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)); {en'8kS
} h ka_Fo
for(int i=0;i<nEndPos.length-1;i++) a <?~1pWtc
{ vFntzN>#
nEndPos = nStartPos[i+1]; a oU"
} W~D_+[P|_
nEndPos[nEndPos.length-1] = nFileLength; u|Mx}
} +D]raU
} 0D@$
-/{FGbpR;
{b4`\I@<
//启动子线程 wDW%v@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *w*>\ZhOm
for(int i=0;i<nStartPos.length;i++) -XCs?@8EQ
{ >Q=^X3to
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q#H"Se
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w0=
nStartPos,nEndPos,i); JRFUNy1+e1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ws!~MSIy
fileSplitterFetch.start(); G(#t,}S}@
} C7NSmZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z_ycH%p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0: hv6Ge^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YuknZ&Q
nEndPos = " + nFileLength); /R=MX>JA;
// fileSplitterFetch[nPos.length-1].start(); r W[;3yMf
`DgK$QM
miQ*enZi
//等待子线程结束 =NC??e{
//int count = 0; *4`5&) `
//是否结束while循环 AK&>3D
boolean breakWhile = false; |w{Qwf!2
MAFdJ+n#
,7)hrA$(
while(!bStop) Yn="vpM1
{ d:K\W[$Bz
write_nPos(); F.$z7ee@
Utility.sleep(500); }p2iF2g9`
breakWhile = true; ,jis@]:
wT":
a!:N C
for(int i=0;i<nStartPos.length;i++) V)/J2-w
{ ,/b!Xm:
if(!fileSplitterFetch.bDownOver) qq&U)-`
{ H@xS<=:lM
breakWhile = false; 3_XLx{["'
break; s)qrlv5H
} jmr .gW
} .UL2(0
if(breakWhile) t sUu
break; z6E =%-`
A3_p*n@
s~ 8g
//count++; 2Wluc37
//if(count>4) Vl5>o$G|<.
// siteStop(); bGeIb-|(
} 3jxC}xz)
g3NUw/]#
$-1ajSVJ
System.err.println("文件下载结束！"); ye$_=KARP
} kpn|C 9r
catch(Exception e){e.printStackTrace ();} 9Tt%~m^
} pK3A/ry<
@y;VV*
.@OQ$D<
//获得文件长度 Pa3-0dUr
public long getFileSize() !9/`PcNIpy
{ QNMZR
int nFileLength = -1; <>\|hno}
try{ `Fr ,,Q81\
URL url = new URL(siteInfoBean.getSSiteURL()); -GPBX?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iG6]Pr|;e
httpConnection.setRequestProperty("User-Agent","NetFox"); {HEWU<5
R~oJ-}iYX
IXa~,a H71
int responseCode=httpConnection.getResponseCode(); *2a"2o
if(responseCode>=400) l6HtZ(
{ ekyCZ8iai
processErrorCode(responseCode); 3i!a\N4 K
return -2; //-2 represent access is error `X@\Zv=}
} d|NW&PG
Pqya%j
N { oVz],
String sHeader; F:ycV~bE
a4^hC[a
[6mK<A,/
for(int i=1;;i++) rueaP
{ "{D/a7]lC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JL87a^ro
//Utility.log(in.readLine()); J2VPOn
sHeader=httpConnection.getHeaderFieldKey(i); (t@)`N{
if(sHeader!=null) wz:e\ !
{ 9t\14tVwx
if(sHeader.equals("Content-Length")) o-RZwufZ`
{ [y`Gp#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); EZB0qZIp
break; ~&)\8@2
} Opu*i
} M,H8ZO:R
else _r3Y$^!U
break; 2v ~8fr4
} !FP ]
} (v/L
catch(IOException e){e.printStackTrace ();} ,Lp"Ia
catch(Exception e){e.printStackTrace ();} }VJ>}i*
,g7O
hTLf$_|P
Utility.log(nFileLength); yg}O9!MJ
ct-Bq
YM_[
return nFileLength; ^aAs=KditO
} {"Sv~L|J;
\UK}B
5\quh2Q_
//保存下载信息（文件指针位置） Ro2V-6/
private void write_nPos() PM84Z@Y
{ Jl\xE`-7
try{ X2Ak
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fw&ImRMk
output.writeInt(nStartPos.length); PdO"e
for(int i=0;i<nStartPos.length;i++) qA7,txQ:
{ L%v@|COQ3
// output.writeLong(nPos); ]j7`3%4uK
output.writeLong(fileSplitterFetch.nStartPos); qLLrR,:
output.writeLong(fileSplitterFetch.nEndPos); <Y"RsW9
} F(`|-E"E;
output.close(); np^&cY]
} b_ZvI\H
catch(IOException e){e.printStackTrace ();} a.%ps:
catch(Exception e){e.printStackTrace ();} 6NV592
} s7 nl
G]aey>)
~Re4zU
//读取保存的下载信息（文件指针位置） Fc`IRPW<
private void read_nPos() 'Jf LTG.
{ 85&7WAco"B
try{ $;Fx Zkp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xf&YcHo
int nCount = input.readInt(); X:Z3R0
nStartPos = new long[nCount]; p)B/(%
nEndPos = new long[nCount]; J(#6Cld`c
for(int i=0;i<nStartPos.length;i++) G;cC!x<
{ O"~[njwkE
nStartPos = input.readLong(); n)5t!
nEndPos = input.readLong(); apm%\dN
} L3I$ K+c
input.close(); ||X3g"2W9
} j$Ndq(<tG
catch(IOException e){e.printStackTrace ();} Nut&g"u2
catch(Exception e){e.printStackTrace ();} >A{Dpsi\
} Q(w;
pl r@
Gz{%Z$A~o
private void processErrorCode(int nErrorCode) kB@gy}
{ Lm}.+.O~d
System.err.println("Error Code : " + nErrorCode); ?=Ceo#Er
} -b!Z(}JK
^)]U5+g?
y_L8i[
//停止文件下载 yrEh5v:
public void siteStop() }@6Ze$>
{ QD%xmP
bStop = true; 26aDPTP$<
for(int i=0;i<nStartPos.length;i++) YNV, dKB
fileSplitterFetch.splitterStop(); &'^.>TJ\
)@DDs(q=i
=!SV;^-q
} 1]''@oh{6U
} Ld.9.d]
//负责部分文件的抓取 nQV0I"f]?]
**FileSplitterFetch.java $#f_p-N
*/ 1#3|PA#>
package NetFox; wyX3qH
w3q'n%
%R?7u'=~
import java.io.*; QErdjjgE
import java.net.*; \9`E17i
V. i{IW
&X:;B'
public class FileSplitterFetch extends Thread { =M-=94
F&!vtlV)
]CLM'$
String sURL; //File URL DQK?y=vf
long nStartPos; //File Snippet Start Position [(Z(8{3i
long nEndPos; //File Snippet End Position ^=^\=9" b
int nThreadID; //Thread's ID KJyCfMH&:@
boolean bDownOver = false; //Downing is over A{\?]]/
boolean bStop = false; //Stop identical X>`03?L
FileAccessI fileAccessI = null; //File Access interface B0|W
QBGm)h?=
(8m_GfT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b}NNkM
{ NUVKAAgMX
this.sURL = sURL; $)NS]wJ]3
this.nStartPos = nStart; ~.3v\Q
this.nEndPos = nEnd; RN 4?]8
nThreadID = id; *_I`{9~'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |Io:D:
} U)f('zD
j"6|$Ze8
#b*4v&<
public void run() jC[_uG
{ Q(-&}cY
while(nStartPos < nEndPos && !bStop) 8>WA5:]v
{ cdkEK
&ox
+pG+ xI
try{ t[+bZUS$~
URL url = new URL(sURL); "9'3mmZm=?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N{bg-%s10i
httpConnection.setRequestProperty("User-Agent","NetFox"); KE"6I
String sProperty = "bytes="+nStartPos+"-"; Hre&a!U
httpConnection.setRequestProperty("RANGE",sProperty); <o|fH~?X
Utility.log(sProperty); c6 &k?Puy
rzHBop-8
rK'Lvt@w
InputStream input = httpConnection.getInputStream(); b||usv[or
//logResponseHead(httpConnection); J:W+'x`@
n[e C
ynM:]*~K
byte[] b = new byte[1024]; \h3HaNC
int nRead; RK-bsf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dQSO8Jf
{ Pa0W|q#?X
nStartPos += fileAccessI.write(b,0,nRead); >ye.rRZd`
//if(nThreadID == 1) TaSS) n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OWrQKd
} k^|z.$+
]@Y!,bw&
IrZ\;!NK
Utility.log("Thread " + nThreadID + " is over!"); <QvVPE}z
bDownOver = true; RuYIG?J=/
//nPos = fileAccessI.write (b,0,nRead); 67&IaDts
} I)1ih
catch(Exception e){e.printStackTrace ();} oS$7k3s fj
} _+9i
} 'z,kxra|n
\5&Mg81
R98YGW_ dT
//打印回应的头信息 ^@8XJ[C,_
public void logResponseHead(HttpURLConnection con) 'kj q C
{ nG3SDL#(k
for(int i=1;;i++) n\D/WLvM
{ `XE>Td>Bs
String header=con.getHeaderFieldKey(i); \Y"S4<"R
if(header!=null) 0cKsGDm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m-4#s
Utility.log(header+" : "+con.getHeaderField(header)); kOo Vqu
else T8\@CV!
break; mK$E&,OkA
} _4) t
} :Ef!gpS}?R
>;Oa|G
C)FO:lLr\
public void splitterStop() @C@9Tw2Y
{ QyL]-zNg
bStop = true; oy jkk
} j?*n@'
$!. [R}
r4[=pfe25
} 1lIs jBo g
IY6Ll6OK
X%s5D&gr
/* Z*w({k7]
**FileAccess.java Zs/-/C|
*//文件访问(定位，写) l=9D!64
package NetFox; tH;9"z# ~
import java.io.*; %8I^&~E1
G"&$7!6[Y
eCKm4l'BZ
public class FileAccessI implements Serializable{ Eh;Ia6}
7Z:3xb&>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9\?&u_ U"
RandomAccessFile oSavedFile; EsWB|V>
long nPos; @F(er
:tO?+1
!]s=9(O
public FileAccessI() throws IOException _YR#J%xa
{ eD7\,}O
this("",0); KL?<lp"
} !-T#dU
037\LPO
s1]Pv/a=y
public FileAccessI(String sName,long nPos) throws IOException z)KoK`\mE"
{ h(nE)j
oSavedFile = new RandomAccessFile(sName,"rw"); s[{8:Px
this.nPos = nPos; 6[XaIco=C
oSavedFile.seek(nPos); {BM:c$3@j
} VB |k
Mz$qe
b/\O;o}]
public synchronized int write(byte[] b,int nStart,int nLen) An(gHi;1$
{ hb~d4J=S
int n = -1; =CFg~8W
try{ *g}==o`
oSavedFile.write(b,nStart,nLen); OO/>}? ob
n = nLen; ,e$RvFB
} <hy!B4
catch(IOException e) 8bMw.u=F
{ m8L %!6o
e.printStackTrace (); \4$Nx/@Q}
} ?~.9:93
n5xG4.#G
anz7ae&P'K
return n; `::j\3B&Y-
} Us "G X_
Ap\]v2G
3@eI?(N
} !^L}LtqHI
as3uz
9VaSCB
/* |af<2(d
**SiteInfoBean.java zB y%$5~Fw
*/ u]B b^[
package NetFox; L ~Vw`C
V^qBbk%l>D
:/? Op
public class SiteInfoBean { J.2BBy
Yy[=E\z
P >0S ZP
private String sSiteURL; //Site's URL Brg0:5H
private String sFilePath; //Saved File's Path ]lJ#|zd8o
private String sFileName; //Saved File's Name >oy%qLHe~t
private int nSplitter; //Count of Splited Downloading File (1{OQ0N+x
A+Je?3/.
ocW`sE?EED
public SiteInfoBean() gDfM}2]/
{//nSplitter的缺省值为5 ,9=P=JH
//default value of nSplitter is 5 =fBr2%qK
this("","","",5); ,t1s#*j\!q
} 3S^Qo9S
YA8/TFu<_
Tz&cm=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P'_ aNU
{ xop\W4s_
sSiteURL= sURL; `,GFiTPd
sFilePath = sPath; K24y;968
sFileName = sName; Q4ii25]*
this.nSplitter = nSpiltter; IP !zg|c,
,V4pFQzL
t?uw^nV3E
} &U.y):
H-5f!>)
Rx%kAt2X
public String getSSiteURL() &#q%#M:
{ 3kJSz-_M
return sSiteURL; T^xp2cZ
} H'EBe;ccM
jq/{|<0
z9#jXC#OdN
public void setSSiteURL(String value) f}FJR6VO
{ R<h0RKiM@
sSiteURL = value; OK}8BY
} gJOswN;([
U8g?
q|D*H9[ke
public String getSFilePath() ;NJM3g0I
{ H~hAm
return sFilePath; ^eYJ7&t
} C$c.(5/O
5o(=?dXm4
p|*b] 36
public void setSFilePath(String value) @qJv
{ d<;XQ.Wo7
sFilePath = value; iN`L*h
} ER$~kFE2yP
kS7T'[d
Y50$2%kM
public String getSFileName() wVs|mG"
{ -gS/
return sFileName; ]}0+7Q
} / dn]`Ge)
R91u6r#
D3 E!jQ1
public void setSFileName(String value) 2gjA>ET`N
{ 483vFLnF
sFileName = value; QaEXk5>e
} KQqQ@D&n
tX}Fb0y
WHF:>0B
public int getNSplitter() %}&9[#
{ Ki@8
return nSplitter; t!Av[K
} V'?nS&,i
55|$Imnf
`}Hnj*
public void setNSplitter(int nCount) CUw 9aH
{ kp;MNRc
nSplitter = nCount; ;6)|'3.B9
} E3KPJ`=!*"
} &q` =xF
j({L6</x
G6Fg<g9:
/* qC|re!K
**Utility.java Wj*6}N/
*/ )I}G:bBa
package NetFox; %I=J8$B]f
{5z?5i ?D
)DLK<10
public class Utility { P?uKDON
SI(8.$1
_bz,G"w+:
public Utility() U&a]gkr
{ "7 4L
n*xNMw1x"T
q B2#EsZ
} [E/3&3
wb9zJAsc
//线程睡眠 / q!&I
public static void sleep(int nSecond) |ZKchd8Yq
{ t-Fl"@s
try{ wLbnsqa
Thread.sleep(nSecond); MdfkC6P
} 3G&1. 8
catch(Exception e) \d;Ow8%d/
{ 1|89-Ii]
e.printStackTrace (); =@f;s<v/
} 8YJ({ Ou_
} hv)($;
`jkn*:m
//日志 5f5`7uVJF
public static void log(String sMsg) 5-QXvw(TH
{ BMW4E 5
System.err.println(sMsg); f<'C<xnf
} `F@yZ4L3S
Cu:-<
yC5|"+ A$
public static void log(int sMsg) EKf4f^<
{ m}E$6E^~O
System.err.println(sMsg); ( FRf.mv{
} kShniN
} Kna'5L5"
;sf/tX
\4[Ta,;t
/* .wSAysiQ|P
**TestMethod.java y()( 8L
*/ >seB["C
package NetFox; AQ5v`xE4
.%A2
;z>YwRV
public class TestMethod { >>r:L3<!
5dk,!Cjg
Ah`dt8t
public TestMethod() v(O.GhJ@
{ ///xx/weblogic60b2_win.exe AngwBZ@
try{ |*5nr5c_L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gib]#n1!p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q/9b'^UJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); Dhoj|lc
fileFetch.start(); 4o3GS8
} *&]l
catch(Exception e){e.printStackTrace ();} *@nUas2"
d#Ajb
O@rb4(
} 'r%oOZk)z
3D0I5LF&
}[`?#`sW
public static void main(String[] args) .)w0C%]
{ pt#[.n#f
new TestMethod(); ex458^N_
} 4#q JX)/
} r.;iO0[/
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