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)); U_M> Q_r(
} o*r\&!NIw
for(int i=0;i<nEndPos.length-1;i++) v?d~H`L
{ chfj|Ce]x
nEndPos = nStartPos[i+1]; $ n 7dIE
} i]F,Y;&|
nEndPos[nEndPos.length-1] = nFileLength; /=Q7RJ@P
} :LcR<>LZ
} i~l0XjQbs
Lxd*W2$3_
ULQ*cW&;?
//启动子线程 2}509X(*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P8;|>OLZ)
for(int i=0;i<nStartPos.length;i++) )+cP8$n6L
{ 2/>AmVM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,v)@&1Wh:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SjG=H%
nStartPos,nEndPos,i); {\lu; b!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4[+n;OI
fileSplitterFetch.start(); -?'u"*#1,
} vco:6Ab$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )v ['p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O]lWaiR`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P9Rq'u
nEndPos = " + nFileLength); T7!a@
// fileSplitterFetch[nPos.length-1].start(); |\N[EM%.@
.c~;/@{
*"1]NAz+
//等待子线程结束 c%i/ '<Afr
//int count = 0; 2r[Q$GPM<
//是否结束while循环 D97oS!*
boolean breakWhile = false; SDdK5@1O4o
?c=l"\^x
f]o DZO%^
while(!bStop) O!/J2SfuDH
{ bO^%#<7
write_nPos(); {-<h5_h@
Utility.sleep(500); <7)Vj*VxC
breakWhile = true; [ &R-YQ@
rj<%_d'Z`
0)9GkHVu(
for(int i=0;i<nStartPos.length;i++) uX`Jc:1q3
{ Cw Z{&
if(!fileSplitterFetch.bDownOver) yUEUIPL
{ {b]WLBy
breakWhile = false; \]y$[\F>
break; VbA#D4;
} 9{ciD "!&V
} Ep?a1&b
if(breakWhile) qj/ 66ak
break; Ct"h.rD]
1Pn!{ bU3@
;~/
//count++; yUNl)E
//if(count>4) vxbO>c
// siteStop(); Ct #hl8b:
} !BK^5,4?--
%&e5i
p3sz32RX
System.err.println("文件下载结束！"); a>""MC2
} h2uO+qEsu
catch(Exception e){e.printStackTrace ();} x?Q;o+2v
} Wq"pKI#x
ap_(/W
SznNvd <
//获得文件长度 ^@L
public long getFileSize() B;?a. 81~
{ $,'r} %
int nFileLength = -1; I#$u(2.H
try{ CIYD'zR[2
URL url = new URL(siteInfoBean.getSSiteURL()); ]iPTB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _0Wdm*
httpConnection.setRequestProperty("User-Agent","NetFox"); EeL~`$f
!~>u\h
qK(?\t$
int responseCode=httpConnection.getResponseCode(); ` LU&]NS3
if(responseCode>=400) t{x&|%u
{ dd98vVj
processErrorCode(responseCode); yK[~(!c5
return -2; //-2 represent access is error tJ'U<s
} .@1\26<
PJkEBdM.
o7hjx hmC
String sHeader; ^"*r'
{Ivu"<`L3
~EX/IIa{
for(int i=1;;i++) B4U+q|OD#
{ dL[mX .j"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5r`g6@
//Utility.log(in.readLine()); }ZR3
sHeader=httpConnection.getHeaderFieldKey(i); gzl_ "j
if(sHeader!=null) mufF_e)
{ Z\LW<**b
if(sHeader.equals("Content-Length")) #gi&pR'$
{ W;Fcp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u~a<Psp&|
break; 'nW:2(J
} `?`\!uP"
} 97<Y. 0
else w[]7{D];
break; +O\6p
} U_oMR$/Z
} =`.9V<
catch(IOException e){e.printStackTrace ();} Nu|?s-
catch(Exception e){e.printStackTrace ();} 9>[$;>
6VCw>x
vgsu~(L;
Utility.log(nFileLength); o5AyJuS-u$
]]9eUw=
njvmf*A?S
return nFileLength; 'B6D&xn'%&
} wGb{O
s)_sLt8?
9SMM%(3, r
//保存下载信息（文件指针位置） @I_A(cr
private void write_nPos() Etn]e;z4
{ HLTz|P0JZ
try{ 2Ni2Gkf@
output = new DataOutputStream(new FileOutputStream(tmpFile)); |V:k8Ab
output.writeInt(nStartPos.length); h*d&2>"0m?
for(int i=0;i<nStartPos.length;i++) }2JSa8
{ \XmtSfFC
// output.writeLong(nPos); MqXA8D
output.writeLong(fileSplitterFetch.nStartPos); rd. "mG.
output.writeLong(fileSplitterFetch.nEndPos); Q:@Y/4=
} va#~ \%`
output.close(); %qN8uQx
} p2w/jJMD
catch(IOException e){e.printStackTrace ();} GawLQst[+
catch(Exception e){e.printStackTrace ();} ZLo3 0*
} sveFxI
&Sc0l/
"T#c#?
//读取保存的下载信息（文件指针位置） h`Y t4-Y
private void read_nPos() ?Yz.tg
{ eN,m8A`/S
try{ (Tc ~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1!BV]&,[
int nCount = input.readInt(); w;{k\=W3Ff
nStartPos = new long[nCount]; scN}eg:5
nEndPos = new long[nCount]; 2lXsD;[
for(int i=0;i<nStartPos.length;i++) "52wa<MVJ
{ pOw4H67
nStartPos = input.readLong(); }]tSWVb*
nEndPos = input.readLong(); 0H;dA1
} =XudL^GF
input.close(); Awe\KJ^`
} WET $H,
catch(IOException e){e.printStackTrace ();} 5%,n[qj4IT
catch(Exception e){e.printStackTrace ();} o<T>G{XYB
} dI'C[.zp[
e`8z1r
gY;N>Yq,C
private void processErrorCode(int nErrorCode) e#&[4tQF
{ :=*>:*.Kb
System.err.println("Error Code : " + nErrorCode); ;?%2dv2d
} Q;5aM%a`
&[JI L=m5
b@5&<V;r2
//停止文件下载 vJXd{iQE@C
public void siteStop() L'z?M]
{ r}03&h~Hc&
bStop = true; QT^( oog=
for(int i=0;i<nStartPos.length;i++) I]ywO4
fileSplitterFetch.splitterStop(); ]:]2f9y
)mwY] !
nef-xxXC^I
} 7|65;jm+
} uA\A4
//负责部分文件的抓取 O(WFjmHx
**FileSplitterFetch.java UDuKG\_J<y
*/ WDgp(Av!
package NetFox; nE::9Yh8z
QR79^A@5
&tp5y}=n
import java.io.*; $#"}g#u
import java.net.*; zz02F+H$Y
Zad+)~@!tq
|%6B#uy
public class FileSplitterFetch extends Thread { yf_<o
xp><7{
?55('+{l
String sURL; //File URL }R}tIC-:
long nStartPos; //File Snippet Start Position HQ2in_'
long nEndPos; //File Snippet End Position F fl`;M
int nThreadID; //Thread's ID C8NbxP
boolean bDownOver = false; //Downing is over yHT}rRS8
boolean bStop = false; //Stop identical c WK@O>
FileAccessI fileAccessI = null; //File Access interface \U~ggg0h
VO++(G)
zA-?x1th&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t"RgEH@
{ X2sK<Qluql
this.sURL = sURL; zA( 2+e 7
this.nStartPos = nStart; {"4t`dM
this.nEndPos = nEnd; gxt2Mq;q~}
nThreadID = id; AS4m227
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a$;+-Y
} $Q]`+:g*}
7e}p:Vfp
x2|DI)J1'
public void run() r@s, cCK9?
{ ]l+2Ca:-[j
while(nStartPos < nEndPos && !bStop) 0r+-}5aSl5
{ y0A2{'w
Z AZQFr'*
\k;raQR4t*
try{ P+"#xH
URL url = new URL(sURL); Xb6@;G"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vs6`oW"{#
httpConnection.setRequestProperty("User-Agent","NetFox"); EXb{/4
String sProperty = "bytes="+nStartPos+"-"; %y8w9aGt
httpConnection.setRequestProperty("RANGE",sProperty); zU1rjhv+
Utility.log(sProperty); QHtpCNTVb
,wZ[Y 3
xB9^DURr\
InputStream input = httpConnection.getInputStream(); R<JI
//logResponseHead(httpConnection); Hi.JL
= ng\
5<d Y,FvX
byte[] b = new byte[1024]; e(!a~{(kq%
int nRead; mHw1n=B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;Oe6SNquT
{ hM>xe8yE
nStartPos += fileAccessI.write(b,0,nRead); vuw1ycy)
//if(nThreadID == 1) |fRajuA;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )xTp7YnZ;
} Vvv -f
}8x[
Ep0Aogp29
Utility.log("Thread " + nThreadID + " is over!"); N}Q,
bDownOver = true; C-4I e
//nPos = fileAccessI.write (b,0,nRead); sU+~#K$b
} }14.u&4
catch(Exception e){e.printStackTrace ();} ]G|@F :
} >E)UmO{S
} u45e>F=
V|b?H6Q
\a|gzC1G
//打印回应的头信息 YK"({Z>U
public void logResponseHead(HttpURLConnection con) ZO0_:T#Z
{ _KD(V2W
for(int i=1;;i++) ijoR(R^r
{ R`s /^0
String header=con.getHeaderFieldKey(i); )NyGV!Zuu
if(header!=null) t'[vN~I'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JziMjR
Utility.log(header+" : "+con.getHeaderField(header)); U/jJ@8
else QW~o+N~~
break; N#ex2c
} EH4WR/x
} :_^9.`
_Zb_9&
'| Ag,x[
public void splitterStop() sy>Pn
{ FK mFjqY
bStop = true; %\5y6
} eZg31.
b[BSUdCB
G%'h'AV"
} ]=]'*Z%
-,XS2[
%iJ6;V4
/* r-[z!S
**FileAccess.java (<8T*Xo
*//文件访问(定位，写) aIqNNR
package NetFox; dIM:U:c
import java.io.*; 7&HP2r
HjV^6oP
y{jv-&!xB
public class FileAccessI implements Serializable{ )03.6Pvs
O`@$YXuD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b*p,s9k7
RandomAccessFile oSavedFile; av`b8cGg
long nPos; zb;2xTH+
;q$<]X_S)}
$xloB
public FileAccessI() throws IOException <`MHra8
{ >6<g5ps.n
this("",0); J^t=.-a|
} ^g~-$t<!
e=2;z
Ulktd^A\
public FileAccessI(String sName,long nPos) throws IOException Dq-h`lh!D#
{ =Oo*7|Z
oSavedFile = new RandomAccessFile(sName,"rw"); A;Zg:
this.nPos = nPos; JaIj9KLNX
oSavedFile.seek(nPos); L`"cu.l
} f_z2d+
czHO)uQ?d`
G~m(&,:Mu
public synchronized int write(byte[] b,int nStart,int nLen) 59EAqz[:
{ <@zOdW|{:
int n = -1; Gjv'$O2_
try{ \Dt0 } ?;k
oSavedFile.write(b,nStart,nLen); % yJs"%
n = nLen; ShSh/0
} 6qHo$#iT
catch(IOException e) 9k83wACry
{ # ^%'*/z
e.printStackTrace (); MhJ`>.z1
} Z2 t0l%
F92n)*[
q<;9!2py
return n; kdoE)C
} wvUph[j}J
<-lz_
`ZNjA},.
} j"YJ1R-5
Q |l93Rb`
lGcHfW)Y
/* $*2uI?87}:
**SiteInfoBean.java x#ouR+<
*/ Ebq5P$
package NetFox; ]-ZD;kOr
y:W$~<E`p
g`1*p|
public class SiteInfoBean { `NGCUGQ_7
4!monaB"e
6 #QS5
private String sSiteURL; //Site's URL ?=PQQx2_*u
private String sFilePath; //Saved File's Path YemOP9
private String sFileName; //Saved File's Name {8UBxFIM(
private int nSplitter; //Count of Splited Downloading File ^U`[P@T
0<^K0>lm p
"ENgu/A!
public SiteInfoBean() Ay2|@1e
{//nSplitter的缺省值为5 *1elUI2Rg
//default value of nSplitter is 5 Duz}e80
this("","","",5); >iG`
} xy|;WB
63k8j[$
gbI0?G6XN/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C6/,-?%)
{ x^C,xP[#Y;
sSiteURL= sURL; ^ qE4:|e
sFilePath = sPath; 31bKgU{
sFileName = sName; "@Te!.~A.
this.nSplitter = nSpiltter; k_y@vW3
{&2$1p/9'
O:u^jcXA
} <89js87
\x|(`;{
g/Qr]:;
public String getSSiteURL() kvo741RO6
{ kmP0gT{Sj
return sSiteURL; 0TVO'$Gvi
} H9 't;Do
|5Z@7
ff{ESFtD
public void setSSiteURL(String value) `T~M:\^D
{ ^:DlrI$
sSiteURL = value; - +>~
} 9g 2x+@5T^
=fRP9`y
-`Z5#8P
public String getSFilePath() xXHz)w
{ op"Cc
return sFilePath; }uZhoA
} hL8QA!
q Rtgk
.[CXW2k
public void setSFilePath(String value) O?{pln
{ ||/noUK
sFilePath = value; QtX ->6P>
} n*-#VKK^
U2SxRFs >
HPU7 `b4
public String getSFileName() 7dW9i7Aj
{ ) d\Se9!
return sFileName; dnN"
} 0gt/JI($
H:0-.a^ZS
)6!SFj>.O
public void setSFileName(String value) OBj.-jL
{ snN1
sFileName = value; g*^"x&
} N\xqy-L9
D* Vr)J
*y`^Fc
public int getNSplitter() Z\@vN[[
{ xat)9Yb}0
return nSplitter; 3xj<ATSe
} 9K)OQDv%6D
|e+I5
2-{8+*_'
public void setNSplitter(int nCount) 8n2*z
{ LkNfcBa_
nSplitter = nCount; Mu{mj4Y{
} (:@qn+ a
} 2{{M{#}S.
C~6aX/:
[*50Ng>P`
/* b7"pm)6
**Utility.java SHhg&~B
*/ A #ZaXu/:X
package NetFox; "\> <UJ
a{]1H4+bQ
hBN!!a|l
public class Utility { Iye
`~*qjA
LsBDfp5/
public Utility() drN^-e
{ 8zZR%fZ
lOZ.{0{f,
A0&~U0*(~
} ~;U!?
&_!BMzp4
//线程睡眠 >~XX'}
public static void sleep(int nSecond) '+-R 7#
{ >Z>*Iz,LP
try{ #7'ww*+
Thread.sleep(nSecond); W+1V&a}E
} S0"OU0`N
catch(Exception e) ts)0+x
{ :X@;XEol~
e.printStackTrace (); "I_3!Yu
} '!En,*'IS
} "jAV7lP
7E|0'PPR
//日志 (&X"~:nm2
public static void log(String sMsg) GK\'m@k
{ } #%sI"9
System.err.println(sMsg); pY-izML
} |nocz]yU$
E<~/AReo
a}e7Q<cGj
public static void log(int sMsg) 0Z9jlwcQ
{ +F 5Dc
System.err.println(sMsg); (<1DPpy95O
} {|>~#a49h
} 12cfqIo9
1w\Y._jK
/\Q{i#v
/* W%Um:C\I
**TestMethod.java h2,AcM
*/ d6(qc< /!r
package NetFox; IO,kP`Wcx
36lIV,YnU
m,=$a\UC
public class TestMethod { yP[GU| >(
o@;w!'
R_Eu*Quj
public TestMethod() zSkM8LM2
{ ///xx/weblogic60b2_win.exe z.[L1AGa|s
try{ wX|]8f2Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >)5rOU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _+^3<MT
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4N#0w]_,>Y
fileFetch.start(); 6x -PGq
} 5X~ko>
catch(Exception e){e.printStackTrace ();} V&GFGds
)P|Ql-rE4
]kc_wFT<
} BRH:5h
8N|*n"`}
u,oxUySeG
public static void main(String[] args) `cZG&R
{ Jr1^qY`0+
new TestMethod(); FRfMtxvU
} s$Roe(J
} >A1Yn]k
点击下载更多相关资料