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)); 6# bTlmcg
} otaRA
for(int i=0;i<nEndPos.length-1;i++) ;~1xhpTk
{ w.rcYywI
nEndPos = nStartPos[i+1]; B|o@|zF
} J<0sT=/2$
nEndPos[nEndPos.length-1] = nFileLength; 5ms]Wbh)
} E;H9]*x/
} mdbi@ms@
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jcC"vr'u|
//启动子线程 InL_JobE8r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %4R1rUrgt|
for(int i=0;i<nStartPos.length;i++) id,'+<
{ C`ZU.|R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OGW3Pe0Z'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aQHR=.S]X
nStartPos,nEndPos,i); ;eo}/-a_Xw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jp"Q[gR##
fileSplitterFetch.start(); M:.+^.h
} XlXt,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ml2/}}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'Jek< 5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X
nEndPos = " + nFileLength); @[v,q_^8
// fileSplitterFetch[nPos.length-1].start(); R:l&2
\(`2@
Y9-F\t=~
//等待子线程结束 e1b?TF@lz
//int count = 0; Q e/XEW
//是否结束while循环 +P9eE,WR
boolean breakWhile = false; r(>812^\
xxg/vaQt=s
o/&K>]8M
while(!bStop) gKQs:25
{ Txl|F\nK`
write_nPos(); ;Y8>?
Utility.sleep(500); #I MaN%
breakWhile = true; v2r|)c,h
wQ/.3V[
z&c}
for(int i=0;i<nStartPos.length;i++) Jza?DhSAZ
{ &E6V'*<93
if(!fileSplitterFetch.bDownOver) )n<p_vz
{ "\vQVZd-E
breakWhile = false; _PGd\>Ve
break; W!"QtEJ,
} !5h8sD;
} d"E3ypPK
if(breakWhile) _B^X3EOc
break; Xk'Pc0@a
pyX:$j2R+%
B[h^]k
//count++; unqUs08
//if(count>4) -ON-0L
// siteStop(); F+NX [
} U8gj\G\`
3mopTzs)
R'vNJDFY
System.err.println("文件下载结束！"); !?).4yr
} [+l6x1Am
catch(Exception e){e.printStackTrace ();} j(k%w
} KiFTj$w,
E ?bqEW(
l{]KA4
//获得文件长度 Yv)c\hm(7j
public long getFileSize() m6^#pqSL
{ _OJfd
int nFileLength = -1; [n&ES\o#(
try{ 2wPc yD
URL url = new URL(siteInfoBean.getSSiteURL()); \M|:EG%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G; exH$y
httpConnection.setRequestProperty("User-Agent","NetFox"); *"Iz)Xzc`
D vU1+y
(~bx%
int responseCode=httpConnection.getResponseCode(); zN;P_@U
if(responseCode>=400) !;vv-v,LQ
{ 3G<4rH]
processErrorCode(responseCode); @PLJ)RL
return -2; //-2 represent access is error 'Q7^bF^
} 8sBT&A6&j
,uNJz-B8
dIh+h|:
String sHeader; g]N'6La
tcRJ1:d
cX4]ViXSr
for(int i=1;;i++) K1R?Qt,qDF
{ 9c*B%A8J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -F*vN'
//Utility.log(in.readLine()); yZm=#.f
sHeader=httpConnection.getHeaderFieldKey(i); |N)),/R_
if(sHeader!=null) _Yp~Oj
{ |v : )9
if(sHeader.equals("Content-Length")) z$d<ep{6
{ \o72VHG66
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -&]!ig5v
break; l\Ww^
} D:IG;Rsc
} E^c*x^
else f)a0!U 44
break; KZ#\ >
} QS\wtTXj
} P zM yUv
catch(IOException e){e.printStackTrace ();} <HN{.p{
catch(Exception e){e.printStackTrace ();} olL? 6)gC
1ZRkVHiz0
q &{<HcP
Utility.log(nFileLength); X's<+hK&
ZvT>A#R;l~
u^JsKG+,:
return nFileLength; YHu]\'Ff
} )cP)HbOd=
L@zhbWY
E]m?R 4
//保存下载信息（文件指针位置） aHYISjZ]>
private void write_nPos() -/Wf iE
{ *TI?tD
try{ `]@=Hx(
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6@8z3JW.A
output.writeInt(nStartPos.length); U~"Y8g#qgy
for(int i=0;i<nStartPos.length;i++) ,=[%#gS
{ FY^Nn
// output.writeLong(nPos); q TN)2G
output.writeLong(fileSplitterFetch.nStartPos); H|wP8uQC
output.writeLong(fileSplitterFetch.nEndPos); 9^8OIv?m8
} )i[Vq|n
output.close(); -TG ="U
} pz)>y&_o
catch(IOException e){e.printStackTrace ();} <m1v+cnqo
catch(Exception e){e.printStackTrace ();} -MTYtw(
} Kr|.I2?"
^[Ka+E^Q
O&|<2Qr
//读取保存的下载信息（文件指针位置） -<5{wQE;|
private void read_nPos() GQCdB>
{ Z(Y:
try{ d(ypFd9z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T{f$S
int nCount = input.readInt(); [>\|QS|
nStartPos = new long[nCount]; ]PoWL;E'
nEndPos = new long[nCount]; B{:a,V7
for(int i=0;i<nStartPos.length;i++) 0{8L^ jB/
{ %-.;sO=g
nStartPos = input.readLong(); rvd%z7Z1o
nEndPos = input.readLong(); !3mt<i]a"
} #C?M-
input.close(); hKWWN`;b !
} =EA:fq
catch(IOException e){e.printStackTrace ();} oo7}Hg>
catch(Exception e){e.printStackTrace ();} Yb/*2iWX
} 9`Fw}yAt
s<k2vbhI
vPz7*w
private void processErrorCode(int nErrorCode) x(eX.>o\
{ ^IIy>
System.err.println("Error Code : " + nErrorCode); v}V[sIs}
} ^V96lKt/
h !R=t
p:Lmf8EI
//停止文件下载 GbL1<P$V
public void siteStop() Px \cT
{ .1{{E8Fj
bStop = true; nR*' 3
for(int i=0;i<nStartPos.length;i++) Km%L1Cd]
fileSplitterFetch.splitterStop(); MsP6C)dz
wB \`3u4
}$L63;/H
} }(ORh2Ri
} "z3rH~q72
//负责部分文件的抓取 qa )BbK^i
**FileSplitterFetch.java uXh:/KO
*/ W [K.|8ho
package NetFox; Ihf :k_;
F!0iM)1o
(A6~mi r!
import java.io.*; VLkAsM5}%
import java.net.*; R( FQ+h
g]2L[4
.\^0RyJE
public class FileSplitterFetch extends Thread { Em@:QmEN
D5?8`U m=
n%J=!z3
String sURL; //File URL BrwC9:
long nStartPos; //File Snippet Start Position k_0@,b3
long nEndPos; //File Snippet End Position !#O[RS
int nThreadID; //Thread's ID uy3<2L#.
boolean bDownOver = false; //Downing is over M]/aW
boolean bStop = false; //Stop identical tMiIlf!>p
FileAccessI fileAccessI = null; //File Access interface V1V0T ,
#T^2=7 w
`/P/2{,~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d"#Zp&#
{ "}fweCBgo
this.sURL = sURL; Zg(Y$ h\
this.nStartPos = nStart; L4g%o9G
this.nEndPos = nEnd; +)jll#}?
nThreadID = id; WxGD*%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $El-pMq
} Lau@HYW0
Z,38eQpM
-y+>^45
public void run() %7)=k}4
{ {G:y?q'z
while(nStartPos < nEndPos && !bStop) "S%t\
{ zzQWHg]/
.Q*X5Fc
5XZ!yYB?
try{ ^QRg9s,T<
URL url = new URL(sURL); eyJ07
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pFd8p@m_2
httpConnection.setRequestProperty("User-Agent","NetFox"); 6@J=n@J$p
String sProperty = "bytes="+nStartPos+"-"; B;1qy[
httpConnection.setRequestProperty("RANGE",sProperty); aKbmj
Utility.log(sProperty); 6gg8h>b
NXY jb(4:
$RPW/Lyiq
InputStream input = httpConnection.getInputStream(); az(<<2=
//logResponseHead(httpConnection); Cl}nPUoL
/fr>Fd
`C+<!)2
byte[] b = new byte[1024]; #@S%?`4,
int nRead; Ma[EgG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V)`2Kw
{ @p+;iS1}
nStartPos += fileAccessI.write(b,0,nRead); x<NPp&GE
//if(nThreadID == 1) @c3xUK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @w[i%F,&`
} yGZsNd {a&
kXMp()N8`
+2~kHrv
Utility.log("Thread " + nThreadID + " is over!"); [. 5m}V
bDownOver = true; o\IMYT
//nPos = fileAccessI.write (b,0,nRead); *v>ZE6CL
} ISbs l=F
catch(Exception e){e.printStackTrace ();} jVj5; }
} J!6FlcsZm
} }h5i Tc
`2s!%/
6o3 bq|
//打印回应的头信息 > VG
public void logResponseHead(HttpURLConnection con) *eVq(R9?T
{ /0h *(nL
for(int i=1;;i++) rz?Cn X.t
{ p*Bty@CRi
String header=con.getHeaderFieldKey(i); N%y i4
if(header!=null) {f!/:bM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `BPTcL<W
Utility.log(header+" : "+con.getHeaderField(header)); dhl[=Y` Q
else %\As
break; yzA05npTl
} GP|=4T}Bf
} pJpapA2l*6
J~Xv R
$Gn.G_"v
public void splitterStop() ) nfoDG#O
{ WeI+|V$
bStop = true; yqK4 "F&
} T5BZD +Ta
^S9y7b^;r
bQAznd0
} !XA3G`}p6s
=lXj%V^8N
"q4tvcK.
/* h$>F}n j
**FileAccess.java [}X|&`'i
*//文件访问(定位，写) B*7kX&Uq
package NetFox; eE;tiX/
import java.io.*; 7\u+%i;YZ
d1/emwH
H^_,e= j
public class FileAccessI implements Serializable{ y!e]bvN
x^f<G 6z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w-jElV
RandomAccessFile oSavedFile; -DDA b(2*
long nPos; 'X~tt#T
h\m35'v!
idmU.`
public FileAccessI() throws IOException d{ (,Gy>I
{ $o"nTl
this("",0); x"W~m.y$h
} ^s,3*cAU
-"(*'hD
U%{GLO
public FileAccessI(String sName,long nPos) throws IOException A#uU]S
{ SpH|<L3
oSavedFile = new RandomAccessFile(sName,"rw"); NgNGq\!
this.nPos = nPos; y48]|%73
oSavedFile.seek(nPos); eK8H5YE
} [f6uwp
PN}+LOD<t
#mH@ /6,#[
public synchronized int write(byte[] b,int nStart,int nLen) vwR_2u
{ 5<?Ah+1
int n = -1; 337.' |ZE
try{ P-m_],
oSavedFile.write(b,nStart,nLen); xh6(~'$
n = nLen; {+N< 9(O
} Z:b?^u4.
catch(IOException e) EZtU6kW"
{ A`c22Ls]
e.printStackTrace (); ,"qCz[aDN1
} ~W'DEpq_
7KT*p&xm
:]"5UY?oF
return n; 5zuwqOD*
} n}p G&&;q
%wD#[<BGn>
T+8Yd(:hX
} 1-RY5R}VR
%V_ XY+o
Jcw^Z,
/* MVatV[G
**SiteInfoBean.java +/OSg.
*/ whI{?NP
package NetFox; .j6udiv5
2j\_svw'
[V}vd@*k
public class SiteInfoBean { KbJ6U75|f
o<g?*"TRh
=g% L$b<i
private String sSiteURL; //Site's URL Khq\@`RaT
private String sFilePath; //Saved File's Path ]l7W5$26 @
private String sFileName; //Saved File's Name S)CsH1Q
private int nSplitter; //Count of Splited Downloading File HG]ARgOB
Z'o0::k
EPo)7<|>
public SiteInfoBean() )1<0c@g=
{//nSplitter的缺省值为5 BRFsw`c
//default value of nSplitter is 5 {R$`YWk
this("","","",5); 3j#VKj+Uc
} "$BkO[IS
1eXMMZ/?
jAQ{H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3G// _f
{ -]EL|_;
sSiteURL= sURL; kHg|!
sFilePath = sPath; ? Fqh i
sFileName = sName; K#FD$,c~
this.nSplitter = nSpiltter; OPvPP>0*8
{/[@uMS_6]
8~y!X0Ov!
} Uo3
qw+7.h#V
ZllmaI
public String getSSiteURL() 4DIU7#GG
{ t/i*.>7
return sSiteURL; PpRS4*nR
} SiNgV\('U
pI@71~|R
Fd8nR9A
public void setSSiteURL(String value) PvKGB01_
{ jLFaf#G]
sSiteURL = value; ;&lXgC^*
} (~|)Gmq2
(4Db%Iw
za>%hZf\
public String getSFilePath() P, x"![6
{ |E13W
return sFilePath; Dw=L]i :0v
} #kQ! GMZH
TjpyU:R,&|
IO7z}![V;
public void setSFilePath(String value) '[r:pwE
{ dX\OP>
sFilePath = value; =K@LEZZ'/<
} f}dlQkZ(
l_yy;e
F,YPIl
public String getSFileName() Iq|h1ie m+
{ <v ub Q4
return sFileName; c|%5SA
} 2tU3p<[
S5|7D[*
:F d1k Jm
public void setSFileName(String value) TT/=0^"
{ =u0=)\0@r
sFileName = value; ZW M:Wj192
} 5ncW s)
1uo |a
b$w66q8
public int getNSplitter() iBWzxPv:z
{ LBio$67F
return nSplitter; nANl9;G
} HubG>]
tE>FL
^uo,LTq+
public void setNSplitter(int nCount) !,-'wT<v
{ `LH9@Z{
nSplitter = nCount; u!xgLf'`
} ,T;sWl
} 8V(~u^!%_
M5[#YG'FlQ
"eoPG#]&
/* 0MT?}D&TL
**Utility.java ,%Pn.E* r;
*/ H!NGY]z*
package NetFox; T7YJC,^m
:Gz$(!j1.'
h-.^*=]R6
public class Utility { uA`e
vkLt#yj~
W)`>'X`
public Utility() ym p*:lH(
{ Bl)D/
'>OEQU5-
)1 @v<I
} $_%
n2aUj(Zs=
//线程睡眠 y2k's
public static void sleep(int nSecond) DvN_}h^nX
{ z@~ZMk
try{ 8<Nz34Y
Thread.sleep(nSecond); 0?R$>=u
} /3+E-|4s
catch(Exception e) 0$XrtnM
{ XffHF^l9F
e.printStackTrace (); ;[zZI~wh
} B8cg[;e81
} qPN
%to.'R
//日志 57 Vn-
public static void log(String sMsg) 9U9ghWH8
{ h1)+QLI
System.err.println(sMsg); +vFqHfmP
} -vT$UP
E=v4|/['N
b6g9!
public static void log(int sMsg) 9~,!+#
{ i(u zb<
System.err.println(sMsg); a"+/fC`
} CE183l\
} _ru<1n[4~
YU87l
U;4;>
/* (^=kV?<
**TestMethod.java &=8ZGjR< }
*/ B_r:daCS:
package NetFox; 4yu=e;C wy
D-e^b'l
4!glgEE*
public class TestMethod { Rlr[uU_
Yk4ah$}%-^
xoSBMf
public TestMethod() 6yaWxpW
{ ///xx/weblogic60b2_win.exe p8y<:8I
try{ +'e3YF+'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yC}x6xG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fQU_A
SiteFileFetch fileFetch = new SiteFileFetch(bean); a.<!>o<t:
fileFetch.start(); '?|.#D#-c
} OUHd@up@n
catch(Exception e){e.printStackTrace ();} Qe<c@i"
Tq6@ 1j6p
HV3D$~gF
} wZ8LY;
YkV-]%c
%D^j7`Z
public static void main(String[] args) :)e/(I]
{ Yh%
new TestMethod(); @iz6)2z
} Io;26F""
} 9/\=6vC|
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