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)); pd`m//G
} CAx eJ`Q
for(int i=0;i<nEndPos.length-1;i++) r9!s@n
{ 9Nna-}e?W
nEndPos = nStartPos[i+1]; k{S8q?Gc
} C[jX;//Jiu
nEndPos[nEndPos.length-1] = nFileLength; Qc!3y>Y=_
} o~CEja&(
} T.')XKP)1N
\b6{u6?+
~z]VDEJ{q
//启动子线程 `'5vkO>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z5F#r>>`
for(int i=0;i<nStartPos.length;i++) y<m[9FC}
{ ]t&^o**
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \Wg_ gA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @PLJ)RL
nStartPos,nEndPos,i); H2Z e\c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GL-b})yy
fileSplitterFetch.start(); }CZw'fhVWO
} dIh+h|:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g]N'6La
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tcRJ1:d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a9 q:e
nEndPos = " + nFileLength); K1R?Qt,qDF
// fileSplitterFetch[nPos.length-1].start(); 9c*B%A8J
G9am}qr
oD9L5c)
//等待子线程结束 An`*![
//int count = 0; CCt\[hl
//是否结束while循环 <]DUJuF-M
boolean breakWhile = false; j_h:_D4
fE)o-q6Z
3OKs?i3A
while(!bStop) imzPVGCD{
{ ."O%pL]!/b
write_nPos(); Ac*J;fI
Utility.sleep(500); \/\w|j
breakWhile = true; .m\0<8C
Wb cm1I)
<Uj9~yVN]
for(int i=0;i<nStartPos.length;i++) {J/Fp#
{ b5Q>e%i#
if(!fileSplitterFetch.bDownOver) /NiD#s0t
{ -])=\n!=
breakWhile = false; Fsx<Sa
break; Z^'\()3t
} F&7|`o3
} gX-hYQrC
if(breakWhile) P,3w b
break; b5 NlL`g
HOCj* O4
v@M^ukk'}
//count++; /K1cP>oE
//if(count>4) h7T),UL
// siteStop(); f{[0;qDJ
} UuF(n$B
y:Of~ ]9@
FINHO058^Y
System.err.println("文件下载结束！"); nu~]9~)I
} $)8,dS
catch(Exception e){e.printStackTrace ();} dVHbIx
} R1w5,Zt
:{lP9%J-
+w?R4Sxjn
//获得文件长度 g*LD}`X/-
public long getFileSize() 8 Zp^/43
{ wD{c$TJ?{F
int nFileLength = -1; Kdp($L9r
try{ G-RDQ
URL url = new URL(siteInfoBean.getSSiteURL()); :lvBcFw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qr7v^H~E4.
httpConnection.setRequestProperty("User-Agent","NetFox"); hh%?E\qM
f^u-Myk
$7g+/3Fu^
int responseCode=httpConnection.getResponseCode(); f38e(Q];m
if(responseCode>=400) 6'@{ * u
{ x{<l8vL=-c
processErrorCode(responseCode); E!mv}
return -2; //-2 represent access is error 'x"(OdM:[
} 2=0HQXXrq
8=joVbs
udLIAV*
String sHeader; 6j6;lNUc
fxr#T'i
{N/%%O.b
for(int i=1;;i++) \#B<'J9.`
{ iQ2j ejd3(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S >CKm:7
//Utility.log(in.readLine()); %Pt){9b
sHeader=httpConnection.getHeaderFieldKey(i); /}L2LMIm
if(sHeader!=null) &TA{US3~
{ ]Zc|<f;
if(sHeader.equals("Content-Length")) -rm[.
{ bGgpPV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e3:L]4t
break; o,*D8[
} uZ-ZZE C
} <9yh:1"X
else u{\'/c7G
break; S5y.H
} zhFm2
} fbOqxF"?we
catch(IOException e){e.printStackTrace ();} )=29Hm"
catch(Exception e){e.printStackTrace ();} rZaO^}u]
Z f\~Cl
fC*cqc~{@
Utility.log(nFileLength); S**eI<QFSk
@v#P u_
7>F{.\Z
return nFileLength; +>vKI8g*RH
} * zyik[o
)hj:Xpj9#
E BBd
//保存下载信息（文件指针位置） 4m1r@ $
private void write_nPos() KAFR.h:p9
{ NE8W--Cg|
try{ tB,(12@W
output = new DataOutputStream(new FileOutputStream(tmpFile)); sTlel&
output.writeInt(nStartPos.length); ja';NIO-
for(int i=0;i<nStartPos.length;i++) B#SVN Lv
{ (A6~mi r!
// output.writeLong(nPos); KbvMp1'9P
output.writeLong(fileSplitterFetch.nStartPos); R( FQ+h
output.writeLong(fileSplitterFetch.nEndPos); @y`xFPB
} G`>]ng
output.close(); ZDR@VYi+~
} C=r2fc~w
catch(IOException e){e.printStackTrace ();} Em@:QmEN
catch(Exception e){e.printStackTrace ();} 9iZio3m
} B<m0YD?>~>
0zq'Nf?#3
BU/A\4xQ,Y
//读取保存的下载信息（文件指针位置） V<I(M<Dj
private void read_nPos() ty0P9.Q
{ ;t\h"K<,|
try{ }A24;'}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M]/aW
int nCount = input.readInt(); X4!7/&
nStartPos = new long[nCount]; Rxd4{L )n
nEndPos = new long[nCount]; )&7.E
for(int i=0;i<nStartPos.length;i++) ^Q$OzsEk
{ #T^2=7 w
nStartPos = input.readLong(); y-1e(:GF
nEndPos = input.readLong(); *<($.c
} ^1bslCe
input.close(); Kx]SiejJ
} m3lz#Pm'0
catch(IOException e){e.printStackTrace ();} .=#jdc/
catch(Exception e){e.printStackTrace ();} CG=c@-"n/
} K\F0nToJ.
L4g%o9G
_f^KP@^j
private void processErrorCode(int nErrorCode) r8Pd}ptPU
{ JL= cIH8
System.err.println("Error Code : " + nErrorCode); chE!,gik
} hb5K"9Y
;J5z
x^f)I|t
//停止文件下载 #lP8/-s^
public void siteStop() ZLv/otf:|"
{ vv @m{,7#Y
bStop = true; .="XvVdkp
for(int i=0;i<nStartPos.length;i++) fq6%@M~
fileSplitterFetch.splitterStop(); ==5F[UX
}bjZeh.
FoyYWj?,R
} '{,xQf*x
} XZM3zlg*
//负责部分文件的抓取 `NsjtT'_
**FileSplitterFetch.java D%YgS$p[M$
*/ MCT1ZZpPr
package NetFox; Fr8GGN~/
}#O!GG{
@%R<3!3v
import java.io.*; '+cI W(F?
import java.net.*; y~ =H`PAE
`um,S
^hC'\09=c
public class FileSplitterFetch extends Thread { 2ndn8_l
\j>7x
~t`s&t'c|
String sURL; //File URL `@h|+`h
long nStartPos; //File Snippet Start Position yJm"vN
long nEndPos; //File Snippet End Position aKbmj
int nThreadID; //Thread's ID %T{]l;5
boolean bDownOver = false; //Downing is over }Q/onBt
boolean bStop = false; //Stop identical AC) M2;
FileAccessI fileAccessI = null; //File Access interface jV3PTU
=^nb+}Nz(
_95296
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DYD<?._I
{ .w9LJ
this.sURL = sURL; BPba3G9H
this.nStartPos = nStart; Cl}nPUoL
this.nEndPos = nEnd; Nz,yd%ua
nThreadID = id; R2~Tr$:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iEr,ly
} []>'Dw_r
kz"uTJK
9Yx(u2PQ
public void run() 'x!\pE-
{ afEa@et'
while(nStartPos < nEndPos && !bStop) fGo4&( U
{ g>@JGzMLP
1sQIfX#2f
~7P)$[
try{ W7i|uTM
URL url = new URL(sURL); t;&XIG~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,S8K!
httpConnection.setRequestProperty("User-Agent","NetFox"); @w[i%F,&`
String sProperty = "bytes="+nStartPos+"-"; y/lF1{}5
httpConnection.setRequestProperty("RANGE",sProperty); E $@W~).!
Utility.log(sProperty); {*ak>Wud
:S+K\
[. 5m}V
InputStream input = httpConnection.getInputStream(); T #\
//logResponseHead(httpConnection); "ZuuSi
&XP(D5lf`B
ff"wg\O4
byte[] b = new byte[1024]; %@/^UE:
int nRead; J-F".6i5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G6sK3K
{ f!Q\M1t)
nStartPos += fileAccessI.write(b,0,nRead); ~Iu!B Y
//if(nThreadID == 1) ggr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \hB BG8=&
} <uH8Fivb
@;Ttdwg#J
6o3 bq|
Utility.log("Thread " + nThreadID + " is over!"); mPV<a&U
bDownOver = true; kSQ8kU_w+
//nPos = fileAccessI.write (b,0,nRead); ':'g!b`/
} n_8[bkbi
catch(Exception e){e.printStackTrace ();} E$e7(D
} ~4S$+*'8
} rz?Cn X.t
*Gbhk8}V'
|?`5~f
//打印回应的头信息 ;?-AFd\i
public void logResponseHead(HttpURLConnection con) o`?rj!\
{ H"C'<(4*\
for(int i=1;;i++) C$3*[
{ T(4d5 fY
String header=con.getHeaderFieldKey(i); ]T4/dk&|o^
if(header!=null) mo0\t#jA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o\AnM5
Utility.log(header+" : "+con.getHeaderField(header)); $`=p]
else f-=\qSo
break; lo1Ui`V
} ]rmBM
} 5\-uo&#
iHK~?qd}
^[L(kHOGzk
public void splitterStop() J~Xv R
{ ]$ew 5%
bStop = true; [uq>b|`RG
} pMc6p0
fCl}eXg6w
]Z JoC!u
} DHidI\*gT
(JhX:1
N0U/u'J!g
/* #Ondhy%h[
**FileAccess.java )Nv1_en<!
*//文件访问(定位，写) VSj!Gm0LB
package NetFox; ~xH&"1
import java.io.*; +Q*`kg'
!,WGd|oJ
;|N:FG
public class FileAccessI implements Serializable{ Tt[zSlIMx
BG{f)2F\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'm%{Rz>j
RandomAccessFile oSavedFile; R;& >PFmq
long nPos; 8#I>`z^F
G4&s_M$
A]1Nm3@
public FileAccessI() throws IOException prBLNZp
{ J3Mb]X)_}
this("",0); e5=d Ev
} 9N]Xa
wN2+3LY{
(z?HyxRT
public FileAccessI(String sName,long nPos) throws IOException ]' mbHkn68
{ \/-c)
oSavedFile = new RandomAccessFile(sName,"rw"); .J#'k+>
this.nPos = nPos; aD/Rr3v>
oSavedFile.seek(nPos); E$d3+``
} FoefBo?g65
OfsP5*d
3JoY-
public synchronized int write(byte[] b,int nStart,int nLen) z(PUoV:?
{ ZTC>Ufu2!
int n = -1; Vs>Pv$kW
try{ w7nt $L5
oSavedFile.write(b,nStart,nLen); #XV=,81w
n = nLen; Er~17$b
} $o6/dEKQ
catch(IOException e) N,ht<l\
{ 2`yhxO
e.printStackTrace (); x"W~m.y$h
} e4X df>B
N&8TG
?M2(80
return n; ;#B(L=/
} I8*VM3
myx/|-V"F
!Jg;%%E3:i
} (Guzj*12
4"@<bKx
aCQtE,.
/* NgNGq\!
**SiteInfoBean.java Hg+<GML
*/ P{L=u74b{x
package NetFox; 7GA8sK
Wj{lb_Rj
B|(g?
public class SiteInfoBean { 91 jRIB
Xo^8o0xi
AXfU$~
private String sSiteURL; //Site's URL 8(3(kZxS
private String sFilePath; //Saved File's Path iT@`dEZ.
private String sFileName; //Saved File's Name >WLPE6E
private int nSplitter; //Count of Splited Downloading File r)(5,*v
P-m_],
dQut8>0&
public SiteInfoBean() '1<Z"InU
{//nSplitter的缺省值为5 nx9PNl@?V
//default value of nSplitter is 5 zVhyAf
this("","","",5); _ %s#Cb
} jiI=tg;
# @\3{;{R
wcHk]mLM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FOaA}D `]
{ gv!8' DKn
sSiteURL= sURL; Z0|5VLk,<{
sFilePath = sPath; pP\Cwo #,
sFileName = sName; !3Dq)ebBz
this.nSplitter = nSpiltter; o7y<Zd`Bj
J?4{#p
H7O~So*N5
} =4ygbk
*MJm:
v|?@k^Ms
public String getSSiteURL() 'Kelq$dn#
{ 68%aDs
return sSiteURL; *4O=4F)x
} Wzq W1<*`
5C w( 4.
p^l#Wq5
public void setSSiteURL(String value) uH_KOiF
{ '.}}k!#
sSiteURL = value; w7)pBsI
} ~Ps*i]n(
zI88IM7/
!E7gIqo
public String getSFilePath() l9p 6I
{ o<g?*"TRh
return sFilePath; /%$Zm^8c
} LUbhTc
+cpb!YEAb
1nVQYqT_
public void setSFilePath(String value) 2g(_Kdj*{
{ qLR;:$]Q&8
sFilePath = value; +in)(a.
} ?pL|eS7
cS&KD@.
O7.V>7Y9H
public String getSFileName() UlXm4\@
{ 9~p;iiKGG
return sFileName; EPo)7<|>
} ZbRRDXk!
)1<0c@g=
PW*Vfjf4
public void setSFileName(String value) x;ik
{ K'OG-fn;
sFileName = value; 'CBwE&AL
} wGHft`Z
Q\oa<R D5
~z^l~Vyg?
public int getNSplitter() |N,^*xP(6
{ 4+olyBht
return nSplitter; pEB3qGA
} 8X;?fjl`"
!~^2Mu(X
N2h5@*1Y
public void setNSplitter(int nCount) "|\hTRQ
{ hV3]1E21"
nSplitter = nCount; _/[qBe
} (lsG4&\0F
} b+s'B4@rb
-]EL|_;
q/U-WQ<+
/* F6{g{ B
**Utility.java 6v@Prw@.b
*/ R P{pEd
package NetFox; Owp]>e
f,YORJ
v]JET9hY
public class Utility { <5Vf3KoC&
BKFO^
81RuNs]
public Utility() aru2H6
{ g5BL"Dn
cMK|t;" 3
DVQr7tQf
} qw+7.h#V
YB*)&@yx
//线程睡眠 5{H)r
public static void sleep(int nSecond) GtRpgM
{ +:A `e+\
try{ 6Dd>ex!-A
Thread.sleep(nSecond); k_g@4x1y*
} <?7CwW
catch(Exception e) Z@Rqm:e
{ {\Pk;M{Y&
e.printStackTrace (); /.:1Da
} [_N1 .}e
} ^P^"t^O
AA-$;s
//日志 $$AZ)#t[
public static void log(String sMsg) ?MDo. z3
{ %/eG{oh-
System.err.println(sMsg); p5In9s
} yf{\^^ i(
Uahh|>s
Q-)(s
public static void log(int sMsg) NbWEP\dS'z
{ ,|f=2t+5X
System.err.println(sMsg); 9^^\Z5
} x]VycS
} (U\o0LI
i7RK*{
^|/<e?~I
/* HOD?i_
**TestMethod.java pIIp61=$
*/ c[J 2;"SP
package NetFox; fwppqIM
CW;zviH5
CfOyHhhKX
public class TestMethod { X8}r= K~
l(Y32]Z
\]Y<d
public TestMethod() fD%/]`y
{ ///xx/weblogic60b2_win.exe J5b3r1~D"[
try{ TT/=0^"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =u0=)\0@r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n6[shXH
SiteFileFetch fileFetch = new SiteFileFetch(bean); GS*O{u
fileFetch.start(); 1uo |a
} b$w66q8
catch(Exception e){e.printStackTrace ();} iBWzxPv:z
LBio$67F
nANl9;G
} 4=MVn
'4{@F~fu
~vP_c(8f
public static void main(String[] args) f*@ :,4@
{ xK8m\=#
new TestMethod(); .0nT*LF
} `LH9@Z{
} N+V#=Uy
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