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)); \4C[<Gbx$(
} V{A`?Jl6{
for(int i=0;i<nEndPos.length-1;i++) `<M>"~W
{ /!MKijI
nEndPos = nStartPos[i+1]; pIYXYQ=Z
} D3P/: 4
nEndPos[nEndPos.length-1] = nFileLength; Fkq^2o ]
} !@N?0@$/
} FoH1O+e
PwthYy
VY+P c/b
//启动子线程 a'dlAda
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]t`SCsoo
for(int i=0;i<nStartPos.length;i++) \hBzP^*"n
{ |g!d[ct]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )7o?}"I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c%gL3kOT
nStartPos,nEndPos,i); kw]?/s`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q9xb7)G
fileSplitterFetch.start(); $uyx
} jY]51B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G :k'm^k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *L$_80
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ka8Y+Gs
nEndPos = " + nFileLength); 2{vAs
// fileSplitterFetch[nPos.length-1].start(); +{V`{'
-GHd]7n
]W`?0VwF
//等待子线程结束 $/;K<*O$
//int count = 0; J@6j^U
//是否结束while循环 #vga qe9
boolean breakWhile = false; 9q_{_%G%
U&Vu%+B
"`4ky]
while(!bStop) 18QqZ,t
{ ; teM^zyI
write_nPos(); ,I x>.^|
Utility.sleep(500); VwPoQ9pIS
breakWhile = true; 'Kbrz
$8%"bR;Hu
seBmhe5qR
for(int i=0;i<nStartPos.length;i++) 6uFw+Ya#
{ G:tY1'5
if(!fileSplitterFetch.bDownOver) Abt<23$h
{ .'<K$:8@|
breakWhile = false; }YFM40H
break; p^<(.+P4
} 9*ZlNZ
} Bps%>P~.
if(breakWhile) :;]9,n
break; /r"<:+
z06,$OYz
5}ftiy[Yc
//count++; o9"?z
//if(count>4) b(;u2 8
// siteStop(); x0(bM g>7
} e7xBi!I)~
N\g=9o|Q
DlE,aYB
System.err.println("文件下载结束！"); Z,E$4Z
} Dn 0L%?_
catch(Exception e){e.printStackTrace ();} =zK4jiM1
} QDQ"Sc06
*0!p_Hco
`7:uc@
//获得文件长度 n2B%}LLa
public long getFileSize() :1j8!R5
{ /ta}12Z
int nFileLength = -1; Nyy&'\`!
try{ 8e*skL
URL url = new URL(siteInfoBean.getSSiteURL()); BL16?&RK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7UMZs7L$
httpConnection.setRequestProperty("User-Agent","NetFox"); -?)^ hbr
e>Z&0lV:
@NRN#~S,_]
int responseCode=httpConnection.getResponseCode(); }]o8}$&(
if(responseCode>=400) ?I[8rzBWU
{ $e7%>*?m
processErrorCode(responseCode); 3P2{M}WIl
return -2; //-2 represent access is error &`l\Q\_[@
} c.IUqin
[8sYEh
%%s)D4sW
String sHeader; JfN '11,$
: x&R'wX-
}h45j84)
for(int i=1;;i++) iv~R4;;)
{ ))|d~m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /f1]U LmC:
//Utility.log(in.readLine()); \(i'iC
sHeader=httpConnection.getHeaderFieldKey(i); {S{%KkAV
if(sHeader!=null) 72OqXa*
{ BJux5Nh
if(sHeader.equals("Content-Length")) l2St)`K8
{ ay7\Ae]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mcd{:/^?
break; Ur xiaE
} HRyFjAR\?
} 'cpm 4mT
else #kM|!U=
break; '/u|32
} ^^"zjl*^
} p6<JpW5@_
catch(IOException e){e.printStackTrace ();} j J{F0o
catch(Exception e){e.printStackTrace ();} U=~?ca
w/*G!o-<
a*5KUj6/TL
Utility.log(nFileLength); D5c 8sB
$^iio@SW{
%jjPs.
return nFileLength; 9-T<gYl
} OK80-/8HI
=6dAF"b)
]%A> swCpn
//保存下载信息（文件指针位置） wI|h9q1U
private void write_nPos() .b]sQ'
{ gvR]"h
try{ g9" wX?*
output = new DataOutputStream(new FileOutputStream(tmpFile)); i"a3POV>
output.writeInt(nStartPos.length); }dzdx"
for(int i=0;i<nStartPos.length;i++) y{@\8B]
{ \:J=tAC
// output.writeLong(nPos); ?2&= +QaT
output.writeLong(fileSplitterFetch.nStartPos); ts,r,{
output.writeLong(fileSplitterFetch.nEndPos); W\zZ&*8$
} hEB5=~A_
output.close(); 0vjCSU-X
} 5bt>MoKxv
catch(IOException e){e.printStackTrace ();} I%J>~=]n_
catch(Exception e){e.printStackTrace ();} BFW b0;+
} d MR?pbD
'w=|uE {^
"HJ^>%ia
//读取保存的下载信息（文件指针位置） T9V=#+8#"
private void read_nPos() s9+):,dKP
{ u"qVT9C$=
try{ I.3~ctzu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C})Dvh
int nCount = input.readInt(); [bHm-X]
nStartPos = new long[nCount]; ,5$G0
nEndPos = new long[nCount]; VP A+/5TW
for(int i=0;i<nStartPos.length;i++) vIJ5iLF
{ ? #rXc%F
nStartPos = input.readLong(); -kk7y
nEndPos = input.readLong(); $L= Dky7
} |s! _;6
input.close(); M]PZwW8
} f8lyH'z0 @
catch(IOException e){e.printStackTrace ();} M v(Pp
catch(Exception e){e.printStackTrace ();} b5|*p(7[
} D@La-K*5
'l^Bb#)"
+JtKVF
private void processErrorCode(int nErrorCode) UH>~Y N
{ /#Pm'i>B
System.err.println("Error Code : " + nErrorCode); #4m5I="
} "a[;{s{{.
>;4q
&b#d4p6&l
//停止文件下载 Nx.9)MjI
public void siteStop() ura&9~
{ dnLjcHFj&
bStop = true; Xq$-&~
for(int i=0;i<nStartPos.length;i++) anW['!T9{s
fileSplitterFetch.splitterStop(); n0l|7:Mk
@HbRfD/!
Trs~KcsD
} e^eJ!~0
} v>LK+|U
//负责部分文件的抓取 6c]4(%8
**FileSplitterFetch.java ~}b0zL
*/ _5 SvZ;4
package NetFox; }BM`4/
GbO j% a
Sk53Lc
import java.io.*; p?$N[-W6-
import java.net.*; F8?,}5j
R_G2C@y*
~:JAWs$\V
public class FileSplitterFetch extends Thread { q,ie)`
>Y4^<!\v
c{Z "'t7
String sURL; //File URL /UunWZ u%
long nStartPos; //File Snippet Start Position $Zyuhji^
long nEndPos; //File Snippet End Position 1L::Qu%E
int nThreadID; //Thread's ID R7rM$|n=o
boolean bDownOver = false; //Downing is over c<_1o!68
boolean bStop = false; //Stop identical 'G65zz
FileAccessI fileAccessI = null; //File Access interface q}Po)IUT`5
"*#f^/LS
SHYekX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :i>LESJq
{ EC$F|T0f
this.sURL = sURL; ^ q ba<#e
this.nStartPos = nStart; ?&0CEfa?
this.nEndPos = nEnd; H%m^8yW1
nThreadID = id; gtH^'vFZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8#$HKWUK
} CX/[L)|Ru
EB&hgz&_
P4"BX*x
public void run() N_:!uR
{ 4wKCzPy
while(nStartPos < nEndPos && !bStop) e;=R8i
{ &kdW(;`
a`yCPnB(
?W ^`Fa)]o
try{ DOtz
URL url = new URL(sURL); < k(n%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g&/lyQ+G
httpConnection.setRequestProperty("User-Agent","NetFox"); w$$pTk|&n
String sProperty = "bytes="+nStartPos+"-"; 9u=]D> kb
httpConnection.setRequestProperty("RANGE",sProperty); y+BiaD!U
Utility.log(sProperty); >1Iw!SO+
rYPuo
qK;J:GT>
InputStream input = httpConnection.getInputStream(); YH^U"\}i
//logResponseHead(httpConnection); )]Zdaw)X
evEdFY
UBv#z&@[
byte[] b = new byte[1024]; Jyd[Sc)
int nRead; -GL.8"c[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i|H^&$|
{ vKoQ!7g
nStartPos += fileAccessI.write(b,0,nRead); 1| WDbk
//if(nThreadID == 1) M&Q&be84
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )sIzBC
} ?jO<<@*2S
4%v-)HGh
D@w&[IF
Utility.log("Thread " + nThreadID + " is over!"); y1Br4K5C
bDownOver = true; agoMsxI9
//nPos = fileAccessI.write (b,0,nRead); I7XM2xM
} qzY:>>d'
catch(Exception e){e.printStackTrace ();} Rz>@G>b:
} sFfargl
} @(/$;I,
vEt=enQ
%> YRNW@%
//打印回应的头信息 /$qB&OWJn
public void logResponseHead(HttpURLConnection con) (Gzq 1+B
{ :gkn`z
for(int i=1;;i++) 0n{+_
{ r,,*kE
String header=con.getHeaderFieldKey(i); jxw8jo06:
if(header!=null) jRk1Iu|7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :d<F7`k H
Utility.log(header+" : "+con.getHeaderField(header)); ayf;'1
else M1DV9~S
break; r_^]5C\
} 's8LrO(=
} O St~P^1
;M#D*<ucI:
wuqB['3
public void splitterStop() &~)1mnv.
{ a,t]>z95
bStop = true; I7#+B1t
} 65c#he[_Y
ui*CA^ Y
}WNgKw
} y9GaxW*&
#Nv0d|0\
Ga"<qmLMc
/* IrP6Rxh
**FileAccess.java V+y:!t`
*//文件访问(定位，写) B&lF! ]
package NetFox; H?pWyc<,
import java.io.*; Q0_|?]v
`ucr;P
TSd;L u%hr
public class FileAccessI implements Serializable{ 4[LzjC
0c:jwtf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FU(s jB
RandomAccessFile oSavedFile; [~rBnzb
long nPos; (/_Z^m9
<+7-^o_
A|GheH!t
public FileAccessI() throws IOException dzc.s8T(0
{ y$pT5X G
this("",0); h3L{zOff
} <j89HtCz
@7B!(Q
uJHf6Ye
public FileAccessI(String sName,long nPos) throws IOException LMte,zs>
{ R*psL&N
oSavedFile = new RandomAccessFile(sName,"rw"); >/F,Z%!&q
this.nPos = nPos; !xh.S#B
oSavedFile.seek(nPos); M&O .7B1}
} ,n?oNU
A ptzBs/
h3Z0NJ=xM
public synchronized int write(byte[] b,int nStart,int nLen) 7L&=z$U@m
{ +-OqO3R
int n = -1; -^LEGKN
try{ :<Y, f(c
oSavedFile.write(b,nStart,nLen); 0/JusQ
n = nLen; vSy#[9}
} 6<<ihm+
catch(IOException e) 6rOd80\
{ 7*r7Q'
e.printStackTrace (); QR($KW(
} GoNX\^A
q\g|K3V)
&iDX+*(
return n; cvvba 60
} \{[Gdj`
Y_49UtJIg
mmG+"g$|
} %g4G&My@J
jn9KQe\3
2!b+}+:
/* t)O$W
**SiteInfoBean.java fWywegh
*/ g2v0!
package NetFox; ZVj/lOP X
'e;]\< 0z
+Q3i&"QB.
public class SiteInfoBean { K$dSg1t
/}\EMP
hYMo5?
private String sSiteURL; //Site's URL ~I%m[fQ S
private String sFilePath; //Saved File's Path x_vaYUl)
private String sFileName; //Saved File's Name kw>W5tNpf:
private int nSplitter; //Count of Splited Downloading File {re<S<j&
tN=B9bm3j
`)5E_E3
public SiteInfoBean() l* =\0
{//nSplitter的缺省值为5 e:E:"elr]
//default value of nSplitter is 5 "RH pj3 si
this("","","",5); %(IkUD
} B'OUT2cgB
fWKI~/eUY|
tk@ T-;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mX9amS&B$
{ ?H\K];
sSiteURL= sURL; F(J6 XnQ
sFilePath = sPath; 'a`cK;X9F
sFileName = sName; P".CZyI-i
this.nSplitter = nSpiltter; \YE(E04w57
~.?,*q7
Wp"+\{@)
} 2HNKq<
B zmmE2~*
a7+w)]r
public String getSSiteURL() qU(,q/l
{ wJs#rkW
return sSiteURL; b!C\J
} h\#\hx
hSQuML
#1-,s.)
public void setSSiteURL(String value) RjC3wO::
{ B|9)4f&\=R
sSiteURL = value; `52+.*J+%
} =]k0*\PS
A}Q6DHh26
WC6yQSnY&
public String getSFilePath() 5eP8nn.D
{ |sP;`h}I%
return sFilePath; ;m<22@,E&
} ZG29q>
eD4D<\*
}^!8I7J.
public void setSFilePath(String value) xeo5)
{ or~2r8
sFilePath = value; (X=JT
} lyY\P6 X
Ass :
*3.K; Ic;
public String getSFileName() _ebo
{ 1b^e4
return sFileName; 7+_TdDBYs
} :G3PdQb^
=<yMB d\
=35g:fL
public void setSFileName(String value) ]Sj<1tx7f
{ 2/XrorV
sFileName = value; dY=]ES}`
} cQg:yoF
PHQ7
3K;V3pJ].
public int getNSplitter() cs+;ijp
{ +2:\oy}!8
return nSplitter; ?3[Gh9g`
} (AYzN3 ?D
%y96]e1
O*Gg57a
public void setNSplitter(int nCount) O0Z!*Hy
{ f.yvKi.Cm
nSplitter = nCount; qQ&=Z`p!
} {lam],#r
} o,r72>|
>X@4wP7l
g=#Cc( q
/* u-s*3Lg&
**Utility.java CvOji1
*/ \wZ 4enm
package NetFox; hs;YMUA"
1tZ7%0R\g]
> J.q3
public class Utility { plNoI1st
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4h*c{do
public Utility() 3<XP/c";
{ AU$<W"%R
=I.uf
O*SJx.
} V7 OhOLK8
"lVbla4b
//线程睡眠 "g5<jp
public static void sleep(int nSecond) &gLXS1O
{ 7+NBcZuG9
try{ >b7Yk)[%
Thread.sleep(nSecond); uv|RpIve:
} XQ'$J_hC
catch(Exception e) X:#}E7]j
{ -<6b[YA
e.printStackTrace (); rff_=(?i
} >qy$W4
} @?n~v^
SgWLs%B
//日志 6ys|'<?
public static void log(String sMsg) ]>/oo=E
{ 1rIL[(r4
System.err.println(sMsg); )%JjV(:
} 8kf5u#,'
1f+z[ad&^
!ra,HkU'
public static void log(int sMsg) .~a.mT
{ HGao}@'
System.err.println(sMsg); lqcPV) n
} ;uho.)%N`F
} B)x^S >
:sS4T&@1=
gXj3=N(l
/* e>UU/Ks
**TestMethod.java \;+TZ1i_
*/ W%1/:_
package NetFox; )GfL?'Z
(sW$2a
q%/\
public class TestMethod { *&z!y/
ro+8d
^KJi|'B
public TestMethod() Y%!k'\n[2
{ ///xx/weblogic60b2_win.exe 98maQQWD
try{ %KPQ|^WE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GMY[Gd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _n0NE0
SiteFileFetch fileFetch = new SiteFileFetch(bean); E&ReQgBft
fileFetch.start(); Us\Nmso z
} ?^ R"a##
catch(Exception e){e.printStackTrace ();} w0O(>
1XpqnyL&
Ekn3ODz,
} DFbhy
O<J<)_W)
yb-4[C:i
public static void main(String[] args) Rw<O%i5/d
{ !ZM*)6^
new TestMethod(); y:Agmr,S
} ^e]h\G
} w}YcAnuB{%
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