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)); >g!a\=-[
} n1n1}
for(int i=0;i<nEndPos.length-1;i++) !4 4)=xW
{ c5?;^a[
nEndPos = nStartPos[i+1]; p4 #U:_
} 7.n/W|\
nEndPos[nEndPos.length-1] = nFileLength; =rV*iLy
} W2VH?-Gw
} xr uQ=Q
tK3.HvD
4}FuoQL
//启动子线程 {%(_Z`vI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]wg+zOJu]+
for(int i=0;i<nStartPos.length;i++) 7u"t4Or
{ 2,c{Z$\kn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #<X+)B6t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U5; D'G
nStartPos,nEndPos,i); OTA@4~{C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2jTP (b2b
fileSplitterFetch.start(); ]VifDFL}
} }|rnyYA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hKq#i8py
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NGD?.^ (G
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B{wx"mK
nEndPos = " + nFileLength); Iz/o|o]#
// fileSplitterFetch[nPos.length-1].start(); 8}3dwr;-
c7mIwMhl~
n&Q{ [E
//等待子线程结束 *Z! #6(G
//int count = 0; 'k=GSb
//是否结束while循环 A2{u("^[6
boolean breakWhile = false; #>+O=YO
- Dm/7Sxd`
7q>WO
while(!bStop) HhN;&67~Z
{ .'md `@t
write_nPos(); x:W nF62
Utility.sleep(500); kw8?:: <
breakWhile = true; 6b9 oSY-8
`+[e]dH
58"Cn ||tF
for(int i=0;i<nStartPos.length;i++) ]de'v
{ #<V/lPz+
if(!fileSplitterFetch.bDownOver) c <8s\2
{ hr&&"d {s
breakWhile = false; m}\G.$h4
break; p2N;-
} D[2I_3[wp
} 3fJGJW!zu
if(breakWhile) f>k<I[C<
break; ]iewukB4
5?+ECxPt
NIcPjo
//count++; xS%Z
//if(count>4) hnM?wn
// siteStop(); XK[cbVu
} zKr\S|yE
Hi$J@xU
T/DKT1P-
System.err.println("文件下载结束！"); A`Vz5WB
} 8OoKP4,;
catch(Exception e){e.printStackTrace ();} \F;V69'
} V)M+dhl
Q}p+/-U\
}D_h*9
//获得文件长度 ~|e?@3_G
public long getFileSize() RG [*:ReB9
{ \ct)/
int nFileLength = -1; @= f2\hU
try{ ~^((tT
URL url = new URL(siteInfoBean.getSSiteURL()); LAG*H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L&O!"[++
httpConnection.setRequestProperty("User-Agent","NetFox"); Az.(tJ X"
5z8CUDt 0
n?vw|'(}
int responseCode=httpConnection.getResponseCode(); '_& Xemz
if(responseCode>=400) q<mDs$^K
{ /t=R~BJu
processErrorCode(responseCode); )N`a4p
return -2; //-2 represent access is error uK6`3lCD
} xc[LbaBG
pPt7M'uL"
%n-:mSus
String sHeader; ]-d:wEj
UR|UGldt_T
HvSKR1wL\
for(int i=1;;i++) M{gtu'.
{ -oo&8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G+N&(:
//Utility.log(in.readLine()); yyke"D
sHeader=httpConnection.getHeaderFieldKey(i); T =r7FU
if(sHeader!=null) BgLW!|T[
{ '=?IVm#C
if(sHeader.equals("Content-Length")) w '?xewx
{ fZU#%b6G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +g8wc(<ik
break; qLkna
} ?;!d5Xuu
} UELni,$
else nN!/
break; Kbjt CI7
} CR*R'KX D%
} EgO=7?(pW
catch(IOException e){e.printStackTrace ();} Hn"xn79nc
catch(Exception e){e.printStackTrace ();} __HPwOCG7
e;KZTH;
Mf)0Y~_:R#
Utility.log(nFileLength); F(*~[*Ff
9U1cH qV
|:_WdU"Q]
return nFileLength; 16"eyt>
} 'f0*~Wq|
C2RR(n=N^
:7&#ej6
//保存下载信息（文件指针位置） "YbvI@pD
private void write_nPos() eekp&H$'s
{ .a._WZF
try{ ^E_`M:~
output = new DataOutputStream(new FileOutputStream(tmpFile)); xBH`=e<
output.writeInt(nStartPos.length); =ML6"jr
for(int i=0;i<nStartPos.length;i++) ?n o.hf
{ 19a/E1
// output.writeLong(nPos); 2Qg.b-C
output.writeLong(fileSplitterFetch.nStartPos); ({=: N
output.writeLong(fileSplitterFetch.nEndPos); ['%]tWT9
} LX{[9
output.close(); a1]@&Dr
} Bw2-4K\"kc
catch(IOException e){e.printStackTrace ();} D<9FSxl6
catch(Exception e){e.printStackTrace ();} q]F2bo
} T1TKwU8l
4%wP}Zj#
My'u('Q%
//读取保存的下载信息（文件指针位置） ?c712a ?
private void read_nPos() PM3kI\:)m
{ jbx@ty
try{ \sB a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *:r@-=M3=
int nCount = input.readInt(); ;WX)g&19x
nStartPos = new long[nCount]; fD1J@57
nEndPos = new long[nCount]; mY9^W2:
for(int i=0;i<nStartPos.length;i++) t,$4J6
{ vt0XCUnK
nStartPos = input.readLong(); {KJ!rT
nEndPos = input.readLong(); 6 R}]RuFQ
} JSXudz5c
input.close(); ,f0|eu>
} j'Ry.8}
catch(IOException e){e.printStackTrace ();} "&;>l<V
catch(Exception e){e.printStackTrace ();} K3jKOV8
} ] h3~>8<
Zcq'u jU
L&3Ak}sh
private void processErrorCode(int nErrorCode) ZuIr=`"j
{ Vae}:8'}
System.err.println("Error Code : " + nErrorCode); Pg[XIfBva
} ZdbZ^DUR<(
^`ah\L
: vN'eL|#
//停止文件下载 o*OYZ/_L
public void siteStop() XOsPKq
{ A[QUFk(
bStop = true; 6Yw;@w\
for(int i=0;i<nStartPos.length;i++) cVjs-Xf7D%
fileSplitterFetch.splitterStop(); FncK#hZ.
*?'nA{a)E
A&%vog]O
} dh r)ra]
} <GoUth.#
//负责部分文件的抓取 5Vo8z8]t`
**FileSplitterFetch.java 8,\toT7
*/ hM~9p{O
package NetFox; 2pR+2p`
`I|$U)'
eSvS<\p
import java.io.*; b77Iw%x7
import java.net.*; &NbhQY`k
GSzb
7:7i}`O
public class FileSplitterFetch extends Thread { bup)cX^
Db"jzMW.
_;baZ-
String sURL; //File URL O iRhp(
long nStartPos; //File Snippet Start Position f9FJ:?
long nEndPos; //File Snippet End Position &'{6_-kh
int nThreadID; //Thread's ID =6FA(R|QU
boolean bDownOver = false; //Downing is over z~b5K\/1B
boolean bStop = false; //Stop identical ^IgxzGD
FileAccessI fileAccessI = null; //File Access interface C3EQzr`
ktlI(#\%
Ny_d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &h1.9AO
{ cMxuG'{=.
this.sURL = sURL; OwhMtYq
this.nStartPos = nStart; R42+^'af
this.nEndPos = nEnd; *?sdWRbu}l
nThreadID = id; DC?U+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u#9H
} tkT:5O6
uE{r09^q\
~qFuS933
public void run() gaFOm9y.e
{ ?N*m2rv
while(nStartPos < nEndPos && !bStop) E= 3Ui
{ -/ 5" Py
l":\@rm`
qffVF|7
try{ fmqHWu*wG
URL url = new URL(sURL); z%ZAN-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "+SnHpNx
httpConnection.setRequestProperty("User-Agent","NetFox"); [D/q
String sProperty = "bytes="+nStartPos+"-"; `M0m`Up
httpConnection.setRequestProperty("RANGE",sProperty); ?` ?HqR0
Utility.log(sProperty); u-v/`F2wN
L1P.@hJ
n*twuB/P 1
InputStream input = httpConnection.getInputStream(); )1#J4
//logResponseHead(httpConnection); -U&k%X
p6)Jzh_/
?K5S{qG'O
byte[] b = new byte[1024]; v6uXik
int nRead; Jz"Yb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Rr>nka)U
{ < cNJrer
nStartPos += fileAccessI.write(b,0,nRead); L\)GPTo!x
//if(nThreadID == 1) }Xa1K;KM{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >@Vap
} =i'APeNaQ
3a|I| NP
Sfl. &A(
Utility.log("Thread " + nThreadID + " is over!"); >;wh0dBe
bDownOver = true; o:oQF[TcFO
//nPos = fileAccessI.write (b,0,nRead); *@;Pns]L-
} lVb{bO9-O
catch(Exception e){e.printStackTrace ();} [S Jx\Os
} X*'i1)_h
} d@d\9*mn
2%!yV~Z
r.WQ6h/eZ5
//打印回应的头信息 Fa]|Y
public void logResponseHead(HttpURLConnection con) JU>F&g/|
{ l~",<bTc
for(int i=1;;i++) 0oT~6BGm
{ "pRi1Y5)l
String header=con.getHeaderFieldKey(i); !>E$2}Q|]
if(header!=null) ,)u1r3@I^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^T>P
Utility.log(header+" : "+con.getHeaderField(header)); %s&"gWi
else Qs\m"yx
break; GXk]u
} Pp{Re|.
} KE$I!$zO
Vt4KG+zm
G;jX@XqZ
public void splitterStop() ;T-`~
{ A,PF#G(
bStop = true; TUy 25E
} 4,g[g#g<q
bd'io O
ZovF]jf k
} ?^} z
Ef)v("'w
g#*LJ`1
/* 4:Ton
**FileAccess.java ~DJILc
*//文件访问(定位，写) uW 7Yem&
package NetFox; >f\$~cp
import java.io.*; 3*8m!gq7s
\&XtPQ
d?6\
public class FileAccessI implements Serializable{ ^55q~DP}>
9*Z!=Y#4,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f%[0}.wp
RandomAccessFile oSavedFile; U;w| =vM
long nPos; (fqU73
xwhS[d
;{j@ia
public FileAccessI() throws IOException RKb{QAK!v
{ ->9waXRDz)
this("",0); R+&{lc
} ;owU]Xk%8K
TdKo"H*C
qsG}A
public FileAccessI(String sName,long nPos) throws IOException '/U%-/@
{ VX6M4<8
oSavedFile = new RandomAccessFile(sName,"rw"); 'hNRIM1
this.nPos = nPos; V*,6_-^l
oSavedFile.seek(nPos); *KYh_i
} uY;7&Lw y1
)u?^w
cgV5{|P
public synchronized int write(byte[] b,int nStart,int nLen) 1lLXu
{ -IE=?23Do?
int n = -1; "2_nN]%u-
try{ %|(Cb!ySX
oSavedFile.write(b,nStart,nLen); P;bOtT --
n = nLen; wl Nl|+ K
} b O9PpOk+z
catch(IOException e) O*lMIWx
{ HO}eu
e.printStackTrace (); v"x'rx#
} F9J9zs*,
|Duf 3u
cv7.=*Kb;
return n; rD!UP1Nb
} #,S0uA
2{A/Fbk
]N^>>k
} 0f;`Zj0l8
1 ~s$<
=`+c}i?
/* p?,T%G+gqO
**SiteInfoBean.java N"Cd{3
*/ WqRaD=R->;
package NetFox; 5E!Wp[^
Hdda/?{b
zlhU[J}"1|
public class SiteInfoBean { }>yQ!3/i
92D :!C
lEC91:Jyt
private String sSiteURL; //Site's URL Ih_=yk
private String sFilePath; //Saved File's Path )YPut.
private String sFileName; //Saved File's Name jmr1e).];
private int nSplitter; //Count of Splited Downloading File +5N09$f;R
1$v1:6
7hAc6M$h;
public SiteInfoBean() A 6j>KTU
{//nSplitter的缺省值为5 A3A"^f$$
//default value of nSplitter is 5 #eY?6Kjn
this("","","",5); Ou5,7Ne
} gE$@:j
w=x [=O
evE$$# 6R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D.,~I^W
{ 115zvW
sSiteURL= sURL; :^J'_
sFilePath = sPath; EMw biGV
sFileName = sName; fctVJ{?
this.nSplitter = nSpiltter; pIgjo>K
-!-1X7v|Fp
8C4v
} m%.7l8vT
UEH+E&BCC
^~DClZ
public String getSSiteURL() 0#!Z1:Y
{ QN8.FiiD
return sSiteURL; ~+anI
} JU!vVA_
r!)jxIL\
V~4yS4
public void setSSiteURL(String value) *GC9o/
{ .ZVo0
sSiteURL = value; sSsRn*LN-:
} a3B^RbDP&8
m ol|E={si
9D H}6fO
public String getSFilePath() R zn%!d^$>
{ !^IAn
return sFilePath; x`Ik747^v
} o]WG8Mo-
dL|*#e
f1RX`rXf
public void setSFilePath(String value) JAS!eF
{ ;2Za]%'
sFilePath = value; *v0}S5^/"
} y R_x:,|g
}x+s5a;!3/
X.)D"+xnH
public String getSFileName() tRmH6
{ ^<v]x; 3
return sFileName; O;SD90
} iNEE2BPp
@WO>F G3
{PQ!o^7y
public void setSFileName(String value) DS>qth
{ XFrgnnt
sFileName = value; Qh!h "]
} (7?jjH^4
I>%@[h,+
{GKqOu
public int getNSplitter() rEY5,'?YHv
{ lPOcX'3\
return nSplitter; =7 ${bp!
} {+x;J4
tjt#2i8/
{aYCrk1
public void setNSplitter(int nCount) /+{1;}AT
{ 9/4Bx!~A
nSplitter = nCount; > @n?W"
} %#-'|~
} "bk'#?9
}@NT#hD
K0z@gWGE
/* |c3Yh,Sv
**Utility.java sA[eKQjaD
*/ -?PXj)<
package NetFox; JN<IMH
"M4gl
_do(
public class Utility { 2` j#eB1
s5D<c'-
2kQa3Pan
public Utility() 8[mj*^P
{ =3<@{^Eg
N[8y+2SZ
[" nDw<U
} ?R\:6x<
5$Aiez~tBq
//线程睡眠 r-IG.ym3
public static void sleep(int nSecond) t*cVDA&K
{ i}}}x
try{ Hsi<!g.
Thread.sleep(nSecond); >2@ a\
} pi?[jU[Tn
catch(Exception e) ,?ci+M)
{ z{ydP Ra
e.printStackTrace (); XbL\l
} wC4:OJ[d
} &W:R#/|
HE>sZ;
//日志 #+6t|
public static void log(String sMsg) T!pjv8y@R
{ q'4qSu
System.err.println(sMsg); &a];"2
} 4>$weu^
M}*#{UV2
K_t!P
public static void log(int sMsg) U2)y fhI
{ >Pw ZHY
System.err.println(sMsg); \`$RY')9|!
} sCwX|
} CxW-lU3G`
7d"gRM;
ECF \/12
/* ;^Y]nsd
**TestMethod.java wk (}q
*/ )OgQ&,#
package NetFox; D?<R5zp
o6~9.~_e
gBCO>nJws
public class TestMethod { ~76qFZe-
*g;4?_f
b+qdl`Vd
public TestMethod() A3=$I&!%
{ ///xx/weblogic60b2_win.exe 35X4] t
try{ >7^i>si
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WG?;Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GVt}\e~"
SiteFileFetch fileFetch = new SiteFileFetch(bean); S|HnmkV66
fileFetch.start(); j,BiWgj$8
} -yH8bm'0"
catch(Exception e){e.printStackTrace ();} H^\2,x Z
}9,^=g-
A/+bwCDP
} _]~= Kjp
jQLiqi`
%.+#e
public static void main(String[] args) =fZMute
{ >84:1`
new TestMethod(); P-c<[DSM'I
} 3~&h9#7Ke
} :4, OA
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