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)); 8sOQ9
} -ijC_`>
for(int i=0;i<nEndPos.length-1;i++) 6'vbT~S!
{ .; Q:p*
nEndPos = nStartPos[i+1]; `3cCH
} uLR<FpM
nEndPos[nEndPos.length-1] = nFileLength; 5's~>up&
} 6%Mt
} r! %;R?c
?C-Towo=i
78 f$6J q
//启动子线程 kz}R[7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U7h(`b
for(int i=0;i<nStartPos.length;i++) 3gEMRy*+
{ 9=`Wp6Gmn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bulS&dAX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YJeyIYCs<
nStartPos,nEndPos,i); #5} wuj%5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YJV%a
fileSplitterFetch.start(); .a'f|c6
} 7gF"=7{-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xf[kI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^teq[l$;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6%G-Vs]*2
nEndPos = " + nFileLength); ~`ny@WD9
// fileSplitterFetch[nPos.length-1].start(); > L2HET
_}xd}QW
I:cg}JZ>|
//等待子线程结束 Yf@e=:
//int count = 0; L{-LX=G^
//是否结束while循环 =c.5874A`
boolean breakWhile = false; W/$Zvl
QS[L~97m2M
$'rG-g!f\
while(!bStop) =FP0\cQ.
{ 4GdX/6C.
write_nPos(); 58Xzup_"
Utility.sleep(500); NoE*/!Sr
breakWhile = true; ia@'%8
*cuuzi&
E H:T
for(int i=0;i<nStartPos.length;i++) \y`+B*\i
{ 8.AR.o
if(!fileSplitterFetch.bDownOver) kRCQv-*
{ D\dWt1n
breakWhile = false; b;sVls
break; F,BOgWwP
} 'xY@x-o
} !E8X~DJ
if(breakWhile) Yb3mP!3q8Z
break; GzXUU@p
N["W Ir
nAIo{ F
//count++; *g}Yw
//if(count>4) YHkcWz
// siteStop(); GPz(j'jU
} JF&$t}
K.<.cJE
i9<pqQ
System.err.println("文件下载结束！"); Q_-_^J
} JxE53ev
catch(Exception e){e.printStackTrace ();} y$FW$Ka
} fWfk[(M'9
2WX7nK;I
TxjYrzC
//获得文件长度 nRL. ppUI
public long getFileSize() 6tHO!`}1
{ M5nWVK7c
int nFileLength = -1; )c n+1R
try{ Qd}m`YW-f$
URL url = new URL(siteInfoBean.getSSiteURL()); )a9 ]US^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DI+]D~N
httpConnection.setRequestProperty("User-Agent","NetFox"); d@`M CchCB
JWvjWY2+P
wN1niR'
int responseCode=httpConnection.getResponseCode(); |8>3`w!
if(responseCode>=400) dI&!e#Y
{ j`^$#
processErrorCode(responseCode); IG)s^bP
return -2; //-2 represent access is error QO;N9ZI
} zJP6F.Ov!
@k[R/,#'[t
b2aF 'y/
String sHeader; EVp,Q"V]
`>0MNmu
B`*ZsS=R-
for(int i=1;;i++) 5;0g!&-t#
{ 5^']+5_vb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *.L81er5~
//Utility.log(in.readLine()); eSWLrryY
sHeader=httpConnection.getHeaderFieldKey(i); /|#&px)G
if(sHeader!=null) 7+X:LA~U
{ Ox#\M0Wn$3
if(sHeader.equals("Content-Length")) |f~@8|MQP+
{ ~\{^%~[48
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *Qugv^-
break; ~gB>) ]
} 5N%93{L
} hxCvk/7sT
else }|PY!O
break; /}Jj
} >e\9Bf_
} 3a.kBzus
catch(IOException e){e.printStackTrace ();} :Y9NLbv
catch(Exception e){e.printStackTrace ();} f$NMM >z
NR;1z
ml\4xp,
Utility.log(nFileLength); G}&Sle]
:'#TCDlOb
afYc\-"
return nFileLength; ylt`*|$
} 0a-:<zm
626Z5Afg
sB;@>NY
//保存下载信息（文件指针位置） Cvn#=6V3
private void write_nPos() h/~n\0,J/
{ A&nU]R8S
try{ gy&[?m6M=
output = new DataOutputStream(new FileOutputStream(tmpFile)); W5SJ^,d)J
output.writeInt(nStartPos.length); |V<h=D5W
for(int i=0;i<nStartPos.length;i++) J_s>N
{ <.Nx[!'~&d
// output.writeLong(nPos); G:zua`u[
output.writeLong(fileSplitterFetch.nStartPos); Me 5_4H&Sg
output.writeLong(fileSplitterFetch.nEndPos); &|/| ''A)
} 0GJn_@hr
output.close(); 3B1cb[2y
} 'fW6 .0fXa
catch(IOException e){e.printStackTrace ();} FQ=@mjh
catch(Exception e){e.printStackTrace ();} ]('D^Ro
} eImn+_ N3
0v9rv.Y"
HttiX/2~
//读取保存的下载信息（文件指针位置） lP<:tR~K
private void read_nPos() '` pDngX
{ <~ Sz04
try{ 7)s^8+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *zr(Zv
int nCount = input.readInt(); r$2P;Cxj
nStartPos = new long[nCount]; ">#wOm+ +
nEndPos = new long[nCount]; cReB~wk
for(int i=0;i<nStartPos.length;i++) Mbb x`
{ 33!oS&L
nStartPos = input.readLong(); o7|eMe?<t
nEndPos = input.readLong(); ]xuG&O"SBV
} trAkcYd
input.close(); <:?r:fQX
} OF\rgz
catch(IOException e){e.printStackTrace ();} H,b5C_D29
catch(Exception e){e.printStackTrace ();} @|\}.M<e*)
} jYe'V#5S#
U"Zmv
O} f80K
private void processErrorCode(int nErrorCode) ?Wz8[u
{ eopD5
System.err.println("Error Code : " + nErrorCode); L'F<ev
} V{JAB]?^
6L)%T02C
s0PrbL%_`
//停止文件下载 R)c'#St
public void siteStop() gvLf|+m
{ nw-I|PVTNa
bStop = true; P>Ez'C
for(int i=0;i<nStartPos.length;i++) J>\B`E
fileSplitterFetch.splitterStop(); 92EWIHEWZ
t^w"w`v\u
p\bDY
} ~$~5qwl
} utIX %0
//负责部分文件的抓取 Nqu>6^-z0
**FileSplitterFetch.java }K&7%N4LZ
*/ e d<n9R
package NetFox; ]w.;4`l*
qzTuxo0B
9]@A]p!
import java.io.*; d+'p@!W_
import java.net.*; bFW=ylF9
@7B$Yy#
.C--gQpIv
public class FileSplitterFetch extends Thread { /Z$&pqs!
>/8yGBD
dxmE3*b`
String sURL; //File URL !_"fP:T>
long nStartPos; //File Snippet Start Position Y*UA,<-
long nEndPos; //File Snippet End Position q}]XYys
int nThreadID; //Thread's ID UXh9:T'%
boolean bDownOver = false; //Downing is over `DC2gJKk%
boolean bStop = false; //Stop identical )Q.>rX,F
FileAccessI fileAccessI = null; //File Access interface 5=Di<!a;
h-%R<[
CO`_^7o9(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :3I@(k\PY
{ #Y4=J 6
this.sURL = sURL; o|$AyS{1
this.nStartPos = nStart; :$n=$C-wp
this.nEndPos = nEnd; kOed ]>H
nThreadID = id; (JM5`XwM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9o+)?1\
} !7kG!)40
(_"*NY0
,]d,-)KX8
public void run() gntxNp[9T
{ 3de_V|%
while(nStartPos < nEndPos && !bStop) /bi}'H+#
{ I= &stsH
PBp^|t]E>
q,+yqrt
try{ eN^qG 42
URL url = new URL(sURL); GgB,tam{p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?W)A
httpConnection.setRequestProperty("User-Agent","NetFox"); xLC3>>P
String sProperty = "bytes="+nStartPos+"-"; 6E^.7%3
httpConnection.setRequestProperty("RANGE",sProperty); K|Di1)7=/
Utility.log(sProperty); oomT)gO 6*
Gy6l<:;
} x2DT8u
InputStream input = httpConnection.getInputStream(); ]4pkcV P
//logResponseHead(httpConnection); EUxGAj$-
@g&ct>@y
c|#8T*`C
byte[] b = new byte[1024]; m5r7
int nRead; N9v1[~ bv_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]VD|xm:kj
{ nuw70*ell
nStartPos += fileAccessI.write(b,0,nRead); W#hj 1
//if(nThreadID == 1) i~{Ufi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ekWePL;rR2
} f>N!wgo[
CL+}|7O(
#N`~xZ|$
Utility.log("Thread " + nThreadID + " is over!"); =_:et0
bDownOver = true; =Xqc]5[i
//nPos = fileAccessI.write (b,0,nRead); IyWI5Q"t
} ])nPPf
catch(Exception e){e.printStackTrace ();} !K'}K>iT
} o !vE~
} rv|)n>m
]{ntt}3G,
50o~ P!Lz|
//打印回应的头信息 Uk6HQQ
public void logResponseHead(HttpURLConnection con) x;8A!8w
{ AD|2qM))
for(int i=1;;i++) ~x]jB
{ 70eb]\%
String header=con.getHeaderFieldKey(i); R~S;sJ& c
if(header!=null) &FF"nE*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [rSR:V?"a
Utility.log(header+" : "+con.getHeaderField(header)); \Ol kM<
else _tYx~J2.Q
break; BS:+~|3w
} 7eV di*
} ;e1ku|>$
U 15H2-`
<|SRe6m
public void splitterStop() b)e *$)
{ [O?z@)dx
bStop = true; 5nKj )RH7M
} xo&]$W8
BEre*J
]hFW73FV
} hMykf4
v#U"pn|M
W7 #9jo
/* i:OK8Q{VI
**FileAccess.java a-|*?{o
*//文件访问(定位，写) Aj+2;]M
package NetFox; iqe%=%ZR
import java.io.*; V4KMOYqm
4*Hgv:0?kI
Q|D @Yd\
public class FileAccessI implements Serializable{ IVAmV!.z
=AEBeiz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?B}{GL2)
RandomAccessFile oSavedFile; $h*L=t(
long nPos; 8n*.).33
<w)r`D6
U'<KC"f:'!
public FileAccessI() throws IOException /Sc l#4bW
{ 'lEA)&d
this("",0); fvdU`*|n)
} B(n{e53 9f
hHT_V2*
z$?~Y(EY
public FileAccessI(String sName,long nPos) throws IOException f]\CD<g3|E
{ <U!`J[n%
oSavedFile = new RandomAccessFile(sName,"rw"); 4Za7^c.
this.nPos = nPos; 8&)DE@W
oSavedFile.seek(nPos); w-t8C=Z
} xT+zU}z
,I%g|'2
+i@y@<l:+
public synchronized int write(byte[] b,int nStart,int nLen) 4Dw@r{
{ mg$]QnbAnH
int n = -1; `CgaS#
try{ aD=A^ktx
oSavedFile.write(b,nStart,nLen); SU/BQ3
n = nLen; *rIk:FehLB
} '>' wK.
catch(IOException e) 5sx1Zq7
{ vM*($qpAy
e.printStackTrace (); q@nP}Pv&5
} ~e+\k>^eN
>U]C/P[+
(3{YM(
return n; c0;t4( &8
} 'VlDh`<W
4:dH]
q&W[j5E
} (}EB2V9Hh
L.jh
XbD4:i%
/* ^`)) C;
**SiteInfoBean.java PGLplXb#[S
*/ ~s]iy9i
package NetFox; 8p@Piy{p
2E)wpgUc?e
dVi!Q@y+
public class SiteInfoBean { jO1r)hw N>
(tZrw5@
/.o^R6
private String sSiteURL; //Site's URL .2v_H5<
private String sFilePath; //Saved File's Path *U]V@;XF
private String sFileName; //Saved File's Name ^wc"&;=c|
private int nSplitter; //Count of Splited Downloading File EuyXgK>g
OG~6L4"
<F`>,Pm
public SiteInfoBean() G}:lzOlMH
{//nSplitter的缺省值为5 m6[0Kws&
//default value of nSplitter is 5 Od%"B\
this("","","",5); O0pDd4)"
} ^ml'?
#7q7PYG4
2gq9k}38
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @]-jl}:]
{ @++.FEf
sSiteURL= sURL; 1M 781
sFilePath = sPath; ZGYr$C~
sFileName = sName; O2f-5Y$@
this.nSplitter = nSpiltter; Ft;^g3N
f'VX Y-
i-6F:\;
} qCqFy#Ms\
|(q9"
0^RXGN
public String getSSiteURL() h >s!K9
{ BC&9fr
return sSiteURL; 8_tK4PwP
} I^8"{J.Q)[
% <qw
t`,`6@d
public void setSSiteURL(String value) aW`Lec{.
{ c;n *AK
sSiteURL = value; '-"/ =j&d[
} D(H>R&b!
oze&
~?FpU
public String getSFilePath() Ju :CMkv
{ s!}ne"&0
return sFilePath; KNLfp1!
} nEkR1^30
86mp=6@
Yo("U8:XX
public void setSFilePath(String value) Vy938qX
{ OC<5E121>Y
sFilePath = value; .P MZX%*v
} J1:1B,^y
1PP $XJtyD
~ ArP9 K"
public String getSFileName() cQ"~\
{ }C>{uXv
return sFileName; _oUHJ~&,
} (Yis:%c\!
qycI(5S,
dOoKLry
public void setSFileName(String value) Jh?dw3Ai^
{ rjPL+T_
sFileName = value; X6mqi;+
} qQsku;C?i
4@ML3d/
frT]5?{
public int getNSplitter() S&\L-@
{ .b-f9qc=
return nSplitter; ##V5-ZG{:
} tP2qK_\e=
YA +E\
h}cy D7Wn
public void setNSplitter(int nCount) N0=ac5
{ m$W <
nSplitter = nCount; S!3S4:]B^
} NZ-\h
} p-zXpK"
[vHv0"
/Ya_>+oo
/* NCk r /#!
**Utility.java =UJ:tSr
*/ (v}>tb*#`
package NetFox; NX/;+{
:h&fbBH
kLni{IYN7
public class Utility { j/nWb`#y
)p~BQ~eip;
l:<?{)N`
public Utility() [-;_ZFS{
{ JNa"8
72Iy^Y[MX
"Za>ZRR
} k=B]&F
n1&% e6XhO
//线程睡眠 S<WdZ=8sA
public static void sleep(int nSecond) SOi*SwQ8
{ oNU0 qZ5
try{ tdSfi<y5I
Thread.sleep(nSecond); Ar:*oiU
} jp"JafS/E
catch(Exception e) L?Qg#YSd~
{ ( |PAx(
e.printStackTrace (); \CXQo4P
} 3`B6w$z>(
} n;$5Cq!v=
?kZTI (
//日志 {FIXc^m'
public static void log(String sMsg) %QKRFPYhS
{ 00SbH$SU
System.err.println(sMsg); 1}:bqI.<W
} _:-ha?W$;y
LX@/RAd vz
'`XX "_k3
public static void log(int sMsg) )d$glI+
{ HN.3
System.err.println(sMsg); u\LFlX0sO
} q|v(Edt|_[
} %9M~f*
0LfU=X0#7
&znQ;NH#
/* KA){''>8
**TestMethod.java & M~`:R
*/ \yd s5g!:
package NetFox; yfx7{naKC`
e|p$d:#!
USVqB\#
public class TestMethod { KTn}w:+B\
mN>h5G>a
~d%Pnw|
public TestMethod() E7CH^]x
{ ///xx/weblogic60b2_win.exe Tjl:|F8
try{ 8&Oa_{1+Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nD)K}4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .GsO.#p{
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;B?DfWX
fileFetch.start(); \L(*]:EP
} #DN0T' B
catch(Exception e){e.printStackTrace ();} 9uer(}WKT
cu%C"
H]$)Eg%6
} gx&Tt
#%D_Y33;
t: IN,Kl4
public static void main(String[] args) FRS>KO=3
{ {2+L@
new TestMethod(); Mnz!nWhk
} #ssN027
} g q}I[N
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