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)); Q@$1!9m
} hJ}G5pX
for(int i=0;i<nEndPos.length-1;i++) !?l 23(d
{ ;euWpE;E\#
nEndPos = nStartPos[i+1]; a@8knJ|
} 3_h%g$04s
nEndPos[nEndPos.length-1] = nFileLength; PA,j;{,(b
} qWanr7n]@
} ?5(L.XFm
Fn[~5/
qb"!
//启动子线程 `Mjm/9+18
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SQ.4IWT(hR
for(int i=0;i<nStartPos.length;i++) 0I#<-9&d-
{ 0(i`~g5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [;?^DAnK2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I7uYsjh@u
nStartPos,nEndPos,i); }s)Z:6;(,q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 92SB'T>
fileSplitterFetch.start(); ;JZXSM-3
} {xH \!!"T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /ZzlC#`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %kcg#p+tE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RU{}qPs?
nEndPos = " + nFileLength); 1B1d>V$*
// fileSplitterFetch[nPos.length-1].start(); RF;N]A?*
yjSN;3t71
`2@-'/$\I|
//等待子线程结束 xS(sRx+A
//int count = 0; TWs|lhC7!
//是否结束while循环 yq<YGNy!
boolean breakWhile = false; QqwXFk
!3b%Q</M H
Wt`D
while(!bStop) 3%P?1s
{ "(xS[i
write_nPos(); .H>Rqikj
Utility.sleep(500); S5d{dTPq
breakWhile = true; q6ikJ8E8b
kl={L{r
- a=yid
for(int i=0;i<nStartPos.length;i++) %bimcRX#W
{ sbs"26IE
if(!fileSplitterFetch.bDownOver) xv*mK1e
{ gRFC n6Q
breakWhile = false; iM9563v
break; V\G>e{
} A]J^{h0k
} hD,-!R
if(breakWhile) AzV5Re8M
break; wH`@r?&
n;=A'g|Q
e7qT;
//count++; t/$xzsoJZr
//if(count>4) 3Yf$WE8#l
// siteStop(); (]V.#JM
} GmHsO/
O-B3@qQ. h
Q?tV:jogY
System.err.println("文件下载结束！"); {Q-U=me\
} %*gO<U4L]
catch(Exception e){e.printStackTrace ();} eeDhTw9
} jG2w(h/"
[D,:=p`
N0piL6Js
//获得文件长度 D#$gdjZ
public long getFileSize() 4w?7AI]Ej
{ q1gf9`0
int nFileLength = -1; G!~BA*
try{ 9=o b:
URL url = new URL(siteInfoBean.getSSiteURL()); N\fT6#5B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nZT@d;]U9
httpConnection.setRequestProperty("User-Agent","NetFox"); |-mazvA
jgstx3
\1Bgs^
int responseCode=httpConnection.getResponseCode(); $W?XxgkB?
if(responseCode>=400) nx4aGS"F:
{ \fhT#/0N
processErrorCode(responseCode); toWmm(7v
return -2; //-2 represent access is error ZX0c_Mk=
} xHGoCFB
3dbf!
VZ,T`8"
String sHeader; &8pXkD#A
9,W-KM
.$k"+E
for(int i=1;;i++) ZFON]$Zk
{ !lF^~x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :qbG%_PJ
//Utility.log(in.readLine()); VMWg:=~$
sHeader=httpConnection.getHeaderFieldKey(i); }"-r;i
if(sHeader!=null) |rvrSab)
{ c|R/,/
if(sHeader.equals("Content-Length")) R\}YD*
{ _y9P]@Q7%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z C93C7lJ
break; cOb%SC[A{
} mQs$7t[>t
} @5wg'mM
else W~tOH=9>
break; OeYLL4H
} @NIypi$T
} T]W -g
catch(IOException e){e.printStackTrace ();} 8x"d/D
catch(Exception e){e.printStackTrace ();} MT`gr
@r?`:&m0
kut|A
Utility.log(nFileLength); p5l$On
?a%i|Z7!
4I*Mc%dD
return nFileLength; Q.1ohj0)
} s]c$]&IGG
d]3sC
sJoi fl 7
//保存下载信息（文件指针位置） !d\GD8|4
private void write_nPos() #+ '@/5{n
{ m3!M L>nLt
try{ GU3/s&9
output = new DataOutputStream(new FileOutputStream(tmpFile)); {9".o,
output.writeInt(nStartPos.length); F29AjW86
for(int i=0;i<nStartPos.length;i++) 1%"` =$q%
{ _zh5KP[{
// output.writeLong(nPos); ku?_/-ko]
output.writeLong(fileSplitterFetch.nStartPos); ]e.+u
output.writeLong(fileSplitterFetch.nEndPos); md"%S-a_dT
} 5@$4.BGcF
output.close(); kDq%Y[6Z
} 3(+#^aw
catch(IOException e){e.printStackTrace ();} r%pFq1/'!
catch(Exception e){e.printStackTrace ();} 6t:c]G'J
} !h!9SE
^kvH/Y&
MjB[5:s
//读取保存的下载信息（文件指针位置） Jt6J'MOq
private void read_nPos() XL^N5
{ 3\r@f_p
try{ <y!r~?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ok[=1gA#h
int nCount = input.readInt(); /zf>>O`
nStartPos = new long[nCount]; v4_OUA>z,
nEndPos = new long[nCount]; yrAzD=
for(int i=0;i<nStartPos.length;i++) Ts .Zl{B
{ j7#GqVS'
nStartPos = input.readLong(); i@5%d!J
nEndPos = input.readLong(); /\cu!yiX
} oh~ vo!
input.close(); _a$DY,;
} \!Zh="hN
catch(IOException e){e.printStackTrace ();} a~F@3Pd
catch(Exception e){e.printStackTrace ();} %J7mZB9
} v8bl-9DQ
xsDa!
<C%-IZv$
private void processErrorCode(int nErrorCode) (V.,~t@
{ $sF#Na4^
System.err.println("Error Code : " + nErrorCode); e[mhbFf-
} ,'CWt]OS'
7&V^BW
|.O!zRm
//停止文件下载 h5rP]dbhXU
public void siteStop() R.IUBw5;/
{ J xm9@,
bStop = true; BddECY,z
for(int i=0;i<nStartPos.length;i++) NcBe|qxQ
fileSplitterFetch.splitterStop(); ^FM9} t/U,
]H#Rm#q
s9kLB.
} U?fN3
} H r^15
//负责部分文件的抓取 `.(S#!gw
**FileSplitterFetch.java \h7J/es^p!
*/ Mp"ci+Iu
package NetFox; =+}}Sv2
BrH;(*H)8
I.+)sB?5
import java.io.*; ClMtl59
import java.net.*; *C@[5#CA2z
iW1ih QX
A?D"j7JD=L
public class FileSplitterFetch extends Thread { 0tCOb9
.(7C)P{.0
x56 F
String sURL; //File URL e9@fQ
long nStartPos; //File Snippet Start Position xSDE6]
long nEndPos; //File Snippet End Position x*&&?nV Iz
int nThreadID; //Thread's ID #VdI{IbW
boolean bDownOver = false; //Downing is over M=[q+A
boolean bStop = false; //Stop identical s i"`
FileAccessI fileAccessI = null; //File Access interface ]Uu(OI<)
fE%[j?[
m>+,^`0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R g0 XW6
{ \W`}L
this.sURL = sURL; J'ZFIT_>
this.nStartPos = nStart; SXBQ
this.nEndPos = nEnd; I0w@S7
nThreadID = id; ?[S >&Vq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @SC-vc
} _A,-[*OKI
0^y@p&;/.
$;2eH
public void run() L);||]B
{ VyoE5o
while(nStartPos < nEndPos && !bStop) ()C^ta_]
{ g)9JO6]
Krr?`n
$}^\=p}X
try{ I*W9VhIOV
URL url = new URL(sURL); -S,ir
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 827)n[#%|
httpConnection.setRequestProperty("User-Agent","NetFox"); =EcIXDzC>
String sProperty = "bytes="+nStartPos+"-"; p_5>?[TW:
httpConnection.setRequestProperty("RANGE",sProperty); #OD@q;
Utility.log(sProperty); ! [|vx!p
cCh0?g7nV
J[<pZ [
InputStream input = httpConnection.getInputStream(); WE5"A| =
//logResponseHead(httpConnection); "6E1W,|{
loeLj4""
_)#=>$k\
byte[] b = new byte[1024]; O,=Q1*c,&
int nRead; (I7&8$Zl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JMirz~%ib
{ r,3Ww2X-
nStartPos += fileAccessI.write(b,0,nRead); hmBnV
//if(nThreadID == 1) g<2lPH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r%y;8$/-
} mo|PrLV
uXQ7eXX
I|F~HUzA"
Utility.log("Thread " + nThreadID + " is over!"); 7O8V1Tt
bDownOver = true; /OhaERv
//nPos = fileAccessI.write (b,0,nRead); ]Z.<c$
} R(2HYZ
catch(Exception e){e.printStackTrace ();} iM?I /\
} us\%BxxI9
} }_a+X
PTzp;.
KH2F#[ !Lw
//打印回应的头信息 vZ[$H
public void logResponseHead(HttpURLConnection con) HzD>-f
{ QN5yBa!Wz
for(int i=1;;i++) Q{qj
{ iHE0N6%q
String header=con.getHeaderFieldKey(i); -7-Fd_F8
if(header!=null) *xX(!t'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [+;FV!M6
Utility.log(header+" : "+con.getHeaderField(header)); ?AV&@EX2C
else W>`g;[ W
break; e8d5(e
} 9C557$nS^
} z-KrQx2
O)R7t3t
y wW-p.
public void splitterStop() >/TB_ykb
{ %aj7-K6:t
bStop = true; gx!*O<|e4
} f?=r3/AO
1z})mfsh
-+3be(u
} O+G~Qp0b>
WFU?o[k-O
6keP':bt
/* ^%n124
**FileAccess.java n_""M:XH
*//文件访问(定位，写) !lQ#sL`
package NetFox; H$~M`Y9I~
import java.io.*; |8&-66pX
!X5o7b)
~In{lQ[QX
public class FileAccessI implements Serializable{ ; g Z%U
fKL'/?LD]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )"(V*Z
RandomAccessFile oSavedFile; g2g`,"T
long nPos; ps"/}u l
to99_2
{l0,T0
public FileAccessI() throws IOException /]ku$.mr\
{ -Wl)Lez@
this("",0); abM84EU
} 5Y(r\Dd
'RDWU7c9]
'R^iKNPs
public FileAccessI(String sName,long nPos) throws IOException ]s*5[=uc2
{ 3C277nx
oSavedFile = new RandomAccessFile(sName,"rw"); KqN!?anPr
this.nPos = nPos; 5a=nF9/
oSavedFile.seek(nPos); .cw!ls7d
} kRmj"9oA
#V<`U:.
n_<mPU
public synchronized int write(byte[] b,int nStart,int nLen) o;ik Z*+*
{ :fxWz%t
int n = -1; mWNR(()v
try{ 90Xt_$_}s
oSavedFile.write(b,nStart,nLen); 0Vf)Rw1%I
n = nLen; >j&1?M2C
} R<Z^L~)
catch(IOException e) $Llta,ULE
{ .D+RLO z
e.printStackTrace (); F|ETug n
} Jzk!K@
Y{,2X~ 7
?V#Gx>\
return n; 'eqiYY|
} i4hJE
n4^*h4J7
{UP'tXah
} Kn']n91m
0r1g$mKb
ows^W8-w
/* BRe{1i 6
**SiteInfoBean.java SEYGy+#K
*/ hO#HvW
package NetFox; ]}'^`
j2M4H@
mRCHrw?WG
public class SiteInfoBean { llNXQlP\B
1XG$ z@NN
/v5qyR7an
private String sSiteURL; //Site's URL rxQ<4
private String sFilePath; //Saved File's Path ?~!tM}X0:3
private String sFileName; //Saved File's Name u0xQ;BQ
private int nSplitter; //Count of Splited Downloading File *]5z^> q;7
*%3oyWwCd
,NDh@VYe
public SiteInfoBean() ])C>\@c6Gm
{//nSplitter的缺省值为5 }xqXd%uz
//default value of nSplitter is 5 $)Wb#B
this("","","",5); @\ }sb]
} TfL4_IAG.
X&s7%]n+
:ztyxJv1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4KE)g
{ |B eA==
sSiteURL= sURL; d^tVD`Fm
sFilePath = sPath; *MI)]S
sFileName = sName; T:U4:"
this.nSplitter = nSpiltter; G[#.mD{k
Khj=llo,
h77IWo6%
} 9[kX/#~W*
e|VJ9|;3
j$+gq*I&E
public String getSSiteURL() ovz#
{ +I&J7ICV0
return sSiteURL; )6G"*
} P&mtA2
m*gj|1k
E[UO5X
public void setSSiteURL(String value) u^l*5F%DK
{ >&1um5K
sSiteURL = value; <9`?Z-lJP
} _e*c
mY`@'
m`c#:s'_
public String getSFilePath() SBX|Bcyk*
{ Yc d3QRB
return sFilePath; rhIGOk1k
} ]/_G-2.R
iOll WkF
[%jxf\9jJ_
public void setSFilePath(String value) FOSbe]
{ AeaPK
sFilePath = value; kQ~ %=pn
} |#V(p^
ge$LIsE8
-?5$ PH
public String getSFileName() Q<yAT(w
{ *2=W5LaK.
return sFileName; ) \4 |
} QF.3c6O@
_W|R;Cz]
-AC`q/bCD
public void setSFileName(String value) 9^!wUwB
{ 7 5|pp
sFileName = value; *0~M
} n$YE !D'
2m\m/O
-E]Sk&4Gj
public int getNSplitter() lBmm(<~Z
{ U. (Tl>K|0
return nSplitter; $3 4j6;oN
} UWw}!1
HlPG3LD!
>t0%?wj)Y
public void setNSplitter(int nCount) @zrNN>
{ GmbIFOT~
nSplitter = nCount; # kEOKmO
} [sj VRW-
} G'9{a'
JOHRmfqR
H|`R4hAk
/* ?+Q$#pb
**Utility.java sB6dpD
*/ #k9<
package NetFox; +#s;yc#=2
D%U:!|G
AW/wI6[T
public class Utility { _q)!B,y-/N
13a(FG
(a }J$:
public Utility() vbp-`M(
{ ;v_V+t<$
O:^'x*}
j#VIHCzlr
} c#QFG1
qo_]ZKL44
//线程睡眠 e\9g->DUs
public static void sleep(int nSecond) _!!}'fMC
{ M6Pw/S!
try{ ]'k[u
Thread.sleep(nSecond); ?'sXgo.}
} ru{f]|
catch(Exception e) ],[)uTZc
{ -CD\+d "
e.printStackTrace (); ^i'y6J
} K%gP5>y*9>
} Q0~j$Jc
HE;V zR
//日志 ZXt?[Ll
public static void log(String sMsg) hH`Jb77L
{ @o#+5P
System.err.println(sMsg); $"8d:N?I[
} kXwi{P3D$
%LQ/q3?_
n+;vjVS%
public static void log(int sMsg) P+Z\3re
{ "- eZZEl(
System.err.println(sMsg); w!`Umll2
} iYKU[UP?
} `*yAiv>
.X'< D*
}fA;7GW+9
/* ?z=\Ye5x
**TestMethod.java U=cWmH
*/ QU/3X 1W
package NetFox; tg85:
NfwYDY
wqy^8N[K]
public class TestMethod { %{C)1*M7
>SDpuG&>
f^9&WT
public TestMethod() PZ,z15PG]
{ ///xx/weblogic60b2_win.exe >uy%-aXiVa
try{ P`TIaP9%E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JE!("]&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =_PvrB2'
SiteFileFetch fileFetch = new SiteFileFetch(bean); &?+WXL>
fileFetch.start(); V=}1[^
} ~R.dPUr
catch(Exception e){e.printStackTrace ();} n"G`b
maC>LBa2/
z[9UQU~x?
} I:$"E% >=
{QQl$ys/
#$'FSy#
public static void main(String[] args) Wx]d $_
{ |!LnAh
new TestMethod(); d?hz LX
} {/}^D-
} B~TN/sd
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