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)); `H|g~7KD&
} I%s/h4x^B[
for(int i=0;i<nEndPos.length-1;i++) QTyl=z7
{ $ `ho+
nEndPos = nStartPos[i+1]; . }1!MK5
} jf2E{48P
nEndPos[nEndPos.length-1] = nFileLength; 3~S~)quwP
} O0I/^
} "{:*fI;!
_6[NYv$"
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//启动子线程 }z*p2)v`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R`<E3J\*
for(int i=0;i<nStartPos.length;i++) [lJ[kr*7
{ z DK+8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bIhL!Ty T.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3whyIXs
nStartPos,nEndPos,i); FPMW"~v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fGfv{4R
fileSplitterFetch.start(); ~>EVI=?
} Av[jFk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C^~iz in
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BxG;vS3>*e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `<Ftn
nEndPos = " + nFileLength); K4tX4U[Z
// fileSplitterFetch[nPos.length-1].start(); D *tBbV
5u!cA4e"
doa$ ;=wg
//等待子线程结束 SW=p5@Hy{
//int count = 0; z(=:J_N
//是否结束while循环 =wQ=`
boolean breakWhile = false; 93rE5eGs
8;5/_BwMu
+l#2u#e
while(!bStop) !`WuLhB`
{ $ S49v
write_nPos(); Mu%'cwp$
Utility.sleep(500); 4H:WpW*r
breakWhile = true; &d2/F i+
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for(int i=0;i<nStartPos.length;i++) _Dv^~e1c
{ {xr]xcM'b
if(!fileSplitterFetch.bDownOver) (/Mc$V
{ 6 qq7:
breakWhile = false; Q9'p2@Z
break; AjS5
} oMVwIdf
} j{PX ~/
if(breakWhile) )<|TEp4r-
break; Q&J,"Vxw
^/+sl-6/F
g[$B90
//count++; Cr` 0C
//if(count>4) Yc$|"to
// siteStop(); fS~.K9
} 1m0':n Vdu
f.= E.%
0v_8YsZ!`$
System.err.println("文件下载结束！"); g DhwJks
} A"'MRYT`
catch(Exception e){e.printStackTrace ();} { nV zN(
} "OPUGwf
=~h54/#[I
s*IfXv
//获得文件长度 L`#+ZLo
public long getFileSize() kpdFb7>|
{ ^WNJQg'
int nFileLength = -1; A=$oYBB
try{ W)#`4a^xj7
URL url = new URL(siteInfoBean.getSSiteURL()); Y!L jy [/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Z=v&d[o)
httpConnection.setRequestProperty("User-Agent","NetFox"); VC.?]'OqD
VPHCPGrk
-:,h8JyMP
int responseCode=httpConnection.getResponseCode(); r>Ln*R,9D
if(responseCode>=400) I?>#neHc6
{ @K9T )p]
processErrorCode(responseCode); No7Q,p
return -2; //-2 represent access is error Y[!a82MTzn
} ]Q3Gj@6
cGp^;> ]M
q0~_D8e,
String sHeader; p{rS -`I
.*j+?
2]+.8G7D%
for(int i=1;;i++) e0L;V@R
{ ,:`6x[ +
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '!R,)5l0h
//Utility.log(in.readLine()); 6fkr!&Dy7
sHeader=httpConnection.getHeaderFieldKey(i); Cu:Zn%
if(sHeader!=null) U]|q4!WE
{ =r~.I
if(sHeader.equals("Content-Length")) z m'jk D|
{ ! Cl/=0$[L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ju#63
break; RVfe}4Stm#
} `y`xk<q
} L?0l1P
else ~S3eatM$9
break; \ax%I)3
} }kj6hnQ
} {Fi@|'
catch(IOException e){e.printStackTrace ();} :j~5(K"
catch(Exception e){e.printStackTrace ();} 7mM;Q
{rT`*P~
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Utility.log(nFileLength); q3F5\6aN
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|Z ,G
return nFileLength; Q7|13^|C
} kre&J
$1+K}tP
Q$1K{14I
//保存下载信息（文件指针位置） Nd!VR+IZ
private void write_nPos() vi8~j
{ F:S,{&jB
try{ W[Bu&?h$
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7g)3\C
output.writeInt(nStartPos.length); ?N*0S'dY
for(int i=0;i<nStartPos.length;i++) QCR-lxO1
{ +,Az\aT/%
// output.writeLong(nPos); $VWzv4^:
output.writeLong(fileSplitterFetch.nStartPos); 0>iFXw:fn
output.writeLong(fileSplitterFetch.nEndPos); 3J T3;O
} h '[vB^
output.close(); ]ufW61W6Ci
} bSf(DSqx
catch(IOException e){e.printStackTrace ();} %v[Kk-d
catch(Exception e){e.printStackTrace ();} 1v&Fo2ML
} ?Z>.G{Wm@
vC:b?0s#(
(:QQ7xc{}
//读取保存的下载信息（文件指针位置） zXZ'nJ5OGG
private void read_nPos() GYC&P]
{ #OWs3$9
try{ (0W}e(D8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jJZsBOW[8
int nCount = input.readInt(); 8%<`$`FyU
nStartPos = new long[nCount]; %i8>w:@NW
nEndPos = new long[nCount]; IY6_JGe_w
for(int i=0;i<nStartPos.length;i++) yvCR =C
{ Jwd&[ O
nStartPos = input.readLong(); d&uTiH?0
nEndPos = input.readLong(); m> (h_j
} SDHc[66'
input.close(); xGfDz*t
} 87KrSZ
catch(IOException e){e.printStackTrace ();} c^O#O
catch(Exception e){e.printStackTrace ();} z,FTsR$x
} br Z,s
/;AZ/Ocy!
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private void processErrorCode(int nErrorCode) i ,pN1_-
{ O[)]dD&'
System.err.println("Error Code : " + nErrorCode); cmhN(==
} eJw="
Eqbe$o`dd
(YHvGGr
//停止文件下载 bz0P49%
public void siteStop() Ia`JIc^e
{ XcMJD(!
bStop = true; ,6;xr'[o*
for(int i=0;i<nStartPos.length;i++) }b+QYSt
fileSplitterFetch.splitterStop(); #we>75l{+R
vo ;F;
t-i6FS-
} +xfW`[.{
} +'/}[1q1/T
//负责部分文件的抓取 (\t_Hs::a
**FileSplitterFetch.java 12sD|j
*/ @GQ8q]N:<
package NetFox; VtO;UN
dAr)%RZ
g'ZMV6b?K
import java.io.*; qzA]2'~Q
import java.net.*; 0sDwTb"
BwJ^_:(p~
b/B`&CIA0"
public class FileSplitterFetch extends Thread { Y^2Qxo3"3
u:$x6/t
j-YJ."
String sURL; //File URL a4(?]ND~6
long nStartPos; //File Snippet Start Position rS )b1nPA
long nEndPos; //File Snippet End Position F`0c?)
int nThreadID; //Thread's ID ge):<k_
boolean bDownOver = false; //Downing is over =+`j?1
boolean bStop = false; //Stop identical #)0Tt>d6
FileAccessI fileAccessI = null; //File Access interface y168K[p
:X1cA3c!
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y^6[[vaj2
{ hyb +#R
this.sURL = sURL; xN3 [Kp
this.nStartPos = nStart; $iqi:vY
this.nEndPos = nEnd; %gu$_S
nThreadID = id; )p<fL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AB"1(PbG
} ZSPgci
W 9Vz[
*el(+ib%
public void run() yYToiW *
{ n<?SZ^X{,/
while(nStartPos < nEndPos && !bStop) }B"|z'u
{ lMwk.#
[.;%\>Qk<
Kr/h`RM
try{ N(:nF5>_
URL url = new URL(sURL); 4e@&QOo`Cu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H+VO.s.a
httpConnection.setRequestProperty("User-Agent","NetFox"); _7lt(f[S
String sProperty = "bytes="+nStartPos+"-"; HX3D*2v":
httpConnection.setRequestProperty("RANGE",sProperty); ],\sRQbv&
Utility.log(sProperty); IAP/G5'Q
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&^&$!Xmu9
InputStream input = httpConnection.getInputStream(); [O7w =
//logResponseHead(httpConnection); {b'}:aMc
hG3m7ht
A{z>D`d
byte[] b = new byte[1024]; 3+(yI 4
int nRead; ]eYd8s+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L/q]QgCoA
{ -".kH<SWv
nStartPos += fileAccessI.write(b,0,nRead); mA(nyF
//if(nThreadID == 1) "($Lx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w dGpt_
} \[hn]@@
9DOkQnnc
UU iNR
Utility.log("Thread " + nThreadID + " is over!"); %1\v7Xw{9
bDownOver = true; D[89*@v
//nPos = fileAccessI.write (b,0,nRead); ZT) !8
} Cf0|Z
catch(Exception e){e.printStackTrace ();} *$i;o3
} HKTeqH_:
} nTys4R
3s`V)aXP
=Kc|C~g
//打印回应的头信息 )o#6-K+b
public void logResponseHead(HttpURLConnection con) %n05Jitl
{ @up&q
for(int i=1;;i++) 7 9Qc`3a
{ 2J;kD2"!
String header=con.getHeaderFieldKey(i); tYs8)\{
if(header!=null) %cH8;5U40
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |XKOXa3.
Utility.log(header+" : "+con.getHeaderField(header)); 7_9+=. +X5
else Hp btj
break; C-llq`(d
} 7hB#x]oQo
} 59{;VY81
{y,nFxLq
{Q5KV%F_
public void splitterStop() "7=bL7wM&
{ ;asm 0H(
bStop = true; MV:W@)rg
} w4\BD&7V
P<%v+O
$!!R:Wn/R
} \U/v;Ijf
9p<:=T
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/* tT;8r8@
**FileAccess.java gjW\ XY
*//文件访问(定位，写) ,*/Pg52?
package NetFox; .#*D!;f
import java.io.*; +7V=aNRlE
GI4?|@%vD!
\V]t!mZ-}l
public class FileAccessI implements Serializable{ 8 AFMn[{
JC=dYP}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 di7A/B
RandomAccessFile oSavedFile; Da-u-_~
long nPos; B@-|b
hZcmP"wgC1
\B_i$<Sz
public FileAccessI() throws IOException N83!C=X'
{ l+%Fl=Q2em
this("",0); :'Zx{F`
} 3 m6$YWO
pvlDjj}
tcZa~3.
public FileAccessI(String sName,long nPos) throws IOException &=G)NeT_
{ Hi^35
oSavedFile = new RandomAccessFile(sName,"rw"); '|Qd0,Z
this.nPos = nPos; rfYP*QQY
oSavedFile.seek(nPos); /vHYMS
} d$pYo)8o({
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p"2m90IO
public synchronized int write(byte[] b,int nStart,int nLen) z&O#v9.NE|
{ \.o=icOx
int n = -1; # Mu<8`T-
try{ ^w.]Hd2
oSavedFile.write(b,nStart,nLen); w&%9IJ
n = nLen; AcKU^T+
} iC\%_5/_
catch(IOException e) alFNSRY
{ le.anJAr
e.printStackTrace (); :vpl+)n
} Z:!IX^q;}n
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)i;un.
return n; _6ZzuVv3/
} +p9- .YM
I_ONbJ9]
dPsLZ"I
} F% `zs\
E, GN|l
W RF.[R"
/* 0LdJZP
**SiteInfoBean.java K4: $=
*/ P1MvtI4gm
package NetFox; I7~|~<
vB.l0!c\e_
[@//#}5v
public class SiteInfoBean { @Gt`Ds9=
V@[rf<,
GF*>~_Yr
private String sSiteURL; //Site's URL @o6R[5(
private String sFilePath; //Saved File's Path {?Od{d9
private String sFileName; //Saved File's Name b]T@gJ4H=
private int nSplitter; //Count of Splited Downloading File 5Q W}nRCZ
P;73Hr[E#
}AlYNEY
public SiteInfoBean() onwjn+"&
{//nSplitter的缺省值为5 l-<`m#/v
//default value of nSplitter is 5 qw<HY$3=
this("","","",5); /&r|ec5
} +"dv7
KFU%DU G
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ];1R&:t
{ &kzj?xK=(j
sSiteURL= sURL; A (okv
sFilePath = sPath; rh66_eV
sFileName = sName; E;9>ePd@
this.nSplitter = nSpiltter; &n:{x}Uc
3@_Elu
zyFUl%
} 2Q@Y^t
y\D=Z N@
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public String getSSiteURL() .fp&MgiQ
{ 5pfYEofK[
return sSiteURL; H>XFz(LWh
} y!~qbh[
Be2lMC
19W:-Om
public void setSSiteURL(String value) lq>AGw
{ Y1)!lTG
sSiteURL = value; nls
} -_em%o3XC
dEp7{jY1O
"hQgLG
public String getSFilePath() #$E)b:xj
{ jo9gCP.
return sFilePath; lyv4fP
} >P=Q #;v
rzUlO5?R=
P6\6?am
public void setSFilePath(String value) 3TS_-l
{ XKS8K4"
sFilePath = value; 2'] KTHm
} <CZgQ\Mt
|gx~gG<
u5+|Su
public String getSFileName() *2e!M^K<
{ }r%X`i|
return sFileName; O"Q7Rx
} sOpep
V 1/p_)A
M'L;N!1A
public void setSFileName(String value) ++jAz<46
{ 4<gb36)|4
sFileName = value; Mxl]"?z
} GpI!J}~m
+?dl`!rE
VUwC-)
public int getNSplitter() ;+/o?:AH
{ Nd@~>&F
return nSplitter; @7<uMasfp
} 2VGg 6%
U*)m',
Iz@)!3h
public void setNSplitter(int nCount) ;j%BK(5
{ 2=iH$v
nSplitter = nCount; C\*4q8(
} ,xfO;yd
} B*3Y!!
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IzLQhDJ1
/* X3%Ic`Lq#
**Utility.java {d<;BLA
*/ F?-R$<Cn2~
package NetFox; aZ|=(]
SF*n1V3hx
3W_PE+:Kr
public class Utility { 2RM+W2!!
_iV]_\0W2
7U|mu~$.!
public Utility() n$n7-7
{ r^,<(pbd
x[3A+
U#&7p)4(
} Ch \&GzQ
m3<+yz$!r
//线程睡眠 oXXC@[??}N
public static void sleep(int nSecond) 2*iIjw3g
{ $*R/tJ.
try{ {0"YOS`3AX
Thread.sleep(nSecond); *%/~mSx
} H1n1-!%d
catch(Exception e) NMOut@
{ QPtGdd
e.printStackTrace (); }g7]?Ee
} n\z,/'d"
} Z|"p*5O,
j _L@U2i
//日志 wV\gj~U;P
public static void log(String sMsg) L|@y&di
{ qqrq11W
System.err.println(sMsg); svf|\p>]H
} jz58E}
Y5ZZ3Ati
$-}e; VZb
public static void log(int sMsg) *^%Q0mU[
{ I/gjenUK
System.err.println(sMsg); -!W<DJ*
} 9}a_:hAy/
} 3I\n_V<
3"n\8#X{
,L bBpi=TJ
/* +l3=3
**TestMethod.java 0sca4G0{
*/ Bw%Qbs0Q
package NetFox; +5VLw
QTX8 L
w@JKl5
public class TestMethod { h\v'9
,to+oSZE
Tm_B^W}
public TestMethod() w}Uhd,
{ ///xx/weblogic60b2_win.exe h.O$]:N
try{ =0uAE7q(9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M" ^PW,k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ./Q,
SiteFileFetch fileFetch = new SiteFileFetch(bean); W@|6nPm
fileFetch.start(); +)o}c"P!
} `\Hf]b
catch(Exception e){e.printStackTrace ();} FFdBtB
b4^`DHRu6
;q N+^;,2
} M9zfT!-
{pM?5"MMJ
hW!)w
public static void main(String[] args) Z R/#V7Pj
{ 3gd&i
new TestMethod(); oy<WsbnS
} 8JmFi
} rV08ad
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