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)); Z)~2{)
} _JS'~JO3{
for(int i=0;i<nEndPos.length-1;i++) $9/r*@bu8d
{ $}@ll^
nEndPos = nStartPos[i+1]; Yc}b&
} \T?O.
nEndPos[nEndPos.length-1] = nFileLength; ;Xns9
} tti.-
} $6N.ykJ
+]X^bB[
p*Cbe\
//启动子线程 U<x3=P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RD^o&VXO
for(int i=0;i<nStartPos.length;i++) 2#!D"F
{ 3h&s=e!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z)<>d.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <_~`)t
nStartPos,nEndPos,i); cl:YN]BK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &x3y.}1
fileSplitterFetch.start(); 'Tn$lh
} ]So%/rOvX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qa=;Elp:[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); })Jp5vv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _]g6 3q
nEndPos = " + nFileLength); :n=+$Dq
// fileSplitterFetch[nPos.length-1].start(); R0>L[1o
'@FKgy;B)-
BshS@"8r
//等待子线程结束 XcXd7e
//int count = 0; 8Vx'sJ>r4
//是否结束while循环 R=l/EK
boolean breakWhile = false; .gB*Y!c7
9ccEF6o0=
VCIG+Gz
while(!bStop) DIY WFVh
{ YG_3@`-<
write_nPos(); 4s~o
Utility.sleep(500); 97lwPjq
breakWhile = true; :3k(=^%G!
JW$#~"@r
BmZd,}{
for(int i=0;i<nStartPos.length;i++) <M=K!k
{ $d'Gh2IGA
if(!fileSplitterFetch.bDownOver) <_+8c{G
{ BN=,>-O%
breakWhile = false; PQ j_j#0
break; \K=Jd#9c
} &Z?uK,8
} OtJS5A
if(breakWhile) W;1Hyk
break; CzgLgh;:T
0R.@\?bhL
+ad 2
//count++; 2IGAZ%%
//if(count>4) plca`
// siteStop(); 4H'9y3dk
} WVVqH_
+XsY*$O
B,676~I
System.err.println("文件下载结束！"); Wl1%BN0>
} z~F!zigNAc
catch(Exception e){e.printStackTrace ();} `'~|DG}a
} /)|*Vzu
GB0] |z5
[mhY_Hmz]
//获得文件长度 oD.f/hi0|
public long getFileSize() Fw|5A"9'a'
{ iS"rMgq
int nFileLength = -1; x`$4
try{ U7OW)tUf
URL url = new URL(siteInfoBean.getSSiteURL()); ~ 60J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )Aj~ xA
httpConnection.setRequestProperty("User-Agent","NetFox"); 9s}--_k?F2
5)}xqE"x
:Z<-J`
int responseCode=httpConnection.getResponseCode(); jYU#] |k~
if(responseCode>=400) VB Ce=<
{ yCwQ0|
processErrorCode(responseCode); | #,b1|af
return -2; //-2 represent access is error +!X^E9ra
} sGV%O=9?2
GDk/85cv0$
X{)M}WO+r
String sHeader; ydpsPU?wj5
SgJQH7N
[;c#LJ/y
for(int i=1;;i++) [Ga9^e$Zv
{ vJYy`k^Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jvW/M.q4
//Utility.log(in.readLine()); Od!j+.OY<
sHeader=httpConnection.getHeaderFieldKey(i); ;yH/GN#O
if(sHeader!=null) DJeG
{ b.$Gc!g
if(sHeader.equals("Content-Length")) =!7yX;|
{ {1FYHM^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vHWw*gg(/E
break; x ha!.&DO
} .*8.{n5
} |[gnWNdR$M
else |g@1qXO3
break; MLUq"f~N
} 1<lLE1fk
} Nj?,'?'O}
catch(IOException e){e.printStackTrace ();} <#:"vnm$j
catch(Exception e){e.printStackTrace ();} Y1+f(Q
WO]dWO6Mm
__)9JF
Utility.log(nFileLength); <MY_{o8d
x}-rAr
07CGHAxJ`
return nFileLength; o#G7gzw)
} &}rh+z
HdVGkv/
vQztD_bX%
//保存下载信息（文件指针位置） )PZ'{S
private void write_nPos() \s[Uq
{ k0%4&pU
try{ UAa2oY&
output = new DataOutputStream(new FileOutputStream(tmpFile)); \07 s'W U
output.writeInt(nStartPos.length); lepgmQ|oY
for(int i=0;i<nStartPos.length;i++) >pr{)bp G
{ X=-pNwO
// output.writeLong(nPos); 7|\[ipVX:3
output.writeLong(fileSplitterFetch.nStartPos); 7x`uGmp1
output.writeLong(fileSplitterFetch.nEndPos); ]ZZ7j
} BB9Z?}
output.close(); 4u A;--j
} /8lGP!z
catch(IOException e){e.printStackTrace ();} &`{%0r[UD#
catch(Exception e){e.printStackTrace ();} W&)OiZN
} T5o9pmD
W%) foJ
RytQNwv3
//读取保存的下载信息（文件指针位置） !\^c9Pg|v
private void read_nPos() db4Ol=
{ J=5G<
try{ UEt#;e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x-Yt@}6mvl
int nCount = input.readInt(); 9w(QM-u
nStartPos = new long[nCount]; KR#Bj?fz-H
nEndPos = new long[nCount]; p<tj6O
for(int i=0;i<nStartPos.length;i++) yin"+&<T
{ TAIcp*)ZM
nStartPos = input.readLong(); {^5r5GB=*
nEndPos = input.readLong(); |v:8^C7
} i e%ZX
input.close(); $D1Pk
} *[k7KG2_U
catch(IOException e){e.printStackTrace ();} _"Y;E
catch(Exception e){e.printStackTrace ();} (WX,&`a<$
} dyD=R
I"y=A7Nq
Y<I/y
private void processErrorCode(int nErrorCode) t :sKvJ
{ hBOI:4u[
System.err.println("Error Code : " + nErrorCode); &K|<7Efx
} oe# :EfT
8}nA8J
}r9f}yX9Q
//停止文件下载 fo^M`a!va0
public void siteStop() _z#zF[%
{ 77.5 _
bStop = true; 79z(n[^
for(int i=0;i<nStartPos.length;i++) RV.*_FG
fileSplitterFetch.splitterStop(); 52,pCyU
wqK>=Ri_
[-=PK\ B
} Rq<T2}K
} eZk [6H
//负责部分文件的抓取 Atzp\oO
**FileSplitterFetch.java dq[j.Nmq
*/ JY~s-jxa
package NetFox; /)e&4.6
x?VX,9;j
&S]\)&Yt
import java.io.*; ;a[56W
import java.net.*; 2(Vm0E
fYl$$.
A!x_R {,yH
public class FileSplitterFetch extends Thread { NyFa2Ihd
pg;agtI
ehoDWO]S
String sURL; //File URL TY],H=
long nStartPos; //File Snippet Start Position Nj@k|_1
long nEndPos; //File Snippet End Position 8yF15['
int nThreadID; //Thread's ID Q+[gGe JUF
boolean bDownOver = false; //Downing is over z+C>P4c-y&
boolean bStop = false; //Stop identical HJ:s)As
FileAccessI fileAccessI = null; //File Access interface >| rID
_A;jtS)SY
l%oie1g l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]Jq1b210
{ eh&?BP?
this.sURL = sURL; mTwz&N\
this.nStartPos = nStart; %e+hM $Q
this.nEndPos = nEnd; ~6Vs>E4G
nThreadID = id; b`usRoD{+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g>CF|Wj
} C7[_#1Oz
TwqyQ49
|)B&-~a+p
public void run() &gw. &/t
{ *1$rg?yGf
while(nStartPos < nEndPos && !bStop) )0 .gW
{ 6Y>MW 4q
&&\ h%-Jc
DvKM[z3j
try{ hHm&u^xY
URL url = new URL(sURL); +^iUY%pm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); By]XD~gcP
httpConnection.setRequestProperty("User-Agent","NetFox"); kOmTji7
String sProperty = "bytes="+nStartPos+"-"; U@@#f;&
httpConnection.setRequestProperty("RANGE",sProperty); Nq/,41
Utility.log(sProperty); NIY0f@1z-
>2_BL5<S
|<96H8
InputStream input = httpConnection.getInputStream(); U}x2,`PI
//logResponseHead(httpConnection); mVcpYyD|k
5wmH3g#0
RFU(wek
byte[] b = new byte[1024]; YR@@:n'TP
int nRead; V7G?i\>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :z_D?UQ
{ EW%%W6O6
nStartPos += fileAccessI.write(b,0,nRead); L=O,OS+
//if(nThreadID == 1) ;]D@KxO$dJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #'^!@+)
} tV<}!~0,*
3;zJ\a.+
m"t\@f
Utility.log("Thread " + nThreadID + " is over!"); ^/47*vcN5
bDownOver = true; DN2K4%cM%'
//nPos = fileAccessI.write (b,0,nRead); >_!pg<{,
} >pW8K[
catch(Exception e){e.printStackTrace ();} Am'5|
} 5)+(McJC
} AyB-+oTf(
/pan{.< k
E3<jH
//打印回应的头信息 ,B(UkPGT
public void logResponseHead(HttpURLConnection con) /J]Yj,
{ T;XEU%:LK
for(int i=1;;i++) *]nha1!S
{ 7L|w~l7R~
String header=con.getHeaderFieldKey(i); pk%I98! Jy
if(header!=null) TG8QT\0G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UTGR{>=>
Utility.log(header+" : "+con.getHeaderField(header)); OkGg4X|9
else 8 k9(iS
break; G(~d1%(
} M=HW2xn
} "^u
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&W:Wv,3
public void splitterStop() c9/w-u~j
{ *v)JX _
bStop = true; 7h?PVobe
} ;{ u{FL
<"{Lv)4
nud,ag
} PwU}<Hrl]
>d!w&0z>
O+%Y1=S[WQ
/* %Qgo0
**FileAccess.java ^N#kW-i
*//文件访问(定位，写) 'C)^hj.
package NetFox; '}dlVf
import java.io.*; pN6!IxN$
zhY VMQ
5gARGA
public class FileAccessI implements Serializable{ -|B?pR
%_;q<@9)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \u?z:mV
RandomAccessFile oSavedFile; m8,P-m
long nPos; H_sLviYLu
{>tgNW>)
h@=H7oV7k
public FileAccessI() throws IOException 1dh_"/
{ d|k6#f-E
this("",0); BoYWx^VHx^
} Q%KH^<
!SEHDRp
$'btfo4H
public FileAccessI(String sName,long nPos) throws IOException LbOjKM^-
{ &>\E >mJ
oSavedFile = new RandomAccessFile(sName,"rw"); `Jhu&MWg
this.nPos = nPos; ~z#Faed=a
oSavedFile.seek(nPos); A^ $9[_
} $j0]+vT
QFU;\H/
m:5*:Ii.
public synchronized int write(byte[] b,int nStart,int nLen) 8fFURk
{ ]b4*`}\
int n = -1; ftq&<8
try{ y;<^[
oSavedFile.write(b,nStart,nLen); XmXp0b7
n = nLen; ,u^i0uOg
} zD}dvI}
catch(IOException e) H>AQlO+J
{ CT+pkNC
e.printStackTrace (); Q<B=m6~
} P$S>=*`n U
a97A{7I&
[_*%
return n; YqX/7b+
} VFz(U)._
*i|O!h1St
NlXHOUw)u
} x!fvSoHp
\gaGTc2&
Ug*:o d
/* Os' 7h
**SiteInfoBean.java P9; =O$s
*/ GV#"2{t j
package NetFox; EpSVHD:*
e#JJd=
/*!K4)$-*2
public class SiteInfoBean { ,2q LiE>
)%Z<9k
o7<pI8\
private String sSiteURL; //Site's URL rU`#3}s
private String sFilePath; //Saved File's Path SjV;& 1Z/
private String sFileName; //Saved File's Name "& 'h\
private int nSplitter; //Count of Splited Downloading File cdVh_"[
y3@R>@$
M@EML @~
public SiteInfoBean() \&ra&3o
{//nSplitter的缺省值为5 hE0 p>R8
//default value of nSplitter is 5 O`5PX(J1&
this("","","",5); Sx?IpcPSm
} jR`q y<
}D/0&<1
++D-,>.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \L}aTCvG
{ &+;z`A'|8
sSiteURL= sURL; RhIRCN9
sFilePath = sPath; zC#[
sFileName = sName; dPgN*Bdv
this.nSplitter = nSpiltter; Jj4!O3\I
+#7e?B
3<sYxA\?w
} pE<dK.v6
pe$" nUy|
8sjAr.iT.
public String getSSiteURL() F+ qRC_C>O
{ 1^^<6e
return sSiteURL; Wcd;B7OH
} 4^\5]d!
8gWifx #N
rdZk2\<
public void setSSiteURL(String value) )!J0e-T-8O
{ $K>'aI;|
sSiteURL = value; &Iv3_T<AF
} Uu ~BErEC
{^zieP!
Y5e6|b|
public String getSFilePath() p'z fo!
{ rKg~H=4x2
return sFilePath; .si!`?K%[
} ew -5VL
N@Pf\D
XA75tU[#
public void setSFilePath(String value) 6&/n/g
{ sT:$:=
sFilePath = value; ;zVtJG`
} {#"[h1
0.C[/u[
dnt: U!TW@
public String getSFileName() hAq7v']m
{ A+v6N>}*
return sFileName; }tue`">h
} 60p*$Vqy
h^o>9s/|/H
'&?cW#J?
public void setSFileName(String value) wh8h1I
{ ZdG?fWWA
sFileName = value; ?IRp3H
} 3>;zk#b2
MQ7d IUs
bso l>M[<
public int getNSplitter() =yo?]ZS
{ M ^gva?{
return nSplitter; 46`(u"RP
} zzOc # /
yg34b}m{
B>sSl1opI
public void setNSplitter(int nCount) 0\XG;KA
{ T=Q"|S]V
nSplitter = nCount; Mg3>/!
} 2;X{ZLo
} b.HfxYt(
trD-qi
^W!w~g+
/* #mu3`,9V
**Utility.java 2_i/ F)W
*/ Sh&n DdF"
package NetFox; 'MZX"t
?Pg{nlJvq
PNVYW?l
public class Utility { anLSD/'4W
b5WtL+Z
z+IHt(
public Utility() O*% 1
{ 7;0$UYDU*
\/=w\Tj
/S9s%scAy
} e$!01Y$HI
sXe=4`O
//线程睡眠 ig G8L
public static void sleep(int nSecond) Y:UDte[Lb
{ ErZYPl
try{ 3%`asCW$
Thread.sleep(nSecond); +<qmVW^X
} P]V/<8o.53
catch(Exception e) YT:])[gVV
{ q6E8^7RtS@
e.printStackTrace (); 7bcl^~lY
} ,c3gW2E
} ^\|Hz\"*
D9.H<.|36
//日志 -<e8\Z`
public static void log(String sMsg) q]PeS~PjF\
{ gZkjh{rQ
System.err.println(sMsg); w.v yEU^
} x-W6W
E1'| ;}/
k)l*L1Y4:
public static void log(int sMsg) B?o ?LI
{ ~\4`tc
System.err.println(sMsg); kC :pal
} A\Ax5eeL
} ^)-* Ubzz
P|M#S9^]
v(Vm:oK,
/* .4I"[$?Q
**TestMethod.java *hugQh]a
*/ 8Ter]0M&
package NetFox; Hz A+Oi
BEU^,r3z
Hzos$1DJ
public class TestMethod { Fh)`A5#
wD9Gl.uQ
bD*z"e
public TestMethod() TF0DQP
{ ///xx/weblogic60b2_win.exe P?QVT;]
try{ a+wc"RQ |
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,V$PV,G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m5Q?g8
SiteFileFetch fileFetch = new SiteFileFetch(bean); /%O+]#$`0
fileFetch.start(); ;4E(n
} F|Y}X|x8Q
catch(Exception e){e.printStackTrace ();} <qGVOAnz+
Z]Zs"$q@
mv%Zh1khn/
} 'ju
e-@=QI^,
oXKH,r
public static void main(String[] args) ZmT N
{ s]=bg+v?j
new TestMethod(); M mihWD02
} Mv\odf\]
} pUTC~|j%:
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