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)); @4MQ021(
} 1Wiz0X/
for(int i=0;i<nEndPos.length-1;i++) wS+!>Q_]w
{ b- bvkPN
nEndPos = nStartPos[i+1]; j dz IU
} X8ZO } X
nEndPos[nEndPos.length-1] = nFileLength; 'IT]VRObP
} ~ch%mI~
} ,fqM>Q
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}"SqB{5e(
//启动子线程 wX_~H*m?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;)wk^W
for(int i=0;i<nStartPos.length;i++) e ;^}@X
{ GgnR*DVP$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C|2|OTtQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~mwIr
nStartPos,nEndPos,i); QPh3(K1w^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UvM4-M%2JN
fileSplitterFetch.start(); s~bi#U;dF
} p&5>j\uJ1&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y/kB`Z(Yj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0igB pHS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @rAV;D%
nEndPos = " + nFileLength); =9W\;xE S
// fileSplitterFetch[nPos.length-1].start(); rV4K@)~
sH_,P
3~V.
//等待子线程结束 4=EA3`l
//int count = 0; 2Q\\l @b\
//是否结束while循环 GNEPb?+T
boolean breakWhile = false; g<,0kl2'S
0 q1x+
0 x' d^
while(!bStop) 8ICV"8(
{ 6GPI gPL,
write_nPos(); wW/q#kc
Utility.sleep(500); Y/"t!
breakWhile = true; O|)b$H_
3"< 0_3?W
"^!y>]j#A
for(int i=0;i<nStartPos.length;i++) *,%$l+\h
{ :>r W`= e'
if(!fileSplitterFetch.bDownOver) uv<_.Jq]
{ zx,9x*g
breakWhile = false; So8 Dwz?
break; psc Fb$b
} i;s;:{cn
} kU=U u>
if(breakWhile) m(}}%VeR"z
break; 2
A<"<DDy
h_+
//count++; PB7-`uz
//if(count>4) j;7E+Yp
// siteStop(); Bf]Bi~w<
} "P54|XIJ\
?FjnG_Uz`D
Wz"H.hf
System.err.println("文件下载结束！"); m{?f,Q=u@
} uwr7 .\7
catch(Exception e){e.printStackTrace ();} mo] l_'
} EApbaS}Up
U%q6n"[ Cr
tl\<:8pI"
//获得文件长度 {V[}#Mf
public long getFileSize() J|DZi2o
{ OXbShA&1
int nFileLength = -1; 5E"^>z
try{ M?L$xE_&
URL url = new URL(siteInfoBean.getSSiteURL()); g}W|q"l?i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hV0fkQ.|
httpConnection.setRequestProperty("User-Agent","NetFox"); EG|dN(qh
'6WS<@%}
t|i<}2
int responseCode=httpConnection.getResponseCode(); 'L-DMNxBr
if(responseCode>=400) M@<9/xPS
{ f,Dic%$q
processErrorCode(responseCode); X(X[v]
return -2; //-2 represent access is error ,Kl?-W@
} %Nvw`H
qIQRl1Tw;V
h~](9es
String sHeader; Uc'}y!R
)RvX}y-
EY<"B2_%
for(int i=1;;i++) m8b,_1
{ {7@*cBqN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s</qT6@
//Utility.log(in.readLine()); 6h,!;`8O
sHeader=httpConnection.getHeaderFieldKey(i); 3NDddrL9
if(sHeader!=null) {srxc4R`
{ `&7tADFB
if(sHeader.equals("Content-Length")) D9A%8[Yo
{ jVQ89vf ~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RR ^7/-
break; r{9fm,
} X!^|Tass
} 9J?s:"j
else vr'cR2
break; dzPewOre*
} K)~aH
} {vCtp
catch(IOException e){e.printStackTrace ();} 1^X)vck
catch(Exception e){e.printStackTrace ();} _"L6mcI6
o0f`/ 6o
y32$b,%Xi,
Utility.log(nFileLength); 3]*1%=~X/
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/\h*v!:
return nFileLength; <?5|(Q"@:
} kDWEgnXK,v
7#%Pry
LlO8]b!P-^
//保存下载信息（文件指针位置） =urGs`\
private void write_nPos() 4}v|^_x-i
{ ;-kDJi
try{ BR@m*JGajz
output = new DataOutputStream(new FileOutputStream(tmpFile)); uHSnZ"#
output.writeInt(nStartPos.length); qx[c0X!
for(int i=0;i<nStartPos.length;i++) ektU,Oo
{ )3:0TFS}}k
// output.writeLong(nPos); >>$`]]7
output.writeLong(fileSplitterFetch.nStartPos); 3dj|jw5
output.writeLong(fileSplitterFetch.nEndPos); v/c]=/
} 3U+FXK#6
output.close(); E KV[cq
} tOLcnWt
catch(IOException e){e.printStackTrace ();} ~vt9?(h
catch(Exception e){e.printStackTrace ();} :vG0 l\
} %J^x `P
p\ ;|Z+0=
M\5|
//读取保存的下载信息（文件指针位置） k-=LD
private void read_nPos() aW&)3C2-x
{ II}M|qHaK
try{ >a<1J(c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .E}lAd.Mn
int nCount = input.readInt(); I"vkfi#=
nStartPos = new long[nCount]; X]D,kKasG
nEndPos = new long[nCount]; T TN!$?G3
for(int i=0;i<nStartPos.length;i++) 9"]#.A^Q*
{ eOE*$pH
nStartPos = input.readLong(); %8tE*3iUF
nEndPos = input.readLong(); @|vH5Pi
} m)Kg6/MV.
input.close(); x'I!f? / &
} </`\3t
catch(IOException e){e.printStackTrace ();} +K`A2&F9
catch(Exception e){e.printStackTrace ();} ~s'tr&+
} kt978qfk
W H/.h$
ZDW=>}~_y
private void processErrorCode(int nErrorCode) ;x/eb g
{ lnyfAq}w
System.err.println("Error Code : " + nErrorCode); Y-a
} <SI|)M,, 3
(jDz[b#OPz
}r5yAE
//停止文件下载 `IUn{I
public void siteStop() UE.kR+1
{ KaNs>[a8
bStop = true; Z%qtAPd
for(int i=0;i<nStartPos.length;i++) 3>aEP5
fileSplitterFetch.splitterStop(); 2.Qz"YDh =
?zf3Fn2y
zR^Gy"
} i9DD)Y<
} M>]A!W=
//负责部分文件的抓取 \MOwp@|y
**FileSplitterFetch.java j,+]tHC-
*/ *c94'Tcl
package NetFox; *kl :/#
{4G/HW28
K%? g6j
import java.io.*; jfY7ich
import java.net.*; =\WF +r]V
r@{TN6U
^U*y*l$
public class FileSplitterFetch extends Thread { *(?Wzanh
3uqhYT;
wwB3m&
String sURL; //File URL Lz'VQO1U=
long nStartPos; //File Snippet Start Position *7jz(iX
long nEndPos; //File Snippet End Position 0B]q /G(
int nThreadID; //Thread's ID rTIu'
boolean bDownOver = false; //Downing is over 6(f'P_*
boolean bStop = false; //Stop identical Yg^ &4ZF
FileAccessI fileAccessI = null; //File Access interface LZRg%3.E
xf]K
c0gVW~I1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;mG*Rad
{ `.W2t5Y
this.sURL = sURL; 67II9\/
this.nStartPos = nStart; +O.-o/
this.nEndPos = nEnd; 2M-[x"\1/
nThreadID = id; >5t%_/yeB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 64zOEjra
} 5*pzL0,Y
AAevN3a#nI
TJO$r6&
public void run() TmQIpeych
{ MIrx,d
while(nStartPos < nEndPos && !bStop) ~P1~:AT
{ P2-&Im`+
{_O!mI*
_5jT}I<k
try{ E^axLp>(I
URL url = new URL(sURL); 8Y?M:^f~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >1Z"5F7=
httpConnection.setRequestProperty("User-Agent","NetFox"); ?BnU0R_r]
String sProperty = "bytes="+nStartPos+"-"; (j&:
httpConnection.setRequestProperty("RANGE",sProperty); \!-BR0+y;
Utility.log(sProperty); N]A# ecm
(jM0YtrD
r!mRUw'u
InputStream input = httpConnection.getInputStream(); ?l0Qi
//logResponseHead(httpConnection); YA4D?'
T }}2J/sj
'+PKGmRW
byte[] b = new byte[1024]; `<C<[JP:o
int nRead; t;e&[eg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M6) G_-
{ lM6pYYEq=
nStartPos += fileAccessI.write(b,0,nRead); L(Y1ey9x
//if(nThreadID == 1) ai{>rO3 }I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f2i:I1 p("
} 08`|C)Z!
#Vq9 =Q2
:aesG7=O
Utility.log("Thread " + nThreadID + " is over!"); 0ns\:2)cEB
bDownOver = true; }Y~Dk]*
//nPos = fileAccessI.write (b,0,nRead); Lnr9*dm6q
} Iux3f+H
catch(Exception e){e.printStackTrace ();} J7`mEL>?
} +xFn~b/
} *;o%*:
6p9fq3~7Y
\#{PV\x:Nn
//打印回应的头信息 *;Jb=
public void logResponseHead(HttpURLConnection con) /T w{JO#Q
{ 6_Fr\H
for(int i=1;;i++) P8tdT3*6/
{ : uncOd.
String header=con.getHeaderFieldKey(i); g^'h4qOa
if(header!=null) ,&P 4%N"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VfX^iG r
Utility.log(header+" : "+con.getHeaderField(header)); ->sxz/L
else ~dYCY_a
break; e8F]m`{_"
} Y2u\~.;oq
} CL=%eSsuD
C0wtMD:G
[n2B6Px
public void splitterStop() #S}orWj
{ VI0wul~M
bStop = true; v ,8;: sD
} <RGH+4LF
sTM;l,
/eF@a!
} S /hx\TzC
;M:AcQZ|_
UVo`jb|> o
/* aSzI5J]/=
**FileAccess.java `q^#u
*//文件访问(定位，写) 2Y vr|] \8
package NetFox; ge~@}&#iO@
import java.io.*; *]$B 9zVs!
DXs an
j#l=%H
public class FileAccessI implements Serializable{ aZOn01v;!&
Pq;OShU_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SH%NYjj
RandomAccessFile oSavedFile; Y{YbKKM
long nPos; 2HE@!*z9H
BI1M(d#1L"
,>;21\D
public FileAccessI() throws IOException aZFpt/.d
{ $DbnPZ2$
this("",0); @(t3<g
} 1[%3kY-h
?:(y
=8AT[.Hh
public FileAccessI(String sName,long nPos) throws IOException tW\yt~q,
{ 4Uy%wB
oSavedFile = new RandomAccessFile(sName,"rw"); =)a24PDG
this.nPos = nPos; -$Oh.B`i
oSavedFile.seek(nPos); F-_u/C]
} 380`>"D
,"v&r(
cU1o$NRx
public synchronized int write(byte[] b,int nStart,int nLen) W__ArV2Z_
{ #@R0$x
int n = -1; B `(jTL
try{ Q+:y
oSavedFile.write(b,nStart,nLen); VoU8I ~
n = nLen; {)[o*+9
} pSs*Z6c)@
catch(IOException e) pgU[di
{ V;M_Y$`Lh
e.printStackTrace (); BEdCA]T
} O'<V[Y}6
O)'CU1vMb
)(iv#;ByL
return n; g`XngRb|j
} W }NUU
~tDYo)hH8
aJu&h2G
} 7sot?gF
jLAEHEs
z0z@LA4k6@
/* Qb536RpcTY
**SiteInfoBean.java "Ep"$d
*/ -+R,="nRQ
package NetFox; vObZ|>.J~O
MmF&jd-=
70'OS:J=\
public class SiteInfoBean { B*,6;lCjX
AO#9XDEM
19!?oeOU
private String sSiteURL; //Site's URL PX:#+bq1
private String sFilePath; //Saved File's Path ;Qi:j^+P)
private String sFileName; //Saved File's Name =pH2V^<<#
private int nSplitter; //Count of Splited Downloading File DIC*{aBf
a<cwrDZ
amBg<P`'_
public SiteInfoBean() !/FRL<mp
{//nSplitter的缺省值为5 7=^{~5#
//default value of nSplitter is 5 U3(+8}Q
this("","","",5); =[B\50]
} /*0t_
7^L
).~ "
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kk3+ ]W<
{ p3s i\Fm!
sSiteURL= sURL; f ULt4
sFilePath = sPath; <c+.%ka
sFileName = sName; 1`cH EAa
this.nSplitter = nSpiltter; 2t= =<x
Ge^`f<f
H 4<"+7
} *2AD#yIKC
Uh}PB3WZ
2]!@)fio`
public String getSSiteURL() xS*UY.>
{ u]p21)m$x
return sSiteURL; -3Kh >b)
} 6o't3Peh
U4D7@KY +m
rH@Rh}#yp
public void setSSiteURL(String value) \8vP"Kr
{ a4Q@sn;]
sSiteURL = value; }(EH5jZ'
} !fOPYgAGKn
epy2}TI
zsL@0]e&
public String getSFilePath() D|uvgu2
{ GppCrQ%Ra|
return sFilePath; =LW!$p
} c_8&4
<WXVUEea
x,B] J4
public void setSFilePath(String value) 'uL4ezTtA
{ (x=$b(I
sFilePath = value; 7KC>?F
} HuhQ|~C+~
\YP,}_~
b8WtNVd
public String getSFileName() cu!%aM,/<-
{ jn(x-fj6R
return sFileName; c1YDln
} "@Vyc6L
*22Vc2[i;
xyL"U*
public void setSFileName(String value) Z.VKG1e}
{ tv#oEM9esl
sFileName = value; kK&w5'
} WzIUHNn'I
IJ^~,+
atL<mhRz
public int getNSplitter() YT(N][V
{ xo>0j#
return nSplitter; Ho &Q}<(
} ,!orD1,'
h}Otz "
F!+1w(b:
public void setNSplitter(int nCount) n!)$e;l
{ 3H2~?CaJ
nSplitter = nCount; S<Dbv?
} ;V,L_"/X
} eL3 _Lz
M2Q,&>M
:_e[xB=Yy
/* ;aQ``B
**Utility.java _ *f>UW*,
*/ omE- c
package NetFox; =AIts[!qd
I&-r^6Yx
dq93P%X24
public class Utility { ]?^V xB7L
adLL7
z33UER"
public Utility() (&}[2pb!
{ )Q2IYCj{
U5Hi9fe
]]j^
} yE}\4_0I/
&8$v~
//线程睡眠 *5)UIRd
public static void sleep(int nSecond) >Hf{Mx{<
{ \jfK']P/H
try{ (/:m*x*6
Thread.sleep(nSecond); {JE [
} eiMP:
catch(Exception e) *yBVZD|?H
{ %8*:VR
e.printStackTrace (); PaCCUF
} BA@E
} 56;u7
Oe5rRQ$O
//日志 $d<NN2
public static void log(String sMsg) }3 xkA
{ b-u@?G|<
System.err.println(sMsg); EGXvz)y
} Sn nfU
_3Eo{^
gFR}WBl/
public static void log(int sMsg) )re<NE&M
{ f,G*e367:
System.err.println(sMsg); `~XksyT
} }e\"VhAl/
} j iKHx_9P
o/Ismg-p
'z|Da&d P
/* UoxlEec
**TestMethod.java nxZz{&
*/ C19N0=
package NetFox; A8-[EBkK
8~Kq"wrbu
e,%|sAs[
public class TestMethod { )7 57
j_<qnBeQ
DTO_IP
public TestMethod() {$8+n::
{ ///xx/weblogic60b2_win.exe | 6{JINW
try{ {H)7K.hQN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 24J c`%7,=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p%DU1+SA
SiteFileFetch fileFetch = new SiteFileFetch(bean); sxT&T=7
fileFetch.start(); n]g"H
} $8\u
catch(Exception e){e.printStackTrace ();} lOm01&^"E
H_&to3b(
jg]KE8(
} 7O55mc>cF
9&sb,^4
0YiTv;mq;
public static void main(String[] args) 5]&sXs
{ }O\IF}X
new TestMethod(); i:s=
} M-@RgWvF
} ZID-~ 6
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