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)); *M6M'>Tin
} dcYUw]
for(int i=0;i<nEndPos.length-1;i++) 0'c<EJ
{ W~Eq_J?I
nEndPos = nStartPos[i+1]; 5-5qm[.;
} +SZ#s:#SE
nEndPos[nEndPos.length-1] = nFileLength; W5EB+b49KM
} *.n9D
} n[AJ'A{
/ QSK$ZDC
/N{xFt/?
//启动子线程 ) l0=jb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )TVyRYZ1
for(int i=0;i<nStartPos.length;i++) %l5Uy??Z
{ 6(<M.U_ft
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [{f{E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /'!F \ kz
nStartPos,nEndPos,i); /$/\$f$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oC^-" (#
fileSplitterFetch.start(); V)_mo/D!D
} d=Q0/sI&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gV$Lfkz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q J@XVN4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q@r8V&-<
nEndPos = " + nFileLength); -8#Of)W
// fileSplitterFetch[nPos.length-1].start(); L+9a4/q
OI::0KOv
0waQw7 E
//等待子线程结束 +wS?Z5%mU
//int count = 0; n)^B0DnIk
//是否结束while循环 W29@`93
boolean breakWhile = false; bUU_NqUf*3
^W3xw[{
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while(!bStop) 83OOM;'
{ E{(7]Wri
write_nPos(); 87r#;ND
Utility.sleep(500); Y{f;qbEQH'
breakWhile = true; AdKv!Ta5b
$:{uF#
FJ}/g ?
for(int i=0;i<nStartPos.length;i++) -]A,SBs
{ f0O"Hm$Z
if(!fileSplitterFetch.bDownOver) vqJiMa j@Z
{ [Xg?sdQCI
breakWhile = false; jaFBz&P/#
break; '\[GquK;P
} doW_vu
} Rm&i"
if(breakWhile) [?.k8;k
break; Go=MG:`
>#)^4-e
8%U+y0j6b
//count++; Nd%,V
//if(count>4) |36d<b Io
// siteStop(); (w6024~
} &Plc
PI)lJ\
^R! qxSj
System.err.println("文件下载结束！"); &?#V*-;^
} zL+jlUkE
catch(Exception e){e.printStackTrace ();} VK[^v;
} %8DU}}Rj
Z[[qW f
a[1^)=/DM
//获得文件长度 9h9 jS~h
public long getFileSize() >DP9S@W
{ SRRqIQz
int nFileLength = -1; 4%Z!*W*
try{ 0L S,(v4
URL url = new URL(siteInfoBean.getSSiteURL()); tMR&>hM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &z+nNkr?yN
httpConnection.setRequestProperty("User-Agent","NetFox"); W.'#pd
zn@<>o8hU
sn+g#v9e
int responseCode=httpConnection.getResponseCode(); +vIpt{733
if(responseCode>=400) {P&{+`sov
{ Hbn%CdDk1
processErrorCode(responseCode); A,Wwt [Qw
return -2; //-2 represent access is error 3X=9$xw_
} Ub2t7MU
k Pi%RvuQ
jhgS@g=@ZC
String sHeader; A<fKO <d
ikX"f?Q;S2
DvB!-|ek
for(int i=1;;i++) _~/F-
{ (~q.YJ'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w$[&ejFb
//Utility.log(in.readLine()); Yd'Fhvo8
sHeader=httpConnection.getHeaderFieldKey(i); $P&{DOiKS
if(sHeader!=null) Y3=5J\d!a
{ wI8
if(sHeader.equals("Content-Length")) e=Ko4Ao2y
{ c<bV3,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .ZQD`SRrI
break; Ne#FBRu5
} N-Fs-uB
} o@:${>jw
else MdXOH$ps
break; ndg1E;>
} 0)F.Y,L
} E)sC:oO
catch(IOException e){e.printStackTrace ();} v=5H,4UMA
catch(Exception e){e.printStackTrace ();} -LzkM"
A0X'|4I
QTr)r;Tro
Utility.log(nFileLength); J>Pc@,y
!z?&
V6Z~#=EQ
return nFileLength; 3E9 )~$
} QiH>!Ssw
-&q@|h'
wN NXUW
//保存下载信息（文件指针位置） B|d-3\sn
private void write_nPos() e~oh%l^C72
{ pPL)!=o!
try{ d~#B,+
output = new DataOutputStream(new FileOutputStream(tmpFile)); $40G$w
output.writeInt(nStartPos.length); Lb]!TOl
for(int i=0;i<nStartPos.length;i++) B7x(<!B
{ 'Em3;`/C*+
// output.writeLong(nPos); >0F)^W?
output.writeLong(fileSplitterFetch.nStartPos); =csh=V@s
output.writeLong(fileSplitterFetch.nEndPos); ,3XlX(P
} i%@blz:_Y
output.close(); H 48YX(HI
} i+qtL3
catch(IOException e){e.printStackTrace ();} *kYJwO^
catch(Exception e){e.printStackTrace ();} |j}D2q=
} A_e&#O
c,CcKy;+
.;\uh$c
//读取保存的下载信息（文件指针位置） ($nQmr;t
private void read_nPos() !;3hN$5
{ <-6f}wN
try{ o5B]?ekpq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0tKVo]EK
int nCount = input.readInt(); 5GK> ~2c(
nStartPos = new long[nCount]; ;!S i_b2
nEndPos = new long[nCount]; ?K\r-J!Y
for(int i=0;i<nStartPos.length;i++) t:x"]K
{ _-|/$ jZ
nStartPos = input.readLong(); .oS[ DTn5S
nEndPos = input.readLong(); DD5cUlOSu
} T)MX]T
input.close(); M!YGv
} Pm7lP5
catch(IOException e){e.printStackTrace ();} T mK[^
catch(Exception e){e.printStackTrace ();} S5BS![-QK
} ).)^\
2= Y8$-
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private void processErrorCode(int nErrorCode) r^7eK)XA_
{ HV&i! M@T
System.err.println("Error Code : " + nErrorCode); f AY(ro9Q(
} 8e5imei
$D='NzE/
i>7]9gBm1q
//停止文件下载 .sjv"D"
public void siteStop() NR,R.N^[
{ NQxx_3*4O
bStop = true; e?7y$H-
for(int i=0;i<nStartPos.length;i++) eZ]>;5
fileSplitterFetch.splitterStop(); Yl&bv#[z
shD4";8*@
2]y Hxo/6
} /PVx
} bE,#,
//负责部分文件的抓取 AJ>$`=
**FileSplitterFetch.java J%]5C}v \
*/ #qu;{I#W3
package NetFox; 6?ky~CV
jM-7
DUSQh+C
import java.io.*; L&KL]n
import java.net.*; d/3bE*gr
bk0<i*ju7(
/2''EF';
public class FileSplitterFetch extends Thread { !UR3`Xk
![!,i\x
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String sURL; //File URL *0vRVlYf
long nStartPos; //File Snippet Start Position XqU0AbQ
long nEndPos; //File Snippet End Position p1[|5r5Day
int nThreadID; //Thread's ID Lf:#koaC
boolean bDownOver = false; //Downing is over 6B]i}nFH{+
boolean bStop = false; //Stop identical 7|"l/s9,
FileAccessI fileAccessI = null; //File Access interface <00nu'Ex1v
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^F qs,^~W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XTA:Y7"O
{ 2I3H?Lrx!m
this.sURL = sURL; #F6<N]i
this.nStartPos = nStart; vTo+jQs^
this.nEndPos = nEnd; @#*{* S8
nThreadID = id; 3kh!dL3D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KMG}VG
} jd2 p~W
KYyoN
L8Q/!+K
public void run() U\W$^r,
{ {3SK|J`
while(nStartPos < nEndPos && !bStop) _>)@6srC
{ #V)l>
y<~(}xsHh
:#\jx
try{ Lctp=X4
URL url = new URL(sURL); .76Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,S m?2<
httpConnection.setRequestProperty("User-Agent","NetFox"); WZjR^6
String sProperty = "bytes="+nStartPos+"-"; K47.zu
httpConnection.setRequestProperty("RANGE",sProperty); xb"e'Zh
Utility.log(sProperty); P8H2v_)X&
C?MKbD=K
\acGSW .c
InputStream input = httpConnection.getInputStream(); ~[kI![
//logResponseHead(httpConnection); 1FG"Ak}D
*3h_'3yo@
m&#D~
byte[] b = new byte[1024]; Y9 Bk$$#\
int nRead; &4%78K\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JaR!9GVN7
{ AFeFH.G6Jr
nStartPos += fileAccessI.write(b,0,nRead); .g7\+aiTUd
//if(nThreadID == 1) t8;nP[`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -O r\
} -<AGCiLz
[g}0.J`_
BlM(Q/z
Utility.log("Thread " + nThreadID + " is over!"); #)i+'L8
bDownOver = true; >I0 a$w
//nPos = fileAccessI.write (b,0,nRead); ?%lfbZ
} D(Q]ddUi'
catch(Exception e){e.printStackTrace ();} &os:h] C
} +.rE|)BPy
} (]VY==t~
<]_[o:nOP
G8MLg#
//打印回应的头信息 ]l3Y=Cl
public void logResponseHead(HttpURLConnection con) $"}[\>e*{
{ sPl3JP&s
for(int i=1;;i++) $Y\7E/T
{ .81 ~ K[
String header=con.getHeaderFieldKey(i); ?5^DQ|Hg ^
if(header!=null) dB QCr{7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )>iPx.hVSS
Utility.log(header+" : "+con.getHeaderField(header)); q0['!G%["
else .$Yp~
break; O%aHQL%Sz
} fQ-IM/z
} k!x`cp
l<(jm{q?u
"ub0}p4V
public void splitterStop() L$"pk{'
{ 5d# 73)x$
bStop = true; Z^%HDB9^
} ~zvZK]JoX
G_WHW(8
H;DjM;be
} )(c%QWz
Df]*S
'z=d&K
/* r;>.*60AT
**FileAccess.java Hq?dqg'%~
*//文件访问(定位，写) ~EvGNnTL
package NetFox; x cZF_elt7
import java.io.*; 9T1-{s R
n;:C{5
6JRFYgI
public class FileAccessI implements Serializable{ rd=+[:7L
I= cayR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vTWm_ed+^
RandomAccessFile oSavedFile; A^zd:h-
long nPos; +=nWB=iCb
gkca{BJ
}gE^HH'
public FileAccessI() throws IOException Qv]rj]%
{ >LPIvmT4D?
this("",0); xX Dj4j,
} Y'#uZA3KA
kP^=
U8,pe;/ln`
public FileAccessI(String sName,long nPos) throws IOException j6L(U~%
{ 6* 0vUy*"
oSavedFile = new RandomAccessFile(sName,"rw"); _?eT[!oO8
this.nPos = nPos; #)iPvV'
oSavedFile.seek(nPos); oR3t vw.
} A!}Ps"Z
gg Nvm
d'b9.ki\
public synchronized int write(byte[] b,int nStart,int nLen) (CJx Y(1K
{ PSyUC#;
int n = -1; VssWtL
try{ k-)Ls~#+
oSavedFile.write(b,nStart,nLen); ,3!4 D^
n = nLen; 8PWEQ<ev7>
} ,K|UUosS-#
catch(IOException e) 8`90a\t'Z
{ Nu'ox. V
e.printStackTrace (); rFp>A`TJ
} BPVOBL@
1jaK N*
r@ !
return n; e{*yV#Wl
} ofPv?_@
}02(Y!Gh
Wv~&Qh}
} n9R0f9:*
z*9 ke
9n"MNedqH
/* T8yMaC
**SiteInfoBean.java QV4FA&f&
*/ M|{NC`fa
package NetFox; )t CNp
:H+8E5
oArJ%Y>
public class SiteInfoBean { Jb-.x_Bf
~qK/w0=j
& x_ #zN]
private String sSiteURL; //Site's URL tf[)| /M
private String sFilePath; //Saved File's Path G&"O)$h
private String sFileName; //Saved File's Name p./0N.
private int nSplitter; //Count of Splited Downloading File ;WgUhA ;q
OB*V4Yv
?/myG{E
public SiteInfoBean() G.PRPl
{//nSplitter的缺省值为5 v *`M3jb
//default value of nSplitter is 5 @[Q`k=h$
this("","","",5); 9PMIF9"
} 'g3T'2"`5
mkl^2V13~
\N$)Q.M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A~ _2"
{ O~Bh(_R&
sSiteURL= sURL; vTTXeS-b
sFilePath = sPath; [AA}P/iW
sFileName = sName; i83[':
this.nSplitter = nSpiltter; d[XMQX
`*D"=5G+
MH9vg5QKp
} )4m`Ya,E3
PTqia!
r4<aEj;l
public String getSSiteURL() l5\V4
{ p@[ fZj
return sSiteURL; 8@RtL,[d
} q6<P\CSHy<
%l6E0[
;mvVo-r*q
public void setSSiteURL(String value) iRbe$v&N
{ "/mtuU3rt
sSiteURL = value; <HzL%DX
} ?_cOU@n
]vP}K
_A])q
public String getSFilePath() Vu=/<;-N
{ z^z`{B
return sFilePath; 8ZLHN',
} 7D4tuXUq2
@BF1X.4-+
#sDb611}#
public void setSFilePath(String value) `E?0jQ
{ [[zNAq)"
sFilePath = value; bLAHVi<.
} qLP/z
%.?V\l
a@d 15CN
public String getSFileName() 3?@6QcHl{
{ i7e6lC
return sFileName; f-71`Pyb
} L+(ng
%^vT7c>
WmN( (
public void setSFileName(String value) ]bY]YNt{7]
{ "aCAA#$J
sFileName = value; x3Y)l1gh
} 2\QsF,@`YU
q$mc{F($D
#/f~LTE
public int getNSplitter() Z0m`%(MJa
{ lM{fld
return nSplitter; ii-AE L
} +E_yEH7_)
% hvK;B?Y|
5<R m{
public void setNSplitter(int nCount) T9H*]LxK
{ 1/2cb-V
nSplitter = nCount; jWv'`c
} _Uq' N0U
} $i5J}
=4a:)g'
(rkg0
/* Wi'}d6c
**Utility.java q*3keB;X
*/ @XV&^l-
package NetFox; E<[ s+iX
A>1$?A8Q
kzDN(_<1
public class Utility { EN2SI+
UI+6\ 3
^hmV?a:Y
public Utility() r(46jV.sD:
{ 0!_?\)X
{YzCgf
'#V@a
} _>Raw
h<`aL;.g
//线程睡眠 Y(.e e%;,
public static void sleep(int nSecond) {;c'@U
{ :aej.>I0
try{ -}|L<~
Thread.sleep(nSecond); KBmOi
} % D
catch(Exception e) O {1" I
{ EIg~^xK
e.printStackTrace (); 'Oue 1[
} QLWnP-
} gHrs|6q9
^H3N1eC,`F
//日志 cMXv
public static void log(String sMsg) qTr P@F4`g
{ Q=`yPK>{$N
System.err.println(sMsg); ;7QXs39S
} -AdDPWn
0\P5=hD)K
>.d/@3 '
public static void log(int sMsg) b0{i +R
{ ?<EzILM
System.err.println(sMsg); si]VM_w6
} nn_O"fZi
} ]?tRO
-WlYHW
c$Kc,`2m7
/* #1DEZ4]jjY
**TestMethod.java e0zP LU}
*/ Z8#nu
package NetFox; 7~e,"^>T
&Q883A J
w\bwa!3Y
public class TestMethod { )4L2&e`k)(
^ `y7JXI:
nF<K84
public TestMethod() uL`#@nI
{ ///xx/weblogic60b2_win.exe !C#oZU]P
try{ f+cb83}n]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QxYm3x5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t0m;tb bg
SiteFileFetch fileFetch = new SiteFileFetch(bean); q? '4&
fileFetch.start(); .gx^L=O:
} Zv;nY7B
catch(Exception e){e.printStackTrace ();} h;gc5"mG
{aY) Qv}
_;j1g%
} 8tx*z"2S
NPT-d
DM^0[3XuV5
public static void main(String[] args) tYu<(Z(l)
{ 'x*C#mt
new TestMethod(); bY" zK',m
} xsZG(Tz
} x77L"5g
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