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)); e1 {t0f
} we H@S
for(int i=0;i<nEndPos.length-1;i++) A}#]g>L
{ mSw?2ba
nEndPos = nStartPos[i+1]; An8%7xa7
} kh>SrW]B%
nEndPos[nEndPos.length-1] = nFileLength; \\2k}TsB
} g@k#J"Q'[
} ,2 g M-
9#EHXgz
Q0L@.`~
//启动子线程 _86*.3fQG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :uIi ?
for(int i=0;i<nStartPos.length;i++) !}L~@[v,uL
{ i>]<*w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Av;q:x?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 94p:|5@
nStartPos,nEndPos,i); B.Zm$JZ:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); veX"CY`hn
fileSplitterFetch.start(); ^ =/?<C4
} 6<qwP?WN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sx[&4 k[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %eutfM-?6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;Oi[:Ck
nEndPos = " + nFileLength); \&\_>X.,
// fileSplitterFetch[nPos.length-1].start(); 20.-;jK
;Txv-lfS
u6iU[5
//等待子线程结束 (/"K+$8'
//int count = 0; nI`f_sp
//是否结束while循环 wZo.ynXT
boolean breakWhile = false; 6=G~6Qu
5M<'A=
v ]/OAH6D
while(!bStop) nL":0!DTRD
{ !y qa?\v9
write_nPos(); R%Ui6dCLo
Utility.sleep(500); `FzYvd"N
breakWhile = true; d4y9AE@k
FUyB"-<
f.aB?\"f6
for(int i=0;i<nStartPos.length;i++) Uw2,o|=O
{ #K:-Bys5v
if(!fileSplitterFetch.bDownOver) $S6HZG:N
{ }XGMa?WR
breakWhile = false; BrlzN='j}
break; cQ3W;F8|n
} n*vTVt)dJ
} H{\.g=01
if(breakWhile) fr}1_0DDz
break; ,?xLT2>J_
7xv4E<r2
,]PyDq6
//count++; i}/e}s<-6
//if(count>4) {) :%WnM9
// siteStop(); #gW /qJ
} c-4m8Kg?L
b!'l\~`{i
N|!MO{sB
System.err.println("文件下载结束！"); biK)&6|`sa
} fBf4]^
catch(Exception e){e.printStackTrace ();} 74@lo-/LY
} &v5G92
P"(z jG9-
heE}_,$|
//获得文件长度 PGPISrf
public long getFileSize() 8)^B32
{ }}^,7npU
int nFileLength = -1; GBH_r0
try{ K3vseor
URL url = new URL(siteInfoBean.getSSiteURL()); =jg#fdM -
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ..t,LU@|
httpConnection.setRequestProperty("User-Agent","NetFox"); 0>,.c2),
Vq3gceo'0A
}xAie(
int responseCode=httpConnection.getResponseCode(); &8[ZN$Xe"
if(responseCode>=400) [>W"R1/
{ !c3```*
processErrorCode(responseCode); EMVk:Vt]
return -2; //-2 represent access is error 1R0ffP]
} ?QCmSK=L
w)+wj[6 E
V]I:2k5
String sHeader; ?PBa'g
,HFs.9#&B
uh]"(h(>
for(int i=1;;i++) k:b/Gq`
{ S~KS9E~\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v,/[&ASz
//Utility.log(in.readLine()); yXJ]U \ %
sHeader=httpConnection.getHeaderFieldKey(i); ~I{EE[F>qL
if(sHeader!=null) 9T(L"9r-e
{ ;B&^yj&;
if(sHeader.equals("Content-Length")) e^j<jV`1
{ c_ La^HS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bGbqfO`
break; 2t+D8 d|c<
} "j{i,&Y$_
} nz4<pvC,*
else xK(IS:HJ*
break; >[ eW">:>K
} ')B =|T)
} ;{|X,;s
catch(IOException e){e.printStackTrace ();} >^a$
catch(Exception e){e.printStackTrace ();} o^3FL||P#r
>(X#<`
H2_/,n
Utility.log(nFileLength); "jMqt9ysN
JnfqXbE
HF"Eys
return nFileLength; >~_Jq|KBB
} "`pNH'
S]}}A
tAF]2VV(e
//保存下载信息（文件指针位置） \tY"BC4.
private void write_nPos() et=7}K]l
{ pmD4j8F_
try{ cv}aS_`f
output = new DataOutputStream(new FileOutputStream(tmpFile)); <OTWT`G2
output.writeInt(nStartPos.length); nqT>qS[Z
for(int i=0;i<nStartPos.length;i++) RctU'T
{ 6?N4l ]l
// output.writeLong(nPos); O|QUNr9
output.writeLong(fileSplitterFetch.nStartPos); X0`j-*,FX
output.writeLong(fileSplitterFetch.nEndPos); m6^ 5S
} lsk_P&M
output.close(); >c<pDNt?
} +R!zs
catch(IOException e){e.printStackTrace ();} ~g6"'Cya?k
catch(Exception e){e.printStackTrace ();} 7paUpQit
} EIr@g
NmJ`?-Z
OTj,O77k
//读取保存的下载信息（文件指针位置） I,b9t\(6
private void read_nPos() ?v:ZU~i
{ Gav"C{G
try{ H$!+A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z7fg 25
int nCount = input.readInt(); U@'F%nHw
nStartPos = new long[nCount]; owvS/"@
nEndPos = new long[nCount]; (&jW}1D
for(int i=0;i<nStartPos.length;i++) yub{8f;v
{ F$Hx`hoy
nStartPos = input.readLong(); 69-:]7.g
nEndPos = input.readLong(); u:@U $:sZ
} Y25^]ON*\^
input.close(); ^T:gb]i'Qa
} ?]c+j1i
catch(IOException e){e.printStackTrace ();} 8V9[a*9
catch(Exception e){e.printStackTrace ();} xACdZB(
} 7Y1GUIRa3
wJe?t$ac?
%%%S"$t
private void processErrorCode(int nErrorCode) UUeB;'E+
{ /@hJpz|+
System.err.println("Error Code : " + nErrorCode); )tS-.PrA-
} [:iv4>ZZ
3GF2eS$$P
!SO8O
//停止文件下载 b O=yi)
public void siteStop() +L0w;wT
{ D8%AV;-Y
bStop = true; $IVwA
for(int i=0;i<nStartPos.length;i++) "X04mQn15
fileSplitterFetch.splitterStop(); 8Hi!kc;f6>
*RWm47
%y&]'A
} EF#QH _X
} 87V1#U^
//负责部分文件的抓取 \ECu5L4
**FileSplitterFetch.java {hQ6K)s
*/ I9Eu',
package NetFox; <xo-Fv
*/z??fI27
_OMpIdY,R*
import java.io.*; TW7:q83{l
import java.net.*; z[C3
1D F/6y
>xqM5#m`E$
public class FileSplitterFetch extends Thread { n_Onr0EvO
c0_E_~
Ow:1?Z{4
String sURL; //File URL `]=oo%(h
long nStartPos; //File Snippet Start Position @*>Sw>oet
long nEndPos; //File Snippet End Position C$d>_r
int nThreadID; //Thread's ID A(8n
boolean bDownOver = false; //Downing is over S QY"OBo<e
boolean bStop = false; //Stop identical =WG=C1Z
FileAccessI fileAccessI = null; //File Access interface EHn"n"Y
I7n3xN&4"
krB'9r<wa`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~6aCfbu%V
{ c+kU o$
this.sURL = sURL; rY0u|8.5Q
this.nStartPos = nStart; + H_WlYg-
this.nEndPos = nEnd; %0,-.(h
nThreadID = id; +oc >S
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Wht(O~F
} 2;$k(x]
FS"eM"z
wW2d\Zd&
public void run() ~Rpm-^
{ ~+G#n"Pn
while(nStartPos < nEndPos && !bStop) WC,+Cn e
{ ?wb+L
!ABiy6d
rJJ[X4$
try{ &QNY,Pj
URL url = new URL(sURL); aG+j9Q_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cXnKCzSxZq
httpConnection.setRequestProperty("User-Agent","NetFox"); -|S]oJy
String sProperty = "bytes="+nStartPos+"-"; HYK!}&
httpConnection.setRequestProperty("RANGE",sProperty); i3VW1~.8
Utility.log(sProperty); S'LZk9E
*\uM.m0$
K_/zuTy
InputStream input = httpConnection.getInputStream(); DgHaOAdU
//logResponseHead(httpConnection); 3;[DJ5
b:J(b?
MZ>6o5K|
byte[] b = new byte[1024]; p(F" /
int nRead; /9pM>Cd*Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IA&L]
{ Oakb'
nStartPos += fileAccessI.write(b,0,nRead); _>m-AI4^
//if(nThreadID == 1) N K]B?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MJ`3ta
} -r7]S
Z8#Gwyinx
o Y}]UB>
Utility.log("Thread " + nThreadID + " is over!"); (ll*OVL
bDownOver = true; iRV~Il#~!
//nPos = fileAccessI.write (b,0,nRead); FR[ B v
} uX/$CM
catch(Exception e){e.printStackTrace ();} ;%C'FV e]
} e({9]
} @f+8%I3D
oR1^/e
5yZTcS z
//打印回应的头信息 -]uUYe c
public void logResponseHead(HttpURLConnection con) nl aM
{ j@gMbiu
for(int i=1;;i++) >'uU)Y{
{ ~[WF_NU1y
String header=con.getHeaderFieldKey(i); b2,mCfLsv
if(header!=null) iIT8H\e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^ KK_qC
Utility.log(header+" : "+con.getHeaderField(header)); |'O[7uT
else TjMe?p
break; mW2,1}Jv
} m([(:.X/IX
} =J-5.0Q\_\
kum#^^4G|
^N}Wnk7ks'
public void splitterStop() &3F}6W6A
{ OO dSKf8
bStop = true; L4u;|-znw
} aNn"X y\ k
>T2LEW
E/&Rb*3
} u%/fx~t$
H=*5ASc
i,A#&YDl
/* 4/kv3rv
**FileAccess.java `1*nL,i
*//文件访问(定位，写) u]NZ`t%AP
package NetFox; =*qD4qYA
import java.io.*; &6 s) X
`@d<n
-oeL{9;
public class FileAccessI implements Serializable{ uwf 5!Z:>
Hs?e0Z=N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E!BPE>
RandomAccessFile oSavedFile; 7]xm2CHx5
long nPos; ]M/9#mD9~
t^]$!H
fkSO( C)
public FileAccessI() throws IOException 7cAXd#sI
{ E:zF/$tG
this("",0); -K,-h[o
} ]<(]u#g_d
Y2B&go
_lzyMEdr
public FileAccessI(String sName,long nPos) throws IOException LMi:%i%\
{ 9a\nszwa
oSavedFile = new RandomAccessFile(sName,"rw"); JO=[YoTr
this.nPos = nPos; |(moWY=
oSavedFile.seek(nPos); IK,|5]*Ar
} D|Iur W1f
gqXS~K9t
6S6f\gAM
public synchronized int write(byte[] b,int nStart,int nLen) <FMq>d$\
{ [b{CkX06
int n = -1; yR{x}DbG
try{ b" xmqWa
oSavedFile.write(b,nStart,nLen); CT0l!J~5m~
n = nLen; C%*k.$#r!
} l`kWz5[~
catch(IOException e) 5aad$f
{ .=m,hu~
e.printStackTrace (); 1im^17X
} +_XmlX A3Z
l4n)#?Q?
H&r,FmI@
return n; y;mj^/SxK
} #HS]NA|e@
y4h=Lki@
EbeI{-'aF
} y\N|<+G+
.@ xF6UZ
%r&-gWTQ,
/* 4Mk-2 Dx
**SiteInfoBean.java gaA<}Tp,
*/ s9dO,FMs0t
package NetFox; i)#:qAtP*
vvUSeG\n#j
DAo~8H
public class SiteInfoBean { iAT)VQ&
8Ll[ fJZA
GgaTn!mJt
private String sSiteURL; //Site's URL Dnc(l(
private String sFilePath; //Saved File's Path 1n%?@+W
private String sFileName; //Saved File's Name .B#l5pfvP
private int nSplitter; //Count of Splited Downloading File 1&fc1uYB4
3=-4%%[M@
G-9iowS/A
public SiteInfoBean() l5l>d62
{//nSplitter的缺省值为5 SIBoCs5
//default value of nSplitter is 5 eEhr140
this("","","",5); \!]Ua.e<
} BBcV9CGU
LZMYr
Z3[S]jC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y#!h9F
{ 4f(Kt,0
sSiteURL= sURL; 6}FO[
sFilePath = sPath; %OgS^_tu
sFileName = sName; Sq:0w
this.nSplitter = nSpiltter; FU=w(< R;
uEc<}pV
]|<w\\^A
} Xl@cHO=i
AoA!q>
WyP W*
public String getSSiteURL() eY{+~|KZ
{ @( n^T
return sSiteURL; Ltjbxw"Qd
} `jST
?\8?%Qk
FI"`DMb}
public void setSSiteURL(String value) s1?[7yC
{ p4p@^@<>X
sSiteURL = value; vkLC-Mzm<
} mSk5u7
1s1=rZ!
%e*@CbO$
public String getSFilePath() 5SkW-+$
{ !mXxAo
return sFilePath; }w4QP+ x
} r-,e;o>9
gWY"w!f
7)h[Zy,A
public void setSFilePath(String value) ?f/n0U4w
{ ;-UmY}MU
sFilePath = value; 9n}p;3{f
} I(=V}s2
QRLt9L
2w)-\/j}
public String getSFileName() > xIJE2
{ tH'2gl
return sFileName; YJ(*wByM
} tpuYiL
@29U@T
o:V|:*1Q
public void setSFileName(String value) r,_?F7
{ h$L"8#
sFileName = value; RmZ]" `
} .xBu-?6s6
"vtCTl~t
NH_<q"gT
public int getNSplitter() 86 W0rS[5
{ Ecs,$\
return nSplitter; kA7mLrON
} %kgkXc~6|x
J*9$;
.5
public void setNSplitter(int nCount) %,ngRYxT#
{ Le%ZV%,
nSplitter = nCount; F:mq'<Q
} 0Ia($.1mY
} 7t.!lh5G%
,]b~t0|B
ZoArQ(YFy
/* vX]Gf4,
**Utility.java ytNO*XoR
*/ &>H!}"Yk
package NetFox; !Ra*)b"
mS0udHod
vOg#Dqn-
public class Utility { ,]T2$?|
"Ky; a?Y
h,"4SSL
public Utility() 1{P'7IEj
{ tnLAJ+-M
GRY2?'`
fU!<HDh
} 9uWY@zu
zRPeNdX
//线程睡眠 vB+ '
public static void sleep(int nSecond) .CFa9"<
{ Ao/ jt<
try{ "?mJqA
Thread.sleep(nSecond); 2U-3Q]/I}
} [LRLJ_~g5
catch(Exception e) /a6Xa&(B
{ '}Ri`
e.printStackTrace (); S]E.KLR?[;
} I"KN"v^
} [|l?2j\
yV^s,P1
//日志 t'ZWc\
public static void log(String sMsg) H<1WbM:w
{ S6[v;{xJ
System.err.println(sMsg); 36am-G
} p0pWzwTG3
@}kv-*
VcoOeAKL
public static void log(int sMsg) <jed!x
{ dXnl'pFS
System.err.println(sMsg); Gm\/Y:U
} "9n3VX)
} g(4xC7xK6
o;?/HE%,[
H@l}WihW
/* !fj(tPq
**TestMethod.java uIZWO.OdU
*/ !A%<#Gjt
package NetFox; rylzcN9RM$
ciMzf$+G$
K#"O a h
public class TestMethod { &~W:xg(jN
zk( U8C+
l<N}!lG|
public TestMethod() ."FuwKSJCo
{ ///xx/weblogic60b2_win.exe KIWe@e
try{ %dY<=x#b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xNbPsoK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yiO.z
SiteFileFetch fileFetch = new SiteFileFetch(bean); F8apH{&t
fileFetch.start(); []D@Q+1
} 2p"WTd
catch(Exception e){e.printStackTrace ();} ^yOZArc'r
4R\Hpt
-a-(r'Qc(
} @*sWu_-Y%
=%/)m:f!^
AF%@VLf
public static void main(String[] args) GI&h`X5,e
{ e;(0(rI
new TestMethod(); y99mC$"Ee`
} )P+7PhE{J
} !50[z:
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