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)); h>p,r\X
} m}]QP\
for(int i=0;i<nEndPos.length-1;i++) MHGaf`7ro
{ m-#]v}0A
nEndPos = nStartPos[i+1]; #V$sb1u
} HZjuL.Tj
nEndPos[nEndPos.length-1] = nFileLength; `R!2N4|;
} FEX67A8/;
} ;9q$eK%d
/O`R9+;
@Fzw_qr M
//启动子线程 @jq H8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fAfB.|cd
for(int i=0;i<nStartPos.length;i++) rV2>;FG
{ foB&H;A4oC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m)]|mYjju
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )@] W=
nStartPos,nEndPos,i); [&l+Ve(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4q(,uk&R[
fileSplitterFetch.start(); @Y<fj^]k
} }:[MSUm5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O&}R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rDu?XJA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KuEM~Q=
nEndPos = " + nFileLength); ggpa!R
// fileSplitterFetch[nPos.length-1].start(); l@]Fzl
:XTxrYt28
!& >LLZ
//等待子线程结束 'Mhnu2d
//int count = 0; /||8j.Tm
//是否结束while循环 = )4bf"~8
boolean breakWhile = false; 8#9OSupp
Cv/3-&5S
Ns#L9T#
while(!bStop) !3o/c w9
{ C4t~k
write_nPos(); EW3--33s
Utility.sleep(500); /Xv@g$
breakWhile = true; uaxkGEXr
j 20mZ
)q/brCq
for(int i=0;i<nStartPos.length;i++) xK4E+^ b
{ |CK/-UG}
if(!fileSplitterFetch.bDownOver) k^K%."INn
{ uKB V`I
breakWhile = false; :qV|rih_Q
break; >SS^qjh/
} A0Q1"b=
} J7~Kjl
if(breakWhile) =$ubSfx
break; NxB/U_j
;=@?( n
?%/*F<UVQ
//count++; ''k}3o.K[
//if(count>4) '*t<g@2$
// siteStop(); @V+KL>Qw
} 5d}bl{
,4}s 1J#
p%/lP{
System.err.println("文件下载结束！"); IxY!.d_s|~
} 7t78=wpLc
catch(Exception e){e.printStackTrace ();} !\5)!B
} ?ZkVk=t?
q^~w:$^U
o[S Mt
//获得文件长度 z5sKV7&\[n
public long getFileSize() -qLNs_ _k
{ %6Y}0>gY
int nFileLength = -1; Ie8SPNY-H
try{ q~X}&}UT
URL url = new URL(siteInfoBean.getSSiteURL()); QqcAmp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G {a;s-OA3
httpConnection.setRequestProperty("User-Agent","NetFox"); Yi19VU|/
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akwS;|SZ
int responseCode=httpConnection.getResponseCode(); h(^[WSa
if(responseCode>=400) maV*+!\
{ a`Q-5*\;z
processErrorCode(responseCode); SL_JA
return -2; //-2 represent access is error Ppx4#j
} jtqU`|FSQ
1J&hm[3[K
~c\2'
String sHeader; ;@n/gU
qVds 2
)Rj?\ZUR
for(int i=1;;i++) cO-^#di
{ 0_t9;;y :
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aDE}'d1qo
//Utility.log(in.readLine()); ^HHT>K-m
sHeader=httpConnection.getHeaderFieldKey(i); 8P2_/)|
if(sHeader!=null) P{,=a]x,mz
{ W=,]#Z+M;
if(sHeader.equals("Content-Length")) QR$m i1Vv\
{ ,{Z!T5 |
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3v)`` n@
break; !{ORFd
} Ihl]"76q/
} w" A{R
else @^HZTuP2;
break; Tb] h<S
} \x"BgLSE
} <V#]3$(S
catch(IOException e){e.printStackTrace ();} #O7phjzgD
catch(Exception e){e.printStackTrace ();} @j%7tfW
xI~c~KC
"b`3
Utility.log(nFileLength); 1#2L9Bi
gNh4c{Al9
Nm3CeU
return nFileLength; \r&(l1R
} 'tVe#oI
Wa%p+(\<uB
X C'|
//保存下载信息（文件指针位置） <h`}I3Ao
private void write_nPos() =z}M(<G
{ ZrWA,~;
try{ #jw%0H;l]
output = new DataOutputStream(new FileOutputStream(tmpFile)); quFNPdP
output.writeInt(nStartPos.length); i\{fM}~W$
for(int i=0;i<nStartPos.length;i++) :/;;|lGw
{ MhN8'y(
// output.writeLong(nPos); ?6:e%YT
output.writeLong(fileSplitterFetch.nStartPos); jf& oN]sZ
output.writeLong(fileSplitterFetch.nEndPos); m .^WSy
} ~vfPsaRh
output.close(); M7neOQHq
} ,6wGdaMR
catch(IOException e){e.printStackTrace ();} vGp`P
catch(Exception e){e.printStackTrace ();} PxJvE*6^H
} .y#>mXm>
AHLXmQl
Lx3`.F\mG
//读取保存的下载信息（文件指针位置） L$[1+*
private void read_nPos() f5.Be%
{ Vv>hr+e
try{ zBqNE`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t>"|~T$9
int nCount = input.readInt(); .kDJuJ^
nStartPos = new long[nCount]; NHzVA*f
nEndPos = new long[nCount]; YKa9]Q
for(int i=0;i<nStartPos.length;i++) 4o( Q+6m
{ +qyx3c+
nStartPos = input.readLong(); vz)zl2F5sY
nEndPos = input.readLong(); ^i17MvT'
} #LG<o3An
input.close(); N\x<'P4q
} P)UpUMt;k
catch(IOException e){e.printStackTrace ();} l,j0n0h.
catch(Exception e){e.printStackTrace ();} J8DKia|h(
} !]P=v`B.
='HLA-uT
g"D:zK)
private void processErrorCode(int nErrorCode) 37|EG
{ 4HyD=6V#
System.err.println("Error Code : " + nErrorCode); ,f[Oy:fr
} ,v(ikPzd
e{*z4q1
Bv}nG|
//停止文件下载 <&}N[
public void siteStop() 0JLQ.%_
{ +kOXa^K
bStop = true; vNAQ/Q
for(int i=0;i<nStartPos.length;i++) MNKY J
fileSplitterFetch.splitterStop(); Qr[".>+
]DI%7kw'
;vgaFc]
} \B8[UZA.&
} |f+fG=a67V
//负责部分文件的抓取 X1%_a.=VF
**FileSplitterFetch.java c)17[9"
*/ R9%"Kxm
package NetFox; N1'$;9 c
'6Yx03t
us^J! s7
import java.io.*; c nV2}U/\
import java.net.*; '_o(I
<#7j~<
1zY"Uxp
public class FileSplitterFetch extends Thread { q]m$%>
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!Bb^M3iA
String sURL; //File URL ngH_p>
long nStartPos; //File Snippet Start Position S{qsq\X
long nEndPos; //File Snippet End Position ^1[u'DW4
int nThreadID; //Thread's ID 6 kAXE\T
boolean bDownOver = false; //Downing is over s!/Q>A
boolean bStop = false; //Stop identical s C?-L
FileAccessI fileAccessI = null; //File Access interface \v([,tiW%
`HsI)RmX
f.Ms3))
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ')j@OO3
{ 5=P*<Dnj
this.sURL = sURL; (rjv3=9\3
this.nStartPos = nStart; /1LQx>1d
this.nEndPos = nEnd; UQ+!P<>w
nThreadID = id; zT jk^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o$,e#q)8
} GhY MO6Q4
l%MIna/Tp
0%]F&|
public void run() Z`kI6
{ s;YuB#Z
while(nStartPos < nEndPos && !bStop) gJuA*^
{ LT)G"U~
8=j_~&*
|kkg1M#
try{ A$o?_
URL url = new URL(sURL); &13#/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,c[f/sT\
httpConnection.setRequestProperty("User-Agent","NetFox"); ^es/xt
String sProperty = "bytes="+nStartPos+"-"; 9Zpd=m8dU
httpConnection.setRequestProperty("RANGE",sProperty); F]^ZdJ2
Utility.log(sProperty); # ,27,#
(T2\
@#&y
InputStream input = httpConnection.getInputStream(); mdukl!_x
//logResponseHead(httpConnection); f#zm}+,`
DbvKpM H
^EmI;ks
byte[] b = new byte[1024]; ]"4\]_?r
int nRead; x)^t5"F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f hr QJ
{ ;TG<$4N
nStartPos += fileAccessI.write(b,0,nRead); .'^Pg
//if(nThreadID == 1) L:RMZp*bK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G,h=5y9_J
} ^`oyf{w@
.wz.Jr`{
S(h+,+289
Utility.log("Thread " + nThreadID + " is over!"); \>r<z46x
bDownOver = true; %v 1NDhaXz
//nPos = fileAccessI.write (b,0,nRead); eh}{\P
} 2 1]87$
catch(Exception e){e.printStackTrace ();} &\/p5RX
} 1A-ess\
} R3gg{hQ
8iwqy0<
tJ!s/|u(
//打印回应的头信息 NU$?BiB?R
public void logResponseHead(HttpURLConnection con) Y+UM>
{ SFx|9$hXm
for(int i=1;;i++) UBvea(z-#
{ e`Vb.E)
String header=con.getHeaderFieldKey(i); AH#klYK
if(header!=null) w-9fskd6e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2';f8JLY
Utility.log(header+" : "+con.getHeaderField(header)); .@(9v.:_u
else W=@]YI
break; @XFy^?
} r__Y{&IO
} =dTsGNz
gl~>MasV&
.l(t\BfE~
public void splitterStop() Ud[Zv?tA:
{ "]0sR
bStop = true; BX=YS)
} 3,RaM^5dV
Erd)P
1dahVc1W
} 2[R{IV8e
i?1g{JW
}qOj^pkJ
/* rkz_h
**FileAccess.java -<Zs7(
*//文件访问(定位，写) S8$kxQg
package NetFox; QvN=<V
import java.io.*; ?A7_&=J%
dwAFJhgh
?E:L6,a
public class FileAccessI implements Serializable{ }+Ne)B E
jLu`DKB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K}p!W"!o
RandomAccessFile oSavedFile; &E&e5(&$
long nPos; 8Qt'Y9|
V"{+cPBO)
uNSbAw3
public FileAccessI() throws IOException dJ}E,rW}
{ $Q cr
this("",0); B1!b@0^
} 0kdPr:B Q0
N?mTAF'M
UBy< vwnU
public FileAccessI(String sName,long nPos) throws IOException PtT=HvP!k
{ W{!GL
oSavedFile = new RandomAccessFile(sName,"rw"); sHSD`mYq
this.nPos = nPos; 8DsXw@o
oSavedFile.seek(nPos); 1IRlFC
} aOH$}QnS
Eu^?e
{Bb:S"7NX
public synchronized int write(byte[] b,int nStart,int nLen) v2uyn
{ HX77XTy
int n = -1; z]Dbca1a`
try{ F qW[L>M'
oSavedFile.write(b,nStart,nLen); vS{zLXg
n = nLen; [j]3='2}G
} k[p7)ec
catch(IOException e) 5 UQbd8
{ NY`$D}Bi
e.printStackTrace (); tgPx!5U
} Y]SX2kk(2
~Yw`w2
Mr3;B+S
return n; =E?!!EIq.
} |E YJbL;1%
]'2;6%.4
SCZ6:P"$qX
} ~K-c-Zs#z
1k *gbXb
Uz`K#Bz
/* NBUSr}8|
**SiteInfoBean.java _*I@ J/
*/ Uczb"k5
package NetFox; @1w9!\7Vt
jeM/8~^4-
[8o!X)
public class SiteInfoBean { t)*MLg<C
R\B-cU[,
nf7l}^/UE
private String sSiteURL; //Site's URL eXqS9`zKr
private String sFilePath; //Saved File's Path d }"Dp
private String sFileName; //Saved File's Name 'F- wC!
private int nSplitter; //Count of Splited Downloading File 8RfFP\AP
4t0B_o"
Sf2pU!5n^
public SiteInfoBean() >(} I7
{//nSplitter的缺省值为5 v;q<h
//default value of nSplitter is 5 8Q%rBl.
this("","","",5); J4-64t nZ
} zdoJ+zRtK
JIl<4 %A
*hP9d;-Ar
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8$H_:*A?
{ d3$&I==;:
sSiteURL= sURL; YtzB/q8I
sFilePath = sPath; ptrQ~m-
sFileName = sName; 5jTBPct
this.nSplitter = nSpiltter; Aqwjs 3
B4yC"55
*[-% .=[7
} >>ncq$
lAxbF
0 s-IW
public String getSSiteURL() r pv`%
{ gRk%ObJGqm
return sSiteURL; UKBVCAK
} }w0>mA0=H
xMAfa>]{n
Iq@:n_~
public void setSSiteURL(String value) ZZ<uiN$
{ 5w\>Whbd
sSiteURL = value; ;<JyA3i^V,
} nty^De%
XQW+6LEQ
b>B.3E\Pc
public String getSFilePath() dc.oK4G}
{ :Kl~hzVSOa
return sFilePath; JP2zom
} |6%B2I&c
'Y ZYRFWXM
FJ|6R(T_
public void setSFilePath(String value) cK;,=\
{ pohA??t2:
sFilePath = value; SD"'
} 7>Af"1$g
u*I=.
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public String getSFileName() MT8BP)C
{ x:h0/f
return sFileName; D5wy7`c
} H8V${&!ho
_%M5 T
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public void setSFileName(String value) hP=^JH
{ 1keH1[
sFileName = value; FCC9Ht8U?
} }/ p>DMN
9t.u9C=!F
qP"+SVqC
public int getNSplitter() %nTgrgS(=
{ h}X^
return nSplitter; ewNzRH,b
} 03F%!Rm/j
Svs!C+:le
x<m{B@3T
public void setNSplitter(int nCount) t:DZow
{ +:hZ,G?>
nSplitter = nCount; E4a`cGb
} 3yWu-U \k
} As&=Pb9
)T-C/ 3
He#5d!cf:M
/* xz-z" 8d
**Utility.java uQwKnD?F+e
*/ 0Q81$% @<
package NetFox; XYJ7k7zc+Y
u!=9.3
O "jX|5
public class Utility { U*G8}W
BO#XQ,
~i)m(65:
public Utility() {*gO1TZt9
{ N$8do?
I7b_dJD;*
9] i$`y
} K.y2 $b/
O]"3o,/]G
//线程睡眠 (;f7/2~`
public static void sleep(int nSecond) q5jLK)
{ 0y>]68D
try{ YVzcV`4w(
Thread.sleep(nSecond); k 8C[fRev
} O5:?nD
catch(Exception e) 5pJ)OX
{ n"[VM=YGI
e.printStackTrace (); *Nv!Kuk
} cs'ylGH
} (=hXt=hZ
Mw=sW5Z
//日志 E\3fL"lM
public static void log(String sMsg) !H,_*u.
{ <r6e23
System.err.println(sMsg); av-l_iE
} {s=n "*Qp)
s:_M+_7_
6`/nA4S4.
public static void log(int sMsg) 8<,b5
{ PNm WZW*
System.err.println(sMsg); >EVlMt27'
} H3$~S '
} (AHZmi V
(8M^|z}q
8Iz-YG~%3
/* t7A '
**TestMethod.java 3~zK :(
*/ ~]+-<O^U~
package NetFox; }LXS!Ff:
3=6`'PKRQ
I) mP?
public class TestMethod { %9D$N
eBZa9X$
cY%[UK$l
public TestMethod() c\X0*GX
{ ///xx/weblogic60b2_win.exe Jr0D:
try{ *?;<buJb?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OYcf+p"<\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x"hZOgFZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); L@ ,-V
fileFetch.start(); fZoV\a6Kj
} Dj=OUo[[d
catch(Exception e){e.printStackTrace ();} 2h<{~;
.rfufx9Sw
{fkW0VB;
} K\Oz ~,z
(C<~:Y?%
aE[>^~Lv}
public static void main(String[] args) J. ]~J|K
{ :K%{?y
new TestMethod(); 9fk@C/$
} #[.vfG
} 6`sOhVD
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