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)); *WE1;msr
} -`f04_@>d
for(int i=0;i<nEndPos.length-1;i++) _U{([M>;
{ w#N?l!5
nEndPos = nStartPos[i+1]; -o+74=E8[?
} $ n,Z
nEndPos[nEndPos.length-1] = nFileLength; F`nb21{0y&
} cst}Ibfi
} 7O`o ovW$
](eN@Xi&@
SEl#FWR
//启动子线程 u*7Z~R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !GW,\y
for(int i=0;i<nStartPos.length;i++) aZKOY
{ [ BT)l]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PY3ps2^K.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {B*W\[ns
nStartPos,nEndPos,i); 0F#>CmD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4f~["[*ea
fileSplitterFetch.start(); ES<{4<Kpx
} zq1mmFIO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hh~n#7w~IR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FuX 8v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dY"}\v6
nEndPos = " + nFileLength); ~|wos-nM
// fileSplitterFetch[nPos.length-1].start(); i)Lp7m z
[!^-J}^g~\
4yaxl\2
//等待子线程结束 T\VNqs@
//int count = 0; 55t\Bms{
//是否结束while循环 l7JY]?p
boolean breakWhile = false; 5cK@WE:
y[O-pD`
+pH@oFNK
while(!bStop) \Hqc9&0
{ aTGdmj!
write_nPos(); A=Dhod
Utility.sleep(500); Px M!U!t
breakWhile = true; kl1Y] ?z}
E3a_8@ZB7
<Fs-3(V+\
for(int i=0;i<nStartPos.length;i++) _,6f#t
{ 7GZgu$'
if(!fileSplitterFetch.bDownOver) P6Bl *@G
{ 6zIgQ4Bp24
breakWhile = false; kC$&:\Rh
break; u)Q;8$`
} 4R>zPEo
} o2-@o= F
if(breakWhile) }a&mY^
break; R7~Yw*#,
BO.dz06(Rw
rZ_>`}O2
//count++; gQ~5M'#
//if(count>4) g8ES8SM
// siteStop(); rZbEvS
} jnuY{0(&
[ neXFp}S
R.j1?\
System.err.println("文件下载结束！"); |m,VTViv;i
} ?p[O%_Xf
catch(Exception e){e.printStackTrace ();} Q\{x)|{$
} &"uV~AM
j1Yq5`ia
7.<^j[?
//获得文件长度 ;]CVb`d
public long getFileSize() 4ZT A>
{ y?30_#[dN
int nFileLength = -1; <Y'>F!?#
try{ (I{ $kB"p
URL url = new URL(siteInfoBean.getSSiteURL()); SQE[m9v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,6<"
httpConnection.setRequestProperty("User-Agent","NetFox"); 0"xPX#Cvj
rFJ[dz
%-;bu|
int responseCode=httpConnection.getResponseCode(); ID};<[
if(responseCode>=400) S"snB/
{ ,D80/2U^
processErrorCode(responseCode); `PI(%N
return -2; //-2 represent access is error i}TwOy<4s
} TUp%FJXA|
3Rl,GWK
ned2lC&'d>
String sHeader; t~K%.|'0
#~?kYCtC)
eIPG#A
for(int i=1;;i++) :ipoD%@
{ m4ApHM2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -E&e1u,Mi
//Utility.log(in.readLine()); ul5|.C
sHeader=httpConnection.getHeaderFieldKey(i); 9w;?-
if(sHeader!=null) 5b#QYu
{ s[3fqdLP&
if(sHeader.equals("Content-Length")) ,[48Mspp
{ H!IDV}dn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %4>x!{jwV
break; >tRHNB_
} i6no;}j
} nl/UdgI
else 8zQfY^/{M
break; !ZtSbOC'
} V*jsq[q=
} Ar, 9U9
catch(IOException e){e.printStackTrace ();} va{#RnU
catch(Exception e){e.printStackTrace ();} Ruh)^g
pe04#zQK
S;@ay/*~
Utility.log(nFileLength); ]j.k?P$U}
0=U70nKr
A{,n;;
return nFileLength; Lue|Plm[y
} 4\ $3
'u[%}S38
;\b@)E}
//保存下载信息（文件指针位置） (fk5'
private void write_nPos() "-i#BjZl/
{ }HZ{(?
try{ 5vZ#b\;#V
output = new DataOutputStream(new FileOutputStream(tmpFile)); @YL}km&Fw
output.writeInt(nStartPos.length); A|x:UQlu
for(int i=0;i<nStartPos.length;i++) ?F$6;N6x
{ lxb8xY
// output.writeLong(nPos); /NBTvTI
output.writeLong(fileSplitterFetch.nStartPos); D$Kea
output.writeLong(fileSplitterFetch.nEndPos); W3pQ?
} H/cTJ9zz
output.close(); h_ !>yK
} c{88m/;eP
catch(IOException e){e.printStackTrace ();} d!{7r7ob\
catch(Exception e){e.printStackTrace ();} :\}U9QfCw
} k 'zat3#f
,-#GX{!
Up?=m^
//读取保存的下载信息（文件指针位置） CB}BQd
private void read_nPos() ;El <%{(
{ BnEdv8\,&s
try{ rFd@mO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6}&^=^-
int nCount = input.readInt(); f~\Xg7<
nStartPos = new long[nCount]; 6M><(1fT
nEndPos = new long[nCount]; $-G`&oT
for(int i=0;i<nStartPos.length;i++) zNtq"T[
{ Lx+`<<_dJ
nStartPos = input.readLong(); 12gw#J/)9h
nEndPos = input.readLong(); fD6GQ*
} emWGIo
input.close(); q.oLmX
} M9"Sgb`g
catch(IOException e){e.printStackTrace ();} 3VP$x@AV
catch(Exception e){e.printStackTrace ();} J|j;g!fK
} M<oA<#IW
xdF guV8
|`]oc,1h@
private void processErrorCode(int nErrorCode) O~'FR[J
{ {\We72!
System.err.println("Error Code : " + nErrorCode); _X%Dw
} yq*JdTF
cf*zejbw
9)ea.Gu
//停止文件下载 <aVfJd/fT
public void siteStop() ,YlQK;
{ ^5)_wUf
bStop = true; B_~jA%0m'
for(int i=0;i<nStartPos.length;i++) TA)LPBG
fileSplitterFetch.splitterStop(); k^*$^;z
1X:&*a"5
ks:{TA27
} d.\PS9l
} l{EU_|q
//负责部分文件的抓取 `p|[rS>
**FileSplitterFetch.java (T;9us0
*/ 1ih*gJPpj
package NetFox; R+Lk~X^*l'
&z ksRX
5P\N"Yjx'
import java.io.*; Zz")`hUG
import java.net.*; tp+=0k2i
#: hVF/
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public class FileSplitterFetch extends Thread { pTET%)3
j`9Nwa
BTs0o&}e
String sURL; //File URL FfXZ|o$;
long nStartPos; //File Snippet Start Position `vEqj v
long nEndPos; //File Snippet End Position b`]M|C [5
int nThreadID; //Thread's ID *<dHqK`?C
boolean bDownOver = false; //Downing is over UPO^V:.R4
boolean bStop = false; //Stop identical ysth{[<5F3
FileAccessI fileAccessI = null; //File Access interface 5&(3A|P2
3ZN>9`
hho%~^bn(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4WG=m}X
{ #Q+R%p[D
this.sURL = sURL; =c]a {|W?
this.nStartPos = nStart; \\s?B K
this.nEndPos = nEnd; vzy!3Hiw
nThreadID = id; <(uTst
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `,m7xJZ?y
} E0jUewG
;+9(;
EE9vk*[@C
public void run() 3{q[q#"
{ LaT8l?q q
while(nStartPos < nEndPos && !bStop) v>:=w|.HC
{ ?%;B`2 nDR
L5C2ng>
&CO|Y(+
try{ }{=8&gA0
URL url = new URL(sURL); /&QQ p3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WVkG2
httpConnection.setRequestProperty("User-Agent","NetFox"); oek #^:pF
String sProperty = "bytes="+nStartPos+"-"; x/_dW
httpConnection.setRequestProperty("RANGE",sProperty); EqQ3=XMUL@
Utility.log(sProperty); xXPUrv5zO
"cQvd(kug
xH@'H?
InputStream input = httpConnection.getInputStream(); tx)OJY
//logResponseHead(httpConnection); #{~7G%GPY5
MC6)=0:KX
DUo0w f#D^
byte[] b = new byte[1024]; N*':U^/t4J
int nRead; j88=f#<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3B -NYJa
{ xfes_v""
nStartPos += fileAccessI.write(b,0,nRead); ?"u'#f_
//if(nThreadID == 1) )O -cw7 >
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O&=KlnI:
} FdM<;}6T
g~|y$T
.xo_}Vw
Utility.log("Thread " + nThreadID + " is over!"); 59~FpjJ
bDownOver = true; r hZQQOQ
//nPos = fileAccessI.write (b,0,nRead); c-`37. J
} r8F{A6iN
catch(Exception e){e.printStackTrace ();} h-,?a_
} b_ZNI0Hp@
} Seg#s.
k!9=
-B,cB
//打印回应的头信息 <B=[hk!
public void logResponseHead(HttpURLConnection con) {9Xm<}%u]]
{ gu!](yEgl
for(int i=1;;i++) [JZ h*A
{ Eh {up
String header=con.getHeaderFieldKey(i); *F|i&2
if(header!=null) /Go>5B>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f!EOYowW
Utility.log(header+" : "+con.getHeaderField(header)); avVmY|I
else wn{]#n=|l
break; InP[yFV-z
} ,Q+\h>I
} _~:j3=1&n
/[6:LnaE
[~!.a\[RW
public void splitterStop() ,5=kDw2
{ e7lo!(>#
bStop = true; Yu1QcFuy
} cNx \&vpd
i<J^:7
i'Wcf1I-=
} t(wZiK}
L%k67>
98h :X%
/* VZt;P%1;h
**FileAccess.java cB_pyX9Z
*//文件访问(定位，写) r)c+".0d^
package NetFox; G I&qwA
import java.io.*; An/>05|
gj[zka0_
{uEu>D$8
public class FileAccessI implements Serializable{ Z4\tY^NI
+{S Maq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L!?v BL
RandomAccessFile oSavedFile; 2 aew6~
long nPos; QN3qF|))
\)p4okpR
^4RO
public FileAccessI() throws IOException ~d&'Lp[3
{ u"*J[M~
this("",0); ^M[#^wv,
} ;,mBT[_ZO
?rAi=w&c
!~?W \b\:
public FileAccessI(String sName,long nPos) throws IOException v^<<[I2 C
{ i0VhG:O;
oSavedFile = new RandomAccessFile(sName,"rw"); #dHr&1(
this.nPos = nPos; r^fxyN2V
oSavedFile.seek(nPos); h\/^Aa0
} /L)?> tg
qwL0~I
Nz3zsP$
public synchronized int write(byte[] b,int nStart,int nLen) 2;3x,<Cg
{ M\9at\$
int n = -1; l#tS.+B7
try{ "L ^TT2
oSavedFile.write(b,nStart,nLen); 0W;q!H[G
n = nLen; jkZ_c!
} ,:c:6Y^
catch(IOException e) gkSGRshf
{ LQ~LB'L
e.printStackTrace (); Z`^ K%P=
} Z@<q/2).|
}m9S(Wal
f:n]Exsy
return n; _e;N'DZ
} O\LjtMF
mipi]*ZfXE
@QvfN>T
} 32M6EEmPG
5JO[+>
xWd9%,mDNR
/* }*xC:A%aS
**SiteInfoBean.java C<zx'lw!
*/ ~l;yr @
package NetFox; zfM<x,XdY
(K^YD K
nrxjN(9V%+
public class SiteInfoBean { #&;m<%
E6,`Ld;c[
OJnPP>
private String sSiteURL; //Site's URL [6Uudiw
private String sFilePath; //Saved File's Path QWU5-p9e8
private String sFileName; //Saved File's Name _K 4eD.
private int nSplitter; //Count of Splited Downloading File $ijx#a&O
8yY"x ['
71K\.[ =-
public SiteInfoBean() Na~g*)uT$
{//nSplitter的缺省值为5 +J\L4ri k
//default value of nSplitter is 5 p*A^0DN'Fn
this("","","",5); e}{8a9J<%_
} V`WI"HO+
gn-=##fT:i
(2\li{$e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `=_7I?
{ 0L3Bo3:k
sSiteURL= sURL; gubb .EY
sFilePath = sPath; U'JP1\
sFileName = sName; Y9z:xE
this.nSplitter = nSpiltter; s98: *o3
D<+ bzC
E#yCcC!wMY
} sV9{4T~#|
g @c=Bt$
&.|;yt%v
public String getSSiteURL() HV]~=Bw2I
{ + TPbIRA
return sSiteURL; T=hm#]
} 'US:Mr3
aRFi0h \
ucIVVT(u
public void setSSiteURL(String value) T{5M1r
{ 31 KDeFg
sSiteURL = value; eukX#0/^
} z6GL,wo#
cP}5}+
C=xo&I7
public String getSFilePath() 5Ws:Ei{R
{ 842Mydom
return sFilePath; E9~&f^f
} {Sd@u$&
f~n' Ki+'
RW|UQY#
public void setSFilePath(String value) <8F->k1"3
{ 2dp*>F0L
sFilePath = value; \t&n jMWpZ
} hW*^1%1
mI_ 6f~
E-*>f"<h
public String getSFileName() LaAgoarN
{ z9OMC$,V
return sFileName; [A.eVuV;+
} $S"zxEJJ Y
HnH2u;
BMtYM{S6
public void setSFileName(String value) QrrZF.
{ >o=axZNa
sFileName = value; (_s!,QUe
} D9@<#2-
~@a) E+LsF
W2X+NacD
public int getNSplitter() }[hDg6i
{ DbPBgD>Q
return nSplitter; AR[M8RA
} YV2pERl
l:kE^=6
J\Oc]gi\L
public void setNSplitter(int nCount) L@^!(
{ <9MQ
nSplitter = nCount; !T&u2=`D
} _3FMQY(
} p!rGPyGC
>E2WZHzd2
6i?kkULBS
/* 52q!zx E
**Utility.java q(${jz4w
*/ K7d1(.
package NetFox; 4F 6ju6w
Ri%Of:zZ
"~i#9L/H
public class Utility { :#"OCXr
U8.0L
$D2Ain1
public Utility() *(XgUJq+
{ c+\Gd}IJq
QKL]O*
~k:>Xo[|O
} =-a?oH-
y+~Aw"J}
//线程睡眠 4=#QN
public static void sleep(int nSecond) .bY1N5=sz
{ Xf'
try{ ]>]H:NEq
Thread.sleep(nSecond); H]]>sE
} `(w kqa
catch(Exception e) %CfTqbB
{ _tg3%X]
e.printStackTrace (); "p_[A
} 5"Xo R)
} 6b1 Uj<
mhHm#
//日志 ::Ve,-0
public static void log(String sMsg) dsft=t8s
{ =}1~~
System.err.println(sMsg); B1AF4}~5
} u{y5'cJ{
{3yws4
RWEgUDX^/
public static void log(int sMsg) lf7H8k,-
{ rO2PbF3
System.err.println(sMsg); tI(t%~>^
} r%?}5"*
} jl?y}
=K&q;;h
M. UUA?d<'
/* vA $BBXX
**TestMethod.java D\i8rqU/l
*/ jind!@}!
package NetFox; ,hcBiL/
?)ZLxLV::
h: (l+jr
public class TestMethod { kv`3Y0R-"
R|^t~h-
BtDgv.;GH
public TestMethod() ohG43&g~
{ ///xx/weblogic60b2_win.exe zJym`NF
try{ ?eZ"UGZg'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); boHm1hPKS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TuT=
SiteFileFetch fileFetch = new SiteFileFetch(bean); @zpHemdB
fileFetch.start(); m0K2p~
} "nS{ ;:
catch(Exception e){e.printStackTrace ();} vcUM]m8k
-1Ki7|0,
z@40g)R2A
} SZ1pf#w!
_[6+FdS],
FV<^q|K/(]
public static void main(String[] args) l[OQo|_
{ )I1V2k$n
new TestMethod(); i2Iu2
} sZ(Q4)r
} ?_`P;}4#
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