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)); lPyY
} 5w+KIHhN|
for(int i=0;i<nEndPos.length-1;i++) r&y0`M
{ @/,:". SM
nEndPos = nStartPos[i+1]; tSVWO]<
} SYE+A`a
nEndPos[nEndPos.length-1] = nFileLength; xk*&zAt
} YLsOA`5X
} ZO#f)>s2
E#!tXO&,
kfV}ta'^S
//启动子线程 0Fw4}f.o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5(=5GkE)>
for(int i=0;i<nStartPos.length;i++) YWFq&II|Z
{ 4^Y{ BS fF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), omMOA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Cvp!(<<gK
nStartPos,nEndPos,i); ZccvZl ;b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9?XQB%44
fileSplitterFetch.start(); 4=~+Bz
} n "bii7h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #PkZi(k hv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &"r /&7:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >I@VHl O
nEndPos = " + nFileLength); ?Xl;>}zj
// fileSplitterFetch[nPos.length-1].start(); gHo sPY[
X`6"^ xme
7 'q *(v
//等待子线程结束 QdrZi.qKH
//int count = 0; g7"2}|qxo
//是否结束while循环 (QTF+~)
boolean breakWhile = false; x:K~?c3
:N^+!,i
y1)ZO_'
while(!bStop) yT~rql
{ -|GKtZ]}
write_nPos(); uCr :+"C
Utility.sleep(500); ?o6X_UxW!
breakWhile = true; (Z0_e&=*
^B)f!HtU
QR2S67-
for(int i=0;i<nStartPos.length;i++) ~].?8C.>*
{ CkV5PU
if(!fileSplitterFetch.bDownOver) Qhq' %LR
{ w^"IR
breakWhile = false; v YJ9G"E
break; ;_=N YG.
} PU,%Y_xR
} UCt}\IJ
if(breakWhile) /go|r '
break; )qRH?Hsb7
Vel}lQD
%s! |,Cu
//count++; H76iBJ66
//if(count>4) s IFE:/1,
// siteStop(); lrAhdi
} -VeCX]
xg}Q~,:
bksv2@ar
System.err.println("文件下载结束！"); ?I[*{}@n"
} : eCeJ~&E
catch(Exception e){e.printStackTrace ();} 3vs{*T"
} 0|Xz-Y
N=PSr4
EE^x34&=
//获得文件长度 kuI~lBWI
public long getFileSize() `a%MD>R_Lg
{ ?P}bl_
int nFileLength = -1; " Lh&s<[
try{ %.m+6 zaF
URL url = new URL(siteInfoBean.getSSiteURL()); Xhq7)/jp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <iA\ZS:
httpConnection.setRequestProperty("User-Agent","NetFox"); /5<=m:
EV?U !O
:KgH7s}
int responseCode=httpConnection.getResponseCode(); sH.=Faos
if(responseCode>=400) f S[-K?K
{ &s(J:P$!
processErrorCode(responseCode); =W &Mt
return -2; //-2 represent access is error "M, 1ElQ
} y^"@$
p- a{6<h
~o>Gm>5!HH
String sHeader; Zwm/c]6`
W#%s0EN<_
f1]zsn:
for(int i=1;;i++) _1NK9dp:
{ EJ>&\Iq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a}uYv:
//Utility.log(in.readLine()); |{&M#qXe
sHeader=httpConnection.getHeaderFieldKey(i); {fnx=BaG
if(sHeader!=null) 1X[^^p~^
{ x9,jXd
if(sHeader.equals("Content-Length")) n m<?oI*\
{ {vGJ}q?Sd"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s-_D,$ |
break; j)2I+[aoB
} <)p.GAZ
} r=&,2meo
else *68 TTBq(
break; Z;%uDlcXI
} p"#\E0GM
} ~W[I
catch(IOException e){e.printStackTrace ();} {G Jl<G1
catch(Exception e){e.printStackTrace ();} ] \M+ju
>UMxlvTg&
c7jmzo
Utility.log(nFileLength); {Q3OT
~g\~x
oX;.v9a
return nFileLength; HJ]xZ83pC
} R7/S SuG6\
MzD1sWmK
w.-x2Zg},
//保存下载信息（文件指针位置） -BH/)$-$
private void write_nPos() !1G KpL
{ `UTPX'Vz
try{ 8i154#l+\
output = new DataOutputStream(new FileOutputStream(tmpFile)); -;7xUNQ
output.writeInt(nStartPos.length); Zp>v
for(int i=0;i<nStartPos.length;i++) 7a1o#O
{ /[<F f
// output.writeLong(nPos); >jX"
output.writeLong(fileSplitterFetch.nStartPos); w6i2>nu_O
output.writeLong(fileSplitterFetch.nEndPos); PjeI&@
} oFj_o
output.close(); #NW+t|E
} 4<i#TCGex3
catch(IOException e){e.printStackTrace ();} NX&dJ 6a
catch(Exception e){e.printStackTrace ();} cuN9RG
} HG;;M6
kk /#&b2
[kg?q5F)
//读取保存的下载信息（文件指针位置） ENZym
private void read_nPos() 2g= 6s
{ 1.du#w
try{ SBreA-2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N1Vj;-
int nCount = input.readInt(); a;xeHbE
nStartPos = new long[nCount]; $|=|"/
nEndPos = new long[nCount]; ,Z~`aHhr
for(int i=0;i<nStartPos.length;i++) 9^XZ|`
{ ^I!Z)/
nStartPos = input.readLong(); :}e<
nEndPos = input.readLong(); |M;Nq@bRv
} gw)4P tb!
input.close(); ,D;8~llM
} \}$|Uo$O
catch(IOException e){e.printStackTrace ();} dPEDsG0$a
catch(Exception e){e.printStackTrace ();} ^3dc#5]Xf
} I{89chi
q`1tUd4G
#kv9$
private void processErrorCode(int nErrorCode) 8g0 #WV
{ h-96 2(LG
System.err.println("Error Code : " + nErrorCode); >%tP"x{
} :^]Po$fl
G<?RH"RZr
v WXo#
//停止文件下载 |HycBTN#E
public void siteStop() 4;6"I2;zfG
{ Fqeqn[,
bStop = true; @&m [w'tn
for(int i=0;i<nStartPos.length;i++) p%$r\G-x
fileSplitterFetch.splitterStop(); N/o?\q8
~EBaVl ({
ec!e
} }rJqMZ]w
} ?ES{t4"
//负责部分文件的抓取 I0F[Z\U
**FileSplitterFetch.java 2E-Kz?,:[
*/ w: BJ4bi=
package NetFox; 'l/l]26rO4
^VYR}1Mw
gveGBi
import java.io.*; Vx!ZF+
import java.net.*; 12 )
.uA O.<
Kh3i.gm7g
public class FileSplitterFetch extends Thread { \;-Yz
;rf{T[i
!\'w>y7
String sURL; //File URL .Yk}iHcW.
long nStartPos; //File Snippet Start Position !S<p"
long nEndPos; //File Snippet End Position `m'RvUc
int nThreadID; //Thread's ID W _[9
boolean bDownOver = false; //Downing is over J)g +I
boolean bStop = false; //Stop identical ~[!Tpq5
FileAccessI fileAccessI = null; //File Access interface LiEEQ
<RxxGD
9+(b7L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %{ U (y#
{ @^0}wk
this.sURL = sURL; :LuA6
this.nStartPos = nStart; &v]xYb)+<
this.nEndPos = nEnd; F4=X(P_6
nThreadID = id; /\fR6|tJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C,ldi"|
} 6Lq8#{/]u
E7$ aT^
LI-ewea
public void run() WDnNVE
{ k Jz^\Re
while(nStartPos < nEndPos && !bStop) k7JC~D E#
{ "S@]yL
+ $M<ck?Bo
XFFm'W6@
try{ +v%+E{F$+
URL url = new URL(sURL); y@}WxSK*0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9|jMN j]vo
httpConnection.setRequestProperty("User-Agent","NetFox"); yodhDSO5i
String sProperty = "bytes="+nStartPos+"-"; UChLWf|'
httpConnection.setRequestProperty("RANGE",sProperty); *r4FOA%P
Utility.log(sProperty); >]B_+r0m^
\`8$bpW[nS
&|IO+'_
InputStream input = httpConnection.getInputStream(); bz:En'2>F
//logResponseHead(httpConnection); DFwiBB6
r{~b4~kAf5
pvWNiW:~k
byte[] b = new byte[1024]; PYCG#U
int nRead; 2n"-~'3\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dM"5obEb
{ YxnZ0MY
nStartPos += fileAccessI.write(b,0,nRead); J^WX^".E
//if(nThreadID == 1) dRs\e(H'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #-L<
} 1< b~="
mJ8EiRSE
"SuG6!k3
Utility.log("Thread " + nThreadID + " is over!"); #m{F*(%
bDownOver = true; U*EBH
//nPos = fileAccessI.write (b,0,nRead); !FK)iQy$0
} ,A#gF_8
catch(Exception e){e.printStackTrace ();} &/Gf@[
} 9r:|u:i7m
} 3W[||V[r]<
\0*dKgN
_+Z;pt$C
//打印回应的头信息 HH3Z?g
public void logResponseHead(HttpURLConnection con) ;<MHl[jJD
{ 4<EC50@.
for(int i=1;;i++) Ga^:y=m
{ '0Q/oU
String header=con.getHeaderFieldKey(i); ,-n_(U
if(header!=null) &i805,lx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <UIE-#
Utility.log(header+" : "+con.getHeaderField(header)); >y!R}`&0^t
else 'K23oQwDB
break; k/Urz*O
} xxgdp. (
} N5MWMN[6aP
29z@ !
PTQN.[bBh
public void splitterStop() =OrVaZ0
{ DLq'V.M:
bStop = true; .5~3D97X&
} Eg4&D4TGp
Q*f0YjH!
Rto/-I0l
} ~1Ffu x
ZlMS=<hgFx
6m:$RW
/* p`"Ic2xPJ
**FileAccess.java on7?V<
*//文件访问(定位，写) l>oJ^J
package NetFox; : t D`e<
import java.io.*; ;Rxc(tR!n
nWd;XR6|
NwKj@Jos
public class FileAccessI implements Serializable{ f(EO|d^u
&j"_hFhv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1O2V!?P
RandomAccessFile oSavedFile; *mw *z|-^V
long nPos; U@}r?!)"f
|41~U\
@E> rqI;`
public FileAccessI() throws IOException }?CKE<#%
{ ws;|fY
this("",0); M>*xbBl
} b-#oE{(\'
$}H,g}@0
msq2/sS~
public FileAccessI(String sName,long nPos) throws IOException [.;I}
{ 2p*!up(
oSavedFile = new RandomAccessFile(sName,"rw"); ACEVd! q
this.nPos = nPos; (F*y27_u
oSavedFile.seek(nPos); tt&{f <*
} <`BDN
;6=*E'
|/u,6`
public synchronized int write(byte[] b,int nStart,int nLen) [t?:CgI)E
{ pe!"!xJE
int n = -1; R$2\Xl@qQF
try{ i66/2BUh.
oSavedFile.write(b,nStart,nLen); SO`b+B
n = nLen; AgOti]`aR
} C)cuy7<
catch(IOException e) rj29$d?Y9
{ 5',&8
e.printStackTrace (); .07kG]
} [KEw5-=i@
;IT'6m`@W
:?gp}.
return n; t&o&gb
} b:x~Jz#%2
Rf!$n7& \
,}^FV~
} Rz<'&Z>;
"!#KQ''R
yi<H }&
/* IRsyy\[kp8
**SiteInfoBean.java m*14n_m'
*/ o#-^Lg&
package NetFox; ^HWa owy=
RV@mAw.T
NC"X{$o2
public class SiteInfoBean { Dyj>dh-
DNRWE1P2bg
o}L\b,])
private String sSiteURL; //Site's URL Vo(bro4ZQi
private String sFilePath; //Saved File's Path 5QG?*Z~?7
private String sFileName; //Saved File's Name %/r:iD
private int nSplitter; //Count of Splited Downloading File wYd{X 8$
yh+.Yn=+
Y";KWA}b
public SiteInfoBean() !!)NER-dv
{//nSplitter的缺省值为5 r:t3Kf`+E-
//default value of nSplitter is 5 > q8)~
this("","","",5); |cl*wFm|3
} rrs0|=
dSE"G>l8
/!pJ"@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2zkOs:
{ m :2A[H+
sSiteURL= sURL; 6&"GTK
sFilePath = sPath; ($,qxPOn
sFileName = sName; -T>i5'2)
this.nSplitter = nSpiltter; YN7JJJ/~T
}k@SmO8
Eg_ram`\R
} iE^=Vf;
O0sLcuT$
vSwRj<|CF
public String getSSiteURL() (~?p`g+I.P
{ "6i3'jc`
return sSiteURL; n"Wlfd0
} *~`BG5w
Ed1y%mR>
O_v*,L!
public void setSSiteURL(String value) UYhxgPGsj
{ 1P G"IaOb
sSiteURL = value; SL`nt
} Lv<vMIr
C/q!!
3]pHc)p!.
public String getSFilePath() se29IhS!e
{ rw[Ioyr-
return sFilePath; pzeCdHF
} JD]uDuE
a" L9jrVrw
`r&]Ydu:
public void setSFilePath(String value) Q6xA@"GJ
{ FQ u c}A
sFilePath = value; M[QQi2:&
} ]&X}C{v)G
x!n8Wx
k\-h-0[|
public String getSFileName() HmbQL2
{ $#E!/vVwD7
return sFileName; N{uVh;_
} plM:7#eA
,OFNV|S$
yV*4|EkvW
public void setSFileName(String value) m"wP]OQH*+
{ ^p3W}D
sFileName = value; ]#vi/6\J
} sEi9<$~R@0
b8glZb*$
gKtgW&PYm
public int getNSplitter() =X7_!vSv
{ $ByP 9=|
return nSplitter; XJ7pX1nf
} "6Z(0 iu:{
\t)`Cp6,[b
/|isRh|
public void setNSplitter(int nCount) \J(kM,ZJ
{ 9T0g%&
nSplitter = nCount; `yO'-(@"gY
} #@F.wV0
} &_74h);2I:
~yJJ00%
%Rk DR
/* :TkMS8
**Utility.java e9>~mtx
*/ `UTUrM
package NetFox; <(i5hmuVd
^,aI2vC
HEw&'
public class Utility { W:K'2j
I+ Y{_yw"f
BAtjYPX'w
public Utility() jwP5pu
{ 3cF8DNh
fElFyOo+
nkf7Fq}
} ?hViOh$.
[v`kqL~
//线程睡眠 :aH5=@[!y
public static void sleep(int nSecond) gFsqCx<q
{ Eihn%Esa
try{ QQv%>=_`
Thread.sleep(nSecond); <T&v\DN
} '.&Y)A6!
catch(Exception e) D}Sww5ZmP
{ h`iOs>
e.printStackTrace (); Hz)i.AA 4
} u08QE,
} QWtDZ>
(e0(GOqf4
//日志 KC)}Mzt6_
public static void log(String sMsg) r-.>3J
{ 6@eF|GoP
System.err.println(sMsg); :>U+HQll
} E;[Uhh|78!
dT[JVl+3=
'by+hXk
public static void log(int sMsg) 4u+0 )<
{ uqLP$At
System.err.println(sMsg); dCeLW
} Nd&UWk^
} XK})?LTD
n>w<vM
NpaS2q-d
/* IdK<:)Q
**TestMethod.java n2EPx(~
*/ Qj*.Z4ue
package NetFox; xF@&wg
jFUpf.v2
MpBdke$
public class TestMethod { ~9E_L?TW*
"%\hDL;
@\o"zU
public TestMethod() I2Imb9k~B
{ ///xx/weblogic60b2_win.exe D <R_eK
try{ G? XS-oSv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @5ud{"|2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ri~$hs!
SiteFileFetch fileFetch = new SiteFileFetch(bean); *0to,$ n
fileFetch.start(); *@H\J e`
} .6xMLo,R
catch(Exception e){e.printStackTrace ();} <fM}Kk
qR_>41JU"
@Z2np{X:
} WTJ{M$
o+7)cI
x~vNUyEN)
public static void main(String[] args) Fx|`0LI+C
{ _DH^ K9,9
new TestMethod(); ');vc~C
} 0Q`v#$?":
} U||GeEd
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