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)); 2[w9#6ly
} H [+'>Id:
for(int i=0;i<nEndPos.length-1;i++) @;EQ{d
{ i?_Q@uA~<:
nEndPos = nStartPos[i+1]; caEIE0H~
} n^'d8Y(
nEndPos[nEndPos.length-1] = nFileLength; mpYBMSLM
} !KV!Tkx h
} " lD -*e4
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C5=^cH8
//启动子线程 +aL6$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3g7]$}
for(int i=0;i<nStartPos.length;i++) $(&uaDYv
{ #mH28UT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eHx {[J?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !UzE&CirV
nStartPos,nEndPos,i); !5 S#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :{w3l O
fileSplitterFetch.start(); 0yjYjIk"T
} +^:uPW^U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `@Z$+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [<+T@"y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5!Er;e
nEndPos = " + nFileLength); uJ"#j X
// fileSplitterFetch[nPos.length-1].start(); ,>6mc=p
65B&>`H~
hQ3@CfW
//等待子线程结束 1sUgjyGQ
//int count = 0; %4VM"C4[
//是否结束while循环 ruhC:rg:/
boolean breakWhile = false; Fkv284,LM
D[T\_3W
L{sFR^-G
while(!bStop) E:}s6l
{ Njo.-k
write_nPos(); j+.E#:tu"
Utility.sleep(500); =>*}qen
breakWhile = true; _bh$ t
p7},ymQ|YQ
7\dt<VV
for(int i=0;i<nStartPos.length;i++) Sn97DCdk
{ "dG*HKrr
if(!fileSplitterFetch.bDownOver) 6\h*SBI?(
{ lyowH{.N"3
breakWhile = false; $1X!Ecq_
break; m[ S1
} Y}vV.q
} c7rC!v
if(breakWhile) +o.#']}Pl
break; &~"N/o
Kj"n Id)
p@$92> '
//count++; o/U}G,|G
//if(count>4) mv<cyWp
// siteStop(); ?zo7.R-Vac
} c3fd6Je5
x}C$/7^
{s@&3i?ZiC
System.err.println("文件下载结束！"); LWo)x
} .ErR-p=-
catch(Exception e){e.printStackTrace ();} ^b&hy&ag
} hzV%QDUpe
X56.Y.
*{fZA;<R
//获得文件长度 ubl Y%{"
public long getFileSize() j%!xb><
{ p,4S?cr>a
int nFileLength = -1; CyS.GdyP
try{ j"0TAYmXwu
URL url = new URL(siteInfoBean.getSSiteURL()); TIV|7nKL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <95*z @
httpConnection.setRequestProperty("User-Agent","NetFox"); +C$wkx]
ZU:c[`
AWZ4h,as{
int responseCode=httpConnection.getResponseCode(); 4YMUkwh
if(responseCode>=400) OoOwEV2p_
{ <SRSJJR|(
processErrorCode(responseCode); m7,"M~\pX
return -2; //-2 represent access is error m,J9:S<5;
} Kt#X'!9/<
,=6;dT
\a:-xwUu<
String sHeader; u_=>r_J[b
&I(3/u
$a')i<m^g
for(int i=1;;i++) P+p:Ed80
{ ;S2/n$Ju_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B3u:D"t
//Utility.log(in.readLine()); ~\R+p~>
sHeader=httpConnection.getHeaderFieldKey(i); cMUmJH
if(sHeader!=null) P; =,Q$e8
{ V=GP_^F
if(sHeader.equals("Content-Length")) )=h+5Z>E1
{ xqVIw!J?/}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ()$tP3o
break; w3Qil[rg
} e=6C0fr
} #w[Ie+
else \T!tUd
break; S#D6mg$Z,
} g<4@5OQKu
} dqL)q3
catch(IOException e){e.printStackTrace ();} i;<H^\%
catch(Exception e){e.printStackTrace ();} yzCamm4~0
o 3 G*
:2&W9v
Utility.log(nFileLength); ma2-66M~j
_nW#Cl~
LwCf}4u"
return nFileLength; M[dJQ(
} _K>YB>W}7
tw]Q5:6
^X?3e1om
//保存下载信息（文件指针位置） [M.!7+$o
private void write_nPos() _%aJ/Y0Cy
{ Pu]Pp`SP
try{ n ^C"v6X
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9&KiG* .
output.writeInt(nStartPos.length); z`@|v~i0`
for(int i=0;i<nStartPos.length;i++) "\Nn,3qp
{ )mXu{uowr
// output.writeLong(nPos); 2G`tS=Un
output.writeLong(fileSplitterFetch.nStartPos); ~LN {5zg
output.writeLong(fileSplitterFetch.nEndPos); 3hzKd_
} K<w$
output.close(); 6SD9lgF*-
} &Sp2['a!
catch(IOException e){e.printStackTrace ();} Oc?]L&ap
catch(Exception e){e.printStackTrace ();} M,9f}V)
} TzY[-YlvF
"PY&NL?
4T:@W C
//读取保存的下载信息（文件指针位置） e/!xyd
private void read_nPos() eN]9=Y~-K
{ w'D=K_h
try{ 64-;| k4F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p#(5 ;
int nCount = input.readInt(); h>'Mh;+
nStartPos = new long[nCount]; 6<C|O-
nEndPos = new long[nCount]; _QOZ`st
for(int i=0;i<nStartPos.length;i++) ]EPFyVt~3
{ nx'D&,VX
nStartPos = input.readLong(); kEM|;&=_
nEndPos = input.readLong(); uY|-: =
} *U^7MU0
input.close(); Wi{ jC?2Q
} r(cd?sL96R
catch(IOException e){e.printStackTrace ();} 2_Otv2
catch(Exception e){e.printStackTrace ();} <-m[0zgq
} 3N5b3F
qUtlh,4)
C.;H?So(
private void processErrorCode(int nErrorCode) p{4nWeH?B
{ 4brKAqg.
System.err.println("Error Code : " + nErrorCode); pbePxOG
} 4XXuj
OB5`a,5dI
>hmBV7nR
//停止文件下载 %oE3q>S$en
public void siteStop() r5g:#mF"
{ #Rcb iV*M
bStop = true; N3g\X
for(int i=0;i<nStartPos.length;i++) 5ki<1{aVtZ
fileSplitterFetch.splitterStop(); j]'7"b5
]728x["(19
avo[~ `.
} RwptFO
} jLG Q^v"
//负责部分文件的抓取 8!(09gW'>
**FileSplitterFetch.java VsM~$ )
*/ JQ)w/@Vu=
package NetFox; ;4ETqi9
0'0GAh2
I7q}<"`
import java.io.*; f/NfvLi(AU
import java.net.*; i@p0Jnh|
Wc qUF"A
+Q+>{HK
public class FileSplitterFetch extends Thread { "nEfk{g
qt!0#z8
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String sURL; //File URL P4S]bPIp
long nStartPos; //File Snippet Start Position YZ0Jei8+-
long nEndPos; //File Snippet End Position @is!VzE
int nThreadID; //Thread's ID TO~Z6NA0
boolean bDownOver = false; //Downing is over ^J-\s_)"
boolean bStop = false; //Stop identical UiLiy?EJ
FileAccessI fileAccessI = null; //File Access interface {gwJ>]z"e
!O}^Y
a08`h.dyN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V 0M&D,
{ I c 2R\}q
this.sURL = sURL; Z0I>PBL@l
this.nStartPos = nStart; hFp\,QSx
this.nEndPos = nEnd; 8\{1y:|
nThreadID = id; ^>ICycJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yTb#V"eR
} 9#X"m,SB
7I`8r2H
{N2MskK
public void run() 84}Pu%
{ 78fFAN`
while(nStartPos < nEndPos && !bStop) \&Zp/;n
{ --chU5
+1o4l i
KrDG
try{ #%$U-ti
URL url = new URL(sURL); A,;V|jv9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M4`.[P4
httpConnection.setRequestProperty("User-Agent","NetFox"); /l&$B
String sProperty = "bytes="+nStartPos+"-"; nA?Ks!9T
httpConnection.setRequestProperty("RANGE",sProperty); EYD24
Utility.log(sProperty); z[~ph/^
gJC~$/2
vlS+UFH0
InputStream input = httpConnection.getInputStream(); O4.`N?Xq
//logResponseHead(httpConnection); 9`X}G`
7`_`V&3s
Z&W*@(dX
byte[] b = new byte[1024]; p.|NZXk%%a
int nRead; }a?(}{z-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X&14;lu%p
{ g<(\#F}/
nStartPos += fileAccessI.write(b,0,nRead); JRYCM}C]
//if(nThreadID == 1) Yfd0Np~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *H({q`j33k
} <*F!A' w2o
"F+m}GJ=a
Q^!x8oUF
Utility.log("Thread " + nThreadID + " is over!"); 1HS43!
bDownOver = true; @&xWd{8'
//nPos = fileAccessI.write (b,0,nRead); sm?V%NX&
} QDdH5EfY
catch(Exception e){e.printStackTrace ();} wXKg^%t\
} k ^(RSu<
} D@ 4sq^|2
B9h'}460H
2{;~Bgd
//打印回应的头信息 s5cY>
public void logResponseHead(HttpURLConnection con) dn}'B%
{ NA;OT7X[
for(int i=1;;i++) SWWeN#Q
{ sf5F$
String header=con.getHeaderFieldKey(i); ~,O&A B
if(header!=null) V+Y;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %-J}m
Utility.log(header+" : "+con.getHeaderField(header)); ;:A/WU.^
else 3s B9t X
break; .TpM3b#r
} /=IBK`
} &~{0@/
IJ E{JH
yYN_]&ag
public void splitterStop() _k O<|ev
{ V3v/hV:
bStop = true; J-d>#'Wb|
} *1c1XN<7
/JbO$A
q)rxv7Iu\
} ]7DS>%mY(
jWNF3\
KzWqHq
/* gO%oA} !i
**FileAccess.java p|9Eue3j2
*//文件访问(定位，写) bTepTWv
package NetFox; .6HHUy
import java.io.*; $3)Z>p
dk>qTY+j5
G{]tB w
public class FileAccessI implements Serializable{ ,LftQ1*;
U]}f]GK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >#[,OU}N
RandomAccessFile oSavedFile; o/4U`U)Q0v
long nPos; (t_%8Eu
B6J<
>&`;@ZOH
public FileAccessI() throws IOException 94Q?)0W$
{ *w5xC5*
this("",0); Pe?=M[u2
} X]+z:!
"rU 2g
#,B+&SK{
public FileAccessI(String sName,long nPos) throws IOException V_"UiN"o
{ !Y^3%B%
oSavedFile = new RandomAccessFile(sName,"rw"); &MJcLM]
this.nPos = nPos; nXM[#~
oSavedFile.seek(nPos); Q|7l!YTzVu
} < VrHWJo
J>N^FR9
&3CC |
public synchronized int write(byte[] b,int nStart,int nLen) |{V@t1`
{ 7&w$@zs87
int n = -1; /5N`Euw
try{ p,K!'\
oSavedFile.write(b,nStart,nLen); G/4~_\YMq
n = nLen; D/&nEMp6
} T0v{qQ
catch(IOException e) J-5E# v
{ eJ+@<+vr;x
e.printStackTrace (); QA=mD^A
} GD@|XwK){
|f{(MMlj
T%O2=h\} E
return n; fVo7wp
} =.(~`ici~
;Q\MH t*
6Ij'z9nJw
} ;Z!x\{-L
9^g?/8
I4(z'C
/* 2F#DJN#
**SiteInfoBean.java 1 .Nfl@]
*/ >SHP,><H/
package NetFox; X[J?
vM?jm!nd
<_3OiU=w
public class SiteInfoBean { [ XBVES8
Lhmb= @
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private String sSiteURL; //Site's URL ?.Lq`~T`
private String sFilePath; //Saved File's Path }s@vN8C
private String sFileName; //Saved File's Name A;Av0@w
private int nSplitter; //Count of Splited Downloading File #u/5 nm
oef]
<~}NxY\5
public SiteInfoBean() R "qt}4m
{//nSplitter的缺省值为5 H6Q!~o\"H
//default value of nSplitter is 5 K+3+?oYKH
this("","","",5); K9QC$b9(
} WPDi)UX
;D|g5$OE&
EYSBC",
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :CGh$d] +
{ bzyy;`;6Q~
sSiteURL= sURL; 6<Txkk
sFilePath = sPath; a/TeBx#yG
sFileName = sName; 8iUYZF
this.nSplitter = nSpiltter; '#NDR:J"
2bAH)=
W*~[KdgC
} o2R&s@%0@B
v{;^>"5o
P2fiK
public String getSSiteURL() Kr%w"$<
{ J936o3F_
return sSiteURL; tJII-\3"
} J0FJ@@
=^mBj?(V7
:!L>_ f
public void setSSiteURL(String value) 7bYN
{ l?O%yf`s
sSiteURL = value; @n^2UJ
} q{uv?{I
;( [^+_/
a[ yyEgm2
public String getSFilePath() y`a]##1j$M
{ -Ra-Ux
return sFilePath; /3j3'~0
} s[Whg!2~
*]*0uo
eOZ"kw"uHu
public void setSFilePath(String value) _j2q
{ JYrOE"!h
sFilePath = value; ,m[#<}xXA
} j7yUya&
Y3g<%6
TEQs9-Uy
public String getSFileName() @+yjt'B
{ 8fA8@O}
return sFileName; "{x+ \Z\
} Odr<fvV,>
A`nzqe#(1
u?SxaGEa
public void setSFileName(String value) '}9 %12\^h
{ Q.g44>
sFileName = value; *T2kxN,Ik
} 09J,!NN
e4<St`K
+2,EK
public int getNSplitter() t#2szr+
{ \kP1Jr
return nSplitter; G;AJBs>Y}
} ;N^4R$Q.
.#LvvAeh
JZ)w
public void setNSplitter(int nCount) V|)nUsU
{ Y2W{?<99
nSplitter = nCount; lyw)4;wt\
} AZva
} #:8V<rc^
FL[w\&fp
Zb:S IJ
/* ]%Lk#BA@A
**Utility.java KqvM5$3
*/ ld7B{ ?]
package NetFox; kiu#THF
^zKP5nzL
H=6-@+ !o
public class Utility { jH[{V[<#X
VEx )
8Ud.}< Zi
public Utility() Q1RUmIe_&
{ KouIzWf.
H](TSt<Q"
s]Z++Lh<{
} /! M%9gu
@5{h+^
//线程睡眠 D 4<,YBvV
public static void sleep(int nSecond) >S@><[C
{ Q&vU|y
try{ 6\RZ[gA?
Thread.sleep(nSecond); w_*$wVl
} O +Xu?W]
catch(Exception e) |`O210B@
{ EO\- J-nM
e.printStackTrace (); & sgzSX
} H={5>;8G
} 0}-MWbG
RY]jY | E
//日志 qU^`fIa
public static void log(String sMsg) B6U4>ZN
{ Q#pgl
System.err.println(sMsg); }@vf=jm>
} NW~`oc)NS
scyv]5Hm!
!_?#f|
public static void log(int sMsg) 6t'vzcQs
{ R]NCD*~
System.err.println(sMsg); KP CZiu7
} %Vhj<gN
} Thuwme
?GGBDql
.=@CF8ArG
/* &Y-jK<
**TestMethod.java *a'I
*/ G!U `8R
package NetFox; M<xF4L3]
oT9qd@uQ0:
m'U>=<!D
public class TestMethod { a.up&g_$
&,'CHBM
y|(?>\jBl
public TestMethod() |fPR7-
{ ///xx/weblogic60b2_win.exe )OZ
try{ w%~Mg3|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -NUA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wcL|{rUXba
SiteFileFetch fileFetch = new SiteFileFetch(bean); n8o(>?Kw
fileFetch.start(); e84O 6K6o
} y)T|1)
catch(Exception e){e.printStackTrace ();} B1o*phM g
' [%?j?2r
( c +M"s
} F+/#ugI
+krDmU9(
a>egH og
public static void main(String[] args) |\N))K-2D
{ y~<_ux,
new TestMethod(); R!2E`^{Wl
} Z;cA_}5
} {$'oKJy*
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