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)); 8DI|+`OgW
} 7kwG_0QO
for(int i=0;i<nEndPos.length-1;i++) p.}[!!m P
{ p4AXQuOP
nEndPos = nStartPos[i+1]; lb6s3b
} /1>
nEndPos[nEndPos.length-1] = nFileLength; q,(&2./
} {Jy%h8n*
} 2b"5/$|6
bT*4Qd4W
Sd\@Q% }o\
//启动子线程 h1gb&?w5P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QJE-$ :
for(int i=0;i<nStartPos.length;i++) N^ET qg
{ }-Ma~/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dDuA%V0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =Fs LF
nStartPos,nEndPos,i); uE|[7,D7;u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -*Pt781
fileSplitterFetch.start(); Zn} )&Xt
} ]`kvq0Gyb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J-ZM1HoB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gdZVc9_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i;xMf5Jz
nEndPos = " + nFileLength); <Ztda !
// fileSplitterFetch[nPos.length-1].start(); eJA{]^Zf
Iw:("A&~
*Fc&DQT(
//等待子线程结束 +UsR
//int count = 0; ,TtDCcjd%f
//是否结束while循环 ,Ex\\p-
boolean breakWhile = false; 2~U+PyeNz
bOdv]nQ1
%Uk/P
while(!bStop) stG&(M
{ &sgwY
write_nPos(); *u>\&`h=
Utility.sleep(500); iQIw]*h^
breakWhile = true; `;qZ$HH
{.OoOqq9
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for(int i=0;i<nStartPos.length;i++) Om"3Q/&
{ Mfr#IzNHN
if(!fileSplitterFetch.bDownOver) <khAc1"
{ UmE{>5Pt
breakWhile = false; \|t0~sRwh
break; _Xv/S_yW
} ;$E[u)l
} M(E_5@?3
if(breakWhile) >z -(4Z
break; t5APD?5 c
Ft rw3OxN
[L(l++.z
//count++; 7tpZE+OX
//if(count>4) -YyH"f
// siteStop(); r97[!y1gt
} Y fA\#N0;3
X&~Eo
R"o,m
System.err.println("文件下载结束！"); NXNon*"
} sZB6zTX J
catch(Exception e){e.printStackTrace ();} HXHPz4
} =eoxT
a0.3$
$?-o
//获得文件长度 zn!
public long getFileSize() 49$4
{ K@~#Gdnl
int nFileLength = -1; }x1IFTa!
try{ G0>Wk#or
URL url = new URL(siteInfoBean.getSSiteURL()); IyN9 +
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rM=A"
httpConnection.setRequestProperty("User-Agent","NetFox"); yjR O9
aF"Z!HD
Hc%\9{zH
int responseCode=httpConnection.getResponseCode(); hF7mJ\
if(responseCode>=400) PcHFj+:
{ JJ0 CM:xe
processErrorCode(responseCode); ejY5n2V#=
return -2; //-2 represent access is error #/dde9y
} jGhg~-m
B/hHkOoo
\87J~K'
String sHeader; 8m6nw0
hb8XBBKR
4Z9 3g{
for(int i=1;;i++) mVAm^JK
{ 7 aD&\?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \X.=3lc&
//Utility.log(in.readLine()); )o</gt)
sHeader=httpConnection.getHeaderFieldKey(i); z 2VCK@0
if(sHeader!=null) 32LB*zc
{ N>Y50
if(sHeader.equals("Content-Length")) Z;'.pU~
{ /j/%wT2m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 08?MS_
break; Z*>/@J}
} f$|v0Xs
} o>-v?Ug
else s7i.p]
break; e=UVsYNx
} z\8yB`8b^
} MH;%Y"EI
catch(IOException e){e.printStackTrace ();} {4aY}= -Q*
catch(Exception e){e.printStackTrace ();} Q]5^Eiq8
b Ne\{k
H8]^f=
Utility.log(nFileLength); sg"D;b:X
)$h9Y
XJ~l5}y ]
return nFileLength; 3t{leuO'
} lO:{tV
M .`
WTYFtZD[yH
//保存下载信息（文件指针位置） |kNGpwpI
private void write_nPos() ^r_lj$:+$
{ LA`VqJ
try{ x0h3jw+6
output = new DataOutputStream(new FileOutputStream(tmpFile)); ![]I%'s
output.writeInt(nStartPos.length); u\6]^T6
for(int i=0;i<nStartPos.length;i++) n=o'ocdS)
{ tm1UH 4
// output.writeLong(nPos); 6Hbf9,vI
output.writeLong(fileSplitterFetch.nStartPos); `h9)`*
output.writeLong(fileSplitterFetch.nEndPos); V<V\0n!0
} J-\?,4mcP
output.close(); pl,Z
} n`z+ w*
catch(IOException e){e.printStackTrace ();} ^%%5
catch(Exception e){e.printStackTrace ();} >-@ U_p
} CCh8?sM
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m?VRX.>
//读取保存的下载信息（文件指针位置） m_"p$m;
private void read_nPos() TBKd|D'H
{ 2ZG1n#
try{ _|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -+=:+LhSMb
int nCount = input.readInt(); #H6g&)Z_
nStartPos = new long[nCount]; @fH&(@
nEndPos = new long[nCount]; c\MsVH2|
for(int i=0;i<nStartPos.length;i++) A$%!9Cma
{ CTkN8{2S
nStartPos = input.readLong(); )ozcr^
nEndPos = input.readLong(); )ClMw!ZrU
} 2vkB<[tSs
input.close(); >6I.%!jU
} 3[=`uO0\7
catch(IOException e){e.printStackTrace ();} aR)en{W
catch(Exception e){e.printStackTrace ();} V9E6W*IE
} Lkl|4L
h [IYA1/y
CC>fm1#i\
private void processErrorCode(int nErrorCode) >U~|R=*
{ ?S&w0}R
System.err.println("Error Code : " + nErrorCode); sVZZp
} ljJz#+H2_
/"Yx@n
>GznG[Ku
//停止文件下载 x1BOW
public void siteStop() GX@W"y
{ W8,tl>(
bStop = true; J,1osG<6x
for(int i=0;i<nStartPos.length;i++) t+ S~u^
fileSplitterFetch.splitterStop(); Sq-3-w,R~
G?ugMl}
JOdwv4(3V
} U$A7EFK'
} Q-`{PJ(p
//负责部分文件的抓取 D!RE-w92X
**FileSplitterFetch.java (}C^_q:7d
*/ fNqmTRu
package NetFox; 7SK3
%[nR|a<
zvGK6qCk
import java.io.*; TsX+. i'
import java.net.*; <4Q12:
!b7'>b'J<1
k%l_N)38
public class FileSplitterFetch extends Thread { -jVaS wt
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String sURL; //File URL Dr6s^}}~n
long nStartPos; //File Snippet Start Position g8,?S6\nMz
long nEndPos; //File Snippet End Position =a9etF%B
int nThreadID; //Thread's ID ~#x:z^U
boolean bDownOver = false; //Downing is over NuD[-;N]
boolean bStop = false; //Stop identical |)-|2cPRur
FileAccessI fileAccessI = null; //File Access interface b4v(k(<
jJUGZVM6)
B [+(r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1 Itil~
{ Q=(@K4
this.sURL = sURL; o9ctJf=qn
this.nStartPos = nStart; %GX uuE}mX
this.nEndPos = nEnd; RVkU+7
nThreadID = id; ^`rpf\GX(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "]T$\PJun
} \TbsoWX
+5HnZ?E\
V#NG+U.B
public void run() m ZtvG,
{ T A\4uy6o
while(nStartPos < nEndPos && !bStop) ou'~{-_xd
{ VT% KN`l
gMs+?SNHAh
'%SR.JL
try{ CGC-"A/W
URL url = new URL(sURL); pcy<2UV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5{13V*<
httpConnection.setRequestProperty("User-Agent","NetFox"); D0/DI
String sProperty = "bytes="+nStartPos+"-"; dn ZzA
httpConnection.setRequestProperty("RANGE",sProperty); /2;dH]o0
Utility.log(sProperty); ]cm6 |`pz
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|(V?,^b^ro
InputStream input = httpConnection.getInputStream(); &~~aAg
//logResponseHead(httpConnection); +Qh[sGDdY
F$Im9T6
D XV@DQ
byte[] b = new byte[1024]; 7}4'dW.
int nRead; <nWKR,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) , 3X: )
{ N]14
nStartPos += fileAccessI.write(b,0,nRead); 9u,8q:I.?
//if(nThreadID == 1) G'f9N^w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <4bz/^
} <S1??
/O|:{LQ
)Hbb&F
Utility.log("Thread " + nThreadID + " is over!"); {O^TurbTFA
bDownOver = true; mn]-rTr
//nPos = fileAccessI.write (b,0,nRead); t;8\fIW5
} Al7<s
catch(Exception e){e.printStackTrace ();} B.$PhmCG
} [o2w1R\H+x
} "h=6Q+Ze
UJz#QkAio
TE^7P0bh
//打印回应的头信息 0"EoC
public void logResponseHead(HttpURLConnection con) "S5S|dBc
{ g(aZT#ii=
for(int i=1;;i++) 4YszVT-MU~
{ AR%hf
String header=con.getHeaderFieldKey(i); "8N"Udu
if(header!=null) TQP+>nS,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R?cUy8?'S
Utility.log(header+" : "+con.getHeaderField(header)); _!n}P5
else OJAx:&]3
break; <lMg\T?K
} *>jjMyn
} LA-_3UJx
B?LXI3sQZ
25:Z;J>
public void splitterStop() x#VyQ[ok
{ k$h [8l(<
bStop = true; zJ9v%.e
} dUS ZNY
)QmGsU}?
h#i\iK&A
} C+w__gO&r
Z@3l%p6V
'>@4(=I
/* LP:nba:
**FileAccess.java $5,~JYcb
*//文件访问(定位，写) !tEe\K\e
package NetFox; 9)+@0fG)
import java.io.*; -G9|n#zCU
BQ#3QL't
rH&G<o&,
public class FileAccessI implements Serializable{ aD9rp V
79ckLd9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Sk:2+inU
RandomAccessFile oSavedFile; AoYaVlKG8
long nPos; IdPn%)>6
bd!U)b(}OV
|; $Bb866/
public FileAccessI() throws IOException fN-Gk(Ic
{ -ynBi;nH
this("",0); P;vxT}1
} e+'%!w"B
MIq"Wy|Zs
B0d%c&N${
public FileAccessI(String sName,long nPos) throws IOException G@gh#[b
{ jd 1jG2=f
oSavedFile = new RandomAccessFile(sName,"rw"); %j7:tf=
this.nPos = nPos; k=[pm5ZvT~
oSavedFile.seek(nPos); 0GZq`a7[
} q"akrI38
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4KXc~eF[M"
public synchronized int write(byte[] b,int nStart,int nLen) %-+j
{ GIT#<+"
int n = -1; IG< H"tQ
try{ J8?2R^;{
oSavedFile.write(b,nStart,nLen); R(k}y,eh.`
n = nLen; a(;!O}3_)(
} `0bP0^w
catch(IOException e) mN*?%t
{ ;I}'}
e.printStackTrace (); tdep|sD
} A%u_&a}
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+dk fcG
return n; 9sSN<7
} =su]w2,Iy
.oqIZ\iik
hmpr%(c`
} 5.vG^T0w
,:)`+v<
1!1!PA9u
/* ZF6c{~D
**SiteInfoBean.java Ipe n
*/ 0K`[,$Y
package NetFox; 9CJ(Z+;OM
"Y;}GlE
`!vUsM.d
public class SiteInfoBean { |4;UyHh
ST1'\Eo
.5w azvA
private String sSiteURL; //Site's URL Vi?q>:E:
private String sFilePath; //Saved File's Path edipA P~!
private String sFileName; //Saved File's Name kJ{+M]pW
private int nSplitter; //Count of Splited Downloading File %Jp|z? [/
vDFGd-S
e(?]SU|
public SiteInfoBean() f>2MI4nMG
{//nSplitter的缺省值为5 wM~H(=s`D
//default value of nSplitter is 5 +1rkq\{l
this("","","",5); 7b[wu~'( n
} 5'KA'>@
),(V6@Z?
g^7MMlY%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o*5U:'=5}
{ IgIYguQ
sSiteURL= sURL; /3!fA=+
sFilePath = sPath; tyh@^7
sFileName = sName; %eg+F
this.nSplitter = nSpiltter; :YP#
d\]Yk]r
M}O}:1Par
} o`n$b(VZ
EON:B>2a
kV;fD$iW;
public String getSSiteURL() 7fHc[,
{ .uF[C{RnO
return sSiteURL; nXy>7H[0
} t `kui.
oD9^ID+
$pyOn2}
public void setSSiteURL(String value) 1oiRWRe
{ aNxAZMg
sSiteURL = value; eJ0?=u!x
} K2{aNvR)t
k(t}^50^j
_oG&OJ@
public String getSFilePath() PPkx4S_>
{ =K\r-'V
return sFilePath; *=AqM14 @
} Fv74bC%
=WIJ>#Go<
1vzb8.
public void setSFilePath(String value) X]%itA
{ *v ?m6R=)h
sFilePath = value; n/~A`%E@
} zCv"]%
!-<p,z
_ :Ag?2
public String getSFileName() e:'?*BYVg3
{ ,:LA.o}h
return sFileName; ntFT>g{B
} !|ak^GE:(%
3ZEB
T*g:# ^4
public void setSFileName(String value) +N`ua
{ 9h&R]yz;
sFileName = value; aJ Z"D8C
} ~6YMD
-m *Sq
Lk\P7w{
public int getNSplitter() d.UQW yLG
{ 21hv%CF\9
return nSplitter; ^XbU~3(
} }}v9 `F
&>d:R_Q]
vM:cWat
public void setNSplitter(int nCount) BTgG4F/)
{ jTO), v:w
nSplitter = nCount; @,Gxk
} hj'(*ND7z
} CI353-`
MZ+^-@X
ls@i".[
/* *Kdda} J+
**Utility.java p sL?Y
*/ #(An6itl
package NetFox; IxLhU45
OnQdq^UB
.7K7h^*F
public class Utility { `]Q:-h
V"c 6Kdtd
=[b)1FUp
public Utility() RuII!}*
{ /1Ue?)g
X 1 57$
okbQ<{9
} DC{>TC[p1k
,) J~,^f6
//线程睡眠 }gJ(DbnV
public static void sleep(int nSecond) 93Co}@Y;Y+
{ 3EJt%}V$k
try{ :VTTh |E%#
Thread.sleep(nSecond); ns6(cJ^a
} xJ#d1[kzo
catch(Exception e) ;4Y%PVz~D
{ D$t k<{)oB
e.printStackTrace (); :POj6j/
} `BlI@6th
} x)(|[
ep)>X@t
//日志 _/i4MtM
public static void log(String sMsg) n2iJ%_zp
{ ty8v 6J#
System.err.println(sMsg); ")d`dj\o
} X5j1`t,
Djg,Lvhm
Na:w]r:y
public static void log(int sMsg) ,7<f9 EVY
{ tQS5hwm*
System.err.println(sMsg); : |>Gc39`t
} +E{|63~q
} s&RVJX>Rt
6Vz9?puD
\[y`'OD~
/* 17`1SGZ
**TestMethod.java ~]QHk?[wc
*/ /5u<78GW1
package NetFox; 4O35"1
=3L;Z[^9
x QIq^/F0
public class TestMethod { @)fd}tV
ouuuc9x]
p6;OL@\~
public TestMethod() ,^C--tgZJg
{ ///xx/weblogic60b2_win.exe k |eBJ%
try{ 2AMo:Jqv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u:=7l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q^Y-}=w
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'IwNTM
fileFetch.start(); u fw]=h)
} 9Gnc9_]I;W
catch(Exception e){e.printStackTrace ();} \SBc;
b:TLV`>/&
!qWH`[:
} h2XfC.f
7eAX*Kgt<_
ev*k*0
public static void main(String[] args) Ru>MFG
{ [k/@E+;
new TestMethod(); )r jiY%F$
} (jAg_$6
} <$IM8Y5p+w
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