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)); E2kW=6VO>|
} {K<uM'ww>
for(int i=0;i<nEndPos.length-1;i++) DCt\E/
{ 1B6C<cL:sU
nEndPos = nStartPos[i+1]; *}>Bkq9h
} Q! Kn|mnN
nEndPos[nEndPos.length-1] = nFileLength; ^p$1D
} <b6s&"%=
} |3 ;u"&(P
v#iFQVBq
bo&\3
//启动子线程 &S<?07Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `'*F1F
for(int i=0;i<nStartPos.length;i++) +mivqR~{{
{ kNRyOUy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nrF%wH/5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "|F.'qZrm
nStartPos,nEndPos,i); {cmo^~[L$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jo<>Hc{g>
fileSplitterFetch.start(); tB GkRd!
} {EOn r1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xR*5q1j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lr`?yn1D(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7X(rLd 6#
nEndPos = " + nFileLength); wDB)&b
// fileSplitterFetch[nPos.length-1].start(); tDEXm^B2Sv
chKF6n
Y=5!QLV4
//等待子线程结束 8rGl&
//int count = 0; \H,V 9!B
//是否结束while循环 5tN%a>D%
boolean breakWhile = false; C]yvK}
Y*`:M(
01&*`0?
while(!bStop) W3FymCI
{ ,@}W@GGP)
write_nPos(); JCM)N8~i
Utility.sleep(500); 'wCS6_K
breakWhile = true; dD[v=Z_
E^oEG4X@
bq c;.4$
for(int i=0;i<nStartPos.length;i++) @:S$|D~
{ lf?Z{^
if(!fileSplitterFetch.bDownOver) \B*k_W/r@
{ (nkUeQQN
breakWhile = false; vs5 D:cZ}
break; zzulVj*
} D /,|pC
} o%vIkXw
if(breakWhile) /IGrp.}
break; Ytl:YzXCi
V_NjkyI
3c1o,2
//count++; vS~AxeW/7R
//if(count>4) .a 'ETNY:>
// siteStop(); k$9Gn9L%
} @)aXNQY
vG'vgUo
^%~Et>C
System.err.println("文件下载结束！"); -=-x>(pRW7
} e1f^:C
catch(Exception e){e.printStackTrace ();} N&R '$w
} :d!i[W*
OlD7-c2L]
?TL2'U|M
//获得文件长度 sRkz WMl
public long getFileSize() +=n x|:no
{ |YG)NO
int nFileLength = -1; X}65\6
try{ S&4w`hdD>~
URL url = new URL(siteInfoBean.getSSiteURL()); ,Ut!u)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '^P*F9
httpConnection.setRequestProperty("User-Agent","NetFox"); Y\Fuj)
kMwIuy
6E*Zj1KX
int responseCode=httpConnection.getResponseCode(); EvGUj$
if(responseCode>=400) Og&0Z)%
{ =y,yQO
processErrorCode(responseCode); \K4CbZ,.
return -2; //-2 represent access is error 6Dr$*9
} PuUon6bZ
2uI`$A:
<.y^
String sHeader; 1*c0\:BQ;z
x~3>1Wr#M
} (GQDJp
for(int i=1;;i++) 8V53+]c$Y
{ i?P]}JENM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h!JjN$
//Utility.log(in.readLine()); 0X S' v,|
sHeader=httpConnection.getHeaderFieldKey(i); ~gzpX,{n
if(sHeader!=null) q)zu}m
{ RY'\mt"W2
if(sHeader.equals("Content-Length")) 0SGczgg
{ ( .6tz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wb}0-U{S'
break; hQW#a]]V:
} %]P@G^Bv
} .DV#-tUh
else ND99g
break; +kdU%Sm
} TF([yZO'
} sN[@mAoH
catch(IOException e){e.printStackTrace ();} |L~gNC
catch(Exception e){e.printStackTrace ();} .q;RNCUt
5p>]zij>
=f{Z~`3
Utility.log(nFileLength); }@Ll!,
0,i+
JY,l#?lM{
return nFileLength; hzf}_1
} 1>O0Iu
YJtOdgG|q
^!s}2GcS`
//保存下载信息（文件指针位置） w|U@jr*H]
private void write_nPos() f"}14V
{ W3{5Do.h
try{ -<VF6k<
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0%L$TJ.''
output.writeInt(nStartPos.length); Yhv`IV-s
for(int i=0;i<nStartPos.length;i++) :-jP8X
{ JeSkNs|vB
// output.writeLong(nPos); C(Bar#
output.writeLong(fileSplitterFetch.nStartPos); I{P$B-
output.writeLong(fileSplitterFetch.nEndPos); 0z2R`=)
} I7-PF?
output.close(); \=:g$_l
} (Gb{ckzs
catch(IOException e){e.printStackTrace ();} ]r{#268
catch(Exception e){e.printStackTrace ();} oeqJ?1=!
} (fjXp75
j?` D\LZhf
.dq.F#2B;
//读取保存的下载信息（文件指针位置） UqQZ A0e
private void read_nPos() uX5B>32
{ %L,,
try{ 9~ .BH;ku
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Mh@ylp+q
int nCount = input.readInt(); U";Rp&\3;
nStartPos = new long[nCount]; Lm2cW$s
nEndPos = new long[nCount]; '{_tDboY
for(int i=0;i<nStartPos.length;i++) kJ:5msKwC
{ !c;p4B)
nStartPos = input.readLong(); ,}xC) >
nEndPos = input.readLong(); OaVL NA^{
} ZkG##Jp\>
input.close(); =:T:9Y_i
} :zTj"P>"I
catch(IOException e){e.printStackTrace ();} +/^q"/f F
catch(Exception e){e.printStackTrace ();} 9#ay(g
} !{- 3:N7
$TUC?e9"h
{ l~T~3/i
private void processErrorCode(int nErrorCode) "PM:&v
{ u(Q(UuI
System.err.println("Error Code : " + nErrorCode); ]7ZC>.t
} ?q8g<-?
A^jm<~
_J#Hq 'K
//停止文件下载 5 BG&r*U
public void siteStop() I(eR3d:
{ *^m.V=
bStop = true; gnK!"!nL
for(int i=0;i<nStartPos.length;i++) 7 @Qlp$[F
fileSplitterFetch.splitterStop(); cnO4NUDv
Y2~{qY
=|^W]2W$
} Rf$6}F
} *8HxJ+[,[
//负责部分文件的抓取 }|,\?7,
**FileSplitterFetch.java X=}0+W
*/ biuo.OG]
package NetFox; k3eN;3#&
;^SgV
Xm+3`$<
import java.io.*; LA3,e (e
import java.net.*; `t"Kq+
Ft>8 YYyU
BuO J0$
public class FileSplitterFetch extends Thread { e 2&i
%zVv3p:
DEuW'.o>
String sURL; //File URL PhdL@Mr
long nStartPos; //File Snippet Start Position T+( A7Qrx%
long nEndPos; //File Snippet End Position a,\u|T:g
int nThreadID; //Thread's ID TW? MS em
boolean bDownOver = false; //Downing is over ;0{*V5A
boolean bStop = false; //Stop identical 2o}FB\4^i
FileAccessI fileAccessI = null; //File Access interface $fG/gYvI\
:O=Vr]Y8K
tV%\Jk),
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U}TQXYAg
{ mSp7H!
this.sURL = sURL; :36^^Wm
this.nStartPos = nStart; !7|9r$
this.nEndPos = nEnd; !I$RE?7eY
nThreadID = id; 1@Gv`{v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x=+H@YO\
} Qk?Jy<Ra
J?DyTs3Z
Z k_&Kw|
public void run() g*9>z)
{ fQ) ;+
while(nStartPos < nEndPos && !bStop) 7qp|Msf},
{ n\,W:G9AR7
WVFy ZpB
oZw#Nd
try{ ~<-h# B
URL url = new URL(sURL); 8=VX` X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SesO$=y
httpConnection.setRequestProperty("User-Agent","NetFox"); eGg#=l=
String sProperty = "bytes="+nStartPos+"-"; HX^ P9jXT
httpConnection.setRequestProperty("RANGE",sProperty); EwsJa3 `
Utility.log(sProperty); "[,XS`
wVX0!y6
^hJ,1{o
InputStream input = httpConnection.getInputStream(); vN+!l3O
//logResponseHead(httpConnection); K>~l6
*O2j<3CHf
~{{:-XkVB
byte[] b = new byte[1024]; $tJJ >"
int nRead; }P#gXG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ':@qE\(
{ iddT.
nStartPos += fileAccessI.write(b,0,nRead); v'=APl+_
//if(nThreadID == 1) (w fZ!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )kUw,F=6
} 7v_e"[s~
^W*/!q7H
oB@C-(M
Utility.log("Thread " + nThreadID + " is over!"); sa($3`d
bDownOver = true; A |B](MW%O
//nPos = fileAccessI.write (b,0,nRead); i)ctrdP-
} ~gD'up@$/
catch(Exception e){e.printStackTrace ();} 6fiJ' j@
} [z9i v~
} _!ed.h.r:
/r6DPR0\
2I
//打印回应的头信息 L $~Id
public void logResponseHead(HttpURLConnection con) wl4yNC
{ qJsEKuOs
for(int i=1;;i++) Nx"?'-3Hm
{ iGIaZ!j aW
String header=con.getHeaderFieldKey(i); YH9BJ
if(header!=null) j(rFORT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -JK+{<
Utility.log(header+" : "+con.getHeaderField(header)); 6{6tg>|L)
else l)Hu.1~
break; IM+PjYJ
} n9%rjS$
} BeRn9[
wFD.3!
9/Ls3U?
public void splitterStop() RB!g,u
{ ]KmYPrCl0
bStop = true; =J,:j[D(
} 711z-
p5*Y&aKj
Wd7*sa3T
} >HDK<1>
3f3?%9
ZO,]h9?4
/* _>*"6
**FileAccess.java `fH6E8N
*//文件访问(定位，写) @RjLDj+)S
package NetFox; mxIEg?r(
import java.io.*; n1QO/1} :
C-Mop,w
jH8F^KJM[
public class FileAccessI implements Serializable{ l}m@9 ~oC
#pZ3xa3R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Oq(JM $M
RandomAccessFile oSavedFile; m4EkL
long nPos; (efH>oY[
UwLa9Dn^
w$pv
public FileAccessI() throws IOException oyUf/Sl
{ h:|aQJG5
this("",0); X/Ae-1!
} #pIb:/2a_
(qaY,>je]D
'b-}KDP
public FileAccessI(String sName,long nPos) throws IOException ?vXy7y&4
{ H)5]K9D
oSavedFile = new RandomAccessFile(sName,"rw"); P%1s6fjU
this.nPos = nPos; |2mEowAd
oSavedFile.seek(nPos); L"IdD5`7T
} =KX:&GU
:5ji.g* 0
Ij"`pdp
public synchronized int write(byte[] b,int nStart,int nLen) J<'4(}^|
{ j}y"
int n = -1; +Ta7b)
try{ @6\8&(|
oSavedFile.write(b,nStart,nLen); =ahD'*R^A
n = nLen; E0GpoG5C
} U5" C"+ 3
catch(IOException e) BsxQW`>^y
{ <h(tW
e.printStackTrace (); <jxTI%'f59
} 8NpQ"0X
LdA&F& pI
BwbvZfV|
return n; 7dAa~!/(
} NJ3b Oq
4PNl3N3,n
B&"fPi
} @;pTQ 5 I
0rF{"HM~
@dGj4h.
/* pm^[ve
**SiteInfoBean.java r6"t`M
*/ 3rs=EMz:w
package NetFox; i: 1V\q%
Bisht%]^
rqifjsv
public class SiteInfoBean { JWC{"6
e)O6k7U$
!x[+rf
private String sSiteURL; //Site's URL xCGvLvFn
private String sFilePath; //Saved File's Path hmQD-E{Ab
private String sFileName; //Saved File's Name @va6,^)
private int nSplitter; //Count of Splited Downloading File #VtlXr>G
_.zW[;84b
;4%^4<+3
public SiteInfoBean() .Q4EmpByCg
{//nSplitter的缺省值为5 4?;1cXXA
//default value of nSplitter is 5 VcA87*pel
this("","","",5); nx84l7<
} X]M)T
]hc.cj`\W&
Vf,t=$.[Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J1hc :I<;
{ M{1't
sSiteURL= sURL; "2$C_aE
sFilePath = sPath; UJ2Tj+
sFileName = sName; !'[f!vsyM{
this.nSplitter = nSpiltter; Bzw~OB{!=J
AKejWh
9H`Q |7g(5
} 7&qunK'
['Hl$2 j
3t)07(x_B
public String getSSiteURL() ULNU'6
{ h:}oUr8
return sSiteURL; $b QD{ {
} mY+Jju1
$~75/
TW" TgOfd
public void setSSiteURL(String value) #"|</*%>
{ E.R,'Y;x
sSiteURL = value; g:7S/L0]
} D37N*9}
Usx8 U
7jQOwzj
public String getSFilePath() 9@9(zUS|
{ s3Pr$h
return sFilePath; m0DD|7}+
} @G@,)`p4?
ycz6-kEp
E_[|ZrIO&*
public void setSFilePath(String value) wuRQ H]N
{ JK))Cuh
sFilePath = value; G>&Tap>
} 1qp<Fz[
x1VBO.t=*
N_Q)AXr)
public String getSFileName() |`B*\\1
{ bFD vCF
return sFileName; w\ 4;5.$
} ux`)jOQ`Y]
O9?t,1
7}>Zq`]~
public void setSFileName(String value) #bc$[%_
{ a|?&
sFileName = value; t.Q}V5t{g
} Fjch<gAofS
(cAWT,
-!V+>.Oh
public int getNSplitter() z=%&?V
{ .,[NJ:l
return nSplitter; 3>asl54
} a@4 Zx
utOATjB.z
WRrCrXP
public void setNSplitter(int nCount) {x_SnZz&
{ Jy<hTd*q
nSplitter = nCount; kd55y
} ~C M%WvS
} R. :~e
E/+H~YzO
Rn?Yz^ 1q
/* 3<F\5|
**Utility.java tV.qdy/]}
*/ 8[v9|r
package NetFox; W3Gg<!*Uo
v\lhbpk
]]Bqte
public class Utility { w1;:B%!H
J n>3c
}Br=eaY
public Utility() vtx3a^
{ 80m<OW1
+9gI^Gt
+|0f7RB+R
} 7+]+S`p
WzinEo{f
//线程睡眠 TwfQq`
public static void sleep(int nSecond) [pY1\$,
{ 9!XXuMWU<
try{ fI<|]c}P&J
Thread.sleep(nSecond); [KcF0%a
} WR|n>i@m
catch(Exception e) xxy (#j$
{ v79k{<Ln
e.printStackTrace (); +jD*Jtb<
} sOVbz2\yb
} LC>bZ!(i#
simD<&p
//日志 !#[B#DZc(
public static void log(String sMsg) I@/s&$H`l
{ ;6)Onwx
System.err.println(sMsg); /`kM0=MMa
} B+VD53 V
?zpN09e
M7`iAa.}
public static void log(int sMsg) y1qJ
{ C<B+!16
System.err.println(sMsg); 'g5 Gdn
} c3__=$)'kP
} [ !<
vk><S|[n
O3JBS^;V2
/* ?mi1PNps#
**TestMethod.java OF1fS\P<>
*/ 'kb|!
package NetFox; FW@(MIH
Lk8[fFa4
"3;b,<0
public class TestMethod { |& Pa`=sp
,9.-A-Yw
Dg=!d)\
public TestMethod() ISDeLUihY
{ ///xx/weblogic60b2_win.exe $! R]!s
try{ 5jey%)=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WKvG|YRDq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o;"Phc.
SiteFileFetch fileFetch = new SiteFileFetch(bean); V48o+O
fileFetch.start(); elDt!9Pu
} FzzV%
catch(Exception e){e.printStackTrace ();} 1yd}F`{8UF
E[a|.lnV
Qq{>]5<
} %8c2d
2A(?9 R9&h
#V-0-n,`
public static void main(String[] args) mx=2lL`
{ Ad)::9K?J
new TestMethod(); vp4NH]fJ
} X:kr$
} I3hN7
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