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)); =,$*-<p=3
} Wf/r@/q
for(int i=0;i<nEndPos.length-1;i++) f_Ma~'3
{ dKTyh:_{
nEndPos = nStartPos[i+1]; 3p6QJuSB
} :m]~o3KRy
nEndPos[nEndPos.length-1] = nFileLength; f6vhW66:?x
} njtz,qt_;G
} 2-728
ukpbx;O:hc
[Ul"I-K
//启动子线程 "s]r"(MX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T\I}s"d
for(int i=0;i<nStartPos.length;i++) XLb lVi@
{ g>-pC a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3O7]~5 j1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qq.M]?Z
nStartPos,nEndPos,i); S[JeW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3u#bx1
fileSplitterFetch.start(); U$v|c%6
} CuC1s>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a?S5 =
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^MIF+/bQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N;4bEcWjp
nEndPos = " + nFileLength); nF>41 K
// fileSplitterFetch[nPos.length-1].start(); =!)Ye:\Q
)UbPG`x8
TwlX'iI_;
//等待子线程结束 iGB1f*K%x
//int count = 0; H xs'VK*
//是否结束while循环 U;`C%vHff
boolean breakWhile = false; J|,Uu^7`
-{`8Av5)E%
\~m\pf?
while(!bStop) 5{Q5?M]
{ N(uHy@
write_nPos(); F]e`-;
Utility.sleep(500); Rd'P\
breakWhile = true; Gu+9R>
:No`+X[Kq
2(LF @xb
for(int i=0;i<nStartPos.length;i++) K+MSjQS"
{ 7irpD7P>
if(!fileSplitterFetch.bDownOver) -fpe
{ H3-(.l[!b)
breakWhile = false; ^Ej$o@PH
break; E|{(O
} %"-bG'Yc
} 9<n2-l|)
if(breakWhile) Ln:6@Ok)5%
break; [NE|ZL~
A12EUr5$
5.ibH
//count++; F t/yPv
//if(count>4) XSk*w'xO
// siteStop(); 2[|52+zhc
} =mR~\R( I
z]_2lx2e
L$L/5/
System.err.println("文件下载结束！"); yPY}b_W
} `eZzYe(N
catch(Exception e){e.printStackTrace ();} YTpiOPf
} QN47+)cVt"
Vu.VH([b]Q
&O +?#3
//获得文件长度 /tm2b<G
public long getFileSize() n(I,pF
{ "DaE(S&
int nFileLength = -1; 4Vtug>
try{ 1lo.X_
URL url = new URL(siteInfoBean.getSSiteURL()); _%g L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P:D;w2'Q
httpConnection.setRequestProperty("User-Agent","NetFox"); aVB/CoM9
$UNC0(4
i;Dj16h
int responseCode=httpConnection.getResponseCode(); Q g~cYwX
if(responseCode>=400) |RjAp.pm
{ zh{,.c
processErrorCode(responseCode); {wy{L-X
return -2; //-2 represent access is error >?<S(
} Tp46K\}Uf
QB uX#bDV
Emy=q5ryl
String sHeader; b?{MXJ|
|L/EH~| O
cwuzi;f
for(int i=1;;i++) E1r-$gf_
{ vA3wn><
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dx@|M{jz'
//Utility.log(in.readLine()); Mj&G5R~_
sHeader=httpConnection.getHeaderFieldKey(i); LBxmozT
if(sHeader!=null) Vv54;Js9
{ @An}
if(sHeader.equals("Content-Length")) 0=0,ix7?#
{ \sMe2OL#z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l1bkhA b
break; Y~xo=v(
} lArKfs/
} X[<%T}s#
else ho-#Xbq#g
break; /KLkrW
} z$gtGrU
} kmUL^vF
catch(IOException e){e.printStackTrace ();} 3CzF@t;5
catch(Exception e){e.printStackTrace ();} 8`<e\g7-
>.M>,m\
X=+|(A,BdY
Utility.log(nFileLength); w73?E#8
fB80&G9
IM% ,A5u
return nFileLength; 5U-SIG*
} 6r|=^3{
W#)X@TlE
8.,d`~
//保存下载信息（文件指针位置） P_4E<"eK
private void write_nPos() @Jx1n Q^
{ H;R~d%!b
try{ 6hMKAk
output = new DataOutputStream(new FileOutputStream(tmpFile)); #f [}a
output.writeInt(nStartPos.length); Oa2\\I
for(int i=0;i<nStartPos.length;i++) v,C~5J3h)
{ ^@3,/dH1 t
// output.writeLong(nPos); 5(gWK{R)*
output.writeLong(fileSplitterFetch.nStartPos); br^ A<@,d
output.writeLong(fileSplitterFetch.nEndPos); &~Pk*A_:
} ,Nt^$2DZW
output.close(); t~7OtPF
} (dfC}x(3h
catch(IOException e){e.printStackTrace ();} TjDtNE
catch(Exception e){e.printStackTrace ();} 'hE'h?-7
} IyI0|&r2A
q{&\nCy
0-~s0R89A
//读取保存的下载信息（文件指针位置） []v$QR&u#v
private void read_nPos() )s,LFIy<A
{ Gx %=&O
try{ =z;]FauR!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RL:B.Lv/W
int nCount = input.readInt(); O6/:J#X%
nStartPos = new long[nCount]; $ay!'MK0d
nEndPos = new long[nCount]; oYdE s&qq
for(int i=0;i<nStartPos.length;i++) &?1O D5
{ Lb)rloca
nStartPos = input.readLong(); 6DU~6c=)
nEndPos = input.readLong(); tKS[
} ,-hbwd~M
input.close(); n$`+03a
} |p!($
catch(IOException e){e.printStackTrace ();} :hT.L3n,
catch(Exception e){e.printStackTrace ();} e!PB3I
} %ufh
NT0n[o^
]J[d8S5
private void processErrorCode(int nErrorCode) S)g:+P
{ 81"` B2
System.err.println("Error Code : " + nErrorCode); Pz34a@%"
} _Dd>e=v
#|4G,!
=\_gT=tZ
//停止文件下载 jz`3xFy *]
public void siteStop() 7Q]c=i cg
{ gyMHC{l/B
bStop = true; iGSA$U P|
for(int i=0;i<nStartPos.length;i++) V3#ms0
fileSplitterFetch.splitterStop(); P3`$4p?
MT"&|Og
)=sbrCl,C/
} (8aj`> y
} J^`5L7CO
//负责部分文件的抓取 -uWV( ,|
**FileSplitterFetch.java q\}+]|nGs
*/ ,cL;,YN
package NetFox; 5@%.wb4
h}!9?:E
x&*f5Y9hCi
import java.io.*; ;}iB9 Tl
import java.net.*; ff5 gE'
z~X/.>
F@k}p-e~
public class FileSplitterFetch extends Thread { 9Q^cE\j
5L:-Xr{
jQzl!f1c3
String sURL; //File URL 'UUj(1 f
long nStartPos; //File Snippet Start Position f+Acs*.GQ
long nEndPos; //File Snippet End Position WB?HY?[r
int nThreadID; //Thread's ID :IU7dpwDl
boolean bDownOver = false; //Downing is over #gqh0 27
boolean bStop = false; //Stop identical m0As t<u
FileAccessI fileAccessI = null; //File Access interface ;xe.0j0h
BO#tn{(#
SF&2a(~s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5e$1KN`
{ vjS=ZinN"
this.sURL = sURL; 4MS#`E7LrC
this.nStartPos = nStart; Jn^b}bk t
this.nEndPos = nEnd; Hc=QSP
nThreadID = id; ghWWJx9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %2T i Rb
} *s*Y uY%y
')!X1A{
Oo@o$\+v
public void run() ^e_LnJ+
{ chKK9SC+|
while(nStartPos < nEndPos && !bStop) n'v\2(&uYN
{ -z~!%4a
Ac|\~w[\
cd1G.10
try{ R8k4?_W?T
URL url = new URL(sURL); R__:~uv,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _0v+'&bz
httpConnection.setRequestProperty("User-Agent","NetFox"); sde>LZet/
String sProperty = "bytes="+nStartPos+"-"; }VZExqm)
httpConnection.setRequestProperty("RANGE",sProperty); V-}}?c1 F
Utility.log(sProperty); <M@-|K"Eb
ey=KAt
N"G aQ
InputStream input = httpConnection.getInputStream(); q50F!yHC-
//logResponseHead(httpConnection); /3,Lp-kp
>PSO]%mE
q:/df]Ntt
byte[] b = new byte[1024]; 4lB??`UN
int nRead; 8rH6L:]S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8{!d'Pks
{ 3{$7tck,
nStartPos += fileAccessI.write(b,0,nRead); -p&u=
//if(nThreadID == 1) L)bMO8JH~m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A}SGw.3
} 0o=HOCL\
^"X.aksA
\jtA8o%n
Utility.log("Thread " + nThreadID + " is over!"); 0SQr%:zG
bDownOver = true; Fs(PVN
//nPos = fileAccessI.write (b,0,nRead); Z-Qp9G'
} 2Qp}f^
catch(Exception e){e.printStackTrace ();} Mg.%&vH\
} N!7}B
} :rUMmO-
B={_}f
Q2VF+g,
//打印回应的头信息 m4 (pMrJ
public void logResponseHead(HttpURLConnection con) n?.;*:
{ W~/d2_|/
for(int i=1;;i++) CpO_p%P
{ aX^T[
String header=con.getHeaderFieldKey(i); Zk%@GOu\
if(header!=null) x/umwT,ov
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `y3'v]
Utility.log(header+" : "+con.getHeaderField(header)); yx5e
else SlG v
break; E7fQ9]
} I_<XL<
} MqnUym
#y83tNev
G kjfDY:
public void splitterStop() 172G
{ _-TplGSO=c
bStop = true; $+'H000x
} I "AjYv4R
^m w]u"5\
x,,y}_YX
} Io]FDPN
V.P<>~W
TlS? S+
/* B-Jd|UE`u
**FileAccess.java \b"rf697,
*//文件访问(定位，写) E$)|Kv^
package NetFox; WR)=VE
import java.io.*; ^)Hf%
&J6`Q<U!
>ou=}/<
public class FileAccessI implements Serializable{ Sf*)Z3f
KdR4<qVV}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h=7q;-@7
RandomAccessFile oSavedFile; b_31\
long nPos; vFVUdxPOw
zFq%[X
N-M.O:p
public FileAccessI() throws IOException Tn}`VW~
{ 6h;(b2p{
this("",0); 8)X9abC
} DXiA4ihr=
%bDxvaftT
MxsLrWxm
public FileAccessI(String sName,long nPos) throws IOException (F4e}hr&
{ xnY?<?J"!
oSavedFile = new RandomAccessFile(sName,"rw"); $Z@*!B^
this.nPos = nPos; ?G,4N<]Nu
oSavedFile.seek(nPos); >!=@TK(~
} G]'ah1W
^c\O,*:
$+*nb4
public synchronized int write(byte[] b,int nStart,int nLen) |Kd#pYt%O
{ f$o^Xu
int n = -1; Sa= tiOv
try{ N(&{~*YE
oSavedFile.write(b,nStart,nLen); f^$,;
n = nLen; Hf`i~6
} GJ,&$@8)
catch(IOException e) 3f7zW3F
{ J/je/PC
e.printStackTrace (); &h334N|4{
} hQn?qJy%W
<~smBd
p;+O/'/j
return n; N[I@}j
} XN df
7rjl-FUA~
:;+!ID_
} \;{ ]YX
* 65/gG8>
d51lTGH7Z
/* <Vhd4c
**SiteInfoBean.java G^c,i5}w
*/ v Y[s#*+
package NetFox; jrib"Bh3,
U#3N90,N=
9-42A7g^C
public class SiteInfoBean { nGF +a[Z
}_D.Hy5
g*V.u]U!i
private String sSiteURL; //Site's URL (T%F^s5D
private String sFilePath; //Saved File's Path pR S!
private String sFileName; //Saved File's Name o:d7IL
private int nSplitter; //Count of Splited Downloading File a"vzC$Hxd
v)5;~.+%
"V|Rq]_+%
public SiteInfoBean() V\L;EHtc$
{//nSplitter的缺省值为5 is<:}z
//default value of nSplitter is 5 .vu7$~7
this("","","",5); \o>-L\`O
} C]ss'
b"I#\;Ym
2 2v"?*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V!Wy[u
{ UleT9 [M
sSiteURL= sURL; !nBbt?*
sFilePath = sPath; *qpu!z2m||
sFileName = sName; LqWiw24#
this.nSplitter = nSpiltter; Af|h*V4Xu
-<g9) CV5
(p{X.X+
} )d3 09O
,?GwA@~$k:
j 3<Ci {3
public String getSSiteURL() ]es|%j 2
{ dSGdK $XA
return sSiteURL; ]\39#
} #/G!nN #
~fXNj-'RW
`^)`J
public void setSSiteURL(String value) lx`?n<-X
{ @@Q4{o
sSiteURL = value; 8SjCU+V
} Id=20og
iJTG+gx
4E''pW]8
public String getSFilePath() eb_.@.a
{ .}dLqw
return sFilePath; 7U [C=NL
} JU8}TX
Za@\=}Tt
f.g!~wGD
public void setSFilePath(String value) Pp?P9s{
{ Q7+WV`&
sFilePath = value; LK h=jB^bT
} ) 57'<
RZz?_1'
Il=6t
public String getSFileName() 2"6L\8hd2
{ oiyvKMHz7
return sFileName; QytO0K5
} ?1\5X<|,
k5RzW4zq;
WAn@8!9
public void setSFileName(String value) |r@;ulO
{ O@$>'Z
sFileName = value; 2-F7tcya|
} xU\!UVQ/
/E6)>y66
UC&$8^
public int getNSplitter() ?wtKi#k'v#
{ xM_#FxJb
return nSplitter; 2tz4Ag
} +:Zwo+\kSN
/M5.Z~|/
&OU.BR>
public void setNSplitter(int nCount) rVabkwYD
{ sX?arI=_U
nSplitter = nCount; ~D5 -G?%$"
} '&CZ%&(Gw
} X"Eqhl<t
}%KQrlbHJl
wo9R:kQ
/* &wNr2PHd#
**Utility.java n l5+#e*\
*/ QmBHD;Gf
package NetFox; X[J<OTj`$
2K~v`c*4
>uCO=T,|
public class Utility { 5]{rim
@Hj]yb5
0,0WdJAe
public Utility() 5+GTK)D
{ A7QT4h&6
IlEU6Rs
mcwd2)
} s\'t=}0q
drCL7.j#L
//线程睡眠 8\il~IFyi
public static void sleep(int nSecond) hj=n;,a9
{ 6@Q; LV+
try{ Tu:lIy~A
Thread.sleep(nSecond); ^cdbM
} QP%AJ[3ea%
catch(Exception e) E:}s6l
{ ZrYRLg
e.printStackTrace (); d3oRan}z
} xqT} 9,
} e23&d
=j_4!^
//日志 = CXX.%N
public static void log(String sMsg) __z/X"H
{ ({4?RtYm
System.err.println(sMsg); UXa%$gwFw
} Na\&}GSf^
"97sH_ ,
f`}u9!jVR
public static void log(int sMsg) 0Dd8c\J
{ s$^ 2Cuhv
System.err.println(sMsg); GWx?RIKF
} x!4<ff.
} 2Z(?pJyDM
$SLyI$<gP
Nj;(QhYZ
/* m=`V
**TestMethod.java PtjAu
*/ ubl Y%{"
package NetFox; j%!xb><
IFSIQ q
7vqE@;:dt
public class TestMethod { yrzyus
'mU\X!- 4<
=+e;BYD#!
public TestMethod() 9dg+@FS}=
{ ///xx/weblogic60b2_win.exe `=TJw,q
try{ S{cK~sZj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'pAq;2AA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ud(w0eX
SiteFileFetch fileFetch = new SiteFileFetch(bean); enMHKN g
fileFetch.start(); wh]v{Fi'
} <.|]%7
catch(Exception e){e.printStackTrace ();} -P]onD
O|;|7fCB\
6%VRQ#g!
} ]xJ2;{JWsO
7r3EMX\#Qm
<l)I%1T_c
public static void main(String[] args) "jq F
{ &>@EfW](
new TestMethod(); m]++ !
} M4XU*piz
} Xt*h2&
点击下载更多相关资料