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)); jHPJk8@y
} #/'5N|?
for(int i=0;i<nEndPos.length-1;i++) sidSY8j
{ ar.w'z
nEndPos = nStartPos[i+1]; 7dl]f#uZU
} Fx']kn9
nEndPos[nEndPos.length-1] = nFileLength; ^E&':6(
} FHVZ/ e
} "R-1G/
yBKkx@o#z
yZ t}Jnv
//启动子线程 "|{O%X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pqPhtWi%PJ
for(int i=0;i<nStartPos.length;i++) =T$-idx1l
{ k36%n *4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >&h#t7<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 45l/)=@@B
nStartPos,nEndPos,i); 4C2JyP3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^|DI9G(Bs
fileSplitterFetch.start(); ($^XF:#5
} RG=!,#X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g+gHIb7{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kd9rvy0oK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B@ZedXi
nEndPos = " + nFileLength); *9}2Bmojv
// fileSplitterFetch[nPos.length-1].start(); {uEu ^6a5
J2_DP
T_CYSS|fX
//等待子线程结束 s$e0;C!D
//int count = 0; L 0kK'n?
//是否结束while循环 !n4p*<Y6
boolean breakWhile = false; kQXtO)
1P&XG@
3IHya=qN
while(!bStop) aF4vNUeG
{ hA)tad]
write_nPos(); }YHoWYR
Utility.sleep(500); z5Hz-.
breakWhile = true; Two$wL/
g:MpN^l
ot P7;l
for(int i=0;i<nStartPos.length;i++) `As.1@
{ IpQ51
if(!fileSplitterFetch.bDownOver) 5-O[(b2O
{ j;eR9jI$T
breakWhile = false; [i24$UT
break; UahFs
} 4-efnB
} NZ`W`#{
if(breakWhile) az3rK4g
break; \MM(w&
;3NA,JA#Y
)|f!}( p
//count++; rkW*C'2fz
//if(count>4) -?n|kSHX
// siteStop(); V}ZF\SG(K
} DWDL|4 og
Q}ho Y
A][\L[8X
System.err.println("文件下载结束！"); jJ86Ch
} Pb=J4Lvz(d
catch(Exception e){e.printStackTrace ();} 31-%IkX+k
} lTsl=
Qy |*[
@%@uZqQ4
//获得文件长度 ;cIs$
public long getFileSize() ;Ad$Q9)EE
{ bJ~]nj 3
int nFileLength = -1; GYYk3\r
try{ k0.|%0?K
URL url = new URL(siteInfoBean.getSSiteURL()); dC;@ Fn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -xtj:UO
httpConnection.setRequestProperty("User-Agent","NetFox"); w$UWfL(
,dK<2XP
g83]/s+
int responseCode=httpConnection.getResponseCode(); x7 jE Ns )
if(responseCode>=400) qazM@
{ \"i2E!
processErrorCode(responseCode); ^yiRrcOo
return -2; //-2 represent access is error [_ESR/&N
} u$d T^c
mjG-A8y
* 3mF.^
String sHeader; )2C`;\/:
" cx\P,<
QcG4~DEX4
for(int i=1;;i++) PO5/j
{ <m"Zk k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mu0ER 3o
//Utility.log(in.readLine()); "<x%kD
sHeader=httpConnection.getHeaderFieldKey(i); /qA\|'~
if(sHeader!=null) <)+9PV<w
{ D_@WB.eL
if(sHeader.equals("Content-Length")) AjB-&Z
{ -4{sr| lm
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +s.r!?49+
break; WjtmV2b<7
} 8@ck" LUzD
} w$4fS
else }7E2,A9_"
break; GL'zs8AKf
} !},_,J~(|
} 0|n1O)>J
catch(IOException e){e.printStackTrace ();} 0dA'f0Uy\X
catch(Exception e){e.printStackTrace ();} sI/Jhw)
zl\mBSBx"
(gZKR2hO
Utility.log(nFileLength); b&X- &F
>8+:{NW
}2;~':Mklz
return nFileLength; fEF1&&8^
} lAz.I
i/`N~r
ntE;*FyH
//保存下载信息（文件指针位置） Q)S0z2
private void write_nPos() 0q(}nv
{ ZW n j-
try{ JlJy3L8L
output = new DataOutputStream(new FileOutputStream(tmpFile)); +DFG762
output.writeInt(nStartPos.length); >.N?y@
for(int i=0;i<nStartPos.length;i++) XhjH68S(
{ cLn&b}8'
// output.writeLong(nPos); IY2caXu
output.writeLong(fileSplitterFetch.nStartPos); +T02AS
output.writeLong(fileSplitterFetch.nEndPos); hDI_qZ
} 0@[]l{N
output.close(); oA`'~~!
} uH S)
catch(IOException e){e.printStackTrace ();} B B*]" gT
catch(Exception e){e.printStackTrace ();} wB~Ag$~
} 4`Qu+&4J
$Kn{x!,"(
aaW(S K
//读取保存的下载信息（文件指针位置） 6tBL?'pG
private void read_nPos() C;#vW FE
{ C5GO?X2
try{ Ge=+0W)&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `b 6j7
int nCount = input.readInt(); ,,vl+Z<&
nStartPos = new long[nCount]; YNV4w{>FD
nEndPos = new long[nCount]; 1:5jUUL8
for(int i=0;i<nStartPos.length;i++) #]pFE.o
{ -@f5d
nStartPos = input.readLong(); eSNi6RvE
nEndPos = input.readLong(); v {E~R
} J P'|v"
input.close(); &y"e|aE
} !2>MaV1,
catch(IOException e){e.printStackTrace ();} ^3?]S{1/#
catch(Exception e){e.printStackTrace ();} 1 i # .h$
} +HvEiY
^6tGj+D9
U{Xg#UN
private void processErrorCode(int nErrorCode) x TEDC,B
{ F3j#NCuO=z
System.err.println("Error Code : " + nErrorCode); N9 yL(2
} gOaL4tu
[O92JT:li
| wuUH
//停止文件下载 YD1 :m3l!
public void siteStop() X,dOF=OJL
{ V*HkFT
bStop = true; w4w[qxV>
for(int i=0;i<nStartPos.length;i++) GqB]^snh
fileSplitterFetch.splitterStop(); R+Q..9P
!*#2~$:
I[u%kir
} $2N)m:X0
} AB92R/
//负责部分文件的抓取 HAJK%zLc
**FileSplitterFetch.java $A"C1)d;
*/ t/xWJW2
package NetFox; w+c%Y\:
vU(2[
<pzCpF<
import java.io.*; /~RY{ c@#L
import java.net.*; _)AX/%^%
##Jg>HL'
xfYDjf :<
public class FileSplitterFetch extends Thread { %DH2]B? 0
e%_2n=p~)%
RQ}0f5~t
String sURL; //File URL ; C/:$l
long nStartPos; //File Snippet Start Position q5<'pi
long nEndPos; //File Snippet End Position BVAxeXO
int nThreadID; //Thread's ID (/6~*<ZGT
boolean bDownOver = false; //Downing is over 8XFs)1s[
boolean bStop = false; //Stop identical q^5j&jx Vl
FileAccessI fileAccessI = null; //File Access interface tB-0wD=PR
Se*o{V3s$
N,N9K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BWRM gN'.
{ vhe[:`=a
this.sURL = sURL; R0|dKKzS
this.nStartPos = nStart; h$3o]~t
this.nEndPos = nEnd; a'3|EWS ?
nThreadID = id; K1i@.`na/$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B.)!zv\{
} 53>y<
DL$O274uZ
RE~9L5i5
public void run() Z]U"i1lA
{ dV_ClH &)
while(nStartPos < nEndPos && !bStop) ECq(i(
{ _J' _9M?>
/1A3 Sw
NrQGoAOw
try{ -2Bkun4Pt
URL url = new URL(sURL); NF9fPAF%;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [=f(u wY>g
httpConnection.setRequestProperty("User-Agent","NetFox"); O"%b@$p\L
String sProperty = "bytes="+nStartPos+"-"; pGS!Nn;K2
httpConnection.setRequestProperty("RANGE",sProperty); ,+LX.f&/8!
Utility.log(sProperty); V $'~2v{_
=gSa?pd
0^?:Zds
InputStream input = httpConnection.getInputStream(); U7GgGMw
//logResponseHead(httpConnection); L-J 7z+{
$Sz@u"ig%
fjD/<`}v
byte[] b = new byte[1024]; YVSAYv_ZG}
int nRead; SxyXz8+e[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^t X}5i`P
{ }2@Aj
nStartPos += fileAccessI.write(b,0,nRead); |a||oyrN
//if(nThreadID == 1) &~9'7 n!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e+`LtEve0
} .x6c.Y.S
#J4{W84B
'E_M,Y
Utility.log("Thread " + nThreadID + " is over!"); v2Lx4:dzi
bDownOver = true; l~_]k
//nPos = fileAccessI.write (b,0,nRead); e+'PRVc
} gXrXVv<)yw
catch(Exception e){e.printStackTrace ();} qIXo_H&\C
} ,gag_o{*a
} x}\_o< d
32#|BBY
Vr%>'XN>"
//打印回应的头信息 Gcu[G]D
public void logResponseHead(HttpURLConnection con) by*?PhfF
{ V?_:-!NJ(
for(int i=1;;i++) 3 VNPdXsh
{ ]' ck!eG
String header=con.getHeaderFieldKey(i); c~,OU7[
if(header!=null) %8U/!(.g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aHhr_.>X
Utility.log(header+" : "+con.getHeaderField(header)); |DB7o+4
else i!AFXVX
break; $-x@P9im
} }MW7,F
} 2=?:(e9
fv;3cxQp
F0Nl,9h('
public void splitterStop() )\xDo<@
{ 06)B<
bStop = true; QB3vp4pBg@
} =x_~7 Xc{
rzl0*CR
]H%SGQPn
} -}_X'h&"
,RA;X
jUtFDw
/* VXfp=JE
**FileAccess.java qwf97pg$
*//文件访问(定位，写) G6*P]<
package NetFox; |o6g{#1
import java.io.*; ET2^1X#j
^/"[jq3F
"W"2Y(
public class FileAccessI implements Serializable{ #L3heb&9
obRYU|T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t@_MWF
RandomAccessFile oSavedFile; =qg;K'M5
long nPos; ?.*^#>-
84X/=l-c=
By&ibN),
public FileAccessI() throws IOException v@qU<\Y>
{ c3L)!]kB
this("",0); @2X{e7+D
} o+}>E31a
o.o$dg(r!
w6Owfq'v
public FileAccessI(String sName,long nPos) throws IOException *_qLLJg
{ R&vV!d
oSavedFile = new RandomAccessFile(sName,"rw"); YA?46[:
this.nPos = nPos; $;k2b4u
oSavedFile.seek(nPos); 2#y-3y<G
} Qp?+G~*
9/yE\p.
KscugX*x
public synchronized int write(byte[] b,int nStart,int nLen) hxT{!g
{ Hv3<gyD
int n = -1; ;ZasK0
try{ y;$ !J
oSavedFile.write(b,nStart,nLen); j0X Jf<
n = nLen; u#Z#NP ~F0
} Z<Rhn
catch(IOException e) u`ezQvrcy
{ o*r 2T48
e.printStackTrace (); "/#=8_f
} .)Wqo7/Gx
.%x1%TN
W Z_yaG$U
return n; 'zUWO_(
} fzk^QrB
Zf,9 k".'C
3$~oQC
} 2jT2~D.U1
grs~<n|o\
F\Z|JCA
/* SQSPdR+
**SiteInfoBean.java VfFXH,j
*/ flXDGoW
package NetFox; V Kw33
57S!X|CE
pWm==Ds|
public class SiteInfoBean { 141G~@-
8TE2q Pm
0Mo?9??
private String sSiteURL; //Site's URL }2!=1|}
private String sFilePath; //Saved File's Path JtbwY@R
private String sFileName; //Saved File's Name <rbzsn"a
private int nSplitter; //Count of Splited Downloading File 0rA&Q0
zHg1K,t:
"NMSLqO
public SiteInfoBean() gK#G8V-,
{//nSplitter的缺省值为5 "C~Zl&3
//default value of nSplitter is 5 <J o\RUx
this("","","",5); ],l}J'.8<V
} eKv{N\E
u$MXO].Q
4\pUA4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?]]7PEee*
{ p*Q *}V
sSiteURL= sURL; '[zy%<2sL
sFilePath = sPath; VZ1u/O?ub
sFileName = sName; fgW>~m.W
this.nSplitter = nSpiltter; Yp@i{$IUW
`iQ9 9
] v8.ym
} ~2L]K4Z^
=;z42oS
"T~ce@
public String getSSiteURL() cxB{EH,2Um
{ |.~0Ulk,
return sSiteURL; )1ct%rue
} \-Ipa59U
6}"t;4@$x
Ty5}5)CRZ
public void setSSiteURL(String value) vdFP ^06
{ Q^@z]Sc[
sSiteURL = value; wticA#mb
} >&?k^nI}J
[IRWmN-
^)%TQ.
public String getSFilePath() o'*7I|7a
{ g?1! /+
return sFilePath; wyC1M
} _!:*&{
4.&hV?Kxz
C'S&
public void setSFilePath(String value) DRy,n)U&
{ x:0nK,
sFilePath = value; e:T8={LU2W
} CGCI3Z'
Gi7p`F.
LO@='}D=
public String getSFileName() ,5Nf9z!hk(
{ P7|x=Ew;`
return sFileName; b!gvvg<
} g7g^iLU
tEl_a~s*3?
a`E1rK'
public void setSFileName(String value) =&-+{txs
{ iRsK;)<
sFileName = value; '^ob3N/Y [
} xL#UMvZ>;h
@";zM&
upefjwm
public int getNSplitter() Bf+7;4-
{ svj0;x5
return nSplitter; u~7 ,v
} UWIw/(Mv/]
l0@+&Xj
d>k"#|
public void setNSplitter(int nCount) >oasA2S
{ t{g7 :A
nSplitter = nCount; +-d)/h.7
} 96]!*}
} 3{FUFx
En:/{~9{F
|9x H9@^f
/* >og- jz
**Utility.java 0hoi=W6AQ
*/ q-5U,!!W/
package NetFox; E,$5V^ 9
qrt2BT)
$`'Xb
public class Utility { RA^-Pa.O
"+k^8ki
HTw7l]]
public Utility() kY.3x#w
{ *c{X\!YBh
#*)X+*
:}{,u6\
} @q<F_'7is
m|%ly
//线程睡眠 Api<q2@R
public static void sleep(int nSecond) /gUD!@
{ T/Fj0'
try{ ;lU]ilYv
Thread.sleep(nSecond); ")i>-1_H
} "4[8pZO/
catch(Exception e) i-E/#zni
{ FAbl5VW'
e.printStackTrace (); L.R4 iN
} R0DWjN$j
} 'A)r)z{X
#}|g8gh
//日志 V0/O T~gS8
public static void log(String sMsg) KXvBJA$
{ EN/e`S$)
System.err.println(sMsg); SM1[)jZ-
} 9n!IdqKN
C[IY9s:Pf
SQ0t28N3h
public static void log(int sMsg) #dEMjD
{ &* 1iW(x
System.err.println(sMsg); GAY f.L"
} de$0DfK
} ,d~6LXr<fM
R(dOQ. ;
\ N;%
/* rQM$lJ[x
**TestMethod.java o{I]c#W
*/ HI%#S&d
package NetFox; 9}*<8%PSt,
dSq3V#Q
.Mz'h9@
public class TestMethod { X|wg7>kh*`
%9Y3jB",2
dRu|*s
public TestMethod() G ;fc8a[X
{ ///xx/weblogic60b2_win.exe {-Q=YDR
try{ <WCTJ!Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); REc+@;B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A$;"9F@
SiteFileFetch fileFetch = new SiteFileFetch(bean); F!pgec%]'
fileFetch.start(); v>oWk:iJP
} 6 ~LCj"
catch(Exception e){e.printStackTrace ();} KE*8Y4#9
7,:$, bL
pxgVYr.
} j$mCU?
lOJ3_8
f'28s*n
public static void main(String[] args) h.WvPZ2U
{ Ka|, qkb
new TestMethod(); C<u<:4^H
} ObIL w
} w/UZ6fu
点击下载更多相关资料