http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); A#"Wk]jX
} 2!/Kt O)i^
for(int i=0;i<nEndPos.length-1;i++) wGArR7r
{ !LN8=u.
nEndPos = nStartPos[i+1]; tUv>1) [
} wX"hUu
nEndPos[nEndPos.length-1] = nFileLength; i?6&4
} QQ3<)i
} >j5\J_(;D
X1| +9
7=6:ZSI
//启动子线程 At(88(y-W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )5Khl"6!z
for(int i=0;i<nStartPos.length;i++) EjR(AqZY
{ ;l@94)@0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uks75W!}U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h:%,>I%{
nStartPos,nEndPos,i); d/7fJ8y8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MgJ6{xzz
fileSplitterFetch.start(); cfLF@LW!])
} *r`=hNr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v/`D0g-uX)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (u,)v_Oo]a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c?A$Y?|9
nEndPos = " + nFileLength); }\"EI<$s
// fileSplitterFetch[nPos.length-1].start(); 3Zb%-_%j
]" 'yf;g
@Po5AK3cy
//等待子线程结束 q#K{~:
//int count = 0; -N45ni87
//是否结束while循环 }@r23g%
boolean breakWhile = false; DB'0
>f]/VaMH{
KUI{Z I
while(!bStop) v ccH(T
{ k"N>pjgd$
write_nPos(); oPSPb(.
Utility.sleep(500); j_8 YFz5
breakWhile = true; !vSI"$xd
B]rdgjz*
w$}q`k'
for(int i=0;i<nStartPos.length;i++) Nm*(?1
{ :5t4KcQ
if(!fileSplitterFetch.bDownOver) -/Q5?0z
{ Qa{5]+E
breakWhile = false; VdHT3r
break; jRK}H*uem
} #dauXUKH
} O =Z}DGa+
if(breakWhile) F]$ Nu
break; n1-p/a.
Xoe|]@U`
t;8)M$ p
//count++; ;wv[';J
//if(count>4) )@g[aRFa
// siteStop(); 1WUSp;JMl
} @.t +
BlVHP8/b
o=m5AUe?J
System.err.println("文件下载结束！"); 7)rQf{q7
} W5R/Ub@g
catch(Exception e){e.printStackTrace ();} m}]{Y'i]R
} k<9,Ypa
"-4|HA
tr0b#4
//获得文件长度 H,7='n7"
public long getFileSize() %BI8m|6
{ P3oYk_oW
int nFileLength = -1; Xb_ V\b0
try{ S:xXD^n#H
URL url = new URL(siteInfoBean.getSSiteURL()); Hg#tSE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c1H.v^Y5
httpConnection.setRequestProperty("User-Agent","NetFox"); 2q?/aw ;Z
{]CZgqE{
vt EfH
int responseCode=httpConnection.getResponseCode(); 46?z*~*G
if(responseCode>=400) W{,fpm
{ 529;_|
processErrorCode(responseCode); K; #FU
return -2; //-2 represent access is error #VQZ"7nI@
} VfnL-bDGV
>.?yz
aBAoSn
String sHeader; %'2P4(
8FsQLeOE
t[|oSF#i
for(int i=1;;i++) }z]d]
{ ?^&ih:"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ac_P^
//Utility.log(in.readLine()); IFLphm5
sHeader=httpConnection.getHeaderFieldKey(i); ql?w6qFs]
if(sHeader!=null) </I%VHP,[f
{ > X~\(|EM
if(sHeader.equals("Content-Length")) xQ9t1b|{e
{ q!z?Tn#!jd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *DJsY/9d}'
break; WIWo4[(
} _H| )g*]t
} `m 5\
else 5_^d3LOT0x
break; Q2fxsa[
} 8eT#-9q@
} RXXHg
catch(IOException e){e.printStackTrace ();} dDcQSshL
catch(Exception e){e.printStackTrace ();} &8VH m?h
vn.5X
\'O/3Y7?X
Utility.log(nFileLength); KXWcg#zFY
[}L?EM
{|9knP
return nFileLength; Dl!0Hl
} .][yH[F
E~y8X9HZ)
U][E`[m#
//保存下载信息（文件指针位置） PMQTcQ^
private void write_nPos() g`y9UYeh
{ <@J$hs9s
try{ B>u`%Ry&
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8@3=SO
output.writeInt(nStartPos.length); 5OdsT-y
for(int i=0;i<nStartPos.length;i++) i4YskhT
{ r/h\>s+N
// output.writeLong(nPos); }s2CND
output.writeLong(fileSplitterFetch.nStartPos); /JNG}*
output.writeLong(fileSplitterFetch.nEndPos); AD
} |gkNhxzB
output.close(); Uw4iWcC
} {aE[h[=r
catch(IOException e){e.printStackTrace ();} /)K')
catch(Exception e){e.printStackTrace ();} lBP?7`U
} SFg4}*"C/
imOIO[<;
/ Xnq0hN
//读取保存的下载信息（文件指针位置） veDv14
private void read_nPos() zlLZ8b+
{ O72g'qFPE
try{ +v/y{8Fu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DN^+"_:TB
int nCount = input.readInt(); =p|IWn{P
nStartPos = new long[nCount]; 3[#^$_96b
nEndPos = new long[nCount]; :[a*I6/^
for(int i=0;i<nStartPos.length;i++) F-kjv\
{ j+!u=E
nStartPos = input.readLong(); '@t,G,FJ
nEndPos = input.readLong(); w/NT5
} \BBs;z[/
input.close(); kQI'kL8>
} %@QxU-k_
catch(IOException e){e.printStackTrace ();} QFTiE1mGH
catch(Exception e){e.printStackTrace ();} iv`G}.Bo
} }w)}=WmD
aPJTH0u
zd_N' :6
private void processErrorCode(int nErrorCode) Ry[7PLn]
{ #>yOp *
System.err.println("Error Code : " + nErrorCode); |X{j^JP5
} "OwM' n8
:U\*4l
<xBL/e %
//停止文件下载 +;+G+Tn
public void siteStop() D*UxPm"pw
{ 2Ys=/mh
bStop = true; D <~UaHfk
for(int i=0;i<nStartPos.length;i++) 9#[,{2pJr
fileSplitterFetch.splitterStop(); 2-m@-
rk=/iD
!@!603Gy
} 7 \xCNOKh
} T6y~iNd<
//负责部分文件的抓取 kRggVRM
**FileSplitterFetch.java HnPy";{
*/ KyIUz9$
package NetFox; |HAbZd7PG
U]pE{^\w
rFcz0
import java.io.*; ~xzr8 P
import java.net.*; dr#%~I
fFEB#l!oUb
}#g]qK
public class FileSplitterFetch extends Thread { :V$\y up
GX23c i
i^WY/ OhL
String sURL; //File URL 'xd8rN%T
long nStartPos; //File Snippet Start Position i&(1<S>P
long nEndPos; //File Snippet End Position L0VZ>!*o
int nThreadID; //Thread's ID H8g6ZCU~
boolean bDownOver = false; //Downing is over .Z]hS7t
boolean bStop = false; //Stop identical ;u`8pF!_eE
FileAccessI fileAccessI = null; //File Access interface !,$K;L
Bor_(eL^
iB99.,o-&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zw'%n+5m
{ V+D<626o
this.sURL = sURL; it{Jd\/hR
this.nStartPos = nStart; {'alA
this.nEndPos = nEnd; z,ryY'ua/I
nThreadID = id; 1N65 M=)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~%lUzabMa
} {$t*XTY6R
%1 RWF6
[PXq<ST
public void run() #P!<u Lc%
{ Sg%s\p]N_#
while(nStartPos < nEndPos && !bStop) ~jJ.E_i
{ iWWtL
6RIbsy
;Ows8
try{ FD!8o
URL url = new URL(sURL); 6yYjZ<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W*iTg%a\k
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Ndy12,M
String sProperty = "bytes="+nStartPos+"-"; ;HYEJ3
httpConnection.setRequestProperty("RANGE",sProperty); IAbQgBvUD
Utility.log(sProperty); ta5_k&3N
NHUJ:j@
YXTV$A+lW
InputStream input = httpConnection.getInputStream(); +<$nZ=,hsy
//logResponseHead(httpConnection); m|B)A"Sm
}>y!I5O
Rkg)yme!N
byte[] b = new byte[1024]; K%`]HW@I{
int nRead; 4cy,'B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vr"Pr4z4i
{ dHAT($QG
nStartPos += fileAccessI.write(b,0,nRead); ic}TiTK
//if(nThreadID == 1) o6w8Y/VPu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zrSYLG
} CN` ~DD{
22ySMtxn
Y>C05?>
Utility.log("Thread " + nThreadID + " is over!"); 9%21Q>Y?b
bDownOver = true; dYOY8r/
//nPos = fileAccessI.write (b,0,nRead); )^P54_2
} k8J zey]X
catch(Exception e){e.printStackTrace ();} oM>UIDCY_v
} AMB{Fssz
} J:'_S `J
z80(+`
y5c\\e
//打印回应的头信息 ,%A|:T]
public void logResponseHead(HttpURLConnection con) 7MZH'nO
{ |_g7k2oLY
for(int i=1;;i++) T9J&^I
{ E;`^`T40
String header=con.getHeaderFieldKey(i); ]jI<Js*F
if(header!=null) OpazWcMoo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +VQD'
Utility.log(header+" : "+con.getHeaderField(header)); :Hb`vH3x
else /? d)01
break; _R]0S
} }M(xN6E
} qGhg?u"n:
?Hdu=+ZV
) x+edYw
public void splitterStop() n(V{ [
{ )RTWt`
bStop = true; nVoWER:
} _pb*kJ
8G$BQ
9iJ$M!
} wA7\K~fHV
zp:QcL"
~s-gnp
/* tBJ4lb
**FileAccess.java RcJtVOrd
*//文件访问(定位，写) )2l @%?9
package NetFox; Yj bp:
import java.io.*; ,)dlL tUm
/zXOtaG
V'RbTFb9Z
public class FileAccessI implements Serializable{ ~a4Y8r
}pf|GdL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pl[@U<8aw
RandomAccessFile oSavedFile; F =*4]O
long nPos; }%PK %/ zI
o_b3G
|ssl0/nk
public FileAccessI() throws IOException >r\GB#\5
{ _OjZ>j<B.
this("",0); du~V=%9
} h*40jZ
YL!{oHs4
' =5B
public FileAccessI(String sName,long nPos) throws IOException Id`V`|q
{ Nr]Fh
oSavedFile = new RandomAccessFile(sName,"rw"); Sx J0Y8#z
this.nPos = nPos; oj{CNa
oSavedFile.seek(nPos); \1<|X].jNY
} !"yr;t>|Zb
7T6Zlp
5y g`TW
public synchronized int write(byte[] b,int nStart,int nLen) ?Be}{Qqlg
{ aaKf4}
int n = -1; W 2[]m>;
try{ (K8Ob3zN_
oSavedFile.write(b,nStart,nLen); t_!p({
n = nLen; 0fvOA*UP
} QD3tM5(Yr
catch(IOException e) })70S8k
{ uJH[C>
e.printStackTrace (); \X\f~CB
} | ?vm.zp
eC%Skw
Cy/VH"G=
return n; eCsk\f`
} <},JWV3
&wY$G! P
8TAJ#Lm
} <B0f
Xj{fM\,"9
M!i|,S
/* \5!7zPc
**SiteInfoBean.java NZ i3U
*/ g<;::'6
package NetFox; ,e9M%VIu6[
IaSpF<&Y;
<>{m+=gA
public class SiteInfoBean { MYjc6@=cR
ojlyW})$%
*-5N0K<kQ
private String sSiteURL; //Site's URL Q0K$ZWM`7
private String sFilePath; //Saved File's Path .?QYqGcG
private String sFileName; //Saved File's Name N2'aC} I
private int nSplitter; //Count of Splited Downloading File %>=6v}f,+
P[G>uA>Z1
#>bj6<
public SiteInfoBean() :EQ{7Op`
{//nSplitter的缺省值为5 B1!xr-kC
//default value of nSplitter is 5 >O24#!9XW
this("","","",5); 0'Ho'wDb
} , p~1fB-/
J+E,UiZU
}]mxKz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kd^.>T-
{ yCN_vrH>
sSiteURL= sURL; [H<TcT8
sFilePath = sPath; /QyKXg6)l
sFileName = sName; G'G8`1Nj
this.nSplitter = nSpiltter; /<8y>
qT(6TP
Ws`ndR
} uz{RV_IX7
rq8 d}wj
lcm[l
public String getSSiteURL() >god++,o
{ _7;:*'>a4
return sSiteURL; 8vR_WHsL
} ; iia?f1
y{hy7w'd
=gQ9>An
public void setSSiteURL(String value) 1F`jptVQ\G
{ Px=@Tw N,
sSiteURL = value; ;mk[!
} }H\I[5*
1\&j)3mC
]1<GZ`
public String getSFilePath() 9/(jY$Ar
{ v}Ju2}IK
return sFilePath; rjK`t_(=
} u7[}pf$}
sg^|dS{3D
w(6n
public void setSFilePath(String value) <8^x Mjc
{ k[ro[E
sFilePath = value; 0Z8"f_GK
} E(PBV
8\lh'8
ciS,
public String getSFileName() 6qH0]7maI
{ <R /\nYXz
return sFileName; >UaQ7CRo
} /gZyl|kdy
Df^F)\7!N?
'&![h7B
public void setSFileName(String value) ~pQN#C)CO>
{ /qX?ca1_4^
sFileName = value; 'V]&X.=zC
} "GK9Y
?FAI@4
!o /=,ZIx
public int getNSplitter() Eu`|8# [ W
{ r!2U#rz
return nSplitter; w]0@V}}u$o
} [Vo5$w
V9<`?[Usv
RPW46l34
public void setNSplitter(int nCount) $mn0I69
{ aZWj52
nSplitter = nCount; Z]]Ur
} !,m
} CP~ZIIip"
\x}\)m_7M<
IFp%Ta
/* aaR& -M@
**Utility.java ;XurH%Mg
*/ 4a-JC"
package NetFox; hF,|()E[
nMyl(kF[
#0P_\X`E
public class Utility { H;1@]|sH#
P0n1I7|
"0An'7'm
public Utility() VLez<Id9(
{ !#c'| *k
by/H:5}7
GXtK3YAr
} qSc-V`*
vQljxRtW
//线程睡眠 gJ \6cZD
public static void sleep(int nSecond) gw]%: WeH
{ ;miif
try{ Q\N*)&Sd<M
Thread.sleep(nSecond); r=H?fTY<3E
} 0X=F(,>9
catch(Exception e) !!y]pMjJa@
{ t}YcB`q)
e.printStackTrace (); ?*fY$93O
} vk92j?
} b6N[t _,
hx:q@[ +J/
//日志 X7},|cmD_
public static void log(String sMsg) _=GjJ~2n
{ V*giF`gq
System.err.println(sMsg); r/j:A#6M]o
} bv[#|^/
9n& &`r
?b;2PH"
public static void log(int sMsg) $Nu{c;7"
{ F8f}PV]b
System.err.println(sMsg); .[Sis<A]%
} 1M]=Nv
} ubcB<=xb
9TW[;P2> )
D=0YLQ*rP
/* SMEl'y
**TestMethod.java ]`/>hH>+~9
*/ %QezC+n
package NetFox; 1<YoGm&
-s3`mc}*
q+?<cjVg
public class TestMethod { oD)]4|
$w0TEO!
YOl$sgg}
public TestMethod() ?jmP]MM
{ ///xx/weblogic60b2_win.exe DrK]U}3fh"
try{ 0!hr9Y]Lx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :os8"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \P<aK$g
SiteFileFetch fileFetch = new SiteFileFetch(bean); +A| Bc~2!
fileFetch.start(); Q|'f3\
} J:Cr.K`
catch(Exception e){e.printStackTrace ();} 4t, 2H"M
aLa<zEssz
D:z'`v0j
} uvId],dQ5
A)f-r
, >LJpv
public static void main(String[] args) +fP.Ewi
{ -?Cr&!*B
new TestMethod(); G:AA>t
} 5\Q Tm;
} p*;!5;OUR
点击下载更多相关资料