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)); qQ]fM$!
} Qa/1*Mb
for(int i=0;i<nEndPos.length-1;i++) <LH6my
{ r{?qvl!q
nEndPos = nStartPos[i+1]; 6I(Y<LZ5
} ~Qif-|[V
nEndPos[nEndPos.length-1] = nFileLength; *VXx\&
} Q*Jb0f
} M*n94L=Sg&
6H2Bf*i
i{N?Y0YQs0
//启动子线程 fX:q]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CB9:53zK9
for(int i=0;i<nStartPos.length;i++) E3p$^['vx
{ g:~q&b[q6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oMYFfnoAa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3d;J"e+?
nStartPos,nEndPos,i); VWt=9D;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !/H `
fileSplitterFetch.start(); 7Oe$Ou
} 2sgp$r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #s(ob `0|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @$kzes\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WU=EJY}#n
nEndPos = " + nFileLength); 5{+>3J
// fileSplitterFetch[nPos.length-1].start(); HZ!<dy3
+68age;dM
P//nYPyzg
//等待子线程结束 4`o0?_.'
//int count = 0; N!<l~[rc
//是否结束while循环 S['%>
boolean breakWhile = false; IAUc.VH
4gEw}WiP
r/':^Ex
while(!bStop) :{S@KsPqE
{ 6b2h\+AP
write_nPos(); dg*xo9Xi`
Utility.sleep(500); x]hG2on!
breakWhile = true; T>*G1-J#
3rZPVR$))
SR.xI:}4
for(int i=0;i<nStartPos.length;i++) gkTwGI+w
{ !Q_Kil.9
if(!fileSplitterFetch.bDownOver) Lwm /[
{ Nk%$;Si
breakWhile = false; Omn$O>
break; -;8a* F
} 9X1vL
} "g"%7jK
if(breakWhile) ;){ZM,Ox
break; 6Rif&W.xy
GU1cMe
mW[w4J+7P
//count++; IcqzMmb
//if(count>4) @o}J)
// siteStop(); <o|k'Y(-
} "5$p=|
L`O7-'`
#/9Y}2G|]
System.err.println("文件下载结束！"); ? YIe<
} bx6=LK
catch(Exception e){e.printStackTrace ();} 6W]C`
} v^t oe
#ax% n
)eSQce7H
//获得文件长度 dci,[TEGu
public long getFileSize() hWn-[w/l_
{ \%]lsml
int nFileLength = -1; *\iXU//^)
try{ tNqSCjQ~_c
URL url = new URL(siteInfoBean.getSSiteURL()); J.g6<n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x6\VIP"9L
httpConnection.setRequestProperty("User-Agent","NetFox"); v13\y^t
Mw+ l>92
6_rgRo&
int responseCode=httpConnection.getResponseCode(); JX>`N5s
if(responseCode>=400) $%&OaAg
{ {pre|r\
processErrorCode(responseCode); (B@\Dw8^
return -2; //-2 represent access is error )VG>6x
} _~>WAm<
}a UQ#x
y'oH>l+n
String sHeader; \ ux{J
|Q%nnN
f/.f08
for(int i=1;;i++) !)J$f_88D
{ )"tM[~e`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2}.~ 6EU/
//Utility.log(in.readLine()); n#?y;Y\
sHeader=httpConnection.getHeaderFieldKey(i); #IqRu:csp
if(sHeader!=null) V!@6Nv
{ FSkX95
if(sHeader.equals("Content-Length")) 6"[,
{ x=\W TC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hSps9*y
break; 0;w 4WJJ
} siV]NI':|
} sQrM"i0Y>
else PF)s>
break; j,i)ecZ>
} #'i,'h+F
} ofYZ!-V
catch(IOException e){e.printStackTrace ();} h y\iot
catch(Exception e){e.printStackTrace ();} R:^jQ'1
#c/K.?
BOdlz#&s
Utility.log(nFileLength); WkpHe
W=HHTvK9Hh
]_!NmB_3
return nFileLength; \x\(36\u
} @,G\`;Ma
.M[t5I'\
xA*6Z)Y
//保存下载信息（文件指针位置） AS4oz:B
private void write_nPos() )T slI
{ v`qXb$YW
try{ 5VVU%STP
output = new DataOutputStream(new FileOutputStream(tmpFile)); >B$ IrM7J
output.writeInt(nStartPos.length); lEQj62zIQ
for(int i=0;i<nStartPos.length;i++) iK5[P
{ }-Nc}%5
// output.writeLong(nPos); i\4YT r,
output.writeLong(fileSplitterFetch.nStartPos); S%G&{5
output.writeLong(fileSplitterFetch.nEndPos); z 7cA5'c
} a=B $L6*4
output.close(); %82:?fq
} v[DxWs8q
catch(IOException e){e.printStackTrace ();} xj]^<oi<
catch(Exception e){e.printStackTrace ();} Efpju(
} anKflt3
?ZhBS3L
TOvsW<cM
//读取保存的下载信息（文件指针位置） nF,zWr[x
private void read_nPos() ),%@X
{ mSEX?so=[
try{ EyV5FWb58
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L?Ih;
int nCount = input.readInt(); V72?E%d0
nStartPos = new long[nCount]; 9D?JzTsyg
nEndPos = new long[nCount]; \z@:OR,
for(int i=0;i<nStartPos.length;i++) Wrm3U/>e
{ :hf%6N='kI
nStartPos = input.readLong(); x97L>>|
nEndPos = input.readLong(); W:}t%agis
} ATV|M[B
input.close(); &!+1GI9z
} <)L[V
catch(IOException e){e.printStackTrace ();} 'RQEktm
catch(Exception e){e.printStackTrace ();} &EC8{.7
} 4~vn%O6n
%Go/\g
2c*}1 _
private void processErrorCode(int nErrorCode) Q} -YD.bx3
{ TTo?BVBK
System.err.println("Error Code : " + nErrorCode); {yxLL-5c
} oy=ej+:
+R8dy
m&MZn2u[4i
//停止文件下载 kFfNDM#D
public void siteStop() zvv/|z2(r
{ x_(K%0+Ca
bStop = true; k~QmDq
for(int i=0;i<nStartPos.length;i++) A'n7u'6=
fileSplitterFetch.splitterStop(); W$z^U)|t
NR^3 1&}It
w[^lxq
} po*r14f
} B+c,3@)x
//负责部分文件的抓取 =,s5>2
**FileSplitterFetch.java 1l.HQ IS
*/ -(#`JT8
package NetFox; 0OtUb:8LX
c'bh`H4
R0GD9
import java.io.*; '^'PdB
import java.net.*; ?uF3Q)rCk
gU@R
c48I-{?
public class FileSplitterFetch extends Thread { D3+<16[,
+}f}!h;
h;OHpvk
String sURL; //File URL T!1XL7
long nStartPos; //File Snippet Start Position {Bpu-R&T
long nEndPos; //File Snippet End Position @G|z_
int nThreadID; //Thread's ID vU#>3[aC
boolean bDownOver = false; //Downing is over E6?0/"
boolean bStop = false; //Stop identical a{.-qp
FileAccessI fileAccessI = null; //File Access interface }C JK9*Z
"2"2qZ*h}
8&7zV:=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AbX#wpp!
{ "'Q~&B;@
this.sURL = sURL; +4[Je$qYa
this.nStartPos = nStart; 0.U- tg0
this.nEndPos = nEnd; (J j'kW6G6
nThreadID = id; qMd4awB R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~x+&cA-0A2
} Saks~m7,
C&.Q|S2_
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public void run() WvcPOt8Bp>
{ :;&3"-
while(nStartPos < nEndPos && !bStop) 7lzmAih
{ ,Mn`kL<F
Ai`0Ud,M@
hdbm8C3
try{ Ed#Hilk'
URL url = new URL(sURL); VF~kjH2>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N1l^%Yf J
httpConnection.setRequestProperty("User-Agent","NetFox"); }~v0o# I
String sProperty = "bytes="+nStartPos+"-"; NU3s^ 8\(
httpConnection.setRequestProperty("RANGE",sProperty); h9&0"LHr
Utility.log(sProperty); A%EGu4
;a(7%
AaM~B`B
InputStream input = httpConnection.getInputStream(); 1f$1~5Z
//logResponseHead(httpConnection); X9YbTN
;jmT5XzL
#*"I?B/fd8
byte[] b = new byte[1024]; 8HWEObRY
int nRead; K/!>[d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2:1 kSR^Ky
{ A-u}&}l<
nStartPos += fileAccessI.write(b,0,nRead); 8?hj}}H
//if(nThreadID == 1) YG#{/;^nm)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &/)To
} X$SXDb~G
[qxDCuxq
y# IUDnRJ
Utility.log("Thread " + nThreadID + " is over!"); CmtDfE
bDownOver = true; [tJp^?6*
//nPos = fileAccessI.write (b,0,nRead); 6^z):d#u
} !*,m=*[3
catch(Exception e){e.printStackTrace ();} N1dM,H
} |#22pq?RP
} bKr73S9
0E^S!A7
|_16IEJ
//打印回应的头信息 dF+:9iiAm
public void logResponseHead(HttpURLConnection con) q)RTy|NJ^
{ %)y-BdSp.
for(int i=1;;i++) fLuOxYQbf
{ )24 1-b V
String header=con.getHeaderFieldKey(i); 2))pB/
if(header!=null) 1HeE$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JiX-t\V~
Utility.log(header+" : "+con.getHeaderField(header)); q=26($
else U)_x(B3d/
break; 0He^r &c3
} hhJs$c(
} BHS8MV L@
@KU^B_{i
(_Rl f$D
public void splitterStop() ;@<e]Ft
{ gzp]hh@4
bStop = true; GAlM:>
} @[O|n)7
P2 z~U
`M ~-(,++
} 9Hs5uBe
%}Z1KiRiX
|N5|B Q(y$
/* g`41d
**FileAccess.java %WFZ&>en&
*//文件访问(定位，写) YDGW]T]i ?
package NetFox; v(Q-RR
import java.io.*; E&\ 0+-Dw
R7Z!
ynZfO2kf
public class FileAccessI implements Serializable{ hJ~=eYK?J
IGI$,C
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :\|<7n
RandomAccessFile oSavedFile; y~py+:_
long nPos; <p#+('N`
3:3>k8
W9jxw4)
public FileAccessI() throws IOException q)y<\cEO
{ P"Y7N?\](
this("",0); >'&|{s[m
} ;x-]1xx_
+3r4GEa Z
+w(B9rH
public FileAccessI(String sName,long nPos) throws IOException 6f;20dn6
{ m@g9+7
oSavedFile = new RandomAccessFile(sName,"rw"); KH9D},
this.nPos = nPos; =L,7~9
oSavedFile.seek(nPos); )_1;mc8B
} +.66Ky`|[
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qyR}|<F8*
public synchronized int write(byte[] b,int nStart,int nLen) J|DY /v
{ _kUtj(re
int n = -1; t:tIzFNv
try{ \T^ptj(0
oSavedFile.write(b,nStart,nLen); @gjA8mL
n = nLen; e^orqw/I
} oN=>U"<\1
catch(IOException e) bA/'IF+
{ g ?{o2gG
e.printStackTrace (); :+meaxbu
} cA B<'44R
QJU\YH%}
A%.ZesjAx
return n; >]ZW.?1h
} uQz!of%x
1F{,Zr
rchKrw
} __,F_9M
!OMl-:KUzE
/2:s g1
/* 1( rN
**SiteInfoBean.java $[+)N~
*/ T<o8lL
package NetFox; ria.MCe\!
m[Cp G=32B
#2?3B
public class SiteInfoBean { \ 9#X]H
oVIc^yk5a
RdLk85<n
private String sSiteURL; //Site's URL `':G92}#
private String sFilePath; //Saved File's Path OF O,5
private String sFileName; //Saved File's Name mD;ioaE
private int nSplitter; //Count of Splited Downloading File !u|s8tN.U
O@`KGZEPY
~SYW@o
public SiteInfoBean() .FA99|:
{//nSplitter的缺省值为5 )Qh*@=$-
//default value of nSplitter is 5 axz.[L_elB
this("","","",5); Zo}vV2
} \-r"%@OkW
R#HX}[Hb
cs*"9nKl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `a9iq>
{ il$eO 7
sSiteURL= sURL; |P7FPmn
sFilePath = sPath; =JN{j2xY
sFileName = sName; UZJ#/x5F
this.nSplitter = nSpiltter; 'j\mz5#s
DJ|lel/'
=!IoL7x
} _a zJ>
}N"YlGY\Yn
L`"V_ "Q#0
public String getSSiteURL() T%SK";PAU$
{ +3Z+#nGtk
return sSiteURL; nK#%Od{GF
} .9vt<<Kwh
MhIHfW]b
3rX40>Cs8
public void setSSiteURL(String value) dF*M"|[
{ (6&"(}Pai
sSiteURL = value; <,Mf[R2N>
} C9*[/|T
$GYy[8{:V
`cPZsL
public String getSFilePath() bmJdZD7-<k
{ FsS.9 `B
return sFilePath; =,8nfJ+x
} Y7;=\/SV
5F#FC89Kk
h.kjJF
public void setSFilePath(String value) p!DOc8a.\e
{ RDEK=^J
sFilePath = value; ]GD&EQ
} ElKMd
)a9C3-8Y'
_%#Uh#7P$
public String getSFileName() a'r1or4
{ k{U[ U1j
return sFileName; `qRyh}Ax"
} z m]R76
g |H
5 ed|]LP
public void setSFileName(String value) P"o|kRO
{ A5Q4wy`
sFileName = value; AQ,"):ofvT
} ./^8L(
\fp'=&tp~a
}pGjc_:']
public int getNSplitter() q(A_k+NL
{ p_)ttcpi1
return nSplitter; q$"?P
} bh#6yvpMR
Q<KF<K'0hg
1 1(GCu
public void setNSplitter(int nCount) L >)|l
{ piqh7u3~
nSplitter = nCount; yXqC
} <":83RCS
} U@D\+T0
~z")';I|
#2"'tHf4
/* Mpco8b-b
**Utility.java #lMC#Ld
*/ 2 /*z5
package NetFox; !6a;/ys
Z
Br.UN~q
public class Utility { A/"2a55
TK%q}bK,
5NhAb$q2Y
public Utility() ]&9=f#k%
{ GG-b)64h`
h7@%}<%
.J8 gW
} $;u[
#2$wI^O
//线程睡眠 J<4_<.o(a
public static void sleep(int nSecond) Gm$1b
{ 1ox#hQBoS
try{ 2|] <U[
Thread.sleep(nSecond); ,4 q^(
} ^f-)gZ&
catch(Exception e) k\9kOZW
{ QDVSFGwr
e.printStackTrace (); \I^"^'CP
} y7+n*|H
} D:?"Rf{)
!%DE(E*'(
//日志 _n{_\/A6f
public static void log(String sMsg) fY?:SPR+
{ EyA(W;r.
System.err.println(sMsg); B&y?Dc
} r!w*y3
%tC[q
Xwjm T
public static void log(int sMsg) V~Z)^.6
{ XD|Xd|/ {
System.err.println(sMsg); uEG4^
} 5e1oxSU
} Z;BEUtR c
rdtzz#7
~66v.`K!
/* A f!`7l-
**TestMethod.java E:+r.r"Y
*/ ZNpC& "`G
package NetFox; A$n.'*gK
!q$>6P
fe"w--v
public class TestMethod { >Z<ZT
vILB$%I
mwN"Cu4t
public TestMethod() m7RyFnR2
{ ///xx/weblogic60b2_win.exe .j"heYF)
try{ x\yr~$}(J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +JY8"a97>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vpzjh,r-j
SiteFileFetch fileFetch = new SiteFileFetch(bean); YC<FKWc
fileFetch.start(); L;A#N9
} ^,?>6O
catch(Exception e){e.printStackTrace ();} ?iEn~9WCS
rj4Mq:pJ
g\?07@Zd|
} g 4|ai*^
m=/HUt3(&0
p_e x
public static void main(String[] args) $:1/`m19
{ Ov4 [gHy&
new TestMethod(); 4>fj@X(3
} g>'6"p;
} ~m0=YAlk?
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