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)); GL>YJ%
} #:[F=2@,A
for(int i=0;i<nEndPos.length-1;i++) zC:Pg4=w]
{ =mX26l`B
nEndPos = nStartPos[i+1]; nT01B1/<]
} %hmRh~/&
nEndPos[nEndPos.length-1] = nFileLength; A#K<5%U{Mv
} J9t?;3
} 1D)0\#><
H;<>uELie
`zq+Xl
//启动子线程 z{ M2tLNb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ' A+L #
for(int i=0;i<nStartPos.length;i++) PPy~dp
{ YH+(N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uu*iL< `
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &Qv HjjQ?u
nStartPos,nEndPos,i); (#6Fg|f4Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aeNbZpFQ
fileSplitterFetch.start(); f`;w@gR`=
} bbjEQby
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X}]A_G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OqRRf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]zAwKuIK
nEndPos = " + nFileLength); u{HO6s\S
// fileSplitterFetch[nPos.length-1].start(); yK&
&N=vs
QEut@L
//等待子线程结束 CvZ\Z472.j
//int count = 0; N3lz-vP-
//是否结束while循环 %A3m%&(m&%
boolean breakWhile = false; WB_BEh[>j
OXpN8Dh5
LibQlNW\
while(!bStop) IS!OO<
{ (x\VGo
write_nPos(); Vh;|qF 9
Utility.sleep(500); vm;%713#1
breakWhile = true; `YwJ.E
yEjiMtQll]
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for(int i=0;i<nStartPos.length;i++) rZ n@i
{ F_-xp1|
if(!fileSplitterFetch.bDownOver) mT-[I<
{ $aU.M3
breakWhile = false; .Mb0++% W
break; 7BINqVS&
} =Yl ea,S
} dR_6j}
if(breakWhile) ' =5B
break; smQl^ 6a
Nr]Fh
Sx J0Y8#z
//count++; oj{CNa
//if(count>4) \1<|X].jNY
// siteStop(); !"yr;t>|Zb
} ia_@fQ
,W[J@4.
DrioBb@
System.err.println("文件下载结束！"); G9Kck|50
} Ua:@,};
catch(Exception e){e.printStackTrace ();} }.'rhR+
} %x{kd8>u!
/ yBrlf
`V<jt5TS
//获得文件长度 gd7r9yV
public long getFileSize() K^@9\cl^
{ @.i#uMWF`
int nFileLength = -1; OE0G*`m
try{ G{4s~Pco[Q
URL url = new URL(siteInfoBean.getSSiteURL()); ilK*Xo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FP=27=
httpConnection.setRequestProperty("User-Agent","NetFox"); Djc-f
"9c=kqkX
LWTPNp:"{w
int responseCode=httpConnection.getResponseCode(); 1,) yEeHjU
if(responseCode>=400) 8TAJ#Lm
{ <B0f
processErrorCode(responseCode); @q>Hl`a
return -2; //-2 represent access is error M!i|,S
} \5!7zPc
BK=w'1U
ToPjBvD
String sHeader; "OwVCym?
#z%D d{E
:8oJG8WH
for(int i=1;;i++) ~AYleM
{ i@5Fne
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ihwJBN>(
//Utility.log(in.readLine()); of_y<dd[G
sHeader=httpConnection.getHeaderFieldKey(i); ej}S{/<*n
if(sHeader!=null) `vOL3`P
{ sfr+W-7kx
if(sHeader.equals("Content-Length")) =c*l!."0
{ >L!c} Ku
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _9 '_w&
break; @>VVB{1@,]
} jy2gR1~
} MA:5'n
else /; Bmh=
break; UsFn!!+
} o.fqJfpj
} m Rw0R{
catch(IOException e){e.printStackTrace ();} EV{Ys}3M
catch(Exception e){e.printStackTrace ();} (oX!D(OI
=(7nl#o
J@$~q}iG
Utility.log(nFileLength); !*"fWahv
B T"R"w
+ppA..1
return nFileLength; a=j'G]=
} lD3nz<p
37jxl+
C[ mTVxd
//保存下载信息（文件指针位置） CKK}Z;~:
private void write_nPos() ]r|oNGD)G
{ :[_msd
try{ $+7uB-KsU
output = new DataOutputStream(new FileOutputStream(tmpFile)); '-RacNY
output.writeInt(nStartPos.length); }}tbOD)t
for(int i=0;i<nStartPos.length;i++) < z2wt
{ A)C)5W
// output.writeLong(nPos); @lE'D":?
output.writeLong(fileSplitterFetch.nStartPos); qJdlZW<
output.writeLong(fileSplitterFetch.nEndPos); \_8wU'7
} X@DW1<wEt
output.close(); 2,q*[Kh1
} 9ET1Er{4
catch(IOException e){e.printStackTrace ();} 0(eaVi-%D
catch(Exception e){e.printStackTrace ();} vsj4?0=
} gd*Gn"
b@;Wh-{d
[TFJb+N&
//读取保存的下载信息（文件指针位置） h.PBe
private void read_nPos() Q&I`uS=F
{ ,.W7Z~z
try{ .M^[/!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8\lh'8
int nCount = input.readInt(); ciS,
nStartPos = new long[nCount]; 6qH0]7maI
nEndPos = new long[nCount]; <R /\nYXz
for(int i=0;i<nStartPos.length;i++) >UaQ7CRo
{ _5-h\RB)
nStartPos = input.readLong(); Df^F)\7!N?
nEndPos = input.readLong(); &2`p#riAS
} (\{k-2t*^
input.close(); /qX?ca1_4^
} V|_ h[hXE
catch(IOException e){e.printStackTrace ();} O[C4xq
catch(Exception e){e.printStackTrace ();} ^E.L8
} m|qktLx
1Hr}n6s
22CET9iCe
private void processErrorCode(int nErrorCode) +GI906K
{ ;Y^'$I2fR#
System.err.println("Error Code : " + nErrorCode); e(?w h
} K@O^\
7pyzPc#_
FzJ7 OE|
//停止文件下载 $0 olqt:
public void siteStop() 4D0jt$==
{ HYfGu1j?X
bStop = true; m[B#k$
for(int i=0;i<nStartPos.length;i++) @vt.Db
fileSplitterFetch.splitterStop(); 9RJF
h)HEexyRg
Kgu8E:nL
} Vb(b3
} (.ir"\k1(
//负责部分文件的抓取 Db,"Gl
**FileSplitterFetch.java -^xbd_'
*/ @x}"aJgl
package NetFox; "=djo+y
Jay"
yfZNL?2x
import java.io.*; "o&8\KSs
import java.net.*; cs+3&T:,*
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$eYL|?P50h
public class FileSplitterFetch extends Thread { KC6Cg?y^
lvO6&sF1
e7RgA1
String sURL; //File URL K*>%,mP$i
long nStartPos; //File Snippet Start Position VVas>/0qr
long nEndPos; //File Snippet End Position 5qb93E"C
int nThreadID; //Thread's ID {]T?)!Vm
boolean bDownOver = false; //Downing is over @Vre)OrN#
boolean bStop = false; //Stop identical 0<uek
FileAccessI fileAccessI = null; //File Access interface Ek_5% n
y7,I10:D
}5;4'l8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >rCD5#DG
{ {o}U"b<+Ra
this.sURL = sURL; )L:zr#
this.nStartPos = nStart; [IL*}M!
this.nEndPos = nEnd; 0[MYQl`
nThreadID = id; Jb QK$[z"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZZY#.
} K~TwyB-h
e&}W#
IfK~~XYG
public void run() Lx0nLJ\
{ cS;3,#$
while(nStartPos < nEndPos && !bStop) SVe]2ONd
{ 9TW[;P2> )
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try{ ]`/>hH>+~9
URL url = new URL(sURL); %QezC+n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yLnQ9BXB&
httpConnection.setRequestProperty("User-Agent","NetFox"); t6DSZ^Zq
String sProperty = "bytes="+nStartPos+"-"; +>Wo:kp3
httpConnection.setRequestProperty("RANGE",sProperty); K-0=#6?y4
Utility.log(sProperty); Xz_WFLq4
ZL( j5E
\}Jznzx;
InputStream input = httpConnection.getInputStream(); !dLu($P
//logResponseHead(httpConnection); 2J7|y\N,
U#jz5<r
@/z\p7e
byte[] b = new byte[1024]; M@Th^yF+8H
int nRead; :os8"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \P<aK$g
{ 5Gz!Bf@!!
nStartPos += fileAccessI.write(b,0,nRead); 2S?7j[@%i`
//if(nThreadID == 1) >,e^}K}C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }[AaI #
} u<-)C)z
n{tc{LII/
0#*6:{/^
Utility.log("Thread " + nThreadID + " is over!"); OQ-) 4Uk}
bDownOver = true; 8q^}AT<C
//nPos = fileAccessI.write (b,0,nRead); dli(ckr
} (` *BZ_
catch(Exception e){e.printStackTrace ();} G:AA>t
} 5\Q Tm;
} %HUex 6!
aAg Qv*
m'rDoly"62
//打印回应的头信息 p='j/=
public void logResponseHead(HttpURLConnection con) '`>%RZ]
{ cQ8[XNa
for(int i=1;;i++) ~gDYb#p
{ F.[%0b E
String header=con.getHeaderFieldKey(i); lLD#|T3
if(header!=null) \V? .^/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mY"7/dw<v
Utility.log(header+" : "+con.getHeaderField(header)); mTZ/C#ir(
else 6TP /0o)
break; pY31qhoZ.
} dGUP|O
} 0AQazhm
6G8No-#y
Rb6BY-/J
public void splitterStop() nLN0zfhE#
{ HpnF,4A>
bStop = true; )w7vE\n3
} 3~>-A=
eh86-tQI~(
CMj =4e
} ,'8%'xit
roADC?@r
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/* 6,>$Jzs)5E
**FileAccess.java 3&hR#;,"X
*//文件访问(定位，写) zp}7p~#k^
package NetFox; p<5]QV7st
import java.io.*; Q((&Q?Vi
%*D=ni#(sT
Y2`sL,'h
public class FileAccessI implements Serializable{ I dK*IA4
\Zj%eW!m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H*=cw<
RandomAccessFile oSavedFile; jPWONz(#
long nPos; &*`dRIQ]
GwX)~.i
C QkY6
public FileAccessI() throws IOException V(';2[)
{ m Q2i$ 0u
this("",0); & NYaKu,}
} JW>k8QjyN
CIW4E
6.@.k
public FileAccessI(String sName,long nPos) throws IOException m{IlRf'
{ zMSwU]4I!
oSavedFile = new RandomAccessFile(sName,"rw"); R{g= N%O
this.nPos = nPos; ;K<VT\
oSavedFile.seek(nPos); wm5&5F4:
} 4Mt3<W5
R@c])\^]
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public synchronized int write(byte[] b,int nStart,int nLen) kckRHbeU
{ ,GSiSn
int n = -1; +( LH!\{^
try{ <LbLMV
oSavedFile.write(b,nStart,nLen); &~:EmLgv
n = nLen; #u&fUxM:AS
} +7.|1x;C
catch(IOException e) KuR]X``2
{ Y@FYo>0O
e.printStackTrace (); \BHZRytQF
} pDS[ecx
2yfU]`qN
!>48`o^
return n; 6z\!lOVjb
} a 0SZw
?_eLrz4>L^
FB6Lz5:Vf
} <*5S7)]BP
LUQ.=:mBR
od `;XVG
/* um9&f~M
**SiteInfoBean.java ]it. R-
*/ 7y Cf3
package NetFox; hz/mNDE]
U$y9f
[ja^Bhu
public class SiteInfoBean { Oo|JIr7i
b7.7@Ly y
o/-RGLzAo
private String sSiteURL; //Site's URL 8m0*89HEu
private String sFilePath; //Saved File's Path j2G^sj"|
private String sFileName; //Saved File's Name ]]|#+$ ~
private int nSplitter; //Count of Splited Downloading File =M1}HF,7>l
y[7M(K
, z\Qd07u
public SiteInfoBean() ]L3U2H`7
{//nSplitter的缺省值为5 3zsp6kV
//default value of nSplitter is 5 JD*HG]
this("","","",5); OY1bFIE
} @Ou H=<YN
<X*oW".
& AK\Pw)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]!ai?z%cK#
{ .@{v{
sSiteURL= sURL; {V7mpVTX.
sFilePath = sPath; d(^8#4
sFileName = sName; #$UwJB]_D
this.nSplitter = nSpiltter; onuG
k|OM?\
SPqJ [F
} uO4 LD}A
3eY>LWx
Zj[m
public String getSSiteURL() .>W [
{ R+!U.:-yz
return sSiteURL; 4b<|jVl\
} ;!f='QuA
|uy@v6
WN]k+0#
public void setSSiteURL(String value) `)cI^!
{ HS|Gz3~
sSiteURL = value; $~5H-wJ
} 1gK|n
j \rGU){
b_sasZo
public String getSFilePath() SY Bp-o
{ t,YRM$P
return sFilePath; K~#?Y,}O
} e6p3!)@P1
sqhMnDn[
M"*NV(".g
public void setSFilePath(String value) d'(n/9K
{ GP+=b:C{E
sFilePath = value; b'pwRKpx
} _#\Nw0{
lL zR5445)
< }K9 50
public String getSFileName() D2VYw<tEA
{ |ru!C(
return sFileName; r(Sh
} eFsl
T"99m^y
Tu-lc)
public void setSFileName(String value) g7323m1=
{ 0j8fU7~6S
sFileName = value; GyL9}
} qG,h 1
zuNm!$
kb 74:
public int getNSplitter() }@LIb<Y
{ 0V6, &rTF
return nSplitter; q25p3
} 2|7:`e~h
{ccc[G?>.Q
|8E~C~d
public void setNSplitter(int nCount) r.)n>
{ yLf9cS6=
nSplitter = nCount; !RJ@;S
} v8F{qT50
} 62nmm/c
Kz b-a$
!84Lvg0&
/* yl?LXc[)
**Utility.java Q=! lbW
*/ > 3x^jh
package NetFox; $cn8]*Z=
Mxw-f4j
QeF:s|[
public class Utility { Ak3^en
y# \"yykB
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public Utility() UG44 oKB
{ .WSn Y71
41/civX>V
Tp@Yn
} Q1Qw45$
(,sz.
//线程睡眠 V}TPt6C2
public static void sleep(int nSecond) Ur 1k3
{ j)G%I y[`
try{ m\*ca3$
Thread.sleep(nSecond); bv <^zuV
} ?1g`'q@T%
catch(Exception e) o#"yFP1
{ +s_a{iMVP
e.printStackTrace (); Ng<ic
} o_\vudXK
} =oXlJ[)h
XR8`,qH>
//日志 )J]NBE:8
public static void log(String sMsg) IZdWEbN1
{ ~*1Z1aZ
System.err.println(sMsg); OqsuuE
} Q`K^>L1
?VxQ&^|
{{gd}g
public static void log(int sMsg) xK0;saG#
{ Q(x=;wf5r
System.err.println(sMsg); 8yYag[m8
} qPi $kecx
} L$a{%]I
u`B/9-K)y
c='W{47
/* A##Q>|>)
**TestMethod.java Dd0yQgCu
*/ b"@-9ke5I
package NetFox; nzxHd7NIZ
!p ~.Y+
M`#g>~bI#R
public class TestMethod { #2\M(5d
Y&M{7
x$Wtkb0<
public TestMethod() StR)O))I
{ ///xx/weblogic60b2_win.exe T__@hfT
try{ {|%^'lS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P{s1NorKDh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PRYm1Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gyy4)dP
fileFetch.start(); ^4JK4+!Zfq
} `6Q+N=k~Z
catch(Exception e){e.printStackTrace ();} aA*h*
XmO]^ `
,F!-17_vt
} )jwovS?V
s%#u)nw19
;=%cA#}_0
public static void main(String[] args) ]ml'd
{ }j6|+
new TestMethod(); L#D)[v"
} Y$^vA[]c>
} ~y Dl& S
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