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)); 0Vy* 0\{S
} to:hMd1T
for(int i=0;i<nEndPos.length-1;i++) dF1Bo
{ OQ!mL3f
nEndPos = nStartPos[i+1]; Hyee#fB
} 1egryp
nEndPos[nEndPos.length-1] = nFileLength; -P'>~W,~
} 7zQD.+&L
} |C-B=XE;3
O5k's
uLL#(bhDr
//启动子线程 Z|wZyt$$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A9lqVMp64
for(int i=0;i<nStartPos.length;i++) rZpc"<U
{ YrZAy5\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hk,Q=};
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?cg+RNI
nStartPos,nEndPos,i); If4YqBG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M6DyOe<
fileSplitterFetch.start(); #axRg=d?K
} {bc<0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .v;2Q7X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?pQ, 5+8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }T(|\ X
nEndPos = " + nFileLength); vBM\W%T|d
// fileSplitterFetch[nPos.length-1].start(); ?0_i{BvN
&V$'{
R9=,T0Y p
//等待子线程结束 jl:O~UL6i
//int count = 0; /9GqEQsfM
//是否结束while循环 'u696ED4
boolean breakWhile = false; +m>Kb edl
-,4_ &V
*r9I 1W
while(!bStop) 7c;59$2(
{ ;\#u19
write_nPos(); ao7|8[
Utility.sleep(500); oMMU5sm
breakWhile = true; m41n5T`
[N7[%iQ%
AvV.faa
for(int i=0;i<nStartPos.length;i++) 1bj75/i<6
{ dYr#
if(!fileSplitterFetch.bDownOver) lfI[r|
{ F ^E(AE
breakWhile = false; u)Y#&qA
break; fylaH(LER
} cwpDad[Kx
} 5~.\rcr%
if(breakWhile) D=dY4WwG
break; wy Le3
6xBP72L;%"
X.UIFcK^
//count++; d3n TJX
//if(count>4) gNZ^TeT
// siteStop(); IFv2S|
} }#yRaIp
5'z&kl0"S
t-E'foYfr`
System.err.println("文件下载结束！"); gXH89n
} 8n&",)U
catch(Exception e){e.printStackTrace ();} EkTen:{G
} vDBnWA
~*2PmD"+:
ff:&MsA|,
//获得文件长度 8{d`N|k
public long getFileSize() (.n" J2qj
{ _$=xa6YA
int nFileLength = -1; %F}`;>C3
try{ ,:L}S03k
URL url = new URL(siteInfoBean.getSSiteURL()); N!Y'W)i16
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /pyKTZ|
httpConnection.setRequestProperty("User-Agent","NetFox"); Y[x ^59
:Z< 5iLq
xaeY^"L
int responseCode=httpConnection.getResponseCode(); nh E!Pk
if(responseCode>=400) 8^4X/n
{ ::M/s#-@
processErrorCode(responseCode); (U7%Z<
return -2; //-2 represent access is error h_A}i2/{
} }"cb^3
2%@j<yS
uF^+}Y ZT
String sHeader; G:@gO2(D
sV77WF
g#70Sg*d
for(int i=1;;i++) 47icy-@kg
{ h hdn9n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x b_C1n
//Utility.log(in.readLine()); :+R||qi
sHeader=httpConnection.getHeaderFieldKey(i); :*oI"U*f
if(sHeader!=null) ,cm2uY
{ 'Y&yt"cs
if(sHeader.equals("Content-Length")) (p2\H>pTr
{ awC&xVf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K=B[MT#V{2
break; ucA6s:!={
} U}qW9X;o
} M_XZOlW5
else 'bT9AV%
break; y'zEaL&SI@
} H}}t)H
} ]X-ZRmB`
catch(IOException e){e.printStackTrace ();} <`N\FM^vo
catch(Exception e){e.printStackTrace ();} @:c 1+
h1Q7(8=Eg
h+Z|s
Utility.log(nFileLength); \|T0@V
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,-{j.
return nFileLength; s!+?)bB
} }& 1_gn15
zBoU;d%p>
| z('yy$
//保存下载信息（文件指针位置） 'Lm.`U
private void write_nPos() $9l3DJ
{ hyTi':
try{ UPgZj\t%{
output = new DataOutputStream(new FileOutputStream(tmpFile)); |H@M-
output.writeInt(nStartPos.length); "1[N;|xa
for(int i=0;i<nStartPos.length;i++) <4!w2vxG
{ +"SBt}1
// output.writeLong(nPos); Az.Y-O<$\
output.writeLong(fileSplitterFetch.nStartPos); DD-DY&2R
output.writeLong(fileSplitterFetch.nEndPos); I|`K;a
} [6-l6W
output.close(); D!X{9q}S1
} Gpgi@ Uf
catch(IOException e){e.printStackTrace ();} Dn6DkD!
catch(Exception e){e.printStackTrace ();} gB0)ec 0
} 7)a=B! 8M
A+ f{j
!c*^:0
//读取保存的下载信息（文件指针位置） T}\U:@b
private void read_nPos() F\]rxl4(L
{ ;nC+Kz:
try{ o?%x!m>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xpS#l"dr
int nCount = input.readInt(); \XpPb{:>
nStartPos = new long[nCount]; {$s:N&5
nEndPos = new long[nCount]; r]]Ke_s!
for(int i=0;i<nStartPos.length;i++) ~ib#x~Db
{ @L~y%#
nStartPos = input.readLong(); ZU:gNO0
nEndPos = input.readLong(); _QErQ^`
} Sqb#U{E
input.close(); U5"F1CaW~
} wIY#TBu
catch(IOException e){e.printStackTrace ();} !W3Le$aL
catch(Exception e){e.printStackTrace ();} oF*Y$OEu?c
} fqr}tvMr=T
cw^FOV*
Et- .[
private void processErrorCode(int nErrorCode) HQE#O4
{ (Ux%7H_d
System.err.println("Error Code : " + nErrorCode); $ &^ ,(z9
} "jpjBH:c$
~ h:^Q
^<E,aCy
//停止文件下载 "~+K`*0r8
public void siteStop() t /47lYN)
{ d>aZpJ[.
bStop = true; v\HGL56T
for(int i=0;i<nStartPos.length;i++) F_-yT[i
fileSplitterFetch.splitterStop(); =-q)I[4#
=djzE`)0
BHK_=2WYz
} d+IPa<N
} (Q'XjN\#
//负责部分文件的抓取 WK=!<FsC$
**FileSplitterFetch.java 1/{:}9Z@
*/ )WFUAzuN,
package NetFox; \u)(+t{
V3m!dp]
M9N|Ql
import java.io.*; l,/5$JGnk
import java.net.*; grS,PKH
tl4;2m3w
UtWoSFZ'o!
public class FileSplitterFetch extends Thread { -meKaQv
AX&1-U
Z@h]dU5%a
String sURL; //File URL $:xUXEi{
long nStartPos; //File Snippet Start Position 3!}#@<j
long nEndPos; //File Snippet End Position Fj5^_2MU:
int nThreadID; //Thread's ID F0|T%!FB>%
boolean bDownOver = false; //Downing is over 'WOWm$2
boolean bStop = false; //Stop identical c^=:]^
FileAccessI fileAccessI = null; //File Access interface 1XZ&X]
NKMB,b
wHY;Y-(ZT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9S<W~# zz
{ D!-zQ`^
this.sURL = sURL; %_z]iz4
this.nStartPos = nStart; fkI<RgM
this.nEndPos = nEnd; Zkz:h7GUG-
nThreadID = id; KE^_09
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I|PiZ1]2Y
} svQDSif
"Fke(?X'
,wFLOfV@
public void run() 'shOSB
{ 6[CX[=P30
while(nStartPos < nEndPos && !bStop) D,)~j6OG8
{ [mwfgh&4%
5I<?HsK@
F>}).qx
try{ tz)L`g/J~
URL url = new URL(sURL); \ 0CGS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `\qU.m0(j
httpConnection.setRequestProperty("User-Agent","NetFox"); ?ph"|LyL
String sProperty = "bytes="+nStartPos+"-"; MKH7d/x
httpConnection.setRequestProperty("RANGE",sProperty); Fdzd!r1 v
Utility.log(sProperty); #._!.P
ybB}|4d&
WL7:22nSHa
InputStream input = httpConnection.getInputStream(); Jne)?Gt
//logResponseHead(httpConnection); [&39Yv.k,7
q3I,3?_
p]>bN
byte[] b = new byte[1024]; d82IEhZ#
int nRead; xE9s=}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) INkrG.=u
{ S=my;M-
nStartPos += fileAccessI.write(b,0,nRead); z1L.
//if(nThreadID == 1) 0J_x*k6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VVf~ULZ-
} ngNg1zV/q
\/,SH?>4x
-Rf|p(SJ,E
Utility.log("Thread " + nThreadID + " is over!"); |{_%YM($
bDownOver = true; 5]F9o9]T
//nPos = fileAccessI.write (b,0,nRead); ?hwQY}
} )wGC=,
catch(Exception e){e.printStackTrace ();} !k[zUti
} ~svu0[Vx
} aN7u j
QF^AnB
@ce4sSo
//打印回应的头信息 /bw-*
public void logResponseHead(HttpURLConnection con) S-L6KA{
{ hQkmB|];5
for(int i=1;;i++) ";zl6g"
{ L72GF5+!!
String header=con.getHeaderFieldKey(i); D QZS%)
if(header!=null) !<~Ig/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k4`v(au^
Utility.log(header+" : "+con.getHeaderField(header)); 9np<r82
else u!X2ju<
break; mq "p"iI
} A#p@`|H#B
} 1%+0OmV&
Llzowlfe
GnLh qm"\
public void splitterStop() ^yb_aCw
{ yn=1b:kid
bStop = true; ,CvU#ab8$
} 5Q^~Z},
Q647a}
ck^Z,AKL+
} 6Z'zB&hM}
p;'vOb
nU`;MW/^w
/* qVY\5`f@
**FileAccess.java w68qyG|wM
*//文件访问(定位，写) Tq?W @DM*
package NetFox; q`\lvdl
import java.io.*; wUSWB{y
}M1<a4~
/ )EB~|4']
public class FileAccessI implements Serializable{ O35f5Kz
:3G9YjzC}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0(..]\p^d
RandomAccessFile oSavedFile; J5\> 8I,a
long nPos; GC{Ys|s
Isi,Tl ^
_}\&;
public FileAccessI() throws IOException : Z.mM5
{ aRV!0?fS
this("",0); |g9^]bT
} )/=J=xw2
Cz(PjS
R52!pB0[
public FileAccessI(String sName,long nPos) throws IOException Eod2vr=Q
{ oL~Yrb%R
oSavedFile = new RandomAccessFile(sName,"rw"); Obd!
this.nPos = nPos; @<AIPla
oSavedFile.seek(nPos); %Wc-.ER
} mHhm~u
]A\n>Z!;
K;Xn!:) V:
public synchronized int write(byte[] b,int nStart,int nLen) E6G^?k~q
{ 0|U<T#t8?
int n = -1; Oe=,-\&_
try{ 6?Wsg`9
oSavedFile.write(b,nStart,nLen); fY `A
n = nLen; 6v1j*'
} FX'W%_f,
catch(IOException e) vD*KJ3(c
{ [;b9'7j'
e.printStackTrace (); a#{a{>
} 9#agI|d~
Hnaq+ _]
Z86[sQBg
return n; b_LzG_n!
} d`xqs,0f
65}:2l2<
$SDx) '!
} !F%dE!
gi`ZFq@
9 (&!>z
/* kfHLjr.
**SiteInfoBean.java Oll\T GXP!
*/ VOiphw`
package NetFox; /q^( uWu
E6US
wg[*]_,a
public class SiteInfoBean { dzcPSbbpt
'3xSzsDn
x^ Wgo`v)
private String sSiteURL; //Site's URL ,p2 Di
private String sFilePath; //Saved File's Path duM>(y
private String sFileName; //Saved File's Name ,5/gNg
private int nSplitter; //Count of Splited Downloading File \gzNMI*
g_q{3PW.
HS2)vd@)
public SiteInfoBean() )oNomsn
{//nSplitter的缺省值为5 &oR&NKk
//default value of nSplitter is 5 t9=rr>8)
this("","","",5); 4]g^aaQFd>
} qv<VKJTi6]
ik]UzB
5n"'M&Ce
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oo qNPLa
{ LPXwfEHOm
sSiteURL= sURL; f&,.h"bS
sFilePath = sPath; [m4<j
sFileName = sName; ':fVb3A[*d
this.nSplitter = nSpiltter; [g/g(RL
H<q:+
,JjTzO
} t &ucqY
Io:xG6yG
N@) D,~
public String getSSiteURL() ei"FN3Rm
{ R"tLu/Sn
return sSiteURL; F!Uk`[L
} * 5j iC
[[)HPHSQ
|5W u0T
public void setSSiteURL(String value) 5zUD W?
{ ;\H2U.
sSiteURL = value; -W oZwqh
} #\"5:.H Oz
mjw:Z,
?>w%Lg{L}
public String getSFilePath() >yaz
{ "{&!fD~w
return sFilePath; ~+1t17
} J4JKAv~3
Y`_6Ny="
p3-sEIw}Ru
public void setSFilePath(String value) :JOF!Q
{ wvgX5P>
sFilePath = value; $}jSIn=~|t
} 0h5T&U]${Y
NTn-4iJy
P!-9cd1C,
public String getSFileName() 9\dC8
{ _[.`QW~
return sFileName; eQNYfWR
} }6o` in>M
%II |;<
=T+<>/[
public void setSFileName(String value) jbG #__#_
{ ~< k'{
sFileName = value; 8J>s|MZ
} .<tb*6rX>
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6.k2,C4dT<
public int getNSplitter() Q!@"Y/
{ =XqmFr;h
return nSplitter; ('>!dXA$
} MN#\P1
DSQ2z3s2
,Z3.Le"
public void setNSplitter(int nCount) "d{ |_Cf
{ b>o38(
nSplitter = nCount; jirxzj
} `M|fwlAJQ
} C`DTPoXN
O8M;q!)y
eE7+fMP{
/* j]jwQRe
**Utility.java 5Zh /D0!|
*/ r% qgLP{v
package NetFox; >y2gfD
%SIbpk%
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public class Utility { oo<,hOv
Bl(we/r
w%`7,du|
public Utility() ?*Jv&f#
{ &,bJ]J)8O
!x&/M*nBE
[X;yJ$
} cE[4CCpy
X62GEqff
//线程睡眠 g }5lGz4
public static void sleep(int nSecond) h19c*,0z!
{ Sl{]Z,
try{ 0<fN<iR`
Thread.sleep(nSecond); qA5tMZ^w
} RtN5\
catch(Exception e) ^ @sg{_.~l
{ =%p0rz|b
e.printStackTrace (); wOn.m
} va| 1N/&
} Hh,q)(Wo
]^E<e!z={$
//日志 g&X$)V4C
public static void log(String sMsg) YGNO]Q~A
{ 4OC^IS
System.err.println(sMsg); jsjH.O
} L_Ff*
e![n$/E3R
vDqmD{%4N
public static void log(int sMsg) TU^UR}=lP
{ eqg|bc[i!t
System.err.println(sMsg); &KT*rL
} ,d$V-~2,
} F0qGkMs|f
r 1nl!
[a`89'"z
/* >6KuZ_
**TestMethod.java 7gNJ}pLDx
*/ Nxp7/Nn3
package NetFox; xZwG@+U=X
o^}K]ML!t
:!n_a*.{
public class TestMethod { 1=}+NK!
9aHV~5
]-&A)M6
public TestMethod() ]oUvC
{ ///xx/weblogic60b2_win.exe r".*l?=
try{ z;J"3kM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }CIH1q3P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JUHmIFjZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); % tTL
fileFetch.start(); Q9Sh2qF^2
} ")}^\Om
catch(Exception e){e.printStackTrace ();} Uf4A9$R.G
>^=upf/
'pa[z5{k+
} ;p)RMRMg
jb|al[p\
EyO=M~nsS
public static void main(String[] args) 5bKM}?=L
{ $SQUN*/>
new TestMethod(); 6j/g/!9c!
} xf% _HMKc
} uB_8P+h7
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