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)); xdf82)
} NzU,va N
for(int i=0;i<nEndPos.length-1;i++) qf=1?=l291
{ 6ezS{Q
nEndPos = nStartPos[i+1]; Tszp3,]f
} 34wkzu
nEndPos[nEndPos.length-1] = nFileLength; {dL?rQ>5L
} 94 e): jS
} ;x:rZV/
%H]lGN)
X=Ys<TM,
//启动子线程 q^A+<d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }|5VRJA
for(int i=0;i<nStartPos.length;i++) RjWqGr;bO
{ -i4&v7"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =egW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8}fu,$$5
nStartPos,nEndPos,i); $&<uT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j'aHF#_
fileSplitterFetch.start(); ukvtQz)
} oyNSh8c7c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^2$ lJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^=:9)CNw(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *;m5'}jsy
nEndPos = " + nFileLength); :.?gHF.?
// fileSplitterFetch[nPos.length-1].start(); '0\@McU]
t=u Qb=
?gPKcjgoH!
//等待子线程结束 Q}!mx7b0]
//int count = 0; ^)?d6nI
//是否结束while循环 #7ov#_2Jd
boolean breakWhile = false; 63.wL0~
^{xeij/
.[Ap=UYI>
while(!bStop) +=]!P#
{ Hewd4k
write_nPos(); ' j6gG
Utility.sleep(500); FJ %
breakWhile = true; _>=L>*
vTaJqEE
$b<6y/"
for(int i=0;i<nStartPos.length;i++) =xsTDjH>
{ ovwQ2TuK
if(!fileSplitterFetch.bDownOver) ?[&2o|
{ u$D*tqxG
breakWhile = false; (u]N
break; MB%Q WU
} \~BDm
} f8SL3+v
if(breakWhile) m$9w"8R
break; f+|$&p%
quvanxV-L
8E8N6
//count++; !q-f9E4`
//if(count>4) &AlJ "N|
// siteStop(); ?7M.o
} *loOiM\5a
eeHP&1= 7
6<'rG''
System.err.println("文件下载结束！"); M[z)6.
} 3Wwj p
catch(Exception e){e.printStackTrace ();} +3a?`Z
} Wm H~m k"
F q!fWl
6Z`R#d #I
//获得文件长度 Cn>ADWpT&
public long getFileSize() k^ YO%_
{ <,AS8^$X[
int nFileLength = -1; _DrJVC~6@
try{ =l.+,|ZH!
URL url = new URL(siteInfoBean.getSSiteURL()); [HN|\afz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D;I6Q1I
httpConnection.setRequestProperty("User-Agent","NetFox"); 0W3i()
>(y<0
A>[|g`;t
int responseCode=httpConnection.getResponseCode(); a6:x"Tv
if(responseCode>=400) 7@6g<"I
{ 'kYwz;gp
processErrorCode(responseCode); .i^7|o:
return -2; //-2 represent access is error X*Z8CM_
} gr-fXZO
h?-#9<A
(;%|-{7e-
String sHeader; nuoPg3Nl
TRZRYm"
JT9N!CGZ
for(int i=1;;i++) $!5\E>y#
{ bWZbG{Y.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W5^.-B,(K
//Utility.log(in.readLine()); ~+<olss_
sHeader=httpConnection.getHeaderFieldKey(i); {V1Pp;A
if(sHeader!=null) n!6Z]\8~$
{ '|7Woxl9
if(sHeader.equals("Content-Length")) |7B!^ K
{ c*`>9mv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); goJ|oi
break; $5L0.$Tj
} OEPa|rb
} -k(CJ5H9
else sz--27es
break; __[xD\ES
} PyA&ZkX>
} ^1Xt]T`e
catch(IOException e){e.printStackTrace ();} }n7th
catch(Exception e){e.printStackTrace ();} bu&t'?zx!
aF|d^
`z0{S!
Utility.log(nFileLength); XE3'`D!
,Rx{yf]k
w'X]M#Q><
return nFileLength; ;.wX@
} }tPk@$
m^_6:Q0F!8
'!P"xBVAu
//保存下载信息（文件指针位置） YUQtMf9
private void write_nPos() hUz[uyt
{ N$TL;T>
try{ ;pD)m/$h`
output = new DataOutputStream(new FileOutputStream(tmpFile)); htm{!Z]s0
output.writeInt(nStartPos.length); q>s-Y|
for(int i=0;i<nStartPos.length;i++) 4wi(?
{ w[_x(Ojq;
// output.writeLong(nPos); =SD\Q!fA
output.writeLong(fileSplitterFetch.nStartPos); \<vNVz7.D
output.writeLong(fileSplitterFetch.nEndPos); fbFX4?-
} - O"i3>C
output.close(); yAL1O94
} ]NhS=3*i+
catch(IOException e){e.printStackTrace ();} aS|wpm)K>8
catch(Exception e){e.printStackTrace ();} ^). )
} D;Gq)]O
OzT#1T1'c
CzV(cSS9-
//读取保存的下载信息（文件指针位置） {FN;'Uc
private void read_nPos() Jti(b*~
{ :Vg}V"QR
try{ dbS +
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /D_+{dtE
int nCount = input.readInt(); 0W`LVue
nStartPos = new long[nCount]; _{jP;W
nEndPos = new long[nCount]; sA9&/p/
for(int i=0;i<nStartPos.length;i++) ^MD;"A<
{ 8hA^`Y
nStartPos = input.readLong(); Fg/dS6=n`?
nEndPos = input.readLong(); wA`"\MWm
} gPzL*6OSA
input.close(); NZu)j["
} j<pw\k{i
catch(IOException e){e.printStackTrace ();} AGYm';z3
catch(Exception e){e.printStackTrace ();} `>D9P_Y"jI
} 7%OKH<i\2<
9Q W&$n^
O3n_N6| q
private void processErrorCode(int nErrorCode) (#q<\`
{ 4R>zPEo
System.err.println("Error Code : " + nErrorCode); o2-@o= F
} }a&mY^
R7~Yw*#,
5&CDHc7Oj
//停止文件下载 rZ_>`}O2
public void siteStop() i.iio-
{ kllQca|$4
bStop = true; /?"8-0d
for(int i=0;i<nStartPos.length;i++) JO@Bf
fileSplitterFetch.splitterStop(); O`cu_
W[NEe,.>
RV-hIdAU
} ? 81X
} '?o9VrO
//负责部分文件的抓取 Wv!<bT8r
**FileSplitterFetch.java N0n^L|(R
*/ d~ng6pA
package NetFox; nY `2uN~9
#>@z 2K7
5;)*T6Y
import java.io.*; %'L;FPxB
import java.net.*; AF4?IH
=A[5= k>
tPHS98y
public class FileSplitterFetch extends Thread { 1'6cGpZY
+c206.
o%M<-l"!/
String sURL; //File URL Bk|K%K
long nStartPos; //File Snippet Start Position Nq8@Nyp
long nEndPos; //File Snippet End Position >s*DrfX6
int nThreadID; //Thread's ID iO!6}yJ*V
boolean bDownOver = false; //Downing is over ++[5q+b
boolean bStop = false; //Stop identical d]0a%Xh[
FileAccessI fileAccessI = null; //File Access interface W( *V2<$o
Em13dem
qH%")7>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException myQ&%M gx
{ IGj`_a
this.sURL = sURL; ;n#%G^!H
this.nStartPos = nStart; Aj"7q
this.nEndPos = nEnd; OIaYHA
nThreadID = id; 3$M3Q]z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0?Yz]+{C
} U;xF#e
Uhh l3%p
O>DNC-m)i{
public void run() fW0$s`
{ c"gsB!xh
while(nStartPos < nEndPos && !bStop) 00vBpsZj2;
{ b_$1f>
+1{fzb>9_
;Fl<v@9
try{ ,ul5,ygA
URL url = new URL(sURL); 5K56!*Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HV]Ze>}
httpConnection.setRequestProperty("User-Agent","NetFox"); O ++/ry%k
String sProperty = "bytes="+nStartPos+"-"; +p:Y=>bTj
httpConnection.setRequestProperty("RANGE",sProperty); eE:&qy^
Utility.log(sProperty); LhJa)jFQ
1]4^V7y
u@ N~1@RT|
InputStream input = httpConnection.getInputStream(); k1N$+h ;\
//logResponseHead(httpConnection); :iY$82wQ
gb-{2p>}
AO0!liQ
byte[] b = new byte[1024]; @Gjny BJ
int nRead; s_wUM)!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J?712=9
{ ~I_owCVZ
nStartPos += fileAccessI.write(b,0,nRead); 8<PKKDgbfd
//if(nThreadID == 1) E[Bo4?s&^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k&s; {|!
} XQ;I,\m
['Z{@9
Sgj/s~j~1
Utility.log("Thread " + nThreadID + " is over!"); )r!e2zc=Q
bDownOver = true; V7<eQ0;m
//nPos = fileAccessI.write (b,0,nRead); Px4/O~bLk
} k 'zat3#f
catch(Exception e){e.printStackTrace ();} ,-#GX{!
} `<vxG4=62\
} we]>(|
o42`z>~
)+~E8yK
//打印回应的头信息 9Vh_[^bR
public void logResponseHead(HttpURLConnection con) .)PqN s:
{ CvTwBJy1
for(int i=1;;i++) `^8*<+
{ INNAYQ
String header=con.getHeaderFieldKey(i); f]_mzF=&
if(header!=null) w7Dt1axB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G%hO\EO
Utility.log(header+" : "+con.getHeaderField(header)); wly>H]i'
else 5:gj&jt;)7
break; QUP|FIpZ
} _PB@kH#
} !$kR ;Q"/
jXcNAl
B?(4f2yE
public void splitterStop() ,{<Fz%
{ ToU.mM?f^
bStop = true; #8?^C]*{0
} };SV!'9s?~
YOw?'+8
:EB,{|m
} dB)[O9K)
%,?vyY
#<#%>Y^
/* ZgF/;8!~V-
**FileAccess.java 76MsrOv55
*//文件访问(定位，写) 1_3?R}$Wl
package NetFox; .uDM_ 34
import java.io.*; /yK"t<p
,ep9V,+|
;X7i/DQ
public class FileAccessI implements Serializable{ j.& ;c'V$.
>h7$v~nra
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T&/_e
RandomAccessFile oSavedFile; nLd~2qBuv
long nPos; B)a@fmp"a
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JD&U}dJ
public FileAccessI() throws IOException <IH*\q:7
{ 22vq=RO7Z
this("",0); a|.20w5
} #WEq-0L
kIM C~Z
b;{h?xc6
public FileAccessI(String sName,long nPos) throws IOException RZ6~c{
{ @XBH.A^7r
oSavedFile = new RandomAccessFile(sName,"rw"); q)oN2-
this.nPos = nPos; E\!n49
oSavedFile.seek(nPos); Xu%d,T$G
} u\5g3BH
d$Em\*C
{G.jB/
public synchronized int write(byte[] b,int nStart,int nLen) Z:^3Fm->+
{ ^srs$ w]
int n = -1; Mdm0g
try{ >)sqh ~P
oSavedFile.write(b,nStart,nLen); |8'B/ p=
n = nLen; s!`H
} T9y768%
catch(IOException e) 5G oK"F0i
{ L]>4Nd
e.printStackTrace (); d#7]hF
} w`Xg%*]}
^BNp`x;;`
#NMJZ
return n; x\]z j!
} SJ[AiHR
<i7agEdZD
qZ?{-Vw
} TK %<a/
%^U"Spv;
"uS7PplyO
/* Wxk;g
**SiteInfoBean.java 9 P~d:'Ib
*/ &qL<C
package NetFox; #'iPDRYy
Q>[Ce3
X\'E4
public class SiteInfoBean { 4L11P
iP,v=pS6
?q6Z's[
private String sSiteURL; //Site's URL 8E 9{ Gf
private String sFilePath; //Saved File's Path ?"u'#f_
private String sFileName; //Saved File's Name )O -cw7 >
private int nSplitter; //Count of Splited Downloading File O&=KlnI:
FdM<;}6T
g~|y$T
public SiteInfoBean() R9q0,yQW
{//nSplitter的缺省值为5 ;x16shH
//default value of nSplitter is 5 !c."
this("","","",5); <L2GUX36#
} -O /T?H
n5>B LtY
0QMaM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <H-tZDh5
{ _r[r8MB
sSiteURL= sURL; qkiJHT
sFilePath = sPath; k_BSY=$e*D
sFileName = sName; 3Mxz_~
this.nSplitter = nSpiltter; g@}6N.]#
_ Q{T';
-Sp/fjlq/
} !6{Jq]
=!YP$hfY
pOX$4$VR<
public String getSSiteURL() eL_^: -
{ Jxf}b}^T
return sSiteURL; %B0w~[!4}
} |FjBKj
s9G)Bd 8
oFb\TiLu
public void setSSiteURL(String value) &b!vWX1N
{ L2<+#O#
sSiteURL = value; Mc!2mE%47m
} ),MU+*`
9n-T5WP
e"lD`*U8R
public String getSFilePath() (;C$gnr.C
{ 2c"/QT
return sFilePath; A0UV+ -PP
} 5d%_Wb'
8B_0!U&]
m'3OGvd
public void setSFilePath(String value) [#7D~Lx/
{ F68},N>vr@
sFilePath = value; i]LU4y%'
} "-28[a3q
T\)dt?Tv#\
5"$e=y/
public String getSFileName() ~37R0`C
{ 48H5_9>:
return sFileName; IN<:P
} dZ.}j&ZH'
LgO i3
aD?# ,
public void setSFileName(String value) =A$Lgk>|
{ ,eyp$^2
sFileName = value; V/@[%w=
} fYb KmB
<=$rU232}
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public int getNSplitter() =.VepX|?D
{ Th.3j's
return nSplitter; yB 1I53E
} !?S5IGLOj
FK-}i|di
wEZ,49
public void setNSplitter(int nCount) >-UD]?>
{ <zfO1~^
nSplitter = nCount; =VCi8jDkP
} /]pX8 d
} _RN/7\
) )fDOJ
r(PJ~8)(=
/* *Ro8W-+
**Utility.java qw9e) `3$
*/ 9)ACgz&(
package NetFox; aIQrb
!&'# a
k,a,h^{}j
public class Utility { Lr K9F^c
FAH[5VDr%
"ugX /r$_
public Utility() 5JO[+>
{ xWd9%,mDNR
}*xC:A%aS
C<zx'lw!
} s'R~r
5Xp$yX =
//线程睡眠 9`OG
public static void sleep(int nSecond) ,G916J*XA
{ jK& Nkp
try{ iSnIBs9\
Thread.sleep(nSecond); Kh>?!`lL
} 0*37D5jH
catch(Exception e) ju8',ZC
{ &gY;`*<
e.printStackTrace (); THrc H
} (k7;
} EG'7}W
i)A`Vpn
//日志 ]$*$0
public static void log(String sMsg) HY*l4QK
{ *=($r%)
System.err.println(sMsg); ~5-~q0Ge
} pP?<[ql[w
*5ka.=Qs
i n[n Aa
public static void log(int sMsg) 9itdRa==
{ n,CD4Nv
System.err.println(sMsg); l=Lmr
} -0=}|$H.
} X7'h@>R
qkIA,Kgy
v1`bDS?*Q
/* S/#) :,YS
**TestMethod.java MAsWds`bpB
*/ u.ULS3`C/X
package NetFox; f]@[4<Ny
},?-$eyX
7H8GkuO
public class TestMethod { 44Seq
Y!K^-Y}
T{5M1r
public TestMethod() 31 KDeFg
{ ///xx/weblogic60b2_win.exe Ri^sQ<~(
try{ nOA,x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YHwVj?6W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TMnT#ypf<5
SiteFileFetch fileFetch = new SiteFileFetch(bean); umq$4}T'$
fileFetch.start(); z{ Zimr
} T>AI0R3
catch(Exception e){e.printStackTrace ();} m)tI
`R4W4h'I
z/c'Z#w%
} ;/6:lL
{,nd_3"Vq
|THkS@Br
public static void main(String[] args) @j)f(Zlu#
{ /NPl2\o.
new TestMethod(); >tE,8
} E-*>f"<h
} JCCx 5
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