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)); `[CXxp
} C2DNyMu
for(int i=0;i<nEndPos.length-1;i++) H-0deJ[>
{ cBc6*%ZD
nEndPos = nStartPos[i+1]; !k%Vw18
} hM+nA::w
nEndPos[nEndPos.length-1] = nFileLength; <R_3;5J%
} H|75,!<
} u9k##a4.E
QeU>%qKT
BA L!6
//启动子线程 W\FKAvS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &5C%5C~ch
for(int i=0;i<nStartPos.length;i++) g[:5@fI#*
{ nD E5A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T>W(Caelq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tAYu|\]
nStartPos,nEndPos,i); ^VoQGP/cl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ml0d^l}'
fileSplitterFetch.start(); BKVvu}V(o
} 9u"im+=:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @Q TG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z`< +8e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _mFb+8C
nEndPos = " + nFileLength); 21w<8:Vg
// fileSplitterFetch[nPos.length-1].start(); e|]g?!
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7|"11^q
//等待子线程结束 B/pNM81(
//int count = 0; D`,@EW].
//是否结束while循环 `(Ei-$ >U&
boolean breakWhile = false; 6n;ewl}
@(Q4
42Ql^ka
while(!bStop) $mp7IZE|
{ sm\/wlbE
write_nPos(); */?L_\7
Utility.sleep(500); x{RTI#a.
breakWhile = true; b!_l(2
dp_J*8
WET $H,
for(int i=0;i<nStartPos.length;i++) 5%,n[qj4IT
{ .DCp)&m l;
if(!fileSplitterFetch.bDownOver) l,sYYU+iY
{ $F\&?B1.
breakWhile = false; QAcvv 0Hv
break; #`}g?6VHo
} a?Q~C<k
} | ql!@M(p
if(breakWhile) 9Q].cDe[
break; YQe @C
LOe!qt\&
Og-Mnx3
//count++; `4Nc(aUr
//if(count>4) `4l>%S8y:
// siteStop(); M,y='*\M
} ]FQ4v.7
E2%7v
9-pd{Z~l
System.err.println("文件下载结束！"); pmHd1 Wub
} QIo|t!7F
catch(Exception e){e.printStackTrace ();} h7(twct
} t1IC0'o-
2c9@n9Vx3a
{zmo7~=
//获得文件长度 ed*=p l3.
public long getFileSize() f{^n<\Jh
{ (|O;Ci
int nFileLength = -1; _VR4|)1g
try{ x{Gih1
URL url = new URL(siteInfoBean.getSSiteURL()); 'KyT]OObS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |oO0%#1H
httpConnection.setRequestProperty("User-Agent","NetFox"); bu@Pxz%_
Wpj.G
nc@ul')
int responseCode=httpConnection.getResponseCode(); ZFrK'BvbR
if(responseCode>=400) yf_<o
{ '_(oa<g
processErrorCode(responseCode); F)v+.5T1
return -2; //-2 represent access is error g/VC$I!'
} cDE?Xo'!
'!IX;OSjH
T /[)U
String sHeader; B(b[Dbb
FKL}6W:
M(oW;^B
for(int i=1;;i++) <2|x]b8
{ 5Ko"-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); REFisH-
//Utility.log(in.readLine()); ls#O0
sHeader=httpConnection.getHeaderFieldKey(i); (Grj_p6O
if(sHeader!=null) V@cRJ3ZF
{ mb\vHu*53
if(sHeader.equals("Content-Length")) *Q51'?y
{ NP%ll e,l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I+u=H2][2
break; [-Q"A 6!Zd
} Mzxz-cE
} S2j7(T;~YB
else 0r+-}5aSl5
break; =X+DC&]%!
} :~6%nFo
} AZ!G-73
catch(IOException e){e.printStackTrace ();} \k;raQR4t*
catch(Exception e){e.printStackTrace ();} !K`;fp!
Xb6@;G"
vs6`oW"{#
Utility.log(nFileLength); EXb{/4
%y8w9aGt
zU1rjhv+
return nFileLength; QHtpCNTVb
} -pX/Tt6
xB9^DURr\
7g(rJGjtg
//保存下载信息（文件指针位置） Hi.JL
private void write_nPos() >@]E1Qfe
{ 5<d Y,FvX
try{ P=u)Q _
output = new DataOutputStream(new FileOutputStream(tmpFile)); nc$?tC9V
output.writeInt(nStartPos.length); |L]dJ<
for(int i=0;i<nStartPos.length;i++) lzuPE,h
{ vuw1ycy)
// output.writeLong(nPos); ?\^u},HnE|
output.writeLong(fileSplitterFetch.nStartPos); |vEfE{
output.writeLong(fileSplitterFetch.nEndPos); paMw88*u
} ed\,FWR
output.close(); '7_'s1
} Y]P $|JW):
catch(IOException e){e.printStackTrace ();} y>wr $
catch(Exception e){e.printStackTrace ();} D8Ni=.ALL
} s,` n=#
%>24.i"l
fI"`[cA"]
//读取保存的下载信息（文件指针位置） CGv(dE,G&]
private void read_nPos() vLpE|QZs
{ ~(hmiNa;
try{ D(Xv shQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |mci-ZT
int nCount = input.readInt(); 5|H?L@_9
nStartPos = new long[nCount]; 5HOhk"
nEndPos = new long[nCount]; ;5 IS58L
for(int i=0;i<nStartPos.length;i++) Of:e6N
{ #2u-L~n
nStartPos = input.readLong(); Zvr(c|Q
nEndPos = input.readLong(); Yz%=
} A.z~wu%(
input.close(); [~jhOv^
} RsrZ1dhPvV
catch(IOException e){e.printStackTrace ();} ?%;uR#4
catch(Exception e){e.printStackTrace ();} 3zh'5qQ
} kTFN.kQx@
p&ow\AO
P#EqeO
private void processErrorCode(int nErrorCode) `o:)PTQNg
{ $g1p!
System.err.println("Error Code : " + nErrorCode); JTz1M~
} 7a@V2cr@
,ew<T{PL
uy`U1>
//停止文件下载 '# (lq5 c
public void siteStop() 's&Vg09D,
{ '*)!&4f
bStop = true; U?>zq!C&R
for(int i=0;i<nStartPos.length;i++) ;#f%vs>Y7i
fileSplitterFetch.splitterStop(); faMUd#o&
y{jv-&!xB
)03.6Pvs
} j-A S {w
} b*p,s9k7
//负责部分文件的抓取 Qt@~y'O
**FileSplitterFetch.java tgrQ$Yjk
*/ lXB_HDY
package NetFox; Tri.>@-u
EH,uX{`e
/~AwX8X
import java.io.*; IM +Dm
import java.net.*; <GoE2a4Va
n.7 $*9)#
QjQJ "
public class FileSplitterFetch extends Thread { {]Lc]4J
&4{%3w_/
.|iUDp6vz
String sURL; //File URL T-<^mX[}
long nStartPos; //File Snippet Start Position ;$|+H"g|
long nEndPos; //File Snippet End Position Z;%qpsq
int nThreadID; //Thread's ID yM#W,@
boolean bDownOver = false; //Downing is over ym${4
boolean bStop = false; //Stop identical w#JF7;
FileAccessI fileAccessI = null; //File Access interface TFM}P
"KFCA9u-
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MN1|k
{ Nwu#,f=X
this.sURL = sURL; nLQ X?:
this.nStartPos = nStart; uO":\<1#
this.nEndPos = nEnd; 4|XE f,
nThreadID = id; hs/nM"V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +x+H(of.
} -Mv`|odY/
x80~j(uVf
B}?/oZW4
public void run() &/7GhZRt
{ F htf4
while(nStartPos < nEndPos && !bStop) 9_TZ;e
{ }[75`pC~O
e7hPIG
<BO|.(ys
try{ ;dB=/U>3U
URL url = new URL(sURL); -iJ[9O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xQmk2S` y
httpConnection.setRequestProperty("User-Agent","NetFox"); G`)I _uO
String sProperty = "bytes="+nStartPos+"-"; [&Qrk8EN
httpConnection.setRequestProperty("RANGE",sProperty); (Ojg~P4;&
Utility.log(sProperty); 8fDnDA.e
Dnd
s"sX#l[J
InputStream input = httpConnection.getInputStream(); y:v0&9L
//logResponseHead(httpConnection); #z5'5|3
M8g=t[\
*XNvb ^<
byte[] b = new byte[1024]; G LE`ba
int nRead; bAW;2 NB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^U`[P@T
{ 0<^K0>lm p
nStartPos += fileAccessI.write(b,0,nRead); "ENgu/A!
//if(nThreadID == 1) Ay2|@1e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *1elUI2Rg
} Duz}e80
>iG`
2+Fq'!
Utility.log("Thread " + nThreadID + " is over!"); >\@6i s
bDownOver = true; gbI0?G6XN/
//nPos = fileAccessI.write (b,0,nRead); C6/,-?%)
} Fa>Y]Y0r
catch(Exception e){e.printStackTrace ();} @c{Z?>dUc#
} 31bKgU{
} "@Te!.~A.
6aj)Fe'2
#G]s.by('
//打印回应的头信息 O:u^jcXA
public void logResponseHead(HttpURLConnection con) <89js87
{ \x|(`;{
for(int i=1;;i++) {yfG_J
{ kvo741RO6
String header=con.getHeaderFieldKey(i); kmP0gT{Sj
if(header!=null) 0TVO'$Gvi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5))?,YkrrI
Utility.log(header+" : "+con.getHeaderField(header)); |5Z@7
else ff{ESFtD
break; `T~M:\^D
} 6}<PBl%qe
} ['sIR+c%'O
9g 2x+@5T^
Z9!goI
public void splitterStop() y`\/eX
{ .oSKSld
bStop = true; @NV$!FB<
} S'?XI@t[
(-~tb-
|1t30_ /gS
} Nzr zLK
qdcCX:Z<
d/* [t!
/* w0 "h,{
**FileAccess.java m&; t;&#
*//文件访问(定位，写) `@`Q"J
package NetFox; |7f}icXKur
import java.io.*; "e(OO/EZS
ss-Be
0gt/JI($
public class FileAccessI implements Serializable{ H:0-.a^ZS
8LiRZ"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 43 |zjE
RandomAccessFile oSavedFile; Oj<2_u
long nPos; Ujw^j
\DfvNeF
Gz6FwU8L
public FileAccessI() throws IOException ){gOb
{ (hmasy6hM
this("",0); &5zUk++
} v 7Pv&|
SXgpj
<QszmE
public FileAccessI(String sName,long nPos) throws IOException fHwh6|
{ ;9;.!4g/T
oSavedFile = new RandomAccessFile(sName,"rw"); [KCh,'&
this.nPos = nPos; (:@qn+ a
oSavedFile.seek(nPos); EJL45R>
} iVmf/N@A|
f2yc]I<lr~
b7"pm)6
public synchronized int write(byte[] b,int nStart,int nLen) SHhg&~B
{ A #ZaXu/:X
int n = -1; "\> <UJ
try{ )Hw;{5p@
oSavedFile.write(b,nStart,nLen); hBN!!a|l
n = nLen; Iye
} `~*qjA
catch(IOException e) ?VReKv1\
{ f^0vkWI2
e.printStackTrace (); }3N8EmS
} lOZ.{0{f,
A0&~U0*(~
V+(
return n; )_+#yaC
} c) 1m4SB@
'+-R 7#
yqCy`TK8
} y.mojx%?a
%f, 9
cZ o]*Gv.
/* a1om8!C
**SiteInfoBean.java R=8!]Oi6
*/ VsUEp_I
package NetFox; E{lq@it32p
n>!E ]
EStHl(DUPq
public class SiteInfoBean { f~"3#MaV
(|bht0
zW+Y{^hf
private String sSiteURL; //Site's URL J$'T2@H#
private String sFilePath; //Saved File's Path AKL~F|t
private String sFileName; //Saved File's Name 7tfFRUw
private int nSplitter; //Count of Splited Downloading File pk"JcUzR
@*_#zU#g
h=)Im)
public SiteInfoBean() 0MPsF{Xw[
{//nSplitter的缺省值为5 ]=h Ts%]w
//default value of nSplitter is 5 A6#ob
this("","","",5); }V9146
} +Mg^u-(A
<pi q?:ac
l65'EO|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]4hXK!^Uu
{ ,[~Ydth
sSiteURL= sURL; to,=Q8)0
sFilePath = sPath; G::6?+S
sFileName = sName; g]jtVQH']
this.nSplitter = nSpiltter; kqHh@]Z0'
Zwq uS9
8l)l9;4 6
} $aGK8%.O
5%G++oLXf
$\a;?>WA"
public String getSSiteURL() Bt.W_p
{ tD>m%1'&
return sSiteURL; q9Fc0(&Vf
} ")Bf^DV
}rGDM
sU{+.k{
public void setSSiteURL(String value) FeCQGT
{ K$(U>D|
sSiteURL = value; WgY\m&
} /:%^Vh3XF
q^12Rj;H
tkJ/h<
public String getSFilePath() : l]>nF4
{ ?g<*1N?:
return sFilePath; '#q"u y
} EB\z:n5
WqTW@-}ID
Q~*A`h#
public void setSFilePath(String value) ((X"D/F]
{ MTqbQ69v
sFilePath = value; %DRDe
} w7%N=hL1
s/A]&!`
Q/0}AQO
public String getSFileName() 8uCd|dJ
{ s]B^Sz=
return sFileName; 9|#h )*
} _&BnET
wmoOp;C
\HH|{
public void setSFileName(String value) ]Q,RVEtKp
{ h`n>6I
sFileName = value; i%\nJs*
} fWLsk
%%-kUe
qo}kwwWN;
public int getNSplitter() [N$@nA-d
{ Jg%sl&65
return nSplitter; t?c*(?Xa
} r#{lpF,3Ib
V-X n&s
MvRuW:
public void setNSplitter(int nCount) PUlb(3p `
{ B,gQeW&
nSplitter = nCount; o}Xp-P
} 2y<d@z:K
} bNL E=#ro
r&TxRsg{
!`aodz*PO
/* VK|!aqA{b
**Utility.java T;FzKfT|
*/ (@&|
package NetFox; WxXVL"
VD=$:F]
*w%;$\^
public class Utility { [KjQW/sb'
c9ghR0WM
xw?G?(WO
public Utility() |E?%Cj^W
{ neZ_TT/3K
} g
#}jf TM
} pXQ&2s$
^Jkj/n'
//线程睡眠 -D V;{8U4
public static void sleep(int nSecond) 3^`bf=R
{ w=f8UtY9@A
try{ ^Xb!dnT.*a
Thread.sleep(nSecond); JP@UvDE|
} p=r{ODw#3
catch(Exception e) 5-&P4
{ | _S9U|
e.printStackTrace (); b,K1EEJ
} As>po+T*
} -eNi;u
-><_J4
//日志 T]i~GkD\
public static void log(String sMsg) 2.:b
{ f<zh-Gq
System.err.println(sMsg); B!-W765Y
} j#~4JGZt
54 8@._-S
dm.3.xXq
public static void log(int sMsg) LpF6e9V\Wp
{ =l_eliM/
System.err.println(sMsg); 8zY)0
} =]Ek12.
} q$HBPR4h
Rd#,Tl\
i>w>UA*t
/* +oiPj3
**TestMethod.java X0C\87xfG
*/ #u2PAZ@qd
package NetFox; ?pxx,o6l
Rdv"Aj:
c76^x
public class TestMethod { uZ'5&k96T
XM_S"
wYF)G;[wM
public TestMethod() ^.<IT"
{ ///xx/weblogic60b2_win.exe DdFVOs|
try{ )lW<:?k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8)H"w$jq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %R_8`4IQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); =|G PSRQ
fileFetch.start(); 5N[Y2
} M.l;!U!}
catch(Exception e){e.printStackTrace ();} Ao]F_hZ
0umfC
e~}+.B0
} \(A>~D8Fo
Fm2t:,=
f.8L<<5 c
public static void main(String[] args) Vj:PNt[
{ =lffr?#&B
new TestMethod(); 2s(K4~ee
} !-7(.i-
} [Q%3=pm_
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