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+eKZo
} m}VM+=
for(int i=0;i<nEndPos.length-1;i++) i5hD#
{ G@S&1=nj3
nEndPos = nStartPos[i+1]; ~;-9X|
} 9?+9UlJ7K
nEndPos[nEndPos.length-1] = nFileLength; mzL[/B#>M
} ]O:M$ $
} _i}wK?n
L{gE'jCC
,xJrXPW
//启动子线程 rl:KJ\*D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b syq*
for(int i=0;i<nStartPos.length;i++) G,&%VQ3P>
{ iNcZ)m/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5IVksg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :lcea6iO
nStartPos,nEndPos,i); 9T2xU3UyY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?y},,
fileSplitterFetch.start(); _17|U K|N
} uK*Nu^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BpAB5=M0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B7NtkMK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5,+\`!g
nEndPos = " + nFileLength); )J/HkOj"V
// fileSplitterFetch[nPos.length-1].start(); uMXc0fs!$
.uZ7 -l
@^nu#R
//等待子线程结束 _3Q8n|
//int count = 0; Mjpo1dw
//是否结束while循环 @b!"joEy
boolean breakWhile = false; A3P9.mur
k/Mp6<?C:
~M?|Vn
while(!bStop) 1`r| op},
{ t7#lsd`_
write_nPos(); .I?@o8'x
Utility.sleep(500); c $;\i
breakWhile = true; TmEYW<
y93k_iq$S
!MZw#=D`
for(int i=0;i<nStartPos.length;i++) ateUpGM QU
{ q/@dR{-
if(!fileSplitterFetch.bDownOver) [_DPxM=V
{ Xer@A;c
breakWhile = false; 7-iIay1h"
break; lhn8^hOJ/
} :,]S}R
} +KK$0pL
if(breakWhile) jy$@a%FD
break; ayp b
5P^U_
_&{%Wc5W~F
//count++; D\L!F6taS
//if(count>4) |:iEfi]j
// siteStop(); ~P1_BD(
} !oSLl.fQd
4-4?IwS
G^h_YjR`*
System.err.println("文件下载结束！"); QrjDF>
} i3V/`)iz
catch(Exception e){e.printStackTrace ();} Hw_o w?
} \&|CM8A
?_4^le[;
:F|\Ij0T
//获得文件长度 *c]KHipUIS
public long getFileSize() <,39_#H?F3
{ W04av_u 5
int nFileLength = -1; P;foK)AM
try{ 4!%]fg}Um
URL url = new URL(siteInfoBean.getSSiteURL()); NXoK@Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VK .^v<Yo
httpConnection.setRequestProperty("User-Agent","NetFox"); w-FnE}"l
ySX/=T:<;
XSD%t8<LO
int responseCode=httpConnection.getResponseCode(); xe:' 8J6L
if(responseCode>=400) FUTn
{ f'/ KMe%<
processErrorCode(responseCode); 2ChWe}f
return -2; //-2 represent access is error /5a;_
} cK}Pf+r>
,7/ _T\d<
hTS|_5b
String sHeader; ]mkJw3
`"<2)yq?
p]f&mBO*
for(int i=1;;i++) $4j^1U`~)K
{ )h"Fla
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }""p)Y&
//Utility.log(in.readLine()); XeUprN
sHeader=httpConnection.getHeaderFieldKey(i); 8fO8Dob]\Y
if(sHeader!=null) J%P)%yX
{ S=9E@(]
if(sHeader.equals("Content-Length")) G.jQX'%4QG
{ t[O+B6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rc~Y=m
break; ,?=KgG1i
} E`E'<"{Yd
} : ^(nj7D
else H1UL.g%d=
break; Z`xyb>$
} !LSs9_w
} Q_lu`F|
catch(IOException e){e.printStackTrace ();} ?[SVqj2-
catch(Exception e){e.printStackTrace ();} ./iXyta
9eSRCLhgD
wixD\t59X
Utility.log(nFileLength); rgR?wXW]jE
#eEvF
g~R/3cm4
return nFileLength; [t}):}~F|
} 2]Fu 1
GVp
d=nh
//保存下载信息（文件指针位置） Gc}0]!nrW9
private void write_nPos() =tq7z =k
{ {{zua-F
try{ BD4"pcr
output = new DataOutputStream(new FileOutputStream(tmpFile)); /$*; >4=>f
output.writeInt(nStartPos.length); p2a?9R
for(int i=0;i<nStartPos.length;i++) a@k.$
{ ,lP7 ri
// output.writeLong(nPos); #Y: ~UVV
output.writeLong(fileSplitterFetch.nStartPos); U,ELqi\
output.writeLong(fileSplitterFetch.nEndPos); 3:O+GQ*
} W:>J864!
output.close(); mS7E_A8
} uE"2kn
catch(IOException e){e.printStackTrace ();} ]-rczl|o
catch(Exception e){e.printStackTrace ();} WhenwQT
} scmto cm
3DI^y`av
G4);/#
//读取保存的下载信息（文件指针位置） ;>/ipnx
private void read_nPos() /MqP[*L
{ Si[eAAd' :
try{ $l43>e{E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v['AB4
int nCount = input.readInt(); af^@ .$ |
nStartPos = new long[nCount]; Yoe les-
nEndPos = new long[nCount]; nO:HB.&@
for(int i=0;i<nStartPos.length;i++) X@eg<]'m
{ W9+h0A-
nStartPos = input.readLong(); y8D 8Y8B
nEndPos = input.readLong(); * T\>
} $uTlbAuv
input.close(); X%35XC.n
} & ]%\.m
catch(IOException e){e.printStackTrace ();} -YAO3
catch(Exception e){e.printStackTrace ();} KwQXA'
} +}\29@{W
i63?"
vnF g%M!
private void processErrorCode(int nErrorCode) M+\rX1T
{ >pa\n9=Q^
System.err.println("Error Code : " + nErrorCode); r5Wkc$
} YBeZN98Nt
ju r1!rg%
FqL`Kt
//停止文件下载 6O]Xhe0d@
public void siteStop() @ikUM+A {
{ (c 1u{
bStop = true; pO5v*oONz+
for(int i=0;i<nStartPos.length;i++) l`oT:
fileSplitterFetch.splitterStop(); QM7[O]@
A>[hC{
%oMWcgsdJi
} i<0D Z_rub
} =nw,*q +
//负责部分文件的抓取 YcEtgpz@
**FileSplitterFetch.java "@aq@mY@
*/ 55(J&q
package NetFox; WNl&v]
Ae3,W
Am]2@ESUP
import java.io.*; VoWA tNU
import java.net.*; m]Hb+Y=;h
o8iig5bp
oPp!*$V
public class FileSplitterFetch extends Thread { Qs~d_;
Bi$ 0{V Z8
HIQ]"Hl
String sURL; //File URL Q>##hG:m
long nStartPos; //File Snippet Start Position 5+J64_
long nEndPos; //File Snippet End Position t*5z1T?
int nThreadID; //Thread's ID @G7w(>_T3
boolean bDownOver = false; //Downing is over QZ6[*_Z6
boolean bStop = false; //Stop identical Ax :3}
FileAccessI fileAccessI = null; //File Access interface 4o)(d=q
C+ZQB)gn
)R8%wk?2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A!Knp=Gw
{ TB;3`
this.sURL = sURL; qr7 X-[&
this.nStartPos = nStart; >Iu]T{QNO
this.nEndPos = nEnd; u4`mQ6
nThreadID = id; +R3\cRM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3(cU)
} A%.J%[MVz
Q:'qw#P/C
'Wo?%n
public void run() ocb%&m;i
{ !hwzKm=%N
while(nStartPos < nEndPos && !bStop) ^aGZJiyJ
{ l{M;PaJ`}
)Ix-5084
@>qx:jx(-S
try{ D|u^8\'.
URL url = new URL(sURL); '-$))AdD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wUh3Hd'
httpConnection.setRequestProperty("User-Agent","NetFox"); -lJx%9>
String sProperty = "bytes="+nStartPos+"-"; y|&.v<
httpConnection.setRequestProperty("RANGE",sProperty); BnKP7e
Utility.log(sProperty); wrZ7Sr!/V
e|2vb GQ
yEMX`
InputStream input = httpConnection.getInputStream(); !D.= 'V
//logResponseHead(httpConnection); i}v}K'`
7.w*+Z>z
*u:;:W&5y
byte[] b = new byte[1024]; ;:#?~%7>
int nRead; oi33{#%t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^&f{beU9
{ *qeic e%E
nStartPos += fileAccessI.write(b,0,nRead); =DeHxPv}f
//if(nThreadID == 1) SH@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?.4yg(
} Fi,e}j=2f
XhHel|!g:
v#FJ+
Utility.log("Thread " + nThreadID + " is over!"); {ar5c&<
bDownOver = true; 'xLM>6[wz
//nPos = fileAccessI.write (b,0,nRead); ,v$2'm)V
} ~#HH;q_7m
catch(Exception e){e.printStackTrace ();} GFASF,+
} X+?Il)Bv
} knNhN=hG+
T:w2
\]L::"![?
//打印回应的头信息 ;PP_3`
public void logResponseHead(HttpURLConnection con) X]3l| D
{ =hZ&66
for(int i=1;;i++) ft~|
{ CPF>^Mp#
String header=con.getHeaderFieldKey(i); xdFP$Y~ogy
if(header!=null) UY}9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X\c1q4oB[
Utility.log(header+" : "+con.getHeaderField(header)); PsF- 9&_
else @1J51< x
break; z$I[kR%I{
} N+C%Z[gt[
} >Rl0%!
O]$*EiO\
h;4y=UU
public void splitterStop() P!)7\.7
{ eCPKpVhP
bStop = true; %+t
} m<,y-bQ*(
z1{E:~f
?:{0
} mCC:}n"#
"2vNkO##
=hOj8;2
/* B4\:2hBq
**FileAccess.java ]|((b/L3
*//文件访问(定位，写) hX'z]Am<
package NetFox; _4XoUE\\
import java.io.*; `ohF?5J,
-Z/6;2Q
%(dV|,|v
public class FileAccessI implements Serializable{ Gct&}]3pm
0%qctZy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YP .%CD(K
RandomAccessFile oSavedFile; 3u"J4%zg|L
long nPos; \ eyQo>(
NXWIE4T>*^
QvK]<HEr
public FileAccessI() throws IOException 6>LQGO
{ ,,wyydG
this("",0); N#-kk3!Z;
} ]'1N_m]?
ZhJ|ZvJ
+*:x#$phx
public FileAccessI(String sName,long nPos) throws IOException _I -0,
{ 0%&fUz36E6
oSavedFile = new RandomAccessFile(sName,"rw"); [6/%V>EM
this.nPos = nPos; T`RQUJO
oSavedFile.seek(nPos); B4*X0x
} 63y':g
hNR>Hy\
1Hk<_no5
public synchronized int write(byte[] b,int nStart,int nLen) "z(fBnv
{ 4?*"7t3
int n = -1; i}$N&
try{ 0=(-8vwd
oSavedFile.write(b,nStart,nLen); WO \lny!
n = nLen; I%zo>s6
} 8G[Y9A(bmP
catch(IOException e) tUAY]BJ*s
{ (8m\#[T+R
e.printStackTrace (); %unK8z
} 1,;qXMhK`;
H/v37%p7
*C:q _/
return n; HS5Ug'\446
} WKYA9BaR
}v(H E%~}
\.{pZMM
} ?+}E
9>$%F;JP44
|qudJucV
/* w4<u@L
**SiteInfoBean.java |"tV["a
*/ 6!}m$Dvt~
package NetFox; ETH#IM8J
~_l:b
BGh8\2
public class SiteInfoBean { WX[dM }L
>`,#%MH#
EK-bvZ
private String sSiteURL; //Site's URL l`5}i|4KTW
private String sFilePath; //Saved File's Path o y%g{,V
private String sFileName; //Saved File's Name Q&U= jX
private int nSplitter; //Count of Splited Downloading File n.H`1@
Lw2YP[CR
abk:_
public SiteInfoBean() 0wE8GmG
{//nSplitter的缺省值为5 FUTyx"
//default value of nSplitter is 5 px(1Ppb9
this("","","",5); Nm:|C 3_I
} *}WqYqOow
xzf)_ <
"F.J>QBd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ewff(e9
{ V{aIhH>P
sSiteURL= sURL; G?/8&%8
sFilePath = sPath; XuAc3~HAd
sFileName = sName; [?r\b
this.nSplitter = nSpiltter; 0#[Nfe*
Z(`K6`KM
* jNu?$
} '~6CGqU*
%$-3fj7
/)<7$
public String getSSiteURL() U?m?8vhR6(
{ lV*&^Q8.
return sSiteURL; )da8Ru
} _"e( ^yiK
`fE:5y
n#AH@`&i
public void setSSiteURL(String value) JU`'?b
{ XXdMppoR
sSiteURL = value; 9*Mg<P"
} y]z#??
B!C32~[
3G0\i!*t
public String getSFilePath() [8g\pPQ
{ !~DkA7i55
return sFilePath; i*rv_G|(Zj
} +( 7vmC.
KE1@z]
]tV{#iIJ*
public void setSFilePath(String value) *xNjhR]7v
{ HDG"a&$
sFilePath = value; FQ&VM6_
} SxQDqoA~
;@\JscNJ|
x~,?Zj)n?C
public String getSFileName() ^rb7`s#G
{ |&*rSp2iH
return sFileName; _5 -"<
} ^O9m11
\nt'I;f
WED7]2>
public void setSFileName(String value) =7Gi4X%
{ fH{$LjH(
sFileName = value; xo3)dsX
} Ppn ZlGQ6
E)SOcM)
$w}aX0dK&
public int getNSplitter() %ieAY-<"
{ Z.f<6<gF
return nSplitter; J\},o|WI
} ({62GWnn_
4p g(QeR
s0'U[]
public void setNSplitter(int nCount) wY)GX
{ nr6[rq
nSplitter = nCount; C /VXyl@o
} PU\q.y0R
} rMx_ <tXX
AYtcN4\/
U}5KAi 9Z
/* |-?b)yuAz
**Utility.java c'4 \F9
*/ x?$Y<=vT
package NetFox; ITOGD
N^>g=Ub
:zZM&r>
public class Utility { g9`ytWmM
#_5+kBA+>'
!kYmrj**
public Utility() 'Pn`V{a
{ v:ZD}Q_
cA^7}}?e
z#!Cg*K(
} sVf7g?
&Vm[5XW
//线程睡眠 .5zJ bZ9
public static void sleep(int nSecond) ;]e"bX
{ V)@scB|>,
try{ N($]))~3&
Thread.sleep(nSecond); =sJHnWL[
} [C#pMLp,~
catch(Exception e) j|w+=A1
{ 27gm_*
e.printStackTrace (); B)iJH
} -4a&R=%p
} YRXe j
l#:Q V:
//日志 Z/;SR""wa
public static void log(String sMsg) O`| ri5d
{ s!\L1E
System.err.println(sMsg); M>#S z
} 8gdOQ=a
G 3x1w/L
k#M W>
public static void log(int sMsg) UJ&,9}L8
{ N:zSJW`1
System.err.println(sMsg); #,pLVt<
} )BB a
} C<)&qx3
Ved:w^ ,
lDXH<W?
/* %;gWl1&5
**TestMethod.java Lr&tpB<
*/ ]y$C6iUY*
package NetFox; >skS`/6
wm4e:&
.YlM'E*X
public class TestMethod { K ajyQ"j
U9s y]7
S]a$w5ZP
public TestMethod() bvKi0-
{ ///xx/weblogic60b2_win.exe YWdvL3Bgk,
try{ _X/`4 G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CSs6Vm!=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :4TcCWG
SiteFileFetch fileFetch = new SiteFileFetch(bean); _XtY/7n
fileFetch.start(); <k1gc,*
} >oNs_{
catch(Exception e){e.printStackTrace ();} w5Z3e^g
"/=xu|
WBdb[N6\
} K}@:>;*9
pcG q
l+,rc*-j0
public static void main(String[] args) Gz:a1-x
{ S7*:eo
new TestMethod(); 5 Da(DA
} [d}1Cq=_
} \~>#<@h
点击下载更多相关资料