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)); ,I9bNO,%JK
} BWNi [^]
for(int i=0;i<nEndPos.length-1;i++) lFkR=!?=
{ 7,MR*TO,
nEndPos = nStartPos[i+1]; s*4dxnS_8
} \^LFkp
nEndPos[nEndPos.length-1] = nFileLength; <$YlH@;)`a
} vIvIfE
} "N;EL0=
=*Lfl'sr_
*hrvYil2b
//启动子线程 teP<!RKNb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t7pFW^&
for(int i=0;i<nStartPos.length;i++) jo7\`#(Q
{ t:S+%u U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LP-o8c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =AT."$r>
nStartPos,nEndPos,i); So6x"1B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IgzQr>
fileSplitterFetch.start(); 3R/bz0 V>
} Zfw,7am/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Ly6`HZ9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5(2;|I,T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F{wzB
nEndPos = " + nFileLength); y} '@R$
// fileSplitterFetch[nPos.length-1].start(); l}h!B_P'
DDZ@$L!
0]L"H<W
//等待子线程结束 m'U0'}Ld};
//int count = 0; N+|d3X!
//是否结束while循环 m~|40)
boolean breakWhile = false; ;"I^ZFYX
54,er$$V
?0.NIu,,o
while(!bStop) ^OdP4m( >>
{ =wJX0A|
write_nPos(); K"6vXv4QO
Utility.sleep(500); iscz}E,Y
breakWhile = true; `V1]k_h
sA~]$A;DM!
mq l Z?-
for(int i=0;i<nStartPos.length;i++) Ef\-VKh
{ hPh-+Hb
if(!fileSplitterFetch.bDownOver) s~>}a
{ r%_djUd
breakWhile = false; U:`Kss`
break; =I<R!ZSN
} aXVFc5C\
} Qrv<lE1V;
if(breakWhile) t1".0
break; baasGa3}s
kstIgcI
b>|6t~}M
//count++; W^Yxny
//if(count>4) l} /F*
// siteStop(); hxx.9x>ow
} K9[UB
H}!r|nG
' QG?nu
System.err.println("文件下载结束！"); 7pd$\$
} txpgO1
catch(Exception e){e.printStackTrace ();} K'bP@y_cq
} Z;i:](
Dv"9qk
;gkM{={`p
//获得文件长度 ZNoDFf*h
public long getFileSize() 'F<TSy|4kI
{ QZs!{sZ
int nFileLength = -1; 4Ig;3 ^%71
try{ 7/H)Az@i45
URL url = new URL(siteInfoBean.getSSiteURL()); :h$$J lP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _w{Qtj~s|
httpConnection.setRequestProperty("User-Agent","NetFox"); !VJoM,b8
Wzh`or
1x)J[fyId
int responseCode=httpConnection.getResponseCode(); .8R@2c`}Cs
if(responseCode>=400) D-c4EV
{ PsYpxNr
processErrorCode(responseCode); 9p/Bh$vJ
return -2; //-2 represent access is error 2iOV/=+
} Z r8*et
3mgD(,(^
>%G1"d?j
String sHeader; H)?z #x
h\o.&6sd
j^'go&p
for(int i=1;;i++) 8Wx=p#_
{ %;_MGae
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); UpG~[u)%@
//Utility.log(in.readLine()); :]KAkhFkbb
sHeader=httpConnection.getHeaderFieldKey(i); L#J1b!D&<6
if(sHeader!=null) fl(wV.Je|
{ \Z/@C lCm
if(sHeader.equals("Content-Length")) s#11FfF`
{ o4X{L`m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wc#24:OKe3
break; +2{Lh7Ks
} JI}'dU>*U:
} 3$ pX
else u[YGm:}
break; L_T5nD^D
} )2.Si#
} UfGkTwoo=
catch(IOException e){e.printStackTrace ();} 29KiuP
catch(Exception e){e.printStackTrace ();} wj,=$RX
+whDU2 "
q1,~
Utility.log(nFileLength); <YY14p
#a6iuO0I
$mILoy B,
return nFileLength; !zo{tI19
} ! mHO$bQ"
CrLrw T
3S{/>1Y
//保存下载信息（文件指针位置） GJrG~T
private void write_nPos() C_Dn{
{ ;+%rw2Z,B
try{ r&CiSMS*
output = new DataOutputStream(new FileOutputStream(tmpFile)); t0S1QC+
output.writeInt(nStartPos.length); Cye.gsCT
for(int i=0;i<nStartPos.length;i++) z_HdISy0
{ /xhKd]Q
// output.writeLong(nPos); d6O[ @CyP
output.writeLong(fileSplitterFetch.nStartPos); L,\Iasv
output.writeLong(fileSplitterFetch.nEndPos); \hXDO_U
} KoT\pY^7\
output.close(); {FkF
} ^W^OfY
catch(IOException e){e.printStackTrace ();} @dKTx#gZ
catch(Exception e){e.printStackTrace ();} 7I}uZ/N
} Y]>t[Lo%
hb$Ce'}N
7dWS
//读取保存的下载信息（文件指针位置） ,bi^P>X
private void read_nPos() P0@,fd<
{ TbU#96"~.
try{ 4 KiY6)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (=0.inZ
int nCount = input.readInt(); ~$'awY
nStartPos = new long[nCount]; By|4m
nEndPos = new long[nCount]; .Mbz3;i0
for(int i=0;i<nStartPos.length;i++) ]gOy(\B
{ COlqcq'qAu
nStartPos = input.readLong(); *@5@,=d
nEndPos = input.readLong(); 9;{CIMg&
} <I?Zk80
input.close(); -RwE%cr
} fC`&g~yK'
catch(IOException e){e.printStackTrace ();} c{|p.hd
catch(Exception e){e.printStackTrace ();} $FVNCFN%
} ]^E?;1$f?
la!~\wpa
_>+Ld6.T6
private void processErrorCode(int nErrorCode) lxx2H1([
{ RZLq]8pM
System.err.println("Error Code : " + nErrorCode); 3fj4%P"
} MtdG>TzUn
^q5#ihM
?s01@f#
//停止文件下载 Hl"N}
public void siteStop() #mdc[.
{ u9e@a9c
bStop = true; K+eM
for(int i=0;i<nStartPos.length;i++) x5Bk/e'
fileSplitterFetch.splitterStop(); SUiOJ[5,
>:-$+I
oJ^P(]dw
} X?O[r3<
} oA 1yIp
//负责部分文件的抓取 y[;>#j$
**FileSplitterFetch.java l?e.9o2-
*/ WWY6ha
package NetFox; r!v\"6:OM
D.:Zx
4hB]vY\T
import java.io.*; j2k"cmsKh
import java.net.*; y29m/i:
IGl9g_18
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public class FileSplitterFetch extends Thread { @ArSC
Jy)/%p~
O.? JmE
String sURL; //File URL F9PxSk_\9
long nStartPos; //File Snippet Start Position V~GDPJ+
long nEndPos; //File Snippet End Position /~1+i'7V.,
int nThreadID; //Thread's ID llq<egZpm
boolean bDownOver = false; //Downing is over dysS9a,
boolean bStop = false; //Stop identical "oyo#-5z
FileAccessI fileAccessI = null; //File Access interface &ZO0r ^
_a, s )
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OUnA;_
{ pa+hL,w{6
this.sURL = sURL; :OT&
this.nStartPos = nStart; M\j.8jG
this.nEndPos = nEnd; E.h*g8bXe
nThreadID = id; 0GwR~Z}Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 43cE`9~
} ).O)p9
KNl$3nX
0GLM(JmK
public void run() "]*tLL:`
{ 0-gAyiKx?
while(nStartPos < nEndPos && !bStop) @7}W=HB
{ >P(.:_^p
Xw1*(ffk
*~`(RV
try{ h[ ZN+M
URL url = new URL(sURL); i8p6Xht
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jXJyc'm7
httpConnection.setRequestProperty("User-Agent","NetFox"); !WlH'y-I
String sProperty = "bytes="+nStartPos+"-"; WH\d| 1)
httpConnection.setRequestProperty("RANGE",sProperty); kZ~~/?B
Utility.log(sProperty); 9r9NxKuAO
9c],<;{'
637: oT_`O
InputStream input = httpConnection.getInputStream(); ceA9){
//logResponseHead(httpConnection); }V>T M{
U$g?!Yl0
crCJrN=
byte[] b = new byte[1024]; \8tsDG(1 '
int nRead; H,J8M{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l;U?Z'n
{ tPvpJX6kP
nStartPos += fileAccessI.write(b,0,nRead); "@kaHIf[
//if(nThreadID == 1) f$( e\++
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3`HV(5U[
} gw(z1L5 n
K3C<{#r
kfNWI#'9
Utility.log("Thread " + nThreadID + " is over!"); f1? >h\F8
bDownOver = true; WIOV2+
//nPos = fileAccessI.write (b,0,nRead); ICCc./l|
} M5B# TAybC
catch(Exception e){e.printStackTrace ();} KoYF]
} pAEx#ck
} ~[: 2I
t^HRgY'NjM
s2?&!
//打印回应的头信息 L];b<*d
public void logResponseHead(HttpURLConnection con) Ac6=(B
{ |ZBw<f
for(int i=1;;i++) *:1ey{w:
{ y(Td/rY.
String header=con.getHeaderFieldKey(i); 9uY'E'm*
if(header!=null) <3iMRe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 13PS2
Utility.log(header+" : "+con.getHeaderField(header)); k9R9Nz|J
else a.'*G6~Qgw
break; ^.tg7%dJ
} GILfbNcd
} qR.Q,(b|
N!32 wJ
^8tEach
public void splitterStop() C~[,z.FvO
{ lr?;*f^3
bStop = true; SuznN L=/$
} Cw%{G'O
c,22*.V/
zi:BF60]=
} ax2B ]L2
]Dzlp7Y}
=sFTxd_"iQ
/* mmsPLv6
**FileAccess.java wBzC5T%,
*//文件访问(定位，写) ]9L oZ)
package NetFox; fVwUe _Y
import java.io.*; f::Dx1VcX
'yth'[
j|n R"!
public class FileAccessI implements Serializable{ OSJ$d
U.TA^S]`g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Al'3?
RandomAccessFile oSavedFile; ZuIefMiG~+
long nPos; uEYtE7
\9d$@V
u>$t'
public FileAccessI() throws IOException X8|EHb<
{ xPgBV~
this("",0); "L1Zi.)
} d3Rw!slIq
':W[A
HDKbF/
public FileAccessI(String sName,long nPos) throws IOException tDo"K3
{ fnY.ao1-s[
oSavedFile = new RandomAccessFile(sName,"rw"); +#By*;BJ
this.nPos = nPos; 8Y3I0S
oSavedFile.seek(nPos); y]imZ4{/
} SaCh 7 ^
:EH=_"
/bEAK-
public synchronized int write(byte[] b,int nStart,int nLen) G:JR7N$
{ k8Xm n6X
int n = -1; 1cGmg1U;
try{ :LTN!jj
oSavedFile.write(b,nStart,nLen); nm+s{
n = nLen; 9cgUT@a
} zJXplvaL;
catch(IOException e) C>~TI,5a3
{ />Nt[o[r
e.printStackTrace (); s(^mZ -i
} R4@6G&2d>
KgG4*<
':}\4j&{E
return n; 2Hdu:"j
} ]d`VT)~vje
!+njS
DJ%PWlK5
} |'.
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kl,3IKHa
/* s7EinI{^
**SiteInfoBean.java L(o15
*/ e*!kZAf
package NetFox; V,9cl,z+
3[&Cg
.G^YqJ 4
public class SiteInfoBean { h1{3njdr
~v83pu1!2s
kR9-8I{J
private String sSiteURL; //Site's URL 0Qd:`HF[
private String sFilePath; //Saved File's Path Jl<2>@
private String sFileName; //Saved File's Name lLD12d
private int nSplitter; //Count of Splited Downloading File Z= !*e~j@
875od
V$~9]*Wn
public SiteInfoBean() 3~\[7I/
{//nSplitter的缺省值为5 d\Zng!Z'
//default value of nSplitter is 5 &0f,~ /%Z
this("","","",5); dTtSUA|V7"
} 2JFpZU"1
2-b6gc7
&OBkevg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MW{8VH6+
{ T>GM%^h,7-
sSiteURL= sURL; XUw/2"D'?
sFilePath = sPath; 4OX^(
sFileName = sName; _ J[
this.nSplitter = nSpiltter; #[a*rD%m
fzA9'i`
{iLT/i%
} s{" 2L{,$
VD:/PL
X7wKy(g
public String getSSiteURL() O~QB!<Q+
{ `XB 9Mi=
return sSiteURL; 05k0n E
} $A`VYJtt#
fX+O[j
0^ibNiSP
public void setSSiteURL(String value) '\GbmD^F
{ v}x&?fU `
sSiteURL = value; G9:l'\
} Z)\@i=m
K@#L)VT!
d/Q%IeEL.
public String getSFilePath() )ANmIwmC#
{ [9 RR8
return sFilePath; EZj9wd"u
} N?>vd*
`@ FYkH
jSAjcLR
public void setSFilePath(String value) 0LKRN|@
{ s0_nLbWwO
sFilePath = value; aATA9V
} 9E tz[`|
e]tDy0@
h@h!,;
public String getSFileName() `p7=t)5k
{ V!dtF,tH
return sFileName; 5Dl/aHb
} CA#,THty
u4_9)P`]0
WT}H>T
public void setSFileName(String value) H4JTGt1"
{ l (%1jC8
sFileName = value; (M ~e?s
} ,1##p77.
N"1B/u
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public int getNSplitter() #u + v_
{ _,d~}_$`i
return nSplitter; @fV9 S"TcM
} 69 o7EA
.}`Ix'.
lA-h`rl/
public void setNSplitter(int nCount) xjUtl
{ N&V`K0FU
nSplitter = nCount; g>9kXP+
} d'I"jZ
} w'3iY,_ufC
-Vhw^T1iV
&=k,?TJO>
/* =kqt
**Utility.java :Lug7bUVD
*/ JSg$wi8
package NetFox; Y)a^(!<H<
evJ.<{M
8h4'(yGQQW
public class Utility { Yir [!{
0{[,E.
C{bgkzr
public Utility() BV+ Bk+
{ S/I/-Bp~
(2 a`XwR
.-X8J t
} .y,0[i V N
~| 6[j<ziL
//线程睡眠 K}U-w:{
public static void sleep(int nSecond) WSY}d Vr
{ Zoc0!84<z
try{ EUgs6[w 4
Thread.sleep(nSecond); zZC9\V}R
} V,?yPi$#E
catch(Exception e) .K<Q&
{ ED& `_h7?
e.printStackTrace (); /Qk4
} kn"(A.R
} mo#04;VF
gOOPe5+ J
//日志 Vl!6W@g
public static void log(String sMsg) (NnH:J`
{ t>B;w14
System.err.println(sMsg); <kd1Nrr!p
} SG4%}wn%
BIWWMg
[\b0Lem
public static void log(int sMsg) 8&Y^""#e)
{ M+9gL3W
System.err.println(sMsg); #`X?=/q
} )Iq<+IJ
} :Qf '2.h)
f.`*Qg L
78%~N`x7
/* <nK?LcP
**TestMethod.java mcX/GO}
*/ 9lDhIqx0~
package NetFox; J{&H+rd
r_;Nt
=6|&Jt
public class TestMethod { A7hVHxNJ-
g!z&~Z:
1q1jZqno
public TestMethod() klR|6u]%
{ ///xx/weblogic60b2_win.exe fLm*1S|%\
try{ |WdPE@P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3J438M.ka
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yD6[\'%
SiteFileFetch fileFetch = new SiteFileFetch(bean); gy9U2Wgf|
fileFetch.start(); _1L![-ac
} }:*]aL<7_
catch(Exception e){e.printStackTrace ();} x*&|0n.D
#3 pb(fbw
B|AV$N*
} RTJ3qhY
fCobzDy
eSmLf*\G
public static void main(String[] args) fGw9!
{ R= o2K
new TestMethod(); 1"M]3Kl
} %(G* ,
} v(D;PS3r 7
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