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)); oXdel Ju?
} =MxpH+spI
for(int i=0;i<nEndPos.length-1;i++) j|mv+O
{ Z&-tMai;
nEndPos = nStartPos[i+1]; _W}(!TKO
} XC2FF&B&
nEndPos[nEndPos.length-1] = nFileLength; (vnoP< 0
} Cs#w72N
} NCn`}QP
"H$@b`)
\ADLMj`F|
//启动子线程 L:pUvcAc?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O>%$q8x@i
for(int i=0;i<nStartPos.length;i++) m<3w^mww
{ tvGlp)?.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), []gRfM]$&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2QL?]Vo
nStartPos,nEndPos,i); \sITwPA[z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dZDK7UL
fileSplitterFetch.start(); Z%OW5]q
} b)`pZiQP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >Mw'eQ0(y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }vY.EEy!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7E\g &R.
nEndPos = " + nFileLength); T)~!mifX
// fileSplitterFetch[nPos.length-1].start(); -=a[J;'q
#|?8~c;RWG
(0R2T"/
//等待子线程结束 Im+7<3Z
//int count = 0; e1UITjy
//是否结束while循环 f3vF"O
boolean breakWhile = false; BPewc9RxV
P$OUi!"
v%nP*i9
while(!bStop) $''UlWK
{ 1x{kl01m%
write_nPos(); G|*G9nQ
Utility.sleep(500); XXm'6xD-
breakWhile = true; xNIGO/uI~
#A )Ab%r8"
7]Rk+q2:
for(int i=0;i<nStartPos.length;i++) -=mwy
{ VE$t%QT
if(!fileSplitterFetch.bDownOver) 6@YH#{~Zpv
{ g YUTt
breakWhile = false; 7 >bMzdH
break; $w/E9EJ)3A
} +>}o;`hPe
} R$d7\nBG
if(breakWhile) P#;Th8k{K2
break; 1'fb @vO
y42#n
=) }nLS3t
//count++; %Kl(>{N
//if(count>4) /[{auUxSX
// siteStop(); I .P6l*$
} `*k@4.J{
'Wp@b678
\0&SI1Yp
System.err.println("文件下载结束！"); ?4[NNL
} RB;BQoGX
catch(Exception e){e.printStackTrace ();} o(fyd)t
} fEwifSp.
=$&&[&
qrE0H
//获得文件长度 !iJipe5
public long getFileSize() :c:V%0Yji
{ .&|L|q}
int nFileLength = -1; (NaK3_
try{ "V}qf3qU
URL url = new URL(siteInfoBean.getSSiteURL()); J@Yj\9U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v2>Z^
httpConnection.setRequestProperty("User-Agent","NetFox"); #&BS ?@
s[X B#)H4
x.UaQ |F
int responseCode=httpConnection.getResponseCode(); #xp(B5
if(responseCode>=400) m9t$h
{ U&W"Ea=R/
processErrorCode(responseCode); `0@z"D5c
return -2; //-2 represent access is error YlKFw|=
} Y.-S=Y
T5e^J"
q.T:0|
String sHeader; H,K`6HH
JC2*$qu J
B;W(iI
for(int i=1;;i++) X8R1a?
{ L!y"d!6C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GTAf
//Utility.log(in.readLine()); (a#pvEY
sHeader=httpConnection.getHeaderFieldKey(i); Yt{&rPv,
if(sHeader!=null) Y;_T=L
{ -Qb0:]sV#
if(sHeader.equals("Content-Length")) J\A8qh8
{ A ~&+F>Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X"<|Z]w
break; Ep ">v>"
} JA6";fl;
} :<utq|#s
else IU9, (E
break; _#pnjo
} 1~Mn'O%
} y6%<zhs
catch(IOException e){e.printStackTrace ();} ;?~ 9hN!
catch(Exception e){e.printStackTrace ();} '[0YIn
Pa&4)OD
9g]M4*?C9P
Utility.log(nFileLength); 1<,/ -H
lT,+bU
s MZ[d\
return nFileLength; mH\@QdF
} BS2?!;,8
Oy$<QXj/
S(t{&+Wc
//保存下载信息（文件指针位置） +tUQ
private void write_nPos() 2f..sNz
{ 9XOyj5
try{ z<<Tk.65
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gru ALx7
output.writeInt(nStartPos.length); c;!9\1sr
for(int i=0;i<nStartPos.length;i++) 3.),bm
{ 4f {+pf^R
// output.writeLong(nPos); c0[k T
output.writeLong(fileSplitterFetch.nStartPos); Zi{0-m6+
output.writeLong(fileSplitterFetch.nEndPos); ^73=7PZ
} AP w6
output.close(); {ERjeuDm]
} e{!vNJ0`
catch(IOException e){e.printStackTrace ();} H(> M
catch(Exception e){e.printStackTrace ();} Zi4d]
} =DMbz`t
28oJFi]
UvBnf+,
//读取保存的下载信息（文件指针位置） ug&92Hdvy3
private void read_nPos() XeU<^ [
{ 8R4qU!M
try{ Sk=N [hwU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w~N-W8xNR
int nCount = input.readInt(); jdlG#j-\
nStartPos = new long[nCount]; mHs:t{q
nEndPos = new long[nCount]; &yLc1#H
for(int i=0;i<nStartPos.length;i++) O?E6xc<8
{ TSQhX~RN
nStartPos = input.readLong(); Tl3"PIb
nEndPos = input.readLong(); 6K 4+0xXv
} YoAg
input.close(); f:vD`Fz1
} RIjM(P
catch(IOException e){e.printStackTrace ();} D]u=PqHk2
catch(Exception e){e.printStackTrace ();} *P xf#X
} #T"64%dX
9L"?wv
;BVDt
private void processErrorCode(int nErrorCode) * nCx[
{ I?M@5u
System.err.println("Error Code : " + nErrorCode); ^'W%X
} x+^Vg3 q
4_Y!elH)
5;Ia$lm=y
//停止文件下载 %6i=lyH-
public void siteStop() `~nCbUUee
{ =]b9X7}
bStop = true; 61:9(*4~!F
for(int i=0;i<nStartPos.length;i++) C3.=GRg~l
fileSplitterFetch.splitterStop(); |Fp'/~|w2d
v[L[A3`"/
P)1EA;
} HNMBXXf,B
} 6"%2,`Nu
//负责部分文件的抓取 \h#9oPy
**FileSplitterFetch.java (\& 62B1
*/ Vp7b4n<
package NetFox; Fu##'#
@L8;VSI
Z4@y?fv7s
import java.io.*; xA-jvu9@
import java.net.*; =4>@8=JA
OX3Xy7
%?dE{ir
public class FileSplitterFetch extends Thread { e5OVq ,
*"T+G*~
|Puj7Ru
String sURL; //File URL 0jTMZ<&zZ
long nStartPos; //File Snippet Start Position j_c+.iET
long nEndPos; //File Snippet End Position e&Rb
int nThreadID; //Thread's ID vgAFuQi(
boolean bDownOver = false; //Downing is over 5/(sjMB
boolean bStop = false; //Stop identical sam[s4@eQ
FileAccessI fileAccessI = null; //File Access interface -'ZxN'*%
V16%Ne
61,O%lV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6[+j'pW?
{ PbN3;c3
this.sURL = sURL; {AgBwBCE
this.nStartPos = nStart; ,qu:<
this.nEndPos = nEnd; s41adw>
nThreadID = id; ]-Lruq#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mn`5pha
} y5%5O xB
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+{*)}[w{x
public void run() 5rN7':(H!%
{ Gh+f1)\FA"
while(nStartPos < nEndPos && !bStop) r?$&Z^
{ JV%nH!Fs
zq=&4afOE
JWWInuH
try{ U'M|=I'
URL url = new URL(sURL); Bac|;+L~L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %rXexy!V
httpConnection.setRequestProperty("User-Agent","NetFox"); ArX]L$D
String sProperty = "bytes="+nStartPos+"-"; yxY h?ka
httpConnection.setRequestProperty("RANGE",sProperty); 'M-)Os"
Utility.log(sProperty); vv* |F
l7~Pa0qD
}5hZo%w[n
InputStream input = httpConnection.getInputStream(); 6>uQt:e
//logResponseHead(httpConnection); U!NI_uk
kQ[Jo%YT?E
|Eu*P
byte[] b = new byte[1024]; mtX31M4
int nRead; Gw`/.0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c_DaNEfaY
{ i'iO H|s
nStartPos += fileAccessI.write(b,0,nRead); g-|Kyhr?=
//if(nThreadID == 1) Z9f/-|r5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NfqJ=9
} I1i:}g/
"$P'Wv
g/B\ObY
Utility.log("Thread " + nThreadID + " is over!"); v^\JWPR/
bDownOver = true; DZ2Fl>7
//nPos = fileAccessI.write (b,0,nRead); f-&ATTx`J
} cdDY]"k
catch(Exception e){e.printStackTrace ();} SctJxY(}!
} $>![wZ3
} SdSgn|S
bq: [Nj
n{$}#NdV
//打印回应的头信息 TH>,v
public void logResponseHead(HttpURLConnection con) =-m(\}
{ XD 5n]AL
for(int i=1;;i++) OOfyGvs
{ []=_<]{
String header=con.getHeaderFieldKey(i); T;J7+0
if(header!=null) $)f"K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i0b.AA
Utility.log(header+" : "+con.getHeaderField(header)); !YY6o V
else {dBB{.hX
break; ^8Z@^M&O"
} ]2PQ X4t0
} eX@v7i,}
"&Gw1.p
U Q)!|@&
public void splitterStop() R~$hWu}}
{ &M$Bt} <
bStop = true; yYM_lobn
} ^?nP$+gq
!*5_pGe
%6N)G!P
} S7Znz@
blUY.{NN3
drbe#FObX
/* "A]?M<R
**FileAccess.java o:H'r7N
*//文件访问(定位，写) 5 >'66gZ
package NetFox; 3hH>U%`-
import java.io.*; hcQSB00D^
9@Q&B+!
X:U=MWc>
public class FileAccessI implements Serializable{ u |'8a1
k?<i*;7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ma1(EJ/
RandomAccessFile oSavedFile; #s*k| j}
long nPos; }iMXXXBOT
xUIvLH=
We\KDU\n
public FileAccessI() throws IOException IeH^Wm&^
{ X=JFWzC
this("",0); J0Jr BXCh
} k&yQ98H$K"
UmYD]
1E8$% 6VV
public FileAccessI(String sName,long nPos) throws IOException /9P^{OZ;y
{ A0S8Dh$
oSavedFile = new RandomAccessFile(sName,"rw"); 6={IMkmA
this.nPos = nPos; RXUA!=e
oSavedFile.seek(nPos); 7,f:Qi@g
} PBCb0[\
YXgWH'i~
tc"T}huypU
public synchronized int write(byte[] b,int nStart,int nLen) )ni"qv~J
{ q)NXyy4BT
int n = -1; DQ%`v=
try{ c!.=%QY
oSavedFile.write(b,nStart,nLen); 0h^uOA; c
n = nLen; vf6`s\6
} 5QKRI)XpZ
catch(IOException e) mlD%d!.
{ 15o9CaQw4"
e.printStackTrace (); :DDO=
} y:~eU
GahaZ F
oN_S}o
return n; #,t2*tM
} P`7ojXy
uijq@yo8-
/g13X,.H
} n'q aR<bY
$I\))*a
d:A\<F
/* +d.u##$
**SiteInfoBean.java rFf:A-#l
*/ hJecCOA)'
package NetFox; >9 q]>fJ
G!nl'5|y
mp!YNI
public class SiteInfoBean { 3Wjq>\
km9Gwg/zT
SRP5P,-y
private String sSiteURL; //Site's URL nWKO8C>
private String sFilePath; //Saved File's Path "(Mvl1^BT
private String sFileName; //Saved File's Name >s;oOo+5
private int nSplitter; //Count of Splited Downloading File izXbp02
${wU+E*
Y,3z-Pa=@
public SiteInfoBean() u9esdOv
{//nSplitter的缺省值为5 Dq{:R
//default value of nSplitter is 5 ~&t!$
this("","","",5); {k kAqJ
} lt }r}HM+
h1n*WQ-
J>><o:~@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q1aHIc
{ lq;
sSiteURL= sURL; /7c2OI=\
sFilePath = sPath; mk#>Dpy?
sFileName = sName; r3n=<l!Jr
this.nSplitter = nSpiltter; UAnB=L,.\
fn4=
5T~3$kuO
} s;vWR^Ll
98X!uh'
?lu_}t]
public String getSSiteURL() d-9uv|SJ
{ kEp.0wL'
return sSiteURL; X(4s;i
} <]Ij(+J;
FgXu1-
29&sydu
public void setSSiteURL(String value) ^wvH,>Yo
{ Gtj(
sSiteURL = value; CkmlqqUHC
} xR\D(FLVS
z8 hTZU
99\{!W
public String getSFilePath() D=jSh
{ Q2JdO 6[96
return sFilePath; RpBiE8F4
} AM>Yj
p>2||
j)g_*\tQ
public void setSFilePath(String value) i58ZV`Rk`
{ 5W*7qD[m
sFilePath = value; 17J}uXA
} 4JX`>a{<
vpZu.#5c
1"8Z y6t
public String getSFileName() `4q5CJ2
{ 43vGgGW
return sFileName; \4[c}l
} )B-MPuB
^VSt9&
KC@k9e
public void setSFileName(String value) Fpy6"Z?z
{ ^n\9AE3
sFileName = value; AZh@t?)
} utYnaeQcn
P5'iYahCq_
XkMs
public int getNSplitter() i_j9/k
{ b:N^Fe
return nSplitter; ioE66-n
} +)/Rql(lY
08TaFzP81
!!?+M @
public void setNSplitter(int nCount) Y|{r vBKjf
{ -ET*M<
nSplitter = nCount; $=e&q
} u=p ;A1oy
} W?*Xy6",JF
aukk|/3Ih
w.4u=e >Z4
/* \zk?$'d
**Utility.java :FX'[7;p
*/ +-Z"H)
package NetFox; OaD Alrm
MgJ%26TZ
3a'Rs{qxn
public class Utility { v#Cz&j
W0+gfg
37j\D1Y
public Utility() eT7!a']x
{ ?z\q Mu
F&W0DaH
.ujs`9d_-
} \_*?R,$3Y,
S5:"_U
//线程睡眠 |i,zY{GI+2
public static void sleep(int nSecond) OqfhCNAY
{ Bo\a
try{ ^l]]qdNr
Thread.sleep(nSecond); =:xV(GK}
} 'Z*\1Ci
catch(Exception e) u)q2YLK8
{ e3yorQ][
e.printStackTrace (); 5PPPd-'Z_
} e.)yV'%L
} }};j2
1kB'sc3N!
//日志 x&hvFG3
public static void log(String sMsg) Hrd5p+j
{ OPvj{Dv$0
System.err.println(sMsg); jRv;D#Hp
} ?~VWW<lR
-Z`(? k
6=Y3(#Ddt
public static void log(int sMsg) c]AKeq]
{ mhHA!:Y
System.err.println(sMsg); rd&*j^?
} EmtDrx4!(f
} U~u6}s]:
dCf'\@<<
Bo](n*i
/* p`E|SNt/W
**TestMethod.java f"5lOzj`C
*/ &y#\1K
package NetFox; ^]#Ptoz^(l
[OFTP#}c
Pi&fwGL
public class TestMethod { B|]t\(~$[
,(@Y%UW:
Dg9--wI}I9
public TestMethod() ;ZxK3/(7
{ ///xx/weblogic60b2_win.exe rQd1Ch
try{ boC>N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h3UZ|B0=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gx(KN57D
SiteFileFetch fileFetch = new SiteFileFetch(bean); wf~5lpI[
fileFetch.start(); :,h=2a_ 8
} {<- ouD
catch(Exception e){e.printStackTrace ();} Ak\D6eHcB
7':5
%KabyvOl)
} sx)$=~o
E>l#0Zw
`'G),{ j
public static void main(String[] args) ^G'yaaLXR
{ haEZp6Z
new TestMethod(); *#prSS
} \28b_,i+
} ~# hE&nq
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