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)); W=9Zl(2C
} N4wv'OrL]
for(int i=0;i<nEndPos.length-1;i++) dcGs0b
{ M^E\L C
nEndPos = nStartPos[i+1]; y[W<vb+F
} \ M_}V[1+
nEndPos[nEndPos.length-1] = nFileLength; F;Lg w^1!
} 4KkjBPV
} Y8Bc &q}
\VTNXEw*G
Q--VZqn
//启动子线程 #00k7y>OyD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hpqM fz1
for(int i=0;i<nStartPos.length;i++) .Kn)sD1
{ D]s8w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x'.OLXx>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z`^DQ8+\j
nStartPos,nEndPos,i); ?)ROQ1-#@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n]N+
fileSplitterFetch.start(); ;0R>Dg
} @"\j]ZEnY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `Z}7G@ol
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pnvHh0ck_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )<kId4E
nEndPos = " + nFileLength); ;-OnCLr
// fileSplitterFetch[nPos.length-1].start(); VGVZ`|
/ox9m7Fz7
4|Wglri
//等待子线程结束 fn1G^a=
//int count = 0; <Tq&Va_w
//是否结束while循环 89I[Dg;"u
boolean breakWhile = false; 9Fe(],AzF
? x1"uH
^*;{Uj+O~Y
while(!bStop) G;:D6\
{ ^y@RfM=A
write_nPos(); ~<M/<%o2*
Utility.sleep(500); sGNVZx
breakWhile = true; Z[.+Wd\)-9
oB9t&yM
_9Pxtf
for(int i=0;i<nStartPos.length;i++) GCxtWFXH
{ 'xNPy =#
if(!fileSplitterFetch.bDownOver) tK<GU.+
{ DRldRm/
breakWhile = false; j8@Eqh
break; l@+WGh
} jB8n\8Bs
} `={s*^Ta
if(breakWhile) zNE"5
break; ;().
f%LzWXA
FHNK%Ko
//count++; zw{cli&S
//if(count>4) #1MEmt
// siteStop(); ,2F4S5F~rC
} 8^fkY'x
9N9dQ}[:g
0phO1h]2S)
System.err.println("文件下载结束！"); } z4=3'
} UOn L^Z}
catch(Exception e){e.printStackTrace ();} qp(F}@
} *}9i@DP1,
p100dJvq
oE+s8Q
//获得文件长度 =e7,d$i
public long getFileSize() ZeD""vJRY
{ )oOcV%
int nFileLength = -1; @MfuV4*
try{ O?uT'$GT
URL url = new URL(siteInfoBean.getSSiteURL()); )z0qKb\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rn O%8Hk
httpConnection.setRequestProperty("User-Agent","NetFox"); !XjvvX"j
)k F/"'o
Z, Kbt
int responseCode=httpConnection.getResponseCode(); Az.k6)~
if(responseCode>=400) a:jRQ-F)
{ T^-fn
processErrorCode(responseCode); t#+X*'/
return -2; //-2 represent access is error R5LzqT,/N:
} 0\tk/<w2
X!5
7s%DM6li 6
String sHeader; C24[brf
gY AXUM,
.p%p_
for(int i=1;;i++) ..qAE.%%
{ V:h-K`~/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R9SJ;TsE
//Utility.log(in.readLine()); '3Ir(]Wfd
sHeader=httpConnection.getHeaderFieldKey(i); q#W|*kL3
if(sHeader!=null) 7<Fp3N 3
{ pv2_A
if(sHeader.equals("Content-Length")) .xT8@]
{ s)$N&0\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -Iz&/u*}f
break; EAQg4N:D7L
} nG;wQvc
} 4!Ez#\
else wiWpzJz
break; s8| =1{
} so|5HR|
} F_ ~L&jHP
catch(IOException e){e.printStackTrace ();} N> RabD
catch(Exception e){e.printStackTrace ();} MnvFmYgxA
ZF :e6em
mj0{Nd
Utility.log(nFileLength); N9r}nqCN
:+ef|,:`/
QRnkj]b
return nFileLength; ~je#gVoUR
} JGPLVw
>=hOjV;
UhCE.# U
//保存下载信息（文件指针位置） eR r.j
private void write_nPos() jR@j+p^e
{ X>mY`$!/
try{ P F!S
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4l2i'H
output.writeInt(nStartPos.length); 6#XB'PR2p
for(int i=0;i<nStartPos.length;i++) ODK$G [-
{ Y:C7S~
// output.writeLong(nPos); OKfJ
output.writeLong(fileSplitterFetch.nStartPos); 8~?3: IZ
output.writeLong(fileSplitterFetch.nEndPos); q10gKVJum
} W=M`Bkw{
output.close(); <}b`2/wP
} %sb)U~gP
catch(IOException e){e.printStackTrace ();} ZdHfZ3)dB
catch(Exception e){e.printStackTrace ();} _[-+%RP
} IM&2SSmYNH
3vPb}
bs!N~,6h
//读取保存的下载信息（文件指针位置） 5uMh#dm^
private void read_nPos() v_f8zk
{ ~lMw*Qw^
try{ "bAkS}(hB(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 43pQFDWa
int nCount = input.readInt(); <=8REA?
nStartPos = new long[nCount]; 6k;__@B,
nEndPos = new long[nCount]; *vFVXJo
for(int i=0;i<nStartPos.length;i++) FblwQ-D
{ /_E8'qlx
nStartPos = input.readLong(); 8DbXv~3@
nEndPos = input.readLong(); Pg" uisT#>
} brJ_q0@
input.close(); O(;K]8
} hK9Trrwau
catch(IOException e){e.printStackTrace ();} Dt)\q^bH)
catch(Exception e){e.printStackTrace ();} {dJC3/Rf
} !b0'd'xe
7''l\3mIn
kH1hsDe|&y
private void processErrorCode(int nErrorCode) 3o%,8l,
{ ?P[uf
System.err.println("Error Code : " + nErrorCode); naCPSsei
} KE:PRX
'EJ8)2
/*g3TbUs
//停止文件下载 WyVFhAuU
public void siteStop() Eq^k@
{ k|Vq-w
bStop = true; {.$5:<8aC
for(int i=0;i<nStartPos.length;i++) y0>asl
fileSplitterFetch.splitterStop(); d_=@1JM>
LAeJz_9U
^Bn)a"Gd
} %o9@[o .]
} 1VK?Svnd
//负责部分文件的抓取 BL<.u
**FileSplitterFetch.java _x 'R8/
*/ Zpg/T K
package NetFox; |WH'aGG
3}=r.\]U
e>~g!S}G
import java.io.*; qLBXyQ;U
import java.net.*; lxy_O0n
GqumH/;
Twyx(~'&R
public class FileSplitterFetch extends Thread { ES!$JWK|
R;&C6S
7l> |G,[c
String sURL; //File URL Jm$.$B&I
long nStartPos; //File Snippet Start Position [2#5;')
long nEndPos; //File Snippet End Position BDSZ'
int nThreadID; //Thread's ID fyPpzA0
boolean bDownOver = false; //Downing is over lP& 7U
boolean bStop = false; //Stop identical ~K}iVX
FileAccessI fileAccessI = null; //File Access interface sm5\> L3V
J$
tFt56/4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O6Bs!0,
{ 1oD,E!+^d
this.sURL = sURL; ^T@ (`H4@
this.nStartPos = nStart; <<`*o[^L
this.nEndPos = nEnd; ntbl0Sk
nThreadID = id; q`z/ S>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *,<A[XP
} d4KTwn5g
w>Iw&US
,?k[<C
public void run() 6yk=4l\
{ P8!ON=
while(nStartPos < nEndPos && !bStop) bA}9He1
{ MyB&mC7Es
|S.G#za
3/c3e{,!
try{ K ;\~otR^
URL url = new URL(sURL); lM1~K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q1ybJii
httpConnection.setRequestProperty("User-Agent","NetFox"); h}-}!v
String sProperty = "bytes="+nStartPos+"-"; hhd%j6
httpConnection.setRequestProperty("RANGE",sProperty); &_Kb;UVRj
Utility.log(sProperty); |,3s]b`
R<.<wQ4I
0_'(w;!wq:
InputStream input = httpConnection.getInputStream(); ^mxOQc !
//logResponseHead(httpConnection); pF kA,
xCN6?
sd4eJ
byte[] b = new byte[1024]; k(LZ,WSR
int nRead; 8K+(CS>xvO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PL$*)#S"$
{ GL;@heP
nStartPos += fileAccessI.write(b,0,nRead); 9V&}%
//if(nThreadID == 1) &"HxAK)f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q#LB 2M
} ?bFP'.
%smQ`u|
l-s%3E3
Utility.log("Thread " + nThreadID + " is over!"); vHR-mQUs
bDownOver = true; WP7RX|7
//nPos = fileAccessI.write (b,0,nRead); &Tz@lvOv%
} 8Aq [@i
catch(Exception e){e.printStackTrace ();} FY;\1bt<<
} ,TeJx+z^
} V~#e%&73FH
m]H[$Q
Zop3[-
//打印回应的头信息 zED#+-7
public void logResponseHead(HttpURLConnection con) E/bIq}R6
{ =^liong0
for(int i=1;;i++) $DPMi9,7^
{ wyzx9`5~d
String header=con.getHeaderFieldKey(i); 0|6]ps4Z7
if(header!=null) 5\\#kjjx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LV4\zd6
Utility.log(header+" : "+con.getHeaderField(header)); RLnsy,
else :Y? L*
break; /zt9;^e
} L'i0|_
} %>,B1nt
s*'L^>iZ
3k YVk
public void splitterStop() E`E$ }iLs
{ bBx.snBK
bStop = true; !Cqm=q{K
} Wp2W:JX:
@|I:A
R$>]7-N}
} @ P:b\WCI
7JC^+rk
c}XuzgSY
/* 2bJqZ,@
**FileAccess.java 'K|Jg.2
*//文件访问(定位，写) k8>(-W"A
package NetFox; }s*H|z
import java.io.*; VSm[80iR0
$? 'JePC
B#o/3
public class FileAccessI implements Serializable{ 8PN/*Sa
';H"Ye:D=7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O &/9wi>!q
RandomAccessFile oSavedFile; r'TxYM-R
long nPos; [_$r-FA
:eK(9o
!yUn|v>&p
public FileAccessI() throws IOException ` u|8WK:
{ CsJ38]=Mt
this("",0); kzky{0yKk=
} Fe:M'.
Cx N]fo
G,jv Mb`+
public FileAccessI(String sName,long nPos) throws IOException C(w?`]Qs
{ 4blw9x N
oSavedFile = new RandomAccessFile(sName,"rw"); @M]uUL-ze
this.nPos = nPos; *.'9eC0s
oSavedFile.seek(nPos); jCJbmEfo9@
} <5Ye')+
os:/-A_m
S\\3?[!p
public synchronized int write(byte[] b,int nStart,int nLen) W^o*^v
{ trl:\m
int n = -1; ZQL4<fy'E
try{ ' 91-\en0
oSavedFile.write(b,nStart,nLen); \>B$x@-wg
n = nLen; t^8ii
} Nu/D$m'PY
catch(IOException e) ^Vbx9UN/
{ !b !C+ \v
e.printStackTrace (); qcNu9Ih
} >M}\_c=
;8|D4+
@Feusprs
return n; xH,D bAC;
} mYU7b8x_
5hhiP2q
'zRi;:UHA
} `.MY"g9
\2UtT@3|C
3 s@6pI
/* ;~A-32;Y4
**SiteInfoBean.java sIM^e
*/ cWNZ +Q8Y
package NetFox; #
BLepCF38
qdM=}lbc
public class SiteInfoBean { }NH\Q$IU
I.4o9Z[?
iY|zv|;]=
private String sSiteURL; //Site's URL P#8+GN+bF
private String sFilePath; //Saved File's Path aEO``W
private String sFileName; //Saved File's Name ^~p^N <
private int nSplitter; //Count of Splited Downloading File {6y@;Fd
@;6I94Bp
#5Q?Q~E@
public SiteInfoBean() ].TAZ-4s
{//nSplitter的缺省值为5 Mu1H*;_8
//default value of nSplitter is 5 #hKaH -j
this("","","",5); B-R& v8F
} a/4!zT
uVSc1MS1
0h3-;%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |9fvj6?Y
{ fGwRv%$^
sSiteURL= sURL; ~BUzyc%
sFilePath = sPath; 6~oo.6bA
sFileName = sName; u{asKUce\
this.nSplitter = nSpiltter; 6\+ZTw
jD<fu
5W Z9z-6
} TKwMgC}<[
Fm{/&U^
L~Hl?bK
public String getSSiteURL() `wMHjcUP
{ MrW*6jY@
return sSiteURL; <FkoWN
} Dc1tND$X3g
2cB){.E
<n+]\a97*
public void setSSiteURL(String value) x5X;^.1Fr
{ >qqI6@h]c
sSiteURL = value; V[Z^Z
} 1#Ls4+]5
Pse1NMK9 [
}k{h^!fV
public String getSFilePath() 8E/wUN,Lxj
{ Au=9<WB%H
return sFilePath; Q#h*C ZT
} zXEu3h
MF41q%9p
fwV2b<[
public void setSFilePath(String value) 8T6NG!/
{ #jW=K&;
sFilePath = value; TjYHoL5
} lw.[qP
}(|gC,
w}zmcO:x
public String getSFileName() ?+^p$'5
{ g$?^bu dxv
return sFileName; Q{L:pce-
} ]+W){W=ai
O=(F46 M
q!@!eC[b
public void setSFileName(String value) ZH9Fs'c=
{ wK#*|
sFileName = value; yb?Pyq.D
} ?_Z-}f
RLB"}&SF]
dIlpo0; F
public int getNSplitter() ||awNSt
{ `Hlf.>b1
return nSplitter; emK*g<]
} .hR <{P
4n7Kz_!SVf
,aC}0t
public void setNSplitter(int nCount) k4{|Xn
{ ;p`to"6IFD
nSplitter = nCount; '5De1K.\`
} PQ[?zNrSV
} MK)}zjw
&{a!)I>
=2Yt[8';
/* kaB|+U9^
**Utility.java 0#!}s&j/
*/ WcNQF!f
package NetFox; 2a eH^:u
/}8Au$nA
,.cR@5qI
public class Utility { C1=&Vm>g+
<TtPwUX
abR<( H12
public Utility() cr{yy :D
{ 4A6Y \ZXI
sA|SOAn
A%Ka)UU+n
} Pg(Y}Tu
f(D'qV T{
//线程睡眠 uH%b rbrU
public static void sleep(int nSecond) PR:B6 F8
{ A+* lV*@0
try{ {/,(F^T>2
Thread.sleep(nSecond); [07E-TT2U
} zdrP56rzZ
catch(Exception e) M?"4{
{ f/UU{vX(
e.printStackTrace (); nLz;L r!
} WX?nq'nr
} 8^y=YUT
S*h^7?Bu
//日志 if|5v^/
public static void log(String sMsg) 9=MNuV9/s
{ }_zN%Tf~
System.err.println(sMsg); -@"3`uv"
} [+dCA
>jhcSvM6
:p/=KI_
public static void log(int sMsg) jsE8=zZs
{ zP #:Tv'
System.err.println(sMsg); Su6kpC!EW
} ;P)oKx
} JP<j4/
M1-tRF
sPvs}}Z]P
/* sT2`y$'
**TestMethod.java =f!A o:Uc
*/ RxYENG]/6
package NetFox; cLf90|YFp
L{%L*z9J
,5;M(ft#
public class TestMethod { `J,>#Y6(J
>:6iFPP
}vZf&ib-
public TestMethod() -J+1V{
{ ///xx/weblogic60b2_win.exe ~iH a^i?2*
try{ :a;F3NJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qr%N/7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `KA==;0
SiteFileFetch fileFetch = new SiteFileFetch(bean); =M;F&;\8
fileFetch.start(); D r(0w{5
} %"mI["{
catch(Exception e){e.printStackTrace ();} q*&H
c8X;4 My
>2{Y5__+e
} qSr]d`7@
giNXXjl
J\*uW|=F
public static void main(String[] args) _F6<ba}o3
{ 1!MJ+?Jl
new TestMethod(); ';FJs&=I
} wz`% (\
} piM4grg \
点击下载更多相关资料