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)); HU'E}8%t6
} FJ[(dGKeE
for(int i=0;i<nEndPos.length-1;i++) a[JgR/E@x
{ u@|yw)
nEndPos = nStartPos[i+1]; #\M<6n{
} EagI)W!s[
nEndPos[nEndPos.length-1] = nFileLength; fAm2ls7c
} lk'RWy"pw
} $H9xM
C/$IF M<
lwB!ti
//启动子线程 s-DtkO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w])Sz*J
for(int i=0;i<nStartPos.length;i++) &S{F"z
{ KG?]MVXA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T<?;:MO88
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >ylVES/V
nStartPos,nEndPos,i); >9klh-f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); doa$ ;=wg
fileSplitterFetch.start(); Q7s1M&K
} z(=:J_N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =wQ=`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LSs={RD2+p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S&0x:VW
nEndPos = " + nFileLength); p[$I{F*a
// fileSplitterFetch[nPos.length-1].start(); {J]|mxo
8,=$>@u
~E\CAZ
//等待子线程结束 ^q6~xC,/
//int count = 0; x{- caOH
//是否结束while循环 +1y#=iM{
boolean breakWhile = false; {xr]xcM'b
@PI\.y_w
(/Mc$V
while(!bStop) 6 qq7:
{ h Na<LZ
write_nPos(); wVVe L$28
Utility.sleep(500); AjS5
breakWhile = true; oMVwIdf
j{PX ~/
)<|TEp4r-
for(int i=0;i<nStartPos.length;i++) Q&J,"Vxw
{ : ?V;
if(!fileSplitterFetch.bDownOver) ?-f>zx8O
{ o6r4tpiR5
breakWhile = false; `#]\Wnp~y
break; Dn[1BWM/7
} `4=b|N+b"
} JjmL6(*ui
if(breakWhile) ymzm x$o=
break; YJy*OS_&
HT&0i,`
3%} Ma,
//count++; cm]]9z_<
//if(count>4) A>?fbY2n
// siteStop(); oxzNV&D[{`
} 7I|%GA_
1mX*0>
U,=K_oBAq
System.err.println("文件下载结束！"); x6t;=
} S|[UEU3FpB
catch(Exception e){e.printStackTrace ();} GXfVjC31z
} g{%';
UyQn onS
w.8~A,5}Dh
//获得文件长度 'GFzI:Xr
public long getFileSize() ]ok>PH]
{ W6~=?C
int nFileLength = -1; Zx_m?C_2_
try{ coWBKWF
URL url = new URL(siteInfoBean.getSSiteURL()); !r|X6`g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9<#D0hh$
httpConnection.setRequestProperty("User-Agent","NetFox"); BUb(BzC
ZwMw g t
<-F"&LI{<
int responseCode=httpConnection.getResponseCode(); =Wf@'~K0k"
if(responseCode>=400) %gaKnT(|r
{ QP#Wfk(C
processErrorCode(responseCode); wLtTC4D
return -2; //-2 represent access is error D}T,z
} ]c)SVn$6
BGX@n#:
h,x]
String sHeader; fDd!Mt
ca=e_sg
z7q2+;L
for(int i=1;;i++) .6K>"
{ o$O,#^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >-P0wowL
//Utility.log(in.readLine()); K +~v<F
sHeader=httpConnection.getHeaderFieldKey(i); k3 l
if(sHeader!=null) f[IchCwX
{ i.sq^]j
if(sHeader.equals("Content-Length")) guv@t&;t0
{ {<kG{i/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z(3"\ ^T
break; akQH+j
} vrzX%'
} U3}R^W~eb
else _ ^{Ep/ME=
break; ]D%k)<YK
} N-gRfra+8L
} H#inr^Xa
catch(IOException e){e.printStackTrace ();} E: GJ$I
catch(Exception e){e.printStackTrace ();} S F>D:$a
.jp]S4~
X}(0y
Utility.log(nFileLength); ^>Y%L(>
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7g)3\C
return nFileLength; ?N*0S'dY
} c~xo@[NaS
`a>vPW
>x4[7YAU{
//保存下载信息（文件指针位置） n5.>;N.*
private void write_nPos() (x qA.(F
{ Jj:6 c
try{ \w^QHX1+
output = new DataOutputStream(new FileOutputStream(tmpFile)); {ah=i8$
output.writeInt(nStartPos.length); *Xoscc
for(int i=0;i<nStartPos.length;i++) It4z9Gh
{ R`2A-c
// output.writeLong(nPos); L]d@D0.Z
output.writeLong(fileSplitterFetch.nStartPos); N;'HR)
output.writeLong(fileSplitterFetch.nEndPos); .gGvyscdH;
} |A0$XU{
output.close(); v9U(sEDq
} 6;cY!
catch(IOException e){e.printStackTrace ();} %i8>w:@NW
catch(Exception e){e.printStackTrace ();} IY6_JGe_w
} abeSkWUL(
DYlvxF`
:(>9u.>l?5
//读取保存的下载信息（文件指针位置） -l H>8+
private void read_nPos() mE`qvavP|/
{ >&QH{!(
try{ {X<4wxeTo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xn@0pL3B~
int nCount = input.readInt(); *ldMr{s<R
nStartPos = new long[nCount]; ]M;6o@hq
nEndPos = new long[nCount]; q9Sz7_K
for(int i=0;i<nStartPos.length;i++) .vS6_
{ 1?|6odc
nStartPos = input.readLong(); b$O_L4CP
nEndPos = input.readLong(); vt@Us\fI
} `t0f L\T
input.close(); Q)`gPX3F
} uxyTu2L7
catch(IOException e){e.printStackTrace ();} H'{?aaK|t
catch(Exception e){e.printStackTrace ();} }m%?&c
} `QdQ?9x{F
rAWl0y_m
+RV-VrV
private void processErrorCode(int nErrorCode) xwnoZ&h
{ ^Opy6Bqb
System.err.println("Error Code : " + nErrorCode); neh;`7~5@K
} H:-A; f!Z
x$GsDV
?[VpN2*
//停止文件下载 8i;)|z7
public void siteStop() ^Wfgwmh
{ IT`=\K/[4
bStop = true; ^qO=~U!{
for(int i=0;i<nStartPos.length;i++) !UoU#YU
fileSplitterFetch.splitterStop(); [W$Z60?RR
Hp}
6_<s=nTX
} c~UAr k S
} $i:||L^8p
//负责部分文件的抓取 ouVjZF@kS
**FileSplitterFetch.java ;,=h59`
*/ F|?'9s*;6G
package NetFox; :e]9T3Q
wB>S\~i
0[:9 Hb6
import java.io.*; Ae j
import java.net.*; 7grt4k
Bw<zc=%
x}&a{;
public class FileSplitterFetch extends Thread { ?96-" l
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Vp$wHB&
String sURL; //File URL ;DD>k bd
long nStartPos; //File Snippet Start Position ("E!Jyc!
long nEndPos; //File Snippet End Position ~sU?"V
int nThreadID; //Thread's ID )p<fL
boolean bDownOver = false; //Downing is over AB"1(PbG
boolean bStop = false; //Stop identical ZSPgci
FileAccessI fileAccessI = null; //File Access interface ?,:#8.9
!ml_S)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5U{4TeUH
{ -/UXd4S
this.sURL = sURL; b>QM~mq3^I
this.nStartPos = nStart; tyuk{*Me:
this.nEndPos = nEnd; jefNiEE[
nThreadID = id; - LiPHHX<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8nIMZV
} ^+.t-3|U
OyJsz]b} M
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public void run() HX3D*2v":
{ @1v3-n=
while(nStartPos < nEndPos && !bStop) kz0I2!bt
{ Y .
>X[|c"l.
=!(*5\IM
try{ X_u@D;$
URL url = new URL(sURL); ;h9-}F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v._Egk0
httpConnection.setRequestProperty("User-Agent","NetFox"); %9T~8L @.
String sProperty = "bytes="+nStartPos+"-"; JFRpsv
httpConnection.setRequestProperty("RANGE",sProperty); }UKgF.
Utility.log(sProperty); \[hn]@@
9DOkQnnc
djsz!$
InputStream input = httpConnection.getInputStream(); K/vxzHSl
//logResponseHead(httpConnection); V(;55ycr
m7r j>X Y
W?qpnPW
byte[] b = new byte[1024]; uw Kh
int nRead; VY/|WD~"CW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }+Rgx@XZ\
{ s, n^
nStartPos += fileAccessI.write(b,0,nRead); EkJVFHfh
//if(nThreadID == 1) *wC\w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /"""z=q
} 2J;kD2"!
tYs8)\{
onnI !
Utility.log("Thread " + nThreadID + " is over!"); t_jyyHxoZ:
bDownOver = true; N[qA2+e$Z
//nPos = fileAccessI.write (b,0,nRead); vG]GQ#
} x37/cu
catch(Exception e){e.printStackTrace ();} _urG_~q
} c ]>DI&$;J
} LH=d[3Y
|7 &|>
XkPv*%Er8
//打印回应的头信息 EKZA5J7kn
public void logResponseHead(HttpURLConnection con) |',M_ e]
{ z,pNb%*O
for(int i=1;;i++) -#LjI.
{ CO-Iar
String header=con.getHeaderFieldKey(i); /8xH$n&xoC
if(header!=null) wgY6D!Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9p<:=T
Utility.log(header+" : "+con.getHeaderField(header)); [34zh="o
else 1ZT^)/G
break; Wrmgu}q
} u`'ki7LA
} >M?H79fF2s
!|:RcH[
7\mDBG
public void splitterStop() :?HSZocf
{ %'N$lF"]
bStop = true; !*&4< _
} ,-@xq.D
807al^s x
sffhPX\I
} -i#J[>=w{C
@-0Fe9 n=
9khjwt
/* N99[.mErU
**FileAccess.java ^_@r.y]
*//文件访问(定位，写) =0,|/1~
package NetFox; ]?[zx'|
import java.io.*; {'NBp0i
"tqnx?pM
YWEYHr;%^?
public class FileAccessI implements Serializable{ 6`acg'sk>
o`idg[l.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K[kds`
RandomAccessFile oSavedFile; a$d:_,\"
long nPos; G.E[6G3
70_}S*T
Y?<)Dg.[
public FileAccessI() throws IOException Gb;99mE
{ z&O#v9.NE|
this("",0); *-0>3
} jh[ #p?:
H"eS<eT
13H;p[$
public FileAccessI(String sName,long nPos) throws IOException <PX.l%
{ z<!O!wX_aI
oSavedFile = new RandomAccessFile(sName,"rw"); >Iuzk1'S
this.nPos = nPos; {@3z\wMK$
oSavedFile.seek(nPos); IroPx#s:i
} J,??x0GDx,
GWhE8EDT
dPsLZ"I
public synchronized int write(byte[] b,int nStart,int nLen) FQ`(b3.
{ oB p3JX9_f
int n = -1; >z(wf>2J
try{ OZf6/10O/
oSavedFile.write(b,nStart,nLen); OVZP x%a
n = nLen; H9U.lb
} oe9lF*$/
catch(IOException e) V@[rf<,
{ `{[RjM`
e.printStackTrace (); SrFx_n
} |d[5l^6
Q=WySIF.
lCR!:~
return n; w9MoT.kI}
} M ,`w A
zEj#arSE4
?E6^!4=,
} qw<HY$3=
/&r|ec5
+"dv7
/* KFU%DU G
**SiteInfoBean.java V,Q4n%h1.
*/ 6kN:*
package NetFox; 0Qnd6mb
\9`#]#1bx5
^XG*z?Tt
public class SiteInfoBean { `<U5z$^QTw
?F_)-
H]&gW/=
private String sSiteURL; //Site's URL 7VAJJv3
private String sFilePath; //Saved File's Path b5<okICD
private String sFileName; //Saved File's Name 22&;jpL'?
private int nSplitter; //Count of Splited Downloading File lj4o#^lC
.1#kDM
iG#}`
public SiteInfoBean() E"6X|I n
{//nSplitter的缺省值为5 :Wc_Utt
//default value of nSplitter is 5 Qs%B'9")
this("","","",5); B2Z_]q$n*
} rOcg+5
MLr-, "gs
,$N#Us(Wa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `XJm=/f
{ "j^MB)YD
sSiteURL= sURL; dEp7{jY1O
sFilePath = sPath; 2%]Z Kd
sFileName = sName; ^nNitF
this.nSplitter = nSpiltter; T]9m:zX9s
[ *>AN7W
[c~kF+8
} uOd&XW
9AQxNbs
=n+ \\D
public String getSSiteURL() eTbg7"waA
{ ,6{iT,~@8
return sSiteURL; JeCg|@
} v-Qmx-N
wNYg$d0M
__Nv0Ru
public void setSSiteURL(String value) 69OF_/23
{ E=$p^s
sSiteURL = value; 2YlH}fnH
} j.%K_h?V5
H C0w;MG)
-1u9t4+`
public String getSFilePath() .4-,_`T?
{ >/=>B7
return sFilePath; \)/yC74r7(
} !5Sd2<N
y >+mc7n
VUwC-)
public void setSFilePath(String value) ;+/o?:AH
{ Nd@~>&F
sFilePath = value; M{mSd2
} 4a''Mi`u
:J/M,3
NxA)@9Q
public String getSFileName() Hy_;nN+e
{ 4(8xjL:
return sFileName; +&i +Mpb
} &JP-O60
gckI.[!b
2%u;$pj
public void setSFileName(String value) qfoD
{ {d<;BLA
sFileName = value; F?-R$<Cn2~
} aZ|=(]
5ZY<JA3
= ieag7!
public int getNSplitter() ~j9O$s~)
{ =]C]=
return nSplitter; c>"cX&
} UVQ7L9%?f
cyM-)r@YQV
jMNU ?m:
public void setNSplitter(int nCount) [U/(<?F{(
{ ._O
nSplitter = nCount; ACq7dLys,B
} w= P9FxB
} L+}n@B
Iw<i@=V
{0"YOS`3AX
/* *%/~mSx
**Utility.java ^-z=`>SrS"
*/ W ~f(::
package NetFox; JM- t<.
k%]=!5F
GL{57
public class Utility { /3B $(
re?s.djT
~{,X3-S_H
public Utility() ig}A9j?]
{ \p{5D`HY
e]=lKxFh&l
e[_m<e
} qMt++*Ls
R:Q0=PzDi#
//线程睡眠 L2Pujk
public static void sleep(int nSecond) uvP2Wgt
{ 6(d}W2GP
try{ Rp7ntI:
Thread.sleep(nSecond); rE9I>|tX
} 5NoI~X=
catch(Exception e) =L;] ;i
{ I`KQ|h0%
e.printStackTrace (); w }^ I
} ?`zXLY9q7
} } :=Tm]S
n_ lo`
//日志 &e-U5'(6v_
public static void log(String sMsg) r%:+$aIt
{ 8{`?=&%6
System.err.println(sMsg); 1$qh`<\
} ,1OyN]f3
c:Wze*vI;
GaX[C<Wt
public static void log(int sMsg) g<{xC_J
{ )q7UxzE+
System.err.println(sMsg); m<FOu<y
} 8#!i[UFdj
} 5%sE]Y#
xk&Jl#v
{:@tQdM:i8
/* w2_bd7Wp<
**TestMethod.java b)(?qfXWP
*/ ?v>ET2wD
package NetFox; -46C!6a
J+d1&Tw&
hW!)w
public class TestMethod { Z R/#V7Pj
fd-q3_f
OO[F E3F
public TestMethod() -'~LjA(
{ ///xx/weblogic60b2_win.exe b#7{{@H
try{ S26MDLk`R3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~/.7l8)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]Oq[gBL"A
SiteFileFetch fileFetch = new SiteFileFetch(bean); .9Y)AtJTS
fileFetch.start(); ~3uP6\F
} 5j~$Mj`
catch(Exception e){e.printStackTrace ();} .tD*2
o,|[GhtHqs
[1.+HyJ}
} >4t+:Ut:
UTXSeNP
g8PTGz
public static void main(String[] args) 0RoU}r@z4
{ `ZC<W]WYX/
new TestMethod(); EkziAON
} pAT7)Ch
} fbUr`~Y"
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