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)); 0qT%!ku&
} ?G&ikxl
for(int i=0;i<nEndPos.length-1;i++) c[Zje7 @
{ Z EO WO
nEndPos = nStartPos[i+1]; Om {'1
} dC4'{n|7
nEndPos[nEndPos.length-1] = nFileLength; y*h<MQ
} 6S\8$
} Y[S1$(K&*
@xZR9Z8]L
RCLeA=/N@0
//启动子线程 ~^b/(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u>/ TE
for(int i=0;i<nStartPos.length;i++) \5cpFj5%
{ g$o&Udgs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;6hOx(>`=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2)~> R
nStartPos,nEndPos,i); 1@=po)Hnp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !5?<% *
fileSplitterFetch.start(); =E{`^IT'R
} da~],MN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tFl"n;~T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &YeA:i?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NW)1#]gg%
nEndPos = " + nFileLength); gv{ >`AN
// fileSplitterFetch[nPos.length-1].start(); j1HW._G
/|#fejPh
W|(1Y D
//等待子线程结束 Vs{|xG7WD
//int count = 0; e(8Ba X_
//是否结束while循环 /JU.?M35
boolean breakWhile = false; Oz#{S:24M+
d*Fj3Wkx
<_KIK
while(!bStop) xi;`ecqS<
{ cPc</[x[W
write_nPos(); -o EW:~y
Utility.sleep(500); 5QO9Q]I#_\
breakWhile = true; ~.lPEA %%
_oDz-
vgN&K@hJ
for(int i=0;i<nStartPos.length;i++) ROZF)|l
{ @!d{bQd,
if(!fileSplitterFetch.bDownOver) *G9V'9
{ k+l b@!
breakWhile = false; 9k[9P;"F:
break; 8qu6.
} n@[O|?S
} %GIr&V4|
if(breakWhile) `x%>8/
break; "Os_vlapHo
ps DetP
u,Kly<0j
//count++; S?BG_J6A7
//if(count>4) 26x[X.C:
// siteStop(); 1 I",L&S1
} Ef13Q]9|
&UlWCOo8
YkQd
System.err.println("文件下载结束！"); eO[b1]WLP
} (0kK_k'T
catch(Exception e){e.printStackTrace ();} @2v_pJy^
} 2gVm9gAHUd
2SR:FUV/
t#eTV@-
//获得文件长度 Hl |z</*+
public long getFileSize() 3%=~)7cF
{ G'aDb/
int nFileLength = -1; tcog'nAz
try{ }?v )N).kW
URL url = new URL(siteInfoBean.getSSiteURL()); )IZ~G\Ra'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hqkz^!rp
httpConnection.setRequestProperty("User-Agent","NetFox"); \:F_xq
_``=cc
^@NU}S):yN
int responseCode=httpConnection.getResponseCode(); k2UVm$}u
if(responseCode>=400) ,UdVNA
{ x.R4%Z
processErrorCode(responseCode); Y% 5eZ=z
return -2; //-2 represent access is error ZO$%[ftb
} jdJ>9O0A,
R]*K:~DM
Q>1[JW{$}
String sHeader; KL Xq\{X
[0D.K}7|
R<N ]B
for(int i=1;;i++) |*tp16+6
{ k~ /Nv=D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (Px OE
//Utility.log(in.readLine()); FH+s s!
sHeader=httpConnection.getHeaderFieldKey(i); \v)+.m?n
if(sHeader!=null) gCY';\f!
{ v0jgki4t
if(sHeader.equals("Content-Length")) [QT#Yf0
{ TBU&6M>{3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I`4*+a'q&
break; q{;:SgZ
} Nf1-!u7
} k7usMVAA
else QGmn#]w\\
break; SS.dY""89
} UFb)AnK
} 0b(N^$js'
catch(IOException e){e.printStackTrace ();} K:30_l<
catch(Exception e){e.printStackTrace ();} OX\F~+
I"7u2"@-8j
bhlG,NTP
Utility.log(nFileLength); l"]}Ts#
GYUn6P
"o}+Ciul
return nFileLength; @@%.t|=
} QWHug:c
1Nd2{(
7g}w+p>
//保存下载信息（文件指针位置） gQ1;],_
private void write_nPos() 3HY9\'t6
{ .];=Pu^
try{ (n9gkO&8"
output = new DataOutputStream(new FileOutputStream(tmpFile)); `~CQU
output.writeInt(nStartPos.length); HJYScwjQ;`
for(int i=0;i<nStartPos.length;i++) ]1pIj i[
{ Z^MNf
// output.writeLong(nPos); W#WVfr
output.writeLong(fileSplitterFetch.nStartPos); .gOL1`b*
output.writeLong(fileSplitterFetch.nEndPos); OMg<V
} >_ 2dvg=U
output.close(); L<{i,'M
} ThbGQ"/
catch(IOException e){e.printStackTrace ();} zi*R`;_`,
catch(Exception e){e.printStackTrace ();} naznayy
} 2'MZ s]??w
Ffta](Z;
,>+p-M8ZL
//读取保存的下载信息（文件指针位置） M,mvys$
private void read_nPos() L"Olwwmk
{ PxkOT*
try{ GD_hhDyD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2{G:=U
int nCount = input.readInt(); b |p)9&^r
nStartPos = new long[nCount]; |T)6yDL
nEndPos = new long[nCount]; +l{=
for(int i=0;i<nStartPos.length;i++) t"'7m^j
{ i3'9>"`
nStartPos = input.readLong(); T\>a!
nEndPos = input.readLong(); .O}%
} dP]\Jo=Yh
input.close(); D#JL!A%O
} >{J(>B\
catch(IOException e){e.printStackTrace ();} :mn>0jK,N
catch(Exception e){e.printStackTrace ();} g:Xhw$x9
} :\7X}n*&
'AEE[
56-dD5{hxR
private void processErrorCode(int nErrorCode) xCl1g4N
{ =uYYsC\T
System.err.println("Error Code : " + nErrorCode); !Bq3Z?xA}
} {w^+\]tC
+8d1|cB"
vbe|hO""
//停止文件下载 6?~"V
public void siteStop() #O} ,`[<
{ 0-yp,G
bStop = true; .j<]mUY
for(int i=0;i<nStartPos.length;i++) TXvI4"&
fileSplitterFetch.splitterStop(); "v({,
~=RT*>G_
KRMQtgahc
} OCaq3_#tZ
} @wo(tf=@P
//负责部分文件的抓取 0+;bh {Eu
**FileSplitterFetch.java 90*5 5\>{
*/ YU5(g^<
package NetFox; J!pygn O
8MzVOF{"
)@Yf]qx+Y<
import java.io.*; mtmjZP(w
import java.net.*; .NC:;@y
x&Kh>PVh\
p &"`RS#Z
public class FileSplitterFetch extends Thread { qUGC"<W
};jN\x?&q
(VEpVn3{
String sURL; //File URL 5T2CISmu
long nStartPos; //File Snippet Start Position ``\i58K{e
long nEndPos; //File Snippet End Position *>2W#D)b=
int nThreadID; //Thread's ID v)t:|Q{I
boolean bDownOver = false; //Downing is over OJ5#4qJ[
boolean bStop = false; //Stop identical <;m<8RjX
FileAccessI fileAccessI = null; //File Access interface r@t9Ci=}
Mh/dpb\Z
*<jAiB,O*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q1 $^v0-)
{ {NFr]LGOp
this.sURL = sURL; >\=3:gb:
this.nStartPos = nStart; "wnzo,
this.nEndPos = nEnd; h"_;IUZ!
nThreadID = id; yt=3sq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :LRYYw
} SVs_dG$
6NM:DI\%
i}mVQ\j5
public void run() RcM/!,B
{ ?Unb? {,&2
while(nStartPos < nEndPos && !bStop) :f}9($
{ ,<tX%n`v=
T;y>>_,
>dG;w6y'
try{ =Og)q$AL
URL url = new URL(sURL); %GA"GYL9'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); evAMJ=
httpConnection.setRequestProperty("User-Agent","NetFox"); pU%n]]qF
String sProperty = "bytes="+nStartPos+"-"; #W'HR
httpConnection.setRequestProperty("RANGE",sProperty); wKYZa# u
Utility.log(sProperty); y4I6
:'3XAntZA
X=!^] 3zH
InputStream input = httpConnection.getInputStream(); w?wG(+X7
//logResponseHead(httpConnection); vss(twg
: $Y9jR
m)v"3ib
byte[] b = new byte[1024]; Nj xoTLI
int nRead; Ba*,-i3ZK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m4&h>9. 8
{ luuX2Mx>o
nStartPos += fileAccessI.write(b,0,nRead); "2P&X
//if(nThreadID == 1) WEQ1 Seq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +HeTtFo{M
} /F-qP.<D,r
Gh}LlX!w
Y*>#T
Utility.log("Thread " + nThreadID + " is over!"); =Ja]T~0A
bDownOver = true; (\a]"g,]v
//nPos = fileAccessI.write (b,0,nRead); 1+qw$T
} t2"O
catch(Exception e){e.printStackTrace ();} qnJt5
} f3&[#%
} iZNts%Y]
D 38$`j
Y/>&0wj)d
//打印回应的头信息 X4AyX.p
public void logResponseHead(HttpURLConnection con) ZP*q4:
{ sCis4gX.]
for(int i=1;;i++) )5%'.P>
{ 'EF9Zt8
String header=con.getHeaderFieldKey(i); wEE\+3b)
if(header!=null) *:t|qgJI#+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *-q"3D`
Utility.log(header+" : "+con.getHeaderField(header)); Nq` C.&
else P8>d6;o($
break; xA1hfe.9
} v:o({Y 1Aq
} KgOqbSJ
Mjfx~I27
~Ro9up
public void splitterStop() s3O} 6
{ Q`D~5ci
bStop = true; YW`,v6
} (TwnkXrR,
, GY h9
3k#/{Z
} }YMy6eW4
t!x5fNo)
y[\VUzD*'
/* m&\h4$[kql
**FileAccess.java 2f:Eof(B
*//文件访问(定位，写) }i`PGx
package NetFox; {Jx4xpvPo
import java.io.*; ]dk8lZ;bo
("+}=*?OF3
X4t s)>"d
public class FileAccessI implements Serializable{ ;A'Z4=*~
K]|> Et`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bKQ"ax>6p
RandomAccessFile oSavedFile; rN<b?KE
long nPos; H nUYqhZS
Eu-RNrYh#
s#DaKPC
public FileAccessI() throws IOException L19C<5>
{ ^Au _U
this("",0); [y)`k@
} 1Q4}'0U4
$Y_i4(
)h|gwERj
public FileAccessI(String sName,long nPos) throws IOException &S]@Ot<z
{ F;[T#N:~
oSavedFile = new RandomAccessFile(sName,"rw"); 7.@TK&
this.nPos = nPos; %]6~Eq%s
oSavedFile.seek(nPos); @@rEs40
} m-DsY
P=&o%K,:f
<Ib[82PU
public synchronized int write(byte[] b,int nStart,int nLen) vab@-=%k
{ tBT<EV{ G
int n = -1; AfP'EP0m
try{ 9D}/\jM
oSavedFile.write(b,nStart,nLen); ,FMx5$
n = nLen; ivz>dJ?T
} :ORR_f`>
catch(IOException e) }kK[S|XVO
{ ]oV{t<0a
e.printStackTrace (); P=+nB*hG
} )aao[_ZS
VX+jadYdq
MJCzo |w
return n; Qb; d:@9
} M=*bh5t%]
xIGfM>uq
''^Y>k
} /`;n@0k>2
rs*Fy@
Kryo}
/* d]i(h~?_
**SiteInfoBean.java RUUk f({(
*/ !>`N$-U X
package NetFox; <ggtjw S
!!V#v9{
+:-57
public class SiteInfoBean { ^1x*lLf
npyAJp
M- 2Tz[
private String sSiteURL; //Site's URL ls`,EFF
private String sFilePath; //Saved File's Path +|{RE.DL
private String sFileName; //Saved File's Name f%)zg(YlO
private int nSplitter; //Count of Splited Downloading File $GQ-(/
KdUnD4d
za9)Q=6FD
public SiteInfoBean() )VK }m9Ae
{//nSplitter的缺省值为5 Za7q$7F7Bc
//default value of nSplitter is 5 7`H 1f]d
this("","","",5); 6^n0[7
} j:&4-K};Z`
'K*AV7>E
OxtOd\0$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l|+BC
{ |Uk" {
sSiteURL= sURL; q;D+ai
sFilePath = sPath; xc:!cA{V
sFileName = sName; 8?O>ZZtu
this.nSplitter = nSpiltter; P;8>5;U4-
Enq|Y$qm
T<joRR
} J5[~LZKW
r-IVb&uFb
deeU@x`f<
public String getSSiteURL() q$.{j"cZV
{ dg7=X{=9jv
return sSiteURL; V~yAE@9
} %tt%`0
J3b4cxm
@[?!s%*2
public void setSSiteURL(String value) d~_`M0+
{ u@P[Vb
sSiteURL = value; >Aq870n
} EIbXmkHl<
BtdXv4V
sz):oea@f@
public String getSFilePath() 7"*|2Xq
{ \mN[gT}LHm
return sFilePath; y3;q_4.
} 5Wj; [2 )
%T=A{<[`
zT* .jv
public void setSFilePath(String value) \#x}q'BC4
{ V*$L;xbC|
sFilePath = value; !b-bP,q
} Na,_
`C+HE$B
ixh47M
public String getSFileName() O0*e)i8
{ ZRUhAp'<qj
return sFileName; ?Jusl8Sm
} wVA|!>v
XfzVcap
PaCzr5!~f
public void setSFileName(String value) jSQ9.%4
{ >(tn"2
sFileName = value; B)h>8 {
} X0+fsf<H}
7W9d6i)
0i8hI6d
public int getNSplitter() oXt,e
{ hsG#6?l3
return nSplitter; rt+..t\
} do>"[RO
?68uS;
|__=d+M'
public void setNSplitter(int nCount) QldzQ%4c\
{ =]Hs|{
nSplitter = nCount; z&$/EP-
} D0]a\,aZ
} g#K'6VK{
y466A]|
i(wgB\9i4
/* dow^*{fqZ
**Utility.java } i)$n(A)K
*/ qturd7
package NetFox; Y ZaP
7/X"z=Q^|
Zq ot{s
public class Utility { N\1/JW+
I]J*BD#n.
/=#~
public Utility() ;+I4&VieK
{ TQ1WVq }*
Lg`Jp&Kg
, Ut Hc]
} [ij,RE7,T
g>7Y~_}
//线程睡眠 {lzG*4?
public static void sleep(int nSecond) [~k]{[NJ
{ >n7["7HHk
try{ z]$j7dp
Thread.sleep(nSecond); vh>{_ #
} DcV<y-`'1
catch(Exception e) azb=(l-
{ oBlzHBn>0
e.printStackTrace (); 8!h'j
} ._p""'Sa
} 5>ST"l_ca
O'}llo
//日志 ?9u4a_x
public static void log(String sMsg) {%']w
{ d\XRUO[
System.err.println(sMsg); i&@,5/'-_O
} ^ZQCIS-R
LEc8NQs
DQ=N1pft2v
public static void log(int sMsg) A@$fb}CF
{ iIU( C.I
System.err.println(sMsg); Gbd?%{Xc-
} 3BMS_,P
} R~B0+:6
udTxNl!
6|;0ax4:P
/* n2;9geq+
**TestMethod.java 6;uBZ&g
*/ 5FuK\y
package NetFox; ?'~;Q)
1]/N2&
,p,Du F
public class TestMethod { U=o Z.\
a0zG(7.D
NR/-m7#-
public TestMethod() |Odu4 Q
{ ///xx/weblogic60b2_win.exe .Y/-8H-3v
try{ l6B.6 '4)w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4IGxI7~27#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T=? bdIl
SiteFileFetch fileFetch = new SiteFileFetch(bean); .{N\<01
fileFetch.start(); )Ul&1UYA
} yer> x
catch(Exception e){e.printStackTrace ();} .g-3e"@
{u]CHN`%Z
TSyzdnMvz
} o#d$[oa
8)Tj H'
1e$[p[
public static void main(String[] args) L+Nsi~YVq
{ qU6BA\ZL
new TestMethod(); 712=rUI%!
} 1XnBK$`
} nJ# XVlHc
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