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)); 3sgo5D-rMI
} (:^YfG~e
for(int i=0;i<nEndPos.length-1;i++) {P3gMv;
{ (Q.tH
nEndPos = nStartPos[i+1]; sX]gL
} 36Lf8~d4"h
nEndPos[nEndPos.length-1] = nFileLength; W.59Al'
} 8g=];@z
} lR/Uboyy
XtE O)
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//启动子线程 a5(9~.9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z{gDEo)
for(int i=0;i<nStartPos.length;i++) pU<GI@gU
{ T)tTzgLD}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t~$8sG\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AF,;3G
nStartPos,nEndPos,i); FxT]*mo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *\_>=sS x;
fileSplitterFetch.start(); $h}w:AV:
} ;Aheeq746
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \mZB*k)+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lk`|u$KPz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8bf@<VTO_
nEndPos = " + nFileLength); E&Zt<pRf;2
// fileSplitterFetch[nPos.length-1].start(); fl40jo]
dA<SVk*0Q
.J=QWfqt
//等待子线程结束 Bat@
//int count = 0; +jS<n13T
//是否结束while循环 '+GY6Ecg
boolean breakWhile = false; n<F3&2w
ItVVI"-
f%JM a]yV
while(!bStop) brK7|&R<
{ qxcTY|&
write_nPos(); N8,g~?r^
Utility.sleep(500); "Z~@"JLb%
breakWhile = true; 1(Z+n,Hh
F=PBEaX
QIdml*Np?H
for(int i=0;i<nStartPos.length;i++) 9Z"WV5o
{ Ft}nG&D
if(!fileSplitterFetch.bDownOver) />uE)R$
{ /7ShE-.5#
breakWhile = false; uL:NWgN
break; ]VEc9?
} 4q?R3\e;
} vP_mS 4X
if(breakWhile) Xc&J.Tw#4*
break; 'Tskx
3JD"* <zs
9yu#G7
//count++; 5g;mc.Cvt
//if(count>4) I0;gTpt9
// siteStop(); muDOY~.
} o)Px d
[h>A<O
fJ=(oF=
System.err.println("文件下载结束！"); k^#*x2b
} 4^9qs%&
catch(Exception e){e.printStackTrace ();} '}OAl
} iG"1~/U
E_P,>f
m:k;?p:x
//获得文件长度 *g9VI;X
public long getFileSize() p9!jM\(
{ ')iyD5/4
int nFileLength = -1; `=kiqF2P}
try{ I]cZcx,<q
URL url = new URL(siteInfoBean.getSSiteURL()); #Fgybokm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2Ky|+s[`[
httpConnection.setRequestProperty("User-Agent","NetFox"); {bC(>k|CQ
P,7R/-u5D
jF(R;?,
int responseCode=httpConnection.getResponseCode(); ]vw%J ^7:a
if(responseCode>=400) p _2Yc]8
{ 6KE64: \;
processErrorCode(responseCode); 7.+vp@+
return -2; //-2 represent access is error )% gU
} cV7a, *
@y6^/'
aU$80
String sHeader; #WE lL2&
i3)7Qa[
B7S)L#l_\
for(int i=1;;i++) bU}l*"
{ iszVM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S2 P9C"
//Utility.log(in.readLine()); 07\]8^/G
sHeader=httpConnection.getHeaderFieldKey(i); bn=7$Ax
if(sHeader!=null) .eCUvX`$
{ 9niffq)h
if(sHeader.equals("Content-Length")) CUft
{ %6&c3,?U\n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5kHU'D
break; VkId6k:>6C
} M"Z/E>ne
} DD6K[\
else n"vO?8Sx
break; 6aWNLJ@
} !G<gp4Js+N
} @lqI,Ce5
catch(IOException e){e.printStackTrace ();} #UvWS
catch(Exception e){e.printStackTrace ();} cKIA.c}N
2ppJ;P{k
*8/cd0
Utility.log(nFileLength); l=a<=i
> lI2r}
/8,cF7XL*
return nFileLength; ^a|
} 0&3zBL%Bo
:#UA!|nV
M(ie1Ju
//保存下载信息（文件指针位置） G*-7}7OAs
private void write_nPos() I]Z"?T
{ 2Y;iqR
try{ M{=p0?X
output = new DataOutputStream(new FileOutputStream(tmpFile)); &$h#9
output.writeInt(nStartPos.length); dd@ D s
for(int i=0;i<nStartPos.length;i++) v5FfxDvw
{ ;Wn0-`_1,
// output.writeLong(nPos); xo(>nFjo
output.writeLong(fileSplitterFetch.nStartPos); WpkCFp
output.writeLong(fileSplitterFetch.nEndPos); Hx9lQ8
} @[5]?8\o
output.close(); /1hcw|cfC
} BtQqUk#L2
catch(IOException e){e.printStackTrace ();} Lf;Uv[^c
catch(Exception e){e.printStackTrace ();} |9)y<}c5oM
} _1jeaV9@
5X^`qUSv
@Dd(
//读取保存的下载信息（文件指针位置） n ,@ge
private void read_nPos() l HZ4N{n
{ -(E-yCu
try{ Q.fD3g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9 vNz yh\
int nCount = input.readInt(); o<g1;
nStartPos = new long[nCount]; WaiM\h?=#
nEndPos = new long[nCount]; ciN*gwI)
for(int i=0;i<nStartPos.length;i++) ko~e*31_E
{ JNI&]3[C>?
nStartPos = input.readLong(); i}C%`1+(
nEndPos = input.readLong(); vtq47i
} Qqp=
input.close(); :x!'Eer n
} )r XUJ29.
catch(IOException e){e.printStackTrace ();} <fDbz1Q;l
catch(Exception e){e.printStackTrace ();} yq` ,)
} wy""02j
O5JG!bGE_F
p0pA|
private void processErrorCode(int nErrorCode) v5L#H=P
{ TezwcFqH
System.err.println("Error Code : " + nErrorCode); y*lAmO
} 9hhYyqGsO
Oz=!EG|N
I$f'BAw
//停止文件下载 .Txwp?};
public void siteStop() X-SR0x
{ "gXvnl
bStop = true; #aadnbf
for(int i=0;i<nStartPos.length;i++) *#B"%;Ln
fileSplitterFetch.splitterStop(); V|;os
D ~NWP%H
B\>3[_n
} _9z+xl
} vARZwIu^D
//负责部分文件的抓取 :]`JcJ
**FileSplitterFetch.java B,A\/%<
*/ '~pZj"uy
package NetFox; ^!K 8nW{*
E{'\(6z_
J*qo3aJjE
import java.io.*; / KKA/
import java.net.*; f'u[G?C
^>h2.AJ
p49T3V
public class FileSplitterFetch extends Thread { ;{"uG>#R
=fI0q7]ndz
!6*4^$i#o
String sURL; //File URL 5pq9x4&
long nStartPos; //File Snippet Start Position 7zu3o
long nEndPos; //File Snippet End Position l i2/"~l
int nThreadID; //Thread's ID "IoY$!Hk
boolean bDownOver = false; //Downing is over t=dZM}wj_\
boolean bStop = false; //Stop identical $# b
FileAccessI fileAccessI = null; //File Access interface zi,":KDz#
qjIcRue'"
TA+/35^?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?$4CgN-
{ \6,Z<.I
this.sURL = sURL; /O$)m[
this.nStartPos = nStart; SqT+rvTh
this.nEndPos = nEnd; fXAD~7T*s
nThreadID = id; #s-li b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ''CowI
} lDG.\u
Y= ^o {C6
{ALOs^_-
public void run() -V}ZbXJD
{ &fifOF#[e
while(nStartPos < nEndPos && !bStop) \LDcIK=
{ Wu693<
(9!kKMQW'
:$oiP
try{ 15!b]':
URL url = new URL(sURL); `wNJ*`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l78:.
httpConnection.setRequestProperty("User-Agent","NetFox"); ZHc;8|}
String sProperty = "bytes="+nStartPos+"-"; H=5#cPI#(^
httpConnection.setRequestProperty("RANGE",sProperty); 6 ZVD<C:\
Utility.log(sProperty); |(R[5q
ZRCUM"R_
%l)~C%T
InputStream input = httpConnection.getInputStream(); zuBfkW95+
//logResponseHead(httpConnection); 9!Vp-bo
`O}bPwa{>
'8fh(`
byte[] b = new byte[1024]; 'a enhj
int nRead; K?mly$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QK`2^
{ "4i_}
nStartPos += fileAccessI.write(b,0,nRead); (OHd}YQ
//if(nThreadID == 1) :,=Z)e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &/lmg!6
} /M~rmIks
p2o66t
IR*:i{
Utility.log("Thread " + nThreadID + " is over!"); xqaw00,s
bDownOver = true; hin6cac
//nPos = fileAccessI.write (b,0,nRead); OTwXc*2u]
} I,!>ZG@6
catch(Exception e){e.printStackTrace ();} wGA%h.[M|
} 1z=}`,?>
} }ilX 2s?>
:a9$f8*b
" qrL:,
//打印回应的头信息 %b`B.A
public void logResponseHead(HttpURLConnection con) 0qD.OF)8
{ ^->vUf7PX
for(int i=1;;i++) !<MW*7P=
{ =DXvt5G
String header=con.getHeaderFieldKey(i); TZk.h8
if(header!=null) lpeo^Y}N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >.#tNFAs
Utility.log(header+" : "+con.getHeaderField(header)); =u]FKY
else T 9?!.o
break; +v'n[xa1v
} 78<QNlKn
} &0S/]E`_M
-qRO}EF
+)K yG
public void splitterStop() {v}jV{'^um
{ EAjo>GLI
bStop = true; BXo9s~5Q
} q9"~sCH
;^:$O6J7T~
hk1jxnQh
} Mt`XHXTp
#n}n %
quw:4W>
/* Li\BRlebR{
**FileAccess.java 1_.#'U>
*//文件访问(定位，写) uu582%tiG
package NetFox; B 9AE*
import java.io.*; Sf0[^"7
:7Q, `W9
"t"&6\
public class FileAccessI implements Serializable{ K1>(Fs$
k|T0Bly3P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kXbdR
RandomAccessFile oSavedFile; 7%4@*
long nPos; 1 +'HKT}
bwAL:
T3 k#6N.
public FileAccessI() throws IOException mF !=H%
{ CiGN?1|
this("",0); F /:2+
} >#\&%0OZw
TID0x/j"K5
}ZWeb#\
public FileAccessI(String sName,long nPos) throws IOException o(@F37r{?
{ l?%U*~*
oSavedFile = new RandomAccessFile(sName,"rw"); !Rw\k'<GKX
this.nPos = nPos; (&u)FB*
oSavedFile.seek(nPos); m=<;)
} \W6|un
"i_}\p.,X
8h2!8'
public synchronized int write(byte[] b,int nStart,int nLen) I:aG(8Bi)H
{ 9jwo f}OU
int n = -1; H;n(qBSB
try{ S[ ,r.+
oSavedFile.write(b,nStart,nLen); C&'Y@GE5
n = nLen; LvNk:99:<
} VgNt
catch(IOException e) =JnUTc_u
{ gZs8BKO
e.printStackTrace (); (7rG~d1iS
} lFY;O !Y5\
f V.(v&
wFaWLC|&
return n; N7xkkAS{
} Yg#)@L
s"?&`S
qEpP%p
} IczEddt@'
?D6rFUs9;
`'[ 7M
/* 3:Sv8csT
**SiteInfoBean.java r(yb%p+
*/ *{)![pDYd
package NetFox; !2N#H~{
+:d))r=n
Om0S^4y]x
public class SiteInfoBean { VMW?[j
;.h5; `&
R@0ELxzA
private String sSiteURL; //Site's URL QE5 85s5
private String sFilePath; //Saved File's Path 2'J.$ h3
private String sFileName; //Saved File's Name pz^"~0o5
private int nSplitter; //Count of Splited Downloading File mHox
d}',Bl+u{$
/=\__$l)
public SiteInfoBean() 0nz k?iP
{//nSplitter的缺省值为5 8L 9;VY^Y
//default value of nSplitter is 5 .{-8gAh
this("","","",5); UgJ^NF2w
} 1p&?MxLN-a
6#5@d^a
\o@b5z]e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9ffRY,1@
{ nx,67u/Pb
sSiteURL= sURL; ^\mN<z(
sFilePath = sPath; >|7&hj$
sFileName = sName; zT~ GBC-IX
this.nSplitter = nSpiltter; 1)NX;CN
Pwz^{*u]
i4!n Oyk
} ^B?koU l^
0tB9X9:,
Zk}e?Grc
public String getSSiteURL() ?#D@e5Wf
{ 2#1FI0,Pa*
return sSiteURL; $X~=M_W
} =W !m`
lLtC9:
^O\tN\g;c
public void setSSiteURL(String value) \{+7`4g
{ m$hSL4N
sSiteURL = value; O,JthlAV4
} =OO_TPEZ
uD:O[H-x
r:Cad0xj;^
public String getSFilePath() Q:VD2<2
{ ,bmTBZV
return sFilePath; a$t [}D2
} nhXa&Nro
rmQGzQnun
/yrR f;}<O
public void setSFilePath(String value) &[\rnJ?D
{ WM=kr$/3
sFilePath = value; >o>'@)I?e6
} o ohf))
B{1+0k
6x/ X8zu
public String getSFileName() 6nGDoW#
{ rzaEVXbz1
return sFileName; |Be.r{l
} -R7f/a8
R?|_`@@A
{Y'_QW1:2
public void setSFileName(String value) //Tr=!TQu
{ $9QVl
sFileName = value; " 31C8
} A7b7IM[
'T|.<u@~
XcfTE m
public int getNSplitter() l]v *h0!
{ sCRBKCR?
return nSplitter; `(o1&
} & bw1
Va*Uwy?x/)
s9[v_(W
public void setNSplitter(int nCount) At bqj?
{ dqKTF_+VhA
nSplitter = nCount; +Qc^A
} p Y>yJ)
} Ca1)>1Vz
u5CT7_#)
&_90E
/* ]B,S<*h
**Utility.java b0t];Gc%b
*/ H8-,gV
package NetFox; %] #; ~I%
Yaa M-o
q75F^AvH
public class Utility { 09%eaoW
%74Ms
hU=J^Gi0
public Utility() \ I?;%
{ x(=kh%\;
ap6Vmp
fnmZJJ,Q
} LiB0]+wzj
m1[QD26
//线程睡眠 T:!sfhrZ~<
public static void sleep(int nSecond) ,<vrDHR
{ "]NQTUb;
try{ E$ngmm[
Thread.sleep(nSecond); KT g$^"\
} 9lD,aOb
catch(Exception e) l[fNftT-
{ %MjPQ
e.printStackTrace (); yh0|f94m
} %*19S.=l
} }zobIfIF
&J~S $
//日志 %~W}262
public static void log(String sMsg) ?&GMp[
{ f^%E]ki
System.err.println(sMsg); _E30t( _.
} k]>k1Mi=
q;>BltU
d#b{4zF"
public static void log(int sMsg) q?^0 o\
{ q!H3JL
System.err.println(sMsg); #/tdZ0
} fFd9D=EW.
} j qdI=!H
G1nW{vce
c'|MC[^A
/* MV/~Rmd.
**TestMethod.java cUm9s>^)/
*/ 7GIv3Dc
package NetFox; v:HgpZo+
b?bYPN+
zgRP!q<9tt
public class TestMethod { I?Zs|A
^6LFho4
n5JB'F)
public TestMethod() fgp7 |;Y
{ ///xx/weblogic60b2_win.exe qA~D*=
try{ 1tr>D:c\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LQh\j|e9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fd\XDc[g
SiteFileFetch fileFetch = new SiteFileFetch(bean); V?O%kd
fileFetch.start(); GVfu_z?
} - dOT/%Ux
catch(Exception e){e.printStackTrace ();} L$Leo6<3a
]8_h9ziz
z67=v9+7
} fhY[I0;}$
3H%HJS
_5K_YhT
public static void main(String[] args) k,@J&
{ ={b ]
new TestMethod(); ,|#>X>^FQQ
} z^Jl4V
} b$ x"&&
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