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)); U~u6}s]:
} dCf'\@<<
for(int i=0;i<nEndPos.length-1;i++) Bo](n*i
{ p`E|SNt/W
nEndPos = nStartPos[i+1]; >cwJl@wx-
} <r_P? lZW
nEndPos[nEndPos.length-1] = nFileLength; >5Q^9 9V
} (uuEjM$3%
} Pi&fwGL
B|]t\(~$[
,(@Y%UW:
//启动子线程 Dg9--wI}I9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;ZxK3/(7
for(int i=0;i<nStartPos.length;i++) rQd1Ch
{ boC>N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h3UZ|B0=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Gx(KN57D
nStartPos,nEndPos,i); wf~5lpI[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :,h=2a_ 8
fileSplitterFetch.start(); {<- ouD
} %8Z|/LGg
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pqr Ou
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7':5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (]zl$*k
nEndPos = " + nFileLength); k=h/i8i2z
// fileSplitterFetch[nPos.length-1].start(); 5p]urfN-f
WryW3];0OR
)*^OPVt
//等待子线程结束 >j(I[_g
//int count = 0; gZ`#tlA~
//是否结束while循环 iGEQXIr3
boolean breakWhile = false; E i\J9zt
)RAv[U1
SxLHFN]
while(!bStop) r 48;_4d)D
{ q_9N+-?{7
write_nPos(); ;3.T* ?|o
Utility.sleep(500); >+A1 V[
breakWhile = true; +,vJ7
jt'Y(u]2
k$$S!qi#
for(int i=0;i<nStartPos.length;i++) O)$N}V0
{ WQIM2_=M
if(!fileSplitterFetch.bDownOver) GDo)6du
{ c"%_]7
breakWhile = false; Gg}LC+Y
break; y]E)2:B[d
} UijuJ(Tle
} !~|"LA!jn
if(breakWhile) w{YtTZp3
break; JL]k:i^`A
&geOFe}R
5H'b4Cyi`
//count++; @ 2%.>0s.
//if(count>4) 6S! lD=
// siteStop(); m5'__<
} 2kp|zX(
A3 Rm0
%4r!7X|O<
System.err.println("文件下载结束！"); =XRgT1>e
} |04}zU%N
catch(Exception e){e.printStackTrace ();} ~Me&cT8
} C~ }Wo5
xdbu|fC
WoClTb>F
//获得文件长度 -Iruua7b
public long getFileSize() IJ #v"! D
{ 5JU(@}Db
int nFileLength = -1; 6gg#Z
try{ <750-d!
URL url = new URL(siteInfoBean.getSSiteURL()); bAy5/G!_R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); st'?3A
httpConnection.setRequestProperty("User-Agent","NetFox"); $:-= >
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int responseCode=httpConnection.getResponseCode(); R+ #.bQg
if(responseCode>=400) YVZSKU
{ qs8K jG@
processErrorCode(responseCode); 3*2&Fw!B
return -2; //-2 represent access is error {Gb)Et]<
} gk_Xu
<4!&iU+;
R^u^y{ohr
String sHeader; sxC{\iLY%
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g*w-"%"O
for(int i=1;;i++) .2(@jx,[
{ >ihe|WN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qRP8dH
//Utility.log(in.readLine()); 9TXm Z
sHeader=httpConnection.getHeaderFieldKey(i); +}G>M=t::
if(sHeader!=null) k.? T.9
{ &' Nk2{
if(sHeader.equals("Content-Length")) $CQwBsYb=
{ j9L+.UVI,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C(%5,|6
break; ,rl <ye*&
} rY_C3;B
} -JyODW#j
else bbPd&7
break; i_ODgc`H
} )Ido|!]0d
} si mX
catch(IOException e){e.printStackTrace ();} z7l;|T
catch(Exception e){e.printStackTrace ();} `aWwF} +Y
2h? r![
^kR^ QL$
Utility.log(nFileLength); {'wU&!
->"h5h
gU 2c--`
return nFileLength; d8BK/b
} f@.Q%+!4
&_%+r5
<2@<r t{
//保存下载信息（文件指针位置） <hF~L k ,
private void write_nPos() @9kk f{?
{ 8Jy1=R*S
try{ \%4+mgiD
output = new DataOutputStream(new FileOutputStream(tmpFile)); :#&U95EC0
output.writeInt(nStartPos.length); T=p}By3a
for(int i=0;i<nStartPos.length;i++) ?=@Q12R)X
{ aab4c^Ms=
// output.writeLong(nPos); :PjUl
output.writeLong(fileSplitterFetch.nStartPos); G'}_ZUy#
output.writeLong(fileSplitterFetch.nEndPos); &LxzAL,3!
} /jL{JF>I
output.close(); RVKaqJ0e<
} ^%OH}Z`ly
catch(IOException e){e.printStackTrace ();} !#|fuOWe
catch(Exception e){e.printStackTrace ();} r`E1<aCr|
} {ZIFj.2
Mp@(/
hjp?/i%TQ
//读取保存的下载信息（文件指针位置） Z FrXw+
private void read_nPos() +uGP(ONY
{ v=Bh A9[
try{ N n-6/]d#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mBgx17K/-_
int nCount = input.readInt(); Y X{
nStartPos = new long[nCount]; "?0G^zu
nEndPos = new long[nCount]; xY}j8~k
for(int i=0;i<nStartPos.length;i++) ^5@"|m1
{ +&zuI
nStartPos = input.readLong(); 7Caap/L:
nEndPos = input.readLong(); Zz*mf+
} PQ#-.K
input.close(); Hr,lA(
} czsoD)N
catch(IOException e){e.printStackTrace ();} F-\8f(\
catch(Exception e){e.printStackTrace ();} ]3# @t:>
} 68br
+n~rM'^4/
9M~$W-5
private void processErrorCode(int nErrorCode) Pg8=
{ 8}`8lOE7
System.err.println("Error Code : " + nErrorCode); GDQg:MgX
} 2uR4~XjF
{kO:HhUg
J2k'Ke97o
//停止文件下载 <W|{)U?p
public void siteStop() kX .1#%Ex
{ b6$A@b
bStop = true; $mg h.3z0
for(int i=0;i<nStartPos.length;i++) m3!MHe~t
fileSplitterFetch.splitterStop(); TV>R(D3T/
8;BwzRtgT
p~;z"Z
} (2\ekct ^
} ~map5@Kd
//负责部分文件的抓取 aeLo;!Jh
**FileSplitterFetch.java /@}# KP=
*/ f2e$BA
package NetFox; m<LzB_G\
:<3;7R'5
$zA[5}{ZtQ
import java.io.*; 90696v.
import java.net.*; GIl{wd
f!Nc+
ZrT|~$*m`
public class FileSplitterFetch extends Thread { <;Z~ vZ]
-ns a3P
U~@B%Msb L
String sURL; //File URL Fm~}A4
long nStartPos; //File Snippet Start Position mNB ]e5;N
long nEndPos; //File Snippet End Position %z_b/yG
int nThreadID; //Thread's ID -@?>nLQb
boolean bDownOver = false; //Downing is over bN%MT#X
boolean bStop = false; //Stop identical ) G&3V
FileAccessI fileAccessI = null; //File Access interface p.Yg-CA
_BaS\U%1(
f5XcBW9E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WSccR
{ 1,D ^,
this.sURL = sURL; aL6 5t\2
this.nStartPos = nStart; %31K*i/]
this.nEndPos = nEnd; ?O^:j!C6
nThreadID = id; hUvH t+d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %pKs- n`
} h0QQP
J3E:r_+
u+FftgA
public void run() aVL%-Il}
{ j'b4Sbs-f
while(nStartPos < nEndPos && !bStop) 4KB?g7_*
{ Mo r-$a8
J, U~.c
j-E>*N}-_
try{ D"aQbQP
URL url = new URL(sURL); >(J!8*7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WoR**J?}w
httpConnection.setRequestProperty("User-Agent","NetFox"); 5 :>
String sProperty = "bytes="+nStartPos+"-"; 62E(=l
httpConnection.setRequestProperty("RANGE",sProperty); I9&<:`
Utility.log(sProperty); 2Ps`!Y5
56aJE .?<
:dc J6
InputStream input = httpConnection.getInputStream(); u3!!_~6,z
//logResponseHead(httpConnection); G?(:Z=
!.N=Y;@lY
~&|i'f[
byte[] b = new byte[1024]; c=E.-
int nRead; e+aQ$1^t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FJ. :*K[
{ jH/%Z5iu
nStartPos += fileAccessI.write(b,0,nRead); 9Dkgu^`
//if(nThreadID == 1) k(^b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f}d@G/L
} YH$`r6\S
\dbtdhT;Z
(~o+pp!
Utility.log("Thread " + nThreadID + " is over!"); 'm((G4
bDownOver = true; *Y?]="8c#;
//nPos = fileAccessI.write (b,0,nRead); f 8U;T$)
} j0M;2 3@[
catch(Exception e){e.printStackTrace ();} </Lqk3S-!
} hZG{"O!2s
} P3>2=qK"E(
8\_,Y ji
AG=1TZI"
//打印回应的头信息 >qZRIDE5$
public void logResponseHead(HttpURLConnection con) %uMsXa
{ y[eNM6p
for(int i=1;;i++) Y^f|}YO%y
{ K|!)<6ZsG7
String header=con.getHeaderFieldKey(i); P1jkoJ
if(header!=null) V!!'S h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Y~?.hs^
Utility.log(header+" : "+con.getHeaderField(header)); v:b%G?o
else |9JYg7<
break; I<#kw)W!
} 4K% YS
} o4795r,jz
Yq.@7cJ
,^T2hY`
public void splitterStop() ]kvE+m&p}^
{ '93&?
bStop = true; c" HCc]
} fTcRqov
@UBp;pb}=h
]sE^=;Pv?
} b`=rd 4cpU
9bvd1bKEW
Kep?=9r4+
/* ?whp_
**FileAccess.java O^hV<+CX
*//文件访问(定位，写) ]e9kf$'
package NetFox; I}{eYXh
import java.io.*; @n3PCH6:Ao
}%|OnEk"
1uE[ %M
public class FileAccessI implements Serializable{ }zi6F.
~yg9ZM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _^ZII
RandomAccessFile oSavedFile; {:cA'6f.b
long nPos; B dUyI_Ks:
6<R U~Gh
&kt#p;/p?
public FileAccessI() throws IOException SuSZ,>
{ Kxn=iv^Ir
this("",0); !Ai;S
} yuq E
0&@6NW&Mu
48VsHqG
public FileAccessI(String sName,long nPos) throws IOException I-I5^s
{ ,$>Z= ~x*
oSavedFile = new RandomAccessFile(sName,"rw"); U/X ^
this.nPos = nPos; s,8%;\!C
oSavedFile.seek(nPos); !LA#c'
} IuL]V TY
u^$ CR
%8/$CR
public synchronized int write(byte[] b,int nStart,int nLen) x(Z@R\C-a
{ P7!Sc
int n = -1; 3m'6cMQ
try{ BDg /pDnwg
oSavedFile.write(b,nStart,nLen); G<I5%Yo6G
n = nLen; aY~IS?!;
} 'Z[R*Ikzq
catch(IOException e) dEnhNPeRl
{ }#1{GhsS
e.printStackTrace (); Q*5d~Yr]R
} |k0VJi
H#:Yw|t
9v A`\\9
return n; 4+0Zj+ q";
} 62q-7nV
Y;WrfO$J
-K{ID$!p
} !~#31kL&
q]aRJ`9f
[S%
/* gkjZX wp
**SiteInfoBean.java n >^?BU
*/ S_atEmQ
package NetFox; ZL Aq8X
uo^>95lkv
)_ y{^kn3^
public class SiteInfoBean { Vl%k:
aap:~F{]X
i8]r}a
private String sSiteURL; //Site's URL L r,$98Dy
private String sFilePath; //Saved File's Path w@4+&v>O
private String sFileName; //Saved File's Name @9L9c
private int nSplitter; //Count of Splited Downloading File k dqH36&<
@NF8?>!
Z'~5L_.]Ai
public SiteInfoBean() &*}S 0
{//nSplitter的缺省值为5 pfG:PrZ
//default value of nSplitter is 5 d$ /o\G
this("","","",5); 0WFZx Ad"
} [g{}0[ew
*w;f\zW
)]}*oO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A,osrv
{ h(fh |R<
sSiteURL= sURL; #KwFrlZ
sFilePath = sPath; 9o6y7hEQy
sFileName = sName; *e R$
this.nSplitter = nSpiltter; mMR[(
Qj~0vx!
pGC`HTo|
} 6 B )
X*sF-T$.
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public String getSSiteURL() ]loO5
{ $t]DxMd
return sSiteURL; _ n>0!
} sTb/l!=o
^ZsME,
a7Jr} "B
public void setSSiteURL(String value) tf,_4_7#$
{ r&qD!l5y
sSiteURL = value; BBX4^;t
} 0Ec -/
9H<:\-:
o8" [6Ys
public String getSFilePath() c}Qc2D3*
{ O;XF'r_
return sFilePath; Og["X0j
} uGv+c.~[j
1+^c3Dd`
%l,Xt"nS#
public void setSFilePath(String value) !#r]f9QP
{ 6l=n&YO
sFilePath = value; {Hb _o)S
} &I70veNY
jq[>PvR
=($qiL'h
public String getSFileName() @cx!m
{ i55']7+0
return sFileName; eRf8'-"#-
} +5Mx0s(5
6};Sn/8
HdGy$m`
public void setSFileName(String value) ev; &$Hc
{ O&)Y3O1
sFileName = value; -~5yl}
} xsa* XR
5=dg4"b]
!vsUL-
public int getNSplitter() 0ul2rZc
{ d#(xP2
return nSplitter; Z/0M9 Q%
} >Nov9<p
R(:q^?
)a.U|[:y[+
public void setNSplitter(int nCount) `aJ[ !O
{ 2@ad!h
nSplitter = nCount; -Oo$\=d
} 5%Q!R%
} | o?@Eh
V7&L+]!
JsH9IK:
/* wk3yz6V2
**Utility.java )qKfTtN`
*/ n>@(gDq
package NetFox; L0|u^J
0uZHH
Di&tm1R1
public class Utility { 2sXWeiJy;
Q{>{ e3z}
A5z`3T;1
public Utility() Tx!mW-Lt
{ %9M_*]
WB= gN:?
S]<Hx_[}
} NZ Xmrc{S
:+u?A
//线程睡眠 b&!X#3(KT
public static void sleep(int nSecond) $idYG<],
{ Y+D#Dv |
try{ Kj'uTEM
Thread.sleep(nSecond); s Ce{V*ua
} HK}C<gg
catch(Exception e) M[X& Q
{ 8&3G|m1-2
e.printStackTrace (); m:'fk;khN
} @P%&Dha
} wL}=$DN
f#[Fqkmj
//日志 kQYX[e7n
public static void log(String sMsg) d/"e3S1
{ 7VR+EV
System.err.println(sMsg); zX)uC<
} L"AZ,|wIk
&'R\yX<J)
]/U)<{6
public static void log(int sMsg) :V8 \^
{ Ix}:!L
System.err.println(sMsg); Jz3u r)|
} Og^b'Kx/
} `,xKK+~YG-
OJ&~uV>2
]mYY1%H8M
/* 'H97D-86/
**TestMethod.java >d_O0a*W-
*/ aQcJjF5x
package NetFox; G!wFG-Y}
X+iUT
b^rPw@
public class TestMethod { _%Jqyc"-
@'dtlY5;
I>:M1Yc0
public TestMethod() f~t*8rG~m
{ ///xx/weblogic60b2_win.exe WOquG
try{ RHeql*`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $O=m/l$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^hLAMaR
SiteFileFetch fileFetch = new SiteFileFetch(bean); `O*+%/(
fileFetch.start(); 9z,V]v=
} .%.J Q
catch(Exception e){e.printStackTrace ();} U }xRvNz
tvavI9
'`^`NI`
} iku) otUc
aO6w:IO
{4\(HrGNk
public static void main(String[] args) p"3_u;cN
{ ~^ Q`dJL
new TestMethod(); !5&% P b
} hjs[$,1
} fpu^
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