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)); n5]<|>Uvx
} ^?xXP=/
for(int i=0;i<nEndPos.length-1;i++) ;|/7o@$n
{ }RUC#aW1
nEndPos = nStartPos[i+1]; 6]gs{zG
} D0k7)\puQ
nEndPos[nEndPos.length-1] = nFileLength; D1O7S]j
} Vq'&t<K#
} m9xu$z|e
>k\*NW
f3l >26
//启动子线程 XLbrE|0A?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SqTm/ t
for(int i=0;i<nStartPos.length;i++) 3nK'yC
{ V`WfJ>{;Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y~S[0]y>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ypd
nStartPos,nEndPos,i); FJL9x,%6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sfrh+o57
fileSplitterFetch.start(); 6y5arP*6e
} Y9w=[[1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m&A/IW,.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |k+&weuY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -I8%
nEndPos = " + nFileLength); PUYo >eB)0
// fileSplitterFetch[nPos.length-1].start(); a5)[?ol
&GD7ldck
" ^eq5?L
//等待子线程结束 Q#g s)2
//int count = 0; ci^-0l_O
//是否结束while循环 _mkI;<d]$T
boolean breakWhile = false; In;z\"NN4
[7s5Vt|
Io"=X!k
while(!bStop) 2iG(v._x
{ $z,bA*j9
write_nPos(); -owfuS?i=
Utility.sleep(500); #i]@"R
breakWhile = true; Xs`:XATb/
ev guw*u
YHRI UYd
for(int i=0;i<nStartPos.length;i++) &'](T9kg=
{ Nm081ic2<
if(!fileSplitterFetch.bDownOver) gaCGU<L
{ F#<PFT4i
breakWhile = false; .$OInh
break; 1)PR]s:-m@
} r?+u}uH
} /Bwea];^Q
if(breakWhile) 8DI|+`OgW
break; R$3JbR.
p.}[!!m P
p4AXQuOP
//count++; lb6s3b
//if(count>4) oF6MV&q/
// siteStop(); q,(&2./
} 0,A?*CO
4*,q1yK
0$_imjZ
System.err.println("文件下载结束！"); [qI*]
} 7S7!
catch(Exception e){e.printStackTrace ();} Y}#^n7*w~
} f:Ja
y;>I'e
!fV6KkV
//获得文件长度 :hr@>Y~r
public long getFileSize() k2WO*xa*
{ xXYens}
int nFileLength = -1; B*AMo5
try{ R`?^%1^N
URL url = new URL(siteInfoBean.getSSiteURL()); 6;b 'j\jG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [;2:lbPx
httpConnection.setRequestProperty("User-Agent","NetFox"); [O)Zof
: [9'nR
,qHG1#^
int responseCode=httpConnection.getResponseCode(); 3"hR:'ts
if(responseCode>=400) zn x_p/V
{ Sp )}
processErrorCode(responseCode); stG&(M
return -2; //-2 represent access is error @iceMD.
} S- \lN|
,+BgY4OY
&}$D[ 4N
String sHeader; / IS WC
j)DZmGg&t
wE \c?*k
for(int i=1;;i++) eC{Z
{ JT9<kB/07
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *!/#39
//Utility.log(in.readLine()); H7=z%Y9y
sHeader=httpConnection.getHeaderFieldKey(i); >z -(4Z
if(sHeader!=null) t5APD?5 c
{ "3MUrIsB>
if(sHeader.equals("Content-Length")) 4<K`yU]"
{ *4:/<wI!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xwxjj
break; h3IkOh4|h
} `4q}D-'TF8
} kZ}u
else PPO<{
break; g DG m32
} NGs9Jke2
} TjK5UML
catch(IOException e){e.printStackTrace ();} 90ag!
catch(Exception e){e.printStackTrace ();} jq)|7_N
P0(~~z&%[
PZR%8 m}]u
Utility.log(nFileLength); @R&D["!
&FVlTo1
7uxPkZbb
return nFileLength; q$rA-`jw
} vUs7#*
'uzv\[
ncr-i!Jjk
//保存下载信息（文件指针位置） o#) !b:/
private void write_nPos() BZc-
{ <'_GQM`G
try{ Lp)8SmN
output = new DataOutputStream(new FileOutputStream(tmpFile)); D*gVS
output.writeInt(nStartPos.length); O mIBk
for(int i=0;i<nStartPos.length;i++) B/hHkOoo
{ \87J~K'
// output.writeLong(nPos); z]|[VM?4L
output.writeLong(fileSplitterFetch.nStartPos); 9prsL#Fn
output.writeLong(fileSplitterFetch.nEndPos); y(
} 7NC8<o;
output.close(); da'E"HN@G~
} X/Rx]}[
catch(IOException e){e.printStackTrace ();} KAcri<^G
catch(Exception e){e.printStackTrace ();} 2rtP.*dd
} PjW+V`
c\{}FGC
C'2 =0oou
//读取保存的下载信息（文件指针位置） Pq>[q?>?
private void read_nPos() I 47GQho
{ HHTsHb{7
try{ hr6e1Er
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (zDk68=v
int nCount = input.readInt(); Su$1 t
nStartPos = new long[nCount]; G?d,$NMo|
nEndPos = new long[nCount]; b]&zDo|8
for(int i=0;i<nStartPos.length;i++) ?mR[A`J58
{ mh7sY;SvM
nStartPos = input.readLong(); b Ne\{k
nEndPos = input.readLong(); H8]^f=
} %O=V4%"m\
input.close(); Zt2@?w;
} 9Pp|d"6]y
catch(IOException e){e.printStackTrace ();} M6*{#Y?
catch(Exception e){e.printStackTrace ();} tZCe?n]
} *F*jA$aY
sVdK^|j
('6g)@=\U
private void processErrorCode(int nErrorCode) &qP-x98E?
{ tZ j,A%<
System.err.println("Error Code : " + nErrorCode); :U.)YHY
} rL sK-qQ
u<shhb-
8{Eo8L'V
//停止文件下载 n=o'ocdS)
public void siteStop() tm1UH 4
{ 6Hbf9,vI
bStop = true; |ch^eb^7"
for(int i=0;i<nStartPos.length;i++) G+X[R^RD
fileSplitterFetch.splitterStop(); d74g|`/
RL Zf{Q>
TWR$D
} t<k[W'#
} }`N2ZxC0AQ
//负责部分文件的抓取 "SU-^z
**FileSplitterFetch.java e_c;D2'F
*/ fTHun?Vn
package NetFox; YATdGLTeq
9N D+w6"
2ZG1n#
import java.io.*; _|
import java.net.*; -+=:+LhSMb
#H6g&)Z_
j"IM,=
public class FileSplitterFetch extends Thread { 51M^yG&M
A$%!9Cma
CTkN8{2S
String sURL; //File URL )ozcr^
long nStartPos; //File Snippet Start Position )ClMw!ZrU
long nEndPos; //File Snippet End Position 2vkB<[tSs
int nThreadID; //Thread's ID >6I.%!jU
boolean bDownOver = false; //Downing is over !UMo4}Y
boolean bStop = false; //Stop identical &u1g7# #
FileAccessI fileAccessI = null; //File Access interface u[i7:V%
7ITl3>
1.0!H.>q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }S vw,c
{ .y7)XLC
this.sURL = sURL; "?SOBA!vy
this.nStartPos = nStart; jfY{z=*]u
this.nEndPos = nEnd; OOBcJC
nThreadID = id; .K@x4 /1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q#(/*AoU
} (HaKF7Jsi
ft/^4QcyAM
<P^hYj-swh
public void run() mheU#&|
{ 1n`1o-&l-
while(nStartPos < nEndPos && !bStop) a}Fkx
{ JOdwv4(3V
U$A7EFK'
Q-`{PJ(p
try{ D!RE-w92X
URL url = new URL(sURL); (}C^_q:7d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $,;S\JmWP
httpConnection.setRequestProperty("User-Agent","NetFox"); '>e79f-O)
String sProperty = "bytes="+nStartPos+"-"; P*SCHe'
httpConnection.setRequestProperty("RANGE",sProperty); (H8C\%g:
Utility.log(sProperty); >nhE%:X>
#$t}T@t>
m(Y.X=EZr
InputStream input = httpConnection.getInputStream(); -jVaS wt
//logResponseHead(httpConnection); Be{/2jU%
Cfr<D3&,]
JEsLF{
byte[] b = new byte[1024]; ;wbUk5Tf/
int nRead; \oB'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M20Bc,VI
{ 6)wy^a|pb
nStartPos += fileAccessI.write(b,0,nRead); i-k >U}[%
//if(nThreadID == 1) |}M0,AS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); If-,c^i
} f]ue#O
7!r#(>I6?1
;v1NL@w*
Utility.log("Thread " + nThreadID + " is over!"); `c'
bDownOver = true; $U>/i@D
//nPos = fileAccessI.write (b,0,nRead); _hy{F%}
} ut$,?k!M
catch(Exception e){e.printStackTrace ();} Hwp{<
} (LRM~5KVg
} Vd%v_Ek
_r\$NgJIM
PUP"ky^q"
//打印回应的头信息 e"fN~`NhY
public void logResponseHead(HttpURLConnection con) "!%wh6`>Md
{ tyEPU^PM
for(int i=1;;i++) I/On3"U%
{ SE^j=1
String header=con.getHeaderFieldKey(i); j,C,5l=
if(header!=null) )u8*zwq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1yBt/U2
Utility.log(header+" : "+con.getHeaderField(header)); :xFu_%7
else hIuMHq7h
break; .hX0c"f]b
} `/O`OrZ1K
} Tm)GC_
OJP5k/U$
<b d1
public void splitterStop() 8K0X[-hs8
{ q^a|wTC
bStop = true; ~)q g
} \ ]
4M}|/?<Br
+VCo$o
} r{\BbUnf)
38c?^
y=AsgJ
/* NunV8atn:
**FileAccess.java :n'yQ#[rn
*//文件访问(定位，写) 0#oBXu
package NetFox; sM9FE{,mx
import java.io.*; @Od^k#
bMN@H\Ek
e-X HN
public class FileAccessI implements Serializable{ KD% TxK
e74zR6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B%tIwUE2
RandomAccessFile oSavedFile; Vb@4(Q
long nPos; U4>O\sU
[o2w1R\H+x
7}be>(
public FileAccessI() throws IOException UJz#QkAio
{ TE^7P0bh
this("",0); 0"EoC
} hv*>%p
g(aZT#ii=
4YszVT-MU~
public FileAccessI(String sName,long nPos) throws IOException 01udlW.
{ bfgz1 `u
oSavedFile = new RandomAccessFile(sName,"rw"); ao#!7F
this.nPos = nPos; M[, D *
oSavedFile.seek(nPos); 4% HGMr
} cjuZBFl
^=EjadVQ
'p%=<0vrr
public synchronized int write(byte[] b,int nStart,int nLen) ZJ;LD*
{ gH %y
int n = -1; F4Zn5&.)
try{ b~7Jh:%@;
oSavedFile.write(b,nStart,nLen); 2-++i:, g
n = nLen; t|}O.u-&;~
} aG%kmS&fv
catch(IOException e) 5m4DS:&
{ !(Krf
e.printStackTrace (); (;aB!(_
} [,=d7*b(l
_%Bz,C8
Lf. 1>s
return n; CSL#s^4T
} gv#4#]
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C.~j'5N
} $>*Yhz `
_\.{6""
k#O,j pbB
/* mwh{"FL(
**SiteInfoBean.java oid[syPB
*/ $;2)s}ci
package NetFox; rK7W(D}
$I@GUtzjp
,CciTXf
public class SiteInfoBean { J$Fnm\
c<wavvfUo
#^6^
private String sSiteURL; //Site's URL -Ep!- a
private String sFilePath; //Saved File's Path Z%}4bJ
private String sFileName; //Saved File's Name B0d%c&N${
private int nSplitter; //Count of Splited Downloading File G@gh#[b
jd 1jG2=f
%j7:tf=
public SiteInfoBean() k=[pm5ZvT~
{//nSplitter的缺省值为5 I"@p aLZ
//default value of nSplitter is 5 q"akrI38
this("","","",5); ['cz;2{:W
} 4KXc~eF[M"
%-+j
GIT#<+"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IG< H"tQ
{ J8?2R^;{
sSiteURL= sURL; n9%]-s\Hn
sFilePath = sPath; >"v9iT
sFileName = sName; pMR,#[U<
this.nSplitter = nSpiltter; 1<.5ub*i4
RRADg^}l|"
ACg;CTBb
} prtK:eGe2
03=5Nof1
?]#OM_,8
public String getSSiteURL() A`[@8
{ j8++R&1f]
return sSiteURL; f'X9HU{Cz
} g # S0V
^s&W>hTX:
5.vG^T0w
public void setSSiteURL(String value) `&!k!FZY*
{ T%$jWndI
sSiteURL = value; !^w E/
} Ipe n
DkDoA;m
k?*KnfVh!
public String getSFilePath() "Y;}GlE
{ `!vUsM.d
return sFilePath; |4;UyHh
} u.,Q4u|!
.@#A|fgv
Vi?q>:E:
public void setSFilePath(String value) z.36;yT/
{ X^s2BW
sFilePath = value; o(!@7Lqq
} a~PK pw2%
;f1qLI
/vxm"CJR
public String getSFileName() os4{0Mxu
{ u5B:^.:p
return sFileName; dtZE67KS
} 4;<ut$G
Dnw|%6Y
Vi*e@IP/
public void setSFileName(String value) 8R/dA<Ww
{ 3BG>Y(v
sFileName = value; E{?au]y$J
} t$J.+}}I
3B0PGvCI1
u JY)4T
public int getNSplitter() )Ry<a$Q3
{ 7f3O
return nSplitter; T/pqSmVpM
} ^v&D;<&R
5]5 KB;
=Yz'D|=t
public void setNSplitter(int nCount) K/L;8a
{ t `kui.
nSplitter = nCount; g%nl!dgS
} h6~$/`&]b
} [P~hjmJ(y
OsqNB'X
]QVNn?PA8
/* &V7M}@
**Utility.java pO7Zs
*/ n]}W``=7
package NetFox; l12{fpm
?t](a:IX
x3 >
public class Utility { /w(e
|~!U4D\
t]aea*B
public Utility() qIIJ4n
{ 8CbXMT
H+E$:)gN
\C,p WW
} 6$\jAd|
_8,()t'"
//线程睡眠 |`TgX@,#9
public static void sleep(int nSecond) En{`@JsM
{ UCWV2Mu
try{ F+m }#p
Thread.sleep(nSecond); Ep9W-n?}
} "]K>j'^Zs<
catch(Exception e) MN^Aw9U
{ `d7n?|pD
e.printStackTrace (); z2_6??tS/c
} $5x ,6[&
} eI45PMP
rf~Y6U?7
//日志 >P6BW
public static void log(String sMsg) 0k)rc$eDF+
{ Q7Iw[=;\
System.err.println(sMsg); fGhn+8VfX
} >NYW{(j
wX >*H
#$1Z
public static void log(int sMsg) k:jSbbQ
{ I[)%,jd
System.err.println(sMsg); mKrh[nA
} 7xRl9
} &xRo^iV?
Q></`QWpoB
L:XC
/* X+UJzR90
**TestMethod.java *na?n2Yzt
*/ c\a_VRN>r
package NetFox; '5&s=M_
.<@8gNm3
#@<9S{F
public class TestMethod { [8tL"G6s
jCbV,0)^
_SW3_8SuM.
public TestMethod() ;rc`OZyE
{ ///xx/weblogic60b2_win.exe i&{DOI%w
try{ k0Ol*L!p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2hzsKkrA {
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {~Rk2:gx
SiteFileFetch fileFetch = new SiteFileFetch(bean); aDO!
fileFetch.start(); .L'.c/ s
} '>r7V
catch(Exception e){e.printStackTrace ();} [w% qV 6
KQB3m"
SkmT`*v@
} ^R:cd8+?%
qkiI/nH3
BD(Z5+EU1
public static void main(String[] args) uEX!xx?Q#
{ |PC*=ykT3
new TestMethod(); j~!X;PV3
} ~l)-wNqR4r
} J0@X<Lt U
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