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)); cYM~IA
} U+PCvl=x
for(int i=0;i<nEndPos.length-1;i++) Cz@FZb8
{ TDFO9%2c
nEndPos = nStartPos[i+1]; ^b!7R <>~
} mH*@d"
nEndPos[nEndPos.length-1] = nFileLength; $7n#\h
} iSr`fQw#
} Ivt} o_b*
L>Oy7w)Y
gJ5wAK+?
//启动子线程 bV$8 >[`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3$N %iE6
for(int i=0;i<nStartPos.length;i++) ^jha:d
{ 9c^skNbS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B >u,)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D<bU~Gd,P
nStartPos,nEndPos,i); [Ba2b: l6v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W`u$7k]$
fileSplitterFetch.start(); =Etwa
} _TOi [GT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y,v0-o~q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <L/M`(:=k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XK%W^a*x
nEndPos = " + nFileLength); Q5y q"/=[a
// fileSplitterFetch[nPos.length-1].start(); e-iYJ?
,V33v<|wc
J7ktfyQ0W
//等待子线程结束 `xX4!^0Hm
//int count = 0; PPCTc|G
//是否结束while循环 $35,\ZO>
boolean breakWhile = false; VXkAFgO
KIKq9*
A3"1D
while(!bStop) umm\r&]A
{ *"ykTqa
write_nPos(); kQwm"Z
Utility.sleep(500); +2EHmuJ;
breakWhile = true; ]D{c4)\7C|
Bn1L?>G
2~M;L&9-
for(int i=0;i<nStartPos.length;i++) dqD;y#/
{ 8K.s@<
if(!fileSplitterFetch.bDownOver) oE!hF}O
{ i'!jx.
breakWhile = false; cBab2/
break; 2{mY:\
} ?-8y4 Ex
} "J P{Q
if(breakWhile) >HcYVp~G
break; TwM1M["3
m|[\F#+C
nY{i>Y
//count++; NokXE
//if(count>4) U~{Sa+
// siteStop(); gb=80s0
} YER:ICQ
ZI58XS+
DYo<5^0
System.err.println("文件下载结束！"); wi\z>'R
} Y_[g_
catch(Exception e){e.printStackTrace ();} 5ys#L&q'Z
} oUQGLl!V
b&=]S(
7.Ml9{M/i
//获得文件长度 <`c25ih.4
public long getFileSize() v9E+(4I9_
{ &<gUFcw7Ui
int nFileLength = -1; 7szls71/=
try{ j`2B}@2
URL url = new URL(siteInfoBean.getSSiteURL()); MV0<^/p|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4ef*9|^x#
httpConnection.setRequestProperty("User-Agent","NetFox"); a9#W9eP
20rN,@2<
n> MD\ZS
int responseCode=httpConnection.getResponseCode(); N@cMM1
if(responseCode>=400) 5mI?pfm
{ 6Cl+KcJH
processErrorCode(responseCode); v]WH8GI
return -2; //-2 represent access is error 9U2Px$E
} Z$!C=
@+?+6sS
AA))KBXq
String sHeader; >vQ6V'F
_&W0e}4
kU#:I9PO
for(int i=1;;i++) f\h%; X
{ ,dHP`j ?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [#7y[<.P
//Utility.log(in.readLine()); lir&e 9I+
sHeader=httpConnection.getHeaderFieldKey(i); D3%l4.h
if(sHeader!=null) T@(6hEmP,
{ LKqRvPnh
if(sHeader.equals("Content-Length")) cJP'ShnCh
{ `aO.=:O_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >65 TkAp
break; "0|BoG
} m9#}X_&x
} X,>(Y8
else 3%XG@OgP
break; ^pJ0nY#c
} {B@*DQv
} .=Pm>o/,
catch(IOException e){e.printStackTrace ();} UUl*f!& o
catch(Exception e){e.printStackTrace ();} n<{aPLQ
{hxW,mmA
M} O[`Fx{W
Utility.log(nFileLength); s,84*6u
4$%`Qh>yA
65lOX$*{-
return nFileLength; Jf_]Z
} c`-YIz)W
pAENXC\,
mH'\:oN
//保存下载信息（文件指针位置） =fo4x|{O
private void write_nPos() f4R1$(<
{ /ca(a\@R
try{ h=hoV5d@
output = new DataOutputStream(new FileOutputStream(tmpFile)); DeA@0HOxh
output.writeInt(nStartPos.length); }g}6qCv7
for(int i=0;i<nStartPos.length;i++) 3nwz<P
{ !loO%3_)
// output.writeLong(nPos); ]a)IMIh;
output.writeLong(fileSplitterFetch.nStartPos); =Q@6c
output.writeLong(fileSplitterFetch.nEndPos); yHl@_rN sC
} M6\7FP6G
output.close(); @|^jq
} Z%Vr+)!4
catch(IOException e){e.printStackTrace ();} ?hKm&B;d
catch(Exception e){e.printStackTrace ();} 6%>/og\%
} NP "ylMr7P
9-b 8`|s
R^w}o,/
//读取保存的下载信息（文件指针位置） M]1;
private void read_nPos() GN0duV
{ N.jA 8X
try{ Hv3W{|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?<E0zM+
int nCount = input.readInt(); 2pz4rc
nStartPos = new long[nCount]; $1~c_<DN
nEndPos = new long[nCount]; uw_H:-J
for(int i=0;i<nStartPos.length;i++) ~,T+JX
{ Oohq9f#!
nStartPos = input.readLong(); )qmFK .;%
nEndPos = input.readLong(); goB;EWz
} gd K*"U
input.close(); F,zG;_
} _1P`]+K\D$
catch(IOException e){e.printStackTrace ();} PzLJ/QER
catch(Exception e){e.printStackTrace ();} YN/u9[=`
} C*a,<`
`T=1<Twc
$}db /hY*
private void processErrorCode(int nErrorCode) n_J5zQJ
{ Jns/v6
System.err.println("Error Code : " + nErrorCode); ]Ym=+lgi
} %0lf
VxkEez'|
|e:rYLxm:
//停止文件下载 ly[lrD0Kn.
public void siteStop() a/b92*&k
{ kB V/rw
bStop = true; >{b3>s~T
for(int i=0;i<nStartPos.length;i++) };^}2Xo+
fileSplitterFetch.splitterStop(); ]'tJ S]
4b=Gg
\KCWYi]
} lr0M<5d=p
} zXjwnep
//负责部分文件的抓取 AxEc^Cof
**FileSplitterFetch.java rEmwKZF'
*/ Si]X rub
package NetFox; gn^!"MN+g
?T <rt
~~@y_e[N#l
import java.io.*; 'aZASPn[
import java.net.*; S_$nCyaH2
eKyqU9
SetX#e?q~
public class FileSplitterFetch extends Thread { p.5e: i^LJ
nn'Af,ko/
~{$L9;x
String sURL; //File URL H~eGgm;p
long nStartPos; //File Snippet Start Position |*ReqM|_C
long nEndPos; //File Snippet End Position 3[.3dy7,Z
int nThreadID; //Thread's ID >C*4_J7
boolean bDownOver = false; //Downing is over nSHNis
boolean bStop = false; //Stop identical lA]N04 d
FileAccessI fileAccessI = null; //File Access interface _CL{IY
m d_g}N(C
}1Z6e[K?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tJAnuhX
{ L?Cjo4xS
this.sURL = sURL; WI{;#A
this.nStartPos = nStart; :xtT)w
this.nEndPos = nEnd; @<a|
nThreadID = id; M|H2kvl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pr/'J!{^
} Y0}4WWV
i(Vm!Y82
F<gMUDB
public void run() c;^A)_/
{ {!r#f(?uT
while(nStartPos < nEndPos && !bStop) R+uw/LG
{ ;?`@"YG)
iu|v9+
C5MqwNX
try{ 7 OWsHlU
URL url = new URL(sURL); # M>wH`Q#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +|0t
httpConnection.setRequestProperty("User-Agent","NetFox"); >:$"a
String sProperty = "bytes="+nStartPos+"-"; }#bZ8tm&
httpConnection.setRequestProperty("RANGE",sProperty); GMw)*
Utility.log(sProperty); *Dc@CmBr
YD9!=a$
fbV@=(y?
InputStream input = httpConnection.getInputStream(); .`+yo0O:
//logResponseHead(httpConnection); OJ>iq@>
5NFRPGYX
a%*_2#
byte[] b = new byte[1024]; -K^41W71
int nRead; ^vM_kArA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1]Lh'.1^
{ P7UJ-2%Y+
nStartPos += fileAccessI.write(b,0,nRead); R>HY:-2
//if(nThreadID == 1) Why"G1`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f"P$f8$
} &`@lB (m
U=DEV7E
Zw24f1iY
Utility.log("Thread " + nThreadID + " is over!"); 8i[LR#D)
bDownOver = true; Yv=g^tw
//nPos = fileAccessI.write (b,0,nRead); T%~SM5
} A2BRbwr>
catch(Exception e){e.printStackTrace ();} -N4z-ozhC
} GXYj+ qJ
} _r5wF(Y?7
7>mhK7l
Wc\+x1:8
//打印回应的头信息 ZB0+GG\
public void logResponseHead(HttpURLConnection con) Eu4 &-i
{ zi.mq&,]R
for(int i=1;;i++) z7k$0&
{ P5P<"
String header=con.getHeaderFieldKey(i); tR;{.
if(header!=null) q5?{1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gwq`_/d}
Utility.log(header+" : "+con.getHeaderField(header)); D )gD<
else #g{Mne
break; HU9p!I.
} `x2,;h!:)N
} & g$rrpTzv
73)Ll"(
ZPvf-PqJl
public void splitterStop() CW;m
{ 1daL y
bStop = true; :q;R6-|.
} }DHUTP2;yz
O4!9{
xEC2@J
} $P;UoqG<&
Man^<T%F
Xb0!( (A
/* O]bKNA.5
**FileAccess.java yKlU6t&` G
*//文件访问(定位，写) i7s\CY
package NetFox; .R\p[rv&
import java.io.*; 8JP6M!F#
FJF3B)Va|
gi1j/j7
public class FileAccessI implements Serializable{ Oq}ip
Ck@M<(x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^9=4iXd
RandomAccessFile oSavedFile; om>VQ3
long nPos; Ko+al{2
Q0WY$w1<
x G^f
public FileAccessI() throws IOException zQ<88E&&Xs
{ 2NYi-@mr
this("",0); ftaBilkjp
} kfRJ\"`
d EIa=e|
K-6p'|
public FileAccessI(String sName,long nPos) throws IOException +dM.-wW
{ 71*>L}H
oSavedFile = new RandomAccessFile(sName,"rw"); PF67z]<o
this.nPos = nPos; >Zo-wYG
oSavedFile.seek(nPos); B>@D,)/bT5
} 9?(x>P
T\fudmj&
Az9J\V~"
public synchronized int write(byte[] b,int nStart,int nLen) 8F)=n \
{ !?6.!2
int n = -1; A6Q c;v+
try{ ,# eO&
oSavedFile.write(b,nStart,nLen); Lrlk*
n = nLen; U&X.
} ) G|"jFP
catch(IOException e) {zu/tCq?
{ ,O2q+'&
e.printStackTrace (); @ct#s:t
} 2]3G1idB
;M-,HK4=
j C9<hLt
return n; %]!?{U\*k
} sSV^5
3<3t;&e
5c)wZ
} aX]y`
Lg b
1 0V+OIC
/* FbuKZp+
**SiteInfoBean.java c[Yq5Bu{y
*/ ]a=l^Pc(xN
package NetFox; PB@-U.Z
h~:H?pj3g
[&Lxz~W][
public class SiteInfoBean { LPMb0F}"5
GV=V^Fl .
i6FP[6H1
private String sSiteURL; //Site's URL 9c%(]Rn:
private String sFilePath; //Saved File's Path Gy$o7|PA"{
private String sFileName; //Saved File's Name g{]ej
private int nSplitter; //Count of Splited Downloading File F; 0Dp
#|q;t
,rXW`7!2
public SiteInfoBean() bu;vpNa
{//nSplitter的缺省值为5 ]Px:d+wX:
//default value of nSplitter is 5 XGL"gD
this("","","",5); aK-N}T
} N*? WUn9]
CO7CNN
)|Jr|8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,I=O"z>9
{ 6B /Jp
sSiteURL= sURL; Z"+(LO!
sFilePath = sPath; } cRi A
sFileName = sName; IK85D>00T
this.nSplitter = nSpiltter; rtoSCj:
r!>es;R8
lf}?!*V`+
} JW2W>6Dgv[
.ZM]%[4
U24V55ZnI
public String getSSiteURL() V.+DP
{ rC=f#YjR
return sSiteURL; h@EJTAi
} <x^IwS
v#w4{.8)
PVS\,
public void setSSiteURL(String value) |I4D(#w.
{ v!iWzN
sSiteURL = value; ^j1Gmv)
} )_WH#-}
^BQ>vI'.4
>Y44{D\`
public String getSFilePath() bXk:~LE
{ x`wZtv\
return sFilePath; Tm0?[[3hC
} m21QN9(i%
u)wu=z8
k:@a[qnY
public void setSFilePath(String value) 1i ?gvzrq
{ j@s=ER
sFilePath = value; &IxxDvP3k
} ^a: Saq-}
ikeJDKSG
@?(nwj~ s`
public String getSFileName() + ?[ ACZF
{ hrUm}@d
return sFileName; \3,$YlG
} 3XMBu*
\;4L~_2$q
-<u- +CbuT
public void setSFileName(String value) Z1E`I89<
{ Q3'(f9 x
sFileName = value; ] `b<"
} [J(@$Qix
WlF+unB!9
)cfp(16
public int getNSplitter() R V_MWv
{ 7/$nA<qM
return nSplitter; nI((ki}v
} $yP'k&b!
9J't[( u|u
qen44;\L
public void setNSplitter(int nCount) WMt&8W5
{ ]0at2
nSplitter = nCount; &6=TtTp"9
} Q%_!xQP`
} E,"b*l.
:..E:HdYO
w-{#6/<kI5
/* /@xr[=L
**Utility.java hnM9-hqm
*/ !xJLeQFJI]
package NetFox; !;BZ#tF&
!07FsPI#{
xF\}.OfWG
public class Utility { Ep#<$6>
p0%6@_FT~
4DG 9`5.
public Utility() ;@h'Mb
{ 98"z0nI%
sYW1T @
4okHAv8;
} n]kQtjJ
fS8XuT
//线程睡眠 _ d(Ks9
public static void sleep(int nSecond) v ](G?L9b
{ i75?*ld
try{ `"^@[1
Thread.sleep(nSecond); =PeW$q+
} N7Z(lI|a;
catch(Exception e) *IjdN,wox
{ ^Y*`D_-G
e.printStackTrace (); Cz$Hk;3\6
} jSOa
} q_%w l5\F
Y'+F0IZ+
//日志 wnZ*k(
public static void log(String sMsg) Xm0&U?dZB
{ oK(W)[u
System.err.println(sMsg); N'Z_6A*-
} <*b]JY V@
iPtm@f,bI
CU7iva
public static void log(int sMsg) j|VlHDqR
{ eX]9mQ]E
System.err.println(sMsg); {U+9,6.`
} MFCbx>#
} pXh^M{.
z?IY3]v*z<
:*w:eKk
/* `,8R~-GPD
**TestMethod.java p0:&7,+a,
*/ 4u{E D(
package NetFox; eF gb6dSh
z!t3xFN&/
Kr+Bty
public class TestMethod { A{n*NxKCX!
x"h)"Y[c5
:a^,Ei-&
public TestMethod() I_Mqh4];
{ ///xx/weblogic60b2_win.exe 0 6G[^
try{ 6{FS/+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w$<fSe7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v=yI#5
SiteFileFetch fileFetch = new SiteFileFetch(bean); QBBJ1U
fileFetch.start(); .-1{,o/&Q
} !MG>z\:
catch(Exception e){e.printStackTrace ();} L{o >D"
>> 8KL`l
ZCOuv6V+
} *|.yX%"k
7HR%rO?'
aGzdur
public static void main(String[] args) VHXR)}
{ $4ZDT]n
new TestMethod(); #\!hBL @b
} "l2N_xX;
} [7Kj$PB3
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