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)); n ua8y(W
} #`L}.
for(int i=0;i<nEndPos.length-1;i++) g*c\'~f;
{ 0V,MDX}#_
nEndPos = nStartPos[i+1]; ~S_IU">E
} irw 7
nEndPos[nEndPos.length-1] = nFileLength; Z *<x
} `8.32@rUB.
} {2clOUi
pfQZ|*>lkb
l}-`E@w
//启动子线程 /\$|D&e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SF7b1jr
for(int i=0;i<nStartPos.length;i++) "XsY~
{ A-Pwi.$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W#_gvW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KdMA58)
nStartPos,nEndPos,i); FRQ("6(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -LK(C`gB
fileSplitterFetch.start(); O8N0]Mz
} h:;eh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `"":
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .:!x*v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }J'wz;t1
nEndPos = " + nFileLength); G/3lX^Z>
// fileSplitterFetch[nPos.length-1].start(); >37}JUG
UXB8sS*wQ?
fvMhq:Bu
//等待子线程结束 ',s7h"
//int count = 0; U105u.#7
//是否结束while循环 !,!tNs1 K
boolean breakWhile = false; E^W*'D
\0T*msYQ
%vYlu%c<
while(!bStop) 1gej$G@
{ (wF$"c3'{
write_nPos(); $v@$oPmMj
Utility.sleep(500); =V]i?31[
breakWhile = true; Q09~vFBg
58'y~Ou
H>X1(sh#}
for(int i=0;i<nStartPos.length;i++) 7tKft
{ g}r5ohqC#
if(!fileSplitterFetch.bDownOver) {&qsh9ob
{ ?o5#Ve$-X
breakWhile = false; G/44gKl
break; ^l9 *h
} jV&W[xKa
} E?D{/k,zZ
if(breakWhile) FGhrf
break; 0M2+?aKif
Xtnmh)'K~#
'z!#E!i
//count++; f|1FqL+T]
//if(count>4) <f{`}drp/
// siteStop(); Cy'W!qH
} <%uZwk>#
rWKLxK4oU
k\Tm?^L)
System.err.println("文件下载结束！"); `9{C/qB
} sc>)X{eb
catch(Exception e){e.printStackTrace ();} u`,R0=<4
} A_U0HVx_
K :ptfD
Bin&:%|9?
//获得文件长度 3"D00~
public long getFileSize() x+`3G.
{ R:x04!}
int nFileLength = -1; c}s3c >`d
try{ |sM#g1D@
URL url = new URL(siteInfoBean.getSSiteURL()); [N+ruc?)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pvxqeC9`
httpConnection.setRequestProperty("User-Agent","NetFox"); g c=|<(
tzJtd
=DwH*U/YR
int responseCode=httpConnection.getResponseCode(); "z4E|s
if(responseCode>=400) UpBYL?+L
{ q`zR6
processErrorCode(responseCode); aKr4E3`
return -2; //-2 represent access is error :8T@96]P
} o%Q2.
.sMi"gg
?IO/zkeXg
String sHeader; <WkLwP3^
:b)@h|4
H}rP{`m
for(int i=1;;i++) $R36`wk
{ * OFT)S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #]^`BQ>
//Utility.log(in.readLine()); ;yrcH+I$_
sHeader=httpConnection.getHeaderFieldKey(i); ]2 N';(R
if(sHeader!=null) oD`BX
{ |8ZAE%/d
if(sHeader.equals("Content-Length")) zaPR>:r0
{ THZ3%o=X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l]cQ7g5
break; cn{l %6K
} 4}j}8y2)H
} oWOZ0]H1
else :g_ +{4
break; Id1[}B-T
} <3OV
} oaE3Aa
catch(IOException e){e.printStackTrace ();} aS2 Y6
catch(Exception e){e.printStackTrace ();} Gu=bPQOj
ZrBxEf$f
qxh\umm+2
Utility.log(nFileLength); hw2Hn
vkLG<Y
['j,S<Bu~
return nFileLength; qI:wm=
} huE#VY /t
c:5BQr '
CPG %*E*
//保存下载信息（文件指针位置） 4mg&H0 !
private void write_nPos() I&0yUhn
{ z/=v@@tj
try{ [g_@<?zg
output = new DataOutputStream(new FileOutputStream(tmpFile)); iV=#'yY
output.writeInt(nStartPos.length); >LSA?dy!?
for(int i=0;i<nStartPos.length;i++) ^,gKA\Wli
{ suwj1qYJ4
// output.writeLong(nPos); #.RI9B
output.writeLong(fileSplitterFetch.nStartPos); TvR2lP
output.writeLong(fileSplitterFetch.nEndPos); va.wdk g
} 1GxYuTZ{
output.close(); %/y/,yd
} Qt$Q/<8U
catch(IOException e){e.printStackTrace ();} ADDpm-]
catch(Exception e){e.printStackTrace ();} V RL6F2 >6
} #S5vX<"9
,MJZ*"V/3
QX4I+x~oo\
//读取保存的下载信息（文件指针位置） CT : ac64
private void read_nPos() Jor?;qo3
{ Sn]A0J_
try{ :?TV6M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h4CB1K
int nCount = input.readInt(); 9}-,dgAB
nStartPos = new long[nCount]; i || /=ai
nEndPos = new long[nCount]; +^.(3Aw
for(int i=0;i<nStartPos.length;i++) k&2I(2S
{ 6S(3tvUr
nStartPos = input.readLong(); ~kL":C>2
nEndPos = input.readLong(); <8Ad\MU
} Hd:ZE::Q'#
input.close(); 8K qv)FjB
} +W}f0@#)<
catch(IOException e){e.printStackTrace ();} 8PQ& 7o
catch(Exception e){e.printStackTrace ();} rRMC<.=
} D 6(w}W
0y(d|;':
g7F>o76M
private void processErrorCode(int nErrorCode) {974m` 5
{ p|Ln;aYc
System.err.println("Error Code : " + nErrorCode); -Fb/GZt|
} |Q{l]D
l4; LV7Ji
CyE.q^Wm
//停止文件下载 5d)G30
public void siteStop() K3jno+U&
{ Qtk'^Fc
bStop = true; #2pgh?
for(int i=0;i<nStartPos.length;i++) TGg*(6'z
fileSplitterFetch.splitterStop(); Y$N|p{Z
>IRo]-,
A2B&X}K|U
} Dv$xP)./
} 1vobfZ-w9
//负责部分文件的抓取 1$c*/Tc:E
**FileSplitterFetch.java 0j3j/={|.1
*/ fUa`YryQ
package NetFox; U_w)*)F
-wY6da*.W
2WKA] l;
import java.io.*; qoEOM%dAqV
import java.net.*; FrB19
\PL92HV
1aSuRa
public class FileSplitterFetch extends Thread { Jg7IGU(dct
ek.L(n,J|
-2f0CAh~
String sURL; //File URL pnf3YuB
long nStartPos; //File Snippet Start Position }=wSfr9g
long nEndPos; //File Snippet End Position iXBc ~S
int nThreadID; //Thread's ID O^LzS&I*
boolean bDownOver = false; //Downing is over 'A4Lr
boolean bStop = false; //Stop identical q+SDJ?v
FileAccessI fileAccessI = null; //File Access interface ?L|@{RS{|
7^S&g.A
H>M0GL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y1P?A]v
{ ~jJu*s$?
this.sURL = sURL; gp;(M~we
this.nStartPos = nStart; wjY3:S~
this.nEndPos = nEnd; <;=X7l+
nThreadID = id; X\M0Q%8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dlyE2MiL:
} eE1w<] Eg
D`Fl*Wc4H
y9:|}Vh
public void run() #*?a"
{ yBeSvsm
while(nStartPos < nEndPos && !bStop) F+9|D
{ ;IwC`!(#
Jzh_`jW0l
6=FF*"-6E
try{ ^lbOv}C*
URL url = new URL(sURL); DLf6D |"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZcIwyh(`
httpConnection.setRequestProperty("User-Agent","NetFox"); GQT|T0>Ro
String sProperty = "bytes="+nStartPos+"-"; =TU"B-*
httpConnection.setRequestProperty("RANGE",sProperty); UtY<R
Utility.log(sProperty); p-MQI }
4_)@Nq
5q@o,d
InputStream input = httpConnection.getInputStream(); v;irk<5
//logResponseHead(httpConnection); t hTY('m
h2K1|PUKl[
q^k6.5*"
byte[] b = new byte[1024]; L7C!rS
int nRead; J$@3,=L6V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ga0W;Vq&X
{ , En D3 |
nStartPos += fileAccessI.write(b,0,nRead); "m(HQ5e)*
//if(nThreadID == 1) nQb{/ TqC'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e*=N\$
} ,"5Fw4G6*
V]<J^m8
8.F]&D0p8
Utility.log("Thread " + nThreadID + " is over!"); `+{|k)2B
bDownOver = true; #|xK>;
//nPos = fileAccessI.write (b,0,nRead); _L<IxOZh+
} mi6<;N2w|
catch(Exception e){e.printStackTrace ();} /a(xUm@.
} [$ vAjP
} 7P|GKN~
eBlVb*nmq
Sc`W'q^X
//打印回应的头信息 aU4v-9@U8
public void logResponseHead(HttpURLConnection con) u#ag|b/C:
{ ;gP@d`s
for(int i=1;;i++) $x)C_WZj?
{ %\Z{~(&-v
String header=con.getHeaderFieldKey(i); OxZw;yD
if(header!=null) L?23Av0W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ag+$qU
Utility.log(header+" : "+con.getHeaderField(header)); Rbm"Qz
else 37Q9goMov
break; Gn>#Mvq
} 6p=AzojoB
} KD11<&4_x
` zeZ7:
}YfM<
public void splitterStop() TGlIt<&
{ nB[Aw7^|A
bStop = true; 0hp*(, L
} j|N;&s`
tg_v\n
gf$5pp-
} KU|dw^Yk
sL[&y'+
1\X1G>60m
/* *F42GiBZR
**FileAccess.java URz$hcI8
*//文件访问(定位，写) 8vjaQ5
package NetFox; D~P I_*h.
import java.io.*; fo;Ftf0
no~hYyW2
HN9!~G
public class FileAccessI implements Serializable{ mI_ ?hl?Pv
iaPrkMhd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wi-O}*O
RandomAccessFile oSavedFile; zUF%`CR
long nPos; R2|v[nh
N|WZk2 "
K; ,2ag
public FileAccessI() throws IOException :FcYjw
{ @8a1a3_F
this("",0); |1iCt1~U
} z~i=\/~tZ
Yx>y(Whu.
16Ym*kWIps
public FileAccessI(String sName,long nPos) throws IOException V<A_c^unO
{ $iu{u|VSu
oSavedFile = new RandomAccessFile(sName,"rw"); 4=^_ 4o2
this.nPos = nPos; zGjf7VV2a
oSavedFile.seek(nPos); 3\j{*f$J
} kGR5!8$z
>|1.Z'r/
0.7*2s-
public synchronized int write(byte[] b,int nStart,int nLen) U{6i5;F#H
{ aZ"9)RJe
int n = -1; 1iyd{r7|
try{ F0 x5(lpQ
oSavedFile.write(b,nStart,nLen); ?nN3K
n = nLen; $Hh3*reSg-
} zX*+J"x
catch(IOException e) MLf,5f;e
{ !|}(tqt
e.printStackTrace (); A14}
} Hyx%FN=
&.~Xl:lq
s4h3mypw
return n; ME4Ir
} t_%6,?S6
MDI[TNYG
rWzw7T~
} 1<g,1TR
aMI\gCB/
g|L" |Q
/* J}a 8N.S
**SiteInfoBean.java 46^LPC"x
*/ "_dh6naZX
package NetFox; 2O}UVp>
fS2 ^$"B|
H=Sy.
public class SiteInfoBean { yv2BbrYyy
}H2<w-,+
5[NF
private String sSiteURL; //Site's URL nW?DlECo?
private String sFilePath; //Saved File's Path z@5t7e)!R
private String sFileName; //Saved File's Name (9R;a np
private int nSplitter; //Count of Splited Downloading File ~{MmUp rS
u7R:7$H
pI*/-!I
public SiteInfoBean() c}(fmJB&(
{//nSplitter的缺省值为5 ,2hZtJ<A
//default value of nSplitter is 5 ;`ZGiax
this("","","",5); Id-?her>B
} V0yQ
t<'-?B2g
^@V$'Bk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^}nz^+R
{ `72 uf<YQ
sSiteURL= sURL; v}w=I}<x
sFilePath = sPath; J<8~w; i
sFileName = sName; +o&&5&HR
this.nSplitter = nSpiltter; %*d(1?\o
DxX333vC
=+@IpXj
} 5\1C@d
B1\@ n$
@#sBom+K`
public String getSSiteURL() |4RuT .-o
{ 7kbeAJ+{
return sSiteURL; ZLK@x.=
} )'\pa2
%*4Gx +b
w783e
public void setSSiteURL(String value) n- cEa/g
{ 49Sq)jd<
sSiteURL = value; uYk4qorA
} doJ\7c5uU
MN|8(f5Gs
-26GOS_8z
public String getSFilePath() T/8*c0mU
{ 9n][#I)a3
return sFilePath; zD8q(]: A
} OW$? 6
"f'pa&oHi
bvM\Qzc!<3
public void setSFilePath(String value) |UbwPL_L
{ xxnMvL;
sFilePath = value; $O|J8;"v
} Rxe sK
6.fahg?E
+{* @36A5A
public String getSFileName() Q=hf,/N
{ xv! QO
return sFileName; 3W*O%9t7
} M[9]t("
C+/D!ZH%P
O{" A3f
public void setSFileName(String value) ((BuBu>
{ nx<q]Juv\
sFileName = value; gB\ a
} 0>jo+b\D$
vF45tw
71GLqn?
public int getNSplitter() Oh9jr"Gm=
{ 4%5H<:V7
return nSplitter; n ETm"
} XO |U4#ya
r{~K8!=oU]
"WKE%f
public void setNSplitter(int nCount) J?Kgev%
{ !?Tu pi
nSplitter = nCount; n1Ag o3NM
} 7QdU|1]
} E%L]ifA9!
,nMc. G3
$~,]F
/* qwka77nNT
**Utility.java 8.vPh
*/ GvQ|+vC
package NetFox; 'WH@Zk/l
M5OH-'
w+vYD2a
public class Utility { d7o~$4h|
kTQ`$V(>&
'ad|@Bh
public Utility() m9^?p
{ #+Lo&%p#3
h#bpog
1a{~B#
} [MM11K
h~$Q\WCm#
//线程睡眠 @vf{_g<
public static void sleep(int nSecond) 7Kx3G{5ja
{ yc,Qz.+g
try{ Z@j$i\,`
Thread.sleep(nSecond); E&k{ubcT
} 6ju+#]T
catch(Exception e) r\+AeCyb"p
{ "HR &Rf k
e.printStackTrace (); ;FYiXK%
} luZqW`?Bt
} Yyl2J#$!
k|l"Rh<\~
//日志 p\e*eV1dxx
public static void log(String sMsg) ;8sEE?C$g
{ o?P(Fuf
System.err.println(sMsg); }#@P+T:b
} ]3#_BL)M8p
;2RCgX!'%
BzH7E[R49
public static void log(int sMsg) (mHFyEG
{ yS/ovd
System.err.println(sMsg); <PkDfMx2
} _-g:T&#
} #'z\[^vp
57+^T}/>
,<zZKR_
/* lqPRUkin
**TestMethod.java iXC/? EK4
*/ =1n>vUW+J
package NetFox; b]6;:Q!d
"/hs@4{u9
,%dn)gt7
public class TestMethod { $y=sT({VVe
-GP+e`d
s@o"V >t
public TestMethod() )@Xdr0
{ ///xx/weblogic60b2_win.exe Y_PCL9G{p
try{ 5n.4>yOY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^f!d8 V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !0`ZK-nA6
SiteFileFetch fileFetch = new SiteFileFetch(bean); : M0LAN
fileFetch.start(); C bG"8F|4
} @]*z!>1
catch(Exception e){e.printStackTrace ();} a|?CC/Ra
hUGIy(
7"4|`y^#
} x)#k$QU
1aYO:ZPy
9>@_};l
public static void main(String[] args) >!? f6 {\|
{ 40%p lNPj
new TestMethod(); !^q<)!9<EO
} @u6#Tvxy[
} ZWf{!L,@Z
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