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)); Ixxs(
} Z 8rD9 k$6
for(int i=0;i<nEndPos.length-1;i++) *I]]Ogpq=
{ H+[?{+"#@l
nEndPos = nStartPos[i+1]; 1 (<n^\J(
} H~j@n!)
nEndPos[nEndPos.length-1] = nFileLength; o+1(N#?m9
} M/<ypJ
} jR/Gd01)
9lYKG^#D
{W,5]-
//启动子线程 &BPYlfB1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d1D f`
for(int i=0;i<nStartPos.length;i++) << 6GE
{ Cf[tNq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A^OwT#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c]9gf\WW
nStartPos,nEndPos,i); mo| D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5T;LWS
fileSplitterFetch.start(); eGEwXza 4
} Jh\KVmfXN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rRe5Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f-F=!^.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +VUkV-kP
nEndPos = " + nFileLength); {lds?AuK
// fileSplitterFetch[nPos.length-1].start(); V8n {k'
,XT,t[w
X?_rD'3
//等待子线程结束 WzzA:X
//int count = 0; \ja6g
//是否结束while循环 ..`c# O&
boolean breakWhile = false; .\XRkr'-
tyR?A>F4
Ub3$`
while(!bStop) KtQs uL%
{ IO\1nB$0nb
write_nPos(); KTm^}')C8
Utility.sleep(500); ^OV; P[
breakWhile = true; P'<i3#;7X
,l>w9?0Z
E'WXi!>7p
for(int i=0;i<nStartPos.length;i++) kORWj<
{ /!Rva"
if(!fileSplitterFetch.bDownOver) x@ =p
{ >fC&bab
breakWhile = false; ']nIa7
break; TQn!MUj/^
} 5=TgOS]R
} XVs]Y'*x
if(breakWhile) tb&?BCp
break; hCQOwk#
(:bf m
/4r2B.91O
//count++; {vD$odi
//if(count>4) }_lG2#Ll5
// siteStop(); ei= 4u'
} j3sz"(
7UBDd1
)w].m
System.err.println("文件下载结束！"); s@L ;3WdO
} #*A&jo'E
catch(Exception e){e.printStackTrace ();} Nn_fhc>
} WDw<kX6p
2? E;(]dQ
1|sem(t
//获得文件长度 n{QyqI
public long getFileSize() MXSD8]je
{ g(&cq
int nFileLength = -1; NO*,}aeG
try{ :a*>PMTn
URL url = new URL(siteInfoBean.getSSiteURL()); "Da1BuX\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T, #-: }
httpConnection.setRequestProperty("User-Agent","NetFox"); *8)?ZZMM
C1-U2@
iF`_-t/k
int responseCode=httpConnection.getResponseCode(); NCk-[I?R
if(responseCode>=400) ,3?=W/Um4
{ "r6qFxY
processErrorCode(responseCode); mu B Y
return -2; //-2 represent access is error XoyxS:=>|[
} g=td*S
M{L<aYe
Qh@Q6
String sHeader; 7#)k-S!B
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dg|+?M^9`
for(int i=1;;i++) +Ug &
{ x;[)#>.'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ( %7V
//Utility.log(in.readLine()); ?h`,@~6u
sHeader=httpConnection.getHeaderFieldKey(i); >9w^C1"
if(sHeader!=null) !hHe`
{ ^6Aa^|
if(sHeader.equals("Content-Length")) 8g=O0Gb
{ S*Ea" vBA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2[Bbdg[O
break; ,.Ofv):=
} E]q>ggeNH
} `6rLd>=R
else 0/~p1SSun
break; Cx;it/8+
} A6szTX#0
} TY]0aw2]|7
catch(IOException e){e.printStackTrace ();} jO"/5x26
catch(Exception e){e.printStackTrace ();} +/&rO,Ql
@C-dCC?
}<G ae5
Utility.log(nFileLength); (lwV(M
kgBkwp
Ie!KIU
return nFileLength; O[Z$~
} 1<9d[N*
moM'RO,M
K14.!m
//保存下载信息（文件指针位置） :/6:&7s
private void write_nPos() p cD}SY
{ L@MCB-@V
try{ lsV>sW4]Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gh_5$@ hF
output.writeInt(nStartPos.length); t_^cqEr
for(int i=0;i<nStartPos.length;i++) &#fPJc
{ Wda?$3!^q
// output.writeLong(nPos); @%g:'^/
output.writeLong(fileSplitterFetch.nStartPos); _Nh])p-
output.writeLong(fileSplitterFetch.nEndPos); ${Lrj}93
} ~/4j&IG
output.close(); ~JZLWTEe
} eZ) |m
catch(IOException e){e.printStackTrace ();} O#tmB?n*
catch(Exception e){e.printStackTrace ();} tln}jpCw
} <c@dE
4PSbr$
TFbc@rfB
//读取保存的下载信息（文件指针位置） k&yBB%g
private void read_nPos() a\-5tYo`u
{ PM*lnd#J
try{ R?:K\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h9Sf
int nCount = input.readInt(); (6[<+j&.
nStartPos = new long[nCount]; '1!%yKc0
nEndPos = new long[nCount]; S%p,.0_
for(int i=0;i<nStartPos.length;i++) ^p4`o>
{ x^3K=l;N
nStartPos = input.readLong(); }f> 81[^
nEndPos = input.readLong(); qUe2(/TQu
} <mLU-'c@
input.close(); v-$X1s
} 0lt1/PEKx2
catch(IOException e){e.printStackTrace ();} \ bNDeA&l
catch(Exception e){e.printStackTrace ();} zV$Z@o
} AJ 0Bb7
Xj?LU7
d}E6d||A
private void processErrorCode(int nErrorCode) $xvwnbq#y
{ -XECYwTh
System.err.println("Error Code : " + nErrorCode); @bkSA
} k;umLyz
K0*er
6mZpyt
//停止文件下载 x=JZ"|TE
public void siteStop() F[ ^ p~u{
{ *[nS*D\:
bStop = true; bN*zx)f
for(int i=0;i<nStartPos.length;i++) }2y"F@{T
fileSplitterFetch.splitterStop(); 7B _Wz9y
09Oe-Bg
/\jRr7 Cd
} v]drDVJ
} "gpfD-BX
//负责部分文件的抓取 N*w{NB7L
**FileSplitterFetch.java Gd&G*x
*/ I~ SFY>s
package NetFox; 1\f8-:C
.:['&; k
0} \;R5a<
import java.io.*; 1 xrmmK
import java.net.*; #z}IW(u<
c_?!V
TGPdi5Eq
public class FileSplitterFetch extends Thread { iaJN~m\ M
_#UhXXD
z<"\I60Fe
String sURL; //File URL ]N'4q}<5o
long nStartPos; //File Snippet Start Position kD+B8TrW
long nEndPos; //File Snippet End Position XK l3B=h
int nThreadID; //Thread's ID A-hWg;
boolean bDownOver = false; //Downing is over Th])jQ*
boolean bStop = false; //Stop identical imS&N.*3m
FileAccessI fileAccessI = null; //File Access interface MM+nE_9lV
53^1;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <CP't[
{ >>7m'-k%D
this.sURL = sURL; $_Lcw"xO
this.nStartPos = nStart; \4q1<j
this.nEndPos = nEnd; fwyz|>H_Y(
nThreadID = id; j"+R*H(#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n]JfdI
} +>h'^/rAE
=dC5q{
ET]`
public void run() nG5:H.)
{ Se5jxV
while(nStartPos < nEndPos && !bStop) 1lUY27MF
{ "6'# L,
U}`HN*Q.q
DOo34l6#
try{ F[|aDj@q e
URL url = new URL(sURL); |w^nCsv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0wl31k{
httpConnection.setRequestProperty("User-Agent","NetFox"); v/Ei0}e6~
String sProperty = "bytes="+nStartPos+"-"; !U+XIr
httpConnection.setRequestProperty("RANGE",sProperty); i3y>@$fRL\
Utility.log(sProperty); 'v3>"b
ZYW=#df R
b~;+E#[*
InputStream input = httpConnection.getInputStream(); a U*cwR
//logResponseHead(httpConnection); Yyh X%S%
;fDs9=3#
[.iz<Yh
byte[] b = new byte[1024]; oxm3R8S
int nRead; hz+x)M`Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OGO4~Up
{ $5l=&
nStartPos += fileAccessI.write(b,0,nRead); T%:W6fH7
//if(nThreadID == 1) <N;HB&mr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {Uu|NA87Cd
} V-iY2YiR
{@[z-)N7\,
Z4Qq#iHZR
Utility.log("Thread " + nThreadID + " is over!"); xBcE>^{1.
bDownOver = true; X6@G)68
//nPos = fileAccessI.write (b,0,nRead); Ik|nL#JH]
} E>SLR8!Cv
catch(Exception e){e.printStackTrace ();} PM%Gsy]q
} *9Nq^+
} Yf(QU`w_
Go_~8w0<
)Wm:Ilq
//打印回应的头信息 DbkKmv&
public void logResponseHead(HttpURLConnection con) rfMzHY}%
{ MY}B)`yx=
for(int i=1;;i++) _gF )aE
{ Dx27s
String header=con.getHeaderFieldKey(i); f?A*g$v
if(header!=null) 4jl-?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ik4U+'z6
Utility.log(header+" : "+con.getHeaderField(header)); &<sDbNS
else j!P]xl0vOZ
break; J;g+
} tcf>9YsOr
} t|aBe7t7
#4*~ 4/
vN%SN>=L<
public void splitterStop() ceR zHq=
{ Ol'Ct'_k,"
bStop = true; r6`v-TY(/
} poYO
<OEu 4,~:
?8Hr 9
} !8U\GR `
Ytnk^/Z1L
AA um1xl
/* Rx 4 ;X
**FileAccess.java *1KrI9i
*//文件访问(定位，写) Og`w~!\
package NetFox; =)3tVH&
import java.io.*; 3X&}{M:Qo
QuJ)WaJkC
$;dSM<r
public class FileAccessI implements Serializable{ ]I#yS=;
TnqspS2;R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hinz6k6!
RandomAccessFile oSavedFile; viT/$7`AI
long nPos; 8I'c83w
<OcD[5
jR#g>MDKB
public FileAccessI() throws IOException O#E]a<N`
{ /K"koV;
this("",0); :YU_ \EV
} Xj&fWuA
--S2lN/:T
z5v)~+"1
public FileAccessI(String sName,long nPos) throws IOException 7N/v
{ Nj_h+=UE!
oSavedFile = new RandomAccessFile(sName,"rw"); Z`23z(+
this.nPos = nPos; 54w..8'
oSavedFile.seek(nPos); wYJ.F
} dhW)<
9BPucXK
#AzZ4<;7
public synchronized int write(byte[] b,int nStart,int nLen) 2#:h.8
{ 7W6tz\Y
int n = -1; DDT)l+:XP
try{ $e7dE$eH
oSavedFile.write(b,nStart,nLen); !PI& y
n = nLen; eEkFZx
} EC2KK)=n}
catch(IOException e) sHSZIkB-r
{ {mK=Vig
e.printStackTrace (); ?A/+DRQ(
} wG4=[d
QcGyuS.B
V_?5cwZ
return n; :;S]jNy}j)
} YT6<1-E#
%SL'X`j
cbD&tsF
} N*N@wJy:5
@JS O=8
cWSiJr):r
/* ]VY}VALZ
**SiteInfoBean.java : uglv6
*/ C#`VVtei
package NetFox; #y"EhwF
Re**)3#gn
B(x i
public class SiteInfoBean { ]?p&sI4
G%w hOIFRq
4~8++b1/;
private String sSiteURL; //Site's URL .V9/0
private String sFilePath; //Saved File's Path j()<.h;'
private String sFileName; //Saved File's Name +(*S@V$c
private int nSplitter; //Count of Splited Downloading File L\--h`~YU
&{?*aK&%3l
Cvr?%+)$M
public SiteInfoBean() JW;DA E<
{//nSplitter的缺省值为5 ,lLkAd?q
//default value of nSplitter is 5 4i>sOP3 B
this("","","",5); K'EGm #I
} )2KQZMtgm]
BD+V{x}P
KPIc?|o/6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z{w!yMp"
{ /l-lkG5
sSiteURL= sURL; p9ligs7V'
sFilePath = sPath; ?'_E$
sFileName = sName; =^m,|j|d>4
this.nSplitter = nSpiltter; &o>ctf.x
B>}=x4-8
:gMcl"t--
} Mvq5s+.
sf\p>gb
47b=>D8
public String getSSiteURL() g/&`NlD
{ 6\ g-KO
return sSiteURL; m0+X 109
} :|3n`,
SnsOuC5Ah
_Gv[ D
public void setSSiteURL(String value) 7jIye8Zi8
{ F3$@6J8<[z
sSiteURL = value; $gU6=vN1#
} }=CL/JHz
?z>7&
E?1"&D m
public String getSFilePath() kXGJZ$
{ y%A!|aBu
return sFilePath; 1Uzsw
} >6ul\xMU
v|:2U8YREf
]RgLTqv4x
public void setSFilePath(String value) WV]%llj^
{ ]]~tFdh
sFilePath = value; E^z\b *
} E_-3G<rt
>h+[#3vD
K]4XD1n7
public String getSFileName() V3j1M?>
{ ns|)VX
return sFileName; )&R^J;W$M1
} ;Z%PBMa
\~|+*^e)
qP6YnJWl
public void setSFileName(String value) bi`{ k\3A
{ |F_Z
sFileName = value; \8v{9Yb
} &VG|*&M
*"4d6
dLb9p"EE#
public int getNSplitter() \mRRx#-r%
{ Y0`@$d&n
return nSplitter; nA:\G":\y
} GRV#f06
0?hJ!IT;q7
=\;yxl
public void setNSplitter(int nCount) Q@B--Omfh
{ 9aYDi)
nSplitter = nCount; :<$B o
} y{CyjYpz^
} _&!%yW@
<i9pJGW
h/u>F$}c
/* NjT#p8d X
**Utility.java ts BPQ 8Ne
*/ "RPX_
package NetFox; Hgs=qH
z8W@N8IqC
KUs\7Sb
public class Utility { 3KFw0(S/
qI-q%]l
m/W0vPM1
public Utility() |3\$\qa
{ 7O6VnKl
Z|&Y1k-h
bo^d!/;
} ;4DqtR"7Y
|BrD:+
//线程睡眠 L`E^BuP/
public static void sleep(int nSecond) V_Owi5h
{ S}zh0`+d'Z
try{ =/xTUI4
Thread.sleep(nSecond); {oIv%U9
} )U4h?J
catch(Exception e) Q}#5mf&cD
{ -oGJPl{r
e.printStackTrace (); 2w>lnJ-
} *Jd,8B/hC
} <YU+W"jQT
dxm_AUM
//日志 1QHCX*_
public static void log(String sMsg) }2qmL$
{ V'vDXzk\
System.err.println(sMsg); B/#tR^R
} q0Rd^c
OE,uw2uaT
!_{2\&
public static void log(int sMsg) 4}nsW}jCc
{ utk'joo
System.err.println(sMsg); Vg1! u+`<
} _ PC}`Y'&
} =Rnx!E
/+pPcK
C4V#qhj
/* Jz(!eTVs
**TestMethod.java =\v./Q-
*/ [H#*#v
package NetFox; T*"15ppfk
4{2)ZI#
" bHeNWZ
public class TestMethod { Wj N0KA
o* qF"xG
SZ+<0Y|
public TestMethod() W?W vT` T{
{ ///xx/weblogic60b2_win.exe BaSNr6 YW
try{ I W_:nm6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [E_+fT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N_jCx*.G
SiteFileFetch fileFetch = new SiteFileFetch(bean); r Ntc{{3_
fileFetch.start(); {bF95Hs-
} m#[tY>Q[b
catch(Exception e){e.printStackTrace ();} ;1Kxqpz_i
IT \Pj_
oYWcX9R
} [.e Y xZ{=
:sT\-MpQvn
W!a~ #R/r-
public static void main(String[] args) i?^Cc\gH
{ RZykwD(
new TestMethod(); g=?KpI-pn0
} USVM' ~p I
} :P$I;YY=A
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