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)); 9feVy\u
} QT`|"RI%
for(int i=0;i<nEndPos.length-1;i++) yn`P:[v
{ 7# !RX3
nEndPos = nStartPos[i+1]; *m$lAWB5D
} nLvF^%P8
nEndPos[nEndPos.length-1] = nFileLength; I!-"SuBy4J
} OQ*BPmS-
} EjY8g@M;t
`_;sT8
L<dJWxf?D
//启动子线程 >G#SfE$0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WlJ=X$
for(int i=0;i<nStartPos.length;i++) n VNz5B
{ ."X}A t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xOY %14%Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d1]1bN4`"0
nStartPos,nEndPos,i); mc FSWmq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p<[gzmU9\b
fileSplitterFetch.start(); E^K<b7
} \mo NpKf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B r`a;yT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (D5sJ$&E@\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cVb&Jzd
nEndPos = " + nFileLength); b aO^Z
// fileSplitterFetch[nPos.length-1].start(); a%g|E'\Jw
O-uno{Fd*
(gHCu
//等待子线程结束 b@s6jNhVO^
//int count = 0; ./l^Iz&0
//是否结束while循环 v^0*{7N'
boolean breakWhile = false; =%=lq0GF0
.m gm1zz
KA#P_e{<@
while(!bStop) Sdo mG?;kV
{ fex<9'e
write_nPos(); > a?K![R
Utility.sleep(500); y]U]b G{
breakWhile = true; _A/q bm
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j:>_1P/
for(int i=0;i<nStartPos.length;i++) 3u,CI!
{ _Jt
if(!fileSplitterFetch.bDownOver) {r>iUgg
{ P$7i>(?(
breakWhile = false; )hy(0 D
break; ye^*Z>|
} d!P3<:+R[
} 7ciSIJ
if(breakWhile) ;}>g/lw
break; wJAJ /
P Y&(ObC
iVSN>APe
//count++; o)]mJb~XG-
//if(count>4) RW4,j&)
// siteStop(); %a\L^w)Xn
} G(;hJ'LT
`uh+d
,wYA_1$$H
System.err.println("文件下载结束！"); BN>t"9XpW
} ABaK60.O[O
catch(Exception e){e.printStackTrace ();} f`W)Z$fN5
} CM`B0[B
=bHS@h8N<
Abc%VRsT
//获得文件长度 \9!hg(-F
public long getFileSize() -_?U/k(Hi
{ x>!bvZ2
int nFileLength = -1; '>:c:Tewy
try{ S.,5vI"s,
URL url = new URL(siteInfoBean.getSSiteURL()); DQI b57j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oniVC',
httpConnection.setRequestProperty("User-Agent","NetFox"); Jk=_8Xvr`
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int responseCode=httpConnection.getResponseCode(); A)%!9i)
if(responseCode>=400) MBn ZO
{ GoUsB|-\
processErrorCode(responseCode); q@=3`yQ
return -2; //-2 represent access is error e0:[,aF`
} %o
LX8A@Yct
259R5X<V
String sHeader; +ktubJ@Qgj
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)R^&u`k
for(int i=1;;i++) nh'TyUd!
{ \=&F\EV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :B7dxE9[r
//Utility.log(in.readLine()); L/c`t7
sHeader=httpConnection.getHeaderFieldKey(i); /6{P ?)]pE
if(sHeader!=null) vq` M]1]FO
{ +(U;+6 b
if(sHeader.equals("Content-Length")) csjCXT=Ve
{ <N(r-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >[0t@Tu,D
break; *8Kx y@
} b!4Z~d0=
} f2iA5 rCV]
else }h+{>{2j
break; 7!g"q\s
} K0fuN)C
} 1:;S6{oQ
catch(IOException e){e.printStackTrace ();} 1smKU9B2)
catch(Exception e){e.printStackTrace ();} BVzMgn;
[/Sk+ID
I} .9
Utility.log(nFileLength); jB"IJ$cD
JKTn
w| eVl{~p
return nFileLength; (yK@(euG
} t2LX@Q"
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[x{Ai( /T^
//保存下载信息（文件指针位置） g#%Egb1
private void write_nPos() 4DgH/Yo
{ ]%2y`Jrl^W
try{ 6]|-%
output = new DataOutputStream(new FileOutputStream(tmpFile)); VOSq%hB
output.writeInt(nStartPos.length); z 4qEC
for(int i=0;i<nStartPos.length;i++) uGpLh0
{ 8RA
// output.writeLong(nPos); Q2Dh(
output.writeLong(fileSplitterFetch.nStartPos); _$KEE|9
output.writeLong(fileSplitterFetch.nEndPos); nrV!<nNBk
} "F:V$,mJ
output.close(); 1|dXbyUd
} |)*9BN
catch(IOException e){e.printStackTrace ();} {,B.OM)J
catch(Exception e){e.printStackTrace ();} Wud-(19
} ^{Fo,7
q.kDx_
\GPTGi5A
//读取保存的下载信息（文件指针位置） : G'a"%x
private void read_nPos() LeV";=_n
{ 7/zaf
try{ @TJ2 |_s6]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8?N![D\@
int nCount = input.readInt(); QlMv_|`9
nStartPos = new long[nCount]; K=1prv2
nEndPos = new long[nCount]; s`en8%
for(int i=0;i<nStartPos.length;i++) ]E$bK
{ >rXDLj-e
nStartPos = input.readLong(); 7.kgQ"?&
nEndPos = input.readLong(); HX{K5+
} N u3B02D*
input.close(); ?vP6~$*B
} "*LQr~k~}
catch(IOException e){e.printStackTrace ();} y!c<P,Lt3f
catch(Exception e){e.printStackTrace ();} '#a;n
} &$heW,
[jR>.H'
0Ibe~!EiQJ
private void processErrorCode(int nErrorCode) q"i]&dMr
{ VCzb[.
System.err.println("Error Code : " + nErrorCode); G 2`hEX%
} ++ZP X'|
a@^)?cH!z
w7c0jIf{
//停止文件下载 XS$#\UQ
public void siteStop() y~'%PUN
{ >8|V[-H
bStop = true; D63?f\
for(int i=0;i<nStartPos.length;i++) \M;cF"e-S
fileSplitterFetch.splitterStop(); qpjiQ,\:b
O^n\lik
OX7a72z
} WmOu#5*;
} D?FmlDTr[
//负责部分文件的抓取 pVM1%n:#
**FileSplitterFetch.java *v$j n
*/ ?pWda<&
package NetFox; N/eus"O;
i|rCGa0}
\D1@UyE
import java.io.*; `!xI!Y\
import java.net.*; 1)3'Y2N*
Wuk!\<T{
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public class FileSplitterFetch extends Thread { .kTOG'K\e
;ojJXH~$}
g'td(i[
String sURL; //File URL ;9<?~S
long nStartPos; //File Snippet Start Position ,$Cr9R&/
long nEndPos; //File Snippet End Position <'48mip
int nThreadID; //Thread's ID YU XxQ|
boolean bDownOver = false; //Downing is over x*p'm[Tdtm
boolean bStop = false; //Stop identical N2 t`
FileAccessI fileAccessI = null; //File Access interface SmAii}-jf
rk47$36X
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2FY]o~@
{ u2IU/z8 ^
this.sURL = sURL; {Iz"]Wh<f
this.nStartPos = nStart; DyCkz"1S
this.nEndPos = nEnd; O^q~dda
nThreadID = id; T*g}^TEh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $Wjx$fD
} ] &SmeTe
?Yx2q_KZk
!DUOi4I
public void run() 3a&HW JBSx
{ [{>3"XJ'
while(nStartPos < nEndPos && !bStop) FOteNQTj
{ \t%iUZ$
/l+"aKW 2
:2V|(:^'
try{ 1,7 }ah_
URL url = new URL(sURL); 7'gk=MQc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I%b5a`7
httpConnection.setRequestProperty("User-Agent","NetFox"); MdFFt:y:
String sProperty = "bytes="+nStartPos+"-"; b`JS&E
httpConnection.setRequestProperty("RANGE",sProperty); <g&.UW4
Utility.log(sProperty); ,g4T>7`&U%
}=B~n0
u08j9) ,4
InputStream input = httpConnection.getInputStream(); [E+J=L.l
//logResponseHead(httpConnection); =q>lP+
,M:[GuXD<
NV==[$(r
byte[] b = new byte[1024]; }57Jn5&'
int nRead; b|*+!v:I>T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ArScJ\/Nwv
{ HCx0'|J
nStartPos += fileAccessI.write(b,0,nRead); C$$Zwgy
//if(nThreadID == 1) bc NyB$S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \qTp#sF
} ^y%8_r&
JDW/Mc1bh
"Pu917_P
Utility.log("Thread " + nThreadID + " is over!"); ?]aVRmL
bDownOver = true; 8hYl73#
//nPos = fileAccessI.write (b,0,nRead); Gm &jlN
} O.Y|},F
catch(Exception e){e.printStackTrace ();} r;{ggwY&J
} $Ld-lQsL
} 2 6 >9$S
&gr T@
p8"C`bCf
//打印回应的头信息 cm!|A?-<
public void logResponseHead(HttpURLConnection con) !? H:?
{ !1K.HdK
for(int i=1;;i++) NJmx(!Xsh
{ @$Yk#N;&(
String header=con.getHeaderFieldKey(i); {NcJL< ;tS
if(header!=null) L,!\PV|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Dm$SW<!l|
Utility.log(header+" : "+con.getHeaderField(header)); 4.Fh4Y:$'
else um%s9
break; mY[*Cj3WJ
} 66sgs16k
} t~)4f.F:
nE?:nJ|%E
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public void splitterStop() f,|;eF-Z
{ Y^C(<N$
bStop = true; 2 E?]!9T~|
} Y]Z&
deq5u>
9P,[MZ
} wkx#WC
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CIsX$W
/* Z[l+{
**FileAccess.java c}|} o^
*//文件访问(定位，写) .3jijc j
package NetFox; >o%X;U 3
import java.io.*; vbX.0f "n
Yakrsi/jV}
L@jpid95
public class FileAccessI implements Serializable{ TaaCl#g$?
3sIdwY)ZS_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '4D7:
RandomAccessFile oSavedFile; IwS<p-
long nPos; h?h)i>
q&O9W?E8dG
wAgVevE
public FileAccessI() throws IOException tk:nth
{ M= |is*t
this("",0); `c|H^*RC
} Z0O0Q=e\Y
VC_F Cz
pAqPHD=
public FileAccessI(String sName,long nPos) throws IOException O*lIZ,!n
{ <AiE~l| D
oSavedFile = new RandomAccessFile(sName,"rw"); 68w~I7D>
this.nPos = nPos; [6 "5
oSavedFile.seek(nPos); HRQfT>"/
} 1(*+_TvZ
~p:hqi1+<+
1HqN`])l/j
public synchronized int write(byte[] b,int nStart,int nLen) t/%[U,m
{ tUW^dGo.
int n = -1; 6i~<,;Cn
try{ UUM:*X
oSavedFile.write(b,nStart,nLen); ydRS\l
n = nLen; !,{N>{I
} Oiqc]4TL
catch(IOException e) H#WqO<<v
{ X+HPdrT
e.printStackTrace (); 6' \M:'<0e
} wuxOFlrg
r+6 DlT a
@3 +
return n; 7l09
} {zc*yV\
E7.{SGH}
\d:Uq5d)0
} x_/l,4_
BeD>y@ it
L_+Fin
/* nB[B FVkU
**SiteInfoBean.java 0S }\ML
*/ 4PR&67|AH_
package NetFox; V?>&9D"m
k8SY=HP
tu@-+<*
public class SiteInfoBean { N6T
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|oX9SUl
private String sSiteURL; //Site's URL C43I(.2g
private String sFilePath; //Saved File's Path Oml /;p
private String sFileName; //Saved File's Name kp!(e0n
private int nSplitter; //Count of Splited Downloading File m]'+Eye ]r
ep`8LQf
_5p]Arg?}&
public SiteInfoBean() E@l@f
{//nSplitter的缺省值为5 2#CN:b]+
//default value of nSplitter is 5 s0h0EpED
this("","","",5); Sht3\cJ8
} G=CP17&h6
!c0x^,iE
\<y|[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -]YsiE?r
{ Nr"GxezU+A
sSiteURL= sURL; 0C"2?etMx
sFilePath = sPath; 7|[Dr@.S
sFileName = sName; C\;%IGn
this.nSplitter = nSpiltter; }N,v&B
=i2]qj\
*+2BZZwT
} Z^J)]UL/
d7x6r3J$
[iyhrc:@
public String getSSiteURL() xk,1D
{ RUut7[r
return sSiteURL; p_fsEY
} LJ9#!r@H
5nmE*(
Wh"xt:
public void setSSiteURL(String value) OMab!
{ V,\}|_GY
sSiteURL = value; .#K\u![@N
} <~svy)Cz
Xg;<?g?k
y.gNjc
public String getSFilePath() Lm0q/d2|\X
{ us<dw@P7{
return sFilePath; Y9%zo~]-W'
} c"Q9ob
V4W(>g
WS1Y maV
public void setSFilePath(String value) V.yDZ"
{ nn">
sFilePath = value; `Cy;/95m
} jCg4$),b
'g}Q@@b
KEq48+j
public String getSFileName() D6\k}4n-
{ )sK_k U{\
return sFileName; Np.<&`p!
} &s\/Uq
q^QLNKOH"
g`"_+x'
public void setSFileName(String value) y>r^ MQ
{ + eZn
sFileName = value; I=YZ!*f/`
} $UdFm8&
7L]Y.7>
^5FwYXAxi
public int getNSplitter() fnFIw=d
{ <#T#+uO
return nSplitter; aLQ]2m
} sE^=]N
3YEw7GIO-
y99|V39'
public void setNSplitter(int nCount) g\aq#QV
{ lXnv(3j3*s
nSplitter = nCount; VrT0S
} Eqx|k-<a
} Z22#lF\N
7|)K!
C}:_&^DQ
/* i[vOpg]J
**Utility.java Dd)L~`k{)
*/ o4aFgal1
package NetFox; _o>?\:A
;4`%?6%
sB'~=1m^
public class Utility { d! _8+~
r+h$]OJ
irGgo-x
public Utility() y"w`yl{_
{ jF{\=&fU
QGXR<Y
-}H EV#ev
} =~k#<q1^
TO] cZZ<
//线程睡眠 ;\Pq
public static void sleep(int nSecond) Z. xOO|
{ j3/K;U/SGJ
try{ "z{rC}
Thread.sleep(nSecond); KU.F4I8}q
} :8lqo%5
catch(Exception e) aR%E"P-6l
{ @ |(Tg
e.printStackTrace (); MQo/R,F }
} (<Kf
} q]P$NeEiZ"
uCf _O~
//日志 *p^*>~i9)
public static void log(String sMsg) K|rG&#1J
{ 7x(z
System.err.println(sMsg); -Vjrh/@
} Tpp?(lT7r
XhJYsq]]J
NH8\&#}nAK
public static void log(int sMsg) /)XN^Jwa;m
{ 2nB{oF-Z
System.err.println(sMsg); H+VjY MvK
} z?C&,mv
} 5oOFl
5?Rzyfwk|
V<t!gT#&o!
/* SD1M`PI
**TestMethod.java jg(cpo d
*/ ;:w0%>X^
package NetFox; *<ww~^a
4@Xd(F_d
'2S?4Z
public class TestMethod { p</V_BIW
;PWx#v+vwF
u 9kh@0
public TestMethod() JS(%:
{ ///xx/weblogic60b2_win.exe DG 6W ^
try{ HP[M"u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T^ RYN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `it
SiteFileFetch fileFetch = new SiteFileFetch(bean); -D^v:aC
fileFetch.start(); |OO2>(Fj
} -AM(-
catch(Exception e){e.printStackTrace ();} !u=A9i!
ac/<N%
j>|mpfU
} I?Q[ZH:M
@-aMj
QfI@=Kbg%#
public static void main(String[] args) HD8*>p.
{ Rj])c^ZA'*
new TestMethod(); ~x g#6%<=
} f9?f!k
} =(p]L
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