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)); *{ =5AW}o
} 2 /rDi
for(int i=0;i<nEndPos.length-1;i++) $p(,Qz(.8
{ FuA8vTV{
nEndPos = nStartPos[i+1]; NXJyRAJ*%
} G>3]A5
nEndPos[nEndPos.length-1] = nFileLength; -G!W6$Y
} @[:JQ'R=
} u{H'evv0O
5|4=uoA<
stb)Tl^
//启动子线程 ,b&-o?.{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1#G(
for(int i=0;i<nStartPos.length;i++) w2 L'j9
{ dG}.T_l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $>72 g.B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =nq9)4o
nStartPos,nEndPos,i); jJX-S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (c'=jJX
fileSplitterFetch.start(); `|["{j}^
} _fVC\18T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lzKJy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IjK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j-?zB.jAh
nEndPos = " + nFileLength); ZPM,ZGlu:
// fileSplitterFetch[nPos.length-1].start(); ?gq',FFDq
FXAP]iqo
BIFuQ?j3
//等待子线程结束 -w0U}Te^
//int count = 0; Up(Jw-.
//是否结束while循环 Rk1B \L|M
boolean breakWhile = false; ^m3[mY [a
QGWfF,q
oAMB}a;
while(!bStop) \Mujx3Fmvx
{ TQcEe@$)
write_nPos(); h-^7cHI}
Utility.sleep(500); L>,j*a_[
breakWhile = true; 1z4s1Y
.g|D
8-A *Jc
for(int i=0;i<nStartPos.length;i++) r*n_#&-7
{ af:wg]g
if(!fileSplitterFetch.bDownOver) 75O-%9lFF
{ S.!0~KR:U
breakWhile = false; _n[4+S*v(
break; uv:DO6 {
} 3\=iB&Gf|
} $'9b,- e
if(breakWhile) +npcU:(Kg
break; v(HCnC
C:]&V*d.v4
,u^RZ[}
//count++; NXwlRMbo
//if(count>4) QO'=O}e
// siteStop(); |bHId!d
} F(-1m A&-
q ;@:,^
A? =(q
System.err.println("文件下载结束！"); mXX9Aa>
} 6l{=[\.Xa
catch(Exception e){e.printStackTrace ();} .szs?
} *kI1NchF
*ybwlLg
jslfq@5v
//获得文件长度 c{iF
public long getFileSize() $WOiXLyCk
{ [n53eC
int nFileLength = -1; if S) < t
try{ t`"]"Re
URL url = new URL(siteInfoBean.getSSiteURL()); `&)khxT/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .] S{T
httpConnection.setRequestProperty("User-Agent","NetFox"); qJ;T$W=NG
w Wx,}=
~MvLrg"i
int responseCode=httpConnection.getResponseCode(); _` %z
if(responseCode>=400) hb6UyN
{ HxC_nh
processErrorCode(responseCode); Vd8BQB,Q
return -2; //-2 represent access is error 8a\ Pjk
} 8:BPXdiK
n..9F$a
)/'y'd<r
String sHeader; e[3rz%'Q
x*)@:W!
(z[|\6O
for(int i=1;;i++) w85PRruW
{ -PHVM=:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zH0{S.3k
//Utility.log(in.readLine()); lC/4CPKtV
sHeader=httpConnection.getHeaderFieldKey(i); :Kc}R)6
if(sHeader!=null) Q7ez?]j6
{ aB`x5vg7ho
if(sHeader.equals("Content-Length")) t^|+|>S
{ ]-6=+\]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qR WWG&
break; {y{&tzZ
} 67uUeCW
} DhQYjC[
else #+1*g4m~B
break; LnN6{z{M
} %hYol89F
} MTKd:.J6
catch(IOException e){e.printStackTrace ();} KcGM=z?:
catch(Exception e){e.printStackTrace ();} +["t@Q4IQ
VfJbexYT
N XwQvm;q
Utility.log(nFileLength); GC{)3)_ t
x< Td
F5CV<-jB
return nFileLength; lP@/x+6tg
} py,B6UB5
c3\z
6%mFiX
//保存下载信息（文件指针位置） SX$Nef9p
private void write_nPos() Ksp!xFk
{ RVxlN*
try{ [Z3B~c
output = new DataOutputStream(new FileOutputStream(tmpFile)); YN\!I
output.writeInt(nStartPos.length); o{EWNkmj
for(int i=0;i<nStartPos.length;i++) MPMa
{ e ;4y5i
// output.writeLong(nPos); QyJ2P{z
output.writeLong(fileSplitterFetch.nStartPos); (6C%w)8'
output.writeLong(fileSplitterFetch.nEndPos); FFTh}>>
} k+^-;=u6<
output.close(); ub|tX 'o
} MZt~ Abt
catch(IOException e){e.printStackTrace ();} wIW]uo/=
catch(Exception e){e.printStackTrace ();} E(i<3U"4h[
} $-dz1}
*mQOW]x%
3>[_2}l
//读取保存的下载信息（文件指针位置） Z4\$h1tl
private void read_nPos() HvWnPh1l
{ Ns6Vf5T.
try{ 83*"58
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fP41B
int nCount = input.readInt(); ZJotg*I
nStartPos = new long[nCount]; *o8DfZ
nEndPos = new long[nCount]; 6Xjr0C+
for(int i=0;i<nStartPos.length;i++) Nz+Jf57t
{ EUvxil
nStartPos = input.readLong(); } k[gR I]
nEndPos = input.readLong(); hWGCYkuW
} ,UFr??ZKm
input.close(); `(|jm$Q
} u!([m; x|
catch(IOException e){e.printStackTrace ();} LbGyD;#_
catch(Exception e){e.printStackTrace ();} L#'B-G4&y
} ^O cM)Z6h
W/O&(t
UR~9*`Z ,
private void processErrorCode(int nErrorCode) lGa'Y
{ d#@N2
System.err.println("Error Code : " + nErrorCode); ^(p}hSLAfQ
} K0xZZ`
'1{#I/P;
dP(*IOO.
//停止文件下载 K!q:A+]
public void siteStop() 1mw<$'pm0
{ ~=5vc''
bStop = true; ~F`t[p
for(int i=0;i<nStartPos.length;i++) $I%75IZ
fileSplitterFetch.splitterStop(); Ku{DdiTg>
L]o 5=K
?XVJ$nzW
} gB!K{ Io'
} m:77pE&o
//负责部分文件的抓取 @g*=xwve=~
**FileSplitterFetch.java ;C8'7
*/ )-FQ_K%
package NetFox; wL]7d3t
n<;TBK
_ i )Z8#
import java.io.*; ,Yg<Z1
import java.net.*; U@$Kp>X
u 89u#gCAC
Xp]tL3-p
public class FileSplitterFetch extends Thread { CqVh9M.ah
T,h,)|:I^
P7n+@L$
String sURL; //File URL &Y2mLPB
long nStartPos; //File Snippet Start Position GI}h)T
long nEndPos; //File Snippet End Position zT|]!',
int nThreadID; //Thread's ID <!h&h
boolean bDownOver = false; //Downing is over bdiyS.a-
boolean bStop = false; //Stop identical NJb5HoYZ
FileAccessI fileAccessI = null; //File Access interface `jR;RczC
8$!/Zg
p&=F:-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @b=b>V[d6
{ `vJ+sRf
this.sURL = sURL; CtwMMZXX3
this.nStartPos = nStart; F{cKCqI?
this.nEndPos = nEnd; %Uk]e5Hu
nThreadID = id; rIz"_r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zmI?p4,
} XfFZ;ul
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2U6j?MyH2
public void run() b'Gn)1NE
{ @>'.F<:P<
while(nStartPos < nEndPos && !bStop) K;2tY+I
{ |5SYKA7CS
4*9y4"
rm*Jo|eH`
try{ 9V&%_.Z
URL url = new URL(sURL); N1ZHaZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fkas*79
httpConnection.setRequestProperty("User-Agent","NetFox"); |y@TI
String sProperty = "bytes="+nStartPos+"-"; I(E1ym
httpConnection.setRequestProperty("RANGE",sProperty); 2 @g'3M
Utility.log(sProperty); Ue|]M36
]@bo;.
jcF/5u5e
InputStream input = httpConnection.getInputStream(); Sk@~}
//logResponseHead(httpConnection); Fl GKy9k
vkan+~H
='=\!md
byte[] b = new byte[1024]; 2~+Iu+
int nRead; e!}R1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <{.o+~k
{ ;p%a!Im_<
nStartPos += fileAccessI.write(b,0,nRead); }et^'BkA(
//if(nThreadID == 1) 'sI=*c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1cS{3
} z#b31;A@$
_Tyj4t0ElV
9="i'nYp
Utility.log("Thread " + nThreadID + " is over!"); fL4F ~@`9l
bDownOver = true; 9I/o;Js
//nPos = fileAccessI.write (b,0,nRead); v"Bv\5f,Ys
} Y[x9c0
catch(Exception e){e.printStackTrace ();} aX6.XHWbDf
} $H^hK0?'
} bh:;ovH
zEJ|;oL
67 >*AL
//打印回应的头信息 !8ub3oj)
public void logResponseHead(HttpURLConnection con) ]>K%,}PS
{ <1]#E@
for(int i=1;;i++) Gs2.}lz
{ HS| &["
String header=con.getHeaderFieldKey(i); '6u;KIG
if(header!=null) d;|Pp;dc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +r9:n(VP
Utility.log(header+" : "+con.getHeaderField(header)); DGdSu6s$
else xtN%v0ZZ
break; M~;Ww-./
} NvXds;EC
} %WHue
,6,#Lc
ZVEq{x1Zc
public void splitterStop() R`Hyg4?
{ axnkuP(
bStop = true; IX;u+B
} LJYFz=p"
f&B&!&gZ
21M@z(q*
} draY/
I :%(nKBK
( du<0J|PT
/* OOs Y{8xM
**FileAccess.java !HM{imT
*//文件访问(定位，写) e?3 S0}
package NetFox; ;OTD1=
import java.io.*; >Rs:Fw|jro
&%L1n?>Q}
\kZxys!4
public class FileAccessI implements Serializable{ >}GtmnF
z'3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bNp RGhlV
RandomAccessFile oSavedFile; "zL<:TQ"
long nPos; i}N'WV`!
:CNWHF4$
]wWN~G)2lV
public FileAccessI() throws IOException O8TAc]B
{ ,ClGa2O
this("",0); ZJ'#XZpr
} w0x,~
?@6N EfQf
3i=+ [
public FileAccessI(String sName,long nPos) throws IOException 6pM[.:TM
{ a,x-akZWf
oSavedFile = new RandomAccessFile(sName,"rw"); E$=!l{Ms
this.nPos = nPos; yYwZZa1
oSavedFile.seek(nPos); bEyZRG
} LJ`*&J
5ycccMx0V
lX/s Q
public synchronized int write(byte[] b,int nStart,int nLen) %WiDz0o
{ ob05:D_bc9
int n = -1; <xOXuve
try{ (4o_\&
oSavedFile.write(b,nStart,nLen); D/^yAfI
n = nLen; aFGEHZJQ
} r) ;U zd
catch(IOException e) Pp3<K649
{ .;)7)%
e.printStackTrace (); pSvRyb.K
} !f[LFQD
G?)NDRM
$!%/Kk4M
return n; #kjN!S*=
} {fFZ%$
N}Q%y(O^
ad1I2
} u:JD
~x^E kE
$_IvzbOh
/* ZmeSm& hQ_
**SiteInfoBean.java j>Wb$p6S
*/ ,r^zDlS<q
package NetFox; r0t4\d_&
67/JsL
-d5b,leC^
public class SiteInfoBean { CAg~K[
F|pM$Kd`
E#}OIZ\S
private String sSiteURL; //Site's URL z#9Tg"8]
private String sFilePath; //Saved File's Path 3'tcEFkH
private String sFileName; //Saved File's Name C'$w*^me
private int nSplitter; //Count of Splited Downloading File )tYu3*'
U[7 &
d1CQ;,Df<
public SiteInfoBean() =2v/f_
{//nSplitter的缺省值为5 X)7_@,7
//default value of nSplitter is 5 ?1Os%9D*
this("","","",5); h|~I'M]*
} SFqY*:svOw
.5$"qb ?
cG!\P:re
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p1tqwV
{ N)yCGo
sSiteURL= sURL; |)~t^
sFilePath = sPath; @7S* ]
sFileName = sName; 5<64 C}fE3
this.nSplitter = nSpiltter; xf2|9Tqt
X5U#^^O$E%
ri.}G
} -sjyv/%_
7b8+"5~
^mwS6WH6
public String getSSiteURL() ,J;Cb}
{ _(7f0p
return sSiteURL; jD}G9=[$1
} N!~O~Eo3
3uXRS,C
r=}v` R&
public void setSSiteURL(String value) q4MR9ig1E_
{ ohU}ST:9
sSiteURL = value; W6c]a/
} px${ "K<
k~%j"%OB
Wn%b}{9Fb
public String getSFilePath() NHaY&\
{ -UB XWl
return sFilePath; =;Q:z^S
} MCO2(E-
X aE;i57$l
\s?8}k
public void setSFilePath(String value) 'fjouO
{ =h\unQ1T
sFilePath = value; dtj+ avG
} H\fsyxM7
38mC+%iC
|:w)$i& *
public String getSFileName() -e4TqzRr
{ s_;o1 K0
return sFileName; S4U}u l
} X5pb9zRq
"&:H }Jd
r;^%D(
public void setSFileName(String value) h+R26lI1x
{ boq=@Qh
sFileName = value; hd*GDjmRQ/
} YK\pV'&+
'NMO>[.
"Zfm4Nx"
public int getNSplitter() ?9;CC]D
{ _\8jnpT:
return nSplitter; [l/!&6
} D0Mxl?S?
}Y^o("c(
Aydpr_lp
public void setNSplitter(int nCount) [D+,I1u2h
{ z/]]u.UP
nSplitter = nCount; x2sKj"2?@
} q3vv^~
} ~N%+ZXh&E
+[R^ ?~VK
?fN6_x2e3
/* 2!6E~<~HC
**Utility.java $4mCtonP=
*/ #*q]^Is"
package NetFox; BhYvEbt
HC}vO0X4
X}xf_3N "
public class Utility { k'_f?_PBu
IG{lr
h\p!J-V
public Utility() D>8p:^3g
{ v6|j.;
>|z:CX$]
?=LT ^Zp`
} R`Fgne$4
]ag{sU@#
//线程睡眠 fgs@oaoZ
public static void sleep(int nSecond) Yj'9|4%+|
{ Z;V(YK(WO.
try{ $OG){'X
Thread.sleep(nSecond); =tbfBK+
} W+GC3W
catch(Exception e) %Z4*;VwQ
{ I`(53LCqo
e.printStackTrace (); ImG8v[Q E
} &TY74w*
} 78{9@\e"0
eM{u>n+`F0
//日志 6}m`_d?
public static void log(String sMsg) 9tU"+
{ P JATRJ1.
System.err.println(sMsg); Q 8Hl7__^
} A yr,
0VcHz$ 6
&9^4-5]
public static void log(int sMsg) ?)J/uU2w
{ /='0W3+o*L
System.err.println(sMsg); p@kRo#~l
} ;&n iZKoe
} zzhZ1;\
1&! i:F#
_qR?5;v
/* +Eh.PWEe
**TestMethod.java >t)Pcf|s
*/ C{}PO u
package NetFox; pHmqwB~|
>zqaV@T
i_Hm?Bi!F
public class TestMethod { x;)I%c
~9 .=t'
>({qgzV`
public TestMethod() cN0 *<
{ ///xx/weblogic60b2_win.exe )-_^vB
try{ %Y%r2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {iX#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;.Bz'Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); nf^?X`g
fileFetch.start(); @JXpD8jn
} )][U6e
catch(Exception e){e.printStackTrace ();} j{OA%G(I
-$W1wb9z
z^U+oG
} c 9f"5~
^T!Zz"/:
>lV,K1Z
public static void main(String[] args) T4]2R
{ gMI%!Y
new TestMethod(); #vBrRHuA#"
} a~7D4G
} It[51NMal
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