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)); +K57. n{
} ^mS |ff
for(int i=0;i<nEndPos.length-1;i++) a|aVc'j
{ bLgH3[{
nEndPos = nStartPos[i+1]; /:&!o2&1H
} Lsmcj{1d
nEndPos[nEndPos.length-1] = nFileLength; ^PksXfk
} J3K=z
} RgE`Hr
"/#JC}]
tT$OnZu&
//启动子线程 *sho/[~_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^URCnJ67Se
for(int i=0;i<nStartPos.length;i++) mP(3[a_Q
{ (C2 XFg_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Nk`UQ~g$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o\AnM5
nStartPos,nEndPos,i); 5gszAvOO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v<qh;2
fileSplitterFetch.start(); z*y!Ml1
} `&$8/_`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JE?p'77C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V|7YRa@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L+%"ew
nEndPos = " + nFileLength); ) nfoDG#O
// fileSplitterFetch[nPos.length-1].start(); =P-&dN
`+JFvn!
P:qmg"i@3
//等待子线程结束 !*IMWm>
//int count = 0; T5BZD +Ta
//是否结束while循环 G7-BeA8
boolean breakWhile = false; wucdXj{%
l.[pnLD
CI|lJ
while(!bStop) +Q*`kg'
{ !,WGd|oJ
write_nPos(); XX;4A
Utility.sleep(500); 30Yis_l2h
breakWhile = true; bdUPo+
g8),$:Uw
)^h6'h`
for(int i=0;i<nStartPos.length;i++) bQll;U^A
{ ?Cq7_rq
if(!fileSplitterFetch.bDownOver) cw;wv+|k
{ ZO}Og&%
breakWhile = false; #m+!<
break; l?Y^3x}j
} `sxfj)s
} 0bNvmZ$
if(breakWhile) bm588UQ
break; +Qs]8*^?;
k_=SDm a
NzRvbj]
//count++; jXcJ/g(X3
//if(count>4) OI R5QH
// siteStop(); ]n ?x tI
} FoefBo?g65
HDyf]2N*N
-DDA b(2*
System.err.println("文件下载结束！"); xVvUx,t
} 'X~tt#T
catch(Exception e){e.printStackTrace ();} fSh5u/F!
} T?9D?u?]
*P()&}JK
<J[le=
//获得文件长度 ?@V R%z
public long getFileSize() B( [x8A]
{ eh#37*-
int nFileLength = -1; yIw}n67
try{ @WJ;T= L
URL url = new URL(siteInfoBean.getSSiteURL()); oL4W>b )
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); We+rFk1ddt
httpConnection.setRequestProperty("User-Agent","NetFox"); |J`EM7qMK
TyxIlI4"
VFT@Ic#]
int responseCode=httpConnection.getResponseCode(); ?-??>& z
if(responseCode>=400) iP/v"g"g
{ U%{GLO
processErrorCode(responseCode); G#iQX`
return -2; //-2 represent access is error A#uU]S
} WlL(NrVA@@
2FcL-?
4Nm>5*]
String sHeader; }E`Y.= S
3f|}p{3
b`0tfXzS5
for(int i=1;;i++) L aTcBcI
{ B|(g?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -K"'F`;W
//Utility.log(in.readLine()); sW^M ]
sHeader=httpConnection.getHeaderFieldKey(i); &K[*vyD
if(sHeader!=null) pjl%Jm
{ 4Z)4WGp!
if(sHeader.equals("Content-Length")) P-m_],
{ dQut8>0&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '1<Z"InU
break; {N(qS'N
} +vc+9E.?9
} 570Xk\R@M
else DF%d/a{]
break; 3)OZf{D[
} `CK~x=
} uf(ayDE
catch(IOException e){e.printStackTrace ();} :XKYfc_y
catch(Exception e){e.printStackTrace ();} ~G@NWF?7
[%IOB/{N
Ht`fC|E
Utility.log(nFileLength); /iW+<@Mas
]kh]l8t^
l![M,8
return nFileLength; ~NGM6+9
} e8a^"Z`a
6(|mdk`i
p l)":}/)
//保存下载信息（文件指针位置） 1-RY5R}VR
private void write_nPos() zal]t$z>
{ IrwQ~z3I
try{ #-az]s|N
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^[ae )}
output.writeInt(nStartPos.length); {9IRW\kn
for(int i=0;i<nStartPos.length;i++) .Xg.,kW
{ >OG189O
// output.writeLong(nPos); w7)pBsI
output.writeLong(fileSplitterFetch.nStartPos); ~Ps*i]n(
output.writeLong(fileSplitterFetch.nEndPos); zI88IM7/
} !E7gIqo
output.close(); KbJ6U75|f
} ^0,}y]5p
catch(IOException e){e.printStackTrace ();} aRd~T6I
catch(Exception e){e.printStackTrace ();} o'Bd. B
} 6:1`lsP
,%i Scr,z
T2{e1 =Z7
//读取保存的下载信息（文件指针位置） h yrPu_
private void read_nPos() 0 _!0\d#c
{ 7KtU\u
try{ M-WSdG[AJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ulR yt^bx|
int nCount = input.readInt(); SH*'<
nStartPos = new long[nCount]; ^Z (cVg
nEndPos = new long[nCount]; /E>;O47a
for(int i=0;i<nStartPos.length;i++) ;_sJ>.=\
{ ;H$Cq' I
nStartPos = input.readLong(); D2e-b
nEndPos = input.readLong(); yoE-a
} goM;Pf "<
input.close(); z:'m50'
} D@=]mh6vl
catch(IOException e){e.printStackTrace ();} ~tUZQ5"
catch(Exception e){e.printStackTrace ();} L K&c~ Uy
} j/v>,MM
3 98)\3o
UrniJB]
private void processErrorCode(int nErrorCode) :kZ]Swi 5
{ g%2G=gR$?z
System.err.println("Error Code : " + nErrorCode); 'afW'w@
} 2BY|Cp4R
b"g^Jm! j
G<Z}G8FW^
//停止文件下载 3Vu}D(PJ
public void siteStop() ];.5*a%*
{ D5zc{) /
bStop = true; ]0i[=
for(int i=0;i<nStartPos.length;i++) L03I:IJ
fileSplitterFetch.splitterStop(); %<i sdvF
b:1B >
5nPvEN/
} O:]']' /
} 1N/4W6
//负责部分文件的抓取 ? Fqh i
**FileSplitterFetch.java /%YW[oY{V
*/ f,YORJ
package NetFox; v]JET9hY
<5Vf3KoC&
A-x^JC=
import java.io.*; 81RuNs]
import java.net.*; mF gqM:
dJ"44Wu+J
,7nu;fOT[
public class FileSplitterFetch extends Thread { g}9,U&$]y
6O4*OR<&
iBE|6+g~Cj
String sURL; //File URL a$W O}g?
long nStartPos; //File Snippet Start Position AFt- V
long nEndPos; //File Snippet End Position V``|<`!gd
int nThreadID; //Thread's ID R6~6b&-8
boolean bDownOver = false; //Downing is over PpRS4*nR
boolean bStop = false; //Stop identical G>~/
FileAccessI fileAccessI = null; //File Access interface 1I;q@g0
74_?@Z(
s$y_(oU,D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException '{`KYKLP+
{ 4'faE="1)S
this.sURL = sURL; Fd8nR9A
this.nStartPos = nStart; d /jx8(0
this.nEndPos = nEnd; 33`bKKO}
nThreadID = id; P IG,a~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U=v>gNba
} -O})Y>=}
$GoS?\G
v9T3=
public void run() hyxv+m[
{ x]VycS
while(nStartPos < nEndPos && !bStop) #kQ! GMZH
{ CI+)0=`<1B
HOD?i_
.J.}}"+U
try{ W *0!Z:?
URL url = new URL(sURL); ( w4XqVT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <v ub Q4
httpConnection.setRequestProperty("User-Agent","NetFox"); sta/i?n
String sProperty = "bytes="+nStartPos+"-"; J5b3r1~D"[
httpConnection.setRequestProperty("RANGE",sProperty); 6I[*p0j5
Utility.log(sProperty); J rK{MhO
7$7|~k
s?<FS@k
InputStream input = httpConnection.getInputStream(); :] Wn26z)
//logResponseHead(httpConnection); d{TcjZ
H:b"Vd"x9
}51QUFhL0
byte[] b = new byte[1024]; A._CCou
int nRead; QeY+imM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [,&g46x22
{ [\F:NLjiUy
nStartPos += fileAccessI.write(b,0,nRead); DN9x<%/-
//if(nThreadID == 1) M5[#YG'FlQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^PdD-tY<
} i~GW
T7YJC,^m
:Gz$(!j1.'
Utility.log("Thread " + nThreadID + " is over!"); h-.^*=]R6
bDownOver = true; uA`e
//nPos = fileAccessI.write (b,0,nRead); lBn<\Y!^
} W)`>'X`
catch(Exception e){e.printStackTrace ();} OL=X&Vaf<
} ;8VZsh
} `?:{aOI
[/ CB1//Y
!d0$cF):
//打印回应的头信息 ~#EXb?#uS
public void logResponseHead(HttpURLConnection con) gISA13
{ Pf8_6z_
for(int i=1;;i++) [:,|g;=Y}
{ ~+6#4<M.~
String header=con.getHeaderFieldKey(i); C&q}&=3r
if(header!=null) R||$Wi[$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [L7S`Z
Utility.log(header+" : "+con.getHeaderField(header)); Ev#,}l+
else W9Us I
break; bil>;&h
} 7ey|~u2
} yyPj!<.MGP
ILNghtm-
+vFqHfmP
public void splitterStop() -vT$UP
{ E=v4|/['N
bStop = true; ABEEJQ
} 4&]NC2I
GNG.N)q#C
: Q,O:
} Z(E.F,k
bz&9]%S<
,0L< wa
/* 11$v~<M
**FileAccess.java 84(jg P
*//文件访问(定位，写) Q1h v2*/U
package NetFox; N9c#N%cu
import java.io.*; T~>&m~} +
U:/_T>f%
NFU=PS$
public class FileAccessI implements Serializable{ cP21x<n
TDtHRhq7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EY1L5Ba.
RandomAccessFile oSavedFile; LGy!{c
long nPos; Yv*i69"
"| oW6@
4[0.M
public FileAccessI() throws IOException +'e3YF+'
{ a(U/70j
this("",0); /[3!kW
} QK~>KgVi
I#yd/d5^
wS2N,X/Y
public FileAccessI(String sName,long nPos) throws IOException u<@ 55k
{ V6<Ki
oSavedFile = new RandomAccessFile(sName,"rw"); !OH'pC5
this.nPos = nPos; BD ,3JDqT
oSavedFile.seek(nPos); 51%<N\>/4
} D@mqfi(x
t/"9LMKs?
ht)KS9Xu
public synchronized int write(byte[] b,int nStart,int nLen) WtSlD9 h
{ [yAR%]i-7
int n = -1; {XS2<!D
try{ &kOb#\11u
oSavedFile.write(b,nStart,nLen); avv/mEf-f
n = nLen; /3vj`#jD
} 4p&SlJ
catch(IOException e) nYY'hjZ
{ MU_ >+Wnf
e.printStackTrace (); b~G|Bhxa
} RK]."m0c~#
'$OLU[(Y
TLzcQ|
return n; m+'X8}GC#O
} XG6UV('
PDh1*bf{u
wa9{Q}wSa
} ;/nR[sibN
X?"Ro`S
pQxi0/dp
/* X/wqfP
**SiteInfoBean.java }Sb&ux
*/ K[|d7e
package NetFox; v3jx2Z
UUql"$q
F9SIC7}uH
public class SiteInfoBean { j#XU\G
(aH_K07
7<ES&ls_
private String sSiteURL; //Site's URL q}R"
private String sFilePath; //Saved File's Path |7T!rnr
private String sFileName; //Saved File's Name /9yA.W;
private int nSplitter; //Count of Splited Downloading File ;c>Rjg&[
'uOp?g'7
Ie;}k;?-
public SiteInfoBean() seH#v
{//nSplitter的缺省值为5 :!EOg4%i
//default value of nSplitter is 5 WxLILh
this("","","",5); 4B8{\"6
} pRdO4?l
&"svt2
h:+>=~\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZjJEjw
{ WS0RvBvb
sSiteURL= sURL; Wm ?RB0
sFilePath = sPath; BPKeG0F7
sFileName = sName; U`"nX)$
this.nSplitter = nSpiltter; Ih95&HsdC
c~Hq.K$d
LNU9M>
} BT+ws@|[
h^0!I TL^
0)qLW& w
public String getSSiteURL() vi>V6IC4v
{ >!YI7)
return sSiteURL; #6JCm!s
} 7QRtNYo#\
{ByT,92
VL<)d-
public void setSSiteURL(String value) IV:Knh+ ?
{ ji2if.t@
sSiteURL = value; G>{;@u
} FyQ^@@
)P.|Xk:r
B|~\m~
public String getSFilePath() D`.CXFI+U
{ NLF{W|X
return sFilePath; |^@TA=_
} o0Hh&:6!M
L+QEFQ:r5
Da8qR+*x
public void setSFilePath(String value) )5X7|*LP
{ ?z60b=f8
sFilePath = value; ^IM;D)X&:
} I#f<YbzD
\Jv6Igu
PHD$E s
public String getSFileName() 4oOe
{ _Oq (&I
return sFileName; s\Cl3
} Ph.$]yQCc]
/^0Hi4+\
J]|-.Wv1
public void setSFileName(String value) ?(U> )SvF
{ U1rh[A>
sFileName = value; Y6fU;
} JX/rAnc@
!H,R$3~
e$tKKcj0T
public int getNSplitter() Dx Vt
{ ;LH?Qu;e
return nSplitter; 4F8`5)RM
} c:~o e
\aT._'=M+
<H E'5b
public void setNSplitter(int nCount) Jo h&Ay
{ K#";!
nSplitter = nCount; 4k$BqM1
} JUU0Tx:`9)
} )CXJRo`j0
$K8ZxH1z@
OH*[
/* m.EWYO0XQ
**Utility.java m(Bv}9
*/ +V7*vlx-
package NetFox; 5'>(|7~%\
Q:kpaMA1P
g >-iBxml
public class Utility { .f&,~$e4
I[<C)IG
35jP</
public Utility() sOLo[5y'
{ F/RV{} 17E
_.FxqH>
qdj,Qz9ly
} K$' J:{yY
tp*AA@~
//线程睡眠 <h7C_^L10\
public static void sleep(int nSecond) l= !KZaH
{ vM\8>p*U
try{ HPwmi[
Thread.sleep(nSecond); 8u;l<^<
} rmR7^Ycv/
catch(Exception e) a50{gb#
{ =`vUWONn
e.printStackTrace (); &sWqSS
} U#,2et6
} ;U}lh~e11
31YzTbl[H
//日志 )Cyrs~
public static void log(String sMsg) }QG6KJh_%
{ HHoh//(\
System.err.println(sMsg); T92k"fBY
} ZZFa<AK4
0V`0="rQ
|3\ mH~Bw
public static void log(int sMsg) {b+!0[
{ ](-:l6
System.err.println(sMsg); tX Z5oG7
} +~02j1Jx
} K}! VY`
ep,kImT
~++y4NB8Q
/* ~XQN4Tv-
**TestMethod.java a{69JY5
*/ (?YTQ8QR
package NetFox; i+T$&$b
Al' sY^B
Kv!CL9^LX7
public class TestMethod { )MW.Y
oXV
~n|*-rca
public TestMethod() eH=lX9
{ ///xx/weblogic60b2_win.exe 3MiNJi#=2
try{ f#/v^Ql*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +vBq,'k`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m/%sBw\rx
SiteFileFetch fileFetch = new SiteFileFetch(bean); 07# ~cVI
fileFetch.start(); !1)lGjMW
} Sep}{`u
catch(Exception e){e.printStackTrace ();} ;wgm 'jr
N~g'Z `
4wMKl6mL
} # TC x8]F
nXk<DlTws
VL&E2^*E
public static void main(String[] args) L5of(gQ5]
{ >Ex\j?
new TestMethod(); N6EH
} q%"]}@a0
} hf8=r5j=
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