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)); "(YfvO+
} \v_R]0m\
for(int i=0;i<nEndPos.length-1;i++) ;L@p|]fu
{ rU |%
nEndPos = nStartPos[i+1]; d6XdN
} CklIrD{
nEndPos[nEndPos.length-1] = nFileLength; |%g)H,6c
} ILIv43QKM(
} *AG01# ZF
$YiG0GK<"
GD1L6kVd1
//启动子线程 &U_T1-UR2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _&RGhA
for(int i=0;i<nStartPos.length;i++) 7P:/ (P
{ .^wBv 'Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T`2a)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @;X#/dZe
nStartPos,nEndPos,i); #('GGzL6c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @ek8t2??x
fileSplitterFetch.start(); %RIlu[J
} %x8vvcO^t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), juA}7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #!C|~=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |F +n7
nEndPos = " + nFileLength); #G\Ae:O
// fileSplitterFetch[nPos.length-1].start(); Gce[RB:
D^S"6v"z
RREl($$p
//等待子线程结束 `-g$ 0lm7
//int count = 0; N>w+YFM
//是否结束while循环 7[1VFc#tf
boolean breakWhile = false; %3yrX>Js
I9h{fB
rX22%~1
while(!bStop) \Rw^&;\1
{ rAk;8)O$
write_nPos(); Mehp]5*
Utility.sleep(500); MhjIE<OI=
breakWhile = true; a1x].{
p.5 *`, )
1ZXRH;J40
for(int i=0;i<nStartPos.length;i++) "?6R"Vk?:
{ ypNeTR$4
if(!fileSplitterFetch.bDownOver) ; hU9_e
{ CoV@{Pi
breakWhile = false; .uB[zJc
break; C't%e
} 6n/KL
} rS0#]Gg
if(breakWhile) Hp@cBj_@P2
break; ~ujg250.L
X{iidTW`xv
EcPvE=^c
//count++; +&*>FeJY
//if(count>4) $#_^uWN-M
// siteStop(); iZ0.rcQj'o
} KP!7hJhw
O]l-4X#8F
uN0'n}c;1.
System.err.println("文件下载结束！"); ~Fo`Pr_
} ?sxf_0*
catch(Exception e){e.printStackTrace ();} I#xhmsF
} I.o3Old
&-x/c\jz
D"K!ELGW
//获得文件长度 xOZvQ\%
public long getFileSize() xM>dv5<E
{ _he~Y2zFz
int nFileLength = -1; xEB4oQ5
try{ ]0pI6"
URL url = new URL(siteInfoBean.getSSiteURL()); DvTbt?i[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G }M!
httpConnection.setRequestProperty("User-Agent","NetFox"); nTsPX Tat
p+2uK|T9
z.W1Za
int responseCode=httpConnection.getResponseCode(); zu1gP/
if(responseCode>=400) !9^GkFR6n
{ +EZr@
processErrorCode(responseCode); >P6U0
return -2; //-2 represent access is error ! &V,+}>)
} VKi3z%kwK
XV!UeBq
HPK}Z|Vl
String sHeader; |\]pTA$2
/sl#M
ik0w\*
for(int i=1;;i++) ^1ks`1
{ eoPoGC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mW)"~sA
//Utility.log(in.readLine()); #|lVQ@=
sHeader=httpConnection.getHeaderFieldKey(i); l> >BeZ
if(sHeader!=null) &jDRRT3
{ tdC kvVE
if(sHeader.equals("Content-Length")) 1'5!")r
{ * =O@D2g0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +7K]5p;!~
break; l_x>.'a
} cr{dl\Na
} hy:K) _
else bre6SP@
break; U7G|4(
} !" : arK
} *c@]c~hY,
catch(IOException e){e.printStackTrace ();} &J=x[{R
catch(Exception e){e.printStackTrace ();} ^9kdd[
t*Wxvoxk
NO#^_N`#\
Utility.log(nFileLength); ,0$b8lb;x/
||?wRMV
OL[_2m*;9p
return nFileLength; tWdP5vfp
} QpifO
fVBRP[,
I3?:KVa
//保存下载信息（文件指针位置） (yz8}L3
private void write_nPos() OZh+x`' #
{ Xg97[I8/
try{ < YuI}d~'
output = new DataOutputStream(new FileOutputStream(tmpFile)); !?)iP
output.writeInt(nStartPos.length); J15$P8J
for(int i=0;i<nStartPos.length;i++) WTh|7&
{ ?/s=E+
// output.writeLong(nPos); L G9#D
output.writeLong(fileSplitterFetch.nStartPos); PiIILX{DuH
output.writeLong(fileSplitterFetch.nEndPos); ;"GI~p2~7
} 4U:+iumy2
output.close(); >l5JwwG
} ^F1zkIE
catch(IOException e){e.printStackTrace ();} mH3{<^Z6
catch(Exception e){e.printStackTrace ();} fKT(.VNq5
} GgjBLe=C
@i:_JOl
VAR/"
//读取保存的下载信息（文件指针位置） 6UJBE<ntj
private void read_nPos() K#p&XIY,
{ FdJC@Y-#uA
try{ "i*Gi \U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k4%> F
int nCount = input.readInt(); L:EJ+bNG
nStartPos = new long[nCount]; RwwX;I"o%
nEndPos = new long[nCount]; :Zd# }P
for(int i=0;i<nStartPos.length;i++) wwmODw<tT
{ 1vxh3KS.
nStartPos = input.readLong(); (.3L'+F
nEndPos = input.readLong(); ?hpk)Qu
} R:JS)>B
input.close(); #$%gs]
} 9/|i.2&
catch(IOException e){e.printStackTrace ();} #Ryu`b
catch(Exception e){e.printStackTrace ();} JXnPKAN
} c5rQkDW
PZl(S}VY
=U".L
private void processErrorCode(int nErrorCode) u]cnbm
{ UoxF00H@!
System.err.println("Error Code : " + nErrorCode); )u&_}6z
} 9~mi[l~
g^En6n)
+e"}"]n
//停止文件下载 D2Go,1
public void siteStop() ?-'Q-\j
{ 3B"rI
bStop = true; Q<``}:y|>
for(int i=0;i<nStartPos.length;i++) fhn0^Qc"+
fileSplitterFetch.splitterStop(); Tm^zoVi
AjANuyUaP
Fk(0q/b
} z_l3=7R
} E(U}$Zey
//负责部分文件的抓取 ddHIP`wb
**FileSplitterFetch.java z?"5="D
*/ JT^E`<nn
package NetFox; J0p,P.G
+;[`fSi
j)IK
import java.io.*; Azz]TO
import java.net.*; L}a3!33)C
xD?{Hw>QT#
,em6wIq,
public class FileSplitterFetch extends Thread { |H_)u
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d8RpL{9\7
String sURL; //File URL p go\(K0
long nStartPos; //File Snippet Start Position Z#o\9/{(R
long nEndPos; //File Snippet End Position iK%Rq
int nThreadID; //Thread's ID X0Oq lAw
boolean bDownOver = false; //Downing is over r IK|}5
boolean bStop = false; //Stop identical ZJ[ Uz_%W
FileAccessI fileAccessI = null; //File Access interface nLfnikw&
*E)Y?9u"
}5tn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AYZds >#Q
{ fF[g%?w
this.sURL = sURL; rw\4KI@ L
this.nStartPos = nStart; H@j^,
this.nEndPos = nEnd; 8:xQPd?3
nThreadID = id; o"1us75P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j'J*QK&Q
} \+AH>I;vO
5PL,~Y
4COf H7Al9
public void run() YKc{P"'/|
{ 49zp@a
while(nStartPos < nEndPos && !bStop) }\*Sf[EMD
{ rzBWk
!3&vgvr
1aT$07G0
try{ d|NNIf
URL url = new URL(sURL); "DN`@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3CHte*NL=
httpConnection.setRequestProperty("User-Agent","NetFox"); QF>[cdl?8
String sProperty = "bytes="+nStartPos+"-"; 'Lw\nO.
httpConnection.setRequestProperty("RANGE",sProperty); Ul'G g
Utility.log(sProperty); )w`Nkx
Hf-F-~E
%ej"ZeM
InputStream input = httpConnection.getInputStream(); `WW0~Tp3
//logResponseHead(httpConnection); }I`|*6Up
Elq8WtS
4QVd{
byte[] b = new byte[1024]; Cp* n2
int nRead; 8Z!ea3kAT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H= y-Y_R
{ Le'\x`B
nStartPos += fileAccessI.write(b,0,nRead); j&mL]'Zy
//if(nThreadID == 1) ,RHHNTB("
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A{o{o++
} v:0i5h&M
Ji[w; [qL
g:clSN,
Utility.log("Thread " + nThreadID + " is over!"); '~cEdGD9H
bDownOver = true; VV4_
//nPos = fileAccessI.write (b,0,nRead); >lW*%{|b$^
} J@TM>R
catch(Exception e){e.printStackTrace ();} TatyD**(
} }00e@a
} awK'XFk
G9[-|[j^N
Jr9}'l8
//打印回应的头信息 )AoFd>
public void logResponseHead(HttpURLConnection con) yW&iUh=0
{ !jW32$YTR
for(int i=1;;i++) "%]dC{
{ 6J*`<k/S
String header=con.getHeaderFieldKey(i); Y"jDZG?
if(header!=null) aS7zG2R4H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !!86Sv
Utility.log(header+" : "+con.getHeaderField(header)); I{PN6bn{>
else W<L6,
break; ^hgAgP{{
} VfwD{+5
} 1W g8jr's
ezvaAhd{
|Q;o538
public void splitterStop() GXRjR\Ch
{ \d+HYLAJn
bStop = true; t_rDXhM
} [s2V-'2
c$|dK
}BrE|'.j'
} gNd J=r4
YeLOd
b9N4Gr
/* o%%fO
**FileAccess.java ^!qmlx*
*//文件访问(定位，写) 0)]1)z(P
package NetFox; kk'w@Sn.(
import java.io.*; n:D*r$ C|p
's?Fip
WLLv a<{
public class FileAccessI implements Serializable{ $hQg+nY.
Snu;5:R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sJ/e=1*
RandomAccessFile oSavedFile; g8"7wf`0k
long nPos; h12wk2@P/]
U08?*{
vWH>k+9&X
public FileAccessI() throws IOException ~a%hRJg
{ `yZZP
this("",0); E3skC%}
} |mmG s
He!!oKK>
v`BG1&/|
public FileAccessI(String sName,long nPos) throws IOException lKUm_; m
{ %},G(>
oSavedFile = new RandomAccessFile(sName,"rw"); \2xBOe-a]
this.nPos = nPos; J\'5CG
oSavedFile.seek(nPos); ~,68S^nP)H
} @t8kN6.
O97bgj]
})lT fy
public synchronized int write(byte[] b,int nStart,int nLen) 1>VS/H`
{ p8dn-4
int n = -1; X);Zm7
try{ &;U7/?Q
oSavedFile.write(b,nStart,nLen); ~UC/|t$
n = nLen; zD;] sk4
} Te}yQ=+
catch(IOException e) O)uM&B=
{ 1cBhcYv"
e.printStackTrace (); EE6|9K>
} bTGK@~
FraW6T}_
d$rUxqB.
return n; Q'%o;z*
} _-J@$d%
sC_UalOC_
/2Lo{v=0[
} V55J[s*6!
=awO63j>
@:9fS
/* t} i97;
**SiteInfoBean.java m8j-lNu
*/ H#6^-6;/
package NetFox; .Pes{uHg
;sR6dT)
?_>^<1I1
public class SiteInfoBean { G=HxD4l
NJf(,Mr*|
]}7rWs[|1
private String sSiteURL; //Site's URL pEj^x[b`^
private String sFilePath; //Saved File's Path 7b,,%rUd
private String sFileName; //Saved File's Name 6//FZ:q
private int nSplitter; //Count of Splited Downloading File 7E3SvC|M
qf`xH"$
p <=%
public SiteInfoBean() !NLvo_[Y
{//nSplitter的缺省值为5 DsJn#>?Kh
//default value of nSplitter is 5 zk'K.! `^
this("","","",5); J.mewD!%z
} ioNa~F&
S?7V "LF
C<t'f(4s`u
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -^4bA<dCCE
{ >2CusT2
sSiteURL= sURL; b]<HhU
sFilePath = sPath; VNrO(j DUv
sFileName = sName; MJKl]&
this.nSplitter = nSpiltter; cYM~IA
U+PCvl=x
Cz@FZb8
} OZ'.}((?n
M2E87w
vk)0n=
public String getSSiteURL() 0\Yx.\X,
{ =ym
return sSiteURL; 4^[}]'w
} aaz"`,7_
+'['HQ)
|@ZqwC=
public void setSSiteURL(String value) (#B^Hyz!
{ 6{+_T
sSiteURL = value; }u-S j/K
} lIVxW+
P"9@8aLB
vDW&pF_eI>
public String getSFilePath() 4l ZJb
{ HKiVEg
return sFilePath; H*{k4
} kV\-%:-
Ue3B+k9w
}kCn@
public void setSFilePath(String value) P,/13tZ#3
{ `[@^m5?b-
sFilePath = value; 2rO)qjiH
} M*O(+EM
IQw %|^
*hZ~i{c,7
public String getSFileName() ;Lsjh#
{ GL5^_`n
return sFileName; i9;27tT~<
} }*.:Hv"
uGa(_ut
'l' X^LMD
public void setSFileName(String value) 0n*rs=\VG
{ VZ2.w4b
sFileName = value; ByhOK}u;P4
} 3|~(?4aE
V9zywM
gj[ >p=Wn
public int getNSplitter() WbQhlsc:
{ mX@j
return nSplitter; niYz9YX
} jy!f{dsC
Eg`R|CF
@TA8^ND
public void setNSplitter(int nCount) JN&MyA"
{ m)@Q_{=6M
nSplitter = nCount; Mr=}B6`
} Na. nA
} KP=D! l&q
t&R!5^R
C|4U78f{
/* |7QVMFZ
**Utility.java E 4='m
*/ p*pn@z
package NetFox; qSEB}1
66~e~F}z
%Lp2jyv.
public class Utility { MUbhEau?
3`&VRF8
V<i<0E
public Utility() pxw{
{ :3a&Pb*PL
;23=p=/h
n2n00%Wu[
} #"Eks79s
t7|MkX1
//线程睡眠 OgEUq''
public static void sleep(int nSecond) k40Ep(M}
{ 7$+P|U
try{ >oft :7p
Thread.sleep(nSecond); e=gboR
} W il{FcHY
catch(Exception e) u}Ei_ O<z
{ c8#T:HM|`
e.printStackTrace (); n> MD\ZS
} N@cMM1
} 5mI?pfm
3D 9N:c
//日志 Az9X#h.vf
public static void log(String sMsg) x*unye7
{ Z$!C=
System.err.println(sMsg); M MAAHo
} ?_VRfeztw
*he7BUO
e> ar
public static void log(int sMsg) ,'FD}yw4v
{ $Q8P@L)[
System.err.println(sMsg); k(zs>kiP
} GhqgRzX
} *-9#/Cp
T$H2'tK|
J3H.%m!V
/* d@-wi%,^
**TestMethod.java Sdgb#?MR|
*/ %S{o5txo
package NetFox; nHSTeFI?
uDILjOT
d4d\0[
public class TestMethod { &bB6}H(
U+4HG
7}<Sg
public TestMethod() 'oC$6l'rQ
{ ///xx/weblogic60b2_win.exe )*!1bgXQ
try{ 54=}GnZN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;xSRwSNDi(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >4Iv[ D1
SiteFileFetch fileFetch = new SiteFileFetch(bean); N\_( w:q
fileFetch.start(); "3@KRb4f
} Lb!r(o>8Cb
catch(Exception e){e.printStackTrace ();} dO+kPC
7k3p'FeS
HKpD2M
} PdR >;$1
Qqp)@uM^
PT mf
public static void main(String[] args) 6yN" l Q7
{ %h0D)6j
new TestMethod(); Am#m>^!qb
} BpH|/7
} LlU'_}>
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