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)); ux)*B}/xh
} R y#C#0
for(int i=0;i<nEndPos.length-1;i++) <n06(9BF
{ N0Y4m_dm*
nEndPos = nStartPos[i+1]; @ci..::5
} Ie!&FQe2q
nEndPos[nEndPos.length-1] = nFileLength; kHylg{i{"
} pCrm `hy(
} 0VSIyG_Z
~F@n `!c
!CcDA/0
//启动子线程 )\EIXTZY=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z|$DchC
for(int i=0;i<nStartPos.length;i++) 3MFTP5~
{ 8K?}!$fz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n#b{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5;HGS{`
nStartPos,nEndPos,i); |[Fb&x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hN6wp_
fileSplitterFetch.start(); Vjv6d&Q
} `Ucj_6&Tqs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D@gC(&U/6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~M-L+XZl(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cI@qt>&
nEndPos = " + nFileLength); 2m:K %Em6u
// fileSplitterFetch[nPos.length-1].start(); (0b\%;}
2#R$-*;#
a-Y6ghs
//等待子线程结束 un_NBv}
//int count = 0; ]!"w?-h Si
//是否结束while循环 rFpYlMct
boolean breakWhile = false; su%-b\8K
GI/NouaNfm
,++HiYOG}e
while(!bStop) 8R!-,I"$
{ g^(gT
write_nPos(); c{I]!y^!
Utility.sleep(500); Cm)TFh6
breakWhile = true; n19A>,m
8Iw)]}T'
{+hABusq
for(int i=0;i<nStartPos.length;i++) .=J- !{z
{ ocW~I3
if(!fileSplitterFetch.bDownOver) XV]xym~
{ 8+}rm6Y+
breakWhile = false; <3BGW?=WP
break; l3>e-kP
} XZARy:+bc
} bRy(`
if(breakWhile) q%])dZ!lE
break; #<b\BqYG
zHZfp_I
[znN'Fg:"
//count++; V<S6a
//if(count>4) G&^8)S@1
// siteStop(); <i</pA
} !>> A@3
%K|f,w=m
$.4A?,d
System.err.println("文件下载结束！"); L<@*6QH
} 5)'Y\~2
catch(Exception e){e.printStackTrace ();} ajk}&`Wj"
} B2Y.1mXq
O[t?*m1/
GkI'.
//获得文件长度 XdCP!iq*8
public long getFileSize() E#:!&{O
{ b.RU%Y#>\
int nFileLength = -1; /Tm+&Jd
try{ 2A~o)7JaZ
URL url = new URL(siteInfoBean.getSSiteURL()); \]f+{d-&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j AOy3c
httpConnection.setRequestProperty("User-Agent","NetFox"); dv\bkDF4A
gR# k'
M9R'ONYAa
int responseCode=httpConnection.getResponseCode(); Eqz|eS*6
if(responseCode>=400) (JlPe)Q5
{ z+Fu{<#(
processErrorCode(responseCode); eZ(ThA*2=t
return -2; //-2 represent access is error Gm:s;w-;v
} %6uZb sa
4vWiOcJF!O
PB$beQ
String sHeader; !;,\HvEZYw
-#9et30
x;yvv3-$
for(int i=1;;i++) &Jj|+P-lY
{ +S0aA Wal
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _|I8+(~)
//Utility.log(in.readLine()); >4luZnWMI
sHeader=httpConnection.getHeaderFieldKey(i); XN Uw
if(sHeader!=null) i,<'AL )
{ Itr4Pr
if(sHeader.equals("Content-Length")) #%nV\ Bl
{ T,9q~*"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2sIt~ Gn
break; PY7H0\S)
} \f^xlX3&`
} ca7Y+9< ;
else EQ~<NzRp=
break; %50)?J=zB
} y@~ VE5N
} }8tF.QjR|
catch(IOException e){e.printStackTrace ();} wW*7
catch(Exception e){e.printStackTrace ();} 7ihcjyXB
^@*`vz^_
mTtaqo_Bh
Utility.log(nFileLength); 46D`h!7L
u~M$<|;
n46!H0mJ
return nFileLength; o0`']-)*2
} 6?[P^{GpH
IxuK<Oe:O
rIFW1`N}i
//保存下载信息（文件指针位置） o!+%|V8Y
private void write_nPos() b-VtQ%Q
{ 7nnF!9JOv
try{ *:xOenI
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8]`#ax 5
output.writeInt(nStartPos.length); |D-[M_T5
for(int i=0;i<nStartPos.length;i++) RR[zvH} E
{ */IiL%g4u
// output.writeLong(nPos); /_m)D;!y
output.writeLong(fileSplitterFetch.nStartPos); &^#iS<s1
output.writeLong(fileSplitterFetch.nEndPos); Fdhgm{Y2s
} S=) c7t?a
output.close(); *1["x;A
} kVWcf-f
catch(IOException e){e.printStackTrace ();} E& 6I`8
catch(Exception e){e.printStackTrace ();} z7IJSj1gQI
} Rmmu#-{Y
\O "`o4
kHhp;<
//读取保存的下载信息（文件指针位置） Ny7*MZ-
private void read_nPos() T>% 5<P
{ hJxL|5Uo
try{ rc[~S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9qCE{[(
int nCount = input.readInt(); m_0y]RfG
nStartPos = new long[nCount]; .8s-)I
nEndPos = new long[nCount]; wX}p6yyN
for(int i=0;i<nStartPos.length;i++) \:{K",2
{ YOLzCnI4
nStartPos = input.readLong(); !i-t6f
nEndPos = input.readLong(); LcvczST
} C`_/aR6
input.close(); i,ZEUdd*_
} Hh;lT
catch(IOException e){e.printStackTrace ();} Lq>lj`>
catch(Exception e){e.printStackTrace ();} *tj(,:!
} I{dy,\p
V4jMx[
cX C[O
private void processErrorCode(int nErrorCode) GgY8\>u
{ #fa,}aj
System.err.println("Error Code : " + nErrorCode); ;GG,Z#\m
} =>5Lp
BM?!?
kE<CuO
//停止文件下载 l,h`YIy
public void siteStop() W>a}g[Ad
{ }~zDcj_
bStop = true; )/'WboL
for(int i=0;i<nStartPos.length;i++) td7(444]
fileSplitterFetch.splitterStop(); Vxap+<m
P _fCb
+7w5m
} rZdOU?U
} })^eaLBR4
//负责部分文件的抓取 xS_;p9{E
**FileSplitterFetch.java ' F.^ 8/>
*/ ;=0mL,
package NetFox; _1E c54D
F_:zR,P%#
X,VI5$
import java.io.*; (n7xYGfYS
import java.net.*; 8%B_nVc
9R8q+2
0,RYO :`
public class FileSplitterFetch extends Thread { ;iX~3[]
_f@,)n
>&;J/ME
String sURL; //File URL ]'Eg2(wy
long nStartPos; //File Snippet Start Position zGU MH7 M
long nEndPos; //File Snippet End Position ?:9y !Q=
int nThreadID; //Thread's ID Vv+nq_
boolean bDownOver = false; //Downing is over 7<]&pSt=
boolean bStop = false; //Stop identical %OgK{h
FileAccessI fileAccessI = null; //File Access interface I"czo9Yspd
W8^A{l4
&T,,fz$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I1>f2/$z*
{ Cydo~/
this.sURL = sURL; u|}\Af
this.nStartPos = nStart; 3>VL>;75[
this.nEndPos = nEnd; GYQ:G=
nThreadID = id; A@< !'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HcIJ&".~
} A)9]^@,
3Ed
eGQ4aQhi
public void run() (LTu=1
{ 8m' f8.x
while(nStartPos < nEndPos && !bStop) x`7Le&4f
{ ":+d7xR?o
</_QldL_
,H6P%
try{ j%` C
URL url = new URL(sURL); @Ik5BT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o`Z3}
httpConnection.setRequestProperty("User-Agent","NetFox"); aMe&4Q
String sProperty = "bytes="+nStartPos+"-"; Vn5%%?]J
httpConnection.setRequestProperty("RANGE",sProperty); yT OZa-
Utility.log(sProperty); ib(|}7Je
bgE]Wk0
0o$RvxJ
InputStream input = httpConnection.getInputStream(); 0(+<uo~6p1
//logResponseHead(httpConnection); m33&obSP
ktqFgU#rT
JmCHwyUK?
byte[] b = new byte[1024]; ?0X$ox
int nRead; d>F7i~W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;/+<N
{ [/hoNCH!
nStartPos += fileAccessI.write(b,0,nRead); zu?112-v2
//if(nThreadID == 1) -x6_HibbD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LI}e_=E
} )2y [#Blo
!U@ETo
NqF*hat
Utility.log("Thread " + nThreadID + " is over!"); U3Gg:onuE
bDownOver = true; [\Wl~ a l
//nPos = fileAccessI.write (b,0,nRead); moFrNcso
} Jk}3c>^D
catch(Exception e){e.printStackTrace ();} ?&:N|cltD
} I\1E=6"
} *%jXjTA0D
U>!TM##1QD
k8ILo)
//打印回应的头信息 4S4MQ
public void logResponseHead(HttpURLConnection con) Nk-xnTZ"
{ 8t=H
for(int i=1;;i++) _"Y7}A\9
{ wE1GyN
String header=con.getHeaderFieldKey(i); />Zfx.Aj6
if(header!=null) &#C&0f8PnD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r|}Pg}O
Utility.log(header+" : "+con.getHeaderField(header)); 7<70\6
else 5,XEN$^
break; *.w6=}
} 1 M!4hM Q
} f1SKOq
O2Y|<m
oVk!C a
public void splitterStop() Yf[Cmn
{ $G0e1)D
bStop = true; %9zpPrWF
} DmgDhNXKq
.6[8$8c
.sit5BX
} nl2Lqu1
t5l<Lm)
DHn\ =M
/* w;$elXP|
**FileAccess.java dAG@'A\f
*//文件访问(定位，写) a{7*um
package NetFox; + rB3\R"d
import java.io.*; p Cx_[#DrP
EK>x\]O%T
@+~URIG)
public class FileAccessI implements Serializable{ \``w>Xy8
tAjT-CXg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ![{/V,V]~
RandomAccessFile oSavedFile; \l0!si
long nPos; h] )&mFiE"
s +S6'g--
W)Y-^i5
public FileAccessI() throws IOException #('R`~
{ 8yI4=P"F,
this("",0); 6&E[hvu
} 5![ILa_
nY;Sk#9
u$nmnd`g
public FileAccessI(String sName,long nPos) throws IOException pT+OPOSR
{ 4avkyFj!h
oSavedFile = new RandomAccessFile(sName,"rw"); '9vsv\A&
this.nPos = nPos; OFv-bb*YZ
oSavedFile.seek(nPos); ;X;x.pi
} Z1W%fT
VZamR}x
dXn$XGF%R
public synchronized int write(byte[] b,int nStart,int nLen) -k>k<bDAI
{ )=glN<*?
int n = -1; ?:GrM!kq76
try{ zBI2cB8;P
oSavedFile.write(b,nStart,nLen); R^@`]dX$
n = nLen; &>.QDO
} :O,,fJ<x.O
catch(IOException e) uUBUUr
{ Y._ACQG3
e.printStackTrace (); Qe7 SH{
} o^uh3,.
Ia9!ucN7DA
?o]NV
return n; _^eA1}3
} PCDvEbpG
'q/C: Yo
w5-^Py
} jfvlkE-uK
|d42?7}
Kzt:rhiB
/* rmX5-k
**SiteInfoBean.java FbdC3G|oA
*/ C_[ d
package NetFox; C2iOF/4
m=pH G
RAEN &M
public class SiteInfoBean { &QHmo*
iRW5*-66f
.aK=z)
private String sSiteURL; //Site's URL [;toumv
private String sFilePath; //Saved File's Path (Ze\<Y#cv
private String sFileName; //Saved File's Name `"~X1;
private int nSplitter; //Count of Splited Downloading File 7|J&fc5BP
i7\>uni
kd p*6ynD
public SiteInfoBean() 9)b{U2&
{//nSplitter的缺省值为5 ,pZz`B#
//default value of nSplitter is 5 ^^xzaF
this("","","",5); oe9S$C;$'
} =AHV{V~
E}36
|~Awm"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u91
{ Jx&+e,OST
sSiteURL= sURL; x41t=E](
sFilePath = sPath; "1P2`Ep;
sFileName = sName; _ -ec(w~/
this.nSplitter = nSpiltter; `Sj8IxO
Frhm4H%,_R
~Ty6]A
} hg+;!|ha
FFN.9[Ly
LXe'{W+bk
public String getSSiteURL() zb9vUxN [
{ k'[\r>T
return sSiteURL; hB:+_[=Kj.
} K^I$05idi
)gR3S%Ju
dt>!=<|k
public void setSSiteURL(String value) Z%-uyT@a
{ 6|Rj YX
sSiteURL = value; w'5W L
} ?GZ?HK|
b DF_
YWq{?'AaR
public String getSFilePath() @zix%x
{ sg]g;U
return sFilePath; &)~LGWBdC
} mL,{ZL ^
l4^8$@;s
,6U=F#z
public void setSFilePath(String value) %#]/]B/4
{ Qbj:^{`>(
sFilePath = value; P6tJo{l8w
} I|mxyyf
k"FY &;G(G
Lr>4~1:`
public String getSFileName() { lZ<'p
{ 1T3YFt@&I
return sFileName; dp1t]
} ~-(X\:z}
;Y &2G'
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public void setSFileName(String value) JAL"On#c#0
{ Ly/5"&HD
sFileName = value; eR8>5:V_
} 'ka"0~:NS{
z<<aT
fli7Ow?M~
public int getNSplitter() l}Vg;"1'J
{ gE!`9#..
return nSplitter; t`4o&vsj=
} Qc:Sf46O
a@gm r%C
7.v{=UP
public void setNSplitter(int nCount) ~HgN'#Y?
{ ZW8;?#_
nSplitter = nCount; DZ;2aH
} (WS<6j[q
} SYK?5_804
(pQ$<c
^m^,:]I0P
/* '8Lc}-M4
**Utility.java p WKpc
*/ &[}5yos r
package NetFox; YWa9|&m1
Jbz>j\
$Jj0%?;
public class Utility { Tb]' b
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[k6,!e[/uG
public Utility() x6*.zo5e
{ 9\NP)Vm$^
SVyJUd_
=}4lx^`oeT
} l'Z `%}R
mc5$-}1V,
//线程睡眠 `?Xt ,
public static void sleep(int nSecond) }A_>J7w
{ ~f%AbDye
try{ cE]#23
Thread.sleep(nSecond); E;x~[MA
} K,GX5c5
catch(Exception e) ;%aWA
{ ol8uV{:"
e.printStackTrace (); 6NqLo^ "g
} GUK3`}!%
} 4?&CK
S{ !m})1?
//日志 &28n1
public static void log(String sMsg) Sst`*PX:
{ l{x?i00tAS
System.err.println(sMsg); m4@w M?
} &($Zs'X
32V,25 (`5
FwGMrJW
public static void log(int sMsg) c'6$`nC
{ F1o"H/:n
System.err.println(sMsg); ?rH=<#@
} |k9A*7I
} s97L/iH
_`Sz}Yk
N[,/VCW
/* _.Bite^
**TestMethod.java ) N"gW*
*/ MtO p][i
package NetFox; 0H{0aQQ
Ycx$CUC
0#KB.2AP
public class TestMethod { *`V-zD
pBu~($%d
DV~1gr,\
public TestMethod() 4==LtEp
{ ///xx/weblogic60b2_win.exe \ow0Y>
try{ #TSLgV'U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W(tXq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R OQIw
SiteFileFetch fileFetch = new SiteFileFetch(bean); =<[ZFO~v
fileFetch.start(); &^YY>]1Py
} ,/>~J]:\;
catch(Exception e){e.printStackTrace ();} i(c'94M
DP_bB(
N6<23kYM
} xX.Ox
Mhw\i&*U
v)2@;Q
public static void main(String[] args) bqg\V8h
{ {#y HL
new TestMethod(); ]H|1quT
} .*g;2.-qv&
} br'/>Un"
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