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)); @"O|[%7e
} W|AK"vf
for(int i=0;i<nEndPos.length-1;i++) Ktn:6=,
{ eR>|1s%^
nEndPos = nStartPos[i+1]; Oe"nNvu/
} 5LJ0V
nEndPos[nEndPos.length-1] = nFileLength; }5]7lGR
} B2l5}"{`
} ,qT+Vqpr{
';KWHk8C
{YF(6wVl
//启动子线程 -xL^UcG0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G?<uw RV
for(int i=0;i<nStartPos.length;i++) bO+]1nZ.
{ 1w'W)x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k\KI#.>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \IO<V9^L
nStartPos,nEndPos,i); c)4L3W-x=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jhH&}d9
fileSplitterFetch.start(); ;C,t`(
} {iYrC m[_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mKuY=#RP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fxknfgbg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L'u*WHj|v
nEndPos = " + nFileLength); (CInt_dBw~
// fileSplitterFetch[nPos.length-1].start(); .,<w_=
/B)`pF.n
d9q`IZqee
//等待子线程结束 xiOAj"}~
//int count = 0; ;L[N.ZY!
//是否结束while循环 d'@i8N["{
boolean breakWhile = false; }h1y^fuGi
!3`X Gg
Scfe6+\EW
while(!bStop) 6k`O
{ OM?FpRVU8
write_nPos(); )3.=)?XW
Utility.sleep(500); B["jndyr
breakWhile = true; 3v~[kVhoG
HutQx
=rA]kGx
for(int i=0;i<nStartPos.length;i++) HT7I~]W
{ TjicltQi4
if(!fileSplitterFetch.bDownOver) @*BVS'\
{ >?[?W|k7V
breakWhile = false; q\xsXM
break; zMh`Uqid
} /sr.MT
} m-]F]c=)w<
if(breakWhile) UJ><B"
break; 9SXpZ*Sx
{t|Q9&
!m8T< LtMl
//count++; EQ]>^VE2B
//if(count>4) ssAGWP
// siteStop(); E:Ul_m8
} ;@qQ^!g2
08/Tk+
Q5]rc`} 5
System.err.println("文件下载结束！"); [9yd29pQ]
} 9Zr6 KA{
catch(Exception e){e.printStackTrace ();} 9M-W 1prb
} SgkW-#
\+Y5b}
:XOjS[wBm
//获得文件长度 -.K'rW
public long getFileSize() =.l>Uw!
{ 2 ,krVb?<
int nFileLength = -1; D;z!C ys
try{ Nz:p(X!
URL url = new URL(siteInfoBean.getSSiteURL()); vhzz(UPUt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JsEnhE}]
httpConnection.setRequestProperty("User-Agent","NetFox"); xl Q]"sm1
}!"Cvu
2OjU3z<J
int responseCode=httpConnection.getResponseCode(); fi%lN_Ev?
if(responseCode>=400) #mD_<@@
{ yv: Op\;R
processErrorCode(responseCode); ]2{]TJ@B
return -2; //-2 represent access is error bK{ VjXF
} QcX&q%*0
i=&]%T6Qk
HkY#i;%N
String sHeader; ru|*xNXKgC
Hs6Kki1
)~`UDaj_
for(int i=1;;i++) 7>F[7_
{ ( X+2vN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uX%$3k
//Utility.log(in.readLine()); 3QF[@8EH{
sHeader=httpConnection.getHeaderFieldKey(i); Ucz=\dO1
if(sHeader!=null) uo;m
{ 'T7Y5X80$j
if(sHeader.equals("Content-Length")) OLV3.~T
{ "U$](k.<VA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x:h)\%Dg<
break; qyh]v[
} (W}DMcuSd
} /lhk} y^
else (Ffa{Tt!
break; #w8.aNU+]
} ab#z&jg!
} 4UK>Vzn
catch(IOException e){e.printStackTrace ();} c= ?Tu
catch(Exception e){e.printStackTrace ();} \rE] V,,2
kq([c r
@Kw&XKe`
Utility.log(nFileLength); 'I:_}q
`wr*@/P
0k4XVd+Nv
return nFileLength; HrMbp
} 0fK#:6
nc1?c1s,f
NG23
//保存下载信息（文件指针位置） yU"#2 *C
private void write_nPos() UMT}2d%
{ PWquu`
try{ ;0NJX)GL
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ps;4]=c
output.writeInt(nStartPos.length); fI'+4 )@x
for(int i=0;i<nStartPos.length;i++) k~F,n
{ qT&zg@m
// output.writeLong(nPos); 4ElS_u^cP7
output.writeLong(fileSplitterFetch.nStartPos); 5+j):_
output.writeLong(fileSplitterFetch.nEndPos); @;KvUR/+FE
} 25r3[gX9`
output.close(); `B,R+==G:
} rFUd
catch(IOException e){e.printStackTrace ();} Og8%SnEpMI
catch(Exception e){e.printStackTrace ();} ?FEh9l)d\
} /b/ 6*&
_1WA:7$C
3C'6i
//读取保存的下载信息（文件指针位置） +}:2DXy@
private void read_nPos() =WEDQ\ c
{ B|{E[]iK
try{ IGab~`c-[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "$ISun=8
int nCount = input.readInt(); L"0?g(< 5
nStartPos = new long[nCount]; D=Yr/qc?
nEndPos = new long[nCount]; 8-cuaa
for(int i=0;i<nStartPos.length;i++) qv4r!x
{ a4Z e!l(
nStartPos = input.readLong(); Vi0D>4{+
nEndPos = input.readLong(); mX?t|:[b
} a=vH:D
input.close(); yf-2E_yB
} NgF"1E
catch(IOException e){e.printStackTrace ();} /;!I.|j
catch(Exception e){e.printStackTrace ();} AsvH@\\
} cmq4w&x/
)5y"T0]
I7#JT?\}
private void processErrorCode(int nErrorCode) 8U7dd[
{ /s+S\ djk
System.err.println("Error Code : " + nErrorCode); 02,.UqCz
} {+3g*s/HI
CC3M7|eO3
oq|`;k
//停止文件下载 4X+I2CD
public void siteStop() <Of-,PcCV
{ <P@O{Xi+K
bStop = true; sYvlf0
for(int i=0;i<nStartPos.length;i++) ={;+0Wjb8
fileSplitterFetch.splitterStop(); EWv[Sp
"/2kf)l{4
$xF[j9nM
} S/RChg_L5
} <s$T7Zk
//负责部分文件的抓取 wfcR[
**FileSplitterFetch.java */K]sQZa
*/ 'C#[iRG4
package NetFox; ZPz=\^
H0.A;`
K@ &;f(Y
import java.io.*; whrDw1>(
import java.net.*; dO,;k+
M=SrZ,W
{Ve`VV5E
public class FileSplitterFetch extends Thread { /WLZyT2
y7GgTC/H
ugTnz$
String sURL; //File URL "pH;0[r]
long nStartPos; //File Snippet Start Position 3"k n5)x
long nEndPos; //File Snippet End Position G|"m-.9F
int nThreadID; //Thread's ID +4rd N\.
boolean bDownOver = false; //Downing is over x\VP X
boolean bStop = false; //Stop identical p<wC{D
FileAccessI fileAccessI = null; //File Access interface =A$d)&
wwJs_f\
BqA_CW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #TH(:I=[
{ &!M6{O=~
this.sURL = sURL; 1rLxF{,
this.nStartPos = nStart; s~o\j/
this.nEndPos = nEnd; raU_Z[
nThreadID = id; _Vt(Eg_\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uss!E!_%,
} R|wS*xd,
aH8]$e8_,\
Sl%6F!
public void run() yT='V1
{ R|Uu
while(nStartPos < nEndPos && !bStop) iWW >]3Q
{ 5Nbq9YY
bUSa#pNO>
MIWc @.i2
try{ G-sQL'L[U
URL url = new URL(sURL); [UB*39D7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *m`x/_y+
httpConnection.setRequestProperty("User-Agent","NetFox"); Re'3bs:+
String sProperty = "bytes="+nStartPos+"-"; dNov= w
httpConnection.setRequestProperty("RANGE",sProperty); ltNY8xrdGN
Utility.log(sProperty); Z J1@z.
hFhC&2HN
3 +`,'Q9
InputStream input = httpConnection.getInputStream(); @uG/2'B(
//logResponseHead(httpConnection); `G:hC5B
2=1qmQE
=@X?$>'
byte[] b = new byte[1024]; u^WZsW
int nRead; pigu]mj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r@wE?hK
{ N$.ls48a4-
nStartPos += fileAccessI.write(b,0,nRead); 1Oak8 \G
//if(nThreadID == 1) 8H8Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;<xPzf
} :/RvtmW
^$RpP+d
#c'}_s2F[
Utility.log("Thread " + nThreadID + " is over!"); q~*|Wd'&
bDownOver = true; \{ C ~B;=
//nPos = fileAccessI.write (b,0,nRead); <dz_7hR"
} `R lWhdE
catch(Exception e){e.printStackTrace ();} u^x<xw6f
} M*~XpT3
} 57;( P
(/t{z=
zgn`@y2
//打印回应的头信息 '] _7Xa'
public void logResponseHead(HttpURLConnection con) qP=a:R-
{ 0TiDQ4}i[
for(int i=1;;i++) v`:!$U* H=
{ ?}u][akM
String header=con.getHeaderFieldKey(i); yHZ&5
if(header!=null) XSx'@ qH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); WM=)K1p0u
Utility.log(header+" : "+con.getHeaderField(header)); 1 7iw`@
else &[yYgfsp
break; /^WawH6)6
} \rS-}DG
} eQqCRXx
vH E:TQo4
QPvWdjf#mM
public void splitterStop() `H^ H#W
{ @]EdUzzKq
bStop = true; >:J1Gc
} 4r7aZDVA\
ICTjUQP
?b(DDQMf
} PX?^v8wlqL
xz7CnW1
5\}QOL
/* :U @L$
**FileAccess.java 'w|N} 4
*//文件访问(定位，写) u}?{1B!
package NetFox; CwO$EL:[`
import java.io.*; :`4LV
zThut!O
c-Qa0Q
public class FileAccessI implements Serializable{ x LK,Je
160BgFM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }MM:qR
RandomAccessFile oSavedFile; 2D3mTpw
long nPos; `_J>R
Maiyd
\@_?mL@=
public FileAccessI() throws IOException ;y>}LGG
{ H\|H]:CE
this("",0); U8zs=tA
} \@6V{y'Zo
i6^-fl
}7qboUGe
public FileAccessI(String sName,long nPos) throws IOException `3dGn.M
{ EDA6b]
oSavedFile = new RandomAccessFile(sName,"rw"); +n|@'= ]
this.nPos = nPos; yJ8_<A
oSavedFile.seek(nPos); ^3Z~RK\}
} 36 ]?4, .
*+J`Yk7}
z,SNJIsx
public synchronized int write(byte[] b,int nStart,int nLen) s 8lfW6
{ 1kh()IrA
int n = -1; $ Vsf?ID
try{ D#X&gE
oSavedFile.write(b,nStart,nLen); k,r}X:<6jz
n = nLen; e~$aJO@B.R
} |eej}G(,m}
catch(IOException e) tSunO-\y
{ H$xUOqL
e.printStackTrace (); Mbtk:GuY
} n<>]7-
->@iw!5xu
H$)otDOE
return n; W0# VDe]>
} &t74T"(d
N<aMUVm
-$(2Z[
} -p20UP 1I
)`<7qT_BM
PE2O$:b\
/* 2S-z$Bi}]
**SiteInfoBean.java Xm^/t#
*/ cb_nlG!
package NetFox; bbFzmS1
1K{hj%
TiSV`V q
public class SiteInfoBean { zR }vw{
Kl*/{&,P
tQIz
private String sSiteURL; //Site's URL ]{pH,vk-
private String sFilePath; //Saved File's Path ?xzDz
private String sFileName; //Saved File's Name r?=3TAA
private int nSplitter; //Count of Splited Downloading File 5m rkw
Rnk&:c
`5t CmU
public SiteInfoBean() !FbW3p f
{//nSplitter的缺省值为5 EdS7m,d
//default value of nSplitter is 5 cK1RmL"3
this("","","",5); O*hQP*Rs
} :.W</o~\s
rJc=&'{&)N
`:EU~4s\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 87:V-*8
{ Ct9*T`Gl
sSiteURL= sURL; ^%m~VLH
sFilePath = sPath; .Wvg{ S-
sFileName = sName; Eilo;-El
this.nSplitter = nSpiltter; 3Cl&1K #5
2p8}6y:}7
]Kp -2KW
} )r:gDd#/X
MGSD;Lgn
r*W&SU9Z
public String getSSiteURL() @d6N[?3;
{ d0N/!;
return sSiteURL; $D(q
} 6yXMre)YV
xs$-^FnD
x.aqy'/`
public void setSSiteURL(String value) G0pqiU6
{ h v/+
sSiteURL = value; !jyy`q=
} WOuk> /
@!2vS@f
]ag^~8bG @
public String getSFilePath() !eGUiE=
{ $h8,QPy
return sFilePath; l08JL
} EMMp4KKOx+
$5Tjo T
8Hh=Sp^
public void setSFilePath(String value) ^ lM.lS>)
{ ETtoY<`#
sFilePath = value; =z +iI;
} H(F9&6}
#kPsg9Y
Q(ec>+oi
public String getSFileName() }-15^2
{ FpFkZFtG'm
return sFileName; 7G5VwO
} 7DCu#Y[
;0]s:0WD0P
_cD-E.E%
public void setSFileName(String value) 6eHw\$/
{ !:9s>0';N
sFileName = value; TrmrA$5f
} %~^:[@xa*
wBIhpiJX0
l\1_v7s
public int getNSplitter() NM&R\GI
{ gaxxB]8
return nSplitter; t[Ywp!y[
} `Uy'YfYF
|t&gyj
6V6,m4e
public void setNSplitter(int nCount) |FxTP&8~
{ f`"@7-N
nSplitter = nCount; #JW~&;
} Y5$VWUrB
} Sx}61?
}ec3qZ@
=Z}=nS?4
/* O t1:z:Pl
**Utility.java h^=9R6im
*/ 4'BZ+A,p
package NetFox; $7'KcG
B{\qYL/~
tA]Y=U+Q
public class Utility { ".Sa[A;~
;J&9l >
JWo).
public Utility() BhCOT+i;c
{ N4[^!}4
l~*D jr~
NB?y/v
} 1@{qPmf^
_1kcz]]F
//线程睡眠 "E}38
public static void sleep(int nSecond) Tmr%r'i3
{ Yi+$g
try{ h1jEulcMtq
Thread.sleep(nSecond); FCA]zR1
} ]iE)8X
catch(Exception e) kH}HFl
{ BNpc-O~
e.printStackTrace (); wwVg'V;
} {&d )O
} Zz@wbhMV
ePxwN?
//日志 u[~= a5:4
public static void log(String sMsg) AxZaV;%*
{ )R@M~d-o
System.err.println(sMsg); Qa-~x8]
} b5.L== >
".:]?Lvt
+#MQ8d
public static void log(int sMsg) TDR2){I
{ H!vX#
System.err.println(sMsg); oES4X{,
} !y syb
} [y(AdZ0*
T,SCK^
)*T<s
/* vQhi2J'
**TestMethod.java xA {1XS}
*/ }Asp=<kCc
package NetFox; $G@^!(
w;(B4^?
XX|wle1Kg
public class TestMethod { 9_I#{?
to"[r
7UA|G2Zr
public TestMethod() #uHl
{ ///xx/weblogic60b2_win.exe ct-;L' a
try{ 9o|#R&0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kt/Wd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y%A KN
SiteFileFetch fileFetch = new SiteFileFetch(bean); !-Br?
fileFetch.start(); ;1[Lwnm
} )o>1=Y`[z
catch(Exception e){e.printStackTrace ();} c0M>CaKD
k<cv80lhK
hDc)\vzr
} Yvbk[Rb
08JVX'X-mr
cAAyyc"yJ
public static void main(String[] args) &6}] v:
{ jXALN
new TestMethod(); %*`yd.L0W
} Vj{}cL"MR
} *2tG07kI
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