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)); u#fM_>ML
} /62!cp/F/D
for(int i=0;i<nEndPos.length-1;i++) P5V}#;v
{ 6wRd<]C
nEndPos = nStartPos[i+1]; K3&qq[8.e
} s[*rzoA
nEndPos[nEndPos.length-1] = nFileLength; #zy:a%
} ODN/G%l
} Wb_J(!da
~_)^X
qwcD`HV,
//启动子线程 \K{ z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]c*4J\s
for(int i=0;i<nStartPos.length;i++) qZh/IW
{ GA)`-*.R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C=xa5Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,ng Cv;s
nStartPos,nEndPos,i); <=&`ZH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R^fPIv`q
fileSplitterFetch.start(); uMv,zO5
} bWS&Yk(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FxY}m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lFj]4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~P qM]^
nEndPos = " + nFileLength); E=Bf1/c\
// fileSplitterFetch[nPos.length-1].start(); {uFO/
Qljpx?E
V &T~zh1
//等待子线程结束 MJ)RvNF
//int count = 0; D)P._?
//是否结束while循环 3M`M
boolean breakWhile = false; v/plpNVp>
`RW HN/U
;;t yoh~t
while(!bStop) I@N8gn
{ (lqC[:
write_nPos(); ]N]!o#q}L
Utility.sleep(500); gVuFHHeUz
breakWhile = true; n8[!pH~6
%2{ye
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for(int i=0;i<nStartPos.length;i++) K5 z<3+
{ R29~~IOqO
if(!fileSplitterFetch.bDownOver) C): 1?@
{ Nx;~@
breakWhile = false; ~8+ Zs
break; @ q3k%$4
} +`0k Fbx
} JR|ck=tq
if(breakWhile) 1&OW4_
break; q i;1L Kc
RB\uK 1+
:OZrH<SW
//count++; _f,C[C[e&
//if(count>4) ({_{\9O,3
// siteStop(); c6]U E@A
} s8Q 5ui]
0mVNQxHI
qR{=pR
System.err.println("文件下载结束！"); hfTY.
} ?^{Ah}x
catch(Exception e){e.printStackTrace ();} H?Wya.7
} IOH}x4
kD%( _K5
B6 ;|f'e!
//获得文件长度 } OR+Io
public long getFileSize() j (d~aqW
{ Ml5w01O
int nFileLength = -1; \)[j_^
try{ & .j&0WE
URL url = new URL(siteInfoBean.getSSiteURL()); ^ytrK Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JbbzV>
httpConnection.setRequestProperty("User-Agent","NetFox"); ,0sm
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U)gH}0n&
int responseCode=httpConnection.getResponseCode(); e*C(q~PQ
if(responseCode>=400) _VN?#J)o
{ B3I`40#
processErrorCode(responseCode); HC8e>kP9b
return -2; //-2 represent access is error '<<t]kK[N
} L*+@>3mu)
t{kG<J/l
Llo"MO*sr
String sHeader; G` A4|+W"
+'a^f5
m0SlOgRsk
for(int i=1;;i++) tk`v:t!6U
{ _{KG 4+5\X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ND;#7/$>
//Utility.log(in.readLine()); cI*;k.KU
sHeader=httpConnection.getHeaderFieldKey(i); p2](_}PK
if(sHeader!=null) Fxz"DZY6
{ fr3d
if(sHeader.equals("Content-Length")) q9_OGd|P
{ 7$=InK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AkV#J, 3LC
break; vE?G7%,
} x;d6vBTUb
} a=2%4Wmz
else 4[eXe$
break; `;C V=,M
} 5;EvNu
} L4HI0Mx
catch(IOException e){e.printStackTrace ();} /4Gt{ygSr
catch(Exception e){e.printStackTrace ();} jLluj
lo+A%\1
:F?C)F
Utility.log(nFileLength); %h@EP[\
vs4>T^8e
'=pU^Oz<}
return nFileLength; y)@wjH{6
} K0>zxqY
yN-9[P8C
0(HU}I
//保存下载信息（文件指针位置） f:} x7_Q
private void write_nPos() S9.o/mr
{ ?@86P|19
try{ ;Y, y4{H3
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~DwpoeYX
output.writeInt(nStartPos.length); XL^GZ
for(int i=0;i<nStartPos.length;i++) <5051UEu
{ 2+XAX:YD
// output.writeLong(nPos); ;V!D:5U
output.writeLong(fileSplitterFetch.nStartPos); @VEb{ w[H
output.writeLong(fileSplitterFetch.nEndPos); }K(TjZR
} 9*M,R,y
output.close(); @yYkti;4-
} zb3tIRH
catch(IOException e){e.printStackTrace ();} =s6 opL)
catch(Exception e){e.printStackTrace ();} N!}f}oF
} %N._w!N<5n
]-#DB^EQ
uY To9A
//读取保存的下载信息（文件指针位置） W>r+h-kR
private void read_nPos() J&_n9$
{ RA 6w}:sq7
try{ 9(Xn>G'iT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SXh-A1t
int nCount = input.readInt(); wCBplaojJ
nStartPos = new long[nCount]; :ws<-Qy
nEndPos = new long[nCount]; (bS&D/N.
for(int i=0;i<nStartPos.length;i++) m&3xJuKih
{ ~} ~4
nStartPos = input.readLong(); Vurqt_nb
nEndPos = input.readLong(); %cn<ych G
} dZuOrTplA
input.close(); tH4B:Bgj!
} #'`{Qv0,
catch(IOException e){e.printStackTrace ();} c:('W16
catch(Exception e){e.printStackTrace ();} n$R)>nY
} 2=}FBA,2
[-w%/D%@
y~V(aih}D
private void processErrorCode(int nErrorCode) .xkM.g4{~
{ %BODkc Zh
System.err.println("Error Code : " + nErrorCode); UiNP3TJ'L
} V;=cwy)I
;tf=gdX;
DY*N|OnqJ
//停止文件下载 EU#^7
public void siteStop() |7~<Is~*
{ >$7B wO
bStop = true; 6S#Cl>v
for(int i=0;i<nStartPos.length;i++) Z\sDUJ
fileSplitterFetch.splitterStop(); "dlVk~
>\8+:oS^
K 8O|?x]
} Z_NCD`i;
} =_^X3z0
//负责部分文件的抓取 a+QpM*n7Lq
**FileSplitterFetch.java *^`Vz?g<
*/ pj(,Zd[47
package NetFox; LP=)~K<
n6v6K1
x)&\z}
import java.io.*; -?a 26o%e
import java.net.*; ]M3yLYK/P
zuCSj~
U0+-W07>
public class FileSplitterFetch extends Thread { MQ2_`pi
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V]^$S"Tv
String sURL; //File URL X8\GzNE~R
long nStartPos; //File Snippet Start Position HaYo!.(Fv
long nEndPos; //File Snippet End Position /L3:
int nThreadID; //Thread's ID B5QFK
boolean bDownOver = false; //Downing is over d;>QhoiL
boolean bStop = false; //Stop identical mkpMfPt
FileAccessI fileAccessI = null; //File Access interface unxqkU/<Z
]$hBMuUa
$cgcX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hr C+Yjp
{ tJmTBsn
this.sURL = sURL; 2 E=L8<
this.nStartPos = nStart; ;VK.2^jW!
this.nEndPos = nEnd; ~J]qP#C
nThreadID = id; rl.}%Ny
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XPPdwTOr
} '%;m?t%q
^J{:x
d-%hjy3N
public void run() Sjj6q`
{ @)}L~lb[)
while(nStartPos < nEndPos && !bStop) Y-9I3?ar
{ c@Is2 9t*
l-3~K-k<@
18Emi<&A
try{ Ort(AfW
URL url = new URL(sURL); p<%d2@lp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _0I@xQj-
httpConnection.setRequestProperty("User-Agent","NetFox"); \U0'P;em
String sProperty = "bytes="+nStartPos+"-"; @VI@fN
httpConnection.setRequestProperty("RANGE",sProperty); "M0z(NkH
Utility.log(sProperty); qgB_=Q#E
QV8g#&z
-g<oS9
InputStream input = httpConnection.getInputStream(); n+p }\msH
//logResponseHead(httpConnection); u&e~1?R
YkADk9fE
A}w/OA97RO
byte[] b = new byte[1024]; ?A0)L27UE&
int nRead; sos5Y}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z9"U!A4
{ .Y|!:t|
nStartPos += fileAccessI.write(b,0,nRead); $Kd>:f=A
//if(nThreadID == 1) 7$#u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AFn7uW!9Gw
} HKeK<V
BLFdHB.$T
=|9!vzG4
Utility.log("Thread " + nThreadID + " is over!"); ^^Vg~){4
bDownOver = true; d_CT$
//nPos = fileAccessI.write (b,0,nRead); MOC/KNb
} eH,or,r
catch(Exception e){e.printStackTrace ();} A(XKyEx
} j1Ezf=N6`
} 4z)]@:`}z
{[F A#
)gi9f1n`
//打印回应的头信息 d5-qZ{W
public void logResponseHead(HttpURLConnection con) <naz+QK'
{ [B3RfCV{
for(int i=1;;i++) SWLo|)@[/
{ /@5YW"1
String header=con.getHeaderFieldKey(i); 13f)&#, F
if(header!=null) )}vl\7=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P {'b:C
Utility.log(header+" : "+con.getHeaderField(header)); `_h&glMJ,q
else R#KU^]"(
break; ULW~90
} :KO2| v\
} Va8&Z
b Zt3|
!9x}
public void splitterStop() R-Sym8c
{ -qoH,4w
bStop = true; 8Y?;x}
} rlD8D|ZG
V8(-
pot~<d`:K"
} ce(#2o&`
Ca\6vR
N21smC}
/* ;}t(Wnu.
**FileAccess.java %)n=x ne
*//文件访问(定位，写) Ho%CDz z
package NetFox; +[P{&\d4}
import java.io.*; "#48% -'x
11lsf/IP
W!<U85-#S
public class FileAccessI implements Serializable{ j.YA2mr
+|rj4j)L&'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _*zt=zn>
RandomAccessFile oSavedFile; 7o4\oRGV
long nPos; 3a|\dav%
oU/5 a>9~
;Xw~D_uv
public FileAccessI() throws IOException ;Qq\DFe.w
{ ~5g~;f[4
this("",0); `{Ul!
} [ 3HfQ
ctUp=po
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public FileAccessI(String sName,long nPos) throws IOException #Dac~>a'
{ *h|U,T7ew
oSavedFile = new RandomAccessFile(sName,"rw"); A=4OWV?
this.nPos = nPos; j39wA~K
oSavedFile.seek(nPos); *`U~?q}
} dRDnJc3
He)%S]RLk
q:(%*sY>
public synchronized int write(byte[] b,int nStart,int nLen) h$*!8=M
{ Ls%MGs9PI
int n = -1; w(rE`IgW
try{ _Y!IEAU/#
oSavedFile.write(b,nStart,nLen); 8-i#8'/x
n = nLen; n|;Im&,
} 6wxs1G
catch(IOException e) $u.z*b_yy
{ D]}G.v1
e.printStackTrace (); +d>IHpt
} .u:GjL'$
a =QCp4^
kP"9&R`E
return n; ceV}WN19l
} VE24ToI?W"
5m*,8]!-
=Uh$&m
} ^s=8!=A(
L$-T,Kze
9gFUaDLo
/* $?Wb}DU7_L
**SiteInfoBean.java PeT'^?>
*/ 6 r"<jh#
package NetFox; ise-O1'
"fI6Cpc
?EL zj
public class SiteInfoBean { ,)XLq8
_LPHPj^Pg
w@b)g
private String sSiteURL; //Site's URL (?c-iKGc
private String sFilePath; //Saved File's Path pGZ8F
private String sFileName; //Saved File's Name P'2Qen*
private int nSplitter; //Count of Splited Downloading File E3i4=!Y
Zh,71Umz
g ?k=^C
public SiteInfoBean() eIlva?
{//nSplitter的缺省值为5 <N)oS-m>
//default value of nSplitter is 5 >bxS3FCX
this("","","",5); liZxBs :%i
} ?0SEMmp`H
#?E"x/$Y6
RpK@?[4s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g*Phv|kI
{ '7/)Ot(
sSiteURL= sURL; B6"0OIDY"
sFilePath = sPath; _+,TT['57s
sFileName = sName; gSgr6TH0
this.nSplitter = nSpiltter; Gq6*SaTk
<UI [%yXj
<[phnU^ 8
} aYeR{Y]
JLYi]nZ
%RVZD#zr
public String getSSiteURL() y(&Ac[foS}
{ 6mE\OS-I
return sSiteURL; y2v^-q3
} ZoeD:xnh[
TV:9bn?r)
GeqPRah
public void setSSiteURL(String value) :Al!1BJQ
{ ;j7#7MN2_E
sSiteURL = value; dI2 V>vk
} y9;Yivr)
=vPj%oLp'a
lk!@?
public String getSFilePath() =-T]3!
{ T+$[eWk"a
return sFilePath; H.;Q+A,8^
} \!(zrfP{(
ZC?Xqp
n|hNM?v
public void setSFilePath(String value) GB^Br6
{ 9$Y=orpWxr
sFilePath = value; 83m3OD_y
} ~>G^=0LT
pdMc}=K
@d_M@\r=j
public String getSFileName() KXrjqqXs
{ i@q&5;%%
return sFileName; k!^{eOM
} K@2),(z
Fcx&hj1gQ
}qUX=s GG
public void setSFileName(String value) $j~RWfw-
{ 3'Rx=G'
sFileName = value; I'Hf{Erw
} gr{ DWCK
z{543~Og59
]iWRo'
public int getNSplitter() {vj)76%y
{ "~nZ GiK
return nSplitter; Zfw,7am/
} *Ly6`HZ9
5(2;|I,T
F{wzB
public void setNSplitter(int nCount) V+\Wb[zDJ
{ l}h!B_P'
nSplitter = nCount; dQvcXl]
} cl1T8vFM
} :3PH8TL
+t.b` U`-
?M2J wAK5
/* RFGffA&
**Utility.java :m;p:l|W
*/ 54,er$$V
package NetFox; pCDmXB
W)/#0*7
*a)n62
public class Utility { !Cs_F&l"j
f<_Cq<q"
]GS bjHsO
public Utility() A,]h),b
{ l{9Y
Wqnc{oq|$
x;S @bY
} S/ *E,))m
gUlo]!$
//线程睡眠 +|v90ed
public static void sleep(int nSecond) ~o(
{ wkq 66?
try{ .}t e>]A*
Thread.sleep(nSecond); 9$t(&z=
} GdwVtqbX
catch(Exception e) x2EUr,7
{ F [M,]?
e.printStackTrace (); }k0_5S
} mw!F{pw
} '91/md5
29rX%09T]
//日志 _$'ashF
public static void log(String sMsg) /z!%d%"
{ }C:r9?T
System.err.println(sMsg); \zY!qpX<
} O^.#d
~&T~1xsFJ
8}[).d160
public static void log(int sMsg) XX@ZQcN
{ dG{A~Z z
System.err.println(sMsg); Y*^[P,+J*}
} 0@(&eH=
} \RiP
_-D{-Bu#
uZ5p#M_
/* +z( Lr=G
**TestMethod.java eDMO]5}Ht
*/ +TJCLZ..
package NetFox; M{@(G5
zda 3 ,U2o
UZMd~|
public class TestMethod { uT{q9=w
uD'6mk*
2HdC |$_+
public TestMethod() 8Wx=p#_
{ ///xx/weblogic60b2_win.exe A<{{iBEI`
try{ d~H`CrQE*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8r{.jFGv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }pYqWTG
SiteFileFetch fileFetch = new SiteFileFetch(bean); >j/w@Fj
fileFetch.start(); uYN`:b8
} )2.Si#
catch(Exception e){e.printStackTrace ();} nKY6[|!#
xEI%D|)<
0;k# *#w
} 3n _htgcv
siI;"?
{.yB'.k?
public static void main(String[] args) {mg2pfhB!
{ M >u_4AY
new TestMethod(); 2ESo2
} ^sw?gH*
} EwN}l
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