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)); yGN2/>]
} UUuB Rtau
for(int i=0;i<nEndPos.length-1;i++) Z fQzA}QD
{ 7v8V0Gp
nEndPos = nStartPos[i+1]; x?*)
} 1_aUU,|.
nEndPos[nEndPos.length-1] = nFileLength; 2A5R3x=\
} (H/2{##
} 42{\u08Z
cKbjW
:7&-<ae2
//启动子线程 {&bjjM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _3_kvs
for(int i=0;i<nStartPos.length;i++) 6~t;&)6J
{ 4~bbng
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^>3q@,C]c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "Q>gQKgL
nStartPos,nEndPos,i); R;6$lO8C&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tgf#I*(^]
fileSplitterFetch.start(); N3Yf3rK
} p,)~w1|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hw(_l,Xf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nNN~Z'bG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rQuozbBb
nEndPos = " + nFileLength); 5\?\|*WT
// fileSplitterFetch[nPos.length-1].start(); 1hz:AUH
~o+:M0)}
(pU@$H
//等待子线程结束 wOlnDQs
//int count = 0; EINjI:/D
//是否结束while循环 _~{Nco7T
boolean breakWhile = false; n B5:X
8n[6BF);
,"@Tm01os
while(!bStop) e\[z Q 2Z3
{ p H5iv>H
write_nPos(); vq.~8c1
Utility.sleep(500); us_o{
breakWhile = true; ]z%X%wL
+p:?blG
oC~8h8"l
for(int i=0;i<nStartPos.length;i++) `ZC{<eVJ}=
{ 6c?;-5.
if(!fileSplitterFetch.bDownOver) :nt 7jm,
{ 0G`FXj}L
breakWhile = false; &V$qIvN$
break; tm"9`
} #)qn$&.H
} N`G* h^YQ
if(breakWhile) =)2sehU/
break; d-W@/J
yX {CV7%O
&V.\Svm8]
//count++; 3k#?E]'
//if(count>4) n%SR5+N"
// siteStop(); 3!&PI
} Mdj?;'Yv
\A{ [2
015 ;'V#we
System.err.println("文件下载结束！"); 61XLL/=P
} ]\qbe
catch(Exception e){e.printStackTrace ();} f>*D@TrU
} \~LwlOo%R
i42M.M6D$
U#u=9%'
//获得文件长度 a5)<roWQ
public long getFileSize() gB&8TE~Y
{ ^B>BA
int nFileLength = -1; ^:Mal[IR
try{ B7*^rbI:X
URL url = new URL(siteInfoBean.getSSiteURL()); \!+#9sq0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q&:UP
httpConnection.setRequestProperty("User-Agent","NetFox"); lBYc(cr
a/k0(
;Sc}e/WJj
int responseCode=httpConnection.getResponseCode(); 6t,_Xqg*
if(responseCode>=400) ||}k99y +
{ K5h2 ~
processErrorCode(responseCode); SY[7<BUZ
return -2; //-2 represent access is error R#n!1~ (
} k3 YDnMRA9
T3JM8
M6j!_0j
String sHeader; }.L\O]~{
h@^d Vg
mmJ$+$JEk
for(int i=1;;i++) "B$r{ vG
{ GY%2EM(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); daX$=n
//Utility.log(in.readLine()); q2pq~LI
sHeader=httpConnection.getHeaderFieldKey(i); RRasX;zK
if(sHeader!=null) UhI T!x
{ " iz'x-wy
if(sHeader.equals("Content-Length")) #},4m
{ 2i4&*&A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .$rt>u,8<
break; e2}5< 7
} 03!!# 5iJ
} ~vL`[JiK
else mF6 U{=
break; kwM1f=!-
} 8iIz!l%O
} T1([P!g*
catch(IOException e){e.printStackTrace ();} ^wtr~D|
catch(Exception e){e.printStackTrace ();} Y\e8oIYu7
4)DI0b"
J/{!_M-
Utility.log(nFileLength); v)!C Dpw
Wpdn^=dhL
T+q3]&
return nFileLength; i:@n6GW+iw
} `nvm>u~[Hq
&3:U&}I
"lT>V)NB'
//保存下载信息（文件指针位置） KJLC2,
private void write_nPos() 5RUhrE
{ 6%^9`|3
try{ pAY[XN
output = new DataOutputStream(new FileOutputStream(tmpFile)); $yi[wwf4
output.writeInt(nStartPos.length); {0ozpE*(
for(int i=0;i<nStartPos.length;i++) iDdmr32E
{ tnn,lWu|
// output.writeLong(nPos); ;Q}pmBkqB
output.writeLong(fileSplitterFetch.nStartPos); EYaX@|)
output.writeLong(fileSplitterFetch.nEndPos); 4Up3x+bg
} (e~vrSk+)~
output.close(); ~Bi{k'A9
} MF}}o0P
catch(IOException e){e.printStackTrace ();} |E7)s;}D
catch(Exception e){e.printStackTrace ();} '-?t^@
} !vQDPLBL
4or8fG
}w%W A&"W
//读取保存的下载信息（文件指针位置） `BGU
private void read_nPos() jaOt"iU.B
{ q*36/I
try{ 6j{O/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |TE\]
int nCount = input.readInt(); {R{Io|
nStartPos = new long[nCount]; Z^?YTykH
nEndPos = new long[nCount]; ,aLdW,<6
for(int i=0;i<nStartPos.length;i++) VSJ08Ngi
{ WV8?zB1
nStartPos = input.readLong(); df$VC
nEndPos = input.readLong(); #P''+$5,
} J% t[{
input.close(); z12c9k%s
} YV 5kzq
catch(IOException e){e.printStackTrace ();} =rrbS8To=
catch(Exception e){e.printStackTrace ();} s7~[7
} .vbUv3NI
~{O9dEI
OGjeE4
private void processErrorCode(int nErrorCode) c_33.i"I}
{ ZMVQo-=
System.err.println("Error Code : " + nErrorCode); NSPa3NE
} Y.<&phv
o=,q4;R'
R4RSXV
//停止文件下载 );cu{GY
public void siteStop() _cW(R,i
{ s|1BqoE
bStop = true; P9RIX;A=
for(int i=0;i<nStartPos.length;i++) 8w[nY.#T
fileSplitterFetch.splitterStop(); ;8G( l
l9 |x7GB
.kGlUb?^Q
} -UPlQL
} ^lP_{c
//负责部分文件的抓取 &d`z|Gx9
**FileSplitterFetch.java y,*>+xk,
*/ f.o,VVYi
package NetFox; :LuzKCvBP
XQ{G)
=.]>,N`C
import java.io.*; sp0j2<$a
import java.net.*; bHr2LhQCN
R7L:U+*V"
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public class FileSplitterFetch extends Thread { EzDj,!!<w
aN.t) DG}J
%r<c>sFJN
String sURL; //File URL Uf`lGGM
long nStartPos; //File Snippet Start Position !*0\Yi,6
long nEndPos; //File Snippet End Position +7jr]kP9
int nThreadID; //Thread's ID QL>G-Rp
boolean bDownOver = false; //Downing is over %0PdN@I
boolean bStop = false; //Stop identical u#8J`%g
FileAccessI fileAccessI = null; //File Access interface brkR,(#L3
iI[Z|"a21
)V^J^1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W |]24
{ 6 1=?(Iw
this.sURL = sURL; 1@nGD<,.
this.nStartPos = nStart; FQR{w
this.nEndPos = nEnd; `% k9@k.
nThreadID = id; _eb:"(m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 izy7.(.a
} secD `]
6Qnerd%Ec
o%XAw
public void run() DXu#07\
{ 4+e9:r]
while(nStartPos < nEndPos && !bStop) Aw9se"d
{ [[2Zcz:
l5_RG,O0A
Z 6KM%R
try{ " 2A`M~
URL url = new URL(sURL); Kq#\P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \ofWD{*j
httpConnection.setRequestProperty("User-Agent","NetFox"); "| cNY_$&s
String sProperty = "bytes="+nStartPos+"-"; /\34o{
httpConnection.setRequestProperty("RANGE",sProperty); 1)yEx1
Utility.log(sProperty); 1Q"w)Ta
2k;>nlVxX
B64L>7\>`
InputStream input = httpConnection.getInputStream(); z+,l"#Vv
//logResponseHead(httpConnection); .RFijr
H~IR:WOw
)d5Hv2/0
byte[] b = new byte[1024]; pxP,cS
int nRead; &x6Z=|Ers
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ks'msSMC
{ dS]TTU1
nStartPos += fileAccessI.write(b,0,nRead); :EJ8^'0Q
//if(nThreadID == 1) x}v]JEIf[Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jm8{@D%
} [&12`!;j
dd1CuOd6(1
#tX\m;
Utility.log("Thread " + nThreadID + " is over!"); +g/TDwyVH
bDownOver = true; K;kaWV
//nPos = fileAccessI.write (b,0,nRead); 4)MKYhm
} Nfe
catch(Exception e){e.printStackTrace ();} 7Nx5n<
} 4@ EY+p
} E57:ap)/
u'Ja9m1
KFQ4vavNh
//打印回应的头信息 ;#-yyU
public void logResponseHead(HttpURLConnection con) DD 8uG`<
{ )}ygzKEa
for(int i=1;;i++) 2XoFmV),F
{ ((KNOa5
String header=con.getHeaderFieldKey(i); ;QYUiR
if(header!=null) g-G;8x'n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |#_IAN
Utility.log(header+" : "+con.getHeaderField(header)); )v\zaz
else DJ&ni`
break; `N;}Gf-'
} %{M_\Ae#
} )9F o
cD^`dn%$
Ug :3)q[O
public void splitterStop() jhRg47A
{ 8w,+Y]X<P[
bStop = true; Ih Yso7g
} KMs[/|HX\
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} 8{0=tOXx{
d6(R-k#B
h=?V)WSM
/* IBP3
**FileAccess.java cy_'QS$W
*//文件访问(定位，写) dUt$kB
package NetFox; gu1:%raXd
import java.io.*; gKPqWh
E&;[E
Np2I*l6W
public class FileAccessI implements Serializable{ u& 4i=K'x8
g3V bP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~mSW.jy}=-
RandomAccessFile oSavedFile; n'?AZ4&z
long nPos; 7dm:L'0
:D|5E>o(
[TW?sW^0
public FileAccessI() throws IOException s'7PHP)LOJ
{ 24g\xNnt
this("",0); \X*Es.;|x
} xmM!SY>
9 HiH6f^5
7I$~E
public FileAccessI(String sName,long nPos) throws IOException 21T#NYfew
{ +nIjW;RU
oSavedFile = new RandomAccessFile(sName,"rw"); iJ&jg`"=F
this.nPos = nPos; Nc da~h Q
oSavedFile.seek(nPos); G(3wI}
} JhU"akoK
i8h^~d2"
1PN!1=F}
public synchronized int write(byte[] b,int nStart,int nLen) 6(1S_b=a
{ )ep1`n-
int n = -1; 5(\H:g\z
try{ 5Ic'6AIz
oSavedFile.write(b,nStart,nLen); mB5Sm|{
n = nLen; A"}Ib'
} 5$?)f&M
catch(IOException e) =j"bLX6;
{ \zT{zO&!
e.printStackTrace (); Be~'@
} %HD0N&
AX]cM)w
@$|8zPs
return n; M{jJ>S{g
} VeipM
20 Z/Y\
0F%/R^mw
} o}=c(u
0B]c`$"aD
7NMy1'-q
/* bs_< UE
**SiteInfoBean.java FmhT^
*/ J(Fk@{!F.*
package NetFox; hEA;5-m
`$Y%c1;
2@Zw#2|]
public class SiteInfoBean { 7P:/ (P
hiEosI C
^8=e8O
private String sSiteURL; //Site's URL 2t;3_C
private String sFilePath; //Saved File's Path ~^J9v+
private String sFileName; //Saved File's Name 2<E@f0BVAy
private int nSplitter; //Count of Splited Downloading File X2mZ~RB(p
~IFafAO&
l:OXxHxRi
public SiteInfoBean() EY@KWs3"H
{//nSplitter的缺省值为5 /jSb^1\
//default value of nSplitter is 5 n]8*yoge
this("","","",5); 5`QfysR5
} y]g5S-G
\j4!dOGZ
TVVu_ib
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 69 J4p=c,
{ (ZP e{;L.
sSiteURL= sURL; \[ W`hhJ
sFilePath = sPath; %reW/;)l{
sFileName = sName; !1mAq+q!
this.nSplitter = nSpiltter; ; hU9_e
93/`e}P"o
E)]emeGd
} ]d*O>Pm
GL^ j |1
_MTvNs
public String getSSiteURL() 2<*Yq8
{ y2PxC. -
return sSiteURL; u1|v3/Q-
} &{8[I3#@
F#o{/u?T
\5b<!Nl
public void setSSiteURL(String value) &<) _7?
{ KF7d`bRe
sSiteURL = value; NJKk\RM@7
} eTt{wn;6
?[ D6|gp
7N0m7SC
public String getSFilePath() &A^2hPe}
{ WX+@<y}%
return sFilePath; x!onan
} r?x~`C
lb]k"L%KU7
^fM=|.?
public void setSFilePath(String value) CF5%&B
{ ~5Rh7
sFilePath = value; ;e~K<vMm;y
} .\)p3pC)
jw]IpGTt
'eoI~*}3WQ
public String getSFileName() +>v{#A_u
{ EKT"pL-EY
return sFileName; 6:\z8fYD
} s_,&"->
b$FXRR\G
-ANq!$E
public void setSFileName(String value) @HXXhYH
{ 2K'}Vm+
sFileName = value; (yz8}L3
} Xg97[I8/
3K_!:[
QLTE`t5w3'
public int getNSplitter() WTh|7&
{ v aaZ
return nSplitter; nzu 3BVv
} Mq,_DQ
*-9b!>5eD
\'N|1!EO|t
public void setNSplitter(int nCount) 0 .p $q
{ 3!B3C(g
nSplitter = nCount; ({x<!5XL
} K#{E87G(
} 8JAT2a61ur
N,_ej@L8
'lNl><e-
/* yQ8H-a.
**Utility.java ,@ Cru=
*/ ]R{=|
package NetFox; z95V 7E
`0Q:d'
}Mo9r4}
public class Utility { 9tC8|~Q
?8C+wW
;3sT>UB
public Utility() |@-WC.
{ |/lIasI
c)E[K-u
Pjb9FCA'
} )SUN+YV^
n8G#TQrAE
//线程睡眠 ::T<de7
public static void sleep(int nSecond) e#HP+b$
{ L kq>>?T=
try{ %#QFu/l
Thread.sleep(nSecond); $=m17GD
} M9OFK\)
catch(Exception e) 4l`gAE$
{ }Rux<=cd|
e.printStackTrace (); Gj_b GqF8}
} dw4)4_
} !yI)3;$*
.yP 3}Nl
//日志 ^ KjqS\<
public static void log(String sMsg) 6kuSkd$.
{ 3z#;0n}
System.err.println(sMsg); BmJ?VJ}Y
} Elq8WtS
5UM[Iz
5k(#kyP
public static void log(int sMsg) 2Ls<OO
{ \~H"!vj
System.err.println(sMsg); I^|bQ3sor
} KE3v3g<
} gPi_+-@
Vi|jkyC8
<FK><aA_i*
/* ~GeYB6F
**TestMethod.java Z7/dRc
*/ o%5bg(
package NetFox; o|W? a#_\
Y"jDZG?
!!86Sv
public class TestMethod { 5xHiq&d.E
HKkf+)%)x
("oA{:@d
public TestMethod() |<*(`\'w
{ ///xx/weblogic60b2_win.exe .'1j5Y-l`N
try{ I@ k8^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >cNXB7]E>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hrD6r=JT<~
SiteFileFetch fileFetch = new SiteFileFetch(bean); k#(cZ
fileFetch.start(); ^IpiNY/%Q
} ^!qmlx*
catch(Exception e){e.printStackTrace ();} ;" *`
>nDnb4 'C
WLLv a<{
} U;GoC$b}|
&^_(xgJL
R6XMBYK^
public static void main(String[] args) @RIEO%S
{ ^^SfIK?p
new TestMethod(); syf"{bBe
} v`BG1&/|
} i@Zj7#e*
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