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)); A5kz(pj
} 'D[g{LkL
for(int i=0;i<nEndPos.length-1;i++) !A=>B=.|D
{ Y N*"q'Yz_
nEndPos = nStartPos[i+1]; Hq."_i{I
} -iySU 6
nEndPos[nEndPos.length-1] = nFileLength; vJfj1 f
} |yYu!+U
} 2>h.K/pC
n+H);Dg<8
DcX,o*ec!
//启动子线程 B`/p[U5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,#hx%$f}d
for(int i=0;i<nStartPos.length;i++) BiI`oCX
{ $94l('B6H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZuVes?&j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L%5g]=
nStartPos,nEndPos,i); X%]m^[6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); We:b1sZR
fileSplitterFetch.start(); yQdoy^d/4
} I1fUV72
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e>Q_&6L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b^C2<'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'G8.)eTA'
nEndPos = " + nFileLength); [.LbX`K:
// fileSplitterFetch[nPos.length-1].start(); n81z0lnr
[O\[,E"K
#7"*Pxb#A
//等待子线程结束 65AG#O5R
//int count = 0; D9-D%R,
//是否结束while循环 4t< mX
boolean breakWhile = false; rh$q]
+5oK91o[y
bqSp4TI
while(!bStop) Fpckb18}(O
{ +lED6]+%
write_nPos(); k \V6q9*
Utility.sleep(500); V^E.9fs,
breakWhile = true; *WK0dn
pipqXe
jblj]/
for(int i=0;i<nStartPos.length;i++) HRF;qR9v
{ KSB{Z TE
if(!fileSplitterFetch.bDownOver) qgk6 \&K[
{ ;nZN}&m
breakWhile = false; q8[I` V{
break; (vb8Mk
} =x^b
} OM 4,Sevk
if(breakWhile) ~CQTPR
break; ^E= w3g&
}.74w0~0^
FCPiU3
//count++; (|_N2R!
//if(count>4) }RN&w]<
// siteStop(); #25%17
} $G.ws
-$+`v<[r
Avr2MaY{h
System.err.println("文件下载结束！"); ZINqIfc
} s6.#uT7h
catch(Exception e){e.printStackTrace ();} =#K$b *#
} `2.2; Vk
oRQJ YH
b@m\ca
//获得文件长度 -3T~+
public long getFileSize() t8\XOj
{ U6 $)e.FO
int nFileLength = -1; U3 y-cgE
try{ i!DO
URL url = new URL(siteInfoBean.getSSiteURL()); \aB>Q"pS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :$?^ID
httpConnection.setRequestProperty("User-Agent","NetFox"); v5`Q7ZZ
m[%*O#_
rA6lyzJ
int responseCode=httpConnection.getResponseCode(); A0`#n|(Ad!
if(responseCode>=400) Fg<rz&MR
{ '980.
processErrorCode(responseCode); J8:f9a:|M
return -2; //-2 represent access is error wR*>9LjeG
} 6im!v<1Qx
>YuiCf?c7
^oT!%"\
String sHeader; C)8>_PY[M
ZQ'bB5I
r~U/t~V=D
for(int i=1;;i++) !i77v, (#|
{ +8~C&K:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sm>5n_Vw
//Utility.log(in.readLine()); Vi o ~2
sHeader=httpConnection.getHeaderFieldKey(i); FEzjP$
if(sHeader!=null) 'I8K1Q=/
{ \.,qAc\[
if(sHeader.equals("Content-Length")) '&n4W7
{ ^;=L|{Xl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r[Zg$CW
break; oGXndfd"
} oP 4z>
} [/iT D=O,
else 0}d^UGD
break; !&b wFO>P
} _)6N&u8
} ]|PDsb"e
catch(IOException e){e.printStackTrace ();} 1?j['~aE
catch(Exception e){e.printStackTrace ();} bJ#]Xm(]D
X cDu&6Dy
k;W`6:Kjp
Utility.log(nFileLength); ;R x Rap
r}]%(D](v
? j8S.d~
return nFileLength; <4m@WG
} z6+D=<
do>,ELS+m
4IH,:w=ofN
//保存下载信息（文件指针位置） p ! _\a
private void write_nPos() H:jx_
{ j|/4V
try{ a/v!W@Zz}
output = new DataOutputStream(new FileOutputStream(tmpFile)); XwNJHOaF
output.writeInt(nStartPos.length); U81--'@y
for(int i=0;i<nStartPos.length;i++) r(Vz(
{ m}oqs0xx
// output.writeLong(nPos); GZ@`}7b}
output.writeLong(fileSplitterFetch.nStartPos); ;ZVT[gi*
output.writeLong(fileSplitterFetch.nEndPos); yv2N5IQ>{V
} ?cRGdLP'D
output.close(); ejjL>'G/|%
} 1#m'u5L
catch(IOException e){e.printStackTrace ();} |1[3RnGS
catch(Exception e){e.printStackTrace ();} UBZ37P
} ?!Bf# "TY
6+s10?
wTw)GV4
//读取保存的下载信息（文件指针位置） <*'%Xgm
private void read_nPos() $wBF'|eU
{ znxP.=GB
try{ Ub_!~tb}?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ].e4a;pt
int nCount = input.readInt(); !/;/ X\d
nStartPos = new long[nCount]; 7u|X .X
nEndPos = new long[nCount]; Z|k>)pv@
for(int i=0;i<nStartPos.length;i++) h]{V/
{ O"6 (k{`
nStartPos = input.readLong(); k(bDj[0q^
nEndPos = input.readLong(); psaPrE
} 0!fT:Ra
input.close(); _9<nM48+t
} 2b i:Q9
catch(IOException e){e.printStackTrace ();} k/;%{@G)
catch(Exception e){e.printStackTrace ();} 6J""gyK.
} )5NjwLs
+ <4gJoI
AIU=56+I\
private void processErrorCode(int nErrorCode) RcG 1J7#i
{ 4[VW~x07
System.err.println("Error Code : " + nErrorCode); Pn|;VCh
} EpsjaOmAF
,^K}_z\9f
"AcC\iq
//停止文件下载 ><Awk~KR
public void siteStop() r|,_qNrw
{ dvX[,*wz
bStop = true; }8e_
for(int i=0;i<nStartPos.length;i++) 818,E
fileSplitterFetch.splitterStop(); YQ7\99tj
w28&qNha
:FN-.1C
} ;.'\8!j
} Z&![W@m@0N
//负责部分文件的抓取 A6Vb'Gqv{
**FileSplitterFetch.java \)'5V!B|s
*/ FMNT0
package NetFox; oH]_2[ !
d"0=.sA
5ca!JLs
import java.io.*; 1&.q#,EMn(
import java.net.*; uK;&L?WB
-2/&i
p-o8Ctc?V
public class FileSplitterFetch extends Thread { 3"O&IY<
L}M%z9K`h
lh`ZEvt
String sURL; //File URL nQaryL
long nStartPos; //File Snippet Start Position /a7N:Z_Bz
long nEndPos; //File Snippet End Position =v:}{~M^$
int nThreadID; //Thread's ID 2K VX
boolean bDownOver = false; //Downing is over Mc@_[q!xY?
boolean bStop = false; //Stop identical kuI$VC
FileAccessI fileAccessI = null; //File Access interface JUpb*B_z
#i'wDvhol
dzRnI*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8quH#IhB
{ R}E$SmFg
this.sURL = sURL; 8c3/n
this.nStartPos = nStart; Bag_0.H&m
this.nEndPos = nEnd; s/\<;g:u^
nThreadID = id; me+u"G9I;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m8Y>4:Nw
} GvTA/zA
qF3s&WI
`P/87=h
public void run() ~oX`Gih
{ U)6Ew4uRxV
while(nStartPos < nEndPos && !bStop) dh-?_|"
{ lKBI3oYn
]MmFtdvE
x,j%3/J^2
try{ <0btwsv}
URL url = new URL(sURL); H.]p\UY9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 044Q>Qz,
httpConnection.setRequestProperty("User-Agent","NetFox"); Y;1s=B9
String sProperty = "bytes="+nStartPos+"-"; oEJxey]B7
httpConnection.setRequestProperty("RANGE",sProperty); U7xKu75G1
Utility.log(sProperty); |<2<`3
J;S Z"I'
t3<HE_B|
InputStream input = httpConnection.getInputStream(); otmyI;v 7<
//logResponseHead(httpConnection); U&o~U] rm
hH]oJ}H \
t;b1<TLn0
byte[] b = new byte[1024]; 5;CqGzgoP
int nRead; >>T,M@s-:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #Fckev4
{ B,4 3b O
nStartPos += fileAccessI.write(b,0,nRead); ,E&W{b
//if(nThreadID == 1) PnJA'@x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lGXr-K?+Y
} f3SAK!V+s
Sd *7jW?
*(o^w'5
Utility.log("Thread " + nThreadID + " is over!"); ^%t{:\
bDownOver = true; p?' F$Wz
//nPos = fileAccessI.write (b,0,nRead); Exz(t'
} "P!zu(h4
catch(Exception e){e.printStackTrace ();} ekCt1^5Y
} T~naAP
} |]'gd)%S\
H><! C
6Tg'9|g
//打印回应的头信息 5 J 7XVe>
public void logResponseHead(HttpURLConnection con) BYZllwxwTE
{ @N6KZn|R
for(int i=1;;i++) J:dNV<A^
{ b8h6fB:2
String header=con.getHeaderFieldKey(i); iUk#0 I
if(header!=null) ]D@y""{--s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?MD\\gN
Utility.log(header+" : "+con.getHeaderField(header)); tg;AF<VI
else 7 aN}lQM
break; ;5:3 =F>ao
} ksV^Y=]
} t]6 4=
)%bY2 pk
6BObV/S Jg
public void splitterStop() bj=YFV+
{ %iD'2e:
bStop = true; J\Z\q
} TL@{yJ;s
$*;ke5Dm4
_))--+cL
} Z`yW2ON$'
0kL tL!3
#IxCI)!I{[
/* eXQzCm
**FileAccess.java #4{9l SbU
*//文件访问(定位，写) +.|8W!h`1
package NetFox; lt|UehJF
import java.io.*; ePY69!pO5e
ol@LLT_m
o%l|16DR
public class FileAccessI implements Serializable{ ^w~Utx4
;mXw4_{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =aRE
RandomAccessFile oSavedFile; 4fau 9bW
long nPos; |r/4 ({n
\q:PU6q
}tPI#[cfK
public FileAccessI() throws IOException F}4jm,w
{ Y-G;;~
this("",0); K2ry@haN
} 8p.O rdp
ek]CTUl*
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public FileAccessI(String sName,long nPos) throws IOException Z$ 6yB
{ H:`[$ ^
oSavedFile = new RandomAccessFile(sName,"rw"); h7[PU^m
this.nPos = nPos; nX-%qc"
oSavedFile.seek(nPos); B#K2?Et!t
} <m+$@:cO
5#$5ct
av}pT)]\
public synchronized int write(byte[] b,int nStart,int nLen) ]y<<zQ_fhY
{ r^!P=BS{
int n = -1; ZH=oQV)6
try{ 28d=-s=[
oSavedFile.write(b,nStart,nLen); aDE)Nf}
n = nLen; `"<tk1Kq"
} P:2 0i*QU
catch(IOException e) ewv[nJD$
{ hFr?84sAd
e.printStackTrace (); l;'c6o0e
} c!=^C/5Ee
&HYs^|ydrr
L }&$5KiwV
return n; VD-2{em
} /]"2;e-s+
y w>T1
"ju0S&
} R{A$hnhW6
%SD=3UK6
l/@t>%
/* Zv)x-48
**SiteInfoBean.java 8Qi@z Jq,
*/ Vq1ve;(8s
package NetFox; kc-v(WIC
G9P)Y#WB
nK5FPFz8
public class SiteInfoBean { &[4lP~
Z}4 `y"By
Hm55R
private String sSiteURL; //Site's URL h`,!p
private String sFilePath; //Saved File's Path x1{gw 5:
private String sFileName; //Saved File's Name E0a &1j
private int nSplitter; //Count of Splited Downloading File Ye) F{WqZ#
B&RgUIrFoY
uQlQ%n%
public SiteInfoBean() 0N19R5NN8
{//nSplitter的缺省值为5 nnPY8pdjSD
//default value of nSplitter is 5 T?'Vb
this("","","",5); o$-!E(p
} ]M5w!O!
o `N /w
&o$Pwk\p/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^z\*; f
{ %wuD4PRK
sSiteURL= sURL; ]EZiPW-uy
sFilePath = sPath; MUfhk)"
sFileName = sName; @>sZ'M2mq
this.nSplitter = nSpiltter; 1O,<JrE+-
V,qc[*_3
O$,MdhyXC
} >|@i8?|E
~i y]X:U
?#0|A?U
public String getSSiteURL() 0O:')R&
{ D<d4"*qo
return sSiteURL; O#962\
} y}t1r |p
hbg:}R=B<
$D)Ajd;
public void setSSiteURL(String value) MF["-GvP/
{ oyeJ"E2
sSiteURL = value; 4]18=?r>
} Dw6mSsC/
_wKaFf
oe{K0.`
public String getSFilePath() nVt,= ?_ U
{ U4*Q;A#
return sFilePath; w`$M}oX(
} 1$#{om9
fyE#8h_>4
s35`{PR
public void setSFilePath(String value) aX$Q}mgb
{ [|!A3o
sFilePath = value; K7CrRT3>6
} IDIok~B=e
;9rS[$^$O
"bC1dl<
public String getSFileName() k6?;D_dm
{ [R~`6
return sFileName; nPU=n[t8O
} J*} warf&
]F4.m
L d;))e
public void setSFileName(String value) qXw^y
{ Z.DO 2=+=
sFileName = value; TppuEC>
} fT.GYvt`
]'iOV-2^'
q&RezHK l
public int getNSplitter() C6T?D5
{ T7bDt
return nSplitter; :7P/ZC%
} hmQ;!9
9_
+xc1cki_{
public void setNSplitter(int nCount) 0<";9qN)6
{ (q]_&%yW
nSplitter = nCount; |r%NMw #y
} (Iz$_(
} =h Lw1~
+-*Ww5Zti
Jb (CH4|7
/* >{HQ"{Q
**Utility.java PV\aQO.mo
*/ 8$TSQ~
package NetFox; ;qN;oSK
P`xQL
!|#W,9
public class Utility { ?~p]Ey}~9
c&GVIrJ
0lm7'H*~
public Utility() H-|%\9&{S
{ z?DI4O#Up
^.HvuG},O
OkV*,n
} 3Hd~mfO\
&{uj3s&C
//线程睡眠 nign"r
public static void sleep(int nSecond) 45aUz@
{ \QvoL
try{ wJ%;\06
Thread.sleep(nSecond); {)?:d6"
} 9k.5'#
catch(Exception e) };Oyv7D+b
{ a7@':Rb n
e.printStackTrace (); g]Jt (aYK
} w5+H9R6
} u$38"&cmA
a-bj! Rs
//日志 Pb`Uxv
public static void log(String sMsg) ?bH&F
{ m0Geq.
System.err.println(sMsg); }nUq=@ej
} SYE+A`a
Db`SNk=
dtT:,&
public static void log(int sMsg) @y!oKF
{ Mm)yabP
System.err.println(sMsg); j"F?^0aR,Q
} I?&/J4o:
} 8v}B-cS
1p5n}|
1)o6jGQ
/* >'1[Bh
**TestMethod.java }] p9
*/ ?yc{@|
package NetFox; v6M4KC2?
y<g1q"F
MO>9A,&f
public class TestMethod { 9$?Sts}6&
JyO2P
)UCc!
public TestMethod() Iz^vt#b
{ ///xx/weblogic60b2_win.exe cE;n>ta"F
try{ 'L@kZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kz\Ss|jl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8g0VTY4$jP
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gl"|t't(
fileFetch.start(); N<PDQ
} 0MI4"<
catch(Exception e){e.printStackTrace ();} .0Kc|b=w
Uc;~q-??#
0,/I2!dF?
} jQrj3*V
|z7V1xF
hp1+9vEN
public static void main(String[] args) -|GKtZ]}
{ -3K01p
new TestMethod(); \(A A|;
} (Z0_e&=*
} @jxP3:s
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