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)); 3P~I'FQ
} u@5vK2
for(int i=0;i<nEndPos.length-1;i++) /:d03N\9k
{ oGx OJyD
nEndPos = nStartPos[i+1]; _R<eWp
} ewg&DBbN"
nEndPos[nEndPos.length-1] = nFileLength; Gf\Dc
} LvgNdVJDP|
} [>QV^2'Z
W&ya_iP~C
!c[(#g
//启动子线程 MKLntX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $,4;_4t
for(int i=0;i<nStartPos.length;i++) 5n! V^ !
{ 3US}('
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S%<RV6{aiM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \.y|=Ql_u
nStartPos,nEndPos,i); IJ2]2FI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tp<uN~rTgh
fileSplitterFetch.start(); 3?SofPtc/
} xZW6Hk_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *CZvi0&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); md:$OC3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y~EKMowI&e
nEndPos = " + nFileLength); {i y[8eLg
// fileSplitterFetch[nPos.length-1].start(); 3XdN\xc
@-nCK Yj
98eiYh
//等待子线程结束 $Nvt:X_
//int count = 0; PhW<)B]
//是否结束while循环 #D M%_HXDi
boolean breakWhile = false; {Ak{ ct\t
t=syo->
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while(!bStop) H_KE^1
{ R}njFQvS)
write_nPos(); QLrFAV
Utility.sleep(500); Wc [@,
breakWhile = true; a)=WDRk
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YYU Di@K
for(int i=0;i<nStartPos.length;i++) rStfluPL
{ l[lUmE
if(!fileSplitterFetch.bDownOver) yPrp:%PS
{ UOHU1.3$T
breakWhile = false; rU<NHFGj4
break; s''?: +
} h1@|UxaE#
} }[XzM/t
if(breakWhile) g\;AU2?p7
break; 3kFSu
w^MU$ubx
}MAQhXI^O|
//count++; ufAp7m@ud
//if(count>4) =<w6yeko
// siteStop(); d!kiWmw,
} wJ@8-H 8}
q(<#7spz
<ABN/nH
System.err.println("文件下载结束！"); 9XWHr/-_@
} )w];eF0c
catch(Exception e){e.printStackTrace ();} 6z v+Av:
} H|_^T.n?E
^{&Vv(~!Q
H?98^y7
//获得文件长度 +shT}$cb1
public long getFileSize() ;@p2s'(
{ `3+yu' Q'
int nFileLength = -1; G0Zq:kJ
try{ tn\Y:
URL url = new URL(siteInfoBean.getSSiteURL()); a$ a+3}\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )R$+dPu>
httpConnection.setRequestProperty("User-Agent","NetFox"); a7'.*H]
` W$
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int responseCode=httpConnection.getResponseCode(); 7NC"}JB&
if(responseCode>=400) 'W>Bz,M6yo
{ WmU4~.
processErrorCode(responseCode); pFi.?|6"
return -2; //-2 represent access is error & V:q}Q
} 1~:7W
(\m4o
jv7-i'I@
String sHeader; bK;I:JK3
^|y6oj
JwWW w1
for(int i=1;;i++) *0]E4]ZO
{ x&9}] E^<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qr]xj7\@i
//Utility.log(in.readLine()); Q4e*Z9YJ
sHeader=httpConnection.getHeaderFieldKey(i); H&jK|]UXoO
if(sHeader!=null) Sx)b~*
{ $3>k/*=
if(sHeader.equals("Content-Length")) ,JIjAm*2
{ {a`t1oX(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jj+|>(P
break; ]-"~?
} s\ft:a@
} $z,lq#zzl
else t"M&Yy
break; 0,+RF"R
} %T@3-V_
} Cj31>k1
catch(IOException e){e.printStackTrace ();} ?B ;+,
catch(Exception e){e.printStackTrace ();} P#-9{T
y<mmv~=
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Utility.log(nFileLength); )6U&^9=
;okFm
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return nFileLength; K];`
} {3=M-U~r
am.}2QZU
%!%G\nv
//保存下载信息（文件指针位置） \GYh"5
private void write_nPos() T0BFit6
{ =Q|_v}
try{ u&Q2/Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); ol]"r5#Q_H
output.writeInt(nStartPos.length); _mVq9nBEf
for(int i=0;i<nStartPos.length;i++) ~EJVlji
{ ufF$7@(+
// output.writeLong(nPos); $YuVM
output.writeLong(fileSplitterFetch.nStartPos); SrGX4
output.writeLong(fileSplitterFetch.nEndPos); P2_UQ
} tDj~+lmdN
output.close(); ;=\vm"I?
} Uywi,9f
catch(IOException e){e.printStackTrace ();} !K a!f1
catch(Exception e){e.printStackTrace ();} >DX\^86x
} q\wT[W31@
t.wB\Kmt\
w@&g9e6E
//读取保存的下载信息（文件指针位置） &K2J$(.t
private void read_nPos() .OFwGOL%
{ ,{wA%Oy,
try{ dL;C4[(N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %oVoE2T{@
int nCount = input.readInt(); q]Y [W1
nStartPos = new long[nCount]; 4oW6&1
nEndPos = new long[nCount]; Y1RiuJtL
for(int i=0;i<nStartPos.length;i++) <=WSX{_D
{ 1F?`.~q
nStartPos = input.readLong(); L=Cm0q 3v
nEndPos = input.readLong(); UHr0J jQK
} y4* }E
input.close(); sevaNs
} p)l>bC?3
catch(IOException e){e.printStackTrace ();} L3[r7 b
catch(Exception e){e.printStackTrace ();} [/_M!&zz2
} =7%1]
_SU%ul
E__^>=
private void processErrorCode(int nErrorCode) UeNa
{ 7hAFK
System.err.println("Error Code : " + nErrorCode); #wz1uw[pI!
} i'Vrx(y3
lGHU{7j\
u&MlWKCi
//停止文件下载 Fy1@B(V%
public void siteStop() /C)mx#h]
{ ,<iJ#$: Sx
bStop = true; !YD~o/t@|
for(int i=0;i<nStartPos.length;i++) &"!s+_
fileSplitterFetch.splitterStop(); ^6&?R?y
W vh3Y,|3
Q1tZ]Q.6
} ?VC[%sjwn
} G#{ Xd6L
//负责部分文件的抓取 ",wv*z)_>
**FileSplitterFetch.java . ] =$((
*/ s;oDwT1
package NetFox; i=b<Mz7|
s9t`!
Glz)-hjJ:n
import java.io.*; 'N1_:$z@(
import java.net.*; }yM /z
OsS5WY0H
JP$@*F@t
public class FileSplitterFetch extends Thread { ]fc9m~0N,\
#1-y[w/
aD yHIh8
String sURL; //File URL 5Fh?YS=
long nStartPos; //File Snippet Start Position a<AT;Tc
long nEndPos; //File Snippet End Position ;3ZHm*xJx
int nThreadID; //Thread's ID Y{c_5YYf
boolean bDownOver = false; //Downing is over "4W@p'
boolean bStop = false; //Stop identical RU} M&&
FileAccessI fileAccessI = null; //File Access interface cEkf9:_La
0*?/s\>PS;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K_\fO|<k
{ 7A7=~:l\G
this.sURL = sURL; l| 1O9I0Gd
this.nStartPos = nStart; #"tHT<8u
this.nEndPos = nEnd; JNY;;9o
nThreadID = id; =HJ)!(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tqI]S X
} th&?
Wi a%rm
p3?!}VM!y
public void run() q5X\wz2N
{ |e+8Xz1>
while(nStartPos < nEndPos && !bStop) S`,(10Y
{ ~ Iin|
J;Y=oB
H(qDQqJHYy
try{ W<Ms0
URL url = new URL(sURL); #vk-zx*v7=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H>8B$fi)$
httpConnection.setRequestProperty("User-Agent","NetFox"); 5xJyW`SWz
String sProperty = "bytes="+nStartPos+"-"; ?m&?BsW$)
httpConnection.setRequestProperty("RANGE",sProperty); /S}0u}jID?
Utility.log(sProperty); L2"fO
1.7tXjRd+
:',.I
InputStream input = httpConnection.getInputStream(); \@yx;}bdI
//logResponseHead(httpConnection); dB{o-R
pJM~'tlHV
3#)I7FG
byte[] b = new byte[1024]; Tac7+=T
int nRead; JffjGf-o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N[$bP)h7
{ . J"g.Q
nStartPos += fileAccessI.write(b,0,nRead); d*7nz=0&$
//if(nThreadID == 1) L<HJ!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S\7-u\)
} PoyY}Ra
"PA:
;{Cr+lqTJ
Utility.log("Thread " + nThreadID + " is over!"); r:h\{DVf
bDownOver = true; OnO56,+S^
//nPos = fileAccessI.write (b,0,nRead); Q;p?.GI?-
} oqzx}?0
catch(Exception e){e.printStackTrace ();} +5n,/YjS`
} xO8-vmf2
} :1Jg;G
}?f%cRT$
0IHcyb
//打印回应的头信息 J}?F4
public void logResponseHead(HttpURLConnection con) *P4G}9B|9:
{ c_#\'yeW
for(int i=1;;i++) I!IWmU6FN
{ 3QL I|VpO
String header=con.getHeaderFieldKey(i); gXtyl]K:
if(header!=null) Q+e|;Mj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); plL##?<D<
Utility.log(header+" : "+con.getHeaderField(header)); RS&l68[6
else g'G"`)~ 2
break; x1['+!01
} HX1RA5O
} w6C0]vh
GX4HW \>a
B+:'Ld](
public void splitterStop() Fb#_(I[aj
{ 8l(_{Y5(-
bStop = true; fVCpG~&t
} w_-v!s2
}S{#DgZ@X
RhVQVjc
} 8BUPvaP<[
${"+bWG2G!
Y.M^tH:
/* xA|72!zk0P
**FileAccess.java Fl,(KSTz
*//文件访问(定位，写) c}9.Or`?
package NetFox; YGVj$\
import java.io.*; UEeD Nl$^u
CBC0X}_`
BU|=`Kb|))
public class FileAccessI implements Serializable{ =,B44:`r
gC-3ghmgS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6onFf* m!x
RandomAccessFile oSavedFile; b/N+X}VMN
long nPos; %%["&
KCR6@{@
Obd@#uab
public FileAccessI() throws IOException s{v!jZ
{ AH$D./a
this("",0); [d="94Ab
} FX QUj&9
_~f&wkc
@dimZsi1
public FileAccessI(String sName,long nPos) throws IOException . IBy'
{ 69)- )en
oSavedFile = new RandomAccessFile(sName,"rw"); 8c-r;DE
this.nPos = nPos; <Wgp$qt;
oSavedFile.seek(nPos); O)g\/uRy
} D/1{v
2y6 e]D
octBt`\Of
public synchronized int write(byte[] b,int nStart,int nLen) Ba$&4?8
{ HIUB:
int n = -1; 4(5NHsvp
try{ W0GDn
oSavedFile.write(b,nStart,nLen); 5VWyc9Q
n = nLen; Q/EHvb]
} Y<lJj"G
catch(IOException e) m44Ab6gpsb
{ Bi7QYi/
e.printStackTrace (); '8+<^%c
} 1m$:Rn^
I5[HD_g:
=<ngtN
return n; x9UF
} +Tnn'^4
Gh3b*O_,
d>j`|(\
} zS]8ma
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z;? 32K
/* #*QnO\.
**SiteInfoBean.java rPf<8oH
*/ 9ohaU
package NetFox; ]"Y? ZS;H
G:'hT=8
xVOoYr>O
public class SiteInfoBean { fUy:TCS
Y.9s-g
7`113`1
private String sSiteURL; //Site's URL R-Y07A
private String sFilePath; //Saved File's Path oWg"f*
private String sFileName; //Saved File's Name {C6,h#|pg
private int nSplitter; //Count of Splited Downloading File 5U[m]W=B
xY]Y
(* WO<V
public SiteInfoBean() ~ ;CnwG
{//nSplitter的缺省值为5 B(+J?0Dj
//default value of nSplitter is 5 N"A863>
this("","","",5); 0Z.bd=H
} X?PcEAi;w
Gt>*y.]
n#F:(MSOp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E0 ~\ A;
{ g\;&Z
sSiteURL= sURL; !Zf< j
sFilePath = sPath; J]|Zh
sFileName = sName; sFhmp
this.nSplitter = nSpiltter; HV_5 +
4hRc,Vq
s];jroW@u
} 565UxG }
0)=U:y.
K"lZwU\:On
public String getSSiteURL() "UUzLa_
{ ;JQ:S~K9
return sSiteURL; q]}fW)r
} ;onhc*{lv
i7N|p9O.
qX,TX 3
public void setSSiteURL(String value) z"[}Sk
{ l_Eeus
sSiteURL = value; (MfPu8j
} eiTG
$^[^]Q
J0{;"
public String getSFilePath() QLr.5Wcg>
{ AXK6AZjX
return sFilePath; 7RE'KH_$
} IdP"]Sv{<
v[P $c$Xi
Pra,r9h,
public void setSFilePath(String value) {,kA'Px)
{ ZboY]1L[j
sFilePath = value; VZ69s{/.B
} PcxCal4
>M`ryM2=D
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public String getSFileName() IYZ$a/{P
{ 3m2hB%SNb
return sFileName; $F^p5EXkc6
} H_ecb;|mP
ix.I)
[^rMM1^,OB
public void setSFileName(String value) 25bLU?x5B
{ ZA1u
sFileName = value; D\"F?>
} #`kLU:
{:peArO
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public int getNSplitter() x(r>iy
{ TOH!vQP
return nSplitter; h3.6<vM
} 57nSyd]PR
Y*}xD;c k
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public void setNSplitter(int nCount) P&3Z,f0
{ ^seb8o7
nSplitter = nCount; OhNEt>
} i.~*G8!DM
} c5vi Y|C^
2|n)ZP2cp
p`oSI}ZwB
/* r]6X
**Utility.java ;";#{B:
*/ ^nPk;%`0
package NetFox; dq.'[
vCj,aSW
&@dMIJK"(
public class Utility { -~PiPYX
L("zS%qr
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public Utility() #YEOY#
{ uaiCyh1:
x JXPtm
.66_g@1
} dc]D 8KX
,p3moD 3
//线程睡眠 cz{5-;$9Z
public static void sleep(int nSecond) TmH'_t.*T~
{ @_:Jm tH<
try{ |_ChK6Q?v
Thread.sleep(nSecond); =~|:93]k
} 8M5a&35J"
catch(Exception e) ,.Sd)JB'
{ v +$3Z5
e.printStackTrace (); :<"b"{X"
} *'BA# /@
} \H6[6*JuB
CLn}BxgD
//日志 K0YUN^St
public static void log(String sMsg) et-<ib<lY
{ r=S6yq}
System.err.println(sMsg); _--kK+rU
} Gdi8Al]\Nl
koTb{UL
~[wh
public static void log(int sMsg) U"0Ts!CABA
{ zfexaf!
System.err.println(sMsg); Bkq3-rX\
} ea\b7a*
} ~"IjT'W3
8`$lsD
})Pq!u:3
/* r/G6O
**TestMethod.java qRX:eo
*/ GELxS!
package NetFox; r6x"D3
Z'@a@Y+
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public class TestMethod { !(&N{NH9
v[}g+3a
kr=&x)Wy!
public TestMethod() 4!3mSWNV
{ ///xx/weblogic60b2_win.exe |IgH0 zZ
try{ l+V#`S*q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h^`!kp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c}l?x \/
SiteFileFetch fileFetch = new SiteFileFetch(bean); doj$chy
fileFetch.start(); >axf_k
} bq}hj Cy
catch(Exception e){e.printStackTrace ();} ^kF-mM=
}2X"
n>5/y c"/q
} kv)IG$S0
<z2*T \B!8
#$dk
public static void main(String[] args) MU-T>S4
{ HAHLF+k
new TestMethod(); LYV\|a{Y
} 6Z,j^: B
} 5|pPzEA>
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