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)); [~W"$sT
} #@;RJJZg
for(int i=0;i<nEndPos.length-1;i++) {<\nl#}5S
{ V);{o>%.K
nEndPos = nStartPos[i+1]; [0lCb"
} 'D1 T"}
nEndPos[nEndPos.length-1] = nFileLength; N~;=*)_VH
} ua0`&,a3I
} WQ\'z?P
dFjB &#Tl
Gk;==~
//启动子线程 WLP A51R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Qi&!IG
for(int i=0;i<nStartPos.length;i++) hvtg_w6K
{ %DqF_4U9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A@Z&ZBDg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y5kqnibh@
nStartPos,nEndPos,i); czi$&(N0w$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %ErLL@e
fileSplitterFetch.start(); L Bb&av
} Cl7IP<.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1tDd4r?Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m>x.4aO1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \;&j;"c,W
nEndPos = " + nFileLength); :2^%^3+V
// fileSplitterFetch[nPos.length-1].start(); KqP!={>"
SuB;Nb7r`
c_~)#F%P
//等待子线程结束 |qH-^b.F
//int count = 0; Sqed*
//是否结束while循环 Lp5LRw
boolean breakWhile = false; >to NGGU=~
[<}:b>a
x>A(016:C
while(!bStop) /1zi(z
{ \L}Soe'
write_nPos(); f>s3Q\+
Utility.sleep(500); !e?=I
breakWhile = true; "A~\$
awB1ryrOF
89v9BWF
for(int i=0;i<nStartPos.length;i++) DxdiXf[j
{ j5Vyo>
if(!fileSplitterFetch.bDownOver) :7KcD\fCj
{ \zR@FOl`q
breakWhile = false; q{ItTvL
break; S;kI\;
} &?"(al?
} Zgkk%3'^'
if(breakWhile) M/x49qO#
break; ( MWh|kp
eGHxiC
^ b{0|:
//count++; Jt\?,~,
//if(count>4) &p8b4y_
// siteStop(); -M2c8P:.b
} <.HX_z3l
m=jxTZK
z4!TK ps
System.err.println("文件下载结束！"); ?x7zYE,6
} &W`."
catch(Exception e){e.printStackTrace ();} gXZC%S
} dT4?8:
W=|sy-N{2
*IG} /O.VT
//获得文件长度 X!ZUR^
public long getFileSize() qa)X\0
{ )cJ9YKKy
int nFileLength = -1; zlco?Rt
try{ =3$JeNK9
URL url = new URL(siteInfoBean.getSSiteURL()); Qh<_/X?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w6zB uW
httpConnection.setRequestProperty("User-Agent","NetFox"); wwE`YY
|k1(|)%G
V|e9G,z~A
int responseCode=httpConnection.getResponseCode(); VI: !#
if(responseCode>=400) es 8%JTi
{ &<2~7?$!
processErrorCode(responseCode); m X{_B!j^
return -2; //-2 represent access is error ;9PJ K5>~
} f]W$4f{
%ZF47P%6
[v( \y
String sHeader; Q'/v-bd?o
/FJ )gQYA
/Fy2ZYs,`8
for(int i=1;;i++) b-ZC~#?|b
{ ^&F8NEb=2>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h)fJ2]JW8W
//Utility.log(in.readLine()); fQ33J>
sHeader=httpConnection.getHeaderFieldKey(i); `n7*6l<k~4
if(sHeader!=null) Z`y%#B6x.
{ Y> ElE-
if(sHeader.equals("Content-Length")) 1vk&;
{ Opx"'HC@G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OPOL-2<wiy
break; bHZXMUewC
} nb::,
} ]awu7}C9Z
else luXcr H+w
break; 0`VA}c
} mj:X'BVA
} @px2/x
catch(IOException e){e.printStackTrace ();} 1ml>
catch(Exception e){e.printStackTrace ();} = i9|lU"Va
(Qq;ySZ#
7%DA0.g
Utility.log(nFileLength); "I+71Ce
}TE4)vXs
7vO3+lT/Y;
return nFileLength; i E p{
} uvC ![j^~
9jW/"
M9so3L<N0
//保存下载信息（文件指针位置） $fZVh%
private void write_nPos() w6FtDl$
{ P(AcDG6K
try{ |rW,:&;
output = new DataOutputStream(new FileOutputStream(tmpFile)); n1n->l*HGP
output.writeInt(nStartPos.length); s\&qvL1D
for(int i=0;i<nStartPos.length;i++) Ot,eAiaX
{ ukNB#2"
// output.writeLong(nPos); .rpKSf.
output.writeLong(fileSplitterFetch.nStartPos); is`O,Met
output.writeLong(fileSplitterFetch.nEndPos); N~Zcrt_D
} R8ZI}C1
output.close(); En-BT0o
} (Klvctoy
catch(IOException e){e.printStackTrace ();} =, kH(rp2
catch(Exception e){e.printStackTrace ();} >wx1M1
} Q|T9tc->
tA;#yM;
/A$mP)}tz
//读取保存的下载信息（文件指针位置） yvN;|R
private void read_nPos() gLp7<gx6
{ (b!`klQ
try{ <;)qyP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Rf*cW&}%
int nCount = input.readInt(); o}QtKf)W
nStartPos = new long[nCount]; U4PnQ K,
nEndPos = new long[nCount]; -hv<8bC~4
for(int i=0;i<nStartPos.length;i++) sUl/9VKl
{ A_nu:K-
nStartPos = input.readLong(); Z'/sZ3Q}
nEndPos = input.readLong(); RC{|:@]8
} y*K]z
input.close(); hf#[Vns
} LYM(eK5V
catch(IOException e){e.printStackTrace ();} &.D#OnRh9
catch(Exception e){e.printStackTrace ();} %#gHa
} aG&ay3[&
s,~)5nL
>2kjd
private void processErrorCode(int nErrorCode) Owt|vceT
{ zNg8Oq&
System.err.println("Error Code : " + nErrorCode); 67,@*cK3?J
} `]*BDSvE
7l+>WB_]
d4(!9O.\
//停止文件下载 w+MCOAB
public void siteStop() !u0|{6U
{ (zv)cw%
bStop = true; znVao %b
for(int i=0;i<nStartPos.length;i++) Fkq;Q
fileSplitterFetch.splitterStop(); 0{0A,;b
<Wz+f+HC
)2lzPK t
} ?|}%A9
} .|d2s
//负责部分文件的抓取 Fqr}zR)
**FileSplitterFetch.java v7Q=
*/ 6xfG`7Az
package NetFox; "V7 SB
s01W_P.@R
T~Z7kc'
import java.io.*; P%%[_6<%M
import java.net.*; 8AX+s\N
Rq,ST:
*U{E[<k{
public class FileSplitterFetch extends Thread { Wu:@+~J.h
R\VM6>SN'S
j4C{yk
String sURL; //File URL *d%U]Hby,
long nStartPos; //File Snippet Start Position Xj;\ROBH-
long nEndPos; //File Snippet End Position f*uD9l%/
int nThreadID; //Thread's ID XwerQwO=
boolean bDownOver = false; //Downing is over )U$]J*LI
boolean bStop = false; //Stop identical Vy+UOV&v-
FileAccessI fileAccessI = null; //File Access interface ~sk{O%OI
uoX] #<1J
+WGL`RP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RMrrLT
{ ,sn/FT^; q
this.sURL = sURL; +[2X@J
this.nStartPos = nStart; rEWPVT
this.nEndPos = nEnd; F~qiNV
nThreadID = id; VlLc[eVV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !"dn!X
} 9[L@*7A`m
?M02|8-
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public void run() fxR}a,a
{ $ 2/T]
while(nStartPos < nEndPos && !bStop) BAQ;.N4
{ 4t Z. T9d
@qGg=)T
vWM'}(
try{ [+j39d.Q
URL url = new URL(sURL); pbM"tr_A{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P0/B!8x
httpConnection.setRequestProperty("User-Agent","NetFox"); *,Mg
String sProperty = "bytes="+nStartPos+"-"; Xy;!Q`h(
httpConnection.setRequestProperty("RANGE",sProperty); Z T5p
Utility.log(sProperty); 6Eu&%`
@Z50S 8
Gkfc@[Z V
InputStream input = httpConnection.getInputStream(); .W9/*cZV0
//logResponseHead(httpConnection); cdH Ug#
~w>Z !RuhT
Ob|[/NN
byte[] b = new byte[1024]; l:Y$A$W]>
int nRead; [;]@PKW?w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JN{xh0*
{ _tGR:E
nStartPos += fileAccessI.write(b,0,nRead); e1k\:]6
//if(nThreadID == 1) cuw3}4m%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OR\-%JX/5
} 0lvX,78G;
VB?mr13}G
+]!`>
Utility.log("Thread " + nThreadID + " is over!"); qZ39TTQ*p
bDownOver = true; JMT?+/Qbu
//nPos = fileAccessI.write (b,0,nRead); kOe~0xoT@u
} 4]\t6,Cz8
catch(Exception e){e.printStackTrace ();} 9hG+?
} YBX7WZCR
} i"rrM1/r
!`VO#_TJ
&M,"%w!
//打印回应的头信息 BBg&ZIYEh
public void logResponseHead(HttpURLConnection con) F[ Itq
{ P'nbyF
for(int i=1;;i++) 9t$%Tc#Z
{ =&-hU|ur
String header=con.getHeaderFieldKey(i); [SW@"C!
if(header!=null) <IF\;,.c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jZ'y_
Utility.log(header+" : "+con.getHeaderField(header)); <N{pMz
else iZ`1Dzxgk
break; us.+nnd
} N1V qK
} Q&rf&8iH
J)l]<##
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public void splitterStop() VH{SE7
{ y %k`
bStop = true; '(/ZJ88JP
} 'z#{'`$a
(VPT% l6
Yg;g!~
} q5$z:'zE
mX8A XWIa
vWJhSpC[
/* ,u}n!quA
**FileAccess.java 328(W
*//文件访问(定位，写) ':7%@2Zo
package NetFox; Q7y6</4f
import java.io.*; -S=Zsr\
HA{-XPAWZ
;z9(
public class FileAccessI implements Serializable{ NVnKgGlHgd
lPS A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (u]ajT
RandomAccessFile oSavedFile; Bc4{$sc"O
long nPos; J! 4l-.-
;3n0 bKDY
}*n(RnCn
public FileAccessI() throws IOException lQ%]](a6
{ 's{-1aW
this("",0); h(;qnV'c
} o8P 5C4y
hfY Ieb#91
? OBe!NDf
public FileAccessI(String sName,long nPos) throws IOException ^i{B8]2,
{ %*.;3;m
oSavedFile = new RandomAccessFile(sName,"rw"); xDBEs*
this.nPos = nPos; r\Wp\LfY&{
oSavedFile.seek(nPos); j$*]'s&_hZ
} -Uz xs5Zl
1K'0ajl1A
q{UP_6OF
public synchronized int write(byte[] b,int nStart,int nLen) m_H$fioha,
{ R]%ZqT{PS
int n = -1; h2Ifq!(:
try{ oHmU|
oSavedFile.write(b,nStart,nLen); 9p!V?cH#8
n = nLen; n=RAE^[M
} k=[!{I
catch(IOException e) -[#Mx}%
{ vd-`?/,||
e.printStackTrace (); tg~&kaz
} 66=6;77
E{r_CR+8
,_T,B'a:
return n; "b*.>QuZ
} $ 8w eh3p
=JyYU*G4
)2oWoZvi9
} |xH"Xvp:
J`O4]XRY
ewgcpV|spn
/* @2 dp5
**SiteInfoBean.java asR6,k
*/ XJ]MPiXj
package NetFox; >b-rAO\{}
UD*#!H
@Qx|!%
public class SiteInfoBean { d@"eWvnlZ
-!MDYj+U
ew4IAF
private String sSiteURL; //Site's URL @hm%0L
private String sFilePath; //Saved File's Path TE*$NxQ 2
private String sFileName; //Saved File's Name 0+8ThZ?n
private int nSplitter; //Count of Splited Downloading File ;,'!
kTex>1W;
*6Rl[eXS
public SiteInfoBean() 'N5qX>Ob
{//nSplitter的缺省值为5 1X2oz
//default value of nSplitter is 5 C[rYVa .
this("","","",5); Y[T;j p(k
} Ii*v(`2b
)?pin|_x
hzPx8sO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5vYh~|
{ "h7-nwm
sSiteURL= sURL; hC]c =$=7
sFilePath = sPath; jjvm<;lv
sFileName = sName; "JVzv U]
this.nSplitter = nSpiltter; D +)6#i Y
S:vv*5
{H $\,
} dqUhp_f2qK
F4Ft~:a
U3lr<(r*
public String getSSiteURL() |i?AtOt@f
{ p`1d'n[
return sSiteURL; |gxU;"2`5~
} Xk]5*C]6<
X@9_ukdpu
2k"a%#H8
public void setSSiteURL(String value) /~7H<^}
{ w}NgFrL
sSiteURL = value; A i9*w?C
} K;6K!6J:[
tb/u@}")
*&UVr
public String getSFilePath() y%TR2CvT
{ Jkm\{;
return sFilePath; 2WE
} I6y&6g
yc]ni.Hz
0 nWV1)Q0=
public void setSFilePath(String value) rxa"ji!)
{ cw"x0 RS
sFilePath = value; _gC<%6#V`r
} EemKYcE@Nr
%/etoK
|,dMF2ADc
public String getSFileName() tt J,rM
{ G:WMocyXI'
return sFileName; ]N=C%#ki!
} .2xypL8(
tsfOPth$*
YXIDqTA+
public void setSFileName(String value) f[.hN
{ 0A?w,A`"
sFileName = value; a' #-%!]
} Q(]-\L'
&1Cq+YpI
d'[aOH4}
public int getNSplitter() 0E\R\KO$>
{ D<++6HN&#
return nSplitter; Mh+'f 93
} >j`*-(`2fa
i;)g0}x`
b1[U9
public void setNSplitter(int nCount) 5)$U<^uy
{ /=e[(5X|O
nSplitter = nCount; sWavxh8A
} ziH2<@
} j~Gu;%tq
bq(*r:`"
[PX'Jer
/* BLaXp0
**Utility.java 'dU$QO
*/ RTY$oUqlZ
package NetFox; o=`9JKB~
sM5 w~R>Y
^G2vA8%
public class Utility { 3lL:vD5(
M0]l!x#7
6J|f^W-fs
public Utility() mu{%%b7|^
{ X2@o"xU
$}KYpSV
@{CpC
} :>3&"T.
c(Ha"tBJ
//线程睡眠 rM=Hd/ki5
public static void sleep(int nSecond) {eZj[*P
{ #[KwR\b{:+
try{ 4tuEC-oh
Thread.sleep(nSecond); \~?s= LT
} E?9_i :IX
catch(Exception e) 1MahFeQ[
{ 8OFrW.>[
e.printStackTrace (); ZcWl{e4
} Y}?@Pm drz
} E,6E-9
rk. UW
//日志 \FKIEg+(2
public static void log(String sMsg) 6op\g].P
{ RDqC$Gu
System.err.println(sMsg); /GeS(xzQ
} ZDDwh&h
,@!d%rL:4]
S~TJF}[k^6
public static void log(int sMsg) Z^~6pH\
{ %@xYg{
System.err.println(sMsg); KdR&OBm
} <.v6w*+{/
} n9J>yud|
[KE4wz+s{
BuvBSLC~
/* u?J(l)gd
**TestMethod.java CD tYj
*/ Q-au)R,
package NetFox; -[`W m7en
5:PZ=jPR
B}FF |0<
public class TestMethod { n=>Gu9`
xeH#)QJt
l|fd,
public TestMethod() A+}4N%kh
{ ///xx/weblogic60b2_win.exe =|#-Rm^YB
try{ PA=BNKlH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W1!eY,1}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "Jwz.,Y\
SiteFileFetch fileFetch = new SiteFileFetch(bean); Grub1=6l
fileFetch.start(); +]e4c;`ko}
} 5 O6MI4:
catch(Exception e){e.printStackTrace ();} FD-)nv2:
b;O+QRa
8&;dR
} }dR*bG
UetmO`qju
zSH#j RDV
public static void main(String[] args) kj#yG"3+
{ ~k%\ LZ3s
new TestMethod(); )~n}ieS
} +OH."4Z
} V&nN/CF
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