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)); uz#eO|z@o
} K#6`LL m
for(int i=0;i<nEndPos.length-1;i++) u_[4n
{ ^*?B)D=,
nEndPos = nStartPos[i+1]; hklO:,`
} 3<UDVt@0
nEndPos[nEndPos.length-1] = nFileLength; r3BDq
} _'v }=:X
} t\|K"
&"H<+>`
3qxG?G N
//启动子线程 x4HMT/@AG2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h2/1S{/n]
for(int i=0;i<nStartPos.length;i++) 2 Zjb/
{ )R a/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3Ld ;zW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )zL"r8si
nStartPos,nEndPos,i); amk42
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Q?|gfJH
fileSplitterFetch.start(); M:1F@\<
} FOUs= E[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +O!M>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,C'w(af@}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GZhfA ;O,
nEndPos = " + nFileLength); EBL,E:_)
// fileSplitterFetch[nPos.length-1].start(); Z\gg<Q
CXP $bt}
3W0E6H"
//等待子线程结束 8yo6v3JqC
//int count = 0; neY=:9
//是否结束while循环 hZ\W ?r
boolean breakWhile = false; LOb'<R\p
MCrO]N($b
DneSzqO"o
while(!bStop) ]R0A{+]n
{ #ZnX6=;X
write_nPos(); : $52Ds!i
Utility.sleep(500); []N$;~R7
breakWhile = true; uA/.4 b
}vxH)U6$q
:_YG/0%I
for(int i=0;i<nStartPos.length;i++) qxcBj
{ g /@yK
if(!fileSplitterFetch.bDownOver) 0*:hm%g
{ \A\yuJ=
breakWhile = false; io33+/
break; F?,&y)ri
} c'Tu,-
} W0T i ^@
if(breakWhile) `0G.Y
break; e%v4,8
(yTz^o$t|
3(GrDO9^
//count++; _}9R}
//if(count>4) K,,@',
// siteStop(); %FI6\|`M
} w{O3P"N2
z&vms
MJ/%$
System.err.println("文件下载结束！"); K#sb"x`
} N[bf.5T
catch(Exception e){e.printStackTrace ();} pr,1Wp0l
} Oi[9b
`"b7y(M
=ObtD"
//获得文件长度 F*].
public long getFileSize() PXu<4VF
{ Tl7:}X<?
int nFileLength = -1; U+r#YE.
try{ 6F&]Mk]V8
URL url = new URL(siteInfoBean.getSSiteURL()); jv=f@:[`I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3jeV4|
httpConnection.setRequestProperty("User-Agent","NetFox"); 32|L $o
_ *s
s]8J+8 <uO
int responseCode=httpConnection.getResponseCode(); "/Q(UV<d
if(responseCode>=400) 3N*C]
{ @#Uiy5N
processErrorCode(responseCode); x&/Syb
return -2; //-2 represent access is error Ci9wF(<k
} la{uJ9Iw@}
$#JVI:
BOQV X&g%
String sHeader; _v=WjN
SWO!E
4x?u5L 9o
for(int i=1;;i++) =}GyI_br;8
{ uWtS83i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y9y*":&%
//Utility.log(in.readLine()); m9w ;a
sHeader=httpConnection.getHeaderFieldKey(i); IeI%X\G
if(sHeader!=null) K}3"KC
{ !enz05VW6.
if(sHeader.equals("Content-Length")) WM )g(i~(
{ "57G@NC{n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $<e .]`R
break; JU1; /3(
} 6U9Fa=%>}
} N_[ Q.HD"
else o? "@9O?
break; kGiw?~t=%
} H>X1(sh#}
} #|h8u`
catch(IOException e){e.printStackTrace ();} I>~BkR+u%o
catch(Exception e){e.printStackTrace ();} {&qsh9ob
?o5#Ve$-X
tS|zf,7
Utility.log(nFileLength); T\CQ
1V$B^/_
7$P(1D4
return nFileLength; ?Cfp=85ea!
} 'z!#E!i
!-nm7Q
Dohe(\C@
//保存下载信息（文件指针位置） 1Klu]J%
private void write_nPos() l<_mag/j9o
{ h,?Yw+#o"
try{ &?sjeC_
output = new DataOutputStream(new FileOutputStream(tmpFile)); C)}LV
output.writeInt(nStartPos.length); 3"D00~
for(int i=0;i<nStartPos.length;i++) jt?%03iuk
{ c}s3c >`d
// output.writeLong(nPos); ui0(#2'h%
output.writeLong(fileSplitterFetch.nStartPos); * xXc$T
output.writeLong(fileSplitterFetch.nEndPos); %t.IxMY
} m|FONQ,@D
output.close(); tzJtd
} Ps4A B#3
catch(IOException e){e.printStackTrace ();} tO3B_zC
catch(Exception e){e.printStackTrace ();} d0E5;3tQ
} :u93yH6~8
481u1
X]%4QIeS
//读取保存的下载信息（文件指针位置） SYLkC [0k
private void read_nPos() <QLj6#d7Y
{ sJ()ItU5i
try{ u)>*U'bM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k5CIU}H"
int nCount = input.readInt(); 5X|aa>/
nStartPos = new long[nCount]; f\w4F'^tj
nEndPos = new long[nCount]; S@-X?Lu
for(int i=0;i<nStartPos.length;i++) 'Q,<_L"
{ .gg0:
nStartPos = input.readLong(); HXo'^^}q;
nEndPos = input.readLong(); wj~8KHan
} .AS,]*?Zn%
input.close(); xF0*q
} l%/,Ef*3
catch(IOException e){e.printStackTrace ();} hUc|Xm
catch(Exception e){e.printStackTrace ();} ^T>.04";x
} 6Z:|"AwC2
^r$5];n
k Er7,c
private void processErrorCode(int nErrorCode) "E#%x{d
{ .<hv&t
System.err.println("Error Code : " + nErrorCode); LnIJwD
} =2'^:4Z
<3OV
e@YR/I8my
//停止文件下载 ]B[Qdn
public void siteStop() )BDi2: u
{ VNPdL
bStop = true; 4f5$^uN$qA
for(int i=0;i<nStartPos.length;i++) RzRLrfV
fileSplitterFetch.splitterStop(); ](pD<FfS]'
.quc i(D
c8MNo'h
} $!lxVZ>
} Ho|n\7$
//负责部分文件的抓取 q~lW
**FileSplitterFetch.java Joj8'
*/ !s:|Ddv
package NetFox; '@bA_F(
9X~^w_cdk
5E8PbV-l
import java.io.*; 7)#/I
import java.net.*; c$;enAf@
m? hX=
*']RYu?X
public class FileSplitterFetch extends Thread { glpdYg *
up?8Pq*
<j'#mUzd
String sURL; //File URL s+11) ~
long nStartPos; //File Snippet Start Position :OM>z4mQ
long nEndPos; //File Snippet End Position V{r@D!}
int nThreadID; //Thread's ID q ^?{6}sy
boolean bDownOver = false; //Downing is over %/y/,yd
boolean bStop = false; //Stop identical rO~D{)Nu
FileAccessI fileAccessI = null; //File Access interface "%Ak[04'
/~Iy1L#
O<*iDd`(e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s*@.qN
{ KpL82
this.sURL = sURL; }m?L/Y'}
this.nStartPos = nStart; wP i=+
this.nEndPos = nEnd; \wd~Y
nThreadID = id; {+MMqJCa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {*m?t 7
} E^!%m8--
`i-&Z`
C~B^sG@;
public void run() +^.(3Aw
{ >jcNo3S
while(nStartPos < nEndPos && !bStop) sXUM,h8$!+
{ c-,/qn/
<8Ad\MU
%<klz)!t
try{ 4%pvw;r
URL url = new URL(sURL); @ 9uwcM1F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f%af.cR*
httpConnection.setRequestProperty("User-Agent","NetFox"); x>Kem$z
String sProperty = "bytes="+nStartPos+"-"; ~b+>o
httpConnection.setRequestProperty("RANGE",sProperty); pD{Li\LY
Utility.log(sProperty); SWu=n1J.?H
.R1)i-^
iL(E`_I<
InputStream input = httpConnection.getInputStream(); p|Ln;aYc
//logResponseHead(httpConnection); 82$^pg>
Eb*DP_
2c}kiqi{
byte[] b = new byte[1024]; 3 . @W.GG8
int nRead; ?#W>^Za=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X(8]9
{ #2}S83 k
nStartPos += fileAccessI.write(b,0,nRead); |YH1q1l
//if(nThreadID == 1) -n6C~Yx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ws=J)2q
} dM QnN[d6
Ys\l[$_`*
P)T:6K
Utility.log("Thread " + nThreadID + " is over!"); E*kS{2NAq
bDownOver = true; j"f]pzg&
//nPos = fileAccessI.write (b,0,nRead); h7g9:10
} fx*Swv%r
catch(Exception e){e.printStackTrace ();} fUa`YryQ
} *d@}'De{8
} Dhq7qz
ct/I85c@P
k|w6&k3
//打印回应的头信息 Bq'hk<ns[
public void logResponseHead(HttpURLConnection con) IqmavnM#
{ \PL92HV
for(int i=1;;i++) ?g9CeeH*
{ ~Su>^T(?-
String header=con.getHeaderFieldKey(i); fz:F*zT1
if(header!=null) m'%F,c)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^b&aDm~(7
Utility.log(header+" : "+con.getHeaderField(header)); k%hif8y
else iXBc ~S
break; ZM<1;!i
} 8R)*8bb
} 7^S&g.A
!I:6L7HdwB
<n0-zCf
public void splitterStop() wjY3:S~
{ x*(pr5k
bStop = true; MYLq2g\
} !DLIIKO78
~aBALD0D;
a "8/y4Y
} bE0cW'6r
yBeSvsm
E-l>z%
/* ?"J5~_U.
**FileAccess.java +>{{91mN
*//文件访问(定位，写) w!%Bc]
package NetFox; ,OG sx
import java.io.*; 24]O0K
g(|p/%H
/SSl$
public class FileAccessI implements Serializable{ XYf;72*
DOf[?vbu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J/=b1{d"n
RandomAccessFile oSavedFile; |7%M:7Q
long nPos; ~u7a50
c!E+&5|n
!%sj-RMvG
public FileAccessI() throws IOException Q_]O[Kx
{ yG{'hx6H
this("",0); 'lg6<M%#[
} ^\J/l\n
@>&UoH}2
s:,BcVLx^
public FileAccessI(String sName,long nPos) throws IOException |G!-FmIK
{ Lw1~$rZg
oSavedFile = new RandomAccessFile(sName,"rw"); `UGHk*DL)
this.nPos = nPos; sYgpK92
oSavedFile.seek(nPos); k oZqoP
} 67%o83\
g/J ^YT!
vaS/WEY
public synchronized int write(byte[] b,int nStart,int nLen) n:x6bPal]
{ Em%"]B
int n = -1; t@.M;b8
try{ pd/{yX M
oSavedFile.write(b,nStart,nLen); UcKpid
n = nLen; 3I@j=:(%Y
} _/]4:("
catch(IOException e) s^)wh v`C
{ IEmtt^C
e.printStackTrace (); rs`H':a/
} R^{Ow
"O!J6
7`thM/fN
return n; &Vd,{JU
} $&OoxC
DfXXN
2aNCcZw0
} vdyLwBz:
t6W$t
/n"Ib)M
/* {|9x*I
**SiteInfoBean.java 'P3CgpF<Z2
*/ 9~J
package NetFox; ou0(C`
7`9J.L&,;
{=pRU_-^
public class SiteInfoBean { }'U"HHv
xPl+ rsU
A'^y+42jY
private String sSiteURL; //Site's URL $<xa "aN!
private String sFilePath; //Saved File's Path !yI , ~`Z
private String sFileName; //Saved File's Name 5|._K(M
private int nSplitter; //Count of Splited Downloading File fRS)YE@a:
@doo2qqIe]
h&|q>M3
public SiteInfoBean() .KSPr
{//nSplitter的缺省值为5 :FcYjw
//default value of nSplitter is 5 kmXpj3
this("","","",5); Lf`LFPKb
} bKRz=$P?
?BtWM4Id8
;4tmnC>OnA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %eW[`uyV
{ kGR5!8$z
sSiteURL= sURL; +n_`*@SE
sFilePath = sPath; *.nC'$-2r
sFileName = sName; lv\C(^mGq
this.nSplitter = nSpiltter; F0 x5(lpQ
G9"2h \
_?$P?
} X2^`Znq9
A14}
%P05k
public String getSSiteURL() = zJY5@^'7
{ 5:ca6H
return sSiteURL; MDI[TNYG
} 9,g &EnvG
~`-z"zM:p
|a/1mUxQ&
public void setSSiteURL(String value) 46^LPC"x
{ gwHNz5 a*V
sSiteURL = value; 94Wf ]
} 2@ 4^ 81
CDOqdBQ
5[NF
public String getSFilePath() 29#&q`J
{ ;/.ZjTRw
return sFilePath; /4w"akB|P
} rWk4)+Tk
,2hZtJ<A
ma9VI5w
public void setSFilePath(String value) U)mg]o-VE
{ e+J|se4L5
sFilePath = value; PW a!7n#A
} "7Qc:<ww
{p#[.E8
7I.7%m,g
public String getSFileName() :i'jQ<|wZN
{ #IH7WaN
return sFileName; k8]=5C?k
} =FZt
ZLK@x.=
6uWzv~!*D
public void setSFileName(String value) %) A-zzj
{ cQj{[Wt4
sFileName = value; \g|u|Y.2[
} ;Kb]v\C:
8GC(?#Kb
("HT0&#a
public int getNSplitter() P=ARttT`(
{ jU K0?S>
return nSplitter; =l&A9 >\
} ,]ALyWGuX
F,B,D^WD
7=jeq|&kN
public void setNSplitter(int nCount) )2c[]d/a4
{ \W73W_P&g
nSplitter = nCount; G[U'-a}I
} (bP\_F5D
} 9p,<<5{
gB\ a
CfFNk "0{
/* iRwqt-WZ
**Utility.java (+g!~MP
*/ \]AsL&
package NetFox; lqC a%V
5x/q\p-{/
2+G_Y>
public class Utility { HRF4 Ro
v5i?4?-Z
wg?:jK
public Utility() .F=15A
{ ?&Y3Fr)%
sePOW#|
w+vYD2a
} *GsrG*OM*D
.^s%Nh2jM
//线程睡眠 h 9V9.'
public static void sleep(int nSecond) _"`wUMee
{ % ~%>3
try{ 6"Tr$E
Thread.sleep(nSecond); A{hwT,zV:
} ~mUP!f
catch(Exception e) hk"^3d!
{ htg+V-,
e.printStackTrace (); ZgO7W]Z4
} e=nExY
} ]2Aqqy
x9PEYhL?
//日志 ;8sEE?C$g
public static void log(String sMsg) LQYT/
{ x@bZ((w
System.err.println(sMsg); zqAK|jbL
} 6USet`#
Ch ` Omq
d87pQ3e:&
public static void log(int sMsg) {: EQ
{ DSix(bs9
System.err.println(sMsg); m^_)aS
} Ki-CJy
} Ov%9S/d
Jg|3Wjq5
S5RS?ya
/* ^sH1YE}0
**TestMethod.java *n?6x!A
*/ ]\P
package NetFox; FQi"OZHq
4BuS? #_
BU:s&+LYUv
public class TestMethod { cZL"e
zE.4e&m%Z?
n*D)RiW
public TestMethod() I}Q3B3Byg
{ ///xx/weblogic60b2_win.exe `Pl=%DR
try{ cJ:BEe
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NLb/Bja
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .(;k]UP
SiteFileFetch fileFetch = new SiteFileFetch(bean); (B]Vw+/
fileFetch.start(); SVXey?A;CJ
} _F^|n}Qbj
catch(Exception e){e.printStackTrace ();} z!Jce}mx
?Pmj}f
}9P)<[>
} \ox:/-[c\<
oB9Fas!N
P9`i6H'~
public static void main(String[] args) 1[3"|
{ 2%vwC]A
new TestMethod(); oF V9t{~j
} KU33P>a"[k
} e%'9oAz
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