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)); I~^t\iujs
} 3 291"0
for(int i=0;i<nEndPos.length-1;i++) F9ys.Bc
{ Frn<~
nEndPos = nStartPos[i+1]; z\d{A7
} 8#m,TOp
nEndPos[nEndPos.length-1] = nFileLength; InO;DA\
} !"v[\||1
} Re=()M
9J3@8h p
4YuJ-
//启动子线程 !lVOZ%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'YKzs;y$
for(int i=0;i<nStartPos.length;i++) )x!b{5'"7
{ Xkqq$A4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uuxx^>"h\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VjI=5)+~
nStartPos,nEndPos,i); 4YV0v,z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >>cb0fH5
fileSplitterFetch.start(); ; _ziRy
} Tvd}5~ 5?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [P'"|TM[~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yt'P,m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IP LKOT~
nEndPos = " + nFileLength); syJLcK+e
// fileSplitterFetch[nPos.length-1].start(); ?*)Q[P5
e(=() :4is
D6$*#D3U
//等待子线程结束 t@&U2JaL>W
//int count = 0; /5!0wxN
//是否结束while循环 ag_*Z\
boolean breakWhile = false; .+07 Ui]I!
-JEiwi,
J~]Y
while(!bStop) |)+s,LT5
{ tJM#/yT
write_nPos(); %,1xOl4l
Utility.sleep(500); "t.Jv%0=
breakWhile = true; !K8Kw W|X
wD\viuq0
g"Tb\
for(int i=0;i<nStartPos.length;i++) `hl8j\HV<}
{ kqH:H~sgD
if(!fileSplitterFetch.bDownOver) eh39"s
{ o=nF.y
breakWhile = false; qj7}]T_
break; W?F Q
} [u $X.=(
} dwpE(G y6c
if(breakWhile) RoFOjCc>D.
break; tEN8S]X
0!Vza?9
aw923wEi
//count++; ~n"?*I`
//if(count>4) O"GuVC}B
// siteStop(); Mp?Gi7o=
} :MP*Xy\7&J
w+wg)$i
b9xvLR8
System.err.println("文件下载结束！"); l(y,lK=YP1
} 1KUM!DUD
catch(Exception e){e.printStackTrace ();} V0<g$,W=
} 3;O4o]`
;e"dxAUe!^
Tc.QzD\
//获得文件长度 0H+!v
public long getFileSize() :#VdFMC<
{ >T#" Im-
int nFileLength = -1; !X[P)/?b0+
try{ ,Y4>$:#n/
URL url = new URL(siteInfoBean.getSSiteURL()); UhKd o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d=p=eUd2
httpConnection.setRequestProperty("User-Agent","NetFox"); Nz77" kC
dq{+-XaEk
7>E>`Nc6
int responseCode=httpConnection.getResponseCode(); GGs7]mhA
if(responseCode>=400) Z[9t?ePL
{ j"A<qI
processErrorCode(responseCode); rJTYCe1*
return -2; //-2 represent access is error `-!kqJ
} GBl[s,g[|
:jf/$]p
Zsn@O2
String sHeader; .k-t5d
Xw#"?B(M]
zIA)se Js
for(int i=1;;i++) 9/`3=r@
{ 9SBTeJ$RZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K(uz`(5
//Utility.log(in.readLine()); X<D fzd oI
sHeader=httpConnection.getHeaderFieldKey(i); 8wrO64_NO
if(sHeader!=null) Bp_8PjQ
{ rEMe=>^
if(sHeader.equals("Content-Length")) OQIr"
{ Zq~Rkx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;Nw)zS
break; p'0X>>$
} <L('RgA@X
} ' GUCXx
else :Xs4C%H;
break; 4wN5x[vp
} AtUtE#K
} m5o$Dus+?'
catch(IOException e){e.printStackTrace ();} i-ww@XOQ
catch(Exception e){e.printStackTrace ();} (HXKa][T
.Y0O.
gq]@*C
Utility.log(nFileLength); MH|F<$42
ifNyVEHy
NcrBp(
return nFileLength; i6f42]Jy
} 4H^ACw
2^=8~I!n&
ucJ}KMz
//保存下载信息（文件指针位置） NM9,AG
private void write_nPos() ify48]
{ }[=)sb_
try{ ULhXyItL
output = new DataOutputStream(new FileOutputStream(tmpFile)); BIS.,
output.writeInt(nStartPos.length); Fi'ZId
for(int i=0;i<nStartPos.length;i++) ilXKJJda
{ D~bx'Wr+
// output.writeLong(nPos); ,c-*/{3
output.writeLong(fileSplitterFetch.nStartPos); psse^rFg
output.writeLong(fileSplitterFetch.nEndPos); J(K/z,4h
} \*&?o51!e
output.close(); $) M2
} ff7#LeB9
catch(IOException e){e.printStackTrace ();} !Eg2#a?
catch(Exception e){e.printStackTrace ();} ^We}i
} +_{cq@c
{P,hH~!
%gQUog
//读取保存的下载信息（文件指针位置） V'gJtF
private void read_nPos() lQiw8qD
{ &Z3%UOY
try{ &uF~t |!c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1KY0hAx
int nCount = input.readInt(); 5 1N/XEk
nStartPos = new long[nCount]; 0y t36Du
nEndPos = new long[nCount]; omGzyuPF
for(int i=0;i<nStartPos.length;i++) Qv`: E
{ S?6-I,]h
nStartPos = input.readLong(); s)fahc(@E
nEndPos = input.readLong(); Q@W!6]*\
} =)G]\W)m
input.close(); 6.a5%:
} 6"+9$nFyW
catch(IOException e){e.printStackTrace ();} ?A3u2-
catch(Exception e){e.printStackTrace ();} o>nw~_ H\
} /E2P
h-|IZ}F7
v%c/eAF
private void processErrorCode(int nErrorCode) 7M _ mR Vh
{ zRd.!Rv
System.err.println("Error Code : " + nErrorCode); R?;mu^B
} +$#<gp"
nW^h +
tcnO`0moK
//停止文件下载 gaxM#
public void siteStop() A'rd1"K
{ O$;#GpR
bStop = true; `d^Q!QxE
for(int i=0;i<nStartPos.length;i++) Dn@ZS_f
fileSplitterFetch.splitterStop(); !H@HgJ -
=+UtAf<n
`"}).{N]C
} uY(8KW
} @87Y/_l
//负责部分文件的抓取 W!R0:-
**FileSplitterFetch.java :<bhQY
*/ |O6/p7+.
package NetFox; M)!"R [V
$./aKJ1B
9r+'DX?>
import java.io.*; *r[V[9+y-D
import java.net.*; /g.c(-#]
b9#(I~}
kW2DKr-[
public class FileSplitterFetch extends Thread { RD"-(T
}:{9!RMO
Tg"? TZO~
String sURL; //File URL @MVul_@6
long nStartPos; //File Snippet Start Position N&p0Emg
long nEndPos; //File Snippet End Position (&Jo. <
int nThreadID; //Thread's ID }eW<P079
boolean bDownOver = false; //Downing is over mv#hy
boolean bStop = false; //Stop identical Z1I.f"XY
FileAccessI fileAccessI = null; //File Access interface 37kVJQcA1
^+CWo@.
L%(NXSfu7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Pzq^x]
{ 9Q}g Vqn
this.sURL = sURL; I<CrEL<5}~
this.nStartPos = nStart; qPD(D{,f$
this.nEndPos = nEnd; qbD 7\%
nThreadID = id; EpNN!s=Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \/<VJB uV
} 7I'C'.6iM
~ z3J4s
>W8"Ar
public void run() 1P[x.t#
{ 8U(o@1PT
while(nStartPos < nEndPos && !bStop) [tof+0Y6
{ H7.l)'
P{UV3ZA%
]vB\yQE
try{ D-LOjMe
URL url = new URL(sURL); I=#`8deH(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {&>rKCi
httpConnection.setRequestProperty("User-Agent","NetFox"); 2b"DkJj'
String sProperty = "bytes="+nStartPos+"-"; Cs[d:T
httpConnection.setRequestProperty("RANGE",sProperty); f$\O:E=
Utility.log(sProperty); &K60n6q{aQ
_qf39fM;\
/q\e&&e
InputStream input = httpConnection.getInputStream(); ~a[/l
//logResponseHead(httpConnection); bA,Zfsr6#
mi<Q3;m
X*@ tp,t
byte[] b = new byte[1024]; jzJTV4&zjs
int nRead; mN}szW,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {eI'0==
{ t4#gW$+^?H
nStartPos += fileAccessI.write(b,0,nRead); r!dWI
//if(nThreadID == 1) .!KsF h,pK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {Ba&
} y)&K9 I
X.;VZwT+
C 5gdvJN
Utility.log("Thread " + nThreadID + " is over!"); c/tB_]
bDownOver = true; hBpa"0F
//nPos = fileAccessI.write (b,0,nRead); O#ZZ PJ"
} X>=`l)ZR
catch(Exception e){e.printStackTrace ();} p__wBUB
} ceE]^X;p
} c?HUW
^@AyC"K
-)oUb=Lk{
//打印回应的头信息 [,Go*r
public void logResponseHead(HttpURLConnection con) N4C7I1ihq
{ =n"kgn
for(int i=1;;i++) |EX=Rj*
{ }q@#M8b
String header=con.getHeaderFieldKey(i); O6G'!h\F
if(header!=null) ]$Z:^"JS3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s2G9}i{
Utility.log(header+" : "+con.getHeaderField(header)); N$]er'`
else \\<=J[R.M
break; &Q~W{.
} A\Ib
} H,L{N'[Xph
\(P?=] -
E|f[#+:+
public void splitterStop() Ha-]U:Vcx
{ U[f00m5{HV
bStop = true; ?$109wZ:9
} I* C~w
rMxIujx
ulIEx~qP
} 5F~l;zT
\6SjJ]o>
)Q =>7%ZA
/* >[|N%9\
**FileAccess.java '1ySBl1>
*//文件访问(定位，写) vlbZ5
package NetFox; xz"60xxY
import java.io.*; `2s@O>RV
:Fb>=e
2r!ltG3}
public class FileAccessI implements Serializable{ ?x #K:a?
~/`/r%1/J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &su'znLV
RandomAccessFile oSavedFile; TSP%5v;Dh
long nPos; 0Xh_.PF
c("|xe
oM~y8O
public FileAccessI() throws IOException jn V=giBu
{ w7U]-MW6A*
this("",0); 32\.-v
} aP
,-y9P
XJ4f;U
public FileAccessI(String sName,long nPos) throws IOException )FQ"l{P
{ LOx+?4|y
oSavedFile = new RandomAccessFile(sName,"rw"); +r8bGS]ki
this.nPos = nPos; eA4:]A"
oSavedFile.seek(nPos); {\[Gl
} %MjoY_<:_
a'i Q("
luf5-XT
public synchronized int write(byte[] b,int nStart,int nLen) j HHWq>=d
{ qLDj\%~(
int n = -1; fkzSX8a9}
try{ X=$Jp.
oSavedFile.write(b,nStart,nLen); ?J\&yJ_B
n = nLen; y d97ys
} w==BSH[
catch(IOException e) | ;tH?E
{ ,@ 8+%KqG
e.printStackTrace (); AatSN@,~z
} j?.F-ar
!2LX+*;
xPm. TPj
return n; X(N~tE
} dE7x SI
"Lbsq\W>
EjR(AqZY
} r[L%ap\{
7]h%?W!
JtL>mH
/* J6Z[c*W
**SiteInfoBean.java i 9) Gt
*/ .Mq#88o.*
package NetFox; 7AqgX0)
7*5B
Ww]$zd-bo
public class SiteInfoBean { +K4XMf
gmL~n7m:K
HbKE;N
private String sSiteURL; //Site's URL @j46Ig4~b
private String sFilePath; //Saved File's Path nh} Xu~#_
private String sFileName; //Saved File's Name j_8 YFz5
private int nSplitter; //Count of Splited Downloading File PF{uaKWk
w$}q`k'
Nm*(?1
public SiteInfoBean() #I/P9)4
{//nSplitter的缺省值为5 X{-4w([
//default value of nSplitter is 5 s5VK
this("","","",5); NdXHpq;
} 0]DOiA
8?yIixhw
.hT>a<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h[ .
{ \((iR>^|
sSiteURL= sURL; dfDjOZSL
sFilePath = sPath; I5Vn#_q+b
sFileName = sName; }je<^]a
this.nSplitter = nSpiltter; .p#kW:zspA
]*2),H1 c
h,{m{Xh
} RHF"$6EAFG
uJ% <+I
7>Scf
public String getSSiteURL() W{6QvQD8
{ +IdM|4$\1
return sSiteURL; q)q3p
} d<m;Q}/l&h
uzd7v,
iQG!-.aX
public void setSSiteURL(String value) tr0b#4
{ H,7='n7"
sSiteURL = value; "#d$$ 8
} Ua1&eCZi
PQHztS"
BZeEZ2"
public String getSFilePath() 2q?/aw ;Z
{ X`8<;l
return sFilePath; =E-x0sr?
} Hv/C40uM-
{wSi?;[Gq
GBz?$]6
public void setSFilePath(String value) _J,**AZ~z
{ uo:RNokjJ
sFilePath = value; $fb%?n{
} P;5)Net1X
?JuJu1
CsR[@&n'
public String getSFileName() nW=6nCyvo
{ x;mw?B[
return sFileName; 9{pT)(Wnb
} 8lF9LZ8
{cdICWy(F3
bmT%?it
public void setSFileName(String value) }<Ydj .85
{ a"(Ws]K
sFileName = value; Jz8P':6[
} b_+o1Zy`
0|GYtnd
_/>ktYo:
public int getNSplitter() "aGmv9\
{ #$WnMJ@
return nSplitter; u(9pRr L
} +)c<s3OCE
q;K]NP-_p
{z oGwB
public void setNSplitter(int nCount) 6#=Iv X4
{ "im5Fnu
nSplitter = nCount; exWQ~&
} 4H 6t" X
} h,[L6-n
z%}"=
|!oC7!+0^
/* PMQTcQ^
**Utility.java <"Y>|X
*/ eD*764tG
package NetFox; Ana[>wSZO@
%|jS`kj
`^#Rwn#
public class Utility { o[;P@F
r\m{;Z#LJm
C|y^{4|R
public Utility() 7w73,r/D8A
{ e1[ReZW
rfDGS%!O%
e N`+r
} CI*JedO]
0Gu77&
//线程睡眠 A rE~6X
public static void sleep(int nSecond) EW$drY@
{ q/?*|4I
try{ Y%}&eN$r
Thread.sleep(nSecond); @3n!5XM{EE
} nOC\ =<Nsg
catch(Exception e) a"s2N%{
{ SU%O\4Ty
e.printStackTrace (); C6ql,hR^h`
} CH7a4qL`
} Rk9n,"xpv
f@sC~A. 9\
//日志 J>X@g;
public static void log(String sMsg) O+!4KNN.-
{ } W]A`-Jv
System.err.println(sMsg); !>(uhuTBF
} :V(C+bm *
WvU[9ME^)
a;$V;3C{b&
public static void log(int sMsg) Lginps[la
{ .*NPoW4Kv
System.err.println(sMsg); -3(*4)h7
} MTt8O+J?P~
} vU *: M8k
g?v/u:v>W
<xBL/e %
/* +;+G+Tn
**TestMethod.java D*UxPm"pw
*/ $.C\H,H
package NetFox; /Ey%aA4v
=U84*HAv
$`OyGeq"T
public class TestMethod { d/GSG%zB
/'oo;e
9ad`q+kY
public TestMethod() f)vnm*&-
{ ///xx/weblogic60b2_win.exe AXcmN
try{ U]pE{^\w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _"*vj-{-y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [vI ;A!
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9T;>gm
fileFetch.start(); 8XVRRk
} <uU<qO;6
catch(Exception e){e.printStackTrace ();} N/>:})dav
CeU=A9
jNbVp{%/S}
} E$_zBD%
^coCsV^CW"
.{eMN[ n@
public static void main(String[] args) V+D<626o
{ r5[pT(XT]
new TestMethod(); 8(ZQM01;
} kjQW9QJ<
} 1N65 M=)
点击下载更多相关资料