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)); =_[Ich,}
} _3{8Zg
for(int i=0;i<nEndPos.length-1;i++) r|3<UR%
{ 3u'@anre
nEndPos = nStartPos[i+1]; x";4)u=
} BLb'7`t
nEndPos[nEndPos.length-1] = nFileLength; 5yf`3vV|3@
} b7HT<$Wg
} uf`/-jY
wpOM~!9R
/p)y!5e
//启动子线程 Hqb-)8 ~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MX7$f (Hy
for(int i=0;i<nStartPos.length;i++) VVc-Dx
{ "Jg* /F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d V3R)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T5aeO^x
nStartPos,nEndPos,i); )_K:A(V>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X`7O%HiX/`
fileSplitterFetch.start(); Hm_&``='
} R".*dC,0'B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3#idXc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G$jw#a[L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oSH]TL2@Cd
nEndPos = " + nFileLength); T8Ye+eP}
// fileSplitterFetch[nPos.length-1].start(); q]v{o8:U
o3.b='HAm
87hU#nVYh
//等待子线程结束 -_f-j
//int count = 0; 2`V(w[zTr
//是否结束while循环 G.qjw]Llf
boolean breakWhile = false; J:\O .F#Fi
aK8X,1g%)
la{o<||Aq
while(!bStop) lht :%Ts$
{ Gk)6ljL
write_nPos(); g?>
Utility.sleep(500); Olr'n% }
breakWhile = true; KXcE@q9
!{XVaQ?x
Cil1wFBb
for(int i=0;i<nStartPos.length;i++) F#|mN0op
{ xS_tB)C
if(!fileSplitterFetch.bDownOver) ;eP.B/N
{ nW]T-!
breakWhile = false; ?d)FYB
break; ]u%Y8kBe
} wfM|3GS+.
} ^Fwdi#g
if(breakWhile) 8%;]]{(B
break; D`PA@t
K# h7{RE
RYM[{]4b5F
//count++; #$JY&!M
//if(count>4) <KZ J
// siteStop(); t#7owY$^
} ~\Udl
`%=!_|
];Y tw6A
System.err.println("文件下载结束！"); 0~cbB
} HCaEETk5
catch(Exception e){e.printStackTrace ();} sDXQ{*6a
} D#11 N^-K
B{NGrC`5)
nk+9J#Gs
//获得文件长度 ZV`o:Gd
public long getFileSize() Sp@{5
{ eit%U
int nFileLength = -1; /?:q9Wy
try{ sB<y(}u
URL url = new URL(siteInfoBean.getSSiteURL()); YF13&E2`\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CjU?3Ag
httpConnection.setRequestProperty("User-Agent","NetFox"); oTf^-29d
6"V86b0)h}
z_87;y;=
int responseCode=httpConnection.getResponseCode(); Uy$?B"Z
if(responseCode>=400) 0lpUn74F
{ s5oU
processErrorCode(responseCode); S[RVk=A1
return -2; //-2 represent access is error 8&v%>wxR@
} {Pe+d3Eoo
bYy7Ul6]
p;LF-R
String sHeader; b IZi3GmRF
2%@<A
k#<Y2FJa
for(int i=1;;i++) CK1gzIg>
{ /XwwB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jn>RE
//Utility.log(in.readLine()); 0zXF{5Up
sHeader=httpConnection.getHeaderFieldKey(i); t/a
if(sHeader!=null) t<znz6
{ }E\u2]
if(sHeader.equals("Content-Length")) u]Dds;~"b
{ B@,#,-=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;h7O_|<%
break; E^t}p[s
} !{ /AJb
} G4)X~.Fy
else \yY2 mr
break; O+o_{t\R
} ~Q5 i0s%
} \>
catch(IOException e){e.printStackTrace ();} /@]@Tz@'
catch(Exception e){e.printStackTrace ();} P6;Cohfh
p}h9>R
{_]<mwd
Utility.log(nFileLength); YMn_9s7<
Yx<wYzD
m/NXifi8l
return nFileLength; 1)ZdkTF@H
} jLreN#:9
PA>su)N$
/` 4B-Y4M4
//保存下载信息（文件指针位置） k_7agW
private void write_nPos() oCuKmK8
{ G1/
try{ <84d Vg
output = new DataOutputStream(new FileOutputStream(tmpFile)); }G1hB#j
output.writeInt(nStartPos.length); 9d&}CZr
for(int i=0;i<nStartPos.length;i++) j'|`:^ Sy
{ `Qo}4nuRs
// output.writeLong(nPos); 4AuJ1Z
output.writeLong(fileSplitterFetch.nStartPos); C9E@$4*
output.writeLong(fileSplitterFetch.nEndPos); Ozs&YZ
} t}-rN5GO
output.close(); R?+:Js/
} G:{\-R'
catch(IOException e){e.printStackTrace ();} r#/Bz5Jb*
catch(Exception e){e.printStackTrace ();} \FjY;rqfKe
} ;.b^A
zNJ-JIo%
rqYx\i?
//读取保存的下载信息（文件指针位置） y`-5/4
private void read_nPos() CFiO+p&
{ F[==vte|
try{ RTvzS]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q<wQ/m
int nCount = input.readInt(); 1<3!
nStartPos = new long[nCount]; =j S
nEndPos = new long[nCount]; wM&WR2
for(int i=0;i<nStartPos.length;i++) ?K^~(D8(
{ #BX^"J{~
nStartPos = input.readLong(); $nW^Gqwj]1
nEndPos = input.readLong(); pN7 v7rs
} cY[qX/0~
input.close(); ~[4zm$R^
} g=x1}nm
catch(IOException e){e.printStackTrace ();} [;hCwj#
catch(Exception e){e.printStackTrace ();} =E' .T0v
} BH`GUIk
V2_I=]p_
>X-*Hu'U#
private void processErrorCode(int nErrorCode) ,{u'7p
{ A0 1D-)
System.err.println("Error Code : " + nErrorCode); wv_<be[?*
} $+@xwuY'+
UJ6zgsD1b?
9>HCt*|_8
//停止文件下载 nW`EBs
public void siteStop() TGu]6NzyZ
{ txXt<]N
bStop = true; 9EKc{1 z
for(int i=0;i<nStartPos.length;i++) 6`;+|H<$
fileSplitterFetch.splitterStop(); `d.4L.],
:_"%o=
|!H@{o
} }?XNA.Wz
} keL!;q|r-)
//负责部分文件的抓取 ?tFsSU
**FileSplitterFetch.java I6Mr[#*
*/ UIi`bbJ
package NetFox; mL[Y{t#N
*IBCThj
u3@v
import java.io.*; e&J_uG
import java.net.*; _f@, >l
6b9&V`
:T#"bY
public class FileSplitterFetch extends Thread { ;#Pc^Yzc1
$yg=tWk
61{IXx_
String sURL; //File URL om}jQJ]KH
long nStartPos; //File Snippet Start Position \cRe,(?O
long nEndPos; //File Snippet End Position gTjhD(
int nThreadID; //Thread's ID 3WQ"3^G
boolean bDownOver = false; //Downing is over 2rJeON
boolean bStop = false; //Stop identical ,7nA:0P
FileAccessI fileAccessI = null; //File Access interface Vm <9/UG<
uw`fC%-xh
Jdp@3mP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o:"^@3
{ UAq%Y8KA
this.sURL = sURL; }g|)+V\A
this.nStartPos = nStart; H.8Vm[W
this.nEndPos = nEnd; 58H%#3Fy
nThreadID = id; hpOUz%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7JHS8C<]
} Kk_h&by?
('VHL!
' 5%`[&
public void run() &i%1\o
{ ccu13Kr>E
while(nStartPos < nEndPos && !bStop) +1j+%&).
{ njN]0l{p
/l@h[}g+d-
2>!?EIE7
try{ U?d4 ^
URL url = new URL(sURL); Y94/tjt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -*r]9f6x
httpConnection.setRequestProperty("User-Agent","NetFox"); .a *^6TC.
String sProperty = "bytes="+nStartPos+"-"; s55t>t,g6
httpConnection.setRequestProperty("RANGE",sProperty); @"E{gM@B
Utility.log(sProperty); >hbT'Or@
^HasT4M+x
Ee?+IZ H7|
InputStream input = httpConnection.getInputStream(); Lb} cjI:
//logResponseHead(httpConnection); 4]/i0\Vbam
)mbRG9P
XU19+mW=P
byte[] b = new byte[1024]; :u$+lq
int nRead; XTOZ]H*^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )Mj $/
{ ';0NWFP
nStartPos += fileAccessI.write(b,0,nRead); J\V.J/
//if(nThreadID == 1) GxR, 3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {BlKVsQ
} U\\nSU
,@'M'S
+\O[)\
Utility.log("Thread " + nThreadID + " is over!"); Udh!%QP%[w
bDownOver = true; 6Y[|xu:N8Y
//nPos = fileAccessI.write (b,0,nRead); WDdp(<
} k;9"L90
catch(Exception e){e.printStackTrace ();} ']]&<B}mz
} U.B=%S
} &RP}w%I1
\1p5$0z
f YuM`O
//打印回应的头信息 {UR&Y
public void logResponseHead(HttpURLConnection con) j2/3NF5&
{ sUP!'Av
for(int i=1;;i++) @~l?hf
{ P_w\d/3
String header=con.getHeaderFieldKey(i); *(4TasQu
if(header!=null) o-D,K dY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9IRvbE~2
Utility.log(header+" : "+con.getHeaderField(header)); _\tGmME37
else GK/Q]}Q8pZ
break; U8b1 sz
} J '^xDIZX
} *KXg;777
8uO@S*)0
M:~/e8Xv
public void splitterStop() /<s$Am
{ f @cs<x
bStop = true; #!FLX*,
} Bw[jrK
426)H_wx
8zRb)B+
} %ycCNS
:~2An-V
kH43 T
/* [?$|
**FileAccess.java Gkr^uXNg#
*//文件访问(定位，写) ?"aj&,q+
package NetFox; iZy`5
import java.io.*; L8~nx}UP5
2z\4?HJy
ecH-JPm'
public class FileAccessI implements Serializable{ ClHaR
H<SL=mb;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p]zYj >e
RandomAccessFile oSavedFile; 47iwb
long nPos; #dLp<l)
x\Y%/C[Kc
3PonF4
public FileAccessI() throws IOException $J |oVVct
{ Dk'EKT-
this("",0); a*pZcv<
} %acy%Sy
B=;pyhc
=oF6|\]{;
public FileAccessI(String sName,long nPos) throws IOException ZHshg`I`
{ Te8BFcJG
oSavedFile = new RandomAccessFile(sName,"rw"); id-VoHdK
this.nPos = nPos; Hr$oT=x[
oSavedFile.seek(nPos); MGO.dRy_
} c#G]3vTdE
s'^zudx
;!@\|E
public synchronized int write(byte[] b,int nStart,int nLen) }eX_p6bBw
{ P#H#@:/3
int n = -1; @Y>3-,o,S
try{ wE75HE`gW
oSavedFile.write(b,nStart,nLen); RZfC?
n = nLen; _^RN C)ol
} z#!xqIg0
catch(IOException e) K)qbd~<\
{ sQ^>.yG
e.printStackTrace (); Y\T*8\h_[
} 'D-#,X C
&F}1\6{fL
&bJ98Nxl
return n; =3=KoH/'
} zJMKgw,i*
l\^q7cXG
LeW.uh3.
} qD\%8l.]Z
lq@Vb{Z
AEwb'
/* 4(4JQ(5
**SiteInfoBean.java 8mA6l0
*/ F$ .j|C1a
package NetFox; $UjSP
2LYd # !i
ZZC= 7FB
public class SiteInfoBean { dW7dMx
1A-8,)
Hcd>\0
private String sSiteURL; //Site's URL i&,U);T
private String sFilePath; //Saved File's Path ~,e!t.339
private String sFileName; //Saved File's Name t%z7#}9$
private int nSplitter; //Count of Splited Downloading File IQ{Xj3;?y
V8&/O)}o
L1QQU
public SiteInfoBean() bT-G<h*M
{//nSplitter的缺省值为5 (?\ZN+V)
//default value of nSplitter is 5 gE=~.P[ZX
this("","","",5); fnnwe2aso
} vP}K(' (
oQ;f`JC^
F.8{ H9`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 29ft!R>[
{ YY!(/<VI
sSiteURL= sURL; \ b9,>
sFilePath = sPath; na']{a1K
sFileName = sName; ;(0:6P8I
this.nSplitter = nSpiltter; `A <yDy
!T,7
TjI NxP-O
} e+R.0E
xdo{4XY^*W
^y6Pkb P
public String getSSiteURL() MF\n@lX
{ jX&&@zMq
return sSiteURL; \wRr6-!_
} \>=YxB q
J#V`W&\,6
w78Ius,
public void setSSiteURL(String value) lIjHd#q-C
{ Aq'%a)Y2
sSiteURL = value; b$R>GQ?#
} , D1[}Lr=K
JNp`@`0V
1yB;"q&Xd
public String getSFilePath() .;KupQ;*
{ M<$l&%<`G
return sFilePath; ` `;$Kr
} ')1sw%[2
peqFa._W
H9)uni
public void setSFilePath(String value) ''v1Pv-
{ Xi{(1o4%
sFilePath = value; 8&C(0H]1
} Jj6kZK
hYd8}BvA
|16 :Zoq
public String getSFileName() VvF&E>fC
{ X3m?zQbhv
return sFileName; *Ra")(RnDK
} n&C9f9S
zRJy3/>
k(qQvn
public void setSFileName(String value) Wq9s[)F"Z
{ ?^ErrlI_
sFileName = value; Ro1' L1:
} ^,KR0
FoG<$9
5nj~RUK
public int getNSplitter() b<( W}$x
{ &vF"I'V
return nSplitter; )(L&+DDy
} <@vE3v;
Fp]8f&l8
-.*\J|S@g
public void setNSplitter(int nCount) M<p)@p
{ ppnj.tLz;r
nSplitter = nCount; p 5o;Rvr
} KFs` u6
} }[DAk~
R]Yhuo9,&n
Azle ;\l`
/* }1W$9\%
**Utility.java y*(YZzF
*/ >@L HJ61C
package NetFox; a2rv4d=
=0)^![y]v
m5p~>]}fYF
public class Utility { "/'=gE
L,D>E
/r%+hS
public Utility() $F-XXBp
{ PW`Tuj
jFXU xf
&rd(q'Vi
} I>5@s;
\Cs<'(=
//线程睡眠 S }n;..{
public static void sleep(int nSecond) J9 =gv0
{ bvx:R ~E$
try{ %pp+V1FH
Thread.sleep(nSecond); ~?&ijhZ
} G'py)C5;
catch(Exception e) flB,_
{ \+uqP:Ty
e.printStackTrace (); biG9?
} 84[^#ke
} r9Z/y*q
qc6IH9i`
//日志 O$H150,Q
public static void log(String sMsg) YzZF^q^I
{ .HBvs=i
System.err.println(sMsg); (6BCFl:/Q<
} m#nxw
cBI)?
%8L<KJd
public static void log(int sMsg) ]p!J]YV ]0
{ i4I0oRp
System.err.println(sMsg); MP,*W}@
} 2jW>uk4/i
} {Pb^Lf >
3I5WDuq
QRlzGRueR&
/* Ng"vBycy
**TestMethod.java Z~(XyaN
*/ RNdnlD#P
package NetFox; y2R=%EFh6
re!8nuBsA
]CZLaID~
public class TestMethod { PBL^xlg
+_eb*Z`5o
pNlisS
public TestMethod() ^JtHTLHL=
{ ///xx/weblogic60b2_win.exe 5 DB>zou
try{ WO-WoPO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i'wF>EBz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V@S/!h+
SiteFileFetch fileFetch = new SiteFileFetch(bean); !7)ID7d
fileFetch.start(); #'x?)AS
} 5Mr;6 ]I<
catch(Exception e){e.printStackTrace ();} {_Qxe1^g
/ D ]B
2]9<%-=S
} U_- K6:tr
kkBU<L2
IBkH+j
public static void main(String[] args) HzV+g/8>A
{ y.:-
new TestMethod(); $-]setdY
} ^,K.)s
} 8uxFXQ
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