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)); ;2k!KW@
} [C>>j;q%
for(int i=0;i<nEndPos.length-1;i++) vtA%^~0
{ *eF'<._[U
nEndPos = nStartPos[i+1]; (9]8r2|.
} 3J3Yt`
nEndPos[nEndPos.length-1] = nFileLength; ^t2b`n60
} "mtEjK5
} }zO>y%eI
\aY<| 7zK
_9pcHhJux
//启动子线程 x\i+MVR-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >WcOY7
for(int i=0;i<nStartPos.length;i++) qexnsL
{ Qo5yfdR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ib&]1ger#=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >d9b"T
nStartPos,nEndPos,i); _?I6[Mz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y),yks?iv
fileSplitterFetch.start(); >7$h
} L=_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JeXA*U#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !r#36kO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1C5~GI`
nEndPos = " + nFileLength); hU~up a<dD
// fileSplitterFetch[nPos.length-1].start(); 4}r.g0L
h`@z61UI
U&'Xsz
//等待子线程结束 =j!nt8]8
//int count = 0; tt03gU`
//是否结束while循环 ml1My1
boolean breakWhile = false; X 2Zp@q(
H?4t\pSS
,{jF)NQaP
while(!bStop) 0PdX>h.t
{ $lAQcG&Q
write_nPos(); .P(Ax:g
Utility.sleep(500); [KW9J}]
breakWhile = true; Da)H/3ii
U:fGIEz{ZY
rNl%I@G
for(int i=0;i<nStartPos.length;i++) Srom@c
{ 3>#io^35
if(!fileSplitterFetch.bDownOver) h @2.D|c)g
{ ]A,Og_g
breakWhile = false; ] ]lN[J
break; El^V[s'3
} KPxf
} FfM,~s<Efz
if(breakWhile) LJwy,-
break; rebWXz7
Ol)M0u
`s\E"QeZN
//count++; THcX.%ToT
//if(count>4) /_V4gwb}|-
// siteStop(); D9r4oRkP*
} d:g0XP
2Xqa?ay0>
|o#pd\
System.err.println("文件下载结束！"); mc|8t0+1`
} X8 A$&
catch(Exception e){e.printStackTrace ();} {S"!c.
} %&M*G@j
Y.#:l<
=PmIrvr'[5
//获得文件长度 Og:aflS
public long getFileSize() _53NuEM1
{ ;edt["Eu
int nFileLength = -1; |D~#9
try{ w^)_Fk3
URL url = new URL(siteInfoBean.getSSiteURL()); -"x25~k!?F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DxzNg_E]
httpConnection.setRequestProperty("User-Agent","NetFox"); B18?)LA
@WuG8G
8M6Qn7{L
int responseCode=httpConnection.getResponseCode(); r~;TId} #
if(responseCode>=400) (2'q~Z+>'
{ RsnFjfb'
processErrorCode(responseCode); o(Q='kK
return -2; //-2 represent access is error ~?:Xi_3Lo
} dRXdV7-!
dk@iAL*v
m8z414o
String sHeader; l/6(V:
Yp6% @c6\
$m0-IyXcv
for(int i=1;;i++) 3NlG,e'T2
{ rB-}<22.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e%v0EJ},
//Utility.log(in.readLine()); b)+;@wa~
sHeader=httpConnection.getHeaderFieldKey(i); !kWx'tJ$
if(sHeader!=null) )Zit6I
{ ziG]BZ
if(sHeader.equals("Content-Length")) TuMD+^x
{ \j~LxV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SkMBdkS9z[
break; ul ag$ge
} B{-+1f4
} Z=y^9]
else E@S5|CM
break; ?KXgG'!!
} few=`%/
} mx")cGGQ
catch(IOException e){e.printStackTrace ();} tCbnB
catch(Exception e){e.printStackTrace ();} =ms o1
D3kx&AR
`|g*T~; kC
Utility.log(nFileLength); U\`H0'
A]mXV4RmI
gj<Y+Dv>
return nFileLength; Vv5#{+eT;
} ]QK@zb}x
So\f[/em
a>/jW-?
//保存下载信息（文件指针位置） Q.`O;D}x
private void write_nPos() :Y>M//0
{ E/N*n!sV
try{ *kWrF* )J
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ex3V[v+D(
output.writeInt(nStartPos.length); hu''"/raM
for(int i=0;i<nStartPos.length;i++) d!]fou
{ VLfE3i4Vwl
// output.writeLong(nPos); {Tym#
output.writeLong(fileSplitterFetch.nStartPos); 4'ymPPY
output.writeLong(fileSplitterFetch.nEndPos); vTF_`X
} f;PvXq<7"
output.close(); ^qD@qJ
} qX?k]m
catch(IOException e){e.printStackTrace ();} v5!G/TZ1
catch(Exception e){e.printStackTrace ();} _N&]w*ce
} 9x0Ao*D<t
]$gBX=
p4-bD_
//读取保存的下载信息（文件指针位置） 1Ev#[FOc
private void read_nPos() -U/m
{ 9e:}qO5)
try{ q[w.[]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dJ0qg_ U&
int nCount = input.readInt(); U~e^
nStartPos = new long[nCount]; <BNCo5*
nEndPos = new long[nCount]; NFQR
for(int i=0;i<nStartPos.length;i++) j.L`@
{ !@<>S>uGG
nStartPos = input.readLong(); 47c` ) *Hc
nEndPos = input.readLong(); M~1 n#
} #FfUkV
input.close(); {} 11U0
} }m6j6uAR6)
catch(IOException e){e.printStackTrace ();} nxc35
catch(Exception e){e.printStackTrace ();} C/!c?$J
} n^7$ST#'bV
3g#fX{e_5!
%hu] =
private void processErrorCode(int nErrorCode) )@]Y1r4U
{ *&vySyt
System.err.println("Error Code : " + nErrorCode); gTp){
} ){.J`X5r
'e(`2
+I?T|Iin
//停止文件下载 lilKYrUmG
public void siteStop() 96.A8o
{ J6H3X;vxQw
bStop = true; nFn@Z'T$N
for(int i=0;i<nStartPos.length;i++) \gE3wmSJ,
fileSplitterFetch.splitterStop(); :W/,V^x}
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jJjD)
} Y(D@B|"'m
} cN>z`xl
//负责部分文件的抓取 Z81{v<c;
**FileSplitterFetch.java pEjA*6v|,
*/ xpf\S10e
package NetFox; jF'azlT
ZcXqH7`r
'CDRb3w}B
import java.io.*; !Z7 ~Rsdm
import java.net.*; 1f 0"z1
kMS[
4:=eO!6
public class FileSplitterFetch extends Thread { (YjY=F
iz`u@QKc%
&8Cuu$T9)
String sURL; //File URL k!]Tg"]JAh
long nStartPos; //File Snippet Start Position '\:?FQ C
long nEndPos; //File Snippet End Position \^wI9g~0
int nThreadID; //Thread's ID edPnC {?s
boolean bDownOver = false; //Downing is over Riq5Au?*)
boolean bStop = false; //Stop identical =;{vfjj
FileAccessI fileAccessI = null; //File Access interface n8zh;vuJ
m7 !Fb
x C'>W"pY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~9qDmt,i
{ P 7 [p$Z
this.sURL = sURL; cI3uH1;#
this.nStartPos = nStart; 0\AYUa?RM
this.nEndPos = nEnd; %ma1LN[
nThreadID = id; #Dx$KPD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7581G$@ym
} voaRh@DZ%/
5|:=#Ql*
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public void run() .1MXQLy
{ M`umfw T
while(nStartPos < nEndPos && !bStop) /Mf45U<
{ ~K^Z4
T7n;Bf
SSi}1
try{ oZ%t!Fl1
URL url = new URL(sURL); 4;|&}Ij
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >k^=+
httpConnection.setRequestProperty("User-Agent","NetFox"); 1K,bmb xRt
String sProperty = "bytes="+nStartPos+"-"; NF0} eom
httpConnection.setRequestProperty("RANGE",sProperty); PG)dIec
Utility.log(sProperty); 4 !~JNO
FFH-Kw,
SR~~rD|V
InputStream input = httpConnection.getInputStream(); g{l;v
//logResponseHead(httpConnection); T:wd3^.CG
hW>@jT"t1C
RKIqg4>E
byte[] b = new byte[1024]; Oa7`Y`6
int nRead; P 2;j>=W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~z>2`^Z"
{ L<QqQ"`
nStartPos += fileAccessI.write(b,0,nRead); WJe
//if(nThreadID == 1) &e_M \D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yXrFH@3
} )y.J2_lI8
if:2sS9r
S! ,.#e(Y
Utility.log("Thread " + nThreadID + " is over!"); x1+8f2[
bDownOver = true; kYxn5+~
//nPos = fileAccessI.write (b,0,nRead); 9+=U&*
} ]Rnr>_>x;
catch(Exception e){e.printStackTrace ();} b)$<aFl
} 7Y@&&
} Uh?SDay
wp.<}=|u
h{J2CWJ
//打印回应的头信息 InNuK0@
public void logResponseHead(HttpURLConnection con) Lc+wS@
{ -UPdgZ_Vxz
for(int i=1;;i++) 8K6yqc H
{ 292e0cE
String header=con.getHeaderFieldKey(i); 7qgHH p
if(header!=null) "-A@>*g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cRT@Cu
Utility.log(header+" : "+con.getHeaderField(header)); M*8Ef^-U`t
else ?8b?{`@V
break; q%Obrk
} ?J6J#{LRd
} Mh[;E'C6
5sFp+_``
EmVE<kY.
public void splitterStop() <.s[x~b\`
{ ^0ipM/Lg
bStop = true; z[}[:H8
} vM1f-I-
)g9Zw_3
F^3Q0KsT
} DE^{8YX,
:JxShF:M
b,]hX
/* ; R&wr_%
**FileAccess.java bh3}[O,L A
*//文件访问(定位，写) N'i%9SBcg
package NetFox; JN$v=Ox{
import java.io.*; D7olu29
Q(T)s
+(`
public class FileAccessI implements Serializable{ jL6u#0
!G90oW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 506B=
RandomAccessFile oSavedFile; a:XVu0`(
long nPos; m@u!frE,
1*Yf[;L
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public FileAccessI() throws IOException O1ofN#u
{ ZXY5Xvt:v
this("",0); x$[<<@F%
} ^}8(o
SWNi@
`kpX}cKK}
public FileAccessI(String sName,long nPos) throws IOException D}>pl8ke~g
{ `{gkL-
oSavedFile = new RandomAccessFile(sName,"rw"); E!8FZv8
this.nPos = nPos; k?;A#L~
oSavedFile.seek(nPos); C\ZL*,%}
} &BY%<h0c
hq6B pE
me_DONW
public synchronized int write(byte[] b,int nStart,int nLen) [2pp)wq
{ ms{:=L2$$
int n = -1; 1XSA3;ZEc
try{ GbFLu`Iu
oSavedFile.write(b,nStart,nLen); *p`0dvXG2
n = nLen; `MAee8u'
} ?l!L )!2
catch(IOException e) l"5$6h
{ 6}='/d-[
e.printStackTrace (); :9Zu&t
} F[<EXLQ
L(\sO=t
>6*"g{/
return n; <W~5;m
} [R+zzl&Zw
bW(+Aw=O
nd3=\.(P
} *%l&'+
h!5^d!2,
O# .^}
/* 9yH95uaDF
**SiteInfoBean.java ]W7(}~m
*/ 8 !Pk1P
package NetFox; WMnR+?q
kT@RA}
R $HIJM
public class SiteInfoBean { h#'(i<5v
U_v{Vs
C7[ge&
private String sSiteURL; //Site's URL @'C f<wns
private String sFilePath; //Saved File's Path \kqa4{7U(
private String sFileName; //Saved File's Name W{O:j
private int nSplitter; //Count of Splited Downloading File -}`ES]
vDZhoD=VR
k$UgTZ
public SiteInfoBean() `2c>M\c4U
{//nSplitter的缺省值为5 Qj5~ lX`W
//default value of nSplitter is 5 R#i|n<x
this("","","",5); AVVL]9b_2
} EF=.L{
aDFu!PLB{)
b}S}OW2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J\<7M8
{ |={><0
sSiteURL= sURL; /%C6e )7BL
sFilePath = sPath; rLs)*A!
sFileName = sName; jXvGL
this.nSplitter = nSpiltter; 0JQy-hpF
Gc>bli<-
WJ=DTON
} tRRPNY
c|3%0=,`
_/bFt6
public String getSSiteURL() TWYz\Hmw
{ K]' 84!l
return sSiteURL; )QE7$|s
} 3#huC=zbf
r7Bv?M^!
G7 >
public void setSSiteURL(String value) Qw4P{>|Y
{ J01w\#62pQ
sSiteURL = value; KY H*5
} GdG1e%y]z
hLFf
dQ?4@
public String getSFilePath() Be}e%Rk
{ n={}='
return sFilePath; F{)YdqQ
} C-d|;R}Ww
ozH7c_ <
WRU/^g3O@'
public void setSFilePath(String value) %])-+T
{ 6~zR(HzV{
sFilePath = value; ta"/R@ k*
} ,!t1( H
IK5FSN]s/
5w"f.d'
public String getSFileName() Ol H{!
{ L;/#D>U(
return sFileName; g0Qg]F5D~
} #Z<pks2 y
bcL>S$B
p 7IJ3YY
public void setSFileName(String value) !Sr^4R+Z
{ j[NA3Vj1P
sFileName = value; u{0+w\xH\
} k1Zu&4C\
d,[.=Jqv[
H6E@C}cyM
public int getNSplitter() Ag}V>i'
{ rubqk4
return nSplitter; u^a\02aV[
} >"?HbR9
0CS^S1/[B`
HRIf)n&~f
public void setNSplitter(int nCount) F7a &-
{ Nge_ Ks
nSplitter = nCount; qY\zZ
} ;y<)RM
} idnn%iO
SF+ ^dPwj
pC(AM=RY!
/* $de_>
**Utility.java ?2[=llS4
*/ ^|xj.
package NetFox; +A8S 6bA[=
PN2\:l+`
KIn^,d0H
public class Utility { TFbCJ@X
7p3 ;b"'
toPA@V
public Utility() v}A] R9TY
{ +P|$T:b
PN/2EmwtC
p9R`hgx
} *{W5QEa
w3Aq[1U0
//线程睡眠 1pXAPTV
public static void sleep(int nSecond) j^KM
{ efMv1>{
try{ o;FjpZ
Thread.sleep(nSecond); N;A1e@bP
} 9Q=g]int u
catch(Exception e) "A__z|sQ
{ N\H{p%8
e.printStackTrace (); \|R`wFn^P
} RTA9CR)JP4
} s .^9;%@$J
6`NsX
//日志 IaE};8a8
public static void log(String sMsg) ,!kyrk6
{ 0'^? m$
System.err.println(sMsg); 6#N1 -@
} *bn9j>|iv
y>2v 9;Qp
w|Zq5|[
public static void log(int sMsg) QC4_\V>[
{ U,iTURd
System.err.println(sMsg); WSDNTfpI
} >~BU<#
} ZeWHSU
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Q C~~
/* ,-] JCcH
**TestMethod.java =6
*/ ]*i>KR@G
package NetFox; ddnWr"_
2_r}4)z
51x^gX|
public class TestMethod { iCAd7=o
7azxqa5:
h^hEyrJw
public TestMethod() <@*mFq0,
{ ///xx/weblogic60b2_win.exe 7MGc+M(p
try{ `9K'I-hv<8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GmAE!+"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9D<^)ShY
SiteFileFetch fileFetch = new SiteFileFetch(bean); J\;~(: ~
fileFetch.start(); e1<28g
} =[1W.Zt
catch(Exception e){e.printStackTrace ();} ` |]6<<'iW
y]?$zbB
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} X]1ep
t9K.Jc0
,{oP`4\Lm
public static void main(String[] args) L~mL9[(,
{ (Nik(Oyj"
new TestMethod(); 8L=QfKr
} uxh4nyE
} n]j(tP
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