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)); X&H"51
} 5{,<j\#L
for(int i=0;i<nEndPos.length-1;i++) W"{N Bi
{ ~D>p0+-c
nEndPos = nStartPos[i+1]; !4+<<(B=E
} ox.F%)eQ
nEndPos[nEndPos.length-1] = nFileLength; p!%pP}I
} OjA,]Gv6
} |[8Th4*n
9\(| D#
Q3?F(ER@
//启动子线程 z F;K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q"#J6@
for(int i=0;i<nStartPos.length;i++) }jPSUdo
{ X:{!n({r=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @H8EWTZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), seJ^s@H5l
nStartPos,nEndPos,i); {'H(g[k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \ Cj7k^
fileSplitterFetch.start(); f|gg
} Y'X%Aw;`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HGg@ _9tW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )4;`^]F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BiBOr}ZQ
nEndPos = " + nFileLength); 9Mcae31
// fileSplitterFetch[nPos.length-1].start(); _yR^*}xJb
e*1_8I#2
R4d=S4i
//等待子线程结束 Tlr v={
//int count = 0; Xch~ 1K
//是否结束while循环 .=; ;
boolean breakWhile = false; `Pnoxm'
~gt@P
K*dCc}:`
while(!bStop) @C aG9]
{ G3v5KmT
write_nPos(); %;!.n{X
Utility.sleep(500); _)-o1`*-
breakWhile = true; X}0cCdW
k9F=8q
}Y4qS
for(int i=0;i<nStartPos.length;i++) 8q7b_Pq1U
{ 3G4-^hY<
if(!fileSplitterFetch.bDownOver) c:.eGH_f
{ &%Tj/Qx
breakWhile = false; `M6)f?|$.
break; cB&:z)i4
} oP.7/*p
} RD&PDXT4
if(breakWhile) Z3!`J&
break; -s/ea~=R
u]@['7
wz8yD8M
//count++; ^<AwG=
//if(count>4) Xn ;AZu^'R
// siteStop(); A+{VGP^
} jc9y<{~x/
6W UrQFK
xkAK!uVy
System.err.println("文件下载结束！"); bZV/l4TU
} %8x#rohP
catch(Exception e){e.printStackTrace ();} *{{89E>wC
} U/BR*Zn]*
:M5l*sIO2
zx7{U8*`<
//获得文件长度 Y <qm{e
public long getFileSize() 9_s`{(0?
{ ?bu>r=oIO]
int nFileLength = -1; nQS|Lt_+
try{ L/^I*p,
URL url = new URL(siteInfoBean.getSSiteURL()); HpnWoDM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >o,TZc\
httpConnection.setRequestProperty("User-Agent","NetFox"); "zy7C*)>r
!f6(Zho
PUX;I0Cf
int responseCode=httpConnection.getResponseCode(); Y nZiTe@
if(responseCode>=400) BsJC0I(
{ n'w.; q
processErrorCode(responseCode); PFK '$
return -2; //-2 represent access is error WuW^GC{7
} g=o4Q< #^y
Yz<1 wt7;
@s^-.z
String sHeader; RpYERAgT
cCc(fF*^
)\^-2[;
for(int i=1;;i++) pD]OT-8
{ ~u+9J}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5/z/>D;
//Utility.log(in.readLine()); =nHgDrA_
sHeader=httpConnection.getHeaderFieldKey(i); gPc=2
if(sHeader!=null) t&DEb_"De
{ jF*j0PkNdb
if(sHeader.equals("Content-Length")) 29q _BR *:
{ ~F7gP{r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iG?[<1~
break; dC4'{n|7
} 4xJQ!>6
} >yh2Lri
else Y[S1$(K&*
break; >@AB<$A
} RCLeA=/N@0
} ~^b/(
catch(IOException e){e.printStackTrace ();} u>/ TE
catch(Exception e){e.printStackTrace ();} 61 ~upQaR
g$o&Udgs
;6hOx(>`=
Utility.log(nFileLength); xAP+FWyV
$u6 3]rypm
'[O;zJN;
return nFileLength; h`.&f
} y18Y:)DkL
6\S~P/PkE
Pr,q*_Yy
//保存下载信息（文件指针位置） *HB-QIl
private void write_nPos() #LN`X8Wz'
{ 3DG_QVg^v
try{ s(roJbJ_;
output = new DataOutputStream(new FileOutputStream(tmpFile)); S`?!G&[!>
output.writeInt(nStartPos.length); 9Lfv^V0
for(int i=0;i<nStartPos.length;i++) 8e"gW >f
{ /vb`H>P
// output.writeLong(nPos); -s'-eQF J
output.writeLong(fileSplitterFetch.nStartPos); ?Pc'C
output.writeLong(fileSplitterFetch.nEndPos); pFz`}?c0
} !$>R j
output.close(); e<q?e}>?
} eKqk= (
catch(IOException e){e.printStackTrace ();} q6X1P"%.
catch(Exception e){e.printStackTrace ();} eQvg7aO;
} 5+ MS^H
,wdD8ZT'Ip
8SS|a
//读取保存的下载信息（文件指针位置） h3@v+Z<}
private void read_nPos() HiJE}V;Vq
{ P}`H ~N~
try{ B^jc3 VsR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fa2kG&, _
int nCount = input.readInt(); S`m]f5u|
nStartPos = new long[nCount]; BJo*'US-Q
nEndPos = new long[nCount]; mU9kVx1+
for(int i=0;i<nStartPos.length;i++) ^L&iR0
{ , SnSW-P
nStartPos = input.readLong(); G;XxBA
nEndPos = input.readLong(); _2 osV[e
} 5d!-G$@
input.close(); yJe>JK~)
} ZWp(GC1NA
catch(IOException e){e.printStackTrace ();} qA5r
catch(Exception e){e.printStackTrace ();} t.\dpBq
} i<g-+Qs
%BB%pC
^D-/`d
private void processErrorCode(int nErrorCode) }f7j8py
{ |)/aGZ+
System.err.println("Error Code : " + nErrorCode); z,%$+)K
} 2SR:FUV/
t#eTV@-
!m?-!:
//停止文件下载 d9|<@A
public void siteStop() 3|Xyl`i4o
{ tcog'nAz
bStop = true; }?v )N).kW
for(int i=0;i<nStartPos.length;i++) )IZ~G\Ra'
fileSplitterFetch.splitterStop(); hqkz^!rp
\:F_xq
x# 5A(g
} >t_6B~x9
} ?=fyc1
//负责部分文件的抓取 F`]2O:[
**FileSplitterFetch.java WQO) =n
*/ G9<X_
package NetFox; /fV;^=:8c
?#UO./"
T:W4$P
import java.io.*; )p%E%6p
import java.net.*; w$-6-rE]d
S#} KIy
)q3p-)@kQ
public class FileSplitterFetch extends Thread { 6<(.4a?
fXQNHZ|4
}U5yQ%N
String sURL; //File URL 'K,:j 388
long nStartPos; //File Snippet Start Position %sQ^.` 2
long nEndPos; //File Snippet End Position 3=]sLn0L
int nThreadID; //Thread's ID "@,}p\
boolean bDownOver = false; //Downing is over ZO c)
boolean bStop = false; //Stop identical o J;$sj
FileAccessI fileAccessI = null; //File Access interface rguCp}r
$z*'fXg
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yY&I dE
{ 85xR2<:
this.sURL = sURL; \6*I'|5d
this.nStartPos = nStart; hTi$.y!k
this.nEndPos = nEnd; #|PS&}6wU
nThreadID = id; pBA7,z"`mP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~Vjl7G\7i
} q.`NtsW!\+
k7A-J\
h2;F
public void run() Bh]P{H%
{ '$zIbQ:
while(nStartPos < nEndPos && !bStop) RQu(Wu|m.
{ (;^syJrh
J!U}iD@occ
S\!ana])
try{ !H>R%g#28_
URL url = new URL(sURL); M?uC%x+S$_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xAMW-eF?d
httpConnection.setRequestProperty("User-Agent","NetFox"); r<Kx0`y
String sProperty = "bytes="+nStartPos+"-"; 3HY9\'t6
httpConnection.setRequestProperty("RANGE",sProperty); O55 xS+3^k
Utility.log(sProperty); !5uGd`^I
cJ @Wt>YI
03S]8l
InputStream input = httpConnection.getInputStream(); HBx=\%;n
//logResponseHead(httpConnection); Z^MNf
xbYi.
dT1H
byte[] b = new byte[1024]; 0T5L_%c
int nRead; s>n)B^64W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ng>h"H
{ dQR-H7U
nStartPos += fileAccessI.write(b,0,nRead); ut/=R !(K
//if(nThreadID == 1) =D#bb<o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2u*KM`fa`
} LvUj9eVb/L
9.B KI/
Px`!A EFd[
Utility.log("Thread " + nThreadID + " is over!"); Q9G;V]./
bDownOver = true; ly3\e_z:G
//nPos = fileAccessI.write (b,0,nRead); HYSIN^<oy
} tr}Loq\y
catch(Exception e){e.printStackTrace ();} mZ"4&U
} `t'W2X
} s 15oN
o.\F.C$
t"'7m^j
//打印回应的头信息 LsS
public void logResponseHead(HttpURLConnection con) T\>a!
{ .O}%
for(int i=1;;i++) 5>N2:9We
{ D#JL!A%O
String header=con.getHeaderFieldKey(i); !LN?PKJ
if(header!=null) s'J:f$flS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xw2[d+mB
Utility.log(header+" : "+con.getHeaderField(header)); AvV|(K"
else 6h,(wo3Y
break; RMWHN:9
} =`s!;
} ?\s+EE&-
/9pwZ%:<
o@i#|kx,
public void splitterStop() 6 EC*
{ l(tOe
bStop = true; ;8{4!S&b
} :;fHDU|
lHe{\N[C
q6`b26
} mahJSz(3
ktBj|-'>
ZO$m["|
/* v+#}rUTF
**FileAccess.java OL,TFLn4
*//文件访问(定位，写) ^qQZT]
package NetFox; |My4SoOF
import java.io.*; FOy|F-j
>DZw
3!oi+_
public class FileAccessI implements Serializable{ dD|OSB7I7
NmJWU:W_@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hD*SpVIU
RandomAccessFile oSavedFile; P?B;_W+~A.
long nPos; LKOwxF#TKT
Rww{:R
w\i\Wp,FP
public FileAccessI() throws IOException P&ptJtNg
{ RM]M@%,K
this("",0); B s#hr3h-
} yS(fILV
v8[I8{41
usK*s$ns
public FileAccessI(String sName,long nPos) throws IOException 8hJ%JEzga
{ RA'M8:$
oSavedFile = new RandomAccessFile(sName,"rw"); ]cZ!y ~
this.nPos = nPos; cir$voL
oSavedFile.seek(nPos); MWpQ^dL_
} 4DOH`6#an
pRIhFf
p=GBUII #
public synchronized int write(byte[] b,int nStart,int nLen) @ljA
{ _ff`y
int n = -1; h"_;IUZ!
try{ yt=3sq
oSavedFile.write(b,nStart,nLen); LzXmb 7A
n = nLen; %9N7Ln|%
} i}mVQ\j5
catch(IOException e) RcM/!,B
{ ?Unb? {,&2
e.printStackTrace (); :f}9($
} ,<tX%n`v=
n;+LH9
Hmd] FC,_
return n; b#toM';T
} B43HNs
_%!c+f7
*@v)d[z_
} QWSTR\!
.C(eh
UT=tT)4b
/* nvJf/90$
**SiteInfoBean.java !K}~/9Z=m
*/ Yu[ t\/
package NetFox; ?:8ido#-
+*T7@1
n}_JB>i~
public class SiteInfoBean { ?Exv|e
B~JwHwIhA
qx8fRIK%
private String sSiteURL; //Site's URL o+QE8H43
private String sFilePath; //Saved File's Path f]|ysf
private String sFileName; //Saved File's Name YoZFwRQU
private int nSplitter; //Count of Splited Downloading File S=<}:#;u0
1#*a:F&re
ceM6{N<_U
public SiteInfoBean() |_*O'#jx
{//nSplitter的缺省值为5 TYmP)
//default value of nSplitter is 5 %Yicg6:
this("","","",5); -pa )K"z
} 7/ysVWt
PMh^(j[
WDc+6/<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EQ`(yj
{ {G}.b)9FG
sSiteURL= sURL; 0Lc9M-Lg
sFilePath = sPath; xtE_=5$~
sFileName = sName; !?p%xj?
this.nSplitter = nSpiltter; ujaGNg?,
!2A:"2Kys:
+!z{5:
} 'EF9Zt8
5b/|!{
lB4GU y$
public String getSSiteURL() p|jV{P
{ Wi2WRJdyu
return sSiteURL; &8>IeK{I
} )XakJU^o
#PanfYR
lBhLf@
public void setSSiteURL(String value) 8V)^R(\;
{ r>"
sSiteURL = value; RGg(%.
} n'01Hh`0
B}?5]N==]
C>$E%=h+_
public String getSFilePath() `m?c;,\
{ qT"Q1xU[
return sFilePath; Jd(,/q
} |8=nL$u
,:`4%
a1.Ptf eW|
public void setSFilePath(String value) +~roU{& o
{ ?~;:jz|9<'
sFilePath = value; gu<'QV"
} ("+}=*?OF3
kc @[9eV
VUYmz)m5
public String getSFileName() Q7$.LEioN
{ Tekfw
return sFileName; h0-hT
} <]4i`6{v
;F#7Px(q
?)[EO(D
public void setSFileName(String value) }!/$M\w
{ k.^coI5
sFileName = value; &f^l^K5:
} Jn3An
1Q4}'0U4
$Y_i4(
public int getNSplitter() )h|gwERj
{ {]_r W/
return nSplitter; ~aOuG5XK
} '+vA\(K
IlE_@gS8
UkHY[M7;
public void setNSplitter(int nCount) =gvBz| +
{ r8&^>4
nSplitter = nCount; IWveW8qJ
} E3l> 3
} :.d:9Z|_
\&3"<6xA
^;maotHn
/* MpqZH{:?G
**Utility.java t|!j2<e
*/ z=_Ef3`M
package NetFox; S:q3QgU=X
.G(llA}
f0<%&2ym
public class Utility { @qjfZH@
MR,R}B$
\uq/x^?yo
public Utility() !$Tw^$n
{ /K{9OT@>
""h)LUrl
)a3J9a;ZS0
} ,H2D
f{i8w!O"~
//线程睡眠 UH>F|3"d
public static void sleep(int nSecond) a/U2xq{x
{ PN<C=gAe
try{ G4;3cT3'
Thread.sleep(nSecond); aKlUX
} ;?~$h-9)
catch(Exception e) )r z+'|,
{ /c-r
e.printStackTrace (); ^/=#UQ*k
} UMp/\&0
} A@D2+fS
e)IpPTj#
//日志 ym/fFm6h
public static void log(String sMsg) Q33"u/-v
{ lz0TK)kuC
System.err.println(sMsg); TO*BH^5R
} .R8 HZ}3
$DC*i-}qFg
CWG6;NT6m
public static void log(int sMsg) wHv]ViNvXE
{ 3bd5FsI^pU
System.err.println(sMsg); |R@~-Ht
} ~h=X8-D
} uV hCxUMQ
ZBG}3Z
}Jh: 8BNuP
/* Xy5s^82?
**TestMethod.java #:|+XLL
*/ j0GMTri3
package NetFox; ?$Wn!"EC8
CGP3qHrXt
Bo+DJizu
public class TestMethod { (j"(
Rek -`ki5F
0\~Z5k`IT
public TestMethod() q )lnS )
{ ///xx/weblogic60b2_win.exe c$,_>tcP
try{ Lru-u:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BH@)QVs-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cx$Gic:4
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1b>C<\
fileFetch.start(); ORWm C!
} &G>(9
catch(Exception e){e.printStackTrace ();} SL&hJs4c'
H{c?lT
C#=bW'C
} 4Kv[e]10(
F;!2(sPS
Q U F$@)A
public static void main(String[] args) G02m/8g3
{ }o,z!_^PLQ
new TestMethod(); +P`(Rf"luu
} \#x}q'BC4
} E%TpJl'U
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