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)); &2P+9j>
} M3 TsalF
for(int i=0;i<nEndPos.length-1;i++) xk#q_!(j
{ }%T8?d]
nEndPos = nStartPos[i+1]; C-}@.wr(
} &P0jRT3e#Y
nEndPos[nEndPos.length-1] = nFileLength; v>[U*E
} w YEkWB^
} t)i{=8rq
$M0F~x
ld7B!_b<
//启动子线程 _oILZ,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r'bPSu,
for(int i=0;i<nStartPos.length;i++) UqA<rW
{ ,\Q^[e!m~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oOAn 5t@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C3]"y7
nStartPos,nEndPos,i); YAc~,N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dPm_jX
fileSplitterFetch.start(); G2[?b2)8
} t|5T,YFG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WXj iKW(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \{@n>Mh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $!ATj`}kb
nEndPos = " + nFileLength); V?zCON
// fileSplitterFetch[nPos.length-1].start(); nj(\+l5
C5F=J8pY
)&") J}@
//等待子线程结束 jY+uOH
//int count = 0; .,9e~6}
//是否结束while循环 n|M~C\*
boolean breakWhile = false; {tDH !sX
}t FRl
M}S1Zz%Ii1
while(!bStop) om1@;u8u
{ dc+U#]tS
write_nPos(); WSKubn?7B
Utility.sleep(500); XH`W(
breakWhile = true; zgnZ72%
z|k0${iu#
qj#C8Tc7
for(int i=0;i<nStartPos.length;i++) z*w.A=r
{ *q$O6B-
if(!fileSplitterFetch.bDownOver) AhCqQ.O71
{ >* )fmfY
breakWhile = false; ^aONuG9
break; }ZKG-~
} .*k$abb
} k0(_0o
if(breakWhile) ;_oJGII?br
break; i>aIuQ`pe
5{Oq* |
wR%F>[6.{
//count++; DCheG7lo{
//if(count>4) wxc24y
// siteStop(); ;]PP+h
} v(`9+*
}I3m8A
; "K"S[
System.err.println("文件下载结束！"); sq45fRAi
} "|^-Yk\U
catch(Exception e){e.printStackTrace ();} [a[.tR38e
} ?lPyapA]
8JFvz(SK>
TCLXO0
//获得文件长度 Pea2ENe3
public long getFileSize() B4MrrW4=
{ 1va~.;/rG
int nFileLength = -1; :AYhBhitC
try{ m5_
URL url = new URL(siteInfoBean.getSSiteURL()); <C<z#M'`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~#];&WE
httpConnection.setRequestProperty("User-Agent","NetFox"); B~h3naSe
8-&c%h 1
hqW),^\>'
int responseCode=httpConnection.getResponseCode(); 6.'j\
if(responseCode>=400) bP)(4+t~
{ *Tum(wWZ
processErrorCode(responseCode); Iy#=Nq=
return -2; //-2 represent access is error 5XzN%<_h9
} d2U+%%Tdw
nXT/zfS
Fxx-2(U
String sHeader; V=de3k&p
0Lx,qZ'
E'cI}q
for(int i=1;;i++) o6/"IIso3
{ <5]ufv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gjL+8Rk
//Utility.log(in.readLine()); L6 IIk
sHeader=httpConnection.getHeaderFieldKey(i); =fcM2O#$
if(sHeader!=null) v vzPt.ag
{ ;W?mQUo:P8
if(sHeader.equals("Content-Length")) (&!RX.i
{ Ial"nV0>0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kn*LwWne
break; 5kik+
} <f9a%`d
} [C`LKA$t
else <]f{X<ef
break; ufn%sA
} zhgvqg-
} \OW.?1d
catch(IOException e){e.printStackTrace ();} _lBHZJ+
catch(Exception e){e.printStackTrace ();} 8.zYa(<2
}Y!v"DO#Q*
\k9]c3V
Utility.log(nFileLength); | r,{#EE
D%*Ryg
PS3jCT
return nFileLength; 2-pv &
} 2(2UAB"u
VVw5)O1'
Y3JIDT^
//保存下载信息（文件指针位置） !<vy!pXg
private void write_nPos() /d*[za'0
{ p5aqlYb6r
try{ nIWY<Z"
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vtv~jJ{m
output.writeInt(nStartPos.length); ]YrgkC35
for(int i=0;i<nStartPos.length;i++) D!V~g72j
{ `4-N@h
// output.writeLong(nPos); RpwDOG
output.writeLong(fileSplitterFetch.nStartPos); U'LPaf$O
output.writeLong(fileSplitterFetch.nEndPos); kD me>E=
} t\WU}aKML
output.close(); fb[? sc
} b#(X+I
catch(IOException e){e.printStackTrace ();} tTbfyI
catch(Exception e){e.printStackTrace ();} 9I[k3
} rV fZ_\|
O$7cN\Z
>zfFvx_q
//读取保存的下载信息（文件指针位置） *Ksk1T+>
private void read_nPos() '<U4D
{ pv,z$3Q
try{ B:VGa<lx5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =wMq!mBd
int nCount = input.readInt(); Z#%s/TL
nStartPos = new long[nCount]; I23"DBR3
nEndPos = new long[nCount]; ~(`&hYE
for(int i=0;i<nStartPos.length;i++) NQcNY=
{ VA@
nStartPos = input.readLong(); aUi^7;R&<
nEndPos = input.readLong(); wUfm)Q#
} B9wQ;[gQB
input.close(); x^Zm:Jrw~
} 48_( 'z*>
catch(IOException e){e.printStackTrace ();} }.D adV
catch(Exception e){e.printStackTrace ();} x~ID[
} AquO#A[,#
<m,bP c :R
=\M6s
private void processErrorCode(int nErrorCode) n?QglN
{ p_i',5H(
System.err.println("Error Code : " + nErrorCode); =&^tfD
} .I]EP-
%<|cWYM="z
s_3a#I
//停止文件下载 !p Q*m`Xo
public void siteStop() 9&zQ5L>
{ sJMpF8
bStop = true; Wf~PP;
for(int i=0;i<nStartPos.length;i++) VAp 1{
fileSplitterFetch.splitterStop(); j_.tg7X
R5xV_;wD
MeYu
} %I;uqf
} ?:6w6GwAA
//负责部分文件的抓取 Bkg./iP5x
**FileSplitterFetch.java N|%X/UjZ2.
*/ `7oYXk
package NetFox; /m4Y87
l{Et:W%|
8Vy/n^3)
import java.io.*; @O|`r(le
import java.net.*; :`c@&WF8
,u9>c*Ss\
})j N 8px
public class FileSplitterFetch extends Thread { <B'PB"R3y
+UiJWO
= toU?:.
String sURL; //File URL 2J (nJT"
long nStartPos; //File Snippet Start Position 8Y_lQfJa
long nEndPos; //File Snippet End Position }@~+%_;
int nThreadID; //Thread's ID ]TN/n%\
boolean bDownOver = false; //Downing is over ]MC5 uKn
boolean bStop = false; //Stop identical [#fz[U
FileAccessI fileAccessI = null; //File Access interface k\RS L
-XnOj2
4?]s%2U6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *J{E1])<a
{ &x$ps
this.sURL = sURL; 6Ilj7m*
this.nStartPos = nStart; q{+}0!o
this.nEndPos = nEnd; L\R(//V
nThreadID = id; 4>/i,_&K K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xZ(d*/6E
} DPCQqV|7
iba8G]2
4y!GFhMh
public void run() rxj#
{ `XM0Mm%
while(nStartPos < nEndPos && !bStop) t^2$ent
{ >Bu_NoM
wxN&k$`a
`|PhXr
try{ NN5G '|i
URL url = new URL(sURL); ZG?e%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5RP5%U
httpConnection.setRequestProperty("User-Agent","NetFox"); d$8K,-M
String sProperty = "bytes="+nStartPos+"-"; u>:j$@56
httpConnection.setRequestProperty("RANGE",sProperty); NErvX/qK
Utility.log(sProperty); +??pej]Rp
?O"zp65d(
~S$ex,~
InputStream input = httpConnection.getInputStream(); Ec^2tx"=
//logResponseHead(httpConnection); ["e;8H[K)%
umt`0m. :
KUC%Da3
byte[] b = new byte[1024]; "rVM23@ tq
int nRead; " t?44[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hz=s)6$ey
{ *?VB/yO=0
nStartPos += fileAccessI.write(b,0,nRead); }h* j{b,
//if(nThreadID == 1) QU(Lv(/O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #V$sb1u
} HZjuL.Tj
`R!2N4|;
t^}"8
Utility.log("Thread " + nThreadID + " is over!"); y|NY,{:]
bDownOver = true; _Fe=:q
//nPos = fileAccessI.write (b,0,nRead); Qz"//=hC|H
} 0#ON}l)>
catch(Exception e){e.printStackTrace ();} 1bHQB$%z
} {:KPEN
} x![G'I
mo,"3YW
L0w2qF
//打印回应的头信息 na 0Zb
public void logResponseHead(HttpURLConnection con) mX, @yCI
{ er2;1TW3E
for(int i=1;;i++) EfkBo5@Qi
{ M:L-j{?y_
String header=con.getHeaderFieldKey(i); v- p8~u1N
if(header!=null) >FJK$>[1:p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RRzLQ7J
Utility.log(header+" : "+con.getHeaderField(header)); t~.^92]s|
else ad9u;uS
break; =LEzcq>XO
} ;bL?uL
} a&dP@)
r{_1M>F D!
>GzH_]
public void splitterStop() T'9M
{ !1@oZ(
bStop = true; c(Fo-4K
} lE!.$L*k
:9(w~bB9$
_@VKWU$$
} &B++ "f
db}lN
7HL23Vrk
/* LX #.
**FileAccess.java 9*Fc+/
*//文件访问(定位，写) Y&y<WN}Q
package NetFox; F!2VTPm9z
import java.io.*; YG)7+94
|!1iLWQ
2z1r|?l
public class FileAccessI implements Serializable{ Ik@MIxLK
1F+nWc2b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {UF|-VaG
RandomAccessFile oSavedFile; RB;2
long nPos; 75A60Uw
Uo[`AzD3
]iZ-MG)J
public FileAccessI() throws IOException ;<%d^
{ Ct:c%D(L
this("",0); PWfd<Yf!
} = N:5#A
.TNJuuO
Zc*#LsQh.`
public FileAccessI(String sName,long nPos) throws IOException fSGaUBiq}
{ a)6?:nY$
oSavedFile = new RandomAccessFile(sName,"rw"); }VVtv1
this.nPos = nPos; faZc18M^1
oSavedFile.seek(nPos); z^y -A?
} GkKoc v
FY]Et=p
~dLe9-_9
public synchronized int write(byte[] b,int nStart,int nLen) N]GF>kf:
{ cCIs~*D
int n = -1; +!G)N~o
try{ MW=rX>tE
oSavedFile.write(b,nStart,nLen); tMo=q7ig
n = nLen; APU~y5vG (
} pvRa
catch(IOException e) s&DAO r!i
{ ;)sC{ "Jb
e.printStackTrace (); 5 L-6@@/
} zCu+Oi6
eEeK ]8@
gV'=uz v
return n; 7'@~TM
} wB<cW>6
{P%\& \{F
[&zSYmDk
} *P`k|-
SW HiiF@
:;Npk9P(N
/* nrM-\'
**SiteInfoBean.java 'ztY>KVj
*/ ,{Z!T5 |
package NetFox; 3v)`` n@
G@<[fO|Iam
Su'l &]
public class SiteInfoBean { =CaSd|
B;Co`o2
AQc9@3T~Bi
private String sSiteURL; //Site's URL :r&4/sN}<
private String sFilePath; //Saved File's Path <S0gIg`)
private String sFileName; //Saved File's Name NF7+Gp6?q
private int nSplitter; //Count of Splited Downloading File $@[Mo
R5<:3tk=X
@X_)%Y-^O
public SiteInfoBean() e^hI[LbNC
{//nSplitter的缺省值为5 I3Ad+]v
//default value of nSplitter is 5 F_V/&OV
this("","","",5); }w)wW1&
} 6O'Y@9#
}jg,[jw_"X
-?ebkHe
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @~IZ%lEQsD
{ jYW-}2L
sSiteURL= sURL; 2JHV*/Q
sFilePath = sPath; !'=<uU-
sFileName = sName; mEV@~){
this.nSplitter = nSpiltter; rwAycW7
lK#uyag
T lB+ tV>
} 0'R}'
AQ,%5MeqJ
w X.]O!^X~
public String getSSiteURL() `V?NS,@$
{ ")W5`9
return sSiteURL; @%6"xnb`
} ?C_Y2JY
]yas]5H
DWU(ld:_
public void setSSiteURL(String value) yuF\YOA9
{ Lx3`.F\mG
sSiteURL = value; L$[1+*
} f5.Be%
Vv>hr+e
zBqNE`
public String getSFilePath() t>"|~T$9
{ .kDJuJ^
return sFilePath; 2c5)pIVEy
} 8ZDWaq8^2N
!:1BuiL
F>5)Clq
public void setSFilePath(String value) <ceJ!"L
{ t;lK=m|
sFilePath = value; 4n2*2 yTg
} A)nE+ec1
tU>4?`)E
KocNJ TB
public String getSFileName() /qXP\ a
{ E_K32)J-
return sFileName; zHvW@A'F
} .H5^N\V|
0Y*Ag,S
v0+$d\mP4<
public void setSFileName(String value) [<#`@Kr
{ <rNz&;m}
sFileName = value; OF`:);
} aOW$H:b
5K$d4KT
sHHu<[psM
public int getNSplitter() vNAQ/Q
{ FX/f0C3CK
return nSplitter; #vT~D>zj
} R"e533
;x4yidb6
Njs'v;-K
public void setNSplitter(int nCount) *0%G`Q
{ nsi&r
nSplitter = nCount; X1%_a.=VF
} 6am<V]Hw0F
} 2B]mD-~
+InFv"wt
4J2C#Cs
/* us^J! s7
**Utility.java c nV2}U/\
*/ '_o(I
package NetFox; <#7j~<
Br"K{g?
0u ,nSvch
public class Utility { hu-6V="^9
h) W|~y@
lf2(h4[1R
public Utility() h=ko_/<
{ ^1[u'DW4
rh6m
[u/Wh+
} fMRMQR=6B
UjS,<>fm
//线程睡眠 /@K1"/fqH
public static void sleep(int nSecond) o,=dm@j
{ I>spJ5ls
try{ )dI `yf
Thread.sleep(nSecond); e}W|wJ):j@
} MrpT5|t
catch(Exception e) 76EMS?e
{ >3y:cPTM5
e.printStackTrace (); GP=&S|hi
} "A&HNkRz
} 6zW3!_tz
k!sk\~>YO
//日志 }%k3
public static void log(String sMsg) |(rTz!!-
{ -{S:sK.o
System.err.println(sMsg); Y kcN-
} =BBDh`$R
8=j_~&*
|kkg1M#
public static void log(int sMsg) A$o?_
{ k54Vh=p
System.err.println(sMsg); 1WLaJ%Fv
} :%"$8o*0W
} psE&Rx3)
!"N-To-c
VAZ6;3@cd
/* k>72W/L^
**TestMethod.java hdx"/.s
*/ VeWvSIP,EQ
package NetFox; G^_fbrZjN
;bes#|^F
@ykM98K
public class TestMethod { Y%)@)$sK
[V.#w|n
)nA fT0()0
public TestMethod() Ct30EZ
{ ///xx/weblogic60b2_win.exe h$q=NTV
try{ $qh?$a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "A,-/~cBV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F<A[S"
SiteFileFetch fileFetch = new SiteFileFetch(bean); `'M}.q,k~
fileFetch.start(); wx)Yl1C
} 8zk?:?8%{
catch(Exception e){e.printStackTrace ();} zsha/:b
p>GxSE)
=aE!y5
} {/SLDyf%Z
0|@*`-:VO
8iwqy0<
public static void main(String[] args) tJ!s/|u(
{ NU$?BiB?R
new TestMethod(); 8^6dK
} mA>u6Rlc
} T_b$8GYfCY
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