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)); j]R[;8g
} Q^05n$ tI
for(int i=0;i<nEndPos.length-1;i++) BYa#<jXtAT
{ a+~b3
nEndPos = nStartPos[i+1]; $o$WFV+h
} /<k5"C%z
nEndPos[nEndPos.length-1] = nFileLength; %Kp^wf#o9
} B J IN
} 7#9%,6Yi
$T7 qd
Nvh&=%{g
//启动子线程 15' fU!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z6Kp-z(l3
for(int i=0;i<nStartPos.length;i++) >*!^pbZfX
{ mU]^PC2[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }ALli0n`V)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =iDd{$
nStartPos,nEndPos,i); Bx$?*y&f!v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UM]3MS:[
fileSplitterFetch.start(); TGPZUyi3!=
} mV4gw'.;7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P7/Xh3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T:|p[Xbo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E:PPb9Kd
nEndPos = " + nFileLength); OP-{76vE&b
// fileSplitterFetch[nPos.length-1].start(); \6"=`H0}
+bJ~S:[
#,XZ@u+
//等待子线程结束 a{rUk%x
//int count = 0; J}#2Wy^{
//是否结束while循环 W5:fY>7
boolean breakWhile = false; ,7k1n{C)
}?c%L8\
=]pEvj9o
while(!bStop) ZZCm438
{ R1<$VR
write_nPos(); ^~@3X[No
Utility.sleep(500); ;<GxonIV
breakWhile = true; h5-yhG
YmjA!n
Eelv i5
for(int i=0;i<nStartPos.length;i++) @>J(1{m=Gy
{ RQ^ \|+_
if(!fileSplitterFetch.bDownOver) W@'*G*f
{ b^ [ z'
breakWhile = false; mh SknyqT
break; 1~LfR
} \n^[!e"`
} pFwJ:
if(breakWhile) u!F\`Gfm_
break; KHJ wCv
C=cn.CX
]?oJxW.
//count++; pQC|_T#u
//if(count>4) s| Q1;%Tj
// siteStop(); *n[BBz
} 7^LCP*
<X1lq9 lW
_p'@.P
System.err.println("文件下载结束！"); -"H0Qafm
} 19!;0fe=
catch(Exception e){e.printStackTrace ();} X(3| (1;sV
} Y> }\'$\b
zn_#}}e;G
7-~)/7L
//获得文件长度 ~%f$}{
public long getFileSize() 8Djki]
{ DQ[7p(
int nFileLength = -1; d&f!\n_~
try{ 3?L[ohKH?:
URL url = new URL(siteInfoBean.getSSiteURL()); -!li,&,A1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >+Iph2]
httpConnection.setRequestProperty("User-Agent","NetFox"); nLv~)IQ}:
Fpeokr"i
cx&\oP
int responseCode=httpConnection.getResponseCode(); n4}e!
if(responseCode>=400) twbxi{8e.
{ 8ZM#.yBB
processErrorCode(responseCode); HJ0;BD.]
return -2; //-2 represent access is error !y'>sAf
} o90g;Vog
v&WK9F\
9PV+Kr!c5I
String sHeader; *p#@W-:9E
[^6z>
EN":}!E:
for(int i=1;;i++) g;nLR<]
{ y;<suGl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #<Xq\yC51
//Utility.log(in.readLine()); [m6+I9
sHeader=httpConnection.getHeaderFieldKey(i); ,R3TFVV!?
if(sHeader!=null) m.! M#x2!
{ t,*1=S5
if(sHeader.equals("Content-Length")) 5;XYF0
{ UwF-*(#41
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .QwB7+V4
break; kS9;Tjcx
} Fu5Y<*x
} T]zD+/=
else mU?~s7
break; uozq^sy
} 7DoU7I\u
} |0}7/^
catch(IOException e){e.printStackTrace ();} WVOj;c
catch(Exception e){e.printStackTrace ();} %iEdUV\$
]7yxXg
3(,m(+J[S
Utility.log(nFileLength); y,ub*-:
k`|E&+og
'<uM\v^k
return nFileLength; S4{vS?>j
} !J X7y%J
M"/Jn[
jX(${j<
//保存下载信息（文件指针位置） \)wch P_0
private void write_nPos() Vwh;QJxb
{ #W3H;'~/5
try{ _od /)#
output = new DataOutputStream(new FileOutputStream(tmpFile)); _;Xlw{FN^
output.writeInt(nStartPos.length); )z18:C3
for(int i=0;i<nStartPos.length;i++) u~Po5W/i
{ gW--[
// output.writeLong(nPos); a7F_{Mm
output.writeLong(fileSplitterFetch.nStartPos); $;Iz7:#jN
output.writeLong(fileSplitterFetch.nEndPos); H.'9]*
} C7*YZe
output.close(); ?E|=eO"I1
} !X~NL+
catch(IOException e){e.printStackTrace ();} K@g ~
catch(Exception e){e.printStackTrace ();} ?*+U[*M
} 5p S$rf
pUF JQ*
8sc2r
//读取保存的下载信息（文件指针位置） YGLq~A
private void read_nPos() v~T)g"_|
{ i$@xb_
try{ D6&P9e_5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jl(D;JnF
int nCount = input.readInt(); Tj_K5uccU}
nStartPos = new long[nCount]; UXdc'i g
nEndPos = new long[nCount]; GIcq|Pe
for(int i=0;i<nStartPos.length;i++) zuW4gJ
{ HR8YPU5
nStartPos = input.readLong(); X';qcn_^
nEndPos = input.readLong(); V6HZvuXV!
} jQ%1lQ#R)
input.close(); Mog [,{w
} C,W_0=!e
catch(IOException e){e.printStackTrace ();} U]vUa^nG
catch(Exception e){e.printStackTrace ();} .PVYYhrt
} M:%g)FgW
:/szA?:W
f'(F'TE
private void processErrorCode(int nErrorCode) 3'`&D/n
{ "#7Q}d!x
System.err.println("Error Code : " + nErrorCode); <3@nv%
} !-470J
F1-"yX1B
eLORG(;h4
//停止文件下载 7=}tJ
public void siteStop() xZ;eV76
{ <Z3C&BM
bStop = true; ^\Q,ACkZb
for(int i=0;i<nStartPos.length;i++) D})/2O p
fileSplitterFetch.splitterStop(); 'l~7u({u
Ot`%5<E^
fx(8 o+
} #<9'{i3
} % R25, V
//负责部分文件的抓取 d$bO.t5CLh
**FileSplitterFetch.java P![ZO6`:W'
*/ { >[ ]iX
package NetFox; V61oK
/4pYhJ8S
lqL5V"2Y
import java.io.*; t`|Rn9-
import java.net.*; @YH>|{S&
4_j_!QH87
[#Gu?L_W
public class FileSplitterFetch extends Thread { @#t<!-8d
qg`ae
Zn r4^i&(
String sURL; //File URL $poIWJMc
long nStartPos; //File Snippet Start Position gAsmPI.K
long nEndPos; //File Snippet End Position Qu=b-9
int nThreadID; //Thread's ID F)Q[ cai
boolean bDownOver = false; //Downing is over [|eIax xR,
boolean bStop = false; //Stop identical XdV>6<gf{
FileAccessI fileAccessI = null; //File Access interface !wpK +.D
mkyYs[
lV^:2I/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ejkUNCKQt
{ h;+O96V4.
this.sURL = sURL; *f;$5B#^
this.nStartPos = nStart; dO1m
this.nEndPos = nEnd; u;rmqo1
nThreadID = id; RS}_cm0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HP[B%
} wk8fa
zNKB'hsK
H.{Fw j4
public void run() Ayqs~&{
{ 4C_1wk('
while(nStartPos < nEndPos && !bStop) 5!Y\STn
{ Wc+(xk
:KX*j$5U
&(,&mE
try{ O]hUOc`k
URL url = new URL(sURL); ,z#D[5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C}xfo}i
httpConnection.setRequestProperty("User-Agent","NetFox"); KP0(w(q
String sProperty = "bytes="+nStartPos+"-"; ~b)X:ku
httpConnection.setRequestProperty("RANGE",sProperty); >m1b/J3#
Utility.log(sProperty); "A~dt5GJ
FO_}9<s
z5iCQ4C<
InputStream input = httpConnection.getInputStream(); lN5PKsGl
//logResponseHead(httpConnection); leNX5 sX
0Q7<;'m
}[PwA[k'
byte[] b = new byte[1024]; [3-u7Fx!
int nRead; .Er+*j;&w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1/:vFX
{ DKMkCPX%
nStartPos += fileAccessI.write(b,0,nRead); P8dMfD*"E
//if(nThreadID == 1) s,[I_IiPf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -nC&t~sD
} LA\3 ,Uv
7lwI]/ZH*
ti9e(Jt!O
Utility.log("Thread " + nThreadID + " is over!"); bIBF2m4
bDownOver = true; iH-,l
//nPos = fileAccessI.write (b,0,nRead); 2RNee@!JJP
} p2b~k[
catch(Exception e){e.printStackTrace ();} <#M1I!R
} Y&=DjKoVh
} a9NuYYr,h
<BBzv-?D
+0ukLc@
//打印回应的头信息 .{8[o[w =
public void logResponseHead(HttpURLConnection con) iCiKr aW
{ |#cqxr"
for(int i=1;;i++) iY@}Q "
{ MH'%E^n `
String header=con.getHeaderFieldKey(i); <eSg%6z
if(header!=null) =*ErN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LNk :PD0m
Utility.log(header+" : "+con.getHeaderField(header)); RXAE jzf
else Z*q&^/N
break; @]~.-(IMh
} ;rL1[qwk
} dT7fyn
wVf 7<@/y
mk~CE
public void splitterStop() MhE".ZRd
{ 7oIHp_Zq
bStop = true; "u~` ZV(
} H*<E5^#dw
ke W7pN?
r>bgCQ#-n
} O!dS;p-F
}+/Vk
xh#_K@8
/* LHZsmUM(dg
**FileAccess.java /O.q4p
*//文件访问(定位，写) R{A$|Ipaq
package NetFox; JleClB(2n/
import java.io.*; _IU5HT}2
6j{ynt
Y}.f&rLe
public class FileAccessI implements Serializable{ 4j'rbbs/
ShV_8F z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lhg
RandomAccessFile oSavedFile; f&5S`}C
long nPos; I'{Ctc
(HeSL),1
Pr%KcR ;
public FileAccessI() throws IOException E,?IIRg&
{ zpf<!x^
this("",0); Wy6a4oY
} 4`oKvL9
=(TMcu$4`
ckP AH E@
public FileAccessI(String sName,long nPos) throws IOException @Q ~;@M
{ yG~Vvpv
oSavedFile = new RandomAccessFile(sName,"rw"); X[<#B5
this.nPos = nPos; J#@+1 Nt
oSavedFile.seek(nPos); e&ZTRgYdi
} a[zVC)N0
525^/d6v
N|)e {|k
public synchronized int write(byte[] b,int nStart,int nLen) N&k\X]U
{ n'pJl
int n = -1; ON!Fk:-
try{ @ kv~2m
oSavedFile.write(b,nStart,nLen); 0;`FS/[(f
n = nLen; %UooZO
} # 7dvT=
catch(IOException e) RlvvO
{ @m`H~]AU
e.printStackTrace (); h1 "#
} oIj/V|ByK
>^#Liwm
YT[=o}jS
return n; ft{i6}
} oTb42a_j{
_N|AI"sj.
l>i:M#z&
} 8?<J,zu@AV
O<>+l*bk
.pl,ujv
/* @*6_Rp"@
**SiteInfoBean.java o^d|/;
*/ }NV<k
package NetFox; zU0JwZi
86qQ"=v
dn42'(p@G
public class SiteInfoBean { $'!n4}$}
;&?ITV
i,Jz7OX
private String sSiteURL; //Site's URL (A}c22qe
private String sFilePath; //Saved File's Path *j1Skd.#At
private String sFileName; //Saved File's Name !](Mt?e
private int nSplitter; //Count of Splited Downloading File {~g7&+9x*
Z!'kN\z
g?j^d:
public SiteInfoBean() "<&o;x<
{//nSplitter的缺省值为5 #sv}%oV,F
//default value of nSplitter is 5 l_2l/ff9
this("","","",5); L4u.cHJ}0
} -s0J8b
/ )[\+Nc
@LU[po1I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~Lu,jLKL=[
{ e+2lus,u6t
sSiteURL= sURL; ~<Wa$~oY
sFilePath = sPath; +Ezl.O@z
sFileName = sName; I%j]pY4
this.nSplitter = nSpiltter; ;U tEHvE*
q9^.f9-
:G^4/A_
} '}>8+vU`
Qd?S~3XT
fR2,NKM@
public String getSSiteURL() oc-o>H
{ 5(Q-||J
return sSiteURL; FS?1O"_
} Skux&'N:
%A&g-4(
)J[Ady^5
public void setSSiteURL(String value) K_N`My
{ NY[48H
sSiteURL = value; F[v^43-^_
} yM-%x1r~
ecp0 hG`%
;gRPTk$X3
public String getSFilePath() >u .u#de
{ >Bm>/%2
return sFilePath; e6T?2`5P
} lL'K1%{+ \
^ilgd
Ut2x4$9
public void setSFilePath(String value) QYBLU7
{ bX%4[BKP
sFilePath = value; 2|M,#2E-
} to\$'2F"q
OXoEA a
EScy!p\*
public String getSFileName() f,-'eW/j
{ cZt5;"xgr]
return sFileName; D9r;Ys%
} 4tapQgj24
G6"4JTWO
U!nNT==
public void setSFileName(String value) T?-K}PUcQ
{ ; Oz p
sFileName = value; itO1ROmu
} sQT,@+JEr
%Si3LQf
7 :u+-U
public int getNSplitter() yN}<l%
{ Z>'hNj)ju
return nSplitter; I=K<%.
} MY&?*pV)
V5I xZn%
iW?NxP
public void setNSplitter(int nCount) ,#.^2O9-^
{ 3ZYrNul"
nSplitter = nCount; rN {5^+w
} `zcpaE.@
} :\1vy5 _
34vH+,!u
-r{]9v2j
/* lWU? R
**Utility.java &G+:t)|S
*/ 2|+4xqNJm
package NetFox; kr]_?B(r
YdAC<,e&A
x C>>K6Nb
public class Utility { 00A2[gO9
vmtmiN8;d
bgmOX&`G
public Utility() DJNM=v
{ 16N`xw+{
Y3luU&'
w6k^|."
} mw=keY9]
-.vNb!=
//线程睡眠 IBv9xP]BZ
public static void sleep(int nSecond) Sj4@pMh4
{ [#2z=Xg
try{ 4f,%@s)zn
Thread.sleep(nSecond); }e,*'mCC*
} 9kU|?JE
catch(Exception e) lN::veD
{ *>Zq79TG
e.printStackTrace (); XZPq4(,9}
} (K>4^E8
} D)JI11a<
7(5 wP(
//日志 }9&~+Q2
public static void log(String sMsg) _d3/="=
{ Ml,87fo
System.err.println(sMsg); Gh{vExH@5(
} l8!n!sC[,
=ThacZHb8
q?Mmkh)g
public static void log(int sMsg) lem\P_V)
{ >K;C?gHo
System.err.println(sMsg); ljj}XJQ
} <F5x}i~(C
} N%QVkuCbM
&#[6a&9#[A
80O[pf*?
/* Z<tJ+
**TestMethod.java V8J!8=2
*/ ,O"zz7
package NetFox; ;z^C\=om
Ha/-v?E
?bK^IHh
public class TestMethod { W6uz G
;(9q, )
kA<58,!
public TestMethod() Y-c_ 2 )
{ ///xx/weblogic60b2_win.exe C+c;UzbD
try{ t[^68]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e?!A]2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "zBYhZr
SiteFileFetch fileFetch = new SiteFileFetch(bean); FDO$(&
fileFetch.start(); D7b] ;Nf\
} Ja#ti y
catch(Exception e){e.printStackTrace ();} :+\B|*T2.L
VSa#X |z
m]:|j[!*M
} 4o*wLCo7^
!BW6l)=L
cYp]zn+6
public static void main(String[] args) V@Fj!/
{ 2AI~Jm#
new TestMethod(); M2e_)f:
} ;?0k>
} %,G0)t
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