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)); 86fK=G:>
} +'KE T,
for(int i=0;i<nEndPos.length-1;i++) W#I:j: p
{ ,M.!z@
nEndPos = nStartPos[i+1]; Y{vwOs
} k_>Fw>Y
nEndPos[nEndPos.length-1] = nFileLength; )kKmgtj
} o Xi}@
} A]Tcj^#
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ds;cfj[
//启动子线程 .#55u+d,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [Am`5&J
for(int i=0;i<nStartPos.length;i++) |( 9#vt#
{ V!77YFen %
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RB7AI!'a?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8+ F}`lLA
nStartPos,nEndPos,i); 76A>^Bs\/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GyAgPz
fileSplitterFetch.start(); dMs||&|&
} 2FIR]@MQd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +O$:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _gm?FxV:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,ah*!Zm.kk
nEndPos = " + nFileLength); #3K,V8(
// fileSplitterFetch[nPos.length-1].start(); [Z5[~gP3
Zfy~mv$
4s~HfxYT
//等待子线程结束 H8$<HhuZM
//int count = 0; AwXt @!(
//是否结束while循环 ^+%tlX_+.
boolean breakWhile = false; t'Eb#Nup3
G_M:0YI@
?QMclzh*-
while(!bStop) !/6\m!e|1R
{ b-BM"~N'
write_nPos(); #PslrA. E
Utility.sleep(500); _2m[(P9d
breakWhile = true; yS)-&t!;
f `y" a@
_}zo /kDA
for(int i=0;i<nStartPos.length;i++) Wm)-zvNY;
{ jF2[bzY4
if(!fileSplitterFetch.bDownOver) }F{C= l2
{ f2 ydL/M,
breakWhile = false; qE0FgqRB
break; ?""\
} CZJHE>
} X'FEOF
if(breakWhile) =t3vbV
break; QB/7/PW{H\
8 "_Bq
{_zV5V
//count++; \E$1lc
//if(count>4) N7*CP|?E
// siteStop(); .Vo"AuC}
} |66m` <
3(!/["@7
cBifZv*l
System.err.println("文件下载结束！"); F0&~ ?2nG
} Ap]4QqU
catch(Exception e){e.printStackTrace ();} 0)d?Y
} vWU%ST
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+_qh)HX
//获得文件长度 f?%qUD_#
public long getFileSize() `'p`PyMt`
{ (2z%U
int nFileLength = -1; m|]j'g?{}(
try{ ,b<9?PM
URL url = new URL(siteInfoBean.getSSiteURL()); 5<89Af&&K8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cMDRWh
httpConnection.setRequestProperty("User-Agent","NetFox"); Ia=_78MgZ
k)`$%[K8
!0Idp%
int responseCode=httpConnection.getResponseCode(); `n 3FT=
if(responseCode>=400) \F 3C=M@:
{ S dIGU[fm
processErrorCode(responseCode); j%pCuC&"
return -2; //-2 represent access is error \ V6
} }{ n\tzR
+0]'| tF>
g<fDY6jt
String sHeader; WP5VcBC
aZ`<PdA
9nn>O?
for(int i=1;;i++) /61by$E
{ LGIalf*7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ispkj'
//Utility.log(in.readLine()); 0Tcz[$?
sHeader=httpConnection.getHeaderFieldKey(i); 2;:lK":
if(sHeader!=null) !\CG,Ek
{ CN7k?JO<
if(sHeader.equals("Content-Length")) su&t7rJ
{ #G3` p!"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .i$,}wtw
break; ^8:VWJM
} "H>.':c"+3
} hG=k1T%=
else [UMLx
break; ?VB#GJ0M9
} bA}Z0a
} rO0ZtC{K
catch(IOException e){e.printStackTrace ();} %c]nWR+/
catch(Exception e){e.printStackTrace ();} ;a|`s
t)9]<pN%
[s~JceUyX
Utility.log(nFileLength); *4t-e0]j@w
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q(IZJGb
return nFileLength; :$=|7v
} rFo\+//
}sv!=^}BY3
ejVdxVr\7
//保存下载信息（文件指针位置） 5MxH)~VQoM
private void write_nPos() WSQ[.C
{ P/ci/y_1
try{ Va7c#P?
output = new DataOutputStream(new FileOutputStream(tmpFile)); BRb\V42i;
output.writeInt(nStartPos.length); 20aZI2sk`
for(int i=0;i<nStartPos.length;i++) S?L#N
{ Go1(@
// output.writeLong(nPos); eJ)1K
output.writeLong(fileSplitterFetch.nStartPos); %tV32l=
output.writeLong(fileSplitterFetch.nEndPos); SBTPTb
} :X_CFW
output.close(); :r&iMb:Ra
} wUoiXi09
catch(IOException e){e.printStackTrace ();} ,9mgYp2
catch(Exception e){e.printStackTrace ();} e8,{|a
} h3kaD
CM9XPr
|QVr`tE<
//读取保存的下载信息（文件指针位置） Gzw@w{JBL
private void read_nPos() A:eFd]E{(
{ PL@~Ys0
try{ FEF"\O|Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L}$z/jo
int nCount = input.readInt(); /s:w^g~
nStartPos = new long[nCount]; &|b4\uj9
nEndPos = new long[nCount]; )CLf;@1
for(int i=0;i<nStartPos.length;i++) y;nvR6)
{ daslaa_A
nStartPos = input.readLong(); ca(U!T68
nEndPos = input.readLong(); f^p^Y F+
} EUy(T1Cl&&
input.close(); xYI;V7
} .n`( X#,*l
catch(IOException e){e.printStackTrace ();} 6\4Z\82
catch(Exception e){e.printStackTrace ();} l&L,7BX
} @RGDhwS47
CbOCk:,g5
GRT]aw
private void processErrorCode(int nErrorCode) 3pSj kS|?>
{ 8Atq,GcG
System.err.println("Error Code : " + nErrorCode); jH>8bXQqZ
} &vkjmiAS
;L~p|sF
i@5)`<?
//停止文件下载 R_1qn
public void siteStop() H_w%'v&
{ l4vTU=
bStop = true; 4(=kE>n}
for(int i=0;i<nStartPos.length;i++) R4{-Qv#8 q
fileSplitterFetch.splitterStop(); E1 |<Pt
"_< 9PM1t
8[zb{PRu
} cJDd0(tD!
} M-J<n>hl
//负责部分文件的抓取 LL(|$}yW
**FileSplitterFetch.java ZyI$M3{J
*/ +j{Y,t{4
package NetFox; eY,O@'"8`
BLn_u,3
$.rzc]s
import java.io.*; Zw{MgoJ0Z
import java.net.*; M0L&~p_F
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public class FileSplitterFetch extends Thread { 8#X_#
>2b`\Q*<
rp's
String sURL; //File URL pu9^e4B9
long nStartPos; //File Snippet Start Position 7Xg?U'X
long nEndPos; //File Snippet End Position ?Go!j?#a
int nThreadID; //Thread's ID aD9q^EoEs
boolean bDownOver = false; //Downing is over 3[d>&xk@$
boolean bStop = false; //Stop identical @;iXp>&&
FileAccessI fileAccessI = null; //File Access interface 6L9,'Bg
WOX}Sw"
yZCX S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .[:VSM7T
{ 8{0k0 &x
this.sURL = sURL; :Q_3hK
this.nStartPos = nStart; @gY\;[#.
this.nEndPos = nEnd; tY+$$GSQj
nThreadID = id; vXv;1T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [AS}RV
} ]$A(9Pn"
~#PLAP3-
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public void run() XNehPZYS
{ -Z0+oU(?YE
while(nStartPos < nEndPos && !bStop) T2FE+A]n9
{ g(Yb^'X/
*?t%0){
i"r!w|j
try{ 65TfFcQ<S
URL url = new URL(sURL); &GhPvrxI?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MHi8E9_O
httpConnection.setRequestProperty("User-Agent","NetFox"); )Si2u5
String sProperty = "bytes="+nStartPos+"-"; YKZa$@fA?
httpConnection.setRequestProperty("RANGE",sProperty); @1-F^G%p8
Utility.log(sProperty); z6*<V5<7
(JUZCP/\
`P}9i@C
InputStream input = httpConnection.getInputStream(); }V]R+%:w@
//logResponseHead(httpConnection); !H@0MQ7
g}x(hF
:E&g%'1
byte[] b = new byte[1024]; YXW%]Uy+
int nRead; (MLwQiop
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "V&I^YSc>
{ |[$~\MU
nStartPos += fileAccessI.write(b,0,nRead); 7f{=w, U
//if(nThreadID == 1) \ZI'|Ad
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;dR=tAf0$Q
} ?D`T7KSe~D
k*mt4~KLT8
7zemr>sIh
Utility.log("Thread " + nThreadID + " is over!"); 5jB*fIz
bDownOver = true; UUc8*yU)
//nPos = fileAccessI.write (b,0,nRead); NSQp< m
} 0Ua%DyJ
catch(Exception e){e.printStackTrace ();} ;30nd=
} XH}'w9VynR
} 9X$ma/P[
a<~77~"4wn
eHiy,IN
//打印回应的头信息 O%8EZyu
public void logResponseHead(HttpURLConnection con) 9(4&KZpK
{ R?o$Y6}5
for(int i=1;;i++) c!K]J
{ *Hz^K0:8(
String header=con.getHeaderFieldKey(i); V)(R]BK{
if(header!=null) AlXNg!j;5K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J aTp}#
Utility.log(header+" : "+con.getHeaderField(header)); 457\&
else kF"@Ngv.
break; @#g<IBG=*
} 6( CDNMzj
} BZ!v%4^9
;!!n{l$r'
&-d&t` `
public void splitterStop() 9H-|FNz?c
{ %a+mk E
bStop = true; G+UMBn
} 6 5N~0t
#X 52/8G
j)C,%Ol
} H,nec<Jp
o%9*B%HO/
{(U %i\F\
/* /1mW|O>0
**FileAccess.java ,I1RV
*//文件访问(定位，写) 0j"8@<
package NetFox; }X*Riu7gk
import java.io.*; D=m'pL/pl
#P l~R
VXIP0p@
public class FileAccessI implements Serializable{ z|EEVNFd&
Sz- Jy:j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p2Zo
RandomAccessFile oSavedFile; 7Mb#O_eh
long nPos; ~cTN~<{dq
+_XzmjnDd
.Asv%p[W
public FileAccessI() throws IOException Lzu.)C@Amx
{ ho##Z*O
this("",0); )E@A0W
} @=}YTtq
r\qj!
W`\R%>$H
public FileAccessI(String sName,long nPos) throws IOException C{gyj}5
{ v\m ]A1
oSavedFile = new RandomAccessFile(sName,"rw"); Zjbc3M5
this.nPos = nPos; 3)\8%Ox
oSavedFile.seek(nPos); MrZh09y
} t2,A@2DU2
+s- lCz
):i&`}SY
public synchronized int write(byte[] b,int nStart,int nLen) CC#;c1t
{ d ,4]VE
int n = -1; Ecd;<$tk
try{ ,lZB96r0
oSavedFile.write(b,nStart,nLen); ,AxdCT
n = nLen; QUu}Xg:
} G:~k.1y[
catch(IOException e) &f^,la
{ \"X!2
e.printStackTrace (); tjupJ*Rt
} C:PMewn
O3I8k\`
:<}=e@/~|
return n; >-H{Z{VDd
} ?b(=1S\E'^
?VP8ycm
N5a*7EJv+
} ?OkWe<:4
sBr_a5QQ#
vI>>\.ED
/* .zi_[
**SiteInfoBean.java o4|M0
*/ E[/\7v\
package NetFox; SQX:7YF~
RhncBKm*M
Ney/[3 A
public class SiteInfoBean { 8C*c{(4
SHe49!RA'{
8_{X1bj
private String sSiteURL; //Site's URL Z'"tB/=W
private String sFilePath; //Saved File's Path :]\([Q+a
private String sFileName; //Saved File's Name eEuvl`&
private int nSplitter; //Count of Splited Downloading File _d5QbTe
"wNJ
9I}-[|`u
public SiteInfoBean() ,6-:VIHQ
{//nSplitter的缺省值为5 Wk)OkIFR
//default value of nSplitter is 5 7@D@ucL
this("","","",5); #"@|f
} *MKO I'
IZpP[hov
G"h'_7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 03q5e
{ < jJ
sSiteURL= sURL; 3yVMXK
sFilePath = sPath; G3Z)Z)N
sFileName = sName; %J+E/
this.nSplitter = nSpiltter; #1OOU
bbE!qk;hEP
As'=tIro
} 8X[:j&@
j0oR)du
F(>Np2oi6
public String getSSiteURL() 4y|BOVl
{ Sc;BCl{=|
return sSiteURL; jIJ~QpNE
} 6 (]Dh;gC
fdFo#P
hgPa6Kd
public void setSSiteURL(String value) pR=@S>!|
{ ].-1v5
sSiteURL = value; 6^]+[q}3
} y [}.yyye
0XE4<U
u_oaebOrpP
public String getSFilePath() NPy&OcRl
{ v[1aWv:
return sFilePath; H#,W5EJzM
} ekWD5,G
*4\:8
geru=7
public void setSFilePath(String value) ]cHgleHQ
{ )_YX DU
sFilePath = value; 9X}10u:
} ]_f_w9]
marQNZ
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public String getSFileName() Q /U2^
{ $V-~Bu-
return sFileName; gb[5&>(#
} NcBIg:V\c
f%][}NN)Xr
6]K_m(F
public void setSFileName(String value) %O|iE M
{ Ag-(5:
sFileName = value; 8\&X2[oAD
} XO.jl"xu
<? q?Mn
*#,7d"6W5
public int getNSplitter() n(1l}TJy
{ J!dm-L
return nSplitter; D+lAhEN
} .s?L^Z^
PxvyN_B#>
L>jY.d2w=K
public void setNSplitter(int nCount) ]C!gQq2'a
{ u-QB.iQ+s
nSplitter = nCount; ha]VWt%}
} ]E5o1eeg
} WlOmJtt4)
|3(' N#|
Ri<u/ ]oR"
/* I fK,b*%
**Utility.java &GpRI(OB/+
*/ YL!P0o13r
package NetFox; g];!&R-
p_RsU`[
>^u2cAi3[
public class Utility { Snj'y,p[
>FeX<L
Cjn#00
public Utility() h79}qU
{ Ouk^O}W6
y8]B:_iU9
Kg{+T`
} is?{MJZ_
?>7[7(|
//线程睡眠 \"7*{L:
public static void sleep(int nSecond) !z\h|wU+
{ "{A(x }'Y4
try{ C7]f*TSC4
Thread.sleep(nSecond); S,88*F(<^q
} &l}^iP'%!
catch(Exception e) aC]$k'71
{ /2&c$9=1
e.printStackTrace (); wW Lj?;bx
} u+9hL4
} k R?qb6
y6g&Y.:o
//日志 >xN .F/[K
public static void log(String sMsg) M[NV)q/)
{ j * %
System.err.println(sMsg); 'NWfBJm
} &h}#HS>l
iDpSj!x/_
mVj9,q0
public static void log(int sMsg) ./\@Km?
{ y'3rNa]G1
System.err.println(sMsg); /4yo`
} sU=H&D99
} D(~U6SR
D,k6$`
f[]dfLS"W
/* _qF+tm
**TestMethod.java P9R9(quI
*/ '6DBs8>1
package NetFox; {y)=eX9
CT&|QH{
b!+hH Hv:
public class TestMethod { -M\<nx
4j-Xi
x[cL Bc<
public TestMethod() A[B<~
{ ///xx/weblogic60b2_win.exe u2tfF
try{ lqy Qf$t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y#`tgJ:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v_yw@
SiteFileFetch fileFetch = new SiteFileFetch(bean); t$`r4Lb9/
fileFetch.start(); &j;wCvE4+
} ez7A4>/
catch(Exception e){e.printStackTrace ();} R8K&R\
%:i7s-0w
;xy"\S]
} [|v][Hwv
\P[Y`LYL
VMZMG$C
public static void main(String[] args) n3WlZ!$
{ aHD]k8m z
new TestMethod(); r-,%2y?
} <]ox;-56
} ldf\;Qk
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