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)); 1{X ;&y
} mo3HUXf}8
for(int i=0;i<nEndPos.length-1;i++) , 8F(R%v
{ ZzuWN&
nEndPos = nStartPos[i+1]; z@em1W0?Z
} d_}q.%*
nEndPos[nEndPos.length-1] = nFileLength; 2r&T.
} ;v1&Rs
} <ekLL{/O'
d>NM4n[h8
@5\ns-%
//启动子线程 7vs>PV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R k).D6
for(int i=0;i<nStartPos.length;i++) 9AdA|/WV
{ g>O O '}lF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PG/xX H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d$`NApr
nStartPos,nEndPos,i); ueazAsk3g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RZ&T\;m,7
fileSplitterFetch.start(); v81H!c.*
} n$T'gX#5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >w"k:O17
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CwVORf,uA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 42: 6=\
nEndPos = " + nFileLength); PKM8MYvo
// fileSplitterFetch[nPos.length-1].start(); 9Iod[ x
]1 OZY@
nE3'm[)
//等待子线程结束 S20L@e"U
//int count = 0; @eGJ_J
//是否结束while循环 2U;ImC1g
boolean breakWhile = false; tk <R|i
eO:wx.PW
IZkQmA=
while(!bStop) ^/kn#1H7&
{ z!GLug*j`
write_nPos(); \L:;~L/
Utility.sleep(500); -q.tU*xf'
breakWhile = true; J,k|_JO
oopACE>
.UuCTH;6`
for(int i=0;i<nStartPos.length;i++) u/BCl!`
{ 2& l~8,
if(!fileSplitterFetch.bDownOver) hs"=>(P)
{ o4"7i 9+g
breakWhile = false; hkq[xgX
break; ZsPT!l,
} t:G67^<3
} uxd5XS
if(breakWhile) 5xawa:K
break; (ft8,^=4
Je#vl4<L
X^U)j N2
//count++; j[fVF3v
//if(count>4) TYQ7jt0=.-
// siteStop(); 9_z u*
} ,5_Hen=PI
g= ql 3N
./009p
System.err.println("文件下载结束！"); 02_%a1g
} U]Vu8$W
catch(Exception e){e.printStackTrace ();} xmEmdOoD
} #q"^6C 5
8)D5loS
Ck|3DiRQ
//获得文件长度 !kl9X-IiI
public long getFileSize() SWYIQ7*
{ L"akV,w4p
int nFileLength = -1; y%21`y&Os
try{ q7 ;TdQ
URL url = new URL(siteInfoBean.getSSiteURL()); w7?&eF(w(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &ESE?{of)
httpConnection.setRequestProperty("User-Agent","NetFox"); SG{> t*E
;L5'3+U
u2SnL$A7
int responseCode=httpConnection.getResponseCode(); #l6L7u0~wC
if(responseCode>=400) s^]F4'
{ S(c,Sinc
processErrorCode(responseCode); ,&;#$ b5
return -2; //-2 represent access is error ?]'Rz\70
} d+_wN2
,{ C
"-'w,g
String sHeader; Efm37Kv5l
Q3M;'m
J2BW>T!tuw
for(int i=1;;i++) MjAF&bD^
{ 0pWF\<IZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lH6zZ8rh
//Utility.log(in.readLine()); G] -$fz
sHeader=httpConnection.getHeaderFieldKey(i); .`OyC'
if(sHeader!=null) b{C3r3B8
{ S(^*DV
if(sHeader.equals("Content-Length")) ]OE{qXr{
{ 0jsU^m<g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9OeY59 :
break; J 00%,Ju_
} +1Ha,Ok
} li4rK<O
else Ng?n}$g*
break; f-N:
} 2t3'"8xJ
} em
catch(IOException e){e.printStackTrace ();} %t&5o>1C
catch(Exception e){e.printStackTrace ();} AR i_m
-'FzH?q:
.u3!%{/v(c
Utility.log(nFileLength); wz-9+VN6
0f).F
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return nFileLength; pJC@}z^cw
} }LDH/# u
[-X=lJ:+h
}JXAG/<
//保存下载信息（文件指针位置） bDa(@QJ-
private void write_nPos() #{)=%5=c
{ =}Np0UP
try{ 2f8fA'|O
output = new DataOutputStream(new FileOutputStream(tmpFile)); `B{N3Kxbp
output.writeInt(nStartPos.length); [HJ^'/bB'
for(int i=0;i<nStartPos.length;i++) ^zv0hGk2
{ NJfI9L
// output.writeLong(nPos); U[/k=}76
output.writeLong(fileSplitterFetch.nStartPos); seh1(q?Va4
output.writeLong(fileSplitterFetch.nEndPos); pei-R
} MS,J+'2
output.close(); x:W nF62
} !Pf_he
catch(IOException e){e.printStackTrace ();} T6[];|%W
catch(Exception e){e.printStackTrace ();} F6*n,[5(
} yUF<qB
-s`/5kD
-/:N&6eRb
//读取保存的下载信息（文件指针位置） S}Wj+H;
private void read_nPos() qJ=4HlLno
{ :-B,Q3d
try{ zY\pZG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1ID0'j$
int nCount = input.readInt(); 7mipj]
nStartPos = new long[nCount]; ]sBSLEie '
nEndPos = new long[nCount]; c:0nOP
for(int i=0;i<nStartPos.length;i++) ) -+u8#
{ {_0m0 8
nStartPos = input.readLong(); H#IJ&w|
nEndPos = input.readLong(); zc&>RM
} 8A{n9>jrb
input.close(); .CI {g2
} 5mwtlC':l?
catch(IOException e){e.printStackTrace ();} *NdSL
catch(Exception e){e.printStackTrace ();} `y5?lS*
} Ca]+*Eb9z{
1 "'t5?XW
t|Cp<k]B
private void processErrorCode(int nErrorCode) uGIA4CUm
{ 1!,xB]v1Ri
System.err.println("Error Code : " + nErrorCode); ~1&%,$fZ
} P?GHcq$\
{&,9Zy]"S
LAG*H
//停止文件下载 L&O!"[++
public void siteStop() Az.(tJ X"
{ 5z8CUDt 0
bStop = true; n?vw|'(}
for(int i=0;i<nStartPos.length;i++) '_& Xemz
fileSplitterFetch.splitterStop(); tbHU(#~
~1xln?Q
uK6`3lCD
} xc[LbaBG
} pPt7M'uL"
//负责部分文件的抓取 %n-:mSus
**FileSplitterFetch.java ?N2/;u>
*/ %~uMa
package NetFox; U4]>8L
+yX\!H"
fHTqLYd-
import java.io.*; KI~BjP\e
import java.net.*; QAYhAOS|e
pI2g\cH>
<11pk
public class FileSplitterFetch extends Thread { UxI0Of&:
[MfKBlA
,7:_M>-3g
String sURL; //File URL qkB)CY7
long nStartPos; //File Snippet Start Position PjriAlxD
long nEndPos; //File Snippet End Position ea-NqdGs;m
int nThreadID; //Thread's ID @vWf-\
boolean bDownOver = false; //Downing is over nQ4s
boolean bStop = false; //Stop identical @!z9.o;
FileAccessI fileAccessI = null; //File Access interface mo1(dyjx
M`!\$D
x&qC~F*QR%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^R.kThG
{ rYUhGmg`
this.sURL = sURL; ^:g8mt
this.nStartPos = nStart; U$o\?4
this.nEndPos = nEnd; %/KN-*
nThreadID = id; <Z%iP{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AfmGA9
} / sI0{
B0Ql1x#x
C%8nr8po
public void run() !e?;f=1+E
{ EsR_J/:Qe
while(nStartPos < nEndPos && !bStop) U 2k^X=yl
{ X]6Hgz66
?3bUE\p
S2nF13u
try{ j)IXe 0dMC
URL url = new URL(sURL); >SO !{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C'x?riJ/
httpConnection.setRequestProperty("User-Agent","NetFox"); q{/>hvl
String sProperty = "bytes="+nStartPos+"-"; v'Y)~Kv@!
httpConnection.setRequestProperty("RANGE",sProperty); pE{ZWW[@+
Utility.log(sProperty); ,H!E :k
L'k)
)rJ{}U:S
InputStream input = httpConnection.getInputStream(); l$KC\$?%*
//logResponseHead(httpConnection); T1TKwU8l
b X.S`
a f[<[2pma
byte[] b = new byte[1024]; QI*Y7R~<
int nRead; PM3kI\:)m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jbx@ty
{ \sB a
nStartPos += fileAccessI.write(b,0,nRead); fY3^L"R
//if(nThreadID == 1) EVc Ees
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fD1J@57
} mY9^W2:
Mx<V;GPm
c>+l3&`
Utility.log("Thread " + nThreadID + " is over!"); .nCF`5T!
bDownOver = true; 7\*_/[B
//nPos = fileAccessI.write (b,0,nRead); J6Uo+0S
} *,g|I8?%VD
catch(Exception e){e.printStackTrace ();} g.-{=kZ
} QixEMX4<
} L\d"|87lX
4QbDDvRQ^
^Glmg}>q
//打印回应的头信息 ?f!w:zp
public void logResponseHead(HttpURLConnection con) 4B>N[#-0=
{ (.~#bl
for(int i=1;;i++) bdh6ii
{ #rSm;'%,
String header=con.getHeaderFieldKey(i); QDCu
if(header!=null) 0M^7#),
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !6yoD
Utility.log(header+" : "+con.getHeaderField(header)); 6gz !K"S
else .&O}/B
break; {+~}iF<%
} ;Z]i$Vi_r
} ?Fgk$WqC
hwkm'$}
po@=$HK
public void splitterStop() tU2 8l.
{ vR$[#`X
bStop = true; 'TWZ@8h~
} xa+=9=<AQ
R;+vE'&CO
??&Q"6Oe
} &2-dZK
&DoYz[q
jOL$kiW0
/* aO:wedfl
**FileAccess.java G'b*.\=
*//文件访问(定位，写) }F3}-5![
package NetFox; ciRn"X=l
import java.io.*; D:`b61sWi_
(]* Ro 8
x6Q,$B
public class FileAccessI implements Serializable{ r;}%} /IX
LIfQh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ne7HPSWiOP
RandomAccessFile oSavedFile; = GUgb2TAT
long nPos; }7p`8?
v x qsK
eXo7_#
public FileAccessI() throws IOException d:08@~#
{ Zpfsh2`
this("",0); b1An2e[
} w1q-bIU
VJW%y)_[
ug]WIG7 S
public FileAccessI(String sName,long nPos) throws IOException ]%AmX-U
{ Ox.6]W~
oSavedFile = new RandomAccessFile(sName,"rw"); z ((Y\vP
this.nPos = nPos; ;S Re`
oSavedFile.seek(nPos); s~N WJ*i
} e}%~S9\UL5
#{-l(016y
*E$&
public synchronized int write(byte[] b,int nStart,int nLen) 38<!Dt+S(,
{ xgsEJE
int n = -1; fuRCM^U(
try{ IM-O<T6r[N
oSavedFile.write(b,nStart,nLen); ;2Aqztp
n = nLen; #.1+-^TQk
} {8b6M
catch(IOException e) V~nqPh!Jc
{ ^{f^%)X
e.printStackTrace (); 3d<Z##`{4
} *F:f\9
SUv(MA&
'3B"@^]
return n; ft |W
} alr'If@7
.gZ1}2GF=
yU ?TdM\
} hnOo T? V
0\W6X;?
A7U]wW9
/* g!/O)X3
**SiteInfoBean.java Ife/:v
*/ D==C"}J
package NetFox; 6ZvGD}/
o$PY0~#
|HT5G=dw
public class SiteInfoBean { 6uNWL `v
]7+9>V
L!/Zw~
private String sSiteURL; //Site's URL c, IAz
private String sFilePath; //Saved File's Path @\ udaZc
private String sFileName; //Saved File's Name _JEe]
private int nSplitter; //Count of Splited Downloading File -@=As00Bg
4MM /i}
;ZOu-B]q
public SiteInfoBean() xWC*DKV
{//nSplitter的缺省值为5 +!"GYPUXy
//default value of nSplitter is 5 0oT~6BGm
this("","","",5); a!?JVhD&
} 0Y|"Bo9k
},eV?eGj
t,D7X1W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f2*e&+LjTP
{ WdtZ{H
sSiteURL= sURL; $"e$#<g
sFilePath = sPath; 5t=7-
sFileName = sName; msf%i!
this.nSplitter = nSpiltter; t%S2D
7XM:4whw
3UR'*5|'
} Bp:PAy
$kAal26z
3Gk\3iU!
public String getSSiteURL() Z'!Ii+'6
{ b8FSVV 7@
return sSiteURL; J?R\qEq%
} |3]#SqX
oy[>`qyz
AHB_[i'>7
public void setSSiteURL(String value) wZe>}1t
{ K;L6<a A#
sSiteURL = value; !c2<-3e
} O su 75@3
Rz03he
Y|X!da/
public String getSFilePath() (&o|}"kRq
{ Xtk3~@
return sFilePath; h/s8".\
} td!YwN*
0bz':M#k &
eeVzOq(
public void setSFilePath(String value) TxA%{0
{ DeK&_)g| Z
sFilePath = value; OCN:{
} Pl/B#Sbf'
JHJIjYG>P
52P^0<Wq
public String getSFileName() K^m`3N"
{ M&SY2\\TB
return sFileName; G=(ja?d
} j=kz^o~mH
ZCAg)/
./qbWr`L
public void setSFileName(String value) &iTTal.6
{ MhDPf]` Gg
sFileName = value; J]ri|a
} $z,rN\[
49!(Sa_]j
i|!D
public int getNSplitter() ?{]"UnyVE*
{ yc7"tptfF
return nSplitter; INNTp[
} WQ1K8B4
VJbn/5+P
O5v~wLx9e
public void setNSplitter(int nCount) 1$n!Lj=5
{ M2Zk1Z
nSplitter = nCount; c~)H" n
} 3gQ2wP*K
} #,S0uA
=`EVg>+^
/4>|6l=
/* yD yMI
**Utility.java ' JAcN@q~z
*/ 4<btWbk5u*
package NetFox; W@t{pXwLv
0RF<:9@x2
fO{'$?K
public class Utility { s*tzU.E(
fq(3uE]nC
g0k{b
public Utility() rd ]dDG
{ Q`HG_n@?
4c,{Js
91oAg[@4G
} ,R*YI
&`B Tw1u
//线程睡眠 mQ=nU
public static void sleep(int nSecond) S]<%^W'
{ jc7NYoT:
try{ XQStlUw8+
Thread.sleep(nSecond); |>dqZ_)v
} H|8i|vbi
catch(Exception e) GmdS~Fhp
{ ia*Bcx_RW+
e.printStackTrace (); +i(;@% kv
} +kM*BCPYE
} OE(!^"5?[
."h>I @MH
//日志 Eemk2>iP?
public static void log(String sMsg) bnxR)b~
{ uuf+M-P
System.err.println(sMsg); _xdFQ
} dk.VH!uVb
PbIir=
</li<1
public static void log(int sMsg) l.%[s6
{ osPrr QoH
System.err.println(sMsg); :rnj>U6<>
} s}Q*zy
} 2X`5YN;
nD!5I@D
te b/
/* e$4$G<8;y
**TestMethod.java G0Wv=tX|
*/ K&;;{~md.
package NetFox; ]GmXZi
j9O"!9$vQ
e"]DIy4s
public class TestMethod { x0ICpt{;
Qg5-I$0
i3<ZFR
public TestMethod() m:C|R-IL
{ ///xx/weblogic60b2_win.exe vx4Jk]h+=L
try{ :M\3.7q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u;H5p\zAzz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6#(rWW"_
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?T7ndXX
fileFetch.start(); 822jZ sb
} *K=Yrisz
catch(Exception e){e.printStackTrace ();} S)z5=N(Xz
g6(u6%MD
zf?U q
} a{! 8T
0RkiD8U5
=Y<RG"]a&J
public static void main(String[] args) nhI1`l&
{ UO8./%'
new TestMethod(); 3vRBK?Q.y
} &/{x7;e
} 1ZRSeh
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