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)); 0C3Y =F
} gv&Hu$ca
for(int i=0;i<nEndPos.length-1;i++) )Jw$&%/{1
{ Y9 Bk$$#\
nEndPos = nStartPos[i+1]; xT( pB-R
} /XA*:8~!
nEndPos[nEndPos.length-1] = nFileLength; 9xK#(M
} bdvpH DA
} WRRR"Q$
!b+!] 2~g}
P(o>UDy
//启动子线程 t8;nP[`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rWqr-"0S.
for(int i=0;i<nStartPos.length;i++) Z#l6BXK
{ .Iz JJp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (LMT'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4N1)+W8k*
nStartPos,nEndPos,i); qVO,sKQ{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ef@)y&hn
fileSplitterFetch.start(); iA`.y9'2
} 2f{a||
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KxBvL[/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xX0wn?,~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {iCX?Sb
nEndPos = " + nFileLength); sk_xQo#Y 3
// fileSplitterFetch[nPos.length-1].start(); gxJ12' m
h`eHoKJ#w
hFan$W$
//等待子线程结束 '*Tt$0#o
//int count = 0; kIe)ocJg
//是否结束while循环 qv>l
boolean breakWhile = false; Y4lNxvY
|VjD. ]I
5/T#>l<
while(!bStop) hZ/p'
{ % .ss
write_nPos(); '|*e4n
Utility.sleep(500); C[l5[DpH
breakWhile = true; J l{My^I5
e2>AL
hSN38wy
for(int i=0;i<nStartPos.length;i++) ><.*5q
{ )nq(XM7
if(!fileSplitterFetch.bDownOver) :22wq{
{ %h;1}SFl0
breakWhile = false; TTWiwPo59
break; b/\l\\$-
} 3<[q>7X
} }AiF 7N0
if(breakWhile) 'geN dx
break; /%F,
c+O:n:L
m;TekJXm
//count++; W&[-QM8
//if(count>4) 5{IbKj|
// siteStop(); RSw;b.t7
} 7osHKO<?2
K(?p]wh
M"msLz
System.err.println("文件下载结束！"); @3U=kO(^+\
} ?k@;,l :s
catch(Exception e){e.printStackTrace ();} MX+gc$Y O
} ?(}~[
h&!$ `)
Z Y5Pf 1
//获得文件长度 !t{
public long getFileSize() JW=q'ibR
{ pX$X8z%
int nFileLength = -1; F}@]Lq+
try{ ,% .)mf
URL url = new URL(siteInfoBean.getSSiteURL()); v`Ja Bn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^X"x,8}&V
httpConnection.setRequestProperty("User-Agent","NetFox"); A!uiM*"W
Jp_ :.4
r Cz,XYV
int responseCode=httpConnection.getResponseCode(); tWQ$`<h
if(responseCode>=400) Qw"%Xk
{ (.wR!l#!
processErrorCode(responseCode); 10GU2a$0"$
return -2; //-2 represent access is error =.):tGDp
} }^b
RXu`DWN
9C!b f \
String sHeader; ?+%bEZ`
N| P?!G-=
V?jWp$
for(int i=1;;i++) #/_ VY.
{ pwB>$7(_h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r]aI=w<(f
//Utility.log(in.readLine()); WD*z..`
sHeader=httpConnection.getHeaderFieldKey(i); WY5HmNX3E
if(sHeader!=null) NQcg}y
{ uU-1;m#N?
if(sHeader.equals("Content-Length")) afu!.}4Ct
{ ,Vof<,x0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '!`]Zc
break; qd~9uo&[Ig
} EN8xn9M?
} m,}GP^<1i
else U]9k,#
break; 8KKhD$
} k 6i&NG6
} KYl!Iw67d
catch(IOException e){e.printStackTrace ();} [8Z !dj
catch(Exception e){e.printStackTrace ();} Ht]O:io`
5v=e(Ph+
[F{P0({%?
Utility.log(nFileLength); e nw*[D !
g+(Y)9h&
&^Gp
return nFileLength; C<w&mFozL
} cJM.Q_I}Y
mHH>qW{`
.*J /F$
//保存下载信息（文件指针位置） PR,8c
private void write_nPos() VtGZB3
{ _?eT[!oO8
try{ aB`jFp-
output = new DataOutputStream(new FileOutputStream(tmpFile)); T#[#w*w/
output.writeInt(nStartPos.length); R D?52\
for(int i=0;i<nStartPos.length;i++) NfmHa
{ $s 'n]]Wq
// output.writeLong(nPos); g8"H{u
output.writeLong(fileSplitterFetch.nStartPos); JBLh4c3
output.writeLong(fileSplitterFetch.nEndPos); C5e;U
} 7*He 8G[W
output.close(); =j{Kxnv
} 3~Ap1_9
catch(IOException e){e.printStackTrace ();} ["<'fq;PJ
catch(Exception e){e.printStackTrace ();} #%V+- b(
} )HX(-"c
Y.#fpG'
LyL(~Jc|
//读取保存的下载信息（文件指针位置） ktp<o.f[
private void read_nPos() 8PWEQ<ev7>
{ HK%W7i/k@
try{ j[dgY1yE:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NYzBfL x
int nCount = input.readInt(); VSh&Y_%
nStartPos = new long[nCount]; Nu'ox. V
nEndPos = new long[nCount]; p\.IP2+c
for(int i=0;i<nStartPos.length;i++) QFgKEUNgl
{ 1y,/|Y
nStartPos = input.readLong(); .8;0O M
nEndPos = input.readLong(); "^Y zHq6
} r@ !
input.close(); H?V b
} 6)>otB8)J
catch(IOException e){e.printStackTrace ();} ofPv?_@
catch(Exception e){e.printStackTrace ();} wrsr U
} JC;&]S.
!%.=35NS@E
OB*V4Yv
private void processErrorCode(int nErrorCode) {<?8Y
{ .N`*jT
System.err.println("Error Code : " + nErrorCode); yT~x7,
} ExeZj8U
E=`/}2
c5:X$k\
//停止文件下载 9PMIF9"
public void siteStop() |--Jd$ dj
{ qwO@>wQ}~
bStop = true; N,3iSH=cN[
for(int i=0;i<nStartPos.length;i++) cv7:5P
fileSplitterFetch.splitterStop(); fPPmUM^C9
qB&Je$_uh
dP`B9>r
} sRqecG(n
} uL^`uI#I
//负责部分文件的抓取 7!\zo mx
**FileSplitterFetch.java |=MhI5gsx
*/ B-PX/Q
package NetFox; 5L_`Fw\l
v G9>e&Be
7R# }AQ
import java.io.*; HxcL3Bh$~}
import java.net.*; `*D"=5G+
m;t&P58f
+'nMy"j1
public class FileSplitterFetch extends Thread { (OA4H1DL^
)4m`Ya,E3
d`=LZio
String sURL; //File URL BRM!g9
long nStartPos; //File Snippet Start Position 4u"Bll
long nEndPos; //File Snippet End Position D2=zrU3Y64
int nThreadID; //Thread's ID b};o:
boolean bDownOver = false; //Downing is over Rd|8=`)
boolean bStop = false; //Stop identical OHrzN']
FileAccessI fileAccessI = null; //File Access interface z,4 D'F&
oR/_{#Mz"
\ Ce*5h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )ax>*
{ /?($W|9+l
this.sURL = sURL; ;mvVo-r*q
this.nStartPos = nStart; +.OdrvN4)
this.nEndPos = nEnd; "?<h,Hvi
nThreadID = id; c*(^:#"9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 't5`Ni
} m^=El7+
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3!vzkBr
public void run() ?~!9\dek,
{ n?;rWq"
while(nStartPos < nEndPos && !bStop) xu%eg]
{ K[LuvS
)nFyHAy-
u05Yy&(f
try{ VxuV`Plf
URL url = new URL(sURL); $mh\`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _(I6o
httpConnection.setRequestProperty("User-Agent","NetFox"); =I@I
String sProperty = "bytes="+nStartPos+"-"; ]V_A4Df
httpConnection.setRequestProperty("RANGE",sProperty); :2&"ak>N
Utility.log(sProperty); Z#bO}!
D W^Zuu/)
,wXmJ)/WZ
InputStream input = httpConnection.getInputStream(); :7mHPe}(
//logResponseHead(httpConnection); 14jN0\
G$%F`R[
.Y"F3 R
byte[] b = new byte[1024]; 32j}ep.*
int nRead; j@D,2B;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C4P<GtR9
{ 0bT[05.
nStartPos += fileAccessI.write(b,0,nRead); KIag(!&
//if(nThreadID == 1) Wpi35JrC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [uLsM<C
} 4+s6cQ]S`
RAP-vVh/C
CxZh^V8LP
Utility.log("Thread " + nThreadID + " is over!"); l`i97P?/W
bDownOver = true; B4wRwrVI>
//nPos = fileAccessI.write (b,0,nRead); [~2imS
} j49Uj}:j
catch(Exception e){e.printStackTrace ();} $LFL4Q
} %yu =,J j
} $Ery&rX.
ovBmo2W/
xLDD;Qm,
//打印回应的头信息 g\ vT7x
public void logResponseHead(HttpURLConnection con) tiHR&v
{ q$mc{F($D
for(int i=1;;i++) upL3M`
{ I "~.p='
String header=con.getHeaderFieldKey(i); G3%Ju=
if(header!=null) _]pu"hZz4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P(TBFu
Utility.log(header+" : "+con.getHeaderField(header)); >3Q|k{97
else aR/?YKA
break; m<#12#D
} XW" 0:}`J
} ]|+M0:2?
9|#cjHf
kuV7nsXiQ
public void splitterStop() ``Q6R2[|)
{ ;'= cNj
bStop = true; c$%*p (zY
} nGkSS_X
=@?[.`
%&| uT
} R]iV;j|
,1$F#Eh
z+yIP ?s}(
/* C?T\5}h
**FileAccess.java G+t:]\
*//文件访问(定位，写) eY5mwJ0K
package NetFox; mV$ebFco0
import java.io.*; 4n@lrcq(
m(6d3P
x9 %=d
public class FileAccessI implements Serializable{ dQ.#8o=
%gh#gH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N}K [Q=
RandomAccessFile oSavedFile; ?YLq iAA
long nPos; D5D *$IC
E)gD"^rex
R=lw}jH[Z
public FileAccessI() throws IOException ;*M@LP{*L
{ "J1A9|
this("",0); a3tcLd|7J
} 89g a+#7
JfIXv
8b)WOr6n
public FileAccessI(String sName,long nPos) throws IOException At4\D+J{Vs
{ 1x:W 3.
oSavedFile = new RandomAccessFile(sName,"rw"); \}s/<Q
this.nPos = nPos; !i^"3!.l,]
oSavedFile.seek(nPos); 2Lf,~EV
} D=TS IJ@
SG&,o=I$
ir_XU/ve
public synchronized int write(byte[] b,int nStart,int nLen) 'bi;Y1:
{ dm4Q'u
int n = -1; ` 3qf}=Z`
try{ <m]0!ii
oSavedFile.write(b,nStart,nLen); d-D,Gx]>$
n = nLen; yx :^*/
} G`Nw]_ Z_
catch(IOException e) m9DFnk<D
{ }kqh[`:
e.printStackTrace (); 3ic /xy;}
} >8e)V ;
Mw/9DrE7/
nn_O"fZi
return n; ]?tRO
} =9GALoGL
Q&eyqk
o utJ/~9;
} ?,>3uD#
lFjz*g2'
dFy$w=
/* s5nw<V9$]
**SiteInfoBean.java \9)5b8
*/ Hd|[>4Z
package NetFox; <l{oE?N
k&ci5MpN
&zdS9e-fF
public class SiteInfoBean { ""0Y^M2I
Rql/@j`JX
ga5Q
private String sSiteURL; //Site's URL 9\_AB.Z:
private String sFilePath; //Saved File's Path g"m' C6;
private String sFileName; //Saved File's Name Zv;nY7B
private int nSplitter; //Count of Splited Downloading File h;gc5"mG
{aY) Qv}
/iU<\+ H
public SiteInfoBean() TTz=*t+D
{//nSplitter的缺省值为5 ]y_:+SHc
//default value of nSplitter is 5 Z-PBCU
this("","","",5); A@}5'LzL
} J\L'HIs
Vp/XVyL}R
WHdMP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EZ)b E9
{ An. A1y
sSiteURL= sURL; xE:jcA d$}
sFilePath = sPath; 1=R$ RI
sFileName = sName; ^k=<+*9
this.nSplitter = nSpiltter; o$*(N
<fvu) f
Nw*<e ]uD
} FEjO}lTK
*7xcwjeP
oy^-?+
public String getSSiteURL() $hhXsu=
{ 0cS$S Mn{
return sSiteURL; U>2KjZB
} 9 C[~*,qx
(U:-z=E#1
cRLw)"|
public void setSSiteURL(String value) ,HZ%q]*:~
{ |?T=4~b
sSiteURL = value; ihrf/b
} fDy*dp4z
^4n#''wJ
U@OdQAX
public String getSFilePath() QLY;@-jF$
{ Msqqjhoy
return sFilePath; 9\Jc7[b
} ]-\68bN
4z<c8 E8
xMjhC;i{
public void setSFilePath(String value) <_YdN)x
{ u7< +)6-
sFilePath = value; D$}hoM1
} X30tO>
}~ D WB"
qp})4XTv
public String getSFileName() Wk%|%/:
{ I3Vu/&8f|
return sFileName; %1i:*~g
} ojM'8z0Hn
32ki ?\P
^~~Rto)Y
public void setSFileName(String value) wA5Iz{uQO
{ w-K A~
sFileName = value; *tqD:hiF
} [7I:Dm
dA)T>
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public int getNSplitter() +#Pb@^6"m
{ ##jJaSxG
return nSplitter; k{qxsNM
} ,Cr%2Wg-
&>jz[3
Q!l(2nva
public void setNSplitter(int nCount) Y$JVxly
{ 8_%GH}{
nSplitter = nCount; AG,><UP
} F$t]JM
} q;eb
@[r[l#4yUi
kLgkUck8]
/* T?1BcY
**Utility.java c(Dp`f,
*/ n#X~"|U`
package NetFox; wkp2A18n
U"GxXrl
qyRN0ZB"A^
public class Utility { yj:@Fg-3g
BM!ZdoKrKt
Y<T0yl?
public Utility() </25J((
{ :E")Zw&sW3
vkG#G]Qs";
SJiQg-+<Uf
} rj=as>6B
c,1 G+.
//线程睡眠 }b2YX+/e$f
public static void sleep(int nSecond) 0nt@}\j
{ dj0%?g>
try{ 9`f@"%h
Thread.sleep(nSecond); $FPq8$V
} (.#nl}fA
catch(Exception e) X_78;T)uA
{ J1w[gf]J
e.printStackTrace (); YoKE=ln7
} i9ySD
} B#g~c<4<
0qN`-0Yk
//日志 _mm(W=KiL
public static void log(String sMsg) Q/|.=:~FO
{ yr%[IX]R
System.err.println(sMsg); .)/."V
} m7k }k)
fqI67E$59
MFq?mZ,
public static void log(int sMsg) aU6l>G`w
{ ]wid;<
System.err.println(sMsg); kZ5#a)U<
} f#ZM2!^!
} ZUS-4'"$
Oi\ s
/si<Fp)z
/* #Vum
**TestMethod.java utmJ>GWSI
*/ GFFwk4n1
package NetFox; 7^i7U-A<A
'HWl_M
cX9o'e:C
public class TestMethod { Tx}Nr^
JMB#KzvN[
XZ%[;[
public TestMethod() icb)JZ1K
{ ///xx/weblogic60b2_win.exe 4M&$wi
try{ a#]V|1*O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RI*n]HNgy+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =AO (
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]njNSn
fileFetch.start(); r|l?2 eO~
} (?l ]}p^[
catch(Exception e){e.printStackTrace ();} X$@`4
LcGKYl(\K
I0x)d`
} ,yC..aI
K<^p~'f4P
g>t1rZ
public static void main(String[] args) bll[E}E|3
{ *)RKU),3nL
new TestMethod(); :6Z2@9.}w
} +6uf6&.@~
} )h@PRDI_
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