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)); &~Hed_
} !EhKg)y=
for(int i=0;i<nEndPos.length-1;i++) 3wq<@dRv4
{ -m%`Di!E
nEndPos = nStartPos[i+1]; `z0q:ME
} /GC&@y0yi
nEndPos[nEndPos.length-1] = nFileLength; 8$ u"92
} h7UNmwj
} ~EPVu
?l^Xauk4Pj
Jq'8"
//启动子线程 1d<Uwb>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aY>v
for(int i=0;i<nStartPos.length;i++) R;c9)>8L
{ kygw}|, N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g=56|G7n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 96(Mu% l
nStartPos,nEndPos,i); \H@1VgmR;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c_D(%Vf5
fileSplitterFetch.start(); _b~{/[s
} aLGq<6Ja
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lr$Mk#'B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {4G/HW28
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K%? g6j
nEndPos = " + nFileLength); VIP7j(#t_g
// fileSplitterFetch[nPos.length-1].start(); =\WF +r]V
r@{TN6U
!ka* rd
//等待子线程结束 !B}9gT
//int count = 0; 3uqhYT;
//是否结束while循环 Ww2@!ng
boolean breakWhile = false; _xp8*2~-
Mz(Vf1pi%
?1SsF>|
while(!bStop) rm,`M
{ W8^m-B&
write_nPos(); WR"D7{>tw
Utility.sleep(500); YOD.y!.zq7
breakWhile = true; TQF+aP8[L
GBbnR:hM
#4msBax4
for(int i=0;i<nStartPos.length;i++) x?+w8jSR
{ :x*)o+
if(!fileSplitterFetch.bDownOver) T`ibulp
{ "0P`=n
breakWhile = false; 20|`jxp
break; \xkKgI/
} &Vz$0{d5
} 3S:Lce'f
if(breakWhile) :hX[8u
break; qq| 5[I.?
USz~l7Xs
#hZ$;1.
//count++; fORkH^Y(&
//if(count>4) K -U}sW
// siteStop(); ,_Z(!| rW
} /uwi$~Ed
_qxI9Q}<"
?FQ#I~'<
System.err.println("文件下载结束！"); XVYFyza;
} @Nek;xJ
catch(Exception e){e.printStackTrace ();} W&?Qs=@
} <OMwi9
"<!U
aixX/se
//获得文件长度 *9aJZWf>V
public long getFileSize() WEimJrAn
{ ^Co$X+
int nFileLength = -1; z~ cW,
try{ N T`S)P*?
URL url = new URL(siteInfoBean.getSSiteURL()); 1`&`y%c?B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hxO}'`:
httpConnection.setRequestProperty("User-Agent","NetFox"); bO=|utpk
h+FM?ct6}
&0F' Ca
int responseCode=httpConnection.getResponseCode(); `@/)S^jBau
if(responseCode>=400) m+TAaK
{ 'r?ULft1
processErrorCode(responseCode); ~zqb{o^pT
return -2; //-2 represent access is error /,Xl8<~#
} Hc)z:x;Sj
{{?g%mQ6
Xu]~vik
String sHeader; HC%Hbc~S_Q
.A2$C|a*
=&WIa#!=
for(int i=1;;i++) 'a['lF
{ 5?kfE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?h= n5}Y
//Utility.log(in.readLine()); {>f"&I<xw
sHeader=httpConnection.getHeaderFieldKey(i); 1@F-t94I
if(sHeader!=null) ju"z
{ uzy5rA==
if(sHeader.equals("Content-Length")) 9P?0D
{ pM?;QG;jA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JE?rp1.
break; 3e_tT8
} /Nf{;G!kg
} ;w7mr1
else y6XOq>
break; 8>&@"j
} #S}orWj
} va6Fp2n<1*
catch(IOException e){e.printStackTrace ();} .uuhoqG0
catch(Exception e){e.printStackTrace ();} >t+U`6xK
=@HS
/eF@a!
Utility.log(nFileLength); S /hx\TzC
;M:AcQZ|_
UVo`jb|> o
return nFileLength; aSzI5J]/=
} `q^#u
L:$4o
Bm$|XS3cD
//保存下载信息（文件指针位置） l4bytI{63
private void write_nPos() ig,.>'+l
{ :<QknU}dwy
try{ d*@T30
output = new DataOutputStream(new FileOutputStream(tmpFile)); e97G]XLR
output.writeInt(nStartPos.length); <xI<^r'C9e
for(int i=0;i<nStartPos.length;i++) X?5{2ulrI
{ Hn|W3U
// output.writeLong(nPos); )4yP(6|lx
output.writeLong(fileSplitterFetch.nStartPos); 8dGsV5"*
output.writeLong(fileSplitterFetch.nEndPos); BI1M(d#1L"
} ,>;21\D
output.close(); aZFpt/.d
} $DbnPZ2$
catch(IOException e){e.printStackTrace ();} 17LhgZs&
catch(Exception e){e.printStackTrace ();} W0qR?jc
} rq+_[!
xe@1H\7:
5'AP:3Gf"
//读取保存的下载信息（文件指针位置） nBh+UT}
private void read_nPos() 2Ez<Iw
{ E9:@H;Gc
try{ #[+# bw_6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]I?.1X5d0
int nCount = input.readInt(); uO%0rKW
nStartPos = new long[nCount]; 2|nm> 4
nEndPos = new long[nCount]; @N=vmtLP
for(int i=0;i<nStartPos.length;i++) hFrMOc&
{ OM86C
nStartPos = input.readLong(); Y t(D
nEndPos = input.readLong(); 9]4Q@%
} sPH2KwEv
input.close(); XkaREE
} J<$@X JLS
catch(IOException e){e.printStackTrace ();} ARH~dN*C
catch(Exception e){e.printStackTrace ();} akj<*,
} a=z] tTs4
M(%H
e &6%
private void processErrorCode(int nErrorCode) TZn 15-O
{ %w`d
System.err.println("Error Code : " + nErrorCode); m'o dVZ7
} ^_2c\mw_I
CMt<oT6.?
$O"ss>8Se
//停止文件下载 /9`4f"
public void siteStop() u47<J?!Q
{ HIg2y
bStop = true; '7iz5wC#
for(int i=0;i<nStartPos.length;i++) ~Amq1KU*Z
fileSplitterFetch.splitterStop(); BoD{fg
2HX/@ERhmu
-l^<[%
} j*{0<hZb}
} !~ox;I}S
//负责部分文件的抓取 >3 o4 U2
**FileSplitterFetch.java 6(n0{A
*/ djd/QAfSC
package NetFox; )U/jD
R9J!}az'
ZpTDM1ro
import java.io.*; o!a,r3
import java.net.*; =sJ?]U
R\j~X@vI
&K ~k'P~m
public class FileSplitterFetch extends Thread { &g`&#IRz
m,.Y:2?*V
+VIA@`4
String sURL; //File URL 0vY_
long nStartPos; //File Snippet Start Position (3Db}Hnn
long nEndPos; //File Snippet End Position I2[U#4n
int nThreadID; //Thread's ID '&IGdB I
boolean bDownOver = false; //Downing is over I"Oq< _
boolean bStop = false; //Stop identical oPe|Gfv\G
FileAccessI fileAccessI = null; //File Access interface x#1Fi$.
i]8O?Ab>?
%OQdUH4x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X9x`i
{ W06aj ~7Z
this.sURL = sURL; ?cU,%<r
this.nStartPos = nStart; |]\zlH"w
this.nEndPos = nEnd; 9&+]YYCS-
nThreadID = id; K<S3gb?0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n`Q@<op
} K;F1'5+=D
01cBAu
Q\Ek U.[I
public void run() SUS=sR/N
{ fG0?"x@>
while(nStartPos < nEndPos && !bStop) gZ@+62
{ RGW@@
4cjfn'x
fdl.3~.C
try{ c(Q@5@1y:
URL url = new URL(sURL); dCC*|b8h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I}C2;[aB
httpConnection.setRequestProperty("User-Agent","NetFox"); v$ ti=uk$
String sProperty = "bytes="+nStartPos+"-"; m2]N%Y
httpConnection.setRequestProperty("RANGE",sProperty); o[Iu9.zJpy
Utility.log(sProperty); f{BF%;
AuNUW0/ 7
4fLRl-)
InputStream input = httpConnection.getInputStream(); \xYVnjG,
//logResponseHead(httpConnection); 4Aj~mA
U>S
4XkI? l
byte[] b = new byte[1024]; k^5Lv#Z
int nRead; J1w;m/oV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /\mtCa.O
{ zv]ZEWVzc
nStartPos += fileAccessI.write(b,0,nRead); A3]A5s6
//if(nThreadID == 1) <PLAAh8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xu$>$D#a
} wZvv5:jKpu
-Vn#Ab_C
o'2eSm0H
Utility.log("Thread " + nThreadID + " is over!"); PK|-2R"M
bDownOver = true; 35\ |#2qw6
//nPos = fileAccessI.write (b,0,nRead); W+h2rv
} <-VBb[M#
catch(Exception e){e.printStackTrace ();} s.J4&2Q
} c^}y9% 4c
} 80lei
'*J+mZtN
BJ|l
//打印回应的头信息 "O34 E?ql.
public void logResponseHead(HttpURLConnection con) \|=6<ZY:
{ oe<i\uX8z
for(int i=1;;i++) u\\t~<8
{ Hw \of
String header=con.getHeaderFieldKey(i); $/wm k7T
if(header!=null) e]4$H.dP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2<D| {
Utility.log(header+" : "+con.getHeaderField(header)); !M^O\C)
else Tmzbh 9
break; IuwE&#
} !"^Zr]Qt+\
} vJWBr:`L
JR!-1tnc
jTa\I&s,A
public void splitterStop() 4H{t6t@-:
{ 7^dr[.Q[*
bStop = true; tZ_'>7)
} ale'-V)5
Fp\;j\pfw
] Q5:JV
} .psb#4
ACRuDY
Ht[$s40P
/* &'uP?r9c$
**FileAccess.java ;cMQ0e
*//文件访问(定位，写) Oeh A3$|#
package NetFox; 7FC!^)x1
import java.io.*; ,Lig6Z`
/VYT](
Oe5rRQ$O
public class FileAccessI implements Serializable{ $d<NN2
>@vu;j\*E5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b-u@?G|<
RandomAccessFile oSavedFile; 9nFL70
long nPos; VZ9 p "
N/tcW
E)-;sFz
public FileAccessI() throws IOException ,rMf;/[
{ 63l3WvoK
this("",0); ~F"S]
} j iKHx_9P
o/Ismg-p
oU\]#e^
public FileAccessI(String sName,long nPos) throws IOException Rqe.=+Qs
{ xfRp_;l+R
oSavedFile = new RandomAccessFile(sName,"rw"); ^KhJBM/Z
this.nPos = nPos; M%E<]H2;S
oSavedFile.seek(nPos); M<-Q8a~
} ;,77|]<XE
Oiib2Ov
#b^6>
public synchronized int write(byte[] b,int nStart,int nLen) UarLxPQ
{ P@v"aa\@2)
int n = -1; 5wue2/gl
try{ 78l);/E{v
oSavedFile.write(b,nStart,nLen); yCQvo(V[F
n = nLen; OAXA<
} IxbQ6
catch(IOException e) I=!kPuw
{ t3)6R(JC
e.printStackTrace (); lOm01&^"E
} H_&to3b(
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m)A:w.o
return n; ;@Zuet
} <$s6?6P
5]&sXs
}O\IF}X
} i:s=
B $u/n
_=HaE&
/* |dR}S!fmG
**SiteInfoBean.java 3Q,&D'];[
*/ k8?._1t
package NetFox; z"f@iJX?2
U'=8:&
h$8h@2%
public class SiteInfoBean { 6{6hz8
'V]C.`9c
qA>#;UTp
private String sSiteURL; //Site's URL {Z2nc)|7C
private String sFilePath; //Saved File's Path \ ca<L
private String sFileName; //Saved File's Name q/@2=$]hH3
private int nSplitter; //Count of Splited Downloading File <tvLKx
(.UU40:t
n.g-%4\q
public SiteInfoBean() 8:0/Cj
{//nSplitter的缺省值为5 h*R@ d
//default value of nSplitter is 5 r^5%0_F]
this("","","",5); 8i',~[
} I8XP`Ccq
^6 wWv&G[8
sU>IETo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P*KIk~J
{ t+v%%N_
sSiteURL= sURL; NgTB4I8P
sFilePath = sPath; +,,(8=5g
sFileName = sName; /4T6Z[=s
this.nSplitter = nSpiltter; !h#ZbErW
%SC Jmn2
kt6)F&;$
} rR6}
#LR4%}mg
!q+ #JW
public String getSSiteURL() D('.17
{ 7"!`<5o^
return sSiteURL; 7<su8*?
} XP)^81i|
9)wYSz'
sSU|N;"Y
public void setSSiteURL(String value) wG49|!l6T
{ 254V)(t^QM
sSiteURL = value; \-yI dKj
} ].s;Yxz
>B6*`3v
vv.E6D^x(
public String getSFilePath() =mXC,<]
{ $wAR cS
return sFilePath; .e7tq\k
} i.^ytbH
Rq|6d M6H
) A:h
public void setSFilePath(String value) a <C?- g|
{ V;eaQ
sFilePath = value; Il [~
} !JXiTI!
~vz%I^xW
u"&?u+1j
public String getSFileName() :(]fC~G~
{ Srx:rUCv
return sFileName; x|m9?[ !_
} > -OOU
6FzB-],
nG<oae6z"
public void setSFileName(String value) ~Ykn|$_"I
{ VgVDTWs7
sFileName = value; Qa,=
} G%sq;XT61
:^ywc O
o MJ`_
public int getNSplitter() eyKxnBz
{ X.>=&~[
return nSplitter; X7!q/1$J
} HThZ4Kg+
wW\[#Ku
Zp)=l Td
public void setNSplitter(int nCount) ;mEn@@{
{ O q$_ q
nSplitter = nCount; jRjeL'"G
} "r46Rfa
} RiQ]AsTtl
%)7t2D
HaVhdv3L
/* jMn,N9Mf
**Utility.java yMWh#[phH
*/ }`gOfj)?i
package NetFox; KhND pwO"
YH\9Je%jx
~yJ2@2I
public class Utility { qt}M&=}8Q
kQmkS^R
&Pb:P?I
public Utility() J$51z
{ N`Q.u-'
8</wQ6&|
=dPokLXn
} Kkp dcc
0Ncpi=6
//线程睡眠 @e<(o UE
public static void sleep(int nSecond) k4iiL<|
{ VaD+:b4
try{ _CHzwNU
Thread.sleep(nSecond); AtJ{d^
} u79- B-YW^
catch(Exception e) f(pq`v^-n
{ _e@8E6#ce
e.printStackTrace (); #VrIU8Q7'
} I6 ?(@,
} _f0AV;S:vd
/:F^*]
//日志 ?)1Y|W'Rv
public static void log(String sMsg) ZjmQ
{ ~Fuq{e9`
System.err.println(sMsg); FL{?W(M
} 5Rl\& G\
uj6'T Sl
aB6xRn9
public static void log(int sMsg) Y]SF0:v!n
{ o*H U^
System.err.println(sMsg); >>J3"XHX
} 5(H%Ia
} upuN$4m&{
zzZEX
C=+9XfP0
/* ]zlA<w8
**TestMethod.java M?lh1Yu"
*/ }R}+8
package NetFox; #Kb /tOp1
8)0]cX
0:v!'
public class TestMethod { -qj[ck(y
rk8pL[|
N; }$!sNIm
public TestMethod() ZwDL
{ ///xx/weblogic60b2_win.exe lfj5?y
try{ OL 0YjU@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S[K5ofV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p{L;)WTI
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1*8;)#%&
fileFetch.start(); e\C-a4[C8P
} dQ8RrD=$&
catch(Exception e){e.printStackTrace ();} U:TkO=/>:
{T-\BTh&Q
Qx4)'n
} :gV~L3YW5
~^obf(N`
`2 <:$]
public static void main(String[] args) +fk*c[FG
{ 7z$Z=cs
new TestMethod(); Y2DL%'K^
} tA#$q;S
} *|=D 0
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