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)); x\R%hGt
} \Wn0,%x2
for(int i=0;i<nEndPos.length-1;i++) (QFu``ae+
{ "Yy)&zKr
nEndPos = nStartPos[i+1]; 4#fgUlV
} :&'[#%h8
nEndPos[nEndPos.length-1] = nFileLength; w vQ.9
} Rnd.<jz+Y
} ?O|CY
UWPzRk#s"
1UwpLd
//启动子线程 =iFI@2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )Bb:?!EuEH
for(int i=0;i<nStartPos.length;i++) /hC'-6:]^
{ Z{ AF8r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Xz[|Xl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A4mnm6Tf
nStartPos,nEndPos,i); Ltrw)H}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PX$_."WA
fileSplitterFetch.start(); AB0>|.
} +*')0I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I&s!}$cD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d>YX18'<Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", px~:'U
nEndPos = " + nFileLength); .}4^b\
// fileSplitterFetch[nPos.length-1].start(); 4r-CF#o
.1@8rVp7
Q\qI+F2?
//等待子线程结束 {*NM~yQ
//int count = 0; Z<4Du
//是否结束while循环 +W}dO#
boolean breakWhile = false; b&_u+g
-nL!#R{e
Dx*tolF
while(!bStop) _C&XwCIm
{ r1R\cor
write_nPos(); Frd`u.I
Utility.sleep(500); [izP1A$r#Q
breakWhile = true; rJ^*8C!
*_,: &Ur
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for(int i=0;i<nStartPos.length;i++) )N}.n2Y8W
{ 0/~20KD{s
if(!fileSplitterFetch.bDownOver) a*3h|b<
{ DFvj
breakWhile = false; D:DtP6
break; &f_ua)cyY
} ` &{
} 11Y4oS
if(breakWhile) s<b(@L 1
break; 4Mr)~f rc
0\tdxi
xC^|S0B
//count++; e{k)]]J
//if(count>4) BqG7Et
// siteStop(); C?-_8OA
} D@iE2-n&V
(V:)`A_-
ll#_v^
System.err.println("文件下载结束！"); h#?)H7ft
} {Hr P;)
catch(Exception e){e.printStackTrace ();} 5y8ajae:
} {K ,-fbE
*T:gx:Sg/
*m.4)2u=
//获得文件长度 =t!$72g\
public long getFileSize() ZD`p$:pT
{ m1{OaHxKh
int nFileLength = -1; y-R:-K XH=
try{ U!D\Vd
URL url = new URL(siteInfoBean.getSSiteURL()); !`qw"i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (|t)MnPfY
httpConnection.setRequestProperty("User-Agent","NetFox"); <HMmsw
/`H{n$
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int responseCode=httpConnection.getResponseCode(); bQBYzvd
if(responseCode>=400) a$2WL g,
{ VcpN PU6
processErrorCode(responseCode); _a&Mk
return -2; //-2 represent access is error ^^+vt8|
} Q|&Wcxq2!
cjyb:gAO
geJO#;
String sHeader; > a"4aYj
"Wz74ble
.N~YVul[a*
for(int i=1;;i++) 6SVh6o@]
{ snti*e4"V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Rf0F`D k
//Utility.log(in.readLine()); yIG*
sHeader=httpConnection.getHeaderFieldKey(i); 0OF]|hH
if(sHeader!=null) nA 5-P}
{ l~j{i/>
if(sHeader.equals("Content-Length")) OdHl)"#
{ `bMwt?[*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S/H!a:_5r
break; 3lo.YLP^
} }v$T1Cw
} 8B"my\
else |p"4cG?)
break; M F_VMAq
} O9jpt>:kZ
} GJP\vsaQ
catch(IOException e){e.printStackTrace ();} b]XDfe
catch(Exception e){e.printStackTrace ();} D! $4
l.AG^b
i48Tb7Rx~n
Utility.log(nFileLength); ~ s# !\Ye
hJasnY7
` 8OA:4).
return nFileLength; QCVwslj,K
} ppXt8G3%x
@ 9q/jv`
a]nyZdt`
//保存下载信息（文件指针位置） Yt#e[CYnu
private void write_nPos() 81&5g'
{ !Q" 3B6 86
try{ +t`QHvxv
output = new DataOutputStream(new FileOutputStream(tmpFile)); wML5T+
output.writeInt(nStartPos.length); XJ9l,:c,
for(int i=0;i<nStartPos.length;i++) u[yUUYe
{ ?KF.v1w7
// output.writeLong(nPos); ]id5jVY
output.writeLong(fileSplitterFetch.nStartPos); GFmVR2z_+
output.writeLong(fileSplitterFetch.nEndPos); w7Y>B`wm?
} \[F4ooe
output.close(); Ey**j
} L7 f'
catch(IOException e){e.printStackTrace ();} `z]MQdE_w
catch(Exception e){e.printStackTrace ();} 50J"cGs~
} Q?"-[6[v
@o6^"
53jtwklA
//读取保存的下载信息（文件指针位置） *3r{s'm
private void read_nPos() 8jxs%N,aI
{ PN@[k:5(
try{ gt= _;KZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fsVQZ$h73
int nCount = input.readInt(); ^7O,Vk"Z
nStartPos = new long[nCount]; G: p!PB>=
nEndPos = new long[nCount]; ' *x?8-KP
for(int i=0;i<nStartPos.length;i++) 6:o?@%
{ >xa k
nStartPos = input.readLong(); JJe?Zu\
nEndPos = input.readLong(); %U$PcHOo
} J;S@Q/s
input.close(); is,r:
} $YCy,Ew
catch(IOException e){e.printStackTrace ();} |=CV.Su
catch(Exception e){e.printStackTrace ();} 3[E)/~-
} //\UthOT
a|\ZC\(xI
3kl\W[`?
private void processErrorCode(int nErrorCode) .Lc<1s
{ i'}Z>g5D
System.err.println("Error Code : " + nErrorCode); ?a]uyw,
} !`-/E']/
F6xQ`T|
!Qd4Y=
//停止文件下载 gbJz5EEq
public void siteStop() }\oy?_8~
{ {V)Z!D
bStop = true; ctg[C$<q|
for(int i=0;i<nStartPos.length;i++) pdQ6/vh
fileSplitterFetch.splitterStop(); jSyF]$"
5I(gP
TXlxnB
} Uhz<B #tj
} P{!r<N
//负责部分文件的抓取 c>*RQ4vE
**FileSplitterFetch.java @'yD(ZMAz
*/ Y=#g_(4*
package NetFox; 4LBMhLy
'[h|f
/o19/Pvwm
import java.io.*; I}aiy.l
import java.net.*; ~+GMn[h
LOkNDmj
6k=ink-/
public class FileSplitterFetch extends Thread { ]zza/O;31(
oKJj?%dHK9
PB :Lj
String sURL; //File URL [foZO&+!
long nStartPos; //File Snippet Start Position =O)dHY}
long nEndPos; //File Snippet End Position ttwfWfX
int nThreadID; //Thread's ID IaU
boolean bDownOver = false; //Downing is over uW8LG\Z>D5
boolean bStop = false; //Stop identical W]UGo,
FileAccessI fileAccessI = null; //File Access interface 6J|Y+Y$
@qfVt
v_gQCS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1o;+.]B
{ [8VB"{{&
this.sURL = sURL; GCUzKf&
this.nStartPos = nStart; <E(#;F^y
this.nEndPos = nEnd; x"Hi!h)v
nThreadID = id; ^/3R/;?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0r?}LWjf
} *\Y \$w
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SY` U]-h
public void run() A(mU,^
{ "(hhb>V1Wl
while(nStartPos < nEndPos && !bStop) R^.oM1qu|
{ =-`}(b2N
*:q3<\y{
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try{ aMSX"N"ot
URL url = new URL(sURL); A3p@hQl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -$E_L:M
httpConnection.setRequestProperty("User-Agent","NetFox"); 8}\Lt
String sProperty = "bytes="+nStartPos+"-"; t]~Lo3
httpConnection.setRequestProperty("RANGE",sProperty); `5[d9z/6
Utility.log(sProperty); >5&'_
(Id]'w4
=8r%zLDw
InputStream input = httpConnection.getInputStream(); 3hOiHO ;
//logResponseHead(httpConnection); h7NS9CgO
jB*%nB*x
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byte[] b = new byte[1024]; ThX%Uzd"[;
int nRead; ,c@^u6a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *v[WJ"8@
{ y#:_K(A" k
nStartPos += fileAccessI.write(b,0,nRead); krPwFp2[*
//if(nThreadID == 1) )QGj\2I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4|uh&4"*@W
} 6uCa iPV
k[]B P4
%X Jv;|
Utility.log("Thread " + nThreadID + " is over!"); zo-hH8J:
bDownOver = true; !F*7Mif_E
//nPos = fileAccessI.write (b,0,nRead); O+Fu zCWj
} gRS}Y8
catch(Exception e){e.printStackTrace ();} i2SR.{&
} ,F7W_f# @3
} 1MH[-=[Q
.v36xXK(
_uuxTNN0x*
//打印回应的头信息 \ %Er%yv)
public void logResponseHead(HttpURLConnection con) (c ?OcwTH
{ \f6SA{vR|
for(int i=1;;i++) %vvA'WG
{ I @TR|
String header=con.getHeaderFieldKey(i); H3YFbR
if(header!=null) ~F^(O{EG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QAigbSn]
Utility.log(header+" : "+con.getHeaderField(header)); G[1:<Vg8
else sr+* q6W
break; Q# w`ZQX3
} \WG6\Zg0A
} |*5Kfxq
?(el6J}
%|$h<~
public void splitterStop() B]dvX
{ GndU}[0J
bStop = true; 6eqxwj{S[
} <(dHh9$~
}>I|\Z0I
_5(lp} s
} w yP|#Z\
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I@a y&NNh
/* .5*h']iFr1
**FileAccess.java ld8E!t[
*//文件访问(定位，写) S>isWte
package NetFox; iB;EV8E
import java.io.*; ES[H^}|Gi
K,{P b?
+G';no\h
public class FileAccessI implements Serializable{ `iYiAc
W 86`R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Tf/jd 3>
RandomAccessFile oSavedFile; &<}vs`W
long nPos; u}ULb F
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"c8 -xG
public FileAccessI() throws IOException T 22tZp
{ 8yEN)RqI
this("",0); 64Gd^.Z
} qRkY-0vBP
'NyIy:
x%Ph``XI
public FileAccessI(String sName,long nPos) throws IOException 7\>P@s
{ 2Fk4jHj
oSavedFile = new RandomAccessFile(sName,"rw"); od=%8z
this.nPos = nPos; [IT*>;b+?
oSavedFile.seek(nPos); u;f${Wn'3
} hK F*{,'
.?T,>#R
6)i4&
public synchronized int write(byte[] b,int nStart,int nLen) c++GnQc.
{ u~WBu|
int n = -1; npC:SrI%
try{ "mlVs/nsyG
oSavedFile.write(b,nStart,nLen); E9e|+$
n = nLen; '4-J0S<<_
} `|maf=SnY5
catch(IOException e) {;uOc{~+
{ 5}S~8
e.printStackTrace (); nBw4YDR!
} {~J'J$hn8
coa+@g,w7#
t5: 1' N9P
return n; d:C|laZHn
} 1t&LNIc|^
a6\0XVU
~6YTm6o
} cu{c:z~
m'{gO9V
jeb]3i=pw
/* e ]-fb{oVH
**SiteInfoBean.java |q0F*\z3
*/ X{cFqW7
package NetFox; D6X0(pU0
D%[yAr;r
mX8k4$z
public class SiteInfoBean { .[mI9dc
Hw"LoVh
r<< ]41
private String sSiteURL; //Site's URL t&5N{C:
private String sFilePath; //Saved File's Path @ sLb=vb
private String sFileName; //Saved File's Name ?'>pfU
private int nSplitter; //Count of Splited Downloading File 'cp1I&>
N_jpCCG~
+H"[WZ5
public SiteInfoBean() #aHPB#
{//nSplitter的缺省值为5 EWz,K]_'
//default value of nSplitter is 5 '" MT$MrT
this("","","",5); 1ym^G0"s
} &+0WZ#VI
{`RCh]W
py\KY R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]#$l"ss,
{ bhk:Szqz
sSiteURL= sURL; d\eTyN'rA
sFilePath = sPath; PB[Y^q
sFileName = sName; a-[:RJW
this.nSplitter = nSpiltter; !*I0}I ~
)gNS%tc*K
tW$Di*h
} dWKjVf
wE*o1.
9NXL8QmC8
public String getSSiteURL() 2TQyQ%
{ :8( "n1^
return sSiteURL; `^d[$IbDW
} 6KH&-ffd
W20qn>{z
9Rf})$o+
public void setSSiteURL(String value) _P].Z8
{ 3lh^maQ]
sSiteURL = value; L0^rw|Z%'
} Nw3K@Ge
[hhPkJf|f
ve3-GWT{C
public String getSFilePath() PiL[&_8g
{ Hl|EySno
return sFilePath; -F->l5
} cc0e(\
{tKi8O^Rb
%[l#S*)~
public void setSFilePath(String value) :,8eM{.Q
{ E]MyP=g$
sFilePath = value; K^6fg,&
} r &.gOC
]K<mkUpY
Xi 8rD"v
public String getSFileName() n0 q$/Y.
{ Jxo#sV-
return sFileName; U"T>L
} s[dq-pc"
i3dV2^O
cXDG(.!n7B
public void setSFileName(String value) K?J?]VCw
{ =w,cdU*
sFileName = value; KtMD?
} V#Pz`D
(_ TKDx_
RCC~#bb
public int getNSplitter() bnZ`Wc*5b
{ b<E0|VW
return nSplitter; C@F3iwTtp
} EJByYk
M[:},?ah0
[&MhAzF
public void setNSplitter(int nCount) hLo'q^mGr
{ .9uw@Eq
nSplitter = nCount; x2M{=MExE.
} o0&pSCK
} .E/NlGm[
SbYsa
zNh$d;(O$^
/* .dw;b~p
**Utility.java :k&5Z`>)
*/ _mG>^QI.
package NetFox; 1)N~0)dO
p=jIDM'
$T2n^yz
public class Utility { -. J@
2;`F`}BA
\L]T|]}(
public Utility() y%Wbm&h
{ gI5Fzk@:
<8sy*A?0z
Su>UXuNdE#
} O_^X:0}
"raC?H
//线程睡眠 au?5^u\
public static void sleep(int nSecond) U/j+\Kc~
{ dk@j!-q^
try{ .!2Ac
Thread.sleep(nSecond); \0bZ1"
} JQO%-=t
catch(Exception e) ) mG
{ Xxmvg.Nl
e.printStackTrace (); OE8H |?%
} nNP{>\x;"
} k<.VR"I p
@'lO~i
//日志 no UXRQ
public static void log(String sMsg) 8 aC]" C
{ qJ5gdID1_
System.err.println(sMsg); ptCAtEO72
} ;Y@"!\t}
Ynx.$$`$=
s]@k,%
public static void log(int sMsg) <uL0M`u3
{ R)u ${
System.err.println(sMsg); >=!$(JgX
} bA*T1Db,t>
} O ]Stf7]%;
O~u@J'4
'boAv%1_sa
/* nv-_\M
**TestMethod.java *p>1s!i
*/ vkg."G:=
package NetFox; L\/YS;Y
@;T?R
1Zi(5S)
public class TestMethod { z<Y >phc
nq3B(
+f]\>{o4
public TestMethod() 7nOn^f D
{ ///xx/weblogic60b2_win.exe AOVoOd+6
try{ A_}%YHb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JzZ9ua
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?:1)=I<A4
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]Yd7
fileFetch.start(); d*(wU>J '
} %n<.)R
catch(Exception e){e.printStackTrace ();} ,Y_[+
[-*8S1
J6m(\o
} )9mUE*[
%. -nZC
Z+J;nl
public static void main(String[] args) ?&>H^}gDZ
{ }y P98N5o
new TestMethod(); /{7we$+,p
} S&w(H'4N
} ].,TSnb
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