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)); $'w>doUlA
} Yq:+.UU
for(int i=0;i<nEndPos.length-1;i++) @=?#nB&
{ 7WHq'R{@
nEndPos = nStartPos[i+1]; !]MGIh#u
} &S[>*+}{+
nEndPos[nEndPos.length-1] = nFileLength; z J V>;
} G)gPL]C0
} BSY7un+`:
km,@yU
nu X`>Oy
//启动子线程 *>T@3G.{Rm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zCrM~
for(int i=0;i<nStartPos.length;i++) JD~]aoH
{ KkSv23In
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h`D+NZtWm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), in>?kbaG+
nStartPos,nEndPos,i); Np?/r}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #U6~U6@
fileSplitterFetch.start(); ,o\~d?4
} B7n1'?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7G%^8 ce{!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v"sN K
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #&Zj6en}M]
nEndPos = " + nFileLength); Gdr7d
// fileSplitterFetch[nPos.length-1].start(); !Xzy:
V0*9Tnc
/<\do 1
//等待子线程结束 .WS7gTw
//int count = 0; 7Pr5`#x#
//是否结束while循环 .c@,$z2M
boolean breakWhile = false; T*#<p;
QKhvP>
tj:>o#D
while(!bStop) O*1la/~m
{ u:>*~$f
write_nPos(); t7/a5x
Utility.sleep(500); ~t^'4"K*
breakWhile = true; y<)q;fI7
)C>M74Bt
b\+9#)Up@
for(int i=0;i<nStartPos.length;i++) 41o~5:&
{ KRh?{
if(!fileSplitterFetch.bDownOver) rlkg.e6
{ H?j}!JzAC
breakWhile = false; -l$-\(,M`#
break; I_'0!@Nn7
} jxZd =%7Q
} }#E~XlX^
if(breakWhile) %loe8yt
break; okD7!)cr=
!qJ|`o Y
#po}Y
//count++; 0GnbE2&
//if(count>4) BoXGoFn
// siteStop(); $1myf Z
} ^qPS&G
Ok_)C+o
#zKF/H|_R
System.err.println("文件下载结束！"); -;U3$[T,J7
} yQ+C}8r5
catch(Exception e){e.printStackTrace ();} lR3JyYY{X
} J,^eq@(
6n'XRfQp)&
vLh,dzuo
//获得文件长度 ^BQ*l5K
public long getFileSize() @Ke3kLQ_\X
{ xkkW?[&
int nFileLength = -1; z*&r@P -
try{ OEs!H]v
URL url = new URL(siteInfoBean.getSSiteURL()); TYgn X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~f]I0FK
httpConnection.setRequestProperty("User-Agent","NetFox"); eX9H/&g
!e:HE/&>i
WAp#[mW.fx
int responseCode=httpConnection.getResponseCode(); n*i1QC
if(responseCode>=400) b+mh9q'5E
{ QP4`r#,
processErrorCode(responseCode); IF.6sJg:
return -2; //-2 represent access is error F anA~
} S-)%#
BW%"]J
fm'Qifq^
String sHeader; ( O/+.qb
0:3<33]x
0x8aKq\'
for(int i=1;;i++) P6o-H$ a+
{ IQCIc@5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )6Qk|gIu(
//Utility.log(in.readLine()); ue#Yh
sHeader=httpConnection.getHeaderFieldKey(i); r!J?Lc])8
if(sHeader!=null) )qx,>PL
{ w(vda0
if(sHeader.equals("Content-Length")) K~aIY0=<
{ ^DS+O>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;COZHj9b
break; &l NHNu[
} C!aK5rqhv
} |{H-PH*Iz
else >L>t$1hXM
break; ^ql+l~
} Ga}&%
} _rf
catch(IOException e){e.printStackTrace ();} nyR4E}@:O
catch(Exception e){e.printStackTrace ();} 7ezf.[{R
l/w<R
kKRZ79"7s
Utility.log(nFileLength); t&=]>blIs
D$ +"n
Xm}~u?$3
return nFileLength; 0`dMT>&I
} o`]u&
XK4idC
4`#3p@-
//保存下载信息（文件指针位置） /|2#s%|-=
private void write_nPos() -wjvD8fL
{ UP}5Eh
try{ yp:_W@
output = new DataOutputStream(new FileOutputStream(tmpFile)); ONw;NaE,
output.writeInt(nStartPos.length); jPf*qe>U
for(int i=0;i<nStartPos.length;i++) fUgI*V
{ QR;E>eEq
// output.writeLong(nPos); 'Nbae-pf
output.writeLong(fileSplitterFetch.nStartPos); X#*|_(^
output.writeLong(fileSplitterFetch.nEndPos); ;n,@[v
} @dj2#
output.close(); P7i G,i
} px1{=~V/
catch(IOException e){e.printStackTrace ();} ^N5BJ'[F:
catch(Exception e){e.printStackTrace ();} H#B~h4#
} RuHMD"
9(( QSX
aGYF\7
//读取保存的下载信息（文件指针位置） 51k^?5cO
private void read_nPos() F!;0eS"xp
{ A+lP]Oy0S
try{ Qpc+1{BQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); //}[(9b'\
int nCount = input.readInt(); /U#{6zeM[,
nStartPos = new long[nCount]; JS<4%@
nEndPos = new long[nCount]; d= -/'_'
for(int i=0;i<nStartPos.length;i++) $6XCHVx
{ N3Jfp3_b@
nStartPos = input.readLong(); zp2IpYQ,3
nEndPos = input.readLong(); !`G7X
} |NcfR"[c
input.close(); Y(4#b`k3
} D{aN_0mT
catch(IOException e){e.printStackTrace ();} IP`;hC
catch(Exception e){e.printStackTrace ();} N+9`'n^x
} 1cyX9X
G,8LF/sR
Jyx6{Oj
private void processErrorCode(int nErrorCode) / ` 7p'i
{ ;@@1$mzK
System.err.println("Error Code : " + nErrorCode); yH8 N8
} : qKxm(
+Zx+DW cq
z6K"}C%
//停止文件下载 qdB@P
public void siteStop() ':fq
{ &Oq&ikw
bStop = true; T/"6iv\1
for(int i=0;i<nStartPos.length;i++) =yfLqU
fileSplitterFetch.splitterStop(); 3JiDi X"|
i`^`^Ka
9T4x1{mO
} MEQ:[;1
} XQu~/{A=
//负责部分文件的抓取 fL8+J]6A6
**FileSplitterFetch.java p*rBT,'
*/ pNo<:p
package NetFox; 05\A7.iy
{iqH 27\E
V=}b>Jo2j
import java.io.*; 9tVA.:FOZ
import java.net.*; `":ch9rK
JU7EC~7|2c
/!kKL$j
public class FileSplitterFetch extends Thread { g(\FG
63d' fgVp
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String sURL; //File URL Y#_,Ig5.
long nStartPos; //File Snippet Start Position d*Y&V$?zl
long nEndPos; //File Snippet End Position .,pGW8Js
int nThreadID; //Thread's ID >ln%3=
boolean bDownOver = false; //Downing is over 9d4PH
boolean bStop = false; //Stop identical dlC)&Ai
FileAccessI fileAccessI = null; //File Access interface zLlu%Oc
M?4)U"_VE
9}FWO&LiB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3y%B&W,sm
{ c,1Yxg]|
this.sURL = sURL; ?Ovl(4VG
this.nStartPos = nStart; cbl2D5s+i]
this.nEndPos = nEnd; 'w`:p{E
nThreadID = id; M* (]hu0!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Bl-nS{9"
} }"<|.[V)
tt`j!!
_-%A_5lCRE
public void run() I)AV
{ 0(;d<u)fS
while(nStartPos < nEndPos && !bStop) Efb>ZQ
{ bE2^sx`(
k~u$&a
xT I&X9P
try{ 0A@'w*=
URL url = new URL(sURL); maLKUSgo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uYlC*z{
httpConnection.setRequestProperty("User-Agent","NetFox"); jRS0(8
String sProperty = "bytes="+nStartPos+"-"; /i$ mIj`
httpConnection.setRequestProperty("RANGE",sProperty); ^zHBDRsb2F
Utility.log(sProperty); 15_OtK
_PrK6M@"L
.N8AkQ(Ok
InputStream input = httpConnection.getInputStream(); <jT6|2'
//logResponseHead(httpConnection); K*Zf^g m
#CoJ S[t
%^m6Q!
byte[] b = new byte[1024]; 2H_|Attoi
int nRead; >[=q9k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,V!s w5_5m
{ cA1"Nek
nStartPos += fileAccessI.write(b,0,nRead); yc2c{<Ya5
//if(nThreadID == 1) <8p53*a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zCT Wi
} imAsE;:
Z VuHO7'
IpmblC4
Utility.log("Thread " + nThreadID + " is over!"); >v@R]9
bDownOver = true; wxXp(o(
//nPos = fileAccessI.write (b,0,nRead); S1{UVkr
} PD12gUU?
catch(Exception e){e.printStackTrace ();} ~AxA ,
} gvO}u2.:
} :3$WY<
.oYUA}
Fd-PjW/E8
//打印回应的头信息 v2:A 4Pd:+
public void logResponseHead(HttpURLConnection con) zR(}X8fP
{ yHl1:cf(y
for(int i=1;;i++) _6&x$*O
{ ozF>2`K }
String header=con.getHeaderFieldKey(i); 2&O!<C j
if(header!=null) &a%|L=FY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xSZgQF~
Utility.log(header+" : "+con.getHeaderField(header)); )y(pd
else WF<`CQg[
break; quHq?oXV,
} );V6YE
} TU{^/-l
Y 9]
0'`>20Y
public void splitterStop() Iodk1Y;
{ >6Y\CixN
bStop = true; /=A?O\B7
} Z9mY*}:U~
6wx;grt'Z
*|ez|*-
} ~;k-/Z"
7udMF3;>
Vm6G5QwM
/* H#x=eDU|k
**FileAccess.java \Q<c Y<
*//文件访问(定位，写) 7OX5"u!2
package NetFox; PI(;t9]b
import java.io.*; b;#3X)
wl #Bv,xf
Lt0JUUa0
public class FileAccessI implements Serializable{ u HqPb8
~~k_A|&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rvuskXdo
RandomAccessFile oSavedFile; xal+buOiP
long nPos; XRCiv
%4Cs c
c1M/:*?%
public FileAccessI() throws IOException L5!aLv#
{ R9nW5f Nf
this("",0); jIwz G+)$P
} 0P^RciC f
(:Rj:8{
AJt*48H*G
public FileAccessI(String sName,long nPos) throws IOException :@{(^}N8u
{ JsI`#
oSavedFile = new RandomAccessFile(sName,"rw"); m07= _4
this.nPos = nPos; yKF"\^`@
oSavedFile.seek(nPos); Yo3my>N&g
} 2apR7
p9Zi}!
=#dW^?p
public synchronized int write(byte[] b,int nStart,int nLen) oBiJiPE=`
{ A#$oY{"2Y
int n = -1; Y3+DTR0|'
try{ iTF`sjL
oSavedFile.write(b,nStart,nLen); &2[OH}4
n = nLen; Gs;wx_k^
} m`gH5vQa
catch(IOException e) e/JbRbZX
{ 5xe}ljo
e.printStackTrace (); &?flH;
} 3ha^NjE
kx0(v1y3gT
S[(Tpk2_
return n; |;e K5(|
} H)z}6[`
4Ra
2%UzCK
} "C%<R
G(W/.*
z ^t6VFM
/* T#kPn#|
**SiteInfoBean.java N|-M|1w96
*/ t=o2:p6&
package NetFox; |N, KA|Gdq
I WKq_Zjkz
F,+nj?i!
public class SiteInfoBean { vFm8T58 7
yXP+$oox9
/ap3>xkt
private String sSiteURL; //Site's URL ){^o"A?-:
private String sFilePath; //Saved File's Path nR'!Ui
private String sFileName; //Saved File's Name OP0KK^#
private int nSplitter; //Count of Splited Downloading File "j-Z<F]]
;:2]++G
F!.Z@y P
public SiteInfoBean() Qc1NLU9:
{//nSplitter的缺省值为5 KSkT6_<
//default value of nSplitter is 5 ieuq9ah#
this("","","",5); :bt;DJ@
} Em8q1P$tm>
BUB$k7{z
#4UKkd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mU@pRjq=
{ UW%zR5q
sSiteURL= sURL; 1;8=,&
sFilePath = sPath; D! TFb E
sFileName = sName; ramYSX@
this.nSplitter = nSpiltter; %;ST7
E;m]RtvH
VRden>vKN
} sZ,xbfZby
-yyim;Nj
cW%QKdTQY0
public String getSSiteURL() ! Rrk
{ j#4 Iu&YJ
return sSiteURL; 5B6twn~[
} \%&BK.t
LB9D6,*t
khFr%u ?S
public void setSSiteURL(String value) IBfLb(I
{ jlaU3qXL
sSiteURL = value; EHI%QT
} ][vm4UY
2kukQj(n
) 0NKL:u
public String getSFilePath() 6!F@?3qCyg
{ (j<FS>##
return sFilePath; ].ZfTrM]
} s'$5]9$S
` mvPbZ0<
K|^PHe
public void setSFilePath(String value) 80J87\)
{ _A]8l52pt
sFilePath = value; 7Yv1et |
} rgq~lZ.U4K
Qc4r?7S<
@QOlo-u
public String getSFileName() /wAx#[c[
{ SXqWq
return sFileName; Uk1|y\
} v@,n]"
H){}28dX
srS2v\1:
public void setSFileName(String value) rF@njw@
{ /;5U-<qf
sFileName = value; y5@#leM
} hHA!.u4&
4Fu:ov ]M
h D5NX
public int getNSplitter() ^Pwtu
{ |ty?Ah,vb
return nSplitter; )NF5,eD
} b@v_db]|t.
q8Jhs7fv
"rl(%~Op
public void setNSplitter(int nCount) "aL.`^.
{ x."R_>
nSplitter = nCount; {beu
} D;1?IeS
} `GDWy^-Q+!
-G'U\EXT
UY5wef2sF
/* 8'sT zB]
**Utility.java }H5~@c$
*/ 7!qO*r
package NetFox; xdLMy#U2
()}(3>O-
'@0Z#A
public class Utility { #}xw *)3
s78MXS?py
/]1$Soo
public Utility() ^5'pJ/BV
{ EjA3hHJ
F>F2Yql&W
C(%b!Q,2
} H^3f!\MC;o
AT6o~u!WU
//线程睡眠 \k4em{K
public static void sleep(int nSecond) B}(r>8?dm
{ /nq\*)S#&
try{ aRV.;S
Thread.sleep(nSecond); WWEZTFL:j
} #"qP4S2
catch(Exception e) N%f% U
{ n 9>**&5L
e.printStackTrace (); C^IPddw>
} A:$4cacu9
} V|{\8&2
8@ZZ[9kt
//日志 Wa5B;X~
public static void log(String sMsg) eS: 8Pn
{ +dG3/vV
System.err.println(sMsg); Hk8lHja+\
} JW},7Ox
?S<`*O +
MvKr~
public static void log(int sMsg) Q]{`m
{ h`n) b
System.err.println(sMsg); 5i@WBa
} nl-y0xD9c
} Nov)'2g7G
yE#.Q<4
r!<)CT}D
/* F~$ay@g
**TestMethod.java I}sb0 Q&
*/ OQ&'3hv{
package NetFox; ?CD[jX}!
~@\sN+VS
L,O.XR
public class TestMethod { +;ylld
%Ze]6TP/><
%M*2j%6
public TestMethod() 2EH0d6nt
{ ///xx/weblogic60b2_win.exe $(]E$ek
try{ ?j;,:n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +-!2nk`"a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K=Z.<f
SiteFileFetch fileFetch = new SiteFileFetch(bean); iv ~<me0F
fileFetch.start(); `]=0oDG:1!
} e-Zul.m
catch(Exception e){e.printStackTrace ();} 7Ucq(,\./
cN:dy#
(DkfLadB
} W)<t7q+
/5Sd?pW;
\<HY'[gr
public static void main(String[] args) ||))gI`3a
{ 9>@Vk vpY
new TestMethod(); 4"pU\g
} twox.@"U
} s o7.$]aV
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