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)); P,zQl;
} ,XscO7
for(int i=0;i<nEndPos.length-1;i++) =84EX<B
{ 6wT ])84
nEndPos = nStartPos[i+1]; |[r7B*fw
} R68:=E4
nEndPos[nEndPos.length-1] = nFileLength; t<c7%i#Od
} NsS;d^%I
} Tei2[siA5
$XcH.z
tKyGD|g S
//启动子线程 [&P@0Fn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *BrGh
for(int i=0;i<nStartPos.length;i++) ,gpEXUp\
{ sWse (_2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Yx,E5}-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 96;5
nStartPos,nEndPos,i); ]jI<Js*F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I*N v|HST
fileSplitterFetch.start(); I.Catm2
} SHSfe{n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (#6Fg|f4Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yMyvX_UNI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <L*`WO]\l
nEndPos = " + nFileLength); yK&
// fileSplitterFetch[nPos.length-1].start(); IYtiX
?zC{T*a
fD(r/~Vu
//等待子线程结束 }pf|GdL
//int count = 0; 04}8x[t
//是否结束while循环 w-R.)
boolean breakWhile = false; Xm|~1 k_3
CLmo%"\s
jTg~]PQ^
while(!bStop) oj{CNa
{ R{Zd ]HT
write_nPos(); 9,JM$ Y {
Utility.sleep(500); } LC
breakWhile = true; n6t@ e^
1|w@f&W"
O9>$(`@I
for(int i=0;i<nStartPos.length;i++) p[xGL } +\
{ Nc4;2~XwRp
if(!fileSplitterFetch.bDownOver) Y-y yg4JH
{ z7AWWr=H
breakWhile = false; *{+{h;p
break; (57!{[J
} RzL(Gnb
} Ic_NQ<8
if(breakWhile) ]OdZlZBsJ
break; `vOL3`P
9NU0K2S
B1!xr-kC
//count++; /; Bmh=
//if(count>4) O8bxd6xb
// siteStop(); [H<TcT8
} !*"fWahv
D%yY&q;
jci,]*X4
System.err.println("文件下载结束！"); `wtso
} 3rKJ<(-2/
catch(Exception e){e.printStackTrace ();} q{Z#}|km#
} %Rn*oV
}H\I[5*
i}DS+~8v
//获得文件长度 esnq/
public long getFileSize() _#:/ ~Jp
{ s||" } l
int nFileLength = -1; s4"OsgP+
try{ <R /\nYXz
URL url = new URL(siteInfoBean.getSSiteURL()); \4>,L_O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LjBIRV7
httpConnection.setRequestProperty("User-Agent","NetFox"); O[C4xq
(6S'wb
IQ I8v
int responseCode=httpConnection.getResponseCode(); e(?w h
if(responseCode>=400) y'K2#Y~1e
{ K"0IWA
processErrorCode(responseCode); fgdR:@]-
return -2; //-2 represent access is error ;XurH%Mg
} "r-P[EKpL
3T2]V?
__g k:a>oQ
String sHeader; RSp wU;o6z
V95o(c.p
%y6(+I#P
for(int i=1;;i++) K($l>PB,y@
{ 3f[Yk#"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !ZYPz}&N_
//Utility.log(in.readLine()); p{g4`o
sHeader=httpConnection.getHeaderFieldKey(i); SiLW[JXd
if(sHeader!=null) k QuEG5n.-
{ <\^0!v
if(sHeader.equals("Content-Length")) !D#"+&&G8
{ 1M]=Nv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y[8;mCh
break; ]`/>hH>+~9
} q[&Kr+)j
} q+?<cjVg
else sQJ\{'g
break; F]\ Sk'}&
} 1BSd9Ydj
} `6Bx8CZ'I
catch(IOException e){e.printStackTrace ();} PG&t~4QM`
catch(Exception e){e.printStackTrace ();} Z`Y&cKsn
d:%b
"q=Cye
Utility.log(nFileLength); %HUex 6!
[wGj?M}
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return nFileLength; YX$(Sc3.6
} 0<,{poMM
L;Ff(0x|
/<rvaR
//保存下载信息（文件指针位置） vV,TT%J8D
private void write_nPos() LA3m,
{ M\]lNQA
try{ IMf|/a9-
output = new DataOutputStream(new FileOutputStream(tmpFile)); aI=p_+.h
output.writeInt(nStartPos.length); zp}7p~#k^
for(int i=0;i<nStartPos.length;i++) Z)@vJZ*7(
{ uo"<}>iJ
// output.writeLong(nPos); k2}DBVu1
output.writeLong(fileSplitterFetch.nStartPos); Rl?1|$%
output.writeLong(fileSplitterFetch.nEndPos); I9X\@lTf
} *:%&z?<Fw
output.close(); s= Fp[>qA
} 4 &bmt
catch(IOException e){e.printStackTrace ();} WVP?Ie8
catch(Exception e){e.printStackTrace ();} kckRHbeU
} 8eXeb|?J
Z(MZbzY7Hq
zluq2r
//读取保存的下载信息（文件指针位置） t&?jJ7 (&8
private void read_nPos() ;Q{D]4
{ AiHU*dp6
try{ ;\pr05
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '\bokwsP
int nCount = input.readInt(); oCT,v0+4O
nStartPos = new long[nCount]; |4+'YgO
nEndPos = new long[nCount]; VY6G{f
for(int i=0;i<nStartPos.length;i++) ?`RlYu
{ y[7M(K
nStartPos = input.readLong(); bB<S4@jF8z
nEndPos = input.readLong(); k$$SbStD
} tl dK@!E3
input.close(); sc*R:"
} uH\EV`@'
catch(IOException e){e.printStackTrace ();} )>~jjR
catch(Exception e){e.printStackTrace ();} V Rv4p5
} i*$+>3Q-
!/G}vu
i$kB6B#==
private void processErrorCode(int nErrorCode) YeCnk:_ kg
{ l~$)>?ZD
System.err.println("Error Code : " + nErrorCode); B W*8
} C]b:#S${
A.*e8a/6X
h] ho? K
//停止文件下载 P[fy
public void siteStop() :?~)P!/xl5
{ YWU@e[
bStop = true; "d<ucj
for(int i=0;i<nStartPos.length;i++) oI#TjF
fileSplitterFetch.splitterStop(); G+#bO5
xDeM7L'
RF*>U a
} od#Lad@p
} Lu^uY7 ?}
//负责部分文件的抓取 Q=! lbW
**FileSplitterFetch.java ajkV"~w',|
*/ z~f;}`0
package NetFox; UG44 oKB
bq5ySy{8
@|;[ ;:h@
import java.io.*; ^jL44?W}l
import java.net.*; \4qF3#
>/Z*\6|Zx#
=oXlJ[)h
public class FileSplitterFetch extends Thread { sRLjKi2D
y}FG5'5$13
wL3BgCxqDL
String sURL; //File URL %@(+`CCA
long nStartPos; //File Snippet Start Position Q(x=;wf5r
long nEndPos; //File Snippet End Position aPe*@py3T
int nThreadID; //Thread's ID ~{g/
boolean bDownOver = false; //Downing is over Y,mo}X<>
boolean bStop = false; //Stop identical )(YJ6l
FileAccessI fileAccessI = null; //File Access interface kLs{B
fFC9:9<
ZH=Bm^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6}@T^?
{ W@GU;Nr
this.sURL = sURL; ,F!-17_vt
this.nStartPos = nStart; H9_>a-> )~
this.nEndPos = nEnd; /QlzWson
nThreadID = id; j AoI`J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %26HB w=JF
} u6E ze4u
rWJRoGk/
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public void run() }!*|VdL0
{ tT A
while(nStartPos < nEndPos && !bStop) 5^qs>k[mN
{ K)Ya%%6[U#
2 =>3B
RT%{M1tkS
try{ RXWdqaENx
URL url = new URL(sURL); FD8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *|+$7j
httpConnection.setRequestProperty("User-Agent","NetFox"); \WUCm.w6\%
String sProperty = "bytes="+nStartPos+"-"; #5{lOeN
httpConnection.setRequestProperty("RANGE",sProperty); |jWA >S
Utility.log(sProperty); 2C_I3S~U
c!$~_?]
Me+)2S 9
InputStream input = httpConnection.getInputStream(); Nw1 .x
//logResponseHead(httpConnection); li`
esv<b>`R
PB:r+[91
byte[] b = new byte[1024]; {X\FS
int nRead; TU2MG VYy
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X*r?@uK5
{ fb!>@@9Z
nStartPos += fileAccessI.write(b,0,nRead); w 3L+7V,!
//if(nThreadID == 1) p!(]`N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (bogAi3<F
} cn ;2&
|y]8gL^
N1]P3
Utility.log("Thread " + nThreadID + " is over!"); a3_pF~Qx
bDownOver = true; `$VnB
//nPos = fileAccessI.write (b,0,nRead); h`:gMhn
} ,Ct1)%
catch(Exception e){e.printStackTrace ();} T!H }^v
} eOd'i{f@F
} u,Cf4H*xS
l9$"zEC
#Bas+8 @,
//打印回应的头信息 WNV}@
public void logResponseHead(HttpURLConnection con) h\OMWJ~
{ zO)3MC7l*
for(int i=1;;i++) R-Z)0S'ZR
{ m3Rss~l
String header=con.getHeaderFieldKey(i); `CEHl &w
if(header!=null) ~fF;GtP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HY7#z2L
Utility.log(header+" : "+con.getHeaderField(header)); |`ZW(}~
else [Xo[J?w],2
break; f5&K=4khn
} _{YUWV50}
} m3 W
E(Y}*.\]#s
77p8|63
public void splitterStop() :5BVVa0oR
{ (<xl _L:*.
bStop = true; Ex}hk!
} F>[T)t{m=
<GO 5}>}p8
v<tr1cUT
} ^ah9:}Ll
]}0QrD
o0:RsODl
/* Q6rvTV'vv
**FileAccess.java \d}>@@U&
*//文件访问(定位，写) S!+}\*
package NetFox; 0 pPSg9
import java.io.*; 7FGi+
HGlQZwf
sA!$}W
public class FileAccessI implements Serializable{ K:(E"d;
)4e?-?bK!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xSy`VuSl
RandomAccessFile oSavedFile; qvG@kuz8g5
long nPos; l~Rd\.O
ZGj ^,?a
N`et]'_A}
public FileAccessI() throws IOException ~EtwX YkRZ
{ _=-B%m
this("",0); h yK&)y?~
} E.eUd4XG
XR|U6bf]
MUn(ZnQy|
public FileAccessI(String sName,long nPos) throws IOException WT63ve
{ y4)iL?!J~
oSavedFile = new RandomAccessFile(sName,"rw"); 'e/wjV
this.nPos = nPos; %z~=Jz^
oSavedFile.seek(nPos); 7!Qu+R
} z3I |jy1
!|Wf mU
)M><09
public synchronized int write(byte[] b,int nStart,int nLen) lFl(Sww!\
{ &-Ylj
int n = -1; slzB#
try{ T~L&c
oSavedFile.write(b,nStart,nLen); N "}N>xe2
n = nLen; )2a)$qx;
} Y (pUd3y
catch(IOException e) #a9O3C/MP
{ "T9UedZ
e.printStackTrace (); NfUt\ p*
} @VPmr}p:{
"9 f+F
bQ(-M:
return n; Re&"Q8I.8
} Evd|_W-
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A; wT`c
} m7DKC,
'ZB^=T
JQ6M,O
/* fjOq@thD
**SiteInfoBean.java 7f4O~4.[i
*/ P#7=h:.522
package NetFox; UKQ"sC
[orL.D]
eIfQ TV
public class SiteInfoBean { !nCq8~#
H=Ilum06
P/girce0
private String sSiteURL; //Site's URL |PlNVd2
private String sFilePath; //Saved File's Path uO`MA% z<
private String sFileName; //Saved File's Name -X~mW
private int nSplitter; //Count of Splited Downloading File u;gO+)wqv
qQi\/~Y[:
2h'Wu qO
public SiteInfoBean() m^G(qoZ]
{//nSplitter的缺省值为5 kB> ~Tb0
//default value of nSplitter is 5 acR|X@\3
this("","","",5); S k~"-HL|
} &J*M
<ZF|2
Ch_rV+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U8w_C\Q
{ `daqzn
sSiteURL= sURL; 67YC;J]n=z
sFilePath = sPath; w8UuwFG?<
sFileName = sName; >w@+cUto
this.nSplitter = nSpiltter; ba);f[>
{K]5[bMT
3/@z4:p0R
} %,kP_[!>Q
&$F<]]&
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public String getSSiteURL() @#)` -]g
{ H<Oo./8+
return sSiteURL; `za,sRFR
} .p&@;fZ
\=AA,Il
8AuBs;i
public void setSSiteURL(String value) W]9*dabem
{ d,b4q&^X8
sSiteURL = value; gBm'9|?
} &riGzU]
%9J@##+
4wl1hp>,
public String getSFilePath() 6pt_cpbR
{ m+kP"]v
return sFilePath; .f\LzZ-I:
} a1U|eLmUb
H_DCdUgC'
J D\tt-
public void setSFilePath(String value) &L;ocd$
{ (vs<Fo|]
sFilePath = value; -8TJ:#|N
} RgJ@J/p"
)g0lI
Xz+%Ym
public String getSFileName() RZOK+!H:
{ +)Z]<O
return sFileName; SepjF
} ~ZHjP_5Q
@T'^V0!-q:
j]Auun
public void setSFileName(String value) Rn1oD3w
{ d>NGCe
sFileName = value; I= mz^c{
} Njq}M/{U
|.<_$[v[x
j{@O%fv=
public int getNSplitter() q!Du J
{ +&GV-z~o
return nSplitter; -;""l{
} ^_7|b[Bt
om3 %\
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public void setNSplitter(int nCount) 'o AmA=
{ K$"#SZEi
nSplitter = nCount; LUOjaX
} T(J'p4
} _&<n'fK[
xc^@"
,7{|90'V<
/* Y(Q 0m|3P
**Utility.java q<3nAE$?=
*/ *PJH&g#Ge
package NetFox; !_QI<=X
Z,&O8Jelf
qeZG/\,
public class Utility { 1w,_D.1'
S%SYvA
)nUdU = m
public Utility() 26V6Y2X
{ OC! {8MR
$LP(\T([
&RR;'wLoQT
} lrrTeE*
"4b{YWv
//线程睡眠 z)Rkd0/X
public static void sleep(int nSecond) dXyMRGRUq
{ R|?n
try{ '}cSBbl&/n
Thread.sleep(nSecond); 6 AO(A *
} }Qo]~/
catch(Exception e) #X(2
{ u#6s^ )W
e.printStackTrace (); g;l K34{
} GRc)3 2,
} \8(Je"S
0fc;H}B*
//日志 }B%9cc
public static void log(String sMsg) ch#)XomN
{ RHsVG &<j
System.err.println(sMsg); :k9T`Aa]
} `.@udfog^0
7[e-3
2)BO@]n
public static void log(int sMsg) % jDH{xSMb
{ .1(_7!m@
System.err.println(sMsg); =1Plu5
} <v1H1'gv
} -axKnfj
olv&K(-ccI
v:lkvMq|=
/* Az8b_:=
**TestMethod.java "s@Hg1
*/ LYAGpcG
package NetFox; H2iIBGu|L
,t_&tbf3
5VE=Oo#&
public class TestMethod { lP=,|xFra
E2l"e?AN~
<Z[Z&^
public TestMethod() 0~<?*{~
{ ///xx/weblogic60b2_win.exe hxdjmc-
try{ ZKW1HL ]m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C{U*{0}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xqdkc^b
SiteFileFetch fileFetch = new SiteFileFetch(bean); S#CaJ}M
fileFetch.start(); yfwR``F
} &R/-~w5
catch(Exception e){e.printStackTrace ();} nUs=PD3)
"#36-
GRpwEfG
} `4ga~Ch
GQ85ykky
9k4z__Ke
public static void main(String[] args) 1z; !)pG.
{ -5os0G80
new TestMethod(); .R)Ho4CE
} N f?\O@
} w3iX "w
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