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)); 9)a:8/Y
} :u7y k@
for(int i=0;i<nEndPos.length-1;i++) uZ-yu|1
{ t9zF WdW
nEndPos = nStartPos[i+1]; j'V# =vH
} 9cu0$P`}5
nEndPos[nEndPos.length-1] = nFileLength; 4ISZyO=
} 5Y\wXqlY
} gt1W_C\
wY`yP!xO
fr1/9E;
//启动子线程 OI9V'W$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dX0"h5v1
for(int i=0;i<nStartPos.length;i++) X=<-rFW
{ :-=,([TJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), os]P6TFFX?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o1"MW>B,4
nStartPos,nEndPos,i); 72gQ<Si
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2U-F}Z
fileSplitterFetch.start(); Qifjv0&;u
} G6N$^HkW?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dwq}O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e)[>E\u_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j zaC
nEndPos = " + nFileLength); }?pY~f
// fileSplitterFetch[nPos.length-1].start(); sz'IGy%
Z2]ySyt]
`2X#;{a:
//等待子线程结束 c8cV{}7Kb
//int count = 0; ]Hp o[IF
//是否结束while循环 fXPD^}?Ux4
boolean breakWhile = false; e7<//~W7W
k:Iz>3O3]
S0_#h)
while(!bStop) BTwLx-p9t
{ \#.@*?fk
write_nPos(); 9}{i8 <$=
Utility.sleep(500); I$o^F/RH
breakWhile = true; *;~*S4/P
/ ;U
cC_L4
for(int i=0;i<nStartPos.length;i++) D2`tWRm0
{ W?a2P6mAh
if(!fileSplitterFetch.bDownOver) rRN7HL+b
{ =dyApR:'
breakWhile = false; tp='PG.6
break; +`_I!
} f&w8o5=|I
} qYHAXc}$
if(breakWhile) ^rI<}cfR
break; .:KZ8'g3}
zW`$T88~
YEZd8Y
//count++; v(vLk\K7
//if(count>4) *TpzX y
// siteStop(); P<+5So0
} vV.TK_y
[Yx)`e
u.wm;eK[
System.err.println("文件下载结束！"); GbC-6.~
} &j\<UPn
catch(Exception e){e.printStackTrace ();} D:9/;9V
} bqwQi>^Cw
SCClD6k=V
[b:$sR;
//获得文件长度 Y"GU"n~
public long getFileSize() I*/?*p/I
{ ?j^[7
int nFileLength = -1; ]&za^%q0&
try{ a D*
URL url = new URL(siteInfoBean.getSSiteURL()); nR7 usL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o#KGENd
httpConnection.setRequestProperty("User-Agent","NetFox"); >^#OtFHuT)
c?qg i"kS
N;XaK+_2F
int responseCode=httpConnection.getResponseCode(); Lw 7,[?,Z
if(responseCode>=400) |sN>/89=/
{ [E_eaez7#
processErrorCode(responseCode); ~c>*3*
return -2; //-2 represent access is error -jc8ku3*
} (3YI>/#
;\@co5.=
olNgtSX
String sHeader; T~%}(0=m
), >jBYMJ
M+<xX)
for(int i=1;;i++) d,fX3
{ <$#b3F"I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (U"Ub;[7
//Utility.log(in.readLine()); Y}_J@&:
sHeader=httpConnection.getHeaderFieldKey(i); WPBn?vb0<
if(sHeader!=null) HS{a^c%
{ W]!{Y'G
if(sHeader.equals("Content-Length")) BlF]-dF\
{ W\s ]qsLS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =HT:p:S
break; Ys@M1o
} ecK{+Z'G
} box(FjrZE
else (f DA
break; *u$MqN
} cd8~y
} tAfdbt
catch(IOException e){e.printStackTrace ();} !`8WNY?K
catch(Exception e){e.printStackTrace ();} #}50oWE
K1rF;7Y6
TqbDj|7`R
Utility.log(nFileLength); \\80c65-
jd9GueV*(
.\kcWeC\
return nFileLength; 2BLcun
} wYtL1D(
`=A*ei5
q=bW!.#?
//保存下载信息（文件指针位置） l MCoc'ae
private void write_nPos() _qg)^M6
{ 6iwIEb
try{ yvxdl=s
output = new DataOutputStream(new FileOutputStream(tmpFile)); [#y/`
output.writeInt(nStartPos.length); AtRu)v6r
for(int i=0;i<nStartPos.length;i++) O$}p}%%y7
{ v\Zni4
// output.writeLong(nPos); tETT\y|'
output.writeLong(fileSplitterFetch.nStartPos); #%CbZw@hJ9
output.writeLong(fileSplitterFetch.nEndPos); Z:VqBqK
} s#,~Zb=
output.close(); [h "*>J{
} yc.Vm[!
catch(IOException e){e.printStackTrace ();} UGuEZ-r
catch(Exception e){e.printStackTrace ();} "4c ?hH:C
} Ue:'55
7^|oO~x6
F|K=].
//读取保存的下载信息（文件指针位置） rn^7B-V
private void read_nPos() O>)<w Ms`
{ q\Cg2[nn2
try{ a []Iz8*6e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ri]7=.QI`
int nCount = input.readInt(); ~~[Sz#(
nStartPos = new long[nCount]; 2}Dd{kC-
nEndPos = new long[nCount]; RZm}%6##ZC
for(int i=0;i<nStartPos.length;i++) '=!@s1;{[;
{ (0s7<&Iu
nStartPos = input.readLong(); LG6VeYe|\X
nEndPos = input.readLong(); 6QsH?!bu
} ^06f\7A
input.close(); w9I7pIIl
} 8X=cGYC#
catch(IOException e){e.printStackTrace ();} TRwlUC3hQ
catch(Exception e){e.printStackTrace ();} rrK&XP&
} f,9jK9/$
laX(?{_
NG-Wn+W@b
private void processErrorCode(int nErrorCode) fY@Y$S`Fh
{ yjZ]_.
System.err.println("Error Code : " + nErrorCode); p<1z!`!P
} ,1'9l)zP
}Z T{
+TW9BU'a^
//停止文件下载 ta]B9&c
public void siteStop() SVsLu2tVY
{ /0Q=}:d
bStop = true; ;seD{y7!
for(int i=0;i<nStartPos.length;i++) |;2Y|>=
fileSplitterFetch.splitterStop(); $mvcqn;
2Y_ `&
VuqN)CE^Uq
} OU;R;=/]
} >$,A [|R
//负责部分文件的抓取 /C(lQs*l
**FileSplitterFetch.java .'o<.\R8
*/ &V5[Zj|]
package NetFox; x\t)uM%
r\7F}ZW/
T"1H%65`V
import java.io.*; <ijf':X=*
import java.net.*; 1@Dp<Q
K8NoY6
u"IYAyzL
public class FileSplitterFetch extends Thread { j.Ro(0%
hS]g^S==2h
[r'PGx
String sURL; //File URL ;-p1z% u
long nStartPos; //File Snippet Start Position SH>L3@Za
long nEndPos; //File Snippet End Position Az4+([
int nThreadID; //Thread's ID Jlw<%}r
boolean bDownOver = false; //Downing is over 9{{QdN8
boolean bStop = false; //Stop identical 2N_8ahc
FileAccessI fileAccessI = null; //File Access interface =}N&c4I[j
a1Q|su{H
fE"Q:K6r2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3`PPTG
{ $o rN>M42
this.sURL = sURL; }gL:"C"~
this.nStartPos = nStart; (.Hiee43
this.nEndPos = nEnd; bJc<FL<E
nThreadID = id; Ed[ tmaEuV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ySP1,xq
} L/Cp\|~ O
L[\m{gN
n1OxT"tD
public void run() pG?AwB~@n
{ `N$:QWJ
while(nStartPos < nEndPos && !bStop) 3nb&Z_/e
{ UM$\{$
pvL)BD
eliT<sw8
try{ A/n-.ci
URL url = new URL(sURL); N ]/N}b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q$)$?"
httpConnection.setRequestProperty("User-Agent","NetFox"); +We_[Re`<
String sProperty = "bytes="+nStartPos+"-"; >]N}3J}47g
httpConnection.setRequestProperty("RANGE",sProperty); ~hi\*W6jg
Utility.log(sProperty); S9~X#tpKe
5WN^8`{'3
tfzIem
InputStream input = httpConnection.getInputStream(); xWk:7,/
//logResponseHead(httpConnection); %:I\M)t}k
yOKpi&! r
shjc`Tqm
byte[] b = new byte[1024]; 5\RTy}w3x
int nRead; 6*`KC)a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6&~8TH
{ qEvHrsw},
nStartPos += fileAccessI.write(b,0,nRead); RlH|G
//if(nThreadID == 1) *?|LE C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JCoDe.
} VOc_7q_=
C!KxY/*Px
$OI 6^
Utility.log("Thread " + nThreadID + " is over!"); o&]b\dV
bDownOver = true; nulCk33x'=
//nPos = fileAccessI.write (b,0,nRead); t)|*-=
} F?!P7 zW
catch(Exception e){e.printStackTrace ();} yWI30hW
} !u@XEN>/
} hV5Aw;7C
O <;Au|>*
kTQ.7mo/\'
//打印回应的头信息 USgZ%xk2
public void logResponseHead(HttpURLConnection con) ^0A}iJL
{ 9Q{-4yF9k
for(int i=1;;i++) yV=Ku
{ &L3OP@;
String header=con.getHeaderFieldKey(i); BJGL &N
if(header!=null) 5,/rh,?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3m RP.<=
Utility.log(header+" : "+con.getHeaderField(header)); Dep.Qfv{-
else tHF-OarUO
break; ~>C@n'\lv
} hY$gzls4
} L?~>eT
12 y=Eh
8K: RoR
public void splitterStop() p;;4b@
{ 3r{3HaN(^'
bStop = true; RmF,x9
} \G}02h
0#\K9|.
+NIq}fZn9
} cd_\?7
JbT+w\o
#2*l"3.$.R
/* P2HR4`c
**FileAccess.java CPJ8G}4
*//文件访问(定位，写) 9a\H+Y~
package NetFox; Ziclw)
import java.io.*; ;bz|)[4/
"Zk# bQ2j
Q-A:0F&{t
public class FileAccessI implements Serializable{ ]=X6* E*/E
s98Jh(~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;#'YO1`gf3
RandomAccessFile oSavedFile; ,1xX`:
long nPos; #cHH<09rl
9o)sSaTx=
UoDS)(i
public FileAccessI() throws IOException A0mj!P9
{ ;E,^bt<U
this("",0); G$#Q:]N
} 'G] P09`*)
NC]]`O2r@
2o8:[3C5
public FileAccessI(String sName,long nPos) throws IOException %S$P<nKN5
{ isU7nlc!
oSavedFile = new RandomAccessFile(sName,"rw"); :P,g,
this.nPos = nPos; ?vA)F)MS
oSavedFile.seek(nPos); P X9GiJN"
} d|I_SI1
!VLk|6mn
:/rl \woA>
public synchronized int write(byte[] b,int nStart,int nLen) n6AN
{ O}#Ic$38
int n = -1; ^?+qNbK
try{ _H{6{!=y
oSavedFile.write(b,nStart,nLen); /-J
n = nLen; .>QzM>zO
} U-F\3a;&
catch(IOException e) Whoqs_Mm{
{ qV;E%XkkS
e.printStackTrace (); =sm<B^yj
} X`/GiYTu
@wvgMu
aPU.fER
return n; >(EC.ke
} RIC\f_Dv
6XP>qI,AJ
"0*yD[2
} w!/\dqjv
D.[h`Hkc
s<z`<^hRe
/* _ MsO2A
**SiteInfoBean.java 2/WtOQIB
*/ PpXzWWU":
package NetFox; GGM|B}U p
[zC1LTXe
CdEQiu
public class SiteInfoBean { EF>vu+YK
]|JQH
IOfxx>=3
private String sSiteURL; //Site's URL h.Y&_=Gc
private String sFilePath; //Saved File's Path ddTsR
private String sFileName; //Saved File's Name lF[m*}l
private int nSplitter; //Count of Splited Downloading File D=+md
nrBpq
}Z/[ "
public SiteInfoBean() %>p[;>jW
{//nSplitter的缺省值为5 G_m$?0\
//default value of nSplitter is 5 ]!c59%f=
this("","","",5); r5RUgt
} J#>)+
a/\SPXQ/9
]iU8n (5f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )])nd"E
{ }}Zwdpo
sSiteURL= sURL; |?cL>]t
sFilePath = sPath; =l)D$l
sFileName = sName; *&vlfH
this.nSplitter = nSpiltter; @:dn\{Zsea
k!Ym<RD%N
c;X%Ar
} X!b+Dk
vw'xmzgA
Z bW!c1s{
public String getSSiteURL() bcR";cE
{ adcH3rV
return sSiteURL; x/pX?k
} B_uhNLd
/~(T[\E<
J9%I&lu/
public void setSSiteURL(String value) {xD\w^
{ 2jVvK"C
sSiteURL = value; '^n,)oA/G
} .Ei#mG-=}&
}WA=
}>5R9
public String getSFilePath() HUFm@?
{ =Lh8#>T\h
return sFilePath; {e+}jZ[L
} |EGC1x]j=
rNK<p3=7)
}PXtwp13&u
public void setSFilePath(String value) bA-/"'Vp9
{ KqL+R$??"(
sFilePath = value; D03QisH=
} <.Dg3RH
U!GfDt
3v91yMx
public String getSFileName() mz2v2ma
{ >vR7l&"
return sFileName; 34 '[O
} MpVZL29)
b$eN]L
43}uW,P
public void setSFileName(String value) [Ot<8)Jm
{ &s(mbpV
sFileName = value; c(kYCVc
} 8 7z]qE
j0b>n#e7
kt#t-N;}x
public int getNSplitter() 8U%y[2sT
{ +h)1NX;o1
return nSplitter; U]]ON6Y&F
} ae#Qeow`
X:/7#fcG8
?$Dc>
public void setNSplitter(int nCount) jK]An;l{Z
{ p[K!.vOt+
nSplitter = nCount; KY%LqcC
} z41v5rB4
} (Fj"<
~c=F$M^"c
#Q1 |]
/* dC/@OV)0#
**Utility.java *7w,o?l
*/ Qp;FVUw9
package NetFox; ;04< 9i
arc{:u.K
w.(?O;
public class Utility { U+Vb#U7;
>|pN4FS
a0jzt!ci
public Utility() #Ibpf ,
{ -uNM_|MO
ja4zLf(<
sE])EwZ
} 1d!TU=*
6VtN4c.Q
//线程睡眠 ]-sgzM]q
public static void sleep(int nSecond) ^&lkh@Y1q
{ tH(g;flO)
try{ cl'wQ1<:
Thread.sleep(nSecond); 'si{6t|
} ,B:r^(}0j
catch(Exception e) hvc3n> Y[}
{ xC9?Wt'
e.printStackTrace (); Nwg?(h#
} =PjxMC._
} h-]c
Ae;mU[MK/
//日志 vO)]~AiB
public static void log(String sMsg) L%<DLe^P`l
{ GvBmh.
System.err.println(sMsg); j6E|j>@u
} ^x2@KMKXZ
Ki>XLX,er=
25;(`Td5
public static void log(int sMsg) **.g^Pyc
{ AHU=`z
System.err.println(sMsg); PDS?>Jg(
} cEIs9;
} )S`=y-L$
txiX1o!/L
Cwl:
/* \[d~O>k2
**TestMethod.java `PT'Lakf;3
*/ >uxAti\
package NetFox; YH&q5W,KX
!ou;yE&<,
tC5>K9Ed
public class TestMethod { (W.G&VSn)
4N5\sdi
*#1J
public TestMethod() nE56A#,Q,
{ ///xx/weblogic60b2_win.exe AYAbq}'Yt
try{ "H]R\xp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mRy0zN>?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V0G[f}tm'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3pe1"maP
fileFetch.start(); dwouw*8
} VHG}'r9KC%
catch(Exception e){e.printStackTrace ();} A@eR~Kp ^
30O7u3Zrb
tF6-@T\6
} o%OwKp s
#itZ~tol
=imJ0V~RW
public static void main(String[] args) _:%i6c*"
{ ]!uId#OH
new TestMethod(); C%|m[,Gx
} \zeuvD
} BZ(DP_}&D
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