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)); 5~l2!PY
} rPO}6lsc
for(int i=0;i<nEndPos.length-1;i++) ]o*$h$?s
{ )4ncutb
nEndPos = nStartPos[i+1]; O<X )p`,`
} 38wq (
nEndPos[nEndPos.length-1] = nFileLength; kl<g;3
} DL4iXULNY
} <V S2]13
SqqDV)Uih1
J]\^QMX
//启动子线程 -*3(a E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z4@y?fv7s
for(int i=0;i<nStartPos.length;i++) xA-jvu9@
{ ,8VXA +'_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r*Z_+a8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z!Hx @){|
nStartPos,nEndPos,i); cL7C2wB`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |Puj7Ru
fileSplitterFetch.start(); j_c+.iET
} OjATSmZ@@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +WLD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $5L(gn[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'tuBuYD\
nEndPos = " + nFileLength); la`"$f
// fileSplitterFetch[nPos.length-1].start(); Hirr=a3
wY`#$)O0*
ZIW7_Y>_
//等待子线程结束 K~@`o-Z[
//int count = 0; "dq>)JF\
//是否结束while循环 :rmauKR
boolean breakWhile = false; 4(|yD;
0BDS_Rx
w4A#>;Qu*
while(!bStop) `^e*T'UPl
{ +XQPjg
write_nPos(); {aIZFe}B
Utility.sleep(500); Pz1G<eh#{g
breakWhile = true; FfSI n3
. s-5N\
t= *Jg/$
for(int i=0;i<nStartPos.length;i++) Hz?,#>{
{ O{BW;Deo
if(!fileSplitterFetch.bDownOver) %rXexy!V
{ ArX]L$D
breakWhile = false; yxY h?ka
break; 'M-)Os"
} )Y[/!
} 0%H24N 9.
if(breakWhile) }VZM,.w
break; 8<c'x]~
+C5#$5];
XHNkQe
//count++; ==`Pb
//if(count>4) Wl TpX`
// siteStop(); WG\Q5k4Ba
} OPLl*bnf
f}blB?e
wt\m+!u`
System.err.println("文件下载结束！"); tNB%eb{
} Y{j7Q4{
catch(Exception e){e.printStackTrace ();} |?yE^$a
} xD^wTtT
)@,N7Y1h
IywiCMjH
//获得文件长度 V8T#NJ
public long getFileSize() S*s:4uf
{ J@gm@ jLc
int nFileLength = -1; "u5KbJW
try{ PY\W
URL url = new URL(siteInfoBean.getSSiteURL()); T+(M8qb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +K&?)?/=
httpConnection.setRequestProperty("User-Agent","NetFox"); *?p ^6vO
$r):d
Lz?*B$h
int responseCode=httpConnection.getResponseCode(); bw020@O*
if(responseCode>=400) 7?,7TR2Ny
{ Nuo^+z E
processErrorCode(responseCode); ~W3:xnBEk
return -2; //-2 represent access is error ;/R kMS
} _hWuAJ9Qy
yIWc\wv
7|{ B#
String sHeader; "R8.P/ 3
}Zt.*%
R)Q/Ff@o0
for(int i=1;;i++) l[Tt[n
{ @wMQC\Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @Jm.HST#S8
//Utility.log(in.readLine()); {x9j_/R
sHeader=httpConnection.getHeaderFieldKey(i); Xout:dn
if(sHeader!=null) [.ey_}X8
{ 2'Y{FY_Z
if(sHeader.equals("Content-Length")) PY2[S[
{ dK`(BA{`3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7oD y7nV4
break; 6N&|2:U
} ovB=Zm
} Y}S.37|+^
else 3hH>U%`-
break; hcQSB00D^
} 9@Q&B+!
} 1*L^^%w
catch(IOException e){e.printStackTrace ();} 3`xsK[
catch(Exception e){e.printStackTrace ();} jmSt?M0.xV
@K7ebYr?
%n4@[fG%K
Utility.log(nFileLength); k~{Fnkt
>n1h^AW
[#IBYJ.6
return nFileLength; [;*\P\Xih
} 40R"^*
VZHr-z$6n
28ja-1dB
//保存下载信息（文件指针位置） gU~ L@R_D
private void write_nPos() >CH
{ "oHp.$+K
try{ xm^N8
output = new DataOutputStream(new FileOutputStream(tmpFile)); hI*`>9l
output.writeInt(nStartPos.length); |y klT
for(int i=0;i<nStartPos.length;i++) 'y< t/qo
{ _a fciyso
// output.writeLong(nPos); y?"$(%3|
output.writeLong(fileSplitterFetch.nStartPos); akMJ4EF/
output.writeLong(fileSplitterFetch.nEndPos); ccRlql(
} )4@M`8
output.close(); J`4Z<b53
} Y$>+U
catch(IOException e){e.printStackTrace ();} PL9<*.U"=
catch(Exception e){e.printStackTrace ();} *3!(*F@M,
} '^8g9E.4K
#]k0Z~Bl
U[IQ1AEr
//读取保存的下载信息（文件指针位置） E=}6X9X
private void read_nPos() [TP
{ Pb0)HlLq
try{ tp7oc_s?.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tsck|;v
int nCount = input.readInt(); 1X[73
nStartPos = new long[nCount]; Ad^dF'SN
nEndPos = new long[nCount]; SE6>vKR/.
for(int i=0;i<nStartPos.length;i++) UP}feN
{ 3(MoXA*
nStartPos = input.readLong(); 2XzF k_6H
nEndPos = input.readLong(); $K`_ K#A
} ;9}w|!/
input.close(); mluW=fE
} p 7 ,f6kG
catch(IOException e){e.printStackTrace ();} [SK2x4
catch(Exception e){e.printStackTrace ();} ]gH wfqx
} TViBCed40
{F<)z%^
)>ug{M%g
private void processErrorCode(int nErrorCode) eH ;Wfs2f
{ o^8*aH)I>Y
System.err.println("Error Code : " + nErrorCode); 4 U3C~J
} Tw2Xe S
=g/4{IL%
:8](&B68gE
//停止文件下载 -K:yU4V
public void siteStop() Y=AH%Gy9)
{ bjuYA/w<
bStop = true; AqKHjCI
for(int i=0;i<nStartPos.length;i++) | -JI`!7
fileSplitterFetch.splitterStop(); s[Y)d>~\$=
mYntU^4f
_TtX`b_Z
} -b].SG5S
} 1R5Yn(
//负责部分文件的抓取 s.|!Ti!]
**FileSplitterFetch.java N<p5p0
*/ AmP#'U5
package NetFox; ue,#,3{m
<l*agH-.3
rdXCWK$E
import java.io.*; n;e."^5
import java.net.*; 98X!uh'
?lu_}t]
,lrYl!,
public class FileSplitterFetch extends Thread { Tm(Q@
X(4s;i
<]Ij(+J;
String sURL; //File URL FgXu1-
long nStartPos; //File Snippet Start Position 29&sydu
long nEndPos; //File Snippet End Position ^wvH,>Yo
int nThreadID; //Thread's ID qXXYF>Z-
boolean bDownOver = false; //Downing is over CkmlqqUHC
boolean bStop = false; //Stop identical xR\D(FLVS
FileAccessI fileAccessI = null; //File Access interface Hlz'a1\:O]
pw0Px
|Dl*w/n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %M|Z}2qv
{ 8:Z@lp^
this.sURL = sURL; j)g_*\tQ
this.nStartPos = nStart; ST[2]
this.nEndPos = nEnd; 9zXu6<|qrL
nThreadID = id; ^</65+OT+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'CP/ymf/a
} mle_*Gy8
r^?)F?n!
L!CX&
public void run() hB|H9+
{ (%``EIc<8
while(nStartPos < nEndPos && !bStop) !7ei1
{ aK8bKlZe
Mfnlue](
OpWeW
try{ yw;ghP;
URL url = new URL(sURL); UN cYu9[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xI=}z
httpConnection.setRequestProperty("User-Agent","NetFox"); AZh@t?)
String sProperty = "bytes="+nStartPos+"-"; utYnaeQcn
httpConnection.setRequestProperty("RANGE",sProperty); P5'iYahCq_
Utility.log(sProperty); XkMs
t/l!KdY$
FY1},sq
InputStream input = httpConnection.getInputStream(); ioE66-n
//logResponseHead(httpConnection); <'PR;g^#
v7s]
o|R*POM
byte[] b = new byte[1024]; C><<0VhU
int nRead; u=p ;A1oy
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]_^"|RJ
{ \_m\U.*
nStartPos += fileAccessI.write(b,0,nRead); .V5q$5j
//if(nThreadID == 1) \zk?$'d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :FX'[7;p
} +-Z"H)
,pQ'w7
MgJ%26TZ
Utility.log("Thread " + nThreadID + " is over!"); 3a'Rs{qxn
bDownOver = true; h(C#\{V
//nPos = fileAccessI.write (b,0,nRead); :zizca4
} =]_d pEEQ
catch(Exception e){e.printStackTrace ();} mQwk!* U
} t9Enk!@
} *r)zBr
21[K[ %
_&k'j)rg
//打印回应的头信息 7Y-FUZ.`>
public void logResponseHead(HttpURLConnection con) &+)+5z_d
{ 47)+'`
for(int i=1;;i++) K;@RUy~
{ 9_M H
String header=con.getHeaderFieldKey(i); JcvHJ0X~a
if(header!=null) ]FY?_DGOA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KKx&UKjV
Utility.log(header+" : "+con.getHeaderField(header)); SR&(HH$
else #~bU}[{
break; Zu2m%=J`
} @Og\SZhn
} @{J!6YGh
N.fQ7z=Z(M
"e1{V8 4
public void splitterStop() hj^G}4
{ E5,%J
bStop = true; ?~VWW<lR
} VfL]O8P>
6=Y3(#Ddt
c]AKeq]
} mhHA!:Y
rd&*j^?
EmtDrx4!(f
/* U~u6}s]:
**FileAccess.java dCf'\@<<
*//文件访问(定位，写) Bo](n*i
package NetFox; p`E|SNt/W
import java.io.*; f"5lOzj`C
&y#\1K
,$MWk(S
public class FileAccessI implements Serializable{ nvO%
EuKrYY]g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;#5-.z
RandomAccessFile oSavedFile; 7AGZu?1]M
long nPos; L:t)$iF5+
%KJ"rvi4K
(c|$+B^*
public FileAccessI() throws IOException Jf%!I
{ n}AR/3}
this("",0); "W?l R4
} {<- ouD
Pqr Ou
7':5
public FileAccessI(String sName,long nPos) throws IOException (]zl$*k
{ k=h/i8i2z
oSavedFile = new RandomAccessFile(sName,"rw"); 5p]urfN-f
this.nPos = nPos; WryW3];0OR
oSavedFile.seek(nPos); )*^OPVt
} >j(I[_g
gZ`#tlA~
iGEQXIr3
public synchronized int write(byte[] b,int nStart,int nLen) E i\J9zt
{ )RAv[U1
int n = -1; SxLHFN]
try{ r 48;_4d)D
oSavedFile.write(b,nStart,nLen); q_9N+-?{7
n = nLen; nK?k<
} DU*g~{8T$
catch(IOException e) .v #0cQX+.
{ 8T>3@kF
e.printStackTrace (); y]QQvCJr3d
} |*]X\UE
,%)WT>
&;NNUT>Q
return n; ((RpT0rP\
} #whO2Mv
fJF8/IQ4
V\k5h
} 7)8rc(58
np'M4^E;
w{YtTZp3
/* ;H m-,W
**SiteInfoBean.java &geOFe}R
*/ 5H'b4Cyi`
package NetFox; (04j4teE
Ru9pb~K
6?<`wGs(
public class SiteInfoBean { , IMT '*
EvH(Po h
=XRgT1>e
private String sSiteURL; //Site's URL .^9/ 0.g8t
private String sFilePath; //Saved File's Path Q8DQ .C
private String sFileName; //Saved File's Name %WJ{IXlz
private int nSplitter; //Count of Splited Downloading File bY"eC i{K
Ol/2%UJXL
AT8B!m
public SiteInfoBean() cOZajC<G
{//nSplitter的缺省值为5 9|G=KN)P:
//default value of nSplitter is 5 "b1R5(Ar
this("","","",5); K;ry4/Vap
} ^;bGP.!p
35@Ibe~
e%@[d<Ta\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4s1kZ`e
{ P5 <85t
sSiteURL= sURL; 1^WA
sFilePath = sPath; QX.F1T2e?
sFileName = sName; t;e]L'z@:
this.nSplitter = nSpiltter; of[|b{Ze4~
yNWbI0a
W"}*Q-8W
} 6M<mOhp@}n
N8L)KgM5#7
V"2AN3~&
public String getSSiteURL() H,4,~lv|
{ g*w-"%"O
return sSiteURL; -%/,j)VKD
} <-oRhi4
ZZFI\o
HZr/0I?
public void setSSiteURL(String value) =DF@kR[CH"
{ 1+i
sSiteURL = value; v0jz)z<#
} b]s1Q ]V
/xrq'|r?C
`>Kk;`
public String getSFilePath() "'H7F,k'
{ k>z-Zg
return sFilePath; "]\":T
} BorfEv} SN
P+zI9~N[
@x-GbK?
public void setSFilePath(String value) Kz*AzB
{ iqv\ag
sFilePath = value; k`4\.m"&
} E*T84Jh6
$O]E$S${
d8BK/b
public String getSFileName() kAQ\t?`x
{ Vp-OGX[
return sFileName; cwW~ *90#
} -m x3^
n5,Pq+[
&<#BsFz
public void setSFileName(String value) Kn9=a-b?,
{ [>]VN)_J5
sFileName = value; u2.r,<rC*Q
} 2S10j%EeI
WCfe!P?g
9:Z~}yX
public int getNSplitter() tL4]6u
{ vM4`u5
return nSplitter; kq.R(z+
} F0ivL`
ks`
CR<pB)F?a
public void setNSplitter(int nCount) )'I<xx'1
{ PS<tS_.
nSplitter = nCount; W-ND<=:Up
} ,"MUfZ
} buM>^A"
vM3|Ti>a'
eS# 0-
/* 6~Oje>w;
**Utility.java Vqp.jF1|
*/ d<cbp[3F
package NetFox; Exs _LN
+MoxvW6
+fQ$~vr{'
public class Utility { O>):^$-K%
KZ >"L
tIy/QN_42
public Utility() 2mp>Mn~K^
{ E~O>m8hF
)I UWM
.N><yQ-j3'
} +5}T!r
|(w#NE5
//线程睡眠 ;<)-*?m9
public static void sleep(int nSecond) C"|_j?
{ d@`:9 G3
try{ /t6u"I~
Thread.sleep(nSecond); Hr,gV2n
} =/'*(\C2
catch(Exception e) -8kW!F
{ Eq.zCD8A
e.printStackTrace (); nhxd
} K[;,/:Y
} U[ O!&:6
^EBM;&;7
//日志 3UtXxL&L`
public static void log(String sMsg) y?4=u,{C
{ p`.fYW:p
System.err.println(sMsg); 2+Y`pz47W
} iwTBE]J
BL^Hj
PaI63 !
public static void log(int sMsg) o|n0?bThS-
{ hahD.P<
System.err.println(sMsg); SSM> ID
} @:&dOqQ
} MJR\ g3
..{^"`FQ
^aM/BS\
/* 5+"8q#X$
**TestMethod.java <@ex})su
*/ LzSusjEW@
package NetFox; b020U>)v
7 ,~Krzv
,ui'^8{gK
public class TestMethod { WG=r? xE
Jj!tRZT
5:3$VWLa <
public TestMethod() krY.Cc]
{ ///xx/weblogic60b2_win.exe WjxBNk'f
try{ {"AYOc>2|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s+G9L)b'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5{f/H] P
SiteFileFetch fileFetch = new SiteFileFetch(bean); zw:b7B]
fileFetch.start(); zYJ`.,#C 5
} a9JJuSRC
catch(Exception e){e.printStackTrace ();} Vk=<,<BB
Vx8.FNJh
m`0{j1K
} c)~|#v
r<H^%##,w
I{UB!0H
public static void main(String[] args) 7ib<Cb>K
{ #yOY&W:N
new TestMethod(); znpZ0O\!
} 0`zq*OQ
} `,=p\g|D
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