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)); @c^ Dl
} q,Gymh;
for(int i=0;i<nEndPos.length-1;i++) W&5/1``u\
{ ^J]&($-
nEndPos = nStartPos[i+1]; '0Cp
} 1(p:dqGS
nEndPos[nEndPos.length-1] = nFileLength; o`f^m
} Vn5T Jw
} [9sEc
?^VPO%
}y6)d.
//启动子线程 y#Dh)~|k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ||hQ*X<m>
for(int i=0;i<nStartPos.length;i++) g}MUfl-L
{ ^QNc!{`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zv!`R($
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ??F* Z"x
nStartPos,nEndPos,i); <Yki8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yzN[%/
fileSplitterFetch.start(); uZ6krI
} \Th<7WbR6#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1(DiV#epG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k[@P526
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T-N>w;P
nEndPos = " + nFileLength); 7^><Vh"qV
// fileSplitterFetch[nPos.length-1].start(); }JFTe g
UDEGQ^)Xz|
=TD`Pet
//等待子线程结束 ,D{7=mDVm
//int count = 0; gGMfy]]R
//是否结束while循环 ]FCP|Jz
boolean breakWhile = false; @HS*%N"*
=zFROB\
krfXvQJwJ
while(!bStop) r *K
{ N|DfE{,
write_nPos(); zamMlmls^
Utility.sleep(500); M!,H0(@G
breakWhile = true; .I:rb~&
Z1 Nep!
?I=1T.
for(int i=0;i<nStartPos.length;i++) Et3]n$
{ os5$(
if(!fileSplitterFetch.bDownOver) '?C6P5fm
{ <IR#W$[
breakWhile = false; I/7!5Z*
break; *X.1b!
} `/sNX<mp
} -$8ew+
if(breakWhile) P3"R2-
break; e \Qys<2r
h /
}StzhV{GS
//count++; z_>~=Mm
//if(count>4) EL~$7 J
// siteStop(); ZeV@ X
} `Na()r$T
# `=Zc7gf
LhO\a
System.err.println("文件下载结束！"); 'OnfU{Ai
} )M0`dy{1
catch(Exception e){e.printStackTrace ();} hF$`=hE,F~
} == wX.y\.n
k3bQ32()
gC?}1]9c
//获得文件长度 {N~mDUoJ|
public long getFileSize() O&?i#@5#
{ |jIHgm
int nFileLength = -1; hJM&rM7
try{ eu5te0{G
URL url = new URL(siteInfoBean.getSSiteURL()); +;W%v7%<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O=A R`r#u
httpConnection.setRequestProperty("User-Agent","NetFox"); llZU: bs
`ArUoYbB
F?6kkLS/
int responseCode=httpConnection.getResponseCode(); F>\,`wP
if(responseCode>=400) 1"y!wsM%
{ Rs=Fcvl
processErrorCode(responseCode); o"JHB
return -2; //-2 represent access is error [WDzaRzd
} c~U0&V_`j
w>2lG3H<
LtB5;ByeQ0
String sHeader; 2E40&
l`\L@~ln
30HUY?'K
for(int i=1;;i++) Z8=?Hu
{ kZF]BPh.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z#+WK|a
//Utility.log(in.readLine()); k^oSG1F
sHeader=httpConnection.getHeaderFieldKey(i); 0se%|Z|8
if(sHeader!=null) -o+t&m
{ <~mqb=qA$
if(sHeader.equals("Content-Length")) 1 fcV&qHR
{ g/C 7wc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eY3:Nl^
break; PSc=k0D
} nC3+Zka
} "1s ]74
else {APfSD_4
break; w}1IP-
} /6rjGc
} +(Y\w^@%H
catch(IOException e){e.printStackTrace ();} #m|el@)
catch(Exception e){e.printStackTrace ();} K21Xx`XK
MNs<yQ9I'
q-t%spkl
Utility.log(nFileLength); lSR\wz*Fk
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EG\L]fmD
return nFileLength; 9-n]_AF`0
} ~"S5KroN
)[hs#nKTh
.U(6])%;@
//保存下载信息（文件指针位置） :vi %7
private void write_nPos() 9y\nO)\Tv
{ 2>"{El|PbN
try{ pXNhU88
output = new DataOutputStream(new FileOutputStream(tmpFile)); %;4#?.W8
output.writeInt(nStartPos.length); ,;6%s>Cvd(
for(int i=0;i<nStartPos.length;i++) {Q/@Y.~<
{ qF3S\ C
// output.writeLong(nPos); -rsS_[$2
output.writeLong(fileSplitterFetch.nStartPos); ;2h"YU-b
output.writeLong(fileSplitterFetch.nEndPos); [vtDtwL
} T\wOGaCW
output.close(); Z2{$FN
} TPb&";4ROf
catch(IOException e){e.printStackTrace ();} {;bec%pq0
catch(Exception e){e.printStackTrace ();} -T+yS BO_3
} -6 v?iiZr
Ew}GPJ
7# 'j>]
//读取保存的下载信息（文件指针位置） L,_U co
private void read_nPos() gu3)HCZ
{ _6FDuCVD-
try{ _)-2h[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,hK =x
int nCount = input.readInt(); J'cE@(US
nStartPos = new long[nCount]; j,,#B4b
nEndPos = new long[nCount]; 21$^k5
for(int i=0;i<nStartPos.length;i++) k'$7RjCu
{ z=k*D^X
nStartPos = input.readLong(); ;F_&h#D]3
nEndPos = input.readLong(); i_6wD
} Kc9)Lzu+
input.close(); T5~Qfl?Y
} X pXhg*}K
catch(IOException e){e.printStackTrace ();} KJ?/]oLr0
catch(Exception e){e.printStackTrace ();} ]H:K$nmX
} AO$aWyI
VyU!r* o
hy"p8j7_
private void processErrorCode(int nErrorCode) jaThS!>v
{ I |D]NY^
System.err.println("Error Code : " + nErrorCode); :+DAzjwO<
} n O}x,sG2'
9DXu*}
43J8PMY
//停止文件下载 qmnCa&C9
public void siteStop() `.6Jgfu
{ /|e"0;{
bStop = true; N_!Zn"J
for(int i=0;i<nStartPos.length;i++) 9]8M{L
fileSplitterFetch.splitterStop(); Q!%CU8!`&
E{9{%J
\t&6$"n(B6
} 6ud<B
} xcIZ'V
//负责部分文件的抓取 =TI|uD6T
**FileSplitterFetch.java EZiGi[t7
*/ B<'V7#L_
package NetFox; ;lWy?53=@
$j}sxxTT
nBiA=+'v
import java.io.*; ~h[lu^ZSi
import java.net.*; ?t.?f`(|
cfe[6N
zck |jhJ6
public class FileSplitterFetch extends Thread { TAJ9Y<
e]X9"sd0=
zZh`go02E
String sURL; //File URL vDOeBw=
long nStartPos; //File Snippet Start Position !xqG-rd '
long nEndPos; //File Snippet End Position yM D*>8/
int nThreadID; //Thread's ID NtOR/*
boolean bDownOver = false; //Downing is over LveqG
boolean bStop = false; //Stop identical k~?}z.g(
FileAccessI fileAccessI = null; //File Access interface E 0pF; P5
0_y%Qj^e
01q7n`o#zf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |]\bgh
{ u]MF r2
this.sURL = sURL; 6k3l/~R
this.nStartPos = nStart; u!`C:C'
this.nEndPos = nEnd; x?<5=,
nThreadID = id; tw3d>H`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w./EJkKI
} f"0H9
O}f(h5!k
_0j}(Q>|H#
public void run() G =4y!y
{ fY"28#
while(nStartPos < nEndPos && !bStop) q(p0#Mk,E
{ X5/{Mx`8Oz
I2DmM"-|
I~qiF%?d
try{ \j;uN#)28
URL url = new URL(sURL); G-(c+6Mn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R39R$\
httpConnection.setRequestProperty("User-Agent","NetFox"); t(rU6miN
String sProperty = "bytes="+nStartPos+"-"; g^4FzJ
httpConnection.setRequestProperty("RANGE",sProperty); yl 8v&e{
Utility.log(sProperty); "AK3t' jF*
.XB] X
+e:ZN tr9
InputStream input = httpConnection.getInputStream(); YPy))>Q>cK
//logResponseHead(httpConnection); #rr-4$w+
"qm>z@K
_Lb& 2PAG
byte[] b = new byte[1024]; rpT<cCem1
int nRead; @Kr)$F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '> Q$5R1
{ ^Q,/C8qeb
nStartPos += fileAccessI.write(b,0,nRead); l.W:6",w
//if(nThreadID == 1) |)-:w?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5#o,]tP
} LI<5;oE;
.KsvRx
-N(MEzAE
Utility.log("Thread " + nThreadID + " is over!"); M<srJ8|'
bDownOver = true; Madaxx
//nPos = fileAccessI.write (b,0,nRead); "\[>@_p h
} Mv=cLG?X
catch(Exception e){e.printStackTrace ();} w$ {
} 8vw]u_e
} y)E2=JQA/
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s-V$N
//打印回应的头信息 k>CtWV5B
public void logResponseHead(HttpURLConnection con) \(FDR
{ __iyBaX
for(int i=1;;i++) mD)O\.uA
{ <Y2!c,"
String header=con.getHeaderFieldKey(i); EvmmQ
if(header!=null) \pGO}{3e*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y%l3SB,5L
Utility.log(header+" : "+con.getHeaderField(header)); j2M(W/_
else 1[`<JCFClc
break; )x&@j4,
} }2,#[mM
} >pvg0Fh
ZG<!^tj
uP2a\C,$
public void splitterStop() & }}WP:U
{ G9inNz*Cx
bStop = true; zpqNmxmF
} QJM!Wx+
S\;.nAR
%:?QE ;
} )6 <byO
ok2~B._+;
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/* ><R.z(4%
**FileAccess.java i(iP}:3
*//文件访问(定位，写) S)@vl^3ec
package NetFox; ;S`-9}6
import java.io.*; >wO$Vu `t
Z[S+L"0
~C7<a48x
public class FileAccessI implements Serializable{ rOb"S*
]=VS~azZ5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?lN8~Ze
RandomAccessFile oSavedFile; |;m`874
long nPos; YQdX>k
qK vr*xlC
'Sy *'&
public FileAccessI() throws IOException 0(/D|
{ A{x 7
this("",0); Guw|00w,Q$
} bH&)rn
EQ63VF
/:{_|P\
public FileAccessI(String sName,long nPos) throws IOException Df:7P>
{ ]Bd3d%
oSavedFile = new RandomAccessFile(sName,"rw"); _pko]F|()
this.nPos = nPos; #lshN,CPm
oSavedFile.seek(nPos); /dJ)TW(Ir
} @PoFxv
q6JW@GT
h<'5q&y
public synchronized int write(byte[] b,int nStart,int nLen) X0Z-1bs
{ 14n="-9
int n = -1; ~K-*q{6Q
try{ B5,QJ W*
oSavedFile.write(b,nStart,nLen); &M3ES}6
n = nLen; JV]u(PL
} _p J_V>l
catch(IOException e) G</I%qM
{ nOal7BNN
e.printStackTrace (); K+@eH#Cv,(
} ezr\T
n^pZXb;Y
iQ|,&K0d]
return n; H8-D'q>R
} CI!Eq&D,
,> (bt%b
Bq~hV;9nf
} 8S1P&+iKs
qH h'l;.
}xf='lE
/* S@}B:}2
**SiteInfoBean.java Le`/
*/ c/=y*2,zo
package NetFox; @UpC{M--Wr
H\=LE
vNz;#Je
public class SiteInfoBean { Ac[|MBaF
1J-Qh<Q
oF;%^XFp
private String sSiteURL; //Site's URL fys5-1@-p
private String sFilePath; //Saved File's Path xi?P(sA
private String sFileName; //Saved File's Name &gA6+b'
private int nSplitter; //Count of Splited Downloading File `&u<aLA
bvipbf[m<
0Oc}rRH(C
public SiteInfoBean() ~IlF*Zz#}6
{//nSplitter的缺省值为5 *U;4t/(
//default value of nSplitter is 5 aJ6#=G61l
this("","","",5); [;?"R-V"z
} *|LbbRu
,C{^`Bk-W
R%b*EBZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =de<WoKnu2
{ <AI>8j6#B
sSiteURL= sURL; O->_/_
sFilePath = sPath; 7_Ba3+9jpa
sFileName = sName; Qj 6gg
this.nSplitter = nSpiltter; cxXbo a
r"{Is?yKe
~LawF_]6
} RDs,sj/Y9?
lo+xo;Nd
T[0V%Br{d+
public String getSSiteURL() X,RT<GNNb
{ cT-K@dg
return sSiteURL; R9tckRG#
} {q&@nm40
DeOXM=&z
;W7hc!
public void setSSiteURL(String value) :O9P(X*
{ Mjb 1
sSiteURL = value; H<`^w)?
} ow2M,KU6Z
{ EA2
B/jrYT$;m
public String getSFilePath() C _8j:Z&
{ DpA\r_D
return sFilePath; f5@.^hi[
} :3*`IB !
QF\kPk(CtD
3YR* ^
public void setSFilePath(String value) QTVa
{ !L4dUMo
sFilePath = value; \).Nag+
} 8NnhT E
x.I][(}
1'NhjL
public String getSFileName() cX2$kIs;
{ y k?SD1hj
return sFileName; 6hZ.{8e0
} aT&t_^[]
ytEQ`
avlqDi1l
public void setSFileName(String value) &a.']!$^"
{ iwUv`>l&
sFileName = value; nt7|f,_J
} W:WQaF`2x
^D>fis
sr\cVv")
public int getNSplitter() _0K.Fk*(!
{ RF:04d
return nSplitter; 6VC-KY
} gt'*B5F(
|7y6 pz
GSP?X$E
public void setNSplitter(int nCount) J<rlz5':
{ C#0brCQq3
nSplitter = nCount; Wj&nUp{
} E${J
} > V8sm/M
=LOk13l\"
gSb,s [p&+
/* +s ULo
**Utility.java GLCAiSMz[
*/ 40u7fojg2
package NetFox; [_V:)
})PO7:
J smB^
public class Utility { ;=a_B1"9u
Ls1B\Aw_
zZ:xEc
public Utility() !.*iw k`
{ yplG18
NEw$q4
K3L"^a
} BKay*!'PX
t!jYu<P
//线程睡眠 \%TyrY+`K
public static void sleep(int nSecond) @MOCug4
{ *1$
try{ l[oe*aYN7
Thread.sleep(nSecond); A@2Bs5F
} q*bt4,D&Es
catch(Exception e) ?`H[u7*%
{ B$?^wo
e.printStackTrace (); 8eN7VT eb
} i$C-)d]
} s1bU
nR[^|CAR
//日志 R5(F)abi
public static void log(String sMsg) H:Y&OZ
{ H O*YBL
System.err.println(sMsg); o/^1Wm=
} cDIBDC
8vSIf+
E{%SR
public static void log(int sMsg) 2"X~ju
{ kAo.C Nj7
System.err.println(sMsg); <*wM=aq
} {[W(a<%bXm
} nZ E)_
"%@v++4y
-ihiG_f
/* ix&'0IrX*
**TestMethod.java 2+Yb 7 uI,
*/ y' [LNp V
package NetFox; 2w?hgNz
R5(T([w'
q.W>4 k
public class TestMethod { T$P-<s
i\Wdo/c-H
"@yyXS r
public TestMethod() !OAvD#
{ ///xx/weblogic60b2_win.exe WD.U"YI8y
try{ W5 ec
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qINTCm j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [Y/:@t"2y
SiteFileFetch fileFetch = new SiteFileFetch(bean); pj8azFZ
fileFetch.start(); K0Tg|9
} E!mmLVa9
catch(Exception e){e.printStackTrace ();} J=H)JH3
GBQn_(b9I
<]U1\~j
} uM S*(L_
v("wKHWTI@
fk{0d
public static void main(String[] args) iqPBsIW
{ `^6 ,kI-c
new TestMethod(); 5-vo0:hk
} AK@L32-S
} OZ(dpV9.S
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