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)); f&NXWo/
} XWv;l)
for(int i=0;i<nEndPos.length-1;i++) D'<'"kUd
{ 95l)w
nEndPos = nStartPos[i+1]; nD\H$5>5
} dBEm7.nh
nEndPos[nEndPos.length-1] = nFileLength; h"t\x}8qq
} {{@*
} h@%a+6b?
^j]_MiA4
5dkXDta[G
//启动子线程 l' 2C/#8F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?3a:ntX h
for(int i=0;i<nStartPos.length;i++) }0idFotck
{ hD9b2KZv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ciGJtD&P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jchq\q)_z
nStartPos,nEndPos,i); jj6yf.r6c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7mtX/w9
fileSplitterFetch.start(); RJOW#e :
} 9A ?)n<3d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :s>x~t8g#n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BV=~!tsl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qrufnu5cC
nEndPos = " + nFileLength); 52t6_!y+V
// fileSplitterFetch[nPos.length-1].start(); lb\VQZp!y
/_</m?&.U&
~}RfepM
//等待子线程结束 ~Xz?H=}U+
//int count = 0; ~|( eh9
//是否结束while循环 KvXFzx|A
boolean breakWhile = false; vp(ow]Q
$rm/{i_7
{BzE
while(!bStop) (!%9#
{ uYC1}Y5N
write_nPos(); CaR-Yk
Utility.sleep(500); ;b!qt-;.<
breakWhile = true; V6Y0#sTU
*" +u^
<nc6&+
for(int i=0;i<nStartPos.length;i++) Z}S7%m
{ L}6!D zl
if(!fileSplitterFetch.bDownOver) _$i)bJ
{ 0+F--E4
breakWhile = false; Q2[;H!"
break; 5GbC}y>
} 0ZJj5<U
} ;Vpp1mk|
if(breakWhile) iFnD`l6)
break; P1ak>T*#2
1Eb2X}XC
EB VG@
//count++; 0+e
//if(count>4) J4u>77I
// siteStop(); hLj7i?
} r1:CHIwK
3S" /l
bEln.)
System.err.println("文件下载结束！"); 6V*,nocL_+
} SEVB.;
catch(Exception e){e.printStackTrace ();} <~P!yLr
} R3%%;`c=
qA"BoSw4
Zz"8
//获得文件长度 ;Y0M]pC
public long getFileSize() 5Dzf[V^]`
{ sNM ]bei
int nFileLength = -1; D -d
try{ O_]hbXV0
URL url = new URL(siteInfoBean.getSSiteURL()); i%[+C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q[?R{w6
httpConnection.setRequestProperty("User-Agent","NetFox"); )FNn
Ft?eqDS1
5RAhm0Op~.
int responseCode=httpConnection.getResponseCode(); hQ'W7EF
if(responseCode>=400) GUZ.Pw
{ %z=:P{0UQ
processErrorCode(responseCode); V~p01f"J
return -2; //-2 represent access is error `mA;1S
} Tdm|=xI
@<`V q
rVP{ ^Jdo
String sHeader; e9HL)=YP
D<|$ZuB4
Va?i#<a
for(int i=1;;i++) &>]U c%JK
{ }0tHzw=#%e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9!FU,4 X
//Utility.log(in.readLine()); xy b=7
sHeader=httpConnection.getHeaderFieldKey(i); "{\xBX~oM
if(sHeader!=null) qYJ<I'Ux O
{ ptrwZ8'
if(sHeader.equals("Content-Length")) ?dbSm3
{ } C:i0Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4\5i}MIS0
break; AwjXY,2
} :9av]Yv&
} rZ|p{ym
else GcDA0%i
break; kDDC@A $
} 2Z%n "z68
} _ xTpW
catch(IOException e){e.printStackTrace ();} 9!(%Vf>
catch(Exception e){e.printStackTrace ();} wN58uV '
Li]96+C$}
>}\s-/
Utility.log(nFileLength); kmX9)TMVO
'tY(&&
'(rD8 pc
return nFileLength; !^&VZh
} D=mmBo
?&-1(&
=Y81h-
//保存下载信息（文件指针位置） rJkJ/9s
private void write_nPos() %~x?C4L8
{ zWhj>Za
try{ 5{oc
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,}&TZkN{-
output.writeInt(nStartPos.length); `YC7+`q
for(int i=0;i<nStartPos.length;i++) NXFi*
{ g(9*!g
// output.writeLong(nPos); w2UEU5%
output.writeLong(fileSplitterFetch.nStartPos); Yj1|]i5b
output.writeLong(fileSplitterFetch.nEndPos); xYCJO(&
} n0T|U
output.close(); in/~' u
} SMD*9&,
catch(IOException e){e.printStackTrace ();} JJ7A` ;
catch(Exception e){e.printStackTrace ();} NI#]#yM+
} d\nXK#)Q
Qy0w'L/@
+T@BOYhgq
//读取保存的下载信息（文件指针位置） d}zh.O5P!
private void read_nPos() rAfz?
{ Rlk3AWl2u
try{ babL.Ua8o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +1YEOOfVY
int nCount = input.readInt(); l;0([_>*j
nStartPos = new long[nCount]; ;W|NG3_y
nEndPos = new long[nCount]; sWte&
for(int i=0;i<nStartPos.length;i++) Lm~<BBp.
{ 0S$k;q
nStartPos = input.readLong(); G9^`cTvv'8
nEndPos = input.readLong(); d/ ^IL*O
} G|KA!q
input.close(); K~vJ/9"|R
} cVW7I
catch(IOException e){e.printStackTrace ();} qsp.`9!
catch(Exception e){e.printStackTrace ();} wDh]vH[
} V^n6~O
.)b<cH~%
kEnGr6e
private void processErrorCode(int nErrorCode) Pd~=:4
{ m%`YAD@2z
System.err.println("Error Code : " + nErrorCode); >-I <`y-H
} cl4z%qv*
}x`Cnn
{\D&*
//停止文件下载 XQ}J4J~Vm
public void siteStop() iVn4eLK^v
{ ;7z6B|8
bStop = true; +Pb:<WT}%
for(int i=0;i<nStartPos.length;i++) ]6^<VC`5D
fileSplitterFetch.splitterStop(); F]yB=
\,G9'c 'u
)~wKRyQff
} N9_* {HOy
} d j\Z}[
//负责部分文件的抓取 iibG$?(
**FileSplitterFetch.java _GG\SWm
*/ q k^FyZ<
package NetFox; d-_V*rYU
'-%1ILK$3r
:,0(aB
import java.io.*; /%& d:
import java.net.*; ~gd#cL%
T06(Q[)
jG[Vp b
public class FileSplitterFetch extends Thread { XG.[C>
PK2;Ywk`
p3U)J&]c6
String sURL; //File URL hi[nUG(OI
long nStartPos; //File Snippet Start Position 8<C*D".T$
long nEndPos; //File Snippet End Position "V>}-G&
int nThreadID; //Thread's ID |X8?B=
boolean bDownOver = false; //Downing is over 1p.c6[9-
boolean bStop = false; //Stop identical |ky40[C
FileAccessI fileAccessI = null; //File Access interface NbU`_^oC
cb9-~*1
GM%OO)dO}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T o["o!(;z
{ \ZLi Y
this.sURL = sURL; }i~k:kmV
this.nStartPos = nStart; (I}owr5:
this.nEndPos = nEnd; xx`YBn~"
nThreadID = id; * hs&^G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OS,!`8cw
} QXZXj#`
<==uK>pET
Zt!#KSF7%
public void run() dxs5woP
{ )*BZo>"
while(nStartPos < nEndPos && !bStop) _Z0 .c@0
{ Nbpn"*L,
uB I/3aQ
S1|u@d'
try{ .]vb\NBK7
URL url = new URL(sURL); u8zL[]>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oVpZR$
httpConnection.setRequestProperty("User-Agent","NetFox"); o`S``?`^)^
String sProperty = "bytes="+nStartPos+"-"; j?N<40z
httpConnection.setRequestProperty("RANGE",sProperty); {1SsHir>
Utility.log(sProperty); ?y-^Fq|h
[MpWvLP"x
|c/=9Bb
InputStream input = httpConnection.getInputStream(); >N|?>M*
//logResponseHead(httpConnection); J 8%gC
;|Mfq`s
OeqKKVuQ
byte[] b = new byte[1024]; jB?SX
int nRead; f`hZb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5C!zEI)
{ ;TJpD0
nStartPos += fileAccessI.write(b,0,nRead); wo0j/4o
//if(nThreadID == 1) zTa5N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,JZ>)(@)
} +7gd1^|$e
oy8jc];SO
PMytk`<`zw
Utility.log("Thread " + nThreadID + " is over!"); Jo {:]:
bDownOver = true; c7XBZ%D
//nPos = fileAccessI.write (b,0,nRead); w,p'$WC*
} qLCNANWnd
catch(Exception e){e.printStackTrace ();} QJ XP-
} o.ZR5`.
} 712nD ?>
D}?p>e|<D
kkjugm{D7
//打印回应的头信息 3mHzOs\jU
public void logResponseHead(HttpURLConnection con) ~X3g_<b_8
{ MZV$YD^S
for(int i=1;;i++) =de'Yy:\-
{ F^.A~{&L
String header=con.getHeaderFieldKey(i); r?/Uu &
if(header!=null) =^KgNQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); to?!qxn
Utility.log(header+" : "+con.getHeaderField(header)); v@=qVwX
else `6~0W5
break; P PJ^;s
} 76!LMNf
} xh2r?K@k>
4k225~GQ:C
{32m&a
public void splitterStop() (u&x.J
{ ?y?9;;
bStop = true; tKV,
} /9pxEidVAS
IAQ<|3Q
n[Q(q[ULV
} zP44 Xhz
UQu6JkbLL
TLsF c^X
/* pT|s#-}
**FileAccess.java bo|THS
*//文件访问(定位，写) |*c1S -#
package NetFox; xE8?%N U
import java.io.*; _Q1p_sdg
_RaE:)
p-iFe\+
public class FileAccessI implements Serializable{ GURiW42
D3C7f'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U 3< 3T
RandomAccessFile oSavedFile; ?>B?*IK!
long nPos; K) }1;
1b3 a(^^E
}[akj8U
public FileAccessI() throws IOException g[(@@TiG
{ BzfR8mD
this("",0); ':(AiD-}
} 5f7id7SI
." xP{
d3c.lD)L9
public FileAccessI(String sName,long nPos) throws IOException O]tR~a
{ @mCe{r*`
oSavedFile = new RandomAccessFile(sName,"rw"); Kzrd<h]`)
this.nPos = nPos; Br!;Ac&N
oSavedFile.seek(nPos); )c4tGT<
} /Z6lnm7wJ
qHub+"2
M*0^<e~]F
public synchronized int write(byte[] b,int nStart,int nLen) <J<"`xKL
{ :XhF:c[.:
int n = -1; ;8^k=8
try{ 1L*[!QT4
oSavedFile.write(b,nStart,nLen); }>6e-]MHfR
n = nLen; xeFx!$3
} S=,czs3N
catch(IOException e) 684& H8
{ hV(^Y)f
e.printStackTrace (); 0;l~B
} ESB^"|9
RFRXOyGz$
Ef`'r))
return n; !K(
} 08xo_Oysq
7dY_b
JH\:9B+:L
} S'!&,Dxq^
+%XByY5
GM2}]9
/* \OVFZ D
**SiteInfoBean.java MAYb.>X#>
*/ yzK<yvN
package NetFox; <XLaJ;j
, ~ 1+MZ=
)!-gT
public class SiteInfoBean { <OEIG0
@.7/lRr@bp
=p4n@C
private String sSiteURL; //Site's URL ]B )nN':
private String sFilePath; //Saved File's Path =;-C;gn:w
private String sFileName; //Saved File's Name F{jxs/~
private int nSplitter; //Count of Splited Downloading File i975)_X(
!-`L1D_hy
b3%x&H<j
public SiteInfoBean() t[TM\j0jW
{//nSplitter的缺省值为5 ,mz;$z6i
//default value of nSplitter is 5 fJr EDj4(
this("","","",5); i6HRG\9nU
} \H .Cmm^I
XnP?hw%
>s5}pkAv|e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 48wt
{ }ex4dhx2M
sSiteURL= sURL; eOb--@~8
sFilePath = sPath; ?w(hPUd!2
sFileName = sName; KD A8x W
this.nSplitter = nSpiltter; n5C,Z!)z
E "=4(
*{VC<<`
} Rf0so
.hH_1Mo8
d2eXN3"
public String getSSiteURL() oIO@#
{ :!s7B|_U
return sSiteURL; [lML^CYQ
} #qVTB@d
G%HG6
^S`hKv&87
public void setSSiteURL(String value) f#&z m} t
{ 'a0M.*f}G
sSiteURL = value; .I~:j`K6
} ynw(wSH=
Lx>[`QT
K9ia|2f
public String getSFilePath() Jd/d\P
{ _yAY5TIv
return sFilePath; W#U|;@"
} <O=0^V
Wi=zu[[qc
lha;|
public void setSFilePath(String value) eV!(a8
{ d;>G
sFilePath = value; vWmp?m
} *Zg=cI@)(
^[SW07o~
JYj*.Q0
public String getSFileName() iPl,KjGk
{ \dU.#^ryp
return sFileName; =c\(]xX
} #Hr'plg 8
MOh&1]2j5
{HY3E}YJL
public void setSFileName(String value) >{{ds--
{ tJu:N'=Dy
sFileName = value; %r.OV_04
} ]v}W9{sY
dH5*%
!S&/Zp
public int getNSplitter() HqsqUS3[
{ <D:q4t
return nSplitter; " 4#&tNQ
} kjPf%*3
kwaZn~
+a*Ic8*
public void setNSplitter(int nCount) 0xDn!
{ =Pn"nkpML
nSplitter = nCount; |WS@q'
} j~Fd8]@
} h-"q <eY"
6<@+J
4Ia'Yr
/* uQbag]&j
**Utility.java Z1 )1s
*/ uSYI X
package NetFox; Y(`Bc8h
Oto8?4[n
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public class Utility { }~&0<8m
d, g~.iS~
3/usgw1
public Utility() 6oQ7u90z*
{ ea @ H
GIYdI#0RC
&k|EG![
} [u*7( 4e
yqK_|7I+
//线程睡眠 SJ22
public static void sleep(int nSecond) q1YNp`]0i8
{ 4J`-&05O
try{ Ux?G:LLz
Thread.sleep(nSecond); q("l?'
} `Ivt)T+n;
catch(Exception e) E$8-8[
{ c)Ef]E\
e.printStackTrace (); (&)uWjq `
} Pl|I{l*o(`
} xS/=9l/G
8hy1yt6t4~
//日志 Xo(W\Pes
public static void log(String sMsg) ,0HID:&
{ OAo03KW
System.err.println(sMsg); <oP`\m
} n&]J-^Tx
@>'Wiq!
H/W&a2R^P
public static void log(int sMsg) t3}_mJ
{ |9 *$6Y
System.err.println(sMsg); &{WEtaXaa
} h$~$a;2cR
} H.n|zGQTB
4 }_}3.
V^D1:9i
/* p+Bvfn
**TestMethod.java nf_(_O=
*/ Y8s-cc(
package NetFox; jMR9E@>~E
KVoi>?a
\(f82kv
public class TestMethod { Lrx"Hn{
OB(~zUe.R
h9c7P@29
public TestMethod() YE"MtL {
{ ///xx/weblogic60b2_win.exe $1Z3yb^
try{ {![E)~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9<!??'@f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 86&r;c:
SiteFileFetch fileFetch = new SiteFileFetch(bean); bw#\"uJ
fileFetch.start(); E9 #o0Di
} odcrP\S
catch(Exception e){e.printStackTrace ();} V^9%+L+E5
L<<v
C}XB%:5H5
} ocp3JR_0
y(K:,CI
:e_yOT}}
public static void main(String[] args) .$x822
{ :SD3
new TestMethod(); ).C>>1ZC
} V3pn@'pr
} a5g1.6hF
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