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)); .M^[/!
} tWIJ,_8l
for(int i=0;i<nEndPos.length-1;i++) yzhNl'Rz
{ DpgTm&}-
nEndPos = nStartPos[i+1]; _&#{cCo:
} R03 Te gwA
nEndPos[nEndPos.length-1] = nFileLength; DaQl ip
} R);Hd1G
} I} jgz
\]u;NbC]
(*9.GyK
//启动子线程 rR#Ditn^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U;MXiE3D
for(int i=0;i<nStartPos.length;i++) erUYR"
{ |R0f--;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lQ;BI~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q- |Y
nStartPos,nEndPos,i); s;Gd`-S>d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ">oySo.B?
fileSplitterFetch.start(); 3O/#^~\'hW
} l&qnqmW<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y'K2#Y~1e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z]]Ur
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CP~ZIIip"
nEndPos = " + nFileLength); IA@>'O
// fileSplitterFetch[nPos.length-1].start(); sF{aG6u
X@\W* nq
DpT9"?g7
//等待子线程结束 g|>LT_
//int count = 0; sCFxn
//是否结束while循环 H&)}Z6C"
boolean breakWhile = false; +P2oQ_Fk`9
!5o j~H
e|\xFV=4
while(!bStop) gA!@oiq@
{ Wb-C0^dTn
write_nPos(); pd|KIs%jl
Utility.sleep(500); Jay"
breakWhile = true; yfZNL?2x
"o&8\KSs
cs+3&T:,*
for(int i=0;i<nStartPos.length;i++) ?;ok9Y
{ G.rz6o;
if(!fileSplitterFetch.bDownOver) <e2l@@#oy
{ lvO6&sF1
breakWhile = false; e7RgA1
break; ITn%
} K oJ=0jM#
} ec&/a2M
if(breakWhile) $a M5jH<
break; f4"UI-8;n
]4l2jY
QrYF Lh
//count++; <q'l7S
//if(count>4) {%R^8
// siteStop(); *q=T1JY
} f+h\RE=BGt
,CfslhO{j
-]Z7^
System.err.println("文件下载结束！"); 0[MYQl`
} Jb QK$[z"
catch(Exception e){e.printStackTrace ();} ZZY#.
} K~TwyB-h
e&}W#
IfK~~XYG
//获得文件长度 Lx0nLJ\
public long getFileSize() cS;3,#$
{ SVe]2ONd
int nFileLength = -1; 9TW[;P2> )
try{ D=0YLQ*rP
URL url = new URL(siteInfoBean.getSSiteURL()); SMEl'y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]`/>hH>+~9
httpConnection.setRequestProperty("User-Agent","NetFox"); %QezC+n
1<YoGm&
)+G"57p
int responseCode=httpConnection.getResponseCode(); vMTf^V
if(responseCode>=400) Q(bOar5
{ {R}F4k
processErrorCode(responseCode); DB/~Z
return -2; //-2 represent access is error mmTpF]t ?`
} 4q}+8F`0F
@J[@Pu O
:@(('X(".
String sHeader; gP2zDI
tT}b_r7h(1
jn<?,UABD
for(int i=1;;i++) uX_H;,n
{ w% %q/![uy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~g{j)"1
//Utility.log(in.readLine()); *~vB6V|1
sHeader=httpConnection.getHeaderFieldKey(i); Er;/zxg9p
if(sHeader!=null) l0qaTpn
{ 1Bj.MQ^
if(sHeader.equals("Content-Length")) |oY{TQ<<d
{ $1yO Zp5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lsz3'!%Y)
break; Rx-\B$G
} fN&,.UB^p
} e^y9Kmd
else 'ygKP6M
break; uo#1^`P
} J(7#yg%5
} !oWB5x~:P
catch(IOException e){e.printStackTrace ();} daE.y_9y
catch(Exception e){e.printStackTrace ();} ;b<w'A_1
'`>%RZ]
cQ8[XNa
Utility.log(nFileLength); ~gDYb#p
&dyQ6i$],
,!#Am13
return nFileLength; Gv-VDRS
} Q:-T'xk@
TnF~'RZYb
;wn9 21r
//保存下载信息（文件指针位置） W/Dd7G#IC
private void write_nPos() L@N%S Sf
{ D=e*rrL7a
try{ 4V@%Y,:ee
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q:A#4Z
output.writeInt(nStartPos.length); nLN0zfhE#
for(int i=0;i<nStartPos.length;i++) 9\Ii$Mp
{ [LYO'-g^F#
// output.writeLong(nPos); F%w!I 9
output.writeLong(fileSplitterFetch.nStartPos); ,lZ19B?WP
output.writeLong(fileSplitterFetch.nEndPos); eh86-tQI~(
} CMj =4e
output.close(); ,'8%'xit
} roADC?@r
catch(IOException e){e.printStackTrace ();} %U\,IO`g
catch(Exception e){e.printStackTrace ();} [l}H:%O,
} Hjm> I'9
c]6b|mHT
6S`_L
//读取保存的下载信息（文件指针位置） \<7Bx[/D4
private void read_nPos() /Hr|u
{ Y2`sL,'h
try{ I dK*IA4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \Zj%eW!m
int nCount = input.readInt(); H*=cw<
nStartPos = new long[nCount]; }z`x-(V
nEndPos = new long[nCount]; hb`9Vn\-E
for(int i=0;i<nStartPos.length;i++) \|PiQy*_?
{ Z@bgJL83
nStartPos = input.readLong(); -CvmZ:n
nEndPos = input.readLong(); dbf<k%i6
} c8uaZvfW
input.close(); wWl?c
} ;s+/'(*
catch(IOException e){e.printStackTrace ();} OSBR2Z;=
catch(Exception e){e.printStackTrace ();} M':-f3aT%
} F9%_@n
`B%%2p&
v;,W ^#`
private void processErrorCode(int nErrorCode) F2N"aQ&
{ "n%j2"TYJj
System.err.println("Error Code : " + nErrorCode); u r$
} s)-An(Uw
{ DYY9MG8
S?688
//停止文件下载 5CI{&E
public void siteStop() h FU8iB`Q
{ }-3 VK%
bStop = true; X=QX9Ux?^
for(int i=0;i<nStartPos.length;i++) #Vk?
fileSplitterFetch.splitterStop(); "laf:Ty1
*AH`ob}
4|x_C-@
} t&?jJ7 (&8
} |`T7}U
//负责部分文件的抓取 -.D?Z8e
**FileSplitterFetch.java v=k+MvX
*/ i}m'#b
package NetFox; d{fd5jv;
lR?y tIY
!tq]kKJ3:
import java.io.*; &y? |$p\;/
import java.net.*; :8yebOs
IdmP!(u
![z2]L+TB
public class FileSplitterFetch extends Thread { @76}d
x6cG'3&T
mP)bOAU
String sURL; //File URL zyPb\/
long nStartPos; //File Snippet Start Position Wl| i$L)7
long nEndPos; //File Snippet End Position w%L4O;E]*{
int nThreadID; //Thread's ID fI1CT)0<e
boolean bDownOver = false; //Downing is over A7L;ims7
boolean bStop = false; //Stop identical [4"(\r\f
FileAccessI fileAccessI = null; //File Access interface \uZpAV)5
$0V+<
Uu7]`Ul
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RP~nLh3=\
{ t|U5]$5
this.sURL = sURL; tA1?8`bQ
this.nStartPos = nStart; bB<S4@jF8z
this.nEndPos = nEnd; 6,q0F*q
nThreadID = id; \&F4Wl>`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +$C9@CZM9
} %R GZu\p
o*K7(yUL4
CR [>5/:M
public void run() DuC#tDP
{ K~:SLCv E%
while(nStartPos < nEndPos && !bStop) qJG;`Ugl:
{ AZ.QQ*GZ#y
-mO#HZIq
;1&"]N%
try{ ';R]`vWFe
URL url = new URL(sURL); NfDS6i.Fqp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &4OOW;,?<
httpConnection.setRequestProperty("User-Agent","NetFox"); lJ3VMYVrUP
String sProperty = "bytes="+nStartPos+"-"; eg;r38
httpConnection.setRequestProperty("RANGE",sProperty); Q0xGd(\
Utility.log(sProperty); 6%V:Z
/ =9Y(v
`,4yGgD!4
InputStream input = httpConnection.getInputStream(); k<*v6 sNs;
//logResponseHead(httpConnection); j&Hui>~
6aB]&WO1@
syu/"KY^!
byte[] b = new byte[1024]; h1S)B|~8
int nRead; (?Ko:0+*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ucv7`W gr
{ h] ho? K
nStartPos += fileAccessI.write(b,0,nRead); ;?u cC@
//if(nThreadID == 1) pj_W^,*/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |mMsU,*gB
} 5&%M L
d5-Q}D,P
PxYK)n9&
Utility.log("Thread " + nThreadID + " is over!"); h GA2.{
bDownOver = true; G^{~'TZv%
//nPos = fileAccessI.write (b,0,nRead); "d<ucj
} IhzY7U)}T
catch(Exception e){e.printStackTrace ();} ou0TKE9 _
} OcUj_Zd
} T^!Q(`*
SE*;6&yL
cq>J]35
//打印回应的头信息 y)KIz
public void logResponseHead(HttpURLConnection con) u.q3~~[=
{ 6n/=n%US
for(int i=1;;i++) L{~ ]lUo
{ ft7M9<#v
String header=con.getHeaderFieldKey(i); n ^9?(a4u
if(header!=null) ZC2aIJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z?13~e[D
Utility.log(header+" : "+con.getHeaderField(header)); dWzf C@]
else XR",.3LD
break; ([<{RjPb
} e!0xh
} +76'(@(1Y
(}F@0WYT^O
xJ<RQCW$
public void splitterStop() Pz*BuL<
{ t>quY$}4
bStop = true; kYCm5g3u
} Q1Qw45$
]2L11"erP
Ur 1k3
} 6Z1O:Bou
EwcFxLa!F
Zz (qc5o,F
/* )0I-N)
**FileAccess.java 8\E=p+C
*//文件访问(定位，写) 8oUR/___
package NetFox; IZdWEbN1
import java.io.*; /Q W^v;^
xN$V(ZX4
[Cd#<Te3
public class FileAccessI implements Serializable{ i.^UkN{
aPe*@py3T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T-n>+G{
RandomAccessFile oSavedFile; >r)UDa+
long nPos; JoB-&r}\V*
b"@-9ke5I
44n41.Q]
public FileAccessI() throws IOException CBdr1
{ rp @%0/[
this("",0); n9 bp0#K
} *kf%?T.
>g+Y//Z
O>f*D+A-
public FileAccessI(String sName,long nPos) throws IOException S\ZCZ0
{ h+dk2|a
oSavedFile = new RandomAccessFile(sName,"rw"); =|O]X|y-lZ
this.nPos = nPos; )jwovS?V
oSavedFile.seek(nPos); CNj |vYj
} wBI:}N@.
IN;!s#cl:
UC`sq-n
public synchronized int write(byte[] b,int nStart,int nLen) ?3LV$S)U
{ uFuH/(}K[
int n = -1; Pvv7|AV
try{ V[^AV"V
oSavedFile.write(b,nStart,nLen); 1mh7fZgn
n = nLen; k,OxGG
} \\Zsxya1
catch(IOException e) kVeY} 8
{ %;_EWs/z8
e.printStackTrace (); i5WO)9Us
} dqU)(T=C
a{;+_J3S
!}`[s2ji
return n; @VND}{j
} 1*#hIuoj'
mWoN\Rwj
)abH//Pps.
} [$>@f{:
7 mA3&<&q
~s?y[yy6i
/* DjZTr}%q
**SiteInfoBean.java blG?("0!
*/ 1_xkGc-z<
package NetFox; 4 q % Gc
u3 +]3!BQ
ok-q9dM
public class SiteInfoBean { ca,JQrm
-)"\?+T
0ikA@SAq
private String sSiteURL; //Site's URL RT%{M1tkS
private String sFilePath; //Saved File's Path Mu" vj*F
private String sFileName; //Saved File's Name iF:NDqc
private int nSplitter; //Count of Splited Downloading File FD8
,ueA'GZ
m*e8j[w#
public SiteInfoBean() C3<_0eI
{//nSplitter的缺省值为5 ]G! APE
//default value of nSplitter is 5 "|WKK}
this("","","",5); *rm[\
} ARJtE@s6Y
\u/=?b
:W'.SRD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6il+hz2&lH
{ 1 !.PH
sSiteURL= sURL; ?a?] LIE8
sFilePath = sPath; zs-,Y@ZL
sFileName = sName; ccW{88II7w
this.nSplitter = nSpiltter; Ac>GF
3\B~`=*q/
4%>tk 8 [
} 5B{Eg?
,+5!1>\
+jGUp\h%9;
public String getSSiteURL() Vx n-
{ V2 }.X+u&<
return sSiteURL; _2})URU<S
} ka8=`cn
>BMtR0
:r_/mzR#
public void setSSiteURL(String value) 5e'**tbKH
{ rqM_#[Y?
sSiteURL = value; $yZP"AsAR
} p!(]`N
U,`F2yD/!
xAf?E%_pi
public String getSFilePath() 6A} 45
{ 0te[i*G
return sFilePath; \D! I"mr
} AIwp2Fz
pWGIA6&v(
j+3=&PkA.]
public void setSFilePath(String value) a3_pF~Qx
{ =co6.Il
sFilePath = value; )|U+<r<
} e0o)Jo.P
-fx$)d~
2CPh'7|l
public String getSFileName() )}\J
{ eKqo6P:#f
return sFileName; Y#Pg*C8>8
} k?Iq 6
OxVe}Fym
rge/qUr/^
public void setSFileName(String value) K~\Ocl
{ (DKQHL;
sFileName = value; !o`h*G-x
} hzy#%FaB
<~.1>CI9D3
AhSN'gWpbF
public int getNSplitter() pU@&-
{ xR5zm%\
return nSplitter; RMxFo\TK;
} HS 1zA
Bjsg!^X7
k iY1
public void setNSplitter(int nCount) >o!~T}J7
{ nTPq|=C
nSplitter = nCount; p+1kU1F0
} H}}C>p"!,
} b(:U]>J
|`ZW(}~
!&vPG>V
/* Z[zRZ2'i5
**Utility.java Jm*wlN [>
*/ sb*)K,U
package NetFox; :pgpE0
[#C(^J*@c
r/mKuGa]
public class Utility { h2m@Q={
qgw)SuwW
]*vv=@"`e
public Utility() I=9sTR)
{ o0F&,|'
W 33MYw
y^hCO:`l3
} $~<]G)*Z
NN@'79x
//线程睡眠 [$%O-_x
public static void sleep(int nSecond) ^;a~_9 m-
{ &`Ek-b!7
try{ %*Lv
Thread.sleep(nSecond); e4(E!;Z!QF
} ])NQzgS
catch(Exception e) )V?:qCuY>
{ ='<789wT
e.printStackTrace (); BDz7$k]
} @pO2A6Ks
} fu $<*Sa2
zM2_z
//日志 T43Jgk,
public static void log(String sMsg) ;dZuO[4\
{ YzVhNJWpw
System.err.println(sMsg); b]k9c1x
} aV`_@F-8
Z=j6c"
,IDCbJ
public static void log(int sMsg) ?]PE!7H
{ 'Uu!K!
System.err.println(sMsg); 3 G_0DS
} 0Tq=nYZA
} :B 9>
="J *v>
4Be'w`Q {
/* N|\Q:<!2_w
**TestMethod.java iqr/MB,W
*/ z1S p'h$
package NetFox; 8(ej]9RObU
_kXq0~
}WDzzjDR+
public class TestMethod { ^Fpc8D,
O QGKH6q
\45F;f_r6
public TestMethod() fs\A(]`$
{ ///xx/weblogic60b2_win.exe D1R$s*{
try{ %8{nuq+c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a&RH_LjM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "Tz'j}< 9C
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~sT1J|
fileFetch.start(); qsWy <yL+
} )k.}>0K |
catch(Exception e){e.printStackTrace ();} o2~P vef
nM|Cv
L@s_)?x0
} ?kdan
|p.|zH
w)C5XX30;
public static void main(String[] args) T.}Y&,n$$5
{ ZeLed[J^xJ
new TestMethod(); [ylRq7^e
} AVi&cvhs
} lHAWZyO
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