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)); 0<V/[$}\D
} $JOtUB{
for(int i=0;i<nEndPos.length-1;i++) y:E$n!
{ Q0-gU+ig
nEndPos = nStartPos[i+1]; U^}7DJ
} ?* +>T@MH
nEndPos[nEndPos.length-1] = nFileLength; I`+,I`~u
} "uplk8iCJ
} ?0 cv
y /vc\e
xsU%?"r
//启动子线程 (e;/Smol
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -V2f.QE%
for(int i=0;i<nStartPos.length;i++) bRggt6$z
{ `\##M=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `)$G}7cRUH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P*[wB_^&UP
nStartPos,nEndPos,i); n+ H2cl }
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n3? msY(*
fileSplitterFetch.start(); uju'Bs7
} |J@ &lBlq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P\@kqf~pC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uNEl]Q]<e]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mY=sh{ir
nEndPos = " + nFileLength); *|q{(KX
// fileSplitterFetch[nPos.length-1].start(); B3yTN6-
GsO(\hR6^
Z6b]EcP)#
//等待子线程结束 D\;5{,:d
//int count = 0; g'!"klS93
//是否结束while循环 N*[b26
boolean breakWhile = false; XlXt,
Pc?"H!Hkn
t!xdKX& }
while(!bStop) W$7H "tg
{ oumbJ7X=L
write_nPos(); du0o4~-
Utility.sleep(500); ld"rL6
breakWhile = true; Ne;0fkO
7'At_oG
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for(int i=0;i<nStartPos.length;i++) d %FLk=]
{ W9} ,f
if(!fileSplitterFetch.bDownOver) r=37Q14v
{ s-IM
breakWhile = false; tYgHJ~1L*
break; DBGU:V,85
} o; 6^:
} 4C?4M;
if(breakWhile) )Ft+eMYti[
break; ?c8(<_I+
Wm{ebx
\FX"A#
//count++; \ C$t
//if(count>4) Ttl m&d+C
// siteStop(); |bQF.n_
} a~R.">>$
Q(Yn8t
cDYOJu.
System.err.println("文件下载结束！"); ]Ar,HaX-
} RnC+]J+?4
catch(Exception e){e.printStackTrace ();} E 6MeM'sx
} J8@.qC'!
I5QtPqB>
sZ7,7E|_
//获得文件长度 pyX:$j2R+%
public long getFileSize() B[h^]k
{ unqUs08
int nFileLength = -1; -ON-0L
try{ i`<L#6RBT
URL url = new URL(siteInfoBean.getSSiteURL()); *:+ZEFMq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3mopTzs)
httpConnection.setRequestProperty("User-Agent","NetFox"); R'vNJDFY
!?).4yr
[+l6x1Am
int responseCode=httpConnection.getResponseCode(); j(k%w
if(responseCode>=400) Jqgm>\y
{ 0;)Q
processErrorCode(responseCode); - q(a~Ge
return -2; //-2 represent access is error k;JDVRL
} -{C Gn5]_#
ShlTMTgS
,B_tAg4~
String sHeader; o~CEja&(
T.')XKP)1N
!Ea9 fe
for(int i=1;;i++) ~z]VDEJ{q
{ `'5vkO>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z5F#r>>`
//Utility.log(in.readLine()); a[z$ae7
sHeader=httpConnection.getHeaderFieldKey(i); LXJ;8uW2y
if(sHeader!=null) \Wg_ gA
{ qQ3pe:n?
if(sHeader.equals("Content-Length")) 2"shB(:z>
{ QBi]gT@&g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q}l~n)=
break; lup2>"?*
} bZAL~z+ V
} IsJx5GO
else PJ?C[+&
break; (C uM*-
} XHdhSFpm
} f[R~oc5P0
catch(IOException e){e.printStackTrace ();} Bxw(pACf
catch(Exception e){e.printStackTrace ();} Y-st2r[,
4{vEW(
|N)),/R_
Utility.log(nFileLength); |*b-m k
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]xoG{%vgb
return nFileLength; C4gES"T
} 34"PtWbV>
.9r85
%{3q=9ii
//保存下载信息（文件指针位置） 7{w}0PMx
private void write_nPos() %\|{_]h}y
{ QY<5o;m`
try{ '+vmC*-I(
output = new DataOutputStream(new FileOutputStream(tmpFile)); r_,;[+!
output.writeInt(nStartPos.length); `jr?I {m;
for(int i=0;i<nStartPos.length;i++) ;PMh>ZE`
{ D*PEIsV
// output.writeLong(nPos); m__pQu:
output.writeLong(fileSplitterFetch.nStartPos); l1O"hd'~s
output.writeLong(fileSplitterFetch.nEndPos); uM,Ps}
} E,K>V:P*
output.close(); gX-hYQrC
} 0b n%L~KU
catch(IOException e){e.printStackTrace ();} GP %hf{
catch(Exception e){e.printStackTrace ();} |#SZdXg
} v@M^ukk'}
uPYH3<
< FO=PM
//读取保存的下载信息（文件指针位置） 1kUlQ*[<|
private void read_nPos() liLhvcd
{ %m[ZU<v
try{ Z_S{$D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f^"pZS
int nCount = input.readInt(); nu~]9~)I
nStartPos = new long[nCount]; :-Py0{s
nEndPos = new long[nCount]; dVHbIx
for(int i=0;i<nStartPos.length;i++) cL03V?} ~
{ rMZuiRz*
nStartPos = input.readLong(); B@6L<oZ
nEndPos = input.readLong(); mK"s*tD
} t#t[cgI
input.close(); gJrWewEe
} Q@NFfJJ
catch(IOException e){e.printStackTrace ();} W-&V:S{<
catch(Exception e){e.printStackTrace ();} U-m MKRV
} ,5ZQPICF
=8<~pr-NO
3b]M\F9
private void processErrorCode(int nErrorCode) Av5:/c.B
{ C&*1H`n
System.err.println("Error Code : " + nErrorCode); 'x"(OdM:[
} 2=0HQXXrq
8=joVbs
w=rD8@
//停止文件下载 u-4@[*^T$
public void siteStop() vW vu&3tx
{ CAs:>s '8
bStop = true; qdv O>k3
for(int i=0;i<nStartPos.length;i++) H, :]S-T
fileSplitterFetch.splitterStop(); $8HiX6r
R(VOHFvW6
'/@wk#,
} k>.8lc\
} 9:VUtx#}2
//负责部分文件的抓取 6Xm'^T
**FileSplitterFetch.java T:m" eD;
*/ CPRVSN0b{4
package NetFox; h"0)spF"d
P}A!C9Frh
m}=E$zPbO
import java.io.*; GbL1<P$V
import java.net.*; 9jEH"`qqk
h3 XSt
0*rD'?)K+
public class FileSplitterFetch extends Thread { b"N!#&O]
]SRpMZ
A0k?$ko
String sURL; //File URL <EN9s
long nStartPos; //File Snippet Start Position ^ W?cuJ8
long nEndPos; //File Snippet End Position 3)\fZYu)
int nThreadID; //Thread's ID X|eZpIA45
boolean bDownOver = false; //Downing is over |llJ%JhF
boolean bStop = false; //Stop identical _(kaaWJ
FileAccessI fileAccessI = null; //File Access interface 0.n[_?<(
lNa+NtQu
1nskf*Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ihf :k_;
{ y*vSt^
this.sURL = sURL; PMB4]p%o
this.nStartPos = nStart; Uza '%R
this.nEndPos = nEnd; :Z6j5V;s
nThreadID = id; TSsZzsdr2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~qGW94
} e}d(.H%l0
FC,=g`Q!
Im/tU6ybV
public void run() A&~fw^HM
{ TxP+?1t
while(nStartPos < nEndPos && !bStop) ^sLx3a
{ "W(Ae="60
+W*~=*h|
RK|*yt"f"
try{ lYQ|NL():
URL url = new URL(sURL); ~:bdS 4w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'Uf?-t*LT@
httpConnection.setRequestProperty("User-Agent","NetFox"); KBN% TqH|
String sProperty = "bytes="+nStartPos+"-"; 9T24dofkJ
httpConnection.setRequestProperty("RANGE",sProperty); sEdz`F
Utility.log(sProperty); #H>{>0q
PKSfu++Z
@3O)#r}\
InputStream input = httpConnection.getInputStream(); `!HD. E[2c
//logResponseHead(httpConnection); "Nj/{BU
PLc5m5
D@*<O=_D(
byte[] b = new byte[1024]; f;zNNx< ;
int nRead; >{IPt]PCn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r%ES#\L6+|
{ ~&73f7
nStartPos += fileAccessI.write(b,0,nRead); "/i$_vl
//if(nThreadID == 1) ?s^3o{!<W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TD}<U8I8_
} 'YNdrvz
0^-1d2Z~
WxGD*%
Utility.log("Thread " + nThreadID + " is over!"); 3Hom0g,V4
bDownOver = true; w#9KtW,tt
//nPos = fileAccessI.write (b,0,nRead); =L" 0]4K
} :V)jm`)#+
catch(Exception e){e.printStackTrace ();} cu0IFNF}[
} ^}d]O(
} P6 OnE18n
JF4A
-Qn7+?P
//打印回应的头信息 FRrp@hE
public void logResponseHead(HttpURLConnection con) YNU}R/u6^
{ kk3^m1
for(int i=1;;i++) <'I["Um
{ :;7I_tb
String header=con.getHeaderFieldKey(i); fo@^=-4A-
if(header!=null) [s{!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); St-uE|8
Utility.log(header+" : "+con.getHeaderField(header)); y!77gx?-
else A]/o-S_
break; { :tO RF
} J/?Nf2L4
} pFd8p@m_2
"n!yK
;"wCBuXcu
public void splitterStop() tF0jH+7J-
{ B;1qy[
bStop = true; ~.m<`~u
} 85GIEUvH/
&[.`xZ(|
H,!xTy"Wh
} )#}>,,S
jV3PTU
=^nb+}Nz(
/* \c}(rqT
**FileAccess.java dw bR,K
*//文件访问(定位，写) Q6@<7E]y
package NetFox; ^"/^)Lb!@M
import java.io.*; zN4OrG0
Ic#xz;elM
R2~Tr$:
public class FileAccessI implements Serializable{ iEr,ly
[]>'Dw_r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kz"uTJK
RandomAccessFile oSavedFile; #&&T1;z"#
long nPos; _>;Wz7
!Lf<hS^
V)`2Kw
public FileAccessI() throws IOException _IDZ.\'>$
{ pN%&`]Wev
this("",0); N4!`iS Y
} Z4j6z>qE
,BU;i%G&s
7~/cz_
public FileAccessI(String sName,long nPos) throws IOException 'YNaLZ20
{ I &t~o
oSavedFile = new RandomAccessFile(sName,"rw"); Eah6"j!B8n
this.nPos = nPos; OU[<\d
oSavedFile.seek(nPos); *U?O4E9
} NB"S,\M0
HGDrH
l90mM'[
public synchronized int write(byte[] b,int nStart,int nLen) (jgk! 6
{ Ej(Jj\
int n = -1; 'ZfgCu)St
try{ Ey46JO"
oSavedFile.write(b,nStart,nLen); c3A\~tHW
n = nLen; }htjT/Nm
} 0lfK} a
catch(IOException e) >H2`4]4]
{ vT'Bs;QR
e.printStackTrace (); !>8~R2
} (yOkf-e2y
1o_kY"D<
BM%wZ: s
return n; h+f>#O+:
} 0B NLTRv
> VG
H",B[ YK
} _'u]{X\k{J
a|aVc'j
bLgH3[{
/* /:&!o2&1H
**SiteInfoBean.java l>?c AB[
*/ ^PksXfk
package NetFox; J3K=z
7|P kc(O
U@lc1#
public class SiteInfoBean { NR{wq|"
l\HdB"nT
aER|5!7(2\
private String sSiteURL; //Site's URL 9(CvGzco<
private String sFilePath; //Saved File's Path |y\Km
private String sFileName; //Saved File's Name OZ,kz2SF#
private int nSplitter; //Count of Splited Downloading File /HC:H,"i
[m t.2.
pm&THd
public SiteInfoBean() Ac7^JXh%
{//nSplitter的缺省值为5 1^p/#jt
//default value of nSplitter is 5 iTVe8eI
this("","","",5); S2~cAhR|M
} )xGAe#E~j
[M_{~1xX
:QCL9QZ'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^E !v D
{ #x%'U}sF
sSiteURL= sURL; bf3!|Um
sFilePath = sPath; L"L3n,%F
sFileName = sName; &J[a.:..
this.nSplitter = nSpiltter; 8s%/5v"
^S9y7b^;r
R`?l.0
} 4JSPD#%f
mYBEjZB
5sD,gZ7
public String getSSiteURL() g;IlS*Ld
{ T)C@6/
return sSiteURL; BxY t*b%
} $EMOz=)I#
s:`i~hjq
85{m+1O~
public void setSSiteURL(String value) o9?@jjqH
{ G4&s_M$
sSiteURL = value; DA=U=F
} W+nu=iQ!
J3Mb]X)_}
e5=d Ev
public String getSFilePath() 9N]Xa
{ 7*'/E#M
return sFilePath; (z?HyxRT
} ]' mbHkn68
\/-c)
'nJF:+30ZH
public void setSFilePath(String value) *pl6 V|
{ LzygupxY!
sFilePath = value; ^\)a[OWp
} WKf<% E$
k#*-<1
`S&a.k
public String getSFileName() 'X~tt#T
{ mgxIxusR
return sFileName; T?9D?u?]
} *P()&}JK
~m%[d. }e
,N/@=As9$
public void setSFileName(String value) D{|qP nE4
{ E3L?6Qfx>
sFileName = value; I8F+Z
} T}~TW26v
BT{;^Hp
J=V
public int getNSplitter() gmTBT#{6yH
{ \}-4(Xdaq
return nSplitter; y)f.ON36I
} !`ol&QQ#
\?bV\/GBR
D+8d^-:
public void setNSplitter(int nCount) w$gvgz
{ R^Rc!G}
nSplitter = nCount; p<R:[rz
} fBO/0uW
} r4.6W[|d
[ X*p [
Re%[t9F&
/* -luQbGcT3
**Utility.java ia6 jiW x
*/ ,,3lH-C
package NetFox; PN}+LOD<t
#mH@ /6,#[
6K2e]r
public class Utility { *7Dba5B
B6XO&I1c
E}^V@ :j>
public Utility() k(Yz2
{ xh6(~'$
|9@,ri\'Rg
0SpB2>_
} :\TMm>%q
>T$0*7wF
//线程睡眠 W?7l-k=S
public static void sleep(int nSecond) LS@TTiN
{ s"(RdJ-,
try{ *k$[/{S1-
Thread.sleep(nSecond); ~cz}C("Z
} O5dS$[`j\p
catch(Exception e) <H[w0Z$
{ \u=d`}E
e.printStackTrace (); `At.$3B
} 2Gyq40
} u ExLj6
Q G)s
//日志 'Kelq$dn#
public static void log(String sMsg) F?L]Dff
{ jKSj);
System.err.println(sMsg); , c.^"5
} _h%Jf{nu
+sNS
+/OSg.
public static void log(int sMsg) whI{?NP
{ .j6udiv5
System.err.println(sMsg); $C16}^
} OT#@\/>
} +)jUA]hJ/
F)P:lvp<r
QE]@xLz
/* =g% L$b<i
**TestMethod.java b3NIFKw
*/ x/QqG1q
package NetFox; s|YH_1r
h yrPu_
+]l?JKV
public class TestMethod { uJ`N'`Z
M-WSdG[AJ
ulR yt^bx|
public TestMethod() .EYL
{ ///xx/weblogic60b2_win.exe ^Z (cVg
try{ /E>;O47a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f5}afPk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gz`Jzh j
SiteFileFetch fileFetch = new SiteFileFetch(bean); X)g X9DA
fileFetch.start(); cIug~ x>
} --HDEc|
catch(Exception e){e.printStackTrace ();} h'ik3mLH
=D zrM%
WC_.j^sW
} #1YMpL
Km2~nkQ
P0N/bp2Uy
public static void main(String[] args) /Qgb t
{ Z;+,hR((
new TestMethod(); tpI/Ibq
} hvt]VC]]
} cGot0' mB
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