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)); R_xRp&5
} /|#fejPh
for(int i=0;i<nEndPos.length-1;i++) t);/'3|
{ Vs{|xG7WD
nEndPos = nStartPos[i+1]; e(8Ba X_
} FNId;
nEndPos[nEndPos.length-1] = nFileLength; ?Pc'C
} 8sK9G` k
} uA#;G/$
{cw /!B
k.15CA`
//启动子线程 #yvGK:F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cPc</[x[W
for(int i=0;i<nStartPos.length;i++) _n\GNUA
{ 5QO9Q]I#_\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~.lPEA %%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xA[mm
nStartPos,nEndPos,i); Q.c\/&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ROZF)|l
fileSplitterFetch.start(); @!d{bQd,
} *G9V'9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k+l b@!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9k[9P;"F:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XHGFf_kW_N
nEndPos = " + nFileLength); LB?u8>a' I
// fileSplitterFetch[nPos.length-1].start(); %GIr&V4|
-;k+GrLr^
"Os_vlapHo
//等待子线程结束 xFg>SJ7]
//int count = 0; wo5
//是否结束while循环 SOvF[,+
boolean breakWhile = false; `n?DU;,
R .2wqkY
t.\dpBq
while(!bStop) 8|58 H
{ %BB%pC
write_nPos(); ^D-/`d
Utility.sleep(500); w917N4$
breakWhile = true; |)/aGZ+
&~U ]~;@
N_q|\S>t/
for(int i=0;i<nStartPos.length;i++) ('p5:d
{ P J[`|
if(!fileSplitterFetch.bDownOver) R0
{ K@w{"7}
breakWhile = false; 0NX,QD
break; b9dLt6d
} D]Xsvv #
} &m:uO^-D
if(breakWhile) /{--+ C
break; =^50FI|
W#WVfr
Sa;qW3dt3E
//count++; _X"N1,0
//if(count>4) **gXvTqI
// siteStop(); o"R7,N0rB
} WWHoi{q
?R.j^S^
@A^;jk
System.err.println("文件下载结束！"); qVwIo.g!
} =xx]@
catch(Exception e){e.printStackTrace ();} 'qX|jtdM
} G<rHkt@[
#d2.\X}A"3
z]D69O b
//获得文件长度 *w0%d1
public long getFileSize() Jcm&RI"{
{ JQHvz9Yg
int nFileLength = -1; SPmq4
try{ eb"5-0
URL url = new URL(siteInfoBean.getSSiteURL()); ZlzjVU/E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =k`Cr0aPF
httpConnection.setRequestProperty("User-Agent","NetFox"); h6`6tk
UVIKQpA]A
uT7B#b7
int responseCode=httpConnection.getResponseCode(); 1 \6D '/G
if(responseCode>=400) KE3;V2Ym f
{ eHNyNVz
processErrorCode(responseCode); 0o*8#i/)!3
return -2; //-2 represent access is error 6-B|Y3)B
} ):_\;.L
Ur=(.%@
R)ITy!z
String sHeader; 6wECo
!.(P~j][
T&o(N3lW
for(int i=1;;i++) VYImI>.t{
{ Ob`d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !AfHk|
//Utility.log(in.readLine()); s?,Ek
sHeader=httpConnection.getHeaderFieldKey(i); Opc ZU{4b
if(sHeader!=null) JB]q
{ iaE^a^*
if(sHeader.equals("Content-Length")) wLJ:\_Jaf
{ "J8vjr1/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0Bi.6r
break; MC:@U~}6
} rJbf_]^
} !"/n/jz
else @wo(tf=@P
break; 8jo p_PG'
} 90*5 5\>{
} YU5(g^<
catch(IOException e){e.printStackTrace ();} D}8[bWF
catch(Exception e){e.printStackTrace ();} 8MzVOF{"
)@Yf]qx+Y<
"PTZ%7YH}
Utility.log(nFileLength); .NC:;@y
x&Kh>PVh\
g+>(dnX
return nFileLength; qUGC"<W
} 64G[|" j D
k" PayyAC
?3zc=J"t
//保存下载信息（文件指针位置） \VyZ
private void write_nPos() 2:7zG"$
{ n+q!l&&
try{ *XbEiMJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]<rkxgMW>
output.writeInt(nStartPos.length); oO|KEY(
for(int i=0;i<nStartPos.length;i++) 0C irfcs}Z
{ 6vNrBB
// output.writeLong(nPos); %Iv,@}kvT+
output.writeLong(fileSplitterFetch.nStartPos); S:oi<F
output.writeLong(fileSplitterFetch.nEndPos); :AF =<X*5
} ;=; 9tX
output.close(); {rH@gz|@i
} :LRYYw
catch(IOException e){e.printStackTrace ();} SVs_dG$
catch(Exception e){e.printStackTrace ();} %9N7Ln|%
} i}mVQ\j5
RcM/!,B
2Mvrey)
//读取保存的下载信息（文件指针位置） F9E<K]7K
private void read_nPos() Bb^;q#S1
{ +|'c>,?2H
try{ _Wp{[TH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B43HNs
int nCount = input.readInt(); _%!c+f7
nStartPos = new long[nCount]; *@v)d[z_
nEndPos = new long[nCount]; QWSTR\!
for(int i=0;i<nStartPos.length;i++) .C(eh
{ >qjq=Ege
nStartPos = input.readLong(); b8"?VS5-"
nEndPos = input.readLong(); LO khjHR
} dx&'fe*?
input.close(); `YLD`(\
} D=m9fFz
catch(IOException e){e.printStackTrace ();} [nc4{0aT'
catch(Exception e){e.printStackTrace ();} +*T7@1
} : $Y9jR
E2@65b$
Q<'nE
private void processErrorCode(int nErrorCode) dzsmIV+
{ v7jq@#-
System.err.println("Error Code : " + nErrorCode); P&)xz7wG
} 1H@>/QC
,)Ju[
9N<<{rQ,F
//停止文件下载 6)-X
public void siteStop() 57zSu3v4Y
{ [los dnH^?
bStop = true; -o[x2u~n\
for(int i=0;i<nStartPos.length;i++) =;3Sx::=
fileSplitterFetch.splitterStop(); 7/ysVWt
Z&4&-RCi
WDc+6/<
} EQ`(yj
} {G}.b)9FG
//负责部分文件的抓取 0Lc9M-Lg
**FileSplitterFetch.java Lz!,kwg
*/ Fzpfoz<N
package NetFox; !*m5F8Qm?A
LuSLkLN
%Bn?n{/
import java.io.*; V|/NB
import java.net.*; zb}9%.U
:xD=`ib
v!Pb`LCqK
public class FileSplitterFetch extends Thread { /<}m? k\
>.'*)@vQi
Nz+949X
String sURL; //File URL rI>aAW'
long nStartPos; //File Snippet Start Position 8lb%eb]U
long nEndPos; //File Snippet End Position SAK!z!t
int nThreadID; //Thread's ID L%K\C
boolean bDownOver = false; //Downing is over c^u"I'#Q
boolean bStop = false; //Stop identical /X(t1+
FileAccessI fileAccessI = null; //File Access interface #qI= Z0Y
{u\Mj
e7(ucE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TUDr\' @/f
{ ? glSC$b
this.sURL = sURL; IOoz^/'
this.nStartPos = nStart; j!4et;
this.nEndPos = nEnd; =fve/_Q~
nThreadID = id; 2viM)+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mc_ch$r!
} 9@52Fg;mj
x2z;6)
PBxCx3a{
public void run() X4t s)>"d
{ ;A'Z4=*~
while(nStartPos < nEndPos && !bStop) 2 :mn</z
{ I8<,U!$
!+4cqO
;3: q?&
try{ !{)tSipd
URL url = new URL(sURL); xw T%),
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M57T2]8,
httpConnection.setRequestProperty("User-Agent","NetFox"); w{uuSe
String sProperty = "bytes="+nStartPos+"-"; }_;!hdYq
httpConnection.setRequestProperty("RANGE",sProperty); g'=B%eO$j:
Utility.log(sProperty); .I'o
c`WHNky%j
R~jHr )0.#
InputStream input = httpConnection.getInputStream(); IS[thbzkZ
//logResponseHead(httpConnection); 2KN6}
;M#_6Hd?qD
O:"*q&;J
byte[] b = new byte[1024]; =gvBz| +
int nRead; r8&^>4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IWveW8qJ
{ E3l> 3
nStartPos += fileAccessI.write(b,0,nRead); _~tEw.fM5
//if(nThreadID == 1) 0=q;@OIf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *U$!I?
} ivz>dJ?T
'd&0Js$^
=;|QZ"%E
Utility.log("Thread " + nThreadID + " is over!"); 'GoZqiYT
bDownOver = true; ]M[#.EX
//nPos = fileAccessI.write (b,0,nRead); HJ[/|NZU$
} 3g~^[&|i
catch(Exception e){e.printStackTrace ();} /K{9OT@>
} kbfC|5S
} L%$|^T=%
jfx8EbQ
.8uz 6~
//打印回应的头信息 pM&YXb?
public void logResponseHead(HttpURLConnection con) RZ7(J
{ 7kK #\dI
for(int i=1;;i++) ZP$-uaa-
{ e9Pk"HHl
String header=con.getHeaderFieldKey(i); ~-t>z
if(header!=null) UMp/\&0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A@D2+fS
Utility.log(header+" : "+con.getHeaderField(header)); 3 M10fI?
else { "xln/
break; :nS;W
} G,<T/f .{$
} A'K%WW*'U
#nO|A\N
j.ldaLdG
public void splitterStop() kR@Yl Yo
{ 7Irau_
bStop = true; o/ mF#
} :BukUket1e
K+)%KP
zYv#:>C8
} q4$+H{xB
F3lw@b3])
xc:!cA{V
/* -;XKcS7Ue
**FileAccess.java Hiv!BV|
*//文件访问(定位，写) wpt='(
package NetFox; %?hsoj&k
import java.io.*; m8JR@!t7
Ty@=yA17
:!f(F9
public class FileAccessI implements Serializable{ q$.{j"cZV
dg7=X{=9jv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KZe)K_1[
RandomAccessFile oSavedFile; tYqs~B3
long nPos; I.@hW>k
A[dvEb;r
X$b={]b
public FileAccessI() throws IOException ORWm C!
{ &G>(9
this("",0); [;oCYb$9
} ,chf~-d
dj&}Gedy
ZC4*{
public FileAccessI(String sName,long nPos) throws IOException iH2n.M "
{ m&0"<V!H/B
oSavedFile = new RandomAccessFile(sName,"rw"); l\!-2 T6Y
this.nPos = nPos; ]G}B 0u3
oSavedFile.seek(nPos); Q2%QLM:.,
} O:/yAc`
0l#)fJo
cj|*_}
public synchronized int write(byte[] b,int nStart,int nLen) u%dKig
{ $7Mtt.d6
int n = -1; >71&]/Rv
try{ &&<9p;E
oSavedFile.write(b,nStart,nLen); O^I[ (8Y8
n = nLen; }2r+%V&4
} 5q<zN
catch(IOException e) ^Ori| 4}'
{ l n}}5Q
e.printStackTrace (); "%QD{z_L
} Y?r po
v)kEyX'K2d
>7U>Yh
return n; j#6|V]l
} iG,t_??
- ?!:{UXl
$O:w(U
} 68'>Zbelb
do>"[RO
1GE|Wd
/* QldzQ%4c\
**SiteInfoBean.java d(*fy}
*/ W {.78Zi9K
package NetFox; hvt@XZT
m>e3vu
dYojm1MQ
public class SiteInfoBean { *NSlo^R-[
pY^9l3y^
l t]B#, '
private String sSiteURL; //Site's URL F X1ZG!
private String sFilePath; //Saved File's Path f|aDTWF
private String sFileName; //Saved File's Name VzRx%j/i
private int nSplitter; //Count of Splited Downloading File ]yX@'f
D;F{1[s(
fd8#Ng"1
public SiteInfoBean() %xyX8c{sP
{//nSplitter的缺省值为5 jB^OP1
//default value of nSplitter is 5 "]-],K
this("","","",5); +MO E
} M\+*P,i
8xI`jE"1
W)SjQp6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Hwe)Tsh e
{ s3lwu :4f
sSiteURL= sURL; @#b0T:+v'
sFilePath = sPath; mg+k'Myo+
sFileName = sName; ~HUZ#rUHm>
this.nSplitter = nSpiltter; 9 K
K2/E#}/
f!-Sz/c#
} Gwd{#7FM`
NyI;v=
c! H 9yk
public String getSSiteURL() r.FLGDU
{ ~k4W<
return sSiteURL; ^,2c-
} 5y_"
2N6=8Xy5K
/'>;JF
public void setSSiteURL(String value) .)8
{ l@d gJ
sSiteURL = value; X#+`e+Df
} h[ 6hM^n
H]qq ~bO[
{B yn{?w
public String getSFilePath() '%3{jc-}
{ LnMwx#^*
return sFilePath; ,\hYEup
} DB&SOe
hD 46@
! VRI_c
public void setSFilePath(String value) z-0:m|=yH
{ -%uy63LbHF
sFilePath = value; ^w6eWzI
} 5urE
Y%vP#>h
ixOw=!@
public String getSFileName() WhUa^
{ "jU
return sFileName; bBE^^9G=Z
} }g,X5v?W
s%dF~DSK
ehc<|O9tY
public void setSFileName(String value) @&/\r 7 '
{ ] EyeBF)$
sFileName = value; NFoZ4R1gy
} TSyzdnMvz
( ji_o^
!5;t#4=
public int getNSplitter() L+Nsi~YVq
{ #DaP=k"XV
return nSplitter; \3 KfD'L
} c57bf
S_!R^^ySG9
s}b*5@8|tA
public void setNSplitter(int nCount) 4ROWz
{ (/q}mB
nSplitter = nCount; t+}uIp42<
} '{D%\w5{
} Hz4uZ*7\|
5~yb ~0
Fi{mr*}
/* ~iT{8
**Utility.java .xv^G?GG
*/ \2eFpy(
package NetFox; 'O1.6*K
j];1"50?
n^Au*'
public class Utility { anitqy#E
xXa#J)'
#HcI4j:s!
public Utility() )9pBu B
{ s@M
kOM-
LI$L9eNv;Y
} )O-sWh4
sRil>6QR
//线程睡眠 8I {56$
public static void sleep(int nSecond) 6NKF'zh
{ >|S>J+(
try{ V?WMj $l<
Thread.sleep(nSecond); I]UA0[8X
} mc56L[
catch(Exception e) Suj}MEiv
{ QZ9M{Y/
e.printStackTrace (); IM|Se4;x
} A&?WP\_z
} O^Dc&w
m>+A*M8
//日志 Bzwx0c2VY8
public static void log(String sMsg) qIUC2,&g
{ T7X!#j"\
System.err.println(sMsg); EXH!glR[$
} 2tlO"c:_/
'NRN_c9
G:){^Z?
public static void log(int sMsg) w-8)YJ Y
{ -{r!M(47
System.err.println(sMsg); f>b!-|
} 5]Z]j[8Y
} 7a27^b
sF, uIr/
Xd5! Ti}
/* &?fvt
**TestMethod.java c[6zX#{`
*/ lP-kZA!
package NetFox; orK+B4
SSo~.)J
xBt4~q;#sE
public class TestMethod { xg4T` ])
}$&);7(w
[cY?!Qd0
public TestMethod() kkG_ +Y
{ ///xx/weblogic60b2_win.exe >J?jr&i
try{ {[rO2<MkA#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |^\Hv5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L)j]~^P$-
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8p3ZF@c~t
fileFetch.start(); Rqt[D @;m
} ejDCmD
catch(Exception e){e.printStackTrace ();} wZ}n3R,
u_hE7#i
yDDghW'\WU
} dW:w<{a!R
T;xHIg4
f45;fT>
public static void main(String[] args) &8o :
{ O>kXysMv>
new TestMethod(); :tg@HyY)
} Cw@k.{*7,
} DHSU?o#jY
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