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)); x_y>j)
} 92aDHECo
for(int i=0;i<nEndPos.length-1;i++) "gN*J)!x
{ J)8pqa
nEndPos = nStartPos[i+1]; Ot$cmBhw!
} P}+|`>L
nEndPos[nEndPos.length-1] = nFileLength; qa$[L@h>
} t7oz9fSz=?
} _c9 WWp?
)fd-IYi-3
[> &+*c
//启动子线程 I0l.KiBm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H]i+o6
for(int i=0;i<nStartPos.length;i++) *T>#zR{
{ FJjF*2.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F0BOhlK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 86[RH!e
nStartPos,nEndPos,i); R!/,E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )1Ma~8Y%r
fileSplitterFetch.start(); Eo {1y
} ZU|V+yT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c(Uj'uLc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7o965h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P96Cw~<Q?
nEndPos = " + nFileLength); UOLTCp?M;J
// fileSplitterFetch[nPos.length-1].start(); I*+LJy;j
I5TQ>WJbf
SgCqxFii
//等待子线程结束 vy{rwZ$
//int count = 0; k lP{yxU'n
//是否结束while循环 M73VeV3DL
boolean breakWhile = false; `r~`N`o5A
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while(!bStop) 3P+4S|@q(4
{ 4hsPbUx9
write_nPos(); .KiPNTh'
Utility.sleep(500); ="5k\1W1M
breakWhile = true; ]b0zkoD9<
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for(int i=0;i<nStartPos.length;i++) m{:"1]
{ */%$6s~
if(!fileSplitterFetch.bDownOver) zK' _e&*
{ lgCHGv2@
breakWhile = false; Vr&el
break; 3JlC/v#0
} P;)2*:--)
} G zJ9N`
if(breakWhile) S F&M (=w<
break; 7.7Cluh5,
[ -9)T
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//count++; ZfFIX5Qd\
//if(count>4) uD.
// siteStop(); ~=`f]IL
} ]iz_w`I\
jHkyF`<+
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System.err.println("文件下载结束！"); 07$/]eO%C
} S`pF7[%rp
catch(Exception e){e.printStackTrace ();} ax-=n(
} &_Cxv8
g6rv`I$l
vbr~<JT=
//获得文件长度 q Axf5
public long getFileSize() G*)s%2c>h
{ W9 n^T+2
int nFileLength = -1; 4u3 \xR?w6
try{ httls>:xB|
URL url = new URL(siteInfoBean.getSSiteURL()); RtW4n:c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]sX7%3P
httpConnection.setRequestProperty("User-Agent","NetFox"); =1gDjF9|
Y;fuh[#
?,WUJH?^
int responseCode=httpConnection.getResponseCode(); <h'8w
if(responseCode>=400) =ied}a :[
{ 'bLP~
processErrorCode(responseCode); K&j'c
return -2; //-2 represent access is error P/FrE~
} k TFz_*6.
'9^E8+=|
w0#%AK
String sHeader; zSEr4^Dk4
bZxv/\
b2a'KczV
for(int i=1;;i++) 8&?^XcJ*x
{ a^@+%?X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ceqFQ
//Utility.log(in.readLine()); '"Bex`
sHeader=httpConnection.getHeaderFieldKey(i); \V._Z>]
if(sHeader!=null) $`E4m8fX
{ OpYmTep#T\
if(sHeader.equals("Content-Length")) P1dN32H o
{ D*|( p6v1&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G=vN;e_$_b
break; (&q@~ dJ
} 1UC2zM"
} }'u3U"9)
else 1oB$MQoc
break; %(fL?
} rU],J!LF
} 1Pu ,:Jt
catch(IOException e){e.printStackTrace ();} 55LgBD
catch(Exception e){e.printStackTrace ();} AzZi{Q ?
;9K[~
"K8nxnq
Utility.log(nFileLength); ^GN5vT+:'
,&0Z]*
5@K\c6
return nFileLength; JFe4/ V
} cS4xe(n8
"pYe-_"@
'=$TyiU
//保存下载信息（文件指针位置） 7Ez}k}aR<
private void write_nPos() cnbo+U
{ &/HoSj>HS
try{ 2ed@HJu
output = new DataOutputStream(new FileOutputStream(tmpFile)); OO$|9`a
output.writeInt(nStartPos.length); yz2(_@R
for(int i=0;i<nStartPos.length;i++) 'HCnB]1
{ k@7kNMl
// output.writeLong(nPos); =<Hy"4+?.
output.writeLong(fileSplitterFetch.nStartPos); u]R$]&<
output.writeLong(fileSplitterFetch.nEndPos); L+Eu d
} Q^nG0<q+
output.close(); CK=ARh#|
} c$/<l5Uw
catch(IOException e){e.printStackTrace ();} o94PI*.
catch(Exception e){e.printStackTrace ();} $kv@tzO
} W.IH#`-9E
"8FSA`>=
3zbXAR*
//读取保存的下载信息（文件指针位置） tO7I&LNE
private void read_nPos() l4zw]AYk+X
{ Ny]lvgu9X
try{ !f@XDW&R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u9BjgK(M
int nCount = input.readInt(); _$!`VA%
nStartPos = new long[nCount]; t]4!{~,
nEndPos = new long[nCount]; wBLsz/
for(int i=0;i<nStartPos.length;i++) 7O"hiDQ
{ lz- iCZ
nStartPos = input.readLong(); PaNeu1cO
nEndPos = input.readLong(); 9+t=|
} L -YNz0A
input.close(); $:(z}sYQ7
} l`*( f9Q
catch(IOException e){e.printStackTrace ();} b1H7
catch(Exception e){e.printStackTrace ();} g(nK$,c
} Ep<YCSQy$i
:4U0I:J#
;|;iCaD a+
private void processErrorCode(int nErrorCode) moaodmt]x
{ 72u db^
System.err.println("Error Code : " + nErrorCode); Hl/7(FJqc>
} ~oo'ky*H!
ZOC#i i`:
V\"1wV~E
//停止文件下载 ^g[J*{+!W
public void siteStop() %Sul4: D#
{ k},>^qE
bStop = true; .N!{ U
for(int i=0;i<nStartPos.length;i++) v[smQO
fileSplitterFetch.splitterStop(); BD4`eiu"
0`6),R'x
h mds(lv7
} z|Ap\[GS
} v~f'K3fLp
//负责部分文件的抓取 `/0u{[
**FileSplitterFetch.java 4QO/ff[ o
*/ >IBTBh_ka
package NetFox; m9woredS,
/,LfA2^_j{
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import java.io.*; .$P|^Zx,
import java.net.*; mTJ"l(,3
TOrMXcn!/
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public class FileSplitterFetch extends Thread { _;7fraqX
gJKKR]4*
><K!~pst}
String sURL; //File URL (_U^
long nStartPos; //File Snippet Start Position -p]>Be+^x
long nEndPos; //File Snippet End Position ZL=N[XW4'
int nThreadID; //Thread's ID d@Q][7
boolean bDownOver = false; //Downing is over j %H`0
boolean bStop = false; //Stop identical NHAH#7]M&1
FileAccessI fileAccessI = null; //File Access interface S~> 5INud
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7 v~ro
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P.h.MA]
{ Z}+yI,
this.sURL = sURL; 5j`v`[B;
this.nStartPos = nStart; =U c$D*
this.nEndPos = nEnd; rH.gF43O:
nThreadID = id; k2.G%]j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {-h, ZdH^
} GG+5/hU
CL1 oAk
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public void run() c.0]1
{ (AuPZ
while(nStartPos < nEndPos && !bStop) Zih ?Bm
{ [;FofuZ
g|4w8ry
n,sY\=vB
try{ }[v~&
URL url = new URL(sURL); HCazwX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;ctU&`
httpConnection.setRequestProperty("User-Agent","NetFox"); OXCQfT@\
String sProperty = "bytes="+nStartPos+"-"; G0/>8_Q>Nr
httpConnection.setRequestProperty("RANGE",sProperty); tr=@+WHp
Utility.log(sProperty); 0;<OYbm3<
dyO E6Ex
C_Gzv'C"L
InputStream input = httpConnection.getInputStream(); r.<JDdj
//logResponseHead(httpConnection); 8lb-}=
R04J3D|
0D~=SekQ9
byte[] b = new byte[1024]; 1a8$f5
int nRead; 11{y}J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KoF iQ?
{ ] D6|o5
nStartPos += fileAccessI.write(b,0,nRead); H;y}-=J+
//if(nThreadID == 1) .`J:xL%Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gt@SuX!@{^
} l;0y-m1
7=3O^=Q^Q
wDw<KU1UK
Utility.log("Thread " + nThreadID + " is over!"); .[(P
bDownOver = true; x5F@ad9
//nPos = fileAccessI.write (b,0,nRead); 8[R1A
} mp:m`sh*i
catch(Exception e){e.printStackTrace ();} 3I*uV!notJ
} Ue!Q."
} KTv4< c]
C0(sAF@
_Wma\(3$
//打印回应的头信息 C0<YH "
public void logResponseHead(HttpURLConnection con) $eX*
{ :\bfGSD/gd
for(int i=1;;i++) ERC<Dd0
{ lD3)TAW@o
String header=con.getHeaderFieldKey(i); Ay%:@j(E
if(header!=null) (}"S)#C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QptOQ3!
Utility.log(header+" : "+con.getHeaderField(header)); GA@ Ue9
else M=[th
break; o(Kcs-W2
} jb3.W
} j+Zt.KXjT
`xIh\q
q,@+^aZ
public void splitterStop() [+gzdLad
{ r<|nwFJ
bStop = true; F.0d4:A+
} Tq#<Po $
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,CKvTxz0
} ^IgS
4>_d3_1sn
rhoeZ
/* `:4MMr91
**FileAccess.java @H+~2;B,
*//文件访问(定位，写) i@6wO?Tv
package NetFox; \xeVDKJH+n
import java.io.*; j{"[Ec
o8tS
^6qjSfFW}
public class FileAccessI implements Serializable{ nuxd S,
XN(tcdCG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JCcQd01z
RandomAccessFile oSavedFile; k9&@(G[K3
long nPos; Q"'V9m7 i
VF=Z`
^W}MM8 '
public FileAccessI() throws IOException AsAFUuI
{ ls]H6z*q
this("",0); A;T[['
} ob]dZ
doH2R@
B.6`cM^
public FileAccessI(String sName,long nPos) throws IOException >-zkB)5<,#
{ L~ 2q1
oSavedFile = new RandomAccessFile(sName,"rw"); [rot
this.nPos = nPos; AWL[zixR
oSavedFile.seek(nPos); 8T7f[?
} Uz $ @(C
1 KB7yG-#6
7t3X`db
public synchronized int write(byte[] b,int nStart,int nLen) O4N-_Kfp/
{ Efvq?cG&
int n = -1; X(b1/lzA
try{ )2]a8JVf
oSavedFile.write(b,nStart,nLen); /6jGt'^U
n = nLen; #]X2^ND47
} ?rQc<;b
catch(IOException e) ZMe}M!V
{ pX^=be_
e.printStackTrace (); ~M; gM]r;
} DUhT>,~]
,0h3x$l)
s_v}=C^
return n; EzUPah
} "\<P$&`HA
3@'lIV ?,q
p#z;cjfSt
} v23TL
;}f6Y['z
FJW`$5?
/* dy'X<o^?W
**SiteInfoBean.java ^GrNfB[Qu
*/ 4{g:^?1=
package NetFox; 'T6B_9GQ8
Wn2Ny jX
B#;s(O
public class SiteInfoBean { R%qX_m\0
4RlnnXY
Z3Bo@`&?
private String sSiteURL; //Site's URL P*}9,VoY
private String sFilePath; //Saved File's Path m9v"v:Pw
private String sFileName; //Saved File's Name t%0r"bTi
private int nSplitter; //Count of Splited Downloading File f2BS[$oV4
iXt4|0
V+P8P7y37B
public SiteInfoBean() u Eu6f
{//nSplitter的缺省值为5 V< 2IIH5^
//default value of nSplitter is 5 QJ[(Y@ O6a
this("","","",5); _G_ &Me0
} *2w_oKE'+5
,?P8m"
v=dKcruR:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WHZe)|n
{ FSI]k:
sSiteURL= sURL; B:.;,@r]
sFilePath = sPath; O6M}W_
sFileName = sName; & y#y>([~
this.nSplitter = nSpiltter; 6R3"L]J
FKDamHL<
j+z'
} p,M3#^ q
xCDA1y;j
KZ367&>b7
public String getSSiteURL() ph}wnIW]
{ D2hAlV)i(
return sSiteURL; z7NGpA(
} _OyP>|L'
&>+I7Ts]
6E)uu; 8
public void setSSiteURL(String value) ?NL&x
{ [Gh%nsH
sSiteURL = value; Res"0Q
} uFA|rX
Wl9I`Itg
\N'hbT=
public String getSFilePath() H|UV+Q0,
{ / h2*$
return sFilePath; Xr
} OuYE-x2]x"
c_D,MW\IC
]$XBd{\D{
public void setSFilePath(String value) 5 b#" G"
{ v4Fnh`{
sFilePath = value; >8F{lbEe
} FrAqTz
.:r2BgL
ctwhfS|Y0
public String getSFileName() goBKr: &]w
{ LB64W ;#h
return sFileName; >M8^Jgh
} 5~kW-x
toYg$IV
q~:'R
public void setSFileName(String value) ;/hH=IT
{ ba:mO$
sFileName = value; l/y Kc8^<
} t?#vb}_
YWn6wzu%Vc
#:Sy`G6!?
public int getNSplitter() twJ|Jmd
{ 7zJh;f/
return nSplitter; ;'WzfJ!q
} V.P5v{
wr;|\<c
^S;RX*
public void setNSplitter(int nCount) )2<B$p
{ ,P; a/{U
nSplitter = nCount; '#An+;x{
} ,N@Icl
} -$]DO5fY
Oa_o"p<Lr
6GrMcI@hS
/* t$PnQ@xu
**Utility.java ~XT a=
*/ p#8LQP~0$
package NetFox; E't G5,/m
a*n%SUP
[:hy
public class Utility { ,ovv
wor'=byh\
,h(f\h(9
public Utility() SUnmp
{ ~|B!.+
(a)@<RF`Q}
@!O&b%8X%
} {;(g[H=q;
OTtanJ?
//线程睡眠 PuoJw~^h
public static void sleep(int nSecond) X#NeB>~
{ :7PSZc:xE
try{ !=Kay^J~.
Thread.sleep(nSecond); ht74h
} [m+O0VK$
catch(Exception e) m$y$wo<K[7
{ ~9/nx|%D
e.printStackTrace (); fz?Wr: I
} u1|Y;*
} @Q1F#IU
Ud(dWj-/
//日志 rM~IF+f0XD
public static void log(String sMsg) N+@@EOmH
{ 6;c{~$s~[
System.err.println(sMsg); qA_DQ):
} }lvP|6Y: y
WxP4{T* <
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public static void log(int sMsg) >_%g8T'
{ 3z. >b
System.err.println(sMsg); %fSk "%u%<
} n\)f.}YD8d
} *l8vCa9Y
owVUL~
_ ~$0cj<
/* 4a-F4j'
**TestMethod.java >v4~:n2D
*/ RKZk/ly
package NetFox; J)&+y;.
[5:7WqB
v2z/|sG
public class TestMethod { H~K2`Cr)4
~PvzUT-^
Re ur#K
public TestMethod() bg. KkJMrR
{ ///xx/weblogic60b2_win.exe .F|WQ7Mu
try{ TBp5xz`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @Oay$gP{T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R63d `W
SiteFileFetch fileFetch = new SiteFileFetch(bean); w~-d4MNM
fileFetch.start(); cO+`8`kv
} bW3o%srxa
catch(Exception e){e.printStackTrace ();} dgD%I
hiM!htc;M
xfSvvCy
} WSwmX3rn
a'~y'6
KO"iauW
public static void main(String[] args) GlZDuU
{ kniMXeiu
new TestMethod(); q|2C>{8
} sVnuSm
} jO.E#Ei}~
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