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)); ?=-/5A4K
} y4=T0[ V
for(int i=0;i<nEndPos.length-1;i++) F8/n;
{ Qs8yJH`v
nEndPos = nStartPos[i+1]; g 4$
} VyNU<}
nEndPos[nEndPos.length-1] = nFileLength; Es\J%*\u
} DPmY_[OAE
} .vi0DuD6
^4Se=Hr z2
uFlf#t =
//启动子线程 :C0)[L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yB{1&S5C
for(int i=0;i<nStartPos.length;i++) &arJe!K
{ gnb+i`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _,e4?grP#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z}SqiT
nStartPos,nEndPos,i); o,0 Z^"|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _oefp*iWS
fileSplitterFetch.start(); 7,uD7R_
} [;:ocy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CkV -L4Jq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r5$!41
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VOg'_#I
nEndPos = " + nFileLength); -?IF'5z
// fileSplitterFetch[nPos.length-1].start(); ``{GU}n
x>A[~s"|N
xnw'&E
//等待子线程结束 !#e+!h@
//int count = 0; )}_}D+2
//是否结束while循环 (b"q(:5oX
boolean breakWhile = false; 43rV> W,
ol {N^fiK
k!6m'}v
while(!bStop) ]j$(so"
{ mGF)Ot R
write_nPos(); h^14/L=|
Utility.sleep(500); W58%Zz4a
breakWhile = true; A ;|P\V
I58$N+#
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for(int i=0;i<nStartPos.length;i++) 8&qtF.i-6
{ 6 lEv<)cC
if(!fileSplitterFetch.bDownOver) vuJEPn%
{ AOV{@b(
breakWhile = false; _?I*:: I
break; 34_ V&8
} <R_)[{ 7
} "%_T7A ![
if(breakWhile) <w?k<%( 4
break; 2l:cP2fa

$ma@z0%8}
//count++; l=$?#^^ /
//if(count>4) Wk!<P" nHd
// siteStop(); VT#`l0I}
} 3RFU
NJQy*~P
2zX9c<S=5
System.err.println("文件下载结束！"); =&FaMR2
} jL'R4z
catch(Exception e){e.printStackTrace ();} lWP]}Uy=5~
} w:R#F( 'B
FNo.#Z5+b
n(SeJk%>9
//获得文件长度 m6gMVon
public long getFileSize() r{Mn{1:O
{ ?papk4w
int nFileLength = -1; w2lO[o~x}
try{ (eHTXk*V`
URL url = new URL(siteInfoBean.getSSiteURL()); S&J5QZjC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \ *g3j
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Lv5>[MnN
S{{wcH$n'i
:1]J{,VG
int responseCode=httpConnection.getResponseCode(); 1vJj?Uqc
if(responseCode>=400) ~K(mt0T)
{ BV}sN{
processErrorCode(responseCode); EDF0q i
return -2; //-2 represent access is error .%M80X{5~
} <l eE.hhf.
;Qc^xIPy
WQBV~.<Yv
String sHeader; G%K&f1q%
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g\iSc~%?
for(int i=1;;i++) Lnq CHe
{ .4<lw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f<'D?d)L^
//Utility.log(in.readLine()); W"A3$/nq^
sHeader=httpConnection.getHeaderFieldKey(i); 6X4r2Vq
if(sHeader!=null) BD]o+96qP
{ 6k{gI.SG
if(sHeader.equals("Content-Length")) Pw6%,?lQ
{ 38:5g_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nXjSf
break; Ies` !W^
} ?t/\ID
} E, oR.B
else ,VzbKx,
break; Zv8_<>e
} ?H_>?,^
} \pP1k.~UnC
catch(IOException e){e.printStackTrace ();} 5Ux=5a
catch(Exception e){e.printStackTrace ();} <@0S]jy
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pA_e{P/
Utility.log(nFileLength); rdAy '38g
x]4>f[>*>
6(ER$
return nFileLength; k(@W z>aCv
} ]a[2QQ+g
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u0qTP]
//保存下载信息（文件指针位置） J]Rh+@r.
private void write_nPos() lfr^NxOU
{ E;q+u[$
try{ sG^{ cn
output = new DataOutputStream(new FileOutputStream(tmpFile)); C@pn4[jTl
output.writeInt(nStartPos.length); OXB 5W#$
for(int i=0;i<nStartPos.length;i++) C3 BoH&
{ d vo|9>
// output.writeLong(nPos); JcfGe4
output.writeLong(fileSplitterFetch.nStartPos); ZzP&Zrm
output.writeLong(fileSplitterFetch.nEndPos); oqg +<m
} ^)aj,U[
output.close(); _'n]rQ'
} 9XUk.Nek
catch(IOException e){e.printStackTrace ();} G6xNR
catch(Exception e){e.printStackTrace ();} b7gN|Hw5 H
} ]]y,FQ,r
_G2)=yj]
xP27j_*m>
//读取保存的下载信息（文件指针位置） bHXoZix
private void read_nPos() w U1[/
{ {Eqx'j
try{ r-Y7wM`TZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +k/=L9#e
int nCount = input.readInt(); /fU-0a8
nStartPos = new long[nCount]; |C0!mU
nEndPos = new long[nCount]; {xICR ~,*
for(int i=0;i<nStartPos.length;i++) l j+p}dt
{ m9\~dD
nStartPos = input.readLong(); t%@u)bp
nEndPos = input.readLong(); Zb'a+8[
} TKVS%//
input.close(); aEun *V^,
} ]Z52L`k
catch(IOException e){e.printStackTrace ();} }VHvC"
catch(Exception e){e.printStackTrace ();} ~&"'>C#
} 9Sl5jn
$FZcvo3@*S
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private void processErrorCode(int nErrorCode) y k\/Cf
{ 2+*o^`%4P
System.err.println("Error Code : " + nErrorCode); 05 .EI)7
} lwjA07i
0WyOORuK
u<+"#.[2v~
//停止文件下载 i<q_d7-W'
public void siteStop() PI"6d)S2
{ ='-/JH~
bStop = true; 5XuQQ!`
for(int i=0;i<nStartPos.length;i++) w@\4ft6d
fileSplitterFetch.splitterStop(); kL<HGQt
Z>dvth
r"t,/@`n
} 7f<@+&
} 1Ve~P"w
//负责部分文件的抓取 ~B7<Yg
**FileSplitterFetch.java VZ7E#z+nM#
*/ *?>52 -&b
package NetFox; ih|&q
,vBB". LY'
&2n5m&
import java.io.*; VJ1rU mO~
import java.net.*; n;~'W*Ln0
Qo*OC 9E`
l%qh^0
public class FileSplitterFetch extends Thread { by$mD_sr
rqKK89fD'
^b^buCYw
String sURL; //File URL n]>L"D,
long nStartPos; //File Snippet Start Position |3hNTH?
long nEndPos; //File Snippet End Position Ix~rBD9
int nThreadID; //Thread's ID mcs!A/]<
boolean bDownOver = false; //Downing is over m\_v{1g
boolean bStop = false; //Stop identical ' t^ r2N/
FileAccessI fileAccessI = null; //File Access interface Ri*mu*r\}
=Ew77
n;QFy5HB8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _:Jma
{ [fs.D /
this.sURL = sURL; S%wdXe
this.nStartPos = nStart; B3I0H6O
this.nEndPos = nEnd; z$Qy<_l
nThreadID = id; NFf`V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y(Em+YTD
} 6=*n$l#}
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kZR(0, W
public void run() zhY]!
{ f=Oj01Ut*
while(nStartPos < nEndPos && !bStop) N9u {)u
{ 4E$d"D5]>p
98vn"=3
o)'06FF\$
try{ D4?cnwU
URL url = new URL(sURL); JM53sx4&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <L2z|%`
httpConnection.setRequestProperty("User-Agent","NetFox"); =dp`4N
String sProperty = "bytes="+nStartPos+"-"; R'oGsaPB2
httpConnection.setRequestProperty("RANGE",sProperty); } V"A;5j`
Utility.log(sProperty); WE+Szg(4x
[}}q/7Lp
sWi4+PAM0
InputStream input = httpConnection.getInputStream(); '>Thn{
//logResponseHead(httpConnection); o?I`n*u"X
8:Dkf v
J?1Eh14KZ
byte[] b = new byte[1024]; *|gl1S
int nRead; P~PM$e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &3itBQF
{ =p dLh
nStartPos += fileAccessI.write(b,0,nRead); 474 oVdGx
//if(nThreadID == 1) 2Tv W 6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $F]*B `
} g'EPdE
di<g"8
+;bZ(_ohG
Utility.log("Thread " + nThreadID + " is over!"); :*cd$s
bDownOver = true; 'CRjd~L
//nPos = fileAccessI.write (b,0,nRead); []?*}o5&>T
} /74)c~.W
catch(Exception e){e.printStackTrace ();} Gsz$H_
} sXY{g0%
} o?aF
wBEBj7(y
FMitIM*]
//打印回应的头信息 .Vs|&c2im
public void logResponseHead(HttpURLConnection con) 7324#HwS
{ 5JG`FRW!
for(int i=1;;i++) om6`>I*
{ Vygh|UEo
String header=con.getHeaderFieldKey(i); Gc;-zq
if(header!=null) /sqfw,h@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j|b$b,rF\
Utility.log(header+" : "+con.getHeaderField(header)); \)2'+R
else Z}3;Ych
break; "kKIv|`
} 4I.)>+8V
} \@zoM:[sN
\[/}Cy
Yfy";C7X
public void splitterStop() QHtN_Q_F
{ >}d6)s|
bStop = true; fr8';Jm
} @[Wf!8_
vF'IK,
~N)(|N
} hK3Twzte
8L`wib2
YI]/gWeu
/* xJOp~fKG
**FileAccess.java |{rhks~
*//文件访问(定位，写) 9MbF:
package NetFox; fS%B/h=
import java.io.*; "Q{7X[$$^
u=0161g
LwH+X:?i
public class FileAccessI implements Serializable{ t{Ks}9B
f+Fzpd?wS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d~T@fa
RandomAccessFile oSavedFile; <<9|*Tz
long nPos; )[=C@U
{l\Ep=O vx
WWLf'89It
public FileAccessI() throws IOException Wq<HsJd/
{ y"H(F,(N
this("",0); %-|$7?~
} khQfLA
`'pfBVBz
eGWwPSIp
public FileAccessI(String sName,long nPos) throws IOException 'a~F'FN$
{ =~q$k
oSavedFile = new RandomAccessFile(sName,"rw"); `Y,Rk
this.nPos = nPos; NYR:dH]N~d
oSavedFile.seek(nPos); r_o\72
} xSq+>,b
)H&ZHaO,_
}x_:v!G
public synchronized int write(byte[] b,int nStart,int nLen) 4OG1_6K
{ DH.CAV
int n = -1; zXe]P(p<
try{ 0bu!(Tpg7
oSavedFile.write(b,nStart,nLen); qR4-~p8
n = nLen; vI(CX]o
} q%XjJ -s:
catch(IOException e) @J6V,
{ ]@l;;Sp
e.printStackTrace (); O_*tDq,e
} _?XR;2]
s|R`$+'{
`*B6T7p1
return n; ^Jc|d,u;s
} OSwum!hzN
M0]J`fL@
XFi9qL^
} 2l~qzT-
w4RtIDW:
= jTC+0u
/* .la_u8A]
**SiteInfoBean.java w(Q{;RNM;
*/ }RQHsS
package NetFox; 3X9
/5?tXH"
66po SZR@
public class SiteInfoBean { k?_uv
k:&B b"
]'z 5%'
private String sSiteURL; //Site's URL `a@YbuLd
private String sFilePath; //Saved File's Path ];QX&";Z
private String sFileName; //Saved File's Name +t(Gt0+
private int nSplitter; //Count of Splited Downloading File !{A#\~,
Jn20^YG
3+!G9T!
public SiteInfoBean() rt\.|Hr4s
{//nSplitter的缺省值为5 +0:]KG!Zs.
//default value of nSplitter is 5 c >xHaA:V
this("","","",5); BD mF+
} P[H 4Yp
4u1au1c
BD M"";u
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F*y7 4j,
{ I0_>ryA
sSiteURL= sURL; Qn@[{%),4
sFilePath = sPath; Yr>7c1FZi
sFileName = sName; WH.3
this.nSplitter = nSpiltter; fhro"5/4
|gfG\fL3V
|8akp
} Iz!]LW
g,f AVM
M[0NB2`Wp
public String getSSiteURL() 9]|C$;kw@
{ y!~ }7=
return sSiteURL; (^~~&/U_U$
} +y 48.5
mS+sh'VH
ZD<e$PxxCd
public void setSSiteURL(String value) O 2+taB
{ 6vg` 8
sSiteURL = value; iVb7>d9}
} 2WB`+oWox
c(s: f@ 1
@\U] hN?
public String getSFilePath() id>2G %Tx
{ Crezo?
return sFilePath; 1#|qT7
} W O'nW
QF$s([
c']m5q39'
public void setSFilePath(String value) +]e) :J
{ caL\ d
sFilePath = value; $]J<^{v
} s=<65
8,)<,g-/=
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public String getSFileName() QH kjxj
{ Yd<9Y\W%?
return sFileName; perhR!#J
} 9e;:(jl^
pR!m
|Pv)&'B"
public void setSFileName(String value) g2YE^EKU~
{ L$@qEsO
sFileName = value; =RHIB1
} l(8@?t^;
#d$lN}8
4@M`BH`
public int getNSplitter() 7MhaLkB_6
{ :,.HJ[Vg&
return nSplitter; jEL"Q?#
} 3s#/d,+
:b,An'H
n/%M9osF
public void setNSplitter(int nCount) q<cxmo0S
{ >oapw5~5
nSplitter = nCount; <Kk?BRxi
} D@m3bsMwe
} !^Q4ZL,-
;Ao`yC2(v
sRC?l_n;
/* S)`@)sr
**Utility.java qCm8R@
*/ VwT&A9&{8
package NetFox; .RWq!Z=)3
_D8:p>=
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public class Utility { RG_6& A
}5}#QHF
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public Utility() L#N]1#;
{ lN*"?%<x>
+^[SXI^JaJ
5-:H
} `~h8D9G
8(* ze+8
//线程睡眠 Ba76~-gK$
public static void sleep(int nSecond) Xvxrz{
{ ,v#3A7"yW
try{ 0hq\{pw_y*
Thread.sleep(nSecond); 8TYoa:pZ
} <m%ZDOMa
catch(Exception e) m" ]VQnQ
{ ozl>Au
e.printStackTrace (); K"Gea`I
} a#&\65D
} $v=(`=
Ib"fHLWA^!
//日志 Cjj(v7[E
public static void log(String sMsg) A%~t[ H
{ "P$')uwE
System.err.println(sMsg); va!fJ
} fH%C&xj'&
gj82qy\:
-'Z-8
public static void log(int sMsg) fBKN?]BdN
{ (Vt5@25JW
System.err.println(sMsg); Q>TNzh
} jV#1d8qm
} WPPDvB
/`7G7pQ+
J!yK/*sO,
/* M[L@ej
**TestMethod.java 8]WcW/1r !
*/ s 4n<k]d
package NetFox; i1!Y{
6df`]sc
o}yA{<"
public class TestMethod { |oR#j `
vhN6_XD
.GvZv>
public TestMethod() {T3wOi
{ ///xx/weblogic60b2_win.exe X @X`,/{X
try{ 4hW:c0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tD]vx`0>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #_zj5B38E
SiteFileFetch fileFetch = new SiteFileFetch(bean); jK2gc^"t
fileFetch.start(); y 48zsm{
} /Ur]U w
catch(Exception e){e.printStackTrace ();} Rj-4K@a8#N
^O**ZndB/
Cf@N>N#t)
} 3vEwui-5
%/R[cj8
/.(F\2+A
public static void main(String[] args) FmQiy+.|
{ QG09=GQ
new TestMethod(); $^W|@et{ ]
} >skl-f
} t!0 IQ9\[*
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