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)); }jfU qqFd
} MlsF?"H p
for(int i=0;i<nEndPos.length-1;i++) 'sY>(D*CQ
{ ^,b*.6t
nEndPos = nStartPos[i+1]; 7vcYI#(2 Y
} JHc|.2Oe
nEndPos[nEndPos.length-1] = nFileLength; @k,u xe-
} )-[ 2vhXz
} ]ODC+q1
fh )QX
IJo`O
//启动子线程 )"jG)c^1*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }vxb, [#
for(int i=0;i<nStartPos.length;i++) hX 9.%-@sR
{ netKt_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HPCgv?E3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7J,W#Ql)5
nStartPos,nEndPos,i); {{[).o/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /^#k/z
fileSplitterFetch.start(); E[t\LTt*n
} CjOaw$s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |VlAt#E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &.+[~2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M`KrB5a+6
nEndPos = " + nFileLength); 4G@vO{$
// fileSplitterFetch[nPos.length-1].start(); zY\v|l<T
,ye>D='
%g0"Kj5
//等待子线程结束 }`IN5NdYp
//int count = 0; c$?qN&X_K
//是否结束while循环 )dJM
boolean breakWhile = false; Nt&}T
]NuY{T&:
FI*.2rdSR
while(!bStop) vf~q%+UqK
{ RXt`y62yK
write_nPos(); } ~=53$+
Utility.sleep(500); <jw`"L[D
breakWhile = true; ]BP/KCjAI<
3oxQ[.o
hof$0Fg
for(int i=0;i<nStartPos.length;i++) Rh9>iA@fd
{ 5 &-fX:/
if(!fileSplitterFetch.bDownOver) eOD;@4lR
{ A,lcR:@w
breakWhile = false; QXq~e
break; gO4J[_
} X+P& up06
} p4W->AVv$
if(breakWhile) OWB^24Z&3
break; {;Mcor3
!;'U5[}8
EZIMp8^
//count++; jLD=EJ
//if(count>4) d~S.PRg=
// siteStop(); y= cBpC
} [_L:.,]g8
?_m;~>C
%I(N
System.err.println("文件下载结束！"); =^q:h<
} O<iE,PN)
catch(Exception e){e.printStackTrace ();} KTBsH;6
} [ #A!B#`
6N~~:Gt
YANg2L>MK
//获得文件长度 x nWapG
public long getFileSize() M)I&^mm39
{ \KLWOj%
int nFileLength = -1; <R*.T)Z1
try{ ~Rk6@&ZS}
URL url = new URL(siteInfoBean.getSSiteURL()); &{x5 |$SD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #?!)-Q%
httpConnection.setRequestProperty("User-Agent","NetFox"); x~j%
\P}~ICZA
}v0oFY$u`H
int responseCode=httpConnection.getResponseCode(); c(ZkK
if(responseCode>=400) !7AW_l9`i
{ [*vk&
processErrorCode(responseCode); BA A)IQF
return -2; //-2 represent access is error }n:'@}
} b,KQG|k
G}BO!Z6
Tp)-L0kD_k
String sHeader; f*1.Vg0`-
2ztP'
bzk@6jR1
for(int i=1;;i++) x?va26FV
{ bH3-#mw5w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?%;7k'0"
//Utility.log(in.readLine()); mZ7.#R*}
sHeader=httpConnection.getHeaderFieldKey(i); lmj73OB3
if(sHeader!=null) d@7 ]=P:
{ WkXa%OZ
if(sHeader.equals("Content-Length")) 2P!Pbl<
{ ud'r?QDM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f/*Xw{s#
break; _D$|lk-
} rm+|xvZ4
} 9N5&N3
else `cy_@Z5A
break; +7^%fX;3pW
} =MB[v/M59w
} a&.8*|w3
catch(IOException e){e.printStackTrace ();} |"5NI'X?
catch(Exception e){e.printStackTrace ();} 5z5#_*)O
EXS 1.3>
^Ml)g=Fq
Utility.log(nFileLength); ;5PXPpJ
tP"C>#LO
p r(:99~3
return nFileLength; tL 3]9qfj
} 2e/ JFhA
Jq<&`6hn
Ad9'q!_en
//保存下载信息（文件指针位置） J6n@|L!yO
private void write_nPos() (](:0H
{ \a<qI
try{ \gDf&I
output = new DataOutputStream(new FileOutputStream(tmpFile)); jC@$D*"J
output.writeInt(nStartPos.length); v'`C16&^]
for(int i=0;i<nStartPos.length;i++) deQ0)A 4g
{ !-U5d9!
// output.writeLong(nPos); (05/}PhB`
output.writeLong(fileSplitterFetch.nStartPos); 2%. A{!
output.writeLong(fileSplitterFetch.nEndPos); pu0IhDMn
} A=I]1r
output.close(); }_@*,
} TlQ#0_as[
catch(IOException e){e.printStackTrace ();} Xb?P'nD
catch(Exception e){e.printStackTrace ();} ?`uY*+u
} {tOu+zy
=n cu#T]
ltwX-
//读取保存的下载信息（文件指针位置） ;v^tUyhCb
private void read_nPos() O B_g:T
{ Xg^`fRg =T
try{ CJz2.yd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =!GUQLS{
int nCount = input.readInt(); K;k_MA310
nStartPos = new long[nCount]; /$|C s
nEndPos = new long[nCount]; 4;<?ec(dc
for(int i=0;i<nStartPos.length;i++) M`q>i B
{ *Cz>r}W
nStartPos = input.readLong(); WUvrC
nEndPos = input.readLong(); blpX_N
} r?nvJHP
input.close(); @mSdksB/L
} P6u9Ngay
catch(IOException e){e.printStackTrace ();} T&oY:1D,g
catch(Exception e){e.printStackTrace ();} [ %cW ?@
} a:r8Jzr
f-F+Y`P
V:fz
private void processErrorCode(int nErrorCode) =ps3=D
{ 9.{u2a\
System.err.println("Error Code : " + nErrorCode); 9E'fM
} P(l$5x]g,
B5GT^DaT
E2 Q[
//停止文件下载 yS^";$2Tc
public void siteStop() /x c<&
{ oM G8?p
bStop = true; R9A8)dDz
for(int i=0;i<nStartPos.length;i++) ",!#7h
fileSplitterFetch.splitterStop(); (dd+wx't
v8Vw.Ce`f
;PCnEs
} NoTEbFrV
} 4zkn~oy
//负责部分文件的抓取 _PLY<i2vr
**FileSplitterFetch.java {_&'tXL
*/ ea kj>7\s
package NetFox; )r3}9J
:hJHjh
= NHuj.
import java.io.*; /{>$E>N;
import java.net.*; IppzQ0'=y1
Ls< ";QJc
@<=xfs
public class FileSplitterFetch extends Thread { G0oY`WXOB
4wjy)VD_
0{^@kxV
String sURL; //File URL |5oK04<
long nStartPos; //File Snippet Start Position Px{Cvc
long nEndPos; //File Snippet End Position c7UmR?m
int nThreadID; //Thread's ID VT8PV5z
boolean bDownOver = false; //Downing is over jd8`D6|Z
boolean bStop = false; //Stop identical gqV66xmJ3
FileAccessI fileAccessI = null; //File Access interface *oopdGue
B>Tfyo
UF0W%Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,n<t':-
{ 'n4Ro|kA
this.sURL = sURL; s~ ||Vv!
this.nStartPos = nStart; nr7#}pzo
this.nEndPos = nEnd; me:~q#k
nThreadID = id; Q&+Jeji
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F*m^AFjs
} a~q_2S]h
nGQc;p5;
O'm><a>8
public void run() O<7Q>m
{ 7ss Y*1b
while(nStartPos < nEndPos && !bStop) ,I6jfXI4
{ M8dv y!D
uu ahR
jr[(g:L
try{ 5&?[Vt
URL url = new URL(sURL); [Jv0^"]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %LyZaU_sB
httpConnection.setRequestProperty("User-Agent","NetFox"); OAJGwm
String sProperty = "bytes="+nStartPos+"-"; rQmDpoy=
httpConnection.setRequestProperty("RANGE",sProperty); FvYgpbEZ
Utility.log(sProperty); |osu4=s|
XJg8-)T#
j/.$ (E
InputStream input = httpConnection.getInputStream(); \ #<.&`8B
//logResponseHead(httpConnection); EQe!&;
"NEg]LB5
}L mhM
byte[] b = new byte[1024]; !dnCrR
int nRead; <A|X4;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?QA![
{ PLD&/SgP*
nStartPos += fileAccessI.write(b,0,nRead); SnIH6k0T_
//if(nThreadID == 1) f>*T0"\c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #b~B 0:U
} -55[3=#
Lx%*IE|c
SeuC7!q{
Utility.log("Thread " + nThreadID + " is over!"); +cH,2^&
bDownOver = true; di.yh3N$
//nPos = fileAccessI.write (b,0,nRead); (~>uFH
} C,;T/9
catch(Exception e){e.printStackTrace ();} +kA>^
} 1oKF-";u(
} 6/-]
*vy^=Yea
Ov$>CA
//打印回应的头信息 f3yH4r?;w
public void logResponseHead(HttpURLConnection con) F/pq9
{ /ILj}g'
for(int i=1;;i++) OlU')0Y
{ ->Z9j(JU
String header=con.getHeaderFieldKey(i); 1Vf?Rw
if(header!=null) v C23
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HQp\0NC]
Utility.log(header+" : "+con.getHeaderField(header)); F}1h
else $4>(}
break; k1lo{jw`
} 5Zf^cou
} B":9C'tip
26M:D&|ZB
aE|'%72g
public void splitterStop() ^bM\:z"M
{ m^k$Z0
bStop = true; V}3'0
} J`6IH#54
zH"a>+st=
}K.Rv(m
} |>^5G@e
H1GmC`\<[:
1JQ5bB"
/* kM6i{{Q
**FileAccess.java J#.f%VJ
*//文件访问(定位，写) Ky0}phGRu
package NetFox; D\:dn
import java.io.*; ^VC/tJ
# &,W x
GB%kxtGD;\
public class FileAccessI implements Serializable{ ,NO2{Ha$
n;@.eC,T/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oACbZ#/@n
RandomAccessFile oSavedFile; mXYG^}
long nPos; !hs33@*u~
2jf73$F
L<XAvg
public FileAccessI() throws IOException ?^whK<"]
{ ,?>{M
this("",0); NX[-Y]t
} #fYRsVQ
K`=9"v'f+
HVJqDF
public FileAccessI(String sName,long nPos) throws IOException a8WWFAC[
{ }/w]+f*
oSavedFile = new RandomAccessFile(sName,"rw"); m?<^b_a}
this.nPos = nPos; ~8 B]
oSavedFile.seek(nPos); f+cN'jH E
} 3"BSP3/[l
~'V&[]nh8
0 k.\o"y
public synchronized int write(byte[] b,int nStart,int nLen) A"e4w?
{ +>&i]x(b
int n = -1; oF0DprP@
try{ hW!2C6
oSavedFile.write(b,nStart,nLen); z''ejq
n = nLen; 85x34nT
} C669:%
catch(IOException e) HNRAtRvnY
{ |.4>#<$__
e.printStackTrace (); Vp7d
} MY60%
C'y4 ~7
`fuQt4
return n; s=e`}4
} %G|Rb MP
jY2mn".N
{#.<hPXn
} i]#"@xQ
UX2@eyejQ7
V3% >TNp
/* S:K$fFcJ
**SiteInfoBean.java y>#_LhTX-
*/ b'ZzDYN
package NetFox; O$nW
]xkh"j+W
<~*[OwN
public class SiteInfoBean { hj=qWGRgI
f\rE{%
;reBJk
private String sSiteURL; //Site's URL DfU]+;AE
private String sFilePath; //Saved File's Path z~-(nyaBS
private String sFileName; //Saved File's Name 4(91T
private int nSplitter; //Count of Splited Downloading File 74 WKy
}rvX}
=9Vo[
public SiteInfoBean() hx*4xF
{//nSplitter的缺省值为5 S"VO@)d
//default value of nSplitter is 5 G|*&owJ
this("","","",5); V|hwT^h
} `W>Sss
TCFr-*x
+1a3^A\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M&jlUr&l
{ {!j)j6(NY
sSiteURL= sURL; L PS,\+
sFilePath = sPath; &1f3e
sFileName = sName; v}J0j
this.nSplitter = nSpiltter; fP[S.7F+No
2FW"uYA;6
2z.~K&+x
} )QWhzY
(Hmm^MV)
[7Q%c!e$*
public String getSSiteURL() :L{*B$c
{ b9ud8wLE[
return sSiteURL; Uqz.Q\A
} QI'-I\Co
NiFe#SLA
.R@s6}C`}=
public void setSSiteURL(String value) aZ|?i }
{ em95ccs'-
sSiteURL = value; |VzXcV-"8)
} q`'"+`h
gkX7,J-0
Z^}[CQ&Am
public String getSFilePath() {/(.Bpld
{ D)bL;h
return sFilePath; xFekSH7[F
} *Ojl@N
L+VQtp&"
?E_;[(Mcr
public void setSFilePath(String value) nbB*d@"
{ , O/IY
sFilePath = value; :5['V#(o
} Ozhn`9L+1!
6" <(M@
]=%6n@z'
public String getSFileName() Fw*O ciC
{ 2y \ogF
return sFileName; UM#.`
} {NQCe0S+p
Mvue>)g~>
@e&0Wk
public void setSFileName(String value) }zS5o [OE
{ ,v 2^Ui
sFileName = value; %.D!J",\/K
} /D1Lh_,2
$_,-ESI
$5/d?q-ts{
public int getNSplitter() 5~/EAK`
{ p!8phS#iP
return nSplitter; Xtfs)"
} +Z2XP76(4A
x;sc?5_`
|`?&
public void setNSplitter(int nCount) %$kd`Rl}
{ RjH68=n
nSplitter = nCount; dWQB1Y*N
} !V(r p80
} s*_fRf:
_~MX~M3MB
wPm
/* |`Noj+T47I
**Utility.java (hdu+^Qj=
*/ SASLeGaV
package NetFox; jI0gf&v8
'e' p`*
7i{(,:
public class Utility { *Ow2,{Nn
W;cYg.W2
tk*-Cx?_
public Utility() Ncsh{.
{ ;9WUt,R
W7b m}JHn
$2}#):`
} p}h.2)PO
:\qapFV
//线程睡眠 \o/eF&
public static void sleep(int nSecond) M2w'cdHk
{ 9&uf
try{ Dw7Xy}I/
Thread.sleep(nSecond); \>pm (gF
} QK#wsw
catch(Exception e) nw%9Qw
{ p/RT*?<
e.printStackTrace (); OA=~i/n~
} (xN1?qXB.
} 2_)UHTwsK
9M3"'^ {$
//日志 DpvHIE:W
public static void log(String sMsg) d23=WNn
{ z'$1$~I
System.err.println(sMsg); rD4umWi
} "f_qG2A{
K)wWqC.
PU,$YPrZ
public static void log(int sMsg) X?[ )e
{ CYQ)'v
System.err.println(sMsg); G%: 3.:E"
} kyvl>I0q@
} GVJ||0D
;Su-Y!&%
W[*xr{0V
/* H\a"=&M
**TestMethod.java ;5.&TQT
*/ _fu <`|kc
package NetFox; bKGX> %-
H!Q72tyo
d?J&mLQ6
public class TestMethod { CX{6
9$z$yGjl
Vc;[0iB
public TestMethod() Tn1V+)
{ ///xx/weblogic60b2_win.exe }.E^_`
try{ &e:+;7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dH;2OWM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B+U:=591
SiteFileFetch fileFetch = new SiteFileFetch(bean); >@Ht*h{~
fileFetch.start(); qf\W,SM
} ?.%dQ0
catch(Exception e){e.printStackTrace ();} r>FwJm!
]#^v754X^T
]S[/a
} .4[3r[
T\bP8D
]q{_i
public static void main(String[] args) QCb%d'_w+
{ 4jC)"tch
new TestMethod(); h2f8-}fsq
} I2}eFz&FE
} ?@,EGY<
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