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)); !(qaudX{>k
} Q_A?p$%;L
for(int i=0;i<nEndPos.length-1;i++) It8@Cp.dU
{ <Kq!)) J'
nEndPos = nStartPos[i+1]; 9K#U<Q0b'
} )7iYx{n
nEndPos[nEndPos.length-1] = nFileLength; @.KFWAm
} .p\<niu7
} C-VkXk
}_cX" s
T28Q(\C:}
//启动子线程 C?PgC~y)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +p &$`(
for(int i=0;i<nStartPos.length;i++) $-_@MT~
{ Ga$EM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @ {8xL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *iujJi
nStartPos,nEndPos,i); ]q@W(\I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MJ`BlE,Fmb
fileSplitterFetch.start(); zY\MzhkX,
} (k>I!Z/&2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M!]g36h[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U("m}^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gz`P~7-w:
nEndPos = " + nFileLength); !T26#>mV
// fileSplitterFetch[nPos.length-1].start(); 1&JB@F9!
yA-UXKT
i>AKXJ+
//等待子线程结束 RhumNP<M
//int count = 0; Ec|5'Kz]
//是否结束while循环 r`d.Wy Zj
boolean breakWhile = false; 8,&QY%8pX
$4]"g}_
m*H6\on:
while(!bStop) aZYs?b>Gm
{ {#uf#J|
write_nPos(); 5\P3JoH:Yg
Utility.sleep(500); y ;T=u(}
breakWhile = true; M9dUo7
atjrn:X
gX*i"Y#
for(int i=0;i<nStartPos.length;i++) YDo,9
{ EyPF'|Qtn
if(!fileSplitterFetch.bDownOver) J l9w/T
{ p+|(lrYC
breakWhile = false; jRo4+8
break; @`#"6y?
} >,QW74o
} /*) =o+
if(breakWhile) hS:j$je
break; $61*Xf+*
he1W22
)w!*6<
//count++; FVS@z5A8<=
//if(count>4) D}:M0EBS
// siteStop(); +G<9|-
} dnUiNs8
d(j|8/tpA
:ODG]-QF
System.err.println("文件下载结束！"); {w|KWGk2
} N"#=Q=)x
catch(Exception e){e.printStackTrace ();} 9W@Tf
} Fwv(J_'q
dEM=U;
iWu^m+"k
//获得文件长度 +b6kU{
public long getFileSize() '9#h^.
{ 5$p7y:
int nFileLength = -1; NHq*&xy
try{ 5qx$=6PT
URL url = new URL(siteInfoBean.getSSiteURL()); [}!obbM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m;"dLUb
httpConnection.setRequestProperty("User-Agent","NetFox"); f1UGDC<p9
&nEQ`3~F
by%k*y
int responseCode=httpConnection.getResponseCode(); yu]nK-Y7S
if(responseCode>=400) H@pF3gh
{ +~]LvZtI_
processErrorCode(responseCode); ~J,e^$u
return -2; //-2 represent access is error h$eVhN&Vv
} oN6 '%
|qTS{qQh{L
8q#Be1u<s2
String sHeader; - Ado-'aaS
8st~ O
13e @
for(int i=1;;i++) a)GT\1q
{ U:o(%dk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L=."<,\
//Utility.log(in.readLine()); $*[-kIy
sHeader=httpConnection.getHeaderFieldKey(i); bp?4)C*R
if(sHeader!=null) 2Sg,b8
{ wth*H$iF
if(sHeader.equals("Content-Length")) vD*9b.*
{ >X!A/;$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Swg%[r=p=
break; dF/HKBJ
} 4Sxt<7[f
} =ADdfuKN
else L 2:N@TP
break; RTR@p =ck
} 3m9ab"
} )dgooq
catch(IOException e){e.printStackTrace ();} 8f0Ytfhw
catch(Exception e){e.printStackTrace ();} 4?)-;Hx_X
t&99ZdE
M8wEy_XB1
Utility.log(nFileLength); gr y]!4Hy
'-[~I>o%
p&~= rp`E
return nFileLength; #XJ`/\E]
} zU$S#4/C
hB)TH'R{:
Ei[>%Ah
//保存下载信息（文件指针位置） 8bIwRVA2\
private void write_nPos() +P. }<
{ $-:j'e:j
try{ 6$|!_94>*)
output = new DataOutputStream(new FileOutputStream(tmpFile)); %+,7=Wt-
output.writeInt(nStartPos.length); J(JqusQd !
for(int i=0;i<nStartPos.length;i++) ^7 oXJu=
{ &0*=F%Fd
// output.writeLong(nPos); -h/KrB
output.writeLong(fileSplitterFetch.nStartPos); >^fkHbgNQ
output.writeLong(fileSplitterFetch.nEndPos); eQvdi|6
} S=bdue
output.close(); ^Gs=U[**
} ?nya;Z-~Hc
catch(IOException e){e.printStackTrace ();} .:)nG(7f<
catch(Exception e){e.printStackTrace ();} ') -Rv]xe
} Y$SwQ;wl
_;1H2o2f
^cy.iolt
//读取保存的下载信息（文件指针位置） JM-rz#;1
private void read_nPos() (?7=$z!h
{ M(_1'2
try{ }.j09[<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RC| t-(Z
int nCount = input.readInt(); ZdP2}w
nStartPos = new long[nCount]; -Ob89Z?2A
nEndPos = new long[nCount]; h7h[!>
for(int i=0;i<nStartPos.length;i++) BbqH02i
{ P}Ud7Vil;l
nStartPos = input.readLong(); j>70AE3[8
nEndPos = input.readLong(); ~20O&2
} 3LaqEj
input.close(); .;&1"b8G
} psHW(Z8G
catch(IOException e){e.printStackTrace ();} oMj;9,WK'
catch(Exception e){e.printStackTrace ();} tL!R^Tf
} C;&44cU/]
/v,H%8S
s28rj6q
private void processErrorCode(int nErrorCode) '[nH]N
{ 2}^fhMS
System.err.println("Error Code : " + nErrorCode); yA/b7x-c
} ,,-g*[/3
H[a1n' "<:
DfNX@gbo
//停止文件下载 LmKG6>Q1#1
public void siteStop() !h "6h
{ #~SQujgB
bStop = true; LK'|sO>|
for(int i=0;i<nStartPos.length;i++) E4nj*Lp~+
fileSplitterFetch.splitterStop(); %j3*j
8=%%C:
@+3@Z?!SZ
} (KF=v31_m
} X~ AE??
//负责部分文件的抓取 IC6}s
**FileSplitterFetch.java ; iK9'u
*/ &!lGx7zf
package NetFox; D6KYkN(,v
Gg3cY{7
~HH#aXh*
import java.io.*; n2JwZ?
import java.net.*; uD2v6x236
Ris5)*7
g`}+K U
public class FileSplitterFetch extends Thread { '01ifA^
x[,HK{U|t
jJN.(
String sURL; //File URL P1Z+XRWOM
long nStartPos; //File Snippet Start Position '7!b#if
long nEndPos; //File Snippet End Position D-[`wCa,
int nThreadID; //Thread's ID O<1qU M
boolean bDownOver = false; //Downing is over V_&>0P{q
boolean bStop = false; //Stop identical @GB~rfB[
FileAccessI fileAccessI = null; //File Access interface XCGJ~
[a&|c%h
Lwg@*:`d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0koC;(<n
{ uH}cvshv
this.sURL = sURL; o0nKgq'w|x
this.nStartPos = nStart; J8T?=%?=
this.nEndPos = nEnd; _dT,%q
nThreadID = id; W+&w'~M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k|^e=I
} m{/?6h 1
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vj+x(
public void run() 1Fado$# 7
{ n6PXPc
while(nStartPos < nEndPos && !bStop) zF6]2Y?k%
{ R(?g+:eCpM
JY+ N+c\
tntQO!pM
try{ C>d_a;pX
URL url = new URL(sURL); #)aUKFX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /mb?C/CI
httpConnection.setRequestProperty("User-Agent","NetFox"); ;$Eg4uX
String sProperty = "bytes="+nStartPos+"-"; @w)Vt$+b]
httpConnection.setRequestProperty("RANGE",sProperty); <_S>-;by
Utility.log(sProperty); l@x/{0
,Qgxf';+$
y^o*wz:D*
InputStream input = httpConnection.getInputStream(); bIR AwktD
//logResponseHead(httpConnection); R89;<,Ie
rKR2v(c
r>=)Y32Q
byte[] b = new byte[1024]; #PzRhanX
int nRead; p nS{W \Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >AT{\W!N
{ E1U~ew
nStartPos += fileAccessI.write(b,0,nRead); A8?uCkG
//if(nThreadID == 1) ~bp^Q| wM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jpl"KN?X
} H1]An'qz,
fa7I6 i
Pd99vq/
Utility.log("Thread " + nThreadID + " is over!"); n5Ad@Bg
bDownOver = true; [MmOPm}@
//nPos = fileAccessI.write (b,0,nRead); c:SA#.
} 6R%Ra
catch(Exception e){e.printStackTrace ();} RJ ,a}w[9
} 0-ISOA&
} #K|:BS
iRo/~(
*C~O[:6D
//打印回应的头信息 R^`#xQ
public void logResponseHead(HttpURLConnection con) S\"/=|\
{ ZGUhje!
for(int i=1;;i++) \/3Xb
{ VP|ga}(
String header=con.getHeaderFieldKey(i); EkV LSur
if(header!=null) #K8kz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g1JBssw&m
Utility.log(header+" : "+con.getHeaderField(header)); }B=`nbgIG7
else Y)kO"
break; :G/T{87H
} ,&Iw5E[
} l.ri]e
|[ymNG
A4lh`n5%
public void splitterStop() -6(u09mb_
{ )z'LXy8
bStop = true; |K(j}^1k
} sb"etc`w%-
y^vB_[6l
-nbo[K
} J. ;9-
:wn9bCom?M
f%Y'7~9bA
/* a?4'',~
**FileAccess.java Nwu,:}T
*//文件访问(定位，写) }g1V6`8&
package NetFox; %#!`>S)O
import java.io.*; Mqu>#lL
q*,g
_~?N3G
public class FileAccessI implements Serializable{ C NDf&dzX8
[89qg+z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y`5(F>/RQG
RandomAccessFile oSavedFile; h|^RM*x
long nPos; Zi&qa+F
Nf.6:=
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public FileAccessI() throws IOException cNi)[2o7
{ M_wqb'=
this("",0); {H FF|Dx
} O?<R.W<QI
oxN~(H)/ #
['p%$4i$
public FileAccessI(String sName,long nPos) throws IOException "PM!03rb
{ !;";L5()
oSavedFile = new RandomAccessFile(sName,"rw"); p>w{.hC@
this.nPos = nPos; M_-LI4>
oSavedFile.seek(nPos); vs3px1Xe#
} Bnju_)U5)
)Mw<e
6%/@b`vZ
public synchronized int write(byte[] b,int nStart,int nLen) OR4ZjogzY
{ Q{hXP*5
int n = -1; o"5Bg%H
try{ \`:X37n)0q
oSavedFile.write(b,nStart,nLen); 2&st/y(hs
n = nLen; %#!pAUP\&
} F9DY\EI
catch(IOException e) [X +E
{ Q~R7]AyR
e.printStackTrace (); S GAu.8Js
} *>x~`
CRK%%;=>
A#:5b5R
return n; %y(oY
} m&EJ@,H
';g]!XsY)
Vo@[
} mK!73<p_
jfxW9][
RQzcsO
/* 6$"gm$3O]
**SiteInfoBean.java o)_;cCr)q
*/ ?LP&VU1
package NetFox; 7_,)"J2^
"c[ D0{\{
uWs5+
public class SiteInfoBean { >EQd;Af
@lo6?9oNo
9mdp\A
private String sSiteURL; //Site's URL h?f)Bt}ry
private String sFilePath; //Saved File's Path vWbf5?
private String sFileName; //Saved File's Name ^a=,,6T
private int nSplitter; //Count of Splited Downloading File FX+;azE7
^rz8c+ly
f0S&_gt
public SiteInfoBean() p&Usl.
{//nSplitter的缺省值为5 NXQdyg,
//default value of nSplitter is 5 y:TLGQ0
this("","","",5); yQkj4v{
} Jvysvi{8
%G~f>
cN/8b0C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =c{/ Z
{ Im9^mVe
sSiteURL= sURL; < * )u\A
sFilePath = sPath; F8(6P1}E
sFileName = sName; \}O'?)(1
this.nSplitter = nSpiltter; ZJL[#}*
.}QR~IR'
gAcXd<a0
} X@$x(Zc
jl# )CEx
Yb57Xu
public String getSSiteURL() AL #w
{ Rk#@{_
return sSiteURL; F1skI _!
} &5Ai&<q"p
/IDfGAE
E9=a+l9
public void setSSiteURL(String value) ZqaCe>
{ ;x.xj/7
sSiteURL = value; sxq'uF(K
} $0[T=9q <+
l`s_Id#
9Ra_[1
public String getSFilePath() y993uP
{ 16q"A$
return sFilePath; ]=5nC)|
} ,U_p6TV5
T\g%.
RIXUzKLO
public void setSFilePath(String value) FsrGI (x?
{ k@qn'Zi
sFilePath = value; L&td4`2y
} ]|cL+|':y
!(=bH"P
b[<Q_7~2
public String getSFileName() v#EXlpS
{ =i jGB~
return sFileName; r"s <;
} P$MAURFm
Yrb[:;Y
a=LjFpv/]
public void setSFileName(String value) ?(Dk{-:T'
{ RC5b'+E&#
sFileName = value; t\2Lo7[Pu
} 1n7tmRl
qV57P6<
V!=1 !"}OG
public int getNSplitter() AhOvI{
{ rSU%!E+|<
return nSplitter; ;qT~81
} KD]8n]c
%a-:f)@
Jq1 Zb
public void setNSplitter(int nCount) !QoOL<(){
{ k8E'wN
nSplitter = nCount; ZRYs7 4<
} yQ)y#5/<6
} wTBp=)1)f
ax7]>Z=%d"
N~H9|CX
/* r0=Aru5n
**Utility.java ^Xjh?+WM
*/ OyVdQ".
package NetFox; 1-C 2Y`
.Y.\D\>~
@C40H/dE
public class Utility { |ToCRM
A!}Wpw%(/
:~JgB
public Utility() e6{}hiM
{ 1X\dH<B}
6yZfV7I
Cg NfqT0
} B42.;4"T
!$ikH,Bh
//线程睡眠 NNC@?A7
public static void sleep(int nSecond) PE1F3u>O
{ hz8Y2Ew
try{ >/;V_(
Thread.sleep(nSecond); N_TWT&o4
} 9kj71Jp&}
catch(Exception e) 4}sfJ0HhX
{ wkm;yCF+
e.printStackTrace (); SEm3T4dfzf
} ,ZyTYD|7
} <F!On5=W*
> t*+FcD
//日志 kDuN3
public static void log(String sMsg) il=y m
{ F0 WM&{v
System.err.println(sMsg); |]`\ak
} mjUln8Jc
wJA`e)>
DZGM4|@<7Y
public static void log(int sMsg) -Y'Qa/:7
{ mXnl-_
System.err.println(sMsg); +rS}f N$L.
} j`1%a]Bwc
} kmjSSh/t
&i*/}OZz
[@MV[$W5
/* yLFc?{~7
**TestMethod.java ]dB6--
*/ Jvt| q5
package NetFox; HJT}v/FZ
7r#U^d(
-AcLh0pc
public class TestMethod { 0?525^
:Rc>=)<7
E[bJ5o**#
public TestMethod() 8/X#thG
{ ///xx/weblogic60b2_win.exe -d?9Acd
try{ 3uO#/EbS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `MFw2nu@t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :JW!$?s8H
SiteFileFetch fileFetch = new SiteFileFetch(bean); xj~/C5@
fileFetch.start(); GEU:xn
} .-t#wXEi
catch(Exception e){e.printStackTrace ();} ehQ"<.sQ
/*J}7
y\&GPr
} fNOsB^Y
t b5k|
kW>Q9Nc=V
public static void main(String[] args) z+5l:f
{ ~[bS+]d!
new TestMethod(); i{zg{$U
} BG!;9Z{u
} 7r,'a{Rcn
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