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)); PI$i_3N
} 9%21Q>Y?b
for(int i=0;i<nEndPos.length-1;i++) g :B4zlKG
{ )^P54_2
nEndPos = nStartPos[i+1]; 2oc18#iG(
} jLn#%Ia}
nEndPos[nEndPos.length-1] = nFileLength; AMB{Fssz
} sWse (_2
} z80(+`
y5c\\e
#?\(l%
//启动子线程 7MZH'nO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,j{tGj_
for(int i=0;i<nStartPos.length;i++) EF$ASNh"
{ UsA fZg8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E,ilJl\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5|jY
nStartPos,nEndPos,i); a0k;way
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Hl{(v\HO
fileSplitterFetch.start(); :B=Gb8?
} &:ZR% f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %nUN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S W6oaa81
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K0oF=|
nEndPos = " + nFileLength); xR$T/]/
// fileSplitterFetch[nPos.length-1].start(); f`;w@gR`=
[f {qb\
X}]A_G
//等待子线程结束 x'?p?u~[
//int count = 0; SAitufS
//是否结束while循环 "~.4z,ha
boolean breakWhile = false; Yh^8 !
RiAMW|M"C
$"( 15U
while(!bStop) 0=U|7%dOL
{ $8(QBZq
write_nPos(); a_0I)' ?
Utility.sleep(500); )l! /7WKY
breakWhile = true; u^MRKLn
:_xfi9L~W0
7f k)a
for(int i=0;i<nStartPos.length;i++) mrsmul{
{ }pf|GdL
if(!fileSplitterFetch.bDownOver) pl[@U<8aw
{ XUVj<U
breakWhile = false; 31 <0Nw;l
break; S"?fa)~
} N<b2xT
} IUEpE9_
if(breakWhile) L58#ri=
break; lw~ V
zx$1.IM"4
du~V=%9
//count++; \6MM7x(U3
//if(count>4) 4sORp^t'Q
// siteStop(); dG0zA D
} k18v{)i~
JF~9efWe>
p/nATvh$
System.err.println("文件下载结束！"); o o'7
} <[ 2?~s
catch(Exception e){e.printStackTrace ();} ZI1]B944ni
} #C.
#Ff8_xhP2
<%d!Sk4
//获得文件长度 xk/-TXB 0
public long getFileSize() {irc~||4
{ &b^~0Z
int nFileLength = -1; gjz-CY.hz
try{ _()1"5{
URL url = new URL(siteInfoBean.getSSiteURL()); n6t@ e^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?ZGsh7<k
httpConnection.setRequestProperty("User-Agent","NetFox"); U$OI]Dd9
o9sPyY$aQ
R ai 04
int responseCode=httpConnection.getResponseCode(); z7sDaZL?_
if(responseCode>=400) z k}AGw
{ >EFWevT{
processErrorCode(responseCode); p[xGL } +\
return -2; //-2 represent access is error yZ[g2*1L
} N>*+Wg$Ne
#\=7A
_A!Fp0}`
String sHeader; U+>M@!=
_4)z:?G5
LWTPNp:"{w
for(int i=1;;i++) z7AWWr=H
{ 8TAJ#Lm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <B0f
//Utility.log(in.readLine()); Xj{fM\,"9
sHeader=httpConnection.getHeaderFieldKey(i); M!i|,S
if(sHeader!=null) \5!7zPc
{ BK=w'1U
if(sHeader.equals("Content-Length")) ToPjBvD
{ RzL(Gnb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |BZrV3;H
break; =+wd"Bu
} jZkc yx
} NNbdP;=:u
else %aw.o*@:
break; gELG/6l
} kD;pj3o&"2
} ^Z;zA@[wt
catch(IOException e){e.printStackTrace ();} AnX<\7bc}
catch(Exception e){e.printStackTrace ();} ZfqN4
ARf{hiV6Wt
'n-y*f
Utility.log(nFileLength); /u.ZvY3,
3BCD0 %8
jMTM:~0N
return nFileLength; ]7K2S{/o{
} 7`A]X,:
<nqv)g"u0
lTq"j?#E]m
//保存下载信息（文件指针位置） YcDKRyrt
private void write_nPos() }kr?+)wB
{ ;XawEG7" U
try{ T#3@r0M
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0&]1s
output.writeInt(nStartPos.length); :(X3?%
for(int i=0;i<nStartPos.length;i++) "EMW'>&m
{ T{3nIF
// output.writeLong(nPos); 7>j~;p{
output.writeLong(fileSplitterFetch.nStartPos); 5a_8`csu
output.writeLong(fileSplitterFetch.nEndPos); CKK}Z;~:
} ]r|oNGD)G
output.close(); RM `qC
} $+7uB-KsU
catch(IOException e){e.printStackTrace ();} L0!CHP/nRS
catch(Exception e){e.printStackTrace ();} W!? h2[
} Qw'905;(
\*e\MOp6
BXYH&2]Q
//读取保存的下载信息（文件指针位置） S=mqxIo@m
private void read_nPos() m!%aB{e
{ c'eZ-\d{
try{ _;;Zz&c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m:?"|.]
int nCount = input.readInt(); (XVBH1p"
nStartPos = new long[nCount]; \/Mx|7<
nEndPos = new long[nCount]; ,oA<xP-*
for(int i=0;i<nStartPos.length;i++) esnq/
{ bqAW
nStartPos = input.readLong(); [#q>Aq$11
nEndPos = input.readLong(); W~ET/h
} l^Rb%?4Z
input.close(); LQ# E+id&
} kzRJzJquP
catch(IOException e){e.printStackTrace ();} I8 :e`L
catch(Exception e){e.printStackTrace ();} s4"OsgP+
} JaRsm'SIk~
n^T,R
G7nhUg
private void processErrorCode(int nErrorCode) [ncK+rGAc
{ qy3@> 1G
System.err.println("Error Code : " + nErrorCode); =,(TP
} MY@&^71i4
a^p#M
yk`qF'4]
//停止文件下载 ?FAI@4
public void siteStop() RTm/-6[N
{ 9dhEQ=K{3
bStop = true; r!2U#rz
for(int i=0;i<nStartPos.length;i++) w]0@V}}u$o
fileSplitterFetch.splitterStop(); [Vo5$w
V9<`?[Usv
RPW46l34
} $mn0I69
} D=#RQ-
//负责部分文件的抓取 !=YKfzE
**FileSplitterFetch.java fu^W# "{
*/ 4D0jt$==
package NetFox; :dSda,!z
LTTMa-]Yy
fgdR:@]-
import java.io.*; tR|dnC4U
import java.net.*; a]T:wUYG'
h)HEexyRg
Kgu8E:nL
public class FileSplitterFetch extends Thread { sCFxn
i3,IEN
+P2oQ_Fk`9
String sURL; //File URL !5o j~H
long nStartPos; //File Snippet Start Position \_ 3>v5k|
long nEndPos; //File Snippet End Position IW0S*mO$
int nThreadID; //Thread's ID n:%4SZn
boolean bDownOver = false; //Downing is over 9D3{[
boolean bStop = false; //Stop identical /kbU<
FileAccessI fileAccessI = null; //File Access interface GXtK3YAr
aj1]ZT\
vQljxRtW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7 $e6H|j@
{ 0ra'H/>Ly
this.sURL = sURL; gw]%: WeH
this.nStartPos = nStart; N,Eap KG
this.nEndPos = nEnd; mn/)_1',
nThreadID = id; +i&<`ov
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K& #il
} t*gZcw5 r
SO$Af!S:bB
!ZYPz}&N_
public void run() `x[Is$
{ %f;dn<m=c
while(nStartPos < nEndPos && !bStop) Re,;$_6o
{ /;*_[g5*i
DiFYVR<@
}KI/fh
try{ .<"XE7
URL url = new URL(sURL); =nhY;pY3u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [7Lr"
httpConnection.setRequestProperty("User-Agent","NetFox"); dHc\M|HCC
String sProperty = "bytes="+nStartPos+"-"; vYed_'_
httpConnection.setRequestProperty("RANGE",sProperty); !D#"+&&G8
Utility.log(sProperty); uuC ["Z
Jka>Er
{zwH3)|Hn
InputStream input = httpConnection.getInputStream(); SYCL\b
//logResponseHead(httpConnection); -&1(~7
nkW})LyB\
\MP~}t}c
byte[] b = new byte[1024]; W[ l
int nRead; .XJ'2yKof
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1<YoGm&
{ )+G"57p
nStartPos += fileAccessI.write(b,0,nRead); vMTf^V
//if(nThreadID == 1) V`Cyx^P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tbFAVGcAM
} pU$k{^'UK
sQJ\{'g
]r Uj<[O
Utility.log("Thread " + nThreadID + " is over!"); 'Gy`e-yB
bDownOver = true; _U s"
//nPos = fileAccessI.write (b,0,nRead); F]\ Sk'}&
} t'n@yX_
catch(Exception e){e.printStackTrace ();} 3UZd_?JI[^
} x-BU$bx5
} I/O3OD
FK _ ZE>
*w+'I*QSt~
//打印回应的头信息 2q~.,vpP
public void logResponseHead(HttpURLConnection con) \SWTP1
{ *uc/| c
for(int i=1;;i++) IO\l8G
{ ^A$=6=CX
String header=con.getHeaderFieldKey(i); #e'>9T
if(header!=null) m$T5lKn}U?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gHg=G+Q@
Utility.log(header+" : "+con.getHeaderField(header)); %?ElC
else fVbjU1N
break; $n\Pw
} ]auvtm-[
} 'nCVjO7o
AV5={KK
i,6OMB $
public void splitterStop() Ykxk`SJ
{ c1#0o)q*7
bStop = true; Xw?DN*`L
} nK>CPqB^(
YX$(Sc3.6
)~ (*q
} $ev+0m_
Bqf(6\)F
O^L]2BVC
/* L;Ff(0x|
**FileAccess.java .shi?aWm
*//文件访问(定位，写) L@N%S Sf
package NetFox; D=e*rrL7a
import java.io.*; 4V@%Y,:ee
Q:A#4Z
rzfLp
public class FileAccessI implements Serializable{ q$:1Xkl
RkYdK$|K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y%KowgP\
RandomAccessFile oSavedFile; `"5Ub,~
long nPos; +A}t_u3<
fap`;AuwK
r w?wi}}gn
public FileAccessI() throws IOException $L*gtZ
{ ,PeR}E;c
this("",0); ~y<0Cc3Vs
} thjr1y.e
tOIqX0dWd
on_h'?2
public FileAccessI(String sName,long nPos) throws IOException 3#7V1
{ r2-iISxg+
oSavedFile = new RandomAccessFile(sName,"rw"); nBy-/BU&
this.nPos = nPos; E'08'8y
oSavedFile.seek(nPos); )U&9d
} 67j kU!
^ja]e%w#
-CvmZ:n
public synchronized int write(byte[] b,int nStart,int nLen) JRl=j2z
{ c8uaZvfW
int n = -1; wWl?c
try{ ;s+/'(*
oSavedFile.write(b,nStart,nLen); OSBR2Z;=
n = nLen; M':-f3aT%
} V:\:[KcL^
catch(IOException e) csP4Oq\g[
{ A8% e_XA
e.printStackTrace (); lc,k-}n
} m?e/MQr
u r$
dxeiN#(XT
return n; ,/f\
} C[7!pd
JwG(WLb:
U0&myj 8L
} _Ewh:IM-
%' DOFiU
R"cQyG4
/* iOiFkka
**SiteInfoBean.java 6n9/`D!
*/ 4|x_C-@
package NetFox; t&?jJ7 (&8
"f91YX_)
2S8;=x}/
public class SiteInfoBean { <cTX;&0=
9D3W_eIc
wd`p>
private String sSiteURL; //Site's URL lR?y tIY
private String sFilePath; //Saved File's Path !tq]kKJ3:
private String sFileName; //Saved File's Name &y? |$p\;/
private int nSplitter; //Count of Splited Downloading File :8yebOs
IdmP!(u
rJiF2W
public SiteInfoBean() @76}d
{//nSplitter的缺省值为5 x6cG'3&T
//default value of nSplitter is 5 mP)bOAU
this("","","",5); zyPb\/
} Wl| i$L)7
$}/tlA&e
7Z>vQf B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >CvhTrPI
{ K|%Am4
sSiteURL= sURL; ^G!cv
sFilePath = sPath; mV}bQ^*?Z
sFileName = sName; xp|1yud
this.nSplitter = nSpiltter; ^Mq/Cf_T
t|U5]$5
u`v&URM
} By1Tum+I1
c7CYulm
\&F4Wl>`
public String getSSiteURL() +$C9@CZM9
{ %R GZu\p
return sSiteURL; o*K7(yUL4
} CR [>5/:M
DuC#tDP
K~:SLCv E%
public void setSSiteURL(String value) 4)iP%%JH
{ %pVsafV
sSiteURL = value; "}()/
} []>rYZ9bv
c/$].VG0
jf)cDj2
public String getSFilePath() ^\PRzY
{ f0P,j~]
return sFilePath; JSUD$|RiJ
} 2TGND-(j
-;cF)C--12
0MRWx%CR
public void setSFilePath(String value) vjX,7NY?
{ P5my]4|x
sFilePath = value; "G%S m")
} ,$`}Rf<
t?9J'.p
?)9L($VVD
public String getSFileName() +2MF#{ tS
{ EMnz;/dMt
return sFileName; dNR/|
} G@P;#l`(D
(1x8DVXNN
<VZ43I
public void setSFileName(String value) 0[UI'2
{ g;Ugr8
sFileName = value; QPm[4Fd{G
} (rFkXK4^J
faOiNR7;h
dEYw_qJ2
public int getNSplitter() O.jm{x!m
{ e (]]
return nSplitter; 3?D, Wu
} z#gebr~_\
{N]WVp*R
:?~)P!/xl5
public void setNSplitter(int nCount) &en2t=a
{ |kZ!-?9Z
nSplitter = nCount; 8s22VL
} g7323m1=
} DOu^
igL5nE=n
zuNm!$
/* ~Bl,_?CBr
**Utility.java d>u^7:
*/ &&CrF~
package NetFox; _wXT9`|3
}V]*FCpQ
0WzoI2Q
public class Utility { f\5w@nX
2<*"@Vj
od#Lad@p
public Utility() XOX$uLm
{ 4x ?NCD=k
], Bafz)4
2{RRaUoRb
} t{UVX%b
uKzx >\}?1
//线程睡眠 e!0xh
public static void sleep(int nSecond) 2MB>NM<xO
{ ajkV"~w',|
try{ 'T^MaLK
Thread.sleep(nSecond); [? "hmSJ
} !Gnm<|.
catch(Exception e) $m ;p@#n
{ hpQ #`rhn
e.printStackTrace (); 1q;R+65
} 6 wd
} Z42q}Fhm*R
YKUAI+ks
//日志 1<~n2}
public static void log(String sMsg) <mP_K^9c
{ 0Gj/yra9MO
System.err.println(sMsg); j&dCP@G
} ()j)}F#Z`
,X|FyO(p
@[joM*U
public static void log(int sMsg) w}6~t\9D
{ 47Vt8oyh%
System.err.println(sMsg); '`k
} ommW
} c1kV}-v
ThP~k9-
8Y%
/* 2FdwX,O.
**TestMethod.java lq-F*r\/~+
*/ o[wiQ9Tl
package NetFox; \RDqW+,
el<Gd.p.d
1\Bh-tzB
public class TestMethod { auIW>0?}
5Bq;Vb
d$o m\@
public TestMethod() !!A(A^s
{ ///xx/weblogic60b2_win.exe iLQO .'{U
try{ 2@T0QJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )/f#~$ws
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W|{!0w
SiteFileFetch fileFetch = new SiteFileFetch(bean); _[8JSw7
fileFetch.start(); >9XG+f66E
} C%z9Q
catch(Exception e){e.printStackTrace ();} _s-X5xU
Y,mo}X<>
p\I3fI0i
} U(+QrC:
ph)=:*A6&
K~]Xx~F
public static void main(String[] args) 9*JxP%8T~X
{ fFC9:9<
new TestMethod(); aiX4;'$x!
} V@LBy1z
} 08@4u L
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