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)); ; $ ?jR c
} V. bH$@ej
for(int i=0;i<nEndPos.length-1;i++) !UgUXN*
{ gvTOCF
nEndPos = nStartPos[i+1]; iX>!ju'V
} D_ Bx>G9
nEndPos[nEndPos.length-1] = nFileLength; O%fp;Y{`
} }Pm(oR'KTJ
} $_URXI
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ulPrb>i
//启动子线程 N?2#YTjR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; evg7d
for(int i=0;i<nStartPos.length;i++) eF8aB?&"
{ z|DA _dG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f9l<$l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o {XwLi
nStartPos,nEndPos,i); |peMr#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VhH]n yi7D
fileSplitterFetch.start(); aaf_3UH.B
} $cJN9|$6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Xd\$)n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yf#%)-7(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M::IE|h
nEndPos = " + nFileLength); bE`*Uw4
// fileSplitterFetch[nPos.length-1].start(); XoxR5arj
e`Zg7CaDd
f5=t*9_-[
//等待子线程结束 ?D~SHcBaN
//int count = 0; io+7{B=u$
//是否结束while循环 )QSt7g|OF
boolean breakWhile = false; (/x@W`
Gs=a(0 0i?
OJ_2z|f<
while(!bStop) Z1V'NJI+
{ NW4 s'roP
write_nPos(); 2YE]?!
Utility.sleep(500); WKrZTPD'm
breakWhile = true; X%9xuc
wD?=u\% &
|jaY[_.@
for(int i=0;i<nStartPos.length;i++) n;k97>m${x
{ 9+is?Pj
if(!fileSplitterFetch.bDownOver) [P&,}o)+E0
{ ~4~Tcn
breakWhile = false; \'LCC-
break; 4 _U,-%/
} tzW<&^
} iQ]c k-
if(breakWhile) v20I<!5w
break; M%5$-;6~_
g7U:A0Z
!NAX6m
//count++; 7f\^VG
//if(count>4) MMA@J
// siteStop(); J2rLsNC]0
} =<'iLQb1
0rm;)[SjF
b gc<)=
System.err.println("文件下载结束！"); ;~@PYIp
} rIFC#Jd/
catch(Exception e){e.printStackTrace ();} }AsF\W+5
} :D+SY
iUG/
nog\,NT
//获得文件长度 i{FC1tVeL_
public long getFileSize() 9hs{uxwuEE
{ Obc3^pV&
int nFileLength = -1; Ae_ E;[mj
try{ ;gW|qb+#)j
URL url = new URL(siteInfoBean.getSSiteURL()); FTYLMQ i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4TQISu)
httpConnection.setRequestProperty("User-Agent","NetFox"); +81+4{*
g/X=#!
33KPo0g7
int responseCode=httpConnection.getResponseCode(); 6% y)
if(responseCode>=400) vS t=Ax3]
{ np\Q&
processErrorCode(responseCode); tEX~72v
return -2; //-2 represent access is error j_WF38o
} qM:)daS1w
/qq&'}TZP
j5Wx*~@(
String sHeader; YlcF-a
v3JIUdU=P
^57fHlw
for(int i=1;;i++) cKYvRe
{ L{0OMyUA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S5 nw
//Utility.log(in.readLine()); IM5^E#-g7
sHeader=httpConnection.getHeaderFieldKey(i); a=B0ytNm
if(sHeader!=null) 5NF&LM;i(
{ qCkg\)Ks5I
if(sHeader.equals("Content-Length")) DF[b?
{ H6JMN1#t$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jx9%8Ek
break; vzm4
} E|4XQ|B@
} >T*g'954xF
else n`KXJ?t
break; |AfQ_iT6c
} \\G6c4fC
} ,M h/3DPgE
catch(IOException e){e.printStackTrace ();} O/^w! :z'
catch(Exception e){e.printStackTrace ();} dDn4nwH
PRlo"kN
8v=47G
Utility.log(nFileLength); IC-xCzR
y{?jr$js<
wG?kcfu
return nFileLength; geN%rD
} jp]geV54
3cFLU^
%+!9
//保存下载信息（文件指针位置） e&4wwP"`<
private void write_nPos() IIn\{*|mW
{ x15tQb+
try{ r~2@#gTbl
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZznWs+
output.writeInt(nStartPos.length); 7%}3Ghc%
for(int i=0;i<nStartPos.length;i++) Ng39D#_)
{ f EiEfu
// output.writeLong(nPos); +;iesULXn
output.writeLong(fileSplitterFetch.nStartPos); :(p rx
output.writeLong(fileSplitterFetch.nEndPos); <({eOh5N
} {]Iu">*
output.close(); %1 ^jd\
} m.a1
catch(IOException e){e.printStackTrace ();} 5a_!&
catch(Exception e){e.printStackTrace ();} l<:E+lU
} JI,hy <3l0
.*f4e3
kpw4Mq@
//读取保存的下载信息（文件指针位置） W!B4<'Fjc
private void read_nPos() wP':B AQ4U
{ 2^ZPO4|
try{ "#k(V=y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E=*Q\3G~
int nCount = input.readInt(); wEc5{ b5M
nStartPos = new long[nCount]; 7CMgvH)O
nEndPos = new long[nCount]; cH-Zj
for(int i=0;i<nStartPos.length;i++) n4&j<zAV{
{ ?N*@o.
nStartPos = input.readLong(); p2vUt
nEndPos = input.readLong(); sx^? Iw,N'
} ;Hr@0f
input.close(); OjEA;;qq
} w&cyGd D5
catch(IOException e){e.printStackTrace ();} uBkny;
catch(Exception e){e.printStackTrace ();} 7=*k@9
} K$GXXE`
J+gsmP-_
3&Rqz9W
private void processErrorCode(int nErrorCode) RX\O'Zwlj
{ @N{Ht)1r
System.err.println("Error Code : " + nErrorCode); |+~2sbM
} 3i}B\ {
|3@Pt>Ikl
kj=2+)!E7
//停止文件下载 :|Nbk58
public void siteStop() TC#B^m`'p
{ 2U+p@}cQUA
bStop = true; r3vj o(
for(int i=0;i<nStartPos.length;i++) =xet+;~ji
fileSplitterFetch.splitterStop(); Zs|sPatV<
\)uad5`N
BD#;3?|
} d$~b`
} OBSJbDqT
//负责部分文件的抓取 :uDB3jN[
**FileSplitterFetch.java N,Bs% p#1
*/ s9bP6N!,
package NetFox; )II,HT-LY
cS7!,XC
R_&z2I
import java.io.*; "a{f? .X.
import java.net.*; becQ5w/~
:P"Gym
rO%+)M$A
public class FileSplitterFetch extends Thread { 2U{RA's
FRk_xxe"K
K+OU~SED%F
String sURL; //File URL k ,(:[3J
long nStartPos; //File Snippet Start Position i~L7h=__
long nEndPos; //File Snippet End Position ]m>MB )9
int nThreadID; //Thread's ID 2wsZ&y%
boolean bDownOver = false; //Downing is over (UXB#I~
boolean bStop = false; //Stop identical (Fd4Gw<sq
FileAccessI fileAccessI = null; //File Access interface io3'h:+9s
K(<P" g(
#7ZBbq3=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w!7/;VJ3d
{ dS=,. }
this.sURL = sURL; L-$g& -
this.nStartPos = nStart; LXV6Ew5E
this.nEndPos = nEnd; Qf]!K6eR
nThreadID = id; FQ)Ekss~C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m/nn}+*C
} $?{zV$r1
CI'5JOqP
1dsxqN(:
public void run() ^ s4|
{ Ft!~w#&-
while(nStartPos < nEndPos && !bStop) 59 Y=VS
{ 4]KceE
H4Ek,m|c
>E=a~ O
try{ O8o18m8UH
URL url = new URL(sURL); 9V\`{(R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P'~3WL4MKs
httpConnection.setRequestProperty("User-Agent","NetFox"); nHjwT5Q+Q
String sProperty = "bytes="+nStartPos+"-"; gMn)<u>
httpConnection.setRequestProperty("RANGE",sProperty); jQ}|]pj+
Utility.log(sProperty); sTyGi1
mIodD)?{
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InputStream input = httpConnection.getInputStream(); tH(#nx8
//logResponseHead(httpConnection); ,-kZ5&r
/WVMT]T6^,
t%@pyK
byte[] b = new byte[1024]; rzLlM
int nRead; miSC'!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B=`!
{ Yg.u8{H
nStartPos += fileAccessI.write(b,0,nRead); +8I0.,'
//if(nThreadID == 1) }3lF;k(2g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 69yyVu_
} I5?LD=tt
9~I WGj?
]:fHvx_?`7
Utility.log("Thread " + nThreadID + " is over!"); JN)t'm[kyE
bDownOver = true; W:J00rsv=`
//nPos = fileAccessI.write (b,0,nRead); d*HAKXd&:j
} JH#+E04#
catch(Exception e){e.printStackTrace ();} N>Y3[G+
} bxq`E!]
} cgOoQP/#
K? k`U,
FG\?_G
//打印回应的头信息 %xz02$k
public void logResponseHead(HttpURLConnection con) ;7>--_?=
{ lUd,-
for(int i=1;;i++) \-yi#N
{ 6I0MJpLW
String header=con.getHeaderFieldKey(i); g*M3;G
if(header!=null) O~VUViS6$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %BKTN@;7
Utility.log(header+" : "+con.getHeaderField(header)); >w2u
else -bF+uCfba
break; * =l9gv&
} + aFjtb
} !ZW0yCwLQ
nE84W$\
9qA_5x%"%u
public void splitterStop() Fu$sfq
{ PV2904
bStop = true; *TkABUL
} NQ!F`
u 36;;z
C7PiuL?
} A )cb
HZ3<}`P_W
i1C'
/* <0m;|Ai'W
**FileAccess.java R?Qou!*]
*//文件访问(定位，写) ):@B1 yR
package NetFox; { L5m`-x
import java.io.*; v5o%y:~
{Xj%JE[V
8J0tya"z
public class FileAccessI implements Serializable{ I j /J
=g:\R$lQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jg(A_V
RandomAccessFile oSavedFile; ->(B:Cz
long nPos; zqkmsFH{
1Rh&04O>VL
tJP(eaqZ
public FileAccessI() throws IOException y(A"g3^=
{ j3><J
this("",0); LmE-&
} A5b}G
8TZe=sD~cr
g d-fJ._1
public FileAccessI(String sName,long nPos) throws IOException mN`a]L'
{ ~cjvo?)&e;
oSavedFile = new RandomAccessFile(sName,"rw"); DI\sq8J^
this.nPos = nPos; Fwr,e;Z
oSavedFile.seek(nPos); P$bo8*
} EbQ}w"{
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*QX$Mo^E
public synchronized int write(byte[] b,int nStart,int nLen) 8 _J:Yg
{ XN@5TZoaW
int n = -1; YAog;QL
try{ I}X8-WFB
oSavedFile.write(b,nStart,nLen); u(R`}C?P'
n = nLen; *))|ZE6jI
} M<nn+vy`
catch(IOException e) h| Ih4
{ Sa0\93oa
e.printStackTrace (); 0Ju{6x(|
} @WmB0cc_
jv ";?*I6.
`xSXGI
return n; "'Q:%_;
} ]x|sTKv2
jcj)9;n=!
/%)J+K)
} ~VKw%WK
`PL!>oa(8
QS_u<B
/* o,-@vp
**SiteInfoBean.java "O4Z).5q3
*/ JF7T1T
package NetFox; -[=`bHo
X:A\{^~
D+V^nCcx%
public class SiteInfoBean { 8Y9mB#X
7"NUof?i
7j Q`i;L}Y
private String sSiteURL; //Site's URL E=y#~W
private String sFilePath; //Saved File's Path G9 !1Wzs
private String sFileName; //Saved File's Name }7V/(K
private int nSplitter; //Count of Splited Downloading File ]O[f#lG
sYz:(hZS
xASjw?
public SiteInfoBean() xiI!_0'
{//nSplitter的缺省值为5 (.c?)_G,
//default value of nSplitter is 5 Umqm5*P(
this("","","",5); #ua#$&p
} ?@nu]~
*VH1(E`hl
0ode&dB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C8?/$1|RL
{ +#W5Qb}VR
sSiteURL= sURL; mUjA9[@
sFilePath = sPath; -+L1Hid.7
sFileName = sName; <AVpFy
this.nSplitter = nSpiltter; W`Soa&9
ZA!vxQ?P,
&~j"3G;e
} yoH6g?!O
+RbCa c
aU3&=aN+
public String getSSiteURL() M1^pW63
{ qAm%h\
return sSiteURL; 0zd1:*KR,
} i@2?5U>h
|y]#-T?)t
*}?^)z7w
public void setSSiteURL(String value) MV/JZ;55
{ .JzO f[g5
sSiteURL = value; u@o3p*bQ
} fROhn}<**[
|$D^LY
1}(g=S
public String getSFilePath() HJ2]xe09
{ Z#F2<*+Pe
return sFilePath; FOZqN K
} ^}WeBU
QKVZ![Y!s
M4QMD;Ez
public void setSFilePath(String value) C}Khh`8@5.
{ &t4j px
sFilePath = value; htaB!Q?V
} k,r\^1h
MW p^.
M?_VYK
public String getSFileName() 03MB,
{ 4'{j'kuv
return sFileName; $tb$gO
} t0wLj}"U
fD!O aK
MPT[f
public void setSFileName(String value) X1+Wb9P
{ -i58FJ`B
sFileName = value; _-EHG
} pdE=9l'
kJ~^ }o
MOj 0"x)
public int getNSplitter() Gm*i='f!?
{ hX;xbl
return nSplitter; KB-7]H
} VQX#P<
[E=t{&t
#Zfg
public void setNSplitter(int nCount) QutQG
{ PPohpdd)
nSplitter = nCount; n&@\[,B
} Qd@`jwjS
} L%<1cE))
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7)[4|I
/* iX4/;2B=,
**Utility.java 9m<>G3Jr
*/ -0>@jfP^D
package NetFox; hG3b7!^#g
*iYs,4
&359tG0@P
public class Utility { [u~#F,_ow
6N]v9uXZ
^oA^z1>3
public Utility() pO"V9[p]
{ wKwireOs
'*22j ]
C7PHZ`<
} Ua(!:5q?
}4+S_b
//线程睡眠 1MOQ/N2BR
public static void sleep(int nSecond) C,K P!B{
{ Zr`:A$
try{ u+S*D\p<`
Thread.sleep(nSecond); W[+E5I
} oZ!rK/qoA
catch(Exception e) 4j/8Otn
{ \p.ku%{
e.printStackTrace (); $NqT={!
} MvObx'+
} V" I+E
QarA.Ne~
//日志 Al 0zL
public static void log(String sMsg) 3pm;?6i6
{ " >;},$
System.err.println(sMsg); #Jg)HU9
} A`IE8@&Z'
!30BZM^
K47W7zR
public static void log(int sMsg) (]rtBeT
{ %<K`d
System.err.println(sMsg); c^I_~OwaE
} 7j{SCE;
} Ao 1*a%-.
DaaLRMQ=
/)6<`S(
/* 3%'$AM}+s
**TestMethod.java 6f0 WN
*/ NO"=\Zn6
package NetFox; %KRAcCa7
O']-<E`1k
p ^T0(\1
public class TestMethod { $--W,ov5j
4R@3jGXb8q
`2Vc*R
public TestMethod() %J7 ;b<}To
{ ///xx/weblogic60b2_win.exe H7*/
try{ a+IU<O-J?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #O qfyY!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G[)QGZ}8b
SiteFileFetch fileFetch = new SiteFileFetch(bean); HLa|ycB%
fileFetch.start(); ,M5J~Ga
} T+RfMEdr
catch(Exception e){e.printStackTrace ();} KZJ;O7'`
Kp8!^os
;E(%s=i
} <SbW QbN
$D\SueZ
vfm|?\
public static void main(String[] args) pzHN:9r
{ U!TFFkX[
new TestMethod(); ]xbR:CYJ
} 4Rp2
} h@t&n@8O?
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