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)); T:/mk`>
} H^sImIEUT
for(int i=0;i<nEndPos.length-1;i++) BcXPgM!Xqz
{ pgUp1goAU
nEndPos = nStartPos[i+1]; yjE$o?A
} emT/5'y
nEndPos[nEndPos.length-1] = nFileLength; >dK# tsp
} S/,)X
} ?*AhGza/
6K7DZ96L
unvS`>)Np
//启动子线程 K&4FFZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wr+/9
for(int i=0;i<nStartPos.length;i++) .RW&=1D6
{ z"%{SI^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eL" +_lW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @oKW$\
nStartPos,nEndPos,i); p!/!ZIo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); um,G^R
fileSplitterFetch.start(); ^vw[z2"
} M!R=&a=Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0<FT=tKm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EQ [K
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j82x$I*
nEndPos = " + nFileLength); `a6AES'w$
// fileSplitterFetch[nPos.length-1].start(); R :*1Y\o(
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*/'j[uj
//等待子线程结束 `c)[aP{vN
//int count = 0; 9y}/ G
//是否结束while循环 J7pF*2
boolean breakWhile = false; ]xxE_B7
FJD;LpW
:@4+}
while(!bStop) {F=`IE3)w
{ ~F"w
write_nPos(); kD46Le++B
Utility.sleep(500); Cu!S|Xj.
breakWhile = true; .^xQtnq
lJ Jn@A
@6kkt~>:
for(int i=0;i<nStartPos.length;i++) +[Izz~_p
{ uOAd$;h@_Z
if(!fileSplitterFetch.bDownOver) kO/YO)g
{ )mH(Hx
breakWhile = false; GJ\bZ"vDo
break; 8b"vXNB.f
} ':|E$@$W
} ,`!>.E.
if(breakWhile) \E1CQP-
break; nxJx8d"
f5z*AeI
2)Q%lEm`SP
//count++; ;TKsAU
//if(count>4) 2WS Wfh
// siteStop(); X`C ozyYuD
} ;w;+<Rd
$}EI3a
>~O/ZDu/@
System.err.println("文件下载结束！"); /%F5u}eW
} siOyp]
catch(Exception e){e.printStackTrace ();} XnKf<|j6k
} [:/mjO K
ky{@*fg.
1()pKBHf
//获得文件长度 T"e"?JSRJ
public long getFileSize() +^q-v-
{ 8&:dzS
int nFileLength = -1; V#+M lN
try{ _D{{C
URL url = new URL(siteInfoBean.getSSiteURL()); %_(^BZd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B A i ^t
httpConnection.setRequestProperty("User-Agent","NetFox"); Lh-+i
Tdxc%'l
)_kU,RvZ
int responseCode=httpConnection.getResponseCode(); m'KEN<)s
if(responseCode>=400) ll ^I;o0
{ RgD:"zeM
processErrorCode(responseCode); XzW\p8D^u
return -2; //-2 represent access is error D1V^DbUm_
} ;ykX]5jGh
bSW~hyI w
"`V:4uz
String sHeader; zUA -
#[]B: n6
K8uqLSP '
for(int i=1;;i++) 6RfS_
{ _6`H`zept
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +.a->SZ5"
//Utility.log(in.readLine()); :n OCs
sHeader=httpConnection.getHeaderFieldKey(i); g6h=Q3@
if(sHeader!=null) ;y;UgwAM
{ l]L"Ex{
if(sHeader.equals("Content-Length")) $VeQvm*
{ !]MGIh#u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &S[>*+}{+
break; z J V>;
} +;a\ gF^
} au+a7~0~
else lT8^BT
break; /BrbP7
} ;It1i`!R
} ahR-^^'$
catch(IOException e){e.printStackTrace ();} ,Qt2?
catch(Exception e){e.printStackTrace ();} wc;^C?PX
IIAm"=*
Y+C6+I<3
Utility.log(nFileLength); ([NS%
&g!yRvM!;Q
p@3 <{kLm
return nFileLength; } DjbVYH
} .G>6_n3
&ZJ$V
wx^1lC2
//保存下载信息（文件指针位置） Sr-!-eC
private void write_nPos() T9AFL;1
{ [ak[ZXC,
try{ mpzm6Ieu
output = new DataOutputStream(new FileOutputStream(tmpFile)); (wp?tMN5#
output.writeInt(nStartPos.length); bKQ-PM&I/t
for(int i=0;i<nStartPos.length;i++) mW#p&{
{ `<?((l%;R
// output.writeLong(nPos); ~Dj_N$_+9
output.writeLong(fileSplitterFetch.nStartPos); Lmc"qFzK
output.writeLong(fileSplitterFetch.nEndPos); lmx'w
} {WuUzq`
output.close(); u:>*~$f
} ?ehUGvV2
catch(IOException e){e.printStackTrace ();} ~t^'4"K*
catch(Exception e){e.printStackTrace ();} y<)q;fI7
} )C>M74Bt
cC$E"m
`3vt.b
//读取保存的下载信息（文件指针位置） R-5e9vyS
private void read_nPos() /&RS+By(i
{ XtIY8wsP
try{ 6S?*z `v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (oB9$Zz!t
int nCount = input.readInt(); mg *kB:p
nStartPos = new long[nCount]; #.<(/D+
nEndPos = new long[nCount]; AeEF/*
for(int i=0;i<nStartPos.length;i++) Es+BV+x[.c
{ M!iYj+nrP
nStartPos = input.readLong(); 88+J(^y>
nEndPos = input.readLong(); r%II` i
} Cc` )P>L
input.close(); Q46sPMH+_
} Q".AmHn
catch(IOException e){e.printStackTrace ();} MU~nvs;:
catch(Exception e){e.printStackTrace ();} FhMl+Ou
} I@YX-@&7
^4tz*i
K[i|OZWu
private void processErrorCode(int nErrorCode) nNcmL/(
{ u/4|Akui
System.err.println("Error Code : " + nErrorCode); zbP#y~[
} /N`E4bKBR
xkkW?[&
z*&r@P -
//停止文件下载 OEs!H]v
public void siteStop() g}'(V>(
{ fu7J{-<<R
bStop = true; 0V?:5r<
for(int i=0;i<nStartPos.length;i++) -_~T;cj6
fileSplitterFetch.splitterStop(); t5
#'Lt_Yf!
X" ;ly0Mb
} 44_CT?t<
} .p(~/MnO
//负责部分文件的抓取 ceGo:Aa<)
**FileSplitterFetch.java JS!
*/ +vCW${U
package NetFox; [&p^h
x0x/2re
} T1~fa
import java.io.*; $,B@yiie
import java.net.*; "K-2y^Dl
w7X], auRC
|.[4$C
public class FileSplitterFetch extends Thread { #[ hJm'G
a |+q:g0M
kDr0D$iE
String sURL; //File URL i:,37INMt
long nStartPos; //File Snippet Start Position "6fTZ<
long nEndPos; //File Snippet End Position `)s>},8W!
int nThreadID; //Thread's ID `Hq)g1a7q
boolean bDownOver = false; //Downing is over }mSfg
boolean bStop = false; //Stop identical 3QzHQU
FileAccessI fileAccessI = null; //File Access interface oyY0!w,Y
~85Pgb<
e{33%5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QH_I<Y:n
{ 5\$8"/H
this.sURL = sURL; nyR4E}@:O
this.nStartPos = nStart; 7ezf.[{R
this.nEndPos = nEnd; B0}f,J\
nThreadID = id; mH*6Q>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #35@YMF
} 6dq*ncNin
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public void run() y #Xq@
{ |lhVk\X
while(nStartPos < nEndPos && !bStop) Qs.g%
{ -l`1j6
V_"K
?H_'L4Wv
try{ _P*<T6\J>
URL url = new URL(sURL); R)?zL;,x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uM<6][^`
httpConnection.setRequestProperty("User-Agent","NetFox"); #D&]5"0cX
String sProperty = "bytes="+nStartPos+"-"; Ii9@ j1-g
httpConnection.setRequestProperty("RANGE",sProperty); )pAN_e"
Utility.log(sProperty); yPqZ ,
9@."Y>1G
+aWI"d--h
InputStream input = httpConnection.getInputStream(); 4_w+NI,;
//logResponseHead(httpConnection); &18CCp\3)c
__,1;=
:D'#CoBA
byte[] b = new byte[1024]; +B#3!
int nRead; Q}MS $[y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ll !J!{
{ F!;0eS"xp
nStartPos += fileAccessI.write(b,0,nRead); A+lP]Oy0S
//if(nThreadID == 1) 9ZEF%&58Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); //}[(9b'\
} O8N\
Xbb('MoI63
1>SCY_Cv
Utility.log("Thread " + nThreadID + " is over!"); ~"+Fp&[9f
bDownOver = true; *M_Gu{xc
//nPos = fileAccessI.write (b,0,nRead); 1MCHwX3/
} j&.MT@
catch(Exception e){e.printStackTrace ();} FaNH+LPe
} )TBG-<wt
} \e/'d~F
9j[%Y?
/v1Rn*VF!
//打印回应的头信息 D$RQD{*
public void logResponseHead(HttpURLConnection con) 9 1r"-%(r
{ 4u zyU_
for(int i=1;;i++) uwl;(zwh_
{ G2%%$7Jj
String header=con.getHeaderFieldKey(i); 1Yy5bg6+E
if(header!=null) E(e'qL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iG1vy'J#o
Utility.log(header+" : "+con.getHeaderField(header)); ncluA~8
else /?jAG3"
break; J['paHSF
} &\$l%icuo
} &r6VF/
~(xIG
s|U?{Byb!
public void splitterStop() MEQ:[;1
{ XQu~/{A=
bStop = true; fL8+J]6A6
} p*rBT,'
pNo<:p
05\A7.iy
} vmW4 3K;
<aR8fU
;K:)R_H
/* 4425,AR
**FileAccess.java i51~/ R
*//文件访问(定位，写) &P%3'c}G
package NetFox; vv _I o
import java.io.*; 1FS Jqad
\k1psqw^O
"qRE1j@%a
public class FileAccessI implements Serializable{ T1pA <6
9d4PH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dlC)&Ai
RandomAccessFile oSavedFile; zLlu%Oc
long nPos; M?4)U"_VE
9}FWO&LiB
3y%B&W,sm
public FileAccessI() throws IOException c,1Yxg]|
{ ?Ovl(4VG
this("",0); cbl2D5s+i]
} 1pC!F ;9Oo
M* (]hu0!
Bl-nS{9"
public FileAccessI(String sName,long nPos) throws IOException }"<|.[V)
{ tt`j!!
oSavedFile = new RandomAccessFile(sName,"rw"); _-%A_5lCRE
this.nPos = nPos; A e&t#,)
oSavedFile.seek(nPos); [0D( PV(n
} pq6}q($Rk
[Z484dS`_
s#ijpc>h
public synchronized int write(byte[] b,int nStart,int nLen) 9cAb\5c|
{ , e{kC
int n = -1; c~(+#a
try{ N %-Cp)
oSavedFile.write(b,nStart,nLen); r>S?,qr
n = nLen; KvC`6
} A('=P}I^
catch(IOException e) ?yF)tF+<
{ wAxXK94#3
e.printStackTrace (); D;It0"
} -cCujDM#T
"w0>
}\`MXh's
return n; w} *;^n
} (bi}?V*
@^:R1c![s
uh3%}2'P
} G}CzeLw
\~1M\gZP
w: ~66 TCI
/* q_5k2'4K
**SiteInfoBean.java 6)m}e?D>
*/ t5#IiPp
package NetFox; o`HZS|>K*
IpmblC4
>v@R]9
public class SiteInfoBean { wxXp(o(
S1{UVkr
PD12gUU?
private String sSiteURL; //Site's URL 1FUadSB5)
private String sFilePath; //Saved File's Path HcA;'L?Dw
private String sFileName; //Saved File's Name 9@ 6y(#s
private int nSplitter; //Count of Splited Downloading File )_OKw?Zi
bE.,)GY
NyI0[]z
public SiteInfoBean() j`A%(()d
{//nSplitter的缺省值为5 s<[%76Y!
//default value of nSplitter is 5 (,`ypD+3q
this("","","",5); zlZ$t{[,
} ^$SI5WK&)
*VH!<k[n
fn )m$\2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .v%H%z~Rl#
{ sPn[FuT>+s
sSiteURL= sURL; EA9`-xs|
sFilePath = sPath; Eym<DPu$n
sFileName = sName; hm>JBc:n-
this.nSplitter = nSpiltter; `uy)][j-
ulV)X/]1
xz5Jli
} jXkz,]Iy
F6R+E;"4R'
5\}A8Ng
public String getSSiteURL() -! Hn,93
{ $-m@cObw!.
return sSiteURL; \];0S4SBy
} V #W,}+_Sz
$Zp\^cIE+
z9pv|
public void setSSiteURL(String value) blNJ
{ )#zc$D^U
sSiteURL = value; ~~k_A|&
} rvuskXdo
xal+buOiP
z=B*s!G
public String getSFilePath() $^?"/;8P5
{ Ehu^_HZ
return sFilePath; nIJ2*QJ
} bB@1tp0+
6lOT5C eJ"
T1jAY^^I
public void setSFilePath(String value) #L5H-6nz
{ R!b<Sg
sFilePath = value; Yo3my>N&g
} Cqy84!Z<
ms8de>A|H
C-lv=FJEk/
public String getSFileName() ;75K:_
{ o<bZ.t
return sFileName; /"?yB$s
} E}Q'Wz|k
m(SGE,("w
ol7%$:S
public void setSFileName(String value) hRTw8-wy:
{ w%R(*,r6
sFileName = value; A@xa$!4}
} os0fwv
HpY-7QTPJ~
3:Q5dr+1_
public int getNSplitter() ;rZR9fR
{ OjTb2[Q
return nSplitter; |l)SX\Qf`@
} _SdO}AiG
HZC^Q7]hy
~``oKiPg@
public void setNSplitter(int nCount) +U{8Mj
{ 6U5L>sQ
nSplitter = nCount; RhR{EO
} PNY"Lqj
} V:HxRMF2X
@ -CZa^g
wb~BY
/* [AkL6
**Utility.java V .+ mK|)
*/ 4H'\nsM
package NetFox; x9Um4!/t
l#u$w&
I^S gWC
public class Utility { 0'q&7 MV
E{x<P0 ;
vYb.Ub+
public Utility() D*.U?
{ k?]`PUrV
bQd'objpY
.kKU MyW(
} tNP>6F/
+l'l*<
//线程睡眠 ]S!:p>R
public static void sleep(int nSecond) M ,!Dhuas
{ 7L3:d7=MIW
try{ [`pp[J-~7
Thread.sleep(nSecond); sZ,xbfZby
} }#%3y&7M7
catch(Exception e) A$d)xq-]K
{ *} @Y"y
e.printStackTrace (); Wk<heF
} Xc8r[dX
} Lv;% z
xE>H:YPm
//日志 Y$JGpeq8w
public static void log(String sMsg) 4z6i{n-k
{ N,kPR
System.err.println(sMsg); xAJ N(8?
} 9~3;upWu!
E%Tpby}^'
4-j3&(
public static void log(int sMsg) })#VO-J
{ T($d3Nn1
System.err.println(sMsg); uBpnfIe
} V9KI?}q:W
} Hwb+@'o
1M@OBfB8
VZveNz@]r
/* zD}@QoB
**TestMethod.java X=C*PWa7
*/ 8w4-Ud*$i
package NetFox; T0HNld
@nWhUH%
/Z3 Mlm{
public class TestMethod { |!t&ZpdD
>qE f991SZ
au=A+
public TestMethod() [d"]AF[#
{ ///xx/weblogic60b2_win.exe XotiKCk|Aq
try{ 6ijL+5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y5@#leM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hHA!.u4&
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4Fu:ov ]M
fileFetch.start(); h D5NX
} ^Pwtu
catch(Exception e){e.printStackTrace ();} TA4>12C6
5:R$xgc
Zc!rL0T
} DsJ ikg(J
qb$&BZj]|
T'^ Do/
public static void main(String[] args) ) |t;nK,
{ ]u5B]ZQnA
new TestMethod(); 1`sLbPW
} ztS:1\
} IL0e:-@!0
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