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)); @bQf =N+
} KPIc?|o/6
for(int i=0;i<nEndPos.length-1;i++) {#aW")x^#
{ ?r"'JO.w
nEndPos = nStartPos[i+1]; 7{ zkqug
} c0.i
nEndPos[nEndPos.length-1] = nFileLength; $IzhaX
} 48JD >=@7
} 47b=>D8
|[/[*hDZ9
3VZeUOxY\W
//启动子线程 PMzPe"3M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vs-%J6}G
for(int i=0;i<nStartPos.length;i++) S3rN]!B+
{ x}t,v.:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kZXsL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u-g2*(ZT
nStartPos,nEndPos,i); AvF:$kG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7/nnl0u8
fileSplitterFetch.start(); 8.4 1EKr2
} WV]%llj^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4<b=;8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #jAlmxN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V3j1M?>
nEndPos = " + nFileLength); =~M%zdIXv
// fileSplitterFetch[nPos.length-1].start(); CPssk,q~C
<smi<syx
-F.A1{l[.
//等待子线程结束 kk_$j_0
//int count = 0; k*)O]M<,
//是否结束while循环 YY~BNQn6d
boolean breakWhile = false; n#,<-Rb-
g.![>?2$8
&w@~@]
while(!bStop) {=]1]IWt
{ S}zh0`+d'Z
write_nPos(); tEEeek(!
Utility.sleep(500); x!$Dje}
breakWhile = true; ZZ1s}TG
2p3ep,
~I^}'^Dbb
for(int i=0;i<nStartPos.length;i++) jA ?tDAx`
{ {4u8~whLp
if(!fileSplitterFetch.bDownOver) E]x)Qr2Ju
{ ofeSGx
breakWhile = false; H`!%"
break; 0fc]RkHs"
} Efo,5
} ppcuMcR{
if(breakWhile) 0:K4,
break; wFr}]<=Mi
=\v./Q-
,/V'(\>
//count++; ZSL:q%:.
//if(count>4) /($!("b
// siteStop(); 5fGUJ[F=
} J7.}2
F^iv1b
,,+ ~./)
System.err.println("文件下载结束！"); H]:z:AAvX
} ~i)O^CKq
catch(Exception e){e.printStackTrace ();} h'8w<n+%)
} d\nBc6
bI^zwK,@4
?H9F"B$a
//获得文件长度 Up|\&2_
public long getFileSize() p{:r4!*L
{ ,6[}qw)*
int nFileLength = -1; f3h&K}x
try{ ,WF)GS|7V
URL url = new URL(siteInfoBean.getSSiteURL()); [ e4)"A"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )r O`K
httpConnection.setRequestProperty("User-Agent","NetFox"); )2Gp3oD?
Gmcx#?|Tx
J90q\_dY.
int responseCode=httpConnection.getResponseCode(); K7&A^$`
if(responseCode>=400) W'{q
{ 02]9OnWw
processErrorCode(responseCode); SfE^'G\
return -2; //-2 represent access is error e=t?mDh#E
} I>b-w;cC
LX<c(i
fTi,S)F'
String sHeader; \~xOdqF/
Y[8w0ve-g
b~ ?TDm7
for(int i=1;;i++) 5*1wQlL
{ ~Z5?\a2Ld
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %l@Q&)f8e
//Utility.log(in.readLine()); ak50]KYo
sHeader=httpConnection.getHeaderFieldKey(i); G)l[\6Dn
if(sHeader!=null) &?3?8Q\
{ r;w_B%9
if(sHeader.equals("Content-Length")) v>Il#
{ }+`W[h&u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x_Ki5~w5
break; D%LM"p
} iUh_rX9A"
} =5&)^
else S[UHx}.
break; fiTMS:
} yz-IZt(
} S>7Zq5*
catch(IOException e){e.printStackTrace ();} kP%W:4l0
catch(Exception e){e.printStackTrace ();} @6GM)N\{[
H<`[,t
<9bQAyL9
Utility.log(nFileLength); w;Qo9=-
MAR kTxzi
TMG:fg&E~
return nFileLength; u*Oz1~
} 5fb,-`m.
&RXd1>|c2
&tZ?%sr
//保存下载信息（文件指针位置） 0[D5]mcv
private void write_nPos() d8M"vd
{ GT%V,OJ
try{ %R;cXs4r
output = new DataOutputStream(new FileOutputStream(tmpFile)); *D<S \6=
output.writeInt(nStartPos.length); (W+9 u0Zq
for(int i=0;i<nStartPos.length;i++) oAWk<B(@
{ p%IR4f
// output.writeLong(nPos); J+\F)k>r
output.writeLong(fileSplitterFetch.nStartPos); YH<F~F _
output.writeLong(fileSplitterFetch.nEndPos); 2xe_Q70II
} w0SzK-&
output.close(); K@n.$g
} q~trn'X>
catch(IOException e){e.printStackTrace ();} kRiWNEw
catch(Exception e){e.printStackTrace ();} z9HQFRbo[
} U]R?O5K
zwU8iVDe
%~p_bKd~
//读取保存的下载信息（文件指针位置） @+1E|4L1vf
private void read_nPos() 77i |a]Kd
{ RMC|(Q<
try{ zp4ru\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9,`mH0jP
int nCount = input.readInt(); Y1k/ngH
nStartPos = new long[nCount]; ]Jnf.3
nEndPos = new long[nCount]; &K>]!yn
for(int i=0;i<nStartPos.length;i++) V"$t>pAG
{ TP{a*ke^5,
nStartPos = input.readLong(); puqLXDjA/
nEndPos = input.readLong(); CHeG{l)<r
} $+Pv fQ
input.close(); 2zFdKs,
} $elrX-(vL
catch(IOException e){e.printStackTrace ();} 1xguG7
catch(Exception e){e.printStackTrace ();} 1 9 k$)m
} M8[YW|VkP
(X>y)V
SOK2{xCG
private void processErrorCode(int nErrorCode) rG\m]C3E
{ !FSraW2
System.err.println("Error Code : " + nErrorCode); fykN\b
} k5/nAaiVE
='VIbE@qC
w:Lu
//停止文件下载 h.?[1hT4R
public void siteStop() MxdfuFss
{ BB%(!O4Dl
bStop = true; w!}1oy
for(int i=0;i<nStartPos.length;i++) Hl;p>>n
fileSplitterFetch.splitterStop(); 'j_H{kQy
DQ\&5ytP
mM}Ukmy
} (U_Q7hja?
} Fnpn_O XlH
//负责部分文件的抓取 N1~V +_mM
**FileSplitterFetch.java F2$bUY
*/ L"h@`3o|
package NetFox; q#&#*6 )B
`Kw"XGT
7NB 9Vu|gD
import java.io.*; c^Jgr(Ow
import java.net.*; ~H|LWCU)K8
{[5L96RH%
KWJgW{{v
public class FileSplitterFetch extends Thread { "&#WMi
%lJiM`a
>&vO4L
String sURL; //File URL {!1n5a3" 1
long nStartPos; //File Snippet Start Position "QO/Jls
long nEndPos; //File Snippet End Position 1Bk*G>CX9(
int nThreadID; //Thread's ID pLQSG}N
boolean bDownOver = false; //Downing is over IR dz(~CP
boolean bStop = false; //Stop identical I?Jii8|W9
FileAccessI fileAccessI = null; //File Access interface %HF$
NhK(HTsvK
tOM3Gs~o6z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]Ec[")"kT
{ 9LEilmPs
this.sURL = sURL; nqxq@.L2
this.nStartPos = nStart; gQh Ccv
this.nEndPos = nEnd; 5Ue^>8-
nThreadID = id; Uaj`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qi SEnRG.
} R_Gq8t$
%wjB)Mae
an=+6lIl
public void run() Hx2j=Q_dw
{ 2b4pOM7W
while(nStartPos < nEndPos && !bStop) OgXZ-<'
{ sMfFm@\N
A-7wkZ.H
r$r&4dY
try{ *2Vp4
URL url = new URL(sURL); '!fFI1s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^wO_b'@v
httpConnection.setRequestProperty("User-Agent","NetFox"); 7c29Ua~[
String sProperty = "bytes="+nStartPos+"-"; {"0TO|%x
httpConnection.setRequestProperty("RANGE",sProperty); 1>@]@ST[:
Utility.log(sProperty); g2aT`=&Z
l<aqiZSY
[)H,zpl
InputStream input = httpConnection.getInputStream(); :nKsZ1bX
//logResponseHead(httpConnection); 7/&C;"
X&9^&U=e
%%as>}.
byte[] b = new byte[1024]; -yl4tW
int nRead; FI`nRFq)C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q+N7:o!;<b
{ EFRZ% Y
nStartPos += fileAccessI.write(b,0,nRead); j$|j8?
//if(nThreadID == 1) 8g[(nxI~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pe$^Mo.q
} C`2*2Y%xkG
=M1a0i|d
Iuu<2#gb8"
Utility.log("Thread " + nThreadID + " is over!"); *#Lsjk~_-
bDownOver = true; _@#uIOcE
//nPos = fileAccessI.write (b,0,nRead); o\@ A2r3
} >J^7}J
catch(Exception e){e.printStackTrace ();} :$M9XZ~\
} $ ]W[y=
} U^[cYTG
`P^u:
DnNt@e2|
//打印回应的头信息 @tr&R==([
public void logResponseHead(HttpURLConnection con) &TP:yA[
{ u8-a-k5<
for(int i=1;;i++) J ?ztn
{ .N5hV3
String header=con.getHeaderFieldKey(i); [Krm .)
if(header!=null) HF&h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5T$}Oy1
Utility.log(header+" : "+con.getHeaderField(header)); ( oQ'4,F
else ,]~u:Y}
break; OwG6i|q
} G0I~&?nDa
} vF9*tK'
b4Ricm
o,?!"*EP
public void splitterStop() 94~"U5oQ:
{ /^++As0pY
bStop = true; x r-;,W
} bK?1MiXb
dV5PhP>6
A#v|@sul
} e1^fUOS
5~@?>)TBv
t2=a(N-/,
/* ^~ Ekg:`
**FileAccess.java B3y?.
*//文件访问(定位，写) 69t7=r
package NetFox; u|(Ux~O
import java.io.*; KKLR'w,A>
i/NDWVFD
7n\ThfH{
public class FileAccessI implements Serializable{ 8 ne/=N|,
}czsa_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !cRfZ
RandomAccessFile oSavedFile; 9.xvV|Sp
long nPos; *,"jF!C&[
LMAmpVo
j'3j}G%\T
public FileAccessI() throws IOException 9 0X?1
{ bRWIDPh
this("",0); ?Fce!J
} hdo&\Q2D8
i][f#e4
#X#8ynt
public FileAccessI(String sName,long nPos) throws IOException EbCIIMbe"
{ ]53O}sH>
oSavedFile = new RandomAccessFile(sName,"rw"); y|^EGnaE
this.nPos = nPos; F;#zN
oSavedFile.seek(nPos); zm3-C%:Bw
} Ffnk1/Zy
:d.1;st
kB8 Mi
public synchronized int write(byte[] b,int nStart,int nLen) Ski G2n]
{ ndr)3tuYu
int n = -1; H#+\nT2m
try{ fb23J|"
oSavedFile.write(b,nStart,nLen); ZI,j?i6\
n = nLen; md?b*
} }<=3W5+
catch(IOException e) ?{eY\I
{ Kv}k*A% S
e.printStackTrace (); R\*)@[y9l
} O16r!6=-n
^00{Hd6
dXl]Pe|v
return n; UgR:qjI
} '@bJlJB9>
?mMW*ico
E tx`K5Tr]
} 1SUzzlRx
X]!D;7^
)|pU.K9qZ
/* KnJx{8@z
**SiteInfoBean.java _42Z={pZZq
*/ DVh)w}v
package NetFox; xdZ<| vMR
+%XnMl
}#6xFTH
public class SiteInfoBean { d`Oe_<
)Q]w6he3
+Rqbf
private String sSiteURL; //Site's URL BxdX WO
private String sFilePath; //Saved File's Path UW6VHA>
private String sFileName; //Saved File's Name <B)
private int nSplitter; //Count of Splited Downloading File Ux}W&K/?'
=We2^W-{
k][h9'
public SiteInfoBean() < bFy(+
{//nSplitter的缺省值为5 59<hV?
//default value of nSplitter is 5 tuLH}tkNY
this("","","",5); ARF\fF|<2
} X?/Lz;,&
;7Okyj6EP
jO8X:j09A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !n<o)DsZR
{ ? %(spV
sSiteURL= sURL; w2OsLi Sv
sFilePath = sPath; VRbQdiZ{
sFileName = sName; : @6mFTV
this.nSplitter = nSpiltter; I\zemW!
R0wf#%97
AnMV <
} RlRs}yF
!E0!-UpY
X>zlb$
public String getSSiteURL() =6\LIbO
{ ]Blf9h7
return sSiteURL; f~ZEdq8
} $a(`ve|
#jA)>z\Q^
S6sq#kcH
public void setSSiteURL(String value) y=Q!-~5|fF
{ |cd-!iJX-
sSiteURL = value; ;>>C)c4V"
} Qxa{UQh}9
}k7'"`#?"
~L{l+jK$p
public String getSFilePath() q \O Ou
{ "2{%JFE
return sFilePath; fS=hpL6]@
} jfp z`zE
M%`\P\A
I7(?;MpI
public void setSFilePath(String value) 2@khSWV
{ +Qj(B@i
sFilePath = value; |+}G|hx@9
} gl7|H&&xV
:a0zT#u
uQ/h'v
public String getSFileName() Q5a)}6-5
{ ig+4S[L~n
return sFileName; {whvTN1#dh
} ~*.-
:iUF7P1I
09h.1/
public void setSFileName(String value) L'Q<>{;Ig
{ 1G^#q,%X_v
sFileName = value; |E)aT#$f'
} $}o b,i^W
F0lOlS
& ,hr8
public int getNSplitter() *d*,Hqn
{ I)SG wt-
return nSplitter; @)6jE!LC
} v]VWDT `
6iA( o*'Yn
19UN*g3(
public void setNSplitter(int nCount) I5ZqBB
{ kHK0(bYK
nSplitter = nCount; Zjh2{ :
} +&=?BC}L9^
} [1yq{n=
;2xO`[#
N.do "
/* z@ 35NZn
**Utility.java 60>.ul2
*/ *%5{'
package NetFox; 6<76H
/~p+j{0L3W
mN_Z7n;^eh
public class Utility { E%N2k|%8d_
x.mrCJn)
'@nbqM
public Utility() {FO$yw=>
{ Fr2N[\>s
R:aa+MX(1
RO(TvZ0pE
} w?Ju5 5
KvFMs\o6p
//线程睡眠 xg@NQI@7
public static void sleep(int nSecond) #KlCZ~s
{ (qMj-l
try{ $.%rAa_H
Thread.sleep(nSecond); J9~i%hzr
} iUk-'
catch(Exception e) 3>M&D20Z
{ ,5 j"ruZ
e.printStackTrace (); @@G6p($
} &DG->$&|
} V N{NA+I
!A3-0zN!
//日志 lCd@jB{
public static void log(String sMsg) OHrY(I6
{ 68fiG
System.err.println(sMsg); bBcp9C)iY
} <6TT)t<h
>4` dy
zw<p74DH
public static void log(int sMsg) qFX~[h8i+
{ B;6]NCxD
System.err.println(sMsg); 2NGeC0=
} ji1HV1S
} D1 Z{W
8LkP)]4^sO
EI~"L$?
/* {~GYj%-^
**TestMethod.java !`JHH&
*/ AI vXb\wL
package NetFox; $q?$]k|M`
%q;jVj[
C;+(Zp
public class TestMethod { fc=Patg
&.13dq
b3-eR5U/
public TestMethod() `N//A}9
{ ///xx/weblogic60b2_win.exe '7Nr8D4L
try{ #m{{a]zm^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w.\w1:d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gbeghLP[?
SiteFileFetch fileFetch = new SiteFileFetch(bean); `vG,}Pt]
fileFetch.start(); x&Vm!,%:1
} Jf)bHjC_V
catch(Exception e){e.printStackTrace ();} rB~W Iu
*_Z#O,
k#Of]mXXz
} qSqI7ptA\
PP~rn fE
kd:$oS_*s
public static void main(String[] args) p9U?!L!y
{ <$w?/y/'
new TestMethod(); \I-#1M
} n~V4nj&_T
} "vYE+
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