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)); 7MreBs(M
} vKppXm1
for(int i=0;i<nEndPos.length-1;i++) 1_uq46
{ :.B};;N
nEndPos = nStartPos[i+1]; ]qCAog
} |V{'W-` |[
nEndPos[nEndPos.length-1] = nFileLength; gCAWRNp
} aF4vNUeG
} hA)tad]
w~>V2u_-
}0c
//启动子线程 Ex35
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wbc*x
for(int i=0;i<nStartPos.length;i++) /X)fWO S6
{ Hk%m`|Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O.S(H1z<G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `i0RLGze
nStartPos,nEndPos,i); X_XeI!,b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xfw)0S
fileSplitterFetch.start(); "YD<pRVB
} #LEK?]y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a?%X9 +1A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DWDL|4 og
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RS@*/.]o
nEndPos = " + nFileLength); SLRQ3<0W_
// fileSplitterFetch[nPos.length-1].start(); (u@p[ncN}
`WHP#z
iF2/:iP
//等待子线程结束 y8jk9Tv
//int count = 0; -8&M^-
//是否结束while循环 t5n$sF
boolean breakWhile = false; ,6?L.L
+avu&2B
rwr>43S5<3
while(!bStop) _O~DJ"
{ 'VCF{0{H~
write_nPos(); MnUal}MO
Utility.sleep(500); n *|F=fl
breakWhile = true; .x7d!t:(D
~0r:Wcj x
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for(int i=0;i<nStartPos.length;i++) K:/%7A_{
{ eZs34${fN
if(!fileSplitterFetch.bDownOver) xS]=WO*
{ ,o\vumx
breakWhile = false; !u@e^J{Ao
break; 09pnM|8A
} G (Fi
} %c)^8k;I
if(breakWhile) k_.%(ZE
break; " cx\P,<
QcG4~DEX4
^.y}2
//count++; <hgt{b4
//if(count>4) mu0ER 3o
// siteStop(); "<x%kD
} ^0ZabR'
r8rU+4\8<
K1a$ m2
System.err.println("文件下载结束！"); AjB-&Z
} -4{sr| lm
catch(Exception e){e.printStackTrace ();} b_@MoL@A!
} dM8`!~#&PI
w$4fS
lpLjfHr
//获得文件长度 Mp9wYM*
public long getFileSize() _!kL7qJ"
{ %{g<{\@4(;
int nFileLength = -1; Dsc{- <v
try{ 1foy.3g-
URL url = new URL(siteInfoBean.getSSiteURL()); .<j\"X(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x\!Q[
httpConnection.setRequestProperty("User-Agent","NetFox"); lO>w|=<
-kT *gIJ}
E9t[Mb %0
int responseCode=httpConnection.getResponseCode(); }N!I|<"/
if(responseCode>=400) ju`x
{ lAz.I
processErrorCode(responseCode); u{maE ,
return -2; //-2 represent access is error H->J.5~,K
} V9qA.NV2
`Xvrf
[f,; +Ze
String sHeader; v<N7o8
8.bIP ju%v
W>+\A"
for(int i=1;;i++) E$dPu
{ VeidB!GyP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :hB/|H*=
//Utility.log(in.readLine()); ~#+ Hhc(
sHeader=httpConnection.getHeaderFieldKey(i); `)$'1,]u
if(sHeader!=null) G4][`C]8c
{ :786Z,')
if(sHeader.equals("Content-Length")) -t2bHhG
{ ?]SSmZpk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HM ;9%rtO
break; Svj%O(
} 1>bG]l1//
} F1%-IBe
else :r*skV|
break; FjD`bhw-
} vfPL;__{Y]
} zLdi
catch(IOException e){e.printStackTrace ();} EEmYfP[3
catch(Exception e){e.printStackTrace ();} Xl^=&!S>me
raRb K8CQ
v:kTZB
Utility.log(nFileLength); ["VUSa
"HSAwe`5jU
cXu"-/
return nFileLength; 8%v1[Wi
} WVlyR\.
GF[onfQY7
&|'k)6Rx
//保存下载信息（文件指针位置） qg6283'?
private void write_nPos() |%.V{vgP7
{ .jW+\mIX
try{ K9h{sC
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;(AVZxCM
output.writeInt(nStartPos.length); wd&Tf R4!
for(int i=0;i<nStartPos.length;i++) 7:'7EqM
{ V'y,{YpP
// output.writeLong(nPos); nS'hdeoW
output.writeLong(fileSplitterFetch.nStartPos); @*'$QD,
output.writeLong(fileSplitterFetch.nEndPos); ~_R8; b
} 0w[#`
output.close(); 60?/Z2w5
} uzjP!qO
catch(IOException e){e.printStackTrace ();} uBp"YX9rx
catch(Exception e){e.printStackTrace ();} x-0S-1M
} z4 4(
f&x7g.I
D/wX
//读取保存的下载信息（文件指针位置） 8V$pdz|[
private void read_nPos() 4,kdP)Md$
{ co^kP##Y
try{ *0M[lR0t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jinDKJ,n;
int nCount = input.readInt(); \=3V]7\&
nStartPos = new long[nCount]; . Z 93S|q
nEndPos = new long[nCount]; NJ\ID=3l
for(int i=0;i<nStartPos.length;i++) . AJ(nJ)
{ uEqL Dg
nStartPos = input.readLong(); NVqJN$z
nEndPos = input.readLong(); ^5n"L29V
} 3Q'Q %2
input.close(); Te&F2`vo
} 08*bYJu
catch(IOException e){e.printStackTrace ();} t;g=@o9YA
catch(Exception e){e.printStackTrace ();} <49Gsm&0
} I29aja
S[g{ )p)
imGg3'
private void processErrorCode(int nErrorCode) V?x&.C2Z
{ V80BO#Pk
System.err.println("Error Code : " + nErrorCode); ;la sk4|
} .dqV fa
yr=$a3web;
ro:B[XE
//停止文件下载 n1D,0+N=
public void siteStop() ?Ybgzb
{ f'501MJu
bStop = true; T \d-r#{
for(int i=0;i<nStartPos.length;i++) oT9dMhx8
fileSplitterFetch.splitterStop(); 90ZMO7_
wQ!C9Gp3e
9p|;Hh:
} PX7@3Y
} X)P;UVR0
//负责部分文件的抓取 |^: A,%>
**FileSplitterFetch.java l\+^.ezD
*/ R'M=`33M
package NetFox; Y|%s =0M
3.[ fTrzJ
J0xV\O !e
import java.io.*; %NH#8#';2
import java.net.*; /Z':wu\
3QNu7oo
|"t)#BUtL
public class FileSplitterFetch extends Thread { V $'~2v{_
hsYS<]
:xqhPr]e
String sURL; //File URL M.b1=Y
long nStartPos; //File Snippet Start Position ~MuD`a7#G
long nEndPos; //File Snippet End Position s#phs`v
int nThreadID; //Thread's ID aNd6#yU$
boolean bDownOver = false; //Downing is over A5U//y![{
boolean bStop = false; //Stop identical t}$WP&XRG<
FileAccessI fileAccessI = null; //File Access interface ollJ#i9
O{YT6&.S0
njhDrwN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O}$@|w(8;
{ +hoZW R
this.sURL = sURL; 6}b1*xQ
this.nStartPos = nStart; e+`LtEve0
this.nEndPos = nEnd; {w/{)BnPG
nThreadID = id; #J4{W84B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W|C>X=zTi
} v2Lx4:dzi
l~_]k
e+'PRVc
public void run() gXrXVv<)yw
{ Xaz`L
while(nStartPos < nEndPos && !bStop) ,gag_o{*a
{ )Q:.1Hgl
e u{
G3Z>,"w;=
try{ BC*)@=7fx
URL url = new URL(sURL); ;^fGQ]`4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j.}@9
httpConnection.setRequestProperty("User-Agent","NetFox"); by*?PhfF
String sProperty = "bytes="+nStartPos+"-"; ~f:y^`+Q[
httpConnection.setRequestProperty("RANGE",sProperty); {lNvKm)w
Utility.log(sProperty); r .&<~x
q oA?
aHhr_.>X
InputStream input = httpConnection.getInputStream(); kMJf!%L(
//logResponseHead(httpConnection); YB;q5[
?o0ro?9j
$_ &Lp\
byte[] b = new byte[1024]; .k_> BD];
int nRead; $C&y-Hnar
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H]zi>;D
{ 6R`q{}.
nStartPos += fileAccessI.write(b,0,nRead); B<V8:vOam
//if(nThreadID == 1) KM'*+.I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VaV(+X
} |+-D@22y
IF>dsAAI<
*F4"mr|\
Utility.log("Thread " + nThreadID + " is over!"); yX`5x^wVw
bDownOver = true; "xr=:[n[
//nPos = fileAccessI.write (b,0,nRead); -XuRQ_)nG
} "#ctT-g`6
catch(Exception e){e.printStackTrace ();} `]u!4pP"
} /"q wC
} H!H&<71-
4y:pj7h
L4Nn:9b
//打印回应的头信息 te<lCD6
public void logResponseHead(HttpURLConnection con) zYCS K~-GW
{ NZ{)&ObBRt
for(int i=1;;i++) !@.9>"FU
{ 5*~]=(BE
String header=con.getHeaderFieldKey(i); cN{(XmX5n
if(header!=null) )(4.7>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E((U=P}+g
Utility.log(header+" : "+con.getHeaderField(header)); goJK~d8M*
else Xc>M_%+R
break; ~4T:v_Q7g
} ulA||
} 3?n2/p 7=
AlVBhR`
@N(*1,s2
public void splitterStop() #8{U0 7]"
{ [9-&Lq_ g
bStop = true; M15jwR!:M
} ^9jrI
<SPT2NyX
G(Ky7SZ
} !0}SZ
%U<1]
&/\Q6$a
/* l-mt{2
**FileAccess.java 1xf Pe#
*//文件访问(定位，写) NKX,[o1
package NetFox; be->ofUYgs
import java.io.*; $FJf8u`
<< XWL:
XCP/e p
public class FileAccessI implements Serializable{ >QA;02
=sIkA)"!=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -wdd'G
RandomAccessFile oSavedFile; X5Fi , /H
long nPos; 5`3Wua
>508-)'
SJ%h.u@&@F
public FileAccessI() throws IOException Y!1x,"O'H
{ =Z(_lLNmh
this("",0); H1fKe=$1
} eX0due
Y}n$s/O:u8
DwNEqHi
public FileAccessI(String sName,long nPos) throws IOException G+SMH`h
{ # fe%E.
oSavedFile = new RandomAccessFile(sName,"rw"); ^U8^P]{R|
this.nPos = nPos; Mhwuh`v%
oSavedFile.seek(nPos); z,f
} ==ZL0 ][
^+MG"|)u~
%b1NlzB+
public synchronized int write(byte[] b,int nStart,int nLen) &BZjQK
{ UG,<\k&
int n = -1; \@eaSa
try{ /=i+7^
oSavedFile.write(b,nStart,nLen); />13?o#
n = nLen; 2 {I(A2
} "C~Zl&3
catch(IOException e) <J o\RUx
{ ],l}J'.8<V
e.printStackTrace (); |z 8Wh
} 4?c4GT9(6S
)wb&kug-
^77Q4"{W
return n; L"(k;Mfe
} >s;>"]
mE)I(< %
/4M~ 6LT`
} vxt<}h5J/!
+#LD@)G
Q|] 9
/* 5<RZht$i
**SiteInfoBean.java Fu$JI8
*/ huTWoMU
package NetFox; n]<>$
ibqJ'@{=e
1$toowb"Zy
public class SiteInfoBean { :H8`z8=0f{
)r`F}_CEL
(kFg2kG
private String sSiteURL; //Site's URL {+N7o7
private String sFilePath; //Saved File's Path WW[Gne
private String sFileName; //Saved File's Name )d =8)9B
private int nSplitter; //Count of Splited Downloading File @\}w8
T:|PSJc0
RK\$>KFE
public SiteInfoBean() TJ`Jqnh
{//nSplitter的缺省值为5 XnNU-UCX
//default value of nSplitter is 5 }}q_QD_
this("","","",5); Xt$o$V
} C#tY};t
^- H
hTS?+l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [39
{ YkJnZ_k/P
sSiteURL= sURL; %1UdG6&J_
sFilePath = sPath; RKtU@MX49
sFileName = sName; %kXg|9Bx!
this.nSplitter = nSpiltter; c-".VF
V")u y&Ob
+m]Kj3-z@
} gu|cQ2xV
=&-+{txs
[[A}MF*@
public String getSSiteURL() 0~GtK8^B
{ Sft+Gb6
return sSiteURL; +/|t8zFWs
} V'm4DR#M
}0f"SWO>
s+7#TdhA
public void setSSiteURL(String value) UR'P,
{ rL3 f%L
sSiteURL = value; M #)@!
} .j l|?o
X0&[cyP!
D%,AdR"m
public String getSFilePath() fKQq]&~ H
{ Q3P*&6wA
return sFilePath; "qxu9Hg!
} ;RW024
N~0~1 WQn
N[j*Q 8X_
public void setSFilePath(String value) a%NSL6
{ 0sGAC
sFilePath = value; G Z~W#*|V
} {OGv1\ol&
[W,}&
pdEUDuX
public String getSFileName() "+k^8ki
{ tZ*z.3\<
return sFileName; aPH6R<G
} o3kVcX^
e>~7RN
Puodsd
public void setSFileName(String value) @p$$BUb
{ v#`7,::
sFileName = value; n04lTME
} A.>L>uR
fXfO9{E
l6z}D;4
public int getNSplitter() {wy#HYhv
{ x2@W,?oPm
return nSplitter; QsC6\Gt#
} _7P#?:h
rFl6xM;F
n[tES6u
public void setNSplitter(int nCount) ZT1IN6;8W
{ ,I^:xw_
nSplitter = nCount; #a|.cm>6
} '~;vp
} S :%SarhBD
%wk3&EC.
o@j)clf
/* dVe
**Utility.java 45H(.}&f
*/ *r|)@K|
package NetFox; f>kW\uC
EI!e0V1!
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public class Utility { 8-uRn38
Y>i5ubR~
b@?pofZ`k
public Utility() R\^XF8n6/
{ p"k[ac{
zilM+BZ8
pon0!\ZT=
} wr{ [4$O
K! e51P
//线程睡眠 Ubf@"B
public static void sleep(int nSecond) '3eL^Aq
{ %FSY}65
try{ lJ$j[Y
Thread.sleep(nSecond); 1C]mxV=%
} 4o``t]
catch(Exception e) Tn"/EO^N
{ T2p;#)dP
e.printStackTrace (); }[c,/NH
} zd-qQ.j0
} (yxHXO9N
[Z$E^QAP
//日志 \\{+t<?J
public static void log(String sMsg) RZrQ^tI3"
{ Y24H` s1u/
System.err.println(sMsg); OS7^S1r-
} E whCX'Vaj
+%: /!T@@
6-!U\R2Z>
public static void log(int sMsg) _zF*S]9 X
{ Pt^SlX^MM
System.err.println(sMsg); zEN3Nn.8
} w(-h!d51+
} 7v{s?h->$
\;F_QV
*Z:'jV<
/* o b,%); m
**TestMethod.java I {&8iUN
*/ WPbG3FrL!
package NetFox; _oBJ'8R\
\Uh$%#}.
GO<,zOqvU
public class TestMethod { "B"Yfg[
( {}Z '
*%;+3SV
public TestMethod() RwyRPc_
{ ///xx/weblogic60b2_win.exe l:$i}.C
try{ TOC2[mc'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~&\}qz3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /CfgxPo
SiteFileFetch fileFetch = new SiteFileFetch(bean); &w"1VOV<
fileFetch.start(); lwj,8
} 0<'Q;'2* L
catch(Exception e){e.printStackTrace ();} /ij)[WK@
;.EW7`)Z
6X`i*T$.
} 5zk^zn)
H4{CiZ
'En|-M5
public static void main(String[] args) "s3eO
{ *uG!U%jY)
new TestMethod(); eemw I
} D_2~ 6
} R m^$Dn
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