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)); ,:POo^!/fT
} uFQ;}k;}
for(int i=0;i<nEndPos.length-1;i++) vYQ0e:P
{ $SAq/VHI1]
nEndPos = nStartPos[i+1]; Nn<TPT[,
} wdg,dk9e$
nEndPos[nEndPos.length-1] = nFileLength; =K'X:UM
} AjBwj5K
} _N!L?b83P
2"+8NfFl
yh0zW $
//启动子线程 *R1m=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IcmTF #{D
for(int i=0;i<nStartPos.length;i++) AyHhq8Y
{ eV:I :::
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A|>~/OW=@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gDbj!(tm
nStartPos,nEndPos,i); dsck:e5agZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V4I5PPz~
fileSplitterFetch.start(); 02B *cz_K
} D2N| A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K8[vJ7(!|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y,BzBUWK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M)4-eo
nEndPos = " + nFileLength); ~q]@Jp
// fileSplitterFetch[nPos.length-1].start(); _9yb5_
v?Dc3
FYPv:k
//等待子线程结束 dr3j<D-Q
//int count = 0; x(oL\I_Z
//是否结束while循环 to9~l"n.s
boolean breakWhile = false; !p$HS0c
P^9y0Q
}-YM>q
while(!bStop) JSz;>
{ pG"pvfEl9f
write_nPos(); ptJ58U$Bb
Utility.sleep(500); f_A'.oq+
breakWhile = true; }AfX0[!O
qw^kA?
cGF_|1`
for(int i=0;i<nStartPos.length;i++) 7#/->Y
{ a#3+PB#
if(!fileSplitterFetch.bDownOver) Ws;S=|9,7~
{ ='r86vq
breakWhile = false; Ff6l"A5
break; +/xmxh$ $
} l~ 3H"
} )[S~W 35
if(breakWhile) ^`M,ju
break; SURbH;[
9*s''=
u|]{|Ya'%
//count++; 6/{V#.(
//if(count>4) wf*G+&b d2
// siteStop(); {qxFRi#\k
} WX.6|
QuFzj`(
akR+QZ,)
System.err.println("文件下载结束！"); ])`+ 78
} x=-dv8N?
catch(Exception e){e.printStackTrace ();} RRSkXDU}
} >ZRCM
{#?$p i[
>O0z+tj
//获得文件长度 J)R2O{z
public long getFileSize() _(A9k{
{ $z1W0
int nFileLength = -1; sKE7U>mz|
try{ GJTKqr|1O
URL url = new URL(siteInfoBean.getSSiteURL()); (]cM;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VtM:~|v
httpConnection.setRequestProperty("User-Agent","NetFox"); )|52B;yZx
GFA D
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int responseCode=httpConnection.getResponseCode(); kdmmfw
if(responseCode>=400) :Q\Es:y
{ UXs=7H".
processErrorCode(responseCode); Cn\5Vyrl
return -2; //-2 represent access is error h>0R!Rl8
} op!ft/Yyb
:vsBobiJ
|:qaF
String sHeader; Tt^PiaS!
/NE<?t N
gc5u@(P"
for(int i=1;;i++) ;Gf,I1d}{
{ <V`1?9c7D1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sY|by\-c
//Utility.log(in.readLine()); |4E5x9J
sHeader=httpConnection.getHeaderFieldKey(i); WA'4y\N
if(sHeader!=null) UQX.
{ *yx5G-#?
if(sHeader.equals("Content-Length")) YJ6y]r K2,
{ v3zd>fDnRp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z~X\Z.
break; vw.rkAGY
} oc|%|pmRd<
} .$o0$`}
else %R?B=W7;Q
break; K[,d9j`^
} *s=jKV#
} +, IMN)?;z
catch(IOException e){e.printStackTrace ();} eT!*_.' e
catch(Exception e){e.printStackTrace ();} v d{`*|x
a9f!f %9
f0^;*Y
Utility.log(nFileLength); {pWb*~!k
0\B31=N(
#1,"^k^
return nFileLength; 0c-.h
} A'zXbp:%
?'xwr)v
(u_?#PjX
//保存下载信息（文件指针位置） XJ$mRh0`K
private void write_nPos() bU3P;a(
{ )2pOCAjL2
try{ "r+v^
output = new DataOutputStream(new FileOutputStream(tmpFile)); G5l?c@o
output.writeInt(nStartPos.length); uGoySt&;(
for(int i=0;i<nStartPos.length;i++) !^Ly#$-X
{ 6@rebe!&=
// output.writeLong(nPos); YK{E=<:
output.writeLong(fileSplitterFetch.nStartPos); l-v(~u7
output.writeLong(fileSplitterFetch.nEndPos); (GCeD-
} e>zv+9'Q
output.close(); eb` !
} Rfx}[!<{N
catch(IOException e){e.printStackTrace ();} c>$PLO^
catch(Exception e){e.printStackTrace ();} n%Rl$
} $~;h}I
-J6G=+s/
K|Cb6''
//读取保存的下载信息（文件指针位置） `SfBT1#5G
private void read_nPos() ;h"St0
{ B=<Z@u
try{ DN X-\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [^D~T
int nCount = input.readInt(); #F^0uUjq
nStartPos = new long[nCount]; ~K2.T7=
nEndPos = new long[nCount]; m)1+D"z
for(int i=0;i<nStartPos.length;i++) f{HjM? Mb3
{ S- N [
nStartPos = input.readLong(); Y[R;UJE`5
nEndPos = input.readLong(); F ]x2;N
} 5R%4fzr&g
input.close(); `;c{E%qeq
} nOQvBc
catch(IOException e){e.printStackTrace ();} Cu $mb}@
catch(Exception e){e.printStackTrace ();} [6u8EP0xM
} \RF{ITV$kD
e[($rsx
|19zjhl
private void processErrorCode(int nErrorCode) r7zS4;b
{ S|Yz5)*
System.err.println("Error Code : " + nErrorCode); HZl//Uq
} 'V`Hp$r
bd;?oYV~
n85d g
//停止文件下载 K\VL[HP-
public void siteStop() %+bw2;a6
{ Uaz$<K6
bStop = true; g;eoH
for(int i=0;i<nStartPos.length;i++) %2ZWSQD
fileSplitterFetch.splitterStop(); YVW`|'7)|
9`FPV`/
-L6V)aK&
} 50R&;+b
} K9=f`JI9
//负责部分文件的抓取 #\T5r*W
**FileSplitterFetch.java +d289"
*/ rk)h_zN
package NetFox; 2_C&p6VGj
G9AQIU%ii
Mrly(*!U"@
import java.io.*; ><DXT nt'x
import java.net.*; !)//b]
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zy\R>4i'#Q
public class FileSplitterFetch extends Thread { slH3c:j\
)+dd
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String sURL; //File URL +2 x|j>
long nStartPos; //File Snippet Start Position S7kZpD$
long nEndPos; //File Snippet End Position iji2gWV}h
int nThreadID; //Thread's ID =LyRCrA
boolean bDownOver = false; //Downing is over uD8,E!\
boolean bStop = false; //Stop identical .[:2M9Rx
FileAccessI fileAccessI = null; //File Access interface ;vp[J&=
_@A%t&l
+<$b6^>!$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Jj'dg6QY'
{ vcz?;lg
this.sURL = sURL; )ad6>Y
this.nStartPos = nStart; bSm*/Q
this.nEndPos = nEnd; =&x u"V
nThreadID = id; 3x3 =ke!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "jA?s9
} QQW]j;'~
*'\xlsp#
o?((FW5.;
public void run() up )JU [
{ ;Sw%t(@
while(nStartPos < nEndPos && !bStop) ]`T*}$|
{ v7#`b}'W
N*6lyFcg
WX}pBmU
try{ R|JBzdK+P
URL url = new URL(sURL); P{[@t_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6[S-%|f
httpConnection.setRequestProperty("User-Agent","NetFox"); !UF(R^
String sProperty = "bytes="+nStartPos+"-"; &A)u!l Ue
httpConnection.setRequestProperty("RANGE",sProperty); ]h4r@L3
Utility.log(sProperty); cFV3
wpV)y Q^
QvvH/u
InputStream input = httpConnection.getInputStream(); p{W'[A{J .
//logResponseHead(httpConnection); [*W l=
#8sv*8&
6< @F
byte[] b = new byte[1024]; Q%.F Mf
int nRead; df@G+v0_1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I6.}r2?;A
{ DWmViuZmL
nStartPos += fileAccessI.write(b,0,nRead); hVf;{p &
//if(nThreadID == 1) u~\l~v^mj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {"n=t`E)3
} x)OJ?l
4>}qdR1L4
R~!md
Utility.log("Thread " + nThreadID + " is over!"); &8M^E/#.^;
bDownOver = true; ! w2BD^V-
//nPos = fileAccessI.write (b,0,nRead); &p_V<\(%
} 1vUW$)?X
catch(Exception e){e.printStackTrace ();} %mr6p}E|
} (hn;C>B
} i;I!Jc_b'
L6n<h
mz?1J4rt
//打印回应的头信息 *7UDTgY
public void logResponseHead(HttpURLConnection con) O#3PUuE%d
{ +xn59V
for(int i=1;;i++) WR5W0!'Tf
{ tr-muhuK
String header=con.getHeaderFieldKey(i); $Fik]TbQp
if(header!=null) 1YJ@9*l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y7WU4He L
Utility.log(header+" : "+con.getHeaderField(header)); = @n`5g
else rO7[{<97m
break; kJK:1;CM?.
} <nbc RO.
} E=L1q)
|jJ9dTD8/
WN3]xw3
public void splitterStop() ,@r 0-gL
{ yYn7y1B
bStop = true; 9KDm<Q-mf
} K}TSwY
xay~fD
-,^Z5N#\|
} -cL wjI
Tv /?-`Y
`|f1^C^
/* 6<m9guv
**FileAccess.java ql(~3/kA_
*//文件访问(定位，写) >@?`n}r|
package NetFox; <-O^ol,fX
import java.io.*; bPUldkB:
;QqC c!b
NNn sq@?6
public class FileAccessI implements Serializable{ 8 GW0w
#v}pn2g%>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Cm~z0c|T
RandomAccessFile oSavedFile; zx`(ojfu
long nPos; dj5@9X
f2G 3cg~H
3fdqFJ O
public FileAccessI() throws IOException H.#zbKj
{ 7p[NuU*Gg
this("",0); cs7K^D;.V
} 3eR c>^wh
` 3h,Cy^
[J +5
public FileAccessI(String sName,long nPos) throws IOException E5 uk<e_
{ (65|QA
oSavedFile = new RandomAccessFile(sName,"rw"); gaU1A"S}
this.nPos = nPos; Q1[EiM3
oSavedFile.seek(nPos); 8&c:73=?X
} eoxEnCU
Z:.*fs5
3B?7h/f
public synchronized int write(byte[] b,int nStart,int nLen) e1Bqd+
{ kadw1sYj
int n = -1; bEli!N$
try{ zCI.^^<?
oSavedFile.write(b,nStart,nLen); "P8(R
n = nLen; g![?P"i^t
} m\@q2l-
catch(IOException e) h1Logm+m
{ w<Ot0&&
e.printStackTrace (); R/Te;z
} ?$~5ti#\
DH!_UV
A0 $ds
return n; J8?V1Ad{
} a}V<CBi
/kNSB;
yt#~n_
} UNyk, #4
BoP,MpF
F&$~]R=&
/* <~n%=^knE
**SiteInfoBean.java 2k+u_tj>
*/ v%;Nyab6$
package NetFox; YSux#*#H
h7J4 p
|Fe*t
public class SiteInfoBean { N7-LgP
<F?UdMT4y
]:.9:RmEV
private String sSiteURL; //Site's URL GU7f27p
private String sFilePath; //Saved File's Path }TRVCF1
private String sFileName; //Saved File's Name b] ~
private int nSplitter; //Count of Splited Downloading File yeIcQ%
vQmqYyOc2
2>/}-a
public SiteInfoBean() nTCwLnX(O
{//nSplitter的缺省值为5 `!y/$7p
//default value of nSplitter is 5 Ny G?^
this("","","",5); k;Ask#rs
} :I8HRkp
Xd5uF/w
&;[e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '1rO&F
{ m.ejGm?
sSiteURL= sURL; fr<V])
sFilePath = sPath; r=S,/N(1
sFileName = sName; 5G l:jRu
this.nSplitter = nSpiltter; ?63ep:QEk
Y?\PU{O
kHd`k.nW
} 3]h*6V1$
Y'76!Y
<\oD4EE_
public String getSSiteURL() }s:~E2?In
{ 1@xdzKua1
return sSiteURL; gm=LM=
} 6&_K;
Z+2 j(
70.Tm#qh
public void setSSiteURL(String value) <jG[ z69)
{ x+EEMv3u:
sSiteURL = value; YRu#JYti
} ]|_+lik#
<KFl4A~
:*MR$Jf
public String getSFilePath() tv%B=E!r
{ aole`PD,l
return sFilePath; N)4R.}
} >tE6^7B*
kY{;(b3Q
6 tl#AJ-
public void setSFilePath(String value) {_UOS8j7
{ Yb4%W-5
sFilePath = value; vGwpDu\RgX
} 5em*9Ko
v(p<88.!m
009Q#[A
public String getSFileName() %Ot*k%F
{ :Z+Jt=;
return sFileName; PxA OKUpI
} RcOfesW o
Rd[^)q4d$w
}#6~/ W
public void setSFileName(String value) g0#w 4rGF)
{ -Eoq#ULvR
sFileName = value; zBc |gx
} Wpc8T="q
yw >Frb5p
u{S"NEc
public int getNSplitter() \LM.>vJ
{ KBa0
return nSplitter; *d9RD~Ee
} !\!j?z=O8
+v< \l=
ij?Ww'p9>
public void setNSplitter(int nCount) 38GZ_z}r
{ . f!dH
nSplitter = nCount; n?"("Fiw
} ZE9.r`
} 1Cw HGO
F |aLF{
<GLn!~Px@5
/* :QC |N@C
**Utility.java nH B
*/ d>V#?1$h
package NetFox; AWi+xo|
PJ\k|
$g),|[x+(
public class Utility { hD{ `j
yW&ka3j\
=MT'e,T
public Utility() BZ(I]:oDL
{ ij1YV2v
R2JPLvs
#Hy\lJ
} wF3 MzN=%
<v=s:^;C0
//线程睡眠 j4u ["O3
public static void sleep(int nSecond) .A0fI";Q
{ h/6^>setz
try{ rAE5.Q!u
Thread.sleep(nSecond); ,T$ GOjt
} i.\ e/9]f
catch(Exception e) wB&5q!{!
{ }F"98s W
e.printStackTrace (); 3W{!\
} nLCaik_,m
} UZ#oaD8H6
~+ 9vz
//日志 Ubgn^+AI
public static void log(String sMsg) wJ7^)tTRF
{ JW)f'r_f
System.err.println(sMsg); G4&?O_\;
} aNA]hl
9M5W4&
g> ~+M
public static void log(int sMsg) [P6m8%Y|s
{ (.X)=
System.err.println(sMsg); FBbaLqgVF{
} zWH)\>X59
} `- (<Q;iO
Gp+\}<^Z
%V+"i_{m
/* w`=O '0d
**TestMethod.java -/V(Z+dj
*/ W6_rSVm
package NetFox; 2pU'&8
Y}:4y$<
cpALs1j:
public class TestMethod { >^GV #z
U|VL+9#hd
C ocw%Yl
public TestMethod() j>B*8*Ss
{ ///xx/weblogic60b2_win.exe - jCj_@n
try{ |xg_z&dX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '&dT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O5Z9`_9<
SiteFileFetch fileFetch = new SiteFileFetch(bean); UoKVl-
fileFetch.start(); {u2Zl7]z^
} .a7RGT3]m
catch(Exception e){e.printStackTrace ();} %y|pVN!U
Ff(};$/&W
\"))P1
} I:G8B5{J
s\pukpf@
elQjPvb
public static void main(String[] args) yCav;ZS_
{ oBo*<6
new TestMethod(); tx~,7TMS/
} d}':7Np
} ES AX}uF
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