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)); XL+kEZ|3
} P[Qr[74)
for(int i=0;i<nEndPos.length-1;i++) 9 Iw+g]`y*
{ :!3P4?a
nEndPos = nStartPos[i+1]; 0[PP-]JS
} 9_HEImk
nEndPos[nEndPos.length-1] = nFileLength; H(0d(c1s
} Vbwbc5m}
} ^@6eN]
s6qe5[
2bCa|HTv
//启动子线程 k_!z=6?[:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c*3ilMP\4
for(int i=0;i<nStartPos.length;i++) D0(gEb
{ C&"8A\we
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [%b<%m}L-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 87*R#((
nStartPos,nEndPos,i); s&c^Wr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |C5i3?
fileSplitterFetch.start(); !x,3k\M
} AKS(WNGEp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BG'gk#J+f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %``FIv15w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `E}2|9
nEndPos = " + nFileLength); ']qC,;2
// fileSplitterFetch[nPos.length-1].start(); 2)U3/TNe
jL2f74?1
5uu{f&?u)
//等待子线程结束 +8~S28"Wg3
//int count = 0; R z[-
//是否结束while循环 ~M <4HC
boolean breakWhile = false; +wQGC
,x_g|J _Y
w|>Y&/IX
while(!bStop) (=p}b:Z
{ *yt/ Dj
write_nPos(); I{M2nQi
Utility.sleep(500); H-I*;
breakWhile = true; Ue8_Q8q5
[V1gj9t=,
YrB-;R1+
for(int i=0;i<nStartPos.length;i++) f(9w FT
{ h>\}-|Ek
if(!fileSplitterFetch.bDownOver) +|o-lb
{ ysL8w"t
breakWhile = false; [TNYPA>{
break; [t ^|l?
} `5>IvrzXrK
} XbHcd8N T
if(breakWhile) Bw{W-&$o
break; &qo'ge8p
EkJo.'0@
o]jo R3
//count++; ~L?p/3m
//if(count>4) t[3Upe%
// siteStop(); 8^M5u>=t;
} S-v9z:M3
\Ud2]^D=
R/P.m~?
System.err.println("文件下载结束！"); 8fdOV&&D~i
} XLM 9+L
catch(Exception e){e.printStackTrace ();} S:DB%V3
} 0`OqD d
ytJ |jgp'
==IL63
//获得文件长度 q/]tJ{FI
public long getFileSize() <nIU]}q
{ &npf %Eub
int nFileLength = -1; CNP?i(Rk
try{ q.MM|;_u`
URL url = new URL(siteInfoBean.getSSiteURL()); FmnA+fA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S>**hMU%
httpConnection.setRequestProperty("User-Agent","NetFox"); HI:E&20y
b"x:IDW qG
<01MXT-
int responseCode=httpConnection.getResponseCode(); az`5{hK
if(responseCode>=400) 15SIZ:Q
{ CIV6Qe"<
processErrorCode(responseCode); '"I"D9;9
return -2; //-2 represent access is error O1/!)E!
} @^`-VF
SqEO ]~
c-gaK\u}j}
String sHeader; HLk/C[`u,
O 89BN6p
dU+1@_
for(int i=1;;i++) ,(lD5iN
{ bXtA4O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K)^.96{/@
//Utility.log(in.readLine()); j8N8|\n-
sHeader=httpConnection.getHeaderFieldKey(i); fDqlN`P@
if(sHeader!=null) smk0*m4
{ qo'pU/@
if(sHeader.equals("Content-Length")) 23Eg|Xk
{ +y-:(aP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :<nL9y jt
break; R$PiF1ffj
} eYS
} CVu'uyy
else @ '<lD*W
break; ULsz<Hj
} ~PS%^zxyn
} vR:t4EJ`
catch(IOException e){e.printStackTrace ();} q!NwfXJM
catch(Exception e){e.printStackTrace ();} Ndx='j0
FUMAvVQ
d{DlW |_
Utility.log(nFileLength); [rGR1>U?i
*mBn''a"*
!a1jc_
return nFileLength; ]%NCKOM
} ]>x674H
1q/z&@+B
<f:b%Pm7
//保存下载信息（文件指针位置） AvH/Q_-b
private void write_nPos() Qa"R?dfr
{ pQW^lqwZ:6
try{ W6]iJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); b$g.">:$
output.writeInt(nStartPos.length); :Rq@%rL
for(int i=0;i<nStartPos.length;i++) f61~%@fE
{ b/E1v,/<
// output.writeLong(nPos); S0kH/A
output.writeLong(fileSplitterFetch.nStartPos); [_b10Z'{
output.writeLong(fileSplitterFetch.nEndPos); SkN^ytKE
} JB**z00;
output.close(); y:pypuwt;
} Be?mIwc_g
catch(IOException e){e.printStackTrace ();} ,P5HR+h
catch(Exception e){e.printStackTrace ();} -@AGQ+e
} 6`%}s3Xq
r`6XF
8CMI\yk
//读取保存的下载信息（文件指针位置） "BEU%,w
private void read_nPos() C%G-Ye|@
{ [<OMv9(l'o
try{ }8 ,b;Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l$PO!JRD
int nCount = input.readInt(); |RHX2sso
nStartPos = new long[nCount]; $8X?|fV)
nEndPos = new long[nCount]; vChkSY([
for(int i=0;i<nStartPos.length;i++) @p}H@#/u\
{ 92eS*x2@
nStartPos = input.readLong(); *FOTq'%i
nEndPos = input.readLong(); #]n[
} TS@EE&Wq
input.close(); I]TL#ywF
} vUJb-
catch(IOException e){e.printStackTrace ();} 0(0Ep(Vj
catch(Exception e){e.printStackTrace ();} bQ_i&t\yzB
} ?c(f6p?%
G=\rlH]N
DlTV1X-^1
private void processErrorCode(int nErrorCode) gM_Z/$
{ Qb9) 1
System.err.println("Error Code : " + nErrorCode); l--xq^,`o]
} SyTcp?H
.viA+V
Jd/5Kx
//停止文件下载 MI<hShc\
public void siteStop() 4AUY8Pxp
{ FL0[V,
bStop = true; *}3~8fu{
for(int i=0;i<nStartPos.length;i++) us$~6
fileSplitterFetch.splitterStop(); )FE'#\
&\K,kS[.r
]+ug:E{7
} %p^C,B{7w
} trM8p
//负责部分文件的抓取 u{exQ[,E
**FileSplitterFetch.java nL@P{,J
*/ hg=\L5R
package NetFox; ; N!K/[p=
x4Eq5"F7}
l&5| =
import java.io.*; q0SvZw]f1
import java.net.*; #P18vK5
=yfr{5}R
7zpwP
public class FileSplitterFetch extends Thread { 5v!Uec'+
}?8KFe7U
R3%T}^;f
String sURL; //File URL $ 'HiNP {c
long nStartPos; //File Snippet Start Position {h|3P/?7
long nEndPos; //File Snippet End Position 5+giT5K*h
int nThreadID; //Thread's ID QMHeU>
boolean bDownOver = false; //Downing is over m,qU})
boolean bStop = false; //Stop identical 1*G7Uh@K}
FileAccessI fileAccessI = null; //File Access interface T3wR0,
,tmo6D62
I0GL/a4s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B% BO
{ kRZ(
this.sURL = sURL; !X*L<)=nh
this.nStartPos = nStart; Ab8~'<F$B
this.nEndPos = nEnd; }+I 8l'
nThreadID = id; t55CT6Se
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _U/etlDTO
} 2-UZ|y
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KiH#*u S
public void run() gO_^{>2
{ dID]{
while(nStartPos < nEndPos && !bStop) K.*zqQKlI|
{ P4Wd=Xoz6
(47jop0RDQ
CK'Cf{S
try{ Ff%m.A8d,4
URL url = new URL(sURL); )QFT$rmX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;k(|ynXv
httpConnection.setRequestProperty("User-Agent","NetFox"); >/ HC{.k
String sProperty = "bytes="+nStartPos+"-"; (f $Y0;v>}
httpConnection.setRequestProperty("RANGE",sProperty); E8#y9q
Utility.log(sProperty); j3sUZg|d
Pr@EpO
UyTq(7uo
InputStream input = httpConnection.getInputStream(); B_c(3n-"
//logResponseHead(httpConnection); g 9>p?XY
x8tRa0-q
)<IbQH|_
byte[] b = new byte[1024]; .#rI9op
int nRead; 'HPw5 L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #d(6q$IE
{ &!KJrQ
nStartPos += fileAccessI.write(b,0,nRead); # |w,^tV
//if(nThreadID == 1) rx|/]NE;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JnV$)EYi
} - stSl*
//K]zu
!Z<Z"R/
Utility.log("Thread " + nThreadID + " is over!"); w[:5uo(
bDownOver = true; ra$_#HY
//nPos = fileAccessI.write (b,0,nRead); qt/"$6]%
} <$,iYx
catch(Exception e){e.printStackTrace ();} 8t9sdqM/C
} \`|,wLgH
} S#2'Jw
B>YrDJUN
9Ni$nZN
//打印回应的头信息 Ya304Pjd
public void logResponseHead(HttpURLConnection con) DCP"
{ (J$JIPF
for(int i=1;;i++) 3l5q?"$
{ 2Xe2%{
String header=con.getHeaderFieldKey(i); d=N5cCqq
if(header!=null) u&2uQ-T0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :,]%W $f=
Utility.log(header+" : "+con.getHeaderField(header)); {K_YW
else 89+m?H]K
break; |~#!e}L(
} ++Az~{W7
} gaTI:SKzc
78y4nRQ*
dy|r:~j3
public void splitterStop() )Ky0q-W
{ tv\P$|LV`8
bStop = true; QqtFNG
} Kgk9p`C(
;y4 "wBX
oA_AnD?G+
} |F9/7 z\5+
vJmE}
@iao"&
/* ]5rEwPB
**FileAccess.java DV{Qbe#In
*//文件访问(定位，写) B7N?"'$i
package NetFox; EDL<J1%
import java.io.*; JcvK]x
gLd3,$Ei
X(g<rz1J]
public class FileAccessI implements Serializable{ _U#ue
y4P mL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j~Rh_\>Q
RandomAccessFile oSavedFile; 6i{W=$RQ
long nPos; aHwrFkn
7}TjOWC
FkKx~I:
public FileAccessI() throws IOException nyTfTn
{ Ql [=
this("",0); <@@.~Qm'
} 83)2c a
YujhpJ<
UO>p-M
public FileAccessI(String sName,long nPos) throws IOException %J2u+K
{ YX@[z 5*
oSavedFile = new RandomAccessFile(sName,"rw"); m:X;dcq'3
this.nPos = nPos; d&.)Dw
oSavedFile.seek(nPos); Y 1LE.{
} T9N /;3
#{i\t E
Tw-gM-m;
public synchronized int write(byte[] b,int nStart,int nLen) won%(n,HT
{ jJ|O]v$N
int n = -1; Q]IpHNt[>
try{ e@=Bl-
oSavedFile.write(b,nStart,nLen); } Tp!Ub\Cc
n = nLen; q$>At}4
} /d8PDc"
catch(IOException e) MP0gLi
{ Yl>@(tu)|
e.printStackTrace (); $+:_>n^#/
} FW=oP>f]w
AqE . TK
/,GDG=ra
return n; ze!7qeW
} </qXKEu`_
T4J(8!7
VY Va8[}
} zcP_-q]1
lE$X9yIt
n#bC,
/* M(I 2M
**SiteInfoBean.java g2w0#-
*/ b@z/6y!
package NetFox; hPD2/M
dhsQfWg#}
}3=]1jH6
public class SiteInfoBean { ),dXaP[
R279=sO,J
d,+d8X
private String sSiteURL; //Site's URL >g8Tl`P,iN
private String sFilePath; //Saved File's Path VmV/~-<Z
private String sFileName; //Saved File's Name !W .ooy5(
private int nSplitter; //Count of Splited Downloading File k+&LOb7
r5tv9#4]
BWfsk/lej
public SiteInfoBean() D]Bvjh
{//nSplitter的缺省值为5 /< h~d
//default value of nSplitter is 5 |HhUU1!
this("","","",5); wM_k D
} l#V"14y
LF{d'jJ&K
MU%C_d%.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9m%[ y1v0
{ b2r@vZ]D
sSiteURL= sURL; [bH6>{3u
sFilePath = sPath; K7U`
sFileName = sName; Fl<BCJY
this.nSplitter = nSpiltter; ()=
:a[L-lr`e
:W-"UW,
} g}P.ksM
;r"YZs&Xd
^szCf|SM
public String getSSiteURL() :TX!lbCq
{ .)ZK42Qd
return sSiteURL; !imm17XQ\
} lLS`Ln)"
*";,HG?|Iz
Ql3hq.E
public void setSSiteURL(String value) ~t.*B& A
{ E@Q+[~H}
sSiteURL = value; ^MKvZ DOP
} 9ZeTS~i
~X*)gS-=
mp+ %@n.;
public String getSFilePath() 4}gqtw:
{ ]fnc.^{
return sFilePath; o!gl :izb
} =K-B I
m9a(f>C
Ca0~K42~
public void setSFilePath(String value) ZlUd^6|:3
{ A"2k,{d
sFilePath = value; OB>Pk_eQK
} gj0gs
NYm2fFPc
q1.w8$
public String getSFileName() y4w{8;Mh
{ t+|c)"\5h
return sFileName; .FtW$Y~y
} /RIvUC1
cAC]%~orx
Z)~.OqRw]
public void setSFileName(String value) aP>%iRk'J!
{ )lTkqz8v
sFileName = value; Z455g/=ye
} $NWXn,Y'
N3!x7J7A
7D@O:yO
public int getNSplitter() >Ke4lO"
{ :{E;*v_!v
return nSplitter; Dny5X.8
} V{HP8f91
soRt<83
_%?}e|epy
public void setNSplitter(int nCount) '+hiCX-_
{ qfd/t<?|D
nSplitter = nCount; Cb%?s
} oe=^CeW"
} 4. 7m*
_{_ybXG|
RLu y;z
/* [nZ3}o
**Utility.java MN}@EQvW==
*/ &}_E~jKK
package NetFox; 4onRO!G,
w4\b^iJz
f R$E*Jd
public class Utility { /. k4Y
d3v5^5kU
\tc4DS
public Utility() C (L1
{ F.<sKQ&A
l{[{pAm
R4.$9_ui
} C!6?.\U/:c
P:eY>~m<;
//线程睡眠 q"7rd?r52
public static void sleep(int nSecond) D(yU:^L
{ PHU#$LG
try{ bS=aFl#
Thread.sleep(nSecond); -aK_
} Ikv@}^p 7
catch(Exception e) Uo>pV9xRG
{ 80TSE*
e.printStackTrace (); v9QR,b`n
} pTT7#b(t
} 9+k7x,
Km7HB!=<
//日志 1:h{( %`&
public static void log(String sMsg) ;m`k#J?
{ uH!uSB2
System.err.println(sMsg); JKN0:/t7Q
} klmRU@D
=~}\g;K1Q
KSe`G;{
public static void log(int sMsg) P1tc*2Z
{ 5v >0$Y{
System.err.println(sMsg); q,w8ca4~y
} r`Y[XzT9
} M S$^m2
FW~%xUSE5
$9k7A 8K
/* 1Tz5tU9kR
**TestMethod.java p_pI=_:
*/ ?WyL|;b*
package NetFox; wQ]!Y?I
|3j'HN5S
do@`(f3g
public class TestMethod { fG_.&!P
hfw$820y[
\Jq$!foYx
public TestMethod() ^x8*]Sz#x
{ ///xx/weblogic60b2_win.exe "& h;\hL
try{ <mN.6@*{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZZ|a`U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 53=5xE= `D
SiteFileFetch fileFetch = new SiteFileFetch(bean); /qM:;:N%j
fileFetch.start(); N.R,[K
} ?"-%>y@w
catch(Exception e){e.printStackTrace ();} ElLDSo@WvR
-]HPDN,OB
j:ze5FA+
} W?is8r:
/o%J /|
rV;X1x}l
public static void main(String[] args) r1dP9MT\8
{ pD;'uEFBQ
new TestMethod(); AT*J '37
} 7L2$(d4
} |&!04~s;E
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