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)); #_|^C(]!
} k<hO9;#qpL
for(int i=0;i<nEndPos.length-1;i++) I~6 ;9TlQ
{ d>-EtWd
nEndPos = nStartPos[i+1]; z2zp c^i
} | N,nt@~
nEndPos[nEndPos.length-1] = nFileLength; >c>ar>4xF
} xEWa<P#.u
} tEb2>+R
L[IjzxUv
5o&L|7]
//启动子线程 /bg8oB4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3fpX
for(int i=0;i<nStartPos.length;i++) S7-?&[oeJ
{ .2OP>:9F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =PXNg!B}D*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m`n51i{U
nStartPos,nEndPos,i); ; <3w ,r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZSxKk6n}J
fileSplitterFetch.start(); K{HdqmxL.I
} )-[X^l j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K&Zdk (l)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @@}A\wA-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ](^VEm}w;
nEndPos = " + nFileLength); %$Mvq&ZZ
// fileSplitterFetch[nPos.length-1].start(); QTM+WD
61CNEzQ
B7va#'ne4{
//等待子线程结束 yU&A[DZQ
//int count = 0; HH8a"Hq)
//是否结束while循环 I5PaY.i
boolean breakWhile = false; ">NBPanJ
(Z sdj
W>'R<IY4#N
while(!bStop) $ 5
{ QR<IHE{~8
write_nPos(); [JsQ/|=z
Utility.sleep(500); <"aPoGda
breakWhile = true; ^i#F+Q`1
sLb[ZQ;j
H|==i2V{
for(int i=0;i<nStartPos.length;i++) \/lH]u\x
{ naW}[y*y;
if(!fileSplitterFetch.bDownOver) T3Qa[>+\
{ TC"mP!1
breakWhile = false; %F1 Ce/
break; MhHygZT[}
} *}cF]8c5W
} e>y"V;Mj
if(breakWhile) B4_0+K H
break; (N0G[(>
!Vv$
a{,EX[~b
//count++; =M ?
//if(count>4) ?,TON5Fl-
// siteStop(); ^~8l|d_
} i{!i%`"
a*KB'u6&
-E?h^J&U
System.err.println("文件下载结束！"); xsV(xk4
} ES<"YF
catch(Exception e){e.printStackTrace ();} )$i7b
} 0=yKE J
%)u5A!"
E;9SsA
//获得文件长度 d*7 Tjs{\
public long getFileSize() %dKUB4
{ bxK1v7
int nFileLength = -1; ^+Ec}+ Q
try{ 0ppZ~}&
URL url = new URL(siteInfoBean.getSSiteURL()); ] +LleS5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [D^KM|I%+
httpConnection.setRequestProperty("User-Agent","NetFox"); 0r.*7aXu
t/#[At5p=
Pv+[N{
int responseCode=httpConnection.getResponseCode(); +}J2\!Jw
if(responseCode>=400) t%/Y^N;
{ wBA[L}
processErrorCode(responseCode); Cn[`]
return -2; //-2 represent access is error 3;>|*(cO
} Lg sQz(-
oost}%WxN
~NMal]Fwx
String sHeader; 5NZob<<
0' @^PzX
&zynfj#o
for(int i=1;;i++) 7eqax33f
{ bN8GRK )
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <9@I50;
//Utility.log(in.readLine()); hp@giu7
sHeader=httpConnection.getHeaderFieldKey(i); KE]!7+8-
if(sHeader!=null) I;S[Ft8d
{ [ft#zxCJ
if(sHeader.equals("Content-Length")) _O Tqm5_
{ KLGhsx35
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cP''
break; c6:"5};_
} y<.0+YL-e+
} !NUsfd
else DK}k||-
break; )Fe-C
} (`>RwooE
} ZqsI\"bj
catch(IOException e){e.printStackTrace ();} Y4sf 2w
catch(Exception e){e.printStackTrace ();} 0Y,_ DU
Uvgv<OR`_
rDX_$,3L
Utility.log(nFileLength); 0(iTnzx0
OW<i"?0
4&~ft
return nFileLength; ,3Y~ #{,i
} *-(J$4RNz
'j6PL;~c
J*Dj`@`4`g
//保存下载信息（文件指针位置） "45O!AjP
private void write_nPos() ja3wXz$2
{ (Hb i+IHV
try{ +|Z1U$0g
output = new DataOutputStream(new FileOutputStream(tmpFile)); e;5n.+m
output.writeInt(nStartPos.length); ,R5NKWo
for(int i=0;i<nStartPos.length;i++) axW3#3#`
{ Nc:, [8{l
// output.writeLong(nPos); V'sp6:3*\
output.writeLong(fileSplitterFetch.nStartPos); J)vP<.3:
output.writeLong(fileSplitterFetch.nEndPos); QijEb
} 8 !]$ljg
output.close(); L!x7]g,^
} `d2}>
catch(IOException e){e.printStackTrace ();} ?sWPx!tU
catch(Exception e){e.printStackTrace ();} S^? @vj
} &2C6q04b
P*_!^2
OiH tobM
//读取保存的下载信息（文件指针位置） C2NJrg4(
private void read_nPos() r e.chQ6
{ -e_IDE
try{ %wn|H>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [hSE^ m
int nCount = input.readInt(); A rC4pT
nStartPos = new long[nCount]; vU0j!XqE
nEndPos = new long[nCount]; Is&z~Xy/
for(int i=0;i<nStartPos.length;i++) 2j&-3W$^
{ L\_MZ*<0[
nStartPos = input.readLong(); `W,gYH7
nEndPos = input.readLong(); z6 2gF|Uj
} :M)B#@ c=
input.close(); NPc]/n?vDj
} ikf!7-,
catch(IOException e){e.printStackTrace ();} n=!]!'h\:
catch(Exception e){e.printStackTrace ();} ~?4'{Hc'
} @ de_|*c
>U.TkB
)X2=x^u*U
private void processErrorCode(int nErrorCode) ]4wyuP,up
{ HTiqErD2_
System.err.println("Error Code : " + nErrorCode); }w .[ZeP
} N)|mA)S)
IH8^ fyQ`
8wz%e(
//停止文件下载 o5?f]Uq5 ,
public void siteStop() I}a`11xb`
{ m?bd6'&FR
bStop = true; d7s? c
for(int i=0;i<nStartPos.length;i++) /T&z :st0
fileSplitterFetch.splitterStop(); 0Ou;MU*v
Q-o}Xnj*!L
`_Iy8rv:P
} 17g\XC@ Cl
} |6/k2d{,(
//负责部分文件的抓取 2>BWu
**FileSplitterFetch.java $/^DY&
*/ 0Y[LzLn
package NetFox; {`5Sh1b
N"Y)
F|p&v7T
import java.io.*; pJ35M
import java.net.*; +k|t[N
*ub]M3O
[r,a0s
public class FileSplitterFetch extends Thread { C-!!1-Eq?:
KP{|xQ>
feM%-
String sURL; //File URL xL8r'gV@
long nStartPos; //File Snippet Start Position i}teY{pyc
long nEndPos; //File Snippet End Position 8|kr|l
int nThreadID; //Thread's ID /RD@ [ 8
boolean bDownOver = false; //Downing is over g-`HKoKe
boolean bStop = false; //Stop identical LVNq@,s
FileAccessI fileAccessI = null; //File Access interface Ibt~e4f
N~7xj?
I3 /^{-n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +vOlA#t%Z
{ tPu0r],`o
this.sURL = sURL; umPd+5i
this.nStartPos = nStart; ;UuCSfs{
this.nEndPos = nEnd; $:IOoS|e
nThreadID = id; CqW:m*c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0/{$5gy&
} ]WlE9z7:8
o5=1
thG;~W
public void run() #OlU|I
{ irj{Or^k
while(nStartPos < nEndPos && !bStop) /5cFa
{ #[ZF'9x
k?r-%oJ7
HJ4T! `'d
try{ j8Nl'"
URL url = new URL(sURL); 4n6EkTa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5G5P#<Vv
httpConnection.setRequestProperty("User-Agent","NetFox"); g\9I&z~?
String sProperty = "bytes="+nStartPos+"-"; p4l^b[p
httpConnection.setRequestProperty("RANGE",sProperty); Wp2b*B=-
Utility.log(sProperty); },r30`)Q
kU uDA><1
5=< y%VF
InputStream input = httpConnection.getInputStream(); u,h,;'J
//logResponseHead(httpConnection); FR%9Qb7
c6 O1Z\M@\
5:3%RTLG
byte[] b = new byte[1024]; $|J16tW
int nRead; 1Z9_sd~/6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p)_v.D3i
{ iWCR5c=
nStartPos += fileAccessI.write(b,0,nRead); 21(8/F ~{
//if(nThreadID == 1) O>8|Lc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sK1YmB :~a
} S"t6 *fWr
[!^Q_O
I~:vX^%9
Utility.log("Thread " + nThreadID + " is over!"); >lyX";X#
bDownOver = true; 3O{*~D&n
//nPos = fileAccessI.write (b,0,nRead); eK<X7m^
} g&z)y
catch(Exception e){e.printStackTrace ();} SZ/}2_;
} $bf&ct*$h
} (_:k s
lrn3yDkR?
+TA'P$j
//打印回应的头信息 . X(^E
public void logResponseHead(HttpURLConnection con) "Jd!TLt\x
{ G8]DK3#
for(int i=1;;i++) X5s.F%Np!
{ +sN'Y/-
String header=con.getHeaderFieldKey(i); ixK&E#
if(header!=null) <Mdyz!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^,P# <,D,
Utility.log(header+" : "+con.getHeaderField(header)); j`fQN
else ld RV JVZc
break; wR7Ja cKv
} |rjHH<
} 8$!&D&v
'hEvW
79DzrLu
public void splitterStop() }6Ut7J]a|
{ % oPt],>
bStop = true; wiwAdYEQ\
} (d> M/x?W
vbo|q[z
gD13(G98
} 7P+qPcRaP
~}lYp^~:J
y4@zi"G
/* Q9i&]V[`
**FileAccess.java {Xw6]d
*//文件访问(定位，写) iMT[sb
package NetFox; `l#|][B)g$
import java.io.*; {V8yJ{.G
nrhzNW>]
wjq;9%eXk
public class FileAccessI implements Serializable{ D(E3{\*R
t!=qt*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |41NRGgY
RandomAccessFile oSavedFile; v>XAzA
long nPos; s%&/Zt
?Iin/<y
1BjMVMH
public FileAccessI() throws IOException %Tv2op
{ q&DM*!Jq
this("",0); `{Jo>L.
} ?Z0NHy;5
<M y+!3\A
H|.cD)&eYy
public FileAccessI(String sName,long nPos) throws IOException &Hi;>
{ |zkZF|-
oSavedFile = new RandomAccessFile(sName,"rw"); )bgaqca_{
this.nPos = nPos; m8T< x>
oSavedFile.seek(nPos); ; u@& [
} NimW=X;c
G%HuB5:u
m|M'vzu1
public synchronized int write(byte[] b,int nStart,int nLen) sGp]jqX2,m
{ lz [s
int n = -1; MQY}}a-oug
try{ (-[73v-w
oSavedFile.write(b,nStart,nLen); iLbf:DXK(
n = nLen; MS~+P'
} 4G_At
catch(IOException e) )ppIO"\
{ -z~;f<+I`
e.printStackTrace (); aGml!N5'
} _)U.5f<
6ec#3~ Y]
P?o|N<46
return n; >+FaPym
} t)l
f.G"[p
d=DQS>Nz
} )gHfbUYS
;i,3KJ[L
>3?p23|;
/* 7t3ps
**SiteInfoBean.java GO]5~4k
*/ d` X1cG
package NetFox; AF\gB2^
$1uT`>%
E0)43
public class SiteInfoBean { oe*CZ
^oMdx2Ow#
@h,3"2W{Ev
private String sSiteURL; //Site's URL _J X>#h
private String sFilePath; //Saved File's Path FaLc*CU
private String sFileName; //Saved File's Name eXAJ%^iD
private int nSplitter; //Count of Splited Downloading File gVI{eoJ
/^sk y!
tUk)S
public SiteInfoBean() (3?W)i
{//nSplitter的缺省值为5 [.'9Sw
//default value of nSplitter is 5 2C AR2V|
this("","","",5); LUzn7FZk
} uI\6":/u
\IP 9EFA
2&zklXuo:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PJL [En*
{ !LJ4 S
sSiteURL= sURL; $'n?V=4
sFilePath = sPath; Om(Ir&0
sFileName = sName; "i,ZG$S#E
this.nSplitter = nSpiltter; x c|1?AFj
3}lIY7O
2j&0U!DX
} snYyxi
9p,PWA
<DN7
public String getSSiteURL() gu"@*,hL
{ $ZkT G
return sSiteURL; t=fr`|!
} jAdZS\?w
\ #N))gAQ
89j*uT
public void setSSiteURL(String value) /vI"v4
{ M<r]a{Yv
sSiteURL = value; +DaKP)H\:
} ft1V1 c
Q^8/"aV\
^% L;FGaA
public String getSFilePath() !JtM`x/yR
{ iB5q"hoZC
return sFilePath; (7ujJ}#,
} Dq-[b+bm
VRTJKi
/VD[:sU7
public void setSFilePath(String value) S9[Y1qH>K
{ \Hw*q|
sFilePath = value; 5Z:T9F4
} fw5+eTQ^
t'Zv)Wu1E
=@c;%x
public String getSFileName() #pyFIUr=w
{ }0sLeGJ!
return sFileName; <"8F=3:uk
} <7! "8e
egAYJK-,!
hcM9Sx"!
public void setSFileName(String value) 4I9Yr
{ kek/C`7
sFileName = value; _5S||TuNS
} uw/N`u
^\[c][fo
_GM?`
public int getNSplitter() <{h\Msx%
{ hhz#IA6,
return nSplitter; {|@}xrB
} ^"~r/@l
`q`ah_
j7$xHnV4
public void setNSplitter(int nCount) .IM]B4m
{ *U}-Y*
nSplitter = nCount; YkE_7r(1
} x!7r7|iV
} L2_[M'
u8t|!pMF8
&8yGVi
/* E;9J7Q 4
**Utility.java hk$I-
*/ zg'.fUZ
package NetFox; K#'$_0.
22;B:
i8p$wf"aW
public class Utility { ?!<Q8=
?JTTl;
RNQq"c\
public Utility() )\PX1198
{ )wXE\$
c`&g.s@N\
^Bo'87!.
} s5 {B1e
E0l&d
//线程睡眠 `'*4B_.
public static void sleep(int nSecond) f$9|qfW'$
{ &5.J y2hO]
try{ "q1S.3V;
Thread.sleep(nSecond); P;K LN9/4
} XR3 dG:
catch(Exception e) &}0QnO_mj
{ 4)>UTMF
e.printStackTrace (); zY7M]Az
} *4LRdLMn
} iq?T&44&
e igVT4
//日志 H+-x.l`
public static void log(String sMsg) F6{/iF
{ l'M/et{:
System.err.println(sMsg); M2RkrW#
} mdQe)>
n%G[Y^^,
r%WHYhD
public static void log(int sMsg) u8<[Q]5
{ &<_q00F
System.err.println(sMsg); Mk=*2=d
} C[hNngb7R
} p&u\gSo
jJNl{nyq
LAM{ ,?~
/* 6rWq hIaI
**TestMethod.java >R_m@$`
*/ KaS*LDzw
package NetFox; (v KJyk+Y
Y~Vc|zM^(
2L[!~h2
public class TestMethod { lZe-A/E
ujN~l_4
)E7wBNV
public TestMethod() b/JjA
{ ///xx/weblogic60b2_win.exe }EHL }Q
try{ 1*$6u5.=F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); | oM`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;$1x_ Cb
SiteFileFetch fileFetch = new SiteFileFetch(bean); JUj.:n2e
fileFetch.start(); ntB#2S
} :;hX$Qz
catch(Exception e){e.printStackTrace ();} #`U?,>2q
s]`6uyW"
d0|{/4IWw;
} 4M|C>My
~;pP@DA
R/fE@d2~In
public static void main(String[] args) 0bJT0_
{ 4 #KC\C
new TestMethod(); \o3s&{+y,
} H^`J(J+
} J}4RJ9
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