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)); PfD.:amN7
} YQ)kRhFA
for(int i=0;i<nEndPos.length-1;i++) TG?brgW
{ 1 ~*7f>
nEndPos = nStartPos[i+1]; ]BZA:dd.G
} *NaB#;+|k`
nEndPos[nEndPos.length-1] = nFileLength; =tn)}Y.<e
} 0c]/bs{}
} vY}g<*
t?&|8SId
I)6+6pm
//启动子线程 k[YS8g-Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z`}qkbvi
for(int i=0;i<nStartPos.length;i++) *3FKt&v 0
{ S-b/S5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?V.cOR`6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w\u=)3qyVV
nStartPos,nEndPos,i); 8)3*6+D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (9GWbB?
fileSplitterFetch.start(); tBWrL{xLe
} P[ck84F/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *?>T,gx}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {.|CdqwY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I@~QV@U
nEndPos = " + nFileLength); v`x.)S1
// fileSplitterFetch[nPos.length-1].start(); Tc:)- z[o
@4#c&h3
({)+3]x
//等待子线程结束 mb3"U"ohs
//int count = 0; |4zIfAO
//是否结束while循环 cn3\kT*
boolean breakWhile = false; 'n]w"]|
jo@6?( *4
F6|]4H.3Q
while(!bStop) 2tEkj=fA-
{ eA?RK.e
write_nPos(); I)[DTCJ~
Utility.sleep(500); qkY:3Ozw
breakWhile = true; :#ik. D
~P,lz!he_
,HV(l+k {|
for(int i=0;i<nStartPos.length;i++) 0<@KG8@hI;
{ gzT*-
if(!fileSplitterFetch.bDownOver) <w9JRpFY
{ ] vsz, 0
breakWhile = false; &64h ;P<
break; 7"x;~X
} S Lj!v&'
} iByf{I>+
if(breakWhile) pRpBhm;iJ
break; m,w A:o$'
hEH?[>9
9>/4W.
//count++; iC~^)-~H=w
//if(count>4) 9T9!kb
// siteStop(); _Y4` xv0/
} Y=I'czg
A,<E\
iy!=6
System.err.println("文件下载结束！"); P>D)7V9Hh
} Pn1^NUMZJ
catch(Exception e){e.printStackTrace ();} Sy_G,+$\
} 'KL0@l
U_Ptqqt%
"m8^zg hL
//获得文件长度 %OCb:s
public long getFileSize() ~jk|4`I?T
{ tw/dD +
int nFileLength = -1; "|q&ea rc
try{ M"Hf :9Rk
URL url = new URL(siteInfoBean.getSSiteURL()); ZJJY8k `
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "Gzz4D
httpConnection.setRequestProperty("User-Agent","NetFox"); lgy<?LI\
@Uvz8*b6
s^9Voi.y
int responseCode=httpConnection.getResponseCode(); Y\P8v
if(responseCode>=400) #p&qUw
{ 7Q9 w?y~c
processErrorCode(responseCode); "+nRGEs6
return -2; //-2 represent access is error cwlRQzQ(
} 4e7-0}0
Iyn(?w
4E+e}\r:6
String sHeader; bsli0FJSh'
JFmC\
pYEMmZ?L
for(int i=1;;i++) xLajso1g69
{ o:'MpKm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )dw'BNz5hT
//Utility.log(in.readLine()); ec;o\erPG
sHeader=httpConnection.getHeaderFieldKey(i); }R2u@%n{
if(sHeader!=null) J]'zIOQ
{ ^uc=f2=>,
if(sHeader.equals("Content-Length")) {}n^cq
{ iWkWR"ysy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |YWD8 +
break; C.-,^+t;g
} [|$h*YK
} VCkq"f7cw
else Q3~H{)[Kq
break; YkSl^j[DHs
} t{9GVLZ
} \V63qg[
catch(IOException e){e.printStackTrace ();} eo?bL$A[s
catch(Exception e){e.printStackTrace ();} oZgjQM$YP
_jVN&\A]mC
^{`exCwMx
Utility.log(nFileLength); q.bSIV|
="H`V V_
:3Ox~o
return nFileLength; |HQW0
} M|h3Wt~7
!f[_+CD
TIDO@NwF
//保存下载信息（文件指针位置） Wn2NMXK
private void write_nPos() <kqo^
{ hn@08t G
try{ cV6D<,)
output = new DataOutputStream(new FileOutputStream(tmpFile)); ED gag
output.writeInt(nStartPos.length); .`eN8Dl1
for(int i=0;i<nStartPos.length;i++) h[Y1?ln&h
{ K\r8g=U
// output.writeLong(nPos); + &Eqk
output.writeLong(fileSplitterFetch.nStartPos); .L~AL|2_
output.writeLong(fileSplitterFetch.nEndPos); (w3YvG.
} 2/^3WY1U
output.close(); </zEg3F\
} C,r;VyW6BI
catch(IOException e){e.printStackTrace ();} <%eG:n,#
catch(Exception e){e.printStackTrace ();} U8?mc
} (L&d!$,Dv
[z{1*Xc
{!L~@r
//读取保存的下载信息（文件指针位置） Lqa4Vi
private void read_nPos() #;yZ
{ ^yp{32
try{ gwMNYMI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _G@GpkSe>
int nCount = input.readInt(); 8nV+e~-w
nStartPos = new long[nCount]; bY:x8fl
nEndPos = new long[nCount]; XRi8Gpg
for(int i=0;i<nStartPos.length;i++) Q197mN+0
{ _Fl9>C"u
nStartPos = input.readLong(); U[MA)41
nEndPos = input.readLong(); )ez9"# MH'
} 99QU3c<.
input.close(); DTL.Bsc-.
} ~f98#43
catch(IOException e){e.printStackTrace ();} aW7^d'ZZ\
catch(Exception e){e.printStackTrace ();} 8l`*]1.W<
} #*Ctwl,T
4!?eRY
y<Ot)fa$
private void processErrorCode(int nErrorCode) F]&*ow
{ +mn[5Y}:
System.err.println("Error Code : " + nErrorCode); q/,O\,
} X \/#@T
NBGH_6DROw
e\L8oOk#r
//停止文件下载 YOO+R{4(
public void siteStop() ?e 4/p
{ 5\nAeP
bStop = true; 7kEn \
for(int i=0;i<nStartPos.length;i++) \4fQMG
fileSplitterFetch.splitterStop(); .Q2V}D85
b>ySv
z2GY:<s
} =Xr.'(U
} 1yhDrpm
//负责部分文件的抓取 Dlvz)
**FileSplitterFetch.java s$j,9uRr
*/ InI$:kJ
package NetFox; ww1[rCh\+
-iZ`Y?
8":Q)9;%
import java.io.*; =I_'.b
import java.net.*; |A(Iti{v
]Y&VT7+Z
;$g?T~v7
public class FileSplitterFetch extends Thread { @r1_U,0e
5{,<j\#L
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String sURL; //File URL 8quaXVj^a
long nStartPos; //File Snippet Start Position !4+<<(B=E
long nEndPos; //File Snippet End Position 1'Dai`
int nThreadID; //Thread's ID p!%pP}I
boolean bDownOver = false; //Downing is over G3T]`Atf
boolean bStop = false; //Stop identical |[8Th4*n
FileAccessI fileAccessI = null; //File Access interface ~k5W@`"W
JxU5 fe
QMm%@zH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [$UI8tV
{ (TM,V!G+U~
this.sURL = sURL; C0Z=~Q%
this.nStartPos = nStart; v3>UV8c'
this.nEndPos = nEnd; vl)l'
nThreadID = id; OY({.uVdX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e\/w'
} )4;`^]F
+=)+'q]S
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public void run() qH_Dc=~la
{ 1$ {SRU7l
while(nStartPos < nEndPos && !bStop) u*9V&>o
{ a 1*p*dM#
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"0TZTa1e
try{ !;'=iNOYR
URL url = new URL(sURL); uyx 2;f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u ^RxD^=L
httpConnection.setRequestProperty("User-Agent","NetFox"); <1!O1ab
String sProperty = "bytes="+nStartPos+"-"; >yDZw!C
httpConnection.setRequestProperty("RANGE",sProperty); TA~{1_l
Utility.log(sProperty); `Q,H|hp;k;
*VN6cSq
a8Wwq?@
InputStream input = httpConnection.getInputStream(); aw>#P
//logResponseHead(httpConnection); }Y4qS
8q7b_Pq1U
HxI" 8A
byte[] b = new byte[1024]; c:.eGH_f
int nRead; &%Tj/Qx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `M6)f?|$.
{ cB&:z)i4
nStartPos += fileAccessI.write(b,0,nRead); zbPqYhJzA
//if(nThreadID == 1) RD&PDXT4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z3!`J&
} apxph2yvS
u]@['7
`r_/Wt{g
Utility.log("Thread " + nThreadID + " is over!"); )!T/3|C
bDownOver = true; Xn ;AZu^'R
//nPos = fileAccessI.write (b,0,nRead); >(RkZ}z
} jc9y<{~x/
catch(Exception e){e.printStackTrace ();} +ck}l2&#
} .N(p=9
} bZV/l4TU
Y<8vw d
/a o5FL
//打印回应的头信息 U/BR*Zn]*
public void logResponseHead(HttpURLConnection con) :M5l*sIO2
{ zx7{U8*`<
for(int i=1;;i++) Y <qm{e
{ 9_s`{(0?
String header=con.getHeaderFieldKey(i); ?bu>r=oIO]
if(header!=null) F6dP,(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L/^I*p,
Utility.log(header+" : "+con.getHeaderField(header)); HpnWoDM
else 8~gLqh8^V
break; "zy7C*)>r
} fikkY=
} cN9t{.m
`9.r`&T6K
H>@+om
public void splitterStop() t |oR7qa{w
{ CJI~_3+K
bStop = true; ;9g2?-svw
} OZ!^ak
cCc(fF*^
)\^-2[;
} $,'*f?d
5/z/>D;
~e.L.,4QZ8
/* gPc=2
**FileAccess.java t&DEb_"De
*//文件访问(定位，写) Ti&z1_u
package NetFox; 8HdAFRw
import java.io.*; `@|$,2[C
^sg,\zD 'X
~y[7K{{ ;T
public class FileAccessI implements Serializable{ 6S\8$
{FTqu.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @xZR9Z8]L
RandomAccessFile oSavedFile; WOf 4o
long nPos; 4v|W-h"K
u>/ TE
61 ~upQaR
public FileAccessI() throws IOException t&Og$@
{ BL58] P84
this("",0); L4?IHNB
} 4nz35BLr
C2)2)
YT8F#t8
public FileAccessI(String sName,long nPos) throws IOException c6/=Gq{.
{ sUm'
oSavedFile = new RandomAccessFile(sName,"rw"); W+1^4::+
this.nPos = nPos; B,fo(kG
oSavedFile.seek(nPos); FU<Jp3<%
} XBw)H
f:P}*^ Gw
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public synchronized int write(byte[] b,int nStart,int nLen) %;"y+YFdv
{ FNId;
int n = -1; r/*D:x|yN
try{ wn)W ?P;k
oSavedFile.write(b,nStart,nLen); pcI uN
n = nLen; PE5G
} {cw /!B
catch(IOException e) k.15CA`
{ maR"t+
e.printStackTrace (); y L~W.H
} d8x;~RA
?@ $r
e64^ChCoV
return n; Lq!>kT<]!
} ;P&OX5~V
N$:8,9.z
w"&n?L
} 1ZB"EQ
FN) $0
$]2vvr
/* !_Z&a
**SiteInfoBean.java R_S.tT!
*/ ?#Q #u|~
package NetFox; lCHO;7YHX
2T[9f;jM'
$a ` G
public class SiteInfoBean { <yg F(
&XUiKnNW
tIS<U(N;
private String sSiteURL; //Site's URL QnX(V[
private String sFilePath; //Saved File's Path L\z~uo3:
private String sFileName; //Saved File's Name K)k<Rh[<
private int nSplitter; //Count of Splited Downloading File VTHH&$ZNq
s=/v';5J2!
n>U5R_T
public SiteInfoBean() 2jCfT>`3
{//nSplitter的缺省值为5 KdbHyg<4
//default value of nSplitter is 5 t#eTV@-
this("","","",5); 6Sn.I1Wy
} r0 uwPf
NSA-}2$
Tc3yS(aq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^\,E&=/}M
{ K@w{"7}
sSiteURL= sURL; 0NX,QD
sFilePath = sPath; 4tmAzD
sFileName = sName; l0i^uMS
this.nSplitter = nSpiltter; delu1r
g5r(>,vY
! #2{hQRu
} xWQ`tWA:J
.y:U&Rw4
c<$OA=n
public String getSSiteURL() w_u\sSQ`!
{ w$-6-rE]d
return sSiteURL; >Wg hn:^
} ls)%c
{h`uV/5@`
>`ZyG5
public void setSSiteURL(String value) Jo23P.#<
{ 1|-Dj|
sSiteURL = value; \=0Vi6!Mc
} x{WD;$J
"wh ,Ue
q;)JISf.
public String getSFilePath() 0v$~90)
{ K0Fh%Y4)QH
return sFilePath; s.NGA.]$
} yY&I dE
#$qTFN
\6*I'|5d
public void setSFilePath(String value) hTi$.y!k
{ Ck7uJI<x
sFilePath = value; pBA7,z"`mP
} ~Vjl7G\7i
001FmiV
5(HG|
public String getSFileName() x{/g(r={}
{ `$aZ0+
return sFileName; WbqWG^W
} Czu\RXJR
8StgsM
O#S.n#{
public void setSFileName(String value) P1' al
{ Otm0(+YB7
sFileName = value; e(=w(;84
} [Nbm|["q~
scLll,~
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public int getNSplitter() c.F6~IHu7
{ j^rIH#V
return nSplitter; s(q_ o
} $43qME
j9+w#G]hV
161xAig
public void setNSplitter(int nCount) >]5P 3\AQV
{ W#WVfr
nSplitter = nCount; Whf.fK
} _X"N1,0
} **gXvTqI
o"R7,N0rB
WWHoi{q
/* ?R.j^S^
**Utility.java @A^;jk
*/ qVwIo.g!
package NetFox; =xx]@
'qX|jtdM
..'_o~Ka
public class Utility { /,Re"!jh
z]D69O b
FZE"7ec>m
public Utility() Bad:no\W
{ O~K>4ax
tc{sB\&-
!6Mo]xh
} O2dW6bt
ptxbDzOz
//线程睡眠 JKGe"
public static void sleep(int nSecond) Jd^,]
{ GKc`xIQ
try{ gz#i.-
Thread.sleep(nSecond); q2:6QM&
} h Pa_VrH
catch(Exception e) I->Ss},U
{ qfRH5)k
e.printStackTrace (); !lc[
} +<3XJ7D
} j@uOOhy
e@* EzvO
//日志 ?\s+EE&-
public static void log(String sMsg) K':;%~I
{ o@i#|kx,
System.err.println(sMsg); 6 EC*
} l(tOe
;8{4!S&b
C-6F]2:
public static void log(int sMsg) 1rF]yi:X
{ !*bMa8]*
System.err.println(sMsg); 3H6lBF
} ~=RT*>G_
} s %\-E9 T
y0.8A-2:
0+;bh {Eu
/* 8=uu8-l8g
**TestMethod.java x$Oq0d{T
*/ 3e;^/kf<9
package NetFox; ]B3=lc"
OGg>#vj,s
3L}!RB
public class TestMethod { `q*M4,
k=JrLfD4
T1Z;r*}
public TestMethod() eMY<uqdw
{ ///xx/weblogic60b2_win.exe ah0`KxO]
try{ # ,_u_'C*!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,-d0b0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /-+xQn]
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]cZ!y ~
fileFetch.start(); cir$voL
} 5aZ2j26
catch(Exception e){e.printStackTrace ();} Xi,CV[L\
^c4@(]v'G
X4Ic;
} *><F'
?+W9az]+
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public static void main(String[] args) y8!4q
{ p,>5\Zre~
new TestMethod(); mmEYup(l0;
} O%!!w
} a>]uU*Xm
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