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)); +NUG
} Nh44]*
for(int i=0;i<nEndPos.length-1;i++) kAUymds;O
{ BI@[\aRLQ
nEndPos = nStartPos[i+1]; [nq@mc~<
} V0mn4sfs
nEndPos[nEndPos.length-1] = nFileLength; a%0EiU
} Q7CsJzk~)
} [$UI8tV
t]G:L}AOl
X:{!n({r=
//启动子线程 @H8EWTZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -KbYOb
for(int i=0;i<nStartPos.length;i++) !&E-}}<
{ vl)l'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jPkn[W# 6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aN3;`~{9
nStartPos,nEndPos,i); j?QDR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #/37V2E
fileSplitterFetch.start(); $*m-R*kt
} YS_;OFsd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^iYj[~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wd ELV3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *LY8D<:zs
nEndPos = " + nFileLength); U6s[`H3I{
// fileSplitterFetch[nPos.length-1].start(); f|(M.U-
xT2PyI_:
9>#6*/Oa7
//等待子线程结束 K*dCc}:`
//int count = 0; @C aG9]
//是否结束while循环 A3*!"3nU
boolean breakWhile = false; %;!.n{X
\_fv7Fdp{
|y!A&d=xYn
while(!bStop) V=3b&TkE
{ Flb&B1
write_nPos(); ],].zlN
Utility.sleep(500); yB6?`3A:
breakWhile = true; 3Zh)]^
TD_Oo-+\
}<:}XlwT%
for(int i=0;i<nStartPos.length;i++) 7 X4LJf
{ \l3h0R
if(!fileSplitterFetch.bDownOver) -s/ea~=R
{ > Nr#O
breakWhile = false; FVBYo%Ap
break; NGWxN8P6
} RG`1en
} xkAK!uVy
if(breakWhile) |Q>IrT
break; 0m ? )ROaJ
Tm?#M&'
4KrL{Z+}
//count++; k VQ\1!
//if(count>4) Rlirs-WQ
// siteStop(); ?z u8)U
} Rx}Gz$
#LOwGJ$yVz
@=kSo -SX
System.err.println("文件下载结束！"); `9.r`&T6K
} SX-iAS[<
catch(Exception e){e.printStackTrace ();} g=o4Q< #^y
} hR|MEn6KC
L8 @1THY
" 2Dngw
//获得文件长度 f y8Uk;
public long getFileSize() =nHgDrA_
{ G*v,GR
int nFileLength = -1; 7t_^8I%[
try{ KY]C6kh
URL url = new URL(siteInfoBean.getSSiteURL()); s"?3]P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3oG,E;(
httpConnection.setRequestProperty("User-Agent","NetFox"); {FTqu.
xn|(9#1o
N)>ID(}F1
int responseCode=httpConnection.getResponseCode(); OK gqT!
if(responseCode>=400) Dn}Jxu'(
{ '[O;zJN;
processErrorCode(responseCode); uSBaDYg
return -2; //-2 represent access is error 3{(/x1a,4
} *HB-QIl
H7+,*
.w,q0<}
String sHeader; S#[j )U-
Fea(zJ_
G9@0@2aY8
for(int i=1;;i++) o,3a4nH;
{ sFTy(A/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eKqk= (
//Utility.log(in.readLine()); #yvGK:F
sHeader=httpConnection.getHeaderFieldKey(i); :T(|&F[(
if(sHeader!=null) ,wdD8ZT'Ip
{ Lq!>kT<]!
if(sHeader.equals("Content-Length")) ROZF)|l
{ -RK- Fu<e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |IUWF%~^$+
break; !_Z&a
} W'u>#
} K,:N
else -+-_I*(
break; S?BG_J6A7
} qA5r
} L\z~uo3:
catch(IOException e){e.printStackTrace ();} YkQd
catch(Exception e){e.printStackTrace ();} _/<x
2jCfT>`3
2SR:FUV/
Utility.log(nFileLength); I[X772K
i8HTzv"J
tcog'nAz
return nFileLength; ^\,E&=/}M
} LvYB7<zk>
_``=cc
"i W"NFO
//保存下载信息（文件指针位置） t}tEvh
private void write_nPos() 07=mj%yV
{ R]*K:~DM
try{ i,9)\1R
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7EO_5/cY
output.writeInt(nStartPos.length); cq4Ipe
for(int i=0;i<nStartPos.length;i++) >Wg hn:^
{ ls)%c
// output.writeLong(nPos); {h`uV/5@`
output.writeLong(fileSplitterFetch.nStartPos); >`ZyG5
output.writeLong(fileSplitterFetch.nEndPos); | (_
} HT1!5
output.close(); ]~hk6kS8Q
} L4y4RG/SJ:
catch(IOException e){e.printStackTrace ();} h>OfOx/{q9
catch(Exception e){e.printStackTrace ();} G+|` 2an
} AbmAKA@
OX\F~+
q.`NtsW!\+
//读取保存的下载信息（文件指针位置） }Y36C.@H
private void read_nPos() 7o5BXF
{ y;@:ulv[
try{ J!U}iD@occ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {fn!'
int nCount = input.readInt(); y>e.~5;
nStartPos = new long[nCount]; E\pL!c
nEndPos = new long[nCount]; ZSd4z:/
for(int i=0;i<nStartPos.length;i++) s(q_ o
{ w%BL
nStartPos = input.readLong(); 3fQuoQuD"}
nEndPos = input.readLong(); **G9H
} _X"N1,0
input.close(); K1!j fp
} ]^K4i)\
catch(IOException e){e.printStackTrace ();} )iK6:s#
catch(Exception e){e.printStackTrace ();} =xx]@
} ^\&e:Nkh
Q9G;V]./
HYSIN^<oy
private void processErrorCode(int nErrorCode) +-CtjhoS
{ eb"5-0
System.err.println("Error Code : " + nErrorCode); 2Gaa(rJ5o
} ve2u=eQ1
i|*)I:SHU
l u%}h7ng
//停止文件下载 R>mmoG}MQ[
public void siteStop() 6-B|Y3)B
{ $F+ LDs
bStop = true; RMWHN:9
for(int i=0;i<nStartPos.length;i++) +8Ymw:D7a
fileSplitterFetch.splitterStop(); Hm'=aff6A
bsA-2*Q+
6?~"V
} |kV*Jc k
} wLJ:\_Jaf
//负责部分文件的抓取 Bj-:#P@
**FileSplitterFetch.java KRMQtgahc
*/ ^mO~W!"
package NetFox; \k!{uRy'
YU5(g^<
e-#BDN(O
import java.io.*; v4c[(&
import java.net.*; Y^}Z>
qPy1;maXP
~T,c"t2
public class FileSplitterFetch extends Thread { Jx](G>F4f1
A5R<p+t6
(UvM@]B
String sURL; //File URL $jI3VB
long nStartPos; //File Snippet Start Position Mh/dpb\Z
long nEndPos; //File Snippet End Position %r}{hq4
int nThreadID; //Thread's ID T)TfB(
boolean bDownOver = false; //Downing is over :AF =<X*5
boolean bStop = false; //Stop identical ;=; 9tX
FileAccessI fileAccessI = null; //File Access interface {rH@gz|@i
:LRYYw
SVs_dG$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6NM:DI\%
{ !y:vLB#q
this.sURL = sURL; ^2on.N q>
this.nStartPos = nStart; 2Mvrey)
this.nEndPos = nEnd; F9E<K]7K
nThreadID = id; Bb^;q#S1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +|'c>,?2H
} _Wp{[TH
nv%rJy*w[
fW3(&@
public void run() I]<_rN8~o
{ B!_mC<*4`X
while(nStartPos < nEndPos && !bStop) (#Gw1
{ ?DQsc9y
2s&*
rrqR}}l
try{ 4Thn])%I
URL url = new URL(sURL); Ix!Iw[CNd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L>W'LNXCv
httpConnection.setRequestProperty("User-Agent","NetFox"); n%C>E.Tq
String sProperty = "bytes="+nStartPos+"-"; NS%xTLow-
httpConnection.setRequestProperty("RANGE",sProperty); >eqxV|]i
Utility.log(sProperty); t2I5hSf
v99B7VH4
uRRQyZ
InputStream input = httpConnection.getInputStream(); `V]5sE]G
//logResponseHead(httpConnection); r1.nTO%
zHL@i0>^
ICs\ z
byte[] b = new byte[1024]; !^=*Jq>
int nRead; 1#*a:F&re
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gh}LlX!w
{ G!W[8UG
nStartPos += fileAccessI.write(b,0,nRead); CBOi`bEf
//if(nThreadID == 1) PMh^(j[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f3&[#%
} WD2]&g
VsgE!/>1
TI#''XCB5
Utility.log("Thread " + nThreadID + " is over!"); LuSLkLN
bDownOver = true; R)z4n
//nPos = fileAccessI.write (b,0,nRead); (m.ob+D
} TRQF^P3o
catch(Exception e){e.printStackTrace ();} M?:c)&$]D
} QP)pgAc
} KgOqbSJ
oCi=4#g%7
S\5bmvqP"
//打印回应的头信息 #qI= Z0Y
public void logResponseHead(HttpURLConnection con) , GY h9
{ OQT;zqup
for(int i=1;;i++) m~Bl*`~M
{ =fve/_Q~
String header=con.getHeaderFieldKey(i); HA`@7I
if(header!=null) 4EZ9hA9+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W$rH"_@m
Utility.log(header+" : "+con.getHeaderField(header)); M^iU;vo
else Tekfw
break; 079'(%
} %8Dzo
} H5]^ 6 HwX
a,+@|TJ,i
y^Kph# F"
public void splitterStop() {]_r W/
{ ./D$dbu3
bStop = true; ?a8(azn
} UIAj]
I_%a{$Gjl
psC mbN
} f=!VsR2o
DUe&r,(4O
:ORR_f`>
/* C2xL1`
**FileAccess.java ]oV{t<0a
*//文件访问(定位，写) MR,R}B$
package NetFox; UybW26C;aU
import java.io.*; n;p:=\uN
!F4@KAv
|'+eMl
public class FileAccessI implements Serializable{ UH>F|3"d
U_$qi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RQp|T5Er*
RandomAccessFile oSavedFile; @81Vc<dJ
long nPos; LIVU^Os.
^/=#UQ*k
nG,U>)
public FileAccessI() throws IOException c$`4*6
{ :nS;W
this("",0); TO*BH^5R
} ww{_c]My
fr}Eaa-{^
B_l{<
public FileAccessI(String sName,long nPos) throws IOException ^(f4*m6`
{ ZBG}3Z
oSavedFile = new RandomAccessFile(sName,"rw"); TLf9>= OVh
this.nPos = nPos; -;XKcS7Ue
oSavedFile.seek(nPos); %Lrd6i_j
} u!U"N*Y"
a=$t&7;,
Q2];RS3.
public synchronized int write(byte[] b,int nStart,int nLen) dg7=X{=9jv
{ ow;R$5G
int n = -1; EQIo5
try{ 1?Aga,~k:a
oSavedFile.write(b,nStart,nLen); $hVYTy~}
n = nLen; n*'<uKpM
} LaIJ1jf
catch(IOException e) \mN[gT}LHm
{ Koln9'tB
e.printStackTrace (); ~;OYtz
} cj|*_}
=}fd6ea(o
(|fm6$
return n; ]43bere
} /<3<. ~
|m?vVLq
q 'a
} B)h>8 {
i_LF`JhEQT
- ?!:{UXl
/* Zx?b<"k
**SiteInfoBean.java ])#\_'fg
*/ Q1&P@Io$
package NetFox; <;t)6:N\
%YlTF\-
3Gr&p6
public class SiteInfoBean { ;}.Kb
c| ' w
y9;#1:ic
private String sSiteURL; //Site's URL 9f}XRz
private String sFilePath; //Saved File's Path 7/X"z=Q^|
private String sFileName; //Saved File's Name %xyX8c{sP
private int nSplitter; //Count of Splited Downloading File w3D]~&]
I7\ &Z q
bYh9sO/l
public SiteInfoBean() cf[vf!vi
{//nSplitter的缺省值为5 ?&h3P8
//default value of nSplitter is 5 a%J6f$A#
this("","","",5); _b4fS'[
} {rkn q_;0
kJ: 2;t=
r.FLGDU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KLt%[$CTi
{ cc>
sSiteURL= sURL; ^4`&EF
sFilePath = sPath; C'9 1d7E
sFileName = sName; X#+`e+Df
this.nSplitter = nSpiltter; h[ 6hM^n
H]qq ~bO[
mR":z|6
} Zy wK/D
IB7tAG8
T }uE0Z,
public String getSSiteURL() ]u&dJL
{ ,bSVVT-b
return sSiteURL; O5 7jz= r
} K ar~I
j=.g:&r)
iWXMKu
public void setSSiteURL(String value) ^w6eWzI
{ 5urE
sSiteURL = value; Y%vP#>h
} ixOw=!@
r2G*!qK*1
Z[,`"}}hv=
public String getSFilePath() 135Par5v
{ U \Dca&=
return sFilePath; -Q`Cq|s
} iAz UaF
y=o=1(
JY4_v>Aob
public void setSFilePath(String value) 8SD}nFQ
{ {u]CHN`%Z
sFilePath = value; $k(9 U\y-
} eECj_eH-
@]3*B%t
C/+nSe.
public String getSFileName() 7L{li-crI
{ p6blD-v
return sFileName; !=M/j}
} 6bL"LM`s
lgG8!Ja
.D@/y uV
public void setSFileName(String value) !yCl(XT
{ 6IF|3@yD
sFileName = value; > I%zd/q?
} UIw?;:Y
s4IKSX
ip5u_Xj?
public int getNSplitter() r|8V @.@i
{ x\;GoGsez
return nSplitter; 3Bd4 C]E
} dt.-C_MO
zlX!xqHj
p[P[#IeL
public void setNSplitter(int nCount) 7jZrU|:yu(
{ |2UauTp5yK
nSplitter = nCount; HU3Vv<lz
} j[T%'%
} er\:U0fr#@
=w,(M
(j`l5r#X#/
/* ArdJ."
**Utility.java \R;K>c7=
*/ T.euoFU{Z
package NetFox; k*9%8yi_ U
{1HB!@%,(
xfUhSt
public class Utility { o(SuUGW
6Wu*.53
InX{V|CW?
public Utility() o;'4c
{ fsb=8>}63}
Pu/lpHm|
=[8d@d\
} QW:Z[?39^
0JOju$Bl,
//线程睡眠 _9qEZV
public static void sleep(int nSecond) i-Ljff
{ r?XDvU
try{ Q~CpP9%
Thread.sleep(nSecond); a j_:|]j
} Rmgxf/
catch(Exception e) 1#kawU6[]
{ %[+/>e/m
e.printStackTrace (); S&`O\!NF
} -&~IOqlui
} I]UA0[8X
mc56L[
//日志 Suj}MEiv
public static void log(String sMsg) u;{T2T
{ z+2u-jG
System.err.println(sMsg); =1&}t%<X
} OUKj@~T
{9,R@>R
8s&2gn1
public static void log(int sMsg) _.hIv8V
{ i&B?4J)
System.err.println(sMsg); T7X!#j"\
} EXH!glR[$
} 2tlO"c:_/
'NRN_c9
Hm<M@M$aG
/* w-8)YJ Y
**TestMethod.java -{r!M(47
*/ f>b!-|
package NetFox; 5]Z]j[8Y
7a27^b
k.h^ $f
public class TestMethod { Xd5! Ti}
&?fvt
c[6zX#{`
public TestMethod() lP-kZA!
{ ///xx/weblogic60b2_win.exe orK+B4
try{ SSo~.)J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .2{6h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y#.6d
SiteFileFetch fileFetch = new SiteFileFetch(bean); P|yGx)'^P
fileFetch.start(); Z@8MhJ
} 4E,hcu
catch(Exception e){e.printStackTrace ();} 1XC*|
Zt7hzW
CiHn;-b;
} B1up^(?
o4U]lK$
0fZ:")&4,
public static void main(String[] args) QJniM"8v
{ s-Q7uohK
new TestMethod(); cG<Q`(5~
} H{&a)!Ms
} m.|qVN
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