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)); ?-O(EY1E
} ^/HE_keY
for(int i=0;i<nEndPos.length-1;i++) 7581G$@ym
{ RIUJ20PfYQ
nEndPos = nStartPos[i+1]; :yvUHx
} 5:f}bW*
nEndPos[nEndPos.length-1] = nFileLength; 6^zuRY;
} R|{6JsjG10
} ]"^GRFK5
(jCE&'?}
EkV v
//启动子线程 nX>k}&^L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /Mf45U<
for(int i=0;i<nStartPos.length;i++) LiJ;A*
{ io:?JnQSA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gq;0j:?CC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6^['g-\2
nStartPos,nEndPos,i); KhZ'Ic[vw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7,|-%!p[
fileSplitterFetch.start(); KoQvC=+WI
} nF}]W14x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4;|&}Ij
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Arz> P@EQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J?5O2n
nEndPos = " + nFileLength); _'Q}Y nEv
// fileSplitterFetch[nPos.length-1].start(); :$[m[y7i
?S!lX[#v
F1?@tcr'
//等待子线程结束 <4*7HY[
//int count = 0; $$\| 3rj!
//是否结束while循环 0;e>kz3o
boolean breakWhile = false; Cs%'Af
Y&k'4Y%
\J0gzi.
while(!bStop) a+*|P
{ 4MRHz{`wa
write_nPos(); CN: 36
Utility.sleep(500); <s-_ieW'
breakWhile = true; ? Z8_(e0U
av wU)6L
RKIqg4>E
for(int i=0;i<nStartPos.length;i++) WJe
{ sBF}j.b
if(!fileSplitterFetch.bDownOver) ImklM7A
{ yYWGM
breakWhile = false; Lc*i[J<s
break; ^']xkS
} rtf>\j+
} `EU=u_N
if(breakWhile) WABq6q!
break; )1J&tV*U
e|AJxn]
j4H,*fc
//count++; )F]E[sga
//if(count>4) |??uVA)\X
// siteStop(); 5`6@CRef
} 2#6yO`?uo
b)$<aFl
E[2c`XFd8
System.err.println("文件下载结束！"); &OGY?[n
} QS_"fsyN:
catch(Exception e){e.printStackTrace ();} X,x{!
} ^7TM.lE
=wU08}
nd_d tsp#
//获得文件长度 GRO[&;d`
public long getFileSize() OMO.-p
{ u Dm=W36
int nFileLength = -1; &bs/a]?Z7
try{ ?KI_>{
URL url = new URL(siteInfoBean.getSSiteURL()); 6/s#'#jh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R S;r
httpConnection.setRequestProperty("User-Agent","NetFox"); .\{GU9|nO
hXbb+j
N$>g)Ml?
int responseCode=httpConnection.getResponseCode(); vlm&)DIt
if(responseCode>=400) "-A@>*g
{ RjSVa.x
processErrorCode(responseCode); #<4h Y7/
return -2; //-2 represent access is error *Yl9%x]3c
} "J%u !~
<d$|~qS_
LurBqr
String sHeader; q%Obrk
M<~z=B#
~naL1o_FZ
for(int i=1;;i++) ];Bh1
{ yXR$MT+~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^C_Y[i ~|
//Utility.log(in.readLine()); HWFo9as""v
sHeader=httpConnection.getHeaderFieldKey(i); #{UM4~|:
if(sHeader!=null) *hAq]VC})
{ >F!2ib8
if(sHeader.equals("Content-Length")) gG~UsA
{ 4[Hf[.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qL,!
break; f77Jn^Dt
} EFqWnz
} &JtK<g
else -+#\WB{AI
break; <8+.v6DCd
} C:0Ra^i ?L
} DE^{8YX,
catch(IOException e){e.printStackTrace ();} +VI2i~
catch(Exception e){e.printStackTrace ();} vv"_u=H
#l+U(zH:JG
,g6w2y7 ]
Utility.log(nFileLength); $3W[fC
k^S=i_ U
bh3}[O,L A
return nFileLength; u! x9O8y
} ,N?~je.
o[O-|XL_
/F4rbL^:
//保存下载信息（文件指针位置） iaLsIy#h
private void write_nPos() y5RcJM
{ /al(=zf
try{ xCEEv5(5
output = new DataOutputStream(new FileOutputStream(tmpFile)); M0S}-eXc5
output.writeInt(nStartPos.length); (w-z~#<
for(int i=0;i<nStartPos.length;i++) o(u&n3Q'
{ 4=%Uv^M
// output.writeLong(nPos); (UAa
output.writeLong(fileSplitterFetch.nStartPos); m3+MRy5
output.writeLong(fileSplitterFetch.nEndPos); V&eti2&zO
} B=jJ+R
output.close(); .Xc, Gq{
} 6p1\#6#@
catch(IOException e){e.printStackTrace ();} =%%\b_\L
catch(Exception e){e.printStackTrace ();} |Z0?
} |ITp$_S
hJ (Q^Z
S1E=E5
//读取保存的下载信息（文件指针位置） _*>bf G
private void read_nPos() _[<R<&jG
{ |h\e(_G\
try{ 'nz;|6uC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1`^l8V(
int nCount = input.readInt(); d(3F:dbk
nStartPos = new long[nCount]; =;W"Pi;*
nEndPos = new long[nCount]; v~H1Il_+
for(int i=0;i<nStartPos.length;i++) '_lyoVP
{ 1XSA3;ZEc
nStartPos = input.readLong(); XZEawJ0
nEndPos = input.readLong(); "o2p|2c
} GpMKOjVm|
input.close(); `MAee8u'
} HgvgO\`]
catch(IOException e){e.printStackTrace ();} gbsRf&4h
catch(Exception e){e.printStackTrace ();} @zL)R b%P$
} ! @{rkp
"w9LQ=mW
vIF=kKl9,
private void processErrorCode(int nErrorCode) Sf);j0G,D
{ )@09Y_9r
System.err.println("Error Code : " + nErrorCode); F[<EXLQ
} Y9Q-<~\z
SpPG
,24NMv7
//停止文件下载 zlF*F8>m
public void siteStop() ([R}s/)$
{ 1+~JGY#
bStop = true; bZHuEh2w
for(int i=0;i<nStartPos.length;i++) 8c(}*,O/
fileSplitterFetch.splitterStop(); bW(+Aw=O
,d(F|5M:
M$DJ$G|Z
} {hGr`Rh
} +c.A|!-
//负责部分文件的抓取 l=8)_z;~D
**FileSplitterFetch.java 9uV/G7Geq
*/ *:J#[ET,
package NetFox; xphw0Es
Q/m))!ikMt
7}OzTup
import java.io.*; %_0,z`f
import java.net.*; k_/hgO
{_0Efc=7
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public class FileSplitterFetch extends Thread { JZQkr
] e!CH <N
'@>FtF[Gu
String sURL; //File URL Rp `JF}~o
long nStartPos; //File Snippet Start Position "D}PbT[V
long nEndPos; //File Snippet End Position a\S"d
int nThreadID; //Thread's ID DQ :w9
boolean bDownOver = false; //Downing is over )f-ux5
boolean bStop = false; //Stop identical jCDZ$W89
FileAccessI fileAccessI = null; //File Access interface >^LVj[.1
D M(WYL{
_P 0,UgZz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F,Y@
{ +Mc kR
this.sURL = sURL; vpcHJ^19
this.nStartPos = nStart; rUEoz|e4a
this.nEndPos = nEnd; ^"7tfo8
nThreadID = id; daf$`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -ZFeE[Z
} ("0@_05OH
dya]^L}fL
T=35?
public void run() 9w'3d@
{ xoF]r$sC8
while(nStartPos < nEndPos && !bStop) -fw0bL%0
{ h>-JXuN
4r;!b;3
}M'h5x
try{ q$z#+2u
URL url = new URL(sURL); #gq4%;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RBIf6oxdE
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 *IF
String sProperty = "bytes="+nStartPos+"-"; OLJb8kO
httpConnection.setRequestProperty("RANGE",sProperty); K-IXAdx
Utility.log(sProperty); ;v'7l>w3\w
hYMIe]kJ
;<`F[V Zau
InputStream input = httpConnection.getInputStream(); I'2:>44>I6
//logResponseHead(httpConnection); =A={Dpv[>
C`+g:qT
pA%XqG*=Y
byte[] b = new byte[1024]; <9 lZ%j;
int nRead; $3S6{"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j89|hG)2
{ tRRPNY
nStartPos += fileAccessI.write(b,0,nRead); kKVd4B[#*
//if(nThreadID == 1) %[\: 8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T0s7aw[zm
} F+,X%$A#?
Kdh(vNB>
TJ[C,ic=D
Utility.log("Thread " + nThreadID + " is over!"); Y,RED5]t
bDownOver = true; }3:DJ(Y
//nPos = fileAccessI.write (b,0,nRead); *#1&IJPI
} >C y
catch(Exception e){e.printStackTrace ();} 0l3v>ty
} 9;2PoW8
} jT"P$0sJAd
WXu:mv,'e
eT1b88_
//打印回应的头信息 `}.K@17
public void logResponseHead(HttpURLConnection con) h=SQ]nV{
{ }[}u5T`w>
for(int i=1;;i++) m6^Ua
{ @*q WV*$h
String header=con.getHeaderFieldKey(i); v'Ce|.;
if(header!=null) *F*c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D5fJuT-bp
Utility.log(header+" : "+con.getHeaderField(header)); W/ZmG]sZE
else H=])o21
break; !R;P"%PHV
} '#$Y:/
} C\Q3vG
jcHs!
<J-bDcp
public void splitterStop() 6TJ5G8z_
{ &B^#?vmO
bStop = true; <GPL8D
} ~R/w~Kc!/A
$V-]DD%Y
r_p9YS@I
} r9z_8#cR
6~zR(HzV{
}HtP8F8!x
/* w{k8Y?
**FileAccess.java 5,`U3na,
*//文件访问(定位，写) EJ{Z0R{{
package NetFox; Ze~$by|9f
import java.io.*; B+S &vV
kB1]_v/
DfwxPt#
public class FileAccessI implements Serializable{ (1H_V(
9\i;zpN\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q"ba~@<BEl
RandomAccessFile oSavedFile; KK4>8zGR
long nPos; 1rh\X[@
Onb*nm
hh<5?1
public FileAccessI() throws IOException +*'
{ J XKps#,(#
this("",0); _?>!Bz m
} (1JZuR<?c
3lH#+@
7vUfA"
public FileAccessI(String sName,long nPos) throws IOException c_clpMx=
{ v'i"Q
oSavedFile = new RandomAccessFile(sName,"rw"); w,TyV%b[_
this.nPos = nPos; !+Z"7e nj
oSavedFile.seek(nPos); ANtp7ad
} X<@ytHBv
6GX'&z
N[X%tf\L]F
public synchronized int write(byte[] b,int nStart,int nLen) rg+28tlDn
{ S!.aBAW
int n = -1; #n%?}
try{ nN>D=a"&F
oSavedFile.write(b,nStart,nLen); 1Lz`.%k`:
n = nLen; o/buU{)y
} zOYkkQE3mJ
catch(IOException e) F48:mfj1r
{ G}ElQD
e.printStackTrace (); |57KTiiNLI
} /{YUM~
>0)E\_ u
@v_E' 9QG^
return n; w8:F^{
} 5~k-c Ua
:}x\&]uC#k
i,rP/A^q
} Y<TlvB)w
ONJW*!(
X@Eq5s
/* ,{ CgOz+Ul
**SiteInfoBean.java VOwt2&mZ
*/ ?2[=llS4
package NetFox; fOiLb.BW
T~8`{^
AbUU#C7
public class SiteInfoBean { 8OH<ppi
ASY uZ
6CO>Tg:%
private String sSiteURL; //Site's URL KIn^,d0H
private String sFilePath; //Saved File's Path y$s}-O]/-
private String sFileName; //Saved File's Name L`FsK64@
private int nSplitter; //Count of Splited Downloading File M['25[
<y'B !d#
jjBcoQU$o
public SiteInfoBean() gXI_S9z
{//nSplitter的缺省值为5 v}A] R9TY
//default value of nSplitter is 5 d hiLv_/
this("","","",5); yd"|HHx
} $m:}{:LDCf
U#G uB&V
S1uW`zQ!+_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *7oPM5J|v
{ mkYM/*qyM&
sSiteURL= sURL; I'"*#QOX
sFilePath = sPath; ar+mj=m
sFileName = sName; 9bgKu6-X
this.nSplitter = nSpiltter; C yC<{D+
FMY r6/I
oV?tp4&
} ~cSC-|$^&
!Y=s_)X
C fQj7{
public String getSSiteURL() +f\tqucI3
{ Zm%}AzM
return sSiteURL; e;x`C
} GW'=/ z7
6v GcM3M
Xfx(X4$9
public void setSSiteURL(String value) }@@1N3nnxV
{ H:U1#bQQ:
sSiteURL = value; ;G!X?(%+
} meR%);\
v|_?qBs"
X X{:$f+
public String getSFilePath() 2t1WbP1
{ v0X5`VV
return sFilePath; IaE};8a8
} OW)8Z60
aO "JT
6BW-AZc
public void setSFilePath(String value) |F<U;xV$p
{ }n=Tw92g
sFilePath = value; .)|jBC8|}
} Y8.0R-:ZAN
$>/J8iB
%P_\7YBC>
public String getSFileName() 'Twi @I
{ C,]Q/6'>
return sFileName; qTqvEa^X`
} N<Bi.\XC
dcU|y%k%
'BAe>r_Pn
public void setSFileName(String value) po=*%Zs*T
{ >~BU<#
sFileName = value; F xFK
} K!|=)G3.`
ehxtNjA
;oh88,*'
public int getNSplitter() Q C~~
{ "4g1I<
return nSplitter; 1{o CMq/v
} -#<,i'
z-7F,$
P%Q}R[Q
public void setNSplitter(int nCount) i=o>Bl@f
{ 2_r}4)z
nSplitter = nCount; NWCnt,FlY
} l[ @\!;|
} ,)]ZD H
ys+?+dY2
#l;Ekjfz
/* 6ap,XFRMh
**Utility.java z@~1e]%
*/ <]wN/B-8J
package NetFox; /unOZVr(
Q2rZMK
m 7 Fz&bN
public class Utility { )QBsyN<x6
*tRJ=
"45BOw&72G
public Utility() u8o7J(aQsR
{ 9\Xl3j!
3M1(an\nW
e1<28g
} "a,Tc2xk
Y%=A>~s*c:
//线程睡眠 WR'A%"qBwi
public static void sleep(int nSecond) 'c &Bmd40
{ +bRL.xY
try{ =PZs'K
Thread.sleep(nSecond); gLpWfT29V
} oAvJ"JH@i
catch(Exception e) oR-_=U^
{ t9K.Jc0
e.printStackTrace (); zv0RrF^
} 2tWUBt\,g
} H>DJ-lG(
N_gjOE`x5
//日志 (Nik(Oyj"
public static void log(String sMsg) 40g&zU-
{ l}O`cC
System.err.println(sMsg); 3\(s=-vh
} /itO xrA
.}Zmqz[
`Z@wWs
public static void log(int sMsg) ,E>VYkoA
{ ;m`I}h<
System.err.println(sMsg); }kOhwT8sI
} klch!m=d
} J25>t^
(nE$};c<b2
CJu;X[6
/* fA3
**TestMethod.java yS3x))
*/ Sl$dXB@
package NetFox; \C<rg|
}`_2fJ6
"lz!'~im
public class TestMethod { yTDoS|B+)
"(C}Dn#
e<C5}#wt
public TestMethod() /FYa{.Vlr
{ ///xx/weblogic60b2_win.exe qp{NRNkQ
try{ ;3?M?E/$s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RK'( {1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r{<u\>6X>P
SiteFileFetch fileFetch = new SiteFileFetch(bean); #%{\59/w
fileFetch.start(); 9J|YP}%
} G2jEwi
catch(Exception e){e.printStackTrace ();} 71)#'ey
t]@Zd*
yNDyh
} @+{S-iD"
uY;/3?k&
/kJ*WA?J
public static void main(String[] args) a)TNVm^
{ VJ$C)0xQA
new TestMethod(); gai?LXM l}
} #Se
} /=3g-$o{`
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