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)); |f"1I4Kg
} ~`Rooh3m
for(int i=0;i<nEndPos.length-1;i++) Cv1CRmqq%
{ 1`EkN0iZ
nEndPos = nStartPos[i+1]; k|_LF[*Z
} n'Z5rXg
nEndPos[nEndPos.length-1] = nFileLength; )'t&LWS~
} 'xc=N
} )m$i``*<
QU^?a~r
Q!}LtR$
//启动子线程 ln=:E$jX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ndB*^nT
for(int i=0;i<nStartPos.length;i++) ]Saw}agE[%
{ W q>qso
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1ba* U~OEg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ng<oz*>U
nStartPos,nEndPos,i); u-#J!Z<T8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &+F}$8,
fileSplitterFetch.start(); ^>!~%Vv7!
} eWAgYe2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6I$:mHEhd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Eg|C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7W\aX*]
nEndPos = " + nFileLength); B"fKv0
// fileSplitterFetch[nPos.length-1].start(); e.pq6D5
\I`g[nT|
!3Me 6&$O
//等待子线程结束 UG<`m]
//int count = 0; d7Devs k
//是否结束while循环 c,RY j
boolean breakWhile = false; SB2Ij',
1:d,8
5!^DKyw:
while(!bStop) :~+m9r
{ -axV;+"b
write_nPos(); joJ:*oL
Utility.sleep(500); rpO>l
breakWhile = true; Z:s:NvFX
H?<ceK'e
0}y-DCuQ
for(int i=0;i<nStartPos.length;i++) "jG-)k`a
{ x$\w^h\F
if(!fileSplitterFetch.bDownOver) '2.11cM3
{ xKC{P{:
breakWhile = false; ac??lHtH9
break; 4Z<
} 0vm}[a4+i;
} G@;I^_gN
if(breakWhile) uA2-&smw
break; 4Gm(P~N
&SE+7HXw
t.E3Fh!o
//count++; o|0QstSCl
//if(count>4) f.SmCgG
// siteStop(); L=WB'*N
} P",E/beV
:Y;\1J<b1
trC+Etc
System.err.println("文件下载结束！"); CuD^@
} PofHe
catch(Exception e){e.printStackTrace ();} *X4$'LSx1
} nmrYBw>
&,B91H*#
X}gnO83
//获得文件长度 lm;G8IP`
public long getFileSize() oPA [vY
{ h*GU7<F:a
int nFileLength = -1; T{%'"mm;
try{ @)YQiE$
URL url = new URL(siteInfoBean.getSSiteURL()); T>;Kq;(9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gwepaW
httpConnection.setRequestProperty("User-Agent","NetFox"); d@72z r
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(\6R"2
int responseCode=httpConnection.getResponseCode(); zsx12b^w
if(responseCode>=400) ?w[M{
{ br9`77J8
processErrorCode(responseCode); = 5E:CP
return -2; //-2 represent access is error yNb :zoT
} dn1Tu6f;|
nBVknyMFNF
.{|AHW&0<
String sHeader; FiQx5}MMhu
<C'S#5,2
F^]?'`7md
for(int i=1;;i++) 6v9{$:
{ *ppb4R;CW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A<&:-Zz
//Utility.log(in.readLine()); *0^t;A+
sHeader=httpConnection.getHeaderFieldKey(i); d[9NNm*htC
if(sHeader!=null) FDAREE\j
{ jnoFNIW
if(sHeader.equals("Content-Length")) B43o_H|s
{ afZPju"-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p ?HODwZ
break; B`4[@$
} A_t<SG5
} S"=oU}'|
else "iof -b=ys
break; `f:5w^A
} A*h)p@3t<
} vR?L/G^.
catch(IOException e){e.printStackTrace ();} Q#bFW?>y,
catch(Exception e){e.printStackTrace ();} V#TA%>
e;=G|E
"z }bgy
Utility.log(nFileLength); P-~Avb
|yI?}zyR
nDvny0^a
return nFileLength; ;e0>.7m
} 'FBvAk6
^3`98y.Q
(D8'qx-M
//保存下载信息（文件指针位置） p;n)YY$
private void write_nPos() jkNZv. )p
{ Ze$:-7Czl
try{ 'q[V*4g
output = new DataOutputStream(new FileOutputStream(tmpFile)); ji(S ?^
output.writeInt(nStartPos.length); RWBmQg^]X
for(int i=0;i<nStartPos.length;i++) r _r$nl
{ JoZC+G
// output.writeLong(nPos); (6\A"jey\x
output.writeLong(fileSplitterFetch.nStartPos); ?NI)3-l
output.writeLong(fileSplitterFetch.nEndPos); 4PUM.%
} i=2+1;K
output.close(); vS<;:3
} RpLm'~N'
catch(IOException e){e.printStackTrace ();} Ro:-u7q
catch(Exception e){e.printStackTrace ();} v%aD:%wlY@
} ]Ly)%a32
4 qW)R{%
dm$:xE":
//读取保存的下载信息（文件指针位置） 72-@!Z0e
private void read_nPos() 6}ax~wYct
{ "E2 g7n&
try{ `bC_J,>_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6-X7C9`C
int nCount = input.readInt(); EoY#D'[
nStartPos = new long[nCount]; 71/6=aq>n
nEndPos = new long[nCount]; ?qK:P
for(int i=0;i<nStartPos.length;i++) &2\.6rb.
{ V,M8RYOnC!
nStartPos = input.readLong(); M(3E b;`
nEndPos = input.readLong(); GV[[[fu
} U |4%ydG
input.close(); hrAI@.Bo
} 3 oWCQ
catch(IOException e){e.printStackTrace ();} "J{,P9P6
catch(Exception e){e.printStackTrace ();} 4t8 Hy
} fCVSVn"o
*smo{!0Gg
P7Y[?='v
private void processErrorCode(int nErrorCode) ng 6G<hi
{ U&eLj"XZ
System.err.println("Error Code : " + nErrorCode); krl yEAK=
} oL6_Ya
i'EXylb
nEn2!)$
//停止文件下载 Y|lMa?\E
public void siteStop() vMI\$E&
{ iCEX|Tj;
bStop = true; '",5Bu#C
for(int i=0;i<nStartPos.length;i++) _88~uYG
fileSplitterFetch.splitterStop(); 7xd}J(l
E|fPI u
%Mu dc
} jf2E{48P
} {l1;&y?
//负责部分文件的抓取 F%|(pHk
**FileSplitterFetch.java JL$RBr
*/ C eg6o&^
package NetFox; G dooy~cn
@rdC/=Y[
{oZ]1Qf_
import java.io.*; =Vv{td
import java.net.*; }$UFc1He\J
l{3utQH-=z
':[y]ep(~|
public class FileSplitterFetch extends Thread { /[-hJ=<Yb
>ylVES/V
cP Y^Bf5)
String sURL; //File URL AuCVpDH
long nStartPos; //File Snippet Start Position =wQ=`
long nEndPos; //File Snippet End Position 0'<S7?~|
int nThreadID; //Thread's ID qnlj~]NV
boolean bDownOver = false; //Downing is over 'F~u \m=E
boolean bStop = false; //Stop identical Z~R i%XG
FileAccessI fileAccessI = null; //File Access interface BKTsc/v2>:
prWid3}
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Il642#Gh
{ l(,;wAH
this.sURL = sURL; 12sD|j
this.nStartPos = nStart; tIb21c q
this.nEndPos = nEnd; ^qO=~U!{
nThreadID = id; @f{_=~+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ggI=I<7M
} ^2^|AXNES
,p!B"# ot
/J.\p/%\
public void run() =6L*!JP<
{ <*"pra{3
while(nStartPos < nEndPos && !bStop) 7grt4k
{ LuP?$~z
(X(1kj3
XDkS ^9
try{ .L7Yf+yFg
URL url = new URL(sURL); sQ}%7BMK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kz0I2!bt
httpConnection.setRequestProperty("User-Agent","NetFox"); o)tKH@`vE
String sProperty = "bytes="+nStartPos+"-"; l*K I
httpConnection.setRequestProperty("RANGE",sProperty); f4'El2>-86
Utility.log(sProperty); j?\$G.Y
& =73D1A
3cOY0Z#T
InputStream input = httpConnection.getInputStream(); 5[,+\
//logResponseHead(httpConnection); VyecTU"W
4D^ M<Xn
By?nd)
byte[] b = new byte[1024]; (;0$i?3\
int nRead; ]By0Xifew
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /!=U+X
{ J?UA:u
nStartPos += fileAccessI.write(b,0,nRead); =oE_.ux\
//if(nThreadID == 1) t_dcV%=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & u$(NbK
} UrO=!Gk
N;-/wip
LH=d[3Y
Utility.log("Thread " + nThreadID + " is over!"); [ rQMD^:M$
bDownOver = true; J>`v.8y
//nPos = fileAccessI.write (b,0,nRead); 6xH;:B)d
} [34zh="o
catch(Exception e){e.printStackTrace ();} 7\IL
} i[$-_
} vO\:vp4fH
GI4?|@%vD!
8r,9OM
//打印回应的头信息 bb|}'
public void logResponseHead(HttpURLConnection con) Hx$.9'Oq\Q
{ /"=29sWB
for(int i=1;;i++) glv ;C/l
{ (tepmcf
String header=con.getHeaderFieldKey(i); 'KH lrmnr
if(header!=null) 4~!Eje!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qQ^d9EK'?~
Utility.log(header+" : "+con.getHeaderField(header)); &=G)NeT_
else :-z&Y492
break; _B)s=Snx
} d$w(-tV42
} Y?<)Dg.[
vX ?aB!nkw
w4UD/zO
public void splitterStop() ".gNeY6)x
{ ~p:?QB>1]
bStop = true; oz LH]*
} le.anJAr
vd`O aM}#U
80C(H!^
} _6ZzuVv3/
sm0fAL
c&E]E(
/* K4: $=
**FileAccess.java LT/mb2
*//文件访问(定位，写) C0QM#"[
package NetFox; gljo;f:
import java.io.*; xYPxg!
>%u@R3PH]
\8{\;L C
public class FileAccessI implements Serializable{ J/vK6cO\
eNbpwne
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4ZwKpQ6
RandomAccessFile oSavedFile; ,!Q]q^{C:W
long nPos; "oR@JbdX
X3',vey
7b,(\Fm
public FileAccessI() throws IOException 3@_Elu
{ E$A3|rjnoN
this("",0); ;'0=T0\
} eklgLU-+fW
kJT+
5!(?m~jJ
public FileAccessI(String sName,long nPos) throws IOException 2}vNSQvG
{ MLr-, "gs
oSavedFile = new RandomAccessFile(sName,"rw"); '1Y\[T*
this.nPos = nPos; @}&_Dvf
oSavedFile.seek(nPos); vcv CD7MD
} LHkQ'O0
'#.#$8l
) #+^ sAO
public synchronized int write(byte[] b,int nStart,int nLen) YlF%UPp
{ 2oCkG~j
int n = -1; f0>!qt
try{ NxA)@9Q
oSavedFile.write(b,nStart,nLen); Qdf=XG5
n = nLen; 3\:y8|
} !.TLW
catch(IOException e) }H"kU2l
{ }4//@J?:
e.printStackTrace (); AUe# RP
} &(N+.T5cp
sN6N >{
{{yZ@>o6
return n; D5,P)[
} _iV]_\0W2
`bjizS'^
0#cy=*E
} ,yd=e}lQx
x[3A+
nh>K`+>co
/* ;j8)KC
**SiteInfoBean.java 3?n>yS
*/ w= P9FxB
package NetFox; eKvV*[Na
cLVeT
:'iYxhM.V
public class SiteInfoBean { =#gEB#$x:
}Gyqq6Aeb
s?R2B)a
private String sSiteURL; //Site's URL u8GMUN
private String sFilePath; //Saved File's Path kOo~%kcQ'
private String sFileName; //Saved File's Name %zk$}}ti.
private int nSplitter; //Count of Splited Downloading File Y!J>U
7R!5,Js+
??60,m:]
public SiteInfoBean() NKb1LbnZ*y
{//nSplitter的缺省值为5 \*f;Xaa
//default value of nSplitter is 5 e[_m<e
this("","","",5); qMt++*Ls
} zOgTQs"ZH
03E4cYxt5
4k-+?L!/G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *jIqAhs0{
{ mE%$HZ}
sSiteURL= sURL; _j?e~w&0b
sFilePath = sPath; _WXtB#
sFileName = sName; uVyGk~
this.nSplitter = nSpiltter; 2owEw*5jl/
o]:3H8
Ig]iT
} kVK/9dy-F
OCZaQ33
Suk
public String getSSiteURL() Sf5X3,Uw
{ $Iv2j">3)
return sSiteURL; W"^wnGa@a
} c:Wze*vI;
om?-WJI
|sRipWh
public void setSSiteURL(String value) Mi'8 ~J
{ 26T"XW'_
sSiteURL = value; ]e.JNo
} <\kr1qHH
iu&wO<)+?
l2N]a9bq@
public String getSFilePath() iY"l}.7)
{ 9z)5Mdf1j
return sFilePath; w?kJ+lmOQy
} dT,o=8fg
"BX!
EdZ\1'&/9
public void setSFilePath(String value) gUyR_5q)8l
{ T^J>ZDA
sFilePath = value; 0d8%T<=J
} GFr|E8
u#}[ZoI
x#Sqn#
public String getSFileName() F 8B#}%JE
{ (Jz;W<E
return sFileName; pPd#N'\*
} 9]q:[zm^
&gzCteS
#>Zzf
public void setSFileName(String value) ;2B{9{
{ @E:,lA
sFileName = value; ?-^~f
} OS8q( 2z?s
(?nCyHC%g
6k#Jpmmr
public int getNSplitter() !%$`Eq)M^7
{ qucq,Yw
return nSplitter; x c{hC4^V
} x?&$ci
,}K<*t[I
[jmd
public void setNSplitter(int nCount) !.d@L6
{ 9k{PBAP
nSplitter = nCount; %2v4<icvq
} L|p Z$HB
} h:9Zt0,
#8)*1?
;Iq/l%vX
/* l+V>]?j
**Utility.java ~6p[El#tS
*/ CHz+814
package NetFox; ocs+d\
e=.]F*:J
ght$9>'n
public class Utility { T?X_c"{8M
R=jI?p
x&0vKo;
public Utility() S\;V4@<Kn
{ M3q|l7|9
x)@G;nZ
Hro-d1J7
} 6fw(T.Pe
>3Eo@J,?d
//线程睡眠 I"GB<oB
public static void sleep(int nSecond) 9g<7i
{ =zz~kon9
try{ t2)rUWg
Thread.sleep(nSecond); 5k.oW=
} ~;N^g4s
catch(Exception e) >Z5gSs0
{ :\|SQKD
e.printStackTrace (); 9E6_]8rl
} `E>1>'
} Ig f&l`\
>G%o,9i
//日志 dUhY\v oQ
public static void log(String sMsg) ajEjZ6
{ @<elq'2
System.err.println(sMsg); `7r@a
} maNl^i
3eF-8Z(f
sc}~8T
public static void log(int sMsg) Sn|BlXrey
{ I"A_b}~*}
System.err.println(sMsg); GaK-t*Q
} e7sp =I,
} <P=twT;P
qHrc9fB
+8RgF
/* Kkm>e{0)AY
**TestMethod.java ++^l]8
*/ B&n<M]7
package NetFox; ]jo1{IcI
^y<<>Y'I
xjKR R?
public class TestMethod { GU( _
;;#qmGoE
)% ~OH
public TestMethod() a m|F?|1
{ ///xx/weblogic60b2_win.exe 73/P&hT
try{ *Qg_F6y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,)vDeU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K/|Z$4S
SiteFileFetch fileFetch = new SiteFileFetch(bean); x$6^R q>2
fileFetch.start(); vzim<;i
} E2Q[ZoVS
catch(Exception e){e.printStackTrace ();} {?:X8&Sf
Hl{S]]z
iT2B'QI=<
} J4fi'
e,W%uH>X
NTYg[VTr
public static void main(String[] args) %H]ptH5
{ ur:3W6ZKl
new TestMethod(); hhCrUn"
} VHIOwzC
} 0Ziw_S\d&s
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