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)); uG\+`[-{0
} "Hmo`EB0
for(int i=0;i<nEndPos.length-1;i++) NDhHU#Q9
{ w$H=GF?"
nEndPos = nStartPos[i+1]; ,TD@s$2x
} _9E7;ew
nEndPos[nEndPos.length-1] = nFileLength; ;m}lmq,
} da3]#%i0
} ?lzg )88I
J<:qzwh
*-bR~
//启动子线程 OGNjn9av
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Vtm5&-
for(int i=0;i<nStartPos.length;i++) :N#gNtC)b
{ \%9,<-~[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @b2{'#9]}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^3QHB1I
nStartPos,nEndPos,i); +/q%29-k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v709#/cR
fileSplitterFetch.start(); TL+a_]3@
} EI2V<v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lY_E=K]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *k'oP~:fT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XpWqL9s_E
nEndPos = " + nFileLength); "A^9WhUpJ
// fileSplitterFetch[nPos.length-1].start(); Tn[DF9;?
qFmvc
A'qJke=
//等待子线程结束 bL+Hw6;
//int count = 0; \>w[#4`m
//是否结束while循环 6 $%^
boolean breakWhile = false; F#@Mf?#2
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Kz!-w
while(!bStop) Q"CZ}B1<
{ MP?9k)f
write_nPos(); 1i9}mzy%
Utility.sleep(500); *&>1A A
breakWhile = true; St/Hv[H'[E
Yt2_*K@rC
RNuOwZ1m
for(int i=0;i<nStartPos.length;i++) ;Gxp'y
{ H$Fz{[[u
if(!fileSplitterFetch.bDownOver) IuTZ2~
{ cS,(HLO91
breakWhile = false; H"d.yZM0
break; zt!mx{l'
} r4jW=?|
} =PyU9C-@
if(breakWhile) M)6_Tal
break; ,T_HE3K
wFpt#_fS
b mZRCvW>A
//count++; InMeD[*^
//if(count>4) 5KU}dw>*g
// siteStop(); DM{7x77
} AV AF!Z
D0=D8P}H:
=jip* E^
System.err.println("文件下载结束！"); ,JRYG<O_T
} e{Pgz0sOQ
catch(Exception e){e.printStackTrace ();} L.lmbxn
} R3wK@D
~my\{q
!Pt|Hk dr
//获得文件长度 #ldNWwvRGj
public long getFileSize() 4(2}O-~
{ rE[*iq,#
int nFileLength = -1; p+#J;.
try{ O9oVx4=
URL url = new URL(siteInfoBean.getSSiteURL()); +"Ek? )?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yt!UIl\<
httpConnection.setRequestProperty("User-Agent","NetFox"); Jg3}U j2By
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2pH2s\r<UJ
int responseCode=httpConnection.getResponseCode(); # SV*6
if(responseCode>=400) !NK8_p|X
{ <6U{I '
processErrorCode(responseCode); $@+\_f'bU>
return -2; //-2 represent access is error 7*d}6\ %
} 4VSIE"8e
%Vrl"4^}t
6T&6N0y+9
String sHeader; s#?Y^bgH
#Qc[W +%
&G5+bUF,
for(int i=1;;i++) )7c\wAs
{ J6_Hlt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8vz9o <I
//Utility.log(in.readLine()); $ w:QJ~,s
sHeader=httpConnection.getHeaderFieldKey(i); #z-6mRB
if(sHeader!=null) Fe%Q8RIh_
{ c'&3[aa
if(sHeader.equals("Content-Length")) TZi%,yK
{ #JeZA0r5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N \[Cuh8Fe
break; Pe!uk4}w
} d"uR1rTk
} CT3wd?)z`
else ]plg@
break; T/MbEqAf
} ,sP7/S)FR
} qbu Lcy3
catch(IOException e){e.printStackTrace ();} m*|3
catch(Exception e){e.printStackTrace ();} {l.) *#O
1$?O5.X:
xKEHNgen
Utility.log(nFileLength); tn+i5Eso
*5sr\b4#S
1Jc-hrN-
return nFileLength; B4pheKZ2
} 5G'X\iR
}E[S%W[
tx}{E<\>$
//保存下载信息（文件指针位置） 0!o&=Qh
private void write_nPos() =B4mi.;@i
{ XUfj 0
try{ "]JE]n}Ulg
output = new DataOutputStream(new FileOutputStream(tmpFile)); v$p<6^kJ
output.writeInt(nStartPos.length); U%"c@%B0
for(int i=0;i<nStartPos.length;i++) BM&95p
{ ~0>g 4 D.
// output.writeLong(nPos); ?Q="w5OOD
output.writeLong(fileSplitterFetch.nStartPos); 8<Asg2]6
output.writeLong(fileSplitterFetch.nEndPos); m[!t7e
} Ex^7`-2,B
output.close(); ;:vbOG#aSN
} ^O6PZm5J}
catch(IOException e){e.printStackTrace ();} Yb]eWLv
catch(Exception e){e.printStackTrace ();} *5hg}[n2
} !h}x,=`z/
*J=`"^BO
52q@&')D4M
//读取保存的下载信息（文件指针位置） s[nXr
private void read_nPos() BC%t[H} >R
{ ])'22sY
try{ 2Prr:k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .AH#D}m
int nCount = input.readInt(); ;t:B:4r(j
nStartPos = new long[nCount]; "639oB
nEndPos = new long[nCount]; X2(TuR*t
for(int i=0;i<nStartPos.length;i++) tk|Ew!M:
{ i*#Gq6qZq
nStartPos = input.readLong(); !F/;WjHz
nEndPos = input.readLong(); `22F@JYN
} .8uJ%'$)
input.close(); ce.'STm=
} D0v!fF~
catch(IOException e){e.printStackTrace ();} qi;@A-cq
catch(Exception e){e.printStackTrace ();} Pan^@B=Q
} ha1 J^e
q!$ZBw-7>A
m!er"0
private void processErrorCode(int nErrorCode) &Zs h-|N
{ {vx{Hwyv
System.err.println("Error Code : " + nErrorCode); CSRcTxH
} z,87;4-
MM3X! tq
uwsGtgd&
//停止文件下载 Z`o}xV
public void siteStop() UaiDo"i
{ qtnLQl"M
bStop = true; |+mhYq|`
for(int i=0;i<nStartPos.length;i++) vo-n9Bj
fileSplitterFetch.splitterStop(); {UQpD
6P;IKOv^
e57}.pF^
} IfF<8~~E
} 3:&!Q*i;
//负责部分文件的抓取 -8HIsRh
**FileSplitterFetch.java l"*qj#FD
*/ ;VSHXU'H
package NetFox; z|=l^u6uS
k]u0US9/
Q[;!z1ur
import java.io.*; *P5Xy@:
import java.net.*; %E3|b6k\
@C0{m7q
) 2wof(
public class FileSplitterFetch extends Thread { I?c# T Rm
6 KP
282 m^ 2
String sURL; //File URL WpP8J1KN[
long nStartPos; //File Snippet Start Position 8b8ui
long nEndPos; //File Snippet End Position { .B^
int nThreadID; //Thread's ID bqJL@!T
boolean bDownOver = false; //Downing is over /d%&s^M:
boolean bStop = false; //Stop identical ^DS9D:oE
FileAccessI fileAccessI = null; //File Access interface "pa5+N&2-
+M$2:[xRT
TW(rK&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W @Y$!V<
{ v}Gq.(b
this.sURL = sURL; j/TsHJ=
this.nStartPos = nStart; >k<.bEx(A
this.nEndPos = nEnd; ?5K.#>{
nThreadID = id; FTI[YR8?Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rV<yM$IA
} 2P`hdg
36`aG Y
^2mmgN
public void run() oJ ,t]e*q=
{ "[L[*>[9!
while(nStartPos < nEndPos && !bStop) ;Z-xum{
{ 3v :PBmE
lsCD%P
wA|m/SZx
try{ *>n<7T0
URL url = new URL(sURL); ~P 1(%FZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K||9m+
httpConnection.setRequestProperty("User-Agent","NetFox"); ;JDn1(6
String sProperty = "bytes="+nStartPos+"-"; ^*#5iT8/
httpConnection.setRequestProperty("RANGE",sProperty); tj;<Z.
Utility.log(sProperty); ?;i O
z\*ii<-@
+yiGZV/X
InputStream input = httpConnection.getInputStream(); {-2I^Ym 5i
//logResponseHead(httpConnection); ~=aD*v<3d
'IY?7+[
UpL?6)
byte[] b = new byte[1024]; k {_X%H/
int nRead; R!0O[i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Qv(}*iq]
{ 0V`s 3,k
nStartPos += fileAccessI.write(b,0,nRead); s+YQ :>F
//if(nThreadID == 1) /zMiy?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q@6OIE
} G4{ zt3{
zGHP{a1O7
j!B+Q
Utility.log("Thread " + nThreadID + " is over!"); ;g?oU"YM
bDownOver = true; JOS,>;;F4
//nPos = fileAccessI.write (b,0,nRead); {1li3K&0s
} ><}FyK4C
catch(Exception e){e.printStackTrace ();} F<Js"z+
} 'e_^s+l)a
} tPIT+1.]z
-'QvUHL|
Ac0C,*|^
//打印回应的头信息 mw!D|
public void logResponseHead(HttpURLConnection con) $YSAD\a<
{ )WF]v"t
for(int i=1;;i++) AWsO?|YT
{ qX^#fk7]
String header=con.getHeaderFieldKey(i); N%v}$58Z
if(header!=null) mjO4GpG3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k"Y9Kc0XoU
Utility.log(header+" : "+con.getHeaderField(header)); U']DB h
else |&eZ[Sy(=l
break; *&9_+F8ly
} <e-9We."
} /.9j$iK#
-lV]((I&
G7yCGT)vQ
public void splitterStop() lyNa(3
{ ? acm5dN
bStop = true; _) k=F=
} Pc#8~t}2
U+>!DtOYK
X<dQq`kZ
} `CA-s
JV(qTb W
De%WT:v
/* `[3Iz$K=
**FileAccess.java _U(b
*//文件访问(定位，写) -CtLL_I
package NetFox; ,l^; ZE
import java.io.*; }R4%%)j(Vj
p \A^kX^5
#_0OYL`(mE
public class FileAccessI implements Serializable{ (JHzwI8+
=># S7=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4+e9:r]
RandomAccessFile oSavedFile; ?$i`K|
long nPos; f4YcZyBGv
^BIB'/Kh)
[y-0w.V=oE
public FileAccessI() throws IOException JwG$lGNJ
{ XdE#l/#
this("",0); M}=X/*T
} " 2A`M~
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xS?[v&"2
public FileAccessI(String sName,long nPos) throws IOException ^ZV1Ev8T6
{ (7^5jo[D
oSavedFile = new RandomAccessFile(sName,"rw"); 1"?3l`i
this.nPos = nPos; rOQ@(aUAZ
oSavedFile.seek(nPos); &6<>hqR^
} 1)yEx1
4XpW#>
BOClMeA4
public synchronized int write(byte[] b,int nStart,int nLen) -9TNU7^
{ \H|tc#::{
int n = -1; d/5i4g[q
try{ /.B7y(
oSavedFile.write(b,nStart,nLen); 0t[|3A~Q
n = nLen; 2z+Vt_%
} p vone,y2
catch(IOException e) kx&Xk0F_g
{ t`=TonLb8
e.printStackTrace (); PDQC^2Z
} jkCa2!WQ'i
C^9G \s'
c-3-,pyM_T
return n; Ks'msSMC
} reseu*5
h&@A'om~
ZGO%lkZ.
} 0?OTa<c
g} \$9
.<&o,D
/* aVkgE>
**SiteInfoBean.java NwPGH=V
*/ j#L"fW^GM
package NetFox; JrlDTNJj'
4M4Y2fBH
DP{kin"4I
public class SiteInfoBean { +g/TDwyVH
JLgk?
!SRElb A;i
private String sSiteURL; //Site's URL )y>o;^5'
private String sFilePath; //Saved File's Path xPMTmx?2
private String sFileName; //Saved File's Name =nPIGI72VO
private int nSplitter; //Count of Splited Downloading File Mh [TZfV
IIrh|>d_7
?pSb,kN}'
public SiteInfoBean() Su.imM!
{//nSplitter的缺省值为5 );EW(7KeL
//default value of nSplitter is 5 XG_h\NIL
this("","","",5); ^w]N#%k\H
} yKupPp);
Itq248+Ci
@ 3n;>oi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -M=#U\D
{ 7|$cM7_r
sSiteURL= sURL; 5?6U@??]
sFilePath = sPath; D<=x<.
sFileName = sName; R>Q&Ax
this.nSplitter = nSpiltter; Ja1[vO"YgP
8 KDF*%7'
'dJ#NT25
} {Yq"%n'0
EJC{!06L'/
c%|K x
public String getSSiteURL() Jv_KZDOdk
{ 0X \OQ;
return sSiteURL; +c4-7/kE
} q8&2M
j"G1D-S:
2cv!85
public void setSSiteURL(String value) ~)J]`el,Q
{ R(YhVW_l
sSiteURL = value; ":=\ci]e%
} RNa59b
hF m_`J&"
GD*rTtDWn
public String getSFilePath() ]M^k~Xa
{ i/Zv@GF
return sFilePath; bogw/)1
} ,Sz`$'^c
\tv^],^`
x<&2`=
public void setSFilePath(String value) Std?p{ i
{ FXLY*eRk
sFilePath = value; TpnJm%9`)t
} 6(#fGH&[
RP!!6A6:
#fB&Hv #s7
public String getSFileName() GjVq"S
{ 8w,+Y]X<P[
return sFileName; 9Yu63s ia
} ~!V5Ug_2
qW~Z#Si
>WYiOXYv
public void setSFileName(String value) 6t zUp/O
{ 8bf_W3
sFileName = value; eXs^YPi
} _:N+mEF
T"h@-UcTl
pr~%%fCh
public int getNSplitter() )I~U&sT\/
{ o )\\(^ld
return nSplitter; h=?V)WSM
} +/"Ws'5E
7hV9nuW
=2Vs))>Y
public void setNSplitter(int nCount) ]|H`?L
{ K)ZW1d;
nSplitter = nCount; h?Y->!'
} 11"- taWj
} =1|^) 4M,x
V(gmC%6%l*
qu8!fFQjYL
/* R_DstpsT
**Utility.java 9F~e^v]zp
*/ 0iKSUwps
package NetFox; "+0Yhr?
2OA0rH"v
8m prK`p
public class Utility { &*Sgyk o`
;+-@AYl
Fx@ovI- 5
public Utility() u"$=:GK
{ 7LFJi@*8
F.rNh`44
OM>,1;UH]
} 7lLh4__;`6
A{Kc"s4fO
//线程睡眠 :.VI*X:aQh
public static void sleep(int nSecond) V yOuw9
{ Etj0k} A
try{ j ."L=
Thread.sleep(nSecond); Ee~<PDzB
} biLNR"/E
catch(Exception e) @p$Nw.{'
{ lmGVSdo
e.printStackTrace (); ?IN'Dc9&%-
} ,H)v+lI
} k^H&IS!
thU9s%,
//日志 =00c1v
public static void log(String sMsg) Mzg zOM
{ c 5%uiv]
System.err.println(sMsg); X[SdDYMY
} >P<8E2}*
04j]W]8#
=8o$
public static void log(int sMsg) ]\JLlQ}#H
{ hR4\:s+[
System.err.println(sMsg); .S_7R/2(?
} aAbK{=/y_!
} &g.do?
cko^_V&x
O|} p=ny
/* IgmCZ?l&0
**TestMethod.java |&oTxx$S
*/ M1mx{<]A
package NetFox; {py"Ob_
sBq-"YcjR
v 1.8]||^
public class TestMethod { /g`!Zn8a
&FpoMW
/Kd9UQU
public TestMethod() i8h^~d2"
{ ///xx/weblogic60b2_win.exe uGc0Lv4i/
try{ 1PN!1=F}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3|0wD:Dy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `;}w!U
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^\f1zg9I
fileFetch.start(); hNRN`\5Z
} mXPA1#qo
catch(Exception e){e.printStackTrace ();} -u$U~?|`
{aVRvZH4
Nd h
} 6/3oW}Oo
kf:Nub+h t
si,)!%b
public static void main(String[] args) ?onEqH>
{ u~~H'*EM
new TestMethod(); ;Tec)Fl
} e~ZxDAd
} t?(fDWd|-
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