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)); >_$DKY>$`
} &~7b-foCq
for(int i=0;i<nEndPos.length-1;i++) A@0%7xm
{ -3<5,Q{G+
nEndPos = nStartPos[i+1]; Y?z@)cL
} J$?*qZ(oO
nEndPos[nEndPos.length-1] = nFileLength; 8vcV-+x
} {>cO&eiCt
} `MtPua\_
O`hOVHDQ
rE bC_<
//启动子线程 @M-+-6+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2|)3Ly9
for(int i=0;i<nStartPos.length;i++) FPu"/4v&
{ =,~h]_\_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :,=no>mMx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D`lTP(] y
nStartPos,nEndPos,i); /)PD+18
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )vK %LmP
fileSplitterFetch.start(); B&`hvR
} B{SzC=4f}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G8lR_gD"!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~Cj55S+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?*z#G'3z1
nEndPos = " + nFileLength); rQbL86+
// fileSplitterFetch[nPos.length-1].start(); t,.MtU>K@
& ;+u.X
5B?>.4R
//等待子线程结束 wvm`JOP:A
//int count = 0; i(JBBE"
//是否结束while循环 5xi f0h-`
boolean breakWhile = false; _e=R[
tw]RH(g+#
?s("@dz_
while(!bStop) d"|XN{
{ V>j6Juh
write_nPos(); lV-7bZ
Utility.sleep(500); _n(NPFV
breakWhile = true; }xHoitOD
~:f9,
%zs 1v]
for(int i=0;i<nStartPos.length;i++) ` =!&9o
{ *Ri?mEv hF
if(!fileSplitterFetch.bDownOver) .foM>UOY
{ '@M
breakWhile = false; dm&F1NkT
break; 9LGJ-gL
} Wr7^
} a'ViyTBo
if(breakWhile) A:EF#2)g
break; DA@YjebP'
PY.c$)az>
$Tt@Xu
//count++; 8ltHR]v
//if(count>4) AyKaazm]9
// siteStop(); #{GUu',?&
} Z xLjh
l,*v/95h
3C8'0DB
System.err.println("文件下载结束！"); rO/mK$
} lkV% k1w
catch(Exception e){e.printStackTrace ();} y5.Z<Y
} gO?+:}!
/b20!3
pK#Ze/!
//获得文件长度 SG8H~]CO)
public long getFileSize() hNXPm~OK\
{ YZf<S:
int nFileLength = -1; 1<^"OjQ
try{ b1jh2pG(V
URL url = new URL(siteInfoBean.getSSiteURL()); 0i9y-32-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jNV2o
httpConnection.setRequestProperty("User-Agent","NetFox"); #JGy2Hk$^
W?G4\ubM3<
abUn{X+f~
int responseCode=httpConnection.getResponseCode(); l'VgS:NT
if(responseCode>=400) wYhWRgP
{ y>u+.z a|
processErrorCode(responseCode); BUv;BzyV
return -2; //-2 represent access is error ~-Rr[O=E
} >/EmC3?b!
_h7+.U=
*"0Yr`)S
String sHeader; ,qpn4`zE~
m~#S76!w
'!Vn
for(int i=1;;i++) BG"~yyKA
{ Tn/T:7C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t-lWvxXe
//Utility.log(in.readLine()); %$I\\qq>{
sHeader=httpConnection.getHeaderFieldKey(i); Vf*!m~]Vqi
if(sHeader!=null) y%=\E
{ +M (\R?@gr
if(sHeader.equals("Content-Length")) Fm{Ri=X<:
{ <dDGV>n4;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s'ntf
break; T.!GEUQ
} M'W@K
} SZ~Ti|^
else LDW":k|
break; R,/?p
} ()K%Rn
} =lS~2C
catch(IOException e){e.printStackTrace ();} 0[xum
catch(Exception e){e.printStackTrace ();} FJv=5L
&7T0nB/)
._=Pa)T
Utility.log(nFileLength); 6 EE7<&
?)7uwJsH
RP7e)?5$s
return nFileLength; XY1NTo.=
} ${KDGJ,^
z}s0D]$+x
?.IT!M}DR
//保存下载信息（文件指针位置） 2;5EH0
private void write_nPos() !k||-Q&
{ 6t TLyI$+
try{ r`i<XGPJ%
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]OM|Oo
output.writeInt(nStartPos.length); 06pLa3oi
for(int i=0;i<nStartPos.length;i++) s9~W( Wi
{ c&3 ]%urL
// output.writeLong(nPos); P`5@$1CJ
output.writeLong(fileSplitterFetch.nStartPos); \)DP(wC
output.writeLong(fileSplitterFetch.nEndPos); u1ggLH!U
} e1S |&W8
output.close(); /lm;.7_J+
} K-)_1
catch(IOException e){e.printStackTrace ();} q>%KIBh(
catch(Exception e){e.printStackTrace ();} Yp./3b VO
} n%3rv?m7
/P5w}n
a =*(>=
//读取保存的下载信息（文件指针位置） %z J)mOu
private void read_nPos() NM/?jF@j*
{ II)\rVP5
try{ PLKp<kg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IBf&'/ 8\
int nCount = input.readInt(); WHqp7NPl
nStartPos = new long[nCount]; s,"<+80%
nEndPos = new long[nCount]; Bra>C
for(int i=0;i<nStartPos.length;i++) ly}6zOC\
{ ?2%d;tW
nStartPos = input.readLong(); .Hl]xI$;+
nEndPos = input.readLong(); -B9C2
} mgL~ $
input.close(); #c'yAa
} Y;p _ff
catch(IOException e){e.printStackTrace ();} C&,&~^_F
catch(Exception e){e.printStackTrace ();} x<"1T w5e
} ^vYH"2
]=2Ba<)m
b~Op1p
private void processErrorCode(int nErrorCode) d47b&.v8e
{ 5.]+K<:h"A
System.err.println("Error Code : " + nErrorCode); \^iJv~d
} E08FUAth]#
VThcG( NF
uo_Y"QiKEH
//停止文件下载 L|qQZ=
public void siteStop() Tw)nFr8oF]
{ `Ff3H$_*
bStop = true; kTAb <
for(int i=0;i<nStartPos.length;i++) ixw3Z D(>+
fileSplitterFetch.splitterStop(); &xgMqv2/
Q$Ga.fI
JWr:/?
} wXMKQ)$(
} KF|+#qCN
//负责部分文件的抓取 >t)vQ&:;u
**FileSplitterFetch.java U>IllNd
*/ !Sy._NE`z
package NetFox; Y _m4:9p
P\tP0+at
=GL}\I
import java.io.*; cZk?o
import java.net.*; xKWqDt
2xhwi.u
Sf B+;i'D
public class FileSplitterFetch extends Thread { \-0@9E<D
`L`qR,R
w0)V3
String sURL; //File URL 4[ M!x
long nStartPos; //File Snippet Start Position MGfDxHg]
long nEndPos; //File Snippet End Position @HxEp;*NH"
int nThreadID; //Thread's ID 6b~Zv$5^Y-
boolean bDownOver = false; //Downing is over =dHM)OXD"
boolean bStop = false; //Stop identical wOOBW0tj
FileAccessI fileAccessI = null; //File Access interface dQYb)4ir
$HF. 02{|
+wXrQV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,=O`'l>K
{ AV Gu*
this.sURL = sURL; +(x^5~QX
this.nStartPos = nStart; O%H_._#N`
this.nEndPos = nEnd; l9lBhltOH
nThreadID = id; MIo<sJuv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k*(c8/<.d
} upg?
gS_)(
vp?87h
public void run() t 9&xk?%{
{ '3 w=D )
while(nStartPos < nEndPos && !bStop) "^F#oo%L
{ :6S!1roi
1 !bODd
B]L5K~d
try{ U&yXs'3a&
URL url = new URL(sURL); .+MJ' bW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QG*=N {%5
httpConnection.setRequestProperty("User-Agent","NetFox"); 'A;G[(SYy
String sProperty = "bytes="+nStartPos+"-"; H;s
httpConnection.setRequestProperty("RANGE",sProperty); CnSfGsE>
Utility.log(sProperty); hEi]-N\X
7Ab&C&3
4sasf94
InputStream input = httpConnection.getInputStream(); ,;)Y1q}Q
//logResponseHead(httpConnection); }l~|c{WH`
&PVos|G
7yD=~l\Bbs
byte[] b = new byte[1024]; /x,gdZPX
int nRead; e:fp8 k<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 91qk0z`N
{ PElC0qCn[
nStartPos += fileAccessI.write(b,0,nRead); <cNXe4(
//if(nThreadID == 1) WSi`)@.XO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J(JsfU4
} u~[HC)4(0
fuSfBtLPR#
^e:C{]S=
Utility.log("Thread " + nThreadID + " is over!"); 59!yz'feF
bDownOver = true; 4e~^G
//nPos = fileAccessI.write (b,0,nRead); i]J*lM7'
} R*a5bKr
catch(Exception e){e.printStackTrace ();} d9>*a$x;/
} k"D6Vyy`
} 5Ds/^fA
0D/u`-
(|)`~z
//打印回应的头信息 c[\ :^w^I6
public void logResponseHead(HttpURLConnection con) 4YDK`:4I~
{ ~XN--4%Q
for(int i=1;;i++) =}>wxO
{ x=T`i-M
String header=con.getHeaderFieldKey(i); ma9q?H#X
if(header!=null) ?j;e/r.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (MhC83|?
Utility.log(header+" : "+con.getHeaderField(header)); &IsQgS7R
else =M'M/vKD
break; PLU8:H@X
} nlmc/1C
} bP\0S@1YL
A'r 3%mC
E9z^#@s
public void splitterStop() =y-L'z&r
{ CF"$&+s9
bStop = true; rCfr&>nn
} <6QG7i
uMVM-(g%
s3qWTdM
} nfpkWyIu{
`q|&;wP.
mAMi-9
/* **_`AM~
**FileAccess.java D,q=?~
*//文件访问(定位，写) g?`g+:nug
package NetFox; .w2QiJ
import java.io.*; i)9}+M5
BC*vG=a
h07Z.q ;
public class FileAccessI implements Serializable{ {6{y"8
&7Frg`B&:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2{;&c
RandomAccessFile oSavedFile; ?#; oqH<
long nPos; ^2f'I iE
7jvy]5y8&~
8 2qf7`
public FileAccessI() throws IOException NbOeF7cq+
{ \{r-e
this("",0); Ft%HWGE
} !wiW#PR
U |I>CDp
2WQKj9iyN
public FileAccessI(String sName,long nPos) throws IOException 5v"r>q[ X
{ @(>XSTh9
oSavedFile = new RandomAccessFile(sName,"rw"); Gt#Jr!N~
this.nPos = nPos; pRI<L'
oSavedFile.seek(nPos); @P=St\;VP
} OS8 ^mC
I)#=#eI*:
iEx.BQ+
public synchronized int write(byte[] b,int nStart,int nLen) &:}e`u@5|
{ L9tjHC]
int n = -1; L%](C
try{ kwxb~~S}h(
oSavedFile.write(b,nStart,nLen); dxqVZksg(9
n = nLen; @X`~r8&
} b3(pRg[Fp
catch(IOException e) BiGB<Jr
{ p@epl|IZp
e.printStackTrace (); 50!/%
} w-2&6o<n-
QZy+`
|GuIp8~
return n; we'<Y
} D|-^}I4
x._IP,vRx^
sYV7t*l
} []HMUL]"
!iKR~&UpAL
u] C/RDTH
/* TymE(,1
**SiteInfoBean.java hUirvDvX
*/ q6A!xQs<
package NetFox; 9pPb]v,6
>55c{|"@L
_;mN1Te
public class SiteInfoBean { O%)@> 5#S
RjS;Ck@;
)"?6EsSF
private String sSiteURL; //Site's URL qz7:jq3N-{
private String sFilePath; //Saved File's Path [8*Ovd
private String sFileName; //Saved File's Name cBf9-k
private int nSplitter; //Count of Splited Downloading File ;t!n%SnK9!
,h21 h?6
'Cy^G;
public SiteInfoBean() /lAB
{//nSplitter的缺省值为5 ?pgdj|"a
//default value of nSplitter is 5 =`2nv0%2
this("","","",5); CU=}]Y
} P.*J'q 28
nb(4"|8}
RZ)sCR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B5J!&suX
{ mhnjYK9
sSiteURL= sURL; 2m.RM&TdB
sFilePath = sPath; AH`n
sFileName = sName; @rs(`4QEh
this.nSplitter = nSpiltter; #.O,JG#H
:T~Aa(%(
/UeLf$%ZW
} f.V;Hl,
qh Ezv~
A^7!:^%K
public String getSSiteURL() VlKy6PSIg
{ 1|Y(XB^os(
return sSiteURL; 8f>=.O*)
} }qfr&Ffh@
8Ml&lfn_8
'Z2:u!E
public void setSSiteURL(String value) r})2-3ZA9
{ g-'y_'%0G
sSiteURL = value; zx^]3}
} h}xUZ:
#1R_* Uh
0 eZfHW&
public String getSFilePath() Hh @q;0ni
{ n<MMO=+bg
return sFilePath; XfA3Ez,}
} ~`2w ul
{ZFa +
$,08y
public void setSFilePath(String value) \V@SCA'
{ *Yv"lB8
sFilePath = value; 2&91C[da0
} $;un$ko6%
E [JXQ76
m1_?xU
public String getSFileName() N_<sCRd]9
{ /H.QGPr
return sFileName; >JT{~SRB|Y
} U`q[5U"
^B@4 w\t
zjgK78!<
public void setSFileName(String value) gd<8RVA
{ oTZ?x}Z1
sFileName = value; Sp)KtMV
} SCeZt [
RAKQ+Y"nl
ANSvZqKh
public int getNSplitter() aKs!*uo0H
{ FtN1ZZ"<*
return nSplitter; []Cvma1\
} 6h>8^l
\Ekez~k{`
Qu]0BVIe
public void setNSplitter(int nCount) z.16%@R
{ H%7V)"
nSplitter = nCount; )hk=wu6
} b{)('C$
} ;a!o$y
[rqe;00]
qx 3.oU
/* k/l@P
**Utility.java 4,9AoK)yp
*/ =f@O~nGm
package NetFox; tYIHsm\b
#%VprcEK
TUhp
public class Utility { x6HebIR+
nzy =0Ox[
LoHWkNZ5:
public Utility() uuj"Er31
{ gT @YG;
IcL3.(!]l
Wy#`*h,
} ->wY|7
;]fpdu{
//线程睡眠 hgj#VY$B
public static void sleep(int nSecond) j>&n5?
{ 567ot|cc
try{ 5!#"8|oY
Thread.sleep(nSecond); el!Bi>b9c!
} E E?v~6"&
catch(Exception e) A`(p6 H"s
{ V$ 38
e.printStackTrace (); *wt yyP@
} /iif@5lw{
} +Smv<^bW
|}Mkn4
//日志 sxL;o>{
public static void log(String sMsg) ]wne2WXE
{ d1e'!y}R5
System.err.println(sMsg); &o"Hb=k<
} }=A6Jv(j
T.ub!,Y
:&yRvu
public static void log(int sMsg) qIjC-#a=m
{ |L;'In
System.err.println(sMsg); :EgdV
} CW\o>yh
} OpxVy _5,
yD1*^~loJ
2DQ'h}BI
/* yE9JMi0
**TestMethod.java ?^BsR
*/ 1@)]+* F*z
package NetFox; gbpm::
k6JB%m\E
$pk3d+0B
public class TestMethod { i`&yPw
]kb%l"&
"EEE09~l\
public TestMethod() b]RCe^E1
{ ///xx/weblogic60b2_win.exe 344,mnAd
try{ j,/o0k,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W\.f:"2qr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6}iIK,Om
SiteFileFetch fileFetch = new SiteFileFetch(bean); OD\x1,E)I
fileFetch.start(); sbK0OA
} ccD+o$7LT
catch(Exception e){e.printStackTrace ();} `m2F.^qrr
DDAqgx
$#R.+B
} W\eB
w2{k0MW
/2'\ya4B
public static void main(String[] args) F!]UaEmV
{ eg(xN/D
new TestMethod(); {h9#JMIA
} );))kYr
} zN5i}U=|r
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