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)); ]gH wfqx
} TViBCed40
for(int i=0;i<nEndPos.length-1;i++) {F<)z%^
{ kZJt~}
nEndPos = nStartPos[i+1]; eH ;Wfs2f
} f#*h^91x
nEndPos[nEndPos.length-1] = nFileLength; f;e_04K
} 2j2mW>Z
} Ga]47pQ"F
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`Q:de~+AM{
//启动子线程 ~&t!$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {k kAqJ
for(int i=0;i<nStartPos.length;i++) i:C.8hmAE
{ ;+TMx(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h1n*WQ-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &\JK%X.Jlt
nStartPos,nEndPos,i); d,zp`S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q1aHIc
fileSplitterFetch.start(); 976E3u"Vt
} " ]aQ Hh]f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AEB/8%l};v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gmXy>{T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vEu Ka<5
nEndPos = " + nFileLength); xylpiSJ
// fileSplitterFetch[nPos.length-1].start(); [Bl $IfU
E~'q?LJOB
1,m\Q_
//等待子线程结束 ) ~ l\
//int count = 0; 1[26w_B3
//是否结束while循环 >`<Ued
boolean breakWhile = false; K4iI:
eKL]E!
!x`;>0
while(!bStop) ?R dmKA
{ Mi;}.K0J
write_nPos(); K#_~ !C4L
Utility.sleep(500); :&xz5c`"04
breakWhile = true; D-'i G%)kA
ev~dsk6k
6\; 4 4,3
for(int i=0;i<nStartPos.length;i++) ;M%oQ>].[
{ m\<<oIlH
if(!fileSplitterFetch.bDownOver) l0qdk#v
{ 5x:Ift *
breakWhile = false; p>2||
break; j)g_*\tQ
} i58ZV`Rk`
} Zkf 3t>[
if(breakWhile) *54>iO- c
break; ^</65+OT+
r~ZS1Tp
5F'%i;)oq
//count++; r^?)F?n!
//if(count>4) aR`_h=a
// siteStop(); hB|H9+
} (%``EIc<8
h$E\2lsE
aK8bKlZe
System.err.println("文件下载结束！"); )B-MPuB
} ^VSt9&
catch(Exception e){e.printStackTrace ();} yw;ghP;
} Fpy6"Z?z
^n\9AE3
L9E;Uii0
//获得文件长度 l=oN X"l=
public long getFileSize() +")qi=
{ {DKXn`V
int nFileLength = -1; F{#N6,T
try{ !yoSMI-
URL url = new URL(siteInfoBean.getSSiteURL()); 8[6ny=S`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7Vz[ji
httpConnection.setRequestProperty("User-Agent","NetFox"); bBkm] >
u Y?/B~
qZT 4+&y
int responseCode=httpConnection.getResponseCode(); Q'n(^tbL
if(responseCode>=400) 4+ASwN9
{ 4e=/f,o1
processErrorCode(responseCode); nz,Mqol
return -2; //-2 represent access is error >i^y;5
} -X"5G
tYI]LL
$nUd\B$.=
String sHeader; 6{JR0
"#mXsp-ut
*u|lmALs
for(int i=1;;i++) ?noETHz)
{ y3 ({(URU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _hAj2%SL
//Utility.log(in.readLine()); 0EL\Hd
sHeader=httpConnection.getHeaderFieldKey(i); c8bca`
if(sHeader!=null) 7\7Brw4
{ ?z\q Mu
if(sHeader.equals("Content-Length")) F&W0DaH
{ 21[K[ %
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tnQR<
break; 7Y-FUZ.`>
} &+)+5z_d
} p9FA_(`^
else uE,i-g0$Id
break; v`[Tl
} %v?jG(o
} AijPN
catch(IOException e){e.printStackTrace ();} "E@NZ*"u
catch(Exception e){e.printStackTrace ();} R-r+=x&
4*p_s8> >
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Utility.log(nFileLength); !$:0E y(S
M iP[UCh
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return nFileLength; u+2xrzf
} Yv#J`b@y
H(5S Kv5
}aHB$}"!
//保存下载信息（文件指针位置） P?Gd}mdX?m
private void write_nPos() VfL]O8P>
{ 8Pr&F
try{ c]AKeq]
output = new DataOutputStream(new FileOutputStream(tmpFile)); mhHA!:Y
output.writeInt(nStartPos.length); 8! |.H p
for(int i=0;i<nStartPos.length;i++) EmtDrx4!(f
{ U~u6}s]:
// output.writeLong(nPos); >:Rt>po8|w
output.writeLong(fileSplitterFetch.nStartPos); z")3_5Br
output.writeLong(fileSplitterFetch.nEndPos); o1 hdO
} {#dp-5V
output.close(); .c=$ bQ>^
} u%+6Mp[E
catch(IOException e){e.printStackTrace ();} E)&NP}k-P
catch(Exception e){e.printStackTrace ();} !#,-
} r+{!@`dYi
E"9/YWv
B#qL$M,|
//读取保存的下载信息（文件指针位置） 38x[Ad4%
private void read_nPos() ^D]7pe
{ ~>}dse
try{ tMD^$E"C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U<ku_(2"#
int nCount = input.readInt(); 7 SjF9x
nStartPos = new long[nCount]; ~.PPf/ Z8]
nEndPos = new long[nCount]; !L0E03')k
for(int i=0;i<nStartPos.length;i++) n&2=6$*,k
{ C|.$L<`
nStartPos = input.readLong(); -)y> c
nEndPos = input.readLong(); U(S@1i(
} EO o'a
input.close(); N27K
} {a+Fx}W
catch(IOException e){e.printStackTrace ();} )*^OPVt
catch(Exception e){e.printStackTrace ();} >j(I[_g
} gZ`#tlA~
qHC*$v#.V?
SHXa{-
private void processErrorCode(int nErrorCode) i#@v_^q
{ gqO%^b)6
System.err.println("Error Code : " + nErrorCode); vc>^.#7
} ??$i*
uJ|5Ve
IEIxjek
//停止文件下载 UZ4tq
public void siteStop() 4 BE:&A
{ {L-{Y<fke
bStop = true; wRV`v$*6
for(int i=0;i<nStartPos.length;i++) 4AJu2Hp
fileSplitterFetch.splitterStop(); J-eA,9J
9:CVN@E
~ X]"P4 u
} o5*74Mv
} ?vht~5'
//负责部分文件的抓取 T(sG.%
**FileSplitterFetch.java 1eE]4Z4Q
*/ JhMrm%
package NetFox; 9AVK_
$.r}g\43P
7N}\1Di5
import java.io.*; q^jqLT&w
import java.net.*; (04j4teE
6S! lD=
m5'__<
public class FileSplitterFetch extends Thread { 2kp|zX(
A3 Rm0
%4r!7X|O<
String sURL; //File URL ' F 6au[
long nStartPos; //File Snippet Start Position |04}zU%N
long nEndPos; //File Snippet End Position (<>Sz(
int nThreadID; //Thread's ID C~ }Wo5
boolean bDownOver = false; //Downing is over xdbu|fC
boolean bStop = false; //Stop identical WoClTb>F
FileAccessI fileAccessI = null; //File Access interface T,xVQ4J?
fr,CH{Uq
;8%@Lan
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ivt)Eg
{ ?4wehcZz
this.sURL = sURL; ?Qo_ KQ%sn
this.nStartPos = nStart; dp//p)B>
this.nEndPos = nEnd; psyH?&T
nThreadID = id; GH; F3s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O'&X aaZV
} wNf*/?N
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t;e]L'z@:
public void run() of[|b{Ze4~
{ H~_^w.P
while(nStartPos < nEndPos && !bStop) RqX4ep5j
{ x w?9W4<
Op$J"R
P :7l#/x_
try{ !Lg}q!*%>V
URL url = new URL(sURL); w=P<4bdT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {6=H/g=:i
httpConnection.setRequestProperty("User-Agent","NetFox"); e~2*>5\:
String sProperty = "bytes="+nStartPos+"-"; y?R <g^A
httpConnection.setRequestProperty("RANGE",sProperty); #:ED 0</
Utility.log(sProperty); m|Q&Lphb8
PE;0 jgsiI
qI V`zZc
InputStream input = httpConnection.getInputStream(); 6q xUT
//logResponseHead(httpConnection); z5o9\.y({
xt<, (4u
{7pE9R5
byte[] b = new byte[1024]; /bNVgK`L5
int nRead; L/ICFa.G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t-<[._:+
{ 2Z IpzH/8
nStartPos += fileAccessI.write(b,0,nRead); (?&_6B.*
//if(nThreadID == 1) ! 4^L $
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +DV6oh
} C)3$";$5)
C"m0"O>
E*T84Jh6
Utility.log("Thread " + nThreadID + " is over!"); gx>mKSzy
bDownOver = true; 7q{v9xKy
//nPos = fileAccessI.write (b,0,nRead); @SQ*/sw (c
} Fp|rMq
catch(Exception e){e.printStackTrace ();} W*/s4 N
} n`I jG
} nO.+&kA
-5-SlQu
3_1Io+uXk
//打印回应的头信息 3xCA\*
public void logResponseHead(HttpURLConnection con) C;:1CK
{ %ucmJ-<y#
for(int i=1;;i++) ##+8GLQM
{ * SON>BSF
String header=con.getHeaderFieldKey(i); Kp=3\)&
if(header!=null) $d??(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )i6U$,]
Utility.log(header+" : "+con.getHeaderField(header)); $b 71
else F0ivL`
break; ks`
} CR<pB)F?a
} )'I<xx'1
PS<tS_.
sxQ,x/O
public void splitterStop() 7!yF5+_d
{ _ L:w;Oy9T
bStop = true; my\oC^/9
} Z FrXw+
Ef*.}gcU
sFz4^Kn
} N n-6/]d#
yNMwd.r[
I3[RaZ2z{
/* "?0G^zu
**FileAccess.java {j=hQL3
*//文件访问(定位，写) <!HDtN
package NetFox; +&zuI
import java.io.*; 7Caap/L:
H2_>Av{m
H><mcah
public class FileAccessI implements Serializable{ ORPl^n-
7u3b aM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @/2wmza%2
RandomAccessFile oSavedFile; E#V-F-@2
long nPos; fD}]Mi:V
<.%8j\j(
j8AR#
public FileAccessI() throws IOException N{z(|2{A#
{ {|wTZ
this("",0); ,'{B+CHoS
} te4"+[ $|
7Hlh (k
>5},qs:lZ
public FileAccessI(String sName,long nPos) throws IOException 3$G25=eN
{ |/Q."d
oSavedFile = new RandomAccessFile(sName,"rw"); 3LnyQ
this.nPos = nPos; 9l^
oSavedFile.seek(nPos); M,U=zNPnk
} NeZYchR
F4{. 7BT
7ofH@U
public synchronized int write(byte[] b,int nStart,int nLen) \^W?
{ z)y(31K<1
int n = -1; ph'SS=!.
try{ a|{<#<6n(
oSavedFile.write(b,nStart,nLen); k.R/X
n = nLen; ZZJ"Ny.2
} YZtA:>;p
catch(IOException e) ZTz(NS EK
{ x3F L/^S
e.printStackTrace (); #K*q(ei,7h
} LzSusjEW@
6]A\8Ty
7 ,~Krzv
return n; ,ui'^8{gK
} WG=r? xE
Jj!tRZT
5:3$VWLa <
} krY.Cc]
WjxBNk'f
8r|
/* :H:}t>X6Vo
**SiteInfoBean.java /*2W?ZM~H
*/ q$*_C kT
package NetFox; |2` $g
sWzXl~JbF
;8Q?`=a
public class SiteInfoBean { e7AI&5Eg{
JV{!Ukuyp+
t7%Bv+Uo
private String sSiteURL; //Site's URL r<H^%##,w
private String sFilePath; //Saved File's Path @!HMd{r
private String sFileName; //Saved File's Name TbM*?\7
private int nSplitter; //Count of Splited Downloading File fBh|:2u
u+FftgA
5W'|qmJ
public SiteInfoBean() (?wKBUi
{//nSplitter的缺省值为5 K4L#%KUPW
//default value of nSplitter is 5 .tZ$a_O
this("","","",5); [<Puh
} 32'9Ch.
itMc!bUQ
ttt&sW`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E*"E{E7
{ td$Jx}'A
sSiteURL= sURL; K`2DhJC
sFilePath = sPath; Z4sjH1W
sFileName = sName; TyXOd,%zl
this.nSplitter = nSpiltter; .b)(_*
Efd[ZJxS6
`G{t<7[[;
} HYa!$P3}[
AU\!5+RDB
?%n9g)>Yej
public String getSSiteURL() v)pWx0l=
{ W]]2Uo.
return sSiteURL; O/@[VPf
} [$+61n}.12
ho<#i(
nXW1:
public void setSSiteURL(String value) ]&BFV%kw
{ 3Or3@e5r
sSiteURL = value; Qp Vm
} Um&@ 0C+L
2l%iXK[
(acRYv(
public String getSFilePath() q@> m~R
{ t')I c6.?i
return sFilePath; Stx-(Kfn4
} nJw1Sl5
l,8|E
#r}c<?>Vw
public void setSFilePath(String value) (P_+m#
{ }RK9Onh3G
sFilePath = value; RH'R6
} J#nEGl|a
SjU6+|l
m8`A~
public String getSFileName() 1 crjRbi
{ Xb;`WE gC
return sFileName; 6P$q7G
} 8b $7#
.=D6<4#t
:v48y.Ij7s
public void setSFileName(String value) ;W:Q}[
{ !%=k/|#
sFileName = value; O;tn5
} Vt>E\{@[t
]t<%>Z$
> [7vXm4
public int getNSplitter() 3EdPKM j&
{ :eO0{JN4T
return nSplitter; Ha\hQ'99
} s=+G%B'
2|EoP-K7
5lbh "m=
public void setNSplitter(int nCount) fA5# 2P{
{ 0U~JSmj:2K
nSplitter = nCount; ]|(?i ,p
} RUO6Co-
} y3GIR f;>
!Zx>)V6.
7dIDKx
/* W3kilhZ
**Utility.java =#Jb9=zdR
*/ ?Ci\3)u,P
package NetFox; m-]"I8[
xCD+qP^
kE}Ib4]J
public class Utility { 1owoh,V6
6ZJQ '9f
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public Utility() P*Nl3?T
{ %-.GyG$i
"tIx$?I
,'}ZcN2)
} wz57.e!Me=
\/%mabLK
//线程睡眠 k2a^gCBC
public static void sleep(int nSecond) yo=d"*E4^
{ mbK$Wp#
try{ %G*D0pE
Thread.sleep(nSecond); qK pU.rP
} zjS<e XLs[
catch(Exception e) EWi@1PAZK
{ OduTg^R
e.printStackTrace (); ?T&D@Ohsx
} shRvwE[
} r}w 9?s^rB
Kk#@8h>
//日志 wO9<An
public static void log(String sMsg) Z'~FZRF
{ t<=L&:<N
System.err.println(sMsg); I&9B^fF6
} 1zffPC8jl
sQ$FtKm6
:1I,:L
public static void log(int sMsg) {z7{ta
{ 6>Fw,$
System.err.println(sMsg); 6 9Cxh
} P#C`/%$S
} !~#31kL&
q]aRJ`9f
1vr/|RWW
/* gkjZX wp
**TestMethod.java n >^?BU
*/ 9cQSS'`F
package NetFox; {rDZKy^f
uo^>95lkv
+y2*[
public class TestMethod { @QofsWC
Q]HRg4r
?bEYvHAzg
public TestMethod() okW3V}/x/z
{ ///xx/weblogic60b2_win.exe iT5%X
try{ A@4Cfb@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l d@^$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5y)kQ<x"
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z'~5L_.]Ai
fileFetch.start(); &*}S 0
} pfG:PrZ
catch(Exception e){e.printStackTrace ();} d$ /o\G
0WFZx Ad"
d0,I]"
} "v06Fj>q
)]}*oO
A,osrv
public static void main(String[] args) @UA>6F
{ :5(TOF
new TestMethod(); We`axkC
} 5D#*lMSP"'
} sr\MQ?\fB
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