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)); ~*~aFf5
} [i>D|X
for(int i=0;i<nEndPos.length-1;i++) Eq8:[o
{ R?}%rP+^e
nEndPos = nStartPos[i+1]; }?O>.W,/
} B2WPbox
nEndPos[nEndPos.length-1] = nFileLength; 5a2;@}%V
} .R@XstQ
} }wJH@'0+
0wF)bQv1
%/!f^PIwX
//启动子线程 !RjC0,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,Hp7`I>/
for(int i=0;i<nStartPos.length;i++) ?/~Q9My
{ 8k.#4}fP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "tDB[?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #&z'?x^a
nStartPos,nEndPos,i); $`lGPi(Jc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R[m+s=+
fileSplitterFetch.start(); a\B?J
} (S6>^:;=~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %.fwNS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5*Dh#FRp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5CH8;sMK
nEndPos = " + nFileLength); bZj5qjl`x
// fileSplitterFetch[nPos.length-1].start(); !QME!c>*$
GNW.n(a
[8 23w.{]#
//等待子线程结束 6J cXhlB`
//int count = 0; wX!0KxR/Z
//是否结束while循环 5 (q4o`
boolean breakWhile = false; "=$uv
zW[HGI6w
azRp4~2?
while(!bStop) S]4!uv^y
{ N,F[x0&?
write_nPos(); 5UG"i_TC
Utility.sleep(500); 4]xD-sc
breakWhile = true; lcfs 1].
uE..1N&*
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for(int i=0;i<nStartPos.length;i++) v9#F\F/
{ RS2uk7MB
if(!fileSplitterFetch.bDownOver) bY~V?yNgKM
{ Iy5)SZ'
breakWhile = false; I-Am9\
break; w.+G+r=
} ~{{7y]3M-
} S&Hgr_/}c
if(breakWhile) gTdr
break; h66mzV:`
_d>{Hz2
\#C]|\
//count++; i7&ay\+@
//if(count>4) DJ1!Xuu
// siteStop(); /7ykmW
} $9W,1wg
iRV=I,
QQ %W3D@
System.err.println("文件下载结束！"); crgVedx~}
} UH((d*HX4
catch(Exception e){e.printStackTrace ();} {GGP8
} Q4g69IE
Y+0GJuBf
hANe$10=H
//获得文件长度 vVjk9_Ul
public long getFileSize() :8]y*j
{ I(z16wQ
int nFileLength = -1; *-E'$
try{ =yPV9#(I/
URL url = new URL(siteInfoBean.getSSiteURL()); I`x[1%y2 F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s+h}O}RV
httpConnection.setRequestProperty("User-Agent","NetFox"); L}K8cB
Kv ajk~
\Y6r !D9
int responseCode=httpConnection.getResponseCode(); 6yC4rX!a
if(responseCode>=400) RQ8;_)%
{ Lx|0G $
processErrorCode(responseCode); .F/s(
return -2; //-2 represent access is error %kP=VUXj
} F><ficT
CbOCL~ "
xX.{(er
String sHeader; h"f_T [
7s Gf_`Z
l4U
for(int i=1;;i++) 5!Ovd O}g
{ YU\k D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $KS!vS7
//Utility.log(in.readLine()); qTGi9OP6/
sHeader=httpConnection.getHeaderFieldKey(i); [* |+ it+!
if(sHeader!=null) }-T,cA_H|
{ O-3aU!L
if(sHeader.equals("Content-Length")) @]Ac >&
{ drbim8!q~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eAjsMED
break; /E:BEm!
} T`GiM%R;g
} .X:,]of
else hUEA)c
break; Mt@Ma ]!
} WYIv&h<h"
} +fQJ#?N2n
catch(IOException e){e.printStackTrace ();} dZ4c!3'F
catch(Exception e){e.printStackTrace ();} I^[[*Bh*C
$<3^( y
,}NTV~
Utility.log(nFileLength); -wh
gJ^taUE
4zZ.v"laVM
return nFileLength; x~](d8*=
} s&XL{FE
o.s(=iG
bRr3:"=sE
//保存下载信息（文件指针位置） F45-M[z
private void write_nPos() /<Z3x _c
{ M C y~~DL
try{ PZI6{KOis
output = new DataOutputStream(new FileOutputStream(tmpFile)); m>*~tP
output.writeInt(nStartPos.length); cM]ZYi
for(int i=0;i<nStartPos.length;i++) m|v$F,Lv
{ ZKM@U?PK
// output.writeLong(nPos); #$}A$sm
output.writeLong(fileSplitterFetch.nStartPos); 5=8t<v1Bn
output.writeLong(fileSplitterFetch.nEndPos); !lBK!'0
} as@? Kv
output.close(); %AmyT
} DVDzYR**4
catch(IOException e){e.printStackTrace ();} $)d34JM
catch(Exception e){e.printStackTrace ();} Mh{>#Gs
} Eqh*"hE7
T wzpq1
;d FJqo82
//读取保存的下载信息（文件指针位置） LjIkZ'HuF
private void read_nPos() nYe:$t3F=
{ 9Q'[>P=1
try{ p1W6s0L
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )KGz -!1c
int nCount = input.readInt(); #w:nj1{_
nStartPos = new long[nCount]; gEw9<Y
nEndPos = new long[nCount]; 0E)M6 jJ
for(int i=0;i<nStartPos.length;i++) "8~PfLJ+
{ ,H1K sN
nStartPos = input.readLong(); }F|B'[wn
nEndPos = input.readLong(); hE<Sm*HU
} }daU/
input.close(); Wfy+9"-;s
} ^x_$%8
catch(IOException e){e.printStackTrace ();} KLG29G
catch(Exception e){e.printStackTrace ();} YOUB%N9+
} =|2F?
X#zp,7j?
U+C^"[B
private void processErrorCode(int nErrorCode) :}-?X\|\
{ {WQ6=wGpS
System.err.println("Error Code : " + nErrorCode); vKfjP_0$
} lS#^v#uS
-!K&\hEjj
k|{ 4"4r
//停止文件下载 /_YTOSZjm
public void siteStop() y|zIuI-p
{ wuW{2+)B
bStop = true; 8H`L8: CM
for(int i=0;i<nStartPos.length;i++) [B+:)i
fileSplitterFetch.splitterStop(); c2?VjuB0
y~su1wUp
G6+6uWvl
} )PW|RW
} EY:H\4)
//负责部分文件的抓取 ?[P>2oz
**FileSplitterFetch.java oB~V~c}8x
*/ @;N(3| n7
package NetFox; i%, 't
j(k}NWPH
b*/Mco 9O
import java.io.*; #=;vg
import java.net.*; B2|0.G|[j
DIJmISk
)dh`aQ%N "
public class FileSplitterFetch extends Thread { B<HN$/
L&~'SC
upX@8WxR
String sURL; //File URL H6Bw3I[
long nStartPos; //File Snippet Start Position lJdYR'/Wd
long nEndPos; //File Snippet End Position j; R20xf0
int nThreadID; //Thread's ID B|,d
boolean bDownOver = false; //Downing is over 3s67)n
boolean bStop = false; //Stop identical <]X6%LX
FileAccessI fileAccessI = null; //File Access interface 9X +dp
xGOVMo +
L./c#b!{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g-1j#V`5
{ X$6QQnyR
this.sURL = sURL; Xo&\~b#-
this.nStartPos = nStart; cbs ;
this.nEndPos = nEnd; adAdX;@e`
nThreadID = id; $RNHRA.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F^aD#
} Tku6X/LF
g"(@+\XZH"
=\oL'>q
public void run() gVI`&W__,
{ %QEyvl4
while(nStartPos < nEndPos && !bStop) uG +ZR: _
{ M&<qGV$A
Px9 K
;(A-
try{ _zi| GD
URL url = new URL(sURL); 8R:Glif
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O0s!3hKu
httpConnection.setRequestProperty("User-Agent","NetFox"); yn_.
String sProperty = "bytes="+nStartPos+"-"; j>uu3ADd2
httpConnection.setRequestProperty("RANGE",sProperty); O:GAS [O`
Utility.log(sProperty); os&FrtDg
*'-t_F';
>,h{`
InputStream input = httpConnection.getInputStream(); ^E:-Uy
//logResponseHead(httpConnection); ByO?qft>u
m7C!}l]9
3,X8 5`v^
byte[] b = new byte[1024]; k7;i^$@c
int nRead; /wl]kGF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U_j[<.aN)
{ !pkIaCxs
nStartPos += fileAccessI.write(b,0,nRead); S^|U"
//if(nThreadID == 1) z Tz_"NI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }/,Rp/+7]
} R!lug;u#
RA;/ ?l
-sZb+2tDa
Utility.log("Thread " + nThreadID + " is over!"); Li"+`
bDownOver = true; W&&|T;P<J
//nPos = fileAccessI.write (b,0,nRead); 8lGM>(:o
} E*wG5]at
catch(Exception e){e.printStackTrace ();} #z<#oC5
} EtaKo}!A}
} ! K_<hNG&
E_DQ.!U!o
odC"#Rb
//打印回应的头信息 Xo]2iQy
public void logResponseHead(HttpURLConnection con) <lWj-+m
{ &1?6Q_p6c
for(int i=1;;i++) s=F[.X9lp
{ G6}&k[d5%
String header=con.getHeaderFieldKey(i); DwZRx@
if(header!=null) URg;e M#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :#35mBe}k
Utility.log(header+" : "+con.getHeaderField(header)); w0lgB%97p
else (Y8LyY
break; =QbOvIq
} vt^7:!r
} R=&-nC5e
EP>Lh7E9n
4,Oa(b
public void splitterStop() <\O8D0.d
{ $eG_LY 1v
bStop = true; _X mxBtk9f
} 6M_:D
_aF8Us
D,[Nn_N
} ]'M B3@T
G &NK
ZfH>UHft
/* 8ih_S2Cd
**FileAccess.java D7JrGaF{
*//文件访问(定位，写) $u'"C|>8
package NetFox; ;UM(y@
import java.io.*; S50}]5K
VltM{-k^
cs.t#C
public class FileAccessI implements Serializable{ xW*Lceb
g,!.`[e'ex
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H.E=m0np
RandomAccessFile oSavedFile; OFyy!r@?
long nPos; *PV"&cx
7aKI=;60.
4%w<Ekd
public FileAccessI() throws IOException bv'>4a
{ law$LL
this("",0); kp*!
} JGTsVa2
SA&(%f1d
naH(lz|v
public FileAccessI(String sName,long nPos) throws IOException %.r\P@7/Q
{ p9u*l
oSavedFile = new RandomAccessFile(sName,"rw"); A%HIfSzQBS
this.nPos = nPos; $p4e8j[EJ
oSavedFile.seek(nPos); G9LWnyQt
} 6kLy!QS
/j}Tv.'d
+Ln^<!P
public synchronized int write(byte[] b,int nStart,int nLen) GD]epr%V
{ b @0=&4
int n = -1; 3di;lzGq
try{ T4p}5ew'
oSavedFile.write(b,nStart,nLen); ?%qaoxG37
n = nLen; e98QT9
} Y6H?ZOq
catch(IOException e) D"$Y, d
{ &*ocr&
e.printStackTrace (); CJ%'VijhD
} K8MET&
,f>9oOqqA
^>Z_3{s:$
return n; 1/w8'Kf'u
} h]t v+\0
%<a3[TQd`\
B ;E"VS0
} 9X=<uS
`y^\c#k
amC)t8L?
/* Ao}<a1f
**SiteInfoBean.java dVj2x-R)
*/ :i?6#_2IC
package NetFox; h8 N|m0W
5R~M@
5$'[R;r
public class SiteInfoBean { tzGQo5\
`4'=&c9
R2a99#J
private String sSiteURL; //Site's URL iz^uj
private String sFilePath; //Saved File's Path -V}xvSVg
private String sFileName; //Saved File's Name Kc2y
private int nSplitter; //Count of Splited Downloading File gDLS)4^w
EJTM >Rpor
O!f37n-TB
public SiteInfoBean() 4c 8{AZ
{//nSplitter的缺省值为5 l1'v`!
//default value of nSplitter is 5 k)*apc\W
this("","","",5); =Q<7[
} + c3pe4
*->*p35
mHW%:a\L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Gt*K:KT=L
{ vr4r,[B6y
sSiteURL= sURL; h+j^VsP zB
sFilePath = sPath; z{\tn.67
sFileName = sName; `14@dk
this.nSplitter = nSpiltter; |e2s\?nB0S
m!w|~Rk
3lZl
} ;#9?3Os
=LV-n
U!r8}@
public String getSSiteURL() XK3O,XM
{ ^O@eyP
return sSiteURL; B!x#|vGXL
} l+P!I{n
b)KEB9w
`MPR-"Z6
public void setSSiteURL(String value) k &J;,)V
{ JfWkg`LqL
sSiteURL = value; axvZA:l
} ph6'(,
tyW}=xs
uuwJ-
public String getSFilePath() c( U,FUS
{ !"qT2<A
return sFilePath; [niFJIsc
} R3_OCM_*
[.xY>\e
qm><}N7f
public void setSFilePath(String value) t :YZua
{ P8By~f32_
sFilePath = value; ;xz_H$g
} 1-?i*C
"J+L]IC?AD
"0jwCX Cu
public String getSFileName() Z8bg5%
{ I]W7FZ=o
return sFileName; 7afG4 (<k
} U?f-/@fc
83Rs1}*
f|w;u!U(
public void setSFileName(String value) AP,ZMpw
{ E!1\9wzM{
sFileName = value; ri8=u$!
} 9MZ)-
hDB(y4/
K 'l-6JY-
public int getNSplitter() Sxc)~y
{ %\48hSe
return nSplitter; TCRTC0_}k
} V;MmPNP|
;a1DIUm'
qCcLd7`$
public void setNSplitter(int nCount) B<r0y
{ |X:`o;Uma
nSplitter = nCount; uXFI7vV6P
} K |=o-
} z*jaA;#
)u{]rb[
|=YK2};
/* vi^YtA
**Utility.java _";w*lg}
*/ rrRv 7J&Q
package NetFox; 5?`4qSUz
V? tH/P
LJ@(jO{z
public class Utility { +`Q]p"G
vFdI?(c-
V':A!
public Utility() 3GE;:;8B
{ eEVB
'9WTz(0?
Yl&[_ l
} d"?"(Q_8n
m85ZcyW1T
//线程睡眠 O-V]I0
public static void sleep(int nSecond) Yh1nXkA!V
{ Q<AOc\oO
try{ ~HGSA(
Thread.sleep(nSecond); SF;\*]["f
} l VD{Y`)
catch(Exception e) P-2DBNB7
{ EoPvF`T
e.printStackTrace (); AA^K/y
} 9;6)b0=$
} 0M;El2 P$
\\:%++}J
//日志 5`fUR/|[
public static void log(String sMsg) zo@vuB.
{ vv,<#4d
System.err.println(sMsg); QAxy?m,'
} %XukiA+
e< @$(w
KPz0;2}
public static void log(int sMsg) $Xt""mlQ
{ eC<RM Q4
System.err.println(sMsg); sjLMM_'
} OW};i|
} meV Z_f/
<B|b'XVH2
$Q#n'#c
/* rucw{) _
**TestMethod.java >e/>@ J*
*/ vd#)+
package NetFox; 0/ 33Z Oc
8Pd9&/Y
p%*s3E1.D
public class TestMethod { Sw E7U~
X);'[/]E*
>>J$`0kM*
public TestMethod() ,}W|cm>
{ ///xx/weblogic60b2_win.exe (kO(R#M
try{ R- >~MLeK]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 08jk~$%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u `xQC/
SiteFileFetch fileFetch = new SiteFileFetch(bean); g$e|y#Ic$
fileFetch.start(); Cx~;oWZ
} Mn&_R{{=
catch(Exception e){e.printStackTrace ();} \Db`RvEmR
3S_H&>K
;\A_-a_(#
} 8%;Wyqdf]
30WOH 'n
9teP4H}m
public static void main(String[] args) 0/]h"5H3
{ D`G;C
new TestMethod(); :I&y@@UG
} _XP}fx7$C
} mYo~RXKGF
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