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)); Glwpu-@X
} {Xp.}c
for(int i=0;i<nEndPos.length-1;i++) ?-VN+ d7
{ &a:aW;^A7
nEndPos = nStartPos[i+1]; N+tS:$V
} {/Cd^CK
nEndPos[nEndPos.length-1] = nFileLength; ~)Z`Q
} D9Z5g3s7R
} _&M>f?l
`+6HHtF
A gPg0(G
//启动子线程 V+8+ 17^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w;_Ds
for(int i=0;i<nStartPos.length;i++) WS(c0c
{ &zT~3>2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w5;EnI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k9,"`dk@
nStartPos,nEndPos,i); Y}6)jzBV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UvI!e4_
fileSplitterFetch.start(); pI!55w|
} )ad-s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w7C=R8^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o#Y1Uamkf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IIPf5 Z}A
nEndPos = " + nFileLength); pxF!<nN1,
// fileSplitterFetch[nPos.length-1].start(); 9f@)EKBK
0(kp>%mbB
+u#x[xO
//等待子线程结束 vZxy9Wmc
//int count = 0; 0jmlsC>
//是否结束while循环 ?m!FM:%
boolean breakWhile = false; .jKO 6f
zk]~cG5dT/
e'6?iLpy
while(!bStop) ..t=Y#
{ 8ah]D
write_nPos(); r:IU+3
Utility.sleep(500); OTm`i>rB
breakWhile = true; r3kI'I|bq
RoTT%c P_
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for(int i=0;i<nStartPos.length;i++) phdN9<Z
{ c1^3lgPv
if(!fileSplitterFetch.bDownOver) p c],H
{ +D@R'$N
breakWhile = false; ?,NAihN]
break; oW_WW$+N
} (nzt}i0
} V6k9L*VP
if(breakWhile) `et<Z
break; *v9G#[gG
[>0r'-kI
+M*a.ra0OF
//count++; 8M|Q^VeT,1
//if(count>4) ,aJrN!fzU
// siteStop(); vEsSqzc
} 2R!W5gs1<
}FXRp=s
3XRG"
System.err.println("文件下载结束！"); D6t]E)FH
} *E]\l+]J
catch(Exception e){e.printStackTrace ();} lySaJd
} NSq"\A\
-AE/,@\P
<'-me09C*
//获得文件长度 (0+m&, z
public long getFileSize() $W]bw#NH
{ Oc.>$
int nFileLength = -1; NEk [0
try{ =FnZkJ
URL url = new URL(siteInfoBean.getSSiteURL()); Jj " {r{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #t O!3=0
httpConnection.setRequestProperty("User-Agent","NetFox"); >U)O@W)
sn(}5;
`9-Zg??8r
int responseCode=httpConnection.getResponseCode(); J$;)TI
if(responseCode>=400) }>w4!
{ 4Z] 35*
processErrorCode(responseCode); C#Jj;Gd
return -2; //-2 represent access is error kQ8WO|bA
} tpN}9N
UwU]l17~
UL%ihWq
String sHeader; F?B=:8,}
#k)\e;,X
ooQ(bF
for(int i=1;;i++) B^9 #X5!
{ .yPx'_e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZTZE_[
//Utility.log(in.readLine()); H~Cfni;
sHeader=httpConnection.getHeaderFieldKey(i); TE~@Bl;{?c
if(sHeader!=null) H JiP:{
{ ]@YQi<d2^
if(sHeader.equals("Content-Length")) C)w*aU,(
{ ,whNh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mxGN[%ve
break; V*}zwms6
} m##=iB|;
} 9:o3JGHSc
else %Qq)=J<H;
break; Xdt+\}\
} K}BX6dA
} w C"%b#(}
catch(IOException e){e.printStackTrace ();} S41>VbtEp
catch(Exception e){e.printStackTrace ();} P{18crC[1
SO/]d70HG
pZxL?N!
Utility.log(nFileLength); ;\+0H$
*q{UipZbx
$Stu-l1e a
return nFileLength; $P3nP=mf
} [3Rj?z"S
5b p"dIe
Qs:r@"hE
//保存下载信息（文件指针位置） s 'xmv{|
private void write_nPos() A]$+ `uS\
{ k#xpY!'7
try{ T"U t).
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5g5NTm`=<
output.writeInt(nStartPos.length); GwBQ pNjy
for(int i=0;i<nStartPos.length;i++) |T*qAJ8c
{ R:N-y."La.
// output.writeLong(nPos); +ctv]'P_
output.writeLong(fileSplitterFetch.nStartPos); K5&C}Ey1
output.writeLong(fileSplitterFetch.nEndPos); LnS>3$t*
} MFuI&u!g:
output.close(); c ?XUb[
} avu,o
catch(IOException e){e.printStackTrace ();} ;!?K.,N:N
catch(Exception e){e.printStackTrace ();} o"[bIXf-h
} $:!T/*p*
Hw&M2a
Bq_P?Q+\
//读取保存的下载信息（文件指针位置） 1o>R\g3
private void read_nPos() 8[;oUVb5
{ (B<AK4G
try{ KTt$Pt/.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xkom@F~]
int nCount = input.readInt(); ton`ji\^
nStartPos = new long[nCount]; :g[x;Q[@
nEndPos = new long[nCount]; {LHe 6#
for(int i=0;i<nStartPos.length;i++) X>7]g670@
{ rJp6d:M
nStartPos = input.readLong(); ]bb}[#AY
nEndPos = input.readLong(); C}_:K)5q
} (y*X8
input.close(); |wQZ~Ux:
} ue<<Y"NR
catch(IOException e){e.printStackTrace ();} WG}CPkj
catch(Exception e){e.printStackTrace ();} "B3:m-'
} X@U1Ri
**w~
y4We}/-<
private void processErrorCode(int nErrorCode) H^;S}<pxW
{ U^BXCu1km
System.err.println("Error Code : " + nErrorCode); 2_n*u^X:_
} 3Lki7QW`
K/v-P <g
cu!bg+,zl
//停止文件下载 9Pk3}f)a
public void siteStop() i03}f%JnuO
{ ^jjJM|a
bStop = true; E:=KH\2f
for(int i=0;i<nStartPos.length;i++) x*8f3^ wE
fileSplitterFetch.splitterStop(); E(kpK5h{
SoU'r]k1x
Pl&`&N;
} =v$s+`cP
} KGmc*Jwy
//负责部分文件的抓取 wn|@D<
**FileSplitterFetch.java ^@L l(?
*/ I7z/GA\x
package NetFox; J?quYlS
cN}A rv
&d3'{~:
import java.io.*; I@Z*Nu1L
import java.net.*; np\2sa`
*M<BPxh0w]
Dh(T)yc
public class FileSplitterFetch extends Thread { !riMIl1
f\_!N "HW
[j]J_S9jJ
String sURL; //File URL ec4%Wk2
long nStartPos; //File Snippet Start Position ]!G>8Rc
long nEndPos; //File Snippet End Position <`j[;>O
int nThreadID; //Thread's ID 2vdQ&H4
boolean bDownOver = false; //Downing is over *a,.E6C*
boolean bStop = false; //Stop identical ) v5n "W
FileAccessI fileAccessI = null; //File Access interface 7h9[-d6
4O_+4yS
3r:)\E+Q_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *r,&@UB
{ :8Ts'OGwI
this.sURL = sURL; eOPCYyN
this.nStartPos = nStart; k.xv+^b9Q
this.nEndPos = nEnd; @*O{*2
nThreadID = id; R5&$h$[/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ->2wrOH|H
} %^?3s5PXD
uj9tr`Zh
P,;b'-5C
public void run() %>9+1lUhV
{ -C-OG}XjI
while(nStartPos < nEndPos && !bStop) 9#T%bB"J
{ ?V)C9@bp
1;:t~Y
nR@,ouB-$
try{ +>:_kE]?nX
URL url = new URL(sURL); `TD%M`a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?I2k6%a
httpConnection.setRequestProperty("User-Agent","NetFox"); ?WQd
String sProperty = "bytes="+nStartPos+"-"; Fr3d#kVR
httpConnection.setRequestProperty("RANGE",sProperty); pG F5aF7T
Utility.log(sProperty); CziaxJ
x"llX
g[wP!y%V
InputStream input = httpConnection.getInputStream(); opcR~tg@r
//logResponseHead(httpConnection); O})u'
J={OOj
H")N_BB
byte[] b = new byte[1024]; /=YqjZTCq
int nRead; B#k3"vk#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5 2@udp
{ a j@C0
nStartPos += fileAccessI.write(b,0,nRead); T5dUJR2k$
//if(nThreadID == 1) $dZ>bXUw:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &. =}g]
} Z"n'/S:q
/pIb@:Y1?
T7lj39pJq
Utility.log("Thread " + nThreadID + " is over!"); ,+\4 '`
bDownOver = true; *0&4mi8
//nPos = fileAccessI.write (b,0,nRead); 2 ]DCF
} 7Z`Mt9:Ht
catch(Exception e){e.printStackTrace ();} N[bR&#p
} %%+mWz a
} ~ACP%QM=
SGBVR^
!M]%8NTt2
//打印回应的头信息 x?f0Hk+
public void logResponseHead(HttpURLConnection con) o[6vxTH
{ (o*e<y,}W
for(int i=1;;i++) vTMP&a'5L
{ 4kaE}uKU
String header=con.getHeaderFieldKey(i); xOVA1pb,
if(header!=null) o!s%h!%L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $d2kHT
Utility.log(header+" : "+con.getHeaderField(header)); {8{t]LK<
else 8_<&f%/
break; esh$*)1
} u 5Eo
} ^x_ >r6
;zZ,3pl-E
ovQS ET18b
public void splitterStop() ~}$\B^z+
{ q?;*g@t
bStop = true; 4/HY[FT
} |6sT,/6
% UW=:
A#Q0{z@H
} Ox7uG{t$#
1Nl&4YLO
Q/QQ:t<XUi
/* qab) 1ft
**FileAccess.java VBbUl|X\
*//文件访问(定位，写) )BF \!sTn
package NetFox; u>,lf\Fgz
import java.io.*; XN~#gm#
e0v9uQ%F5
`jb0+{08
public class FileAccessI implements Serializable{ ^o $W
[j:}=:feQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZRXI?Jr%
RandomAccessFile oSavedFile; MfXt+c`r
long nPos; ~A[YnJYA#
8/Et&TJ`
IOsXPf9@
public FileAccessI() throws IOException uQ:ut(
{ VD9 q5tt7
this("",0); vx\nr8'k
} y3={NB+
`d}W;&c
I"8d5a}
public FileAccessI(String sName,long nPos) throws IOException j<l#qho{h
{ 8qFUYZtY
oSavedFile = new RandomAccessFile(sName,"rw"); 69[V <1
this.nPos = nPos; < 72s7*Rv
oSavedFile.seek(nPos); Yl)eh(\&J
} ERp:EZ'
i(M(OR/4
u;+%Qh
public synchronized int write(byte[] b,int nStart,int nLen) $:f.Krj
{ tk`: CT *
int n = -1; 84[|qB,ML
try{ }iPo8Ra
oSavedFile.write(b,nStart,nLen); tXf}jU}
n = nLen; 2j8Cv:{Nn%
} #joF{M{
catch(IOException e) }': EJ~H
{ /{fZH,!L
e.printStackTrace (); F3r S6_
} 9USrgY6_
!: m`9o8
"t5 +*
return n; "2ZIoa!^
} u{g]gA8s
:FoOQ[Q
<WM -@J(1
} x9xzm5
DgDSVFk ~
2-8YSHlh
/* .HyjL5r-
**SiteInfoBean.java }Q`/K;yq
*/ pGY [f@_x-
package NetFox; Y[f,ia
b%3Q$wIJ6
W:`5nj]H9
public class SiteInfoBean { 6b%`^B\
l*QIoRYFW
- waX#UT=
private String sSiteURL; //Site's URL rU; g0'4e
private String sFilePath; //Saved File's Path 8'3"uv
private String sFileName; //Saved File's Name AU0$A403
private int nSplitter; //Count of Splited Downloading File ow-+>Y[qZ
Ezi' 2Sc
"I5uDFZR&
public SiteInfoBean() |*%/ovg+
{//nSplitter的缺省值为5 jZa25Z00
//default value of nSplitter is 5 >oe4mW
this("","","",5); B1y<.1k
} 6eD(dZ
`ajx hp
h^['rmd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;rNd701p"
{ `!zQ
sSiteURL= sURL; n)tU9@4Np
sFilePath = sPath; B:e.gtM5
sFileName = sName; vAi"$e
this.nSplitter = nSpiltter; NV:>a
Mx^y>\X)v
kXigX-
} b+W)2rFO
ah 4kA LO
*]FgfttES
public String getSSiteURL() 'n>K^rA
{ $X`bm*
return sSiteURL; Mg#`t$u
} U%Dit
{*sGhGwr
0xN!DvCg>.
public void setSSiteURL(String value) (2: N;
{ <H<!ht%q3
sSiteURL = value; \.5F](:
} .H ,pO#{;
Dp^"J85}
E yd$fcRK
public String getSFilePath() @o`sf-8x
{ +IvNyj|
return sFilePath; "Lb fF
} n.@#rBKZ
aZP2R"
z|uOJ0uK
public void setSFilePath(String value) ]n~yp5Nbr
{ eUYZxe :6
sFilePath = value; P=2wkzeJj
} w(/7Jt$
sD{j@WEZ
bdCykG-
public String getSFileName() x,w8r+~5
{ yXkt:O,i
return sFileName; _0w1kqW
} `q^(SM
^Fn%K].X
Bu&So|@TL
public void setSFileName(String value) [Uswf3
{ S[Vtq^lU
sFileName = value; |0lLl^zp
} kPWBDpzN
:RHm*vt
p*Xix%#6
public int getNSplitter() K6-6{vt
{ 5Wo5n7o
return nSplitter; YDW|-HIF
} jg?bf/$s
%W(^6p!
nkTYWw
public void setNSplitter(int nCount) )u<eO FI+
{ C B6A}m
nSplitter = nCount; vlvvi()
} _wmI(+_
} 00"CC
/\d(c/,4
rjXnDh]MC
/* *u}'}jC1X
**Utility.java 3\1#eK'TK.
*/ h 5Hr[E1
package NetFox; Sg_O?.r
9YAM#LBTWi
*-6?
public class Utility { iM"asEU
v_.HGGS
0JK2%%
public Utility() +N7"EROc
{ 0iF-}o
ndqckT@93
eIsT!V"7
} )Z("O[
p=H3Q?HJ}
//线程睡眠 s"q=2i
public static void sleep(int nSecond) &Bm&i.r
{ 02(h={
try{ qIz}$%!A
Thread.sleep(nSecond); 0t+])>
} CG.,/]_
catch(Exception e) %Uf'+!4l`
{ >otJF3zw
e.printStackTrace (); Xo\S9,s{
} \X5 3|Y;=
} ';Nu&D#Ph
G0Hs,B@5?
//日志 1 =^
public static void log(String sMsg) sCkO0dl8
{ (vnoP< 0
System.err.println(sMsg); Cs#w72N
} JYQ.EAsr!
)nOE8y/
ctHEEFWm
public static void log(int sMsg) F{\=PCZ>7
{ *,&S',S-
System.err.println(sMsg); 9n"V\e_R
} Kr]z]4.d@
} kutJd{68
>L=;"+B0U&
modC6d%
/* "W5rx8a
**TestMethod.java #3+~.,X9
*/ 0p `")/
package NetFox; ke\[wa_!6b
W+\?~L.
`c9'0*-
public class TestMethod { l!:^6i
lm*g Gy1i
2T?TM! \Q
public TestMethod() zqf[Z3
{ ///xx/weblogic60b2_win.exe o,*=$/or
try{ x6v,lR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BPewc9RxV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P$OUi!"
SiteFileFetch fileFetch = new SiteFileFetch(bean); xCq'[9oU
fileFetch.start(); tDt :^Bc
} NH4?q!'G
catch(Exception e){e.printStackTrace ();} SO_>c+Dw
s4bv;W
5z Kqb
} ]Jn2Ra"j
JD*8@N
N2Ssf$
public static void main(String[] args) >Nh`rkR2[
{ = ^s$ <
new TestMethod(); l `R KqT+
} /NU103F yt
} ke]Yfwk
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