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)); ,i@X'<;y
} +@r*}
for(int i=0;i<nEndPos.length-1;i++) f5`g
{ kwsp9 0)
nEndPos = nStartPos[i+1]; JfPD}w
} G}p\8Q}'
nEndPos[nEndPos.length-1] = nFileLength; ++E3]X|
} Z@r.pRr'
} 6^DR0sO
$q 2D+_
q:g2Zc'Y~W
//启动子线程 )vxUT{;sH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A`R{m0A
for(int i=0;i<nStartPos.length;i++) /t(C>$ }p
{ &iV{:)L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vhhC> 7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h yv2SxP*
nStartPos,nEndPos,i); 2PG [7u^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sf8{h|71
fileSplitterFetch.start(); `jOX6_z?I
} P~ &$l2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TiH)5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b5^OQH{v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )5 R=Z<
nEndPos = " + nFileLength); M+x,opl
// fileSplitterFetch[nPos.length-1].start(); Fgh]KQ/5
QPq7R
KZeQ47|
//等待子线程结束 N\bocMc,X
//int count = 0; ZWS`\M
//是否结束while循环 W|o'&
boolean breakWhile = false; KI+VXH}Y5{
,GgAsj: K
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while(!bStop) M %Qt|@O
{ Sfr&p>{,
write_nPos(); S.a%
Utility.sleep(500); iJ~Vl"|m
breakWhile = true; GQ-Rtn4v
Km^&<3ch#
,\@O(; mF
for(int i=0;i<nStartPos.length;i++) c;'[W60
{ Y3=_ec3w
if(!fileSplitterFetch.bDownOver) CoA6
{ 8}(]]ayl
breakWhile = false; oqeSG.1
break; }C|dyyr
} )Dz+X9;g+
} F,'exuZ
if(breakWhile) b3VS\[p
break; -! K-Htb-
/S lYm-uQ+
=xS+5(
//count++; hh[jN7K
//if(count>4) x@Hc@R<!
// siteStop(); ~#/hzS
} b4pm_Um
=ha{Ziryo
&:7ZQ1
System.err.println("文件下载结束！"); k%G1i-]4
} Ft!],n-n*
catch(Exception e){e.printStackTrace ();} Tq~=TSD
} vz!s~cAt
h3;bxq!q
RG4sQ0
//获得文件长度 /7YF mI/0
public long getFileSize() YSe.t_K2C
{ 9tqF8pb7v
int nFileLength = -1; _x5 3g A
try{ tq|hPd<C
URL url = new URL(siteInfoBean.getSSiteURL()); @i*|s~15
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7!N2-6GV
httpConnection.setRequestProperty("User-Agent","NetFox"); mtjh`
FeTL&$O
piZJJYv t
int responseCode=httpConnection.getResponseCode(); Zg.&V
if(responseCode>=400) _:VB}>
{ :*2ud(
processErrorCode(responseCode); (!zy{;g|
return -2; //-2 represent access is error NW&b&o
} IOV(seEY
]S5JUAGkE*
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String sHeader; $81*^
)d>!"JB-
L:'J Bhg
for(int i=1;;i++) 5hy""i
{ J`^I./
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oo.2Dn6z
//Utility.log(in.readLine()); }O4^Cc6
sHeader=httpConnection.getHeaderFieldKey(i); `9b7>Nn<
if(sHeader!=null) fP `b>]N_
{ 1N>|yQz
if(sHeader.equals("Content-Length")) aUtnR<6
{ uF3qD|I\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t0T"@t#c
break; @$+ecaVW
} qhz]Wm P
} QD>"]ap,o
else >:|q&|x-
break; <|Pun8j
} ez6EjUk
} r'*}TM'8
catch(IOException e){e.printStackTrace ();} d:U9pC$
catch(Exception e){e.printStackTrace ();} [`):s= FC
GHeVp/u
se>MQM5 )
Utility.log(nFileLength); .8G@%p{,
,5*eX
ksN+?E4w
return nFileLength; }I2@%tt?
} WpRc)g:
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iS<I0\D
//保存下载信息（文件指针位置） MEGv}
private void write_nPos() O~^"
{ IDG}ZlG
try{ \9g+^vQg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1cD! :[
output.writeInt(nStartPos.length); u9EgdpD
for(int i=0;i<nStartPos.length;i++) 6 jn3`D
{ `6xkf&Kt
// output.writeLong(nPos); lh;:M-b9
output.writeLong(fileSplitterFetch.nStartPos); >M/V oV
output.writeLong(fileSplitterFetch.nEndPos); ixT:)|'i
} )}?#
output.close(); B,=H@[Fj
} /x1![$oC0
catch(IOException e){e.printStackTrace ();} ={xE!"
catch(Exception e){e.printStackTrace ();} 7!JQB
} Yn G_m]
2mGaD\?K
[a wjio
//读取保存的下载信息（文件指针位置） fu]s/'8B
private void read_nPos() ]3l9:|
{ k>g_Z`%<
try{ !GNBDRr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t8+X%-r
int nCount = input.readInt(); ]@Uq=?%
nStartPos = new long[nCount]; 0PrLuejz
nEndPos = new long[nCount]; t?'!$6
for(int i=0;i<nStartPos.length;i++) ~S7D>D3S
{ X'qU*Eo
nStartPos = input.readLong(); jmFz51
nEndPos = input.readLong(); ftF@Wq1f
} pj?f?.^
input.close(); $H9%J
} Q{5kxw1ZF
catch(IOException e){e.printStackTrace ();} 3skC$mpJHw
catch(Exception e){e.printStackTrace ();} ,~]tg77
} < RH UH)I
57&b:0`p
u;/ Vyu
private void processErrorCode(int nErrorCode) VeQg-#&I
{ N<-gI9_
System.err.println("Error Code : " + nErrorCode); j4R(B
} 5X:*/FuS@
xM&Wgei]10
8;+B*+%@n
//停止文件下载 #kaY0M
public void siteStop() @dPTk"P
{ K8UP,f2
bStop = true; %*0^0wz
for(int i=0;i<nStartPos.length;i++) U5.LDv;
fileSplitterFetch.splitterStop(); /q`xCS
0p}D(m2B
70Wggty
} ?1K#dC52#
} 5jgR4a*_v
//负责部分文件的抓取 #nPQ!NB/
**FileSplitterFetch.java &b%zQ4%d-`
*/ PC-"gi=h
package NetFox; /*X2c6<d
I ,z3xU
`yH<E+
import java.io.*; ne_TIwfw-
import java.net.*; t~#zMUfac
mSb#Nn6W
sWc*5Rt
public class FileSplitterFetch extends Thread { \Yc'~2n
"Pu!dJ5[]
f>UXD
String sURL; //File URL Xy$3VU*
long nStartPos; //File Snippet Start Position +>{Y.`a;Jo
long nEndPos; //File Snippet End Position pw)||Q
int nThreadID; //Thread's ID P;ci9vk
boolean bDownOver = false; //Downing is over + |#O@k
boolean bStop = false; //Stop identical *&^:T~|=!
FileAccessI fileAccessI = null; //File Access interface g|vNhq0|i
G(G{RAk>
|6K+E6H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rp!oO>F
{ 4hTMbS_;
this.sURL = sURL; YW( Qmo7
this.nStartPos = nStart; pH"#8O&
this.nEndPos = nEnd; \b?" b
nThreadID = id; JSCZ{vJ$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j)/nKh4O
} /7|V+6jV
; Q3n
mR?5G:W~R
public void run() ~nh:s|l6%M
{ pxCK;]
while(nStartPos < nEndPos && !bStop) S/e2P|}
{ C8 xZ;V]
pu 7{a
H1QJk_RL
try{ iV*q2<>
URL url = new URL(sURL); 0Tx{3#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (nlvl?\d
httpConnection.setRequestProperty("User-Agent","NetFox"); XF;ES3 d
String sProperty = "bytes="+nStartPos+"-"; ;;C?{
httpConnection.setRequestProperty("RANGE",sProperty); d9;g]uj`
Utility.log(sProperty); _lGdUt 2
o:3dfO%nuM
iB%gPoDCL@
InputStream input = httpConnection.getInputStream(); }dWq=)*
//logResponseHead(httpConnection); o7sT=x9
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MbZJ;,e?
byte[] b = new byte[1024]; V@cM|(
int nRead; #t:S.A@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XBb~\p3y
{ HUv/ ~^<
nStartPos += fileAccessI.write(b,0,nRead); C9n?@D;S
//if(nThreadID == 1) }%'?p<^M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M42Ssn)
} U |Jo{(Y
@Z\,q's
][9%Kl*%@p
Utility.log("Thread " + nThreadID + " is over!"); DRp~jW(\y
bDownOver = true; clL2k8VS
//nPos = fileAccessI.write (b,0,nRead); _m gHJ0v'
} YW_Q\|p]M
catch(Exception e){e.printStackTrace ();} 1m:XR0P
} Sjyoc<Uo
} 17oa69G
Q@<S[Qh[.
S+atn]eU@
//打印回应的头信息 VC\S'z
public void logResponseHead(HttpURLConnection con) \n8]M\<
{ [<g?WPCcC
for(int i=1;;i++) u'|4?"uz
{ ||hb~%JK6
String header=con.getHeaderFieldKey(i); PT=2@kH
if(header!=null) a!<8\vzg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); si`A:14R
Utility.log(header+" : "+con.getHeaderField(header)); 52 fA/sx
else Crho=RJPR
break; Sa?ksD2IaB
} g*e
} 7hlO#PYZ
Jq&uF*!
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public void splitterStop() (e!0]Io@
{ 4'g;TI^
bStop = true; wVicyiY]
} >VP=MbN
^;Y|3)vvB
vY }A
} TZ(cu>
G-xDN59K
8S mCpg
/* H:t$'kb`
**FileAccess.java E9Np0M<
*//文件访问(定位，写) zR1^I~ %
package NetFox; @z4*.S&tz
import java.io.*; 544X1Ww2
}XV+gyG=@
x(etb<!jd
public class FileAccessI implements Serializable{ #{?PbBE}
P9^-6;'Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 trPAYa}W
RandomAccessFile oSavedFile; FbaEB RM
long nPos; }=gx#
Xjo5v*Pu
/'].lp
public FileAccessI() throws IOException "?ucO4d
{ !;i`PPRwk
this("",0); DnCP aM4%
} -8:&>~4`
Ghx3EVqnx"
E^ P,*s
public FileAccessI(String sName,long nPos) throws IOException q|o}+Vr
{ DoJ\ q+
oSavedFile = new RandomAccessFile(sName,"rw"); J&[@}$N
this.nPos = nPos; HJXT9;w
oSavedFile.seek(nPos); !UG 7Uer
} 4 N H
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Sp@^XmX(S
public synchronized int write(byte[] b,int nStart,int nLen) <tF9V Jq
{ hU`wVy
int n = -1; Gn|F`F
try{ M m[4yP%
oSavedFile.write(b,nStart,nLen); 8oUpQcim
n = nLen; .y_/Uwu
} +Z7th7W/,
catch(IOException e) YQ+tDZY8`
{ #E?(vA1
e.printStackTrace (); Mr;E<Lj ^K
} VL%UR{
~$iIVJ`
P3cRl']
return n; _LMM,!f
} !>{G,\^=pT
TH; R
& -{DfNKc
} ]h>_\9qO
L\)ZC
-yE/f2PgQ
/* ?nofUD.
**SiteInfoBean.java ?WF/|/
*/ ]+|~cRQ9I
package NetFox; Y ;u<GOe
#w,Dwy
$FlW1E j
public class SiteInfoBean { 'oF%,4 !Y
As3.Q(#Z
LQ(yScA@
private String sSiteURL; //Site's URL CN#+U,NZV
private String sFilePath; //Saved File's Path QW$G
private String sFileName; //Saved File's Name @y='^DQ*
private int nSplitter; //Count of Splited Downloading File >TOu|r
+W:=e,=
{Or;
public SiteInfoBean() %MrWeYd1
{//nSplitter的缺省值为5 0'V5/W
//default value of nSplitter is 5 )2V:
this("","","",5); eoai(&o0$
} W=#:.Xj[
}`W){]{kO
J6U$qi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \R|4( +]x
{ HG+%HUO$
sSiteURL= sURL; ]bj&bk#
sFilePath = sPath; .q `Hjmg<
sFileName = sName; Xe<sJ.&Wf
this.nSplitter = nSpiltter; ]$Yvj!K*Q
Fs{x(_LOr
Y%PwktQm
} ~aMlr6;
A*2 bA
_AQb6Nb
public String getSSiteURL() \^ZlG.
{ 5jd,{<
return sSiteURL; 4a'N>eDR
} r<K(jG[:{f
GliwY_
k.uMp<)D
public void setSSiteURL(String value) zaah^.MA|
{ uT}' Y)m
sSiteURL = value; 5]n[]FW
} V}dJ.I /#
FrTi+& <
AWP"b?^G|
public String getSFilePath() ]|MEx{BG-
{ A%`[mc]4#
return sFilePath; k\WR ]
} 1#.>a$>
Z @^9PQG$
J3n-`k8
public void setSFilePath(String value) Tav*+
{ H*[M\gN$
sFilePath = value; X:6c}p%,!
} &?q/1vLa
*MJX?
_59huC.
public String getSFileName() g=QDu7Ux
{ c|M6<}
return sFileName; UD8op]>L
} kKAP"'v
.Nw=[
W7U2MqQ
public void setSFileName(String value) #=6E\&NC
{ W}5xmz
sFileName = value; kL$!E9
} B?4boF?~
xL{a
>N]7IU[-
public int getNSplitter() 95YL]3V
{ %]>KvoA
return nSplitter; pgOQIzu
} KO]T<R h<
eu(:`uu
+tVaBhd!
public void setNSplitter(int nCount) So0f)`A
{ kdl:Wt*4o
nSplitter = nCount; 5<UVD:~z
} s (zL
} gREzZ+([
my}-s
:P<]+\m
/* KU8Jbl*
**Utility.java B5X(ykaX~
*/ f6p-s y>
package NetFox; &Rvm>TC=
1XD,uoxB
a{R%#e\n
public class Utility { j!]YNH@
fZ*+2T>
vJ'2@f$
public Utility() s;3={e.
{ VzY8rI
K?BOvDW"`
B]uc<`f
} !t gi
>U%gctIg
//线程睡眠 9D7+[`r(-
public static void sleep(int nSecond) xO&eRy?%
{ y~F,0"N\r
try{ *XT/KxLa7
Thread.sleep(nSecond); V+VkY3
} 4<k9?)~(J
catch(Exception e) /+@p7FqlE
{ MM(xk
e.printStackTrace (); X4 A<[&F/
} q U]gj@R
} kzt(i Y_6
<})2#sZO!
//日志 w-Da~[J
public static void log(String sMsg) v"#mzd.tW
{ X22[tqg;&
System.err.println(sMsg); k +H3Bq
} (=* cK-3
R,pX:H&#+
TrLu~4
public static void log(int sMsg) U$_xUG
{ Yy)tmq
System.err.println(sMsg); `/EGyN6X
} w+1|9Y
} \lZf<f
bdQ_?S(
d` jjGEj
/* qzf!l"bT
**TestMethod.java %Ti}CwI`
*/ kPF9Z "l
package NetFox; (Q.waI
T>R0T{A
1T-8K r
public class TestMethod { M#As0~y
9J9)AV
fjs [f'L
public TestMethod() f"qga/
{ ///xx/weblogic60b2_win.exe 6WU(%
try{ SVO3821
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *Df,Ijh$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b\-&sM(W"
SiteFileFetch fileFetch = new SiteFileFetch(bean); f]JM /
fileFetch.start(); K }Vv4x1U
} XqW@rU
catch(Exception e){e.printStackTrace ();} Aq0S-HKF
5[* qi?w=
_Jme!Oaa
} }Rz3<eON
eC[$B99\
kH]yl 2
public static void main(String[] args) fO0XA"=
{ +eFFSt
new TestMethod(); V>A.iim
} -Xxqm%([71
} pXJpK@z
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