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)); s0CRrMk
} Zh$Z$85p
for(int i=0;i<nEndPos.length-1;i++) sQw-#f7t
{ )XFMlSx)
nEndPos = nStartPos[i+1]; $8)/4P?OL
} :([,vO:
nEndPos[nEndPos.length-1] = nFileLength; Lfor0-j
} W7 $yE},z
} u|E,Wy1
4p]Y`];U
M6>l%[
//启动子线程 a%kj)ah
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PNq#o%q
for(int i=0;i<nStartPos.length;i++) U4gZW]F
{ kI]1J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0)Z7U$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U w)1yzX
nStartPos,nEndPos,i); R)v`ZF,/b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lWR
fileSplitterFetch.start(); kDrGl{U}
} GC~::m~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R9HRbVBJf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~vgW:]i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |R4](
nEndPos = " + nFileLength); ZISR]xay
// fileSplitterFetch[nPos.length-1].start(); uQDu<@5^[
S"dQ@r9
\l`;]cA
//等待子线程结束 q+ .=f.+Z
//int count = 0; X@ss d
//是否结束while循环 +1rJ;G
boolean breakWhile = false; *ULXJZ%
,PB?pp8C}
_&T$0SZco
while(!bStop) }.Ug`7%G
{ E^rN)
write_nPos(); wL{Qni3A
Utility.sleep(500); It4F;Ah
breakWhile = true; - na]P3 s
uJ%ql5XDV
V/03m3!q
for(int i=0;i<nStartPos.length;i++) d"V^^I)yx&
{ ;gF"o5/Q
if(!fileSplitterFetch.bDownOver) %T&kK2d;
{ v>,XJ7P
breakWhile = false; 5EU3BVu&u
break; 6K,AQ.=V2
} D=3NI
} 'rSM6j
if(breakWhile) ~ >6(@~6
break; f#!Ljjf$;
CzwnmSv{.
wy7f7zIa
//count++; a{y;Ub
//if(count>4) ETmfy}V8
// siteStop(); + 505
} G-Y8<mEh
Baq&>]
+] FdgmK:
System.err.println("文件下载结束！"); NZv1dy`fa
} 7r:!HmRl
catch(Exception e){e.printStackTrace ();} /:B!hvpw
} {`{U\w5Af
0PZpE "$X
JVN0];IL}
//获得文件长度 0DGXMO$;
public long getFileSize() X'O3)Yg
{ mzDbw-#
int nFileLength = -1; V4_ZBeWA
try{ <5=^s%H
URL url = new URL(siteInfoBean.getSSiteURL()); c!b4Y4eJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &S/KR$^ %
httpConnection.setRequestProperty("User-Agent","NetFox"); \:8 >@Q
l7\Bq+Q
G{)2f&<
int responseCode=httpConnection.getResponseCode(); ttgb"Wb%S
if(responseCode>=400) ca5Ir<mL
{ Ean #>h
processErrorCode(responseCode); CnN PziB
return -2; //-2 represent access is error ;~F&b:CyG
} 'V/+v#V+>
F8KSB"!NR
r761vtC#
String sHeader; 4'[/gMUkw
rjz$~(&m6
(} ?")$.
for(int i=1;;i++) qi!+Ceo}
{ ,Tjc\;~%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o-c.D=~
//Utility.log(in.readLine()); t[ cHdI
sHeader=httpConnection.getHeaderFieldKey(i); C8ek{o)%W
if(sHeader!=null) B^nE^"b
{ c<Fr^8
if(sHeader.equals("Content-Length")) ~qT5F)$B-
{ dD ?ZF6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J#ujIe
break; m7!Mstu
} aYW9C<5
} (l}W\iB'd
else SJ8Ax_9{q
break; ebfT%_N
} }LeizbU
} n<3qr}ZG^
catch(IOException e){e.printStackTrace ();} x4v@o?zW
catch(Exception e){e.printStackTrace ();} VUmf;~
:J6 xYy$
gjFpM.D-.
Utility.log(nFileLength); 2+s#5K&i
"lLwgh;
?sD4S
return nFileLength; /xq^]0xy
} }ff+RGxLIG
:<gC7UW
rel_Z..~
//保存下载信息（文件指针位置） Zo`_vx/{j
private void write_nPos() .7BJq?K.
{ 4Dy|YH$>S
try{ ANWfRtiU#
output = new DataOutputStream(new FileOutputStream(tmpFile)); z|bAZKSRYx
output.writeInt(nStartPos.length); QlE]OAdB42
for(int i=0;i<nStartPos.length;i++) ` {/"?s|
{ uo9FLm
// output.writeLong(nPos); Zz/ z7~{
output.writeLong(fileSplitterFetch.nStartPos); t03X/%H
output.writeLong(fileSplitterFetch.nEndPos); BD,J4xH;
} gx9=L&=d
output.close(); `NySTd)\
} CFXr=.yz
catch(IOException e){e.printStackTrace ();} ,J(shc_F
catch(Exception e){e.printStackTrace ();} L8,/
} TrPw*4h 9s
\&/V p`
"O~7s}
//读取保存的下载信息（文件指针位置） zb3,2D+P
private void read_nPos() 8'qq!WR~
{ +\-cf,WkI
try{ [nA1WFfM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (T!#7
int nCount = input.readInt(); mor[AJ
nStartPos = new long[nCount]; XM f>B|
nEndPos = new long[nCount]; T*z*x=<5
for(int i=0;i<nStartPos.length;i++) ~jJF&*)
{ |@5G\N-
nStartPos = input.readLong(); m<sCRWa-
nEndPos = input.readLong(); )=nB32~J"
} ZZ>F ^t
input.close(); <&kl:|
} ";jKTk7
catch(IOException e){e.printStackTrace ();} MbxJ3"@
catch(Exception e){e.printStackTrace ();} k%R(Qga
} |G)P I`BH
v:"Y
:28[k~.bo
private void processErrorCode(int nErrorCode) RK/>5
{ rn]F97v@]
System.err.println("Error Code : " + nErrorCode); O{p7I&
} lWDSF]ZYV
iD.p KG
Z.`0
//停止文件下载 K5 EJ#1ov
public void siteStop() `(r0+Qx
{ >9y!M'V
bStop = true; Bk] `n'W
for(int i=0;i<nStartPos.length;i++) @^%YOorr
fileSplitterFetch.splitterStop(); m2HO .ljc
BoXPX2:
cv;2zq=T
} 1:RK~_E
} f\FqZ?w
//负责部分文件的抓取 Z+=WICI/2
**FileSplitterFetch.java ;{Yr|
*/ XZ2 ji_D
package NetFox; E5?$=cL?
7Y)i>[u3
Tv `&
import java.io.*; Fr-Vq=j&
import java.net.*; 7[0<,O6Q
~R\ $Z
pd|l&xvka
public class FileSplitterFetch extends Thread { Q9c*I,Oj
?4#
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String sURL; //File URL mKoDy`s
long nStartPos; //File Snippet Start Position lk[u
long nEndPos; //File Snippet End Position .$1S-+(kV
int nThreadID; //Thread's ID t>Yl=79,
boolean bDownOver = false; //Downing is over 4&%E?_M
boolean bStop = false; //Stop identical 'J)9#
FileAccessI fileAccessI = null; //File Access interface G5lBCm
XtE O)
$KBW{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YV'B*arIA
{ F$'po#
this.sURL = sURL; -c{Y+M`
this.nStartPos = nStart; k@pEs# a
this.nEndPos = nEnd; p&\DG
nThreadID = id; X5(oL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VF+g+~
} ^F-2tc
\9~Q+~@{G
b!`6s
public void run() n<F3&2w
{ 7V5kYYR^F
while(nStartPos < nEndPos && !bStop) /`t}5U>S_
{ 8Pva]Q
6W~JM^F
GnCs_[*&r
try{ +U>Y.YP
URL url = new URL(sURL); 9ph>4u(R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i2-]Xl
httpConnection.setRequestProperty("User-Agent","NetFox"); mRt/d
String sProperty = "bytes="+nStartPos+"-"; m|;gl|dTB
httpConnection.setRequestProperty("RANGE",sProperty); -=n!k^?lK
Utility.log(sProperty); ]VEc9?
@i#=1)Ze
LMN`<R(q]
InputStream input = httpConnection.getInputStream(); 1;!dTh
//logResponseHead(httpConnection); &i6JBZ#~,
R?dMM
vst;G-ys
byte[] b = new byte[1024]; ScQ9p379
int nRead; e&K7n@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jw/@]f;N
{ |h&okR+_,
nStartPos += fileAccessI.write(b,0,nRead); Bsk` e
//if(nThreadID == 1) b(adM3MP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #Fgybokm
} vg1E@rH|}
jF(R;?,
P,#l~\
Utility.log("Thread " + nThreadID + " is over!"); K;`W4:,
bDownOver = true; b/tcD r
//nPos = fileAccessI.write (b,0,nRead); iQgr8[ SFf
} tVNFulcz$
catch(Exception e){e.printStackTrace ();} aU$80
} .3wx}!:*|
} I9nm$,i]7
Moi>Dp
dsK*YY jH
//打印回应的头信息 '#yIcV$
public void logResponseHead(HttpURLConnection con) X|4Kdi.r@
{ [(vV45(E
for(int i=1;;i++) W@+ge]9m&
{ c0_512
String header=con.getHeaderFieldKey(i); .$+,Y4q~(
if(header!=null) d6zq,x!cI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TXbi>t:/S{
Utility.log(header+" : "+con.getHeaderField(header)); j*~z.Q|
else f%P#.
break; 0}e&ONDQ
} jS|jPk|I.
} 4KW_#d`t
R[#B|$
0OnqKgf
public void splitterStop() ZfS"
{ /<J5?H
bStop = true; eMP0BS"
} #9A*BbY
%4/X;w\3
q1A0-W#4
} ApcE)mjpc
@[5]?8\o
H.O&seY
/* }To-c'
**FileAccess.java jk])S~xl?
*//文件访问(定位，写) J$(79gH{
package NetFox; 2W/*1K}
import java.io.*; }9Q<<a
9 vNz yh\
WaiM\h?=#
public class FileAccessI implements Serializable{ QD 0p
b\xse2#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U.ew6`'Te
RandomAccessFile oSavedFile; 1Nz#,IdQ
long nPos; F[X;A\
1R#1Fy%
:ZXaJ!
public FileAccessI() throws IOException |W SvAM3
{ KPa@~rU
this("",0); 1+ V<-I@{
} sw,p6T[
?cD_\~
W"s)s
public FileAccessI(String sName,long nPos) throws IOException Z}>+!Z
{ KwxJ{$|xH
oSavedFile = new RandomAccessFile(sName,"rw"); tk+t3+
this.nPos = nPos; vARZwIu^D
oSavedFile.seek(nPos); :(4];Va
} l, -q:8
px^brzLQo
Rm@F9D[,
public synchronized int write(byte[] b,int nStart,int nLen) Hnbd<?y
{ DjiWg(X
int n = -1; ZRC7j?ui8`
try{ <-!'V,c
oSavedFile.write(b,nStart,nLen); :;o?d&C
n = nLen; p5bM/{DP;K
} <##aD3)
catch(IOException e) R-\"^BV#Z
{ >V@,K z1
e.printStackTrace (); /O$)m[
} t\lx*_lr
o6S`7uwJ*/
lDG.\u
return n; Z DnAzAR
} |bjLmGb
jHc/ EZB
4?~Ei[KgQn
} eRIdN(pP
liVDBbS_A?
Y\{lQMCy
/* 1)!]zV
**SiteInfoBean.java DZX4c2J
*/ /Pa<I^-#
package NetFox; s_`y"'^
zuBfkW95+
.t{?doOT
public class SiteInfoBean { ~Nl`Zmn(A|
+,bgOq\aG
IV$2`)[A&X
private String sSiteURL; //Site's URL (OHd}YQ
private String sFilePath; //Saved File's Path m{0u+obi&w
private String sFileName; //Saved File's Name C,3yu,'
private int nSplitter; //Count of Splited Downloading File JLV?n,nF
w7h=vy n?
|b)N;t
public SiteInfoBean() ^ px)W,O
{//nSplitter的缺省值为5 }ilX 2s?>
//default value of nSplitter is 5 M.}QXta
this("","","",5); {,i='!WIm
} $6\W8v
c)=UX_S!
IctLhYZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6c&OR2HGqO
{ cOEzS
sSiteURL= sURL; (ZuV5|N
sFilePath = sPath; JZrUl^8E
sFileName = sName; U*em)/9
this.nSplitter = nSpiltter; sR*JU%
M;qV% k
{v}jV{'^um
} j<*`?V^
_7w2E
) XHcrm&
public String getSSiteURL() J'y*>dW
{ H0i\#)Xs
return sSiteURL; U9p^?\-=
} T?E[LzZg
@Ao E>
S~DY1e54GF
public void setSSiteURL(String value) A'X, zw^}
{ ss>?fyA
sSiteURL = value; m=2e1wc
} bwAL:
XS/5y(W
+bK.{1
public String getSFilePath() %S<( z5
{ /1q] D8
return sFilePath; cZ~\jpK
} $R<eXDW6:
=F}e>D
lCyp&b#(L
public void setSFilePath(String value) oWUDTio#[
{ 8W_X&X?Q
sFilePath = value; Sm%MoFf
} e?D,=A4mV"
%7?v='s=
8Cr?0Z
public String getSFileName() aJDu_
{ r8~U@$BBK
return sFileName; lFY;O !Y5\
} []M+(8Z_P
g3%t+>$*
Yg#)@L
public void setSFileName(String value) 7M1*SC
{ z {J1pH_X
sFileName = value; ^ffh
} FBPT@`~v
&~Q ?k
O"mU#3?
public int getNSplitter() [J+K4o8L<A
{ QE5 85s5
return nSplitter; ";e0-t6:
} EQ>bwEG
D] 2+<;>`>
^dP@QMly6
public void setNSplitter(int nCount) I=^%l7
{ p$@=N6)I.k
nSplitter = nCount; l(zkMR$b8
} }~-)31e'`
} TR@$$RrU
,Ql3RO,
);;UNO21+
/* 9#6ilF:F
**Utility.java {\ziy4<II
*/ a@,tf'Sr
package NetFox; AJ:@c7:eS
$YaL3n
{M E|7TS=
public class Utility { N &p=4
rf1nC$Sop
n]coqJ
public Utility() Yjk A^e
{ xYt{=
9LJ/m\bi
^"+cJ)
} P!YT{}
WM=kr$/3
//线程睡眠 N??<3j+Iu
public static void sleep(int nSecond) W {dx\+
{ pdnL~sv
try{ #^#)OQq]
Thread.sleep(nSecond); /'VCJjzZ
} N}FG%a
catch(Exception e) !8=uBS%
{ xI:;%5{LN
e.printStackTrace (); \wDOE(>
} 6u:5]e8
} QTn-n)AE
n{' [[2U
//日志 ={L:q8v)
public static void log(String sMsg) c@nl;u)n
{ MB"?^~Sm
System.err.println(sMsg); =C3l:pGMB;
} cF vGpZ
bh7 1Zu
T.`%1S
public static void log(int sMsg) 3UN Jj&-`
{ A<.Q&4jb
System.err.println(sMsg); 0U/:Tpyr
} BxZop.zwE(
} q75F^AvH
?pF;{
`chf8
/* f1~3y}7^Jq
**TestMethod.java WX\%FJ
*/ ReK@~#hLY
package NetFox; SpkVV/
J<`RlDI
zA"D0fr
public class TestMethod { A|>C3S
|t]9RC.;7
nL:vRJr-$
public TestMethod() D{l.WlA.
{ ///xx/weblogic60b2_win.exe HRb_ZJz
try{ >6kWmXK[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -91l"sI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qs?+vk?*h
SiteFileFetch fileFetch = new SiteFileFetch(bean); v;RQVH;,
fileFetch.start(); H_AV3 ;
} #/tdZ0
catch(Exception e){e.printStackTrace ();} .nSupTyG
C3b'Q
_+Q$h4t
} Cir =(
eY(usK
%&]}P;&
public static void main(String[] args) fN4pG*D
{ {//F>5~[
new TestMethod(); $@Ay0GEI"
} 7YN)T?
} Z~,.l
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