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)); N0=ac5
} ?hWwj6i&
for(int i=0;i<nEndPos.length-1;i++) S!3S4:]B^
{ NZ-\h
nEndPos = nStartPos[i+1]; c(n&A~*AJ%
} isZAoYVu
nEndPos[nEndPos.length-1] = nFileLength; 'toa@5
} nx^]>w
} B{C??g8/
Xp8]qH|K
vL\&6n~M>
//启动子线程 <B6&I$Wc+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d)R:9M}v
for(int i=0;i<nStartPos.length;i++) KB'qRnkc
{ sPMa]F(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V8HnUuz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N.]qU d
nStartPos,nEndPos,i); :SGF45>B@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9lW;Nk*j:
fileSplitterFetch.start(); Eg2[k.{P
} MF'$~gxo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t$xY #:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ghX|3lI\q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", krC{ed
nEndPos = " + nFileLength); (h5'9r
// fileSplitterFetch[nPos.length-1].start(); 8rMX9qTO@
Ar:*oiU
!2'jrJGc
//等待子线程结束 L?Qg#YSd~
//int count = 0; dUF&."pW e
//是否结束while循环 7"w2$*4'0
boolean breakWhile = false; -xDGH
5KDGSo
`}lJH i
while(!bStop) bBS,-vN
{ bLQ ^fH4ww
write_nPos(); u#V5?i
Utility.sleep(500); K!'AkTW+-
breakWhile = true; _`_%Y(Xat
w - Pk7I
'eJ+JM<0%
for(int i=0;i<nStartPos.length;i++) lI-L` x
{ o_D?t-XH
if(!fileSplitterFetch.bDownOver) Lv'D^'I
{ 6C]1Q.f;
breakWhile = false; S`"LV $8
break; M\Z6$<H?U
} I-WhH>9
} &znQ;NH#
if(breakWhile) m"fNK$_d
break; kRTwaNDOD
_%B^9Yl3(
@H7Wb}
//count++; >9q&PEc
//if(count>4) |iR T! ]
// siteStop(); (A?H1 9
} |d*&y#kV
ewfP G,S
rfgI$eu
System.err.println("文件下载结束！"); E7CH^]x
} Wo7F
catch(Exception e){e.printStackTrace ();} Tjl:|F8
} OnF3lCmu
pDh{Z g6t
-|Y(V5]
//获得文件长度 BVr0Gk
public long getFileSize() v|Yh w
{ Xy@7y[s]
int nFileLength = -1; Pj4/xX
try{ *+\SyO
URL url = new URL(siteInfoBean.getSSiteURL()); h~p>re
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7G\\{
httpConnection.setRequestProperty("User-Agent","NetFox"); H'LD}\K l
j8fpj{hp
;Ww7"-=sw
int responseCode=httpConnection.getResponseCode(); FRS>KO=3
if(responseCode>=400) {2+L@
{ ;[W"mlM
processErrorCode(responseCode); UQ+?\wi*
return -2; //-2 represent access is error VH(S=G5Yb
} F@*+{1R
)QG<f{wS
`X`2:@gQ
String sHeader; E[*Fz1>
aS pWsT
#F*1V(!
for(int i=1;;i++) )*Q-.Je/U
{ KM!k$;my
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6X\ 2GC9
//Utility.log(in.readLine()); =Apxdnz,
sHeader=httpConnection.getHeaderFieldKey(i); {qmdm`V[
if(sHeader!=null) o.'g]Q<}UB
{ TP"1\O
if(sHeader.equals("Content-Length")) {O,{c\
{ Uv?|G%cD-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KLL;e/Gf
break; V hk_
} TzntO9P+
} 0%Z]h?EYy|
else u&9 r2R959
break; ]\xy\\b/`
} ]_8qn'7
} i@B[ eta
catch(IOException e){e.printStackTrace ();} ~>:Z6Le@
catch(Exception e){e.printStackTrace ();} h?f>X"*|(
MUA%^)#u4Q
wo3wtx
Utility.log(nFileLength); ylB7*>[
m@Qt.4m%g
X5`AGyX
return nFileLength; KMV=%o
} ?qX)ihe%k
:Pg}Zz<
n f.wCtf].
//保存下载信息（文件指针位置） 4<?8M vF
private void write_nPos() ;i"*Ll>Q)
{ Y)$ ;Ax-D
try{ #."Hh<C
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3`#6ACF
output.writeInt(nStartPos.length); m1IKVa7-\}
for(int i=0;i<nStartPos.length;i++) 6sE{{,OGB
{ !p[9{U->o;
// output.writeLong(nPos); g(Io/hyj
output.writeLong(fileSplitterFetch.nStartPos); #!$GH_
output.writeLong(fileSplitterFetch.nEndPos); `c69?/5
} sj8~?O
output.close(); Ht-t1q
} w~;I7:
catch(IOException e){e.printStackTrace ();} eh,~F
catch(Exception e){e.printStackTrace ();} i:cXwQG}B
} Pf$pt
r 3M1e+'fc
DwV4o^J:l
//读取保存的下载信息（文件指针位置） `zR+tbm
private void read_nPos() Kv rX{F=
{ $rhgzpZ!X_
try{ uu/+.9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d @*GUmJ
int nCount = input.readInt(); @_"9Dy Y%
nStartPos = new long[nCount]; O4g+D#Lu
nEndPos = new long[nCount]; rx5B=M
for(int i=0;i<nStartPos.length;i++) `xc^_781\
{ 7]BW[~77
nStartPos = input.readLong(); Hi yc#-4
nEndPos = input.readLong(); Lj"A4i_
} TP}h~8 /;
input.close(); R.s^o]vT
} Ic{F*nnM
catch(IOException e){e.printStackTrace ();} `g_"GE
catch(Exception e){e.printStackTrace ();} p)=~% 7DV
} YqV8D&I
37q@rDm2
ZKz,|+X0G
private void processErrorCode(int nErrorCode) ?6k}ii!c
{ * FeQ*`r
System.err.println("Error Code : " + nErrorCode); -@F fU2
} (Si=m;g
.,i(2^
*1'`"D~
//停止文件下载 QnI.zq V
public void siteStop() >?]_<:
{ `Bw9O%]-S
bStop = true; bC^(U`y32
for(int i=0;i<nStartPos.length;i++) 9~0^PzTA
fileSplitterFetch.splitterStop(); ;ml 3
)%X;^(zKM
/q@s
} 3s:%2%jVK
} +'G0{;b
//负责部分文件的抓取 <|*'O5B
**FileSplitterFetch.java om3`[r[{
*/ }%-t+Tf,
package NetFox; #-"VS-.<
J@L9p46,
S|zW^|YU
import java.io.*; <X_!x_x
import java.net.*; v6GsoQmA
jhGlG-^
$3d}"D
public class FileSplitterFetch extends Thread { ;D.h65rr
+"ueq
cM&2SRBZ
String sURL; //File URL M('d-Q{B7L
long nStartPos; //File Snippet Start Position y#<MVH
long nEndPos; //File Snippet End Position npDIX
int nThreadID; //Thread's ID zD)pF1,7:8
boolean bDownOver = false; //Downing is over ==H$zmK
boolean bStop = false; //Stop identical QJW`}`R
FileAccessI fileAccessI = null; //File Access interface Vi]c%*k
fIocq
G2#d$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y=*P 8pg
{ 0fs$#j
this.sURL = sURL; gFPi7 o1
this.nStartPos = nStart; =pIy
this.nEndPos = nEnd; s-W[.r|
nThreadID = id; 7dX/bzUVz8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M0c9pE
} o+?rI p
UkfB^hA
W"Jn(:&
public void run() 8yWoPm<A
{ %>WbmpIyc
while(nStartPos < nEndPos && !bStop) e9^2,:wLB
{ tehUD&
.5Q:Xp
l+wc'=]
try{ 4.K'\S
URL url = new URL(sURL); a45ss7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^# A.@
httpConnection.setRequestProperty("User-Agent","NetFox"); }E}8_8T6
String sProperty = "bytes="+nStartPos+"-"; jko"MfJ
httpConnection.setRequestProperty("RANGE",sProperty); 2uk x (Z
Utility.log(sProperty); cE{ =(OQ
#)`A7 $/,
6<5Jq\-h
InputStream input = httpConnection.getInputStream(); O}#yijU3e
//logResponseHead(httpConnection); O{k:yVb
"%@uO)A /
plV7+?G
byte[] b = new byte[1024]; DJQglt}~
int nRead; 8@M'[jT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) np WEop>
{ ]$M<]w,IJ2
nStartPos += fileAccessI.write(b,0,nRead); cUK\x2
//if(nThreadID == 1) 'FzN[% K"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fMeZ]rb
} M;Wha;%E"
0m+8P$)C%
fj4^VXD
Utility.log("Thread " + nThreadID + " is over!"); n~Szf
bDownOver = true; }~o ikN:
//nPos = fileAccessI.write (b,0,nRead); qUf)j\7"Fn
} Z0fJ9HW
catch(Exception e){e.printStackTrace ();} &!y]:CC{
} -U>7 H`5
} ]=D5p_A(
{6xPdUhw
>&H~nGP.
//打印回应的头信息 t#<KxwhcN
public void logResponseHead(HttpURLConnection con) hN(L@0)
{ '5};M)w
for(int i=1;;i++) b0a}ME&1
{ L8V3BH7B
String header=con.getHeaderFieldKey(i); C%ytkzG_
if(header!=null) 5@XV6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hkW{88
Utility.log(header+" : "+con.getHeaderField(header)); qSQ@p\O~
else PMKb ]y
break; 135vZ:S
} 9DEh*%q
} jxy1
2W3W/> 2h
$Kq<W{H3ut
public void splitterStop() B;-2$ 77
{ [U_[</L7
bStop = true; 0k?Sq#7q
} >$F:*lO
k_3j '
qa}>i&uO
} CtT~0Y|
;o$;Z4:.D
;IC'Gq
/* KtTza5aF
**FileAccess.java kb|eQtH
*//文件访问(定位，写) bZ#X9fT
package NetFox; F$*3@Y
import java.io.*; B4O6>'
=ef1XQ{i*
h39e)%x1
public class FileAccessI implements Serializable{ _@E "7<\
G[q9A$yw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g8yN%)[
RandomAccessFile oSavedFile; _=6OP8
long nPos; fr#Qz{
yL"i
#'>?:k
public FileAccessI() throws IOException S!7g)
{ iMWW%@U^=
this("",0); e~Hr(O+;e6
} GOW"o"S
p`GWhI?
ek[kq[U9
public FileAccessI(String sName,long nPos) throws IOException :l~EE!
{ ~|R[O^9B
oSavedFile = new RandomAccessFile(sName,"rw"); 5.k}{{+
this.nPos = nPos; >38 Lt\
oSavedFile.seek(nPos); G&o64W;-s
} 0VIZ=-e
k_Tswf3
1D$::{h
public synchronized int write(byte[] b,int nStart,int nLen) d_iY&-gq/
{ baIbf@t/
int n = -1; l7Lj[d<n
try{ a`38db(z
oSavedFile.write(b,nStart,nLen); pb$fb
n = nLen; $WNG07]tU
} m;h<"]<
catch(IOException e) 6{7 3p@
{ )nnCCRS6
e.printStackTrace (); L*O>IQh2
} qG^_c;l6a
k6J\Kkk(
1CiA 8
return n; S$K}v,8.sr
} M]B3vPA/v
W^(Iw%ek
taCCw2s-8*
} m %Y(O
F;a3
l7Y8b`
/* WFj*nS^~l
**SiteInfoBean.java O!];_q/
*/ ss; 5C:*y
package NetFox; S*rO0s:
`r]TA]DR
yId;\o B
public class SiteInfoBean { y.fs,!|%@
&9@gm--b:
_vIO!*h0
private String sSiteURL; //Site's URL fkBLrw
private String sFilePath; //Saved File's Path 8;8YA1@w
private String sFileName; //Saved File's Name od(:Y(4
private int nSplitter; //Count of Splited Downloading File <p)Z/
#|ddyCg2
/4H[4m]I
public SiteInfoBean() fPrb%
{//nSplitter的缺省值为5 tO4):i1
//default value of nSplitter is 5 yXXvs'$R \
this("","","",5); s@z{dmL
} 2)?
lDlj+fK
I)rGOda{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [%t3[p<)O
{ 9H[/Tj-;
sSiteURL= sURL; W'V@
sFilePath = sPath; Hy;901( %
sFileName = sName; a!?.F_T9A
this.nSplitter = nSpiltter; +h|K[=l\
n_u`B|^Pj
UE{,.s
} }<.7xz|V
@?Fx
[='p!7z
public String getSSiteURL() aSTFcz"
{ m'SmN{(t
return sSiteURL; y3IA '
} *i%.{ YH
N tO?
pY,O_ t$
public void setSSiteURL(String value) ?-d Ain1w
{ e"PMvQ
sSiteURL = value; srsK:%`
} @7)Z
n+X1AOE[L
fMyE&#}z
public String getSFilePath() |@+8]dy:l
{ [qW<D/@
return sFilePath; zdqnL^wb
} {f&NStiB
3y/1!A3
9E^~#j@Zr
public void setSFilePath(String value) m,=)qex
{ .B6`OX&k
sFilePath = value; QTeFR&q8
} 8i[".9}G\
,;7`{Nab
E3LBPXK
public String getSFileName() W\'Nv/L
{ 1Jl{1;c
return sFileName; 7F=2t_2O
} P&,hiGTDi
>/8ru*Oc
I'xC+nL@
public void setSFileName(String value) /z..5r^,ZZ
{ .r7D)xNa@
sFileName = value; Q6eN+i2 ;
} ZU)BJ!L,s
>1m)%zt
xnT3^ #-h
public int getNSplitter() lD9%xCo9(
{ g)X7FxS,z
return nSplitter; &3WkH W
} Mp^^!AP9
4|FRg
NP$e-" 1
public void setNSplitter(int nCount) ^v ]UcnB0
{ `}[VwQ
nSplitter = nCount; yLjV[qP
} +g)_4fV0|
} N&?T0Ge;
lt{lHat1
`i=JjgG@
/* h-Tsi:%b
**Utility.java =d}gv6v2S
*/ *Yj~]E0`1
package NetFox; \5t`p67Ve_
ESn6D@"
D&4u63^
public class Utility { D~5yj&&T;
sKe,
7U&5^s )J
public Utility() .4H_Zt[2
{ 1d/NZJ9
Po'-z<}wS
+ylxezc
} O~${&(
P/C&R-{')
//线程睡眠 j?Cr31
public static void sleep(int nSecond) RP,A!pa@
{ qUifw @
try{ _{lx*dq
Thread.sleep(nSecond); ;,<r|.6U
} \s.1R/TyD
catch(Exception e) P#w}3^
{ r hiS
e.printStackTrace (); m$7x#8gF
} +8Of-ZUx
} m5X3{[a:
u+I3IdU3
//日志 wy,Jw3
public static void log(String sMsg) J"/JRn
{ 5dg-d\6S
System.err.println(sMsg); |P^]@om
} '.]e._T
,DexJ1
h9w@oRp`~
public static void log(int sMsg) <P|`7wfxE
{ "L9C
System.err.println(sMsg); N|UBaPS|o
} jN31\)/i
} =''mpIg(
nu#aa#ex>
-Pqi1pj]
/* Tg3:VD
**TestMethod.java <I>%m,
*/ =@Q#dDnFu%
package NetFox; mY$nI -P
U(rr vNt:t
Ix*BI9E
public class TestMethod { -@YVe:$%b
V<7R_}^_7
zj~8>QnKk
public TestMethod() ATKYjhc _
{ ///xx/weblogic60b2_win.exe ^zvA?'s
try{ 'dmp4VT3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N90\]dFmy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jHs<s`#h
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3C>2x(]M
fileFetch.start(); A6{t%k~F
} Xy[4f=X}z
catch(Exception e){e.printStackTrace ();} +CsI,Uf4*
>v^2^$^u
c+@d'yR
} o,*folL
#g@
4(` 2#
public static void main(String[] args) cxtLy&C
{ hg%@W
new TestMethod(); >{O[t2&
} l@,);w=_P
} g0^~J2sDd
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