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)); Fm3-Sn|Po
} CM>/b3nOW
for(int i=0;i<nEndPos.length-1;i++) brb8C%j}9
{ jZ7/p^c5R
nEndPos = nStartPos[i+1]; V`TXn[7
} bS3qX{5
nEndPos[nEndPos.length-1] = nFileLength; KunK.m
} "6~pTHT
} U>(5J,G
aa_&WHXkt
hQ i[7r($8
//启动子线程 2xZg, \
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t^&:45~Q
for(int i=0;i<nStartPos.length;i++) Oo`P +S#
{ (s %T18
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i92{N$*x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &jl'1mZ
nStartPos,nEndPos,i); :@wO' o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iH9g5G`O
fileSplitterFetch.start(); l#7,<@)
} V-}d-Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :M`|*~V~$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xl#vVyO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1(gb-u0
nEndPos = " + nFileLength); %/oOM\}++
// fileSplitterFetch[nPos.length-1].start(); t^Aios~F
Fla[YWS
/>Wh
//等待子线程结束 N;F1Z-9
//int count = 0; 0'TqW9P
//是否结束while循环 +%>s\W+?]
boolean breakWhile = false; X9/V;!
C(3yJzg>y
?6p6OB
while(!bStop) v>c[wg9P
{ jm =E_86_
write_nPos(); Oe'Nn250
Utility.sleep(500); c#OZ=`
breakWhile = true; S&6}9r
)*G3q/l1u6
M`FsKK`
for(int i=0;i<nStartPos.length;i++) DvG.G+mo#
{ W2wDSP-
if(!fileSplitterFetch.bDownOver) ?f1%)]>
{ H#E
breakWhile = false; 6ApW+/
break; ""^9WLH4g-
} o2W pi
} x]euNa
if(breakWhile) (iP,F]
break; #v:<\-MjN
HoT5 5v!o
2 L%d,Ta>
//count++; `-\4Dx1!q
//if(count>4) `kwyF27v]
// siteStop(); x~$P.X7(~
} XU2HWa
NRcg~Nu
L-Xd3RCD
System.err.println("文件下载结束！"); +DF<o U~
} S5"xb
catch(Exception e){e.printStackTrace ();} )FMpfC>An
} j*I0]!-
'an{<82i
jn^i4f>N
//获得文件长度 GL@s~_;T6
public long getFileSize() 8hQ"rrj+
{ cK(}B_D$
int nFileLength = -1; |O+R%'z'<
try{ E5jK}1t4V
URL url = new URL(siteInfoBean.getSSiteURL()); /Or76kE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %saTyF,
httpConnection.setRequestProperty("User-Agent","NetFox"); Fy`VQ\%7t
).9-=P HlX
Yl&eeM
int responseCode=httpConnection.getResponseCode(); 5>j,P
if(responseCode>=400) nkS6A}i3o
{ 3dcZ1Yrn
processErrorCode(responseCode); *7ap[YXZ\w
return -2; //-2 represent access is error 8ji!FZf
} ,G"?fQ7zR
e:AB!k^xp$
>7vSN<w~m
String sHeader; FDbx"%A
$ ohwBv3S
^dZ,Itho
for(int i=1;;i++) 5irewh'R
{ >Eik>dQ a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HjGT{o
//Utility.log(in.readLine()); /p<mD-:.M
sHeader=httpConnection.getHeaderFieldKey(i); ^P"t "
if(sHeader!=null) I4m)5G?O2
{ 2}[rc%tV:?
if(sHeader.equals("Content-Length")) d;D^<-[i
{ q1r\60M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tK g%5;v
break; /%=#*/E7
} Bpo~x2p
} j[iJo 5
else U,RIr8G
break; Kl(}s{YFn.
} ]K XknEaxl
} ;f?OT7>kN
catch(IOException e){e.printStackTrace ();} d^ipf*aLC
catch(Exception e){e.printStackTrace ();} A |NX"
RZOk.~[v
J-Sf9^G
Utility.log(nFileLength); tI.(+-q
g|)e3q{M
(niZN_qv
return nFileLength; Qyt6+xL
} 8uyVx9C0
Sl:\5]'yJ
-/#3U{O
//保存下载信息（文件指针位置） pm5Yc@D
private void write_nPos() qbqJ1^!6R
{ n0!S;HH-
try{ ai#EFo+#
output = new DataOutputStream(new FileOutputStream(tmpFile)); `'0opoQRe
output.writeInt(nStartPos.length); Y)BKRS~
for(int i=0;i<nStartPos.length;i++) 5kC#uk
{ +8Peh9"
// output.writeLong(nPos); 0AR4/5.
output.writeLong(fileSplitterFetch.nStartPos); 5Tn4iyg;B
output.writeLong(fileSplitterFetch.nEndPos); !RiPr(m@y
} ;wW6x
output.close(); uKpl+>
} }!n<L:njX
catch(IOException e){e.printStackTrace ();} {sX*SbJt
catch(Exception e){e.printStackTrace ();} :JW~$4
} "q#(}1Zd
_AVCh)Zb
I*K^,XY+
//读取保存的下载信息（文件指针位置） YH<@->Ip
private void read_nPos() {7(h%]
{ 8P5xRUkV
try{ b<=K@I.=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^$?8!WE
int nCount = input.readInt(); eRVu/TY
nStartPos = new long[nCount]; pKr3(5~
nEndPos = new long[nCount]; JXPn <
for(int i=0;i<nStartPos.length;i++) @o;m!CYB
{ >x!N[N@G
nStartPos = input.readLong(); (&njZdcb*
nEndPos = input.readLong(); {W `/KU?u
} :^l*_v{
input.close(); 2$T~(tem
} WY*}|R2R
catch(IOException e){e.printStackTrace ();} )}?dYk
catch(Exception e){e.printStackTrace ();} !my5-f>{(
} laFkOQI
?#FAa,
hrS/3c'<Z
private void processErrorCode(int nErrorCode) ~x4Y57
{ jg%D G2
System.err.println("Error Code : " + nErrorCode); XZKOBq B]
} ghms-.:b8
<<UlFE9"
k{@z87+&
//停止文件下载 .3ic%u;|D
public void siteStop() JmY"Ja,&
{ }jIb ^|#CD
bStop = true; [oKB1GkA
for(int i=0;i<nStartPos.length;i++) tH W"eag
fileSplitterFetch.splitterStop(); 78 UT]<Q;K
rbP.N ?YU%
vo0[Z,aH5
} ?d_<S0j-)
} aP"i_!\.aa
//负责部分文件的抓取 !w C4ei`
**FileSplitterFetch.java 8Oc*<^{#
*/ ](Sp0t
package NetFox; P!]DV$o
F"0tv$
FEdyh?$
import java.io.*; c)E'',-J_2
import java.net.*; -Tz9J4xU&
ja9y
E)Hp.
public class FileSplitterFetch extends Thread { &JF^a
aZBaIl6I
cDAO5^
String sURL; //File URL $"_D"/*
long nStartPos; //File Snippet Start Position Z ,T TI>P
long nEndPos; //File Snippet End Position pl7!O9bo
int nThreadID; //Thread's ID x&;{4F Nw
boolean bDownOver = false; //Downing is over %ecg19~L/}
boolean bStop = false; //Stop identical _oLK"* [#
FileAccessI fileAccessI = null; //File Access interface [9>1e
-MOf[f^
=Wl CE_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;zh|*F>
{ H:~LL0Md%
this.sURL = sURL; hPEK@
this.nStartPos = nStart; $(_i>&d<
this.nEndPos = nEnd; c\RDa|B,
nThreadID = id; v$,9l+p/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _N*4 3O`
} (# ?~^ut
*/Y@:Sjf
]INbRytvc
public void run() 3UH=wmG0w
{ 9D 0ujup
while(nStartPos < nEndPos && !bStop) \wnQ[UNjP
{ p\!+j@H:
O #0:6QX
UQhfR}(
try{ z{tyB
URL url = new URL(sURL); .c BJA&/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'zpj_QM
httpConnection.setRequestProperty("User-Agent","NetFox"); LrK6*y,z
String sProperty = "bytes="+nStartPos+"-"; P/ug'
httpConnection.setRequestProperty("RANGE",sProperty); A\ LTAp(I
Utility.log(sProperty); -M(:z
? ZN8Ku
%=_Iq\lC
InputStream input = httpConnection.getInputStream(); .}z&$:U9[
//logResponseHead(httpConnection); |EF*]qI
*SC~_
M6g!bK2l
byte[] b = new byte[1024]; N4$0ptz#}G
int nRead; Z!hDTT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #X|'RL($
{ H!s &]b
nStartPos += fileAccessI.write(b,0,nRead); n:;2Z
//if(nThreadID == 1) 0p~:fm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #V~r@,
} bup;4~g
Ig S.U
c%v%U &
Utility.log("Thread " + nThreadID + " is over!"); /Nxy?g|,
bDownOver = true; sV{[~U,|
//nPos = fileAccessI.write (b,0,nRead); !d"J,.)
} 9ft7
catch(Exception e){e.printStackTrace ();} *^QfTKN
} g*!2.P
} ,V|>nkQ
3Vt-]DGX
PUucYc
//打印回应的头信息 scrNnO[3j
public void logResponseHead(HttpURLConnection con) #~ /-n&#
{ )5e}Id
for(int i=1;;i++) T!J\Dm-
{ f<y""0L9
String header=con.getHeaderFieldKey(i); ,qaIdw[
if(header!=null) )eUb@Eu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UWmWouA
Utility.log(header+" : "+con.getHeaderField(header)); 8R-?x/:
else tl0_as
break; \N7 E!82
} b vUYLWzS
} h-#Glse<
q/&Z6LJ)
DBVe69/S
public void splitterStop() @(oz`|*
{ l|\Q~ D!o
bStop = true; _DH,$evS%
} .D>%-
\@tt$ m%
fMhMB |W.
} @hg1&pfxZ<
Elm/T]6
pdmeB
/* L?0dZY-"
**FileAccess.java &]uhPx/
*//文件访问(定位，写) ^[d)Hk}L
package NetFox; r;}kw(ukC
import java.io.*; !3d+"tL S
z<s]Z
?%;)> :3N
public class FileAccessI implements Serializable{ m#DC;(Pn
\6nWt6M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /sC$;l
RandomAccessFile oSavedFile; epz2d~;
long nPos; mltN$b%G=d
oIX]9~
t'FY*|xk
public FileAccessI() throws IOException /__we[$E
{ [T !#s
this("",0); Q%q_
} /GfC/)1_
ym<G.3%1
E^Q|v45d
public FileAccessI(String sName,long nPos) throws IOException Hza{"I*^
{ i]xyD'0
oSavedFile = new RandomAccessFile(sName,"rw"); Exk[;lI
this.nPos = nPos; t\u0\l>
oSavedFile.seek(nPos); lSl=6R
} > : \lDz
[%z~0\lu8
P\N$TYeH
public synchronized int write(byte[] b,int nStart,int nLen) +'Tr>2V
{ JdFMSmZ@
int n = -1; R:Z{,R+
try{ rEs,o3h?po
oSavedFile.write(b,nStart,nLen); @yS
n = nLen; r|6S&Ia>
} fW|1AUD,
catch(IOException e) MQw{^6Z>1
{ LW0't} z
e.printStackTrace (); w\s$
} sf7'8+wj>
>\3=h8zw
OBl-6W
return n; H2|&
} t&H):P
-=5z&) X
D_(xhM
} j`ggg]"&$
.6f %"E,
[6)`wi
/* vR-rCve$P
**SiteInfoBean.java l 0jjLqm:
*/ Y(W>([59
package NetFox; RY&Wvkjh
)r5QOa/
]X;Ty\UD&
public class SiteInfoBean { _U%!&_m6
>jRz4%
mEr*n
private String sSiteURL; //Site's URL ub0]nov
private String sFilePath; //Saved File's Path ??ah
private String sFileName; //Saved File's Name d,6 Z
private int nSplitter; //Count of Splited Downloading File vw>O;u.]B
4Z1-RS
j+w*Absh
public SiteInfoBean() P ;PS+S9
{//nSplitter的缺省值为5 R0, Q`
//default value of nSplitter is 5 8yA:C
this("","","",5); Tg)Fr)
} 1E=%:?d
3RZP 12x
s>76?Q:i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qte=<Z)
{ \y"!`.E7\d
sSiteURL= sURL; r,!7TuBl
sFilePath = sPath; B&+V%~/
sFileName = sName; OjJKloy'
this.nSplitter = nSpiltter; #rF|X6P
rhHX0+
-=s7Q{O8Z
} o5@ l!NQ
#4Xe zj,g*
|wQ|h$|
public String getSSiteURL() 7Ha +@
{ (zCas}YAKI
return sSiteURL; .~4%TsBaY
} wJ/k\
e(O"V3wq*6
!!%vs 6
public void setSSiteURL(String value) u B~/W
{ JyvXNV,
sSiteURL = value; l;b5v]~
} ,3!l'|0jJ
#]q<fhJhr$
^mm:u<Yt
public String getSFilePath() oJvF)d@gU
{ =Bu d!
return sFilePath; .3Jggp
} d_-{-@
.^X IZ
{UT^pIP\
public void setSFilePath(String value) :%{MMhbx
{ O\q|b#q}/
sFilePath = value; p>96>7w
} TGY^,H>J
]Z&2
TWK(vEDM
public String getSFileName() ZUVk~X3
{ L*6Tz'Qp
return sFileName; W+Z] Y
} Z6 E-FuO
dUk^DI,:l
%TyR8 %
public void setSFileName(String value) X25cU{
{ S6*3."Sk
sFileName = value; W1w)SS
} 24}r;=U
gxycw4kz
Sx5r u?$.
public int getNSplitter() wv #1s3
{ ]/XNfb
return nSplitter; BXiuVx
} JVD#wwic
5#p [Q _
6! \a8q'z
public void setNSplitter(int nCount) _S7GkpoK
{ Jk!}z+X'A
nSplitter = nCount; sF:3|Yy0
} ZXsm9
} x\)0+c~\}x
KA#4iu{
M~t S *
/* D"oyl`q
**Utility.java Y?=+A4v
*/ 8sOM%y9M
package NetFox; ?_3K]i1IS
40<ifz[7
/0>Cy\eN0
public class Utility { MoIVval/
lY yt8H
$cHA_$ `
public Utility() 2_6x2Ia4
{ Z)Nl\e& M
~9#\+[ d_
X!2/cgU7
} U-6b><
V/j+Z1ZW
//线程睡眠 7z9gsi
public static void sleep(int nSecond) k%?wNk>
{ 2~AGOx
try{ 6Daz1Pxd+
Thread.sleep(nSecond); -z)I;R
} !n~p?joJ*
catch(Exception e) 'KMyaEh.u
{ -)(HG)3
e.printStackTrace (); uli,@5%\
} |XzqP +t
} nqg=I
*q{/`Z{wy
//日志 9]r6V
public static void log(String sMsg) ymT&[+V
{ &ok2Xw
System.err.println(sMsg); $/ew'h9q
} qP-*
;?"2sS!AHQ
js/N qf2>
public static void log(int sMsg) T.HS.
{ x>m_ v
System.err.println(sMsg); #8z2>&:|
} r5tC
} sc\4.Ux%Q
8q{ %n
tbrjTeC
/* s"#>Xc
**TestMethod.java /\"=egB9
*/ -&oJ@Aa
package NetFox; `ySLic`
zFmoo4P/
RNE})B
public class TestMethod { kaQn'5
m!L&_Z|j
%?1k}(qUeY
public TestMethod() )"s <hR,
{ ///xx/weblogic60b2_win.exe eL[BH8l
try{ h lD0^8S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C vfm ,BL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dp\pkx7
SiteFileFetch fileFetch = new SiteFileFetch(bean); H@GiHej
fileFetch.start(); Ufd{.o[{-
} 6|+I~zJ88
catch(Exception e){e.printStackTrace ();} ;0(|06=
*6=2UJcJ
,{MA90!
} `O ?61YUQH
AI}29L3C
fT9$0:eO
public static void main(String[] args) 422d4Zu
{ ~ \z7$9Q
new TestMethod(); }"BXqh"\`
} gf7%vyMo$
} RI9&KS
点击下载更多相关资料