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)); At"$Cu!k
} HT6 [Z1
for(int i=0;i<nEndPos.length-1;i++) #n'.a1R
{ v&|65[<
nEndPos = nStartPos[i+1]; `Bw]PO
} "bIb?e2h9G
nEndPos[nEndPos.length-1] = nFileLength; X+C*+k,z
} a8f#q]TyQ
} %\v8FCb
aknIrblS\
VD~5]TQ
//启动子线程 \4L ur
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0eNdKE
for(int i=0;i<nStartPos.length;i++) %W"u4 NT7
{ uMEM7$o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vY-CXWC7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \ dFE.4
nStartPos,nEndPos,i); V6X )L>!xx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '< U&8?S
fileSplitterFetch.start(); -BH/)$-$
} O|V0WiY<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !,$#i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7ocUFY0"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Xj 1Oxm42
nEndPos = " + nFileLength); :YI5O/gsk?
// fileSplitterFetch[nPos.length-1].start(); =3.dgtH
wX0D^)NtF
kU[hB1D5
//等待子线程结束 F#gA2VCm
//int count = 0; l!f_ +lv
//是否结束while循环 Qds<j{2
boolean breakWhile = false; rXi&8R[
[zx|3wWAX-
l S)^8
while(!bStop) '9zW#b
{ E.h
write_nPos(); pM?~AYWb
Utility.sleep(500); oI;ho6y)
breakWhile = true; V 9Qt;]mQ
byxlC?q7
t,?,T~#9
for(int i=0;i<nStartPos.length;i++) q< XFw-Pv
{ DjM*U52Yfj
if(!fileSplitterFetch.bDownOver) sfyLG3$/
{ LN|(Z*
breakWhile = false; 5rows]EJJl
break; { c#US
} Y(g_h:lf,]
} Z 2N6r6
if(breakWhile) Vr EGR$
break; w$:\!FImx
gx.\H3y
In1W/?
//count++; ;OlnIxH(W
//if(count>4) 1'qXT{f/~
// siteStop(); ~.:{ Ik]
} :C*}Yg
]E-/}Ysz
^OKm (
System.err.println("文件下载结束！"); f~NS{gL*
} J8emz8J
catch(Exception e){e.printStackTrace ();} N1Vj;-
} A0<g8pv
$@L;j
k|/VNV( =0
//获得文件长度 /oT~CB..
public long getFileSize() ZAr6RRv ^
{ H~Uf2A)C
int nFileLength = -1; Sb[>R(0:
try{ k24I1DlR8
URL url = new URL(siteInfoBean.getSSiteURL()); \J+a7N8m,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !|Q&4NS
httpConnection.setRequestProperty("User-Agent","NetFox"); X5iD<Lh
~JT`q:l-q
] 0X|_bU
int responseCode=httpConnection.getResponseCode(); wH ,PA:
if(responseCode>=400) G}8tFo.d1
{ <D.E.^Y
processErrorCode(responseCode); !-lI<$S:
return -2; //-2 represent access is error N;3!oo4
} sfX~X/
uOA/r@7I}S
k+9F;p7
String sHeader; g>VtPS5 y
q-(~w!e
6{I7)@>N
for(int i=1;;i++) $VmV>NZ
{ e3ZRL91c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F_qApyU,7
//Utility.log(in.readLine()); rr tMd
sHeader=httpConnection.getHeaderFieldKey(i); k*C69
if(sHeader!=null) l$gJ^Wf2gY
{ A;;#]]48
if(sHeader.equals("Content-Length")) =3035{\
{ nX (bVT4i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z?+ )ox
break; ,7B7X)m{3
} P8YnKyI,.
} LA6XTgcu
else g=\(%zfsxr
break; !0l|[c4 e>
} L ci?
} SSI> +A
catch(IOException e){e.printStackTrace ();} ]Ozz"4Z
catch(Exception e){e.printStackTrace ();} X"TL'"?fo
nk|(cyt)
vFe=AY<Rt|
Utility.log(nFileLength); ~T@E")uR
E<yQB39
(d&" @
return nFileLength; &`m.]RV
} `:iMGqZN
96\FJHtZ
1|p\rHGd
//保存下载信息（文件指针位置） <sC(a7i1
private void write_nPos() fQ9af)d
{ )zWu\JRp
try{ (Mfqzy
output = new DataOutputStream(new FileOutputStream(tmpFile)); TIp\-
output.writeInt(nStartPos.length); .uA O.<
for(int i=0;i<nStartPos.length;i++) %`$bQU
{ Z2W&_(^.h
// output.writeLong(nPos); s>DFAu!
output.writeLong(fileSplitterFetch.nStartPos); W>' DQB
output.writeLong(fileSplitterFetch.nEndPos); XIMh<
} 570ja7C:
output.close(); >7WT4l)7!b
} iX?j"=!
catch(IOException e){e.printStackTrace ();} .Yk}iHcW.
catch(Exception e){e.printStackTrace ();} 4M"'B A<
} Ue9d0#9
|}77'w :
'@24<T]
//读取保存的下载信息（文件指针位置） k x:+mF
private void read_nPos() 8;qOsV)UDT
{ mg*iW55g
try{ NkUY_rKPb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F42^Uoaz
int nCount = input.readInt(); ;R+Gf!1
nStartPos = new long[nCount]; s1OSuSL>
nEndPos = new long[nCount]; ~Xx}:@Ld
for(int i=0;i<nStartPos.length;i++) P=}l.R*1G
{ i{}m 8K)
nStartPos = input.readLong(); 3x(Y+ ymP
nEndPos = input.readLong(); bSTori5
} "A[.7w
input.close(); {v!w2p@
} =&g:dX|q8
catch(IOException e){e.printStackTrace ();} @[D5{v)S
catch(Exception e){e.printStackTrace ();} C,ldi"|
} lGet)/w;c
ZW))Mx#K=T
E7$ aT^
private void processErrorCode(int nErrorCode) LI-ewea
{ tG]W!\C'h
System.err.println("Error Code : " + nErrorCode); [Qr_0O
} un\o&0}
^d>m`*px
$m)eO8S+
//停止文件下载 .&u @-Vm
public void siteStop() ^Cp;#|g,
{ <DqFfrpc
bStop = true; Urw =a$
for(int i=0;i<nStartPos.length;i++) #+i5'p(4
fileSplitterFetch.splitterStop(); MNh:NFCRA
{%2p(5FB
5bZ0}^FYF
} JiqhCt\
} rxxVLW
//负责部分文件的抓取 Eb,M+c?
**FileSplitterFetch.java oVl:g:K40
*/ )3F}IgD
package NetFox; A _7I0^
`MT.<5H
P{RGW.Ci@
import java.io.*; k(`>(w
import java.net.*; e0C_ NFS+
\]FPv7!
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public class FileSplitterFetch extends Thread { ndyIsR
./tZ*sP:
JrxQ.,*i
String sURL; //File URL :MYLap&L&
long nStartPos; //File Snippet Start Position zW?=^bE
long nEndPos; //File Snippet End Position ~- aUw}U
int nThreadID; //Thread's ID 2*W|s7cc
boolean bDownOver = false; //Downing is over uKY1AC__
boolean bStop = false; //Stop identical L{ej<0yr
FileAccessI fileAccessI = null; //File Access interface IM,d6lN6s
>z3l@
nr>Yj?la
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0#5&*
{ a U<+ `
this.sURL = sURL; h5vetci/
this.nStartPos = nStart; 6R2F,b(_
this.nEndPos = nEnd; MO1H?Uhx
nThreadID = id; jJ RaY3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6EY0Fjsi
} O*F= xG
N+]HJ`K
6 {`J I
public void run() [$]-W$j+
{ A(XX2f!i
while(nStartPos < nEndPos && !bStop) }Oe4wEYN)
{ -g"Wi@Qr
>N0L
cI6Td*vM
try{ ?:5/4YC
URL url = new URL(sURL); (s+}l?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tI0D{Xrc
httpConnection.setRequestProperty("User-Agent","NetFox"); (j%"iQD
String sProperty = "bytes="+nStartPos+"-"; yJw.z#bB#
httpConnection.setRequestProperty("RANGE",sProperty); sVlQ5M oo(
Utility.log(sProperty); #|V)>")
U$=Z`^<
fn5!Nr ,
InputStream input = httpConnection.getInputStream(); SJ,];mC0
//logResponseHead(httpConnection); D;:p6q}hT
l?X)]1
P#:nXc$
byte[] b = new byte[1024]; 9*s:Vff{
int nRead; Q{ g{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eS%8WmCV9<
{ fG@]G9Z
nStartPos += fileAccessI.write(b,0,nRead); ]P_yN:~
//if(nThreadID == 1) zq$0 ?vGd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bdBLfWe
} ;e2D}
.8|"@
qP9`p4c8i
Utility.log("Thread " + nThreadID + " is over!"); b$/7rVH!
bDownOver = true; y?iW^>|?L=
//nPos = fileAccessI.write (b,0,nRead); R_80J=%0
} s?9`dv}P
catch(Exception e){e.printStackTrace ();} /.UISArH
} S2 -J1x2N
} (V}?y:)
)ItW}1[I
nx!+:P ,
//打印回应的头信息 >+%0|6VSb
public void logResponseHead(HttpURLConnection con) H@|m^1
{ Kciz^)'Z
for(int i=1;;i++) IR8qFWDZ
{ 2%-/}'G*
String header=con.getHeaderFieldKey(i); RRpCWcIv"
if(header!=null) yx<-M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4^^=^c
Utility.log(header+" : "+con.getHeaderField(header)); jU{~3Gn?
else XCGK&OGI
break; 0Fs2* FS
} "JgwL_2
} _Q*,~ z~
OL.{lKJ3DV
cVaGgP}\
public void splitterStop() rj29$d?Y9
{ rLp0)Go
bStop = true; <. V*]g/;
} ~T=a]V
\O*W/9 +
&<(&u`S
} ~qE:Nz0@
!#4b#l(e6
1#XZVp;M
/* ddlF4L_
**FileAccess.java j9f QV
*//文件访问(定位，写) Wm!cjGK
package NetFox; \5#eBJ
import java.io.*; IRsyy\[kp8
h\|T(597.
nKch:g
public class FileAccessI implements Serializable{ {T5u"U4
}(#;{_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F ^)( 7}ph
RandomAccessFile oSavedFile; -{p~sRc&
long nPos; 5[`f(;
G4EuW *~
dlDO?T
public FileAccessI() throws IOException [n$6T
{ &3 x [0DV
this("",0); K*tomy
} xE6hE'rh.O
p%+'iDb
_"#n%@
public FileAccessI(String sName,long nPos) throws IOException }4q1"iMlO
{ N3\vd_D(
oSavedFile = new RandomAccessFile(sName,"rw"); T=[/x=
this.nPos = nPos; !wo
oSavedFile.seek(nPos); 50Ov>(f@7
} C|S~>4`
`>HrO}x^
kq>I?wg
public synchronized int write(byte[] b,int nStart,int nLen) &iaS3x
{ Pu,2a+0N
int n = -1; 3 t+1M
try{ V?n=yg
oSavedFile.write(b,nStart,nLen); 7J|nqr`>t
n = nLen; whQJWi=ck
} CS;4ysNf
catch(IOException e) 5M#LO@U
{ n}8}:3"
e.printStackTrace (); $OaxetPH
} {Lsl2@22
Bh65qHQO
E_#?;l>
return n; rs0Wy
} lB
HDj260a
a-NicjV#
} V=H:`n3k
Bm+Ca:p%
,Y7QmbX^
/* SL`nt
**SiteInfoBean.java Lv<vMIr
*/ ,#j'~-5
package NetFox; ^MvBW6#1
!d1a9los
_W>xFBy
public class SiteInfoBean { HnKXO
!9_'_8
,k}(]{ -
private String sSiteURL; //Site's URL R#W=*cN
private String sFilePath; //Saved File's Path G|z%T`!U1;
private String sFileName; //Saved File's Name #@P0i^pFTB
private int nSplitter; //Count of Splited Downloading File E^m;Ab=
M]SeNYDy
f%rZ2h)
public SiteInfoBean() wotw nE
{//nSplitter的缺省值为5 sAoxLI
//default value of nSplitter is 5 EvF[h:C2
this("","","",5); v4,Dt
} *$@u`nM
A}(o1wuw
FzG>iC}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %RzCJxT
{ EKEJ9Y+47H
sSiteURL= sURL; ?$VkMu$2k
sFilePath = sPath; M<P8u`)>4H
sFileName = sName; :a9
this.nSplitter = nSpiltter; tNz(s)
Sv!JA#Ag
==EB\>g|
} 4u#TKr.
Hz>Dp !
jW>K#vj
public String getSSiteURL() xL"O~jTS
{ d-TpY*v
return sSiteURL; DTHWL
} P=Su)c
z#2n+hwE
|^"0bu"
public void setSSiteURL(String value) S:1g(f*85
{ mp z3o\n
sSiteURL = value; ~JO.h$1C
} <jBRUa[j_
@4n>I+6*&
Z}.ZTEB
public String getSFilePath() Z{1B:aW
{ `UTUrM
return sFilePath; <(i5hmuVd
} ^,aI2vC
ER0B{b
`4g}(-
public void setSFilePath(String value) me-uPm
{ m~uT8R#$
sFilePath = value; L+}<gQJ(
} LL==2KNUo
w/*m_O\!
5GGO:
public String getSFileName() M~~)tJYsu
{ t(jE9t|2e6
return sFileName; w"C,oo3
} M{4XNE]m
kT:I.,N
nu(7YYCM$
public void setSFileName(String value) o=Y'ns^a(
{ ]J@-,FFC
sFileName = value; n]i#&[*A(
} mi[8O$^iJ
!s:e
'xEK0~awD
public int getNSplitter() IhOAMH1
{ ?:G 3U\M
return nSplitter; GxEShSGOE
} wxYGr`f
ZB`d&!W>
6@eF|GoP
public void setNSplitter(int nCount) :>U+HQll
{ E;[Uhh|78!
nSplitter = nCount; dT[JVl+3=
} h~ZLULW)B
} wE}Wh5
=[LorvX+
216$,4i
/* [2h.5.af
**Utility.java MdmN7>
*/ !#=3>\np+X
package NetFox; Gr#3GvL
u@CQ+pnf:(
gd*2*o$g(
public class Utility { :2K@{~8r
]qxl^Himq
Dp!91NgB p
public Utility() 8KYIHw
{ e.~11bx
,~DV0#"
ZvMU3])u
} P-3f51Q
=1@LMIi5x
//线程睡眠 EC 1|$Co
public static void sleep(int nSecond) 6|~^P!&
{ _^NyLI%
try{ t"Ah]sD
Thread.sleep(nSecond); cvG*p||
} Id&e'
catch(Exception e) MX8|;t
{ @`dlhz
e.printStackTrace (); *@H\J e`
} gKQV99
} W"GW[~ h
eLnS1w2
//日志 I7~) q`
public static void log(String sMsg) ~f[ Y;
{ k5Fj"U
System.err.println(sMsg); igW* {)h3
} |`t 6lVO,Z
X%3?sH
H!&_Tv[
public static void log(int sMsg) Tjhy@3
{ cR_pC 9z
System.err.println(sMsg); O^j*"#f
} &K{8- t
} ');vc~C
rQyjNh
-Ep#q&\
/* U||GeEd
**TestMethod.java =$fz</S=J
*/ KmTFJ,iM
package NetFox; w"wW0uE^
b^Re947{g
T7^;!;i`X
public class TestMethod { `Z8k#z'bN
<|jh3Hlp
<r.QS[:h
public TestMethod() owQ,op#
{ ///xx/weblogic60b2_win.exe IEMa/[n/
try{ -v.\W y~\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zh*D2/r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FK593z
SiteFileFetch fileFetch = new SiteFileFetch(bean); f?51sr
fileFetch.start(); dGn0-l'q
} eqsmv[
catch(Exception e){e.printStackTrace ();} j~G(7t
3ie k>'T
RYjK4xT?Y/
} }b&lHr'Uw
?VmgM"'md
mXOI"B9Sq
public static void main(String[] args) XFvl
{ L_RVHvA=M/
new TestMethod(); jr?/wtw
} ^2nrA pF
} %,_ZVgh0
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