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)); |w>DZG!}1-
} {< wq}~
for(int i=0;i<nEndPos.length-1;i++) m3|,c[M1
{ Hv IN'
nEndPos = nStartPos[i+1]; p,1RRbyc
} 0<Pe~i_=
nEndPos[nEndPos.length-1] = nFileLength; @?%"nK
} :#|77b0
} \NSwoP
?=T&|pp
vu#:D1/BB
//启动子线程 %%3ugD5i!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Em?skUnG,
for(int i=0;i<nStartPos.length;i++) /JfXK$`
{ ~&qe"0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |LjCtm)@+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ca`=dwe>
nStartPos,nEndPos,i); kO9yei
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >l7 o/*4
fileSplitterFetch.start(); cCj3,s/p
} :g\qj? o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d6n6= [*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |0bSxPXn!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xGH%4J\
nEndPos = " + nFileLength); LS_QoS
// fileSplitterFetch[nPos.length-1].start(); ^wHO!$
xFvSQ`sp
"?il07+w%
//等待子线程结束 v EX <9
//int count = 0; VEpQT Qp
//是否结束while循环 n/8fv~zU
boolean breakWhile = false; AKWw36lm
Gs9jX/#
u*U?VZ5
while(!bStop) +HcH]D;
{ m[7a~-3:J
write_nPos(); E7D^6G&i
Utility.sleep(500); R.fRQ>rI
breakWhile = true; C[Fh^
zZ wD)p?_g
U?rfE(!
for(int i=0;i<nStartPos.length;i++) 2Hd6
{ 8~I>t9Q+
if(!fileSplitterFetch.bDownOver) h?O-13v
{ %Wu8RG}
breakWhile = false; MdKZH\z/
break; Ay_<?F+&
} Gm%[@7-
} QJTC@o
if(breakWhile) Zsuh8t
break; 5eU/ [F9
'nLv0.7*
!Zwl9DX3
//count++; jBQQ?cA
//if(count>4) 2V0R|YUt
// siteStop(); - Z|1@s&
} fXqe7[
/bb4nM_E/
{.2C>p
System.err.println("文件下载结束！"); :G`_IB\
} rm cy-}e
catch(Exception e){e.printStackTrace ();} 0O:TKgb&C.
} )I<.DN&
R5FjJ>JE
mB,7YZv
//获得文件长度 |~/{lE=I
public long getFileSize() p\HXE4d'
{ IW46-;l7
int nFileLength = -1; ?L $KlF Y
try{ MaEh8*
URL url = new URL(siteInfoBean.getSSiteURL()); `#UTOYx4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N,O[pTwj
httpConnection.setRequestProperty("User-Agent","NetFox"); [J];
AsLAm#zq
|p+VitM7
int responseCode=httpConnection.getResponseCode(); +X&B'
if(responseCode>=400) Ry(!<w,
{ $M8'm1R9
processErrorCode(responseCode); B}jZ~/D}
return -2; //-2 represent access is error J2R<'(
} Ug"B/UUFd
[DE8s[i-
+:t1PV;l
String sHeader; HOw][}M_w
;L`'xFo>>
#8RQ7|7b|
for(int i=1;;i++) C +IXP
{ 'D-imLV<<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RDZq(rKc
//Utility.log(in.readLine()); m ;KP
sHeader=httpConnection.getHeaderFieldKey(i); uaGg8
if(sHeader!=null) ^\CQWgY(
{ (&B & V
if(sHeader.equals("Content-Length")) |fA[s7)
{ MHbRG_zW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x}roPhZ
break; E*ic9Za8`h
} <E^:{J95
} x?%vqg^r
else Gg&jb=
break; RsY<j& f
} AiyjrEa%
} QA%GK4F70
catch(IOException e){e.printStackTrace ();} |9Y9pked8
catch(Exception e){e.printStackTrace ();} z(]*'0)P
%1 v)rg y
N7E[wOP
Utility.log(nFileLength); @M,_mX
87HVD Di
OUs2)H61
return nFileLength; !At_^hSqz
} X=JSqO6V9
OVd"'|&6_
=thgNMDm"
//保存下载信息（文件指针位置） tQ)8HVKF
private void write_nPos() w7 QIKsI0
{ $'&5gFr9
try{ vxwctJ&
output = new DataOutputStream(new FileOutputStream(tmpFile)); }:BF3cH> 0
output.writeInt(nStartPos.length); /Ly%-py-$
for(int i=0;i<nStartPos.length;i++) ctCfLlK
{ p7k0pSt
// output.writeLong(nPos); Q`oi=OYB
output.writeLong(fileSplitterFetch.nStartPos); #e#8I7P
output.writeLong(fileSplitterFetch.nEndPos); A>PM'$"sT
} *L^{p.K4
output.close(); YF;8il{p
} Ri,UHI4 W
catch(IOException e){e.printStackTrace ();} }ri"u;.R
catch(Exception e){e.printStackTrace ();} \Lc pl-;?
} 5~sJ$5<,
'UB<;6wy
mr/^lnO
//读取保存的下载信息（文件指针位置） 1xx-}AIH#
private void read_nPos() jeW0;Cz J~
{ fer'2(G?W
try{ Zj},VB*T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X{ Nif G
int nCount = input.readInt(); A$ S9 `
nStartPos = new long[nCount]; L*5&hPU
nEndPos = new long[nCount]; Yd,*LYd2EL
for(int i=0;i<nStartPos.length;i++) Y,0O&'>
{ B@F1!8l
nStartPos = input.readLong(); D8h~?phK
nEndPos = input.readLong(); r^@*Cir
} [<%yUy
input.close(); u54+oh|,M
} QQ?` 1W
catch(IOException e){e.printStackTrace ();} 8kqxr&,[
catch(Exception e){e.printStackTrace ();} Bb1dH/8
} C[pAa8
>g F
$EtZ5?qS
private void processErrorCode(int nErrorCode) ;~@2YPj
{ P8TiB
System.err.println("Error Code : " + nErrorCode); 8n'C@#{WV
} >i0FGmxH
+/Z:L$C6
Q0r_+0[7j
//停止文件下载 3wr~P
public void siteStop() 2V
{ I*24%z9
bStop = true; Ohjqdv@
for(int i=0;i<nStartPos.length;i++) j$Kubg(I5
fileSplitterFetch.splitterStop(); MVTU$ 65
p%G\5.GcJL
ckTnb
} Bg#NB
} GI~;2 `V
//负责部分文件的抓取 S</"^C51J
**FileSplitterFetch.java ]=pEs6%O3
*/ U%KoG-#
package NetFox; XjX<?W
!|`YNsR
3)T5}_
import java.io.*; ;hKn$' '
import java.net.*; Z1>pOJm
PvA%c<z
x &\~4,TN
public class FileSplitterFetch extends Thread { PL VF
Gd'^vqo<
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String sURL; //File URL ly{~X
long nStartPos; //File Snippet Start Position + W +<~E
long nEndPos; //File Snippet End Position (C. 1'<]
int nThreadID; //Thread's ID Tn-H8;Hg
boolean bDownOver = false; //Downing is over XL"e<P;t
boolean bStop = false; //Stop identical ?$o8=h
FileAccessI fileAccessI = null; //File Access interface Jw86P=
Nl(Aa5:!
21;n0E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xXyzzr1[
{ }b+=,Sc"
this.sURL = sURL; ^%_LA't'R
this.nStartPos = nStart; on(W^ocnD
this.nEndPos = nEnd; bhg"<I
nThreadID = id; Oo#wPT;1^(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #7g~Um%p
} u{\`*dNx
1&m08dZm5
iPs()IN.O
public void run() 5v?6J#]2
{ _o`'b80;
while(nStartPos < nEndPos && !bStop) 1~_]"Y'
{ PPmZ[N9(;
K7y}R%QF
]r#tJT`M
try{ #_H=pNWe
URL url = new URL(sURL); nhy3E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H{+U; 6b
httpConnection.setRequestProperty("User-Agent","NetFox"); 2/h Mx-
String sProperty = "bytes="+nStartPos+"-"; "cti(0F-d
httpConnection.setRequestProperty("RANGE",sProperty); TX 12$p\
Utility.log(sProperty); 6bU/IVP
*FqNzly
yJgnw6>r2
InputStream input = httpConnection.getInputStream(); "3!4 hiU9
//logResponseHead(httpConnection); mT~:k}u~W
iedoL0#
D@0eYX4s
byte[] b = new byte[1024]; JM M\
int nRead; j7i[z>:Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &18} u~M
{ W<58TCd
nStartPos += fileAccessI.write(b,0,nRead); NW~n+uk5v
//if(nThreadID == 1) dLo%+V#/A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6)H70VPJ
} T9(~^}_+9
2Ejs{KUj
B\4SB
Utility.log("Thread " + nThreadID + " is over!"); VGe/;&1h
bDownOver = true; |&C.P?q
//nPos = fileAccessI.write (b,0,nRead); $<T)_g
} ) .#,1
catch(Exception e){e.printStackTrace ();} (I\aGGW
} 8mMrGf[Q\
} H,?AaM[V
3J@#V '
IoA"e@~t
//打印回应的头信息 ) I@gy
public void logResponseHead(HttpURLConnection con) ?SS?I
{ y/Nvts2!C
for(int i=1;;i++) 4cs`R+]o
{ ;B tRDKn
String header=con.getHeaderFieldKey(i); }G-qOt
if(header!=null) 9}5Q5OZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vL-%"*>v
Utility.log(header+" : "+con.getHeaderField(header)); jd~r~.y
else _hXadLt
break; \24neD4cM@
} *S;v406
} ~C[R%%Gu
qA*QFQ'-
Kw'A%7^e
public void splitterStop() RMsr7M4<91
{ Oa*/jZjr
bStop = true; KaO8rwzDN
} r$*k-c9Bf
F[Peil+|`
B9+oI cO
} P 0,]Ud
<m9IZIY<
PN<Y&/fB
/* jb77uH_
**FileAccess.java o.sa?*
*//文件访问(定位，写) 3}XUYF;
package NetFox; V_0e/7}Ya
import java.io.*; II),m8G
?2Bp^3ytJ
3~M8.{ U#V
public class FileAccessI implements Serializable{ $yOfqr
Kx#G_N@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |f`!{=?
RandomAccessFile oSavedFile; I_N"mnn@Nr
long nPos; pcL02W|J
G!%1<SLi.
lQ)ZsFs=
public FileAccessI() throws IOException -O-_F6p'D
{ utRvE(IbmV
this("",0); E-&=I> B5
} {iHC;a5gb$
S[*e K Z
.lRO;D
public FileAccessI(String sName,long nPos) throws IOException Rqu;;VI[
{ =@B9I<GKf
oSavedFile = new RandomAccessFile(sName,"rw"); ()XL}~I{!A
this.nPos = nPos; !+CRS9\D
oSavedFile.seek(nPos); Qx$Yj
} |9}G
Z@j0J[s
44wY5nYNt
public synchronized int write(byte[] b,int nStart,int nLen) CJ KFNa
{ 6ffrV
int n = -1; 6rdm=8WFA
try{ }LQ&AIRN
oSavedFile.write(b,nStart,nLen); "jb?P$
n = nLen; \'j%q\Bl;
} 5AQ $xm4
catch(IOException e) kg+"Ta[9
{ >m%\SuXq
e.printStackTrace (); H6*F?a`)I
} ;J2=6np
}1epn#O_4
-`#LrO;n
return n; nqy\xK#.^
} 3u-j`7
5(TI2,4
_?`3zm4
} vhdT"7`U
8h-6;x^^
BDc*N]m}B1
/* u'LA%l-
**SiteInfoBean.java Pp#!yMxBr
*/ CEZ*a 0}=
package NetFox; aRg- rz
8tLkJOu
!!dNp5h`
public class SiteInfoBean { LV'v7 2yUH
Ij/c@#q.
v5 $"v?PT
private String sSiteURL; //Site's URL Uu8Z2M
private String sFilePath; //Saved File's Path q4lL7@_
private String sFileName; //Saved File's Name jbfMTb4
private int nSplitter; //Count of Splited Downloading File :^! wQ""
F5{~2~Cw(
8`9!ocrM
public SiteInfoBean() 8[ :FU
{//nSplitter的缺省值为5 A+NLo[swwu
//default value of nSplitter is 5 D",ZrwyJ
this("","","",5); )7[>/2aGd
} ka*VQXk*
'2v,!G]^
; #e-pkV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c:hOQZ
{ !dSY?1>U<
sSiteURL= sURL; f4]nz:2
sFilePath = sPath; ^MDBJ0 I.
sFileName = sName; ) Q]kUG#`
this.nSplitter = nSpiltter; Pgs4/
v!K%\h2A
!f]F'h8
} |OuZaCJG
qvhTc6oH
Kl\A&O*{
public String getSSiteURL() ub./U@1
{ cM.q^{d`
return sSiteURL; ~@MIG
} [Gysx
=-`X61];M
`N ;!=7y7Y
public void setSSiteURL(String value) p*n$iroy_{
{ ,$7LMTVDrE
sSiteURL = value; e2k!5OS
} {_KuztJGA
3-~_F*%ST
$Ob]JAf}
public String getSFilePath() <fWho%eOK
{ /Y%) Y
return sFilePath; I?Eh 0fI
} 5|wQeosXxI
XOVZ'V
J(g!>Sp!p
public void setSFilePath(String value) u*}6)=+:
{ Xq+7l5LP
sFilePath = value; Z9 }qds6 y
} _N0x&9S$
q$~S?X5\
4- N>#
public String getSFileName() I)O%D3wfMW
{ jZe]zdml
return sFileName; 1K4LEga`
} QWxCNt:^?
E+UOuf*(
k;l^wM
public void setSFileName(String value) 6D_4o&N
{ <o^mQq&
sFileName = value; OA&NWAm4
} ?^5W.`Y2i
ps_CQh0
ib*$3Fn~
public int getNSplitter() I&1h/
{ R qOEQ*k
return nSplitter; 64o`7
} Td X6<fVV
>LwAG:Ud
l?Bv9k.^?
public void setNSplitter(int nCount) "JbFbcj
{ :G$NQ*(z
nSplitter = nCount; Uiv;0Tovl
} g}L2\i688
} VOp8 ,!
6@; w%Ea
73Tg{~
/* [&3G `8hY
**Utility.java f+1)Ju~
*/ #^%Rk'W
package NetFox; /,$6`V
daY^{u3
>{ne!
public class Utility { g6;O)b
pG:FDlR~
H /*^$>0Uo
public Utility() ?gH[tN:=
{ mzfj!0zR*
Q3_ia5 `O
,r:. 3.
} ([`-*Hy
`"Tx%>E(U
//线程睡眠 2p(K0PtX
public static void sleep(int nSecond) OBF5Tl4
{ T->O5t c
try{ Y&]pC
Thread.sleep(nSecond); 3QM.X^ANH
} |P>> ^,iUn
catch(Exception e) 3[-L'!pOX3
{ ?v8B;="#w
e.printStackTrace (); >=r094<
} aG`G$3_wx
} ~Se/uL;*
FwmE1,
//日志 ].7)^
public static void log(String sMsg) =/Vr,y$
{ Bn-%).-ED
System.err.println(sMsg); #0hX)7(j
} *.ZV.(
Xp4pN{he
+w%MwPC7`
public static void log(int sMsg) yngSD`b_P
{ rM_8piD
System.err.println(sMsg); D9 ,~Fc
} d=Q0/sI&
} [;h@q}
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mY |$=n5X
/* zA\DI]:+
**TestMethod.java %(,JBa:G
*/ <?2[]h:wp
package NetFox; s{Ryh.IyI
0Eo*C9FP~
57%:0loW
public class TestMethod { *-ZJF6
pc:~_6S
haqL DVrf
public TestMethod() cuW$%$F
{ ///xx/weblogic60b2_win.exe $*`fn{2
try{ `?2S4lN/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W29@`93
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;_1D-Mf
SiteFileFetch fileFetch = new SiteFileFetch(bean); :&9#p%/
fileFetch.start(); N=)N
} y*2:(nI
catch(Exception e){e.printStackTrace ();} KR?-<
(VU: &.
;~tKNytD`B
} dHg[0Br)r
SI4M<'fK
o%RyE]pw,
public static void main(String[] args) 7K%Ac
{ B ,e3r
new TestMethod(); pR; AqDQ
} s@K|zOx
} ko=vK%E[
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