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)); Cj{1H([-
} -'t)=YJ
for(int i=0;i<nEndPos.length-1;i++) 0:9.;x9_
{ xa<UM5eI
nEndPos = nStartPos[i+1]; vUohtS*
} XCU7xi$d
nEndPos[nEndPos.length-1] = nFileLength; L)@?e?9
} G#d{,3Gq1
} !,6c ~ w
C~o7X^[R\
X]wRwG
//启动子线程 vb<oi&X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |}(`kW
for(int i=0;i<nStartPos.length;i++) 7?GIS '
{ m^ tFi7c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^/\Of{OZ-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vgfcCcZ_iZ
nStartPos,nEndPos,i); (9Ux{@$o[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }]lr>"~y}
fileSplitterFetch.start(); @ycDCB(D}
} B?'#4J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \=:~ki=@B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y]/%t{Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +n{#V;J
nEndPos = " + nFileLength); mLP.t%?#
// fileSplitterFetch[nPos.length-1].start(); -f%'
-* WXMzr
+l9!Fl{MK\
//等待子线程结束 n1ly y0%u
//int count = 0; BG6B:
//是否结束while循环 4^WpS/#4
boolean breakWhile = false; <<+\X:,
^c^#dpn
4dO~C
while(!bStop) IC1NKn<k
{ $$Oey)*
write_nPos(); WvBc#s-
Utility.sleep(500); p i %<Sy
breakWhile = true; A OISs4
fI{&#~f4C
x:),P-~w
for(int i=0;i<nStartPos.length;i++) 5nT"rA
{ jL%x7?*U0
if(!fileSplitterFetch.bDownOver) W6?pswQ
{ ="Ho%*@6
breakWhile = false; eg(6^:z?f
break; OBOtuu.
} @k,z:~[C=
} =t9\^RIx)?
if(breakWhile) j27?w<
break; VH9dleZ
%?}33yV
LhOa{1SY
//count++; bCo7*<I4
//if(count>4) 6$kqaS##
// siteStop(); cq}EZ@ .
} '*5i)^
=Je[c,&j$?
QEz?w}b*
System.err.println("文件下载结束！"); B* ?]H*K
} JmxH"7hTE
catch(Exception e){e.printStackTrace ();} B:'J`M"N
} Z/k:~%|E
OGK}EI
~Sj9GxTe
//获得文件长度 i,>khc
public long getFileSize() '[AlhBX
{ 63\/ * NNB
int nFileLength = -1; XGYbnZ~
try{ K2TcOFQ
URL url = new URL(siteInfoBean.getSSiteURL()); "I3@m%qv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OLyf8&AU@
httpConnection.setRequestProperty("User-Agent","NetFox"); #.rdQ,)<
8aK)#tNWN
^q{9
int responseCode=httpConnection.getResponseCode(); |iakz|])
if(responseCode>=400) l4F%VR4KT
{ z* ^_)Z
processErrorCode(responseCode); SIBtmm1W
return -2; //-2 represent access is error =bfJ^]R
} wjHzE
8EW_V$>R
aOlT;h
String sHeader; dq(uVW^&ae
.YhA@8nc~l
"|EM;o
for(int i=1;;i++) LInz<bc<(
{ T1ut"Zu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4w*Skl=F}
//Utility.log(in.readLine()); 7?#J~.d5
sHeader=httpConnection.getHeaderFieldKey(i); >"^ O"E
if(sHeader!=null) ]O]4z,n
{ 2^r<{0@n
if(sHeader.equals("Content-Length")) }JF13beU
{ %'bM){
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /KFfU1
break; zwhe
} y&6FybIz
} N4v~;;@(
else fY{1F
break; H=<S 9M
} 3k\#CiB{
} Z_$%.
catch(IOException e){e.printStackTrace ();} Lf16j*}-Q
catch(Exception e){e.printStackTrace ();} (7vF/7BZ|_
t>L;kRujVJ
vmU@^2JSJ
Utility.log(nFileLength); J=\HO8E6>
#*D)Q/k
M\o9I
return nFileLength; >=qf/K+#
} )B T
r/YMLQ
\.0^n3y
//保存下载信息（文件指针位置） YJ^] u}
private void write_nPos() 7r7YNn/?
{ TITKj?*o
try{ ;ic3).H
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?Y$JWEPJ
output.writeInt(nStartPos.length); iJ-23_D
for(int i=0;i<nStartPos.length;i++) \MA+f~)9
{ IshKH-
// output.writeLong(nPos); .7Dtm<K#
output.writeLong(fileSplitterFetch.nStartPos); i5en*)O8
output.writeLong(fileSplitterFetch.nEndPos); Z~AO0zUKY
} V_R@o3kv;
output.close(); ./-5R|fN
} iIvc43YV%
catch(IOException e){e.printStackTrace ();} *M[?bk~~
catch(Exception e){e.printStackTrace ();} O[\iE5+$
} r(6Y*<
18|m)(W
QCD.YFM
//读取保存的下载信息（文件指针位置） srr :!5
private void read_nPos() q]\:P.x!>
{ GD&uQ`Y5
try{ ls_'')yp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); aEFJ;n7m
int nCount = input.readInt(); JUsQ,ETn
nStartPos = new long[nCount]; 9/{(%XwX
nEndPos = new long[nCount]; Y#]+Tm(+
for(int i=0;i<nStartPos.length;i++) .S!mf
{ [^R^8k
nStartPos = input.readLong(); #9B)Xx!g
nEndPos = input.readLong(); (jnzT=y
} y_'Ub{w
input.close(); Hu^1[#
} hjU::m,WX
catch(IOException e){e.printStackTrace ();} 0QBiC]9
catch(Exception e){e.printStackTrace ();} H~oail{EQ
} 0m7Y>0wC6T
x5|I
5<iV2Hx
private void processErrorCode(int nErrorCode) ,QOG!T4
{ OtY`@\hy
System.err.println("Error Code : " + nErrorCode); <m!h&_eg
} \n"{qfn`r
jPC[_g
~9?cn
//停止文件下载 _ ?TN;
public void siteStop() d4m=0G`
{ ?RX3MUN
bStop = true; *w$W2I>b7
for(int i=0;i<nStartPos.length;i++) $[9%QQk5<L
fileSplitterFetch.splitterStop(); ~{?_p@&n
E_gD:PPU5
S_iMVHe
} +cWLjPD/}
} A]y`7jJ
//负责部分文件的抓取 7.-V-?i
**FileSplitterFetch.java x9NEFtqjm
*/ ?42<J%p
package NetFox; u=Fv2
>@BnV{ d
> pgX^
import java.io.*; he#J|p
import java.net.*; y9_V
HPpR.
3yANv?$a
public class FileSplitterFetch extends Thread { I\hh8abAp
gwNq x"
-_ I_W&
String sURL; //File URL 3sc+3-TF
long nStartPos; //File Snippet Start Position MU>k,:[
long nEndPos; //File Snippet End Position *v?`<)P#
int nThreadID; //Thread's ID YW-usvl&
boolean bDownOver = false; //Downing is over H!vax)%-\
boolean bStop = false; //Stop identical s.EI`*xylY
FileAccessI fileAccessI = null; //File Access interface 2`.cK 3
?xK8#
b>_o xK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fz;iOjr>
{ TPVVck-T8
this.sURL = sURL; M]<?k]_p
this.nStartPos = nStart; UsgK
this.nEndPos = nEnd; R5"K]~
nThreadID = id; $GYm6x\4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tM2)k+fg
} tzZ63@cm
3WN`y8l
/`9sPR6e
public void run() aF8fqu\
{ SH3|sXH<
while(nStartPos < nEndPos && !bStop) ^<;V]cY`
{ h1:aKm!
b`L%t:u{d
r/& sub"X
try{ Z.d7U~_
URL url = new URL(sURL); Y;nZ=9Sw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f @8mS
httpConnection.setRequestProperty("User-Agent","NetFox"); ,PlO8;5]
String sProperty = "bytes="+nStartPos+"-"; >Wh}f3C
httpConnection.setRequestProperty("RANGE",sProperty); H&F9J^rC
Utility.log(sProperty); %509\;el
3Uqr,0$p
'iy*^A `Y
InputStream input = httpConnection.getInputStream(); ^?$WVB
//logResponseHead(httpConnection); vK(i9>;7
b:=TB0Fx?n
Fd?"-
byte[] b = new byte[1024]; y'FS/=u>0
int nRead; OF%B[h&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b5,x1`#7k
{ "8'@3$>R=
nStartPos += fileAccessI.write(b,0,nRead); jxiC Kx,G
//if(nThreadID == 1) 3:5 &Aa!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :k7uGD
} p7);uF^O%
;`l'2 z@N
"~=mG--I
Utility.log("Thread " + nThreadID + " is over!"); 1?)Xp|O
bDownOver = true; $k0kk
//nPos = fileAccessI.write (b,0,nRead); wx\v:A
} H(2!1?N+
catch(Exception e){e.printStackTrace ();} aUxGzMZ
} D6CS8 ~"
} MepuIh
7Q7-vx
\|]Z8t7
//打印回应的头信息 ,QC{3i~
public void logResponseHead(HttpURLConnection con) ;=geHiQHA
{ +zu(
for(int i=1;;i++) o[v\|Q`d
{ ak->ML
String header=con.getHeaderFieldKey(i); *\(r+>*x*
if(header!=null) /c"efnb!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ET_W-
Utility.log(header+" : "+con.getHeaderField(header)); ^M%uV
else z^_*&
break; so)"4 SEu
} SF}<{x_
} _ ):d`O e
F.-R r
vohoLeJTj
public void splitterStop() RletL)
{ <EPj$::
bStop = true; rEHkw '
} AtU v71D:
lZyG)0t,g
.Q@S #d
} W?0 lV5/
"Vw m
SrFS#
/* AjJURn0`,!
**FileAccess.java >ELlnE8
*//文件访问(定位，写) hX`hs-*qM
package NetFox; K`/`|1
import java.io.*; ?."&MZ
`W dD8E
,ldI2]
public class FileAccessI implements Serializable{ V$"ujRp
>N;F8v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JYrY[',u
RandomAccessFile oSavedFile; ZDD..j
long nPos; rsF\JQk
5DXR8mLoaJ
/;7y{(o
public FileAccessI() throws IOException y"6y!
{ e'*`.^
this("",0); +2K:qvzZ
} N[<H7_/3
cTXri8K_
H;U)b{
public FileAccessI(String sName,long nPos) throws IOException JCPUM*g8
{ FuUD 61JHY
oSavedFile = new RandomAccessFile(sName,"rw"); &K43x&mFF
this.nPos = nPos; pG34Qw
oSavedFile.seek(nPos); 21ppSN>
} -DN8Yb
|y h\
P7 ]z
public synchronized int write(byte[] b,int nStart,int nLen) 'Q =7/dY3I
{ 7}GK%H-u
int n = -1; WYIQE$SEv
try{ 277ASCWLkU
oSavedFile.write(b,nStart,nLen); ~%/Wupf
n = nLen; ?9HhG?_x
} E]J:~H'Er
catch(IOException e) &n[~!%(
{ Z1ALq5
e.printStackTrace (); iweD @b
} T1`|~Z?g-
qC_mu)6
zOHypazOTq
return n; Nrah;i+H\o
} [w0/\]o
GyW.2
[3W*9j
} 0l=+$&D
tM,%^){p$
ESg+n(R
/* O1D6^3w
**SiteInfoBean.java ~1*A
*/ dl5=q\1=
package NetFox; QN>7~=`
FG%j{_Ez
sBK <zR
public class SiteInfoBean { '~ 4pl0TWc
EQIUSh)M
oyk>vIZ
private String sSiteURL; //Site's URL ?( =p<TUw
private String sFilePath; //Saved File's Path 0@5E|<A
private String sFileName; //Saved File's Name 16X@^j_
private int nSplitter; //Count of Splited Downloading File Z~6[ Z
Fl{WAg
3ta$L"a
public SiteInfoBean() :%JC^dV(
{//nSplitter的缺省值为5 0rokR&Y-d
//default value of nSplitter is 5 S'U@X
this("","","",5); CKlL~f EL
} 2X88:
'R9g7,53R
bm}6{28R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~|Z'l%<Os
{ J$9:jE-4
sSiteURL= sURL; 64j|}wJ$
sFilePath = sPath; k$Rnj`*^
sFileName = sName; y69J%/c ra
this.nSplitter = nSpiltter; /^#G0f*N
u-DK_^v4M
!EF(*~r!9L
} (LJ@SeM;
'GJVWpvUU
IeF keE
public String getSSiteURL() ] c}91
{ uXQ >WI@eF
return sSiteURL; Di Or{)a
} kII7z;<^`
VjbG(nB?_
~ eN8|SR
public void setSSiteURL(String value) *(GZ^QH.
{ cs_}&!c{
sSiteURL = value; Di=9mHC
} oP,9#FC|(
BH@b1}
xi'<y
public String getSFilePath() %85Icg
{ !rTmR@e$/
return sFilePath; 6J%iZ
} (U87}}/l
IS]{}Y\3H
ua 8m;>R
public void setSFilePath(String value) }fIqH4bp
{ }qC SS<a
sFilePath = value; ARL
} d*;$AYI#R
J\W-dI
*,#q'!Hq
public String getSFileName() s`>H
{ o;J;*~g
return sFileName; @R:#"
} V2kWiyN
s3lJu/Xe{
oL *n>dH
public void setSFileName(String value) )&Z>@S^
{ c<qe[iyt/
sFileName = value; }.%s xw
} +cfziQ$'
_J"mR]I+
0B3 QVbp'
public int getNSplitter() 9[>Lp9l'
{ zW'/2W.
return nSplitter; ;9rTE|n
} ^eTZn[qH>w
=g0*MZ;"
;?im(9h"v!
public void setNSplitter(int nCount) sX'U|)/pD
{ :{CFTc5:A
nSplitter = nCount; MTB@CP!u
} h=f6~5l5
} Ff/Ig]Lb
Ve:&'~F2 s
T0L+z/N_m.
/* ggCr-
**Utility.java 7jezw'\=~
*/ M]0^ind
package NetFox; 4 ?2g&B\
_[$# b]V
wG:$6
public class Utility { S_T
FH -p!4+]
XWF7#xM
public Utility() s*{mT6s+T
{ QJM(UfHUD
=|#w.(3y
zPE#[\O21B
} {3SdX
ris;Iu^v0
//线程睡眠 Uf[T_
public static void sleep(int nSecond) R8{e&nPE
{ Z]e4pR6!
try{ hwZ6.
Thread.sleep(nSecond); toN
} qV?sg
catch(Exception e) u mqKFM$
{ 9g+UJ\u^
e.printStackTrace (); MyM+C}
} Ku&*`dME
} J2Y 3er
<q1'Li)_R
//日志 &V FjHW
public static void log(String sMsg) q'fPNQg
{ Yg|l?d"
System.err.println(sMsg); j`+0.Zlq
} WkcH5[
T!&jFy*W
XzN-slu!
public static void log(int sMsg) [ArO$X3\
{ bA0uGLc
System.err.println(sMsg); s|BX>1
} qU}lGf!dVn
} ^$8Vh=D
Qlf 9]ug)
HUD7{6}4
/* Sn+FV+D
**TestMethod.java olHH9R9:
*/ rSzQUn<
package NetFox; EI%M Azj}
li1v 4
65;|cmjv
public class TestMethod { v hR twi
u~ VswXc4
;K>{_kf
public TestMethod() (0X,Qwx
{ ///xx/weblogic60b2_win.exe 8H&_,;
try{ |K'Gw}fX/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l@~1CMyN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :QxL 9&"
SiteFileFetch fileFetch = new SiteFileFetch(bean); >a?OXqYP
fileFetch.start(); 9*7Hoi4Ji
} &NlS =
catch(Exception e){e.printStackTrace ();} xI-=tib
)PsN_ 42~
kQqBHA
} N)9pz?*V
9k714bnMLX
Fl8w7LcF7
public static void main(String[] args) E\ K
{ =# k<Kw#
new TestMethod(); i5ajM,i/K
} ;,Of\Efc|
} D2>hMc
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