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)); Ig}G"GR
} PElC0qCn[
for(int i=0;i<nEndPos.length-1;i++) '9c`[^
{ lPx4=O
nEndPos = nStartPos[i+1]; 8]skAh
} ig<Eyr
nEndPos[nEndPos.length-1] = nFileLength; 8^\}\@
} Zt4g G KG
} eQu%TZ(x-$
wwrP7T+d
8@]*X,umc
//启动子线程 I=o[\?u*_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "X0"=1R~
for(int i=0;i<nStartPos.length;i++) SF$7WG3Q
{ 4)0 %^\p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XI:8_F;Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z:DEET!c'k
nStartPos,nEndPos,i); 4 AZ~<e\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =+5z;3
fileSplitterFetch.start(); ~\kJir
} (XA=d 4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,Tc3koi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A<P3X/i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %|E'cdvkX
nEndPos = " + nFileLength); 28FC@&'H
// fileSplitterFetch[nPos.length-1].start(); OzY55
JLUG=x(dA
?PVJeFH
//等待子线程结束 Go~bQ2*'(/
//int count = 0; $* 1?"$LN
//是否结束while循环 )*#Pp)Q
boolean breakWhile = false; 2gz}]_
&7Frg`B&:
Vcn04j#Q
while(!bStop) ,dT.q
{ jJFWPD]u
write_nPos(); 8|^dM$
Utility.sleep(500); j_N><_Jc
breakWhile = true; \{r-e
y_O[r1MF
vvA=:J4/i)
for(int i=0;i<nStartPos.length;i++) -c-af%xD
{ 4w,=6|#
if(!fileSplitterFetch.bDownOver) =B4,H=7Spf
{ W}m-5L
breakWhile = false; s2f95<B
break; Yhdt"@;..
} 79 zFF
} HT]W2^k
if(breakWhile) dmh6o *
break; A4LGF
@X`~r8&
U'^AJ2L8
//count++; p@epl|IZp
//if(count>4) bwh7.lDAl
// siteStop(); QZy+`
} v|5:;,I
Z(Da?6#1
/H#- \r&r
System.err.println("文件下载结束！"); lfjY45=
} YnnpgR.
catch(Exception e){e.printStackTrace ();} fR_ jYP1
} k=w;jX&;`
R=M"g|U6
2p\CCzw
//获得文件长度 ~3}Gu^@
public long getFileSize() }~P%S(zB
{ %bI(
int nFileLength = -1; [NcS[*qp
try{ .DSn H6O
URL url = new URL(siteInfoBean.getSSiteURL()); qW]gp7jK4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <hi@$.u_Q^
httpConnection.setRequestProperty("User-Agent","NetFox"); =4GJYhj
"|W .o=R
WqN=D5
int responseCode=httpConnection.getResponseCode(); |\Nj
if(responseCode>=400) [% chN/
{ 4 -)'a} O
processErrorCode(responseCode); {Z[yY6Nu
return -2; //-2 represent access is error ZJ(/cD
} %bf+Y7m
qGMM3a)Q
PoMkFG6
String sHeader; ~82[pY
G yZYP\'S+
UnNvlkjq9
for(int i=1;;i++) A.7:.5Cx'
{ ={' "ATX(U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =jD[A>3I
//Utility.log(in.readLine()); ^q6H =Dl
sHeader=httpConnection.getHeaderFieldKey(i); CG'NC\x5
if(sHeader!=null) MhC74G
{ Du3OmXMk
if(sHeader.equals("Content-Length")) `}o4&$
{ }GvoQ#N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <'A>7M~h?*
break; }_XW?^/8
} GZT}aMMSJ
} !f_GR Pj'
else N_<sCRd]9
break; ,oe e'
} a?'3
} k*|dX.C:
catch(IOException e){e.printStackTrace ();} qG"|,bA
catch(Exception e){e.printStackTrace ();} hZnT`!iFE^
|)6(_7e9
WO*yJ`9]
Utility.log(nFileLength); FtN1ZZ"<*
BOJh-(>I
LLmgk"
return nFileLength; S-Va_t$
} Qo
b{)('C$
OXDlwbwL
//保存下载信息（文件指针位置） @RotJl/>
private void write_nPos() i=_leC)rl
{ 1=#r$H
try{ Z_' %'&Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); !mBsDn(J
output.writeInt(nStartPos.length); nzy =0Ox[
for(int i=0;i<nStartPos.length;i++) t )Z2"_5
{ x$CpUy{6
// output.writeLong(nPos); !boKrSw
output.writeLong(fileSplitterFetch.nStartPos); ..FUg"sSO
output.writeLong(fileSplitterFetch.nEndPos); F$r8hj`
} MSeO#X
output.close(); 7^sU/3z
} hM\QqZFyp
catch(IOException e){e.printStackTrace ();} yG&kP:k<
catch(Exception e){e.printStackTrace ();} =khjD[muC
} >0 !J]gK
{%D "0*^
N=D Ynz_~
//读取保存的下载信息（文件指针位置） +lJuF/sS8m
private void read_nPos() ZC"6B(d
{ %fP^Fh
try{ R $'}Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p8s2#+/
int nCount = input.readInt(); QZ{&7mc>
nStartPos = new long[nCount]; u-UUF
nEndPos = new long[nCount]; !qrF=a
for(int i=0;i<nStartPos.length;i++) F/j=rs,*|D
{ {J})f>x<xM
nStartPos = input.readLong(); 7P/j\frW
nEndPos = input.readLong(); p<*-B
} x(}tr27o
input.close(); 0IDHoNaT<
} 7vr)JT=
catch(IOException e){e.printStackTrace ();} WY 2b
catch(Exception e){e.printStackTrace ();} K'?ab 0
} s^C*uP;R
$L</{bXW
hN\E8"To
private void processErrorCode(int nErrorCode) w2{k0MW
{ Jq6p5jr"
System.err.println("Error Code : " + nErrorCode); z*yN*M6t
} P]Gsc
@TgCI`E
Dj!J 4uD
//停止文件下载 dUO~dV1
public void siteStop() 2gt08\
{ IR/0gP
bStop = true; A1Q]KS@
for(int i=0;i<nStartPos.length;i++) 1&jX~'
fileSplitterFetch.splitterStop(); tm]75*?
iZjvO`@[
1Za\T?V
} ev8E.ehD
} f7s]:n*Ih
//负责部分文件的抓取 |{9"n<JW
**FileSplitterFetch.java 0A 4(RLGg
*/ ke3=s
package NetFox; ~]"}s(J;
)3)L
;7m>40W
import java.io.*; #v&&GuF
import java.net.*; (5yg\3Jvp
4uNcp0
PFPfLxna
public class FileSplitterFetch extends Thread { PI{sO |
k.lnG5e
tkuN$Jl
String sURL; //File URL E0)v;yRcw
long nStartPos; //File Snippet Start Position :=i0$k<E/
long nEndPos; //File Snippet End Position r`S]`&#}(
int nThreadID; //Thread's ID Qy6Avw/$
boolean bDownOver = false; //Downing is over QT|mN
boolean bStop = false; //Stop identical -Q$$2QW!
FileAccessI fileAccessI = null; //File Access interface H<NYm#a"
.IKK.G
@#T?SNIL5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nmSpNkJ5
{ o1n c.2/0J
this.sURL = sURL; U3za}3
this.nStartPos = nStart; jM7}LV1Ck
this.nEndPos = nEnd; C&5T;=<jKO
nThreadID = id; 2<988F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mB1)!
} _aDx('
CLYcg$V
EI_J7J+
public void run() X,OxvmDm
{ /4T%&#6s
while(nStartPos < nEndPos && !bStop) w1KQ9H*
{ i5AhF\7F9
*=sU+x&X
]7VK&YfN
try{ #Kh`ATme
URL url = new URL(sURL); p[/n[@<8=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zc2,Mn2
httpConnection.setRequestProperty("User-Agent","NetFox"); |QzPY8B9O
String sProperty = "bytes="+nStartPos+"-"; Jz|(B_U
httpConnection.setRequestProperty("RANGE",sProperty); qb9%Y/xy
Utility.log(sProperty); k[zf`x^
>)5vsqGZaK
snK9']WXo
InputStream input = httpConnection.getInputStream(); 8WyG49eic
//logResponseHead(httpConnection); P,%|(qB
Z7f~|}
-!}1{
byte[] b = new byte[1024]; a%]p*X!
int nRead; 1U9iNki
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T }8aj
{ (*;u{m=
nStartPos += fileAccessI.write(b,0,nRead); 9z-"JnM
//if(nThreadID == 1) utTek5/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cbteNA!>
} )l"0:1Ig
FE5R ^W#u-
xz%ig^L
Utility.log("Thread " + nThreadID + " is over!"); 4Cfwz-Qo
bDownOver = true; Vnl~AQfk|
//nPos = fileAccessI.write (b,0,nRead); K:Ap|F
} @V-ZV
catch(Exception e){e.printStackTrace ();} T8\,2UWsj2
} P*LcWrK
} hlVP_h"z
)N=wJN1
s R~&S))
//打印回应的头信息 [:k'VXL
public void logResponseHead(HttpURLConnection con) ^g0 Ig2'
{ c]LH.
for(int i=1;;i++) *H$nydQ:
{ V|D;7
String header=con.getHeaderFieldKey(i); Zb1v
if(header!=null) V4"AFArI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jmb\eOq+~V
Utility.log(header+" : "+con.getHeaderField(header)); 226s:\d
else a} /Vu"
break; j NY8)w_
} < d]|5
} J8%|Gd0#4
w iq{Jo#
-`RJk(
public void splitterStop() 8fN0"pymo
{ I*ej_cFQ^
bStop = true; zZxP= c
} U%4g:s
4/jY;YN,2
I45A$nV#Q
} ,VZ&Gc
RpXQi*c0
9,Mp/.T"\
/* 1D`RR/g&
**FileAccess.java 29]8[Z,4
*//文件访问(定位，写) d#*5U9\z
package NetFox; lVFX@I=pI
import java.io.*; miKi$jC}vq
.~8+s.y
4"2/"D0
public class FileAccessI implements Serializable{ PHXP1)^}S
7L]?)2=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <8bO1t^*
RandomAccessFile oSavedFile; w(U/(C7R
long nPos; YfalsQ8
[E^X=+Jnz
+E:(-$"R
public FileAccessI() throws IOException [0LqZ<\5
{ 10rGA=x'(
this("",0); :2My|3H\
} c-T ^ aR
[w/t
5:d2q<x:{
public FileAccessI(String sName,long nPos) throws IOException VB\6SG
{ D5>~'N3b
oSavedFile = new RandomAccessFile(sName,"rw"); ~ t H s+
this.nPos = nPos; Zz-;jkX)
oSavedFile.seek(nPos); FNM"!z
} 2P ?Iu&
qtN29[x
AL7O-D
public synchronized int write(byte[] b,int nStart,int nLen) DxgT]F%
{ 3R*@m
int n = -1; Y/66`&,{
try{ =)YYx8gR
oSavedFile.write(b,nStart,nLen); fB96Q
n = nLen; D:E_h
} D,j5k3< #
catch(IOException e) )JQQ4D
{ $0SZlq>En
e.printStackTrace (); 1$VI\}
} S1`0d9ds#
UMwMXmZNJ
$jm<' 4
return n; p.] .M"A
} 4_I{Q^f
Sc$wR{W<:
/VO@>Hoh
} %`'z^W
eJGos!>*
]C6[`WF
/* 7B\(r~f`t
**SiteInfoBean.java w a<C*o
*/ !#:$u=
package NetFox; o;>3z*9?3
)UZ0gfx
F]A~~P
public class SiteInfoBean { fKz"z{\,0
\e8*vos
E9B*K2l^{
private String sSiteURL; //Site's URL nl9Cdi]o
private String sFilePath; //Saved File's Path pb6^sA%l
private String sFileName; //Saved File's Name ,e FQ}&^A
private int nSplitter; //Count of Splited Downloading File W}2 &Pax
4_762Gu%
I,<54?vS
public SiteInfoBean() Gz|%;
{//nSplitter的缺省值为5 V"by9p|V`
//default value of nSplitter is 5 \*%i#]wO@
this("","","",5); k\c &2T]W
} B+e_Y\Bu
n*i'vtQ8
NVc!g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #}!>iFBcH
{ Wbn[Q2h5
sSiteURL= sURL; blfE9Oy
sFilePath = sPath; 8f,'p}@!d
sFileName = sName; .5!sOOs$P
this.nSplitter = nSpiltter; B3>Uba*-)}
Ku/H=
{y&\?'L'
} >1r[]&8
'lN*Ys iDi
hD$p;LF
public String getSSiteURL() N* ] i G~
{ uZo`IKJ
return sSiteURL; K=c=/`E
} l$-=Pqb
tt7PEEf
5X`w&(]m
public void setSSiteURL(String value) c}IX"
{ Ig02M_
sSiteURL = value; UAx.Qq
} {1Ju}=69
AB2mt:^
!dyxE'T2
public String getSFilePath() U0h)pdo
{ 8O8\q ;US
return sFilePath; =mKfFeO.
} _K0izKTA.
8! H8[J
s;B j7]
public void setSFilePath(String value) O t *K+^I
{ `Di ^6UK(
sFilePath = value; mUrS&&fu8
} r~$}G-g
4|> rwQ~t
&/>;LgN
public String getSFileName() s[G|q5n
{ L_THU4^j
return sFileName; aF&r/j+}o
} :DtZ8$I`]C
+cz"`T`X 2
(dzH3_U
public void setSFileName(String value) je&dioZ>
{ Rk($lW)
sFileName = value; FX HAZ2/\
} P0%N Q1bn
Ur'9bl{5
= n+q_.A
public int getNSplitter() NuC-qG#
{ >I$B=
return nSplitter; {0is wq'J
} t8+?U^j
]b4pI*:$I
!oZQ2z~
public void setNSplitter(int nCount) WGH%92
{ b8rp8'M)
nSplitter = nCount; ^cYStMjpy
} <Q2u)m'
} ]i-P-9PA4
=nJ{$%L\x,
H_VEPp,T
/* EkN_8(w
**Utility.java GwcI0~5
*/ AXz-4,=xX
package NetFox; :]vA2
ZU=,f'bU
:1:3Svb<Y
public class Utility { xC<=~(
hT?6sWa
M2}np
public Utility() ? m&IF<b
{ ZAMeqPt
q[-|ZA bbr
Eu|sWdmf l
} w#oGX
G3G/xC"
//线程睡眠 $0_^=DEW
public static void sleep(int nSecond) q(,cYu
{ t{!/#eQC
try{ ~e{H#*f&1/
Thread.sleep(nSecond); aSel* L
} l09Fn>wa
catch(Exception e) tE@FvZC'=
{ T=WNBqKo]
e.printStackTrace (); C\7u<2c
} aR _NyA
} qpI]R
2UiR~P]%
//日志 k}GjD2m
public static void log(String sMsg) ]bm=LA
{ wqUQ"d
System.err.println(sMsg); NetYg]8`
} Y(_KizBY
9e!vA6Fx
@D)Z{=>{=5
public static void log(int sMsg) [& ^RP,N~
{ %#u.J
System.err.println(sMsg); 61} i5o
} 1]T|6N?
} 9t?L\
=Q-k'=6\
L;S}s, 2x
/* kx:jI^
**TestMethod.java f8=]oa]
*/ 8u>gbdU
package NetFox; 4J5pXlzV
,X68xk.'
?sXG17~Bm
public class TestMethod { 9C/MRmv`
)1lu=gc
^]>aHz9
public TestMethod() s5&=Bsv
{ ///xx/weblogic60b2_win.exe hJf2o
try{ H=p`T+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'H|~u&?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NLyXBV[hV
SiteFileFetch fileFetch = new SiteFileFetch(bean); O-#TZ
fileFetch.start(); _fn1)
} ~jN'J+_$
catch(Exception e){e.printStackTrace ();} w2dcH4&
Y/fJQ6DY
w<NyV8-hL
} F PR`tE
wvN`R
S_b/DO
public static void main(String[] args) =rFN1M/n{E
{ $4m*kQ
new TestMethod(); 7 ^$;
} `s"d]/85VW
} `VT>M@i/
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