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)); 0a)LZp|
} et6@);F
for(int i=0;i<nEndPos.length-1;i++) it=ir9
{ Qexv_:C
nEndPos = nStartPos[i+1]; `I5So-^&z
} }4xz,oN
nEndPos[nEndPos.length-1] = nFileLength; $2k9gO
} ~"vRH
} p,#**g:
e&=T`
g0RfvR
//启动子线程 Il<ezD{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [2zS@p
for(int i=0;i<nStartPos.length;i++) yrR,7vJ
{ +RD{<~i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w Yr M2X@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P Z+Rz1x
nStartPos,nEndPos,i); G~Fjla\?Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @X#e
fileSplitterFetch.start(); OlYCw.Zu
} 0S>U_#-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X!0m,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {hKf 'd9E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1${Cwb/F
nEndPos = " + nFileLength); .^uYr^(|[
// fileSplitterFetch[nPos.length-1].start(); xA"7a
^g n7DiIPH
K]Q1VfeL=
//等待子线程结束 eHI7= [h
//int count = 0; Jgf=yri
//是否结束while循环 gz"I=9
boolean breakWhile = false; )Ft>X9$
d##'0yg
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while(!bStop) C)0JcM
{ /;rk-I
write_nPos(); J(x42Q}*S
Utility.sleep(500); ;S^7Q5-
breakWhile = true; pkEqd"G
OYNPZRu
/9soUt
for(int i=0;i<nStartPos.length;i++) _cXLQ)-
{ w]VdIS
if(!fileSplitterFetch.bDownOver) `n~bDG>
{ ngQ]
breakWhile = false; n$(_(&
break; O8WLulo
} nHmi%R7k
} m=%WA5c?
if(breakWhile) npdpKd+*K"
break; {!7 ^w
+"2IQme5
5oE!^bF?
//count++; (8OaXif
//if(count>4) EU-=\Y
// siteStop(); M}tr*L
} hKYA5]
JGKiVBN
IH0qx_;P&
System.err.println("文件下载结束！"); )]C7+{ImC
} I:%O`F
catch(Exception e){e.printStackTrace ();} Z,m;eCLG]
} M `bEnu
l*C(FPw4
^ G(GjW8
//获得文件长度 H0\5a|X-
public long getFileSize() YDr/Cw>J
{ gsp|?)]x
int nFileLength = -1; !<xeAo%8
try{ `l8^n0-
URL url = new URL(siteInfoBean.getSSiteURL()); _Tj`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jB!Q8#&Q
httpConnection.setRequestProperty("User-Agent","NetFox"); .ahYjn
;.P9t`*
]za1=~[
int responseCode=httpConnection.getResponseCode(); +gQoYlso
if(responseCode>=400) mOvwdRKn
{ l~V^
processErrorCode(responseCode); F2$Z4%x#
return -2; //-2 represent access is error }^ j"@{~
} Lz'05j3!
-I#1xJU
Lg[_9`\
String sHeader; h tn?iLq
Dk XB
RwC1C(ZP
for(int i=1;;i++) 5w+X
{ F7zBm53
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4^mpQ.]lO
//Utility.log(in.readLine()); Cp2$I<T
sHeader=httpConnection.getHeaderFieldKey(i); @< @\CiM
if(sHeader!=null) OJ:iQ
{ P9aGDma
if(sHeader.equals("Content-Length")) "##Ylq("
{ J9 iQW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #{8n<sE
break; EJrn4QOs
} JtrLTo
} ,U#$Qb 12
else w1+xlM,,9
break; r-$SF5uv
} |?Z;tAF!
} `|i[*+WC
catch(IOException e){e.printStackTrace ();} tOK lCc
catch(Exception e){e.printStackTrace ();} {$ghf"
C4 &1M
7VdG6`TDR
Utility.log(nFileLength); P+Ta|-
(Wu_RXfCw_
Q!<b"8V]
return nFileLength; qUY QN2wG
} ]#N~r&hmQ
_f8<t=R
v]tbs)x;h
//保存下载信息（文件指针位置） QDg\GA8|
private void write_nPos() "&ElKy 7j
{ vq~btc.p{&
try{ ?6gC;B
output = new DataOutputStream(new FileOutputStream(tmpFile)); N!}r(Dd*
output.writeInt(nStartPos.length); 9?M><bBX
for(int i=0;i<nStartPos.length;i++) \i-HECc"U
{ (@H'7,
// output.writeLong(nPos); )h0F'MzW
output.writeLong(fileSplitterFetch.nStartPos); jMvWS71
output.writeLong(fileSplitterFetch.nEndPos); B|-E3v:f4
} h<50jnH!
output.close(); .OHjn|
} }l/!thzC
catch(IOException e){e.printStackTrace ();} h4 s!VK1X
catch(Exception e){e.printStackTrace ();} ZCZYgf@
} mRT`'fxK
R30{/KK
m 4VhR_
//读取保存的下载信息（文件指针位置） (q!tI*}
private void read_nPos() |7V:~MTkk&
{ Xx~XW^lsh
try{ RSLMO8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Jp<Y2-
int nCount = input.readInt(); TixXA:Mf
nStartPos = new long[nCount]; BK>uJv-qU
nEndPos = new long[nCount]; .r/6BDE"
for(int i=0;i<nStartPos.length;i++) zice0({iJ
{ fD#VI
nStartPos = input.readLong(); piE9qXn
nEndPos = input.readLong(); I|?zSFa
} X#$mBRK7
input.close(); ,nJYYM
} !biq7f%6#
catch(IOException e){e.printStackTrace ();} <j93
catch(Exception e){e.printStackTrace ();} uX-]z3+
} U[1Ir92:
oW*e6"<R7
jjgjeY
private void processErrorCode(int nErrorCode) w1-/U+0o
{ -,t2D/xK
System.err.println("Error Code : " + nErrorCode); Q Fv"!Ql
} oGi;S="I
8m0GxgS
F)mlCGv:R
//停止文件下载 X0Q};,
public void siteStop() _ 13M
{ URbu=U
bStop = true; cNzn2-qv
for(int i=0;i<nStartPos.length;i++) R&13P&:g
fileSplitterFetch.splitterStop(); v*+.;60_
_e<3 g9bj
p.9VyM
} beyC't
} Farcd!}
//负责部分文件的抓取 /`YHPeXu
**FileSplitterFetch.java #\kYGr-G)
*/ %Y"@VcN
package NetFox; [:geDk9O#'
Tti]H9g_
N'nI ^=
import java.io.*; =FkU:q$
import java.net.*; $*ujX,}xG
zT[[WY4
] 8sVXZ
public class FileSplitterFetch extends Thread { Ij_Y+Mnl4:
Suixk'-
k\UDZ)TQV
String sURL; //File URL U$j*{`$4
long nStartPos; //File Snippet Start Position x j6-~<
long nEndPos; //File Snippet End Position >1[Hk0 <x
int nThreadID; //Thread's ID Fa`/i v
boolean bDownOver = false; //Downing is over ;Ub;AqY
boolean bStop = false; //Stop identical u%FG% j?C
FileAccessI fileAccessI = null; //File Access interface &h.E B
PT7L65
E\2|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )J&1uMp{
{ FI1R7A
this.sURL = sURL; q(0V#kKC
this.nStartPos = nStart; hX\z93an
this.nEndPos = nEnd; eqK6`gHa6
nThreadID = id; B[:-SWd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9ZjSM,+
} GU99!.$
6@`Y6>}$_
xy>~15
public void run() Zvd^<SP<?
{ ;0Yeo"-
while(nStartPos < nEndPos && !bStop) gbOd(ugH
{ bKsl'3~ k
.l$'%AG:~
Wpo:'?!(M^
try{ P!qU8AJkt
URL url = new URL(sURL); <^?64
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rWKc,A[
httpConnection.setRequestProperty("User-Agent","NetFox"); 8<}f:9/
String sProperty = "bytes="+nStartPos+"-"; |7Z7_YWs
httpConnection.setRequestProperty("RANGE",sProperty); (J(JB}[X,
Utility.log(sProperty); 'ojI_%9<
KD9Y
~C6Qp`VF
InputStream input = httpConnection.getInputStream(); ]K'iCYY
//logResponseHead(httpConnection); 6 <JiHVP7
*i#m5f}
\M>}-j`v
byte[] b = new byte[1024]; n5i#GvO^
int nRead; MsMNP[-l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^v.~FFK
{ iJ HOLz"!
nStartPos += fileAccessI.write(b,0,nRead); H~1&hF"d
//if(nThreadID == 1) -g'[1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p!<Y 'G
} wjGD[~mB
1A;>@4iC0
^sxcBG
Utility.log("Thread " + nThreadID + " is over!"); |,c\R"8xS
bDownOver = true; :d7Ju.*J
//nPos = fileAccessI.write (b,0,nRead); Ie(vTP1Cj
} VmM?KlC
catch(Exception e){e.printStackTrace ();} w8M,35b
} F;l*@y Tq
} xh[De}@
5 3=zHYQ
b]s.h8+v;
//打印回应的头信息 :4]^PB@dl
public void logResponseHead(HttpURLConnection con) 8 ;oU{
{ zmk#gk2H
for(int i=1;;i++) sFaboI
{ <%fcs"Mb
String header=con.getHeaderFieldKey(i); 4J3cQ;z
if(header!=null) Op^r}7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $OK}jSH*v)
Utility.log(header+" : "+con.getHeaderField(header)); %lsk>V
else a=3?hVpB
break; B.nq3;Y
} [UN`~
} AZ~=]1
=H&@9=D*
?k)(~Y&@p
public void splitterStop() {Rb|";
{ 2aiZ
bStop = true; yD6lzuk{X
} S<"T:Y&
_h1n]@ d5
KTX;x2r
} NLZTIZCK
uXPvl5(Y?
kWs"v6B
/* ;2X/)sxWz
**FileAccess.java h^#K4/
*//文件访问(定位，写) |` gSkv
package NetFox; ni$7)YcF
import java.io.*; 3#7D g't
w@U`@})r.
NsYeg&>`
public class FileAccessI implements Serializable{ H6Q1r[(B
%,Fx qw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @&!HMl
RandomAccessFile oSavedFile; ,<]X0;~oB
long nPos; z>HeM Mei
N- E)b
Dg](?^
public FileAccessI() throws IOException C]{:>= K
{ r9@4-U7v&
this("",0); xB=~3
} V4Yw"J
h\GlyH~
h?H:r <
public FileAccessI(String sName,long nPos) throws IOException G @ib
{ >W%tEc
oSavedFile = new RandomAccessFile(sName,"rw"); #SiOx/
this.nPos = nPos; B=K&+
oSavedFile.seek(nPos); FbRq h|
} cY1d6P0
*3_@#Uu7
+/,J$(
public synchronized int write(byte[] b,int nStart,int nLen) "_Wv,CYmNr
{ =lIG#{`Q
int n = -1; r@;n \
try{ x5/O.5>f
oSavedFile.write(b,nStart,nLen); )L}6to
n = nLen; 9Tbi_6[
} F)x^AJie
catch(IOException e) <0!/7*;#ZT
{ Ic_>[E?k
e.printStackTrace (); (h;4irfX
} /$v0Rq9
Ik_u34U
8RC7Ei
return n; /DPD,bA
} +[$d9
5e^t;
0zR4Kj7EE
} Z["[^=EP
JY4sB8
H4#|f n
/* f>d aK9$(
**SiteInfoBean.java V> K sbPqR
*/ [0v`E5
package NetFox; 7Ddo^Gtx
9z)p*+rUK
R{zAs?j
public class SiteInfoBean { ,[6N64fy
+m Plid\
md8r"
private String sSiteURL; //Site's URL %hcn|-"F
private String sFilePath; //Saved File's Path oZ%rzLH
private String sFileName; //Saved File's Name XI+m
private int nSplitter; //Count of Splited Downloading File WJ)( *1
E3X6-J|
NbPv>/r
public SiteInfoBean() ZuV/!9qU
{//nSplitter的缺省值为5 e RiPC
//default value of nSplitter is 5 ,A`.u\f(:
this("","","",5); 0"q^`@sZ
} $ekJs/I&
qi!Nv$e
[o]^\ay
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *m_B#~4
{ nqX)+{wAXe
sSiteURL= sURL; nSWW^ ;
sFilePath = sPath; 3\J-=U
sFileName = sName; @k_xA-a
this.nSplitter = nSpiltter; 1_}*aQ
ZMs$C3
$2l<X KT-
} iQryX(z
aYIAy]*1e
SM3Q29XIw
public String getSSiteURL() YcJZG|[
{ # fvt:iE
return sSiteURL; 7]}n0*fe
} \nQV{J
l(;~9u0sa
q'u^v PO
public void setSSiteURL(String value) VFUuG3p)
{ N 2|?I(\B
sSiteURL = value; *_Y{wNF*
} *Mu X]JK
>>}4b2U
".Lwq_
public String getSFilePath() [kfLT::mT
{ }Yd7<"kp
return sFilePath; 7GN>o@t
} O>P792)
7A!E~/nSC
JO\F-xO
public void setSFilePath(String value) 9b KK
{ obYXDj2
sFilePath = value; 2)O-EAn
} pwq a/Yi
&PJ&XTR
Hggp*(AQK
public String getSFileName() yht|0mZV
{ ')ZM# :G
return sFileName; D[d+lq#p
} *;(wtMg
r`? bYoz
U/v }4b
public void setSFileName(String value) N_AAhD
{ SJ/($3GkBd
sFileName = value; v;=F$3
} 6y;R1z b
bUR;d78
O3Jp:.ps
public int getNSplitter() yXg #<H6V
{ Jzqv6A3G
return nSplitter; *AEN
} CxyL'k
4~;x(e@S
@m*^v\q<u
public void setNSplitter(int nCount) rnB-e?>
{ DEmU},<S
nSplitter = nCount; <B,z)c
} p[kEFE,%
} nP9zTa
$w,&h:.p
]xO`c
/* +Usy
**Utility.java nJEm&"AI
*/ Qfx:}zk{
package NetFox; >Q159qZ
~N2<-~=si
_0Mt*]L }
public class Utility { ^SdorPOq&
==$>M d
-ti nL(?3
public Utility() Aqi9@BH
{ ~_XJ v
;xp^FKP
xp+Z%0D
} (`z`ni
. 4$SNzv3V
//线程睡眠 5u(B]_r.
public static void sleep(int nSecond) 8Ja't8
{ D;~c`G "f
try{ 4d\1W?i-
Thread.sleep(nSecond); :%&~/@B
} 'IR2H{Q
catch(Exception e) :i;iSrKy
{ e -sZ_<GH
e.printStackTrace (); gpo+-NnG
} Ebmd[A&&
} (QARle(i
$j ZU(<4,
//日志 7od6`k
public static void log(String sMsg) %hEhZW{:
{ Oy>V/
System.err.println(sMsg); $Tc"7nYu
} W{z7h[?5,
A^:/*
Sb9O#$89
public static void log(int sMsg) bf9LR1
{ "mBX$t'gb
System.err.println(sMsg); "YUh4uZ~P
} Us5P?}
} eiiI Wr_7
]yvHb)X
`%PU_;Y5Q
/* zOV.cI6fZz
**TestMethod.java >^<%9{
*/ DOk(5gR
package NetFox; _]g?3Gw7!
]KsL(4PY
}]i re2j8
public class TestMethod { Sdk:-Zuv
rD7L==Ld
]z^*1^u^ig
public TestMethod() g;|3n&
{ ///xx/weblogic60b2_win.exe U{^~X_?
try{ Iuh1tcc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9ZKB,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yXuc<m
SiteFileFetch fileFetch = new SiteFileFetch(bean); KF'DOXBw>
fileFetch.start(); dZSv=UY)
} 3,Dc}$t
catch(Exception e){e.printStackTrace ();} o.)8A8
#&L[?jEn
xEX"pd
} {6V;$KqH6
aGUKpYF
`i'72\(
public static void main(String[] args) -d|Q|zF^x
{ G;^},%<
new TestMethod(); {$dq7m(
} tEj-c@`"x-
} H%}ro.u
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