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)); iPt{v5}]
} 4$8\IJ7G
for(int i=0;i<nEndPos.length-1;i++) S{c;n*xf
{ ??=7pFm
nEndPos = nStartPos[i+1]; oOHr~<
} IsP!ZcV;
nEndPos[nEndPos.length-1] = nFileLength; Vc|uQ8Mi
} G:{\-R'
} r#/Bz5Jb*
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;.b^A
//启动子线程 (Kaunp5_`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K"9V8x3Wg
for(int i=0;i<nStartPos.length;i++) y`-5/4
{ Qb&gKQtt@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F[==vte|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RTvzS]
nStartPos,nEndPos,i); oHkjMqju
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qn~:B7f
fileSplitterFetch.start(); 5`[B:<E4
} w1 tg7^(@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kIYV%O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &p:GB_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N!^5<2z@eT
nEndPos = " + nFileLength); kS$m$ D
// fileSplitterFetch[nPos.length-1].start(); a1# 'uS9W
iU a `<
Ems0"e
//等待子线程结束 2~2j?\AEd.
//int count = 0; FK.Qj P:
//是否结束while循环 *p7_rY
boolean breakWhile = false; \x+"1
ajALca4
g'1ASMuR
while(!bStop) \9s x_T
{ -87]$ ax
write_nPos(); 6T{SRN{
Utility.sleep(500); z+%74O"c
breakWhile = true; Shb"Jc_i
RT+_e
5mB'\xGO2
for(int i=0;i<nStartPos.length;i++) 9U~sRj=D
{ $|r p5D6
if(!fileSplitterFetch.bDownOver) !x1ivP
{ s+XDtO
breakWhile = false; dNgjM Q
break; APT/z0X>
} :Y2J7p[+
} sn.&|)?Fi
if(breakWhile) "N*i!h
break; X"3Za[9j
h5.AM?*TNd
]~-vU{
//count++; ,Frdi>7 ~
//if(count>4) OFcqouGE
// siteStop(); rLOdQN
} (w{C*iB
+2S#3m?1
)90K^$93"
System.err.println("文件下载结束！"); R SqO$~
} 7T}r]C.
catch(Exception e){e.printStackTrace ();} o!ycVY$yW
} )NCkq~M
RTRi{p
q X>\*@
//获得文件长度 ;m cu(J
public long getFileSize() *]RCfHo\=
{ , 1`-u$
int nFileLength = -1; 2%(RB4+
try{ *oU-V#
URL url = new URL(siteInfoBean.getSSiteURL()); '`fz|.|cbB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <tp#KZE
httpConnection.setRequestProperty("User-Agent","NetFox"); u.Z,HsEOb
@O%d2bgEWV
e3b|z.^8
int responseCode=httpConnection.getResponseCode(); 6`l7saHXE
if(responseCode>=400) l9X\\uG&
{ T&PLvyBL
processErrorCode(responseCode); |8YP8o
return -2; //-2 represent access is error {r2fIj~V
} 8'6$t@oT9w
Jh)K0>R
cPm-)/E)i
String sHeader; a#o6Nv
N"wp2w
,%%}d9
for(int i=1;;i++) fK{[=xMr@
{ JDy;Jb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =j{r95)|u
//Utility.log(in.readLine()); b&1-tYV
sHeader=httpConnection.getHeaderFieldKey(i); <m3or
if(sHeader!=null) c/\$AJV.H
{ #\)tz z
if(sHeader.equals("Content-Length")) yL>wCD,L
{ t=Um@;wh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,Y3wXmG
break; I_h{n{,sr
} 81<0B@E
} X0"f>.Lg
else hpVu
break; Qo;#}%}^^
} 8${Yu
} eX@7f!uz
catch(IOException e){e.printStackTrace ();} J\V.J/
catch(Exception e){e.printStackTrace ();} GxR, 3
/P3s.-sL
Pqm)OZE?
Utility.log(nFileLength); }lzN)e
]9}T)Df'
`bF]O"
return nFileLength; OnKPD=<
} AZTn!hrU
_p`@/[(|
^,M&PP6
//保存下载信息（文件指针位置） &G"r>,HU
private void write_nPos() &RP}w%I1
{ j$8i!C
try{ q T pvz
output = new DataOutputStream(new FileOutputStream(tmpFile)); {UR&Y
output.writeInt(nStartPos.length); j2/3NF5&
for(int i=0;i<nStartPos.length;i++) sUP!'Av
{ @~l?hf
// output.writeLong(nPos); Jqt&TqX@s
output.writeLong(fileSplitterFetch.nStartPos); >`@yh-'r
output.writeLong(fileSplitterFetch.nEndPos); S=wJ{?gzAK
} njy^<7;
output.close(); V^U1o[`
} i!=28|_
catch(IOException e){e.printStackTrace ();} ?98]\pI
catch(Exception e){e.printStackTrace ();} Dxwv\+7]
} 0y3<Ho,+$
,t]qe
<15POB
//读取保存的下载信息（文件指针位置） %$l^C!qcY
private void read_nPos() 8uO@S*)0
{ qWzzUM1=
try{ l^IPN'O@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {vJ)!'Eh
int nCount = input.readInt(); #!FLX*,
nStartPos = new long[nCount]; Bw[jrK
nEndPos = new long[nCount]; l?/.uNw
for(int i=0;i<nStartPos.length;i++) 8zRb)B+
{ %ycCNS
nStartPos = input.readLong(); :~2An-V
nEndPos = input.readLong(); kH43 T
} [?$|
input.close(); Gkr^uXNg#
} ?"aj&,q+
catch(IOException e){e.printStackTrace ();} R "&(Ae?LR
catch(Exception e){e.printStackTrace ();} /Lc= K<
} 2z\4?HJy
7Pc0|Z/
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private void processErrorCode(int nErrorCode) Vd{h|=J
{ #NVqS5
System.err.println("Error Code : " + nErrorCode); ] _/d
} YW}1iT/H
x\Y%/C[Kc
3PonF4
//停止文件下载 $J |oVVct
public void siteStop() Dk'EKT-
{ a*pZcv<
bStop = true; %acy%Sy
for(int i=0;i<nStartPos.length;i++) B=;pyhc
fileSplitterFetch.splitterStop(); G@)I
)6?.; B
!_`T8pJ`
} vl@t4\@3
} 1]@}+H
//负责部分文件的抓取 9@yP;{Q
**FileSplitterFetch.java bw7!MAXd
*/ LC/w".oq?
package NetFox; ^/W7Xd(s
tH:K6^oR
2.2Z'$W
import java.io.*; 6[9E^{(z
import java.net.*; 4M8AYh2)
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wE75HE`gW
public class FileSplitterFetch extends Thread { /s%I(iP4
1>*]jj}
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String sURL; //File URL ~^.&nph
long nStartPos; //File Snippet Start Position 6,xoxNoPP3
long nEndPos; //File Snippet End Position g)'tr '
int nThreadID; //Thread's ID `~(C\+gUp
boolean bDownOver = false; //Downing is over Siw9_c
boolean bStop = false; //Stop identical r2T?LO0N{
FileAccessI fileAccessI = null; //File Access interface LoG@(g&)
=&fBmV
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 33kI#45s
{ Yf:utCvv
this.sURL = sURL; Kfj*uzKB
this.nStartPos = nStart; 2t { Cpw
this.nEndPos = nEnd; s8|#sHT
nThreadID = id; A*pihBo7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2H<?
} N,ik&NIWy
FZ>*<&
vc2xAAQ
public void run() yT&bS\
{ .Qh8I+Q%
while(nStartPos < nEndPos && !bStop) ^BM/K&7^
{ %:o@IRTRU
+^+wS`Y
x#0C+cU
try{ 2al~`
URL url = new URL(sURL); >V(2Ke Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ) Q=G&
httpConnection.setRequestProperty("User-Agent","NetFox"); GxZQ{ \
String sProperty = "bytes="+nStartPos+"-"; *vhm
httpConnection.setRequestProperty("RANGE",sProperty); tL+8nTL
Utility.log(sProperty); RQ,(?I*8\
>`NY[Mn
b=T+#Jb
InputStream input = httpConnection.getInputStream(); z K8#gif@
//logResponseHead(httpConnection); ~DZ;l/&Mz7
p2~Q
YLd 5
byte[] b = new byte[1024]; d L%E0o
int nRead; i`]M2Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \ b9,>
{ na']{a1K
nStartPos += fileAccessI.write(b,0,nRead); ;(0:6P8I
//if(nThreadID == 1) k7{fkl9|#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ga^<_;5<
} *gz{:}NX
#>'1oC{
<vt^=QA'
Utility.log("Thread " + nThreadID + " is over!"); )dL?B9d:
bDownOver = true; rF0zGNH
//nPos = fileAccessI.write (b,0,nRead); ^RWt
} P'9aZd
catch(Exception e){e.printStackTrace ();} J#V`W&\,6
} )N=b<%WD
} /1li^</|p`
G0s:Dum
Z `\7B e
//打印回应的头信息 ^}1RDdQ"U
public void logResponseHead(HttpURLConnection con) oh@r0`J]x
{ 3`9*Hoy0c
for(int i=1;;i++) iKabo,~
{ Y(SI`Xo[
String header=con.getHeaderFieldKey(i); qk,cp},2K
if(header!=null) qfYb\b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3X!~*_iC
Utility.log(header+" : "+con.getHeaderField(header)); $Qy(ed
else _SP u`=~K
break; 3sZK[Y|ax
} Jj6kZK
} e4)gF*
sId5pY!
aq5<Ks`r
public void splitterStop() E7eVg*Cvi
{ ygfqP
bStop = true; ;5|EpoM
} &yA<R::o
(x^|
=-VV`
} >Ed^dsb&
|%V.Lae
fBLd5
/* u3. PHZ
**FileAccess.java >rFvT>@NU
*//文件访问(定位，写) GC\/B0!
package NetFox; Ez$5wY^J
import java.io.*; I@S<D"af
xRY5[=97
(&*F`\
public class FileAccessI implements Serializable{ '9/kDkt!
654%X(:q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Z`)*TRp4
RandomAccessFile oSavedFile; kTk?[BK
long nPos; Np-D:G
^r& {V"l]
?0(B;[xEJ
public FileAccessI() throws IOException O^xt
{ nDOIE)#
this("",0); oPbD9
} a,4g`?
\fKE~61
Ur-^X(nL
public FileAccessI(String sName,long nPos) throws IOException ZkIQ-;wx
{ LuqaGy}>-
oSavedFile = new RandomAccessFile(sName,"rw"); IB6]Wj
this.nPos = nPos; ;?o C=c
oSavedFile.seek(nPos); Kmnr}Lp9
} K?tk&0
/< :;^B
"QF083$
public synchronized int write(byte[] b,int nStart,int nLen) W^N"y&
{ +i>q;=~
int n = -1; @ubz?5
try{ \fz j fZ1n
oSavedFile.write(b,nStart,nLen); 5VTbW
n = nLen; Zb}PP;O
} g7P1]CZ}
catch(IOException e) |:#mw1
{ E nvs[YZe
e.printStackTrace (); 9>#|~P&FE
} %KA/
3-R3Qlr
gCJ'wv)6|%
return n; yn#h$o<
} A%PPG+IfA
l17ZNDzLU
UH.cn|R
} bevT`D
}m H>lN
\$C4H
/* SHk[X ]Uo
**SiteInfoBean.java +Y~+o-_
*/ W =zG
package NetFox; g=C<E2'i*
ifs*-f
=eqI]rVj^
public class SiteInfoBean { 4B]61|A
CP#79=1
eC$v0Gtq
private String sSiteURL; //Site's URL F&*M$@u5
private String sFilePath; //Saved File's Path S0+zq<
private String sFileName; //Saved File's Name upDQNG>d
private int nSplitter; //Count of Splited Downloading File u,m-6@il
iW?9oe
1,j9(m2
public SiteInfoBean() QP B"EW
{//nSplitter的缺省值为5 ^PQV3\N
//default value of nSplitter is 5 _")h %)f
this("","","",5); |&Pl4P
} m=MT`-:
BB.TrQM.#
a+/|O*>#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X6.O;
{ :xPvEK[B7
sSiteURL= sURL; TyWy5J< :+
sFilePath = sPath; r(i)9RI+(
sFileName = sName; Y/0O9}hf
this.nSplitter = nSpiltter; j>*SJtq7
3-bcY4
W6O.E
} ikhX5 &e
kkBU<L2
2NknC>9(\
public String getSSiteURL() HzV+g/8>A
{ y.:-
return sSiteURL; M@g gLW
} JJ?ri,
wWw/1i:|'
k_n{Mss'9
public void setSSiteURL(String value) n ;5?^Un%
{ txo?k/w
sSiteURL = value; vB5iG|b}
} #`4^zU)
t4@g;U?o
Q)BoWd
public String getSFilePath() j dhml%pAd
{ f#kevf9zc
return sFilePath; mzB#O;3=
} pqN[G=0
k6L373e#Q
)[sO5X7'^
public void setSFilePath(String value) P$/A!r
{ /Q8A"'Nk
sFilePath = value; R0mT/h2
} &H1D!N
'1'1T5x~
9!HMQ
public String getSFileName() bM^A9BxD
{ \a2oM$PX
return sFileName; DD 5EHJR
} Gu`Vk/&
**r?
DG*o w^
public void setSFileName(String value) @Q\$dneY
{ %C6zXiO"
sFileName = value; '&:x_WwVrO
} 8+a<#?;
Q(5:~**I
xO<-<sRA
public int getNSplitter() 0nz@O^*g(
{ pZ~>l=-
return nSplitter; V1nZ M
} $t# ,'M
Ym{%"EB
gpK_0?%
public void setNSplitter(int nCount) C.)&FW2F_
{ Bb[e[,ah
nSplitter = nCount; &9dr+o-(~
} y2"S\%7$h
} z!C4>,
*<1x:PR
`V):V4!j),
/* JJ9e{~0I
**Utility.java "8iiRzt#
*/ B Ff.Rd95
package NetFox; h"1"h.
*!]Epb
199hQxib:
public class Utility { 5;MK1l
[{p?BTs
-)a_ub
public Utility() 8pL>wL &C
{ Ky9No"o
XBWSO@M'
O4d^ig-xaH
} Rc:cVK
M |Q
//线程睡眠 JeTrMa2
public static void sleep(int nSecond) Hrg=sR
{ -~O;tJF2
try{ e|5B1rMM
Thread.sleep(nSecond); tct5*.|
} =PKt09b^
catch(Exception e) <x0uO
{ @7l=+`.i
e.printStackTrace (); kYA'PW/[)
} 95?5=TF
} hXQg=Sj
?^48Zq6wM
//日志 N7$DRG/<b
public static void log(String sMsg) Z_V&IQo-7
{ o(X90X
System.err.println(sMsg); O{ %A&Ui
} 0]eh>ab>
Z!RRe]"y
`YmI'
public static void log(int sMsg) Q0q)n=i}]
{ )_Xxk_
System.err.println(sMsg); t`8e#n 9
} \|pK Z6*s
} wO_pcNYZ8
A.$VM#
RZ)vU'@kx
/* 1f@U:<:
**TestMethod.java uWR,6\_jY
*/ uU[[[LQq
package NetFox; bV )PT`-,
J!A/r<
34m']n
public class TestMethod { Q9eYF-+
m['v3m:
01-\:[{
public TestMethod() q(&^9"
{ ///xx/weblogic60b2_win.exe _]=TFz2O
try{ cEdz;kbUM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *<.WL"Qhl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Yn$>QS 4
SiteFileFetch fileFetch = new SiteFileFetch(bean); SD|4ybK>d
fileFetch.start(); c5iormb"#
} m.HX2(&\3
catch(Exception e){e.printStackTrace ();} -@ UN]K
k;K> ,$F
z%}CBTm
} /UaNYv/
C6D=>%uY
liCCc;&B;
public static void main(String[] args) RQ*|+~H
{ !4 4mT'Y
new TestMethod(); #.MIW*==
} L.TgJv43
} :_fjml/
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