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)); ,*@6NK,.
} <U]#722
for(int i=0;i<nEndPos.length-1;i++) ,, G6L{&Z
{ qZ7/d,w
nEndPos = nStartPos[i+1]; tJ9i{TS
} r-a/vx#
nEndPos[nEndPos.length-1] = nFileLength; j/xL+Y(=
} !(<Yc5
} URD<KIN>
#wZ:E,R
K)"cwk-
//启动子线程 hol54)7$3:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ng3MfbFG
for(int i=0;i<nStartPos.length;i++) DOm5azO!>
{ %%w]-`^h,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3q.O^`y FU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xFY;aK
nStartPos,nEndPos,i); Y@Kp'+t(!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m,U`hPJ
fileSplitterFetch.start(); z_p/.kQ'5
} *tda_B 2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vWwnC)5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fH7o,U|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uFT&r|
nEndPos = " + nFileLength); AhARBgf<
// fileSplitterFetch[nPos.length-1].start(); qe:,%a-9
mSzBNvci
f9g#pyH4
//等待子线程结束 vO2o/
//int count = 0; ?q<"!U|e
//是否结束while循环 +`x8[A)-
boolean breakWhile = false; Osdw\NNH~M
QMfa~TH#p
[S/]Vk|4
while(!bStop) r^k:$wJbRK
{ l*]*.?m/5
write_nPos(); GiN\nu<!
Utility.sleep(500); PQRh5km
breakWhile = true; YGObTIGJvf
V(Ps6jR"BS
rQbL86+
for(int i=0;i<nStartPos.length;i++) 3~4e\xL
{ & ;+u.X
if(!fileSplitterFetch.bDownOver) o~F @1
{ q@p-)+D;
breakWhile = false; Vet7a_
break; "Kz=ZC
} 0*"auGuX
} \z<B=RT\
if(breakWhile) 0f 1Lu) 2
break; g@.RfX=
M ,8r{[2
D!~-53f@
//count++; ;jTP|q?|{
//if(count>4) 31y=Ar""
// siteStop(); ubIGs|p2c
} S ;x;FU
dm&F1NkT
9LGJ-gL
System.err.println("文件下载结束！"); Wr7^
} a'ViyTBo
catch(Exception e){e.printStackTrace ();} A:EF#2)g
} DA@YjebP'
PY.c$)az>
`av8|;
//获得文件长度 8ltHR]v
public long getFileSize() AyKaazm]9
{ ](vshgp2
int nFileLength = -1; Z xLjh
try{ !=#E/il,
URL url = new URL(siteInfoBean.getSSiteURL()); 3C8'0DB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A?3hNvfx
httpConnection.setRequestProperty("User-Agent","NetFox"); lkV% k1w
:QsGwhB
dfe 9)m>
int responseCode=httpConnection.getResponseCode(); hq/\'Z&!+P
if(responseCode>=400) pK#Ze/!
{ d+%1q
processErrorCode(responseCode); hNXPm~OK\
return -2; //-2 represent access is error @YP\!#"8
} uYS?# g
\@Gyl_6^
pc5-'; n
String sHeader; TdP_L/>|J
Rs:<'A
G.O0*E2V
for(int i=1;;i++) #H(|+WEu
{ )]!Ps` ,u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7ju7QyR
//Utility.log(in.readLine()); Gu<3*@Ng
sHeader=httpConnection.getHeaderFieldKey(i); C8y 3T/G
if(sHeader!=null) [zK|OMxoV
{ %lV&QQa
if(sHeader.equals("Content-Length")) %L{H_;z
{ KGkzE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'bkecC
break; {SW104nb&#
} Lm9y!>1"O
} 0X-u'=Bs
else XZA3TZ
break; fSl+;|Kn
} }#q9>gx
} y%=\E
catch(IOException e){e.printStackTrace ();} q~r)B}
catch(Exception e){e.printStackTrace ();} ~o%|#-S
6!/e_a
+GgWd=X.Y
Utility.log(nFileLength); ji`N1e,l
BXaA#} ;e
,>2ijk#
return nFileLength; hyL3fkMJ,
} n w @cAv
KSuP'.l
FgNO#%
//保存下载信息（文件指针位置） _$0<]O$
private void write_nPos() jwTb09
{ `,aPK/
try{ PX[taDN
output = new DataOutputStream(new FileOutputStream(tmpFile)); c}Y(Myd
output.writeInt(nStartPos.length); UMo=bs
for(int i=0;i<nStartPos.length;i++) Qwk
{ oKz|hks[6
// output.writeLong(nPos); Uq~{=hMX
output.writeLong(fileSplitterFetch.nStartPos); >c\'4M8Cz
output.writeLong(fileSplitterFetch.nEndPos); i=reJ(y-
} _+%-WFS|
output.close(); xg'z_W
} E$34myOVf
catch(IOException e){e.printStackTrace ();} iquB]z'
catch(Exception e){e.printStackTrace ();} ss%ahs
} jio1#&
$B*Ek>EK
RqXcL,,9
//读取保存的下载信息（文件指针位置） vd SV6p.d
private void read_nPos() 4<70mUnt
{ >;nE.]
try{ De4UGX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uezqC=v$h
int nCount = input.readInt(); mmAikT#k
nStartPos = new long[nCount]; Vur$t^zE
nEndPos = new long[nCount]; ,`G8U/
for(int i=0;i<nStartPos.length;i++) %U)/>Z
{ $91c9z;f^
nStartPos = input.readLong(); 22`W*e@6h
nEndPos = input.readLong(); p<'#f,o
} f3|ttUX
input.close(); RhnSQe
} -$?xR](f
catch(IOException e){e.printStackTrace ();} $f*N
catch(Exception e){e.printStackTrace ();} ln'7kg
} &'N{v@Oi)
,4jkTQ*@2
wZh&w<l'
private void processErrorCode(int nErrorCode) yd`xmc)
{ v6HBO#F'V{
System.err.println("Error Code : " + nErrorCode); fr;>`u[;
} /lx\9S|
R?(0:f
(i1FMd}G
//停止文件下载 ?7@B$OlU
public void siteStop() j=r`[Bm
{ :f ybH)*
bStop = true; ,<zGvksk
for(int i=0;i<nStartPos.length;i++) nyi}~sB
fileSplitterFetch.splitterStop(); Av^{$9yl
f`.8.1Rd
O>wGc8Of\
} vJ7I [Z
} E08FUAth]#
//负责部分文件的抓取 cTHSPr?<
**FileSplitterFetch.java xpx=t71Hq
*/ Tw)nFr8oF]
package NetFox; `Ff3H$_*
KIC5U50J
ixw3Z D(>+
import java.io.*; &xgMqv2/
import java.net.*; s-}|_g.Pt
JWr:/?
bA@!0,m
public class FileSplitterFetch extends Thread { tU>wRw=d
n&D<l '4
Z%y>q|:
String sURL; //File URL 2^bq4c4J
long nStartPos; //File Snippet Start Position |[CsLn;
long nEndPos; //File Snippet End Position xpxUn8.
int nThreadID; //Thread's ID <MB]W`5
boolean bDownOver = false; //Downing is over 9s6@AJf
boolean bStop = false; //Stop identical LUl6^JU
FileAccessI fileAccessI = null; //File Access interface :@rE&
BDNn~aU#m
P_B#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -/ ;y*mP
{ zu5'Ex`gQa
this.sURL = sURL; h +.8Rl
this.nStartPos = nStart; bvuoGG*
this.nEndPos = nEnd; !lKO|Y
nThreadID = id; +J} wYind
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R5g-b2Lm
} y{,HpPp#o
"fdgBso
A07g@3n
public void run() s:7^R-"
{ QzPq^
while(nStartPos < nEndPos && !bStop) U[*VNJSp
{ F^7qLvh
iE=Yh
=<e|<EwSZ
try{ (wEaa'XL
URL url = new URL(sURL); L@HPU;<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y;8Ys&/t
httpConnection.setRequestProperty("User-Agent","NetFox"); ^ llZf$`
String sProperty = "bytes="+nStartPos+"-"; {E-.W"t4
httpConnection.setRequestProperty("RANGE",sProperty); "XT7;!
Utility.log(sProperty); PUV)w\!&is
uMh[Ht^.
_T&?H&#
InputStream input = httpConnection.getInputStream(); J0*hJ-/u
//logResponseHead(httpConnection); _G|hKk^,
K 4QJDC8
9 [v=`
byte[] b = new byte[1024]; X^ckTIdR
int nRead; |!E>I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dqnH7okZ
{ "~(qp_AI
nStartPos += fileAccessI.write(b,0,nRead); z8_m<uewz
//if(nThreadID == 1) ns[v.YDL
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1 0lvhzU
} L6./b;
&)JQ6J_|\
=.(yOUI
Utility.log("Thread " + nThreadID + " is over!"); _ui03veA1
bDownOver = true; 5XySF #
//nPos = fileAccessI.write (b,0,nRead); Q1jU{
} Ig}G"GR
catch(Exception e){e.printStackTrace ();} lT#&\JQ
} #qrZ(,I@n
} 6!dbJ5x1
k!3X4;F!_
|t+M/C0y/
//打印回应的头信息 )Fx"S.Ok
public void logResponseHead(HttpURLConnection con) 9]fhH
{ M(|Qvh{Q6
for(int i=1;;i++) v".q578 0B
{ 1j0OV9-|
String header=con.getHeaderFieldKey(i); \ZX5dFu0
if(header!=null) T]-yTsto
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i]J*lM7'
Utility.log(header+" : "+con.getHeaderField(header)); g}"`@H(9r3
else xI}o8GKQq
break; k"D6Vyy`
} XTEC0s"F
} I=o[\?u*_
(|)`~z
c[\ :^w^I6
public void splitterStop() Hy^Em
{ '?=SnjMX
bStop = true; L9Sd4L_e
} W2/FGJD
#N^TqOr
\95qH,w)T
} %a=K:" oU[
>}Qj|05G
Ec IgX_\
/* 9pUvw_9MY
**FileAccess.java <~;;iM6
*//文件访问(定位，写) '{dduHo
package NetFox; %E#OUo[y/
import java.io.*; #<0Yx9Jh.
,Tc3koi
`Fa49B|`D
public class FileAccessI implements Serializable{ nfpkWyIu{
`q|&;wP.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E}AOtY5a
RandomAccessFile oSavedFile; VeiJ1=hc
long nPos; JLUG=x(dA
Py7!_TX
t\~lGG-p
public FileAccessI() throws IOException ddvSi6
{ pYZ6-s
this("",0); QR4rQu
} Atl`J.;G
VH[r@Pn
sqTBlP
public FileAccessI(String sName,long nPos) throws IOException d]1%/$v^
{ :K.%^ag=j
oSavedFile = new RandomAccessFile(sName,"rw"); R}Pw#*B
this.nPos = nPos; [M>Md-pj
oSavedFile.seek(nPos); :*bv(~FW
} f?8cO#GU
}/~%Ysl
L#sw@UCK
public synchronized int write(byte[] b,int nStart,int nLen) \{r-e
{ fm$eJu
int n = -1; t`NZ_w /
try{ !wiW#PR
oSavedFile.write(b,nStart,nLen); U |I>CDp
n = nLen; $jT&]p
} 2WQKj9iyN
catch(IOException e) A{\#.nC/z
{ zRTR
e.printStackTrace (); :#D?b.=
} 5\93-e
s2f95<B
J)1:jieQ
return n; ~^d. zIN!
} r/v'h@
<;O=h; ~|
]=\Mf<
} m|q?gX9R
z'@j9vT
n8<o*f&&9>
/* dFY]~_P472
**SiteInfoBean.java 3TUW+#[Gu
*/ i`[5%6\"&
package NetFox; [MSLVTR
9$,x^Qx
bwh7.lDAl
public class SiteInfoBean { kN3T/96
tP; &$y.8
)|;*[S4
private String sSiteURL; //Site's URL `nBCCz'Y!
private String sFilePath; //Saved File's Path `$og]Dn;
private String sFileName; //Saved File's Name zNSix!F
private int nSplitter; //Count of Splited Downloading File iVq4&X_x
").MU[q%Y
*M5: \+
public SiteInfoBean() <viIpz2jh%
{//nSplitter的缺省值为5 u@|izRk
//default value of nSplitter is 5 aE}1~`
this("","","",5); u\YH,
} iku8T*&uc
_XT],"
'[#a-8-JY_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~3}Gu^@
{ 4d&#NP
sSiteURL= sURL; {FzL@!||
sFilePath = sPath; Ol,;BZHc\
sFileName = sName; rfqw/o
this.nSplitter = nSpiltter; xdWfrm$;ZA
(Wkli:Lq
|1^>n,C
} _^4\z*x
1*S5:7Tb
p:M#F:
public String getSSiteURL() t~pA2?9@
{ {MmHR
return sSiteURL; `@GqD
} >cwyb9;!kK
=! v.VF\;
;t47cUm6j
public void setSSiteURL(String value) jvx9b([<sG
{ J6x\_]1:*
sSiteURL = value; /64jO?mp
} 8r[ZGUV
4 -)'a} O
T1zft#1~
public String getSFilePath() Ta#vD_QP
{ u#5/s8
return sFilePath; FFXDt"i2
} .0]4@'
d_9Fc"C~
Hj ]$
public void setSFilePath(String value) PoMkFG6
{ ps0wN%tA
sFilePath = value; Q,Tet&in )
} ]2G5ng' @
s vn[c*
w?CbATQ
public String getSFileName() 0P`wh=")
{ `mPmEV<
return sFileName; ^_4TDC~h
} ".L+gn}u-
&d`T~fl|
0 eZfHW&
public void setSFileName(String value) H"(:6 `
{ n<MMO=+bg
sFileName = value; XfA3Ez,}
} zM6yUEg
3_=~7B) 8
CCKg,v
public int getNSplitter() >Bp%~8f
{ xO'I*)
return nSplitter; ~45u a
} E#"QaI8`
\C.%S +u
1A^iUC5)
public void setNSplitter(int nCount) i} 96,{
{ P8NKpO\
nSplitter = nCount; )gdv!
} || ?B1
} 5A1oZ+C#
RsBo\#`
oR}ir
/* y8: 0VZox
**Utility.java Okk[}G)
*/ 4W8rb'B!Ay
package NetFox; |Hn[XRsf
q!W~>c!
1!8*mk_R{
public class Utility { q3Umqvl)oe
G],+?E_,
O<4i)Lx2
public Utility() 2>Kq)Ii
{ <[C9F1]Ya
"_+X#P x
)hk=wu6
} b{)('C$
;a!o$y
//线程睡眠 [rqe;00]
public static void sleep(int nSecond) ,4j$kR
{ /Nq!^=
try{ %u }|4BXoh
Thread.sleep(nSecond); IyG5Rj2
} (PGmA>BT
catch(Exception e) T\c;Ra
{ ?>MD/l(l
e.printStackTrace (); DHpU?;|3
} m6V1m0M
} 5X&<+{bX
Bir}X
//日志 R+]p -NI^
public static void log(String sMsg) %9M; MK
{ D{o1G?A
System.err.println(sMsg); d_J?i]AP|'
} iMx+y5O
Y=X"YH|
MSeO#X
public static void log(int sMsg) 9BI5qHEp
{ 4 E3@O
System.err.println(sMsg); ,- ]2s_
} cYx=8~-
} )$q<"t\#P#
1E$Z]5C9
xy mK|
/* qU8UKIP
**TestMethod.java VR?7{3
*/ N(Y9FD;H
package NetFox; {%D "0*^
jbIWdHZ/US
Z.6`O1OY}?
public class TestMethod { :'y
|UnTd$m
?f']*pD8
public TestMethod() ,b>cy&ut
{ ///xx/weblogic60b2_win.exe e"r'z n
try{ UQ|0Aqwq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PL~k `L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >&^w\"'
SiteFileFetch fileFetch = new SiteFileFetch(bean); :Tuy]]k
fileFetch.start(); gZM{]GQ
} L:Wy- Z
catch(Exception e){e.printStackTrace ();} b("CvD8
4NR,"l)
miS+MK"
} {J})f>x<xM
HKOJkbVZ2^
u MzefRN
public static void main(String[] args) b]RCe^E1
{ j,/o0k,
new TestMethod(); W\.f:"2qr
} /<:9NP'^
} #*S/Sh?Q
点击下载更多相关资料