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)); 1WaQWZ:=
} [GCaRk>b,
for(int i=0;i<nEndPos.length-1;i++) vZQraY nJ
{ I5j|\ /Ht
nEndPos = nStartPos[i+1]; jKcl{',
} .HTRvE`X
nEndPos[nEndPos.length-1] = nFileLength; iPCn-DoIS
} 0{d)f1
} fvta<
cC9Zc#aK
~Q^.7.-T
//启动子线程 l^tRy_T:-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ??Urm[Y.Z
for(int i=0;i<nStartPos.length;i++) i%i s<'
{ b$Ei>%'/";
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @(6P L^I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t0<RtIh9e
nStartPos,nEndPos,i); P7X3>5<;q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?W dY{;&
fileSplitterFetch.start(); yz>S($u
} sc-+?i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !F?j'[s8]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r0f&n;0U4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d8Cd4qIXX
nEndPos = " + nFileLength); >}Mw"
// fileSplitterFetch[nPos.length-1].start(); `o{_+Li9
c=-qbG0`
1"t9x.
//等待子线程结束 8YPX8d8u
//int count = 0; mxH63$R
//是否结束while循环 LGtw4'yr
boolean breakWhile = false; ijcF[bmE
K{Nj-Rqd
@G>eCj
while(!bStop) B)d 4]]4\\
{ "Qc4v@~)
write_nPos(); 4K~>
Utility.sleep(500); r^E(GmW
breakWhile = true; _iA oNT!
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5ld?N2<8/
for(int i=0;i<nStartPos.length;i++) wU/fGg*M2
{ .2|(!a9W
if(!fileSplitterFetch.bDownOver) 1TzwXX7
{ $PlMyLu7jc
breakWhile = false; ;xFB /,
break; /A>nsN?:]
} 6c>:h)?
} <RbsQ^U
if(breakWhile) ^VnnYtCRz
break; 71IM`eL=ED
^IvQdVB
0<<ATw$aQ
//count++; 9%Vy,
//if(count>4) %<|<%~l&
// siteStop(); n%}#e!
} {QN 5QGvK
H:Q4!<
J}bLp Z
System.err.println("文件下载结束！"); i}f"'KW
} O#{`Fj`
catch(Exception e){e.printStackTrace ();} GAs.?JHd
} svt3gkR0
[tC=P&<
2h@&yW2j
//获得文件长度 ww+,GnV
public long getFileSize() A&ceuu
{ Rb^G~82d?
int nFileLength = -1; B<.ZW}#v
try{ EZp >Cf7
URL url = new URL(siteInfoBean.getSSiteURL()); ;Ob^@OM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]W`M <hEI
httpConnection.setRequestProperty("User-Agent","NetFox"); 8F$]@0v`%
}QCn>LXE
Jh4pY#aF
int responseCode=httpConnection.getResponseCode(); Gy6x.GX
if(responseCode>=400) YoK )fh$
{ 9B>P Qbs
processErrorCode(responseCode); }Q^*Zq9-
return -2; //-2 represent access is error 3:c6x kaw
} cUw$F{|W
)RWY("SUy1
?oV|.LM:W
String sHeader; &tiJ=;R1
&-My[t
2PNe~9)*#
for(int i=1;;i++) {g4w[F!77
{ !X[7m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b`GKGqbJ
//Utility.log(in.readLine()); pz{ ]O_px
sHeader=httpConnection.getHeaderFieldKey(i); &:}WfY!hX
if(sHeader!=null) J9J/3O Q=
{ XrXW6s;Z
if(sHeader.equals("Content-Length")) |v#rSVx
{ ~?iQnQYI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o>]z~^c
break; m*lcIa
} yI-EF)A@;
} oykb8~u}}
else 5CfD/}{:#I
break; U{@2kg-
} (*T$:/zIS
} 2P=~6(
catch(IOException e){e.printStackTrace ();} fL-$wK<p<
catch(Exception e){e.printStackTrace ();} Vhe$vH
u3Zu ~C
X<v1ES$
Utility.log(nFileLength); /z}b1m+
/*"pylm
>$a;+v
return nFileLength; g<$2#c}
} ?1LRR ;-x
Q^xk]~G$(
}Q6o#oZ
//保存下载信息（文件指针位置） v@J[qpX
private void write_nPos() ?jvuTS2
{ #\K"FE0PGz
try{ <LJb,l"
output = new DataOutputStream(new FileOutputStream(tmpFile)); mwZ)PySm)
output.writeInt(nStartPos.length); lPtML<a
for(int i=0;i<nStartPos.length;i++) Jm0.\[J
{ <29K! [
// output.writeLong(nPos); \#N?
output.writeLong(fileSplitterFetch.nStartPos); r'o378]=
output.writeLong(fileSplitterFetch.nEndPos); i If?K%M7
} H%}/O;C
output.close(); |tse"A5Z
} rrphOG
catch(IOException e){e.printStackTrace ();} QTN'yd?WE
catch(Exception e){e.printStackTrace ();} vbG&F.P
} 43O5|8o
i;juwc^n}
EiZa,}A
//读取保存的下载信息（文件指针位置） "-rqL
private void read_nPos() H_aG\
{ 5;HCNwX
try{ Zzb?Nbf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bUYjmb2g)
int nCount = input.readInt(); <:8Ew
nStartPos = new long[nCount]; YJ~mcaw
nEndPos = new long[nCount]; K7nyQGS
for(int i=0;i<nStartPos.length;i++) > +00[T
{ _]eyt_
nStartPos = input.readLong(); qmvQd8|XR
nEndPos = input.readLong(); N\rL ~4/
} MGre_=Dm_
input.close(); G68@(<<Z
} ;=6EBP%
catch(IOException e){e.printStackTrace ();} ,^DP
catch(Exception e){e.printStackTrace ();} *O_^C
} 3Y&4yIx
=([4pG
dt"&
private void processErrorCode(int nErrorCode) _,d<9 Y)
{ &rl;+QS
System.err.println("Error Code : " + nErrorCode); roBb8M|q
} ~_g{P3
@S>;t)\J
Ap4.c8f?Q-
//停止文件下载 | :id/
public void siteStop() )%lPKp4]
{ {2i8]Sp1d/
bStop = true; 33&\E- Q>
for(int i=0;i<nStartPos.length;i++) Hk(=_[S
fileSplitterFetch.splitterStop(); Mq'm TM
$TK= :8HY
a(ml#-M
} pUW7p
} RAuVRm=E
//负责部分文件的抓取 w8 `1'*HG
**FileSplitterFetch.java k_Y7<z0G
*/ es=OWJt^
package NetFox; Ki&a"Fu3
YBF$/W+=9|
<$otBC/%
import java.io.*; Htln <N
import java.net.*; & Y2xO
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1i'y0]f
public class FileSplitterFetch extends Thread { 1uB$@a\
k,f/9e+#
nr,Z0
String sURL; //File URL |{_>H'
long nStartPos; //File Snippet Start Position $J&c1
long nEndPos; //File Snippet End Position hhFO,
int nThreadID; //Thread's ID 7T t!hf
boolean bDownOver = false; //Downing is over ]]3rSXs2}J
boolean bStop = false; //Stop identical j]vEo~Bbh
FileAccessI fileAccessI = null; //File Access interface Nd{U|k3pL
a;M{-G
Fop +xR,Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,LxkdV
{ TY'61xWi
this.sURL = sURL; IOY7w"|LW
this.nStartPos = nStart; N]6t)Zv
this.nEndPos = nEnd; %qTIT?6'
nThreadID = id; #N'9 w .
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZmNNR 1%/
} p(8@
B;W%P.<.
jIVDi~Ld
public void run() 2A:h&t/|C
{ \xv(&94U
while(nStartPos < nEndPos && !bStop) G.v(2~QFd
{ {8`$~c
UT9u?
aql8Or1[
try{ a(ITv roM/
URL url = new URL(sURL); sf# px|~9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RVLVY:h|F
httpConnection.setRequestProperty("User-Agent","NetFox"); 4RYH^9;>K
String sProperty = "bytes="+nStartPos+"-"; @qj]`}Gx'
httpConnection.setRequestProperty("RANGE",sProperty); |r36iUHZS
Utility.log(sProperty); Id>4fF:o
t8rFn
D|Wlq~IpQ
InputStream input = httpConnection.getInputStream(); D}j`T
//logResponseHead(httpConnection); cC+2%q B
`|nCnT'
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byte[] b = new byte[1024]; 0Oc?:R'$
int nRead; $(]nl%<Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X{OWDy
{ !2Z"Lm
nStartPos += fileAccessI.write(b,0,nRead); 85;bJfY
//if(nThreadID == 1) SgehOu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )|^8`f
} jlFlhj:/I
di0@E<@1:
L$.3,./
Utility.log("Thread " + nThreadID + " is over!"); 0yq
bDownOver = true; vv{+p(~**O
//nPos = fileAccessI.write (b,0,nRead); 4KnBb_w
} zB~<@
catch(Exception e){e.printStackTrace ();} Y:t?W
} :zLf~W
} T<?kH
FO:L+&hr?>
^\?Rh(pu
//打印回应的头信息 s&-MJ05y
public void logResponseHead(HttpURLConnection con) aekke//y
{ *kg->J
for(int i=1;;i++) |iUC\F=-
{ g$?^bu dxv
String header=con.getHeaderFieldKey(i); Q{L:pce-
if(header!=null) ]+W){W=ai
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O=(F46 M
Utility.log(header+" : "+con.getHeaderField(header)); EwA*
else 4gsQ:3
break; 7bihP@I!
} ZDgT"53
} ^-[ I;P
=CZRX' +yN
qqf*g=f
public void splitterStop() wCruj`$
{ Zis,%XY
bStop = true; ^jwzCo-
} t'@mUX:-A
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t^FE]$,
} fx[&"$X
1BZ##xV*:G
3Z=yCec]
/* }6/M5zF3
**FileAccess.java H>+])~#
*//文件访问(定位，写) fe98Y-e
package NetFox; HbsNF~;
import java.io.*; Opcszq5n
jTIG#J)
W/>a 1
public class FileAccessI implements Serializable{ ['.])
1ruI++P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "g&f:[a/
RandomAccessFile oSavedFile; H~:oW~Ah
long nPos; -ZZJk-::
?{J1Uw<
4oiE@y&{4
public FileAccessI() throws IOException `cXLa=B)9
{ >RkaFcq
this("",0); 8X"4RyNSn
} 6{=U= *
sA|SOAn
fJc(
public FileAccessI(String sName,long nPos) throws IOException u@#%SX
{ $jE<n/8
oSavedFile = new RandomAccessFile(sName,"rw"); EOXkMr
this.nPos = nPos; otR7E+*3
oSavedFile.seek(nPos); IONo&~-l
} vjx'yh|
Yr_B(n
xsj,l@Ey
public synchronized int write(byte[] b,int nStart,int nLen) K6p\ >J
{ _uMG?Sbx
int n = -1; aO&{.DO2
try{ 9U6$-]J
oSavedFile.write(b,nStart,nLen); K {v^Y,B
n = nLen; _Fa\y ZX
} Jj>Rzj!m
catch(IOException e) N wk
{ bXF8V
e.printStackTrace (); D!,5j_,j%
} y1%OH#:duD
Q:megU'u
)LFbz#;Y
return n; I!*P' {lh
} B]G2P`sN
]A%3\)r
0j!3\=P$
} fGlvum
v9:J 55x
2[+.*Ef
/* B+Qf?1f
**SiteInfoBean.java EtN,
*/ %QEBY>|lI
package NetFox; N'ER!=l)
O|8@cO
yC\UT ~j/
public class SiteInfoBean { z.-yL,Rc`-
q=5aHH% |
+\Jo^\
private String sSiteURL; //Site's URL @e3+Gs
private String sFilePath; //Saved File's Path )y*&&q
private String sFileName; //Saved File's Name *mp:#'
private int nSplitter; //Count of Splited Downloading File D r(0w{5
%"mI["{
q*&H
public SiteInfoBean() 5WHz_'c
{//nSplitter的缺省值为5 zU&Iy_Ke.
//default value of nSplitter is 5 {im?tZ,
this("","","",5); V_J0I*Qa4
} k37?NoT
)v_Wn[Y.H
T"vf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g@>llve{
{ '=E;^'Rl
sSiteURL= sURL; 3oLF^^^g
sFilePath = sPath; kiM:(=5
sFileName = sName; IsI5c
this.nSplitter = nSpiltter; yHw @Z
m)p|NdTZc8
(dSYb&]
} EO)JMV?6
(1D1;J4g
A)]&L`s
public String getSSiteURL() vK)'3%
{ Zo&i0%S\E
return sSiteURL; vlkwWm
} $8eiifj
,@f"WrQ
GbQi3%
public void setSSiteURL(String value) #9|&;C5',!
{ d9S/_iCI
sSiteURL = value; 0o>C, `
} {FvFah
'/8/M{`s
<WIIurp
public String getSFilePath() b:F;6X0~Hl
{ iuY,E
return sFilePath; xS1n,gTA
} USyc D`
)v;O2z
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public void setSFilePath(String value) ^>l <)$s
{ -8qCCV&1i
sFilePath = value; 7zw0g~+
} ?P0b/g
L/:l>Ko>7
*zPqXtw!j
public String getSFileName() 3F|p8zPS
{ h}SZ+G/L
return sFileName; A3/[9}(U
} \09A"fs{
fVn4=d6X
Yg.[R] UC
public void setSFileName(String value) HZ'rM5Kq
{ F@Sk=l(
sFileName = value; z<55[~3
} 2@tnOs(*
9k;,WU(K<
aU(.LC
public int getNSplitter() oC|oh
{ z9S (<
return nSplitter; k)I4m.0a5
} 7/~=[#]*
iG54 +]
KUU{X~w
public void setNSplitter(int nCount) =OO4C
{ }lp37,
nSplitter = nCount; f1aZnl
} htbE Q NW
} I;'{X_9$a
Nt$4;
]YI9
/* eX#.Zt]
**Utility.java &qg6^&
*/ yx|iZhK0:}
package NetFox; GrG'G(NQ
gV.?Myy
^o5;><S]
public class Utility { rB".!b
1+*sEIC"
MuD ? KK
public Utility() phH@{mI
{ sA?8i:]O:
iKo2bC:.&
,1~zYL?
} 2|bt"y-5r
kfnh1|D=aY
//线程睡眠 Qq:}Z7 H
public static void sleep(int nSecond) Q$5t~*$`
{ 4\-11!'08
try{ m'}`+#C%)
Thread.sleep(nSecond); =%~- M
} &fB=&jc*j
catch(Exception e) }T$BU>z33N
{ K/*R}X
e.printStackTrace (); >niv>+!N
} m?Y-1!E0
} ~RVlc;W
< +*
//日志 =,zB|sjn
public static void log(String sMsg) PMTrG78p*
{ `W1uU=c
System.err.println(sMsg); KMi$0+
} GwF8ze+cH
$[A^8[//
+&7V@
public static void log(int sMsg) *l`yxz@U
{ |*t2IVwX
System.err.println(sMsg); f@;pN=PS
} g "Du]_,
} uEb:uENk'(
V7U*09 0*5
goiI*"6M
/* :N<Qk
**TestMethod.java _fk}d[q0
*/ gN<7(F
package NetFox; 6V$ )ym*F
82,^Pu
6Tmz!E0
public class TestMethod { s@:Yu
BGi'UL,
p7> 9 m
public TestMethod() % WDTnEm
{ ///xx/weblogic60b2_win.exe 1P"7.{
try{ W)ug%@)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WwsNAJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $H+X'1
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^J>m4`
fileFetch.start(); ng+sK
} <|k :%
catch(Exception e){e.printStackTrace ();} -Wa<}Tz
CP\[9#]:
YZfi-35@g
} c&bhb[
<b"^\]l
h'S0XU ;
public static void main(String[] args) 1y:fH4V
{ Fq~Zr;A
new TestMethod(); F1BvDplQ>G
} wowf1j-
} >QYx9`x&
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