http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); y rH@:D/
} =Z}$X: $
for(int i=0;i<nEndPos.length-1;i++) j]P'xrWl]8
{ z[|2od
nEndPos = nStartPos[i+1]; iC2``[m"
} -?z#
nEndPos[nEndPos.length-1] = nFileLength; )xm[mvt
} {#y~ Qk;T
} x18(}4
XtCG.3(LY
\:y oS>G
//启动子线程 z*k(` '
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h>k[
for(int i=0;i<nStartPos.length;i++) < #FxI
{ Nux
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4]G J+a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;|U !\Xp
nStartPos,nEndPos,i); !:baG]Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *{DpNV8"
fileSplitterFetch.start(); duQ,6
} TAB'oLNp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1 K(0tG:5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sD#*W<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m)Ta5w^
nEndPos = " + nFileLength); 3LRBH+Tt
// fileSplitterFetch[nPos.length-1].start(); ^m Ua5w
6U9FvPJ
~)CGwST[
//等待子线程结束 qf T71o(
//int count = 0; WF] |-)vw
//是否结束while循环 };Pdn7;1G:
boolean breakWhile = false; g~p43sVV
BD,J4xH;
g>E.Snj}
while(!bStop) tJ$gH;
{ 2Y>#FEW/
write_nPos(); 4ibOVBG:*,
Utility.sleep(500); #?"^:,Y
breakWhile = true; ;"B@QPX
[]:&WA9N
(h"-#q8$
for(int i=0;i<nStartPos.length;i++) PCx:
{ d0V*[{
if(!fileSplitterFetch.bDownOver) w~4T.l#1
{ \&/V p`
breakWhile = false; X6<Ds'I
break; l#IN)">1
} Zz?)k])F
} SwE bVwB
if(breakWhile) [[#zB-|
break; m`BE{%
gz#2}
XFSHl[uS1
//count++; +I3j2u8L
//if(count>4) (T!#7
// siteStop(); nT :n>ja
} W#&BU-|2
&yRR!1n)H
?U+nR/H:6
System.err.println("文件下载结束！"); Fe1XczB
} !?)aZ |r
catch(Exception e){e.printStackTrace ();} )LAG$Cn
} qh|fq b
`ztp u ~?
m<sCRWa-
//获得文件长度 RiG]-K:
public long getFileSize() #+&"m7 s
{ } `Cc-X7
int nFileLength = -1; <!=:{&d%
try{ GC`/\~TM
URL url = new URL(siteInfoBean.getSSiteURL()); ;Wgkf_3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MzMVs3w|
httpConnection.setRequestProperty("User-Agent","NetFox"); wEZieHw
T]x]hQ
bgeJVI
int responseCode=httpConnection.getResponseCode(); MFn\[J`Ra
if(responseCode>=400) "[ieOFI
{ c+{ ar^)*
processErrorCode(responseCode); W2{4s 1
return -2; //-2 represent access is error .On3ZN
} vddl9"V)
C<#_1@^:8e
O"}O~lZ[6T
String sHeader; +w?-#M#
!t[;~`d9
%$_Y"82
for(int i=1;;i++) O{p7I&
{ e(I;[G +%,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &z05h<]
//Utility.log(in.readLine()); N :OLN[
sHeader=httpConnection.getHeaderFieldKey(i); Q!5W x
if(sHeader!=null) Z.`0
{ 97dF
if(sHeader.equals("Content-Length")) rgo!t028^
{ j-d542"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); woa|h"T
break; z))rk vL%
} N)/7j7c~;
} tzY?LX[3
else 9a#Y D;-p
break; LJA uTg
} _yp<#q]
} ~7gFddi=i
catch(IOException e){e.printStackTrace ();} Yyw9IYB;
catch(Exception e){e.printStackTrace ();} @"B{k%+
~x[(1
f\FqZ?w
Utility.log(nFileLength); 0v#p4@Z
/IlO
_FU}IfG>t
return nFileLength; mA#;6?6
} MP_/eC ;
XZ2 ji_D
CDY3+!
//保存下载信息（文件指针位置） "pO**z$Z
private void write_nPos() cT@H49#uB
{ K#Xl)h}y7
try{ O;$}j:;KF
output = new DataOutputStream(new FileOutputStream(tmpFile)); p0D@O_ :5
output.writeInt(nStartPos.length); |9Y~k,rF
for(int i=0;i<nStartPos.length;i++) y7,t"XV
{ L#WGOl
// output.writeLong(nPos); 9VMk?
output.writeLong(fileSplitterFetch.nStartPos); &;RBG$t
output.writeLong(fileSplitterFetch.nEndPos); pd|l&xvka
} (G~ME>
output.close(); _C=01 %/
} _88X-~.
catch(IOException e){e.printStackTrace ();} OKAmw>{
catch(Exception e){e.printStackTrace ();} 21my9Ui]
} wb%4f6i
*uSlp_;kB
ZENblh8fs
//读取保存的下载信息（文件指针位置） +Ht(_+To1
private void read_nPos() T+PERz(
{ ~>Y^?l
try{ Rp!"c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !}5+hj!6
int nCount = input.readInt(); Vh^ :.y
nStartPos = new long[nCount]; qoZe<jW (
nEndPos = new long[nCount]; ;I6C`N
for(int i=0;i<nStartPos.length;i++) #%pY,AK:=
{ E2tUL#
nStartPos = input.readLong(); ]K+8f-
nEndPos = input.readLong(); $KBW{
} `<#O8,7`
input.close(); N!Xn)J
} "([lkn
catch(IOException e){e.printStackTrace ();} );?tGX
catch(Exception e){e.printStackTrace ();} L3\(<[
} I+`>e*:@W
1ed^{Wa4$9
{suQ"iv
private void processErrorCode(int nErrorCode) }rnu:7
{ p&\DG
System.err.println("Error Code : " + nErrorCode); C~^T=IP
} 2Ima15^+F
nGsFt.
#bCUI*N"P
//停止文件下载 =@&>r5W1
public void siteStop() s@g _F
{ 7#N ?{3i
bStop = true; "Xl"H/3r
for(int i=0;i<nStartPos.length;i++) jAovzZ6BL
fileSplitterFetch.splitterStop(); %zR5q Lb
[;l;kom
1r5Z$3t\
} ^5)=)xVF
} {E}D6`{
//负责部分文件的抓取 xTqP`ljX
**FileSplitterFetch.java #ApmJLeCO
*/ cEn|Q
package NetFox; #Zi6N
VCT1GsnE
+U>Y.YP
import java.io.*; 9{rE7OX*A
import java.net.*; Iu(]i?Y
ZXf&pqmG
fF2]7:
public class FileSplitterFetch extends Thread { tv2k&\1
` +)Bl%*
jkAru_C
String sURL; //File URL `=Rxnl,<U
long nStartPos; //File Snippet Start Position r9<#R=r)}J
long nEndPos; //File Snippet End Position !| q19$
int nThreadID; //Thread's ID roBbo
boolean bDownOver = false; //Downing is over mE'HRv
boolean bStop = false; //Stop identical H_ NoW
FileAccessI fileAccessI = null; //File Access interface n0t+xvNDF_
#TV #*
o=PW)37>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I0;gTpt9
{ uc\G)BN
this.sURL = sURL; R?dMM
this.nStartPos = nStart; K,+z^{Hvh
this.nEndPos = nEnd; y5?kv-"c
nThreadID = id; ^f0-w`D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s=1k9
} "Y"`'U=v
uz:r'+v
x7i,jMR
public void run() :.f(}sCS
{ ezhfKt]j
while(nStartPos < nEndPos && !bStop) di]CYLf
{ b(adM3MP
L-m' #
[#AI!-
try{ 7\H_9o0$
URL url = new URL(sURL); vg1E@rH|}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); twt's,dO
httpConnection.setRequestProperty("User-Agent","NetFox"); WpMm%G~'4t
String sProperty = "bytes="+nStartPos+"-"; '5A&c(
httpConnection.setRequestProperty("RANGE",sProperty); _bv9/#tR
Utility.log(sProperty); V0*MY{x#S
KI].T+I
x]608I T
InputStream input = httpConnection.getInputStream(); +:/.\3v71
//logResponseHead(httpConnection); P%d3fFzK
\Hq=_}]F
A'D2uV
byte[] b = new byte[1024]; @wVDe\% ,
int nRead; Xi~I<&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w}M)]kY
{ K.}jyhKIKi
nStartPos += fileAccessI.write(b,0,nRead); 4tvZJS hV
//if(nThreadID == 1) i&<@}:,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ] pv!Ll
} ]4'V59\
q4vHsy36
'$4&q629d
Utility.log("Thread " + nThreadID + " is over!"); dIA1\;@
bDownOver = true; [(vV45(E
//nPos = fileAccessI.write (b,0,nRead); IK8"3+(
} cnDF`7xrT
catch(Exception e){e.printStackTrace ();} 31F^38
} DD6K[\
} E{\T?dk1$
DweF8c
V<U9Pj^?^
//打印回应的头信息 q AsTiT6r
public void logResponseHead(HttpURLConnection con) 1l^`
{ SPvKq=,
for(int i=1;;i++) O7J V{'?
{ ?xwZ< A
String header=con.getHeaderFieldKey(i); 0}e&ONDQ
if(header!=null) r jnf30
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )Q<u0AxAn
Utility.log(header+" : "+con.getHeaderField(header)); %wGQu;re
else :>jzL8
break; %+(fdk-k+
} L9l]0C37e
} 6kONuG7Yv
`:dGPBBO
dO9bxHMnM
public void splitterStop() ~F;>4q
{ Smd83W&
bStop = true; R0nUS<b0
} ,0?3k
qg*xdefQ%
Q.V+s
} l\u5RMS('
3'7X[{uBr
n0uL^{B
/* VT;cz6"6b4
**FileAccess.java _z#S8Y
*//文件访问(定位，写) mhNgXp)_56
package NetFox; y#nyH0U
import java.io.*; Nig)!4CG
7!e kINQ
~`0=-Qkd
public class FileAccessI implements Serializable{ ("=B,%F_
A8ClkLC;I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #-PUm0|
RandomAccessFile oSavedFile; g{hbq[>X]
long nPos; D&6.> wt .
#* 8^ar<
kcP&''
public FileAccessI() throws IOException .|y{1?f_
{ /f>I;z1
this("",0); NRs%q}lX
} SPINV.
)<T2J0*
l i%8X.
public FileAccessI(String sName,long nPos) throws IOException ?~;q r
{ LEAU3doK;
oSavedFile = new RandomAccessFile(sName,"rw"); LOk J
this.nPos = nPos; 1R#1Fy%
oSavedFile.seek(nPos); wy""02j
} O5JG!bGE_F
q=k[]vD
:eSwXDy&
public synchronized int write(byte[] b,int nStart,int nLen) KPa@~rU
{ - ysd`&
int n = -1; raZ0B,;eFu
try{ )+a]M1j
oSavedFile.write(b,nStart,nLen); }5u;'>$
n = nLen; ?cD_\~
} "@itn
catch(IOException e) nwJc%0
{ %:Zp7O2UB'
e.printStackTrace (); Lnl-han%
} {HP.HK
G+NTn\
7K/t>QrBtU
return n; (2/i1)Cq
} }G<A$*L1
T>v`UN Bl]
#o(@S{(NZ
} +F^X1
mXUe/*r0T
&G7@lz@sK+
/* eS2VLVxu
**SiteInfoBean.java wOR#sp&
*/ FNXVd/{M3
package NetFox; pF:C
(9+N_dLx~P
r6e!";w:U
public class SiteInfoBean { Bh6lK}9
4Gsq)i17j
buxyZV@1
private String sSiteURL; //Site's URL U,,rB(
private String sFilePath; //Saved File's Path P}D5 j
private String sFileName; //Saved File's Name sV`XJ9e|
private int nSplitter; //Count of Splited Downloading File Aoy=gK
zi,":KDz#
qjIcRue'"
public SiteInfoBean() o q cu<]
{//nSplitter的缺省值为5 ?$4CgN-
//default value of nSplitter is 5 \6,Z<.I
this("","","",5); ypY7uYO^"
} %?z;'Y7D
L$}'6y/@
oRl@AhS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @Hst-H.l<l
{ +/Vzw
sSiteURL= sURL; BWsD~Ft
sFilePath = sPath; $)7Af6xD
sFileName = sName; |bjLmGb
this.nSplitter = nSpiltter; jHc/ EZB
oX[I4i%G
(9!kKMQW'
} :$oiP
s *<T5Z
O9)k)A]`O
public String getSSiteURL() *9}~?#b
{ Ky'\t7p u
return sSiteURL; 1)!]zV
} ,+RoJwi m
L9 H.DNA
_2Fa.gi
public void setSSiteURL(String value) f2{qj5 K
{ #pX+~{
sSiteURL = value; 'Ie!%k^
} M,N(be-
qAuq2pHA+d
v5`Odbc=w
public String getSFilePath() Tq5F'@e
{ Q9 RCN<!
return sFilePath; c]:@y"W5$
} IV$2`)[A&X
axd9b,
CV6W)B%Se
public void setSFilePath(String value) >Y&o2zJy
{ Re'Ek
sFilePath = value; '>|5
} ZQrgYeQl"
O}"fhMk
4(\7Or(''
public String getSFileName() ?[ vC?P
{ |c!lZo/
return sFileName; 1z=}`,?>
} nB86oQ/S
1V1T1
!)'|Y5 o
public void setSFileName(String value) 69/qH_Y
{ $6\W8v
sFileName = value; Jl,\^)DSw
} ]mvVX31T
9i#K{CkC|
-X#qW"92q
public int getNSplitter() fT_swhIO
{ Qmn'G4#@E
return nSplitter; E{6X-C[)v
} q"pnFK9/L
Nh\y@\F>
t8FgQ)tk
public void setNSplitter(int nCount) MFLw^10(T
{ w'Q2Czso
nSplitter = nCount; u+uu?.bM
} auQfWO[ u
} vW4N[ .+
\Rvsy;7
Bn{0-5nj
/* j<*`?V^
**Utility.java 64qQ:D7C
*/ Yg14aKZl
package NetFox; MEn#MT/Cz
&:)e
x+5y287#
public class Utility { @;@Wt`(2a
N\dr_
SvGs?nUU
public Utility() s *1%I$=@
{ E|Z7art
._z[T@!9
\:wLUGFl5
} b(H)8#C
}\/f~?tEh
//线程睡眠 yw)Ztg)
public static void sleep(int nSecond) |1(9_=i'
{ m=2e1wc
try{ LlG~aGhel
Thread.sleep(nSecond); 8?7:sfc
} iP~dH/B|v
catch(Exception e) >w=xGb7
{ D?"TcA
e.printStackTrace (); }~28UXb23
} >xE{& ):
} /1q] D8
mDp|EXN
//日志 3eFBe2
public static void log(String sMsg) ;i><03
{ emI]'{_G
System.err.println(sMsg); 7eg//mL"6
} +C !A@
r3b~|O^}
&c!=< <5M
public static void log(int sMsg) @*c) s_
{ L"6@3
System.err.println(sMsg); kY6))9 O
} ?RD)a`y51
} )(pJ~"'L
h&6x.ps@
lEC58`Ws
/* P&Q 5ZQb
**TestMethod.java 3It'!R8$
*/ 4n@, p0
package NetFox; ZWJFd(6
V-w[\u
ynN[N(m#
public class TestMethod { G{ $Zg
%R{clbbbn
-h8!O+7 .
public TestMethod() }?Y+GT"E
{ ///xx/weblogic60b2_win.exe 7>m#Y'ppl@
try{ 7M1*SC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R%Yws2Le2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d0 tN73(
SiteFileFetch fileFetch = new SiteFileFetch(bean); Pz"!8b-MN
fileFetch.start(); _dEf@==
} 9D_4]'KG
catch(Exception e){e.printStackTrace ();} #+eV5%Si
wWflZ"%
F#^.L|d4
} ;D[b25
jL)aU> kN
5\tYs=>b<
public static void main(String[] args) yXw xq(32
{ y o[!q|z
new TestMethod(); hGF(E*
} V@K}'f~
} x9HA^Rj4-
点击下载更多相关资料