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)); z_)OWWdN
} >e5q2U
for(int i=0;i<nEndPos.length-1;i++) ^!-E`<jW8
{ {Zd)U "
nEndPos = nStartPos[i+1]; ui0J}DM
} z&6]vN'
nEndPos[nEndPos.length-1] = nFileLength; P'FPe55F
} t1*BWY
} BWqik_
[MSDk"o&
ZEXj|wC
//启动子线程 *Xf[b)FR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WOe{mwhhj
for(int i=0;i<nStartPos.length;i++) zz+M1n-;o
{ 4w?]dDyc%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @ ~0G$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), UpE1PLZlB
nStartPos,nEndPos,i); $;KQY7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;%3thm7+
fileSplitterFetch.start(); 9!Q $GE?vl
} Q0[CH~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YFC0KU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]k3GFPw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6KZ8 .m}:
nEndPos = " + nFileLength); 5 O{Ip-
// fileSplitterFetch[nPos.length-1].start(); { c6DT
troy^H
f<$K.i
//等待子线程结束 Dn{19V.L
//int count = 0; TA-(_jm
//是否结束while循环 :_I wc=
boolean breakWhile = false; a{%52B"
"'&>g4F`o
d=c1WK
while(!bStop) *cI6&;y
{ !z"a_
write_nPos(); 3f7t%
Utility.sleep(500); }tl8(kjm
breakWhile = true; H *z0xxa
KNUMz4
gpO_0U4lQ]
for(int i=0;i<nStartPos.length;i++) nf+"vr}1
{ +Y>cBSO
if(!fileSplitterFetch.bDownOver) ,]>`guDV
{ Sx4UaV~"
breakWhile = false; k7Be'E BKG
break; qQ?,|4)y
} *BP\6"X
} 1z$}*`
if(breakWhile) zwniS6R1
break; k8t Na@H
0W<nE[U
`*2*xDuP
//count++; 4BUK5)B
//if(count>4) JE8p5WaR
// siteStop(); ^|:{,d#Y
} v2W"+QS}u
Ej{eq^n
^r?sgJ
System.err.println("文件下载结束！"); ]Pg?(lr6)
} ,~=z_G`R
catch(Exception e){e.printStackTrace ();} ,co9f.(w
} V]CK'
VES4x%r=
D/%b@Ls2ze
//获得文件长度 IZ(CRKCGBl
public long getFileSize() $M8>SLd
{ dBD4ogo1
int nFileLength = -1; ^F{)&#4
try{ p;QX"2
URL url = new URL(siteInfoBean.getSSiteURL()); ?#{2?%_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T\$^>@
httpConnection.setRequestProperty("User-Agent","NetFox"); WriJco<v
N6m*xxI{
( _F
int responseCode=httpConnection.getResponseCode(); lDX&v$
if(responseCode>=400) 0z<]\a4
{ VlQwVe
processErrorCode(responseCode); Wp~4[f`,
return -2; //-2 represent access is error #I{Yf(2Z
} tRrY)eElS
DoPF/m}
I5<#SW\a?
String sHeader; piM11W}|/
%n`iA7j$W
Xk9r"RmiOb
for(int i=1;;i++) j/`qd(=B
{ Lq8Z!AIw>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]F)-}
//Utility.log(in.readLine()); NcY0pAR*
sHeader=httpConnection.getHeaderFieldKey(i); F~0%j}ve
if(sHeader!=null) N~K)0RETn
{ YC,.Y{oY{
if(sHeader.equals("Content-Length")) 3S2p:\]
{ VA&OI;=ri
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ok{:QA~#
break; _F$t#.o
} +$ay"+ d
} CR|&VxA
else kjKpzdbD
break; JgjL$n;F
} ?0)XS<
} < $?}^ 0R
catch(IOException e){e.printStackTrace ();} @Y<ZT;J
catch(Exception e){e.printStackTrace ();} >*Z{@1*h
ug3lMN4UX
yp/V8C
Utility.log(nFileLength); t-gNG!B
hq[gj?P
v>cE59('0
return nFileLength; k2,oyUT=S
} 1NHoIX
,8-_=*
$6x:aG*F
//保存下载信息（文件指针位置） F3r
private void write_nPos() lp%.n= '\
{ JX,#W!d
try{ 1AkHig,
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3Os3=Ix
output.writeInt(nStartPos.length); O.8m%ZjD
for(int i=0;i<nStartPos.length;i++) 4a50w:Jy]
{ YH+\rb_
// output.writeLong(nPos); gm\o>YclS
output.writeLong(fileSplitterFetch.nStartPos); X$KVn`
output.writeLong(fileSplitterFetch.nEndPos); 48NXj\L[y
} 6!D
output.close(); o0+BQ&A)s*
} r^tXr[}
catch(IOException e){e.printStackTrace ();} = (h;L$
catch(Exception e){e.printStackTrace ();} VKJ~ZIO@A
} ^9f`3~!#bc
6XCX#4'i%
7D_kkhN
//读取保存的下载信息（文件指针位置） *SG2k .$
private void read_nPos() ?g#t3j>zoF
{ bFxJ|
try{ ex!wY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gy7x?
int nCount = input.readInt(); adPU)k_j:
nStartPos = new long[nCount]; Lj* =*V
nEndPos = new long[nCount]; cb&In<q
for(int i=0;i<nStartPos.length;i++) teNQUIe-
{ bRe*(
nStartPos = input.readLong(); Saq>o.
nEndPos = input.readLong(); Dj&bHC5%
} ?-&D'
input.close(); c5+lm}R?
} r!gCh`PiK
catch(IOException e){e.printStackTrace ();} <>/MKMq!
catch(Exception e){e.printStackTrace ();} ^* v{t?u
} #$rT 4Nc;
$P9$ ,w4
wgP3&4cSUc
private void processErrorCode(int nErrorCode) 6i=wAkn_J
{ pXEVI6 }
System.err.println("Error Code : " + nErrorCode); V~"d`j
} f]65iE?x
:q[n1 O[Ch
. pEeR
//停止文件下载 (mr`?LI}
public void siteStop() @[Qg}'i
{ l0 :xQV`
bStop = true; k3h53QTmC
for(int i=0;i<nStartPos.length;i++) &{{f|o=u.
fileSplitterFetch.splitterStop(); M\4;d #
BQ)43Rr>
[ +@<T)
} Lk+1r8
} Jm,X~Si
//负责部分文件的抓取 aT1W]i
**FileSplitterFetch.java Y]0y -H
*/ a8P6-)W
package NetFox; CP#MNNvgrw
g' U^fN
T>o# *{qn
import java.io.*; W/X;|m`
import java.net.*; 717m.t,x
,qqV11P]
? NK}q\$
public class FileSplitterFetch extends Thread { fT~<C {
)F2tV ]k\
9+|,aG s
String sURL; //File URL IoX9yGq
long nStartPos; //File Snippet Start Position -T6%3>h
long nEndPos; //File Snippet End Position >{=RQgGy
int nThreadID; //Thread's ID YAG3PWmD
boolean bDownOver = false; //Downing is over Z6ex<[`I
boolean bStop = false; //Stop identical f^)nZ:~
FileAccessI fileAccessI = null; //File Access interface Q'M Ez
3!UP>,!
3`q`W9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oob0^}^
{ j2n@8sCSO
this.sURL = sURL; 0t0:soZx
this.nStartPos = nStart; . M$D
this.nEndPos = nEnd; a{.n(M
nThreadID = id; pD/S\E0@t
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H<?yG->
} 55KL^+-~
haK5Oe/cE
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public void run() 9xp ;$14
{ |?W
while(nStartPos < nEndPos && !bStop) 8{e 3
{ ^:j:;\;
<p .[E]a2_
&NnMz9
try{ hY9u#3
URL url = new URL(sURL); )ISTb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h2<$L
httpConnection.setRequestProperty("User-Agent","NetFox"); 4(ZV\}j1
String sProperty = "bytes="+nStartPos+"-"; >GRuS\B
httpConnection.setRequestProperty("RANGE",sProperty); E/ )+hK&
Utility.log(sProperty); 5E|2S_)G
|g+5rVbd
F9hWB17u
InputStream input = httpConnection.getInputStream(); j(2T,WM
//logResponseHead(httpConnection); [D\AVx&
_s,svQ8#
\OH:xW~
byte[] b = new byte[1024]; 31Du@h8YX
int nRead; ajr8tp'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4!|ar?Zy
{ @SXgaWr
nStartPos += fileAccessI.write(b,0,nRead); ^Y |s^N
//if(nThreadID == 1) =c4U%d2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~`.%n7
} |XZf:}q5:
[%Xfl7;Wh
9$i`B>C~
Utility.log("Thread " + nThreadID + " is over!"); $ 7!GA9Bn
bDownOver = true; 5}ah%
//nPos = fileAccessI.write (b,0,nRead); Dh<e9s:
} cxdM!L; `
catch(Exception e){e.printStackTrace ();} (5 hu W7v
} XPKcF I=
} 58,mu#yq6
;zODp+4@Q
OwUbm0)h^V
//打印回应的头信息 EG6fC4rfC
public void logResponseHead(HttpURLConnection con) IgJC>;]u
{ %4J?xhd
for(int i=1;;i++) !y.7"G*
{ 3\ed4D
String header=con.getHeaderFieldKey(i); IuD<lMeJJ
if(header!=null) 3.Kdz}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;<H2N0qJ(
Utility.log(header+" : "+con.getHeaderField(header)); Hy'&x?F6
else o~p^`5#
break; M`'2 a
} *1Q?~
} GYO"1PM
9:s!#FYFM
?=&*6H_v
public void splitterStop() =j-{Mxb3
{ 3E-&8x7uYR
bStop = true; O8%/Id
} KW\`&ki
\)*qW[C$a
H#K|SSqY?
} ,H8Pmn?
tTal<4
uDR(^T{g#
/* X,~C&#
**FileAccess.java Xob##{P3
*//文件访问(定位，写) PX]v"xf
package NetFox; A:(uK>5{Kk
import java.io.*; Y!zlte|P
62) F
Zlhr0itf
public class FileAccessI implements Serializable{ aoN[mV'
l]gfT&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sXA=KD8
RandomAccessFile oSavedFile; /DCUwg=0
long nPos; T=vI'"w
N{0 D<"
XOMWqQr|
public FileAccessI() throws IOException lx SGvvP4
{ cqDnZ`|6
this("",0); G(i/ @>l
} hE${eJQ| U
fqxMTTg@
ryPzq}#
public FileAccessI(String sName,long nPos) throws IOException p{Uro!J,K
{ S3w? X
oSavedFile = new RandomAccessFile(sName,"rw"); lUmaNZ
this.nPos = nPos; %?ad.F+7
oSavedFile.seek(nPos); -VL3em|0
} Jh1fM`kB5K
8}2 `^<U
* -)aGL
public synchronized int write(byte[] b,int nStart,int nLen) oID,PB*9
{ &LE/hA
int n = -1; wbTw\b=
try{ <#sK~G
oSavedFile.write(b,nStart,nLen); x\WKsc
n = nLen; NeH^g0Q2,g
} GI/o!0"_
catch(IOException e) 70@:!HI]
{ xQ4Q'9
e.printStackTrace (); }/=_
} Yyf8B
[LE_lATjU
3$_wAt4w
return n; Ktoxl+I?
} {>#Ya;E
*:iFhKFU
JdE=!~\8
} {.v+ iSM
t5S S]
~_Aclm?
/* S[Et!gj:
**SiteInfoBean.java /n_N`VJ7H
*/ tG'c79D\
package NetFox; !U@[lBW
K=V)"v5o3
)9s[-W,e
public class SiteInfoBean { CAk.2C/
IIzdCa{l
n=`UhC
private String sSiteURL; //Site's URL EG,RlmcPp
private String sFilePath; //Saved File's Path z[th@!3
private String sFileName; //Saved File's Name B|tP3<
private int nSplitter; //Count of Splited Downloading File cOcm9m#
&W1c#]q@r
P69S[aqW
public SiteInfoBean() 7+fFKZFKF
{//nSplitter的缺省值为5 i9Qx{f88
//default value of nSplitter is 5 3/iGSG`
this("","","",5); U.&=b<f(0r
} ,Ao8QN
E8/P D
7C=t19&R'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (sY?"(~j?T
{ \%UA6uj
sSiteURL= sURL; (fC [Y
sFilePath = sPath; /p~gm\5Z
sFileName = sName; w1[F]|
this.nSplitter = nSpiltter; a!;?!f-i
?g1%-F+
I%|W O*x
} US-P>yF
pl5!Ih6
M*nfWQ a
public String getSSiteURL() dI3U*:$X
{ dLLF#N
return sSiteURL; )!'SSVaRs
} Ef69]{E
) b?HK SqI
(V*ggii@
public void setSSiteURL(String value) M^a QH/=:"
{ Pl U!-7
sSiteURL = value; {A{=RPL
} :*1bhk8~
fn)c&|aCt
mjfU[2
public String getSFilePath() MbYAK-l.h
{ 6#v"+V
return sFilePath; ZhW>H
} Y<l{DmrsA
!$P&`n]@
Ie4}F|#=
public void setSFilePath(String value) &{99Owqg
{ U)2\=%8
sFilePath = value; M '[.ay
} ,u/GA<'#M
CtS*"c,j
nI&Tr_"tm
public String getSFileName() 72.ZE%Ue
{ Ygr1 S(=
return sFileName; w[t!?(![>
} Iq MXd K|
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y8VLFe;
public void setSFileName(String value) \f.ceh;!
{ bmFnsqo
sFileName = value; 49cQA$Ad
} zxY
~]3y667
k1W q$KCwG
public int getNSplitter() iXeywO2nP
{ zmF_-Q`c
return nSplitter; F|9 W7
} Qn_*(CSp
h5>JBLawQP
7YrX3Hx8
public void setNSplitter(int nCount) 46Vx)xX
{ YQLp#
nSplitter = nCount; (=,p"3^
} l-g+E{ZM
} I8rtta
C[gy{40}
4fgA3%
/* '7 SFa]tH
**Utility.java a~jM^b;VN
*/ G<U MZg
package NetFox; 6x7pqHM
{dTtYL$'"
@|sDb?J
public class Utility { [kaj8
r$<[`L+6
1 :<f[l
public Utility() 8SR~{
{ _gxI=EYi
_Gvn1"l
|5^tp
} e4ym6q<6!
kO>F, M
//线程睡眠 .IXkdy
public static void sleep(int nSecond) |]y]K%
{ v!JQ;OX
try{ BxVo>r
Thread.sleep(nSecond); 0rP`BK|
} bS[;d5
catch(Exception e) p'tB4V qT
{ 5ELKL#(
e.printStackTrace (); Zl^#U c"
} bxLeQWr6
} d2Pqi* K
( E;!.=%
//日志 ~H`~&?
public static void log(String sMsg) 3Uw}!>`%
{ {a;my"ly
System.err.println(sMsg); JI##l:,7r
} R-5EztmLae
s~V%eq("}
N{w)}me[YY
public static void log(int sMsg) .sCi9d WR
{ V/"P};n
System.err.println(sMsg); lB3@jF
} X] cI ?
} I@ "%iYL
~?`V$G=?,
qD0sD2 x
/* HE6kt6
**TestMethod.java f}qR'ognUu
*/ av~dH=&=
package NetFox; &iYy
jg%HaA<zO
W(.q.Sx>
public class TestMethod { >..C^8 "
m$6u K0
F6,[!.wl
public TestMethod() <O+T4.z
{ ///xx/weblogic60b2_win.exe ;]XKe')
try{ G>Uam TM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pH!e<m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MOp06
SiteFileFetch fileFetch = new SiteFileFetch(bean); fg}&=r
fileFetch.start(); C 0@tMB7
} BUhLAO
catch(Exception e){e.printStackTrace ();} Y;n;7M<F
P4H%pm{-
2g?O+'JD
} 8y:c3jzP_
l.gt+e
c0}* $e
public static void main(String[] args) =GGt:3Kx-
{ oVDqX=G
new TestMethod(); ?2LRMh")$
} 98"/]ERJ
} iPoh2
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