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)); 6QHUBm2
} M"-53|#:w\
for(int i=0;i<nEndPos.length-1;i++) #p{8
{ 1@-l@ P
nEndPos = nStartPos[i+1]; ?iaO+G&|
} rIyIZWkI
nEndPos[nEndPos.length-1] = nFileLength; t[({KbIy
} / H GPy
} Qm[ )[M
p-oEoA
AHa]=ka>
//启动子线程 C-:|A* z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; < A`srmS?
for(int i=0;i<nStartPos.length;i++) )):D&wlq
{ ()Img.TIt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .<K9Zyi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p:|7d\r
nStartPos,nEndPos,i); F(U(b_DPM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V+u0J"/8
fileSplitterFetch.start(); 8`<3rj
} bHDZ=Ik
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZSwhI@|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 25vq#sS]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m9'bDyyK
nEndPos = " + nFileLength); ^MWp{E
// fileSplitterFetch[nPos.length-1].start(); mphs^k< Z
1<]?@[l<
;%AY#b4m
//等待子线程结束 T[ zEAj
//int count = 0; \ 6Y%z
//是否结束while循环 6m9\0)R
boolean breakWhile = false; DI :
`'rvDaP
xM&`>`;^e
while(!bStop) 4SkCV
{ EBmkKiI;
write_nPos(); ?;rRR48T9E
Utility.sleep(500); 9:!V":8q
breakWhile = true; >(gbUW
B.?@VF
4E$6&,\
for(int i=0;i<nStartPos.length;i++) ?R@u'4yK
{ V4*/t#L/
if(!fileSplitterFetch.bDownOver) bM,%+9oz;
{ Z%{`j!!p
breakWhile = false; [Z[ p@Ux
break; 2"Ki5
} BS?rKtdm(
} _:XX+3W7
if(breakWhile) gp\o|igT
break; %pxHGO=)E
GSGaYq
aqP"Y9l
//count++; s8*Q@0
//if(count>4) aO *][;0
// siteStop(); 7$kTeKiP
} +W|VCz
7MX5hZF"
:<6gP(
System.err.println("文件下载结束！"); _nIt4l7
} kc[<5^b5
catch(Exception e){e.printStackTrace ();} q$B|a5a?
} pQCW6X
_o6Zj1p
ib(4Y%U6~
//获得文件长度 7] >z e
public long getFileSize() P.Qz>c^-C
{ )9{!=k
int nFileLength = -1; D' h%.
try{ X$<CIZ
URL url = new URL(siteInfoBean.getSSiteURL()); /,9n1|FrG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AR)A <
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Q#3S
Y-y}gc_L
_lw:lZM?
int responseCode=httpConnection.getResponseCode(); wEix8Ow*
if(responseCode>=400) P7qzZ
{ k|rbh.Q
processErrorCode(responseCode); )tx!BJiZ[
return -2; //-2 represent access is error p v*f]Yzx
} 9,wU[=.0
Ix.Y_}
bl8y o4
String sHeader; E(an5x/r
V}/AQe2m&
R@[1a+}5
for(int i=1;;i++) UmP\;
{ -pN'r/$3V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j>O!|V
//Utility.log(in.readLine()); ugQySg>
sHeader=httpConnection.getHeaderFieldKey(i); GOY!()F
if(sHeader!=null) (p?B=
{ !?GW<Rh
if(sHeader.equals("Content-Length")) LE+#%>z>
{ 4^K<RSYs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jY$3
break; _vOSOnU
} Vdb X4^V
} ~J1UzUxX2
else K;~I;G
break; u[LsH
} 6;}W)S
} 0?,%B?A8O
catch(IOException e){e.printStackTrace ();} ?[hkh8|
catch(Exception e){e.printStackTrace ();} 90 pt'Jg
cD9axlJ
I~>Ye<g#
Utility.log(nFileLength); +`~kt4W
6F?U:N#<
71k>_'fl
return nFileLength; zy@ nBi^
} dJ=z'?|%g
tQ(gB_
2~!+EH
//保存下载信息（文件指针位置） &&|c-mD+*
private void write_nPos() QR[i9'`<
{ V?-OI>
try{ ^}<h_T?<_-
output = new DataOutputStream(new FileOutputStream(tmpFile)); l'#a2Pl
output.writeInt(nStartPos.length); )C#b83
for(int i=0;i<nStartPos.length;i++) 1|H(q
{ k`r`ZA(kQ-
// output.writeLong(nPos); =o,6iJ^?$m
output.writeLong(fileSplitterFetch.nStartPos); Qg gx:
output.writeLong(fileSplitterFetch.nEndPos); +Am\jsq
} KOVR=``"/
output.close(); W< :7z
} 4w(#`'I>
catch(IOException e){e.printStackTrace ();} 8Rd*`]@[pk
catch(Exception e){e.printStackTrace ();} [UYE.$Y#(
} PG'+vl
\t%rIr
m7.6;k.
//读取保存的下载信息（文件指针位置） +{H0$4y
private void read_nPos() )\fLS d
{ P~ODd(
try{ c>yqq'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); //-;uEO
int nCount = input.readInt(); U<.,"`=l
nStartPos = new long[nCount]; $g]'$PB
nEndPos = new long[nCount]; ])$Rw$`w
for(int i=0;i<nStartPos.length;i++) 'mE!,KeS;
{ t(5PKD#~Dc
nStartPos = input.readLong(); Zf8_ko;|:-
nEndPos = input.readLong(); 6,Y<1b*|Vo
} VgcLG ]tE[
input.close(); l5CFm8%
} x10u?@
catch(IOException e){e.printStackTrace ();} "'*w_H0
catch(Exception e){e.printStackTrace ();} okQ<_1e{
} J=AF`[
?bH!|aW(H
/nVGr]t_pj
private void processErrorCode(int nErrorCode) |lVoL.Z,0
{ \"?5CHz*
System.err.println("Error Code : " + nErrorCode); Z-rHYfa4
} TAKvE=a;
hScC<=W
.{ r %C4q9
//停止文件下载 @_C?M5v
public void siteStop() p2uZ*sY(D
{ pn-`QB:{h
bStop = true; 8;1,saA_9
for(int i=0;i<nStartPos.length;i++) !t!\b9=
fileSplitterFetch.splitterStop(); b[`fQv$G
2mfKy9QxO
fFJu]
} %<[U\TL`
} b*W01ist
//负责部分文件的抓取 8$V:+u
**FileSplitterFetch.java MtKM#@
*/ 'MY0v_
package NetFox; vZ/Bzy@|
a?ux
>`=<(8bu
import java.io.*; e)A-.SRiO$
import java.net.*; GR>kxYM%q
(bo-JOOdY(
>Eqr/~Q
public class FileSplitterFetch extends Thread { |++\"g
/O&{fo
,RIC _26
String sURL; //File URL B4 +A
long nStartPos; //File Snippet Start Position U)iq
long nEndPos; //File Snippet End Position s\3OqJo%)
int nThreadID; //Thread's ID fsz:A"0H
boolean bDownOver = false; //Downing is over 9@yi UX
boolean bStop = false; //Stop identical .p$tb2%r
FileAccessI fileAccessI = null; //File Access interface {bD:OF
p^THoF'~T
,)%$Zxng
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vG'I|OWg
{ b&\f 8xZ
this.sURL = sURL; {'$+?V"&
this.nStartPos = nStart; mo
this.nEndPos = nEnd; w
nThreadID = id; ^M~Z_CQL2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mq6TwM
} y)GH=@b
\:D"#s%x
u;3wg`e
public void run() ]x:>!y
{ 3T84f[CFJ
while(nStartPos < nEndPos && !bStop) br4?_,
{ 1XPYI
}\3jcnn
cPbAR'
try{ ?3Y~q;I]O
URL url = new URL(sURL); EEdU\9DH(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SKeX~uLz
httpConnection.setRequestProperty("User-Agent","NetFox"); w$4*/D}Y
String sProperty = "bytes="+nStartPos+"-"; {dXmSuO
httpConnection.setRequestProperty("RANGE",sProperty); }(/\vTn*1
Utility.log(sProperty); g=L80$1
(,OF<<OH
^g N/5
InputStream input = httpConnection.getInputStream(); \k>1q/T0V
//logResponseHead(httpConnection); ;\(X;kQi
Td,s"p>Vq
iWp 6^g
byte[] b = new byte[1024]; S\R5SRE
int nRead; + [~)a4#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KuJNKuHa.
{ 2pmqP-pKd
nStartPos += fileAccessI.write(b,0,nRead); UWo*%&J
//if(nThreadID == 1) GvI8W)d3,R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $~)YI/b
} W@FSQ8b>$m
0AD8X+M{P
,jq:%Y[KZ
Utility.log("Thread " + nThreadID + " is over!"); :b`ywSp`
bDownOver = true; 5N(OW:M
//nPos = fileAccessI.write (b,0,nRead); xZ(ryE%
} }BI|M_q.1~
catch(Exception e){e.printStackTrace ();} #6*20w_u
} iOJ5KXrAO
} k keDt+^
ODNZLCB~t
gAr=fq-|
//打印回应的头信息 ]8/g[Ii
public void logResponseHead(HttpURLConnection con) ToX--w4
{ Jp"yb`w
for(int i=1;;i++) o1Nfn'!3/>
{ &M{;[O{
String header=con.getHeaderFieldKey(i); L%;[tu(*
if(header!=null) ;LqpX!Pi f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3*=_vl3
Utility.log(header+" : "+con.getHeaderField(header)); /I &wh
else DPr~DO`b
break; RmRPR<vGW
} ve^gzE$<I
} yS1i$[JV
YF)k0bu&;
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public void splitterStop() ;cfPS
{ <S3s==Cg
bStop = true; u~7fK
} E<sd\~~A:
JA~q}C7A7o
Lu CiO
} X^Fc^U8
o[)*Y`xq<w
3?e~J"WXC5
/* c8LMvL
**FileAccess.java Zm*qV!
*//文件访问(定位，写) 7~Z(dTdSG
package NetFox; (0E<Fz V
import java.io.*; Jq?Fi'2F%
6bN8}\5
!<>*|a
public class FileAccessI implements Serializable{ L7]o^p{g}Q
'0w</g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i>O8q%BnJ
RandomAccessFile oSavedFile; Xo$SQ0K
long nPos; mDx=n.lIz
]=ADX}
RT|1M"?$
public FileAccessI() throws IOException .$fSWlM;
{ " v<O)1QT
this("",0); 9oYE
} 0D Lw
ohjl*dw
2Z>8ROv^X
public FileAccessI(String sName,long nPos) throws IOException Eq|5PE^7
{ }N&?8s=
oSavedFile = new RandomAccessFile(sName,"rw"); ?|~KF:,#}
this.nPos = nPos; z69u@
oSavedFile.seek(nPos); cn: L]%<
} 60 %VG
S~bhh&
C\4d.~C:w3
public synchronized int write(byte[] b,int nStart,int nLen) -^3uQa<zN^
{ -lrcb/)Gz
int n = -1; k~F;G=P
try{ nZ)E @
oSavedFile.write(b,nStart,nLen); \)?+6D'#
n = nLen; )-0+O=v
} /_qHF-
catch(IOException e) 3N5@<:2`
{ P=PeWX*L<Z
e.printStackTrace (); C]Y%dQh+a
} !_FTy^@c2
cyo[HI?WM
XFYa+]B2q
return n; C^;>HAK|F
} H+Aidsn
=X9fn
m/"([Y_
} -y>~ :.
<<b]v I
+#\7 #Y
/* ex BLj *]
**SiteInfoBean.java ?GlXxx=eV
*/ W*%(J$E
package NetFox; ]&N>F8.L+
TB-dV'w
XhA tf@n
public class SiteInfoBean { I{h KN V
0' oXA'L-J
F]t=5 -O<
private String sSiteURL; //Site's URL +u&[ j/
private String sFilePath; //Saved File's Path Paeq
private String sFileName; //Saved File's Name s/.P/g%tA>
private int nSplitter; //Count of Splited Downloading File wqi0%Cu*
Z~<=I }@
~>N63I6
public SiteInfoBean() *AP"[W
{//nSplitter的缺省值为5 F{.\i*$
//default value of nSplitter is 5 mz+UkA'
this("","","",5); fs?H
} ;6~5FTmV
Eh)VT{vp
l4dG=x}M]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Oi zj|'
{ z1]nC]2
sSiteURL= sURL; ;rF[y7\
sFilePath = sPath; S~hu(x#
sFileName = sName; 6ypLE@Mk
this.nSplitter = nSpiltter; .rITzwgB
1=7ASS9
UhrRB
} m"'}{3$%
\A,zwdt P
!\$V?*p7
public String getSSiteURL() W+/_0GgQ3
{ _m[DieR
return sSiteURL; >:4`y"0
} }i,r{Y]s]
&q@brX<,=
.6T0d 4,1
public void setSSiteURL(String value) Q4hY\\Hi
{ R :(-"GW'
sSiteURL = value; q2s0g*z
} d,?Tq
1.+6x4%rV
Fi67"*gE
public String getSFilePath() N'WC!K.e
{ J{.UUw9Agd
return sFilePath; |35OA/O?X
} s'oNW
tv.<pP9-C
NPS*0y/
public void setSFilePath(String value) #4b]j".P!n
{ TYb$+uY
sFilePath = value; 3fp&iz
} n=bdV(?4
7KX27.~F
o{! :N>(
public String getSFileName() ! xG*W6IT
{ \Dy|}LE
return sFileName; PCHspe9!y
} )Z:D}r8[
`:;q4zij;
E_aBDiyDf
public void setSFileName(String value) Y#XRn_2D
{ ~mARgv
sFileName = value; AB`.K{h
} ~r!(V;k{
*<!q@r<d
&H]/'i-
public int getNSplitter() RG""/x;
{ [5& nH@og
return nSplitter; #MlpOk*G
} Y}v3J(l
U31@++C[
<K`E*IaW
public void setNSplitter(int nCount) j7gw?,
{ eu9*3'@A
nSplitter = nCount; 4$[o;t>
} CDRbYO
} {\(MMTQ
@$T$hMl
`vgaX,F*
/* 4minzrKM\
**Utility.java 5N;'CAk
*/ Mh4MaLw
package NetFox; D,ZLo~
|DJ8 "T]E
+IWH7qRtp
public class Utility { #YYJ4^":k
~cCMLK em
@)uV Fw"\
public Utility() twq~.:<o
{ jh)@3c
(+epRC
7!pKlmQ
} ZQ_6I}i")
~}}<+JEEO
//线程睡眠 :86:U 0^
public static void sleep(int nSecond) nYjrEy)Q
{ e))L&s
try{ 3@Mh* \;\b
Thread.sleep(nSecond); X!ruQem /
} jRg gj`o
catch(Exception e) 3WJk04r
{ #mw!_]
e.printStackTrace (); @m9pb+=v
} q\?s<l63
} > 0MP[
Z|uvrFa
//日志 3TF_$bd{
public static void log(String sMsg) {uaDpRt
{ Iz09O:ER
System.err.println(sMsg); 1xW!j!A;
} B/1j4/MS
Oh*~+/u}q
eZa*WI=
public static void log(int sMsg) 3- Kgz
{ w}>%E6UY
System.err.println(sMsg); gmRc4o
} }q.D)'g_
} 5]N0p,f
|(3y09
:rVR{,pL
/* 0%rDDB
**TestMethod.java fd&Fn=!
*/ q()o|V
package NetFox; iY,C0=n5Y
pT]hPuC
G+8)a$?v
public class TestMethod { E+@Q u "W
mvEhP{w
0\tac/
public TestMethod() S} m=|3%y
{ ///xx/weblogic60b2_win.exe 't5ufAT
try{ @-!P1]V|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #:gd9os :
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z4:!*:.Asu
SiteFileFetch fileFetch = new SiteFileFetch(bean); )A7^LLzG
fileFetch.start(); 0!\C@wnH
} l/'GbuECm
catch(Exception e){e.printStackTrace ();} f=F:Af!
A*y4<'}<
2d[q5p
} L/tpT?$fi
?$f.[;mh
4H-eFs%5
public static void main(String[] args) :W*yfhLt
{ <T}U 3lL^
new TestMethod(); L7C ;l,ot
} ~v;I>ij
} nHdQe
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