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)); K]RkKMT,
} vsc&$r3!5{
for(int i=0;i<nEndPos.length-1;i++) rXA7<_Vg
{ |XeuqZa
nEndPos = nStartPos[i+1]; zdr?1=
} 7.]ZD`"Bb
nEndPos[nEndPos.length-1] = nFileLength; gbF.Q7?$u
} 67d0JQTu
} -E.EI@"
sC/T)q2
F$)Ki(mq
//启动子线程 vQA: \!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tvP"t{C6,
for(int i=0;i<nStartPos.length;i++) &DgIykqN
{ 't wMvm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WO]dWO6Mm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m~#O ~)
nStartPos,nEndPos,i); zp d4uto5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x}-rAr
fileSplitterFetch.start(); gCd9"n-e
} "}EydG"=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t0/fF'GZD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sURHj&:t|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "xw2@jGpG
nEndPos = " + nFileLength); Z[|(}9v?~
// fileSplitterFetch[nPos.length-1].start(); N1_nBQF )
^/c&Ud
=8[HC}s|$
//等待子线程结束 0LxA+
//int count = 0; ;gf^;%FK
//是否结束while循环 Up`zVN59.
boolean breakWhile = false; ]U]{5AA6
xZBmQ:s',S
PZQ}G*p3
while(!bStop) ceAK;v o
{ lv,<[Hw1
write_nPos(); d!!5'/tmS
Utility.sleep(500); u"tv6Qp
breakWhile = true; X=-pNwO
|Zz3X
"{|9Yis=
for(int i=0;i<nStartPos.length;i++) r%F{1.
{ 'H:lR1(,
if(!fileSplitterFetch.bDownOver) Rom|Bqo;
{ BB9Z?}
breakWhile = false; b bX2D/
break; B2VUH..am
} 6MF%$K3
} a(!:a+9WOP
if(breakWhile) A:>G:X5t
break; amOBUD5Ld`
SI U"cO4
wC;N*0Th
//count++; ]e 81O#t3
//if(count>4) R:zjEhH)
// siteStop(); >AV?g8B;
} -49OE*uF
_<&IpT{w+
KD=T04v
System.err.println("文件下载结束！"); J %URg=r
} u JGYXlLE
catch(Exception e){e.printStackTrace ();} }Z"<KF
} ^2XoYgv
&H<-joZ)Z\
ewD61Y8-
//获得文件长度 !ZHPR:k|
public long getFileSize() FX 0^I 0
{ vV,H@WK
int nFileLength = -1; 4>gkXfTF
try{ XV]`?
URL url = new URL(siteInfoBean.getSSiteURL()); %.[t(F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |{<g-)
httpConnection.setRequestProperty("User-Agent","NetFox"); n"$D/XJO
%mg |kb6n
=D<46T=(RB
int responseCode=httpConnection.getResponseCode(); YB.r-c"Y
if(responseCode>=400) ZmUS}
{ hI]KT a
processErrorCode(responseCode); P*Uu)mG)G
return -2; //-2 represent access is error |&o%c/
} /\(0@To
mq do@
mS6L6)] S
String sHeader; OANn!nZ.
#P<v[O/rA
JEGcZeq)
for(int i=1;;i++) 26&^n Uy
{ AS'a'x>8>,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 79z(n[^
//Utility.log(in.readLine()); RV.*_FG
sHeader=httpConnection.getHeaderFieldKey(i); 52,pCyU
if(sHeader!=null) qJKD|=_
{ hT#[[md"
if(sHeader.equals("Content-Length")) `fj(xrI
{ mM&H;W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8S&`
break; [wi "
} v_En9~e^n
} o *S"`_
else 1B}6 zJ
break; T1LtO O
} !Yz~HO,u+
} 'cu( Sd}
catch(IOException e){e.printStackTrace ();} z ~T[%RjO
catch(Exception e){e.printStackTrace ();} @_YlHe&W
y!h$Z6.
g< M\zD
Utility.log(nFileLength); OIe {Sx{y
)UO:J7K
FU E/uh
return nFileLength; OXK?R\ E+
} ZjF$zVk
~ucOQVmz@
.yd{7Te
//保存下载信息（文件指针位置） 80x %wCY`
private void write_nPos() 0bVtku K;G
{ FDkRfhK
try{ VX2KE@
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1.4]T, `
output.writeInt(nStartPos.length); s 'u6Ep/V
for(int i=0;i<nStartPos.length;i++) ^8a,gA8.
{ -"UK NB!
// output.writeLong(nPos); (&=-o(
output.writeLong(fileSplitterFetch.nStartPos); k:nr!Y<
output.writeLong(fileSplitterFetch.nEndPos); [>=D9I@~
} K, WNM S
output.close(); ]3BTL7r
} m1heU3BUWU
catch(IOException e){e.printStackTrace ();} EgFV
catch(Exception e){e.printStackTrace ();} ;@Alr?y
} ;^^u_SuH
u`xmF/jhQ
DvKM[z3j
//读取保存的下载信息（文件指针位置） dw5.vXL`
private void read_nPos() n{6XtIoYq
{ 6@t4pML
try{ U"v(9m@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); No=Ig-It
int nCount = input.readInt(); G^ZL,{
nStartPos = new long[nCount]; @kenv3[Lc
nEndPos = new long[nCount]; FVPhk2
for(int i=0;i<nStartPos.length;i++) H 0aDWFWS
{ ~*GJO74
nStartPos = input.readLong(); J}Bg<[n
nEndPos = input.readLong(); ka0T|$ u(s
} 5?&k? v@
input.close(); rbHrG<+7zO
} Xai ,
catch(IOException e){e.printStackTrace ();} CS)&A4`8
catch(Exception e){e.printStackTrace ();} ;EP7q[
} J^R))R=
s/Fc7V!;
Z,M?!vK
private void processErrorCode(int nErrorCode) Py^F},?J
{ tV<}!~0,*
System.err.println("Error Code : " + nErrorCode); KwndY,QD
} Og4 X3QG
2asA]sY
R] tHd=kf
//停止文件下载 5)+(McJC
public void siteStop() AyB-+oTf(
{ oJ ~ZzW
bStop = true; E3<jH
for(int i=0;i<nStartPos.length;i++) Kn SXygT
fileSplitterFetch.splitterStop(); QXY-?0RO#
};o6|e:2E
*]nha1!S
} OmQSNU.our
} UO47XAO
//负责部分文件的抓取 zmQ V6o=k
**FileSplitterFetch.java %<6oKE
*/ IHZ WNT2
package NetFox; 'S@%
iA3d[%tBb
FbO-K-
import java.io.*; $Q{)AN;m
import java.net.*; +Pd&YfU9
_A|1_^[G(
,UopGlA ,
public class FileSplitterFetch extends Thread { 4(o: #9I
i[`nu#n/
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String sURL; //File URL y44FejH(v
long nStartPos; //File Snippet Start Position RIJ+]uir4
long nEndPos; //File Snippet End Position T8h.!Vef
int nThreadID; //Thread's ID sesr`,m.,
boolean bDownOver = false; //Downing is over :~3sW< PR
boolean bStop = false; //Stop identical 1k6f|Al-
FileAccessI fileAccessI = null; //File Access interface Wp/!;
H0Qpc<Z4/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MNzq,/Wf
{ wv>Pn0cO
this.sURL = sURL; }jBr[S5
this.nStartPos = nStart; AR\>P
this.nEndPos = nEnd; JP)/ O!
nThreadID = id; '}dlVf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pN6!IxN$
} "(PJh\S>S
3Q*K+(`{
r5%K2q{
public void run() #F@53N
{ %_;q<@9)
while(nStartPos < nEndPos && !bStop) \u?z:mV
{ M7^PWC
\~UyfVPRT
Ck8`$x&t
try{ O Ul+es
URL url = new URL(sURL); N3g[,BE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _m;0%]+
httpConnection.setRequestProperty("User-Agent","NetFox"); EKZ40z`
String sProperty = "bytes="+nStartPos+"-"; XL c&7
httpConnection.setRequestProperty("RANGE",sProperty); zuUf:%k}I
Utility.log(sProperty); ;ZPAnd:pb
.%_scNP
d!7cIYVZ
InputStream input = httpConnection.getInputStream(); KT~J@];Fb
//logResponseHead(httpConnection); Z+`mla
S!A)kK+
A^ $9[_
byte[] b = new byte[1024]; $j0]+vT
int nRead; #~*fZ|sq+3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ';us;xR#
{ I~y[8
nStartPos += fileAccessI.write(b,0,nRead); 3C 84b/A
//if(nThreadID == 1) ,uqSq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AX}l~ sv
} \!j{&cJ
S9d+#6rn
*X+T>SKL
Utility.log("Thread " + nThreadID + " is over!"); (`x6QiG!
bDownOver = true; CT+pkNC
//nPos = fileAccessI.write (b,0,nRead); jJdw\`
} cG1-.,r
catch(Exception e){e.printStackTrace ();} oNY;z-QK
} \g< M\3f
} PeEf=3
:]iV*zo_
*i|O!h1St
//打印回应的头信息 NlXHOUw)u
public void logResponseHead(HttpURLConnection con) x!fvSoHp
{ \gaGTc2&
for(int i=1;;i++) Ug*:o d
{ Os' 7h
String header=con.getHeaderFieldKey(i); P9; =O$s
if(header!=null) W=41jw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D@*<p h=
Utility.log(header+" : "+con.getHeaderField(header)); ,2q LiE>
else -twV?~f
break; rU`#3}s
} SjV;& 1Z/
} "& 'h\
cdVh_"[
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public void splitterStop() M@EML @~
{ \&ra&3o
bStop = true; hE0 p>R8
} O`5PX(J1&
Sx?IpcPSm
jR`q y<
} Tm~a&p
L^uO.eI"m
\L}aTCvG
/* &+;z`A'|8
**FileAccess.java vggyQf%
*//文件访问(定位，写) <gRv7 ?V[z
package NetFox; ysm)B?+k
import java.io.*; ku3Vr\s
<o,]f E[
f#}P>,TP
public class FileAccessI implements Serializable{ K n%[&
37Ux2t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]+\;pb}bq
RandomAccessFile oSavedFile; ~6L\9B)
long nPos; z}&w7O#
:5IbOpVM
PrqN5ND
public FileAccessI() throws IOException vp7J';
{ kaf4GME]
this("",0); xU+c?OLi
} <|9s{z
l\<*9m<
>utm\!Gac
public FileAccessI(String sName,long nPos) throws IOException INqD(EG
{ KR4X&d6
oSavedFile = new RandomAccessFile(sName,"rw"); B|U*2|e
this.nPos = nPos; k"X<gA
oSavedFile.seek(nPos); T {Q]
} - `F#MN
C# IV"Pkq
NF+^
public synchronized int write(byte[] b,int nStart,int nLen) It>8XKS
{ F33&A<(,
int n = -1; ={P
try{ 78&(>8@m
oSavedFile.write(b,nStart,nLen); a<-NB9o~v
n = nLen; " UaUaSg#
} ~/s(.oji
catch(IOException e) 6cH.s+
{ cnJ(Fv_F$
e.printStackTrace (); &?C% -"|c
} s<,[xkMB
H:byCFN-
tmEF7e`(o
return n; &U/7D!^X
} F;$z[z
7 -yf
pv);LjF
} s8;/'?K
t;X !+
#rnO=N8
/* 5#kN<S!
**SiteInfoBean.java -DD2
*/ /NRdBN
package NetFox; L-Qc[L
s/#L?[YH
Xm,w.|dx
public class SiteInfoBean { 1KwUp0%&
iV<4#aBg
1_$ybftS
private String sSiteURL; //Site's URL S%J$.ge
private String sFilePath; //Saved File's Path =_~bSEqyRI
private String sFileName; //Saved File's Name :uwB)G
private int nSplitter; //Count of Splited Downloading File sk*AlSlM
j6x1JM
n<RvL^T=
public SiteInfoBean() m/}(dT;
{//nSplitter的缺省值为5 g=W1y
//default value of nSplitter is 5 $OEhdz&Fi
this("","","",5); Q'-g+aN
} :: IAXGH)
oAaUXkQE
e(nT2E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #+$pE@u7A
{ n?uVq6c
sSiteURL= sURL; ,m ^q>
sFilePath = sPath; .3Ex=aQcX
sFileName = sName; *^agwQ`
this.nSplitter = nSpiltter; F?"#1je
|VC|@ Q
fePt[U)2
} U Px7u%Do
.A 12Co
}EFMJ,NQ
public String getSSiteURL() ^|Bpo(
{ #a7 Wx}
return sSiteURL; \X&LrneR"t
} 7-Bttv{
bEx8dc`Q
NlLgXn!
public void setSSiteURL(String value) & !0[T
{ .FV wZ:d
sSiteURL = value; t<sy7e='
} N=4`jy =
!l2=J/LJj
qU!xh)
public String getSFilePath() }~/u%vI@M5
{ #"PI%&
return sFilePath; Tz/=\_}
} 4q%hn3\
m3o+iYkMD
WEX6I16
public void setSFilePath(String value) @log=^
{ _Nze="Pt
sFilePath = value; H|Vq
} KBVW<;C$
R^t )~\d
Hzos$1DJ
public String getSFileName() Fh)`A5#
{ wD9Gl.uQ
return sFileName; bD*z"e
} .Y@)3
w?u4-GT
H~fX>6>
public void setSFileName(String value) mC-'z
{ PH,MZ"Z%
sFileName = value; N%3 G\|~Q
} bBwMx{iNNz
~lg1S
%~z/,[wk
public int getNSplitter() BgPwIK x
{ 'j6)5WL$
return nSplitter; "0BuQ{CQ
} 'ju
e-@=QI^,
oXKH,r
public void setNSplitter(int nCount) ZmT N
{ (<.uvq61
nSplitter = nCount; {u7%Z}<0
} 8vP:yh@
} a04I.5!
^LaOl+;S
bKAR}JM&
/* 6x6xv:\
**Utility.java c UJUZ@ol
*/ Z:TW{:lrI
package NetFox; X?3?R\/
IiX`l6L~W
^ W/,Z`
public class Utility { WziX1%0$n
gOk<pRcTb=
|dP[_nh?
public Utility() R9dC$Y]\M
{ g 0=Q>TzY
zYL</!6a[
PxqRb
} |Wo_5|E
~c;D@.e\
//线程睡眠 NTj:+z0
public static void sleep(int nSecond) 6Vq]AQx
{ BK+(Uf;g
try{ HizMjJ|
Thread.sleep(nSecond); Muhq,>!U
} tA,#!Z0
catch(Exception e) OfSy_#aEK
{ S7/0B4[
e.printStackTrace (); E~k_4z%M
} ;t^8lC?>V
} oM')NIW@
9!aQ@ J^
//日志 NrC(.*?m
public static void log(String sMsg) h[Hn*g
{ M=HP!hn
System.err.println(sMsg); MV+S.`R
} !a(#G7zA
E`^?2dv+/
!'ylh8}
public static void log(int sMsg) e3|@H'~k
{ X?RnP3t~
System.err.println(sMsg); kO1.27D
} C>1fL6ct
} M*& tVG
X={n9*Sd8
f]P&>j|
/* ?O]iX;2vM
**TestMethod.java !!WSGZUR
*/ ^p'iX4M
package NetFox; I eQF+Xz
;OE=;\
Q%x |
public class TestMethod { 3A~53W$M
n'dxa<F2|
`0]kRA8=
public TestMethod() ?<Tt1fpG
{ ///xx/weblogic60b2_win.exe Do&em8i z
try{ R0 g-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1|+Zmo"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pf?*bI
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,gvv297
fileFetch.start(); C2~t
} 6NvdFss'A{
catch(Exception e){e.printStackTrace ();} )\iOwA
hx'p0HDta
@M:Uf7
} %*>ee[^L ,
\~3g*V
jz\LI
public static void main(String[] args) yNwYP%"y
{ 8T}Ycm5}
new TestMethod(); M.h)]S>
} [sM~B
} qre.^6x
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