http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); hi`\3B
} R l^ENrv!]
for(int i=0;i<nEndPos.length-1;i++) 3oE *86
{ najd~%?Rs
nEndPos = nStartPos[i+1]; v?-pAA)ht
} m~(]\
nEndPos[nEndPos.length-1] = nFileLength; Rkw)IdB
} Y>R|Uf.o z
} "'^#I_*Mf
W*}q;ub;
;]KGRT
//启动子线程 b H?dyS6Bx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #RbPNVs
for(int i=0;i<nStartPos.length;i++) '7u#uL,pa1
{ [-{L@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F?T3fINR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4WzB=C(f
nStartPos,nEndPos,i); )+u|qT3%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CmY'[rI
fileSplitterFetch.start(); Gv?'R0s
} " F~uTo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C.}Z5BwS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZiSy&r:(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kQsyvE
nEndPos = " + nFileLength); dAm(uJ
// fileSplitterFetch[nPos.length-1].start(); LXJ"ct
=S|SQz5%w
9fzbR~s
//等待子线程结束 5d*k[fZ
//int count = 0; Y\& 4`v'
//是否结束while循环 CLdLOu"
boolean breakWhile = false; uG${`4
Ae<v
IgG@v9'
while(!bStop) n/=&?#m}d
{ [JO'ta
write_nPos(); {h7*a=
Utility.sleep(500); 600-e;p
breakWhile = true; BN|+2D+S
HulN84
4 "@BbVYR
for(int i=0;i<nStartPos.length;i++) PHyS^J`
{ %)i?\(/
if(!fileSplitterFetch.bDownOver) p*-o33Ve
{ T,TKt%
breakWhile = false; r[Qk-}@vp
break; DSM,dO'
} kK16+`\+
} cr27q6_
if(breakWhile) vMRM/.
break; |F iL1_
i(a2FKLy
z5=&qo|f9l
//count++; Yih^ZTf]O?
//if(count>4) H8`K?SXU
// siteStop(); TMhUo#`I|
} 2(\~z@g
CGbW]D$@
vAy`8Q
System.err.println("文件下载结束！"); 71z$a
} ujXC#r&
catch(Exception e){e.printStackTrace ();} WW:@%cQ@
} #]_S{sO
Qx>S>f
/E2/3z
//获得文件长度 j\P47q'v#
public long getFileSize() w3:Y]F.ot
{ _WVeb}
int nFileLength = -1; Ja4O*C<
try{ S=U*is
URL url = new URL(siteInfoBean.getSSiteURL()); %A,4vLe~6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9mEC|(m*WK
httpConnection.setRequestProperty("User-Agent","NetFox"); 17a'C
+w?RW^:Q=
$*Njvr7
int responseCode=httpConnection.getResponseCode(); &DYHkG
if(responseCode>=400) G[)Ll=
{ CSN]k)\N(
processErrorCode(responseCode); K=;z&E=<c
return -2; //-2 represent access is error a-MDZT<xA+
} 5)wz`OS
razVO]]E
q=M!YWz
String sHeader; Hq?-e?Nc
z:ue]7(.
nr Jl>H
for(int i=1;;i++) 7M=LyrO
{ y[UTuFv~Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); npkE[JE:
//Utility.log(in.readLine()); yEJ}!/
sHeader=httpConnection.getHeaderFieldKey(i); I8d#AVF2
if(sHeader!=null) <{Wsh#7}.
{ il(dVW
if(sHeader.equals("Content-Length")) X2 c<.
{ 9fp1*d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [[}KCND
break; Du k v[/60
} $z"3_4a
} R*`A',]:9
else i(Cd#1<
break; 02g}}{be8
} _Jn-#du
} T\eOrWt/
catch(IOException e){e.printStackTrace ();} t4R=$ km
catch(Exception e){e.printStackTrace ();} aze}koNE
Ms;:+JI
bF;g.-.2
Utility.log(nFileLength); +!\$SOaR{
R3`!Xj#&M
ne4j_!V{Mf
return nFileLength; 2%y}El^+_
} _5uzu6:y
_Qs=v0B//
^31X-}tv
//保存下载信息（文件指针位置） Q&}`( ]k
private void write_nPos() -&I)3
{ -/*-e /+b
try{ ]mYT!(}
output = new DataOutputStream(new FileOutputStream(tmpFile)); v)mO"\
output.writeInt(nStartPos.length); 9YS&RBJu
for(int i=0;i<nStartPos.length;i++) &x =}m
{ _5 Zhv-7
// output.writeLong(nPos); >T[1=;o]
output.writeLong(fileSplitterFetch.nStartPos); PE4#dx^
output.writeLong(fileSplitterFetch.nEndPos); ~mP#V
} \R#]}g0!
output.close(); bnt>j0E
} 1K.i>]}>
catch(IOException e){e.printStackTrace ();} Q%o:*(x[O
catch(Exception e){e.printStackTrace ();} w#_/CUL
} PTfTT_t
o(Yj[:+m
T$RVz
//读取保存的下载信息（文件指针位置） }ac0}
private void read_nPos() O>9+tQ
{ f'` QW@U
try{ 48l!P(>?y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q>]FO
int nCount = input.readInt(); l ?RsXC
nStartPos = new long[nCount]; FvQ>Y')R7Z
nEndPos = new long[nCount]; #!(OTeL
for(int i=0;i<nStartPos.length;i++) 6}zargu(;
{ c193Or'6Y
nStartPos = input.readLong(); MO|aN,
nEndPos = input.readLong(); BO)K=gl;8
} :Lu=t3#
input.close(); W9nmTz\8
} LxaR1E(Cc'
catch(IOException e){e.printStackTrace ();} qOAK`{b
catch(Exception e){e.printStackTrace ();} Qxr&zT7f
} T|RW-i3
w7aC=B/{?i
\6~(#y
private void processErrorCode(int nErrorCode) ~ HFDX@m*
{ 0IO#h{t
System.err.println("Error Code : " + nErrorCode); OP>rEUtj
} 4d~Sn81xW
-8H0f-1
(`<X9w,
//停止文件下载 f'._{"
public void siteStop() w ryjs!
{ "l0z?u
bStop = true; j_i/h "
for(int i=0;i<nStartPos.length;i++) s3?pv
fileSplitterFetch.splitterStop(); r/E'#5 Q
qk!")t
#Duz|F+%
} hZ6CiEJB
} #;,dk(URo
//负责部分文件的抓取 :=9?XzCC
**FileSplitterFetch.java =s3f{0G
*/ JtA tG%
package NetFox; P?D;BAP2
}Jfi"L
Ch;C\H:X
import java.io.*; P(B:tg
import java.net.*; KtH-QQDluj
Bs7/<$9K/
mT enzIp
public class FileSplitterFetch extends Thread { /sHWJ?`&/,
4E\Jk5co,
!U,W; R
String sURL; //File URL lQ/u#c$n
long nStartPos; //File Snippet Start Position x`:zC#
long nEndPos; //File Snippet End Position (prqo1e@
int nThreadID; //Thread's ID :2^j/
boolean bDownOver = false; //Downing is over 6yZ!K
boolean bStop = false; //Stop identical <Sw>5M!j
FileAccessI fileAccessI = null; //File Access interface DLMM1 A
rZ}y'A
(`%$Aa9J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c!#DD;<Q
{ Wc]L43u
this.sURL = sURL; lxsBXXZg
this.nStartPos = nStart; Wl!|+-
this.nEndPos = nEnd; ;#c=0*.
nThreadID = id; OX|nYTp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dxj&9Ra
} x%<oeM3U
Y*oT(
6, =oTmFP
public void run() NJ" d`
{ :f1Q0klwP
while(nStartPos < nEndPos && !bStop) (vL-Z[M!
{ v8=7
,D#ssxV
II(7U3
try{ X'BFR]cm
URL url = new URL(sURL); ca~nfo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @nIoYT='
httpConnection.setRequestProperty("User-Agent","NetFox"); @&H Tt
String sProperty = "bytes="+nStartPos+"-"; liu%K9-r
httpConnection.setRequestProperty("RANGE",sProperty); eAvOT$
Utility.log(sProperty); 6KT]3*B
}@VdtH
qo,uOi
InputStream input = httpConnection.getInputStream(); LRe2wT>I
//logResponseHead(httpConnection); ! n@*6
A}K2"lQ#>,
ib$_x:OO"
byte[] b = new byte[1024]; lN@SfM4\
int nRead; ;fg8,(SM^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8#?jYhT7
{ +OGa}9j-
nStartPos += fileAccessI.write(b,0,nRead); rK^Sn7U
//if(nThreadID == 1) (- ]A1WQ?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %qN_<W&Ze
} Pr|:nJs
d"h*yH@
CJ'pZ]\G
Utility.log("Thread " + nThreadID + " is over!"); 53vnON#{*
bDownOver = true; 6;|6@j
//nPos = fileAccessI.write (b,0,nRead); Id_?
} yWsJa)e3*@
catch(Exception e){e.printStackTrace ();} uU+R,P0
} kH&KE5
} 8v eG^o
7t8[M(
k(<:
//打印回应的头信息 '!$g<= @
public void logResponseHead(HttpURLConnection con) d46PAA{'
{ ,\t:R1.
for(int i=1;;i++) 0Fd<@wQ0
{ *RPdU.
String header=con.getHeaderFieldKey(i); -)='htiU
if(header!=null) 2>bTcud>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oRJ!J-Z]
Utility.log(header+" : "+con.getHeaderField(header)); kX0hRX
else p_ H;|m9
break; vUlGE
} PAYbsn
} D/& 8[Z/Cn
iR_j h=2{
}@+3QHwYU
public void splitterStop() N*vBu`
{ '{e9Vh<x
bStop = true; pb>TUKvT&
} 6oh\#v3zV
r8]y1 Om<
V5]}b[X
} "4`i]vy8
5"5tY
%3"xn!'vf
/* osBwX.G'l
**FileAccess.java pQ:7%+Om
*//文件访问(定位，写) ;F)j,Ywi)H
package NetFox; QJeL&mf
import java.io.*; '>8IOC
_zuaImJ0o
H8$l }pOz
public class FileAccessI implements Serializable{ CxvL!ew
yJyovfJz.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V'-}B6 3S>
RandomAccessFile oSavedFile; ?W6qwm,?L
long nPos; nTG@=C#
{Kbb4%P+h
@y"/hh_?
public FileAccessI() throws IOException F_<n8U:Y
{ df85g
this("",0); 8[PD`*w
} [2WJ];FJ
{~L{FG)O
;7;=)/-
public FileAccessI(String sName,long nPos) throws IOException +-s$Htx
{ eUY/H1
oSavedFile = new RandomAccessFile(sName,"rw"); { :^;byd
this.nPos = nPos; -k4w$0)
oSavedFile.seek(nPos); R]LRgfi9
} 5ov F$qn
D7X8yv1
&3@{?K
public synchronized int write(byte[] b,int nStart,int nLen) 6}(;~/L
{ %a'Nf/9=:
int n = -1; <`PW4zSI
try{ a/@F?\A
oSavedFile.write(b,nStart,nLen); FrKI=8
n = nLen; ?h$ =]
} @Rc/^B:
catch(IOException e) :!'!V>#g
{ ?j'Nx_RoX
e.printStackTrace (); Ht{Q=w/9
} <6!;mb ;cX
6k4ZzQ}
hggP9I:s,
return n; zp4aiMn1F
} q=,
6h?v/\
)\`.Ru~,
} bjR:5@"
b6]MJ0do
3dl#:Si
/* ?3duW$`
**SiteInfoBean.java B.Szp_$
*/ l?f%2:}m
package NetFox; zUQn*Cio e
, z-#B]
4\#b@1]}
public class SiteInfoBean { EC:u;2f!
VR'R7
'5f6 M^}|2
private String sSiteURL; //Site's URL 7o99@K,
private String sFilePath; //Saved File's Path :l;SG=scx
private String sFileName; //Saved File's Name w3<%wN>tE
private int nSplitter; //Count of Splited Downloading File 0gIJ&h6*f
?q*,,+'0
r;7&U<j~Z
public SiteInfoBean() ]ChGi[B~9
{//nSplitter的缺省值为5 ]%Db%A
//default value of nSplitter is 5 :`Z'vRj
this("","","",5); }hm"49,O
} \]Nt-3|`0
crDm2oA~t
R(1N]>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ##\ <mFE
{ Xc}~_.]
sSiteURL= sURL; ((AsZ$[S
sFilePath = sPath; bTd94
sFileName = sName; ,B'n0AO/'
this.nSplitter = nSpiltter; ^e~m`R2fHh
b}-/~l-:
r8wip\[
} # o;\5MOE%
(fTi1 I!
)q8!:Z
public String getSSiteURL() OL2 b
{ /[FES78p
return sSiteURL; |eu:qn8
} *a[iq`499
8q"C=t7
te*|>NRS
public void setSSiteURL(String value) ,|7!/]0&
{ &OXWD]5$6
sSiteURL = value; G@(ukt`0}
} !A|ayYBb\
%&81xAt
4e!>A
public String getSFilePath() M3EB=tU
{ D=!T,p=
return sFilePath; l`b%imX
} &UextGk7
Iq% 0fX
^}{`bw{
public void setSFilePath(String value) ]nQC
{ -LnNA`-
sFilePath = value; -]-?>gkN5
} hLo>jE
AnW72|=A(
.~C[D T+,
public String getSFileName() nuucYm%IF-
{ !]l!I9
return sFileName; $j"TPkW{M
} |9;MP&68
Y2oN.{IH
LvcGh
public void setSFileName(String value) Mv1V Vk
{ ln*_mM/Q%
sFileName = value; '7ps_pz
} OGGuVY
7.!`c-8 u
fEYo<@5c]
public int getNSplitter() ?E|be )
{ 8)m
return nSplitter; wF.S ,|
} *D:"I!Ho
&`}8Jz=S
:OC(93d)0
public void setNSplitter(int nCount) 2`V[Nb
{ `U6bI`l
nSplitter = nCount; .8~zgpK
} PpWn+''M
} SJd,l,Gg)
i4g99Kvl
XT<{J8 0z
/* s4kkzTnXE3
**Utility.java y7LT;`A
*/ f{j.jfl\x
package NetFox; c%O8h
R;3Tyn+
T!3_Q/~^r
public class Utility { `ZLA=oD
Yd>ej1<
WVkJ=r0Ny
public Utility() iL\eMa
{ <`Q*I Y
n| [RXpAp3
jv5Os-
} jC3)^E@:"
8r-'m%l
//线程睡眠 <}z,!w8
public static void sleep(int nSecond) <7X6ULQ
{ m@#@7[6]o
try{ |h{#r7H0
Thread.sleep(nSecond); 9+"\7MHw
} mq!_/3
catch(Exception e) Tu9[byfrI
{ SGA!%=Lp
e.printStackTrace (); ^Ss4<
} ry[NR$L/m
} P+s-{vv{0
r_?il]l
//日志 D8r=Vf
public static void log(String sMsg) ??g`c=R!V
{ hrZ=8SrW
System.err.println(sMsg); se,0Rvkt
} 7$/%c{o
idLCq^jnJ
\UR/tlw+/
public static void log(int sMsg) aa10vV
{ <RPy
System.err.println(sMsg); 6d%'>^`(o-
} [T>a}}@
} <-%OXEG
7$HN5T\!
P3u,)P&
/* 1~_&XNb&
**TestMethod.java w=K!U]
*/ { kF"<W
package NetFox; szG0?e
*LZ^0c:r
vi-mn)L6#
public class TestMethod { %I>-_el
Or9`E(
q(YFt*(;w
public TestMethod() A=a~ [vre
{ ///xx/weblogic60b2_win.exe -|\SNbPTV
try{ *M^t@hl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2ij/!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QZ:xG:qyk;
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0A.PfqYi
fileFetch.start(); WymBjDos:
} YnLwBJ2i
catch(Exception e){e.printStackTrace ();} xw5LPz;B
JRT,%;*,
~3F\7%Iqc
} 7\e96+j|f
pS C5$a(
;{e=Iz}/
public static void main(String[] args) <>9zXbI
{ ))z1T8
new TestMethod(); 48 |u{
} e_{!8u.+
} 7HkQ|~zGT
点击下载更多相关资料