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)); Ai*+LSG
} 1C5~GI`
for(int i=0;i<nEndPos.length-1;i++) JYK4/gJ
{ EJid@
nEndPos = nStartPos[i+1]; SR$?pJh D%
} %_L~"E 2e
nEndPos[nEndPos.length-1] = nFileLength; O'~>AC5{
} INRP@Cp1
} PiVp(; rtQ
KKRj#m(:!
0hpU9w}12
//启动子线程 s}93nv*ez
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O4g2s8k
for(int i=0;i<nStartPos.length;i++) \hO}3;*&
{ c$n`=NI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .5E6MF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p6&6^v\
nStartPos,nEndPos,i); ']:>Ww.S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bCg)PJuB
fileSplitterFetch.start(); rUW/d3y
} IQ $/|b/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }? :T*CJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g@Z7f y7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #ULzh&yO
nEndPos = " + nFileLength); b(Nxk2uv
// fileSplitterFetch[nPos.length-1].start(); peZ'sZ6
g/W&Ap;qVL
Da)H/3ii
//等待子线程结束 n.b_fkZNr
//int count = 0; )~{8C:
//是否结束while循环 *?x[pqGq
boolean breakWhile = false; er0y~
9&"wfN N
vWZ?*0^
while(!bStop) A5IW[Gu!
{ w\}Q.$@
write_nPos(); ,c&%/"i:w
Utility.sleep(500); O|mWQp^?q
breakWhile = true; p_EWpSOt7
8=,?Bh".
Ro.br:'Bw
for(int i=0;i<nStartPos.length;i++) P_F0lO
{ }Ryrd!3bY
if(!fileSplitterFetch.bDownOver) [l*;+N+
{ Ewa/6=]LA
breakWhile = false; &`2$,zX#
break; LJwy,-
} _X~xfmU
} }Sh3AH/
if(breakWhile) /y3Lc.-
break; }PX8#C_P
fU>4Ip1?y/
`G<|5pe
//count++; o9+fAH`D
//if(count>4) H03R?S9AQ
// siteStop(); , D}
} @ [<B:Tqo
:+v4,=fHy
d:g0XP
System.err.println("文件下载结束！"); _}l7f
} X_(n
catch(Exception e){e.printStackTrace ();} b" kL)DL1L
} >/9Qgyc0
~mvD|$1z
Q[&CtM
//获得文件长度 X8 A$&
public long getFileSize() +<^c2diX
{ T1A/>\Ns
int nFileLength = -1; t $u.
try{ Io4Ss1="
URL url = new URL(siteInfoBean.getSSiteURL()); t]XF*fZH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8S@"6TG`
httpConnection.setRequestProperty("User-Agent","NetFox"); )E}eK-Yu
blmY=/]
VX'G\Zz@h|
int responseCode=httpConnection.getResponseCode(); [-hsG E
if(responseCode>=400) @ 5V3I^
{ )vD|VLV
processErrorCode(responseCode); [g@.dr3t
return -2; //-2 represent access is error *|S{%z9>
} 7,2#0Z`ge
) B[S4K2
tWI%P&b
String sHeader; <]u]rZc$
hOr4C4
<(x!P=NM-
for(int i=1;;i++) nzl3<Ar
{ :Y[?@/m4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {TC_ 4Y|8
//Utility.log(in.readLine()); hEfFMi=a`
sHeader=httpConnection.getHeaderFieldKey(i); Z#flu Q%V
if(sHeader!=null) T-.Bof(?w
{ jWGX:XB
if(sHeader.equals("Content-Length")) wQrD(Dv(yA
{ RO.bh#A$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); : G0^t
break; FK,Jk04on
} DX<xkS[P
} ;s w3MRJ
else 'ExTnv ~
break; %P`|kPW1
} l/6(V:
} 0r%,|FaS
catch(IOException e){e.printStackTrace ();} `YK%I8
catch(Exception e){e.printStackTrace ();} Vv.q{fRvYB
5`f\[oA
D|"^ :Gi
Utility.log(nFileLength); KZI-/H+
k^Uk=)9
E>NL/[1d
return nFileLength; v$EgVcK
} j?s+#t
xi!R[xr1
{>zQW{!
//保存下载信息（文件指针位置） 7w5 L?,a
private void write_nPos() \:_!!
{ 5dEek7wnf
try{ y*5$B.u`.
output = new DataOutputStream(new FileOutputStream(tmpFile)); jrm L>0NZ
output.writeInt(nStartPos.length); \j~LxV
for(int i=0;i<nStartPos.length;i++) I.'sK9\Zp
{ xXNLUP
// output.writeLong(nPos); W=?s-*F[~
output.writeLong(fileSplitterFetch.nStartPos); <dX7{="&
output.writeLong(fileSplitterFetch.nEndPos); ZO!)G
} zXT[}J VV
output.close(); '-KrneZ!
} KGsW*G4U=
catch(IOException e){e.printStackTrace ();} Fhbp,CX4p
catch(Exception e){e.printStackTrace ();} d;LBV<Z?
} Tsl0$(2W
|p @,]cz
m;m4/z3U
//读取保存的下载信息（文件指针位置） GoRSLbCUR
private void read_nPos() P:tl)ob
{ a3(q;^v
try{ H_+!.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6ZwFU5)QE/
int nCount = input.readInt(); q@&.)sLPgO
nStartPos = new long[nCount]; UZ3oc[#D=]
nEndPos = new long[nCount]; =]hPX
for(int i=0;i<nStartPos.length;i++) e(;nhU3a*,
{ I DtGtkF
nStartPos = input.readLong(); Zmr*$,v<y
nEndPos = input.readLong(); sp&)1?!M
} bx%P-r31
input.close(); .LEn~ 8
} 2 NrMse
catch(IOException e){e.printStackTrace ();} o0Pc^
catch(Exception e){e.printStackTrace ();} ^g*2jH+
} #e(P~'A0
2_#Vw&v
62z"cFN
private void processErrorCode(int nErrorCode) h]#bPb
{ pxO?:B
System.err.println("Error Code : " + nErrorCode); ]WP[hF
} DeL7sU
nLv"ON~
yct^AN|%
//停止文件下载 WMXk-?v4
public void siteStop() <-m?l6
{ uZ7~E._
bStop = true; ziBg'
for(int i=0;i<nStartPos.length;i++) L?p,Sy<RI
fileSplitterFetch.splitterStop(); d!]fou
Kh;jiK !
=_Y#uE$
} ~LuR)T=%es
} Xv1mjHZCC
//负责部分文件的抓取 qOd*9AS'|M
**FileSplitterFetch.java =/]d\JSp
*/ ,6FmU$ Kn
package NetFox; ,c\3b)ax
0(~,U!g[=
3-Xc3A=w
import java.io.*; Ib665H7w
import java.net.*; 3gzcpFNqX
v5!G/TZ1
yvz2eAXa
public class FileSplitterFetch extends Thread { FD*w4U5
, ,=7deR
><Z`)}f
String sURL; //File URL ;p}X]e l}
long nStartPos; //File Snippet Start Position 0/Wo":R:
long nEndPos; //File Snippet End Position LVX01ox$
int nThreadID; //Thread's ID p .^#mN
boolean bDownOver = false; //Downing is over 7ZVW7%,zF
boolean bStop = false; //Stop identical T2V# fYCc
FileAccessI fileAccessI = null; //File Access interface iSz?V$}?
'aoHNZfxw
;'x\L<b/)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q[w.[]
{ ntT~_Ba8;u
this.sURL = sURL; d5ivtK?
this.nStartPos = nStart; j*aYh^
this.nEndPos = nEnd; 7JI&tlR4\c
nThreadID = id; E5}wR(i,4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l;gj],*
} Ie%twc
/K./k!'z
(}C%g{8
public void run() .`ppp!:a4
{ ,`lVB#|
while(nStartPos < nEndPos && !bStop) ^%qhE8
{ .g6DKjy>
M~1 n#
x>yeF,q1
try{ 8O5@FU 3
URL url = new URL(sURL); _4VS.~}/R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); + ^9;<>P
httpConnection.setRequestProperty("User-Agent","NetFox"); i+z;tF`
String sProperty = "bytes="+nStartPos+"-"; wEImpsC`
httpConnection.setRequestProperty("RANGE",sProperty); CdN,R"V0$@
Utility.log(sProperty); ^Q\O8f[u
"?~u*5
:RnFRAcr
InputStream input = httpConnection.getInputStream(); ped3}i+|]
//logResponseHead(httpConnection); K&WNtk3hT
!hJ% :^ xL
%hu] =
byte[] b = new byte[1024]; *?#t (Y[
int nRead; ,^_aqH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p|D-ez8
{ `jur`^S|
nStartPos += fileAccessI.write(b,0,nRead); = yH#Iil
//if(nThreadID == 1) #!%\97ZR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }m~2[5q%/
} p<@0b
O!(FNv0
!PfIe94{`
Utility.log("Thread " + nThreadID + " is over!"); ir4uy
bDownOver = true; n./onv
//nPos = fileAccessI.write (b,0,nRead); fJ?$Z|
} 2@(Qd3N(
catch(Exception e){e.printStackTrace ();} !:[kS1s>M
} tilL7
} 79>8tOuo
`euk&]/^.)
+=y ktf
//打印回应的头信息 ms%Ot:uA
public void logResponseHead(HttpURLConnection con) o9:GKc
{ F+`DfI]/m
for(int i=1;;i++) IJ%S[>
{ jJjD)
String header=con.getHeaderFieldKey(i); *Iu .>nw
if(header!=null) ZhWtY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); # Z*nc0C
Utility.log(header+" : "+con.getHeaderField(header)); a?IL6$z
else K_Jo^BZ
break; Xj\SJ*
} o'3t(dyyH
} Xjal6e)[
aeESS;JxJj
A|BvRZd
public void splitterStop() nx(O]R,Sw
{ L}&U%eD
bStop = true; wNuS'P_(:T
} p1=sDsLL
h<wF;g,
"/).:9],}
} 9^m& [Z
4:=eO!6
`nO!_3
/* S?}@2[
**FileAccess.java RN?z)9!
*//文件访问(定位，写) ;mXr])J
package NetFox; /:a~;i
import java.io.*; 4ifWNL^)
7CGKm8T
W"mkNqH
public class FileAccessI implements Serializable{ #![i {7
Ml)Xq-&wc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "R$ee^
RandomAccessFile oSavedFile; JF>mybB
long nPos; ##7,
2#nn}HEOC
n8zh;vuJ
public FileAccessI() throws IOException w+cI0lj
{ 1rV?^5
this("",0); {PHxm
} ybtje=3E
}6P]32d
PX](hc=
public FileAccessI(String sName,long nPos) throws IOException _4z>I/R>Z
{ K<b -|t9f
oSavedFile = new RandomAccessFile(sName,"rw"); zxCxGT\;
this.nPos = nPos; nTSGcMI
oSavedFile.seek(nPos); %D z|p]49!
} %ma1LN[
SvH=P!`+
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public synchronized int write(byte[] b,int nStart,int nLen) l}X3uyS
{ t-SGG{
int n = -1; +fzZ\
try{ u>(s.4]+
oSavedFile.write(b,nStart,nLen); P%smX`v
n = nLen; C,Je>G
} d]h[]Su/?
catch(IOException e) &^thKXEC
{ ]?U:8%
e.printStackTrace (); J$PE7*NU
} p/WEQ2
@4_CR
&l%#OI}OE
return n; 4EuZe:'X
} tkWWR%c"
aO'$}rDf$
L[+65ce%*
} 8|7fd|6~
VLtb16|
!.iA^D//]
/* *Yov>lO
**SiteInfoBean.java >k^=+
*/ )zt*am;
package NetFox; 52*zX 3
^zqz$G#
<?Fgm1=o
public class SiteInfoBean { v}-'L#6
z@&_3 Gl
R\yw9!ESd
private String sSiteURL; //Site's URL ms3Ec`i9
private String sFilePath; //Saved File's Path vVKiE 6^
private String sFileName; //Saved File's Name 1O9V Ej5
private int nSplitter; //Count of Splited Downloading File e)\s0#
+(r8SnRX
jKQnox+=
public SiteInfoBean() T:wd3^.CG
{//nSplitter的缺省值为5 eUqsvF}l!
//default value of nSplitter is 5 &cDnZ3Q;
this("","","",5); pz?.(AmU\
} sJ?Fque
Oa7`Y`6
L4SFu.J'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z-(dT
{ blaxUP:
sSiteURL= sURL; Z/hSH 0(~
sFilePath = sPath; R^dAwt`.D
sFileName = sName; m+DkO{8F
this.nSplitter = nSpiltter; 2c!?!:s
W32mAz;
Ik=KEOz
} I2|iqbX40Q
~oT0h[<
Cb.~Dv !
public String getSSiteURL() KWy4}7a@,s
{ X"8Jk4y
return sSiteURL; tTF/$`Q#*
} H*yX Iq:
PWLMux
>F,~QHcz
public void setSSiteURL(String value) v"_hWJ)
{ &hd+x5
sSiteURL = value; z7{b>oub('
} r6 ,5&`&
8Z/P<u
4<Bj;1*4
public String getSFilePath() kHX- AsRc
{ 5@Ot@o
return sFilePath; !K(0)~u
} ]_|qv1K6
vYmRW-1Zxq
FL0(q>$*8
public void setSFilePath(String value) $+S'Boo
{ l4hC>q$T
sFilePath = value; '!{zO" 1*
} $C(}
8K6yqc H
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public String getSFileName() D19uI&U4
{ gjvKrg
return sFileName; vlm&)DIt
} "-A@>*g
RjSVa.x
#<4h Y7/
public void setSFileName(String value) *Yl9%x]3c
{ "J%u !~
sFileName = value; <d$|~qS_
} ^#lPXC Bg
n/S1Hae`
~naL1o_FZ
public int getNSplitter() h+CTi6-p
{ ,V.X-`Y
return nSplitter; 5sFp+_``
} [=7|LHjU
#s)6u?N
kVy%y"/
public void setNSplitter(int nCount) @aY 8VL7C0
{ & 2>W=h
nSplitter = nCount; +<|6y46
} z[}[:H8
} =+'4u
rC[*x}
g15e|y)th
/* j5G8IP_Wx
**Utility.java `kVy1WiY
*/ m+"?;;s
package NetFox; L@t<%fy@
Z-*L[
M7fw/i
public class Utility { 80&JEtRh
%W+*)u72(
!d&K,k
public Utility() ;6U=fBp7<
{ K82pWpR
)(_}60
sZFjkfak
} M@E*_U!U
*(PGLYK
//线程睡眠 l}5@6;}
public static void sleep(int nSecond) yO]Vex5)
{ GFYAg
try{ loLQ@?E
Thread.sleep(nSecond); op/HZa
} 0}PW<lU-
catch(Exception e) 7^ITedW@
{ >|/NDF=\s
e.printStackTrace (); 7Xw;TA
} # ~} 26
} `QnKal)
)d2<;c
//日志 k*w]a
public static void log(String sMsg) Ky8sLm@
{ imZi7o
System.err.println(sMsg); 3uZY.H+H
} ^j0Mu.+_
~kD/dXt
UMma|9l(i
public static void log(int sMsg) -*_D!
{ k>FMy#N|@
System.err.println(sMsg); +=)< Su.
} (I IPrW;>
} #Ne<=ayS
gah3d*d7
8T):b2h
/* sbjAZzrX2i
**TestMethod.java (/a2#iW
*/ <IC=x(T
package NetFox; 26G2. /**<
SsIy;l
1y2D]h/'
public class TestMethod { {Uz@`QO3
9gZMfP
C},;M@xV
public TestMethod() w-C~ Ik
{ ///xx/weblogic60b2_win.exe TUw^KSa
try{ u}\F9~W-{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }/nbv;)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X};m\Bz
SiteFileFetch fileFetch = new SiteFileFetch(bean); r/$+'~apTk
fileFetch.start(); =!w5%|r.
} v~H1Il_+
catch(Exception e){e.printStackTrace ();} mSp-
.{1G"(z
{0nZ;1,m
} yM}}mypS
#g#vDR!
#v0"hFOH,
public static void main(String[] args) *p`0dvXG2
{ /`Yy(?,
new TestMethod(); 5Q#;4
} w},' 1
} DJ_,1F
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