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)); EjR_-8@FK
} CxbSj,
for(int i=0;i<nEndPos.length-1;i++) yn/?= ?0
{ I*A0?{
nEndPos = nStartPos[i+1]; 7Wwp )D
} ~A`&/U
nEndPos[nEndPos.length-1] = nFileLength; (C`FicY
} O{k89{
} >~I xyQp
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AT B\^;n.
//启动子线程 Hp)X^O"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eyeNrk*2o
for(int i=0;i<nStartPos.length;i++) [G{rHSK5tQ
{ `fBG~NDw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -}{%Q?rYj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qQfqlD<
nStartPos,nEndPos,i); #XTY7,@P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [3O^0-:6E
fileSplitterFetch.start(); $Wit17j
} 0U82f1ei
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cGgM8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tcBC!_vF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xS6(K
nEndPos = " + nFileLength); aO8ch
// fileSplitterFetch[nPos.length-1].start(); ]y3pE}R
#TMm#?lC
B4]AFRI
//等待子线程结束 ,CJAzGBS
//int count = 0; )W&o?VRfO
//是否结束while循环 GWF/[%
boolean breakWhile = false; EY+/.=$x
XR*Q|4
QS3U)ZO$@
while(!bStop) TZ?Os4+
{ g%`i=s&N%
write_nPos(); hi!L\yi
Utility.sleep(500); Y,k(#=wg
breakWhile = true; A2m_q>> !
^"3\iA:
.z=U= _e
for(int i=0;i<nStartPos.length;i++) 2R^O,Vu*W
{ s%eyW _
if(!fileSplitterFetch.bDownOver) 0B=[80K;8
{ w3^NL(>
breakWhile = false; 9YR]+*
break; N>+P WE$
} S8 :"<B)
} &J8Z@^
if(breakWhile) hf;S]8|F
break; Q*]$)D3n
QL2Nz@|k
)|v^9
//count++; IUOxGJ|rO
//if(count>4) L2KG0i`+
// siteStop(); -x{dc7y2
} !7}IqSs
/-h6`@[
,zQo {.
System.err.println("文件下载结束！"); U1OFDXHG
} c\At0.QCA
catch(Exception e){e.printStackTrace ();} AgIazv1
} P Q7A~dw9
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XMGx^mn
//获得文件长度 /QQ8.8=5
public long getFileSize() LH4>@YPGE#
{ {3VZ3i
int nFileLength = -1; J , V
try{ pgT9hle/
URL url = new URL(siteInfoBean.getSSiteURL()); [`d$X^<y;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p8Iw!HE
httpConnection.setRequestProperty("User-Agent","NetFox"); 7_-w_"X
nSS>\$
P` #QGZ>
int responseCode=httpConnection.getResponseCode(); h;-a`@rO ;
if(responseCode>=400) ;x-(kIiE
{ _5mc('
processErrorCode(responseCode); f\fdg].!
return -2; //-2 represent access is error |'tW=
} moMYdArj
L'lF/qe^
#/|75 4]]
String sHeader; Z,K7Ot0
(:5G#?6,
~3gru>qI&
for(int i=1;;i++) Y$g}XN*)E
{ n-$VUo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s2FngAM;f
//Utility.log(in.readLine()); EFAGP${F
sHeader=httpConnection.getHeaderFieldKey(i); =+Im*mgNn
if(sHeader!=null) EeB ]X24
{ h4/X 0@l`
if(sHeader.equals("Content-Length")) mLwoi!]m
{ 'B_\TU0 O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p,F^0OU2}:
break; 9IA$z\<<w
} %a];
} .-0%6] cFD
else $6T3y8
break; '_dzcN,z
} K$H <}e3
} piOXo=9H.
catch(IOException e){e.printStackTrace ();} BYi)j6"
catch(Exception e){e.printStackTrace ();} UNDi_6Dy
9GgA6#
q_ %cbAcD
Utility.log(nFileLength); @b2`R3}9R
c8{]]
9I`Y-D
return nFileLength; *:_P8G;
} 3NIUW!gr
+R6a}d/K
][d,l\gu+s
//保存下载信息（文件指针位置） y:d{jG^
private void write_nPos() X<]qU3k5
{ XX6 T$pA6
try{ :~zv t
output = new DataOutputStream(new FileOutputStream(tmpFile)); /4$4h;_8
output.writeInt(nStartPos.length); Z)pz,
for(int i=0;i<nStartPos.length;i++) #D*r]M
{ jTb-;4N'
// output.writeLong(nPos); g%xGOA
output.writeLong(fileSplitterFetch.nStartPos); )4R:)-"f
output.writeLong(fileSplitterFetch.nEndPos); k6"KB
} r[_4Lo@G
output.close(); "CQw/qZw
} dRI^@n
catch(IOException e){e.printStackTrace ();} -h#mn2U~3r
catch(Exception e){e.printStackTrace ();} zP!J/}z
} >O7~h[FN
kS :\Oz\
JN'cXZJPn
//读取保存的下载信息（文件指针位置） {f/]5x(_
private void read_nPos() w~Ff%p@9
{ ZDx@^P y
try{ V-!"%fO.s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Kmz7c|
int nCount = input.readInt(); 4=Gph
nStartPos = new long[nCount]; TZRcd~5$
nEndPos = new long[nCount]; @ O>&5gB1u
for(int i=0;i<nStartPos.length;i++) 8' K0L(3[
{ ;n6b%,s
nStartPos = input.readLong(); -x`G2i
nEndPos = input.readLong(); M+`Hg_#Q
} xd-XWXc
input.close(); 9}29&O
} BVw Wj-,
catch(IOException e){e.printStackTrace ();} 2+o|A
catch(Exception e){e.printStackTrace ();} &|Pu-A"5~
} Xm1[V&
cK`"lxO
>TjJA#
private void processErrorCode(int nErrorCode) AoaN22
{ !@A#=(4R4
System.err.println("Error Code : " + nErrorCode); fP HLXg5s
} %ZP+zhn}
QHt4",Ij
`^9(Ot $
//停止文件下载 WO</Mw
public void siteStop() =~KsS}`1,
{ !yOeW0/2[
bStop = true; SC &~s$P;
for(int i=0;i<nStartPos.length;i++) C\ZkGX
fileSplitterFetch.splitterStop(); !? 5U|
sZ&G%o
"xRBE\B
} oslJC$cy'
} <?Wti_ /M
//负责部分文件的抓取 q2rUbU_A(
**FileSplitterFetch.java x]|+\1
*/ vhuw&.\
package NetFox; ULH0'@BJ
TBrGA E
M$Zo.Bl$(
import java.io.*; U`|0 jJ
import java.net.*; Q&'}BeUbm
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Wu6<\^A
public class FileSplitterFetch extends Thread { US [dkbKo
dq1:s1
L I>(RMv
String sURL; //File URL JPn$FQD
long nStartPos; //File Snippet Start Position W5L iXM
long nEndPos; //File Snippet End Position t*<#<a
int nThreadID; //Thread's ID I zbU)ud
boolean bDownOver = false; //Downing is over eM7Bc4V
boolean bStop = false; //Stop identical BvrB:%_:
FileAccessI fileAccessI = null; //File Access interface fFvF\
CzCQFqXI
6]zd.W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =qy=-j]
{ 4_v]O
this.sURL = sURL; {O<l[|Ip
this.nStartPos = nStart; C:8_m1Y{
this.nEndPos = nEnd; c#IYFTz
nThreadID = id; b1XRC`Gy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PQKaqv}N
} .`<@m]m-
SUKxkc(
)Or.;
public void run() :'F}Dy
{ klgy;jSEr
while(nStartPos < nEndPos && !bStop) !+)AeDc:j
{ cRd0S*QN2
G$0c'9d*(
'J&f%kx"
try{ v[plT2"s
URL url = new URL(sURL); :0)3K7Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {j5e9pg1L|
httpConnection.setRequestProperty("User-Agent","NetFox"); cKb)VG^
String sProperty = "bytes="+nStartPos+"-"; ]ul$*
httpConnection.setRequestProperty("RANGE",sProperty); x_Jwd^`t!
Utility.log(sProperty); R" )bDy?
%CUGm$nH
'I;!pUfVp
InputStream input = httpConnection.getInputStream(); ;w|b0V6
//logResponseHead(httpConnection); hQ6a~?f
.h&k jD
;$Y4xM`=m
byte[] b = new byte[1024]; 9Y>8=#.c
int nRead; kF;DBN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HHX-1+L
{ >>aq,pH
nStartPos += fileAccessI.write(b,0,nRead); 8d*/HF)h
//if(nThreadID == 1) :ISMPe3'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r78TE@d
} 7XKY]|S,'
b"!Q2S~
}g#&Q0
Utility.log("Thread " + nThreadID + " is over!"); t5)+&I2
bDownOver = true; Hqnxq
//nPos = fileAccessI.write (b,0,nRead); c|F[.;cR
} XNQAi (!GS
catch(Exception e){e.printStackTrace ();} [V'QrcCF
} ^Q*atU
} o?1;<gs
Xc"&0v%;#
[aI]y=v
//打印回应的头信息 s&\I=J.
public void logResponseHead(HttpURLConnection con) B+^(ktZp@
{ \AL f$88>@
for(int i=1;;i++) h~{aGo
{ N]KxAttt
String header=con.getHeaderFieldKey(i); /%_OW@ ?
if(header!=null) '13ZX:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V=fEPM
Utility.log(header+" : "+con.getHeaderField(header)); 2I*;A5$N1
else fDG0BNLY
break; lds-T
} 8-y{a.,u.
} U=hlu
Y"-^%@|p
k} ]T;|h]
public void splitterStop() dlhdsj:
{ >^XBa*4;Y
bStop = true; P/EM :
} J|'7_0OAx
Ut$;ND.-
L\y;LSTU
} 6c^e\0q
asY[8r?U
ui(^k $
/* 0b4R
**FileAccess.java CR6R?R3b
*//文件访问(定位，写) P!"&%d
package NetFox; el:9wq
import java.io.*; 5@^ dgq
bdGIF'p%
M33_ja+L
public class FileAccessI implements Serializable{ /-bO!RTwf
aW!@f[%~F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A:7k+4
RandomAccessFile oSavedFile; JK.ZdY%
long nPos; (@iMLuewK
^"J8r W6[
QWMdn
public FileAccessI() throws IOException \GHiLs,!
{ =gcM%=*'
this("",0); lFTF ,G
} o] mD"3_
2h[85\4
0P\$2lk
public FileAccessI(String sName,long nPos) throws IOException &QhX1dT+
{ B<C*
oSavedFile = new RandomAccessFile(sName,"rw"); rj6#1kt
this.nPos = nPos; $H+VA@_
oSavedFile.seek(nPos); e["2QIOe
} LBF 1;zjK
_E@:O+K
nu'M 39{
public synchronized int write(byte[] b,int nStart,int nLen) XS$OyW_Q
{ Mi]L]-L
int n = -1; 1KjU ] r2
try{ R'S0 zp6
oSavedFile.write(b,nStart,nLen); hAHq\
n = nLen; 97ql5
} Z!U)I-x&
catch(IOException e) M`ip~7"
{ Yv:55+e!|
e.printStackTrace (); y#XbJuN/
} }#X8@
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A^p[52`
return n; |g=="
} }d<}FJ-,
ve\X3"p#
lkBdl#]9
} F^hBtfz
W"Gkq!3u{
}g4 M2|
/* H<^/Ati,|
**SiteInfoBean.java <n(*Xak{a
*/ /~^rr f
package NetFox; A'2w>8
a{[x4d,z
6P';DB
public class SiteInfoBean { U^Xm)lL
tO0!5#-VR
[H=)
private String sSiteURL; //Site's URL 4q<=K=F
private String sFilePath; //Saved File's Path P3oI2\)*i
private String sFileName; //Saved File's Name R+Y4|
private int nSplitter; //Count of Splited Downloading File %rxO_
H/Llj.-jg
g&`pgmUX
public SiteInfoBean() fJ ,1Ef;Z
{//nSplitter的缺省值为5 j\m_o% 4
//default value of nSplitter is 5 L(U"U#QZ
this("","","",5); F4K0);
} /Ml.}7&
v'e[GB0
48Mpf=f`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X,LD
{ `\+@Fwfx
sSiteURL= sURL; X$yN_7|+
sFilePath = sPath; %*\es7m}
sFileName = sName; &8z[`JW,T
this.nSplitter = nSpiltter; hEw- O;T0
og0*Nt+
gH G
} NOp609\^
V =-WYu
aJcf`<p
public String getSSiteURL() 95z]9UL
{ ca>Z7qT!
return sSiteURL; 2z|*xS'G
} &o<F7U'R
/r=tI)'$
~{Mn{
public void setSSiteURL(String value) n(el]_d
{ -Y='_4s
sSiteURL = value; Q_t`.jus
} .B\5OI,]
FHC\?Cg
$H-!j%hV
public String getSFilePath() (`:O~>[N
{ J.8IwN1E
return sFilePath; W16,Alf:
} 4fKC6UR
5:kH;/U
#b~JDO(
public void setSFilePath(String value) m'f,_ \'
{ >ss/D^YS
sFilePath = value; ;v$4$D]L
} /FIE:Io
$ >EYhLBa
MX@_=Sp-
public String getSFileName() l~M_S<4n
{ A7n\h-b
return sFileName; Yc'kvj)_M
} yfm^?G|sW
8)4P Ll
o";Z$tAJkC
public void setSFileName(String value) zF`c8Tsx])
{ {>F7CT'G6
sFileName = value; d,=r9.
} q5#J~n8Wr
y>aZXa
xQ@^$_
public int getNSplitter() |JVk&8 ?8
{ FD8N"p
return nSplitter; |Z*J/v'@p
} }5(Ho$S(
ka3u&3"
vo#UtN:q
public void setNSplitter(int nCount) +mp@b942*
{ <-u8~N@43W
nSplitter = nCount; ^Y iJV7
} %b"\bHH
} 1[yq0^\]M[
('hEr~&
E~_]Lfs)
/* ^/U|2'$'>E
**Utility.java 8f3vjK'
*/ YWxc-fPZ
package NetFox; UNkCL4N
l'TWkQ-
u,w:SM@*(
public class Utility { `4~H/'%QB
n;:rf7hGY
)kkhJI*v
public Utility() n2fbp\I
{ 7__Q1>o
4'LB7}WG
mD/MJt5
} 7Ddaf>
FGh]S-A
//线程睡眠 H `(exa:w
public static void sleep(int nSecond) 'FS?a
{ :M6+p'`j
try{ uIDuGrt
Thread.sleep(nSecond); Xt'sQ}
} ~R@Nd~L
catch(Exception e) sn?]n~z
{ _`pD`7:aI^
e.printStackTrace (); H[='~%D
} I;1lX L
} ?A )hN8
&[;HYgp
//日志 6A=8+R'`F
public static void log(String sMsg) #2EI\E&$
{ S!sqbLrBn
System.err.println(sMsg); W<E47
} h@LHRMO
jWYV#ifs2
n2IV2^ "
public static void log(int sMsg) 17OH]
{ 4~N[%>zJ
System.err.println(sMsg); C|o`k9I#
} tT79p.z B
} rrCNo^W1
wW/7F;54
@, Wvvh
/* %3$*K\Ai
**TestMethod.java Vb'7>
*/ Q;D0<Bv
package NetFox; U_{Ux2
K/}rP[H
bpxeznz
public class TestMethod { H Tz
`Ps:d^8*P
gB4U*D0[e~
public TestMethod() +a*^{l}AST
{ ///xx/weblogic60b2_win.exe (S v~2
try{ $&2UTczp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j8sH#b7Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /-i!;!
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6HlePTf8
fileFetch.start(); ,yTjU{<"
} <fs2fTUeqF
catch(Exception e){e.printStackTrace ();} s\P2Bp_{
2^^=iU=!<|
d`/tE?Gw
} G7CG~:3h+
zH*KYB
%zOh
public static void main(String[] args) d%0~c'D8a
{ Ogp"u b8
new TestMethod(); \~5C7^_
} S*sT] J`!
} !Lh^oPT"I
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