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)); {u#;?u=|
} +kzo*zW$L
for(int i=0;i<nEndPos.length-1;i++) j@SQ~AS
{ $npT[~U5
nEndPos = nStartPos[i+1]; Dp)=0<$y
} sg$rzT-S4
nEndPos[nEndPos.length-1] = nFileLength; Tk5W'p|6f
} _F$aUtb%O
} Dpl A?
.P[ _<8
thifRd$4
//启动子线程 :_g$.h%%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yXHUJgjl/
for(int i=0;i<nStartPos.length;i++) KY51rw.
{ [n \2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]Q>.HH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m 8aITd8
nStartPos,nEndPos,i); [8T^@YN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :9QZPsL
fileSplitterFetch.start(); 2zs73:z
} 1Cgso`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v^d]~!h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CF?1R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (O.d>
nEndPos = " + nFileLength); v7iuL6jl
// fileSplitterFetch[nPos.length-1].start(); C-\S/yd
DXJ`oh
23Nw!6S
//等待子线程结束 7?GIS '
//int count = 0; -uMSe~
//是否结束while循环 #~C]ZrK
boolean breakWhile = false; $ZugBh[b
Rb%8)t x
G!>z;5KuS
while(!bStop) +yk24 `>
{ 19E8'@
write_nPos(); tt0f-:#
Utility.sleep(500); @zU6t|mhz
breakWhile = true; .J)I | '
6W]9$n\"?
ABD)}n=%c
for(int i=0;i<nStartPos.length;i++) ?0v-qj+
{ NbgK@eV}+{
if(!fileSplitterFetch.bDownOver) i{`FmrPO~
{ $a ]_w.@
breakWhile = false; JM x>][xD
break; pe]A5\4c
} 60J;sGW
} G9xmmc
if(breakWhile) _B/dWA,P
break; 2jR r,Nl
"4riSxEyF
}o(zj=7
//count++; MvK !u
//if(count>4) PIu1+k.r?
// siteStop(); yku5SEJ\
} 0 q}*S~
vms|x wb
$~VRza 8Q
System.err.println("文件下载结束！"); JtEo'As:[
} 1IC~e^"
catch(Exception e){e.printStackTrace ();} 5ni~Q 9b
} T 6)bD&
b{L/4bu
r:f[mk"-"A
//获得文件长度 S- pV_Ff
public long getFileSize() K/i*w<aPb7
{ `6lr4Kk @R
int nFileLength = -1; V^3L3|k
try{ r'^Hg/Jzt
URL url = new URL(siteInfoBean.getSSiteURL()); G,o6292hj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E"qRw_ ~t
httpConnection.setRequestProperty("User-Agent","NetFox"); &cxRD
Y9uC&/_C
$c]fPt"i
int responseCode=httpConnection.getResponseCode(); D^l%{IG
if(responseCode>=400) ,z;cbsV-{
{ ]P.'>4
processErrorCode(responseCode); :=u?Fqqws
return -2; //-2 represent access is error xe{!wX
} %E#s\B,w
_ba>19csq%
+jS|2d
String sHeader; Sdt`i
NdMb)l)m
nuk*.Su
for(int i=1;;i++) NidIVbT.A
{ v|uAzM{73
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ABQ('#78
//Utility.log(in.readLine()); oW ::hB
sHeader=httpConnection.getHeaderFieldKey(i); s5CXwM6cx
if(sHeader!=null) 7 n8"/0kc:
{ fI&t]
if(sHeader.equals("Content-Length")) U>]$a71
{ &;^YBW:I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }=<
break; YC++&Nk
} ;j[>9g
} h"X;3b^ m
else .E`\MtA
break; X:HacYqtC
} T ]t'39
} i,>khc
catch(IOException e){e.printStackTrace ();} hIy~B['
catch(Exception e){e.printStackTrace ();} &J[:awQX
63\/ * NNB
%zG;Q@
Utility.log(nFileLength); w65K[l;2
K2TcOFQ
J]{QB^?
return nFileLength; ]^h]t~
} Uwf+
yv t.
]A~WIF
//保存下载信息（文件指针位置） >V-A;S:
private void write_nPos() [@VP?74
{ }Yb[
try{ ^E;kgED5
output = new DataOutputStream(new FileOutputStream(tmpFile)); U#lCj0iUt,
output.writeInt(nStartPos.length); IwQ"eUnK
for(int i=0;i<nStartPos.length;i++) eD,.~Y#?=
{ _zY#U9
// output.writeLong(nPos); FHj" nB
output.writeLong(fileSplitterFetch.nStartPos); ur)9x^y
output.writeLong(fileSplitterFetch.nEndPos); Of*Pw[vD
} 4ezEW|S
output.close(); _ TiuY
} ] eotc2?u
catch(IOException e){e.printStackTrace ();} jyZ (RB
catch(Exception e){e.printStackTrace ();} bo2H]PL*
} =bfJ^]R
B^4&-z2|
E{XH?_xo
//读取保存的下载信息（文件指针位置） |XQIfW]A
private void read_nPos() 'GNK"XA^
{ SheM|I~de
try{ \H1(PA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \y97W&AN
int nCount = input.readInt(); J"!vu.[
nStartPos = new long[nCount]; \hTm)-FP
nEndPos = new long[nCount]; mk;&yh
for(int i=0;i<nStartPos.length;i++) 4w*Skl=F}
{ fz|cnU
nStartPos = input.readLong(); IHB}`e|
nEndPos = input.readLong(); 3eb%OEMYk
} Si_ _8D
input.close(); Z"/p,A9W9|
} uZNTHD
catch(IOException e){e.printStackTrace ();} }JF13beU
catch(Exception e){e.printStackTrace ();} 3 }duG/
} \nXtH}9ZF
=$u! 59_dE
<CS(c|7
private void processErrorCode(int nErrorCode) l{5IUuUi
{ "sS}N%!
System.err.println("Error Code : " + nErrorCode); bGN:=Y'
} 6Y^23W F
&*##bA"!B
Vx$\hcG
//停止文件下载 WJQvB=D&
public void siteStop() +9M^7/}H
{ :0Bq^G"ge
bStop = true; \HqNAE2T
for(int i=0;i<nStartPos.length;i++) t)~"4]{*}D
fileSplitterFetch.splitterStop(); @@R7p
tI`Q/a5@
BBaQ}{F8>2
} *1uKr9
} o*-)Tq8GHE
//负责部分文件的抓取 U_M$#i{_
**FileSplitterFetch.java Z?6%;n^ 54
*/ @3) (BpFe
package NetFox; dzARI`
J1,9kCO
(/z_Q{"N
import java.io.*; E%yNa]\P
import java.net.*; o*b] p-
*QpMF/<?
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public class FileSplitterFetch extends Thread { +NeOSQSj
\.0^n3y
VU#`oJ:{
String sURL; //File URL X.OD`.!>
long nStartPos; //File Snippet Start Position q8FTi^=Kb
long nEndPos; //File Snippet End Position 0pK=o"^?@
int nThreadID; //Thread's ID 7S-ys+
boolean bDownOver = false; //Downing is over MDnKX?Y
boolean bStop = false; //Stop identical G/k2Pe{SL
FileAccessI fileAccessI = null; //File Access interface vleS2-]|
XeW<B0~
6g2a[6G5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S'k_olx7
{ I&2c&yO
this.sURL = sURL; H['N
this.nStartPos = nStart; Vy6qbC-Kt
this.nEndPos = nEnd; VyXKZ%\dQ/
nThreadID = id; _G[g;$<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i5en*)O8
} ~FZ&.<s
xu>9(,l
-?H#LUk
public void run() &b.=M>\9Q
{ ?ME6+Z\
while(nStartPos < nEndPos && !bStop) [glLre^
{ oL!EYbFD'Z
5-|:^hU9
,-$LmECg
try{ ,g%0`SO
URL url = new URL(sURL); $ZUdT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 18|m)(W
httpConnection.setRequestProperty("User-Agent","NetFox"); '<jyw
String sProperty = "bytes="+nStartPos+"-"; u#Pa7_zBj]
httpConnection.setRequestProperty("RANGE",sProperty); #pT"BSz]
Utility.log(sProperty); Vrjc~>X
\MsTB|Z
]}Mj)J"m
InputStream input = httpConnection.getInputStream(); p09HL%~R
//logResponseHead(httpConnection); 3r<~Q7e
X@'uy<tI-
Qk0R a_
byte[] b = new byte[1024]; spGb!Y`mR
int nRead; HD@$t)mn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )YYf1o[+
{ /1Qr#OJ(]
nStartPos += fileAccessI.write(b,0,nRead); BTlk Etm
//if(nThreadID == 1) HeK/7IAqp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c%^7!FSg
} 7G:s2432
AhCW'.
)s)I2Z+
Utility.log("Thread " + nThreadID + " is over!"); 4qphA9i1
bDownOver = true; h(<,fg1
//nPos = fileAccessI.write (b,0,nRead); /vY(o1o x
} _- [''(E
catch(Exception e){e.printStackTrace ();} o906/5M
} bH-ub2@qO
} P#E&|n7DT
Yab%/z2:
_A M*@|p,
//打印回应的头信息 l3KVW5-!gS
public void logResponseHead(HttpURLConnection con) kj|6iG
{ 8|b3j^u
for(int i=1;;i++) 2;[D;Y}
{ P]<4R:yb
String header=con.getHeaderFieldKey(i); so^lb?g
if(header!=null) :#2Bw]z&z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eeIhed9
Utility.log(header+" : "+con.getHeaderField(header)); g!cUF+
else })uGRvz
break; KgV3j]d
} *?o{9v5}(
} %?LOs H
jNu9KlN
!GOM5z,
public void splitterStop() [N1hWcfvd
{ h"`ucC8X
bStop = true; )S`jFQ1
} W>!_|[a
UU'|Xz9~
:iFIQpk
} wNq;;AJ$
p/(~IC"!J
BLN^ <X/
/* .b\$MZ"(
**FileAccess.java 8iW;y2qF
*//文件访问(定位，写) 0$_oT;{8
package NetFox; M@h|bN
import java.io.*; ~i@Y|38C
r~+\ Y"rM
"nm FzN
public class FileAccessI implements Serializable{ b'P eH\h{
K6y :mJYp\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZPc@Zr`z
RandomAccessFile oSavedFile; $f,n8]
long nPos; MWI4Y@1bS
BQBeo&n6
)Y]{HQd
public FileAccessI() throws IOException 0~HKiH-
{ pX/n)q[
this("",0); cKN$ =gd
} !l_lo`)
.U"8mP=&
I96Ci2)m
public FileAccessI(String sName,long nPos) throws IOException :`E8Z:-R
{ Q9Uf.Lh2
oSavedFile = new RandomAccessFile(sName,"rw"); ;=geHiQHA
this.nPos = nPos; fR)m%m
oSavedFile.seek(nPos); 6}4'E
} z?[r
}K1JU`Lz
"8~:[G#
public synchronized int write(byte[] b,int nStart,int nLen) !l|5z G
{ 8i|w(5m;
int n = -1; n8uv#DsdK
try{ Y7#-Fra0W
oSavedFile.write(b,nStart,nLen); Na$Is'F&p
n = nLen; b8$gx:aJ>$
} CSGz3uC2D
catch(IOException e) Rp*R:3 C
{ ~zil/P8
e.printStackTrace (); RletL)
} QYa(N[~a
%)[+%57{
lZyG)0t,g
return n; @[#$J0qq
} s <
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qb5#_1qz+^
} ysmNio
?pYKZg/c
%STliJ
/* %|^OOU}
**SiteInfoBean.java )x}l3\s
*/ %{(x3\ *&
package NetFox; hX`hs-*qM
o;W`4S^
$e\h}A6
public class SiteInfoBean { 'eo KZX+
i<H wTmm$
B=>RH!&
private String sSiteURL; //Site's URL Q:|l`*.R
private String sFilePath; //Saved File's Path K=C!b?
private String sFileName; //Saved File's Name oY1';&BO9
private int nSplitter; //Count of Splited Downloading File rj6tZJZ#o0
Ma'_e=+A
=Zu^80/
public SiteInfoBean() /n5F(5<
{//nSplitter的缺省值为5 %q!8={J8
//default value of nSplitter is 5 T[,/5J
this("","","",5); U~} U\_
} HDda@Jy
{fha`i
pl5P2&k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5DXR8mLoaJ
{ by'DQ 00
sSiteURL= sURL; ^qg?6S4
sFilePath = sPath; L7= Q<D<
sFileName = sName; "6R 5+
this.nSplitter = nSpiltter; z >YFyu#LF
'mH)d
VA"*6F
} Xg=x7\V
GK9/D|h4
%]gn?`O
public String getSSiteURL() :N<.?%Kf
{ s:2|c]wQ#R
return sSiteURL; ~6pr0uyO`
} yC3yij<oR
2:BF[c`
9Ro6fjjE
public void setSSiteURL(String value) -29gL_dk.
{ 2u"7T_"2D
sSiteURL = value; =/u%c!
} pG34Qw
V7Z4T6j4
rQOWLg!"
public String getSFilePath() t~e<z81p
{ ~_9n.C
return sFilePath; b{d4xU8'
} ) c/% NiN
< -uc."6\
'Q =7/dY3I
public void setSFilePath(String value) 2+cNo9f
{ 9%iUG(DC
sFilePath = value; `C_jP|[e
} BnCKSg7V
ed!:/+3e/
zF@o2<cD@
public String getSFileName() &O)&k
{ ?9HhG?_x
return sFileName; RP2_l$
} WpS1a440
^A][)*SZ
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public void setSFileName(String value) $B#6tk~u
{ Bd^"=+c4
sFileName = value; 'S<%Xm
} W(25TbQ
[L6w1b,
^9_UUzf\
public int getNSplitter() c(U
{ [w0/\]o
return nSplitter; Z2Zq'3*
} y8s!M
[3W*9j
;uqx@sx ;
public void setNSplitter(int nCount) `:wvh(
{ f`8OM}un&
nSplitter = nCount; ESg+n(R
} YC=S5;
} T# lP!c
WKpA|
!mRx$ %ul
/* hH->%*
**Utility.java >tG+?Y'{
*/ ? b[n|^wS
package NetFox; 7l."b$U4yv
!ph" mf$-
li] 6Pj,
public class Utility { =39 ?:VoD
EQIUSh)M
`p0ypi3hn
public Utility() A])P1c. 7"
{ KECElK3uj
yMc:n"-[
Jz:r7w{4eB
} Bi~:>X\[^6
spQLG_o,J
//线程睡眠 1|ZhPsD.}g
public static void sleep(int nSecond) ++}\v9Er
{ GIftrYr
try{ *U=]@I}J
Thread.sleep(nSecond); {ub/3Uh
} o5Y2vmz?9
catch(Exception e) sM\lO
{ 85|fyX
e.printStackTrace (); tfkr+ /
} >p])it[q&$
} B|%tE{F
02JoA+
//日志 zTo8OPr
public static void log(String sMsg) ~u&|G$1!0
{ W~ULc9
System.err.println(sMsg); 6QZ5|T ]
} q (+ZwaV@
C+F*690h
4ZC!SgJo
public static void log(int sMsg) 64j|}wJ$
{ ~%#mK:+
System.err.println(sMsg); `C_'|d<HA
} b-@\R\T
} 7S$&S;
PT9v*3Bq~
R4e&^tI@*
/* 8[bkHfI
**TestMethod.java DF1<JdO+
*/ LS.r%:$mb
package NetFox; K(T\9J.
'GJVWpvUU
MR'o{?{e`
public class TestMethod { n&-496H
VY+>=!
DB`QsiC)
public TestMethod() 5IqQ|/m<6
{ ///xx/weblogic60b2_win.exe fT Y/4(
try{ !q4x~G0d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W9J1=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :Dl%_l
SiteFileFetch fileFetch = new SiteFileFetch(bean); WW "i
fileFetch.start(); r;iV$Rq!
} *(GZ^QH.
catch(Exception e){e.printStackTrace ();} 8v yG*UK
{UH9i'y:t
:DkAQ-<~
} ~fzuwz
dl l%4Sd
O.k\]'
public static void main(String[] args) zuL7%qyv
{ 0y%L-:/c|
new TestMethod(); *]s&8/Gmb
} ';RI7)<
} x:5dCI
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