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)); jtW!"TOY
} S.-TOE
for(int i=0;i<nEndPos.length-1;i++) '!!CeDy
{ ! |<Fo'U
nEndPos = nStartPos[i+1]; kuszb~`zPY
} Oi8.8M
nEndPos[nEndPos.length-1] = nFileLength; |EX(8y
} TJ6*t!'*X
} A>o*t=5
5K>3My#
+0nJ
//启动子线程 dMv=gdY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nrub*BuA
for(int i=0;i<nStartPos.length;i++) 4;yKOQD|
{ keL&b/@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | *2w5iR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )rn*iJ.e8
nStartPos,nEndPos,i); OEA&~4&{7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'vbsvT
fileSplitterFetch.start(); }ppN k:B
} <Tzrj1"Q3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D9^h; 8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n|Q@UPb/=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cUKE
nEndPos = " + nFileLength); Hq:X{)"
// fileSplitterFetch[nPos.length-1].start(); 3no%E03p
`T@i.'X
u8&Z!p\
//等待子线程结束 Y']\Jq{OS
//int count = 0; E7j(QOf
//是否结束while循环 SJb&m-
boolean breakWhile = false; . qO@Q=
2_HNhW
qkDI](4
while(!bStop) n8~N$tDU
{ #Z?A2r!1
write_nPos(); O_oPh]x)
Utility.sleep(500); "l3_=Gua
breakWhile = true; H1|?t+oP
ype$ c
gc_:%ki
for(int i=0;i<nStartPos.length;i++) il4^zj82
{ !/'t5~x[
if(!fileSplitterFetch.bDownOver) <J<{l
{ _S<3\%(0
breakWhile = false; *+Ek0M
break; #L=x%8B
} e$<0 7Oc
} ^oBtfN>4
if(breakWhile) :~&~y-14
break; c}lb%^;)E
VA6}
at#ja_ hd
//count++; ?~BC#B\>o
//if(count>4) BKCA<
// siteStop(); I0D(F i
} eI$oLl@
lA| 5E?
oK6tTK
System.err.println("文件下载结束！"); ?GKb7Oj
} >)fi^
catch(Exception e){e.printStackTrace ();} q/4J.jL
} 9UdM`v)(
[M]
=upeRY@u5
//获得文件长度 u^@f&BIG]:
public long getFileSize() }eCw6
{ H%qsjB^
int nFileLength = -1; 1gL2ia
try{ b|l:fT?&
URL url = new URL(siteInfoBean.getSSiteURL()); #^u$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `uv2H$
httpConnection.setRequestProperty("User-Agent","NetFox"); W#9BNKL
u_w#gjiC
2Q/x@aT,h
int responseCode=httpConnection.getResponseCode(); 2e+UM$
if(responseCode>=400) SE@LYeC}dE
{ \tf<B\oa
processErrorCode(responseCode); !`Fxa4i>
return -2; //-2 represent access is error >K_(J/&p
} [_R~%Yh+'E
,k +IPkN+
CpUkCgg
String sHeader; o5Dk:Bw
x[FJgI'r
lHN5Dr
for(int i=1;;i++) sXLq*b?
{ ^bGNq X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \pa"%c)
//Utility.log(in.readLine()); ]R+mKUZ9
sHeader=httpConnection.getHeaderFieldKey(i); {2O1"|s ,
if(sHeader!=null) gh/EU/~d
{ a@_4PWzF:
if(sHeader.equals("Content-Length")) ~8'sBT
{ -^&<Z 0m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zi*2nv'
break; kvL=> A
} vv72x]
} x,=&JtKVc
else ;5]Lf$tZ
break; 5Yg'BkEr
} |kyX3~
} ~8q)^vm>f?
catch(IOException e){e.printStackTrace ();} [+rfAW>p}
catch(Exception e){e.printStackTrace ();} >6ni")Q9
D$w6V
v,FU^f-'
Utility.log(nFileLength); 3+)J @(a
3]5^r}
#3i3G(mQ
return nFileLength; [;n9:Qxf
} G?L HmTHg
JrJo|0Q
lUOF4U&r
//保存下载信息（文件指针位置） Vh'P&W?[
private void write_nPos() F%@A6'c
{ E-T)*`e
try{ u4t7Ie*Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); kYzIp
output.writeInt(nStartPos.length); )X1{
for(int i=0;i<nStartPos.length;i++) !EvAB+`jLI
{ F~,Mw8
// output.writeLong(nPos); &Qf/>@ l}
output.writeLong(fileSplitterFetch.nStartPos); A=$04<nP8!
output.writeLong(fileSplitterFetch.nEndPos); W>${zVu
} %^?fMeI|Y
output.close(); Y@;CF
} &C`Gg<
catch(IOException e){e.printStackTrace ();} E(*0jAvO[z
catch(Exception e){e.printStackTrace ();} wg9t)1k{e
} *D'22TO[[!
9&$y}Y
-WY<zJ
//读取保存的下载信息（文件指针位置） 7o7)0l9!
private void read_nPos() 0eT(J7[ <
{ LoURC$lS
try{ UE8kpa)cQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vk}n,ecl
int nCount = input.readInt(); OSRp0G20k\
nStartPos = new long[nCount]; dcDyK!zz"
nEndPos = new long[nCount]; !8TlD-ZT/
for(int i=0;i<nStartPos.length;i++) MUaq7B_>
{ +Zb;Vn4
nStartPos = input.readLong(); (of#(I[m7
nEndPos = input.readLong(); qrb[-|ie&
} !]"@kl%
input.close(); sfpZc7
} y%&q/tk
catch(IOException e){e.printStackTrace ();} q_MPju&*
catch(Exception e){e.printStackTrace ();} [8Y:65
} _'#n6^Us<
ayn)5q/z
:">!r.Q
private void processErrorCode(int nErrorCode) BOX{]EOj
{ T(#J_Y
System.err.println("Error Code : " + nErrorCode); R}-(cc%5
} 4zXFuTr($
aHV;N#Lx3
G0CW}e@)
//停止文件下载 qz"}g/;?
public void siteStop() xipU8'ac/
{ Jz\%%C
bStop = true; '*Z1tDFS
for(int i=0;i<nStartPos.length;i++) C(eTR1
fileSplitterFetch.splitterStop(); a4mn*,
JYMiLph<
I5X|(0es
} ny]?I
} :,3C 0T3r
//负责部分文件的抓取 OTvPUkp*
**FileSplitterFetch.java 1D7nkAy
*/ 9>=;FY
package NetFox; 9"N~yKa`"K
B~'vCuE
>f|||H}Snw
import java.io.*; P9/q|>F
import java.net.*; `}D,5^9]
kI,yU}<Fq
g!FuY/%+
public class FileSplitterFetch extends Thread { Giid~e33
S){)Z
rF3wx.
String sURL; //File URL !eGC6o}f
long nStartPos; //File Snippet Start Position Bj+S"yS
long nEndPos; //File Snippet End Position #QS`_TlKk
int nThreadID; //Thread's ID Q1T$k$n
boolean bDownOver = false; //Downing is over IDad9 Bx
boolean bStop = false; //Stop identical ]vz%iv_
FileAccessI fileAccessI = null; //File Access interface fJ=0HNmX
sSr&:BOsi
$|zX|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d8DV[{^
{ f- K+]aZ)
this.sURL = sURL; @#l `iK
this.nStartPos = nStart; ^\hG"5#
this.nEndPos = nEnd; \q>bs|2
nThreadID = id; DRSr%d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RaO-H
} w0[6t#$F
ZFA`s qT
*2ZjE!A
public void run() N&.H|5
{ 9#23FK
while(nStartPos < nEndPos && !bStop) Yc`o5Q\>
{ Fh)IgzFj
48J@CvU
-$t{>gO#Y
try{ ^gN6/>]qrY
URL url = new URL(sURL); @T@<_ ?)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v>6"j1Z
httpConnection.setRequestProperty("User-Agent","NetFox"); ~Sdb_EZ
String sProperty = "bytes="+nStartPos+"-"; loEPr5bL
httpConnection.setRequestProperty("RANGE",sProperty); 5A,K6f@:g
Utility.log(sProperty); ,j#XOy`mzy
V"[g.%%Y
; 8_{e3s
InputStream input = httpConnection.getInputStream(); LHyB3V
//logResponseHead(httpConnection); G?9"Y%
_Ym]Mj' ln
zZ:>do\2
byte[] b = new byte[1024]; bpOYHc6,*`
int nRead; gK+4C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @Y?#Sl*
{ e-~N"
nStartPos += fileAccessI.write(b,0,nRead); _H9 MwJ
//if(nThreadID == 1) Mhm@R@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w{{gu1#]G
} .nO\kgoK
&U{#Kt5q
fIM,lt
Utility.log("Thread " + nThreadID + " is over!"); .14~J6
bDownOver = true; #F:p-nOq
//nPos = fileAccessI.write (b,0,nRead); 2kqup)82e
} q'+)t7!
catch(Exception e){e.printStackTrace ();} 7( #:GD
} T*I{WW
} ]q\b,)4 e
<c*FCblv
4aug{}h("
//打印回应的头信息 ?(xnSW@r
public void logResponseHead(HttpURLConnection con) LY+@o<>
{ BfXgh'Z~
for(int i=1;;i++) K> %Tq
{ CVDV)#JA
String header=con.getHeaderFieldKey(i); 36.Z0Z1'F>
if(header!=null) ke!?BZx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'Oxy$U
Utility.log(header+" : "+con.getHeaderField(header)); oph}5Krd)
else ;^+\K-O]c
break; .7^c@i[
} .4S.>~^7
} ]z;P9B3@&
)tG\vk=@
NxfOF
public void splitterStop() {0r0\D>bw
{ V[mT<Lc
bStop = true; 2v:]tj
} 9/9j+5}+
'_<{p3M
sXqz+z$*
} bkRLC_/d
n*o-Lo+Fe.
f0!))/rSD
/* 6d:zb;Iz
**FileAccess.java <<UB ^v m
*//文件访问(定位，写) 6o^,@~:R
package NetFox; `34zkPB??
import java.io.*; j 'FVz&
?}qttj
S&e0u%8mc
public class FileAccessI implements Serializable{ !H#bJTXB
O3;u G.:1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ky8_UnaO
RandomAccessFile oSavedFile; *FWMn.
long nPos; [m+2(I1
iyN:%ofh
'Jiw@t<o3`
public FileAccessI() throws IOException 9y6-/H ,
{ ,y1PbA0m
this("",0); # q~e^A b
} xg30xC[
Gw=B:kGk
?yZ+D z\
public FileAccessI(String sName,long nPos) throws IOException 1}S S+>`
{ rUwZMli
oSavedFile = new RandomAccessFile(sName,"rw"); bw(a6qKK
this.nPos = nPos; 'QJ:`)z
oSavedFile.seek(nPos); 90Pl$#cb2
} dMPc:tJT
c>,KZ!
s:?SF.
public synchronized int write(byte[] b,int nStart,int nLen) ``V" D
{ WJ$bf(X*
int n = -1; i1UiNJh86
try{ Ha(c'\T(\
oSavedFile.write(b,nStart,nLen); dW_KU}
n = nLen; d^@dzNv
} I?]ohG K
catch(IOException e) @#<D ^"
{ Q`~jw>x
e.printStackTrace (); ^pxX]G]
} 7X`l&7IXP
bW$,?8(
)}g(b=
return n; *RDn0d[
} 2SD`OABf#
Ut*`:]la
tankR9(o
} vhe>)h*B
7z/|\D_{
w+C7BPV&
/* t\?ik6
**SiteInfoBean.java mGtdO/C#B
*/ FFl!\y*0z
package NetFox; cIUHa
\}+_Fo/
R}'bP
public class SiteInfoBean { R(!s
UXeN8
;"KJ7p
private String sSiteURL; //Site's URL mkMq
private String sFilePath; //Saved File's Path yu;+o3WlK
private String sFileName; //Saved File's Name t!*?dr
private int nSplitter; //Count of Splited Downloading File kv]~'Srk
Z"Zmo>cV4
<x@}01~
public SiteInfoBean() YO#M/%^j
{//nSplitter的缺省值为5 :Uz|3gq
//default value of nSplitter is 5 J\/cCW-rF
this("","","",5); 2I%MAb&1@
} J{'>uD.@
*Tas`WA
a!ud{Dx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #G.ulX
{ zxJ]"N
sSiteURL= sURL; 0f~C#/[t7
sFilePath = sPath; d^Inb!%w
sFileName = sName; u_hD}V^x4
this.nSplitter = nSpiltter; kEJj=wx
.GV;+8HzS
zepm!JR1
} x%}^hiO<q
,">]`|?
7_%"BVb"
public String getSSiteURL() {`J)j6;
{ Hv!U|L
return sSiteURL; o%v0h~tn
} kr+D,h01
{,3>"
!i{aMxUP
public void setSSiteURL(String value) } uO);k5H
{ !5.8]v
sSiteURL = value; OSlvwH%(EE
} V}bjK8$$
R?68*} `7
j!_;1++q
public String getSFilePath() H#NCi~M>3
{ %4ePc-
return sFilePath; gMY1ts}Z
} Lilr0|U+
l%[EXZ
?6yjy<D)$e
public void setSFilePath(String value) YX=a#%vrl
{ kv3E4,<9
sFilePath = value; 3_txg>P"
} 4~y(`\0?4
tro7Di2Q
?h.wK
public String getSFileName() TX$r`~
{ JM=JH 51`
return sFileName; GYJ80k|
} MJOz.=CbhR
;hYS6
6;u$&&c(
public void setSFileName(String value) iEd\6EZ
{ /h+8A',
sFileName = value; ?6Jx@Sh
} e91aK
m=?KZ?U`
&f"-d
public int getNSplitter() mk1bcK9
{ Id'X*U7Q
return nSplitter; ]4~lYuI4
} plUZ"Tr
,-izEr
FB _pw!z
public void setNSplitter(int nCount) 'h/CoTk@,
{ ZNf6;%oGG
nSplitter = nCount; v 0 }@
} %`OJ.:k
} #1`-*.u
>ZPsjQuf"
=4[v3Qx
/* AmaT0tzJC
**Utility.java ]e^c=O`$
*/ }R1< 0~g
package NetFox; E}Y!O"CAV
)f}YW/'
R<[qGt|L
public class Utility { V=zi >o`
'$|[R98
V^JV4 `o
public Utility() Z3{>yYR+
{ #bMuvaP~
/4c\K-Z;
{k>Ca
} y=`2\L" O
e?opkq\f
//线程睡眠 R#2t)y
public static void sleep(int nSecond) ZT,B(#m
{ Q,p}:e
try{ U'R)x";=
Thread.sleep(nSecond); dik:4;
} ]3VI|f$$
catch(Exception e) Ko;{I?c
{ >;L6xt3
e.printStackTrace (); '@p['#\uI
} 9:,V5n=
} WpF2)R}G=
q0$ !y!~
//日志 {P{bOe
public static void log(String sMsg) HR ;)|j{!
{ ;k7xMZs
System.err.println(sMsg); nx8a$vI-TY
} #Yr9AVr}K
.Jt[(;
et,f_fd7v
public static void log(int sMsg) O>^C4c!
{ "NgxkbDEbG
System.err.println(sMsg); 3~}uqaGt
} &K/ya7
} gA:5M
t: #6sF
HuwU0:*
/* pcT:]d[1)
**TestMethod.java JcbwDlUb
*/ >p.O0G gg
package NetFox; J(c{y]`J
1E73i_L
y($%;l
public class TestMethod { po$ /7
wvbPnf^y
rb1`UG"h$
public TestMethod() $% 1vW=d
{ ///xx/weblogic60b2_win.exe %n hm
try{ q o\?o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )yTm.F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q|Qk2M
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]`&Yqg
fileFetch.start(); p;W.lcO`0
} `FsH}UPu b
catch(Exception e){e.printStackTrace ();} ]3g?hM6
'ow.=1N-
\ gLHi~
} czm&~n6$
'B@e8S)y
Y]L9Y9
public static void main(String[] args) B<~ NS)w
{ ^my].Qpt
new TestMethod(); *cC_j*1@
} qUxRM_7U
} =:/BV=tv
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