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)); _iA oNT!
} `uDOIl
for(int i=0;i<nEndPos.length-1;i++) tJ7tZ~Ak
{ Z"l].\= F
nEndPos = nStartPos[i+1]; _/ 5
} vEE\{1
nEndPos[nEndPos.length-1] = nFileLength; ^;{uop"DS
} -:!Wds
} r|z B?9Q
G `eU
Om;`"5
//启动子线程 W}k/>V_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K4RQ{fWpm
for(int i=0;i<nStartPos.length;i++) 00>knCe6
{ c[3x>f0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), klc$n07
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L[5U(`q[
nStartPos,nEndPos,i); benqm ~{\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b!/-9{
fileSplitterFetch.start(); %ol1WG9
} GAs.?JHd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), svt3gkR0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [tC=P&<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Oku7&L1
nEndPos = " + nFileLength); g%)cyri
// fileSplitterFetch[nPos.length-1].start(); 39pA:3iTd
Q7zpu/5?
N3)n**
//等待子线程结束 d|gfp:Z`a
//int count = 0; 8X? EB6=c
//是否结束while循环 ~XXNzz]?
boolean breakWhile = false; oOLj? 0t
W8-vF++R
J_<6;#
while(!bStop) X_3hh}=
{ oZL# *Z(h
write_nPos(); "ChJR[4@
Utility.sleep(500); lQRtsmZ0
breakWhile = true; w}97`.Kt!n
D)[(
pOB<Bx5t
for(int i=0;i<nStartPos.length;i++) K|D1
{ ^@Qc!(P
if(!fileSplitterFetch.bDownOver) W%MS,zkAE
{ +T,0,^*
breakWhile = false; Xe\v6gbD
break; #Hl?R5
} L|'B*
} VTX6_&Hc1g
if(breakWhile) bq8h?Q
break; QM~~b=P,\
NE &{_i!
#7YJ87<E
//count++; gTLBR
//if(count>4) o>]z~^c
// siteStop(); G~4G$YL*
} M D&7k,!
<a+@4d;
B<G,{k
System.err.println("文件下载结束！"); w)R5@ @C*
} s._,IW;
catch(Exception e){e.printStackTrace ();} g">^#^hBE
} {=,I>w]T|W
+KTHZpp!c2
.jbxA2
//获得文件长度 CFoR!r:X
public long getFileSize() r&F 6ZCw
{ 4`o<e)c3
int nFileLength = -1; \0e`sOS`L
try{ nYBa+>3BDf
URL url = new URL(siteInfoBean.getSSiteURL()); ^nFP#J)_5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?1LRR ;-x
httpConnection.setRequestProperty("User-Agent","NetFox"); ^q|W@uG-(
HHs!6`R$0c
v@J[qpX
int responseCode=httpConnection.getResponseCode(); ?jvuTS2
if(responseCode>=400) #\K"FE0PGz
{ <LJb,l"
processErrorCode(responseCode); mwZ)PySm)
return -2; //-2 represent access is error lPtML<a
} Jm0.\[J
&xt GabNk
)4,U
String sHeader; -I;\9r+
f)r6F JLU
50T^V`6
for(int i=1;;i++) ##alzC
{ v}IhO~`uEq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Otf{)f
//Utility.log(in.readLine()); s5*HS3D
sHeader=httpConnection.getHeaderFieldKey(i); D O||o&u
if(sHeader!=null) 2,|;qFJY-@
{ ~Jj~W+h
if(sHeader.equals("Content-Length")) Tgbq4xR(
{ -]n%+,3L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y(^\]-fE
break; W|s";EAM
} M7&G9SGZ
} P>`|.@
else nC!L<OMr
break; EP+LK?{%
} &$l#0?Kc^
} M23r/eg]
catch(IOException e){e.printStackTrace ();} sN#ju5
catch(Exception e){e.printStackTrace ();} $>+g)
kZi/2UA5Z
dB:c2
Utility.log(nFileLength); mGkQx -|
uW!saT5o
#nAq~@X
return nFileLength; ;&O *KhLH
} [r'A8!/|[
ki1j~q
&H+n0v
//保存下载信息（文件指针位置） ' d?6 L
private void write_nPos() 7lKatk+7K
{ "I9r>=
try{ Zp9kxm'
output = new DataOutputStream(new FileOutputStream(tmpFile)); >6)|>#Wi
output.writeInt(nStartPos.length); lJT"aXt'M
for(int i=0;i<nStartPos.length;i++) 7;&,LH
{ Sn' +~6i
// output.writeLong(nPos); ,g,Hb\_R)
output.writeLong(fileSplitterFetch.nStartPos); cRWB`&
output.writeLong(fileSplitterFetch.nEndPos); lWT`y
} <vD(,||
output.close(); n.C5w8f
} H/={RuU
catch(IOException e){e.printStackTrace ();} kJNwA8 7
catch(Exception e){e.printStackTrace ();} h@y>QhYU0
} hr hj4
8Kk41=
m^,VEV>
//读取保存的下载信息（文件指针位置） TZ!@IBu
private void read_nPos() S_;r!.
{ 8lA,3'z
try{ W,_2JqQp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @YG-LEh
int nCount = input.readInt(); h ^s8LE3
nStartPos = new long[nCount]; JO90TP $
nEndPos = new long[nCount]; I`i"*z
for(int i=0;i<nStartPos.length;i++) t*u#4I1
{ :M<] 6o
nStartPos = input.readLong(); [9#zEURS
nEndPos = input.readLong(); )OVa7[-T
} (XY`1|])`
input.close(); gFTlP
} }d;6.~Gw
catch(IOException e){e.printStackTrace ();} <iGW~COd
catch(Exception e){e.printStackTrace ();} l"jYY3N|h
} ~-B+7
zgH*B*)bj
4??LK/s*
private void processErrorCode(int nErrorCode) ARs]qUY
{ =2ED w_5E
System.err.println("Error Code : " + nErrorCode); g2=PZR$
} y~VI,82*
$em'H,*b3
='m%Iq7X
//停止文件下载 z0#2?o
public void siteStop() ,CuWQ'H
{ qPN9Put
bStop = true; %O<8H7e)V
for(int i=0;i<nStartPos.length;i++) PL3hrI 5
fileSplitterFetch.splitterStop(); Kpa$1x
D!.1R!(Z
w*;"@2y;eY
} `u PLyS.
} lBAu@M
//负责部分文件的抓取 m]vV.pwv
**FileSplitterFetch.java fFWi 3.
*/ Hrph>v
package NetFox; 6 .)Xeb"
R^P>yk8
"Aw)0a[j1
import java.io.*; H\\FAOj
import java.net.*; 5Z5x\CcC3
<V Rb
Id>4fF:o
public class FileSplitterFetch extends Thread { t8rFn
D|Wlq~IpQ
D}j`T
String sURL; //File URL kxJ[Bi#
long nStartPos; //File Snippet Start Position j0V/\Ep)T<
long nEndPos; //File Snippet End Position QCE7VV1Rw
int nThreadID; //Thread's ID 0Oc?:R'$
boolean bDownOver = false; //Downing is over $(]nl%<Q
boolean bStop = false; //Stop identical X{OWDy
FileAccessI fileAccessI = null; //File Access interface !2Z"Lm
' VKD$q
:."oWqb)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n+te5_F
{ jlFlhj:/I
this.sURL = sURL; di0@E<@1:
this.nStartPos = nStart; L$.3,./
this.nEndPos = nEnd; 0yq
nThreadID = id; vv{+p(~**O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4KnBb_w
} zB~<@
Y:t?W
f.+1Ubq!5
public void run() WvSm!W
{ 9OW8/H&!
while(nStartPos < nEndPos && !bStop) }u=Oi@~
{ =!xX{o?64
D&D6!jz
"QiR
try{ PPIO<K 3`
URL url = new URL(sURL); $?bD55
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L\E>5G;
httpConnection.setRequestProperty("User-Agent","NetFox"); ]+W){W=ai
String sProperty = "bytes="+nStartPos+"-"; O=(F46 M
httpConnection.setRequestProperty("RANGE",sProperty); EwA*
Utility.log(sProperty); 4gsQ:3
7bihP@I!
VJ&<6
InputStream input = httpConnection.getInputStream(); ,m5i(WL
//logResponseHead(httpConnection); p\lR1
UU MB"3e
E5M/XW\E6
byte[] b = new byte[1024]; !]82$
int nRead; |D"L!+J-$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #?jsC)
{ Z?!AJY
nStartPos += fileAccessI.write(b,0,nRead); 3IlVSR^py
//if(nThreadID == 1) ,aC}0t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1BZ##xV*:G
} 3Z=yCec]
;p`to"6IFD
~uty<fP
Utility.log("Thread " + nThreadID + " is over!"); /pPHD]
bDownOver = true; PQ[?zNrSV
//nPos = fileAccessI.write (b,0,nRead); X )tH23
} -bzlp7q*
catch(Exception e){e.printStackTrace ();} 5~@-LXqL
} aaT3-][
} cK u[4D{
k'#3fz\
iC=>wrqY>
//打印回应的头信息 +KIz#uqF8Z
public void logResponseHead(HttpURLConnection con) X~0-WBz
{ _#:7S sJ
for(int i=1;;i++) OB$Jv<C@
{ pTwzVz~
String header=con.getHeaderFieldKey(i); Pd"c*n&9
if(header!=null) a'?;;ZC-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a(]&H "
Utility.log(header+" : "+con.getHeaderField(header)); e8^/S^ =&d
else m1Ya
break; `?(J(H
} &l1t5 !
} fI<LxU_n:
O8A1200
f(D'qV T{
public void splitterStop() $) "\N
{ RBn/7
bStop = true; A+* lV*@0
} L,y q=%h|
8xgBNQdPT
ocZ}RI#Q
} ?%hd3zc+f
nsU7cLf"^V
N'WTIM3W
/* vHcl7=)Q
**FileAccess.java 6dr'nP
*//文件访问(定位，写) \EVT*v=}/
package NetFox; x,25ROaHY
import java.io.*; y 2> 93m
-6kX?sNl)X
>B**fZ~L
public class FileAccessI implements Serializable{ @i>)x*I#AI
BNCM{}e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '`k7l7I[@
RandomAccessFile oSavedFile; |ffHOef
long nPos; K?'m#}]
)2?]c
zMbFh_dcq
public FileAccessI() throws IOException 18rV Acj
{ Y:TfD{Xgc
this("",0); QjY}$
} 7CH&n4v
KJec/qca
cLf90|YFp
public FileAccessI(String sName,long nPos) throws IOException L{%L*z9J
{ l%"DeRp,/
oSavedFile = new RandomAccessFile(sName,"rw"); k4LrUd
this.nPos = nPos; ?5nEmG|kO
oSavedFile.seek(nPos); [S,$E6&j$"
} |w|c!;,
pS+w4gW
?;~E*kzO&
public synchronized int write(byte[] b,int nStart,int nLen) ~F'6k&A^q
{ m_/Ut
int n = -1; u'l4=e
try{ ojnO69v
oSavedFile.write(b,nStart,nLen); c8X;4 My
n = nLen; >2{Y5__+e
} q@bye4Ry%W
catch(IOException e) giNXXjl
{ J\*uW|=F
e.printStackTrace (); _F6<ba}o3
} ^t4^gcoZ4Z
';FJs&=I
wz`% (\
return n; piM4grg \
} $TXiWW+
|hika`35K
3k/E$wOj
} \[3~*eX6
h6D4CT
)mm0PJF~q
/* _{k*JT2
**SiteInfoBean.java >B0AJW/u
*/ +=E\sEe
package NetFox; \KhcNr?ja=
(_e[CqFu
vlkwWm
public class SiteInfoBean { $8eiifj
,@f"WrQ
\HLo%]A@M
private String sSiteURL; //Site's URL !lNyoX/
private String sFilePath; //Saved File's Path ; oa+Z:;f
private String sFileName; //Saved File's Name vEg%ivj3
private int nSplitter; //Count of Splited Downloading File 0QZT<Zs
'/8/M{`s
b:F;6X0~Hl
public SiteInfoBean() PEvY3F}_rh
{//nSplitter的缺省值为5 xS1n,gTA
//default value of nSplitter is 5 USyc D`
this("","","",5); )v;O2z
} B=d<L^
I+kAy;2
-8qCCV&1i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1}\p:`
{ 3Sfd|0^
sSiteURL= sURL; k^%=\c
sFilePath = sPath; LhLAQ2~
sFileName = sName; GoybkwFjZ
this.nSplitter = nSpiltter; w~6UOA8}
g0zzDv7~
Mrrpm%Y
} sr;&/l#7h
>ZOlSLu
5m~9Vl-&
public String getSSiteURL() $XQgat@&]
{ \09A"fs{
return sSiteURL; @)h>vg
} Yg.[R] UC
HZ'rM5Kq
Yt#; +*d5
public void setSSiteURL(String value) F0_w9"3E~
{ fU|v[
sSiteURL = value; V_~lME
} Jd7chIK
M99ku'
6m?<"y8]
public String getSFilePath() XF(D%ygeC
{ =Iop
return sFilePath; myfTztJ
} 6{.U7="
(y]Z*p:EW
L@H^?1*L?
public void setSFilePath(String value) U_IGL
{ o.!o4&WH
sFilePath = value; fPD.np}
} ?P+Uv
p48enH8CO
q3#[6!
public String getSFileName() nvndgeSy
{ WCsf_1
return sFileName; GrG'G(NQ
} gV.?Myy
^o5;><S]
GV0@We~
public void setSFileName(String value) w|&lRo@1
{ i+O7,"(@
sFileName = value; 'l5
} &6s&nx
x,mt}>
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public int getNSplitter() `$> Y
{ QtnNc!,n
return nSplitter; [voZ=+/
} ~Fh+y+g?
+ytP5K7
q~> +x?30
public void setNSplitter(int nCount) RWR{jM]V
{ } TUr96
nSplitter = nCount; oVK:A;3T|
} a,oTU\m C
} PoaCnoNS
vU%K%-yXG7
;w.la
/* "yQBHYP
**Utility.java [mv? \HDa~
*/ 9 3)fC
package NetFox; ^Saf z8-3o
*4 LS``
K[iAN;QCe%
public class Utility { |c0^7vrC
fd *XK/h
R-m5(
public Utility() %/I:r7UR{
{ By@65KmR"
Yd4X*Ua
=7}1NeC`
} iHNQxLkk{:
\Ki3ls
//线程睡眠 Ac U@H0
public static void sleep(int nSecond) AwG0E`SU
{ )dfhy
try{ ]^"Lc~w8&
Thread.sleep(nSecond); w?_8OJ
} O=bkq}
catch(Exception e) 2gO@
{ _0$>LWO~
e.printStackTrace (); !$l<'K$
} Brxnl,%\
} 5!A:xV]6]
4)e1K/PJ)
//日志 Fb1<Ic#
public static void log(String sMsg) VX&g[5zr
{ 6Tmz!E0
System.err.println(sMsg); 9 RDs`>v
} {v'eP[
EpF9&)
z$^wCd:
public static void log(int sMsg) X% 05[N
{ <J%Z?3@T
System.err.println(sMsg); Kkq-x'gt^
} Y$v d@Q
} XdA]);,
@cIYS%iZ
NB<8M!X/
/* ?<4pYEP
**TestMethod.java ~"%'(j_4
*/ Ry}4MEq]
package NetFox; 2fkyz
&*/= `=:C8
uT=r*p(v
public class TestMethod { h'S0XU ;
TP#Ncqh
g8E5"jpXx3
public TestMethod() a^LckHPI>
{ ///xx/weblogic60b2_win.exe ~.x#ic
try{ `scW.Vem
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5)Z=FUupA~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qnyacI
SiteFileFetch fileFetch = new SiteFileFetch(bean); nmn/4>
fileFetch.start(); GpTZp#~;
} .$peq
catch(Exception e){e.printStackTrace ();} >dK0&+A
G.O;[(3ab
neu<zSS
} Q^va+O
!+$QN4{9
.Bkfe{^
public static void main(String[] args) l4$ sku-
{ L *\[;.mk
new TestMethod(); 9j^rFG!n
} CC^]Y.9
} 9LPXhxNwB
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