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)); 0K<x=-cCB
} .,3Zj /
for(int i=0;i<nEndPos.length-1;i++) ^rv"o:lF
{ z %x7fe
nEndPos = nStartPos[i+1]; &<,SV^wag
} l~bKBz
nEndPos[nEndPos.length-1] = nFileLength; Jyj0Gco
} g(/{.%\k
} Hjs}
0YzsA#yv
^Q0&.hL@
//启动子线程 ?Jt$a;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t5.`!3EO
for(int i=0;i<nStartPos.length;i++) ~>V-*NT8
{ $<B +K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1O |V=K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .K IVf8)"
nStartPos,nEndPos,i); =/FF1jQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gH %y
fileSplitterFetch.start(); w |_GV}#_
} \6sqyWI %
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zZ%DtxUoU.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }A]BpSEP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CRFCqmevR
nEndPos = " + nFileLength); 6*IpAIh
// fileSplitterFetch[nPos.length-1].start(); mjb{~
x97L6!
<FY&h#
//等待子线程结束 }e 9!xA
//int count = 0; mN;+TN'?{
//是否结束while循环 y&"!m}
boolean breakWhile = false; 17}$=#SX
Sk:2+inU
7^$)VBQ/
while(!bStop) ~-TOsRvxR
{ P z ?m>>#
write_nPos(); P;vxT}1
Utility.sleep(500); %KtU1A(["
breakWhile = true; A\z`c e!
{.st`n|xz
u$%A#L[
for(int i=0;i<nStartPos.length;i++) `>6T&
{ M;+IZr Wkl
if(!fileSplitterFetch.bDownOver) +4et7
{ /.R<,/gj
breakWhile = false; -v]Qhf&>
break; >"v9iT
} /b5>Qp
} *5k+t
if(breakWhile) a?F!,=F
break; gZO&r#
m:uPEpcU
j8++R&1f]
//count++; 48O~Jx,
//if(count>4) .2W"w)$nuq
// siteStop(); mT@nn,
} n[,XU|2
|a-fE]{7
6)qp*P$L
System.err.println("文件下载结束！"); rh!;|xB|+
} 7"4z+w
catch(Exception e){e.printStackTrace ();} -)v@jlg02
} d(-EcY>?
irbw'^;y
R_ ZK0ar
//获得文件长度 $TG=w
public long getFileSize() ?>$l
{ N\NyXh$
int nFileLength = -1; -fy9<
try{ B4h5[fPX
URL url = new URL(siteInfoBean.getSSiteURL()); >|g?wC}V;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :z&7W<
httpConnection.setRequestProperty("User-Agent","NetFox"); 8|@9{
e(?]SU|
=2Cj,[$
int responseCode=httpConnection.getResponseCode(); :>+\17tx
if(responseCode>=400) 29&bbfU
{ iafE5b)
processErrorCode(responseCode); I9?Ec6a_
return -2; //-2 represent access is error \]uV!)V5B
} V`kMCE;?l
-]srp;=i
u0QzLi,
String sHeader; <lE?,jl
XJ1=m
LzML%J62
for(int i=1;;i++) |kJ%`j(7R
{ )Ry<a$Q3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M f~}/h
//Utility.log(in.readLine()); 7f3O
sHeader=httpConnection.getHeaderFieldKey(i); 6gH{R$7L=
if(sHeader!=null) cl@g
{ e}hmS1>H
if(sHeader.equals("Content-Length")) nXy>7H[0
{ Qm4o7x{q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]e'fa/I
break; kD5!}+y
} |'d>JT:
} I_1e?\
else I%j_"r9-I
break; *.#oxcll
} >UDd @
} ~PnTaAPJ
catch(IOException e){e.printStackTrace ();} asHxL!
catch(Exception e){e.printStackTrace ();} :,B7-kBw
X]%itA
r [:
Utility.log(nFileLength); n/~A`%E@
CVNj-&vj
bi[IqU!9
return nFileLength; !-<p,z
} _ :Ag?2
?W>qUrZ
qpIC{'A.
//保存下载信息（文件指针位置） TaE~s
private void write_nPos() iOAbaPN
{ sEMQ
try{ zcrY>t#l
output = new DataOutputStream(new FileOutputStream(tmpFile)); |`Or'%|PR
output.writeInt(nStartPos.length); #@HF<'H}mu
for(int i=0;i<nStartPos.length;i++) $+p?Y)h .
{ LbEM^D
// output.writeLong(nPos); .*g0w`H5pU
output.writeLong(fileSplitterFetch.nStartPos); ':{>a28=
output.writeLong(fileSplitterFetch.nEndPos); a.N{-2ptH
} &i+Ce
output.close(); Rk!X]-`=
} WOzf]3Xcj
catch(IOException e){e.printStackTrace ();} 5GA C`}}
catch(Exception e){e.printStackTrace ();} ,R%q}IH#
} SZaS;hhhHu
[S5\#=_4S
ljTBvU
//读取保存的下载信息（文件指针位置） >zAUW[]C:I
private void read_nPos() S*o[ZA
{ ,XDRO./+T
try{ Gmwf4>"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A, 3bC
int nCount = input.readInt(); f+8wl!M+6
nStartPos = new long[nCount]; / 0 O=(
nEndPos = new long[nCount]; '3zc|eJt&
for(int i=0;i<nStartPos.length;i++) <-D/O$q
{ ^8.]d~j
nStartPos = input.readLong(); #@<9S{F
nEndPos = input.readLong(); [8tL"G6s
} ^[:p|U2mA
input.close(); 1-lu\"H`
} ;rc`OZyE
catch(IOException e){e.printStackTrace ();} i&{DOI%w
catch(Exception e){e.printStackTrace ();} M5gWD==uP
} -f*P nxg
7}M2bH} \K
O T.*pk+<)
private void processErrorCode(int nErrorCode) X}+>!%W!}
{ ;)N>t\v
System.err.println("Error Code : " + nErrorCode); wF((
} EoK~S\dS
'!/<P"5t
hzkcP
//停止文件下载 UQ{L{H
public void siteStop() ggJO:$?$L
{ vZ.x{"n'~
bStop = true; <HbcNE~
for(int i=0;i<nStartPos.length;i++) ``wSc0\
fileSplitterFetch.splitterStop(); u~A6bK*
,l<6GB2\
uEX!xx?Q#
} JvY}-}?c
} dCRyOid$
//负责部分文件的抓取 /~zai}
**FileSplitterFetch.java 8F._9U-EN
*/ &Z`#cMR{H
package NetFox; ~ 4kc/a
#B4%|v;`E?
+HBd %1
import java.io.*; 8F'x=lIO
import java.net.*; s&RVJX>Rt
P9T}S
%}%Qc6.H
public class FileSplitterFetch extends Thread { 'FDef#P<
x QIq^/F0
-3Hy*1A.
String sURL; //File URL 2 B
long nStartPos; //File Snippet Start Position p6;OL@\~
long nEndPos; //File Snippet End Position 2nR[Xh?L
int nThreadID; //Thread's ID :Of^xj>A
boolean bDownOver = false; //Downing is over ZzSz%z_sE
boolean bStop = false; //Stop identical 8uWa=C)
FileAccessI fileAccessI = null; //File Access interface 0tXS3+@n=
"'t0h{Wr8
.>WxDQIo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C#Na&m
{ ; #&yn=^
this.sURL = sURL; XT4{Pe7{[P
this.nStartPos = nStart; Le\?+h42>
this.nEndPos = nEnd; PpAu!2lt9
nThreadID = id; x^y'P<ypw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y!_C/!d
} -4 SY=NC_
JU)dr4S?
v_DedVhe
public void run() 5yP\I+Fm
{ )v.=jup[
while(nStartPos < nEndPos && !bStop) {0WHn.,2Y
{ $42{HFGq
;IZwTXu!S
*2,VyY
try{ T(U_
URL url = new URL(sURL); `~By)?cT_>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5fd]v<
httpConnection.setRequestProperty("User-Agent","NetFox"); ~5}* d
String sProperty = "bytes="+nStartPos+"-"; De'_SD|=
httpConnection.setRequestProperty("RANGE",sProperty); Zg{KFM%
Utility.log(sProperty); ppVHLrUh
;EP:o%r
}f6HYU
InputStream input = httpConnection.getInputStream(); oYH^_V
//logResponseHead(httpConnection); R8a3 1&
.nx2";oi
?gt l)q
byte[] b = new byte[1024]; %5"9</a&G
int nRead; G$F<$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Wa{`VS
{ [q8 P~l
nStartPos += fileAccessI.write(b,0,nRead); )QU
//if(nThreadID == 1) P&*2pX:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @emK1iwm
} Ezd_`_@R
D$I5z.a
wNpTM8rfU#
Utility.log("Thread " + nThreadID + " is over!"); j}.\]$J
bDownOver = true; CDK5
//nPos = fileAccessI.write (b,0,nRead); >JFO@O5
} /}b03
catch(Exception e){e.printStackTrace ();} rrik,qyv6
} Nh_Mz;ITuu
} B#Vz#y
r{L> F]Tw
4R1<nZ"e~
//打印回应的头信息 vunHNHltW0
public void logResponseHead(HttpURLConnection con) V{/?FO?E
{ $QLcH;+7t
for(int i=1;;i++) .$+#1-
{ 61k"p2?+
String header=con.getHeaderFieldKey(i); }HFN3cq;C
if(header!=null) 'h|DO/X~L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P2#XKG
Utility.log(header+" : "+con.getHeaderField(header)); K8GP@yD]M
else nxnv,AZG
break; W{6|tx)
} Y5- F@(
} $5aV:Z3P
z[L8$7L
!Prg_6 `
public void splitterStop() v$?+MNks
{ | *2w5iR
bStop = true; "n(hfz0y%
} >UiYL}'br6
^ *k?pJ5
K*LlW@
} yerg=,$_i
,Z&xNBX
XDOY`N^L
/* 96( v
**FileAccess.java `{3<{wgw
*//文件访问(定位，写) L*xhGoC=
package NetFox; D#cyOrzy
import java.io.*; 4'/nax$Bx;
ls\WXCH
S&Zm0Ku
public class FileAccessI implements Serializable{ vlmB`T
Z'`<5A%;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0l)~i''
RandomAccessFile oSavedFile; n'n/Tu
long nPos; 6F!+T=
A5c%SCq;
pjKWtY@=X
public FileAccessI() throws IOException `VA"vwz
{ =Y{(%sn
this("",0); <\rT%f}3^
} %g{X?
K[YI4pt7
kCWV r
public FileAccessI(String sName,long nPos) throws IOException YxYH2*q@
{ y-'$(x
oSavedFile = new RandomAccessFile(sName,"rw"); :~"CuB/
this.nPos = nPos; g:g\>@Umo
oSavedFile.seek(nPos); -$,TMqM
} t3 8m'J :>
1H? u Qy
I&#| w"/"U
public synchronized int write(byte[] b,int nStart,int nLen) x nsLf?>]
{ S 6@u@C
int n = -1; 4KhV|#-;k
try{ i1ixi\P{0
oSavedFile.write(b,nStart,nLen); )B"jF>9)[
n = nLen; ]sf7{lVT
} :%tU'w
catch(IOException e) ~7*.6YnI
{ 6iVxc|Ia
e.printStackTrace (); 6M @[B|Q(
} Ra)3+M!x
Y2N>HK0
Q 3hKk$Y
return n; I667Gz$j5
} \=VtHu92=
:C(=&g<]D
^me-[ 5
} S'Q@ScJ
SD"FErJ
Yg]-wQrH
/* QO<jI#
**SiteInfoBean.java `06;
*/ jl4rbzse
package NetFox; K -nF lPm\
~ (|5/ p7t
d[@X%
public class SiteInfoBean { {j.bC@hWw
Ec3}_`
| k&Ck
private String sSiteURL; //Site's URL $?rQg@U
private String sFilePath; //Saved File's Path CM/H9Kz.
private String sFileName; //Saved File's Name $O&b``
private int nSplitter; //Count of Splited Downloading File pA'4|ffwe
zqimR#u
b z`+k,*
public SiteInfoBean() B nFwlw
{//nSplitter的缺省值为5 1{)5<!9!l
//default value of nSplitter is 5 K[I=6
this("","","",5); N]>=p.#j
} zGb|)A~,
F+YZE[h%
f',Op1o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =_.l8IYX$%
{ dN$0OS`s[
sSiteURL= sURL; e>} s;H,
sFilePath = sPath; J{.{f
sFileName = sName; 0.`/X66;V
this.nSplitter = nSpiltter; Z;ht
Q- cFtu-w
m|SUV
} wL+s8#{
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*RI]?j%B
public String getSSiteURL() (!ux+K
{ )tC5Hijq,
return sSiteURL; 8}I$'x
} LdYB7T,
v> LIvi|]
h9t$Uz^N
public void setSSiteURL(String value) VACQ+
{ &|s0P
sSiteURL = value; R6` WN
} F%@A6'c
j@n)kPo,1
l.q&D< _
public String getSFilePath() Yz<3JRw
{ u0JB$(-/h
return sFilePath; }zeO]"`
} QmQ=q7
%6|nb:Oa
5MroNr
public void setSFilePath(String value) TJ10s%,V
{ p)KheLiZ
sFilePath = value; Tr_w]'
} F6|TP.VY_.
0pZ4BZdT|
GSoX<*i
public String getSFileName() RVZ")Z(
{ %"q9:{m
return sFileName; _~'=C#XI)
} h=W:^@G
[]\+k31D
eQ$Y0qH1E
public void setSFileName(String value) W\>fh&!)
{ y%&q/tk
sFileName = value; +jAGGv^)
} MU($|hwiL
.eS<Dbku<
'f#{{KA
public int getNSplitter() ^7w+l @
{ `{f}3bO7C
return nSplitter; 3(="YbZ
} qz"}g/;?
xipU8'ac/
Jz\%%C
public void setNSplitter(int nCount) '*Z1tDFS
{ `XJG(Oas\
nSplitter = nCount; R
} MR;1 2*p
} YDIG,%uv
> $O]Eu!
1D7nkAy
/* gt\E`HB8E
**Utility.java Z&G+bdA>,
*/ P9/q|>F
package NetFox; |'e^QpU5
o8 IL$:
)\1QJ$-M&
public class Utility { 46}g7skD
J-[,KME_^
]V[q(-Jk
public Utility() vt/x ,Y
{ e+=y*OmQ
^3G{|JB!+
.Hescg/S
} m~w[~flgZ
RaO-H
//线程睡眠 P:hBt\5B
public static void sleep(int nSecond) h!M
{ B~?*?Z'
try{ ,[N%Q#
Thread.sleep(nSecond); >>QY'1Eu
} k)i3
catch(Exception e) kq?Ms|h
{ nxO"ua
e.printStackTrace (); v|Pv 03%?7
} bYcV$KJk
} R]JT&p|w.1
,A9]CQ
//日志 hE &xE;
public static void log(String sMsg) G?9"Y%
{ _Ym]Mj' ln
System.err.println(sMsg); zZ:>do\2
} bpOYHc6,*`
'g">LQ~a+
):P?
public static void log(int sMsg) }cM}Oavh
{ V~UN
System.err.println(sMsg); "0$a)4]
} FK^p")i
} T5|qRlW
biLs+\C
Z EQ@IS:Y
/* W1WYej"
**TestMethod.java 4%{,] q\p
*/ zp6C3RG(
package NetFox; af6M,{F
|e=,oV"
ay4 %
public class TestMethod { \Yy$MLs
['b}QW@Fx
Z/G ev"p
public TestMethod() w3N[9w?1
{ ///xx/weblogic60b2_win.exe 0}<|7?
try{ 3t.l5m Rg5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *}Xf!"I#]N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :Oy%a'w
SiteFileFetch fileFetch = new SiteFileFetch(bean); +<'Ev~
fileFetch.start(); -TLlwxc^%
} I"xo*}
catch(Exception e){e.printStackTrace ();} BIH-"vTy
O6@j &*jS
,1hxw<sNR
} f@6QvkIa
e*sfPHt
HsxVZ.dS
public static void main(String[] args) 87=&^.~`
{ 1}"++Z73P
new TestMethod(); a a<8,;
} 0`Kj25
} md+nj{Ib
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