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)); `]q>A']Dl
} t;?TXAA
for(int i=0;i<nEndPos.length-1;i++) {}W9m)I
{ CI~P3"`]
nEndPos = nStartPos[i+1]; ,8vqzI
} P`$"B0B)
nEndPos[nEndPos.length-1] = nFileLength; 3S97hn{|=
} .-[d6Pnw
} 06dk K)`
B"903g 1
ycr\vn t
//启动子线程 F*bmV>Qq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N!u(G
for(int i=0;i<nStartPos.length;i++) IQ`#M~:
{ fF"\$Ny
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aUBGp: (
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 64hl0'67y
nStartPos,nEndPos,i); z'(][SB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \U0p?wdr:
fileSplitterFetch.start(); k$u/6lw]IB
} C]xKdPQj%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \"X<\3z2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )<vU F]e~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J'%
nEndPos = " + nFileLength); Buue][[
// fileSplitterFetch[nPos.length-1].start(); n&`=.[+A
Rqk;!N
{}#W~1`
//等待子线程结束 )Ycjx~
//int count = 0; TCC([
//是否结束while循环 QNk\y@yKw
boolean breakWhile = false; C|@6rr9TA
{5$.:Y
.sO.Y<-fl
while(!bStop) 2}ttCm
{ 78iu<L+If
write_nPos(); Yb~[XS |p
Utility.sleep(500); ?_!} lg
breakWhile = true; ";&5@H|
aMxg6\8
IC1oW)
for(int i=0;i<nStartPos.length;i++) W[dK{?RB
{ /MErS< 6
if(!fileSplitterFetch.bDownOver) OF4iGFw
{ tqnvC UIE
breakWhile = false; :$>Co\D
break; 7V^\fh5~
} *kliI]BF]
} fO;#;p.
if(breakWhile) L=ala1{O
break; lf<?k
jO|D#nC
GkhaB(btk'
//count++; 8f""@TTp
//if(count>4) i#uc
// siteStop(); gJkk0wokC
} EH*Lw c
cTU%=/gbc<
r34q9NFT5
System.err.println("文件下载结束！"); O?6ph4'
} D4@'C4kL
catch(Exception e){e.printStackTrace ();} +A 4};]W|
} (1tb
i'[o,dbE
z'FpP
//获得文件长度 l7+[Zn/v *
public long getFileSize() o=&tT,z
{ TJ&Z/k3-
int nFileLength = -1; 8?YWE62
try{ {^Y0kvnd
URL url = new URL(siteInfoBean.getSSiteURL()); 9kpCn.rJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }i)^?@
httpConnection.setRequestProperty("User-Agent","NetFox"); ceW,A`J
3NLC~CJ
L.cGt"{
int responseCode=httpConnection.getResponseCode(); jm~qD T,
if(responseCode>=400) /2<1/[#
{ UBgheu
processErrorCode(responseCode); L~WC9xguDl
return -2; //-2 represent access is error 12Lc$\3P
} +d$l1j
-0 e&>H%
=;) M+"
String sHeader; lZt{L0
NoR=:Q 9e
fsA-}Qc
for(int i=1;;i++) B.J_(V+
{ }'"4q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $bGe1\
//Utility.log(in.readLine()); Fz3QSr7FU
sHeader=httpConnection.getHeaderFieldKey(i); FL,av>mV
if(sHeader!=null) zvDg1p
{ 9b8kRz[ c
if(sHeader.equals("Content-Length")) T!iRg=<bz
{ A`H&"A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "EE=j$8u+
break; $69ef[b
} GC<zL}
} 8|*=p4_fn
else M_ GN3
break; ,.g9HO/R1
} zRz7*o&l
} @S-p[u
catch(IOException e){e.printStackTrace ();} kY$vPHZpN
catch(Exception e){e.printStackTrace ();} +FYQ7UE
0Xke26ga
dV:vM9+x
Utility.log(nFileLength); M.[A%_|P
#Q6.r.3@x
A18&9gY
return nFileLength; t!u{sr{j=
} GOzV#
h/AL`$
6{qI
//保存下载信息（文件指针位置） 5W(S~}
private void write_nPos() !alO,P%>r
{ Y(`# J[
try{ }+" N '
output = new DataOutputStream(new FileOutputStream(tmpFile)); .QaHE`e{
output.writeInt(nStartPos.length); !OO{qw(*g
for(int i=0;i<nStartPos.length;i++) 8%Wg;:DZx
{ M[Kk43;QY!
// output.writeLong(nPos); dWCUZ,6}
output.writeLong(fileSplitterFetch.nStartPos); y*AB=d^
output.writeLong(fileSplitterFetch.nEndPos); 3=SN;cn
} 5GwXZ;(G
output.close(); ,z*-93H1
} /{j")
catch(IOException e){e.printStackTrace ();} UB4M=R|
catch(Exception e){e.printStackTrace ();} z@_9.n]
} *>ilT5q
y'a(>s(
WC?}a^ 8
//读取保存的下载信息（文件指针位置） !JkH$~
private void read_nPos() 0UHX Li47Y
{ nhUL{ER
try{ F$;vPAxbK"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )bM #s">Y
int nCount = input.readInt(); }iK_7g`yKa
nStartPos = new long[nCount]; vfh0aW-O
nEndPos = new long[nCount]; !Gphs`YI
for(int i=0;i<nStartPos.length;i++) `wyX)6A|bt
{ zeXMi:X
nStartPos = input.readLong(); ^aW?0qsH
nEndPos = input.readLong(); %o~w
} %/^kr ZD
input.close(); bwo{ Lw~
} Cw=wU/)
catch(IOException e){e.printStackTrace ();} ic"n*SZa
catch(Exception e){e.printStackTrace ();} )LA^j|Y}
} sF/X#GG-
4-?'gN_
a-`OE"
private void processErrorCode(int nErrorCode) pY3N7&m\:
{ 0P5!fXs*
System.err.println("Error Code : " + nErrorCode); gAx8r-` `
} rQncW~
wGqQR)a
H3#xBn>9
//停止文件下载 O\5*p=v
public void siteStop() /f_c?|
{ =,aWO7Pz
bStop = true; R|Oy/RGY$
for(int i=0;i<nStartPos.length;i++) LNp%]*h
fileSplitterFetch.splitterStop(); iwHy!Vi-5
brQkVt_)EE
/nK)esB1L
} ,RkL|'1l
} ~IHjj1s
//负责部分文件的抓取 "EoC7 1
**FileSplitterFetch.java X^tVq..0
*/ hIj[#M&6
package NetFox; XFeeNcqF
XA[GF6W,Y
q\qV~G`
import java.io.*; XUD/\MoV
import java.net.*; ~&/|J)}
&FWPb#
xM1>kbo|
public class FileSplitterFetch extends Thread { n'/w(o$&
7Q<uk[d0
VV(>e@Bc4
String sURL; //File URL H=vrF-#
long nStartPos; //File Snippet Start Position c<V.\y0x
long nEndPos; //File Snippet End Position _tfZg /+)
int nThreadID; //Thread's ID o7feH 6Sh
boolean bDownOver = false; //Downing is over S9Fg0E+J
boolean bStop = false; //Stop identical U.oxLbJ`
FileAccessI fileAccessI = null; //File Access interface @:@0}]%z9
'3>kDH+
^4LkKYMS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,jBd3GdlZ
{ khl(9R4a
this.sURL = sURL; {xw*H<"f<
this.nStartPos = nStart; k]<
this.nEndPos = nEnd; }>JFO:v&
nThreadID = id; y2V9!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0s = h*"[
} d\`A ^
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#&.&Uu$
public void run() (Rvke!"B
{ (NUk{MTX
while(nStartPos < nEndPos && !bStop) cL&V2I5O
{ I)ub='+&;
lgZ3=h
Lj"~6l`)
try{ sXI_!)H
URL url = new URL(sURL); rE"`q1b#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @v9PI/c
httpConnection.setRequestProperty("User-Agent","NetFox"); >Fm}s,
String sProperty = "bytes="+nStartPos+"-"; *=L3bBu?
httpConnection.setRequestProperty("RANGE",sProperty); aG?ko*A;
Utility.log(sProperty); Wy%q9x]}
4NL TtK
vq*N
InputStream input = httpConnection.getInputStream(); 2q J}5
//logResponseHead(httpConnection); Qi|jL*mj&
CzxU @
vV1F|
byte[] b = new byte[1024]; 9Y1&SEsNX
int nRead; `G\uTCpk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ahkSEE{
{ k,M%/AXd
nStartPos += fileAccessI.write(b,0,nRead); T#^
//if(nThreadID == 1) < pI2}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D;)Tm|XizW
} $j^Jj
eX9{wb(
go/]+vD
Utility.log("Thread " + nThreadID + " is over!"); >`p`^:
bDownOver = true; <3z]d?u
//nPos = fileAccessI.write (b,0,nRead); p~I+ZYWF'
} [AQ6ads)
catch(Exception e){e.printStackTrace ();} `pzp(\lc
} _{&znXf>?6
} =)m2u2c M
A1@tp/L=o
STs~GOm-
//打印回应的头信息 J&S$F:HM
public void logResponseHead(HttpURLConnection con) ?U~C= F?K
{ bT}P":*y
for(int i=1;;i++) LF <fp&C)h
{ aOfL;I
String header=con.getHeaderFieldKey(i); T5NO}bz
if(header!=null) }kI-UEn$EP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?8. $A2(Xw
Utility.log(header+" : "+con.getHeaderField(header)); {bL6%._C
else S*],18z?
break; q=ZLSBZ
} ji<b#YO4
} 0/S|P1!b
,rc5r3
WM NcPHcj
public void splitterStop() vb)Z&V6(
{ vL@N21u
bStop = true; {<iIL3\mC
} MPA<?
r]Bwp i%
] o tjoM
} jI(~\`
<",4O
{NXc<0a(
/* f:\jPkf'
**FileAccess.java .2/(G{}U
*//文件访问(定位，写) LEvdPG$)
package NetFox; AZt~ \qf
import java.io.*; &Eg>[gAIlp
NqvL,~1G
!OekN,6
public class FileAccessI implements Serializable{ o0&jel1a
o!^':mll
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c 6@!?8J
RandomAccessFile oSavedFile; Teu4;
long nPos; 6tB-
<Rob.x3
>3s9vdUp4h
public FileAccessI() throws IOException x0@J~ _0
{ A;m)/@
this("",0); !L:!X88
} A>(m}P
==`K$rM
YFOSv]w
public FileAccessI(String sName,long nPos) throws IOException FYR%>Em
{ ?~uTbNR
oSavedFile = new RandomAccessFile(sName,"rw"); RzQ1Wq
this.nPos = nPos; GiJ|5"
oSavedFile.seek(nPos); ,n TC7V
} Y*;Z(W.V#
&F9BaJ
{\jh?P|
public synchronized int write(byte[] b,int nStart,int nLen) JDfkm+}uY
{ 'A .c*<_
int n = -1; :,%~rR
try{ 1O*5>dkX;%
oSavedFile.write(b,nStart,nLen); /cF 6{0XS9
n = nLen; p#hs8xz
} hH[UIe
catch(IOException e) xCFk1%qf
{ E ;65kZ
e.printStackTrace (); \k/ N/&;
} _O2},9L n
c<L^ 1,G2
F&.iY0Pt
return n; I!&|L0Qq
} z(d@!Cd
=`[08
)(~4fA5j)
} IlG)=?8XZ
V$%%nG uE
w'z?1M(*
/* (g xCP3
**SiteInfoBean.java iM+K&\{_h
*/ Kj,C9
package NetFox; vJVL%,7
_"_ W KlN
a_XM2dc%
public class SiteInfoBean { /uS(Z-@
z=:<]j#=
T{3C3EE?]
private String sSiteURL; //Site's URL l_GvdD
private String sFilePath; //Saved File's Path h\".TySz
private String sFileName; //Saved File's Name S453oG"
private int nSplitter; //Count of Splited Downloading File /=I&-gxC
h~haA8i?{
{Ak{ ct\t
public SiteInfoBean() x=Z\c,@O
{//nSplitter的缺省值为5 HMGby2^+
//default value of nSplitter is 5 Qg;A (\z
this("","","",5); |#8u:rguy
} \9;u.&$mNB
sG`||Kb;n
0yr=$F(]s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O9*cV3}H
{ B2t.;uz(,
sSiteURL= sURL; XlIRedZ{
sFilePath = sPath; HSGM&!5mW
sFileName = sName; *5Upb,**
this.nSplitter = nSpiltter; zJJ KLr;
=<w6yeko
6, \i0y5n
} \~!9T5/*
e@'rY#:u
0Ci\(
public String getSSiteURL() k_%2Ok
{ cnr&%-
return sSiteURL; {Ts@#V=:
} Rr! PU
3|zqEGT*
f"t\-ux.b
public void setSSiteURL(String value) Li~(kw3
{ fD+'{ivN4
sSiteURL = value; ?hUC#{
} u4TU"r("A
9Axk-c
TP'
public String getSFilePath() wHm{4
{ ,ButNBv
return sFilePath; =g4^tIYq
} *0]E4]ZO
pOP`n3m0
o`S|
public void setSFilePath(String value) Sx)b~*
{ T|^rFaA
sFilePath = value; %7=B?c|
} x*td nor&
ETvn$ Jdp
m[ *)sm
public String getSFileName() @ hH;d\W#
{ i? 5jl&30
return sFileName; MMg"G6?
} MGpP'G:v
9bvzt8pc
5W"&$6vj
public void setSFileName(String value) {<0=y#@u
{ I>ks H
sFileName = value; 3wZA,Z
} M{I8b<hY
am,UUJ+h>
ol]"r5#Q_H
public int getNSplitter() JJ@O5
{ gwE#,OY*
return nSplitter; -oc@$*t
} tDj~+lmdN
!K a!f1
,b;eU[!]
public void setNSplitter(int nCount) :SFcnYv0
{ $s$j</.q
nSplitter = nCount; )>,; GVu"
} oc.H}Eb%Z
} mFCDwh]
eytd@-7uX
UHr0J jQK
/* ,iKEIxA!
**Utility.java *m2{6N_
*/ [/_M!&zz2
package NetFox; rPaUDR4U
^8dd
SF$'$6x}
public class Utility { I|jGu9G
l)y$c}U
,>(/}=Z.
public Utility() Y rq-(
{ .b'o}DLa
tXj28sh$
W vh3Y,|3
} bvHF;Qywg
5 :O7cBr
//线程睡眠 ^Mw>'*5^
public static void sleep(int nSecond) s;oDwT1
{ -h=K]Y{`
try{ 2c?-_OCy;
Thread.sleep(nSecond); @C[]o.r
} j2GO ZKy
catch(Exception e) 8r"$o1!
{ ZJUTtiD
e.printStackTrace (); Pl|e?Np
} 7R9S%
} qRXQL"Pe_l
E]G#"EV!Y
//日志 &Xr@nt0H
public static void log(String sMsg) >uMj}<g#Z?
{ K_\fO|<k
System.err.println(sMsg); 3SbtN3
} z[xi
=HJ)!(
e[txJ*SuO
public static void log(int sMsg) qmzg68
{ q5X\wz2N
System.err.println(sMsg); Rw4"co6
} qJq49}2
} K-D{Z7J^l
hh\\api
s>}ScJZK
/* ` VL`8
**TestMethod.java ;CbQ}k
*/ h-0sDt pR
package NetFox; \@yx;}bdI
Az+}[t
3#)I7FG
public class TestMethod { ]"'$i4I{R
~jK'n4
d*7nz=0&$
public TestMethod() WfbG }%&J
{ ///xx/weblogic60b2_win.exe r>fx55dw
try{ oK;.|ja
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1r6>.&p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cID{X&or
SiteFileFetch fileFetch = new SiteFileFetch(bean); #:rywz+
fileFetch.start(); YGp8./ma<I
} q,k/@@Qd9
catch(Exception e){e.printStackTrace ();} FBit/0
21Z}Zj
fmH"&>Loc
} <uGc=Du
fIOI
I[|5 DQ
public static void main(String[] args) 9IFK4>&O6
{ xE/r:D#
new TestMethod(); [t^Z2a{
} jYAD9v%
} 63b?-.!b
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