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)); cn'>dz3v
} RZa/la*
for(int i=0;i<nEndPos.length-1;i++) DH(<{ #u
{ ,B <\a
nEndPos = nStartPos[i+1]; <kn2
} !=[Y yh
nEndPos[nEndPos.length-1] = nFileLength; <L}@p8Lq
} tLE8+[ SU
} c./\sN@
zoq;3a5cqB
ho\1[xS
//启动子线程 \""^'pP@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `|t,Uc|7!
for(int i=0;i<nStartPos.length;i++) y=3 dGOFB
{ 59E9K)c3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), il0K^i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PxkV[nbS
nStartPos,nEndPos,i); SuE~Wb5&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hm-#Mpw
fileSplitterFetch.start(); q<YM,%mgj
} }lZEdF9GhG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N`8K1{>BH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -cgO]q+Oq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sn=6[RQ>P
nEndPos = " + nFileLength); (NJ{>@&
// fileSplitterFetch[nPos.length-1].start(); #6 M]tr
.S` q2C\
kWzp*<lWe
//等待子线程结束 F`D$bE;|
//int count = 0; HE}0_x.
//是否结束while循环 J8'"vc}=
boolean breakWhile = false; y0%@^^-Ru
JVAyiNIH>M
$QJ3~mG2
while(!bStop) j>k ;Zj
{ E$"NOR
write_nPos(); hh;kBv07o
Utility.sleep(500); AR|4^
breakWhile = true; ;*%rFt9FK
fUw:jExz
M9"Bx/
for(int i=0;i<nStartPos.length;i++) Q 3WD!Z8y
{ I;4quFBlMu
if(!fileSplitterFetch.bDownOver) EX)&|2w
{ Y9.3`VX
breakWhile = false; [-(^>Y
break; )fJ"Hq
} 'm<Lx _i
} cAR `{%b
if(breakWhile) OZ`cE5"i
break; +wi=IrRr
poz_=,c
Y3 $jNuV
//count++; yZlT#^$\
//if(count>4) s&73g0$$
// siteStop(); 6Zi{gx
} b0~r/M;J
>LBA0ynh {
>a8iY|QY
System.err.println("文件下载结束！"); ,dRaV</2
} qT#e -.G
catch(Exception e){e.printStackTrace ();} lY,^
} $N?8[
~[CFs'`(2
$PJ==N
//获得文件长度 o\8?CNm1(
public long getFileSize() '!m6^*m|c
{ oN032o?S
int nFileLength = -1; eB0exPz%
try{ TFXBN.?9T
URL url = new URL(siteInfoBean.getSSiteURL()); snaAn?I4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uw mN!!TS
httpConnection.setRequestProperty("User-Agent","NetFox"); ,X!6|l8
:^7w
R4p Pt
int responseCode=httpConnection.getResponseCode(); <-I69`
if(responseCode>=400) KF(H >gs
{ }`qAb/Ov
processErrorCode(responseCode); D4VDWv
return -2; //-2 represent access is error f|{iW E2d
} bYsX?0T!p
&g|[/~dIr
fZiAl7b!
String sHeader; d]DV\*v
f~VlCdf+
<YvXyIs
for(int i=1;;i++) V\`Z|'WIQD
{ >jt2vU@t.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]oP1c-GEk
//Utility.log(in.readLine()); (d_z\U7l
sHeader=httpConnection.getHeaderFieldKey(i); GD4S/fn3
if(sHeader!=null) J?o
{ 9nR\7!_
if(sHeader.equals("Content-Length")) TUfj\d,
{ ?X@!jB,Pv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `nF SJlr&
break; sh :$J[
} v~mVf.j1
} uSfHlN4l
else ed6@o4D/kf
break; J5{;+ysUMl
} :+\0.\K0!
} c5ij2X|I
catch(IOException e){e.printStackTrace ();} 0:V/z3?
catch(Exception e){e.printStackTrace ();} ^8 VW$}
,iV%{*p]
X.b8qbnq[
Utility.log(nFileLength); Mq\=pxC@
4\n ~
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return nFileLength; |Y uf/G%/
} n{gEIUo#
WFF?VBT'^
JV~ Dly>
//保存下载信息（文件指针位置） )Q1>j 2&
private void write_nPos() <Z^by;d|z
{ D /QLp3+o
try{ %0GwO%h},
output = new DataOutputStream(new FileOutputStream(tmpFile)); \OW:-
output.writeInt(nStartPos.length); I Cc{2l
for(int i=0;i<nStartPos.length;i++) gKh*q.
{ NsB]f{7>8+
// output.writeLong(nPos); W9?* ~!
output.writeLong(fileSplitterFetch.nStartPos); AX`Tku
output.writeLong(fileSplitterFetch.nEndPos); #QwkRzVoy
} }y6|H,t9
output.close(); Y D<3#Dr]
} M/ 64`lcb
catch(IOException e){e.printStackTrace ();} j!4{+&Laq
catch(Exception e){e.printStackTrace ();} X /c8XLe"
} I# tlaz#
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;+~5XLk
//读取保存的下载信息（文件指针位置） O h@z<1eYZ
private void read_nPos() h7#\]2U$[5
{ <q7o"NI6FZ
try{ T]\1gs41
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V#Wy` ce
int nCount = input.readInt(); VukbvBWPN
nStartPos = new long[nCount]; cy^=!EfA
nEndPos = new long[nCount]; }2]|*?1,
for(int i=0;i<nStartPos.length;i++) e* [wF}))
{ w-Ph-L/
nStartPos = input.readLong(); xeF>"6\
nEndPos = input.readLong(); Zv@qdY<:
} `PARZ|
input.close(); E^)FnXe5
} 'iW
catch(IOException e){e.printStackTrace ();} vbmt0df
catch(Exception e){e.printStackTrace ();} &. =8Q?
} lrE"phYk
TdPd8ig8{
"}3sL#|z
private void processErrorCode(int nErrorCode) PSJj$bt;<+
{ &@6xu{o
System.err.println("Error Code : " + nErrorCode); $UzSPhv[
} EGl<oxL*R2
%mQ&pk
DWU=qD+
//停止文件下载 Ur+U#}
public void siteStop() Ae7FtJO
{ ]zYIblpde
bStop = true; <,:{Q75
for(int i=0;i<nStartPos.length;i++) X(tx8~z
fileSplitterFetch.splitterStop(); @1oX&#
[l-o*@
y7+@ v'
} 6) i-S<(
} K9@.l~n
//负责部分文件的抓取 Y*BmBRN
**FileSplitterFetch.java yhKH} kR
*/ uUjjAGZ
package NetFox; ?;RY/[IX6
uqcG3Pi
U$5x#{AFp
import java.io.*; J?V$V >d
import java.net.*; byI" ?
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L!:NL#M
public class FileSplitterFetch extends Thread { I7_8oq\3D
k<1i.rh
2{j$1EdI@-
String sURL; //File URL _|\X8o_
long nStartPos; //File Snippet Start Position 0f5 ag&
long nEndPos; //File Snippet End Position -1dD~S$
int nThreadID; //Thread's ID >T;!Z5L1
boolean bDownOver = false; //Downing is over $TK*w8@:
boolean bStop = false; //Stop identical Lyc6nP;F
FileAccessI fileAccessI = null; //File Access interface bhD-;Y!6;
!Q"L)%)'A
L,R}l0kc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6 ZRc|ZQ
{ hj1;f<' U
this.sURL = sURL; dCo)en
this.nStartPos = nStart; UnDCC_ud
this.nEndPos = nEnd; )<HvIr(xr
nThreadID = id; :WRD<D_4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =bh: U90y
} 1{M?_~g4
Vja 4WK*
Un8' P8C
public void run() %ap]\o$^4
{ $*eYiz3Ue
while(nStartPos < nEndPos && !bStop) >\K=)/W2
{ x=H{Rv
M IIa8;
t<te{yt%
try{ ~2>Adp
URL url = new URL(sURL); M_!]9#:K7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d21thV ,S
httpConnection.setRequestProperty("User-Agent","NetFox"); 2:|vJ<Q
String sProperty = "bytes="+nStartPos+"-"; BPj?l
httpConnection.setRequestProperty("RANGE",sProperty); ~j[?3E4L}
Utility.log(sProperty); ~ox}e(xy
n#}@|"J
3chx4
InputStream input = httpConnection.getInputStream(); WzFXF{(
//logResponseHead(httpConnection); _xAru9=n^
vk|f"I
B{\Y~>]Pj
byte[] b = new byte[1024]; KGDN)@D
int nRead; (LsVd2AbR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <N<0?GQ
{ W!HjO;
nStartPos += fileAccessI.write(b,0,nRead); (ORbhjl
//if(nThreadID == 1) .=YV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g5#LoGc
} hYyIC:PXR
K3vZ42n
[GbrKq(
Utility.log("Thread " + nThreadID + " is over!"); n`^jNXE
bDownOver = true; ,JI]Eij^
//nPos = fileAccessI.write (b,0,nRead); #8XmOJ"W3k
} 9wCgJ$te
catch(Exception e){e.printStackTrace ();} (P?|Bk[
} \X\< +KU
} a)W|gx6Y
t8Pf~v
~hq\XQX
//打印回应的头信息 8L:AmpQdpA
public void logResponseHead(HttpURLConnection con) ue3 ].:
{ ,W+=N"`a'
for(int i=1;;i++) w&YUb,{Y
{ e,#w*|
String header=con.getHeaderFieldKey(i); T7i>aM$+
if(header!=null) "3jTU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zW\a)~E
Utility.log(header+" : "+con.getHeaderField(header)); %H?B5y
else f'ld6jt|%
break; *[cCY!+Qy
} $|Ol?s
} R/1e/t
ri-&3%%z<
}{+?>!qDt
public void splitterStop() Z[[*:9rY|
{ '9]?jkl
bStop = true; DCa[?|Y
} i5(qJ/u
.qe+"$K'n
[3=Y 9P:
} ,l!>+@
An>ai N]
+D @B eQu
/* w)J-e gc
**FileAccess.java 5.-:)=
*//文件访问(定位，写) r=.@APZB
package NetFox; G "+[@|
import java.io.*; f\?Rhyz
\a0{9Xx F
ir}*E=*
public class FileAccessI implements Serializable{ u0)O Fz
Vxrj(knck,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M&=SvM.f
RandomAccessFile oSavedFile; 7]So=%q
long nPos; LTBH/[q5
X)(K|[
QpzdlB44l
public FileAccessI() throws IOException <gX({FA
{ A/9<} m
this("",0); kqX%y
} pno}`Cer
]~$@x=p2e
~:,}?9
public FileAccessI(String sName,long nPos) throws IOException _Cf:\Xs m
{ nGTGX
oSavedFile = new RandomAccessFile(sName,"rw"); Ax|'uvVAPT
this.nPos = nPos; I`xC0ZUKj
oSavedFile.seek(nPos); [x?9<#T
} ":e6s co
'/D2d
BbFLT@W4
public synchronized int write(byte[] b,int nStart,int nLen) QDJ#zMxFD
{ o *U-.&
int n = -1; >&>EjK4?
try{ XRM/d5
oSavedFile.write(b,nStart,nLen); Jo8fMG\P
n = nLen; G \a`F'Oo
} })8D3kzX)
catch(IOException e) Qd~7OH4Lp
{ [V /f{y~{
e.printStackTrace (); )6"p@1\u
} BGVnL}0
GLub5GrxR
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return n; <:(;#&<
} d|87;;X|u
VJA/d2Oys
AEf[:]i]
} l'Li!u
'rXf
N?S;v&q+
/* 'G[G;?F
**SiteInfoBean.java H{_D#It
*/ Q<szH1-
package NetFox; ,d!@5d&Zi
Qhe<(<^J,
08AD~^^
public class SiteInfoBean { 2xi;13?
?FS0zc!+
]ZR` 6|"VO
private String sSiteURL; //Site's URL c#u_%*
private String sFilePath; //Saved File's Path B(FM~TVZ
private String sFileName; //Saved File's Name <7T}b95
private int nSplitter; //Count of Splited Downloading File ;9#W#/B
v}5YUM0H`
m' j1
public SiteInfoBean() g"!cO^GkT
{//nSplitter的缺省值为5 }/tf^@
//default value of nSplitter is 5 2>.b~q@
this("","","",5); mo tW7|p.e
} n}9<7e~/
9I5AYa?
L|D9+u L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) npytb*[|c
{ zSMM?g^T
sSiteURL= sURL; &&jQ4@m}j
sFilePath = sPath; 'lEIwJV$
sFileName = sName; 6]GHCyo
this.nSplitter = nSpiltter; um<$L
r.u\qPT&
2u0B=0x
} ETX>wZ
AL&<SxuP
eC 2~&:$L
public String getSSiteURL() sAjUX.c
{ lpB:lRM
return sSiteURL; GaJE(N
} f;+.j/ +
]4')H;'y
RV]QVA*i
public void setSSiteURL(String value) U![$7k>,pr
{ Dbx zqd
sSiteURL = value; n0K+/}m
} J_XkQR[Y
B1I{@\z0G
@yQ1F> t
public String getSFilePath() xU{0rM"
{ dB&<P[$+8
return sFilePath; FKe/xz
} ,T^A?t
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"9X(.v0ze
public void setSFilePath(String value) Jv%)UR.]
{ qv2J0'd'.
sFilePath = value; VWYNq^<AT
} Jp8,s%
I@Yk &aU
_TJkYz$
public String getSFileName() iYdg1
{ ;$]a.9 -
return sFileName; Hit)mwfYE
} z#n+iC$9
SEu:31k{o
SN}3
public void setSFileName(String value) Xrc{wDn
{ -nD}k
sFileName = value; FyXO @yF
} 0>;[EFL
7)>L#(N
wpNb/U
public int getNSplitter() p Zxx
{ q+;lxR5D
return nSplitter; cF iTanu
} <)J@7@!P
A??a:8id^
jCx*{TO
public void setNSplitter(int nCount) 1xsJz^%V
{ ;<cCT!A
nSplitter = nCount; "}[ ]R
} OB+cE4$
} kA2)T,s74
HFYe@2r
RN&8dsreZp
/* z>=;Xe8P8n
**Utility.java sUkn.g!
*/ W=#jtU`:5
package NetFox; gId :IR
'Vhnio;qC
8[ ZuVJ]
public class Utility { )5x$J01S
fkk9&QB%(
iP9Dr<P
public Utility() Y{t}sO%A
{ _?$')P|
z,!A4ws
G!D~*B9G
} ]r#NjP
96gaun J
//线程睡眠 xo-{N[r
public static void sleep(int nSecond) ]N1,"W}
{ hbx+*KM
try{ ,oEAWNbgQ
Thread.sleep(nSecond); b$*G&d5
} Jcp=<z*0
catch(Exception e) 20A:,pMb
{ S4E@wLi
e.printStackTrace (); @}%kSn5y:
} Idj Z2)$
} OaByfo<S
idS+&:'
//日志 %yR80mn8
public static void log(String sMsg) YR)^F|G
{ :X1Y
System.err.println(sMsg); g,RhUt9
} ;>]dwsA*P
[H2su|rBI`
#m'+1 s L
public static void log(int sMsg) 7i=ER*F~
{ 'Rv.6>xqc
System.err.println(sMsg); B\dhw@hM
} L'"od;(6R
} 0U2dNLc
X`]>J5
I wu^@
/* |g\CS4$
**TestMethod.java |c2;`T#`o
*/ "nNT9 K|
package NetFox; (d[JMO^@8
B+'w'e$6
^w*vux|F
public class TestMethod { grDz7\i:
S2=x,c$
L[:M[,?=`
public TestMethod() ,nw5 M.D_
{ ///xx/weblogic60b2_win.exe s6oIj$
try{ !U1V('
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n+'s9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k{\a_e`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9H%ixBnM
fileFetch.start(); b]WvKdq
} ?bG82@-
catch(Exception e){e.printStackTrace ();} j2#B l
bWB&8&p
lF$$~G
} p"n3JV.~k+
m&Y?]nbq
w`Rt"d_B
public static void main(String[] args) tQ2S*]"f
{ W6yz/{Rf
new TestMethod(); / DST|2
} y$?O0S%F
} t3.I ` Z
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