http断点续传简单实现（java)

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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)); $hjP}- oUX
} M&qh]v gC
for(int i=0;i<nEndPos.length-1;i++) 'dIX=/RZ
{ v[{8G^Z}54
nEndPos = nStartPos[i+1]; >d8x<|D
} b^[W_y
nEndPos[nEndPos.length-1] = nFileLength; G$;] ?g
} M5GY>3P$c
} t."g\;
c=A(o
9Fy\t{ks
//启动子线程 pg~zUOY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -?< Ww{
for(int i=0;i<nStartPos.length;i++) Pz]bZPHn
{ 7?=43bZl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q_&}^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hrs#ZZ:E
nStartPos,nEndPos,i); q&XCX$N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M.ZEqV+k
fileSplitterFetch.start(); ]d@^i)2LF
} 4F05(R8k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zm%VG(l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kmm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E rop9T1
nEndPos = " + nFileLength); r]A"Og_U
// fileSplitterFetch[nPos.length-1].start(); k}-yOP{
tcBC!_vF
xS6(K
//等待子线程结束 =?/N5O(
//int count = 0; lGdM80f
//是否结束while循环 ]2Sfkl0
boolean breakWhile = false; Guk.,}9
N\9}\Rk@
[YC=d1F5
while(!bStop) 4$yV%[j
{ TZ?Os4+
write_nPos(); qqnclqkw&
Utility.sleep(500); hi!L\yi
breakWhile = true; m7$8k@r
A2m_q>> !
P^ptsZ%
for(int i=0;i<nStartPos.length;i++) wL4ZW8_
{ 3/X-Cr+d
if(!fileSplitterFetch.bDownOver) `J72+RA
{ 5]jx5!N
breakWhile = false; )O,wRd>5
break; 2Y400
} >(hSW~i~
} cVO,~I\\
if(breakWhile) 8g\wVKkTQp
break; 81~Kpx
A0G)imsW:_
v#
//count++; v`y6y8:>
//if(count>4) ,Pn-ZF
// siteStop(); (2UW_l
} 4L8z>9D
>; aCf#q
|#{-.r6Y]
System.err.println("文件下载结束！"); #@9)h
} G+0><,S
catch(Exception e){e.printStackTrace ();} :6XguU
} /\na;GI$
6gXIt9B.h$
l0I}&,+
//获得文件长度 <lUOJV{&\
public long getFileSize() _`H.h6h
{ >D 97c|?c
int nFileLength = -1; <"W?<VjO
try{ dXmV@ Noo
URL url = new URL(siteInfoBean.getSSiteURL()); ))!Bg?t-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ).LTts7c
httpConnection.setRequestProperty("User-Agent","NetFox"); fX_#S|DlSG
!)N|J$FU
wMGk!N
int responseCode=httpConnection.getResponseCode(); O7%2v@j|8
if(responseCode>=400) !<&m]K
{ *n8%F9F
processErrorCode(responseCode); #kyl?E
return -2; //-2 represent access is error oBr.S_Qe
} gw"~RV0
o/C(4q6d
g& k58{e
String sHeader; )l_@t(_
$f#agq_
S=' wJ@?;
for(int i=1;;i++) MU'@2c
{ zF8'i=b&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'Y.Vn P&H
//Utility.log(in.readLine()); []|;qHhC~(
sHeader=httpConnection.getHeaderFieldKey(i); D3`}4 A
if(sHeader!=null) Br}h/!NU/
{ ({4]
if(sHeader.equals("Content-Length")) 9:5:`'b
{ f;gZ|a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'Gjq/L/x
break; XAPYpBgm
} Ur^j$B}
} @9Q2$
else Ow3P-UzU3
break; p,F^0OU2}:
} <\" .L
} (zG.aaz*C
catch(IOException e){e.printStackTrace ();} SVagT'BB
catch(Exception e){e.printStackTrace ();} H6gU?9%
. V$ps-t
~]BMrgn
Utility.log(nFileLength); Bn?:w\%Ue
YzAFC11,
%r;w;`/hA
return nFileLength; ?vgH"W~3>
} G/vC~6x
m#f{]+6U
6"U8V?E
//保存下载信息（文件指针位置） -I":Z2.fR
private void write_nPos() 1S0pd-i
{ 4,G w#@
try{ =oX>Ph+ P
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'xnnLCm.
output.writeInt(nStartPos.length); @m~RtC-Q
for(int i=0;i<nStartPos.length;i++) ;Wc4qJ.@
{ ]u#JuX
// output.writeLong(nPos); 8!mc@$Z
output.writeLong(fileSplitterFetch.nStartPos); jTb-;4N'
output.writeLong(fileSplitterFetch.nEndPos); B@O@1?c[
} N8v'70
output.close(); Ue*C>F
} MgJ36zM
catch(IOException e){e.printStackTrace ();} zP!J/}z
catch(Exception e){e.printStackTrace ();} `TtXZ[gP}
} JN'cXZJPn
GKiukX$'
{_#yz\j
//读取保存的下载信息（文件指针位置） QvLZg
private void read_nPos() 9!U@"~yB
{ w!SkWS b,~
try{ 'Z&;uv,l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4v'A\~ZU
int nCount = input.readInt(); w,1Ii}d9
nStartPos = new long[nCount]; 06*rWu9P3
nEndPos = new long[nCount]; VR5fqf|*
for(int i=0;i<nStartPos.length;i++) uj|BQ`k
{ kforu!C
nStartPos = input.readLong(); bU54-3Ox*
nEndPos = input.readLong(); }-@4vl x$
} cK`"lxO
input.close(); 6rN(_Oi-
} =Z G:x<Hg
catch(IOException e){e.printStackTrace ();} tMp=-"
catch(Exception e){e.printStackTrace ();} %XTcP2pRJ
} }(XdB:C8
PX(pX>
=~KsS}`1,
private void processErrorCode(int nErrorCode) FG@-bV
{ ]@^coj[
System.err.println("Error Code : " + nErrorCode); m-/j1GZ*
} gEQNs\Jn L
[5$w=u"j
H ?M/mGP
//停止文件下载 DI|:p!Nx
public void siteStop() 8Q{9>^
{ <plC_{Y:wu
bStop = true; C0*@0~8$9
for(int i=0;i<nStartPos.length;i++) mTNVU@TY=
fileSplitterFetch.splitterStop(); (Y%Q|u
Q&'}BeUbm
p&-'|'![l
} e`>{$t
} U-kVNBs
//负责部分文件的抓取 5kNzv~4B,;
**FileSplitterFetch.java LPYbHo3fq
*/ %ir:ASk
package NetFox; NS)}6OI3~"
Z?Hs@j
dsx]/49<
import java.io.*; <"D=6jqZ
import java.net.*; 2F#q I1
Sn4[3JV$l
hwN?/5
public class FileSplitterFetch extends Thread { r7]zQIE
^u}L;`L
Cxod[$8
String sURL; //File URL VQ5nq'{v
long nStartPos; //File Snippet Start Position >odbOi+X
long nEndPos; //File Snippet End Position UO*Ymj 1
int nThreadID; //Thread's ID 'J&f%kx"
boolean bDownOver = false; //Downing is over p!O(Y6QM
boolean bStop = false; //Stop identical {U<xdG
FileAccessI fileAccessI = null; //File Access interface RB* J=
e!Y0-=?nf#
uEyH2QO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G0u LmW70
{ 'Jf^`ZT}
this.sURL = sURL; iRg7*MQu
this.nStartPos = nStart; @_:]J1jw7
this.nEndPos = nEnd; N>(g?A; Z+
nThreadID = id; [gy*`@w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R8rfM?"W
} f7h*Vu`>
D`J6h,=2l/
Q+b D}emd
public void run() YEkh3FrbwH
{ 3d<HN6&U
while(nStartPos < nEndPos && !bStop) Xc"&0v%;#
{ ~%?`P/.o
pfu1O6R
E*L iM5+I
try{ 7eWk7&Xul
URL url = new URL(sURL); fwK}/0%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;nC.fBu
httpConnection.setRequestProperty("User-Agent","NetFox"); {hln?'
String sProperty = "bytes="+nStartPos+"-"; fDG0BNLY
httpConnection.setRequestProperty("RANGE",sProperty); /Q~gU<
Utility.log(sProperty); :Mm3 gW)
>.dWjb6t
hx/N1x
InputStream input = httpConnection.getInputStream(); >^XBa*4;Y
//logResponseHead(httpConnection); EkGQ(fZ1|
G8Nt 8U~
6c^e\0q
byte[] b = new byte[1024]; h3dsd
int nRead; dnV[ P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [<'-yQ{l\
{ dCj,b$
nStartPos += fileAccessI.write(b,0,nRead); [D*UT#FM
//if(nThreadID == 1) ?c0xRO%y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rvr-XGK36\
} Vp>|hj po
?nP*\8
t3dlS`O
Utility.log("Thread " + nThreadID + " is over!"); lFTF ,G
bDownOver = true; +3KEzo1=)
//nPos = fileAccessI.write (b,0,nRead); |&Ym@Jyj
} P-ri=E}>
catch(Exception e){e.printStackTrace ();} SM`w;?L:?
} K_K5'2dE
} wm+/e#'&
/4xki_}
k?2k'2dy
//打印回应的头信息 R'S0 zp6
public void logResponseHead(HttpURLConnection con) sg+uBCGB
{ |=&cQRY!p
for(int i=1;;i++) Yv:55+e!|
{ B/` !K
String header=con.getHeaderFieldKey(i); :O(^w}sle
if(header!=null) Ot]Ru,y->+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <vXGi
Utility.log(header+" : "+con.getHeaderField(header)); W3iZ|[E;
else vap,y $C
break; H<^/Ati,|
} f%V4pzOc"
} 8=]Tr3
\?jeWyo
3Kn_mL3V-
public void splitterStop() D}vmwg@3
{ (&!NC[n,
bStop = true; &gjF4~W]
} fJ ,1Ef;Z
P{u0ftyX}
e[8LmuIZ
} 5|1T}Z#;
Ox@sI:CT
~q~MoN<R
/* CxfRVL`7
**FileAccess.java &B|D;|7H
*//文件访问(定位，写) mQY_`&Jq
package NetFox; s&NX@
import java.io.*; ,u/aT5\_
rta:f800z
EI^06q4x
public class FileAccessI implements Serializable{ eGX%KT"O
-Y='_4s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =MvjLh"s
RandomAccessFile oSavedFile; FHC\?Cg
long nPos; f/V 2f].
kS!viJwtT
Hbpqyl%O>
public FileAccessI() throws IOException C?2'+K
{ 0fYj4`4=n
this("",0); bP^Je&nS*
} d$ ^ ,bL2p
$ >EYhLBa
t1%_DPD%W
public FileAccessI(String sName,long nPos) throws IOException 2"B_At
{ ~I}&V T
oSavedFile = new RandomAccessFile(sName,"rw"); o";Z$tAJkC
this.nPos = nPos; rf$X>M=G
oSavedFile.seek(nPos); 3:C oZ
} 7R\oj8[
3#TV5+x*"`
*q1%IJ
public synchronized int write(byte[] b,int nStart,int nLen) beu\cV3
{ =|YxDas
int n = -1; 8:/e GM
try{ 9F*+YG!
oSavedFile.write(b,nStart,nLen); QI3Nc8t_2
n = nLen; di>cMS 4 c
} IzpZwx^3''
catch(IOException e) 1Y]TA3:
{ UNkCL4N
e.printStackTrace (); oDU ;E
} qIAoA.
Yx>"bv
nTz6LVF
return n; J;f!!<l\
} P`e!Z:
-Q U^c2
fOMvj%T@2
} QJ7L7S
%C=]1Q=T)
sn?]n~z
/* aM$W*-Y
**SiteInfoBean.java ~mR'Q-hi<
*/ ](^(=%
package NetFox; [/BE8]M~
HVC>9_:]
Z%n(O(^L
public class SiteInfoBean { ]| +<P-
mb!9&&2-t
W[^qa5W<FB
private String sSiteURL; //Site's URL B0ndcB-
private String sFilePath; //Saved File's Path w#g#8o>'
private String sFileName; //Saved File's Name Yp:KI7
private int nSplitter; //Count of Splited Downloading File T0]*{k(FR
zD?K>I=
Jzp#bgq}|
public SiteInfoBean() <bD>m[8,
{//nSplitter的缺省值为5 aN,M64F
//default value of nSplitter is 5 uSR~@Lj ~
this("","","",5); 'gt-s547
} j8sH#b7Z
IEcf
MXyaE~LK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5Fz.Y}
{ <$hu
sSiteURL= sURL; "hdvHUz
sFilePath = sPath; o#hjvg
sFileName = sName; ]J#9\4Sq
this.nSplitter = nSpiltter; FEJ~k1z
A<B=f<N3gV
E.U_W
} O/!bG~\Y
5P'p2x#U
wGZR31
public String getSSiteURL() \{EpduwZ
{ &wB\ ~Ie-
return sSiteURL; :(H>2xS,s
} %H+\>raLz
b%Eei2Gm%
>B>CB3U
public void setSSiteURL(String value) BY]i;GVq
{ p^pOuy8
sSiteURL = value; OGY"<YH6
} chEn|>~
A=j0On
Wn>@9"
public String getSFilePath() L=8+_0
{ ?Q72;/$
return sFilePath; i:l<C
} ":nQgV\9
$*W6A/%O
~M(5Ho
public void setSFilePath(String value) _fwb!T}$
{ h/,${,}J
sFilePath = value; JO@|*/mL
} LE%7DW(
_H^^y$+1
SKW%X8
public String getSFileName() L-9~uM3@\
{ ~I(Hc.Q
return sFileName; x+G0J8cW
} 9RWkm%?
-$,%f?
3bNIZ#`|MB
public void setSFileName(String value) VG>vn`x>a
{ Z,.G%"i3C
sFileName = value; ?r2#.W
} $8crN$ye
0=="^t_
c1xrn4f@a
public int getNSplitter() *;XWLd#
{ Y+3!f#exm
return nSplitter; $:of=WTY(
} 8#D:H/`'
`4 y]Z)
8#&q$kE
public void setNSplitter(int nCount) s-ZI ^I2\
{ K2<~(78C
nSplitter = nCount; z~\t|Z]G,|
} EbZdas!l
} 5p +ZD7jK
3or\:
#YSF&*
/* &ciN@nJ|$z
**Utility.java S{K0.<,E
*/ 8/"fWm/
package NetFox; q-Qxbg[>e
P6Mhbmt9*
7FF-*2@
public class Utility { _qWliw:0#
Gc$gJnQio
WX4;l(PL=
public Utility() y4Er@8I`
{ wIf {6z{
,]5Ic.};p
_xLHrT!y
} X1vNF|o~
HBB{m
//线程睡眠 DSxUdEK6
public static void sleep(int nSecond) .6~`Ubr}E
{ **>/}.%?K
try{ /xJqJ_70X
Thread.sleep(nSecond); LZ~"VV^
} $M:3XAN
catch(Exception e) Em7 WDu0
{ J# kl 7
e.printStackTrace (); n& $^04+i
} !JBae2Z
} {5|("0[F
|([R'Orm
//日志 /1`cRyS
public static void log(String sMsg) }!TL2er_
{ Bg8#qv
System.err.println(sMsg); z5]bia,
} *{o UWt
=?X$Yaw*
` rm?a0
public static void log(int sMsg) 90xk$3(
{ BN,>&1I
System.err.println(sMsg); lHB) b}7E
} [ REf>_R
} *xR 2)u
a8AYcEb
yA[({2%
/* x&A vUJ
**TestMethod.java ,1/}^f6
*/ [4J6iF
package NetFox; De_CF8
V#q}Wysft
MP>n)!R[`
public class TestMethod { e&9F\e
@uH#qg7
_DP|-bp D
public TestMethod() ~svO*o Wa
{ ///xx/weblogic60b2_win.exe Vc3mp;6"
try{ gX5&d\y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H0"=Vs,n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "gW7<ilw
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5f:DN\ ]
fileFetch.start(); XUV!C7
} i.1U|Pi
catch(Exception e){e.printStackTrace ();} DDd|T;8
StYzGJ
VK3it3FI>3
} o5aLUWi-
9TxyZL
as"N=\N
public static void main(String[] args) /\Q*MLwD
{ =wq;@'U
new TestMethod(); r(2R<A
} 'PWQnt_U
} s4T}Bsr
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