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)); 2j&0U!DX
} M.67[Qj~"u
for(int i=0;i<nEndPos.length-1;i++) wpg7xx!
{ Ot{~mMDp
nEndPos = nStartPos[i+1]; 5><T#0W?
} <DN7
nEndPos[nEndPos.length-1] = nFileLength; _9y!,ST
} 8GeJ%^0o}
} FEdFGT
yRR[M@Y
9v/=o`J#
//启动子线程 'fYF1gR4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #$;}-*
for(int i=0;i<nStartPos.length;i++) ^/I.? :+
{ gh `]OxA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \ #N))gAQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^p~QHS/
nStartPos,nEndPos,i); "(mF5BE-E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p,BoiYdi
fileSplitterFetch.start(); tYp 185
} M<r]a{Yv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gkm{b[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F#^/=AR'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Nw '$r
nEndPos = " + nFileLength); owx0J,,G
// fileSplitterFetch[nPos.length-1].start(); mFmxEv
tL M@o|:
ZgfhNI\
//等待子线程结束 B'I_i$g4w
//int count = 0; (duR1Dz
//是否结束while循环 [Z^26/5a
boolean breakWhile = false; 7Vuf4Z5
~gaWZQXyu
nrR2U`
while(!bStop) 6mqp`x`
{ K >Q6
write_nPos(); OAaLCpRp
Utility.sleep(500); Dq-[b+bm
breakWhile = true; &W3Hj$>
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for(int i=0;i<nStartPos.length;i++) cRE6/qrXGg
{ M)~sL1)
if(!fileSplitterFetch.bDownOver) -O\fy!
{ b&6lu4D
breakWhile = false; R$`%<Y3)
break; xDNXI01o
} R'pfA B|!
} ~~@dbB
if(breakWhile) _WZ{i,
break; k2(k0HFR
h.wffk,
'e_e*.z3
//count++; g_JQW(_
//if(count>4) gvr&7=p
// siteStop(); *'*n}fM
} ~14|y|\/
% s@
B|.A6:1g+
System.err.println("文件下载结束！"); vdigw.=z
} qHvU4v
catch(Exception e){e.printStackTrace ();} V.ETuS;
} Et y?/
Ezev ^O]
G#ELQ/Q
//获得文件长度 _St":9'uU
public long getFileSize() Q5A,9ovNZ
{ G'`^U}9V\
int nFileLength = -1; "gFw:t"VV
try{ uAs!5h
URL url = new URL(siteInfoBean.getSSiteURL()); (b.4&P"0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UCj:]!P
httpConnection.setRequestProperty("User-Agent","NetFox"); _GM?`
> H&v
P 5.@LN
int responseCode=httpConnection.getResponseCode(); OO</d:
if(responseCode>=400) xUNq!({T
{ 5gkQ6&m
processErrorCode(responseCode); /N#=Tol
return -2; //-2 represent access is error Lq2jXy5#n
} `q`ah_
^j@+!A_.Q
'u%vpvF
String sHeader; W.%p{wB|
8llXpe
LG:d
for(int i=1;;i++) 6"NtVfui
{ X(BX+)YR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eeBW~_W
//Utility.log(in.readLine()); gW<4E=fl
sHeader=httpConnection.getHeaderFieldKey(i); RF;[:[*W
if(sHeader!=null) OT(0~,.GJ
{ y}is=h3
if(sHeader.equals("Content-Length")) ~0[(-4MA
{ 0$0 215
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )CHXfO w
break; jT/P+2hMW
} X,Rl&K\b"
} #;5Qd'
else dkY JO!
break; j5og}Pq:
} It<VjN9
} bxzx@sF2l
catch(IOException e){e.printStackTrace ();} e"*1l>g
catch(Exception e){e.printStackTrace ();} $:# :"
w~&#:F?
+XSe;xk;rD
Utility.log(nFileLength); aXzb]">
?!<Q8=
7yXJ\(6R_
return nFileLength; `7'^y
} 2h#.:!/SMw
T1R~^x1
f*ABIm
//保存下载信息（文件指针位置） mU
private void write_nPos() D>;_R HK
{ "shX~zd5
try{ WnOvU<Z <
output = new DataOutputStream(new FileOutputStream(tmpFile)); s5 {B1e
output.writeInt(nStartPos.length); 8B]\;m
for(int i=0;i<nStartPos.length;i++) J"@X>n
{ fmJK+
// output.writeLong(nPos); w^=(:`
output.writeLong(fileSplitterFetch.nStartPos); CU*TY1%
output.writeLong(fileSplitterFetch.nEndPos); t)uxW 7
} kr@!j@j$
output.close(); 3,`M\#z%K
} KhP_U{)D
catch(IOException e){e.printStackTrace ();} U&{w:P
catch(Exception e){e.printStackTrace ();} h_\( $"
} CBNt _y
pQ!lY
Q2)(tB= )
//读取保存的下载信息（文件指针位置） sdiWQv
private void read_nPos() _sZ&=-FR
{ US=K}B=g
try{ )Vrp<"v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ` AD}6O+x
int nCount = input.readInt(); SAj#+_db
nStartPos = new long[nCount]; cNFHbMd
nEndPos = new long[nCount]; xB[W8gQ6fa
for(int i=0;i<nStartPos.length;i++) GmE`YW
{ XA(.O|VZ
nStartPos = input.readLong(); (:o:_U
nEndPos = input.readLong(); b|@zjh;]A7
} "FhC"}N
input.close(); k}I65 ^l#
} H+-x.l`
catch(IOException e){e.printStackTrace ();} GN Ewq$
catch(Exception e){e.printStackTrace ();} F6{/iF
} isdNW l
= Ezg3$%-
xK)<763q>
private void processErrorCode(int nErrorCode) M2RkrW#
{ s;E(51V<>
System.err.println("Error Code : " + nErrorCode); Xit@.:a;
} Nd_A8H,&B
eM5-v-
r[T(R9k
//停止文件下载 _Pa@%/
public void siteStop() tw=A] a*
{ k.2GIc:5
bStop = true; n*' :,m
for(int i=0;i<nStartPos.length;i++) u8<[Q]5
fileSplitterFetch.splitterStop(); 8~yP?#p
&<_q00F
:Ny[?jtc
} LFqY2,#i
} evD=]iVD
//负责部分文件的抓取 !syyOfu`}
**FileSplitterFetch.java H=*0KX{
*/ %Y0BPTt$
package NetFox; avM8-&h
)4-!]NsV
`sIm&.d
import java.io.*; LAM{ ,?~
import java.net.*; `B&=ya|bl
K'e,9P{
u"%D;
public class FileSplitterFetch extends Thread { +5I'? _{V
6v]`s
#Ef!X
String sURL; //File URL qT #=C'?
long nStartPos; //File Snippet Start Position ZXkrFA |
long nEndPos; //File Snippet End Position %Tu(>vnuj
int nThreadID; //Thread's ID !.MbPPNp
boolean bDownOver = false; //Downing is over |pbetA4&
boolean bStop = false; //Stop identical _(~LXk^C
FileAccessI fileAccessI = null; //File Access interface Y2tBFeWY
?u;m ],w!
#@5VT*/7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^c/3!"wK
{ <gGO
this.sURL = sURL; )E7wBNV
this.nStartPos = nStart; L[<Y6u>m!1
this.nEndPos = nEnd; =Ti@Y
nThreadID = id; z_'!?K{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t^>P,%$
} lq]8zm<\)]
rZ5xQ#IA
=8TBkxG
public void run() ;I80<SZ
{ 2A =Y
while(nStartPos < nEndPos && !bStop) X2;72
{ -{J0~1'#-
?~T(Cue>
+4Wl
try{ m8x?`Gw~jw
URL url = new URL(sURL); %K8YZc(&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a5O$he
httpConnection.setRequestProperty("User-Agent","NetFox"); 0H.bRk/P+
String sProperty = "bytes="+nStartPos+"-"; kka{u[ruA
httpConnection.setRequestProperty("RANGE",sProperty); $;}@2U
Utility.log(sProperty); M #0v# {o
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)c1Pj#|
InputStream input = httpConnection.getInputStream(); ,3eN&
//logResponseHead(httpConnection); ]Ol w6W?%
tJQZRZViu
jk_yrbLc
byte[] b = new byte[1024]; [`E_/95
int nRead; [McHl1a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H^`J(J+
{ ])bgUH
nStartPos += fileAccessI.write(b,0,nRead); hVT>HER
//if(nThreadID == 1) $FIJI^Kd7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >Di`zw~
} =jpRv<X|,
0)\(y
;{&4jcV*
Utility.log("Thread " + nThreadID + " is over!"); 1:M'|uc
bDownOver = true; pFiE2V_aS
//nPos = fileAccessI.write (b,0,nRead); bF*Kb"!CF
} xC=$ym]
catch(Exception e){e.printStackTrace ();} i$}G[v<4
} @MFEBc}
} aO?KRn
5T9[a
q o-|.I
//打印回应的头信息 'qo(GGC M
public void logResponseHead(HttpURLConnection con) a #s Nd
{ <;>k[P'
for(int i=1;;i++) $Jn.rX0}$
{ xiQc\k$
String header=con.getHeaderFieldKey(i); "?<`]WG\
if(header!=null) /#"9!8%V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yLnTIE3)
Utility.log(header+" : "+con.getHeaderField(header)); bO6cv{>x
else fpjFO&ML
break; |F'eT 4
} e.(d?/!F_
} ygm6(+
n}1hmAhZ
%iYro8g!,
public void splitterStop() +!`$(
{ Ln+ k_
bStop = true; *!Gb_!98
} ;[g~h |{6
Eg&Q,dH[
4\ )WMP
} MIZ!+[At
[xGL0Z%)t
^ yF Wvfh4
/* RLLL=?W@
**FileAccess.java tpeMq-
*//文件访问(定位，写) {- MhhRa5
package NetFox; @Xh8kvc81
import java.io.*; ,O^kZ}b
z5<&}Vh;P
$gk=~p|
public class FileAccessI implements Serializable{ Aq(,
6"rS?>W/mO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &?y|Pn
RandomAccessFile oSavedFile; |\"%Dy[m
long nPos; i*09m^r
ygQAA!&']
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public FileAccessI() throws IOException eCg|@d%D
{ lD_iIe~c
this("",0); l#w0-n%S
} ogdAJw6 9
*l0i}"T^_
GIR12%-EO
public FileAccessI(String sName,long nPos) throws IOException 1.~^QH\p?3
{ f_hG2Sk
oSavedFile = new RandomAccessFile(sName,"rw"); +_f813$C
this.nPos = nPos; *_Pkb.3R
oSavedFile.seek(nPos); jlUT9Zp
} s <$*A;t
qe0ZM-C_
'=(yh{W
public synchronized int write(byte[] b,int nStart,int nLen) b+CvA(*
{ q^@*k,HG
int n = -1; {w99~?
try{ ,? &$c+
oSavedFile.write(b,nStart,nLen); ,p..h+l
n = nLen; O7,:-5h0
} ?DNeL;6
catch(IOException e) &,]yqG 2
{ [t5Dd
e.printStackTrace (); L>57eF)7
} g^\>hjNX
2Myz[)<P_
i.ivHV~-
return n; Y[;Z7p
} PC!X<C8*
C$v !emu
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} '1\UFz
f{]W*!VV-
GMob&0l8_
/* )f%Q7
**SiteInfoBean.java S8]YS@@D
*/ &v+Hl^
package NetFox; E `%*lGu_
P$`k* v
H.2aoZ-w
public class SiteInfoBean { m W4tW
6~8dMy;w
k~$}&O
private String sSiteURL; //Site's URL M:K4o%
private String sFilePath; //Saved File's Path SR9M:%dga
private String sFileName; //Saved File's Name #)KQ-x,
private int nSplitter; //Count of Splited Downloading File P?iQ{x}w~
-9"[/
(i^<er q
public SiteInfoBean() k,[[ CZ0j
{//nSplitter的缺省值为5 FWyfFCK
//default value of nSplitter is 5 #~qY%X
this("","","",5); 9z?B@;lMc
} I{u+=0^Y
o7:"Sl2AD
~T'$gl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ')E4N+h/
{ 88atj+N]
sSiteURL= sURL; LO,k'gg<
sFilePath = sPath; DEpn>
sFileName = sName; =,W~^<\"
this.nSplitter = nSpiltter; 8';huq@C{
/KCIb:U
H^w Inkf>
} _We4%
6J\A%i
Dt+uf5o(
public String getSSiteURL() IeE6?!,)
{ 5'3H$%dC
return sSiteURL; T4"*w
} x*F_XE1#M
uy=E92n3
1Q??R}
public void setSSiteURL(String value) +0n,>eDjg^
{ d7L|yeb"
sSiteURL = value; ;8<lgZ9H<
} xo(3<1mD
p/&s-GF
d0 yZ9-t
public String getSFilePath() %@[ ~s,6<
{ CLY>M`%?+p
return sFilePath; ]=0$-ImQ@x
} NE!]
uB3Yl=P
@>hXh +!2h
public void setSFilePath(String value) >U[YSsFt6
{ u]QG^1.qYe
sFilePath = value; JztSP?
} T#R*]
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Vb8{OD3PK
public String getSFileName() :.NCS`z_
{ w<=-n;2
return sFileName; se]QEd7]7
} ln=:E$jX
YU%U
L)/^%/!
public void setSFileName(String value) WEugm603
{ ,[ M^rv
sFileName = value; n%:&N
} ;"DI)hdz
eop7=!`-~~
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public int getNSplitter() cP(is!
{ tY$4k26
return nSplitter; }h_= n>
} LDq(WPI1#
nM&UdKf3
,L7:3W
public void setNSplitter(int nCount) *v9 {f?
{ Eg|C
nSplitter = nCount; ZuQ\Pyx
} :l?/]K
} B"fKv0
/kK:{
Hqm1[G)
/* 91j.%#[v'
**Utility.java t_ZWd#x+;
*/ RkXW(T`
package NetFox; [^E{Yz=8,
F6 c1YI[
8&KqrA86
public class Utility { 8n)3'ok
Nc[V kJ]
,O]AB
public Utility() 2*@.hBi
{ ?o6\>[O
RI64QD
1q;r4$n
} l>:\% ol
wZ =*ejo
//线程睡眠 K+J fU J
public static void sleep(int nSecond) G .k\N(l
{ [I7([l1Wvd
try{ #^&.*'z%z
Thread.sleep(nSecond); 66shr
} ,2_!hm/
catch(Exception e) 8ORr
{ 5Dlx]_
e.printStackTrace (); aXO|%qX
} r:uW(<EP^
} Di8;Tq
\mp5G&+/Q
//日志 [xsiSt?6
public static void log(String sMsg) iKN800^u
{ ck4g=QpD{
System.err.println(sMsg); /C)FS?=
} X mX .)h'Y
$y&1.caMa
[E/}-m6g
public static void log(int sMsg) )!(etB=`y
{ AilfeHG
System.err.println(sMsg); $*i"rlJC
} _ 0Ced&i
} bB|P`lL
R~&i8n.
-6u#:pVpU
/* qo"_w%{
**TestMethod.java z("Fy
*/ Um'r6ty
package NetFox; !4l\*L
``4lomz>
xg2 &
public class TestMethod { M,b^W:('4
,HM~Zs
[r5k8TB1
public TestMethod() Jz6,2,LN
{ ///xx/weblogic60b2_win.exe *X4$'LSx1
try{ &k2nt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); znl_~:.4]X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jB-)/8.qk
SiteFileFetch fileFetch = new SiteFileFetch(bean); CD+2 w cy
fileFetch.start(); h8lI#Gs
} v/B:n
catch(Exception e){e.printStackTrace ();} rv?d3QqIC
~NtAr1
qxe%RYdA'j
} 8^Ov.$rP
j,/t<@S>
`F<[\@\d5
public static void main(String[] args) B=`"!?we
{ 9&`ejeD
new TestMethod(); )c$)am\I{
} >av.pJ(>
} ';z5]O~
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