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)); `Dz]z_
} mHI4wS>()+
for(int i=0;i<nEndPos.length-1;i++) D?\"
{ k67i`f=
nEndPos = nStartPos[i+1]; XMeL^|D
} /]k ,,&
nEndPos[nEndPos.length-1] = nFileLength; *2"bG1`
} &3 XFgHo
} ^T}}4I_Y
8tT&BmT
GLaZN4`
//启动子线程 c>u>Pi;Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eHR&N.2
for(int i=0;i<nStartPos.length;i++) <i:*p1#Bm
{ hyk|+z`B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H)j[eZP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _>jrlIfc
nStartPos,nEndPos,i); ;9p#xW6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =q"w2b&
fileSplitterFetch.start(); [$1: &!(!
} {m_A1D/_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RWh9&O:6'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J3lG"Ww
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iL7-4Lv#
nEndPos = " + nFileLength); 9&O#+FU
// fileSplitterFetch[nPos.length-1].start(); e8XM=$@
y(/jTS/hd
Xc8= 2n
//等待子线程结束 kwDh|K
//int count = 0; ^Hz
//是否结束while循环 h\D_
boolean breakWhile = false; &prdlh=UE
]HJ{dcF
cotxo?)Zv
while(!bStop) o;M.Rt\A
{ XI@6a9Uk
write_nPos(); `x%U
Utility.sleep(500); 5T$9'5V7
breakWhile = true; 0\\ueMj
{2}tPT[a(
zqHpT^B?
for(int i=0;i<nStartPos.length;i++) pIID=8RJ.
{ Wz6]*P`qv
if(!fileSplitterFetch.bDownOver) ~8H&m,{j
{ m0xJ05Zx
breakWhile = false; >G-8FL
break; mHK@(D7X
} #/n|@z'
} cS"f
if(breakWhile) G8^0^@o
break; ":UWowJO
2X qTyf<
pY{; Yn&t
//count++; iwG>]:K3
//if(count>4) 3iu!6lC
// siteStop(); L\/u}]dPQ
} SWNU1x{,c\
3o+KP[A
L?=#*4t
System.err.println("文件下载结束！"); {f`lSu
} _L&n&y1+%
catch(Exception e){e.printStackTrace ();} IZ4W_NN
} ONjC(7
rmY,v
XysFwi
//获得文件长度 bDciZ7[b
public long getFileSize() m!HC-[<
{ ;,v!7
int nFileLength = -1; s"I-YFP%c
try{ R4#;<)
URL url = new URL(siteInfoBean.getSSiteURL()); CTh1+&Pa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]^iFqQe
httpConnection.setRequestProperty("User-Agent","NetFox"); |_l<JQvf`E
0OleO9Ua
A5CdLwk
int responseCode=httpConnection.getResponseCode(); jGO9n
if(responseCode>=400) .+{nA}Bc
{ tj#=%m?8V;
processErrorCode(responseCode); K(-G: |
return -2; //-2 represent access is error Zvd ;KGO(a
} r+imn&FK8
g8%MOhg
4mEzcwo'
String sHeader; >X;xIyRL
=]=B}L`
fp.!VOy
for(int i=1;;i++) +IwdMJ8&8
{ Xtuhcdzu[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Hnfvo*6d.e
//Utility.log(in.readLine()); T6sr/<#<(
sHeader=httpConnection.getHeaderFieldKey(i); kVV\*"9y
if(sHeader!=null) fC=fJZU7$
{ <T(s\N5B=
if(sHeader.equals("Content-Length")) =}~NRmmF
{ I["F+kt^^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e(?:g@]-r
break; 6?53q e
} GLo\q:5A
} 0L!er%GM
else 4fu'QZ(}
break; 5Waw?1GL
} z[WC7hvU
} fm3(70F\
catch(IOException e){e.printStackTrace ();} 8# 6\+R
catch(Exception e){e.printStackTrace ();} ^36M0h|R
VYL@RL'
6P0y-%[Gk
Utility.log(nFileLength); cDfx)sL
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return nFileLength; @)9REA(U
} Jb(DJ-&
f&6w;T=
6{5q@9F
//保存下载信息（文件指针位置） PPUEkvH W
private void write_nPos() q $t&|{
{ mG0L !5
try{ aML#Z|n
output = new DataOutputStream(new FileOutputStream(tmpFile)); ' be P
output.writeInt(nStartPos.length); u8|@|t
for(int i=0;i<nStartPos.length;i++) v2IEJ
{ 5iP8D<;o5
// output.writeLong(nPos); VMaS;)0f@
output.writeLong(fileSplitterFetch.nStartPos); 9TqoLX
output.writeLong(fileSplitterFetch.nEndPos); +#0~:&!9
} u@AI&[Z
output.close(); pI &o?n
} Bk&-1>cY
catch(IOException e){e.printStackTrace ();} Xwn3+tSIa
catch(Exception e){e.printStackTrace ();} !A~d[</]m
} F;pTXt}?5
yPSVwe|g
66/Z\H^d
//读取保存的下载信息（文件指针位置） E^7C _JP
private void read_nPos() aPprMQ5
{ "]v uD
try{ I%SuT7"Do
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I4rV5;f H4
int nCount = input.readInt(); ojX%RU
nStartPos = new long[nCount]; NPS.6qY
nEndPos = new long[nCount]; ;?0_Q3IML
for(int i=0;i<nStartPos.length;i++) _B}9f
{ :qBGe1Sv(
nStartPos = input.readLong(); /j11,O?72
nEndPos = input.readLong(); I"B8_
} f(!E!\&n^
input.close(); &j3` )N
} GaHA%
catch(IOException e){e.printStackTrace ();} K*[9j 0
catch(Exception e){e.printStackTrace ();} BlL|s=dlQV
} w2k<)3 g~
-<xyC8$^$
:MK=h;5Z
private void processErrorCode(int nErrorCode) B#1:Y;Z
{ "<qEXX
System.err.println("Error Code : " + nErrorCode); b9`iZ
} Jth=.9mrM
hBjVe?{
ooY\t +
//停止文件下载 =PV/`I_h
public void siteStop() wcwQjHwd
{ ~eHRlXL'
bStop = true; \N?7WQ
for(int i=0;i<nStartPos.length;i++) JfbKf~g
fileSplitterFetch.splitterStop(); 6eM6[
yji>*XG
?<! nm&~
} =9^Q"t4
} p+RAtRf
//负责部分文件的抓取 b"Zq0M0l
**FileSplitterFetch.java s_xV-C#q@
*/ #Gd7M3
package NetFox; B=r0?%DX"1
TiQ^}5~M
GYd]5`ri
import java.io.*; EA6t36|TX
import java.net.*; !Qcir&]C>
]Dh1~k.Kp
te)n{K",
public class FileSplitterFetch extends Thread { 8`*`nQhWa
\2j|=S6
wrabyRjK
String sURL; //File URL ka#K [qI
long nStartPos; //File Snippet Start Position t}VwVf<K
long nEndPos; //File Snippet End Position 6%E~p0)i%
int nThreadID; //Thread's ID nx B32
boolean bDownOver = false; //Downing is over Q{[@`bZB
boolean bStop = false; //Stop identical Lbsr_*4t
FileAccessI fileAccessI = null; //File Access interface 9^au$KoU
+>4^mE" \
[]"=]f{1};
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !9DX=?
{ ~\[?wN
this.sURL = sURL; p'g^Wh
this.nStartPos = nStart; %&tb9_T)d
this.nEndPos = nEnd; .1LPlZ
nThreadID = id; 7-X/>v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {\EOo-&A
} J,(7.+`~#
MQJ%He"
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public void run() 0yz~W(tsm
{ S7CV w,2
while(nStartPos < nEndPos && !bStop) 'l|R5
{ FN!1|'VK
'#W_boN
W^k,Pmopy
try{ iV!@bC,
URL url = new URL(sURL); 5}XvL'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1q]&7R
httpConnection.setRequestProperty("User-Agent","NetFox"); 1[s0Lz
String sProperty = "bytes="+nStartPos+"-"; g8l5.Mpx
httpConnection.setRequestProperty("RANGE",sProperty); @o&Ytd;i
Utility.log(sProperty); ?Wa<AFXQ
[Tp%"f1
m6i%DE
InputStream input = httpConnection.getInputStream(); J(e7{aRJ9
//logResponseHead(httpConnection); iDw.i"b
&\^rQi/tf
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byte[] b = new byte[1024]; yUe+":7k.
int nRead; =Dk7RKoHF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @\jQoaLT$_
{ _=EZ `!%
nStartPos += fileAccessI.write(b,0,nRead); h>klTPM>
//if(nThreadID == 1) I+",b4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AkA!:!l
} "r..
OJpj}R
'E-FO_N
Utility.log("Thread " + nThreadID + " is over!"); ^C7C$TZS
bDownOver = true; G6Nb{m
//nPos = fileAccessI.write (b,0,nRead); NAJVr}4f
} 7Cy<mS
catch(Exception e){e.printStackTrace ();} DsGI/c
} %i"}x/CD[
} EnJ!mr
=EpJZt
0hwj\{"
//打印回应的头信息 PS@*qTin
public void logResponseHead(HttpURLConnection con) Ri @`a
{ J633uH}}
for(int i=1;;i++) 7W|Zq6pi
{ :gf;}
String header=con.getHeaderFieldKey(i); k.GA8=]>
if(header!=null) XYAmJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .S7:;%qL6
Utility.log(header+" : "+con.getHeaderField(header)); "SR5wr
else [PWL<t::c
break; <lj\#'G3
} R ]P;sk5
} >1ZJ{se
6P*O&1hv
sS9%3i/>
public void splitterStop() TzKK;(GX
{ wkBL=a
bStop = true; 3?`"
} ?WHy0x20
#epy%>
p`P~i&_
} x=*L-
aWGon]2p
EB,4PEe:
/* 1'O0`Me>#
**FileAccess.java Im)EDTm$
*//文件访问(定位，写) Uc&iZFid2K
package NetFox; ,S!w'0k|n
import java.io.*; CW`!}yu%
f Iy]/
ipjkZG@
public class FileAccessI implements Serializable{ 3Aj*\e0t
o`6|ba
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }l;Lxb2`
RandomAccessFile oSavedFile; Yb:pAzw6
long nPos; :(p)1=I
r}W2Ak\
8\Hr5FqB(
public FileAccessI() throws IOException wC` R>)
{ 1mH\k5xu
this("",0); SlaDt
} F,T~\gO5,
1*UNsEr
LchnBtjn
public FileAccessI(String sName,long nPos) throws IOException &tE.6^F
{ /k6fLn2;
oSavedFile = new RandomAccessFile(sName,"rw"); 6+`tn
this.nPos = nPos; Yc;ec9~
oSavedFile.seek(nPos); n7l%gA*
} >]?H`>4(
|W7rr1]~S
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public synchronized int write(byte[] b,int nStart,int nLen) b{5K2k&,
{ Tlodn7%",
int n = -1; 9wh2f7k
try{ YRcps0Dx9
oSavedFile.write(b,nStart,nLen); L*]0"E
n = nLen; Xy7Z38G
} jd:B \%#![
catch(IOException e) 1RqgMMJL
{ *b)Q5dw@1
e.printStackTrace (); 0LL c 1t>}
} Zyye%Ly
9[Qd)%MO
\#,t O%D
return n; KnzsHli,~k
} YQ]\uT>}&
!;3PG9n3|h
a07=tD
} ll<NIdf\r
M1!pQC_9
\Fb| {6+
/* Qe$k3!
**SiteInfoBean.java %b}gDWs
*/ _*6v|Ed?
package NetFox; k\7:{y@,
)=^w3y
`<fh+*
public class SiteInfoBean { 9|WV~
ga0'zo9K
Ph,-sR
private String sSiteURL; //Site's URL cQUC.TZ_
private String sFilePath; //Saved File's Path i7Z=|&
private String sFileName; //Saved File's Name ]axh*J3`i
private int nSplitter; //Count of Splited Downloading File *xs!5|n+
%fjuG
z#Nl@NO&
public SiteInfoBean() Fn|gVR
{//nSplitter的缺省值为5 ]v29 Rx
//default value of nSplitter is 5 uTvv(f
this("","","",5); K_/B?h
} SO?8%s(
m{%t?w$Au
;4#D,zlO^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LE=k
{ [QczlwmO
sSiteURL= sURL; *"{&FEV
sFilePath = sPath; x?yD=Mq_
sFileName = sName; #kmh:P
this.nSplitter = nSpiltter; _GoVx=t
KL?)akk
Pz"`MB<'Ik
} (pR.Abq
\\4Eh2 Y
A74920X`W
public String getSSiteURL() ,|T7hTn=
{ BavO\{J#|0
return sSiteURL; SpSnoVI
} b=[?b+
0$vj!-Mb^j
E~hzh /,34
public void setSSiteURL(String value) slW3qRT\k
{ T-" I9kM
sSiteURL = value; "ZMkL)'7-
} ]MTbW=*}ED
q/&y*)&'O
8im@4A+n`
public String getSFilePath() &h~aChJ
{ MXvXVhCU
return sFilePath; ;%!m<S|%k
} [rYT
YJF#)TkF
`,>wC+}
public void setSFilePath(String value) 2#5,MP~r
{ nCxAQ|P?
sFilePath = value; "$^0%-
} } :?.>#
" Ar*QJ0]
!K0JV|-?t
public String getSFileName() <vc`^Q&4B
{ 3I=kr
return sFileName; XhW %,/<
} M8;lLcgu.
$#NQ<3
F} DUEDND*
public void setSFileName(String value) eiMH['X5
{ 6[dur'x
sFileName = value; ,^s
} )R)a@op
40P) 4w
4FMF|U
public int getNSplitter() 6`H.%zM
{ xi'>mIT
return nSplitter; z(HaRB3l
} ~,gXaw
1yqoA*
;3ft1
public void setNSplitter(int nCount) /CX VLl8~
{ {padD p
nSplitter = nCount; `$5UHa2/
} \FzM4-
} 15H6:_+=0
:14i?4Fd
L2z2}U=<
/* ":;@Hnb/
**Utility.java i6PM<X,{;
*/ '/%zi,0
package NetFox; UVuDQ
)mcEQ-!b
fys
public class Utility { K\.5h4k
VM=+afY5M
oR#:NtX@
public Utility() K`KLC.j
{ v90T{1+M|4
9}tG\0tL*
m~l F`?
} ,TC;{ $O5
x8#ODuH
//线程睡眠 SAv<&
public static void sleep(int nSecond) `k{& /]
{ \c`oy=qY0
try{ Es5p}uh.[Y
Thread.sleep(nSecond); ra7uU*
} qv{o|g QB
catch(Exception e) zsl,,gk9Y
{ aw $L$7b}
e.printStackTrace (); %:C ]7gQ
} r64u31.)
} ! T9]/H?
Yxd X#3
//日志 -p,x&h,p
public static void log(String sMsg) b'@we0V@S
{ v"DL'@$Ut{
System.err.println(sMsg); H:{7X1bV
} {{yt*7k{
hZ\+FOx;
8nNsrat
public static void log(int sMsg) C'mL&
{ H}0dd"
System.err.println(sMsg); u=+q$Q]
} c9Es%@]
} =([av7
=H5\$&xj4.
alFjc.~}
/* c@m5~
**TestMethod.java ub?K,
*/ hq>Csj==@
package NetFox; g=)J~1&p
<g2_6C\j
%g"eV4j
public class TestMethod { ]rBM5~
VDEv>u4
}OShT+xeX
public TestMethod() j8,n7!G
{ ///xx/weblogic60b2_win.exe `cB_.&
try{ 748CD{KxW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uZ6d35MJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WgGm#I>K
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7Hw<ojkt
fileFetch.start(); }odV_WT
} |01?w|
catch(Exception e){e.printStackTrace ();} bMoAD.}
d}I(`%%)
KU&G;ni2
} _Tm0x>EM
?[)S7\rP
|I8Mk.Z=FA
public static void main(String[] args) /i|z.nNO
{ jk~:\8M(A
new TestMethod(); !mfJpJ
} dx_6X!=.J
} Bo_ym36N
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