Qh
_wm~}_Q
public Utility() McT\ R{/
{ ky'|Wk6
a<f;\$h]
5c<b|
} MS{Hz,I,
m3U+ du
//线程睡眠 ISpeV
public static void sleep(int nSecond) eZynF<i
{ :6 Uk)
try{ tegOT]|
Thread.sleep(nSecond); c*.G]nRc
} D",A$(lG
catch(Exception e) xM%H~(
{ hX0RET
e.printStackTrace (); G+ :bL S#:
} 2#'rk'X,K
} |d~B]65t
jZa25Z00
//日志 IgLVn<5n
public static void log(String sMsg) ])N|[|$
{ sk#9x`Rw
System.err.println(sMsg); jz %;4e~t
} hbVE; 9
|)^clkuGX
:L]-'\y
public static void log(int sMsg) /pO{2[
{ K1;zMh
System.err.println(sMsg); J=@hk@Nq#
} CIIY|DI`l
} Lqg]Fd
kVWGDI$~
$=\d1%_R|
/* grGhN q
**TestMethod.java `f%&<,i
*/ A)OdQFet(
package NetFox; <"N:rn{Qq
~q{\;
!K!)S^^Po?
public class TestMethod { -_s%8l^
DD2adu^
IS-}:~Pi
public TestMethod() 7Aqn[1{_O
{ ///xx/weblogic60b2_win.exe 5RW@_%C
try{ s5Pq$<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *f{7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3b#L17D3_
SiteFileFetch fileFetch = new SiteFileFetch(bean); j0AwL7
fileFetch.start(); }|AX_=a
} L?C\Q^0"`G
catch(Exception e){e.printStackTrace ();} !syU]Yk
kl| g
3*G5F}7%=
} {!lNL[x
P_Z M'[
P2O\!'aEh
public static void main(String[] args) uG4$2
{ O97VdNT8
new TestMethod(); bk.*k~_
} yXkt:O,i
} _0w1kqW
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