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)); ~appY Av
} 6!(@@^7{*
for(int i=0;i<nEndPos.length-1;i++) )<Hd T
{ D~\$~&_]=
nEndPos = nStartPos[i+1]; Qg<(u?7N
} (!zy{;g|
nEndPos[nEndPos.length-1] = nFileLength; $-*!pRaVU
} >HS W]"k
} C;vtY[}<
0a"c2J
fP `b>]N_
//启动子线程 ) v,:N.@Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uF3qD|I\
for(int i=0;i<nStartPos.length;i++) $ <#KA3o\
{ X7g1:L1Ys
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yT,.z 0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =>! Y{: y(
nStartPos,nEndPos,i); EB8\_]6XJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x3"#POp
fileSplitterFetch.start(); c*@E_}C#
} 1wP-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,5*eX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^:Gie
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n;T7=1_"
nEndPos = " + nFileLength); ?28N ^
// fileSplitterFetch[nPos.length-1].start(); Aj4T"^fv
CtSl
3z&Fi;<+j
//等待子线程结束 >M/V oV
//int count = 0; 8Bjib&im
//是否结束while循环 XUlS\CH@{
boolean breakWhile = false; Q{lpKe0
rq/I` :
t>$kWd{9e;
while(!bStop) eXf22;Lz
{ k>g_Z`%<
write_nPos(); ikSt"}/hd
Utility.sleep(500); d>t<_}
breakWhile = true; +lMX{es\O
tyqT
+P`*kj-P\
for(int i=0;i<nStartPos.length;i++) 7w6cwHrL@
{ csW43&
if(!fileSplitterFetch.bDownOver) PIwFF}<(
{ Tap.5jHL
breakWhile = false; O2%?
break; "*srx]
} LBa[:j2
} c:o]d)S
if(breakWhile) [CXrSST")E
break; Z Z:}AQ
[.uG5%fa
$NZ-{dY{
//count++; 8Y7Q+p|O
//if(count>4) 7OJ'){R$
// siteStop(); W)f/0QX}W
} qtQ6cqLd
5?F__Hx*2
ei[j1F
System.err.println("文件下载结束！"); .Lsavpo
} N%*5T[.
catch(Exception e){e.printStackTrace ();} <BMXCk
} E{Ov>osq
\Yc'~2n
r'HtZo$^R
//获得文件长度 l^pA2yh|
public long getFileSize() P>NF.BCq
{ r[b(I@T+
int nFileLength = -1; c_'OPJ
try{ Ne[7gxpu
URL url = new URL(siteInfoBean.getSSiteURL()); =06gj)8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #\ X#w<\?
httpConnection.setRequestProperty("User-Agent","NetFox"); rzm:Yx
noml8o
x"gd8j]s
int responseCode=httpConnection.getResponseCode(); 5BlR1*
if(responseCode>=400) j)/nKh4O
{ +~mA}psr
processErrorCode(responseCode); 'kL#]
return -2; //-2 represent access is error R|(q
} ;kS&A(
C8 xZ;V]
QSszn`e
String sHeader; !`,Sfqij
"NXB$a!:
]<cK";
for(int i=1;;i++) :+z4~% jA
{ d(:8M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FrL]^59a
//Utility.log(in.readLine()); o7sT=x9
sHeader=httpConnection.getHeaderFieldKey(i); %t" CX5n
if(sHeader!=null) ~M7y*'oY
{ &:dH,
if(sHeader.equals("Content-Length")) --%N8L;e
{ qUob?| ^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DRp~jW(\y
break; lyy W
} %.^_Ps0
} Jrti cK$
else *E/`KUG]
break; Q@<S[Qh[.
} )4<__|52"1
} R`DKu=
catch(IOException e){e.printStackTrace ();} <`B,R*H{
catch(Exception e){e.printStackTrace ();} D#il*
s;S?;(QI
VEqS;~[
Utility.log(nFileLength); w$z}r
g*e
_wkVwPr
return nFileLength; AX;8^6.F3
} h_:C+)13`x
Gb#Cm]
ur$ _
//保存下载信息（文件指针位置） G-xDN59K
private void write_nPos() ftvG\Tf
{ juka0/
try{ Rs-]N1V
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1zm ulj%&
output.writeInt(nStartPos.length); tiB_a}5IB
for(int i=0;i<nStartPos.length;i++) 3DiLk=\~
{ 8\^}~s$$A
// output.writeLong(nPos); 9[b<5Llt
output.writeLong(fileSplitterFetch.nStartPos); -Zf@VW,NI
output.writeLong(fileSplitterFetch.nEndPos); Xjo5v*Pu
} <>s`\ %
output.close(); cZB7fmq%
} ,SynnE68
catch(IOException e){e.printStackTrace ();} =(NB%}
catch(Exception e){e.printStackTrace ();} E^ P,*s
} uC+V6;
%{AO+u2i
e+$p9k~
//读取保存的下载信息（文件指针位置） T (OW
private void read_nPos() P `}zlml
{ ^?cz,N~
try{ *)ardZV${
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R< ,`[*Z
int nCount = input.readInt(); Pz>s6 [ob
nStartPos = new long[nCount]; n[T[DCQ,
nEndPos = new long[nCount]; #E?(vA1
for(int i=0;i<nStartPos.length;i++) MBt9SXM
{ uw[<5
nStartPos = input.readLong(); lD^]\;?
nEndPos = input.readLong(); 8YZbP5'
} ??PC k1X
input.close(); Izhee%c
} ^B(V4-|
catch(IOException e){e.printStackTrace ();} y4t7`-,~
catch(Exception e){e.printStackTrace ();} S4^vpY DeN
} W3IpHV
aGJC1x
Bg&i63XL$$
private void processErrorCode(int nErrorCode) mQCeo}7N5
{ CN#+U,NZV
System.err.println("Error Code : " + nErrorCode); SH_(rQby
} 9:ze{ c $
-~v|Rt
&y3OR1_Sm*
//停止文件下载 i=i(%yQ%
public void siteStop() RIb4!!',c
{ 73V|6tmgY
bStop = true; 3a?o3=
for(int i=0;i<nStartPos.length;i++) *+j*{>E
fileSplitterFetch.splitterStop(); gZLP\_CL
.q `Hjmg<
ZAv,*5&<
} Fs{x(_LOr
} z.GMqW%B
//负责部分文件的抓取 E=e*VEjy
**FileSplitterFetch.java e?7&M
*/ aa>xIW,u
package NetFox; bn^{c
4 !y%O
BFL`!^
import java.io.*; jUSmqm'
import java.net.*; V}dJ.I /#
n` xR5!de
2] zq#6ix
public class FileSplitterFetch extends Thread { /LO-HnJ
[x9KVd ^d
3):A
String sURL; //File URL t.laO. 3
long nStartPos; //File Snippet Start Position 9?0^ap,T
long nEndPos; //File Snippet End Position I_<I&{N>
int nThreadID; //Thread's ID -7S g62THS
boolean bDownOver = false; //Downing is over KVD8YfF
boolean bStop = false; //Stop identical +6';1Nb@
FileAccessI fileAccessI = null; //File Access interface i%/Jp[e\W>
qOSM}ei>s
~ vJ,`?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VH+%a<v"
{ c17_2 @N
this.sURL = sURL; f7=((5N
this.nStartPos = nStart; pgOQIzu
this.nEndPos = nEnd; i(iXD
nThreadID = id; G*-b}f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |962G1.
} _>| =L W@7
$4/yZaVb
DpUbzr41+k
public void run() Fxm$9(Y
{ w)Q0_2p.
while(nStartPos < nEndPos && !bStop) )rekY;
{ cUA7#1\T=
+R|z{M)*
|h;0H`
try{ m^bNuo
URL url = new URL(sURL); B oC5E#;G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~S8*t~
httpConnection.setRequestProperty("User-Agent","NetFox"); i70wrW#k
String sProperty = "bytes="+nStartPos+"-"; ApAO/q
httpConnection.setRequestProperty("RANGE",sProperty); i[?Vin
Utility.log(sProperty); \3pc"^W
R'C2o]
&o,<ijJ:^m
InputStream input = httpConnection.getInputStream(); fpFhn
//logResponseHead(httpConnection); cNM3I,o7
Bh;7C@dq
iZM+JqfU|D
byte[] b = new byte[1024]; Q0&H#xgt
int nRead; " N9 <wU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =y0C1LD+
{ yuat" Pg
nStartPos += fileAccessI.write(b,0,nRead); OH">b6>\
//if(nThreadID == 1) UFp,a0|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DV<` K$ET
} joiL{
4}4Pyjh
rvXWcu-"
Utility.log("Thread " + nThreadID + " is over!"); 1 D<_N
bDownOver = true; 2vAQ
//nPos = fileAccessI.write (b,0,nRead); Kfh|
} YKO){f5
catch(Exception e){e.printStackTrace ();} @I_8T$N=
} ;|vpwB@B
} ?e,pN,4
"a8j"lPJ
)6|yb65ZUX
//打印回应的头信息 hvDNz"ec{
public void logResponseHead(HttpURLConnection con) 5[* qi?w=
{ c6X}2a'
for(int i=1;;i++) %jJ>x3$F
{ /J:bWr
String header=con.getHeaderFieldKey(i); /4` 0?/V
if(header!=null) <iH`rP#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1e&QSzL
Utility.log(header+" : "+con.getHeaderField(header)); .zn;:M#T
else ]8f ms(
break; RV5n,J
} -5I2ga
} QrYpZZ;
1rkE yh??
WIv?}gi: X
public void splitterStop() ~[\_N\rm
{ a^=-Mp
bStop = true; ? P( ZA
} uoXAQ6k
!!`!|w
2UFv9
} t=-SH^$SR
/Rg*~Ers *
_c,'>aH=
/* ,ztI,1"k
**FileAccess.java s;64N'HH
*//文件访问(定位，写) }w1~K'ck}>
package NetFox; z&{5;A}Q@
import java.io.*; *7h!w!LN~
IaT$6\>
%YSu8G_t
public class FileAccessI implements Serializable{ `~ * @q!
VxXzAeM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 US%^#D q
RandomAccessFile oSavedFile; N9vP7
long nPos; >&p0d0
'ul~7h;n
IjR'Qou5
public FileAccessI() throws IOException opJMS6%r
{ -tyK~aasQ
this("",0); ;d'Z|H;
} |"9 #bU
Xa[?^P
:P@rkT3Qt
public FileAccessI(String sName,long nPos) throws IOException ltD37QZQ
{ <F.Tx$s
oSavedFile = new RandomAccessFile(sName,"rw"); NN1$'"@NL
this.nPos = nPos; ]f_6 '|5A
oSavedFile.seek(nPos); YBP:q2H
} a'jR#MQl?
Xixqxm*8
* C6a?]
public synchronized int write(byte[] b,int nStart,int nLen) =n' 4?W@
{ ty*@7g0k
int n = -1; mBG=jI "xh
try{ hweaGL t0
oSavedFile.write(b,nStart,nLen); -atGlu2
n = nLen; nE^Qy=iE
} 1s{^X -
catch(IOException e) " $ew~;z
{ NM6Teu_
e.printStackTrace (); pmFk50`
} N]<!j$pOz
!DI{:I_h(
Z+StB15
return n; p!<$vE
} 3t0[^cY8=z
B-T/V-c7
5n ^TRB
} ,s_T pq
]wWPXx[>/
Q26qNn bK
/* W5'3$,X9
**SiteInfoBean.java vUnRi=:|
*/ vQa'S-@u
package NetFox; vYU;_R
(}5S
4ON_$FUe
public class SiteInfoBean { |K^"3`SJ
mnID3=JF
Vm|Y$C
private String sSiteURL; //Site's URL \6 93kQ
private String sFilePath; //Saved File's Path 80$fG8
private String sFileName; //Saved File's Name /2RajsK
private int nSplitter; //Count of Splited Downloading File [*Z`Kc
Na\WZSu'"
/2m?15c+
public SiteInfoBean() ~WpGf,
{//nSplitter的缺省值为5 N<L`c/
//default value of nSplitter is 5 tWdhDt8$&
this("","","",5); lMz<s
} Ol')7d&
c0Dmq)HK?
:vL1}H<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A~dQ\M
{ .Xdj(_&
sSiteURL= sURL; $) 5Bf3P0
sFilePath = sPath; Do]*JO)(
sFileName = sName; nSCWg=E^
this.nSplitter = nSpiltter; 1'4J[S\cM
M@thI%lR
\Yoa:|%*y
} =9LC<2
"|m|E/Z-9
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public String getSSiteURL() ./p|?pu
{ M]-VHI[&W
return sSiteURL; (Bo bB]~a
} Fn^C{p^
s(_+!d6
b59{)u4F
public void setSSiteURL(String value) .!}hhiF,Z
{ ?R5'#|EyX
sSiteURL = value; wVq\FY%
} 5=KF!?
AA:no=
YGsS4ia*4i
public String getSFilePath() `Vq`z]}
{ +3,|"g::
return sFilePath; Z7jX9e"L
} OSzjK7:
/dDzZ%/@
@1R8-aa-r
public void setSFilePath(String value) jLcHY-P0V
{ QT#6'>&7-b
sFilePath = value; <SVmOmJ-K
} <3hA!$o~
jK8'T_Pah
*wi}>_\
public String getSFileName() N*DhjEU)[
{ Xev54!619
return sFileName; 0p fnV%
} tL0`Rvl
"D*Wi7
&C-;Sa4
public void setSFileName(String value) :k46S<RE
{ oj}"H>tTp
sFileName = value; )qPSD2h
} F?Or;p5`Y
J?P]EQU
~_!ts{[E
public int getNSplitter() .9LL+d
{ #B\=Aa`*
return nSplitter; r@T| e
} r3I,11B
2w?G.pO#
bdV3v`
public void setNSplitter(int nCount) .#^0pv!
{ 1a9w(X
nSplitter = nCount; Kla:e[{
} Q:S\0cI0
} ~4 FDKUC
s?O&ZB2GM[
~q%
/* Goj4`Hc
**Utility.java BV9*s
*/ |#TXE|#ux
package NetFox; da*9(!OV
;.Zh,cU
DY><qk
public class Utility { ) YSh D
X9'xn 0n;
R@r{
public Utility() ]+IVSxa!u
{ XUsy.l/
@;9()ad
.]Ybp2`"U
} MOV =n75
jA2ofC
//线程睡眠 ?;8M^a/
public static void sleep(int nSecond) ug6r]0]
{ i=Kvz4h
try{ a!.!2a&t
Thread.sleep(nSecond); onzA7Gre
} -fM1$/]
catch(Exception e) z\[(g
{ fH!=Zb_{8
e.printStackTrace (); ct\<;I(H
} nx :)k-p_[
} Z90Fcp:R
70<K.T<b
//日志 S 1ibw\'
public static void log(String sMsg) pSrsp r
{ sUda
System.err.println(sMsg); >PH< N
} ZPYH#gC&T
N K"%DU<
{Vl"m2
public static void log(int sMsg) <"ae4
{ | W?[,|e
System.err.println(sMsg); F=5kF/}x-z
} hE5G!@1F
} 3APYO
o?=fhc
%f#\i#G<k
/* MZiF];OY
**TestMethod.java GsRt5?X/*
*/ (o{)>D
package NetFox; c.6QhE
>!G5]?taa
}Y$VB%&Hy
public class TestMethod { +TWJNI
lzI/\%
`~KAk
public TestMethod() SJF2k[da
{ ///xx/weblogic60b2_win.exe fcn_<Yh0W
try{ %SFw~%@3&~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (T;1q^j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zlN+edgY#,
SiteFileFetch fileFetch = new SiteFileFetch(bean); fIlIH
fileFetch.start(); X~#@rg!"
} p?KCVvx$
catch(Exception e){e.printStackTrace ();} OT"lP(,
(F_7%!g1d
G)K9la<p
} C!I\Gh
}cyq'mi
5M]6'X6I
public static void main(String[] args) <6gU2@1
{ rufRaar
new TestMethod(); ^S3A10f,
} PwRNBb}6
} 7?*~oVZW
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