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)); t>\sP
} 7y'uZAF
for(int i=0;i<nEndPos.length-1;i++) ^<CVQ8R7
{ D!rPF)K )
nEndPos = nStartPos[i+1]; 7&ED>Bk
} bqcCA91
nEndPos[nEndPos.length-1] = nFileLength; AEyvljv
} 1|MRXK
} B}iEhWO6
h3CA,$HJ
8z#Qp(he
//启动子线程 F^u12R)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0kkDlWkzo
for(int i=0;i<nStartPos.length;i++) =8\.fp
{ ~5N}P>4*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P1-eDHYw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FDz`U:8
nStartPos,nEndPos,i); HT;^u"a~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ljKIxSvCFp
fileSplitterFetch.start(); +X=*>^G(-
} dz_S6o ]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R*[sO*h\k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =fcg4h5(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _ox+5?>
nEndPos = " + nFileLength); b7QE
// fileSplitterFetch[nPos.length-1].start(); L^sjV/\oW
&jP1Q3
oACAC+CP
//等待子线程结束 CxFd/X,
//int count = 0; %!<Y
//是否结束while循环 ;77K&#1
boolean breakWhile = false; X;I9\Cp]!
VzP az\e
[;u#79aE
while(!bStop) MR#*/Iw~
{ ))"gWO
write_nPos(); KNVu[P)rv
Utility.sleep(500); %_OjmXOfe
breakWhile = true; ue_wuZi
I^y<W%Et
YWFE*wQ!
for(int i=0;i<nStartPos.length;i++) ^jL '*&l
{ m@Z#
if(!fileSplitterFetch.bDownOver) $h#sb4ek
{ OEW'bT)
breakWhile = false; ETp?RWXX
break; %O"8|ZG9{
} bKQho31a'
} M-o'`e'
if(breakWhile) WMB%?30
break; jf9+H!?^N
bv+u7B6,
){;XI2
//count++; QZzamT)"
//if(count>4) _ \D%
// siteStop(); q(KjhM
} 0fsVbC
-vvyG
\Vyys[MMY8
System.err.println("文件下载结束！"); #<*Vc6pC
} ~t6q-P
catch(Exception e){e.printStackTrace ();} $^]K611w9
} I1Q!3P
GcBqe=/B!
<tr]bCu}
//获得文件长度 ;l$$!PJ
public long getFileSize() ~YYnn7)
{ Su#0F0
int nFileLength = -1; i>m%hbAk
try{ %* "+kwZ
URL url = new URL(siteInfoBean.getSSiteURL()); KgL!~J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q/i2o[f'n
httpConnection.setRequestProperty("User-Agent","NetFox"); QNNURf\[(
-#v~;Ci
da$FY7
int responseCode=httpConnection.getResponseCode(); zxyl+tU &
if(responseCode>=400) #D`@G8~(
{ XM$~HG
processErrorCode(responseCode); G/_IY;
return -2; //-2 represent access is error '}.Yf_
} /R#zu_i
iGyetFqKw
jP+yN|
String sHeader; 28MMH Q
qN!oN*
t-\+t<;
for(int i=1;;i++) Q0U~s\<
{ 4V+bE$Wu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1h,iWHC
//Utility.log(in.readLine()); .~]|gg~
sHeader=httpConnection.getHeaderFieldKey(i); &uq.k{<p\
if(sHeader!=null) &K^0PzWWof
{ UC!mp?
if(sHeader.equals("Content-Length")) !_Lmrs
{ Sc<dxY@w7-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -&Rv=q>
break; {;yO3];Hqw
} yM_/_V|G
} A}9Z%U
else f}:C~L!
break; a'J0}j!
} -C=0Pg]ga
} `[/#,*\
catch(IOException e){e.printStackTrace ();} "5hk%T'
catch(Exception e){e.printStackTrace ();} U&^q#['
)jM%bUk,!
0m@+ &X>w
Utility.log(nFileLength); -Jd|H*wWo
QS#@xhH
eM7@!CdA9q
return nFileLength; f|d~=\0y
} W`>|OiuF
;:;E|{e
aKI"<%PNn
//保存下载信息（文件指针位置） y=3 dGOFB
private void write_nPos() 1/DtF
{ j\y;~ V
try{ wi2`5G6|z
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^z?b6kTC
output.writeInt(nStartPos.length); (v]%kXy/G
for(int i=0;i<nStartPos.length;i++) 3?93Pj3oPt
{ X=)V<2WO
// output.writeLong(nPos); bC{4a_B
output.writeLong(fileSplitterFetch.nStartPos); *$Q>Om]
output.writeLong(fileSplitterFetch.nEndPos); iq&3S0
} oi #B7
output.close(); wuqe{?
} ;_}pIO
catch(IOException e){e.printStackTrace ();} 2#wnJdr6E
catch(Exception e){e.printStackTrace ();} 'xW=qboOp
} ;UdM8+^/V]
77RZ<u9/`
wh:;G`6S
//读取保存的下载信息（文件指针位置） .LzA'q1+z
private void read_nPos() vq$6e*A
{ `PWKA;W$0
try{ J)|3jbX"I]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y>x{ [er
int nCount = input.readInt(); EC+t-:a]
nStartPos = new long[nCount]; CK_dEh2c
nEndPos = new long[nCount]; i<uU_g'M
for(int i=0;i<nStartPos.length;i++) q;{(o2g
{ bt}8ymcG
nStartPos = input.readLong(); {##G.n\~
nEndPos = input.readLong(); 9b. kso9.
} c`O~I<(Pm
input.close(); DUOoTlp
} g)hEzL0k
catch(IOException e){e.printStackTrace ();} [ 8Ohg
catch(Exception e){e.printStackTrace ();} /!6'K
} 66=[6U9 *
]kj^T?&n.
Jqoo&T")
private void processErrorCode(int nErrorCode) Yh<F-WOo2
{ )nm+_U
System.err.println("Error Code : " + nErrorCode); LU3pCM{
} h&"9v~
LjZlKB5C
EP>u%]#
//停止文件下载 , ZsZzZ#
public void siteStop() 7[ ovEE54
{ +gl\l?>sr
bStop = true; Z-@nXt
for(int i=0;i<nStartPos.length;i++) &L6Ivpj-
fileSplitterFetch.splitterStop(); N/a4Gl(
|Ajd$+3
DB}Uzw|
} 6-U_TV
} } z'Jsy[s
//负责部分文件的抓取 [LVXXjkFI
**FileSplitterFetch.java |$WHw*F^
*/ j0l,1=^>l
package NetFox; 1?'4%>kp
-P]O t>%S
i/>k_mG$d
import java.io.*; ing'' _
import java.net.*; o"z()w~
/|EdpHx0
4D65VgVDM
public class FileSplitterFetch extends Thread { a%#UF@I
Tm%5:/<8
}7.A~h
String sURL; //File URL [$dVs16K
long nStartPos; //File Snippet Start Position Q{/z>-X\x
long nEndPos; //File Snippet End Position t=%zY~P
int nThreadID; //Thread's ID \Ec<ch[)c
boolean bDownOver = false; //Downing is over sI,cX#h&Y
boolean bStop = false; //Stop identical wNa5qp 0
FileAccessI fileAccessI = null; //File Access interface =!TUf/O-
E\iK_'#
?P9aXwc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K^WDA])
{ %.bDK}
this.sURL = sURL; *HrEh;3^J
this.nStartPos = nStart; }*x1e_m}H
this.nEndPos = nEnd; BM :x`JY
nThreadID = id; N*gJu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /k.0gYD
} E'6>3n
\h ~_<)
#*(}%!rD*
public void run() !vz'zy)7
{ hFV,FBsAO
while(nStartPos < nEndPos && !bStop) 6,t6~Uo/
{ & SXw=;B
rm-d),Zt
M=,pn+}y>
try{ XYU5.
URL url = new URL(sURL); OZ`cE5"i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E%w^q9C
httpConnection.setRequestProperty("User-Agent","NetFox"); k_pv6YrE
String sProperty = "bytes="+nStartPos+"-"; ZU 3Psj
httpConnection.setRequestProperty("RANGE",sProperty); <H-Nft>O
Utility.log(sProperty); 2ZK]}&yC
45~x #Q
l b(
InputStream input = httpConnection.getInputStream(); &bTCTDZh
//logResponseHead(httpConnection); n Bm ]?
J2O,wb)U
a_N7X
byte[] b = new byte[1024]; Us`=^\
int nRead; x?AG*' h&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yY VR]HH
{ p]aEC+q
nStartPos += fileAccessI.write(b,0,nRead); J3yK^@&&
//if(nThreadID == 1) e#[Klh$]EW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sH6;__e
} (.-4Jn
-XYvjW,|
D07M!U
Utility.log("Thread " + nThreadID + " is over!"); z:Am1B
bDownOver = true; ~"+"6zg
//nPos = fileAccessI.write (b,0,nRead); 1EU4/6!C
} _=g&^_ #t
catch(Exception e){e.printStackTrace ();} 9evr!=":
} n>ryS/1
} '/O:@P5qY
MCN>3/81
']k<'`b|
//打印回应的头信息 FJvY`zqB
public void logResponseHead(HttpURLConnection con) HXq']+iC
{ JM7mQ'`Ud
for(int i=1;;i++) ?L<B]!9HZt
{ ~& -h5=3
String header=con.getHeaderFieldKey(i); 5RPG3ppS
if(header!=null) B&cIx~+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3=enk0$
Utility.log(header+" : "+con.getHeaderField(header)); ;!<}oZp{
else OnTe_JML
break; 5dj" UxH
} ]\*^G@HA2
} 3d}v?q78
NQ{(G8x9
)oIh?-WL
public void splitterStop() v3r3$(Hr
{ ?V6,>e_+
bStop = true; #E]K*mE'
} #/>TuJc
=E9\fRGU
YTTyMn
} %IsodtkDu
f.w",S^
PK]3uh
/* +byOThuE
**FileAccess.java wOAR NrPx2
*//文件访问(定位，写) o/N!l]r
package NetFox; h'*v$lt
import java.io.*; Mj@2=c
7 $y;-[E[
3U<m\A1
public class FileAccessI implements Serializable{ V'vWz`#
B=0^Rysg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4l 67B]o
RandomAccessFile oSavedFile; x9YQd69
long nPos; I?rB7*:
[ <X%
A.>mk598
public FileAccessI() throws IOException 'rB%a<
{ ]oP1c-GEk
this("",0); !|[rh,e]
} ;1(^H:7T
ofB:7
RHUZ:r
public FileAccessI(String sName,long nPos) throws IOException >~o-6g
{ GK$[!{w;
oSavedFile = new RandomAccessFile(sName,"rw"); TUfj\d,
this.nPos = nPos; v0DDim?cc
oSavedFile.seek(nPos); /p !A:8
} bWTfP8gT
aqON6|6K
) H,Xkex
public synchronized int write(byte[] b,int nStart,int nLen) = wz}yfdrC
{ g~DuK|+
int n = -1; |N/d}
try{ httywa^
oSavedFile.write(b,nStart,nLen); v]k-xn|$j
n = nLen; s|\)Y*B`
} %jL^sA2;c+
catch(IOException e) p}^G#h{
{ RqA>"[L
e.printStackTrace (); W %*#rcdq
} g<Z :`00|
R/=rNUe
Ll]5u~
return n; CXq[VYM&X
} 81Z;hO"~
>ai,6!
*L^W[o
} L$5,RUy
x?L[*N_ml
FJ3S
/* @1*^ttC
**SiteInfoBean.java phy}Hk/
*/ av'm$I|O
package NetFox; oh{>nwH
w~@"r#-
2 5 \S>
public class SiteInfoBean { .8YxEnXw)(
Uj5-x%~
h4]^~stI
private String sSiteURL; //Site's URL iwF_'I$#N
private String sFilePath; //Saved File's Path 'WW:'[Syn'
private String sFileName; //Saved File's Name @} Ig*@
private int nSplitter; //Count of Splited Downloading File cQEUHhRg!
FI^Wh7J
CV0id&Nv
public SiteInfoBean() Lap?L/NS
{//nSplitter的缺省值为5 %Y&48''"
//default value of nSplitter is 5 M/ 64`lcb
this("","","",5); S)U*1t7[
} kp*v:*
lsax.uG5x
CzBYH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;+~5XLk
{ h`6 (Oo|
sSiteURL= sURL; u IXA{89
sFilePath = sPath; m}l);P^
sFileName = sName; <H^jbK
this.nSplitter = nSpiltter; GlJ[rD
^("b~-cJ
~uhW~bT
} AMyg>n!
Y#os6|MV#
>` s"C
public String getSSiteURL() s&$?m[w
{ _}5vO$kdO
return sSiteURL; Tf3CyH!k
} S/E&&{`ls
"WKOlfPa
QATRrIj{e
public void setSSiteURL(String value) Bc8&-eZ,
{ ,SIS3A>s
sSiteURL = value; c4AJ`f.5
} naR<
d`/8Q9tQ
IP`lx
public String getSFilePath() OH/9<T?
{ :A8r{`R'N
return sFilePath; 8c) eaDu
} 'pt(
af|h4.A
FGn"j@m0
public void setSFilePath(String value) /bykIUTKI
{ ]zYIblpde
sFilePath = value; lc <V_8
} :of([e|u6
@1oX&#
[l-o*@
public String getSFileName() DZqG7p$u4i
{ Sn[xI9}O
return sFileName; 6) i-S<(
} K9@.l~n
neU=1socJ
Y*BmBRN
public void setSFileName(String value) Jh.~]\u
{ k@7#8(3
sFileName = value; J'2 Yrn
} |YLja87
wS=vm}}u
Gor9&aJ1
public int getNSplitter() J=-z~\f56
{ ;87PP7~
return nSplitter; dy+A$)gY<
} {]6-,/3UR
-Mr_Ao`E
B=OzP+
public void setNSplitter(int nCount) !\#Wq{p>W*
{ DCp8rvUI
nSplitter = nCount; P6_Hz!vE
} K3mP6Z#2
} ! \s}A7
%fg6',2
(wL$h5SG
/* u0#KBXRo
**Utility.java wnC-~&+6
*/ eZ:iW#YF
package NetFox; u43Mo\"<&%
Ct'tUF<K5
n>)aw4
public class Utility { d*|RFU
,Mw93Kp Va
WdOxwsq"
public Utility() (RI)<zaK ;
{ C rR/
$*eYiz3Ue
[CEV&B
} "3VX9{'%@
qoZi1,i'
//线程睡眠 s O#cJAfuu
public static void sleep(int nSecond) bqH [-mu6
{ d3znb@7
try{ P DY :?/
Thread.sleep(nSecond); At@0G\^
} rd&d~R6
catch(Exception e) _Yo)m|RaB
{ s=)W
e.printStackTrace (); qcO~}MJr}^
} 5 Y&`ZJ
} \SmsS^z(]
WT\wV\Pu
//日志 mW]dhY 3X
public static void log(String sMsg) X_'tgP9
{ 6{;6~?U
System.err.println(sMsg); 2K_ QZ
} 6)sKg{H
4Yvz-aSyO
c9c]1XJ
public static void log(int sMsg) #jBmWaP.
{ ?8$`GyjS
System.err.println(sMsg); 2@bOy~$A
} J t.<Z&
} 8{0XqE~ix=
SOG(&)b
(_#E17U)_
/* ^;/~$
**TestMethod.java @"s<0T^H
*/ b$;oty9Y
package NetFox; T[OI/WuK
-Y+pLvG*
g<;pyvq|:
public class TestMethod { ,]\cf
P8=|#yCi
`ZL^+h<b>M
public TestMethod() +E9G"Z65iP
{ ///xx/weblogic60b2_win.exe ue3 ].:
try{ ,W+=N"`a'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,l AZ4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gwIR3u
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,62~u'hR5
fileFetch.start(); N^B7<~ bD
} ;S^"Y:7)
catch(Exception e){e.printStackTrace ();} \ o2oQ3
KPy)%i
(@NILK
} M>=@Z*u/+
ZzK^bNx)0
RUr ~u
public static void main(String[] args) zU[o_[+7^
{ 6v{&,q
new TestMethod(); fahQ^#&d`
} rZ,3:x-:
} Uy=yA
点击下载更多相关资料