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)); v3tJtb^'!
} bOS)vt*V
for(int i=0;i<nEndPos.length-1;i++) MK$u}G
{ 'M90Yia
nEndPos = nStartPos[i+1]; D #ddx
} QLA.;`HIE
nEndPos[nEndPos.length-1] = nFileLength; bz>X~
} cr7MvXF-
} $vO&C6m$
{Kz,_bo
7nZPh3%
//启动子线程 e#eVc'=cDR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x&}]8S)
for(int i=0;i<nStartPos.length;i++) !40>LpL[
{ /zn=AAYb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o5<<vvdA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '%)R}wgV
nStartPos,nEndPos,i); *{o7G a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0D X_*f
fileSplitterFetch.start(); .6B\fr.za
} U)S=JT~h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :!ya&o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gL;Kie6Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6%D9;-N)
nEndPos = " + nFileLength); " qI99e
// fileSplitterFetch[nPos.length-1].start(); p{FI_6db
:|7#D,2
'`];=QY9pg
//等待子线程结束 |@qw
//int count = 0; 3r\8v`^>
//是否结束while循环 d|`Ll
boolean breakWhile = false; v*;d
8xpplo8
xNP_>Qa~
while(!bStop) 7ubz7*
{ 6Rd4waj_,U
write_nPos(); vDy&sgS$<
Utility.sleep(500); p7h#.m~Qu
breakWhile = true; WWT1=#"
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}\pI`;*O|
for(int i=0;i<nStartPos.length;i++) PT"}2sR)
{ tF2"IP.
if(!fileSplitterFetch.bDownOver) dWqn7+:
{ l,ENMKA^D
breakWhile = false; #;!&8iH
break; 'sNZFB#
} S63Zk0(25
} )Q)qz$h@
if(breakWhile) BFLef3~.0
break; 8;PkuJR_]
yNTd_XPL
DE?v'7cmA
//count++; &W `xZyb3
//if(count>4) R>Ra~b
// siteStop(); 9KSi-2?H
} _IH" SVub
rg/{5f
%H{p&ms
System.err.println("文件下载结束！"); |HazM9=
} xO$P C,
catch(Exception e){e.printStackTrace ();} @hLkU4S
} Cs $5Of(
pYO =pL^Q
\& JZ >h
//获得文件长度 jDzQw>TX
public long getFileSize() (8nv&|
{ ]@q%dsz
int nFileLength = -1; en<mm#Ab
try{ Lu.zc='\
URL url = new URL(siteInfoBean.getSSiteURL()); *kr/,_K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >rG>Bz^Pu
httpConnection.setRequestProperty("User-Agent","NetFox"); Io6/Fv>!
yNu_>!Cp5
{.Tx70kn
int responseCode=httpConnection.getResponseCode(); 18g_v"6o
if(responseCode>=400) :_{8amO
{ UD I{4+z
processErrorCode(responseCode); .UyE|t4
return -2; //-2 represent access is error HL)!p8UHJ
} oy+|:[v:Fk
7y=>Wa?T[
E-LkP;
String sHeader; A_9WSXR
f~IJ4T2#N
)7q$PcY
for(int i=1;;i++) 3;nOm =I
{ -@TY8#O#-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XTol|a=
//Utility.log(in.readLine()); f%Q)_F[0D4
sHeader=httpConnection.getHeaderFieldKey(i); +`y(S}Z
if(sHeader!=null) +9)JtmoL
{ ]5!3|UYS
if(sHeader.equals("Content-Length")) /-=fWtA
{ lFBdiIw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Aq i:h]x
break; +X?ErQm
} ~ELY$G.xl
} =w2 4(S
else XN<SKW(H3
break; K+g[E<x\=
} X-pbSq~5
} 8-$t7bV5
catch(IOException e){e.printStackTrace ();} ?W/.'_
catch(Exception e){e.printStackTrace ();} 0zt]DCdY
4WT[(
ZR.k'
Utility.log(nFileLength); !\4x{Wa]
&(F c .3m
g` rr3jP
return nFileLength; =]5tYIU
} ~/OY1~c
w$2q00R>
'g v0;L
//保存下载信息（文件指针位置） .ZXoRT
private void write_nPos() 1$E(8"l
{ vEv kC
try{ FaHOutP
output = new DataOutputStream(new FileOutputStream(tmpFile)); =~^b
output.writeInt(nStartPos.length); =?sG~
for(int i=0;i<nStartPos.length;i++) "~KDm(D
{ PN* .9;5Z
// output.writeLong(nPos); blc?[ [,!
output.writeLong(fileSplitterFetch.nStartPos); [-~pDkf:
output.writeLong(fileSplitterFetch.nEndPos); U?[ (
} K7}.#*% ~
output.close(); k %I83,+
} bWPsfUn#
catch(IOException e){e.printStackTrace ();} [lmF2
catch(Exception e){e.printStackTrace ();} {DO9%ej)
} 1\hLwG6Jj
E0HqXd?
CTMC78=9}
//读取保存的下载信息（文件指针位置） }T5@P {3P3
private void read_nPos() w OL,LU
{ r"H::A
try{ xd Z$|{,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A;AQw
int nCount = input.readInt(); i'Y8-})
nStartPos = new long[nCount]; =NB[jQ :(
nEndPos = new long[nCount]; aNbS0R>l
for(int i=0;i<nStartPos.length;i++) ly0R'4j \
{ ;hj lRQ\
nStartPos = input.readLong(); F^UtZG+
nEndPos = input.readLong(); :e<jD_.X
} MU<(O}
input.close(); 6?Ncgj &@
} Om3Ayk}
catch(IOException e){e.printStackTrace ();} InPE_
catch(Exception e){e.printStackTrace ();} ^WA7X9ed
} !Tzo&G
&/@V$'G=
Mj0,Y#=76
private void processErrorCode(int nErrorCode) ZmK=8iN9J
{ +eVYy_bL-
System.err.println("Error Code : " + nErrorCode); 1tuvJ+`{
} 2mLZ4r>WE
Q14zc0N
5es t
//停止文件下载 Ek+R
public void siteStop() s$Vl">9#
{ Ni~IY# '
bStop = true; dsTX?E<R
for(int i=0;i<nStartPos.length;i++) $8^Hkxy
fileSplitterFetch.splitterStop(); /wDf,Hduz
bY_'B5$.^2
}[0nTd
} qqDg2,Yb
} +n^M+ea;
//负责部分文件的抓取 -()WTdIy
**FileSplitterFetch.java qS?o22
*/ ~aC ?M&
package NetFox; PD#,KqL:
OqtGKda
^*.[b
import java.io.*; ]545:)Q1
import java.net.*; (\\;A?
*%xbn8
Y ^^4n$
public class FileSplitterFetch extends Thread { 4m*)("H
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C-M_:kQ[U
String sURL; //File URL ^'3c%&Zf3
long nStartPos; //File Snippet Start Position jY6GWsh:9
long nEndPos; //File Snippet End Position %QP[/5vQ
int nThreadID; //Thread's ID *_D/_Rp7
boolean bDownOver = false; //Downing is over hHJiGVJ=V
boolean bStop = false; //Stop identical TzL|{9
FileAccessI fileAccessI = null; //File Access interface 0O3O^ 0
Q-x>yau"
#XQ/y}(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^s~)"2 g
{ "GMU~594
this.sURL = sURL; M}] *j
this.nStartPos = nStart; Ow0>qzTg
this.nEndPos = nEnd; SxF'2ii
nThreadID = id; aH}/+Hu-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $6Ma{rC|
} RELNWr
<4rnOQ:
*aErwGLB8
public void run() .W]k8N E
{ l!ow\ZuQBF
while(nStartPos < nEndPos && !bStop) ]V"P &;m
{ l7`{O/hN
a (U52dO,
[?K>s>it
try{ [>ghs_?dZ
URL url = new URL(sURL); ; Y/nS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j!+jLm!l
httpConnection.setRequestProperty("User-Agent","NetFox"); %q5dV<X'c
String sProperty = "bytes="+nStartPos+"-"; 8eqTA8$?
httpConnection.setRequestProperty("RANGE",sProperty); T Q41i/{
Utility.log(sProperty); .7Mf(1:
?G`m;S
_E'?U
InputStream input = httpConnection.getInputStream(); [O3:?BNY
//logResponseHead(httpConnection); 9NTNulD>P
8LV6E5Q
n)yDep]$G
byte[] b = new byte[1024]; M?l v
int nRead; =l(euBb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v3"6'.f;bY
{ "Enb
nStartPos += fileAccessI.write(b,0,nRead); aRTy=~
//if(nThreadID == 1) 're:_;lG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FJn-cR.n
} L<FXtBJ
E{ /, b)
/LFuf`bXV
Utility.log("Thread " + nThreadID + " is over!"); |WB-Ng
bDownOver = true; ixA.b#!1
//nPos = fileAccessI.write (b,0,nRead); /&Q{B f
} AJyNlQ
catch(Exception e){e.printStackTrace ();} |z)s9B;:#i
} /3s&??{tv
} T0 K!Msz
2^[dy>[y0
tz;3
//打印回应的头信息 1ksFxpE
public void logResponseHead(HttpURLConnection con) UZ<K'H,q
{ ;JxL>K(
for(int i=1;;i++) "_/ih1z]
{ HH*y$
String header=con.getHeaderFieldKey(i); 97liSd
if(header!=null) dWz?`B{'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [}szM^
Utility.log(header+" : "+con.getHeaderField(header)); jPSVVOG
else s)Y1%#
break; {Zgd
} [IAUJ09>I
} `cp\UH@
?R]`M_^&u!
9a*#r;R
public void splitterStop() ^kfqw0!
{ 5W)ST&YPL*
bStop = true; `D;*.zrA
} j(%N.f6
VAiJL
M5{#!d}^D
} 1.14tS-}[4
w_{tS\
!(lcUdBd
/* ~,/@]6S&Y
**FileAccess.java ?tYZ/
*//文件访问(定位，写) .D@J\<,+l
package NetFox; q-!H7o
import java.io.*; }{R*pmv$bN
NQ`D"n
|aDBp
public class FileAccessI implements Serializable{ ~N!HxQ
k6CXuU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;VE y{%nF
RandomAccessFile oSavedFile; m*m),mZ"
long nPos; >Y>R1b%
811>dVq3/
#gbB// <
public FileAccessI() throws IOException 2.3_FXSt
{ [6a-d>e{
this("",0); l!*_[r
} +gd5&
t"$~o:U&)
b`X''6
public FileAccessI(String sName,long nPos) throws IOException m(8Tup|
{ <>6j>w_|
oSavedFile = new RandomAccessFile(sName,"rw"); u1/>)_U
this.nPos = nPos; IV,4BQ$
oSavedFile.seek(nPos); G(t:s5:
} 6qT@M0)i
SES.&e|!6
r *K
public synchronized int write(byte[] b,int nStart,int nLen) !JA;0[;l=
{ Cu7{>"
int n = -1; 529b. |
try{ =Pv_,%
oSavedFile.write(b,nStart,nLen); ~ *&\5rPb
n = nLen; y?OP- 27y
} \:;MFG'
catch(IOException e) irQ'Rm[
{ L('1NN2
e.printStackTrace (); ~/G)z?+E
} AERJ]$\
aDdxR:
_V$'nz#>e
return n; 4<Vi`X7[F
} M FIb-*wT
cK'g2S
!Ubm 586!
} g,d_
2iNLm6"
W{;Qi&^ca
/* (p2`ofj
**SiteInfoBean.java :u4|6?
*/ AA5G`LiT
package NetFox; Um+_S@h
ko@ej^
L"ho|v9:
public class SiteInfoBean { `N\ ^JAGW
:9QU\{2
g`pq*D
private String sSiteURL; //Site's URL mn@1&#c4y
private String sFilePath; //Saved File's Path ZeV@ X
private String sFileName; //Saved File's Name S"!6]!~^
private int nSplitter; //Count of Splited Downloading File 8$NVVw]2,
YNBM\Q
=2&\<Q_Fi
public SiteInfoBean() b~zSsws.
{//nSplitter的缺省值为5 AQZ<,TE0,
//default value of nSplitter is 5 bqbG+g
this("","","",5); ]q"&V\b
} hF$`=hE,F~
.{ v$;g
SXw r$)4_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +JErc)%
{ =7V4{|ESfy
sSiteURL= sURL; SrKitSG
sFilePath = sPath; uq3pk3 )W9
sFileName = sName; #}#m\=0
this.nSplitter = nSpiltter; ob>)F^.iS
eB~\~@
u 8o!
} JwMRquQv
@V:K]M 5
Wx0i_HFR
public String getSSiteURL() h@`Rk
{ O=A R`r#u
return sSiteURL; g}%ODa !H
} ;7\Fx8"s[
%* 0GEfl/
F>\,`wP
public void setSSiteURL(String value) fAJyD`]Z
{ Kxr{Nx
sSiteURL = value; (}b~}X9
} g!^N#o
~IZ-:?+S^
I<2`wL=
public String getSFilePath() ?J2{6,}O*.
{ ^ =C>
return sFilePath; O::FB.k
} J#`7!
6SCjlaGW5
|*?N#0s5h
public void setSFilePath(String value) c';~bYZ
{ Fu.aV876\f
sFilePath = value; &6\&McmkX
} yu6~:$%H
9(]_so24,
cB,^?djJ3
public String getSFileName() *fm?"0M5
{ z#+WK|a
return sFileName; \hX,z =
} 7(2}Vs!5
Tu(:?
z<eu=OD4t
public void setSFileName(String value) K#A&
{ P"NI> HM
sFileName = value; +jE)kaV%
} %R$)bGT
q.J6'v lj/
im*sSz 0 (
public int getNSplitter() 7=fM}sk
{ "\*)KH`C
return nSplitter; a>GA=r
} 3.YH7rN
Z`*V9
%ZoJu
public void setNSplitter(int nCount) O ?T~>|
{ R"OT&:0/
nSplitter = nCount; d_ =K (}eR
} '5aA+XP|
} aX.BaK6I
lB27Z}
oI-Fr0!
/* W_XFTqp^
**Utility.java (m1m}* @
*/ wA{)9.
package NetFox; W^elzN(
D&m1yl@\J
d*+}_EV)Y3
public class Utility { "dCIg{j
b!g)/%C
9-n]_AF`0
public Utility() DSs/D1mj&
{ <vl(a*4a
)[hs#nKTh
^(&2
} ^RnQX#+
Y<;C>Rs
//线程睡眠 >> cW0I/`
public static void sleep(int nSecond) ?4SYroXUX|
{ q[/g3D\G
try{ @16y%]Q-E#
Thread.sleep(nSecond); IRM jL.q
} %enJ[a%Qg
catch(Exception e) ` .`:~_OE
{ ]}SV%*{%
e.printStackTrace (); s;h`n$
} f@Mku0VT
} PE7V1U#$o,
'0 Ys`Qo
//日志 +]t9kr
public static void log(String sMsg) >kAJS??
{ 1%M^MT%&
System.err.println(sMsg); leHKBu'd
} QqL?? p-S>
~oOv/1v},
2h5T$[fV
public static void log(int sMsg) (a!E3y5,
{ \nOV2(FAT
System.err.println(sMsg); r;f\^hVy
} HV`u#hZ7C
} %/zHL?RqJ
z*nztvY@e
rREev
/* yzpa\[^
**TestMethod.java 3>(~5
*/ WL%T nux
package NetFox; >`30 ib
NO*~C',cI/
_)-2h[
public class TestMethod { &\?{%xj
UDpI @
$_ $%L0)5
public TestMethod() a w~a/T:
{ ///xx/weblogic60b2_win.exe q&ed4{H<
try{ <\:*cET3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ve#[LBOC8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0jpyc
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;F_&h#D]3
fileFetch.start(); ?{Xp'D\z
} s5 Fn("h]n
catch(Exception e){e.printStackTrace ();} yPbOiA*lHz
o\j<EQb.
*=z.H *
} |q o3 E
hQSJt[8My
5}NO~Xd<
public static void main(String[] args) Cyv_(Oh?dv
{ 'iYaA-9j
new TestMethod(); uJ*|SSN~
} YVY(uq)d
} !oV'
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