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)); Q m*z
} 3>n&u,Xe
for(int i=0;i<nEndPos.length-1;i++) xY?p(>(
{ 'jO2pH/%
nEndPos = nStartPos[i+1]; _N;@jq\q
} +C\79,r
nEndPos[nEndPos.length-1] = nFileLength; e(wc [bv
} (+gTIcc >
} "]jN'N(.
G+#bO5
tD`^qMua
//启动子线程 }Bv1fbD4U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xD*Zcw(vj~
for(int i=0;i<nStartPos.length;i++) oL9<Fi
{ E 14DZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ft7M9<#v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n ^9?(a4u
nStartPos,nEndPos,i); TeuZVy8a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v8F{qT50
fileSplitterFetch.start(); 62nmm/c
} Kz b-a$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !84Lvg0&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yl?LXc[)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q=! lbW
nEndPos = " + nFileLength); > 3x^jh
// fileSplitterFetch[nPos.length-1].start(); $cn8]*Z=
d7BpmM
O-[YU%K3?
//等待子线程结束 F3V:B.C
//int count = 0; }c||$
//是否结束while循环 cAN8'S(s1
boolean breakWhile = false; n',7=~
wmV=GV8 d
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while(!bStop) Q1Qw45$
{ (,sz.
write_nPos(); vE`;1UA}
Utility.sleep(500); cFie;k
breakWhile = true; a1_ N~4r`
N5l`Rq^K
,X|FyO(p
for(int i=0;i<nStartPos.length;i++) @[joM*U
{ rmBzLZ}
if(!fileSplitterFetch.bDownOver) 47Vt8oyh%
{ '`k
breakWhile = false; M &-p
break; K?M~x&Q
} ThP~k9-
} oeKl\cgFx
if(breakWhile) sRLjKi2D
break; Q~"Lyy8
/Q W^v;^
DNj<:Pdd)
//count++; $'}|/D
//if(count>4) zEQQ4)mA
// siteStop(); xBc$qjV
} N6kMl
O<wH+k[
~i?Jg/qcxN
System.err.println("文件下载结束！"); ~tTa[_a!
} Q(x=;wf5r
catch(Exception e){e.printStackTrace ();} ;~ Xjk
} [qxpu{
_[8JSw7
"r;cH53
//获得文件长度 j/O9LygB
public long getFileSize() b"@-9ke5I
{ nzxHd7NIZ
int nFileLength = -1; !p ~.Y+
try{ o9ys$vXt*
URL url = new URL(siteInfoBean.getSSiteURL()); #2\M(5d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -mO<(wfV>
httpConnection.setRequestProperty("User-Agent","NetFox"); x-@?:P*
n9 bp0#K
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int responseCode=httpConnection.getResponseCode(); L})fYVX
if(responseCode>=400) G,6`:l
{ |CQjgI|;
processErrorCode(responseCode); 2N-p97"g
return -2; //-2 represent access is error k^JgCC+
} 902A,*qq
EhD%
cMtUb
String sHeader; QHXpX9
oT:wGBW
SANbg&$
for(int i=1;;i++) CNj |vYj
{ F*z>B >{)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {a>JQW5=
//Utility.log(in.readLine()); #6y fIvap
sHeader=httpConnection.getHeaderFieldKey(i); {?w*n_T.
if(sHeader!=null) Ac*)z#H
{ *XDe:A
if(sHeader.equals("Content-Length")) 9]chv>dO)=
{ q}'<[Wg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \2f?)id~
break; Ozulp(8*
} 3?gfDJfE
} |J-tU)|1vl
else $D^27q:H
break; _MQh<,Z8
} Z5wDf+
} @d5t%V\
catch(IOException e){e.printStackTrace ();} BVv-1$ U^
catch(Exception e){e.printStackTrace ();} b!QRD'31'j
7 mA3&<&q
Rc@lGq9
Utility.log(nFileLength); Z@JTZMN_
:hB6-CZkqN
A[Ce3m
return nFileLength; .ezko\nU
} ndBqXS
*!NW!,R
K^/.v<w
//保存下载信息（文件指针位置） fP;I{AiN~
private void write_nPos() 0ly6 |:
{ (t"|XSF
try{ Vw.4;Zy(
output = new DataOutputStream(new FileOutputStream(tmpFile)); t=fAG,k5
output.writeInt(nStartPos.length); n68qxD-X
for(int i=0;i<nStartPos.length;i++) <g&GIFE,
{ RY,L'GtO
// output.writeLong(nPos); FD8
output.writeLong(fileSplitterFetch.nStartPos); 't\sXN+1
output.writeLong(fileSplitterFetch.nEndPos); pP\^bjI
} ]]u_Mdk
output.close(); C3<_0eI
} w(Mi?
catch(IOException e){e.printStackTrace ();} Nhjz~S<o
catch(Exception e){e.printStackTrace ();} VzM (u_)
} L'a s^Od
*rm[\
|jWA >S
//读取保存的下载信息（文件指针位置） /HSg)
private void read_nPos() DfOigLG*
{ xy)W_~Mk
try{ :W'.SRD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '7]9q#{su
int nCount = input.readInt(); 5"x1Pln
nStartPos = new long[nCount]; obX2/
nEndPos = new long[nCount]; ZE/Aj/7Qy
for(int i=0;i<nStartPos.length;i++) g1UQ6Oa
{ ?a?] LIE8
nStartPos = input.readLong(); aXbj pb+
nEndPos = input.readLong(); hg^klQD
} c)QOgXv
input.close(); .?F`H[^)^u
} 7pH[_]1"
catch(IOException e){e.printStackTrace ();} x;7p75Wm
catch(Exception e){e.printStackTrace ();} 4%>tk 8 [
} ~W gO{@Mw
AUU(fy#<
b Sg]FBaW
private void processErrorCode(int nErrorCode) &3~R-$P
{ (WGEX(|
System.err.println("Error Code : " + nErrorCode); n>lQ:l~
} 2ZxZ2?.uJ
DY87NS*HF
bOlb
//停止文件下载 XOZ@ek)LY
public void siteStop() \7(OFT\u:
{ tgrZs8?
bStop = true; JkNRXC:
for(int i=0;i<nStartPos.length;i++) OH5#.${O
fileSplitterFetch.splitterStop(); u])MI6LF
I\82_t8
2$ \#BG
} (>om.FM
} ZN;fDv
//负责部分文件的抓取 ;Ac!"_N?7
**FileSplitterFetch.java 0te[i*G
*/ $O9#4A;
package NetFox; I]~UOl
i:^ 8zW
*pGbcBQ
import java.io.*; Js,.$t
import java.net.*; `b5pa`\4
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G7HvA46
public class FileSplitterFetch extends Thread { .!1E7\
oPA m*
s.!gsCQme
String sURL; //File URL VC NQ}h[D
long nStartPos; //File Snippet Start Position 4L2TsuLw
long nEndPos; //File Snippet End Position lHgmljn5u
int nThreadID; //Thread's ID L3C'q
boolean bDownOver = false; //Downing is over `[4{]jX+<
boolean bStop = false; //Stop identical z0tm3ovp
FileAccessI fileAccessI = null; //File Access interface ,HW[l.v
eOd'i{f@F
bO gVCg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0 !F!Y_
{ R?kyJ4S
this.sURL = sURL; Qb1hk*$=
this.nStartPos = nStart; #$-`+P
this.nEndPos = nEnd; (DKQHL;
nThreadID = id; iC<qWq|S_m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +r]2.
} hzy#%FaB
4{=^J2z
Cy\! H&0wg
public void run() &o)eRcwH`
{ WS ^%< h#
while(nStartPos < nEndPos && !bStop) ohB@ijC!
{ ncij)7c)u
p w`YMk
3gba~}c)
try{ +C[%^G-:
URL url = new URL(sURL); O>2i)M-h9x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <SNu`,/I
httpConnection.setRequestProperty("User-Agent","NetFox"); (yhnvZ
String sProperty = "bytes="+nStartPos+"-"; MvlqxJ$
httpConnection.setRequestProperty("RANGE",sProperty); oei2$uu
Utility.log(sProperty); #;>v,Jo
]KRw[}z
2xpI|+a%
InputStream input = httpConnection.getInputStream(); |VML.u:N
//logResponseHead(httpConnection); n]P,5
]hi5nA
j|ZhGerp
byte[] b = new byte[1024]; e[L%M:e9U
int nRead; IM~2=+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [Xo[J?w],2
{ eq$.np
nStartPos += fileAccessI.write(b,0,nRead); |Skhx9};
//if(nThreadID == 1) kG3m1: :
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zm/I&
} Gmh6|Dsg
2lRE+_qz
IX 2 dic'
Utility.log("Thread " + nThreadID + " is over!"); =$Sd2UD
bDownOver = true; Q)\4 .d
//nPos = fileAccessI.write (b,0,nRead); p6W|4_a?
} lH1gWe
catch(Exception e){e.printStackTrace ();} _air'XQ&!
} 7,EdJ[CR$
} Ya-kMUW
I=9sTR)
!"QvV6Lq\
//打印回应的头信息 8~8VoU&
public void logResponseHead(HttpURLConnection con) rl](0"Y0 t
{ h_K!ch}
for(int i=1;;i++) y` 6!Vj l
{ phqmr5s^H
String header=con.getHeaderFieldKey(i); L~>~a1p!
if(header!=null) K)F6TvWv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !juh}q&}|
Utility.log(header+" : "+con.getHeaderField(header)); pt=H?{06
else [^2c9K^NK
break; 6ly`lu9
} SK;c D>)
} m>ApN@n
BXB ZX@jVk
#8qhl
public void splitterStop() TnQ"c)ta
{ 6h:2,h pE
bStop = true; nb}rfd.
} B0|!s
;30SnR/
~l"]J'jF"H
} VH7nyqEM
G#nZ%qQ:I
K:(E"d;
/* 2nkymEPu
**FileAccess.java b.|k j
*//文件访问(定位，写) }YCpd)@
package NetFox; ME.a * v
import java.io.*; ZfP$6%;_
^c|_%/
R]<N";-
public class FileAccessI implements Serializable{ kmT5g gy
f O,5 u;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1U6z2i+y
RandomAccessFile oSavedFile; _kXq0~
long nPos; K$/&C:,Q
&$g{i:)Z
;7E c'nC4
public FileAccessI() throws IOException 2xK v;
{ V;29ieE!
this("",0); F(KsB5OY?
} w?:tce
@A'@%Zv-
'M!M$<j
public FileAccessI(String sName,long nPos) throws IOException Lz{z~xNHW.
{ !QSj*)V#
oSavedFile = new RandomAccessFile(sName,"rw"); ^xm%~
this.nPos = nPos; Mqv[7.|
oSavedFile.seek(nPos); h0a|R4J
} D0^h;wJ=4+
/odDJxJ k
*WaqNMD[%
public synchronized int write(byte[] b,int nStart,int nLen) N>xdX5
{ j9xu21'!%
int n = -1; )k.}>0K |
try{ zd|n!3;
oSavedFile.write(b,nStart,nLen); 5y8VA4L/o
n = nLen; c*.-mS~Z`
} @L$!hTaP
catch(IOException e) yQ0:M/r;0
{ G& m~W
e.printStackTrace (); je85G`{DC
} s>*xAIx
<.".,Na(J0
i936+[
return n; V:h7}T95
} N@0cn q:"
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bEm9hFvd
} 8PR\a!"
7@ \:l~{
lHAWZyO
/* ^!fY~(=U4
**SiteInfoBean.java V]NCFG
*/ ^B:;uyG]M
package NetFox; VwOcWKD
JED\"(d(
YD;G+"n?T
public class SiteInfoBean { \@[,UZ
BU#3fPl
3$wK*xK
private String sSiteURL; //Site's URL >L')0<!&
private String sFilePath; //Saved File's Path +pRNrg?k
private String sFileName; //Saved File's Name A `{hKS
private int nSplitter; //Count of Splited Downloading File }OY/0p-Z
X,{ 3_
ALj~e#{;z
public SiteInfoBean() RqX^$C8M
{//nSplitter的缺省值为5 F3hG8YX
//default value of nSplitter is 5 E!_3?:[S_
this("","","",5); #a9O3C/MP
} 5;+KMM:zb
_b$ yohQ
M|NQoQ8q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .$@+ /@4
{ dIfy!B"
sSiteURL= sURL; Y_K W9T_
sFilePath = sPath; m*jTvn
sFileName = sName; Ol~M BQs
this.nSplitter = nSpiltter; l dqU#{
#_{Q&QUk
}R11G9N.
} Z&O6<=bg!
tzthc*-<
jD${ZIv
public String getSSiteURL() inip/&P?V
{ `/^ _W <
return sSiteURL; M*f]d`B
} P?S]Q19Q4
5vg="@O K
sn"z'=ch
public void setSSiteURL(String value) xv&h>GOg
{ oC-v>&bW
sSiteURL = value; yzv"sd[8N
} 1jej7p>K
`nKN|6o#x
^=5x1<a9$
public String getSFilePath() +IO>%
{ Ek1c>s,t
return sFilePath; AgZ?Ry
} GC:q6}
}Ba_epM
em'ADRxG+
public void setSFilePath(String value) <Se9aD
{ \5 rJ
sFilePath = value; M~N/er
} +:"0%(
J>5rkR@/
GbclR:G
public String getSFileName() $dF3@(p
{ G:p85k`
return sFileName; 0Ni{UV? k
} P#7=h:.522
*mVg_Kl
MXa^g"
public void setSFileName(String value) "?.#z]']
{ #=={h?UDT
sFileName = value; 9v[V"m`M
} N!Rt040.%
a eeor
MM_:2 ^P)
public int getNSplitter() +D:8r|evH
{ -rn6ZSD)
return nSplitter; N-]/MB8
} W"^=RY
5|nc^ 12
<l$ d>,
public void setNSplitter(int nCount) X.#)CB0c1Q
{ P6R_W
nSplitter = nCount; RFyMRE!?
} y;uR@{
} 31@Lr[!
c~?Zmdn:
q;")
/* uINdeq7|F
**Utility.java 0'fswa)
*/ :Ys~Lt54
package NetFox; S.)Jp-&K
avL_>7q
=jJEl=*S
public class Utility { C!*.jvhT
\1Xk[%
dniU{v
public Utility() eM:J_>7t
{ Iz5NA0[=2
_BmObXOp.
#5Z`Q^
} X 3$ W60Q
> 'hM"4f
//线程睡眠 6eB;
public static void sleep(int nSecond) 8.#{J&h
{ iBd6&?E?<
try{ %^pi
Thread.sleep(nSecond); XS[L-NHG
} -(8I?{"4i
catch(Exception e) jk{(o09
{ %)x9u$4W2
e.printStackTrace (); <aJQV)]\
} wDZ<UP=X
} 12KC4,C&1i
=d<RgwscJ
//日志 q.VYPkEib
public static void log(String sMsg) (Z SaAn),
{ "|L"C+tE
System.err.println(sMsg); DS<1"4 b|
} a+E&{pV
Ki2!sADd
3/@z4:p0R
public static void log(int sMsg) -f)fiQ-<
{ FT@uZWgQ=
System.err.println(sMsg); _!R$a-
} 15\m.Ix
} ^AS\a4`/
r8J7zTD&
#Ub_m@@4
/* Z[oEW>_A
**TestMethod.java lUm(iYv;H
*/ T)rE#"_]{
package NetFox; L^3&
t'vt'[~,U
0jf6 z-4
public class TestMethod { \ ;npdFy
,vJt!}}
HYmC3
public TestMethod() l%0bF9\
{ ///xx/weblogic60b2_win.exe " B#|C'
try{ Yf w>x[#e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i#]e&Bru5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mm-s?+&M;
SiteFileFetch fileFetch = new SiteFileFetch(bean); RZm%4_p4s
fileFetch.start(); [@vz0!@s5
} NQk aW)
catch(Exception e){e.printStackTrace ();} GiV%Hcx
zTF{ g+
qd*}d)!
} &riGzU]
IOcQI:4.`
8Xotly
public static void main(String[] args) QF#w$%7
{ 3@>F-N
new TestMethod(); BBB@M
} vk& gR
} {LO Pm1K8Y
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