http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); GTgG0Ifeh
} 8vpB(VxV+
for(int i=0;i<nEndPos.length-1;i++) JVy-Y
{ ~\B1\ G
nEndPos = nStartPos[i+1]; I.As{0cc
} Tk\?$n
nEndPos[nEndPos.length-1] = nFileLength; C^oj/}^
} v50w}w'
} <Ih)h$8`
R~TzZ(Ah]
)(V|d$n
//启动子线程 lKKg n{R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "jS@ug
for(int i=0;i<nStartPos.length;i++) %xv }
{ j N":9+F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V9 Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 90<z*j$EK
nStartPos,nEndPos,i); 2%o@?Rp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b/"&E'5-`\
fileSplitterFetch.start(); "V|&s/9
} i286 J.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mu`:@7+Yp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NNDW)@p6z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T)4pLN E
nEndPos = " + nFileLength); CNP!v\D
// fileSplitterFetch[nPos.length-1].start(); [[ {L#
t,H=;U#
O\0]o!
//等待子线程结束 &q8oalh
//int count = 0; mcO/V-\5'
//是否结束while循环 drRi<7 i
boolean breakWhile = false; W@S>#3,
nD#QC=}
W5a7HkM
while(!bStop) '$nm~z,V
{ &}}UdJ`
write_nPos(); fib#)KE
Utility.sleep(500); % \N52
breakWhile = true; 8);G'7O
iwM$U( 9
J[0o6
for(int i=0;i<nStartPos.length;i++) r2!\Ts5v
{ H 5\k`7R
if(!fileSplitterFetch.bDownOver) 9W5~I9%
{ uUmkk
breakWhile = false; L F<{/c9,
break; vT1StOx<V
} iG+hj:5
} =*2_B~`
if(breakWhile) *z852@
break; ^W8kt
zH)M,+P
qK=uSLo\+
//count++; nev@ykP6
//if(count>4) {"e)Jj_=
// siteStop(); V7~tIhuJH
} GQ-fEIi{
]]"O)tWHj
gdr"34%vbM
System.err.println("文件下载结束！"); ^\"@r%|
} , yd]R4M
catch(Exception e){e.printStackTrace ();} zvEofK
} NAg9EaWja{
HgY [Q}7s
8_*31Y
//获得文件长度 2?c##Izn
public long getFileSize() ]:"<if gp$
{ Q3h_4{w
int nFileLength = -1; .R";2f3
try{ U=ek_FO
URL url = new URL(siteInfoBean.getSSiteURL()); z.vERP56
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M_BG:P5
httpConnection.setRequestProperty("User-Agent","NetFox"); rg5ZxN|g
"39\@Ow
AT{rg/oSf
int responseCode=httpConnection.getResponseCode(); MJ.K,e
if(responseCode>=400) Z(h.)$yH*=
{ Wxeg(L}E
processErrorCode(responseCode); t@"i/@8x$
return -2; //-2 represent access is error arWP]%E0W
} $:l>g)c
A.YXK%A%
=%=lq0GF0
String sHeader; &hnI0m=X
KA#P_e{<@
vw
for(int i=1;;i++) 'r0kX||
{ @'AjEl:&-_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _-+xzdGvX
//Utility.log(in.readLine()); j:>_1P/
sHeader=httpConnection.getHeaderFieldKey(i); 9'" F7>d
if(sHeader!=null) K`vc&uf
{ ?zP/i(1y
if(sHeader.equals("Content-Length")) x9!3i{_
{ {r>iUgg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j0wpaIp
break; z?3t^UPW
} :HiAjaA1pg
} '-KYeT\;
else 14DHU
break; u5Tu~
} T9'd?nw9
} 2j=i\B
catch(IOException e){e.printStackTrace ();} ]_5qME#N
catch(Exception e){e.printStackTrace ();} _TbQjE&6
~NV 8avZ
'qy LQ:6
Utility.log(nFileLength); o'?[6B>oj
Kg;u.4.-M
h<0&|s*a)
return nFileLength; l^k/Y ]
} iwVsq_[]L
yQz6K6p
;Pw\p^wz
//保存下载信息（文件指针位置） A||,|He~
private void write_nPos() 6"djX47j
{ S*3*Q l*
try{ YQ-!>3/)-
output = new DataOutputStream(new FileOutputStream(tmpFile)); )W,.xP
output.writeInt(nStartPos.length); @{q:179w^
for(int i=0;i<nStartPos.length;i++) cF V[k'F
{ CqVeR';2
// output.writeLong(nPos); WcHL:38
output.writeLong(fileSplitterFetch.nStartPos); omoD+
output.writeLong(fileSplitterFetch.nEndPos); Rp0`%}2 o
} tv 7"4$T
output.close(); 4`[2Te>
} nRHxbE}::
catch(IOException e){e.printStackTrace ();} VV+gPC
catch(Exception e){e.printStackTrace ();} xO_u
} 8\VP)<<
{9Ug9e{ ~
3YO%$
//读取保存的下载信息（文件指针位置） J\l'nqS"
private void read_nPos() ;O~k{5.iS
{ e2_p7
try{ dJ(<zz+;b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]8+ D
int nCount = input.readInt(); Ys@OgdS@:
nStartPos = new long[nCount]; Q)[DSM
nEndPos = new long[nCount]; dMw}4c3E
for(int i=0;i<nStartPos.length;i++) Liv.i;-qE
{ !)4'[5t"U
nStartPos = input.readLong(); %M5{-pJ|C
nEndPos = input.readLong(); kxH` c
} ?RPVd8PUhN
input.close(); =1r!'<"h
} ,CxIA^
catch(IOException e){e.printStackTrace ();} 90Bn}@t=Q
catch(Exception e){e.printStackTrace ();} *8Kx y@
} vdaG?+_o
f2iA5 rCV]
#V$h?`qhwr
private void processErrorCode(int nErrorCode) 7!g"q\s
{ K0fuN)C
System.err.println("Error Code : " + nErrorCode); 1:;S6{oQ
} 1smKU9B2)
SpC6dkxD\
[/Sk+ID
//停止文件下载 $W;f9k@C!
public void siteStop() SVn $!t
{ %7hf6Xo=
bStop = true; kyH0J[/n
for(int i=0;i<nStartPos.length;i++) 9)*218.
fileSplitterFetch.splitterStop(); Am@:<J
2|A?9aE%0
k?;@5r)y-
} qYP;`L}o#
} J{U 171
//负责部分文件的抓取 ]o?r(1
**FileSplitterFetch.java f=hT o!i
*/ VOSq%hB
package NetFox; eq(1'?7]`G
uGpLh0
GS&I6
import java.io.*; ZJ8"5RW
import java.net.*; }eAV8LU
/hSEm.<
*X /i<
public class FileSplitterFetch extends Thread { G{74o8
7 MS-Gs|
|,Kk#`lW<f
String sURL; //File URL cV4]Y(9
long nStartPos; //File Snippet Start Position 3gv@JGt7`
long nEndPos; //File Snippet End Position tx7B?/5D
int nThreadID; //Thread's ID :/R>0n,
boolean bDownOver = false; //Downing is over t{-*@8Ke
boolean bStop = false; //Stop identical : G'a"%x
FileAccessI fileAccessI = null; //File Access interface l:+$Ks
<Rfx`mn
k&9[}a*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bn{i+8I
{ wx8Qz,Z
this.sURL = sURL; }R!t/8K
this.nStartPos = nStart; 4Opf[3]
this.nEndPos = nEnd; 4I8QM&7
nThreadID = id; wvmcD%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w0X})&,{`m
} FQ"ED:lks
= N^Ec[u(l
~gdnD4[G
public void run() ?sv[vR(
{ a+^,EY
while(nStartPos < nEndPos && !bStop) 9@8'*a{`m
{ WP{U9YF2
9aBz%* xo
Qp9QSyMs}
try{ 8ZCR9%
URL url = new URL(sURL); 'Q"Mu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eD|"?@cE
httpConnection.setRequestProperty("User-Agent","NetFox"); uD\rmO{
String sProperty = "bytes="+nStartPos+"-"; 3 MCV?"0
httpConnection.setRequestProperty("RANGE",sProperty); ${e5Ka
Utility.log(sProperty); biG :Xn
3BSZz%va
XS$#\UQ
InputStream input = httpConnection.getInputStream(); :_|Xr'n`A
//logResponseHead(httpConnection); ojyP.R
D63?f\
Z*n4$?%W
byte[] b = new byte[1024]; qpjiQ,\:b
int nRead; \]0#jI/:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OX7a72z
{ WmOu#5*;
nStartPos += fileAccessI.write(b,0,nRead); D?FmlDTr[
//if(nThreadID == 1) pVM1%n:#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ITy/h]0
} ?pWda<&
N/eus"O;
i|rCGa0}
Utility.log("Thread " + nThreadID + " is over!"); \D1@UyE
bDownOver = true; DzIV5FG
//nPos = fileAccessI.write (b,0,nRead); P%;lHC #i
} \5-Dp9vG
catch(Exception e){e.printStackTrace ();} E`Br#"/Bl
} .kTOG'K\e
} }`aT=_B
g'td(i[
;9<?~S
//打印回应的头信息 ,$Cr9R&/
public void logResponseHead(HttpURLConnection con) G8WPXj(
{ YU XxQ|
for(int i=1;;i++) x*p'm[Tdtm
{ XQ2YUe]DJ
String header=con.getHeaderFieldKey(i); l.(|&U~
if(header!=null) rk47$36X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .Fx3WryF
Utility.log(header+" : "+con.getHeaderField(header)); ++eT 0
else u2IU/z8 ^
break; {Iz"]Wh<f
} DyCkz"1S
} O^q~dda
T*g}^TEh
$Wjx$fD
public void splitterStop() ] &SmeTe
{ ?Yx2q_KZk
bStop = true; !DUOi4I
} CM6! 1 7
[{>3"XJ'
FOteNQTj
} \t%iUZ$
/l+"aKW 2
:2V|(:^'
/* 1,7 }ah_
**FileAccess.java 7'gk=MQc
*//文件访问(定位，写) I%b5a`7
package NetFox; MdFFt:y:
import java.io.*; "<Yxt"Z4
<g&.UW4
\}\# fg
public class FileAccessI implements Serializable{ ~Kl"V%>
lbGPy'h<rt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :9e4(7~ona
RandomAccessFile oSavedFile; ?mF:L"i
long nPos; S..8,5mBH
:YPi>L5
1!yd(p=cL
public FileAccessI() throws IOException xLms|jS
{ Xpv<v[a
this("",0); -zWNQp$
} B)/c]"@89
qO/3:-
#*%?]B=
public FileAccessI(String sName,long nPos) throws IOException 7VskZbj\
{ 6@"E*-z$
oSavedFile = new RandomAccessFile(sName,"rw"); =A~5?J=
this.nPos = nPos; {c~w Ms#
oSavedFile.seek(nPos); _~'MQ`P
} H?FiZy*[Y
s8 u`v1
tvBLfqIr
public synchronized int write(byte[] b,int nStart,int nLen) q#1G4l.
{ | O9b
int n = -1; s8'!1rHd
try{ G$luGxl[
oSavedFile.write(b,nStart,nLen); ]o8yZ x
n = nLen; fqBz"l>5A
} k!G{#(++&6
catch(IOException e) /q8B | (U
{ ?NvE9+n
e.printStackTrace (); 0:-z+`RHE
} J1w3g,
5s;@;V
C(UWir3mW?
return n; !Pt4\
} Spu;
l8:!{I?s=
-x:7K\=$SX
} kd_!S[
!T2{xmHKv$
$5\!ws<cZ
/* {=,G>p
**SiteInfoBean.java %_!0V*X*
*/ [k75+#'
package NetFox; =M9R~J!
0l/7JH_@V
;JgSA&'e
public class SiteInfoBean { EQk omjv
-0BxZ AW=
Q&lb]U+\u
private String sSiteURL; //Site's URL a8v\H8@X
private String sFilePath; //Saved File's Path >rSCf=
private String sFileName; //Saved File's Name C1(RgY|
private int nSplitter; //Count of Splited Downloading File & P%#
:'xZF2
{<a)+S.6U
public SiteInfoBean() sva-Sd8
{//nSplitter的缺省值为5 [z"oi'"fQ
//default value of nSplitter is 5 )2q r^)
this("","","",5); !I\eIV>0b
} P: L6Zo-J
,7Ejb++/M,
&x=_n'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _/"e'@z
{ F>^KXq:Z
sSiteURL= sURL; t:P7ah
sFilePath = sPath; f="ZplW
sFileName = sName; E{QjmlXQ<
this.nSplitter = nSpiltter; +]GP"yv-
OoRg:"9{#
he@Y1CY
} <%W&xk
f3^qO9R
SUIu.4Mz
public String getSSiteURL() O_GHvLO=
{ >wL!`:c'"
return sSiteURL; B.smQt
} MRZN4<}9
ZsCwNZR
Nf2lw]-G4
public void setSSiteURL(String value) b|G~0[g
{ :7X{s4AU6
sSiteURL = value; Vq/hk
} ,aq>9\pi
+fKV/tSWi
;8 *"c
public String getSFilePath() ;CoD5F!
{ __1Hx?f
return sFilePath; \TnK<83
} {X<_Y<
S6C DK:
MtgY `p
public void setSFilePath(String value) 2P${5WT
{ *a0#PfS[
sFilePath = value; `Fe/=]<$
} bD3dT>(+
K6)IBV;
I2NMn5>
public String getSFileName() [} d39
{ 9eE FX7
return sFileName; :;hm^m]Y
} a;kiAJ'
jsF5q~F
<Wj/A/
public void setSFileName(String value) TEGg)\+D>
{ Im};wJ&
sFileName = value; (lq%4h
} bE=[P}E
Jk:ZO|'Z
()$m9%x
public int getNSplitter() &B1!,joH~
{ SOMAs'=
return nSplitter; ,%zE>^~
} {w,<igh
7|bBC+;(
YguW2R=6]
public void setNSplitter(int nCount) FPZ@6
{ cRCji^,KJ
nSplitter = nCount; "(~fl<;
} OwgPgrV
} !\$4A,
paYS<8In
G9#3 |B-?
/* vXSA_"0t
**Utility.java E@l@f
*/ 2#CN:b]+
package NetFox; s0h0EpED
Sht3\cJ8
%,@e- &>
public class Utility { m(5LXHJnv
ae2I,Qt%
e5lJ)_o
public Utility() Jvj* z6/a
{ Cv&>:k0V
T :^OW5d
:RYYjmG5;
} /?|;f2tbV2
vS:=%@c>ta
//线程睡眠 k^B7M}
public static void sleep(int nSecond) Wcl =YB%
{ Gg:W%&#
try{ _g D9oK
Thread.sleep(nSecond); EpCNp FQT<
} $bBUL C
catch(Exception e) CG J_k?h
{ sebuuL.l0<
e.printStackTrace (); jxq89x
} &Ot9"Aq:
} ,?%o ~
YluvWHWi
//日志 ]D^; Ca
public static void log(String sMsg) Y[m*
{ N ;n55N
System.err.println(sMsg); N[DKA1Ei
} %+;amRb
@kba^z
41rS0QAM
public static void log(int sMsg) &`-e; Xt
{ O -p^S
System.err.println(sMsg); <K/iX%b?
} >Il{{{\>
} :g-vy9vb
nn">
`Cy;/95m
/* [s%uE+``S
**TestMethod.java g(S4i%\
*/ |uRYejj#j
package NetFox; ZLf(m35
>{rD3X"d
r-[YJzf@P
public class TestMethod { 9):^[Wkx
}Py Z{yS
Z%SDN"+'g
public TestMethod() ?fpI,WFu
{ ///xx/weblogic60b2_win.exe O31.\ZR2
try{ |+<o(Q(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >{0,dGm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N~(?g7
SiteFileFetch fileFetch = new SiteFileFetch(bean); /de~+I5AB~
fileFetch.start(); %Rm`YH?
} PA,\o8]x
catch(Exception e){e.printStackTrace ();} vv`53 Pbw)
;jlI>;C;V
k4"O}jQO
} Rp}Sm,w(
Q[aBxy (
H^$7=
public static void main(String[] args) COH>B1W@
{ &>ykkrY
new TestMethod(); _w%{yF6
} A{DE7gp!
} Z[\nyj
点击下载更多相关资料