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)); aFbA=6
} _H;ObTiB
for(int i=0;i<nEndPos.length-1;i++) Lu<'A4Q1
{ #2`tsZ]=I
nEndPos = nStartPos[i+1]; &-&6ARb7o
} 0phGn+"R
nEndPos[nEndPos.length-1] = nFileLength; %f^TZ,q$
} .]jKuTC\<
} %]:u^\7
.E@yB`AR
"q%Q[^b
//启动子线程 uEk$Y=p7!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fdPg{3x*k
for(int i=0;i<nStartPos.length;i++) iveWau292
{ Ddu$49{S:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /FQumqbnt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gsZCWT
nStartPos,nEndPos,i); 2B*9]AHny
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]pFYAe ?
fileSplitterFetch.start(); u9?85
} 7o;}"Y1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _p90Zm-3X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d_OHQpfK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ypp>7J/
nEndPos = " + nFileLength); vZk+NS<
// fileSplitterFetch[nPos.length-1].start(); Dn9Ta}miTO
T3Tk:r
Q"\*JV5
//等待子线程结束 Iunt!L
//int count = 0; 7?F0~[eGG
//是否结束while循环 ?6a:!^eL
boolean breakWhile = false; 6@nEcr
2avSsN{^
x0 3|L!n
while(!bStop) |)0kvf?
{ NBLOcRSh
write_nPos(); (h2bxfV~+
Utility.sleep(500); UW40Y3W0
breakWhile = true; \N!k)6\
whD%Oz*f
F9Mv$g79
for(int i=0;i<nStartPos.length;i++) &%FpNU9
{ E5Z,4B
if(!fileSplitterFetch.bDownOver) IV!&jL
{ Pxl7zz&pl=
breakWhile = false; >7 4'g}
break; r`mfLA]d
} ,%D \
} y%z$_V]
if(breakWhile) TqzkF7;k4
break; yfi.<G)S
a2sN$k
TTBl5X
//count++; ]G&d`DNV
//if(count>4) Vo%@bj~>
// siteStop(); <w8*Ly:L
} [1l,I[
8/]5h%
A LKU
System.err.println("文件下载结束！"); mKn:EqA
} poQY X5
catch(Exception e){e.printStackTrace ();} }oloMtp$
} /\OjtE
ix6j=5{
`@-H ;
//获得文件长度 3~"G27,
public long getFileSize() cgml^k\k^
{ c:4i&|n
int nFileLength = -1; "Bn!<h}mg
try{ -Y;(yTtz
URL url = new URL(siteInfoBean.getSSiteURL()); >e'6RZRLA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @G^ l`%
httpConnection.setRequestProperty("User-Agent","NetFox"); Nx,.4CI
w {6kU
vz/.*u
int responseCode=httpConnection.getResponseCode(); #2/k^N4r
if(responseCode>=400) epR7p^`7
{ v2/@Pu!kg
processErrorCode(responseCode); 1iig0l6\m
return -2; //-2 represent access is error #r>
} jl%27Ld
a%V6RyT4qW
t4~Bn<=
String sHeader; P^T]Ubv"
-n+=[M
c|IH|y
for(int i=1;;i++) Z!v)zH\
{ NRgNh5/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xw_AZ-|1D
//Utility.log(in.readLine()); k0Rd:DxO
sHeader=httpConnection.getHeaderFieldKey(i); R~PD[.\u
if(sHeader!=null) yC(xi"!
{ jgK8} C
if(sHeader.equals("Content-Length")) lN-vFna
{ tp7cc;0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vYcea
break; NirG99kyo
} |W:xbtPNy
} JPRo<jt=
else &,JrhMr\
break; W0R<^5_
} ..)O/g.
} )E;B'^RVR
catch(IOException e){e.printStackTrace ();} K!=Y4"5%
catch(Exception e){e.printStackTrace ();} F^fL
6Q"fRXM
>;:235'(M
Utility.log(nFileLength); 7A<X!a
3"!h+dXw
CD]"Q1 t}
return nFileLength; >cpT_M&C,
} vz[oy|{F
mu@He&w"
suiO%H^t
//保存下载信息（文件指针位置） ] -iMo4H
private void write_nPos() avxr|uk
{ FN0)DN2d}
try{ waT'|9{
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y=6569U2
output.writeInt(nStartPos.length); `#Z=cq^_
for(int i=0;i<nStartPos.length;i++) (_1(<Jw
{ 6&xpS9
// output.writeLong(nPos); z0!k
output.writeLong(fileSplitterFetch.nStartPos); 4AW-'W
output.writeLong(fileSplitterFetch.nEndPos); z_nv|5"
} |Y"nZK,
output.close(); %k3A`ClW
} 5e1;m6
catch(IOException e){e.printStackTrace ();} $S(<7[Z
catch(Exception e){e.printStackTrace ();} (qo ?e2K
} x *:v]6y
!p #m?|Km
g6aIS^mU
//读取保存的下载信息（文件指针位置） wo>7^ZA
private void read_nPos() ,58XLu
{ `X)y5*##wq
try{ Lp31Y .4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -j& A;G
int nCount = input.readInt(); .=G?Zd
nStartPos = new long[nCount]; weX%S&#?
nEndPos = new long[nCount]; _?~EWT
for(int i=0;i<nStartPos.length;i++) F)K&a
{ #w]UP#^io
nStartPos = input.readLong(); y Ny,$1
nEndPos = input.readLong(); kZ5;Fe\*
} S,0h &A9
input.close(); ^-nL!>FYY
} c`,'[Q5(O
catch(IOException e){e.printStackTrace ();} U-+o6XX
catch(Exception e){e.printStackTrace ();} W=G8l%
} l;7T.2J'Z
qL2!\zt>g
E>_N|j)9
private void processErrorCode(int nErrorCode) 1#tFO
{ n Nu~)X
System.err.println("Error Code : " + nErrorCode); h8XoF1wuw
} {3Y R_^>?
= q\TWz
yjE$o?A
//停止文件下载 }vK8P r%
public void siteStop() >dK# tsp
{ S/,)X
bStop = true; ?*AhGza/
for(int i=0;i<nStartPos.length;i++) 6K7DZ96L
fileSplitterFetch.splitterStop(); unvS`>)Np
>p*7)
Wr+/9
} V |cPAT%
} z"%{SI^
//负责部分文件的抓取 zu_bno!
**FileSplitterFetch.java @oKW$\
*/ R,8 W7 3
package NetFox; #IvHxSo&
3-Bz5sj9
A'6-E{
import java.io.*; "UYlC0 S\
import java.net.*; HkPdqNC&
n:"0mWnL$y
l~Hu#+O
public class FileSplitterFetch extends Thread { YQ|o0>
:P8X?C63W]
l6T^e@*
String sURL; //File URL `c)[aP{vN
long nStartPos; //File Snippet Start Position {[pzqzL6
long nEndPos; //File Snippet End Position J7pF*2
int nThreadID; //Thread's ID =JaxT90x
boolean bDownOver = false; //Downing is over FJD;LpW
boolean bStop = false; //Stop identical :@4+}
FileAccessI fileAccessI = null; //File Access interface {F=`IE3)w
]bP1gV(b-
kD46Le++B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 719lfI&s
{ S'(IG m4
this.sURL = sURL; {ui{Yc
this.nStartPos = nStart; y9Pw'4R
this.nEndPos = nEnd; k 1lK`p
nThreadID = id; a9_KoOa.H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1lYQR`Uh
} ~KYA{^`*
M 4E|^p=5
Hb3..o:
public void run() ku)/ 8Z`$
{ kO/YO)g
while(nStartPos < nEndPos && !bStop) bfq%.<W
{ cO8yu`4!e
B7.<A#y2
7Hg;SK6t0
try{ ]T=o>%
URL url = new URL(sURL); &3Ry0?RET
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 14`S9SL{V
httpConnection.setRequestProperty("User-Agent","NetFox"); eRm*+l|?
String sProperty = "bytes="+nStartPos+"-"; #AH gY.
httpConnection.setRequestProperty("RANGE",sProperty); f5z*AeI
Utility.log(sProperty); 2)Q%lEm`SP
;TKsAU
R8>17w.
InputStream input = httpConnection.getInputStream(); X`C ozyYuD
//logResponseHead(httpConnection); KK?R|1VK9
u p zBd]
V]Kk=
byte[] b = new byte[1024]; q*!Vyk
int nRead; I6i qC"BK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jZk dTiI
{ ?aQVaw&L!7
nStartPos += fileAccessI.write(b,0,nRead); rRXF@
//if(nThreadID == 1) -amNz.`[PR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8dh ?JqX
} &,QBJx<#
gm$<U9L\v
;EsfHCi)
Utility.log("Thread " + nThreadID + " is over!"); 8&:dzS
bDownOver = true; V#+M lN
//nPos = fileAccessI.write (b,0,nRead); ZEB,Q~
} &8dj*!4H
catch(Exception e){e.printStackTrace ();} B A i ^t
} Ju"/#@
} [U,hb1Wi3
s(:N>K5*
(g>&ov(d
//打印回应的头信息 * $|9e
public void logResponseHead(HttpURLConnection con) jA3xDbM
{ 3F9dr@I.7
for(int i=1;;i++) lQL/I[}
{ B$G9#G6pZ
String header=con.getHeaderFieldKey(i); h^f?rWD:nz
if(header!=null) 7g4IAsoD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?NxaJ^
Utility.log(header+" : "+con.getHeaderField(header)); Xc9NM1bp=
else {>d\
break; >CYz6G j
} Hv*+HUc(:
} _4LDzVjNRe
?]\v%[ho
ybcCq]cgt
public void splitterStop() nFjaV`6`@
{ 2UMX%+ "J
bStop = true; 8#|PJc
} n[7=
2E.D0E Cu
z>HM$n`YD
} ^qtJcMK+hq
[M?&JA_$}
(r-PkfXvIf
/* ;m"R.Q9*
**FileAccess.java acI%fYw5p`
*//文件访问(定位，写) CtHsi8m
package NetFox; _o-01gu.
import java.io.*; D.YT u$T
-yMD9b
lrmz'M'
public class FileAccessI implements Serializable{ eK/rsr
8*sP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~V/?/J$
RandomAccessFile oSavedFile; h@{CMe
long nPos; [ak[ZXC,
mpzm6Ieu
`8D'r|=`Eh
public FileAccessI() throws IOException +2m\Sv V
{ fK4NmdTV
this("",0); \O\veB8
} R}$A>)%dx
~g&Gi)je
A[Vhy;xz
public FileAccessI(String sName,long nPos) throws IOException 3Ol`i$
{ xKXD`-|W
oSavedFile = new RandomAccessFile(sName,"rw"); \7q>4[
this.nPos = nPos; AE4>pzBe
oSavedFile.seek(nPos); Y~ Nt9L
} @|}=W Q
`7_s@4:
`%.x0~ih
public synchronized int write(byte[] b,int nStart,int nLen) lsOZ%p%fV
{ A"B[F#
int n = -1; &z"yls
try{ o vX9
oSavedFile.write(b,nStart,nLen); ETaLE[T%1
n = nLen; ~ym-Szo
} &Fl*,
catch(IOException e) .*L_*}tno
{ 5dhT?/qvc
e.printStackTrace (); xilA`uw`1
} HNV"'p;
Cc` )P>L
w]Ci%W(
return n; Q".AmHn
} MU~nvs;:
mTZgvPJ!
I@YX-@&7
} PxgLt2dXa
,8@U-7f,
~'/_q4
/* 5OX5\#Ux
**SiteInfoBean.java R^GLATM
*/ H_7X%TvXb
package NetFox; #VM-\02o
%I;iP|/
/-1 F9
public class SiteInfoBean { a\v@^4
G8F43!<
TYgn X
private String sSiteURL; //Site's URL 1ogh8%
private String sFilePath; //Saved File's Path Z#|IMmT;*=
private String sFileName; //Saved File's Name M2y"M,k4
private int nSplitter; //Count of Splited Downloading File =#{i;CC%
*M()z.N
b+mh9q'5E
public SiteInfoBean() AME6Zu3Y
{//nSplitter的缺省值为5 Js!V,={iX
//default value of nSplitter is 5 30$Q5]T
this("","","",5); <@:LONe<
} BW%"]J
fm'Qifq^
#:M)a?E/%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0:3<33]x
{ 0x8aKq\'
sSiteURL= sURL; P6o-H$ a+
sFilePath = sPath; P7kb*
sFileName = sName; 6WX+p3Kv
this.nSplitter = nSpiltter; ue#Yh
r!J?Lc])8
4)~GHb
} i:,37INMt
lBnG!!VrWa
`)s>},8W!
public String getSSiteURL() `Hq)g1a7q
{ }mSfg
return sSiteURL; 3QzHQU
} =o+))R4
6z80Y*|eJ
Yet!qmZ
public void setSSiteURL(String value) \!,@pe_
{ jaImO
sSiteURL = value; 5x; y{qT
} N>4uqFo
vd'd@T
edD"jq)J
public String getSFilePath() VC@{cVT
{ @AU<'?k
return sFilePath; b ZEyP W
} !{L`Zd;C>w
4`#3p@-
BKQI|i
public void setSFilePath(String value) -wjvD8fL
{ UP}5Eh
sFilePath = value; yp:_W@
} ONw;NaE,
B!cg)Y?.bd
-(fvb
public String getSFileName() '@<aS?@!t
{ pu +"bq
return sFileName; aPMqJ#fIr
} aD:vNX
KW.QVBuVO#
(C EXPf
public void setSFileName(String value) 4_w+NI,;
{ ;/8oP ;X2
sFileName = value; $}G03G@
} }{Ncww!iN
+\a`:QET
Y|iJO>_Uu=
public int getNSplitter() DdL0MGwX
{ RjS&^uaP
return nSplitter; n(#159pZ
} -S"$S16D
N{<=s]I%x
s]=s|
public void setNSplitter(int nCount) ;h"?h*}m!\
{ w3=Bj
nSplitter = nCount; OO:^#Mvv5
} e)~7pXYV)
} t%n3~i4X:
0?",dTf3i
wcT0XXh
/* {^xp?zpV
**Utility.java XHu2G t_
*/ t$z FsFTQ
package NetFox; D$RQD{*
9 1r"-%(r
^p0BeSRiy;
public class Utility { FasA f(3
nKJJ7 RL
IZ;%lV7t
public Utility() rI5)w_E?
{ U'st\Dt
F-k3F80=
1YA_`_@w
} O0{M3-
$:%?-xy(
//线程睡眠 T/"6iv\1
public static void sleep(int nSecond) XTHy CK
{ 3JiDi X"|
try{ i`^`^Ka
Thread.sleep(nSecond); 9T4x1{mO
} MEQ:[;1
catch(Exception e) XQu~/{A=
{ fL8+J]6A6
e.printStackTrace (); p*rBT,'
} pNo<:p
} {@u;F2?
_-*Lj;^V
//日志 BC0T[o(f8
public static void log(String sMsg) x8sSb:N
{ (L?fYSP!
System.err.println(sMsg); yFT)R hN
} "$?f&*
?#^_yd|<
Z4Nl{ 6
public static void log(int sMsg) bGvALz'
{ W^W^5-'"D,
System.err.println(sMsg); J3fcnI
} 'Pudy\Ab
} $-$^r;
oXgKuR
32=Gq5pOc
/* N9D<wAK##)
**TestMethod.java A-O@e e
*/ U3 e3
package NetFox; +k'5W1e
) =<,$|g
w<*tbq
public class TestMethod { <@}~Fp@
*]fBd<(8
d*=P8QwL|
public TestMethod() /lSz8h2
{ ///xx/weblogic60b2_win.exe -y{o@
try{ d_&R>GmR$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q&Sd+y&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E8WOXoP(
SiteFileFetch fileFetch = new SiteFileFetch(bean); LoLmT7
fileFetch.start(); ?9_<LE q
} +Eh1>m
catch(Exception e){e.printStackTrace ();} 4!<8Dd
dF*@G/p>V
N %-Cp)
} ^o]ZDc
KAmv7
1e*+k$-{
public static void main(String[] args) *M5=PQfb
{ NaSgK
new TestMethod(); f0fN1
} 'H2TwSbIXI
} iIq='xwa9
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