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)); T_lexX[\
} (x2I*<7P
for(int i=0;i<nEndPos.length-1;i++) 5 S$*YRp
{ /lCn^E6-
nEndPos = nStartPos[i+1]; ?{mFQ
} Q7gBxp
nEndPos[nEndPos.length-1] = nFileLength; fT!n*;h
} FZ DC?
} m jC6(?V
LNmsvU
Nc()$Nl8
//启动子线程 3ybEQp9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lY yt8H
for(int i=0;i<nStartPos.length;i++) CTv-$7#
{ [RiCa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B8NOPbT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #G:~6^A
nStartPos,nEndPos,i); 2VyLt=mdh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f*04=R?w7>
fileSplitterFetch.start(); UxzZr%>s
} oIdMDp^$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1tHTjEG4^3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8QV+DDZx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -8X*(7
nEndPos = " + nFileLength); ;]3Tuq
// fileSplitterFetch[nPos.length-1].start(); ,YX[6eZr
N93 ZI|T
kep.+t[
//等待子线程结束 ~v$gk
//int count = 0; Z#IRNFj
//是否结束while循环 8 C@iD%
boolean breakWhile = false; x3xBl_t
s de|t
O:"gJ4D
while(!bStop) ymT&[+V
{ &ok2Xw
write_nPos(); LGGC=;{}
Utility.sleep(500); :PuJF`k
breakWhile = true; tRZCOEo4
/PN[g~3
UbE*x2N
for(int i=0;i<nStartPos.length;i++) <ppM\$
{ BY.'0,H=k
if(!fileSplitterFetch.bDownOver) #lRkp.e
{ )=V0
breakWhile = false; $rD&rsx6
break; 7 [N1Vr(1
} Zmw'.hL
} +FRXTku(
if(breakWhile) pPem;i^~
break; WBLfxr
D|} y{~
SE&J)Sj]
//count++; S-Mn
//if(count>4) kaQn'5
// siteStop(); m!L&_Z|j
} 8*V^DM3n-
Jf{6'Ub
}A;J-7g6
System.err.println("文件下载结束！"); B@D3aOvO
} Xs$k6C3
catch(Exception e){e.printStackTrace ();} \2~Cn c*O
} P#-Ye<V~J(
d#cw`h<c~
a^t#kdT
//获得文件长度 2uu"0Rm%
public long getFileSize() %:yJ/&-Q,Z
{ NitWIj[U;
int nFileLength = -1; :KGUO{_u
try{ }DjW
URL url = new URL(siteInfoBean.getSSiteURL()); yyb8ll?@a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NCbn<ojb
httpConnection.setRequestProperty("User-Agent","NetFox"); xhLVLXZ9
nm2bBX,fh
?a+>%uWt
int responseCode=httpConnection.getResponseCode(); UM%]A'h2O"
if(responseCode>=400) $e1==@ R
{ a[bu{Z]%
processErrorCode(responseCode); 42kr&UY&
return -2; //-2 represent access is error |{udd~oE&
} gZF-zhnC
GawQ~rD
tP8>0\$)
String sHeader; t$m~O?I
0+p <Jc!
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for(int i=1;;i++) 9;KQ3.Fa}q
{ wGD*25M7$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Li)rs<IX;m
//Utility.log(in.readLine()); XgE\q
sHeader=httpConnection.getHeaderFieldKey(i); *o <S{
if(sHeader!=null) bim}{wMb
{ 97;`R[^J
if(sHeader.equals("Content-Length")) ~{lSc/SP|
{ D#R5G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KvW{M
break; X<{kf-GP
} -,+zA.{+W
} |Am +f.
else 3.>M=K~09
break; #InuN8sI
} 2>3#/I9Y
} +j Z,vKr
catch(IOException e){e.printStackTrace ();} |#G.2hMFr
catch(Exception e){e.printStackTrace ();} ]/&qv6D*d
5'>DvCp%M
,Axk\7-
Utility.log(nFileLength); DtLga[M
OOJg%y*H
BnJpC<xm
return nFileLength; r/o1a't;
} 1P i_V
"@uKe8r|y
yh~*Kt]9Ya
//保存下载信息（文件指针位置） 3VNYDY`>
private void write_nPos() G+&ug`0]5
{ }EM vEA
try{ Q{FK_Mv<
output = new DataOutputStream(new FileOutputStream(tmpFile)); 03Czx`
output.writeInt(nStartPos.length); eU/o I}A
for(int i=0;i<nStartPos.length;i++) ,`kag~bZ
{ eW%Cef
// output.writeLong(nPos); J?9K|4 )
output.writeLong(fileSplitterFetch.nStartPos); mAO$gHQ
output.writeLong(fileSplitterFetch.nEndPos); g{0a]'ph
} ,=!_7'm
output.close(); 62BT3/~
} 5qZebD2a
catch(IOException e){e.printStackTrace ();} zpi Q;P
catch(Exception e){e.printStackTrace ();} n$]78\C
} fL-lx-~
S~L;oX?(!
v__n>*x
//读取保存的下载信息（文件指针位置） iF0x>pvJ@
private void read_nPos() X+6`]]
{ `b.KMOn
try{ ZbBz@1O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cP8g.+
int nCount = input.readInt(); SLI(;, s
nStartPos = new long[nCount]; /Mq9~oC
nEndPos = new long[nCount]; }.`no
for(int i=0;i<nStartPos.length;i++) $#2zxpr,
{ o_=t9\:
nStartPos = input.readLong(); ^!a4!DGVT
nEndPos = input.readLong(); 2;&K*>g&.
} B<^yT@Wc
input.close(); Gs`[\<;LI
} ",&^ f
catch(IOException e){e.printStackTrace ();} d'p]F~a
catch(Exception e){e.printStackTrace ();} Z9S5rPHEL
} e'"2yA8dh"
v/ $~ifY"
,_+Gb
private void processErrorCode(int nErrorCode) wg-qq4Q\
{ OGA_3|[S
System.err.println("Error Code : " + nErrorCode); .AHf]X0
} al#BfcZW
=17d7#-
R9+0ZoS
//停止文件下载 K+WbxovXU
public void siteStop() lk/T|0])
{ vMD%.tk
bStop = true; (*6kYkUK
for(int i=0;i<nStartPos.length;i++) DT2uUf
fileSplitterFetch.splitterStop(); (3. B\8s
}.ZT?p\
8/i];/,v*M
} &oJ1v<`
} 5f#N$mh
//负责部分文件的抓取 ]{.iv_I
**FileSplitterFetch.java z8VcV*6
*/ '.{tE*
package NetFox; zeqwmV=
v,}Mn7:
$%:=;1Jl
import java.io.*; \t=ls
import java.net.*; [:Upn)9
,>C`|
;*J_V/&?
public class FileSplitterFetch extends Thread { o54/r#~fi
Yee% <<S
)c6t`SBwi
String sURL; //File URL 4DwQ7KX
long nStartPos; //File Snippet Start Position p+.xye U(
long nEndPos; //File Snippet End Position I-glf?F)
int nThreadID; //Thread's ID x^sSAI(
boolean bDownOver = false; //Downing is over eE=}^6)(*
boolean bStop = false; //Stop identical A r=P;6J
FileAccessI fileAccessI = null; //File Access interface ZBY*C;[)*P
vz~`M9^
]cmq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "z8iuF
{ fo$s9g^<
this.sURL = sURL; `<#Ufi*c
this.nStartPos = nStart; xU6rZCqE
this.nEndPos = nEnd; " J4?Sb<
nThreadID = id; d~QZcR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z JBcz,
} +<})`(8
6?`3zdOeO
c*!xdK
public void run() )i^+=TZq
{ Jc=~BT_G
while(nStartPos < nEndPos && !bStop) vB?(|
{ v?@=WG
Zws[C
8MZ:=
try{ lWyg_YO@
URL url = new URL(sURL); 0F5QAR O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,5XDH6L1
httpConnection.setRequestProperty("User-Agent","NetFox"); -J& b~t@
String sProperty = "bytes="+nStartPos+"-"; W Te1E,M
httpConnection.setRequestProperty("RANGE",sProperty); lj US-6
Utility.log(sProperty); )x<oRHx]
)k~{p;Ke
n/ CP2A
InputStream input = httpConnection.getInputStream(); SHA6;y+U/~
//logResponseHead(httpConnection); 6uu49x_^L4
p=T6Ix'_2e
BD_"w]bqD
byte[] b = new byte[1024]; IW>\\&pJ
int nRead; 8ioxb`U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hw\hTTK
{ IM(=j
nStartPos += fileAccessI.write(b,0,nRead); D:56>%y@
//if(nThreadID == 1) _(_U=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q2LAXTF]y
} . g8WMm
{P7 I<^,
_8{6&AmIw
Utility.log("Thread " + nThreadID + " is over!"); C"cBlru8B
bDownOver = true; .4%6_`E
//nPos = fileAccessI.write (b,0,nRead); 3E$h W
} y,F|L?dIq
catch(Exception e){e.printStackTrace ();} /ReOf<%B
} (GJX[$@
} ] <y3;T\~
pKzrdw-!
[ApAd
//打印回应的头信息 @wTRoMHPQ
public void logResponseHead(HttpURLConnection con) 5uAUi=XA>S
{ ^@-qnU lH
for(int i=1;;i++) Y- tK
{ aUyJi
String header=con.getHeaderFieldKey(i); #W2#'J:l
if(header!=null) =rzhaU'A'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )uK Tf=;
Utility.log(header+" : "+con.getHeaderField(header)); VD0U]~CWR
else b|-7EI>l9
break; sOBuJx${m
} q +*>T=k
} KrqO7
#+SdX[N
(jtkY_
public void splitterStop() @sG5Do
{ ,/Yo1@U
bStop = true; )%Lgo${[;
} HI!bq%TZ4
dx)v`.%V
e)Pm{:E
} fK1^fzV
J?[}h&otQ
wrEYbb
/* EWp'zbWP
**FileAccess.java W't.e0L<6
*//文件访问(定位，写) &aWY{ ?_
package NetFox; IfF&QBi
import java.io.*; &Tn7
40Z/;,wp{
V?C_PMa
public class FileAccessI implements Serializable{ W}.p,d
F94Qb}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :qxd s>Xm
RandomAccessFile oSavedFile; 3=Va0}#&
long nPos; 7p+uHm
5imqZw
1+NmiGKg
public FileAccessI() throws IOException aj6{
{ od`:w[2\
this("",0); :}[[G2|9
} j.vBld
w*qmC<D$A
I3D#wXW
public FileAccessI(String sName,long nPos) throws IOException S$%Y{
{ ba"a!#wA
oSavedFile = new RandomAccessFile(sName,"rw"); nyr)d%I{
this.nPos = nPos; 1`I#4f
oSavedFile.seek(nPos); Oo`b#!L
} ealh>Y
[0-zJy|,
Jm{~H%
public synchronized int write(byte[] b,int nStart,int nLen) R:FyCT_,
{ hP]zC1s
int n = -1; %{K6
try{ u9^R ?y
oSavedFile.write(b,nStart,nLen); _.ELN/$-
n = nLen; }hX"A!0
} G8ksm2}
catch(IOException e) wA>bLPTw
{ aFrVP
e.printStackTrace (); xrky5[XoD
} m[!AOln)
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^"\.,Y
return n; H=k`7YN
} $[-{Mm
C%+>uzVIw
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} 8L}N,6gC4_
Zjh9jvsW
?FRQ!R
/* fl18x;^I
**SiteInfoBean.java NurbioFL
*/ j[o5fr)L
package NetFox; q;a#?Du o
DUK.-|a7
ALY% h!L
public class SiteInfoBean { vXi}B
ds9`AiCW>
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private String sSiteURL; //Site's URL k<3_!?3
private String sFilePath; //Saved File's Path 5`3f"(ay/
private String sFileName; //Saved File's Name .5m^)hi
private int nSplitter; //Count of Splited Downloading File ^. i;,
MB,P#7|
f3]u-e'b
public SiteInfoBean() H9Pe,eHs
{//nSplitter的缺省值为5 1yIo'i1
//default value of nSplitter is 5 .DkDMg1US
this("","","",5); L5*,l`lET
} 8E!I9z
TAt9+\'
,`JXBI~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oFeflcSz
{ "@[xo7T
sSiteURL= sURL; ;ckv$S[p
sFilePath = sPath; d#eHX|+
sFileName = sName; m'%Z53&
this.nSplitter = nSpiltter; ^(0tNX/XD
OWK)4[HY(
\T_?<t,UT
} ?JD\pYg[/
|k4ZTr]?
)>LC*_v
public String getSSiteURL() r4c3t,L*$I
{ Gr;~P*
return sSiteURL; (A*r&Ak[
} "Rp]2'?
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'c<@SVF{Zz
public void setSSiteURL(String value) #:68}f"$
{ Hvq< _&2
sSiteURL = value; 7=ZB;(`L1
} xUD$i?3z
F*d{<
u[jdYWQa
public String getSFilePath() s geP`O%
{ <>JDA(F"
return sFilePath; >gr6H1
} 'Sc3~lm(dH
GSW{h[Op
'}5}wCLA
public void setSFilePath(String value) ~^"cq S(
{ HC8{);
sFilePath = value; V_(?mC
} Iq\sf-1E
#V8='qD
%;zWS/JhL
public String getSFileName() 7q|(ZZa
{ Z<r&- !z
return sFileName; |"P5%k#6^>
} P N_QK Z
Y#6@0Nn[G
^D B0C
public void setSFileName(String value) T"Q4vk,3*J
{ l{Hi5x'H
sFileName = value; {F k]X#j
} F,O+axO ja
)}c$n
+X;6%O;
public int getNSplitter() DI}h?Uf ,
{ L#u6_`XJ+
return nSplitter; RkLH}`#
} XR\ iQ
hBE}?J>
IHo6&
public void setNSplitter(int nCount) %1HW ) 7
{ xm YA/wt8
nSplitter = nCount; eS@RA2
} mc(&'U8R0I
} YQN=.Wtc
\lR~!6:
=WEfo;
/* ;gm){ g
**Utility.java &,&+/Sr11
*/ @R2|=ox
package NetFox; \hM6 ykY-
H[,.nH_>+
>M:5yk@
public class Utility { 4g1u9Sc0
K)Db3JIIk
fJE ki>1
public Utility() ooZ7HTP|
{ $zmES tcm
2z[Pw0#V
FcW ?([l
} Vn/6D[}Tu
&7DE$ S
//线程睡眠 Ya9uu@F
public static void sleep(int nSecond) q]Qgg
{ i]$d3J3
try{ V7[qf "
Thread.sleep(nSecond); ]K9x<@!
} j9u-C/Q\r
catch(Exception e) ;v0sM*x%V
{ LOida#R
e.printStackTrace (); "W+4`A(/l
} \R-u+ci$ZY
} NM8F
2CxdNj
//日志 ?|hzAF"U
public static void log(String sMsg) e#'`I^8l
{ KFV]2mFN
System.err.println(sMsg); -~(0:@o ;
} u8<=FV3
x:2[E-
iqoPD4A
public static void log(int sMsg) tIr66'8
{ d,QJf\fc"
System.err.println(sMsg); ,OasT!Sr
} huTJ a2
} f8&=D4)-w
ixS78KIr
D!mhR?t
/* {9l4 pT3
**TestMethod.java `\Npu
*/ |M K-~ep
package NetFox; )@Zel.XD
"7<4NV@yQ
X&lkA (
public class TestMethod { ,!Hl@(
#SqOJX~Q
tRv#%>fj
public TestMethod() XW#4C*5?d
{ ///xx/weblogic60b2_win.exe Lw#hnLI.
try{ J`mp8?;%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .Nf*Yqs0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +'Ge?(E4_
SiteFileFetch fileFetch = new SiteFileFetch(bean); <K0lS;@K
fileFetch.start(); Sc0ZT/Lm
} [MEa@D<7N
catch(Exception e){e.printStackTrace ();} vv8$u3H
$o@?D^
uVO9r-O8p
} JV/,QWar
{ &qBr&kg
bR6bS7$
public static void main(String[] args) f/c}XCH_h
{ |(V%(_s
new TestMethod(); eP2 yU
} {Y@[hoHtF
} >'T%=50YH
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