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)); l1O"hd'~s
} o[WDPIG
for(int i=0;i<nEndPos.length-1;i++) Z zp"CK 5
{ eV(9I v[
nEndPos = nStartPos[i+1]; uifVSf*
} ,LSiQmV5
nEndPos[nEndPos.length-1] = nFileLength; 4$ihnb`DQN
} 34N~<-9AY
} wYV>Qd Z
uPYH3<
3Z me?o*bY
//启动子线程 f{[0;qDJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; liLhvcd
for(int i=0;i<nStartPos.length;i++) %m[ZU<v
{ hOj+z?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f^"pZS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f.66N9BHL,
nStartPos,nEndPos,i); :-Py0{s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dVHbIx
fileSplitterFetch.start(); R1w5,Zt
} rMZuiRz*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B@6L<oZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g*LD}`X/-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8 Zp^/43
nEndPos = " + nFileLength); b8YdONdy
// fileSplitterFetch[nPos.length-1].start(); Kdp($L9r
G-RDQ
3/ }
//等待子线程结束 Qr7v^H~E4.
//int count = 0; XGC\6?L~
//是否结束while循环 vDi Opd
boolean breakWhile = false; q-_!&kDK"
^->S7[N?
"&4r!2A
while(!bStop) :E~rve'
{ #RU8yT
write_nPos(); m~Q24Z]!'&
Utility.sleep(500); NT5'U
breakWhile = true; j4#uj[A
Sx e6&
Qs59IZ
for(int i=0;i<nStartPos.length;i++) !d!u{1Y&
{ vW vu&3tx
if(!fileSplitterFetch.bDownOver) DU]KD%kl
{ qdv O>k3
breakWhile = false; A%$~
break; $8HiX6r
} blIMrP%
} '/@wk#,
if(breakWhile) k>.8lc\
break; 9:VUtx#}2
8 p[n>qV9
|}UkVLc_^
//count++; \( #"g
//if(count>4) #eJ<fU6Da
// siteStop(); V(DY!f_%
} j4!O,.!T
;`:YZ+2 Z
1,bE[_
System.err.println("文件下载结束！"); zhFm2
} 7dACbqba
catch(Exception e){e.printStackTrace ();} pb)8?1O|s
} (?JdiY/
Z f\~Cl
fC*cqc~{@
//获得文件长度 -,p=;t#(
public long getFileSize() ZcyGLg0I
{ \i%mokfbc
int nFileLength = -1; (4A'$O2
try{ je2_.^
URL url = new URL(siteInfoBean.getSSiteURL()); W [K.|8ho
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]6)u$4X6$
httpConnection.setRequestProperty("User-Agent","NetFox"); Jut&J]{h
u YT$$'S
` K{k0_{
int responseCode=httpConnection.getResponseCode(); ';/J-l/SE
if(responseCode>=400) 0Q_*Z (
{ /YF:WKr2
processErrorCode(responseCode); 'D ?o^
return -2; //-2 represent access is error oR=i5lAU
} cAEvv[
rHX^bcYK
B<m0YD?>~>
String sHeader; 0zq'Nf?#3
S\&3t}_
`;;l {8
for(int i=1;;i++) %g.cE}^
{ uy3<2L#.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wAprksZL#
//Utility.log(in.readLine()); &gY) x{
sHeader=httpConnection.getHeaderFieldKey(i); #Q^".#
if(sHeader!=null) }a6t<m`V
{ VoZ{I{>|
if(sHeader.equals("Content-Length")) qVE0[ve
{ ~RuX2u-2&u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c!4F0(n4
break; #[lhem]IC
} G!r)N0?_f
} &R_7]f+%)
else Q]xkDr?
break; \BXzmok
} +C{-s
} eNAxVF0
catch(IOException e){e.printStackTrace ();} ?s^3o{!<W
catch(Exception e){e.printStackTrace ();} TD}<U8I8_
'YNdrvz
1" cv5U
Utility.log(nFileLength); 1w^wa_qx
fj5g\m
X&qx4DL
return nFileLength; k*hl"oL"X
} lZcNio
UPfO;Z`hJ
s.}K?)mH
//保存下载信息（文件指针位置） \7/yWd{N$
private void write_nPos() U+)p'%f;
{ y3dk4s77
try{ `)n4I:)2
output = new DataOutputStream(new FileOutputStream(tmpFile)); Pj-INc96
output.writeInt(nStartPos.length); \@:,A]
for(int i=0;i<nStartPos.length;i++) YS9RfK/
{ NFs5XpZ~
// output.writeLong(nPos); N"ga-u
output.writeLong(fileSplitterFetch.nStartPos); ;Y`Y1
output.writeLong(fileSplitterFetch.nEndPos); .Q*X5Fc
} [s{!
output.close(); St-uE|8
} y!77gx?-
catch(IOException e){e.printStackTrace ();} A]/o-S_
catch(Exception e){e.printStackTrace ();} { :tO RF
} @dDeOnF
pFd8p@m_2
"n!yK
//读取保存的下载信息（文件指针位置） ;"wCBuXcu
private void read_nPos() i/ilG3m>
{ _6ZjF>f
try{ LmF,en5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \beO5]KS<
int nCount = input.readInt(); C8}:z\A_@Z
nStartPos = new long[nCount]; !LI<%P)
nEndPos = new long[nCount]; :jLL IqhB
for(int i=0;i<nStartPos.length;i++) q!5:M\
{ %SM;B-/zHt
nStartPos = input.readLong(); +J X;T(T
nEndPos = input.readLong(); g\JJkXjD#
} @LKQ-<dZG
input.close(); (CmK>"C+
} >M,oyM"s
catch(IOException e){e.printStackTrace ();} $RaN@& Wm
catch(Exception e){e.printStackTrace ();} *glZb;_
} +$,Re.WnP
O<gfZ>
k&]nF,f
private void processErrorCode(int nErrorCode) Z',!LK!
{ Ma[EgG
System.err.println("Error Code : " + nErrorCode); &7aWVKon
} ^/2I)y]W0
S\e&xUA;|
xAQtX=FoX+
//停止文件下载 C9n%!()>
public void siteStop() 7~/cz_
{ %z><)7
bStop = true; iQwQ5m!d &
for(int i=0;i<nStartPos.length;i++) Eah6"j!B8n
fileSplitterFetch.splitterStop(); OU[<\d
*U?O4E9
wHc my
} HGDrH
} l90mM'[
//负责部分文件的抓取 200yN+ec
**FileSplitterFetch.java ~U9K<_U
*/ 'ZfgCu)St
package NetFox; Ey46JO"
2@&r!Q|1vR
|\5^ub,m
import java.io.*; g`7XE
import java.net.*; "F<CGSo
BX,)G HE
!'7fOP-J]
public class FileSplitterFetch extends Thread { #%0V`BS7n
~C.*Vc?|
l4Xz r:]
String sURL; //File URL rl*O-S/
long nStartPos; //File Snippet Start Position Ifj&S'():
long nEndPos; //File Snippet End Position O !L`0 =%c
int nThreadID; //Thread's ID VM"cpC_8
boolean bDownOver = false; //Downing is over *Z5^WHwg
boolean bStop = false; //Stop identical [VCC+_
FileAccessI fileAccessI = null; //File Access interface yPm2??5MW>
/Rp]"S vt
[I $+wWW_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _FLEz|%~
{ ^.SYAwL
this.sURL = sURL; C_.9qo]DT7
this.nStartPos = nStart; ]b/]^1-(b
this.nEndPos = nEnd; )*,/L <
nThreadID = id; @ D+ftb/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gV_/t+jI
} ^u/%zL
a^|DD#5
_]Hna<Ly
public void run() g*|j+<:7
{ (B7G'h.?
while(nStartPos < nEndPos && !bStop) 7io["zW
{ i=8iK#2 h
@=Kq99=\U
}{aGh I~<
try{ Lpchla$
URL url = new URL(sURL); pJpapA2l*6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jcH@*c=%e
httpConnection.setRequestProperty("User-Agent","NetFox"); .1x04Np!
String sProperty = "bytes="+nStartPos+"-"; ^rkKE dd
httpConnection.setRequestProperty("RANGE",sProperty); PxHFH pL
Utility.log(sProperty); pMc6p0
fCl}eXg6w
]Z JoC!u
InputStream input = httpConnection.getInputStream(); XC4Z,,ah"
//logResponseHead(httpConnection); ,g`%+s7u
c}x1-d8
YdY-Jg Xm
byte[] b = new byte[1024]; )&DAbB!O
int nRead; h`fVQN.3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CUA @CZ6{
{ mYBEjZB
nStartPos += fileAccessI.write(b,0,nRead); /'O8RUjN
//if(nThreadID == 1) ^ k^y|\UtZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T)C@6/
} BxY t*b%
$EMOz=)I#
s:`i~hjq
Utility.log("Thread " + nThreadID + " is over!"); 85{m+1O~
bDownOver = true; <_tmkLeZf
//nPos = fileAccessI.write (b,0,nRead); G4&s_M$
} DA=U=F
catch(Exception e){e.printStackTrace ();} prBLNZp
} J3Mb]X)_}
} e5=d Ev
<t%gl5}|
wN2+3LY{
//打印回应的头信息 (z?HyxRT
public void logResponseHead(HttpURLConnection con) ]' mbHkn68
{ \/-c)
for(int i=1;;i++) .J#'k+>
{ aD/Rr3v>
String header=con.getHeaderFieldKey(i); LzygupxY!
if(header!=null) ^\)a[OWp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HDyf]2N*N
Utility.log(header+" : "+con.getHeaderField(header)); bP,<^zA|X
else ]AP1+ &9fN
break; GnV0~?
} Pg4&}bX:I
} ,CO2d)}
vG&>-Z
yev!Nw
public void splitterStop() Vla,avON
{ X/]@EF
bStop = true; C2LPLquD+
} ~PQ.l\C
NGra/s,9|
~{c ?-qb
} ]5W$EvZ9)
lwnO
}ze+ tf
/* XLpP*VH3
**FileAccess.java [)H 6`w
*//文件访问(定位，写) !\]^c
package NetFox; #GsOE#*>T
import java.io.*; SpH|<L3
4Nm>5*]
\lL[08G
public class FileAccessI implements Serializable{ !+xQ
?}||?2=P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SNEhP5!
RandomAccessFile oSavedFile; J5@08bZm
long nPos; pA7-B>Y
<Ij!x`MS+
5'lVh/
public FileAccessI() throws IOException K/4@2vF
{ ^5 >e
this("",0); U}v`~'K
} 2:+8]b3i
2 a<\4w'
3WV(Ok
public FileAccessI(String sName,long nPos) throws IOException ycGY5t@K@
{ |9@,ri\'Rg
oSavedFile = new RandomAccessFile(sName,"rw"); 0SpB2>_
this.nPos = nPos; h!"2Ux3!x
oSavedFile.seek(nPos); 8K8u|]i
} 3qYGEhxv
Z[vx0[av&
` Xc7b
public synchronized int write(byte[] b,int nStart,int nLen) D?|D)"?qb
{ hW7u#PY
int n = -1; 9O[IR)O~
try{ :]"5UY?oF
oSavedFile.write(b,nStart,nLen); OY*y<>
n = nLen; 4^_6~YP7
} BU nujC
catch(IOException e) ,5'o>Y
{ <,.$U\W
e.printStackTrace (); D(cD8fn,J
} p l)":}/)
1-RY5R}VR
zal]t$z>
return n; IrwQ~z3I
} y@LImiRG
^[ae )}
{9IRW\kn
} W5jwD
>OG189O
z%&FLdXgW+
/* o$_0Qs$
**SiteInfoBean.java /SvhOi
*/ g`EZLDjt
package NetFox; w0QtGQ|
rcnH^P
_K5<)( )
public class SiteInfoBean { 2w>%-_]u+
W 4{ T<
ET*A0rt
private String sSiteURL; //Site's URL .[={Yx0!I
private String sFilePath; //Saved File's Path Po>6I0y
private String sFileName; //Saved File's Name SA,~q&
private int nSplitter; //Count of Splited Downloading File t@KTiJI ]
q|5WHB
K5>3
public SiteInfoBean() eAHY/Y!
{//nSplitter的缺省值为5 5!0iK9O
//default value of nSplitter is 5 /08FV|tX)
this("","","",5); 2:LUB)&i
} %$BRQ-O
7uBx
j }~?&yB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {uDW<u_!
{ 8lQ/cGAc
sSiteURL= sURL; hzD)yf
sFilePath = sPath; XY0kd&N8
sFileName = sName; ;W0J
this.nSplitter = nSpiltter; 0'&C5v'
g%2G=gR$?z
'afW'w@
} m:_#kfC&K"
v[CR$@Y
G<Z}G8FW^
public String getSSiteURL() \Z*:l(
{ jAQ{H
return sSiteURL; zK0M WyXO
} %PW-E($o<
:?f<tNU$
k|fM9E
public void setSSiteURL(String value) 5 nt3gVy
{ 1q}32^>+o
sSiteURL = value; +\dVC,,=^g
} $G=^cNB|JB
C&O8fNB_
AArLNXzVW
public String getSFilePath() l&& i`
{ 3h bHS~
return sFilePath; >WHajYO"
} v}>g* @
+=WBH'
8~y!X0Ov!
public void setSFilePath(String value) 6Ga'_P:
{ lw=kTYbq
sFilePath = value; ueg%yvO
} \Y xG
l@Lk+-[D
+m_.?V6
public String getSFileName() o HK
{ HB9"T5Pd*
return sFileName; &0 QUObK
} `(W"wC
F"Dr(V
8%4;'[UV
public void setSFileName(String value) Y58H.P
{ 5%'ybh)@
sFileName = value; 74_?@Z(
} 2d[tcn$;h]
_ $PeFE2
4'faE="1)S
public int getNSplitter() Fd8nR9A
{ d /jx8(0
return nSplitter; 33`bKKO}
} P IG,a~
U=v>gNba
>A )Sl'
public void setNSplitter(int nCount) $GoS?\G
{ j,rc9
nSplitter = nCount; 8;M,l2pmR{
} \t{iyUxY
} Jq1oQu|rs
5|0}bv O
n3e,vP? R
/* /G5KNSi
**Utility.java 8] LF{Obz[
*/ _d!sSyk`
package NetFox; 5?3v;B6
E2Sj IR}
CW;zviH5
public class Utility { CfOyHhhKX
X8}r= K~
l(Y32]Z
public Utility() c|%5SA
{ 2tU3p<[
S5|7D[*
:F d1k Jm
} TT/=0^"
&"u(0q
//线程睡眠 7Kym|Zg
public static void sleep(int nSecond) 7$7|~k
{ !19T=p/:$
try{ -cUW,>E
Thread.sleep(nSecond); 3 EAr=E]
} JP!e'oWxi
catch(Exception e) ln<[CgV8
{ /5%'q~
e.printStackTrace (); 2k!uk6
} u%L6@M2
} Wz^;:6F
oD%n}
//日志 QeY+imM
public static void log(String sMsg) ~N/%R>(v
{ Sh;`<Ggi~
System.err.println(sMsg); %X\J%Fj
} QM!UMqdj
yS)k"XNb
wgDAb#Zuk
public static void log(int sMsg) i<&z'A6&]*
{ *7*_QW%?A
System.err.println(sMsg); eDo4>k"5
} QVn2`hr
} }P=FMme{F(
-/3h&g
lBn<\Y!^
/* !B[Y?b:
**TestMethod.java e_Zs4\^ef
*/ C&F% j.<
package NetFox; kFJ]F |^7
oCwep^P(v
;E}&{w/My
public class TestMethod { x~l"'qsK
e?\Od}Hbw
0#c-qy
public TestMethod() 1`II%mf[
{ ///xx/weblogic60b2_win.exe SdufI_'B
try{ AU*]D@H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ldG8hK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); HJr*\%D}1
SiteFileFetch fileFetch = new SiteFileFetch(bean); MPp:EH
fileFetch.start(); (*26aMp
} YTgT2w
catch(Exception e){e.printStackTrace ();} vU/sQt8
qHrIs-NR
5m;pHgkb
} [)IaXa
"6e3Mj\
1>_$O|dE
public static void main(String[] args) -8:O?]+Q/
{ tIA)LF
new TestMethod(); lYS4Q`z$
} qq^[(n
} u 'ng'j'
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