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)); r8xv#r1
} h-[VH%
for(int i=0;i<nEndPos.length-1;i++) $69oV:
{ =o$sxb E(
nEndPos = nStartPos[i+1]; 4GX-ma,
} .?loO3 m
nEndPos[nEndPos.length-1] = nFileLength; :s7m4!EF
} \hx1o\
} &__es{;P
^y<<>Y'I
xjKR R?
//启动子线程 GU( _
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `)_dS&_\
for(int i=0;i<nStartPos.length;i++) 6;ixa hZV
{ G6$kv2(k`@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;5659!;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zo4qG+>o
nStartPos,nEndPos,i); Y!nJg1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3`t%g[D1
fileSplitterFetch.start(); F9,DrB,B{
} ,Y/ g2 4R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !:q/Ye3.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,X`)ct
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sTn<#l6
nEndPos = " + nFileLength); hHV";bk
// fileSplitterFetch[nPos.length-1].start(); e,W%uH>X
NTYg[VTr
[PNT\ElT
//等待子线程结束 ?#}N1k\S
//int count = 0; =A83W/4
//是否结束while循环 e&&53?
boolean breakWhile = false; BRgXr
JvVWG'Z"
iKX-myCz
while(!bStop) ]&lY%"U$i
{ _./Sk|C
write_nPos(); )b)-ZS7
Utility.sleep(500); xc=b |:A
breakWhile = true; ^")Q YE
MkfBuW;)
U:^PC x`
for(int i=0;i<nStartPos.length;i++) --$ 4Q(#
{ Cv6'`",Yzm
if(!fileSplitterFetch.bDownOver) _V7s#_p
{ x!5'`A!W%
breakWhile = false; )48QBz?
break; TJK[ev};S
} *Q?tl\E
} M l Jo`d
if(breakWhile) _`&m\Qe>
break; 1v.c 6~
1Q<^8N)pf
)u[emv$
//count++; D1zBsi94D
//if(count>4) \Q0[?k
// siteStop(); 2mVD_ s[`
} |H;F7Y_
Qz5sxi
ZX9TYN
System.err.println("文件下载结束！"); pwL;A3$|
} < $J>9k
catch(Exception e){e.printStackTrace ();} 49GkPy#]L=
} .F
JTSlWq4
RP[{4Q8
//获得文件长度 le/,R@]B9
public long getFileSize() hI]Hp3S
{ B-ngn{Yc
int nFileLength = -1; .HS"}A T
try{ Ve}(s?hU5
URL url = new URL(siteInfoBean.getSSiteURL()); _(%d(E2?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <D<4BnZ(
httpConnection.setRequestProperty("User-Agent","NetFox"); "p_J8
$rv8K j+
Wh+{mvu#
int responseCode=httpConnection.getResponseCode(); I&}L*Z?`
if(responseCode>=400) 8 OY3A
{ ]zE;Tw.S
processErrorCode(responseCode); >,gg5<F-E
return -2; //-2 represent access is error x@P y>f2
} $PTP/^
:61Tun
EMwS1~3dD
String sHeader; 3er nTD*`
$HHs^tW
+b0eE)
for(int i=1;;i++) ~.{/0T
{ G&D7a/G\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +)!YrKuu
//Utility.log(in.readLine()); Q sZx) bO
sHeader=httpConnection.getHeaderFieldKey(i); dP#|$1
if(sHeader!=null) .7e2YI,S
{ #hfXZVD
if(sHeader.equals("Content-Length")) \KMToN&2
{ tItX y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [I'0,y
break; nw-xSS{
} gw#5jW\
} dgR g>)V
else {MtpkUN
break; 1C}NQ!.
} mHV%I@`Y6
} CtyoHvw+M
catch(IOException e){e.printStackTrace ();} @e(o129
catch(Exception e){e.printStackTrace ();} +giyX7BPJ
{@6=Q 6L
Wk~WOzr}^
Utility.log(nFileLength); 0h#lJS*
_ky,;9G]
_"?.!
return nFileLength; %<k2#6K
} Gw>^[dmt!
.AR#&mL9
d4u})
//保存下载信息（文件指针位置） e@Fo^#ImDx
private void write_nPos() lD)%s!
{ Rp.Sj{<2
try{ zL$@`Eh-KP
output = new DataOutputStream(new FileOutputStream(tmpFile)); *w^C"^*
output.writeInt(nStartPos.length); f[<m<I
for(int i=0;i<nStartPos.length;i++) B:5Rr}eY+
{ )WRLBFi3
// output.writeLong(nPos); *W.C7=
output.writeLong(fileSplitterFetch.nStartPos); <;vbsksZeH
output.writeLong(fileSplitterFetch.nEndPos); f,h J~
} h].<t&
output.close(); $Z.7zH
} @Z*W
catch(IOException e){e.printStackTrace ();} Dd'm U
catch(Exception e){e.printStackTrace ();} >.Chl$)<
} YLqGRE`W
$bW3_rl%X
f\]sz?KY
//读取保存的下载信息（文件指针位置） _,p/l&<
private void read_nPos() $+P>~X)
{ ?oVx2LdD|
try{ S=5<^o^h3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OVm\
int nCount = input.readInt(); X &uTSgN
nStartPos = new long[nCount]; /xsF90c\h
nEndPos = new long[nCount]; }+)fMZz
for(int i=0;i<nStartPos.length;i++) wT;0w3.Z
{ Z>QF#."m
nStartPos = input.readLong(); kE:nsXI )
nEndPos = input.readLong(); XG}C+;4Aw
} pOGeruu?
input.close(); v=0(~<7B
} a][f
catch(IOException e){e.printStackTrace ();} \]</w5 Pi,
catch(Exception e){e.printStackTrace ();} GGNvu)"
} BzkooJ
3L<wQ(
7op`s5i
private void processErrorCode(int nErrorCode) dYT%
{ SQ44
System.err.println("Error Code : " + nErrorCode); ^Y=\#-Dd
} k3u"A_"c
F20E_2;@@
[<2<Y
//停止文件下载 P^A!.}d
public void siteStop() {9?JjA
{ ?ATOXy
bStop = true; W}m)cn3@
for(int i=0;i<nStartPos.length;i++) iL7DRQ1
fileSplitterFetch.splitterStop(); R9'b-5q
:yRo3c
/35R u}c
} +fC=UAZ
} @LS@cCC,a
//负责部分文件的抓取 rX4j*u2u
**FileSplitterFetch.java kW*f.!
*/ tQ8.f
package NetFox; dYG,_ji
v'U{/ ,x
y`\@N"Cf
import java.io.*; fa++MNf}3
import java.net.*; :Pvzl1
gYNjzew'
1$D_6U:H0
public class FileSplitterFetch extends Thread { +b.g$CRr
$CY~5A`l9
@aAW*D~-J
String sURL; //File URL |%J{RA
long nStartPos; //File Snippet Start Position -7*ET3NSI/
long nEndPos; //File Snippet End Position v/](yT
int nThreadID; //Thread's ID [Yo,*,y31
boolean bDownOver = false; //Downing is over brW :C?}
boolean bStop = false; //Stop identical 3?c3<`TW
FileAccessI fileAccessI = null; //File Access interface 5k`l$mW{
%6t2ohO"
\Pj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !zkZQ2{Wn
{ u -;_y='m
this.sURL = sURL; eIz<)-7:
this.nStartPos = nStart; : ]sUpO
this.nEndPos = nEnd; $K]m{
nThreadID = id; [#l*_0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MXw hxk#E
} b6Wqr/
byLft1
b:Wm8pp?
public void run() /LvRP yj@
{ Of"
while(nStartPos < nEndPos && !bStop) T?x[C4wf+
{ +?:7O=Y
#pb92kA'
e4!:c^?
try{ X'd9[).
URL url = new URL(sURL); $ {O#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Km(n7Ah"
httpConnection.setRequestProperty("User-Agent","NetFox"); $"FQj4%d
String sProperty = "bytes="+nStartPos+"-"; jBgP$g
httpConnection.setRequestProperty("RANGE",sProperty); @ o3T
Utility.log(sProperty); =<{np
)+[ gd/<C.
P0W*C6&71|
InputStream input = httpConnection.getInputStream(); *pSQU=dmS
//logResponseHead(httpConnection); [3(74
+Af"f' )
[U5\bX@$
byte[] b = new byte[1024]; kS_(wpA
int nRead; `Gn50-@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s$cK(S#
{ b6U2GDm\s
nStartPos += fileAccessI.write(b,0,nRead); Y&S24aql
//if(nThreadID == 1) #:[t^}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qv]}$WU
} vgsJeV`}I
lr`&mZ( j
9fhsIe
Utility.log("Thread " + nThreadID + " is over!"); ;\]b T;#
bDownOver = true; f4Xk,1Is
//nPos = fileAccessI.write (b,0,nRead); ?AJKBW^
} PcA2/!a
catch(Exception e){e.printStackTrace ();} )TVFtI=,NN
} mS~o?q-n
} *v9 2
d/BM&r
LcUh;=r}&
//打印回应的头信息 ~\Hc,5G
public void logResponseHead(HttpURLConnection con) EdlTdn@A
{ <kGU,@6PF
for(int i=1;;i++) F P* lQRA
{ hWD;jR
String header=con.getHeaderFieldKey(i); M%ICdIc'
if(header!=null) ujlY!-GM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \/: {)T~
Utility.log(header+" : "+con.getHeaderField(header)); [R=yF ~-
else 3~uW I%I`
break; $,,op(
} Jtr"NS?a]
} ~/98Id}v
L3@82yPo!
/J=v]<87a
public void splitterStop() ~:Ll&29i
{ SKkUU^\#R`
bStop = true; nEJY5Bz$
} n2)@S0{
GBRa.;Kk
/atW8 `&
} R)QC)U
/ro=?QYb
m9.{[K"
/* ] lrWgm
**FileAccess.java n[G&ksQI
*//文件访问(定位，写) 2/"u5
package NetFox; IIn"=g=9
import java.io.*; G/7cK\^u
ioYGZ%RG#
5@+,Xh,H|t
public class FileAccessI implements Serializable{ ,N!o
2E}*v5b,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?}kG`q
RandomAccessFile oSavedFile; (O.d>
long nPos; *7ZN]/VRT
C-\S/yd
;<j0f~G`
public FileAccessI() throws IOException yCVI\y\B
{ @~YYD#'vNY
this("",0); \$*7 >`k
} LUM@#3&
0{,Z{&E
dep=&
public FileAccessI(String sName,long nPos) throws IOException (Iaf?J5{
{ `$W_R[
oSavedFile = new RandomAccessFile(sName,"rw"); '}B+r@YCN
this.nPos = nPos; Q9Kve3u-i
oSavedFile.seek(nPos); mi,E-
} P<M?Qd1.
$W!!wN=B
gG*X^Uo
public synchronized int write(byte[] b,int nStart,int nLen) ZWc]$H?
{ ykV 5
int n = -1; 05b_)&4R
try{ A v2 08}Y
oSavedFile.write(b,nStart,nLen); -jb0o/:
n = nLen; + HK8jCa
} 7"20hAd
catch(IOException e) x{n`^;Y1
{ JM x>][xD
e.printStackTrace (); pe]A5\4c
} 60J;sGW
H!5\v"]WB
nxWY7hU
return n; ]:Nsf|C0
} Yu)NO\3&
f!I[>&n
GO`Ru 8
} $\]&rZVi
El.hu%#n*G
C8Qa$._
/* S|7!{}
**SiteInfoBean.java Y }$/e
*/ ow_W%I=6
package NetFox; {2=jAz'?
pTPi@SBaP{
lI*o@wQg
public class SiteInfoBean { = \'}g?
n `&/D
==3dEJS
private String sSiteURL; //Site's URL Tn*9lj4
private String sFilePath; //Saved File's Path QdL`|
private String sFileName; //Saved File's Name o0ifp=V y
private int nSplitter; //Count of Splited Downloading File ADDSCY=,
++6`sMJ
="Ho%*@6
public SiteInfoBean() *AO,^R&e.
{//nSplitter的缺省值为5 'EbWFMjy
//default value of nSplitter is 5 QPx_-
this("","","",5); Pv_Jm
} 9N@W\DT
,z;cbsV-{
3Z5D)zuc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j27?w<
{ `j,Yb]~s79
sSiteURL= sURL; iBF|&h(\
sFilePath = sPath; %?}33yV
sFileName = sName; i~I%D%;
this.nSplitter = nSpiltter; 2NC.Z;
bCo7*<I4
L ^q""[
} w80oXXs[#
,l!Ta"
_FH`pv
public String getSSiteURL() B8f8w)m
{ `|{-+m
return sSiteURL; oW ::hB
} "P7nNa
;<&*rnH
ar__ Pf6r
public void setSSiteURL(String value) &;^YBW:I
{ uJzG|$;
sSiteURL = value; @;*Ksy@1O
} ^hc!FD
OGK}EI
,]9P{k]O
public String getSFilePath() 9oYgl1}d
{ * @ 3Ag(
return sFilePath; hIy~B['
} B"h#C!E
@ [:ZS+1
jrr EAp
public void setSFilePath(String value) W>) M5t4i
{ d,+Hd2o^X
sFilePath = value; B2>H_dmQ
} ;LcZ`1
3EJj9}#x"'
G<}()+L
public String getSFileName() ?zh9d%R
{ B3We|oe!
return sFileName; rDm~h~u5
} 1oR7iD^
Zq+v6fk_Mn
>3p\m
public void setSFileName(String value) [k.tWA,&
{ cpL7!>^=
sFileName = value; FHj" nB
} ur)9x^y
l4F%VR4KT
%|auAq&w
public int getNSplitter() _Gn2o2T
{ 7''??X
return nSplitter; W0dSsjNio
} ZGexdc%
3@kf@Vf
Bmr>n6|
public void setNSplitter(int nCount) uGwm r
{ 6a[}'/
nSplitter = nCount; |:nn>E}ZA/
} ;&9)I8Us
} J"!vu.[
Ubh{!Y
Pt@%4 :&-h
/* #VB')^d<U
**Utility.java j.*VJazb;
*/ KhCzD[tf
package NetFox; TMs,j!w?I
Mva3+T
O(tX8P Q5N
public class Utility { }tH[[4tw,
nSF``pp+
uch>AuF:
public Utility() PqyA1
{ R)M_|ca
f6_];]yP
Xcrk;!IB?
} pM{nh00[
Z.W66\8~}^
//线程睡眠 s[K^9wz
public static void sleep(int nSecond) RlqQ
{ &ISb~5
try{ UOGuqV-
Thread.sleep(nSecond); :l2g#* c
} M t*6}Cl
catch(Exception e) _*IPk
{ "S&@F/
e.printStackTrace (); iT;@bp
} DHw&+MY
} Py>{t4;S
!@x+q)2
//日志 FuUD 61JHY
public static void log(String sMsg) /0W9g
{ @*0cMO;SpG
System.err.println(sMsg); :9R=]#uD
} HJ2*y|u
21ppSN>
}w/;){gu
public static void log(int sMsg) Iq#ZhAk
{ b{d4xU8'
System.err.println(sMsg); Ti2Ls5H}
} `}m Q
} JXixYwm
~`GhS<D
kdxz!
/* WYIQE$SEv
**TestMethod.java sK"9fU
*/ yf?h#G%24
package NetFox; T;diNfgg
N7b1.]<
OdQT2PA_
public class TestMethod { Qd_Y\PzS
.MVYB\6Q0
4EXB;[]
public TestMethod() rUlS'L;$"
{ ///xx/weblogic60b2_win.exe Cv>o.Bp|
try{ iweD @b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'S<%Xm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a8dXH5_
SiteFileFetch fileFetch = new SiteFileFetch(bean); rrnNn'
fileFetch.start(); u>Rb ?`
} 'lo
catch(Exception e){e.printStackTrace ();} o7TN,([W
RQkyCAGx
iJv48#'ii
} xrqv@/kJ
jSOS}!=
IcrL
public static void main(String[] args) D?~8za`5
{ lJzl6&
new TestMethod(); tM,%^){p$
} 'JdkUhq1V
} WKrX,GF
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