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)); =bUVGjr%96
} !<"H73?fl
for(int i=0;i<nEndPos.length-1;i++) -9"hJ4
{ A[lkGQtS4
nEndPos = nStartPos[i+1]; .tB[8Y=J
} D7%`hU
nEndPos[nEndPos.length-1] = nFileLength; S3-3pJ]~Zk
} [YT"UVI
} C7%+1w'D8
L+@RK6dq
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//启动子线程 u</21fz'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ifo7,
for(int i=0;i<nStartPos.length;i++) UzVnC:
{ P,Fs7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %g3@m5&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3@e#E4+ff
nStartPos,nEndPos,i); !+T9NqDv[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wi]|"\
fileSplitterFetch.start(); |H&2[B"l
} g/+P]c6/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8UB-(~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mDmy637_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zBWn*A[4
nEndPos = " + nFileLength); {z?e<
// fileSplitterFetch[nPos.length-1].start(); 'xAfcP[^
clQN@1] M
7O{c>@\
//等待子线程结束 /?l@7
//int count = 0; P@'<OI
//是否结束while循环 8W?/Sg`
boolean breakWhile = false; bet?5Dk
}E$^!q{
wy&s~lpV,7
while(!bStop) \p"`!n
{ b_*Y5"(*
write_nPos(); CuPZ0
Utility.sleep(500); vukI`(#
breakWhile = true; yG?,8!/]
/jih;J|
#SQao;>
for(int i=0;i<nStartPos.length;i++) U7U-H\t7
{ lmb5Z-xB
if(!fileSplitterFetch.bDownOver) qp>O#tj[
{ ev>gh0
breakWhile = false; 1R)4[oYN\<
break; j+Nun
} KFHn)+*"
} UJ1Ui'a(!!
if(breakWhile) D0,U2d
break; &eq>>
v\ggFrG]
xtL_,ug
//count++; U3MfEM!x
//if(count>4) ^G{3x
// siteStop(); ny17(Y =
} xd\k;nq
w> `3{MTQ
j{EN %
System.err.println("文件下载结束！"); uWR\#D'
} zzi%r=%r&
catch(Exception e){e.printStackTrace ();} ]ERPWW;^
} Ia:n<sZU
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>=c<6#:s<9
//获得文件长度 g7@G&Ro9J\
public long getFileSize() Cul^b_UmP#
{ 6=2M[T
int nFileLength = -1; wwVK15t
try{ ',nGH|K.
URL url = new URL(siteInfoBean.getSSiteURL()); ;1}~(I#Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pq`]^^=be'
httpConnection.setRequestProperty("User-Agent","NetFox"); ^R\0<\'
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b Mi,z3z
int responseCode=httpConnection.getResponseCode(); Iz^~=yV)
if(responseCode>=400) zh)qo
{ 2'tZ9mK
processErrorCode(responseCode); k'Fc:T8:~5
return -2; //-2 represent access is error Be"D0=<
} =mYY8c Yl
)s1W)J?8
! FbW7"yE
String sHeader; 0V ,R|Ln
/\_`Pkd3m
-:t<%]RfY
for(int i=1;;i++) 0 } uEM_a
{ t8 g^W K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hv te)
//Utility.log(in.readLine()); m/3b7c@r
sHeader=httpConnection.getHeaderFieldKey(i); B<(v\=xZ
if(sHeader!=null) `s(T(l
{ ZWaHG_ U)
if(sHeader.equals("Content-Length")) .)|r!X
{ xJrRJwL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )]L:OE
break; vttmSdY
} eZR{M\Q
} }5-^:}gL
else $J&wwP[
break; =<j8)2
} 'S\YNLqQ
} K?:rrd=7q
catch(IOException e){e.printStackTrace ();} 6"C$]kF?
catch(Exception e){e.printStackTrace ();} msOk~ZPE6\
iZ2|/hnw
B'>(kZYMs
Utility.log(nFileLength); `=^;q6f
V6Ie\+@.\
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return nFileLength; ) D:M_T2
} !7t,(Id8
?it49
pJ-/"Q|:i
//保存下载信息（文件指针位置） [xq"[*Evv
private void write_nPos() 9{_D"h}}
{ 6T0[ ~@g5
try{ }@Lbvaa
output = new DataOutputStream(new FileOutputStream(tmpFile)); lx,^Y647
output.writeInt(nStartPos.length); .w2X24Mmb
for(int i=0;i<nStartPos.length;i++) YFgQ!\&59
{ *.4;7#
// output.writeLong(nPos); R}7>*&S:
output.writeLong(fileSplitterFetch.nStartPos); 289teU
output.writeLong(fileSplitterFetch.nEndPos); n.P$7%G`2
} {t`UV,
output.close(); jrT5Rw_}q
} F }l_=
catch(IOException e){e.printStackTrace ();} Kg^L 4Q
catch(Exception e){e.printStackTrace ();} q@1!v
} ZOvMA]Rf
FM:ax{
afOb-G$d=
//读取保存的下载信息（文件指针位置） v+dt1;
private void read_nPos() (%]&Pe]
{ QWG?^T fi
try{ i~:FlW]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .n1]Yk;,1
int nCount = input.readInt(); !~PLW]Z4
nStartPos = new long[nCount]; ;=.VKW%U
nEndPos = new long[nCount]; C^I h"S
for(int i=0;i<nStartPos.length;i++) uSp=,2)
{ "J^M@k\!
nStartPos = input.readLong(); m@ b~
nEndPos = input.readLong(); `r;e\Cp
} H~x,\|l#
input.close(); 'zV/4iE=
} r168ft?c
catch(IOException e){e.printStackTrace ();} |Z}uN!Jm
catch(Exception e){e.printStackTrace ();} Jx[Z[RO2
} o mstJ9
U&#1qRm\h
+*-u_L\'
private void processErrorCode(int nErrorCode) Q?rb(u(
{ x"0*U9f
System.err.println("Error Code : " + nErrorCode); wQiRj.
} Z[:fqvXQ
v{9< ATi
M?pu7wa
//停止文件下载 r2H_)Oi
public void siteStop() ~$} `R=
{ :{<( )gfk
bStop = true; W_(
for(int i=0;i<nStartPos.length;i++) -~T?xs0_
fileSplitterFetch.splitterStop(); fbp6lE
y)_T!&ze
Pda(O;aNU
} &A>Hq/Y
} Y0iL+=[k`m
//负责部分文件的抓取 UV8,SSDTV
**FileSplitterFetch.java aR30wxW&)
*/ f;M7y:A8q,
package NetFox; m5Gt8Z 6a
#UGm/4C
RkP g&R;i
import java.io.*; ukBj@.~
import java.net.*; e(E6 t_
3Tv;<hF
X?5M)MP+I
public class FileSplitterFetch extends Thread { 1MV\Jm
A|p O
1L.H"
String sURL; //File URL @A6P[r
long nStartPos; //File Snippet Start Position X&EcQ
long nEndPos; //File Snippet End Position o(5Xj$Z
int nThreadID; //Thread's ID JJlwzH
boolean bDownOver = false; //Downing is over ;7CE{/Bq.p
boolean bStop = false; //Stop identical D/C,Q|Ya6
FileAccessI fileAccessI = null; //File Access interface y1P KoN|K
Bgs3sM9
}I_/>58
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `ZL~k
{ m'H%O-h\
this.sURL = sURL; v7"' ^sZ?
this.nStartPos = nStart; qXO@FW]
this.nEndPos = nEnd; @WVpDhG
nThreadID = id; BhC.#u/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Enr8"+.(
} )HWf`;VQ
@mM'V5_#
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public void run() 8*yhx
{ _:F0>=$
while(nStartPos < nEndPos && !bStop) Nq %@(K
{ dX|(n.}
\5.36Se
3D>syf
try{ LO{{3No
URL url = new URL(sURL); w7}m T3p,)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]&%_Fpx
httpConnection.setRequestProperty("User-Agent","NetFox"); C8i6ESmU
String sProperty = "bytes="+nStartPos+"-"; 1B+uv0lA
httpConnection.setRequestProperty("RANGE",sProperty); q]+'{Ci@
Utility.log(sProperty); Ru8k2d$B
nE+OBdl
tM3eB= .*
InputStream input = httpConnection.getInputStream(); D4WvRxki
//logResponseHead(httpConnection); "i/ l'
3x2*K_A5:Q
7,U^v}$
byte[] b = new byte[1024]; ?:F#WDD
int nRead; Iqe=)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q$Y ]KV
{ ``bIqY
nStartPos += fileAccessI.write(b,0,nRead); 9A0wiKp
//if(nThreadID == 1) 'B&gr}@4O=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &`hx
} M]PH1 2Ob
"@IrBi6
z^s/7Va[
Utility.log("Thread " + nThreadID + " is over!"); R5=2EwrGP
bDownOver = true; A?I/[zkc
//nPos = fileAccessI.write (b,0,nRead); ,YzrqVY
} )`5kfj
catch(Exception e){e.printStackTrace ();} w yi n
} _(=[d
} w_o|k&~,
rMkoE7n
--*Jv"/0
//打印回应的头信息 t,|`#6Ft
public void logResponseHead(HttpURLConnection con) _kR);\V.8
{ (}1 gO
for(int i=1;;i++) \]pRu"
{ ;ew j
String header=con.getHeaderFieldKey(i); <:=}1t.Z
if(header!=null) B;f\H,/59
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F!m/n!YR
Utility.log(header+" : "+con.getHeaderField(header)); 0c*y~hUVZ
else RzG7Xr=t
break; Z9rmlVU6!
} $*EK v'g[n
} d$~q
\ci'Cbn\o
)Zx;Z[
public void splitterStop() #P[d?pY
{ oJ}!qrrH
bStop = true; Qu4Bd|`(k
} et[n;nl>V
6`(x)Q9
w6ZyMR,T
} Y>v(UU
bs{i@1$
D|`O8o?)
/* !Yuu~|
**FileAccess.java 7q_B`$ata
*//文件访问(定位，写) @&!`.Y oy
package NetFox; Th&-n%r9K
import java.io.*; 8%-+@\=
#gjhs"$~
AWkXWl}
public class FileAccessI implements Serializable{ dN'2;X
$#q:\yQsPC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \ZSZ(p#1
RandomAccessFile oSavedFile; q1C) *8*g
long nPos; rybs9:_}
cs0;:H*N*
]PlDe8
public FileAccessI() throws IOException ,khB*h14;h
{ t+C9QXY
this("",0); 72J@Dc
} Y`$dtg {
AUCk]
!*Hgl\t6a
public FileAccessI(String sName,long nPos) throws IOException \KmgFyF
{ Rw8l"`
oSavedFile = new RandomAccessFile(sName,"rw"); 9='a9\((mH
this.nPos = nPos; a:$hK%^ \
oSavedFile.seek(nPos); v X=zqV
} 6:Eu[PE~w
p6=L}L
=3KK/[2M
public synchronized int write(byte[] b,int nStart,int nLen) .9r+LA{
{ ;IklS*p]
int n = -1; HoA[UT
try{ rof&O
oSavedFile.write(b,nStart,nLen); >kK!/#ZA
n = nLen; Co`O{|NS}!
} VK/@jrL+
catch(IOException e) Snm m(.
{ R.KqTEs<k
e.printStackTrace (); P<&-8QA
} 6$42-a%b
~nul[>z
!VNLjbee.
return n; Vn:BasS%
} P3[!-sv
.m',*s<CMQ
qIm?F>>@
} ,:RHhg
n.}A :Z
{R`,iWV
/* Ml)0z&jQX
**SiteInfoBean.java iR k.t=B
*/ \?n4d#=$o
package NetFox; -Fi{[%&u
n%N|?!rB
tCkKJ)m
public class SiteInfoBean { vn5X]U"
HTfHAc?W
Z^P]-CB|6A
private String sSiteURL; //Site's URL Jptzc:~B
private String sFilePath; //Saved File's Path B.:DW3
private String sFileName; //Saved File's Name dy>iIc>
private int nSplitter; //Count of Splited Downloading File RL0#WBR
014p= W
P<Wtv;Z1Z
public SiteInfoBean() oH;0_!
{//nSplitter的缺省值为5 o: \&4z&=
//default value of nSplitter is 5 al{;]>W
this("","","",5); V1aWVLltj
} TDvUiJm
41\r7 BS
z^tws*u],5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #g)$m}tv?
{ HiTn5XNf
sSiteURL= sURL; :g1C,M~
sFilePath = sPath; 3Thb0\<"
sFileName = sName; )(&Z&2~A
this.nSplitter = nSpiltter; gY)NPi}!`
qU ESN!
a'sa{>
} /^#8z(@B
^]iIvIp
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public String getSSiteURL() {|Ew]Wq
{ !8cS1(a
return sSiteURL; H l'za
} <IiX_*
f 7g?{M
'|v??`o#
public void setSSiteURL(String value) IU f1N+-z
{ ~d+.w%Z`
sSiteURL = value; < 5%:/j
} 43i@5F]
g>])O
Vl91I+Ev
public String getSFilePath() qu}`;\9@ld
{ AOh\%|}
return sFilePath; (%\vp**F
} )v1y P
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+ ?z=,')
public void setSFilePath(String value) I-@A{vvPK
{ r9),F.6,
sFilePath = value; [K(|V
} *pu ,|
};rxpw>ms
+/">]QJ
public String getSFileName() Eb9 eEa<W
{ K^H{B& b8
return sFileName; =Gka;,n
} Ek0zFnb[Gx
O$'BJKj-4
?*2DR:o>@
public void setSFileName(String value) v'x)AbbC
{ ^lF'KW$
sFileName = value; s7x&x;-
} 'X()|{
f-w-K)y$ht
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public int getNSplitter() =qQH,{]c6
{ ?CaMn b8
return nSplitter; p};B*[ki
} [| \Z"
-k$*@Hq
5>E]C=maD
public void setNSplitter(int nCount) B%~hVpm,eM
{ 5xHP5+&
nSplitter = nCount; WtT* 1Z
} z>\vYR$
} "OIra2O
||M;[-JoJ
}8H_^G8
/* /dT7:x*
**Utility.java !B&OK&*
*/ M Y2=lT
package NetFox; a>3#z2#
O WJv<3
U Bo[iZ|%
public class Utility { F\!Va
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PrA?e{B5m
public Utility() lT`y=qR|
{ 0E6>PE;
S;!l"1[;
: h"Bf@3
} {8!\aYI
W@X/Z8.(
//线程睡眠 v;S_7#
public static void sleep(int nSecond) q%G"P*g$(
{ t`b!3U>I
try{ ;y"=3-=vM"
Thread.sleep(nSecond); q_5hKipd\b
} hKG)* Q
catch(Exception e) =/ b2e\
{ -E*VF{IG1
e.printStackTrace (); kOu C@~,
} \`FpBE_e)
} !$q *~F"S
+prr~vgE
//日志 3RwDIk?>%
public static void log(String sMsg) rA=iBb3`
{ nUp, %z[
System.err.println(sMsg); ~\UH`_83[
} anM]khs?
E< 57d,3l
P(n_eIF-f
public static void log(int sMsg) OMl<=;^:|
{ yvQRr75
System.err.println(sMsg); NCid`a$
} il=:T\'U9
} E46+B2_~zk
JO|%Vpco
xI'sprNa_1
/* HDV@d^]-
**TestMethod.java 4#dS.UfI
*/ ( 04clU^F
package NetFox; qs9q{n-Aj
T:~c{S4&
|8DMj s()*
public class TestMethod { u\&F`esQ2
| Ns-l (l
E`M, n,
public TestMethod() n`W7g@Sg#I
{ ///xx/weblogic60b2_win.exe Rxl )[\A*
try{ n7CwGN%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1N3qMm^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h$[tEmD%
SiteFileFetch fileFetch = new SiteFileFetch(bean); sQIzcnKB
fileFetch.start(); Vo G`@^s
} 8p91ni'
catch(Exception e){e.printStackTrace ();} bL6, fUS
w&b?ze{
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} _J N$zZ{
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"8BZj;yS
public static void main(String[] args) u{Rgk:bn
{ AA&5wDMV>
new TestMethod(); i_[nW
} E1"H(m&6
} Xb/W[rcs
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