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)); /oL8;:m
} _a5(s2wq+
for(int i=0;i<nEndPos.length-1;i++) OipqoI2
{ i_ QcC
nEndPos = nStartPos[i+1]; Q9slfQ
} m@\ZHbq
nEndPos[nEndPos.length-1] = nFileLength; .~mCXz<x
} 8\# ^k#X
} ]tY:,Mfs
t&}6;z 3
Fo}7hab
//启动子线程 u|fXP)>.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PJ q yvbD
for(int i=0;i<nStartPos.length;i++) 1mH\k5xu
{ %e_"CS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &HDP!SLS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'Cc(3
nStartPos,nEndPos,i); !w2gGy:I>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A-uB\ L
fileSplitterFetch.start(); F]_cbM{8/
} *e/K:k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `.v(fC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &`Ck
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ln<]-)&C
nEndPos = " + nFileLength); 8)wt$b
// fileSplitterFetch[nPos.length-1].start(); vAi$[p*im
o6L9UdT
!')y&7a~
//等待子线程结束 y%cO#P@
//int count = 0; -F1- e+=
//是否结束while循环 .CbGDZ
boolean breakWhile = false; 1-VT}J(
SEd5)0X^
CxF-Z7 '
while(!bStop) ~cqryr9
{ _[K#O,D,
write_nPos(); z`U Ukl}T
Utility.sleep(500); c`G&KCw)d
breakWhile = true; ;3m!:l
i8PuC^]
=? :@
for(int i=0;i<nStartPos.length;i++) A6"Hk0Hf
{ }Je>;{&%
if(!fileSplitterFetch.bDownOver) :}q\tNY<
{ \a|L/9%
breakWhile = false; pq!%?m]
break; ,k0r
} N_DT7
} )S@jDaU<
if(breakWhile) L%cVykWY"
break; vqNsZ 8|`
5#2F1NX
jC, FG'P
//count++; R;}22s
//if(count>4) XFqJ 'R
// siteStop(); =A!S/;z>
} [aqu}Su
,/,9j{|"j
39TT{>?`w
System.err.println("文件下载结束！"); O'DW5hBL0
} uCP>y6I
catch(Exception e){e.printStackTrace ();} rrBAQY|.
} KMK`F{
HOi C
E]} n(
//获得文件长度 A74920X`W
public long getFileSize() ,|T7hTn=
{ -yx/7B5@
int nFileLength = -1; ktH8as^54!
try{ g:#dl\k
URL url = new URL(siteInfoBean.getSSiteURL()); M>H=z#C>/A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); my.`k'
httpConnection.setRequestProperty("User-Agent","NetFox"); [_6&N.
'mMjjG9
8E^@yZo{
int responseCode=httpConnection.getResponseCode(); \wav?;z
if(responseCode>=400) f [o%hCS
{ x"4%(xBu
processErrorCode(responseCode); \fLvw
return -2; //-2 represent access is error r/:%}(7;
} +cB&Mi5
>cR)?P/o
|M~ON=
String sHeader; 1s7^uA$}6
2k -+^}r
C!x/ ^gw
for(int i=1;;i++) >'=MH2;
{ %{5n1w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9'~-U
//Utility.log(in.readLine()); FG-L0X
sHeader=httpConnection.getHeaderFieldKey(i); ;</Lf=+Vm
if(sHeader!=null) F?4(5 K
{ 'cdN3i(
if(sHeader.equals("Content-Length")) Iw=Sq8
{ }nx=e#[g%2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T1Ta?b
break; *~VxC{
} 40P) 4w
} 4FMF|U
else 6`H.%zM
break; ]$iN#d|ZU
} d^Di*&X
} (Xxn\*S
catch(IOException e){e.printStackTrace ();} n&XGBwgW
catch(Exception e){e.printStackTrace ();} {1lO
0t.p1
-8Ti*:
Utility.log(nFileLength); m:CTPzAt
\E4B&!m
\FzM4-
return nFileLength; 15H6:_+=0
} uOi&G:=
t}p@:'
NX6nQ
//保存下载信息（文件指针位置） ' [0AHM
private void write_nPos() d]v+mVAyE
{ +V(5w`qx
try{ I=Zx"'Um
output = new DataOutputStream(new FileOutputStream(tmpFile)); )9j06(<A
output.writeInt(nStartPos.length); -pb&-@Hul
for(int i=0;i<nStartPos.length;i++) %!j:fJ()
{ [J#1Ff;
// output.writeLong(nPos); Bx~[F
output.writeLong(fileSplitterFetch.nStartPos); Ubz"rCjq
output.writeLong(fileSplitterFetch.nEndPos); Ukphd$3J=
} Q=cQLf;/'
output.close(); 'ktHPn ,K
} C;B}3g&
catch(IOException e){e.printStackTrace ();} u=l1s1>
catch(Exception e){e.printStackTrace ();} JiS5um=(.
} /X8<C=}
7,$z;Lr0S
|QZ58)>
//读取保存的下载信息（文件指针位置） ' P"g\;Ij
private void read_nPos() [IBQvL
{ aw $L$7b}
try{ %:C ]7gQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rXi uwz\
int nCount = input.readInt(); TCVl8)j
nStartPos = new long[nCount]; '?*g%Yuz
nEndPos = new long[nCount]; j -O2aL
for(int i=0;i<nStartPos.length;i++) n-;y*kD
{ =bt]JRU
nStartPos = input.readLong(); >`T5]_a
nEndPos = input.readLong(); ]dPZ.r
} p='-\M74K
input.close(); deX5yrvOie
} hP@(6X,"
catch(IOException e){e.printStackTrace ();} wo^Sy41bF
catch(Exception e){e.printStackTrace ();} b3$k9dmxV+
} T3&`<%,f
t,%iL
SS.jL)
private void processErrorCode(int nErrorCode) !>^JSHR4t
{ E_ucab-Fi
System.err.println("Error Code : " + nErrorCode); f<jb=\}x
} Q[ieaL6&
hq>Csj==@
g=)J~1&p
//停止文件下载 72db[
public void siteStop() n]!fO 6kj
{ rp34?/Nz
bStop = true; &lc8G
for(int i=0;i<nStartPos.length;i++) V`hu,Y;%
fileSplitterFetch.splitterStop(); UH`hOJ?
xl4=++pu)
QP I+y8N=
} ctmQWrk|B
} u62)QJE
//负责部分文件的抓取 }odV_WT
**FileSplitterFetch.java |01?w|
*/ ,Fqz e/
package NetFox; pb;")Q'
{y^3> 7
=d;Vk
import java.io.*; 2YwVU.*>
import java.net.*; y>VcgLIB
do/)~9[4\
"E!mva*NU
public class FileSplitterFetch extends Thread { &x:JD1T}
ztM<J+
wzcai 0y*
String sURL; //File URL USML~]G z
long nStartPos; //File Snippet Start Position 0(>rG{u
long nEndPos; //File Snippet End Position ph:3|d
int nThreadID; //Thread's ID w2gf&Lc\
boolean bDownOver = false; //Downing is over [pOg'
boolean bStop = false; //Stop identical 7hNb/O004
FileAccessI fileAccessI = null; //File Access interface /L=(^k=a.;
" BTE
F 8yF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]hw-Bu\{
{ p QE)p
this.sURL = sURL; YhKZ|@
this.nStartPos = nStart; NY
this.nEndPos = nEnd; MLVB^<qkeH
nThreadID = id; j#A%q"]8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mPZGA\
} yf1CXldi
<_S@6?
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public void run() ~.tvrxg
{ UV7%4xM5v
while(nStartPos < nEndPos && !bStop) "u^EleE!
{ #} ,x @]p
=J'P.
Qu*1g(el!o
try{ <EX7WA
URL url = new URL(sURL); |(IO=V4P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rhgj&4
httpConnection.setRequestProperty("User-Agent","NetFox"); h,t|V}Wb
String sProperty = "bytes="+nStartPos+"-"; .=RlOK
httpConnection.setRequestProperty("RANGE",sProperty); ?2J?XS>
Utility.log(sProperty); x!TZ0fq0
t={0(
q%3<Juq~$
InputStream input = httpConnection.getInputStream(); OmMX$YID
//logResponseHead(httpConnection); ~9o6 W",
lPq\=V
O_,O,1
byte[] b = new byte[1024]; U..<iNQE5
int nRead; [IX+M#mf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f_mhD dq
{ .QWhK|(.!
nStartPos += fileAccessI.write(b,0,nRead); L^Wz vv]
//if(nThreadID == 1) &V=7D#L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6DF
} XJ\hd,R
3fS}:!sQ
xh9qg0d
Utility.log("Thread " + nThreadID + " is over!"); %|Qw9sbd
bDownOver = true; Y>6.t"?Q^
//nPos = fileAccessI.write (b,0,nRead); B&KL2&Z~Pq
} {ShgJ;! Q
catch(Exception e){e.printStackTrace ();} mB55PYA
} Un=a fX?j
} +Ghi}v
r#876.JK
w<wV]F*
//打印回应的头信息 `^F: -
public void logResponseHead(HttpURLConnection con) _2Zp1h,
{ =yiOJyx
for(int i=1;;i++) 7qIB7_K5
{ '&yg{n
String header=con.getHeaderFieldKey(i); Q\_{d0 0
if(header!=null) @"87F{!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *YV S|6bs
Utility.log(header+" : "+con.getHeaderField(header)); fv'4f$U
else 85Y|CN] vQ
break; X)Gp7k1w
} v|t{1[C
} ?m%h`<wgMc
%e%7oqR?
*> 3Qd7
public void splitterStop() o+?@5zw-&
{ htJuGfDx1
bStop = true; 4jwu'7Q
} =7/-i
u=K2Q4
~UMOT!4}3
} t8J/\f=
F@W*\3)
'5.\#=S1
/* }0/a\
**FileAccess.java F1W+o?B
*//文件访问(定位，写) zmFws-+A
package NetFox; :[7lTp
import java.io.*; [~%`N*G
&w\I<J`T
CY"i-e"q<Q
public class FileAccessI implements Serializable{ %vqT#+x
pO/%N94s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a5c'V
RandomAccessFile oSavedFile; nfE@R."A
long nPos; _n O.-
Jbw!:x [
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public FileAccessI() throws IOException 'p}`i/
{ dk5|@?pe
this("",0); G2Qjoe`Uc
} DZ`k[Z.VZ
=Viy^ieN$
F8mC?fbK9
public FileAccessI(String sName,long nPos) throws IOException Yv\!vW7I
{ ExhL[1E
oSavedFile = new RandomAccessFile(sName,"rw"); &a #GXf
this.nPos = nPos; HYClm|
oSavedFile.seek(nPos); /=T"=bP#/
} L]-w;ll-
;iX<`re~
YMB~[]$V<
public synchronized int write(byte[] b,int nStart,int nLen) 3)E(RyQA3
{ Y`li> .\
int n = -1; >)Dhi+D
try{ ,;iA2
oSavedFile.write(b,nStart,nLen); JeQ[qQ
n = nLen; s-D?)
} ([pSVOnIz
catch(IOException e) oXal
{ ~<O,Vs_C/
e.printStackTrace (); \+B?}P8N*l
} JZx%J)
[X"k> Sq
VTw/_Hf2p
return n; ~ =.CTm]vf
} $$gtZ{ukQ
0s%6n5>
hPO>,j^
} Q<=Y
O%$O(l
Rt4di^v
/* KTmaglgp
**SiteInfoBean.java CT"Fk'B'
*/ k|j:T[_
package NetFox; OgMI
+VOb
w-rOecwFvu
public class SiteInfoBean { [b1hC ~I;
#+G`!<7/@f
}~zO+Wf2
private String sSiteURL; //Site's URL Uf2:gLrF
private String sFilePath; //Saved File's Path c E76L%O
private String sFileName; //Saved File's Name xqWj|jA
private int nSplitter; //Count of Splited Downloading File i^/54
sR79 K1*j
6VR[)T%
public SiteInfoBean() u4"r>e6_B
{//nSplitter的缺省值为5 <Jwo?[a
//default value of nSplitter is 5 L8P36]>
this("","","",5); #v/ry)2Y=
} l,bZG3,6
wRbw
.TN2s\:]jw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l2/@<0P
{ jgRCs.6
sSiteURL= sURL; VO-784I
sFilePath = sPath; qZsnd7o{l.
sFileName = sName; VkXn8J
this.nSplitter = nSpiltter; ~CFMIQ et
Bz:0L1@,4a
(j N]OE^
} Wem?{kx0
3+ asP&n
iS-K ~qa
public String getSSiteURL() /0\QL+^!
{ HD00J]y_
return sSiteURL; _LLshV3
} 4x]NUt
hAAUecx
Mjw[:70
public void setSSiteURL(String value) {PmzkT}LF
{ B\zoJg&7(
sSiteURL = value; @_O3&ZK
} 04\Ta
..$>7y}
a7 )@BzF#
public String getSFilePath() LDX y}hm)
{ ?N_)>&b
return sFilePath; T{HfP
} Oga1u
G5umeqYC
n)CH^WHL&
public void setSFilePath(String value) 88YC0!Ni
{ 'FxYMSZS$
sFilePath = value; BvJ\x)
} ^0eO\wc?O
ybYXD?
-x?Hj/
public String getSFileName() D(@SnI+
{ \E&thp
return sFileName; JP%RTGu
} jrcc
Rk{$S"8S_
@Yarz1
public void setSFileName(String value) `skH-lk,
{ J~'~[,K
sFileName = value; S5/p=H:
} *vD/(&pQ1:
E6Q91Wz9f
QRiF!D)Nk
public int getNSplitter() 5iv@@1c
{ `.`FgaJ |
return nSplitter; APOea
} ZmP1C`>
o{g@Nk'f
VLx T"]f
public void setNSplitter(int nCount) iz(m3k:w
{ C#T)@UxBZ
nSplitter = nCount; .W-=x,`hY4
} pKYLAt+^>
} BArJ"t*/z
3l+|&q[v
(E IRz>
/* F*. /D~K
**Utility.java \CDAFu#
*/ P 4H*jy@?
package NetFox; aYR\<02
9Mnem*
Bd QQ9$@5
public class Utility { k=FcPF"
pBvo M={2!
W*3o|x
public Utility() Ipg\9*c`
{ ym[+Rw
,A^L=+
9M;I$_U`vj
} {#0Tl
% hNn%Oy:E
//线程睡眠 2-PI JO
public static void sleep(int nSecond) @_(nd57oSs
{ EI<"DB
try{ R:BBF9sK?
Thread.sleep(nSecond); KZi+j#7O
} H]U"+52h
catch(Exception e) @ljZw(
{ U:J /\-
e.printStackTrace (); <kROH0+
} D. 77WjwQ
} F6~b#Jz&i
F61+n!%8
//日志 >[ @{$\?x:
public static void log(String sMsg) p-a]"l+L
{ _pJX1_vD
System.err.println(sMsg); fO0-N>W'P
} *P&OxVz
?Z5$0-g'hU
uAChu]
public static void log(int sMsg) =":@Foa
{ IM$'J
System.err.println(sMsg); LxIuxt=X|p
} `Nkx7Z~w:
} T3 =)F%
o:h)~[n|
byp.V_a}/
/* W5TqC
**TestMethod.java #cR57=M}
*/ twAw01".
package NetFox; p0"BO4({{
U9bFUK/z
TeOFAIU
public class TestMethod { FW/6{tm
1a \=0=[
M_yZR^;^-
public TestMethod() {c.}fyN
{ ///xx/weblogic60b2_win.exe N45s'rF
try{ OX'/?B((
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^.nwc#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (L]T*03#
SiteFileFetch fileFetch = new SiteFileFetch(bean); D-;J;m \
fileFetch.start(); BASO$?jf4
} /M5=tW#e
catch(Exception e){e.printStackTrace ();} :h3#1fko
,oy4V^B&
F^4*|g
} B(HNB\3u
h}Fu"zK
0]f?Dx/8
public static void main(String[] args) !.x=r
{ :/n ?4K^
new TestMethod(); fo/(()
} MZgmv
} k i~Raa/e
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