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)); [MD"JW?4B
} V7D<'!
for(int i=0;i<nEndPos.length-1;i++) 6q,CEm
{ O\h%ZLjfO
nEndPos = nStartPos[i+1]; H|/"'t OZ
} bD?gwhAKA
nEndPos[nEndPos.length-1] = nFileLength; )~IOsTjI
} fS p
} #}Bv/`t
)(pgJLW
T "#DhEM
//启动子线程 ,rOh*ebF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Tq?f5swsI
for(int i=0;i<nStartPos.length;i++) A,c_ME+DVB
{ ZA}!Rzo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $QwzL/a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ),$^h7[n
nStartPos,nEndPos,i); iH>b"H>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V7vojm4O
fileSplitterFetch.start(); ZgmK~iJ
} C~PP}|<~V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 65tsJ"a<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {mLv?"M]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "2 D{X
nEndPos = " + nFileLength); q(BRJ(
// fileSplitterFetch[nPos.length-1].start(); Iz&d S?p_
Sg13Dp@x
8E>2 6@.
//等待子线程结束 [C!m,4
//int count = 0; SQN{/")T
//是否结束while循环 g_eR&kuh
boolean breakWhile = false; rEWuWv$
cW?6Iao
(l/i#
while(!bStop) ebLt:gGo
{ ~`5[Li:eP
write_nPos(); |BO5<`&I
Utility.sleep(500); ZIc-^&`r=
breakWhile = true; (e9hp2m
~se ;L
xscR Bx
for(int i=0;i<nStartPos.length;i++) 89W8cJ$yW
{ )}k"7"
if(!fileSplitterFetch.bDownOver) #nKGU"$+
{ aw7pr464
breakWhile = false; GT3}'`f B
break; Rli`]~!w
} BJqb'Hjd
} @;[.#hK
if(breakWhile) }(WUZ^L
break; N8!e(YK_
-CPLgT
]ij:>O@{$
//count++; MN>U jFA
//if(count>4) luz,z( v
// siteStop(); 7K!n'dAi6
} Ge24Lp;Y6
(e<p^TJ]
@VsK7Eo
System.err.println("文件下载结束！"); 54f?YR
} u7-0?
catch(Exception e){e.printStackTrace ();} uW,rmd
} ! n?j)p.
],wzZhA
^.Q/iXgh
//获得文件长度 O)r>AdLGn
public long getFileSize() p\xsW"=8q
{ X<H+Z2d
int nFileLength = -1; w Qp{z
try{ <a2Kc '
URL url = new URL(siteInfoBean.getSSiteURL()); u_$Spbc]/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o2LUB)=R'
httpConnection.setRequestProperty("User-Agent","NetFox"); TJs@V>,
tNW0 C]
puGy`9eKv1
int responseCode=httpConnection.getResponseCode(); AOCiIPw
if(responseCode>=400) ||4++84{
{ 2K2jko9'a
processErrorCode(responseCode); $7\hszjZ
return -2; //-2 represent access is error ;] #Q!
} oc&yz>%q
Zg!E}B:z
q5~fU$ ,
String sHeader; ':,p6
N_E:?Jo
i)d'l<RA
for(int i=1;;i++) 65pC#$F<x
{ 1 BVpv7@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'gz@UE1
//Utility.log(in.readLine()); D5 ^WiQ<
sHeader=httpConnection.getHeaderFieldKey(i); -Cf< #'x_
if(sHeader!=null) U^$l$"~"
{ Xdc>Z\0V
if(sHeader.equals("Content-Length")) skfFj&_T
{ l@%7] 0!T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e@{8G^o>D
break; L+"5g@
} ZD]5"oHY
} 9Dy/-%Ut9
else `LCxxpHi|
break; G(y@Tor+
} ]]bL;vlw
} V9kL\Ys
catch(IOException e){e.printStackTrace ();} <rFY$ ?x
catch(Exception e){e.printStackTrace ();} >=Un=Q%
B(dq$+4
X2p9KC
Utility.log(nFileLength); 4*9:
*1;}c z
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return nFileLength; ~4+=C\r
} l]o&D))R
9:l>FoXS
d.uJ}=|
//保存下载信息（文件指针位置） ~ugK&0i[2
private void write_nPos() ?yt"
{ W.AN0N
try{ `$D2w|
output = new DataOutputStream(new FileOutputStream(tmpFile)); hE>i~:~R
output.writeInt(nStartPos.length); HLcK d`$/
for(int i=0;i<nStartPos.length;i++) -?WhJ.U
{ G.a^nQ@e%
// output.writeLong(nPos); t`X-jr)g
output.writeLong(fileSplitterFetch.nStartPos); Yxt`Uvc(^h
output.writeLong(fileSplitterFetch.nEndPos); g^DPbpWxu
} +LM/< l
output.close(); e&(Di,%:
} \^+=vO;A
catch(IOException e){e.printStackTrace ();} w%[`'_[
catch(Exception e){e.printStackTrace ();} N8| ;X
} ggUJ -M'2h
NK+iLXC
,IW$XD
//读取保存的下载信息（文件指针位置） I2=?H<
private void read_nPos() Q1Sf7)
{ JYB<};,
try{ `AA[k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <Vk^fV
int nCount = input.readInt(); L;0ZB=3n
nStartPos = new long[nCount]; %K_[Bx{B
nEndPos = new long[nCount]; bqxbOQd
for(int i=0;i<nStartPos.length;i++) W|@/<K$V
{ (:>:tcE
nStartPos = input.readLong(); )0P>o]fWI
nEndPos = input.readLong(); daIt `}s
} ttPa[h{!
input.close(); $gN1&K
} 8qfg=mu+%
catch(IOException e){e.printStackTrace ();} H|H!VPof]
catch(Exception e){e.printStackTrace ();} zM^ux!T=
} m1X0stFRs"
&LO<!WKQ
L "L@4B
private void processErrorCode(int nErrorCode) )x-iru A:
{ A|V |vT7cb
System.err.println("Error Code : " + nErrorCode); 2 fX-J
} P"%i 4-S
;N4b~k)
)Aa98Eu?2
//停止文件下载 O1Gd_wDC/i
public void siteStop() m?G}%u
{ h:3`e`J<h
bStop = true; XX5 ):1
for(int i=0;i<nStartPos.length;i++) ANy=f-V
fileSplitterFetch.splitterStop(); jZcjiOX
5rqjqfFa
cy)gN g
} #~54t0|Cd>
} ip4:px-
//负责部分文件的抓取 R ;^[4<&
**FileSplitterFetch.java Cd.pMoS
*/ `?PZvGi
package NetFox; }'dnL
C:g2E[#
h[%`'(
import java.io.*; I.j`h2
import java.net.*; |n3PznV
EN()dCQHr
ho2o/>Ef3
public class FileSplitterFetch extends Thread { o;mXk2
b7{)B?n
eMVfv=&L<3
String sURL; //File URL &"fMiK3
long nStartPos; //File Snippet Start Position OB8fFd
long nEndPos; //File Snippet End Position l}%!&V0
int nThreadID; //Thread's ID kssS,Ogf\_
boolean bDownOver = false; //Downing is over }%[TJ@R;
boolean bStop = false; //Stop identical ts3%cRN r
FileAccessI fileAccessI = null; //File Access interface +/7UM x1
`f}c 1
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ErJi
{ &h-d\gMJ
this.sURL = sURL; bV&/)eqv
this.nStartPos = nStart; M~;mamTP
this.nEndPos = nEnd; QP)-O*+AA
nThreadID = id; _L(6F TJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w"bQxS~$y
} 5[esW
3k5OYUk
I)V2cOrXM
public void run() {QTfD~z^K
{ qi}HJkOq
while(nStartPos < nEndPos && !bStop) {LbNKjn
{ gAC}
AYd7qx:~
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try{ ]]Ypi=<'
URL url = new URL(sURL); 2BBGJE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wt[MzpRP
httpConnection.setRequestProperty("User-Agent","NetFox"); bQow,vf
String sProperty = "bytes="+nStartPos+"-"; 3zp)!QJi
httpConnection.setRequestProperty("RANGE",sProperty); AQU4~g mI
Utility.log(sProperty); {7[^L1
%+ig7a:
hAHl+q)w?
InputStream input = httpConnection.getInputStream(); x"K<@mR5G
//logResponseHead(httpConnection); m'XzZmI
Ku*@4#<L6h
[#$-kd~
byte[] b = new byte[1024]; E:T<mI?d
int nRead; XL>Vwd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q-eC=!#}
{ a9mLPP
nStartPos += fileAccessI.write(b,0,nRead); sbZ)z#Tr
//if(nThreadID == 1) Kjc"K36{L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vr/V_
} VZ'[\3J
] NL-)8u
9xyj,;P>
Utility.log("Thread " + nThreadID + " is over!"); _N$3c<dY'
bDownOver = true; RlyF#X#7{
//nPos = fileAccessI.write (b,0,nRead); )&+j#:
} ++-HdSHY
catch(Exception e){e.printStackTrace ();} $FZ~]Ef
} #Z)e]4{!l
} %N7b XKDP
fQ=Yf?b
=LDzZ:' X
//打印回应的头信息 d+rrb>-OU
public void logResponseHead(HttpURLConnection con) !JzM<hyg3
{ *r@7:a5
for(int i=1;;i++) 5'd$TC
{ ]@vX4G/
String header=con.getHeaderFieldKey(i); $[T^S
if(header!=null) [-_3Zr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "}!|V)K
Utility.log(header+" : "+con.getHeaderField(header)); !'wh hi
else z6]dF"N
break; B\r2M`N5
} jOa .h
} .LhIB?
E^rKS&P
'FgBYy/
public void splitterStop() @)1>ba
{ R8I%Cyc
bStop = true; L15?\|':Y
} de1cl<
f6vhW66:?x
U(P^-J<n1
} 1fm4:xHH
yhv(KI
a$r- U_?
/* *`Swv`
**FileAccess.java S[JeW
*//文件访问(定位，写) z`$jxSLm
package NetFox; (hNTr(z
import java.io.*; `)%zk W
<*EMcZ
m0QE S
public class FileAccessI implements Serializable{ G2qv)7{l2
/4/'&tY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G%^jgr)
RandomAccessFile oSavedFile; J|,Uu^7`
long nPos; vz5x{W
ve($l"T
q\s"B.(G"
public FileAccessI() throws IOException )Tjh
{ 7irpD7P>
this("",0); O+x"c3@Z)D
} [As9&]Bv5
'&hz*yk
yN[aBYJx,M
public FileAccessI(String sName,long nPos) throws IOException oCfO:7
{ A,67)li3
oSavedFile = new RandomAccessFile(sName,"rw"); ~_Q~AOFM
this.nPos = nPos; 4> k"$l/:
oSavedFile.seek(nPos); V=^B7a.;>
} 4`yE'%6.}
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Z$?(~ln
public synchronized int write(byte[] b,int nStart,int nLen) GDF/0-/Z
{ Kzwbr?&z
int n = -1; Kb X&E0
try{ (4o<U%3kGq
oSavedFile.write(b,nStart,nLen); V>Dqw!
n = nLen; 'Qdea$o
} Z(j"\d!y
catch(IOException e) 7Tb[sc'
{ ]K?;XA3dZ
e.printStackTrace (); e!W U
} Tp46K\}Uf
Gj_7wP$
Q":,oZ2
return n; j,n\`7dD$
} >``sM=Wat
ZnKjU ]m
E5aRTDLq
} x~Y{ {
xU/7}='T
|`ya+/ff+
/* @An}
**SiteInfoBean.java Ff{,zfN+3
*/ apOXcZ
package NetFox; (> W\Nf
cY5w,.Q/!
2&"qNpPtE
public class SiteInfoBean { .k:heN2-x
8`<e\g7-
NnH]c+
private String sSiteURL; //Site's URL /#WvC;B
private String sFilePath; //Saved File's Path T;G<62`.h
private String sFileName; //Saved File's Name 6r|=^3{
private int nSplitter; //Count of Splited Downloading File O1D|T"@
oXjoQ
IRGcE&m
public SiteInfoBean() FsO_|r
{//nSplitter的缺省值为5 @ ]40xKF
//default value of nSplitter is 5 @R-11wP)M
this("","","",5); -Bl]RpHCe
} &~Pk*A_:
h@E7wp1'~
<UF0Xc&X'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zYrJHn#vB
{ u^G Y7gah
sSiteURL= sURL; O\CnKNk,
sFilePath = sPath; hq&|
sFileName = sName; (dZ]j){
this.nSplitter = nSpiltter; pdB\D
j+fib} 8}
DK eB%k
} hxzA1s%~
"u]&~$
%3O))Ug5
public String getSSiteURL() ufCpX>lNF
{ Vpne-PW
return sSiteURL; GGnlkp& E
} ?2l`%l5(
=n5n
L2+cVR
public void setSSiteURL(String value) 51JB,}dGH}
{ I?St}Tl
sSiteURL = value; iGSA$U P|
} u7^(?"x
F)KR8(
7UY4* j|[C
public String getSFilePath() =6qTz3t
{ od{\z
return sFilePath; VP>*J`'H
} SkMFJ?J/
]iGeqwT
;}iB9 Tl
public void setSFilePath(String value) yq49fEgc@U
{ _XT'h;m
sFilePath = value; O>pv/Ns
} Db<#gH
E(j#R"
9sT5l"?g
public String getSFileName() ]VxC]a2
{ w6Nnx5Ay
return sFileName; ,5"(m?[m
} );':aXj
|mE;HvQF
njf\fw_
public void setSFileName(String value) Vn4wk>b}$2
{ ZaU8eg7
sFileName = value; R?O)vLmd
} @U18Dj[
7M~sol[*
fCx(
public int getNSplitter() sa4w.9O1GS
{ dgF%&*Il]O
return nSplitter; 5\MC5us3
} g/JF(nkP
jZzTnmm&?
!CWe1Dm
public void setNSplitter(int nCount) >i,_qe?V:w
{ uD>=
nSplitter = nCount; ,JE_aje7
} UMR?q0J
} k[D_L`
d]]z )
)^ Y+Vn
/* )rK2%\Z
**Utility.java Ha`N
*/ }I&.xzJ
package NetFox; +Cw_qS"=
WHY/x /$
:.,9}\LK
public class Utility { P[WkW#
3$nK
>MHlrSH2
public Utility() h6 {vbYj
{ 5,1<A@H
}yEV&& @
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} e~SK*vR%]
n"Ie>
//线程睡眠 ^ ~Eh+
public static void sleep(int nSecond) TC?B_;a
{ [j+:2@
try{ Reikf}9Q
Thread.sleep(nSecond); HeAXZA,
} ;7lON-@BI
catch(Exception e) ;o!p9MEpz;
{ X ."z+-eh
e.printStackTrace (); F3}MM dX
} }tW-l*\U
} hy*{{f;
^HSxE
//日志 vmqa_gU\
public static void log(String sMsg) 4k;FZo]S
{ NUFz'MPv
System.err.println(sMsg); &:&89<C'
} u#@/^h;
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a;HAuy`M x
public static void log(int sMsg) r)iEtT!p*
{ *): |WDR
System.err.println(sMsg); ~=|}!A(
} *,\"}x*
} o&?c,FwN
1INX#qTZ
E=s,-
/* f$o^Xu
**TestMethod.java +~^S'6yB
*/ QH/py
package NetFox; }iUK`e
ra$:ibLN
]@&X*~c^Z
public class TestMethod { C}8#yAS9M
QtW9!p7(
E\[BE<y
public TestMethod() y(COB6r
{ ///xx/weblogic60b2_win.exe d51lTGH7Z
try{ pDR~SxBXr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3Vk8'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *2/Jg'de
SiteFileFetch fileFetch = new SiteFileFetch(bean); X0.H(p#s
fileFetch.start(); Xh@K89`uX
} NHd@s#@
catch(Exception e){e.printStackTrace ();} o:d7IL
cbJgeif
vzIo2,/7
} F!vrvlD`s
t+?Bb7p,H
gu k,GF9p]
public static void main(String[] args) ?2<) Jw
{ @;/Pl>$|'G
new TestMethod(); %N8I'*u
} Bz]tKJ
} WcN4ff-
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