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)); B~k{f}
} '3U,UD5EG
for(int i=0;i<nEndPos.length-1;i++) _ Pzgn@D
{ H! 5Ka#B
nEndPos = nStartPos[i+1]; 8+dsTX`|S
} R+0gn/a[G
nEndPos[nEndPos.length-1] = nFileLength; P^=B6>e
} 0^Vw^]w
} $[ S 33Q
!vRN'/(Vyu
u{&=$[;
//启动子线程 7P}l^WX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Jk`Jv;
for(int i=0;i<nStartPos.length;i++) kjp~:Bg_(
{ 5de1rB|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WRkuPj2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A^+kA)8
nStartPos,nEndPos,i); -T1R}ew*t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F.x7/;
fileSplitterFetch.start(); =WI3#<vDG
} }Hg\ tj}i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R!7--]Wcg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <dE~z]P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S LeA,T
nEndPos = " + nFileLength); -6uLww=w4
// fileSplitterFetch[nPos.length-1].start(); 9<y{:{i
l l*g *zt3
+PWm=;tcC
//等待子线程结束 @HB=hN
//int count = 0; -c1-vGW/
//是否结束while循环 Yc-5Mr8*,
boolean breakWhile = false; E&z^E2
FZ<6kk4
ib 'l:GM
while(!bStop) 2-qWR<E
{ 42hG}Gt
write_nPos(); f%t N2k
Utility.sleep(500); c)N_"#&
breakWhile = true; ".Q]FE@>
g8&& W_BI
% q!i
for(int i=0;i<nStartPos.length;i++) uEr.LCAS
{ R\n@q_!`X
if(!fileSplitterFetch.bDownOver) PBW_9&d
{ 6tP!(
breakWhile = false; muF&t'k
break; ow 6\j:$?
} -L2 +4
} (QqeMG,Y
if(breakWhile) J0e^v
break; :N^B54o%6
-{JReplc
y c<%f
//count++; g(s}R ?
//if(count>4) rk&oKd_&i
// siteStop(); 2uY:p=DxG9
} xJ:Am>%\^
A>F&b1
X"g,QqDD
System.err.println("文件下载结束！"); cdH`#X
} -gC%*S5&
catch(Exception e){e.printStackTrace ();} +kxk z"fP
} H3d|eO4+W
K)`R?CZ:s
=? q&/ cru
//获得文件长度 I|Hcs.uW
public long getFileSize() 1 rbc}e
{ HlkjyD8
int nFileLength = -1; &.z-itiV
try{ *"F*6+}w"
URL url = new URL(siteInfoBean.getSSiteURL()); h<?I?ZR0$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "FGgem%9
httpConnection.setRequestProperty("User-Agent","NetFox"); _h=h43'3
s:,fXg25J
GO][`zZJ]
int responseCode=httpConnection.getResponseCode(); XM?c*,=fu
if(responseCode>=400) p((.(fx
{ P??pWzb6HH
processErrorCode(responseCode); ?H!&4o
return -2; //-2 represent access is error }c4F}Cy
} Y%]g,mG
e2;=OoBK
7|"G 3ck
String sHeader; 98<^!mwF
WYCDEoqU2
_J"J[$
for(int i=1;;i++) 3+U2oI:I
{ [ CU8%%7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T%}x%9VO7
//Utility.log(in.readLine()); d]=>U^K
sHeader=httpConnection.getHeaderFieldKey(i); +`m0i1uI3
if(sHeader!=null) &|zV Wl
{ J(XK%e[8
if(sHeader.equals("Content-Length")) ]Qx-f* D6
{ -M[BC~!0;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W`wT0kP?*]
break; F 'HYWH0?
} <sGioMr
} W$" >\A0%
else J/vcP
break; AucX4J<
} xxdxRy9/
} 1BzU-Ma
catch(IOException e){e.printStackTrace ();} WPu%{/[
catch(Exception e){e.printStackTrace ();} z5[Qh<M
5M3)7
i2Gh!5]f
Utility.log(nFileLength); ,?GAFgK:
#: ,X^"w3
<lSo7NkR
return nFileLength; DB] ]6
} d k|X&)xTJ
[vCZD8"Y8
mP)im]H
//保存下载信息（文件指针位置） ~BI! l
private void write_nPos() B"RZpx
{ iF+50d
try{ 90$`AMR
output = new DataOutputStream(new FileOutputStream(tmpFile)); X^0jS
output.writeInt(nStartPos.length); G{|FV m
for(int i=0;i<nStartPos.length;i++) jBd9 $`
{ :4238J8
// output.writeLong(nPos); ."v&?o Ck]
output.writeLong(fileSplitterFetch.nStartPos); ou&7v<)x4
output.writeLong(fileSplitterFetch.nEndPos); kca Y
} N%?8Bm~dP
output.close(); K9'AYFse
} hN:2(x
catch(IOException e){e.printStackTrace ();} FkoN+\d
catch(Exception e){e.printStackTrace ();} LGVGr
} Tj=g[)+K
GwlAEhP
cFG%Ew@
//读取保存的下载信息（文件指针位置） ;\+A6(GX{
private void read_nPos() *icxK
{ +)d7SWO6]!
try{ Wuji'sxTs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MXpj_+@
int nCount = input.readInt(); m=IA/HOR^
nStartPos = new long[nCount]; \RTXfe-`
nEndPos = new long[nCount]; W;wu2'
for(int i=0;i<nStartPos.length;i++) nHL(v
{ zd[cp@
nStartPos = input.readLong(); Lec%kC
nEndPos = input.readLong(); }EHmVPe
} DfP vi1
input.close(); +f?xVW<h
} gMZ?MG
catch(IOException e){e.printStackTrace ();} 4,R1}.?BzJ
catch(Exception e){e.printStackTrace ();} .gHL(*1P
} ;0\
j2{ '!
%OsV(7
private void processErrorCode(int nErrorCode) BhJ~jV"
{ YJrZ
System.err.println("Error Code : " + nErrorCode); X?.LA7)CK
} FY]z*=
uH!;4@uI
C{):jH,Rf
//停止文件下载 -n$fh::^
public void siteStop() >@d=\Kyu
{ $X;fz)u
bStop = true; =zW.~(c{
for(int i=0;i<nStartPos.length;i++) ^k?Ig.m
fileSplitterFetch.splitterStop(); <:BhV82l
:ITz\m
}mw31=2bD
} "ealYveu
} 4E& 3{hnp
//负责部分文件的抓取 L$FLQyDR
**FileSplitterFetch.java cB7=4:U
*/ GP/3r[MH
package NetFox; 7nHlDPps)
"VcG3.
t1 .6+
import java.io.*; wBXgzd%L
import java.net.*; KArnNmJ9
eESJk14
-3c?Yaf"
public class FileSplitterFetch extends Thread { 5fBW#6N/
hU `H\LE
cS ;hyLd
String sURL; //File URL 9Kyr/6w4-k
long nStartPos; //File Snippet Start Position Re b^w,
long nEndPos; //File Snippet End Position PF- sb&q
int nThreadID; //Thread's ID a8%/Xwr~
boolean bDownOver = false; //Downing is over '?k*wEu
boolean bStop = false; //Stop identical B9^@]
FileAccessI fileAccessI = null; //File Access interface Jj'~\j
/Et:',D
#3u;Ox
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @4b"0ne}h
{ )vk$]<$
this.sURL = sURL; E-irB/0
this.nStartPos = nStart; S-:l 60.
this.nEndPos = nEnd; Y0U<l1(|
nThreadID = id; ^YKEc0"w(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }45&s9m=
} ([ xYOxcp5
W%.Kr-[?`o
^r$P&}Z\b
public void run() mi3yiR
{ e p;_'
while(nStartPos < nEndPos && !bStop) C;;dCsiV5
{ pFD L5
Z%MP:@z
qgU$0enSs
try{ VHB5
URL url = new URL(sURL); A=|&N%lP'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O&irgc!
httpConnection.setRequestProperty("User-Agent","NetFox"); %Ow,.+m
String sProperty = "bytes="+nStartPos+"-"; 1NT@}j~/
httpConnection.setRequestProperty("RANGE",sProperty); dM7-,9Vc
Utility.log(sProperty); Vo"\nj
f|_iHY
t*^Q`V wQ
InputStream input = httpConnection.getInputStream(); m^Btr
//logResponseHead(httpConnection); fXBA P10#
_y),C
!B(6
byte[] b = new byte[1024]; 4RNB\D
int nRead; (~N&ov
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Yt7R[|
{ a!P?RbW
nStartPos += fileAccessI.write(b,0,nRead); TgVvp0F;
//if(nThreadID == 1) .QzHHW4&0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X5527`?e
} *^Wx=#w$V
2RidI&?c<
-}{c;pT
Utility.log("Thread " + nThreadID + " is over!"); >ZuWsA0q
bDownOver = true; NS;,(v{*N
//nPos = fileAccessI.write (b,0,nRead); X[}5hZcX
} uG2Hzav
catch(Exception e){e.printStackTrace ();} J(VJMS;_
} c:4M|t=
} *K'(t
+EJIYvkFm
8AVM(d@
//打印回应的头信息 ?x"<0k1g
public void logResponseHead(HttpURLConnection con) X4lz?Y:*
{ TP[<u-@G
for(int i=1;;i++) kc\^xq~
{ ,l#Ev{
String header=con.getHeaderFieldKey(i); %<DXM`Y
if(header!=null) _1f!9ghT\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kb]PWOz
Utility.log(header+" : "+con.getHeaderField(header)); ksT2_Ic
else lh&Q{t(+8
break; M;,Q8z%
} _K3?0<=4
} NSUw7hnWvz
k/?5Fs!#
1j "/}0fx
public void splitterStop() I1S*=^Z_U
{ DDyeNuK
bStop = true; V.6h6B!vB
} \vXo~_-&
c%yhODq/
x-,+skZs
} +;tXk
U@!e&QPn
+LCpE$H
/* nc!P !M
**FileAccess.java /mX/ "~
*//文件访问(定位，写) _$]3&P
package NetFox; ;tP-#Xf
import java.io.*; $+!/=8R)
V<Q''%k
9`81br+~
public class FileAccessI implements Serializable{ UmcPpZ
:[|4Zn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o<`Mvw@Z
RandomAccessFile oSavedFile; /qa{*"2Qo
long nPos; YD_hg#=n
4!64S5(7t
lM~ 3yBy
public FileAccessI() throws IOException OaY.T
{ P3UU~w+s
this("",0); OOn{Wp
} t<wjS|4
U,Ya^2h%
(pN:ETB
public FileAccessI(String sName,long nPos) throws IOException 4t]ccqX*{
{ 'hN_H}U
oSavedFile = new RandomAccessFile(sName,"rw"); mN?y\GB
this.nPos = nPos; N"1o> !
oSavedFile.seek(nPos); d(9ZopJrQ
} @&#k['c
kVR_?ch{
YEH /22
public synchronized int write(byte[] b,int nStart,int nLen) F_.rLgGY
{ CT,PQ
int n = -1; Yl4XgjG
try{ Hd]o?q\
oSavedFile.write(b,nStart,nLen); .\XFhOsa
n = nLen; ^3"~ T
} /k8Lu+OJ
catch(IOException e) .}!"J`{W
{ Z"j #kaXA
e.printStackTrace (); p5`iq~e9
} BdBwfH%:
,Ta k',
C+o1.#]JM
return n; (7Su{tq
} P/i{_r
qF'lh
oGt,^!V1
} 1T&NU
)` ~"o*M
Y;2WY0eq
/* $eHYy,,
**SiteInfoBean.java >NLG"[\
*/ x*>@knP<-
package NetFox; U'~M(9uv:
J5dwd,FQ
)Fk*'6
public class SiteInfoBean { 9o%k [n
e1cqzhI=nA
[$\KS_,Mn
private String sSiteURL; //Site's URL vH1IVF"DS
private String sFilePath; //Saved File's Path ^UU@7cSi|G
private String sFileName; //Saved File's Name B xAyjA6
private int nSplitter; //Count of Splited Downloading File `/ <y0H
atr0hmQ
u@&e{w~0
public SiteInfoBean() 0O>T{<
{//nSplitter的缺省值为5 Qe,jK{Y< -
//default value of nSplitter is 5 o3b=)E
this("","","",5); X1DE
} r2ZSkP.
an q1zH
9w3KAca
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g[G+s4Nv
{ L%S(z)xX3
sSiteURL= sURL; gXJtk;
sFilePath = sPath; }%75Wety
sFileName = sName; z)%Ke~)<\@
this.nSplitter = nSpiltter; l,fwF ua
&{4KymB:
Q|KD$2rB
} /]U),LbN
8*zORz
fQm3D%
public String getSSiteURL() / R-1s
{ z}BuR*WSY{
return sSiteURL; *.us IH2
} B:)PUBb
P5Bva
G*s5GG@Z.
public void setSSiteURL(String value) , wXixf2
{ H0(.p'eN
sSiteURL = value; ^O0trM>h-
} @`mr|-Rp@
J]W? Vvv
vzX%x ul
public String getSFilePath() >O]u4G!
{ J,G/L!Bp
return sFilePath; .R^R32ln
} QXI#gA =
&3Y"Zd!
_xsHU`(J#
public void setSFilePath(String value) OYyF*F&S[
{ C5,\DdCX,
sFilePath = value; ,NAwSmocVP
} 3>>Ca;>$
KzZfpdI92
!L[$t~z
public String getSFileName() F4NMq&_
{ 'QSj-
return sFileName; =Q,D3F -+f
} bV$g]->4e
uK%0,!q
?%cZO"
public void setSFileName(String value) &8;Fi2}(L
{ w-];!;%
sFileName = value; Xv+!)j<
} )Vz=:.D
qXprD.; }
qP[_!C.
public int getNSplitter() o\<JG?P
{ xsIfR3Ze9
return nSplitter; J``5;%TJp
} eN'b"_D
6W<Ig;
}S"qU]>8a
public void setNSplitter(int nCount) a|5<L
{ !q~f;&rg
nSplitter = nCount; mGpBj9jr1
} s"`Oj5
} (zPsA
_b`/QSL
"r=p/"4D
/* J8B0H1
**Utility.java DaBy<pGb?
*/ qgs:9V xF
package NetFox; |hS^eK_
[{0/'+;9
hWiHKR]
public class Utility { 1@N4Y9o
aA -j
KBoW(OP4'
public Utility() vjVa),2
{ 3!h3flE
%(S!/(LWW
]|N"jr?7H
} .E9$j<SP-
{`Z=LLL
//线程睡眠 hltUf5m'b
public static void sleep(int nSecond) _&N:%;9uD
{ v8 II=9
try{ RT2&^9-
Thread.sleep(nSecond); _PLZ_c:O
} *'BI=*`
catch(Exception e) tI
{ v+i==vxg
e.printStackTrace (); ]M 2n%9
} M<x><U#]A
} ?y@;=x!'
|RBL5,t^
//日志 a# Uk:O!
public static void log(String sMsg) J[UTn'M8]
{ #^_7i)=~
System.err.println(sMsg); F ~e}=Nb
} *l@T 9L[M'
Odm1;\=Eg+
@.=2*e.z|b
public static void log(int sMsg) VrKLEN\
{ MH]?:]K9V
System.err.println(sMsg); 5! ]T%.rM
} " ;o,D
} ,D.@6bJW
fc<,kRp
OTEx9
/* j'XND`3
**TestMethod.java w[uwhd
*/ uZP(-}
package NetFox; Qqd+=mgc
}5d|y*
FC4hvO(/m
public class TestMethod { dCWq~[[
T2to!*T
_AiGD
public TestMethod() >p3S,2SM
{ ///xx/weblogic60b2_win.exe h2aO-y>K
try{ ?#:!!.I:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L(/wsw~y*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [3]h(D
SiteFileFetch fileFetch = new SiteFileFetch(bean); (#Xgfb"S3
fileFetch.start(); TrVQ]9;jWk
} kqCUr|M.P
catch(Exception e){e.printStackTrace ();} $cGV)[KWp@
`J}FSUn\
` kZ"5}li
} gT|&tTS1@
^izf&W.j!
c-[IgX e
public static void main(String[] args) WWA!_
{ )IuwI#pm
new TestMethod(); Lf,C50
} 7':<I-Fm
} ,*wj~NE
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