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)); NaG1j+LN
} ZP*Hx %U
for(int i=0;i<nEndPos.length-1;i++) SS O$.rp
{ k\Oy\z@
nEndPos = nStartPos[i+1]; l},*^Sn<5
} Q <^'v>~n
nEndPos[nEndPos.length-1] = nFileLength; d#I'9O0&
} zrU0YHmt
} kJ>l,AD/
H]"Z_n_
CBs0>M/
//启动子线程 }k duN0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +KDB^{
for(int i=0;i<nStartPos.length;i++) I5Foh|)
{ O9A.WSJ >}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d4[M{LSl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f&H):.
nStartPos,nEndPos,i); ~y_TT5+3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m}]"TFzoVM
fileSplitterFetch.start(); xx nW1`]
} fV Ah</aZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e<l Wel
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DM!vB+j+,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #It{B
nEndPos = " + nFileLength); aT(Pf7 O
// fileSplitterFetch[nPos.length-1].start(); '%V ;oJ"
g{8>2OK$c
<N=p_m 2T
//等待子线程结束 wX#=l?,K
//int count = 0; 8~EDmg[
//是否结束while循环 +=|Q'V
boolean breakWhile = false; nO$(\ z)
hBz~FB];&
9/{+,RpC
while(!bStop) ai`fP{WlX
{ .gv J;A7
write_nPos(); JV/K ouL
Utility.sleep(500); 2z:4\Y5
breakWhile = true; W4QVWn %3
=!9+f
}a"T7y23
for(int i=0;i<nStartPos.length;i++) 7zVaj"N(
{ mNKe,H0
if(!fileSplitterFetch.bDownOver) ;6L<Syl5
{ 0DIaXdOdW+
breakWhile = false; n+rAbn5o$
break; g*b%
} T5-50nU,~
} C z4"[C`;
if(breakWhile) EfcoJgX
break; ^;<s"TJ(m)
PsEm(.z
Exc`>Y q
//count++; vy[*xT]
//if(count>4) ^EjZ.#2l;
// siteStop(); TWQf2
} EW0H"YIC
_wCp.[3?t
ub{<m^|)
System.err.println("文件下载结束！"); e~W35Y>A
} D+LeZBJ
catch(Exception e){e.printStackTrace ();} yps7MM-r
} [O&2!x
]3NH[&+
"|]'\4UdzQ
//获得文件长度 %TPnC'2
public long getFileSize() Zu_m$Mx
{ Dvo.yn|kB
int nFileLength = -1; W~POS'1
try{ @PZ&/F^
URL url = new URL(siteInfoBean.getSSiteURL()); a_L&*%;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f&js,NU"
httpConnection.setRequestProperty("User-Agent","NetFox"); 1G=1FGvP
^%)'wDK
H-nk\ K<|
int responseCode=httpConnection.getResponseCode(); <)uUAh
if(responseCode>=400) hc"+6xc
{ 7cK#fh"hvg
processErrorCode(responseCode); ]N:SB
return -2; //-2 represent access is error &%>l9~F'~
} 37v!:xF!
z=N'evx~
YnNB#x8|
String sHeader; {e<J}-/?
!Jh-v
G>M# BuU
for(int i=1;;i++) Vu*yEF}
{ \d&j`UVY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bguhx3s
//Utility.log(in.readLine()); M9_ y>N[0
sHeader=httpConnection.getHeaderFieldKey(i); a,#f%#J\
if(sHeader!=null) H(lq=M0~
{ `D>PU@s$nT
if(sHeader.equals("Content-Length")) bDeHU$
{ TixHEhw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gkI(B2,/
break; b~Y$!fc
} fS>W-
} W7WHH \L/O
else oR[,?qu@f
break; Zuo7MR
} {<\nl#}5S
} R^1sbmwk
catch(IOException e){e.printStackTrace ();} [0lCb"
catch(Exception e){e.printStackTrace ();} Z WL/AC
-=&r}/&
2wlrei
Utility.log(nFileLength); G':mc{{
f#ID:Ap3
=V5<>5"M?
return nFileLength; U8c0N<j
} Qi&!IG
X{| 1E85fl
)r~$N0\D
//保存下载信息（文件指针位置） pT>[w1Kk^
private void write_nPos() J|W~\(W6i
{ ?#-"YO7
try{ 3=o3VGZP
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y1rU
output.writeInt(nStartPos.length); B0?E$8a
for(int i=0;i<nStartPos.length;i++) |+~CdA
{ Pg{Dy>&2`I
// output.writeLong(nPos); pZ/x,b#.
output.writeLong(fileSplitterFetch.nStartPos); 7 }4T)k(a
output.writeLong(fileSplitterFetch.nEndPos); C;0H _
} 4rO07)~l
output.close(); b*',(J94
} ]ctUl#j
catch(IOException e){e.printStackTrace ();} ]!d #2(
catch(Exception e){e.printStackTrace ();} MOP/q4j[
} >~){KV1~
R56:}<Y,
_k\*4K8L
//读取保存的下载信息（文件指针位置） -7fsfcGM$
private void read_nPos() /+1+6MqRn*
{ p(8H[L4Y
try{ R(74Px,/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >)=FS.?]
int nCount = input.readInt(); t4GG@`
nStartPos = new long[nCount]; Fx0E4\-
nEndPos = new long[nCount]; M n`gd#
for(int i=0;i<nStartPos.length;i++) MRxzOs
{ sTP`xaY
nStartPos = input.readLong(); Wrf('
nEndPos = input.readLong(); KqG:o+V=
} J/>Y mi,
input.close(); XpJT/&4
} (@B gsY
catch(IOException e){e.printStackTrace ();} :;cKns0OA
catch(Exception e){e.printStackTrace ();} = 7d{lK
} "a6[FqTs
\sEq r)\k
SQDllG84E
private void processErrorCode(int nErrorCode) 3V?JX5X\
{ &p8b4y_
System.err.println("Error Code : " + nErrorCode); -M2c8P:.b
} s$4!?b$tw
TppR \[4]
{" woBOaA
//停止文件下载 26B]b{Iz{
public void siteStop() =H%c/Jty
{ v#q7hw=
bStop = true; -Ob'/d5&
for(int i=0;i<nStartPos.length;i++) 'h53:?~
fileSplitterFetch.splitterStop(); z|^:1ov,
X=USQj\A
\HF|&@}hU
} KhIg
} (2RZc].M~
//负责部分文件的抓取 ;{[&&qMwU
**FileSplitterFetch.java wHq*)7#h#
*/ }dQW-U
package NetFox; @;_xFL;{g
K'kWL[Ut!
"_WOtJr
import java.io.*; =+%QfuK
import java.net.*; 9_)*b
&}_ $@
lQj3#!1}
public class FileSplitterFetch extends Thread { ;9PJ K5>~
87l(a,#J
%ZF47P%6
String sURL; //File URL _CN5,mLNRk
long nStartPos; //File Snippet Start Position 15U]/?jv8
long nEndPos; //File Snippet End Position V*5 ~A[r
int nThreadID; //Thread's ID X:+lD58
boolean bDownOver = false; //Downing is over ]&w8"q
boolean bStop = false; //Stop identical _LU]5$\b
FileAccessI fileAccessI = null; //File Access interface Xb6X'rY
=Y Je\745
h}r.(MVt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .xo#rt9_"=
{ !LB#K?I
this.sURL = sURL; Opx"'HC@G
this.nStartPos = nStart; %MGbIMpY
this.nEndPos = nEnd; >Vc;s!R
nThreadID = id; 4WU%K`jnXb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b)/,
} aqJ>l}{
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"i0{E!,XL
public void run() ,j\1UAa
{ r#hA kOw
while(nStartPos < nEndPos && !bStop) OZ##x
{ (Qq;ySZ#
%ub\+~
Q{-T;T
try{ *gF8"0s
URL url = new URL(sURL); O(q1R#n-}+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZmU7tK
httpConnection.setRequestProperty("User-Agent","NetFox"); uv,&/,;S
String sProperty = "bytes="+nStartPos+"-"; '*gY45yT`
httpConnection.setRequestProperty("RANGE",sProperty); n=Qz7N(M
Utility.log(sProperty); !o+[L
hDBVL"
+PT/pybA
InputStream input = httpConnection.getInputStream(); J:WO%P=Q
//logResponseHead(httpConnection); fGGGz$;N
0}v_usP
$p? gai{o
byte[] b = new byte[1024]; (jhDO7
int nRead; j0P+<@y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zv/owK
{ Y,0D+sO4
nStartPos += fileAccessI.write(b,0,nRead); >F7v'-*{
//if(nThreadID == 1) vU|=" #
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]$7dkP
} 4:m/w!q$
bDK%vx!_
4'EC(NR7N
Utility.log("Thread " + nThreadID + " is over!"); fP 4
bDownOver = true; p+6L qk<
//nPos = fileAccessI.write (b,0,nRead); P(h[QAM
} ^}Vx5[
catch(Exception e){e.printStackTrace ();} e+416 ~X v
} X'[93 C|K
} -aj) _.d
3s25Rps
fbv%&z
//打印回应的头信息 \ k&(D*u
public void logResponseHead(HttpURLConnection con) j!m42
{ >Vp#
for(int i=1;;i++) 8/4i7oOC
{ i_<Uk8
String header=con.getHeaderFieldKey(i); .zDm{_'
if(header!=null) |Iq#Q3w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3"B$M
Utility.log(header+" : "+con.getHeaderField(header)); ]CLt Km
else XNZW J
break; s,~)5nL
} >2kjd
} lxSCN6
gxa@da
2o5Pbdel
public void splitterStop() ~# ~XDcc
{ (Qf"|3R4
bStop = true; Fh[Gq
} -%I 0Q
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N5]}m:"pk
} 'UW]~
g+ZQ6Hz
4\Nt"#U)g
/* h4N%(?7
**FileAccess.java Pgdv)i3
*//文件访问(定位，写) BZUA/;Hz &
package NetFox; ~r%>x
import java.io.*; HzuB.B<
83~9Xb=!\
bi=IIVlH
public class FileAccessI implements Serializable{ ;_]Z3
e3YdHp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I{rW+<)QGC
RandomAccessFile oSavedFile; !/]vt?v#^
long nPos; (j*1sk
R\VM6>SN'S
%+Az X
public FileAccessI() throws IOException o>G^)aRa
{ /C: rr_4=
this("",0); FXF#v>&
} zG%ZDH^82_
'OERW|BO
Z3jtq-y
public FileAccessI(String sName,long nPos) throws IOException 3B+ F'k&#
{ Tw)"#Y!T
oSavedFile = new RandomAccessFile(sName,"rw"); /d/Quro
this.nPos = nPos; gr&Rkuyfv
oSavedFile.seek(nPos); ?:8wDV
} "M`ehgCBr
0SJ7QRo|K
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public synchronized int write(byte[] b,int nStart,int nLen) !"dn!X
{ 9[L@*7A`m
int n = -1; ?M02|8-
try{ UN,y/V
oSavedFile.write(b,nStart,nLen); fxR}a,a
n = nLen; @1p,
} ,vN0Jpf}\8
catch(IOException e) \q |n0>
{ @qGg=)T
e.printStackTrace (); A&dNCB
} q1d'L*
o{QU?H5h
GiF})e}
return n; r]0UF0#
} W@:a3RJ
:zL.dJwa
TAXl73j_CY
} ~582'-=+
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p]7Gj&a
/* ;4g_~fB
**SiteInfoBean.java p| #gn<z}
*/ O8J:Tw}M*
package NetFox; UdSu:V|
C}~/(;1V=
Rlq6I?S+
public class SiteInfoBean { e>oE{_e
fK$N|r
_:tclBc8R
private String sSiteURL; //Site's URL c=-2c&=&
private String sFilePath; //Saved File's Path q|8p4X}/]
private String sFileName; //Saved File's Name "eH~/6A
private int nSplitter; //Count of Splited Downloading File _z3Hl?qk=
5xEk 7g.
iN}BMd.U
public SiteInfoBean() <_|H]^o
{//nSplitter的缺省值为5 bnWKfz5
//default value of nSplitter is 5 `Al[gG?/!
this("","","",5); F!|?S:X
} u D.E>.B
K7x,>
-CTsB)=\,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1qs~[7{C1
{ cZ" Ut
sSiteURL= sURL; L-ZJ[#D
sFilePath = sPath; t;DZ^Z"{
sFileName = sName; AJ;Y Nb
this.nSplitter = nSpiltter; Y[Gw<1F_
cVZCBcKC?
ZSuMQ32
} 3q:-98DT
ifu"e_^
l|-TGjsX
public String getSSiteURL() X7sWu{n
{ >4d2IO1\
return sSiteURL; ksxacRA7\
} `p&ko$i2
>#@1 I
-(n[^48K
public void setSSiteURL(String value) |Hbe]2"x>
{ X$O,L[] 4
sSiteURL = value; Xu1l6jr_
} @1#$
vf@d(g
sz.(_{5!
public String getSFilePath() blZiz2F
{ (n-8p6x(
return sFilePath; IbpE@C
} 1Tn!.E *
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3zb;q@JV
public void setSFilePath(String value) y+RT[*bX5o
{ VI%879Z\e
sFilePath = value; /Q"nQSG
} M* W=v
p[e|N;W8A
+w/Ax[K
public String getSFileName() Ep}KIBBO
{ O.=~/!(
return sFileName; {6<7M
} )o[ O%b
yI9l*'
>taS<.G
public void setSFileName(String value) pBt/vSad
{ \n850PS
sFileName = value; @A6\v+ih
} )_T[thf]
Sv-}w$
w\Q3h`.
public int getNSplitter() !^ 6x64r
{ L{~L6:6An
return nSplitter; tc@U_>{
} 5(MWgC1
>TsJ0E?3x
%^"Tz,f
public void setNSplitter(int nCount) IxCEE5+`%
{ .i/]1X*;r^
nSplitter = nCount; (0W%YZ!&
} ,"PwNv
} iQ-;0<=G
n?pCMS|
i{VjSWq
/* UTUIL D
**Utility.java }se)=7d8 Z
*/ dv%gmUUf}k
package NetFox; j:|60hDz^
3h"; 2
O6;>]/`
public class Utility { m7kDxs(KO
U:MkA(S%c
Ii*v(`2b
public Utility() n<CJx+U
{ )QTk5zt
xn@?CP`-y
scqG$~O)
} 1q~U3'l:$
!j4C:L3F
//线程睡眠 "JVzv U]
public static void sleep(int nSecond) D +)6#i Y
{ S:vv*5
try{ {H $\,
Thread.sleep(nSecond); dqUhp_f2qK
} F4Ft~:a
catch(Exception e) U3lr<(r*
{ |i?AtOt@f
e.printStackTrace (); p`1d'n[
} |gxU;"2`5~
} {L$b$u$7:
]-%ZN+
//日志 yixW>W}
public static void log(String sMsg) WGG|d)'@
{ B0q![
System.err.println(sMsg); 8t}=?:B+{
} gRdE6aIZ
#jr;.;8sQ
S97.O@V!$
public static void log(int sMsg) Z6>:k,-Ot
{ )\^o<x2S
System.err.println(sMsg); :v{$]wg
} #TW$J/Jb
} 9z'</tJ`
lbg6n:@
7@EYF
/* Yc?taL)
**TestMethod.java ,l; &Tb=k
*/ (GPJ=r
package NetFox; D{'Na5(
T,7Y7MzF
tt J,rM
public class TestMethod { G:WMocyXI'
]N=C%#ki!
.2xypL8(
public TestMethod() tsfOPth$*
{ ///xx/weblogic60b2_win.exe |,sUD/rt
try{ J@Zm8r<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mkE*.I0=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IH~H6US
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2z0HB+Y}x
fileFetch.start(); (m04Z2#
} mZ/B:)_
catch(Exception e){e.printStackTrace ();} 1LPfn(
'b661,+d
yH#;k:O=
} [po+a@ %
kOdS^-
@z/]!n\~
public static void main(String[] args) i6`8yw
{ _&(ij(H
new TestMethod(); JEHV\=
} zZ32K@
} 'hya#rC&(
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