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)); 2Y;iqR
} a!&m\+?
for(int i=0;i<nEndPos.length-1;i++) |T*t3}
{ 3g0v,7,Zv
nEndPos = nStartPos[i+1]; YdYaLTz
} qy-Hv6oof
nEndPos[nEndPos.length-1] = nFileLength; %4/X;w\3
} g}BS:#$
} cA{,2CYc
\}gITc).j
Re1}aLd
//启动子线程 5X9*K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?9~|K/`l
for(int i=0;i<nStartPos.length;i++) #qEUGD`
{ S@ItgG?X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TUQe.oAi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jzI,B
nStartPos,nEndPos,i); 1NAtg*`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `R-VJR 2"
fileSplitterFetch.start(); c=Zurqj
} m'2EiYX$}\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .G/RQn]x}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |KSoS#Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oCKn
nEndPos = " + nFileLength); +@do<2l]
// fileSplitterFetch[nPos.length-1].start(); `Tr !Gj_
%.:]4jhk
iP?lP= M
//等待子线程结束 7V"Jfh4_
//int count = 0; H$,wg!kY!
//是否结束while循环 ~S0T+4$
boolean breakWhile = false; l i%8X.
\'B%lXh
|e2s{J2
while(!bStop) i>=y3x"
{ C1-Jj_XQ.
write_nPos(); nd h\+7
Utility.sleep(500); pQ`S%]k.<
breakWhile = true; ~b9fk)z!
0}\8,U
k[1w] l8
for(int i=0;i<nStartPos.length;i++) {dvsZJj
{ n&E/{o(
if(!fileSplitterFetch.bDownOver) eM^Y
{ "gXvnl
breakWhile = false; n%{oFTLCo
break; *#B"%;Ln
} V|;os
} D ~NWP%H
if(breakWhile) B\>3[_n
break; _9z+xl
Fz]!2rt
:]`JcJ
//count++; %z["TVH
//if(count>4) k-$J #
// siteStop(); c`#4}$
} oXGP6#
,"T[#A~
^C{?LH/2
System.err.println("文件下载结束！"); 9}11>X
} 6/|"y
catch(Exception e){e.printStackTrace ();} 0"u=g)3
} r6e!";w:U
ZRC7j?ui8`
4Gsq)i17j
//获得文件长度 3\5I4#S
public long getFileSize() }ct*<zj[~u
{ -raZ6?Zjc
int nFileLength = -1; 5:l"*
try{ dg;E,'e_ p
URL url = new URL(siteInfoBean.getSSiteURL()); !jN$U%/,%.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X+//$J
httpConnection.setRequestProperty("User-Agent","NetFox"); ^ANz=`N5,
Cx8 H
.Mzrj{^Y
int responseCode=httpConnection.getResponseCode(); vpu
if(responseCode>=400) Ap`D{u/
{ ~h444Hp=
processErrorCode(responseCode); RH;Kbu
return -2; //-2 represent access is error Cta!"=\
} =5M '+>
Q8bn|#`
6hqqZ
String sHeader; T!Uf PfEI
%* @hS`
p;{w0uld"
for(int i=1;;i++) 6X$iTJ[\x
{ fU4{4M+9"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '59l.
//Utility.log(in.readLine()); -257g;
sHeader=httpConnection.getHeaderFieldKey(i); .%mjE'
if(sHeader!=null) ZHc;8|}
{ *q(HW
if(sHeader.equals("Content-Length")) DZX4c2J
{ 5$ rV0X,O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S3YAc4
break; "QV1G'
} SrXuiiK
} q^b_'We_9
else z0 _/JwJn
break; zKaEh
} Redxg.P
} ^s?i&K,!
catch(IOException e){e.printStackTrace ();} @#| R{5=+
catch(Exception e){e.printStackTrace ();} F2["AkNM
Rj,M|9Y)o
r7N%onx
Utility.log(nFileLength); m{0u+obi&w
SP5t=#M6
n/GJ&qLi:g
return nFileLength; )hK1W\5
} s B!2't
`jCq`-.
wGA%h.[M|
//保存下载信息（文件指针位置） Px"K5c*
private void write_nPos() }ilX 2s?>
{ :a9$f8*b
try{ " qrL:,
output = new DataOutputStream(new FileOutputStream(tmpFile)); F84?Mi{r2
output.writeInt(nStartPos.length); , MU9p*
for(int i=0;i<nStartPos.length;i++) aV?r%'~Z
{ Jl,\^)DSw
// output.writeLong(nPos); ]mvVX31T
output.writeLong(fileSplitterFetch.nStartPos); iMOf];O)
output.writeLong(fileSplitterFetch.nEndPos); TZk.h8
} fT_swhIO
output.close(); Qmn'G4#@E
} E{6X-C[)v
catch(IOException e){e.printStackTrace ();} q"pnFK9/L
catch(Exception e){e.printStackTrace ();} Nh\y@\F>
} t8FgQ)tk
=;A~$[g
~b{j`T
//读取保存的下载信息（文件指针位置） rzgzX
private void read_nPos() Zu%oIk
{ @?"t&h
try{ RlTVx:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )ur&Mnmm
int nCount = input.readInt(); X+XbIbUuL
nStartPos = new long[nCount]; MBH/,Yd
nEndPos = new long[nCount]; &b&o];a
for(int i=0;i<nStartPos.length;i++) $~*d.
{ L\asrdL?=
nStartPos = input.readLong(); "n=Ih_J
nEndPos = input.readLong(); Gu9x4p
} )d-{#
input.close(); EM.rO/qcW
} uDi#a~m@
catch(IOException e){e.printStackTrace ();} %uLyL4*L(p
catch(Exception e){e.printStackTrace ();} W4(O2RU
} :7Q, `W9
{01wW1
Nm/Fc
private void processErrorCode(int nErrorCode) ?YbZVoD)J
{ EaGS}=qY5
System.err.println("Error Code : " + nErrorCode); Y^f12%
} Gk5SG_o
%;9+`U
r#[YBaCZJ
//停止文件下载 /q8?xP.
public void siteStop() >w=xGb7
{ D?"TcA
bStop = true; i<Be)Y-'
for(int i=0;i<nStartPos.length;i++) vmXY}Ul
fileSplitterFetch.splitterStop(); L)ry!BuHI
#FV(a~
o<-+y\J8K
} v{2Vg
} ^~dvA)bH
//负责部分文件的抓取 +(<}`!9M*
**FileSplitterFetch.java i@ avm7
*/ L~FE;*>7
package NetFox; g#ONtY@*U
I:aG(8Bi)H
9jwo f}OU
import java.io.*; ?RD)a`y51
import java.net.*; )(pJ~"'L
h&6x.ps@
&j7l#Urq
public class FileSplitterFetch extends Thread { ai,Mez
]jzINaMav
=JnUTc_u
String sURL; //File URL ico(4KSk
long nStartPos; //File Snippet Start Position c!%:f^7g
long nEndPos; //File Snippet End Position 'HV}Tr
int nThreadID; //Thread's ID PF(P"f.?D
boolean bDownOver = false; //Downing is over ,uP1U@Cas
boolean bStop = false; //Stop identical AcF;5h
FileAccessI fileAccessI = null; //File Access interface 1dK^[;v>3
`&U ['_%
gU}?Yy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9bT,=b;
{ U)p P^:|
this.sURL = sURL; oB$D&
this.nStartPos = nStart; rkl/5z??
this.nEndPos = nEnd; J)n g,i
nThreadID = id; 2aN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wWflZ"%
} O"mU#3?
ASLRP
O!uB|*
public void run() }r/L 9
{ E}qeh"sJt
while(nStartPos < nEndPos && !bStop) -K/' }I
{ 6P;1I+5m{q
D] 2+<;>`>
0nz k?iP
try{ Q_#X*I
URL url = new URL(sURL); 3Pp*ID
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1W HR;!u
httpConnection.setRequestProperty("User-Agent","NetFox"); ? F fw'O
String sProperty = "bytes="+nStartPos+"-"; $/45*
httpConnection.setRequestProperty("RANGE",sProperty); ,Fg&<Be}Jx
Utility.log(sProperty); 0r=Lilu{q
s/Wg^(&M
ASaG }h
InputStream input = httpConnection.getInputStream(); !U/:!e`N
//logResponseHead(httpConnection); (.!q~G
_ #l b\
);;UNO21+
byte[] b = new byte[1024]; eeb8v:4
int nRead; # dxlU/*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |_~BV&g,N
{ $zz=>BOk
nStartPos += fileAccessI.write(b,0,nRead); .?S#DS )
//if(nThreadID == 1) W9V%Xc`LQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AJ:@c7:eS
} :"O=/p+*Us
#D+Fq^="P
6M$.gX G.
Utility.log("Thread " + nThreadID + " is over!"); &H5 6mL{
bDownOver = true; bTHa;* `
//nPos = fileAccessI.write (b,0,nRead); j&m<=-q
} xyz-T1ib
catch(Exception e){e.printStackTrace ();} 5 |C;]pq
} XW]|Mv[M
} %_SE$>v^
?-\KVha
}.zgVLL
//打印回应的头信息 o<P%|>qX
public void logResponseHead(HttpURLConnection con) L +.K}w
{ G68N@g
for(int i=1;;i++) h/(9AO}t
{ 3[aJ=5
String header=con.getHeaderFieldKey(i); dGh<R|U3
if(header!=null) 5'V'~Q%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r?/>t1Z
Utility.log(header+" : "+con.getHeaderField(header)); HNjkRl)QR
else 2 >xV&
break; Gh|1%g"gm
} +S%@/q
} _W#27I
05pCgI}F>
Z@C D1+G
public void splitterStop() s9`T%pg
{ 9R;s;2$.
bStop = true; `(B1 "qRi
} a/)TJv
u{p\8v%7
Bdbw!zRR$
} <6L$:vT_
N{p2@_fnB
<O\z`aA'q
/* p6}jCGJ
**FileAccess.java *%)L?*
*//文件访问(定位，写) vlj|[joXw
package NetFox; 4?yc/F=kI
import java.io.*; ;-]f4O8
)s=z i"
^ACp_RM
public class FileAccessI implements Serializable{ [sKdIw_
#{ Uk4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q}fAAZ&7h
RandomAccessFile oSavedFile; q}\\p
long nPos; GF/p|I D
UN>hJN;c
{&h&:
public FileAccessI() throws IOException >MP PYVn7
{ acGmRP9g
this("",0); wH${q@z_
} m/6oQ
^~`8 - TE
;_Rx|~!!
public FileAccessI(String sName,long nPos) throws IOException ryn)
{ [Z5x_.k"I
oSavedFile = new RandomAccessFile(sName,"rw"); +.lO8
this.nPos = nPos; `chf8
oSavedFile.seek(nPos); y6PAXvv'{
} o$-8V:)6d
dU&.gFw1
>$Fc=~;Ba
public synchronized int write(byte[] b,int nStart,int nLen) mML^kgy\N
{ U<6k!Y9ny
int n = -1; dl":?D4H
try{ 'g=yJ
oSavedFile.write(b,nStart,nLen); ,-b{oS~u
n = nLen; vy"Lsr3
} ;!~;05^iD
catch(IOException e) dIpt&nH&$
{ 'Vrev8D
e.printStackTrace (); /e7'5#v
} /t9w%Y
q/B+F%QiMQ
ASYUKh,h
return n; vSnb>z1
} %cm5Z^B1"
a<Ns C1
FQ-(#[
} ]nQ$:%HP
rL,)Tc|"
YwF6/JA0^
/* =6W:O
**SiteInfoBean.java Zgg7pL)#c
*/ @Op8^8$`
package NetFox; l =_@<p
0zTv'L
<7jb4n<
public class SiteInfoBean { <#s-hQ
=)zq%d?i;
_+Q$h4t
private String sSiteURL; //Site's URL Asn0&Ys4
private String sFilePath; //Saved File's Path MV/~Rmd.
private String sFileName; //Saved File's Name cUm9s>^)/
private int nSplitter; //Count of Splited Downloading File 7GIv3Dc
v:HgpZo+
b?bYPN+
public SiteInfoBean() zgRP!q<9tt
{//nSplitter的缺省值为5 I?Zs|A
//default value of nSplitter is 5 vXnpx}B
this("","","",5); {tT`It
} ~NcJLU!au
NuooA
cdfll+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xBZ9|2Y s
{ apMYBbC
sSiteURL= sURL; c0qv11,:t
sFilePath = sPath; kCwTv:)
sFileName = sName; EIYM0vls(
this.nSplitter = nSpiltter; U.)G#B
7IHD?pnZ
NSgHO`gU8
} ( Lu.^
>C-_Zv<!T\
c==Oio("
public String getSSiteURL() jF3!}*7,
{ 8x9kF]=
return sSiteURL; )>Q 2G/@
} dq8 /^1P
p;7 4+q
kR6 t .
public void setSSiteURL(String value) PPqTmx5S
{ j^ _I{
sSiteURL = value; 3N bn|_`(
} 4y1>!~f
7>zKW?
@*uX[)
public String getSFilePath() 9V],X=y~
{ J@GfO\ o
return sFilePath; )]%9Tgn
} YT5>pM-%
4'd{H Rs
#LN I&5
public void setSFilePath(String value) \i,cL)HM
{ -PnC^r0L$
sFilePath = value; HEuM"2{DMM
} *3/7wSV:
Hr+-ndH!Pq
VBX# !K1Q
public String getSFileName() `es($7}P_W
{ [[e|GQ
return sFileName; (v`;ym
} Y1 P[^ws
V{h@nhq
bNROXiX
public void setSFileName(String value) ,OKM\N,
{ yo*iv+l
sFileName = value; }K>HS\e
} ~t:b<'/
rEhf_[Dv
j&/.[?K
public int getNSplitter() 99!{[gOv
{ 3] qlz?5
return nSplitter; O&,O:b:@
} fl"y@;;#h
9 <KtI7
O$Vm#|$sq
public void setNSplitter(int nCount) gFT~\3jp=
{ t%U[\\ic
nSplitter = nCount; A(n=kx
} m"G N^V7
} "k-ov9yK
\B2d(=~4
O^}v/}d
/* }o^A^
**Utility.java g&4~nEp
*/ z/KZ[qH\
package NetFox; j#e.rNG
#eC;3Kq#-
~RXpz-Ye
public class Utility { B/=q_.1F>
C|f7L>qe
"rGOw'!q>
public Utility() y<`?@(0$
{ q.MVF]
r.W,-%=bL
rh`.$/^
} Yg)V*%0n
M%{?\)s
//线程睡眠 h_~|O[5|)
public static void sleep(int nSecond) R*@[Pg*
{ jBv$^L
try{ 2 1~7{#
Thread.sleep(nSecond); b%;59^4AjD
} L)lQ&z?
catch(Exception e) }[z<iij4
{ v1r_Z($
e.printStackTrace (); )_v\{N
} )@qup _M@
} *e<Eu>fW#&
fcICFReyV
//日志 W3/ 7BW`
public static void log(String sMsg) 5)yOw|Bd
{ "PyWo
System.err.println(sMsg); @%<?GNSO
} yvz?4m"_yB
nnE_OK!}T
FxfL+}?Q
public static void log(int sMsg) `<J#l;y
{ v (ka,Dk3
System.err.println(sMsg); irsfJUr[V
} 3%R{"Q"
} +%wWSZ<#
lKEX"KQ!
~pevU`}Uqc
/* x48'1&m
**TestMethod.java 7B(bH8
*/ `4%;qLxngP
package NetFox; 5_)@B]~nM
3eTrtCe$
ESMG<vW&f
public class TestMethod { *J_iXu|
VD24X
@ EmGexLPM
public TestMethod() ZCQ<%f
{ ///xx/weblogic60b2_win.exe 90s;/y(
try{ '_qQrP#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rKzlK 'U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >`89N'lZBm
SiteFileFetch fileFetch = new SiteFileFetch(bean); MCeu0e^)
fileFetch.start(); @8nLQh^
} qWO]s=V!
catch(Exception e){e.printStackTrace ();} wn+j39y?ZY
j/9WOIfa
\2Og>{"U
} Xlv#=@;O]
-\kXH"%
a jQqj.
public static void main(String[] args) O4EIE)c
{ 4;C*Fa
new TestMethod(); yW\XNX
} {/d4PI7)tK
} {7?9jEj
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