http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); &0TheY;srf
} K!mgh7Dx
for(int i=0;i<nEndPos.length-1;i++) ' ga2C\)
{ 5sUnEHN
nEndPos = nStartPos[i+1]; =Ch#pLmH
} $<#sCrNX
nEndPos[nEndPos.length-1] = nFileLength; '%4,!
} Ks-><-2+N
} 19DW~kvYk
.j.=|5nVo4
|F`'m":$m
//启动子线程 HB^azHr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `XP Tf#9j
for(int i=0;i<nStartPos.length;i++) ];YOP%2
{ 03y<'n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .?TVBbc%5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \k8_ZJw
nStartPos,nEndPos,i); }#M|3h;q9+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TjdYCk]'
fileSplitterFetch.start(); fE iEy%o
} xg&vZzcl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P{ o/F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +aap/sYp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5kz`_\&
nEndPos = " + nFileLength); 4RNzh``u
// fileSplitterFetch[nPos.length-1].start(); ^S@b*
|Can
J)_42Z
//等待子线程结束 $Re %+2c
//int count = 0; &iivSc;#
//是否结束while循环 ljRR
boolean breakWhile = false; sj~'.Zs%
1+Oo Qs
r+2dBp3
while(!bStop) }ls>~uN
{ .u&g2Y
write_nPos(); 5q[@N J
Utility.sleep(500); N 2\,6<
breakWhile = true; 1^mO"nX
l0f6Lxfz
$I%]jAh6
for(int i=0;i<nStartPos.length;i++) .*{LPfD|
{ YDJc@*D
if(!fileSplitterFetch.bDownOver) !% Md9Mu!o
{ fQdQ[
breakWhile = false; pe8MG(V
break; TaH9Nu
} KAGq\7
} ~?FKww|_*J
if(breakWhile) 9,IGZ55C
break; t<-Iiq+tL
$= gv
d>f5Tl\E
//count++; ~rD* Y&#.
//if(count>4) I`7[0jA~
// siteStop(); }j x{Cw
} ESAh(A)8
y!j1xnzki
C|+5F,D
System.err.println("文件下载结束！"); (Y%}N(Jg
} EW)]75o{QF
catch(Exception e){e.printStackTrace ();} LdcP0G\"VG
} ,fbO}
xYbF76B
HDYoM
//获得文件长度 PeOgXg)L`z
public long getFileSize() @U,cj>K
{ \VW.>@s~
int nFileLength = -1; \%#jT GFs~
try{ ;,D7VxWhY
URL url = new URL(siteInfoBean.getSSiteURL()); \I>,j,c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p-Z5{by
httpConnection.setRequestProperty("User-Agent","NetFox"); umciP
+-ue={'
TAP/gN'
int responseCode=httpConnection.getResponseCode(); Rh39x-`Z
if(responseCode>=400) "dIoIW
{ a,X3=+_K
processErrorCode(responseCode); / wEr>[8S
return -2; //-2 represent access is error )57OZ
} 9E+^FZe
!|SawT5t
HRk+2'wjAz
String sHeader; NGNn_1
I>:'5V
Xo P]PR`cQ
for(int i=1;;i++) lw7wvZD
{ 3=z'Ih`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,%u\2M
//Utility.log(in.readLine()); |yS4um(w
sHeader=httpConnection.getHeaderFieldKey(i); |m~|
if(sHeader!=null) 0@2%pIq\
{ s`TfNwDvU
if(sHeader.equals("Content-Length")) _:T\[sz5
{ k5^'b#v
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w1.~N`g$
break; |@ia(U~
} NWFZ:h@v
} I3A](`
else '8Yx
break; fV3J:^)F
} 27)$;1MT:
} r]TeR$NJ
catch(IOException e){e.printStackTrace ();} mIOx)`$
catch(Exception e){e.printStackTrace ();} 2e+DUZBoC
| r2'B
O*CKyW_$t
Utility.log(nFileLength); [qc90)^Q,
`":< ]lj
'kp:yI7w
return nFileLength; |>m@]s7Z
} ?=6zgb"9-
ezFyd'P
(UpSi6?\
//保存下载信息（文件指针位置） XMpPG~XdN
private void write_nPos() @D%VV=N~[
{ 6x_8m^+m
try{ F<oJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); _TH'v:C
output.writeInt(nStartPos.length); h|wyvYKZ
for(int i=0;i<nStartPos.length;i++) yQ\c<z^e
{ rN OwB2e
// output.writeLong(nPos); =5+:<e,&
output.writeLong(fileSplitterFetch.nStartPos); LqW~QEU(
output.writeLong(fileSplitterFetch.nEndPos); \SyfEcSf2v
} U4%P0}q/
output.close(); o;}o"-s
} oA`Ncu5
catch(IOException e){e.printStackTrace ();} pj'Yv
catch(Exception e){e.printStackTrace ();} ="MG>4j3.F
} zvE]4}VL?
~Xa >;
"@.hz@>
//读取保存的下载信息（文件指针位置） Yf|+p65g
private void read_nPos() iX}EJD{f
{ Nq-qks.&
try{ >[NNu Y~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZM0vB% M|
int nCount = input.readInt(); "H6DiPh.E
nStartPos = new long[nCount]; .F |yxj;I7
nEndPos = new long[nCount]; @N34 Q-l
for(int i=0;i<nStartPos.length;i++) . F_pP2A
{ C4ge_u#
nStartPos = input.readLong(); [Qr#JJ
nEndPos = input.readLong(); pLNv\M+
} 1Z|q0-Dw0
input.close(); k]w;(<
} c.r]w
catch(IOException e){e.printStackTrace ();} E<Efxb'p
catch(Exception e){e.printStackTrace ();} G8H=xr#
} 1#6c sZW5
("ql//SL
bt"*@NJ$
private void processErrorCode(int nErrorCode) y@e/G3
{ kect)=T(
System.err.println("Error Code : " + nErrorCode); sZA7)Z`7
} /U+0T>(HS
sBt,y_LW
[Q6PFdQ_JT
//停止文件下载 d=yuuS/
public void siteStop() yO.q{|kX
{ XC%u`UG
bStop = true; "KSzn
for(int i=0;i<nStartPos.length;i++) H+6+I53
fileSplitterFetch.splitterStop(); M:rE^El
&( aw
.7_<0&kW
} ZuH@qq\
} 6C7|e00v
//负责部分文件的抓取 IZn|1X?}\s
**FileSplitterFetch.java IN~Q(A]Z%
*/ E:(DidSE@
package NetFox; )lwxFP;
[2ez"4e
Ia %> c
import java.io.*; RR |Z,
import java.net.*; B'SLyf
[`2V!rU
hR(\%p
public class FileSplitterFetch extends Thread { =*>ri
)G a5c
gwO]U=Y
String sURL; //File URL +~Wg@
long nStartPos; //File Snippet Start Position clyZD`*
long nEndPos; //File Snippet End Position _<}oBh
int nThreadID; //Thread's ID n.F^9j+V
boolean bDownOver = false; //Downing is over fAYp\k
boolean bStop = false; //Stop identical crTRfqF
FileAccessI fileAccessI = null; //File Access interface }xJ ).D
)&Af[mS
zO)Bf(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )jm!bR`
{ N.(wR
this.sURL = sURL; -Ph"#R&
this.nStartPos = nStart; 4z6kFQgu
this.nEndPos = nEnd; |q!O~<H@
nThreadID = id; @` 5P^H7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *QH~z2:[
} pV[SY6/
_D.4=2@|l8
dT?mMTKn+
public void run() "!,)Pv
{ #|-i*2@oR
while(nStartPos < nEndPos && !bStop) r"YOA@
{ M5c$
xe`SnJgA
>W>3w
try{ @KJ~M3d0l
URL url = new URL(sURL); E/OfkL*\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cb82k[L6
httpConnection.setRequestProperty("User-Agent","NetFox"); ?vh1 >1D
String sProperty = "bytes="+nStartPos+"-"; %^pm~ck!
httpConnection.setRequestProperty("RANGE",sProperty); |pgrR7G'
Utility.log(sProperty); GBSuTu8
tqk^)c4FF(
vLI'Z)\
InputStream input = httpConnection.getInputStream(); tw k
//logResponseHead(httpConnection); grVPu! B;
A9Kt^HR
:yxP3e%rp
byte[] b = new byte[1024]; b,hRk1
int nRead; \uG^w(*)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N.'-9hv
{ 7/e25LS!`U
nStartPos += fileAccessI.write(b,0,nRead); hik.c3
//if(nThreadID == 1) B}fd#dr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fzmc#?
} '/2)I8
/`s{!t#Y
aO&!Y\=@
Utility.log("Thread " + nThreadID + " is over!"); 5J~@jPU
bDownOver = true; o#uhPUZ
//nPos = fileAccessI.write (b,0,nRead); #u"$\[G
} pL5Bz!_r
catch(Exception e){e.printStackTrace ();} PjE%_M<
} hm,H3pN
} <I 0EjV
<g$bM;6%
thLx!t
//打印回应的头信息 z?<Xx?Kk
public void logResponseHead(HttpURLConnection con) a! gj_
{ >c)-o}bd^
for(int i=1;;i++) ^UmhSxQ##
{ Qa#Em1co
String header=con.getHeaderFieldKey(i); y/Ui6D
if(header!=null) `gvd8^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @+>t]jyz
Utility.log(header+" : "+con.getHeaderField(header)); s{uSU1lQn
else b?,''t
break; JuDadIrd{
} X"!tx
} fA)4'7UT
Ex<@:
yYH>~,
public void splitterStop() w!r.MWE
{ G?+0#?'Y
bStop = true; ~P fk
} \=c@
)0o|u>
*4y0Hq
} ?>Bt|[p:s)
]|QA`5=$
'$h0l-mQ
/* }6To(*
**FileAccess.java ;>CM1
*//文件访问(定位，写) m`&6[[)6~
package NetFox; RveEA/&&
import java.io.*; mXT{c=N)w
L"L a|
Um!LF"Z
public class FileAccessI implements Serializable{ |Hv8GT
;"2(e7ir
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8vx#QU8E/
RandomAccessFile oSavedFile; xf3;:soC
long nPos; jwp?eL!7
Bq~?!~\?.
CqLAtS X7
public FileAccessI() throws IOException awgS5We|
{ _iH:>2p5R
this("",0); lm8<0*;,
} ({<qs}H"
| MXRNA~
_^h?JTU^
public FileAccessI(String sName,long nPos) throws IOException wV q4DE
{ Y z],["*Q
oSavedFile = new RandomAccessFile(sName,"rw"); !JQ'~#jKN
this.nPos = nPos; chur(@Af
oSavedFile.seek(nPos); R:y u
} Q"k #eEA
.-:@+=(
_#yd0E
public synchronized int write(byte[] b,int nStart,int nLen) Of;$ VK'
{ a?X#G/)
int n = -1; :0% $u>;O:
try{ vv1W<X0e<
oSavedFile.write(b,nStart,nLen); @4wN-T+1
n = nLen; Ai~d
} e@DVf
catch(IOException e) j34lPo `
{ pnGDM)H7
e.printStackTrace (); Y'?{yx{
} ^o(C\\>{&
8Yw V"+Fu/
`G2!{3UD
return n; =c#;c+a
} )2?A|f8
"b0!h6$!H
g7r0U6Y
} b`^mpB*6R
?Lem|zo
oF.H?lG7`
/* 2f2.;D5g_'
**SiteInfoBean.java |#5_VEG
*/ `7Dj}vVu
package NetFox; SXRND;-W8
wV"C ,*V
d=a$Gd_$
public class SiteInfoBean { +~?K@n
*}Gu'EU
aFDCVm%U|
private String sSiteURL; //Site's URL h5ZxxtGU
private String sFilePath; //Saved File's Path ^ oh%Ns
private String sFileName; //Saved File's Name u4~(0
private int nSplitter; //Count of Splited Downloading File nE"0?VNW$
M7gM#bv>L
trg&^{D<
public SiteInfoBean() CW@G(R
{//nSplitter的缺省值为5 &\Yd)#B/
//default value of nSplitter is 5 8Og)(BC
this("","","",5); 7WN$ rl5/
} vW03nt86
.KxE>lJbqM
sX#7;,Ft7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KDYyLkI dr
{ C72btS
sSiteURL= sURL; P"k,[ZQ
sFilePath = sPath; 1#jvr_ ga
sFileName = sName; _R;+}1G/
this.nSplitter = nSpiltter; ^jg{MTa
etL)T":XV
vA#?\j2
} Kvh6D"
YL@d+ -\
1~9AQ[]w8
public String getSSiteURL() ;aUI3n%
{ mG+hLRTXP
return sSiteURL; !@@rO--&
} `*Jw[Bnh8
WyJXT.
Ge4tc
public void setSSiteURL(String value) +( V+XT
{ cP[]\r+Kj
sSiteURL = value; }$1Aw%p^
} Gq^#.o]
x^JjoI2vf
}NETiJ"6
public String getSFilePath() 8A|i$#.&
{ Mta;6<
return sFilePath; ]@7]mu:oL
} eZ +uW0
\ /6m
Ia>>b #h
public void setSFilePath(String value) me/ae{
{ P7p'j
sFilePath = value; Nx"v|"
} e3{L%rQE
_Rnq5y
Abf=b<bu
public String getSFileName() -~ycr[}x
{ g63?(+Fz
return sFileName; {>=#7e-]
} U-3uT&m*9.
Is !DiB
xn)r6
public void setSFileName(String value) &_y+hV{
{ [EV}P&U
sFileName = value; N0G-/
} z/t:gc.
;t}ux
7<%Rx19L*
public int getNSplitter() LYX\#
{ 5s2334G
return nSplitter; 7&9'=G
} wq"AWyu
[/I1%6;
1MzOHE
public void setNSplitter(int nCount) me`(J y<
{ $[P>nRhW
nSplitter = nCount; JTg0T+
} mLn =SU{#
} q7%eLJ
5CuK\<
uH-*`*
/* =xX\z\[A
**Utility.java 6">jf #pE
*/ 'zhw]L;'g
package NetFox; 0yxMIX
id.W"5+
J8yi#A>+
public class Utility { Wy%F
DqHVc)9
^y"$k
public Utility() =7`0hS<@F
{ GcPhT
k&P_ c
GX lFS#`
} 'yM)>]u"
mckrR$>
//线程睡眠 "@I"0OA
public static void sleep(int nSecond) cuP5cL/Y
{ ?y{C"w!
try{ N{G+|WmQ
Thread.sleep(nSecond); UI:{*N**Z
} eMvb*X6
catch(Exception e) Z qg(\
{ b\w88=|
e.printStackTrace (); :/IcFU~)M
} (&$|R\W.
} 1XO*yZF
Mr(~ *
//日志 QPfS3%p`
public static void log(String sMsg) |8"~ou:.
{ -$4%@Z
System.err.println(sMsg); WLWE%bDP
} 3EcmNwr
Cs %-f"
BKm$H!u
public static void log(int sMsg) O/\jkF
{ )gCHwu
System.err.println(sMsg); 2eu`X2IBcT
} [hS?d.D
} QWf)5S
Rh%/xG#k
aM9St!i
/* _|Ml6;1aZ
**TestMethod.java L&'0d$Tg8
*/ VmkYl$WZo
package NetFox; 6mBX{-Z[
WU1o4&OF
K0\a+6kh
public class TestMethod { Wx/!Myu
WJU` g
\wNn c"
public TestMethod() t{>66jm\R
{ ///xx/weblogic60b2_win.exe c+G: bb%p
try{ 685o1c|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 38Z"9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =3oz74O[
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7-ba-[t#A
fileFetch.start(); 9VN@M
} <E BgHD)
catch(Exception e){e.printStackTrace ();} Prhq ~oI4
vd /_`l.D
KX)xCR~
} 4W.;p"S2
%`}CbD6
uPV,-rm[F_
public static void main(String[] args) Z=!*7@QY
{ !r.}y|t?;
new TestMethod(); @WEem(@
} ojVpw4y.
} BPrA*u}T
点击下载更多相关资料