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)); c|f)k:Q
} 410WWR&4_
for(int i=0;i<nEndPos.length-1;i++) &9Vm3X
{ l\vvM>#S
nEndPos = nStartPos[i+1]; /eM_:H5
} {gSR49!Q
nEndPos[nEndPos.length-1] = nFileLength; [+=h[DC
} /ae]v+
} -:O~J#D
S-FoyID\H
QlbhQkn
//启动子线程 !PCw-&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HvITw%`
for(int i=0;i<nStartPos.length;i++) 8}Pd- .se
{ zTFfft<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (7P{k<5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +6vm4(3?
nStartPos,nEndPos,i); =4RBHe8`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G\ twx ;
fileSplitterFetch.start(); /MS*_
} ]jWe']T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T=8>0D^v5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b;!oPT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |?c v5l7E
nEndPos = " + nFileLength); >$gWeFu
// fileSplitterFetch[nPos.length-1].start(); t7VXW{3
F,CQAgx
Qp{rAAC:
//等待子线程结束 9R XT
//int count = 0; 9v(&3,)a
//是否结束while循环 S.o@95M
boolean breakWhile = false; 'bP-pgc
_7SOl.5ZE
&[BDqi
while(!bStop) -I1Ne^DZn4
{ Sr_]R<?
write_nPos(); e_6@oh2s-
Utility.sleep(500); CtbmX)vE
breakWhile = true; EP#3+BsH
+ M2|-C
}U$Yiv
for(int i=0;i<nStartPos.length;i++) EthnI7Y
{ %g3@m5&
if(!fileSplitterFetch.bDownOver) @?_<A%hz
{ 9:^SnHAa
breakWhile = false; 48]1"h%*qB
break; #uNQ+US0
} wVCZ=\L}
} 6xSdA;<+]
if(breakWhile) ukV1_QeN[
break; tP2hU[7Z
,R=Mr}@u
}E$^!q{
//count++; D@tuu]%p
//if(count>4) TD+V.}
// siteStop(); =!_e(J
} H kDT14 `&
//VgPl
#5)E4"m
System.err.println("文件下载结束！"); ml7]sN(
} C|c'V-f
catch(Exception e){e.printStackTrace ();} \R45#. P6X
} ^w4FqdGM
i'|rx2]e
'7Dg+a^x7
//获得文件长度 O3#4B!J$E
public long getFileSize() $Jo[&,
{ `,~I*}T>5W
int nFileLength = -1; :0ZFbIy
try{ g$eb@0$
URL url = new URL(siteInfoBean.getSSiteURL()); 1]#qxjZ~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yhQv $D,^f
httpConnection.setRequestProperty("User-Agent","NetFox"); zDY!0QZLF\
hdtb.u~
R[5*]$(b
int responseCode=httpConnection.getResponseCode(); MIasCH>r
if(responseCode>=400) xlF$PpRNM
{ 0EfM~u
processErrorCode(responseCode); yWsV !Ub
return -2; //-2 represent access is error A-r-^S0\
} =mYY8c Yl
'E+Ty(ED5
HMJx[ yD
String sHeader; 1pogk0h.:
O=8:K'
\D>vdn"Lx
for(int i=1;;i++) B<(v\=xZ
{ @U'I_`LL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i]gF 6:&
//Utility.log(in.readLine()); vtG_A{l
sHeader=httpConnection.getHeaderFieldKey(i); IQxY]0\uf6
if(sHeader!=null) |,L_d2lb
{ v|`f8M2
if(sHeader.equals("Content-Length")) sG*1?
{ =xScHy{$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ss+e*e5Ht
break; K?:rrd=7q
} q:@$$}FjL
} }Wjb0V
else -S\74hA
break; 7H~StdL/>
} zz3Rld!b[
} / 2>\Z(
catch(IOException e){e.printStackTrace ();} IT]D;
catch(Exception e){e.printStackTrace ();} ykc$B5*
O0Y/y2d
2i`N26On
Utility.log(nFileLength); `!Ei H<H}
CS2AKa@`
i&\N_PUm[
return nFileLength; ^XEX"E
} U,S&"`a
Q`}1 B
JnE\E(ez
//保存下载信息（文件指针位置） 67Rsd2
private void write_nPos() \TqKm
{ pH5"g"e1
try{ j/_@~MJBt
output = new DataOutputStream(new FileOutputStream(tmpFile)); "&Ym(P
output.writeInt(nStartPos.length); Kg^L 4Q
for(int i=0;i<nStartPos.length;i++) \hv1"WaJ
{ ?LAKH$t
// output.writeLong(nPos); +ou5cQ^
output.writeLong(fileSplitterFetch.nStartPos); Ag QR"Nu6
output.writeLong(fileSplitterFetch.nEndPos); uCuXY#R+
} ,y@`=
output.close(); z 3)pvX5
} o!EPF-:
catch(IOException e){e.printStackTrace ();} |9.`qv
catch(Exception e){e.printStackTrace ();} @q2If{Tk
} l}B,SkP^
xB"o 7,
Q| > \{M
//读取保存的下载信息（文件指针位置） ]Ija,C!#
private void read_nPos() S?*pCJ0
{ OO5k_J
try{ O{hGh{y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -N+'+
int nCount = input.readInt(); v&oE!s#
nStartPos = new long[nCount]; ^50#R<Ny
nEndPos = new long[nCount]; ~$} `R=
for(int i=0;i<nStartPos.length;i++) ma.yI};$
{ n| =k9z<y8
nStartPos = input.readLong(); Av[L,4A
nEndPos = input.readLong(); sIpq
} is_`UDaB
input.close(); Z7?C^m
} ~L j[xP
catch(IOException e){e.printStackTrace ();} vG9A'R'P
catch(Exception e){e.printStackTrace ();} H@%Y!z@\
} p\5DW'
ZZqImB.Cz6
RMU]GCa
private void processErrorCode(int nErrorCode) [|<2BQX
{ H: q(T >/w
System.err.println("Error Code : " + nErrorCode); KZ^W@*`D
} Q.:SIBP
`ZL~k
8d.5D&
//停止文件下载 j<w";I&Diz
public void siteStop() ImQ?<g8$
{ CbTYt6DC
bStop = true; 7Z;bUMYtx
for(int i=0;i<nStartPos.length;i++) gE8p**LT+
fileSplitterFetch.splitterStop(); v#i,pBj
jeM %XI
'P(S*sr
} iDej{95
} mD`v>L
//负责部分文件的抓取 L/,#:J
**FileSplitterFetch.java z$OKn#%T
*/ Sgp$B:
package NetFox; "i/ l'
"{-jZdq'
Z>1\|j
import java.io.*; k@r%>Ul@
import java.net.*; e\%emp->
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*|S.[i_7
public class FileSplitterFetch extends Thread { z^s/7Va[
#T_m|LN7
hd*bPj;
String sURL; //File URL w yi n
long nStartPos; //File Snippet Start Position tVJ}NI #
long nEndPos; //File Snippet End Position n<47#-
int nThreadID; //Thread's ID 63R?=u@
boolean bDownOver = false; //Downing is over F&?&8.
boolean bStop = false; //Stop identical #;ezMRKM"
FileAccessI fileAccessI = null; //File Access interface <:=}1t.Z
zFVNb
>D20f<w(H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z9rmlVU6!
{ #4uuT?!
this.sURL = sURL; R_iQLBrd
this.nStartPos = nStart; ox9$aBjJ
this.nEndPos = nEnd; *h59Vaoc
nThreadID = id; ,m<t/@^]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m,UMb#7Y
} ~Y=v@] 2/
nk8jXZ"w
;Y<Hi\2oy
public void run() <)01]lKH
{ V'[Lqe,y
while(nStartPos < nEndPos && !bStop) uA]Z"
{ Jv*[@ -.k
Jo%5NXts4
GF(<!PC
try{ #NU;$&
URL url = new URL(sURL); 7RW5U'B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tNsiokOm
httpConnection.setRequestProperty("User-Agent","NetFox"); 9a_B
String sProperty = "bytes="+nStartPos+"-"; l)@Zuh
httpConnection.setRequestProperty("RANGE",sProperty); ')!+>b(P
Utility.log(sProperty); 92y<E<n
jhs('n,
3Yu1ZuIR
InputStream input = httpConnection.getInputStream(); cWG>w6FI
//logResponseHead(httpConnection); ""LCyKu
;IklS*p]
x\/N09
byte[] b = new byte[1024]; 3=r#=u5z
int nRead; VK/@jrL+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C)w11$.YQ9
{ P<&-8QA
nStartPos += fileAccessI.write(b,0,nRead); jkz.qo-%
//if(nThreadID == 1) 8=XfwwWHy<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -Ucj|9+(a
} {@XzY>
'3B\I#
rU^?Z
Utility.log("Thread " + nThreadID + " is over!"); iR k.t=B
bDownOver = true; ED9uKp<Wbv
//nPos = fileAccessI.write (b,0,nRead); JPeZZ13sS
} p.Y =
catch(Exception e){e.printStackTrace ();} Z^P]-CB|6A
} 8&q|*/2
} /]0-|Kg+R
Rg4'9I%B
hYm$Sx(=
//打印回应的头信息 &c;@u?:@S
public void logResponseHead(HttpURLConnection con) -N'xQ(#n3q
{ Qi&!Ub]
for(int i=1;;i++) r3OTU$t?
{ hqEnD
String header=con.getHeaderFieldKey(i); q(tdBd'o6
if(header!=null) gY)NPi}!`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '%JIc~LJ
Utility.log(header+" : "+con.getHeaderField(header)); k]J!E-yI8
else {|Ew]Wq
break; t:pgw[UJ
} 1J(` kQ)c
} .f+ul@o
mkJC*45
Tt,<@U[/}
public void splitterStop() 9XU"Ppv
{ u9 LP=g
bStop = true; (%\vp**F
} =(!&8U9
@-uV6X8|
^TC<_]7
} ".n,R"EF
]Q?`|a+i
]_8bX}_n
/* %/b3G*$W
**FileAccess.java @S69u s}
*//文件访问(定位，写) Y)X 'hk)5|
package NetFox; );8Nj zX1
import java.io.*; sTn}:A6
J>H$4t#HX
^jY'Hj.Bs
public class FileAccessI implements Serializable{ {km~,]N
J$9`[^pV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %Tc P[<
RandomAccessFile oSavedFile; -vRZCIj!
long nPos; \0K3TMl)J
H9@24NFb
4|?y [j6
public FileAccessI() throws IOException })I_@\q
{ o09)esy
this("",0); QD<GXPu?N
} ~OuKewr\
-r.Qy(}p
j. @CB`
public FileAccessI(String sName,long nPos) throws IOException 15o<'4|=Lm
{ : h"Bf@3
oSavedFile = new RandomAccessFile(sName,"rw"); [,s{/32s
this.nPos = nPos; B=4xZJPy
oSavedFile.seek(nPos); 0j=xWC
} L7\rx w
=)Aav!
y:C=Ni&,"
public synchronized int write(byte[] b,int nStart,int nLen) w=dTa5
{ *,hg+?lZ
int n = -1; 3RwDIk?>%
try{ (%bqeI!ob
oSavedFile.write(b,nStart,nLen); Cb`2"mpWS
n = nLen; n54}WGo>9
} K\bA[5+N
catch(IOException e) X&s@S5=r]
{ 2 Nr*
e.printStackTrace (); DlD;rL=
} '@jP$6T&
lQkCA-
K!L0|WH%!
return n; L0sb[:'luz
} Wu{cE;t
KOYU'hw
)BJZ{E*
} Eku+&f@RB
pGwBhZnb>
{.,-lFb\
/* 3 P)N,
**SiteInfoBean.java B&bQvdp
*/ ,MmX(O0
package NetFox; km 0LLYG
"\CUHr9k
eeOE\
public class SiteInfoBean { -45xa$vv
oP%'8%tk
cBGR%w\t%
private String sSiteURL; //Site's URL hFLLg|@
private String sFilePath; //Saved File's Path 4ayZ.`aK
private String sFileName; //Saved File's Name E U# M.
private int nSplitter; //Count of Splited Downloading File UHaY|I${U
P {8d.
#rps2nf.j
public SiteInfoBean() 8-"lK7
{//nSplitter的缺省值为5 %]KOxaf_z
//default value of nSplitter is 5 'Cq)/}0
this("","","",5); K+F]a]kld
} ?h1r6?Sug{
f,s1k[w/;
Vs:x3)m5j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Iu=n$H
{ aj\ zc I
sSiteURL= sURL; :wRaB7
sFilePath = sPath; T`Jj$Lue{
sFileName = sName; :Qekv(z
this.nSplitter = nSpiltter; (&=gM
[ELg:f3}5
]NRQM8\
} [<!4 a
`;\<Fr
xUw)mUn@N
public String getSSiteURL() P&2/J%@zG
{ l`M7a9*U
return sSiteURL; uY"Bgz:=d
} !=t.AgmL
>oOZDuj
aplOo[
public void setSSiteURL(String value) !92zC._
{ )V6<'>1WZ
sSiteURL = value; fMSB
} u,f$cR
7L"Pe'Hw
z~R:!O-
public String getSFilePath() zo{WmV7[|
{ #sg^l>/*
return sFilePath; to%n2^^K
} G|,'6|$jE
)K"7=TvY
gb,X"ODq
public void setSFilePath(String value) x8v2mnk
{ q,->E<8
sFilePath = value; ^7zXi xp
} Kz`g Q|S
YlP8fxS
]!=,8dY
public String getSFileName() ?--EIA8mfp
{ wFHbz9|@I
return sFileName; n\x@~ SzrX
} Ce%fz~*b
PE7D)!d T
i[\`]C{gf
public void setSFileName(String value) $w@0}5Q
{ #rs]5tx([
sFileName = value; XzH"dDAVE
} #;WKuRv
sBuOKT/j
v[UrOT:
public int getNSplitter() '9R.$,N
{ =,4iMENm!
return nSplitter; "F3M m
} vXP+*5d/ K
0qPbmLMK
X\yy\`o
public void setNSplitter(int nCount) l2lyi
{ [G=+f6 a
nSplitter = nCount; n(}zq
} dhAkD-Lh
} 4U1!SR]s
}bZcVc2
c%bGVRhE
/* MMYV8;c
**Utility.java MkCq$MA
*/ g=gWkN <
package NetFox; >2%*(nL
oieZopYA
BnL[C:|
public class Utility { bx5f\)
UDUj
IB sQaxt.
public Utility() 0';U3:=i,
{ @2>j4Sc
ox2?d<dC6
M]RbaXZ9
} l\NVnXv:>
yl#(jb[?1
//线程睡眠 u0M? l
public static void sleep(int nSecond) F*bmV>Qq
{ VX`E7Sf!}
try{ wy1xZQ<5
Thread.sleep(nSecond); 4%]wd}'#Un
} xMb)4cw}
catch(Exception e) _eE hIQ9
{ ~G;lEp
e.printStackTrace (); Pl>S1
} sUki|lP
} (}|QSf:
w[A$bqz
//日志 <H,q( :pM
public static void log(String sMsg) n'&Cr0{
{ u$"dL=s!
System.err.println(sMsg); 2[#7YWs
} n&51_.@Q
G/w&yd4
*A>I)a<:
public static void log(int sMsg) $eI=5
{ mo$`a6[h<
System.err.println(sMsg); U1Z.#ETnM
} YCWt%a*I'
} xw)$).yc
iEtnwSt
}=+J&cR
/* ";&5@H|
**TestMethod.java *G<K@k
*/ '\&t3?;
package NetFox; zB8 @Wl
d^0vaX6e}
6eUM[C.
public class TestMethod { Spnshv8
efK|)_i :
M[C9P.O%w
public TestMethod() #LGAvFA*_F
{ ///xx/weblogic60b2_win.exe ~w&_l57
try{ kb27$4mm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AB!P(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wVSk.OOB
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8f""@TTp
fileFetch.start(); LQ7.RK
} aSKLSl't`
catch(Exception e){e.printStackTrace ();} (iwZs:k-
{hS9FdWA;
_I"T(2Au
} 4\cJ}p}LZ{
MDHTZ94\Q
Gk!06
public static void main(String[] args) HF2w?:
{ XM9}ax
new TestMethod(); !e+^}s
} ^7qqO%
} 6AM-^S@
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