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)); lAk1ncx
} ^eW.hNg
for(int i=0;i<nEndPos.length-1;i++) ]uvbQ.l_t
{ >t2b?(h/x
nEndPos = nStartPos[i+1]; 4c=kT@=jX
} (@E#O$'
nEndPos[nEndPos.length-1] = nFileLength; GX)QIe~;qJ
} g8+,wSE
} zb/Xfu.)?6
@(c<av?
@S7=6RKa[
//启动子线程 H040-Q;S'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; : xZC7"
for(int i=0;i<nStartPos.length;i++) aELT"b,x
{ udGGDH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zt2-w/[Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }qv-lO
nStartPos,nEndPos,i); XyphQ}\u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E ZKz-}
fileSplitterFetch.start(); ? SP7vQ/
} 9Nu#&_2R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~{YgM/c|dt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xD#I&.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WWcm(q=
nEndPos = " + nFileLength); AtlR!IEUb
// fileSplitterFetch[nPos.length-1].start(); &t/<yq}{
9yo[T(8
%"Q!5qH&
//等待子线程结束 iwJ-<v_:h
//int count = 0; hZWK5KwT
//是否结束while循环 iFG5%>5F
boolean breakWhile = false; /JeqoM"x
W<91m*
`_U0>Bfg;
while(!bStop) s|r7DdI
{ Zk#i9[g9*
write_nPos(); y]]Vp~R:[
Utility.sleep(500); ^Cn]+0G#C8
breakWhile = true; ff1B)e
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!7`=rT&
for(int i=0;i<nStartPos.length;i++) pE/3-0;}N
{ d4>-a^)V
if(!fileSplitterFetch.bDownOver) 1IQOl
{ rg^\BUa-W,
breakWhile = false; z%3"d0
break; Jf<yTAm
} {2k< k(,
} 0nz@O^*g(
if(breakWhile) pZ~>l=-
break; V1nZ M
qV8\/7'A0a
Ym{%"EB
//count++; qm8n7Z/
//if(count>4) C.)&FW2F_
// siteStop(); m2uML*&O5K
} 8N* -2/P&
5rA!VES T
+'j*WVE%5
System.err.println("文件下载结束！"); OO\biYh o
} /Np"J
catch(Exception e){e.printStackTrace ();} b/,!J]W
} 8^/Ek<Qb|
ENXW#{N.v
6a]f&={E
//获得文件长度 cw]>a&d
public long getFileSize() K'5sn|)
{ #X@<U <R
int nFileLength = -1; v#%>uLl
try{ {9.~]dI|L
URL url = new URL(siteInfoBean.getSSiteURL()); <fsn2[V:B%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iC|6roO!jk
httpConnection.setRequestProperty("User-Agent","NetFox"); QjjJtKz
Na 9l#
$ lsRg:J
int responseCode=httpConnection.getResponseCode(); HvgK_'
if(responseCode>=400) zHoO?tGf
{ hW!@$Ph
processErrorCode(responseCode); }Q r0T
return -2; //-2 represent access is error 2}`Vc{\
} )-?uX.E{
J%f=A1Q
&PBWJ?@O)r
String sHeader; a.}:d30
wdcryejCkr
h/0-Mrk;e
for(int i=1;;i++) OZB}aow
{ &>zy_)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?fa,[r|G
//Utility.log(in.readLine()); U~#^ ^
sHeader=httpConnection.getHeaderFieldKey(i); >RL6Jbo|
if(sHeader!=null) Z_V&IQo-7
{ o(X90X
if(sHeader.equals("Content-Length")) 3w^J"O/T
{ ^,Y~M_=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j&[3Be'pQ
break; J'&B:PZObB
} ??zABV
} IJ_'w[k
else Pvg
break; xL39>PB
} OZC/+"\,
} RZ)vU'@kx
catch(IOException e){e.printStackTrace ();} 1f@U:<:
catch(Exception e){e.printStackTrace ();} @[>+Dzn[6
uU[[[LQq
ttbQergS
Utility.log(nFileLength); M~z(a3@[V
3<)@ll
$E`iqRB
return nFileLength; Y6f+__O
} 7<QYT+6xV
HzG~I8o(d
ndKvJH4
//保存下载信息（文件指针位置） @u"kX2>Eq
private void write_nPos() C?/r}ly<\
{ C;)Xwm>e
try{ 8!&ds~?
output = new DataOutputStream(new FileOutputStream(tmpFile)); }W@#S_-e8
output.writeInt(nStartPos.length); ,Og[[0g
for(int i=0;i<nStartPos.length;i++) VO @ 4A6
{ zy5s$f1IA
// output.writeLong(nPos); EN-8uY.
output.writeLong(fileSplitterFetch.nStartPos); /HjI=263
output.writeLong(fileSplitterFetch.nEndPos); ek(kY6x:
} :@QK}qFP
output.close(); 4iYKW2a
} fbHWBb
catch(IOException e){e.printStackTrace ();} ]U#[\ Z
catch(Exception e){e.printStackTrace ();} "S B%02
} *fQ?A|l!x
*2"bG1`
&3 XFgHo
//读取保存的下载信息（文件指针位置） ^T}}4I_Y
private void read_nPos() N'eQ>2>O@
{ 2sd ) w
try{ s.p1L
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \sHy.{
int nCount = input.readInt(); OXIu>jF
nStartPos = new long[nCount]; yd0=h7s
nEndPos = new long[nCount]; >ggk>s|
for(int i=0;i<nStartPos.length;i++) a9? v\hG
{ =q"w2b&
nStartPos = input.readLong(); [$1: &!(!
nEndPos = input.readLong(); {m_A1D/_
} RWh9&O:6'
input.close(); J3lG"Ww
} iL7-4Lv#
catch(IOException e){e.printStackTrace ();} F= _uNq
catch(Exception e){e.printStackTrace ();} Cz=A{<^g
} |c06ix;).
<4l.s
Qr|N)
private void processErrorCode(int nErrorCode) I8<Il^
{ Giy3eva2
System.err.println("Error Code : " + nErrorCode); y"|K |QT
} (E"&UC[
uKR\Xo}
so?pA@O
//停止文件下载 cotxo?)Zv
public void siteStop() o;M.Rt\A
{ XI@6a9Uk
bStop = true; `x%U
for(int i=0;i<nStartPos.length;i++) 5T$9'5V7
fileSplitterFetch.splitterStop(); 0\\ueMj
{2}tPT[a(
zqHpT^B?
} pIID=8RJ.
} Wz6]*P`qv
//负责部分文件的抓取 ~8H&m,{j
**FileSplitterFetch.java ||{T5E-.F
*/ 5YTb7M
package NetFox; *} *!+C3
2y9:'c|
T@K7DkP@
import java.io.*; w|!YoMk+o
import java.net.*; ^f^-.X
KAj"p9hq+k
_Hz~HoNU
public class FileSplitterFetch extends Thread { ? -v
3iu!6lC
L\/u}]dPQ
String sURL; //File URL [n!$D(|"!V
long nStartPos; //File Snippet Start Position EpRXjz
long nEndPos; //File Snippet End Position /~H[= Pf
int nThreadID; //Thread's ID /[\6oa
boolean bDownOver = false; //Downing is over BKa A=Bl
boolean bStop = false; //Stop identical -vyIOH,
FileAccessI fileAccessI = null; //File Access interface G*kE~s9R
07.nq;/R
3c01uObTL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -rEeKt
{ Zij"/gx\
this.sURL = sURL; 7!O^;]+,
this.nStartPos = nStart; R<0Fy=z
this.nEndPos = nEnd; R^jlEt\&P
nThreadID = id; GwgFi@itN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AkxH
} #=X)Jx~
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Jy]FrSm^
public void run() 8!Wfd)4=,F
{ =jJ H^Y2
while(nStartPos < nEndPos && !bStop) >}-~rZ
{ `)rg|~#k
L_tjcfVo
%)zk..K{l
try{ 9k+N3vA
URL url = new URL(sURL); mZ`1JO9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \\Y,?x_0T
httpConnection.setRequestProperty("User-Agent","NetFox"); gb.f%rlZ`
String sProperty = "bytes="+nStartPos+"-"; Q{H17]W
httpConnection.setRequestProperty("RANGE",sProperty); wY' "ab
Utility.log(sProperty); M%7`8KQ
@''&nRC1
w@87]/4Rq
InputStream input = httpConnection.getInputStream(); _aVJ$N.
//logResponseHead(httpConnection); /)sDnJ1r
* eA{[
Gh2#-~|cB
byte[] b = new byte[1024]; %GM>u2baw
int nRead; ^$e0t;W=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~RcNZ\2y
{ VT'0DQ!NIq
nStartPos += fileAccessI.write(b,0,nRead); o^6jyb!j
//if(nThreadID == 1) 4uFIpS|rq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Z_t%J5QZ$
} [_j6cj]
:9(3h"
`2>XH:+7F
Utility.log("Thread " + nThreadID + " is over!"); `>%-
bDownOver = true; 7;^((.]ln
//nPos = fileAccessI.write (b,0,nRead); {?w"hjy
} MKomq
catch(Exception e){e.printStackTrace ();} BqQ] x'AF
} ||R0U@F,
} /rqqC(1
_~juv&
Nfr:`$k
//打印回应的头信息 P=c?QYF
public void logResponseHead(HttpURLConnection con) L{!ihJr
{ :lNg:r$4
for(int i=1;;i++) 9H>BWjS
{ A_@I_V$
String header=con.getHeaderFieldKey(i); p=2zS.
if(header!=null) R|-6o)$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wjL|Z8
Utility.log(header+" : "+con.getHeaderField(header)); P= e4lF.
else B#1:Y;Z
break; "<qEXX
} b9`iZ
} Jth=.9mrM
;{Xy`{Cg!
F{;; :
public void splitterStop() Ky *DfQA
{ 4ffU;6~l'
bStop = true; ~xw5\Y^
} ,`yyR:F
4b]_ #7Qm
Yhe+u\vGs\
} "2%>M
6eM6[
#^Ys{
/* ^/k,
**FileAccess.java z9 O~W5-U
*//文件访问(定位，写) O)OUy
package NetFox; 21ViHV
import java.io.*; _$8{;1$T?
8qN"3 Et
!I~C0u
public class FileAccessI implements Serializable{ n3'dLJH|
lw s(/a*c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {$0&R$v3
RandomAccessFile oSavedFile; !Qcir&]C>
long nPos; ]Dh1~k.Kp
te)n{K",
8`*`nQhWa
public FileAccessI() throws IOException \2j|=S6
{ wrabyRjK
this("",0); ka#K [qI
} t}VwVf<K
6%E~p0)i%
nx B32
public FileAccessI(String sName,long nPos) throws IOException c8<xFvYG
{ *!Y-!
oSavedFile = new RandomAccessFile(sName,"rw"); b_|u<
this.nPos = nPos; F;pQ\Y
oSavedFile.seek(nPos); .A(i=!{q
} .9OFryo
IfMpY;ow=
9qr UM`z$g
public synchronized int write(byte[] b,int nStart,int nLen) Z^*NnL.'
{ )yrAov\z*
int n = -1; ./7v",#*.'
try{ Ssf+b!e]
oSavedFile.write(b,nStart,nLen); MQJ%He"
n = nLen; 3"Yif
} 0yz~W(tsm
catch(IOException e) S7CV w,2
{ 'l|R5
e.printStackTrace (); FN!1|'VK
} '#W_boN
~r&D6Y
TY~Vi OC
return n; +;dXDZ2
} q? 9GrwL8F
]IS;\~
1[s0Lz
} iX%n0i
> ws!5q
@cIgxp
/* LWD#a~
**SiteInfoBean.java m6i%DE
*/ w.uK?A>W,
package NetFox; hg8Be6G<
&\^rQi/tf
U-g9C.
public class SiteInfoBean { yUe+":7k.
=Dk7RKoHF
(sCAR=5v\
private String sSiteURL; //Site's URL I+" lrU
private String sFilePath; //Saved File's Path Xk,>l6vc
private String sFileName; //Saved File's Name VoM6
private int nSplitter; //Count of Splited Downloading File "r..
OJpj}R
'E-FO_N
public SiteInfoBean() #ib^Kg
{//nSplitter的缺省值为5 c+2sT3).D
//default value of nSplitter is 5 a+Ab]m8`
this("","","",5); 63M=,0-Qt
} DsGI/c
%i"}x/CD[
EnJ!mr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =EpJZt
{ 0hwj\{"
sSiteURL= sURL; |dk[cX>
sFilePath = sPath; Ri @`a
sFileName = sName; J633uH}}
this.nSplitter = nSpiltter; 7W|Zq6pi
:gf;}
k.GA8=]>
} XYAmJ
.S7:;%qL6
"SR5wr
public String getSSiteURL() [PWL<t::c
{ <lj\#'G3
return sSiteURL; R ]P;sk5
} >1ZJ{se
6P*O&1hv
sS9%3i/>
public void setSSiteURL(String value) TzKK;(GX
{ wkBL=a
sSiteURL = value; 3?`"
} p/*"4-S
_a5(s2wq+
,2,5Odrz
public String getSFilePath() x=*L-
{ aWGon]2p
return sFilePath; EB,4PEe:
} 1'O0`Me>#
Im)EDTm$
Uc&iZFid2K
public void setSFilePath(String value) C-w5KW
{ mQr0sI,o]
sFilePath = value; 8\# ^k#X
} 2d`c!
@;Y~frT
_u5dC
public String getSFileName() /S~m)$vu
{ A,#2^dR
return sFileName; SaO3zz@L
} {rXs:N@
61@EDIYPc
yZ3nRiuRT
public void setSFileName(String value) RH[+1z8
{ %e_"CS
sFileName = value; dR+1aY;
} :2y"3azxk
"HlgRp]u
zwr\:Hu4
public int getNSplitter() ZnfNQl[
{ v>mn/a
return nSplitter; XUmR{A
} v(O=IUa
`hrQw)5?r
XvKFPr0~
public void setNSplitter(int nCount) GwLFL.Ke
{ o#D.9K(
nSplitter = nCount; GoE 'L
} ^Z}Ob= .G
} s>%Pd7:
T):SGW
Uyx&E?SlEq
/* ,t,wy37*D
**Utility.java *b)Q5dw@1
*/ x0Z5zV9
package NetFox; &.N$
r;m`9,RW
|vILp/"9=W
public class Utility { O#_b7i
<Kt3PyF
>M;u*Go`QO
public Utility() g^~Kze
{ tju|UhP3
&`!^Zq vG
aGoE,5
} 7r 0,> 3"
0KvVw rWJ
//线程睡眠 ,1UZv>}S
public static void sleep(int nSecond) Qa`hR
{ 11UB4CA
try{ tIuoD+AW
Thread.sleep(nSecond); nII^mg~
} sl|_=oXT
catch(Exception e) B0Xl+JIR#
{ glUo7^ay7
e.printStackTrace (); nH[+n `{o
} ux-CpI
} ~<9{#uM
c&'JmKV>&
//日志 %fjuG
public static void log(String sMsg) z#Nl@NO&
{ Fn|gVR
System.err.println(sMsg); .EP6oKA
} `-UJ /{
'Kbl3fUF
QIU,!w-3X
public static void log(int sMsg) Is.WZYa
{ 0l\y.
System.err.println(sMsg); %NARyz
} Qt+:4{He
} S h4wqf
vO@s$qi
-kj< 1~YW
/* :k,Q,B.I
**TestMethod.java KMK`F{
*/ 7^:4A'
package NetFox; ;LwqTlJ*[L
.dmi#%W
l!~ mxUb
public class TestMethod { $2#7D* Rx
SpSnoVI
b=[?b+
public TestMethod() 0$vj!-Mb^j
{ ///xx/weblogic60b2_win.exe E~hzh /,34
try{ 6oL1_)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T-" I9kM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "ZMkL)'7-
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]MTbW=*}ED
fileFetch.start(); Qx`~g,wk8
} !|G(Yg7C
catch(Exception e){e.printStackTrace ();} (lH,JX`$a
k(s;,B\
O8u3y
} ~H6;I$e[
UlovXb
G*}F5.>8(
public static void main(String[] args) saZ>?Owz
{ >_ \<E!j
new TestMethod(); v."Dnl
} 9.+/~$Ht
} ,LYFEq_
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