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)); m?0caLw<
} vjmNS=l
for(int i=0;i<nEndPos.length-1;i++) TZ3"u@ 06
{ "]B:QeMeF!
nEndPos = nStartPos[i+1]; f }P6P>0T
} PVLLuv
nEndPos[nEndPos.length-1] = nFileLength; c7Jfo x V
} V9bn
} lXjhT
0M-=3T
A63=$
//启动子线程 ,Y ./9F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [2ez"4e
for(int i=0;i<nStartPos.length;i++) Ia %> c
{ "w7wd5h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C/_Z9LL?F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?)X0l
nStartPos,nEndPos,i); wF[%+n (*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qv~lH&jG
fileSplitterFetch.start(); e#BxlC
} EIug)S~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sYE|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :"{("!x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eaB6e@]@
nEndPos = " + nFileLength); rK(TekU
// fileSplitterFetch[nPos.length-1].start(); _X;xW#go
9(eTCe-~6
+6-_9qRq
//等待子线程结束 1UdET#\
//int count = 0; #\1)Tu%-
//是否结束while循环 m#|;?z
boolean breakWhile = false; o+*7Q!
Pg4go10|
kT^|%bB[i
while(!bStop) 3e,"B S)+
{ ld
write_nPos(); E&G]R!
Utility.sleep(500); {0?^$R8j
breakWhile = true; Tg/?v3M88
I'[gGK4F
p.)IdbC`B
for(int i=0;i<nStartPos.length;i++) [+;>u|
{ Zmx[:-
if(!fileSplitterFetch.bDownOver) `"Lk@
{ o=C:=
breakWhile = false; 0Sx$6:-~
break; qg1tDN`s
} r|av|7R
} Dqu?mg;L
if(breakWhile) ;T hn C>U
break; `]F}O \H
M,w5F5
$/J4?Wik
//count++; ;x,yGb`
//if(count>4) ^J~5k,7jX
// siteStop(); 4m1@lnjp
} }o[NB
T\v~"pMu*0
jEMnre3/
System.err.println("文件下载结束！"); _kEU=)Xe
} 5D+rR<pD}"
catch(Exception e){e.printStackTrace ();} ,76Q*p
} ^i[bo3
,4mb05w;d
F rd>+
//获得文件长度 tfIUH'Ez>
public long getFileSize() P1_6:USBM
{ &[b(Lx|i
int nFileLength = -1; t9~Y ?
try{ <I 0EjV
URL url = new URL(siteInfoBean.getSSiteURL()); XcFu:B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >zX`qv&>
httpConnection.setRequestProperty("User-Agent","NetFox"); fD<0V
-[}AhNYK
+k;][VC[O
int responseCode=httpConnection.getResponseCode(); zD@RW<M
if(responseCode>=400) NjFlV(XT}
{ o)WzZ,\F^J
processErrorCode(responseCode); HuLvMYF
return -2; //-2 represent access is error ak_n
} *JArR1J
1EMrXnv,
cC pNF `DN
String sHeader; ]?sw<D{
sjy/[.4-
@HQqHO&N
for(int i=1;;i++) Esdv+f}4;
{ _a\$uVZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); * `3+x
//Utility.log(in.readLine()); Owz>g4l r
sHeader=httpConnection.getHeaderFieldKey(i); |33_="
if(sHeader!=null) {Q021*xt/
{ bQ`2ll*(
if(sHeader.equals("Content-Length")) '$h0l-mQ
{ }6To(*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1VA%xOURh
break; m`&6[[)6~
} RveEA/&&
} mXT{c=N)w
else $C t(M)
break; efK WR
} C]a iu
} 09 vm5|
catch(IOException e){e.printStackTrace ();} R^6]v`j;
catch(Exception e){e.printStackTrace ();} ZdJQ9y
"lA8CA
Zt \3y
Utility.log(nFileLength); Y;=GM:*H
]#;u]
kS62]v]
return nFileLength; w""
} {!*dk V
Ask~
>P}6/L
//保存下载信息（文件指针位置） Wb#ON|.2
private void write_nPos() Yb348kRF
{ x75 3o\u!
try{ ]]hsLOM]
output = new DataOutputStream(new FileOutputStream(tmpFile)); EouI S2e;a
output.writeInt(nStartPos.length); }F-,PSH Ml
for(int i=0;i<nStartPos.length;i++) TOsHb+Uv
{ ]RuH6d2d|
// output.writeLong(nPos); NchEay;`
output.writeLong(fileSplitterFetch.nStartPos); b6^#{))"
output.writeLong(fileSplitterFetch.nEndPos); V9;O1
} ;F:Qz^=.a
output.close(); ejpSbVJ
} Bgs,6:
catch(IOException e){e.printStackTrace ();} \ccCrDz
catch(Exception e){e.printStackTrace ();} B/K{sI
} 2{01i)2y
;HmQRiCg
^.>XDUO F
//读取保存的下载信息（文件指针位置） S[y?>
private void read_nPos() TUi<
{ /mQ9}E4X
try{ ,-)ww:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PG*FIRDb
int nCount = input.readInt(); 9u1Fk'cxG,
nStartPos = new long[nCount]; yHmNO*(
nEndPos = new long[nCount]; `aM8L
for(int i=0;i<nStartPos.length;i++) a;v;%rs
{ nm`}Z'&)
nStartPos = input.readLong(); WYW@%t
nEndPos = input.readLong(); 9R N ge;*
} ?mh0^G
input.close(); $uUJV% EX
} yb-/_{Y
catch(IOException e){e.printStackTrace ();} eR!K8W
catch(Exception e){e.printStackTrace ();} oN[#C>#(
} #1[Q?e4,0
M(.]?+
;f[@zo><r
private void processErrorCode(int nErrorCode) pbNW l/|4
{ 98!H$6k
System.err.println("Error Code : " + nErrorCode); `$>cQwB,D
} +||[H)qym
J Sms \
2KSt4oa
//停止文件下载 /i IWt\J
public void siteStop() *Edr\P
{ 9S{?@*V
bStop = true; z1LY|8$G
for(int i=0;i<nStartPos.length;i++) A5YS "i
fileSplitterFetch.splitterStop(); <Q?_],ip
.GuZV'
g&L $5
} }\d3
} $F~hL?"?
//负责部分文件的抓取 Ffr6P }I
**FileSplitterFetch.java n$jf($*
*/ V2*m/JyeB
package NetFox; 5YgUk[J
F>rf cW2
]|4mD3O
import java.io.*; 6N'HXL UlQ
import java.net.*; }9>X M
&>z}u&oF
Bk8 '*O/)
public class FileSplitterFetch extends Thread { ;/ao3Q
1a;&&!X
zNQ|G1o
String sURL; //File URL <P<^,aC/j
long nStartPos; //File Snippet Start Position E3E$_<^
long nEndPos; //File Snippet End Position uT{.\qHo
int nThreadID; //Thread's ID -u%'u~s
boolean bDownOver = false; //Downing is over P8;f^3V(+/
boolean bStop = false; //Stop identical ot.R Gpg%
FileAccessI fileAccessI = null; //File Access interface :]-? l4(%
AV?<D.<
}S>:!9f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jY5BVTWnV
{ \ /6m
this.sURL = sURL; Ia>>b #h
this.nStartPos = nStart; me/ae{
this.nEndPos = nEnd; P7p'j
nThreadID = id; Nx"v|"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JulxFjC
} 1@A*Jj[R%
4r>buEU
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public void run() 1Qgd^o:d
{ 0-w^y<\
while(nStartPos < nEndPos && !bStop) ^Sz?c_<2P
{ d 3}'J
od~`q4p1(-
js8\"
try{ 7<c&)No;
URL url = new URL(sURL); S~4HFNe^&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i*%2 e)
httpConnection.setRequestProperty("User-Agent","NetFox"); }V %b
String sProperty = "bytes="+nStartPos+"-"; \^%5!
httpConnection.setRequestProperty("RANGE",sProperty); Y/w) VV
Utility.log(sProperty); 9 ulr6
fO{E65uA
B^G{k3]t
InputStream input = httpConnection.getInputStream(); @X6|[r&Z
//logResponseHead(httpConnection); >SZ9,K4Gs
#]5|Qhrr+
WS)u{ or
byte[] b = new byte[1024]; O@bDMg
int nRead; CmPix]YMQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ICgyCsZ,
{ $\@yH^hL
nStartPos += fileAccessI.write(b,0,nRead); 5PlTf?Ao
//if(nThreadID == 1) A4W61f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :}18G}B
} GQ8r5V4:
`g iCytv
4c=oAL
Utility.log("Thread " + nThreadID + " is over!"); y3!=0uPf
bDownOver = true; D?_#6i;DJ
//nPos = fileAccessI.write (b,0,nRead); g$*VA} s
} zorTZ #5
catch(Exception e){e.printStackTrace ();} /< CjBW:
} __V6TDehJ$
} 6'6@VB
/Iu._2
')w*c
//打印回应的头信息 Y">;2Pt;
public void logResponseHead(HttpURLConnection con) *ad"3>
{ M('cG
for(int i=1;;i++) l<$c.GgFd
{ V ;)q?ZHg
String header=con.getHeaderFieldKey(i); :22IY>p
if(header!=null) @kKmkVhu*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ; (+r)r_
Utility.log(header+" : "+con.getHeaderField(header)); {q:o}<-L+
else _k@{> ?(a
break; Q(KLx)
} 0fPqO2
} ?%h JZm;
g~@0p7]Y
VPTT*a`
public void splitterStop() )Cz^Xp)#
{ >cD+&h34
bStop = true; [@= [< _r
} r\"O8\
tH"SOGfSt
q'?:{k$%
} hqY9\,.C
${ ~UA6
8E Y<^:
/* Rh%/xG#k
**FileAccess.java bkl'0 p
*//文件访问(定位，写) )8yee~+TN
package NetFox; szwXr
import java.io.*; 5@Q4[+5&_
@"HR"@pX
WJU` g
public class FileAccessI implements Serializable{ S~F:%@,*
dTaR8i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j78xMGKO
RandomAccessFile oSavedFile; GD'C^\EaZ
long nPos; @X/S h:
l#o43xr
Em@h5V
public FileAccessI() throws IOException d#a
{ Ik1,?A
this("",0); h{sW$WA
} KW&&AuPb}
r[Q$w>
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public FileAccessI(String sName,long nPos) throws IOException uPV,-rm[F_
{ $_Qo
oSavedFile = new RandomAccessFile(sName,"rw"); A0rdQmrOL
this.nPos = nPos; Ytx+7OLe
oSavedFile.seek(nPos); VJCh5t*
} ok\+$+$ju
GKY:"q&h
nHKEtKDd
public synchronized int write(byte[] b,int nStart,int nLen) 0m`7|80#P
{ 7"xd'\c@
int n = -1; 4'54
try{ n/@/yJ<EFi
oSavedFile.write(b,nStart,nLen); i?AZ|Ha[
n = nLen; D-3/?"n
} &,."=G
catch(IOException e) ?GFxJ6!%I
{ OqBw&zm
e.printStackTrace (); !icpfxOpjQ
} OV8b~k4=
R/^JyL
|7`Vw Z
return n; Uzb"$Ue4
} /"CKVQ
HxY,R^
h0.Fstf]
} }h_Op7.5D
@?B=8VHR
EkSTN
/* Lf0Hz")
**SiteInfoBean.java cfeX(0
*/ +X*`}-3
package NetFox; FYcMvY
GYO\l.%V5y
4E |6l
public class SiteInfoBean { ;7`<.y
g=Qga09
z{#F9'\&
private String sSiteURL; //Site's URL zW0AB8l
private String sFilePath; //Saved File's Path 50DPzn
private String sFileName; //Saved File's Name NNl/'ge<\
private int nSplitter; //Count of Splited Downloading File ^2kWD8c*
Yn<0D|S;X
uAjGR
public SiteInfoBean() Ab2g),;c
{//nSplitter的缺省值为5 CY>NU
//default value of nSplitter is 5 rIb[gm)Rk
this("","","",5); B?0{=u
} ~M'\9
G'Q7(c
)%y~{j+M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .@6]_h;
{ +cV!=gDT
sSiteURL= sURL; (J$A
sFilePath = sPath; K<]fElh-
sFileName = sName; T![K i
this.nSplitter = nSpiltter; #>v7" <
pz&=5F
jujx3rnK?
} D} .t
3-mw-;.
+1)C&:
public String getSSiteURL() 9>i6oF]Oq
{ ZM#WdP
return sSiteURL; Vw{Ys6q
} %C3cdy_c
xapkhIW2\
]F@md(J
public void setSSiteURL(String value) }a9C/t3
{ p_z"Uwp
sSiteURL = value; h+74W0 $
} <y.D0^68
"q`%d_
EkL\~^
public String getSFilePath() nUd\4;J#
{ Vd?v"2S(9
return sFilePath; m_(hCY=Q$
} i52R,hz
1!f'nS
EORRSP,$2
public void setSFilePath(String value) 2YN`:"
{ FvJSJ.;E,
sFilePath = value; GBphab|
} llleo8
k_a'a)`$6
ob00(?;H
public String getSFileName() lXPn]iLJ
{ 4 P;O8KA5y
return sFileName; b{I`$E<[
} ?:FotnU*p
Hxl,U>za#
T8441qo{>
public void setSFileName(String value) <dN=d3S
{ epbp9[`
sFileName = value; =a!6EkX *
} pMquu&Td
`e9uSF:9C
;:|KfXiC8
public int getNSplitter() $McO'Bye{h
{ 'i(p@m<'
return nSplitter; 5qr!OEF2
} vf yva
2wBU@T1
w+37'vQ
public void setNSplitter(int nCount) 9(l'xuX
{ =_dd4`G&<
nSplitter = nCount; cP2R24th
} &JlR70gdHi
} Cv~hU%1T
Qf|}%}%fp
"?{yVu~9
/* d8kwW!m+
**Utility.java e\_6/j7'
*/ '&QT}B
package NetFox; X}-H=1T?
f`,Hr?H
7q:bBS
public class Utility { 0tqR wKL
ee_\_"
Tqa4~|6
public Utility() 9AYe,R
{ 5)zB/Ta<
nTU~M~gky
?03Zy3/
} 2jZ}VCzRG
W[>TqT63
//线程睡眠 XC1lo4|
public static void sleep(int nSecond) +7/*y}.U
{ `Y\/US70{c
try{ x#0@$
Thread.sleep(nSecond); QiweM?-
} 'Xl>,\'6
catch(Exception e) V3W85_*
{ NydW9r:T
e.printStackTrace (); k6-n.Rl01
} mF}k}0
} Zax]i,Bx
Cj1UD;
//日志 B^(rUR
public static void log(String sMsg) $l;tP
{ d95N$n
System.err.println(sMsg); (1,#=e+
} IA`8ie+
+@uC:3jM
^Ai_/!"
public static void log(int sMsg) .r|vz6tU?
{ &E &iaw!
System.err.println(sMsg); ,*Z[P%<9
} WJU NJN
} OPY/XKyY,
i>Bi&azx
6&QTVdK'O
/* 7 3z Y^x
**TestMethod.java 9H}iX0O
*/ `VFl|o#H
package NetFox; ZU.)K>'
:ZfUjqRE
,N7l/6
public class TestMethod { @ KPv&UB
e~s7ggg2k
'+I 2$xE
public TestMethod() K}=8:BaUL
{ ///xx/weblogic60b2_win.exe LEngZ~sV/
try{ h!N&gZ[0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y]YS2^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }Q=se[((
SiteFileFetch fileFetch = new SiteFileFetch(bean); Zc3:9
fileFetch.start(); e3={$Ah
} O?,i?
catch(Exception e){e.printStackTrace ();} ) .-(-6=R
Bb[0\Hs7
lZA>L, \d
} aho<w+l@
3zA=q[C
EOnp!]Y
public static void main(String[] args) ?> MoV5
{ YeExjC
new TestMethod(); eN<pU%7
} \m~\,em
} v6P~XK}G
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