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)); O<A$,<67
} Qktj
for(int i=0;i<nEndPos.length-1;i++) $d<vPpJ3
{ Ek0zFnb[Gx
nEndPos = nStartPos[i+1]; QKj8~l(
} dNQR<v\IL
nEndPos[nEndPos.length-1] = nFileLength; (k{rn3,
} ~Y- !PZ
} s7x&x;-
'X()|{
f-w-K)y$ht
//启动子线程 XkG:1H;Q%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZGstD2N$
for(int i=0;i<nStartPos.length;i++) 'N-nFc^
{ %Tc P[<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Td7f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;7Hse^Oc
nStartPos,nEndPos,i); d0@&2hO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =}bDT2Nb
fileSplitterFetch.start(); jRk"#:
} Bz&6kRPv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >8I?YT.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X/=*o;":
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d&!;uzOx
nEndPos = " + nFileLength); ,BUDo9h
// fileSplitterFetch[nPos.length-1].start(); WFl, u!"A
k0%*{IVPN
0|1)cO}Dy
//等待子线程结束 =5a|'O
//int count = 0; V^n?0^o
//是否结束while循环 qDMVZb-(#
boolean breakWhile = false; L7~9u|7a#
utH,pGs C.
0E6>PE;
while(!bStop) S;!l"1[;
{ byT@O:fL
write_nPos(); z0@{5e$#Y
Utility.sleep(500); oWJ0>)
breakWhile = true; /QA:`_</oh
aan)yP
O{4G'CgN(
for(int i=0;i<nStartPos.length;i++) $#b@b[h<w
{ :\]TAQd-
if(!fileSplitterFetch.bDownOver) T^"-;
{ Ukf4Q\@w
breakWhile = false; X?2ub/Nr#Y
break; qy]tuKZI
} %OI4}!z@l
} !$q *~F"S
if(breakWhile) cO&(&*J r
break; 4,nUCT
*wSz2o),
\yQs[l%J
//count++; ~9[^abz
//if(count>4) 5:oteNc3
// siteStop(); cph&\ V2jt
} SFj:|S=v6j
#@quuiYq
<)f1skJsP
System.err.println("文件下载结束！"); -&AgjzN!
} 12D>~#J
catch(Exception e){e.printStackTrace ();} hd~3I4D
} u$vA9g4
4[&L<D6h
m%=] j<A
//获得文件长度 vpnOc2 -
public long getFileSize() +7`7cOqXg
{ '@jP$6T&
int nFileLength = -1; D-v}@tS'
try{ jcC"SqL
URL url = new URL(siteInfoBean.getSSiteURL()); uR;m<wPH,f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d*M:PjG@
httpConnection.setRequestProperty("User-Agent","NetFox"); C(4r>TNm
/t4#-vz
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int responseCode=httpConnection.getResponseCode(); vs*Q {
if(responseCode>=400) ##_`)/t,
{ z2/E?$(
processErrorCode(responseCode); V2v}F=
return -2; //-2 represent access is error j'2:z#
} s-S#qGZ
:n%KHen3\
a 8(mU%
String sHeader; 3 P)N,
EG7.FjnVu
>j%4U*
for(int i=1;;i++) <i!:{'%
{ KF.d:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BEfP#h=hr
//Utility.log(in.readLine()); L/39<&W
sHeader=httpConnection.getHeaderFieldKey(i); 'yIz<o
if(sHeader!=null) A9D vU)1
{ `A\|qH5`W
if(sHeader.equals("Content-Length")) h#e((j3-2Z
{ }$5e!t_K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \DgWp:|
break; gq:2`W&5
} kuQ+MQHs
} hFLLg|@
else aRc2#:~;
break; @hz~9AII9
} /'g/yBY
} :S_3(/} \
catch(IOException e){e.printStackTrace ();} z:Q4E|IX
catch(Exception e){e.printStackTrace ();} +|iJQF
P {8d.
'1f:8
Utility.log(nFileLength); #mFY?Zp)
YXFUZ9a#e
axpn*(yE
return nFileLength; /XeCJxo8
} ws_/F
O{Y_j&1
x&['g*[L0
//保存下载信息（文件指针位置） 2Nau]y]=
private void write_nPos() $+%eLx*
{ r ?e''r
try{ )W0zu\fL =
output = new DataOutputStream(new FileOutputStream(tmpFile)); =KCAHNr4?
output.writeInt(nStartPos.length); xO` `X<
for(int i=0;i<nStartPos.length;i++) K'DRX85F
{ Iu=n$H
// output.writeLong(nPos); FL8?<bU
output.writeLong(fileSplitterFetch.nStartPos); ]K^#'[
output.writeLong(fileSplitterFetch.nEndPos); ?T (@<T
} NH$!<ffz
output.close(); 5@3hb]J
} ej^pFo
catch(IOException e){e.printStackTrace ();} k2@|fe
catch(Exception e){e.printStackTrace ();} v;_k*y[VV$
} >'MT]@vez
)LRso>iOO
Y`tv"v2
//读取保存的下载信息（文件指针位置） k O8W>
private void read_nPos() \c .^^8r
{ ;q;}2
try{ ky^u.+cZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (vXes.|+t
int nCount = input.readInt(); ! ,v!7I
nStartPos = new long[nCount]; QV_e6r1t#m
nEndPos = new long[nCount]; wgV?1S>Z
for(int i=0;i<nStartPos.length;i++) >oOZDuj
{ <aVfgVS
nStartPos = input.readLong(); P+/6-CJ
nEndPos = input.readLong(); )=EJFQ*v
} "6} #65
input.close(); +kdZfv>
} fcLVE
catch(IOException e){e.printStackTrace ();} TQjM3Ri=V
catch(Exception e){e.printStackTrace ();} fdCN?p[_
} Ac,Qj`'V
x_eR/B>
0.4Q-?J
private void processErrorCode(int nErrorCode) ] 1:pnd
{ tXu_o6]
System.err.println("Error Code : " + nErrorCode); -sqoE*K[8
} Pd^v-}[
$SAk|
Y{v\m(D
//停止文件下载 ~6HaZlBB
public void siteStop() THXG~3J<
{ @4ECz>Q
bStop = true; !JOM+P:
for(int i=0;i<nStartPos.length;i++) x[w!buV0\
fileSplitterFetch.splitterStop(); kNnI$(H"H
sm1(I7y
^@a|s Sb
} _+?v'#
} 99]&Xj
//负责部分文件的抓取 Q&d"uLsx
**FileSplitterFetch.java Jd0I!L
*/ MRn;D|Q
package NetFox; D3MRRv#
U`HSq=J
:t#N.[=&#
import java.io.*; 0**.:K<i
import java.net.*; \A'tV/YAd
D$OUy}[2`.
lgL|[ik`
public class FileSplitterFetch extends Thread { n\x@~ SzrX
)vcyoq
re-;s
String sURL; //File URL W.O]f.h
long nStartPos; //File Snippet Start Position }1)tALA
long nEndPos; //File Snippet End Position *>%tx k:)
int nThreadID; //Thread's ID O,+ZD^
boolean bDownOver = false; //Downing is over m0(]%Kdw
boolean bStop = false; //Stop identical }wkZ\q[
FileAccessI fileAccessI = null; //File Access interface @$bEY#*C
,^#{k!uaC{
74u_YA<"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t R(Nko
{ @9X+ BdQU
this.sURL = sURL; &qO#EEqG]
this.nStartPos = nStart; O 6}eV^y
this.nEndPos = nEnd; 2&+Nr+P
nThreadID = id; Z91GM1lrf8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +l8`oQuG
} HAtf/E]
JPq2C\Ka
wm<`0}
public void run() / ~\ I
{ m+7/ebj{A
while(nStartPos < nEndPos && !bStop) W? ^ ?Kx
{ 2U Q&n`A
i;GF/pi
%Uz 5Ve
try{ l2lyi
URL url = new URL(sURL); TODTR7yGo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m+ww
httpConnection.setRequestProperty("User-Agent","NetFox"); ; wpX
String sProperty = "bytes="+nStartPos+"-"; wP: w8O
httpConnection.setRequestProperty("RANGE",sProperty); -{tB&V~+v
Utility.log(sProperty); (X?'}Ur
>Y\$9W=t
1m5=Nu
InputStream input = httpConnection.getInputStream(); |'R^\M Q
//logResponseHead(httpConnection); R | &+g\{;
zx7g5;J
#XaTUT
byte[] b = new byte[1024]; +"HLx%k
int nRead; ER ^#J**
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EG|fGkv"
{ 0OrT{jo
nStartPos += fileAccessI.write(b,0,nRead); tU :,s^E"#
//if(nThreadID == 1) cp&- 6 w+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hj_%'kk-A
} 6hvmp
U~)i&":sN
ktu{I
Utility.log("Thread " + nThreadID + " is over!"); pFZ2(b&
bDownOver = true; ;<9dND
//nPos = fileAccessI.write (b,0,nRead); 9t1aR*b&@
} mK>c+ u)
catch(Exception e){e.printStackTrace ();} x^J}]5{0
} |1@/gqa
} l?AWG&
1$]hyC/f
AusCU~:>
//打印回应的头信息 !&ly :v!
public void logResponseHead(HttpURLConnection con) 6u'+#nm
{ a+--2+~=
for(int i=1;;i++) !RJuH;8
{ EC]b]'._
String header=con.getHeaderFieldKey(i); wj'5D0
if(header!=null) )l|/lj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Pl>S1
Utility.log(header+" : "+con.getHeaderField(header)); t5qNfiKC
else VEuT!^0Z
break; Jbmi[`O
} \"X<\3z2
} }!W,/=z*
J=*X%^jX9Z
<H,q( :pM
public void splitterStop() PS13h_j
{ Buue][[
bStop = true; ];vEj*jCX
} S"/M+m+ ]
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2GHmA_7P
} xP3v65Q1
*A>I)a<:
w,<nH:~
/* xux j
**FileAccess.java bK7j"
*//文件访问(定位，写) sI7<rI.t){
package NetFox; K)z!e;r
import java.io.*; 4}4K6y<q
z&3in
xw)$).yc
public class FileAccessI implements Serializable{ ex-0@
vp4l g1/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?(up!3S'x
RandomAccessFile oSavedFile; (}E ] g
long nPos; sI@y)z
AWY#t&
y" (-O%Pe
public FileAccessI() throws IOException <vP{U
{ jlf.~vt
this("",0); ZW6ZO[`6
} 3kAhvL
M[C9P.O%w
#i8] f{
public FileAccessI(String sName,long nPos) throws IOException /!V)2j,
{ 2=&4@c|cn
oSavedFile = new RandomAccessFile(sName,"rw"); gCVgL]jj(
this.nPos = nPos; GkhaB(btk'
oSavedFile.seek(nPos); wRa$b
} LQ7.RK
X0h`g)Bbf
]dx6E6A,
public synchronized int write(byte[] b,int nStart,int nLen) WSt&?+Y
{ 7)2Co[t
int n = -1; G,VTFM6
try{ O%1X[
oSavedFile.write(b,nStart,nLen); MDHTZ94\Q
n = nLen; r+4<Lon~
} o@&Hc bN^
catch(IOException e) vZDM}u
{ Zj(2$9IU
e.printStackTrace (); KA=cIm
} M<4tjVQ6
*A2D}X3s
S? -6hGA j
return n; ^ #6Ei9di
} 5uVSbo.
|#y+iXTJ
Rxg^vM*
} j4!g&F _y
Y-0o>:SM
H=_ Wio
/* "kS(b4^
**SiteInfoBean.java sQ4~oZZ
*/ 0u3"$o'R
package NetFox; Gkc.HFn(
*dTI4k
o7qZy |\4S
public class SiteInfoBean { 4 Qo(Wl
'@{'T LMCi
L.cGt"{
private String sSiteURL; //Site's URL "_g3{[es!
private String sFilePath; //Saved File's Path 9d\B*OU
private String sFileName; //Saved File's Name U2lDTRt
private int nSplitter; //Count of Splited Downloading File Xy0KZ !
ZwC\n(_y
|#87|XIJ&~
public SiteInfoBean() aUqVcEU1
{//nSplitter的缺省值为5 MPexc5_
//default value of nSplitter is 5 m(CbMu
this("","","",5); 6 4fB$
} =;) M+"
ogOUrJ}P
@TvoCDeI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8[z<gxP`?
{ K}r@O"6*\
sSiteURL= sURL; @(~m.p|
sFilePath = sPath; eSC69mfD
sFileName = sName; p+t79F.js
this.nSplitter = nSpiltter; ggy 7p44
`T-lBwH
lT<4c5%
} Zi!6dl ev
JdP[ cN
T%opkyP>=
public String getSSiteURL() 6v]y\+
{ )|Ho"VEmg
return sSiteURL; 5Tb3Yy< .
} 53i7:1[uV
r8k.I4
:~% zX*
public void setSSiteURL(String value) }"sZ)FE
{ M)<4|x
sSiteURL = value; ,{pC1A@s
} 4!I;U>b b
S~Z`?qHWh
pE^jUxk6
public String getSFilePath() "1-|ahW
{ `:4\RcTb/
return sFilePath; [i ]
} Q9\6Pn ]T
,.g9HO/R1
ssWSY(j]
public void setSFilePath(String value) No'^]r
{ aS7%x>.A!
sFilePath = value; x+X^K_*
} Y!+q3`-%T
t$*V*gK{
hPM:=@N$
public String getSFileName() ff1Em.
{ )(aj
return sFileName; Zl:Z31
} M.[A%_|P
r N.<S[
PXH"%vVF
public void setSFileName(String value) MV~-']2u
{ ^EG@tB $<
sFileName = value; z.xOT;t
} UImd*;2TE
X-Q;4M-CJ
/.[;u1z"^
public int getNSplitter() 1Ar6hA
{ knPo"GQW
return nSplitter; :We}l;.jQ
} Wl4T}j
c^$+=-G{fd
(I) e-1
public void setNSplitter(int nCount) w|;kL{(W
{ =>_k;x
nSplitter = nCount; 4raKhN"
} CQ(;L{}
} xIrRFK9[Q
8%Wg;:DZx
og! d
/* B F,rZZL
**Utility.java dp&bcR&#)
*/ 4ZRE3^y\"
package NetFox; 7Lv5@
#hNp1y2
tSZd0G<A<o
public class Utility { 5GwXZ;(G
d- wbZ)BR
&>0ape
public Utility() +mr\AAFn
{ oI!L2
SvE|"
<0,szw
} s[ CnJZ\q
0( s io\
//线程睡眠 ?;//%c8,.
public static void sleep(int nSecond) TDMyZ!d
{ WC?}a^ 8
try{ 'A|OVyH
Thread.sleep(nSecond); :EXH8n&|
} N~w4|q!]
catch(Exception e) Fp`MX>F
{ bc".R]
e.printStackTrace (); @`</Z)
} SiM1Go}#
} @_O,0d g
XyS|7#o
//日志 _QhB0/C
public static void log(String sMsg) xEA%UFB.!G
{ p PF]&:&-b
System.err.println(sMsg); l9 K 3E<g
} <IX)D `mf
*@C4~Zo
N1O& fMz
public static void log(int sMsg) s`bC?wr5h
{ A(xCW+h@)
System.err.println(sMsg); (4U59<ie
} )ny,vcU]
} Rj/9\F3H
T}?vp~./
w'Kc#2
/* C&\vVNV;9
**TestMethod.java D-/aS5wM
*/ OfR\8hAY
package NetFox; ""dX4^gtU
PR&D67:Jy
l<](8oc. w
public class TestMethod { R/yOy^<
CQq'x+{F
Tz=YSQy$9
public TestMethod() }x[d]fcC
{ ///xx/weblogic60b2_win.exe Dm3/i|Y
try{ +Rtz`V1d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +18)e;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )A`Zgg'L7D
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]Tje6iF
fileFetch.start(); gAx8r-` `
} sH^?v0^a
catch(Exception e){e.printStackTrace ();} h-XMr_F
wGqQR)a
NMSpi[dr
} UL/|!(s
O\5*p=v
]g>@r.Nc
public static void main(String[] args) I92c!`{
{ =,aWO7Pz
new TestMethod(); 5X7kZ!r
} O1o.^i$-M
} LNp%]*h
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