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)); gu[3L
} h^h!OQKQ
for(int i=0;i<nEndPos.length-1;i++) DbdxHuKa>
{ !YlyUHD
nEndPos = nStartPos[i+1]; );*A$C9RA
} E}aTH
nEndPos[nEndPos.length-1] = nFileLength; 5fK#*(x
} LY%`O#i.
} Cebl"3Q
G!J{$0.
x;,H>!r"i
//启动子线程 }\E2Z[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^d!(8vh
for(int i=0;i<nStartPos.length;i++) YPraf$
{ +SGM3tY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 85P7I=`*d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G'/36M@
nStartPos,nEndPos,i); !A(*?0`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oe$Y=`
fileSplitterFetch.start(); IiG~l+V~
} ^Tbw#x]2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lS.*/u*5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1>$fLbmkI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6>! ;g'k
nEndPos = " + nFileLength); ho#]i$b}f2
// fileSplitterFetch[nPos.length-1].start(); _VFxzM9f
-z]v"gF?Px
o7N3:)
//等待子线程结束 [:geDk9O#'
//int count = 0; Tti]H9g_
//是否结束while循环 Cf'O*RFD
boolean breakWhile = false; =FkU:q$
$*ujX,}xG
vDgf}
while(!bStop) :^+ aJ]
{ &[*F!=%8
write_nPos(); tkBp?Wl
Utility.sleep(500); 0p\cDrB?
breakWhile = true; Y4]USU!PA
zK`z*\
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for(int i=0;i<nStartPos.length;i++) /xmUu0H$R
{ <QGf9{m
if(!fileSplitterFetch.bDownOver) Omkl|l9
{ wV- kB4^4
breakWhile = false; &BnK[Q8X
break; F.)b`:g
} x4jn45]x@
} #F\}PCBe'
if(breakWhile) 5`oVyxJ<
break; +5Yf9
&CCp@" +
(B@:0}>
//count++; >r] bfN,
//if(count>4) JTw\5j
// siteStop(); |tC`rzo
} _{z.Tu
U$R+&@;
'./j<2|;U
System.err.println("文件下载结束！"); `a}!t=~#w
} qkpnXQ
catch(Exception e){e.printStackTrace ();} .!T]sX_P
} d5gYJ/Qv
?ic7M
)jbYWR*&
//获得文件长度 N5u.V\F!z\
public long getFileSize() L4I1nl
{ zG|}| //}
int nFileLength = -1; ;h>s=D,r
try{ (P {o9
URL url = new URL(siteInfoBean.getSSiteURL()); V QE *B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1df}gG
httpConnection.setRequestProperty("User-Agent","NetFox"); +$Q33@F5l
J,ZvaF
LyM"
int responseCode=httpConnection.getResponseCode(); hC@oyC(4
if(responseCode>=400) WyH2` xxX
{ $Yh7N5XH,
processErrorCode(responseCode); FCv3ZF?K
return -2; //-2 represent access is error sr!m
} 2x-67_BHY=
Wu]Dpe
b&s"/Y89
String sHeader; r'7>J:cy=
#Jt9U1WbF
@RW=(&<1
for(int i=1;;i++) E"7 iU
{ tZR%s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5/<?Y&x
//Utility.log(in.readLine()); vzVXRX
sHeader=httpConnection.getHeaderFieldKey(i); ^<fN
if(sHeader!=null) oTj9/r
{ d4h1#MK
if(sHeader.equals("Content-Length")) n gA&PU
{ swv1>52{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {]1+01vI-
break; |IL..C
} `!<RP'
} %dMq'j
else sFaboI
break; <%fcs"Mb
} OM,-:H,
} B>, O@og
catch(IOException e){e.printStackTrace ();} Op^r}7
catch(Exception e){e.printStackTrace ();} k^-HY[Q9
jRP.Je@t
;`IZ&m$
Utility.log(nFileLength); j#e^PK <
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.[Ezg(U}ze
return nFileLength; .c~`{j}
} SS;[{u!
{VqcZhqy/l
dLQV>oF
//保存下载信息（文件指针位置） L1;IXCc=
private void write_nPos() :=u Ku'~
{ c}K>#{YeB
try{ R(Y4nw+Y-
output = new DataOutputStream(new FileOutputStream(tmpFile)); FV|/o%XqK
output.writeInt(nStartPos.length); ]i\C4*
for(int i=0;i<nStartPos.length;i++) Yhu 6QyRV
{ 9l9h*Pgt
// output.writeLong(nPos); ,Q~C F;qe
output.writeLong(fileSplitterFetch.nStartPos); ^i}*$ZC72
output.writeLong(fileSplitterFetch.nEndPos); 5(kRFb'31F
} ajFSbi)l
output.close(); :|i jCg+
} '(M8D5?N-
catch(IOException e){e.printStackTrace ();} / 0Z_$Q&e
catch(Exception e){e.printStackTrace ();} bM`7>3 d7E
} 5nL,sFd
z.itVQs$I
X2PQL"`
//读取保存的下载信息（文件指针位置） 86(8p_&zC
private void read_nPos() o)<c1\q
{ _+z5~6>
try{ 3(|8gWQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z>HeM Mei
int nCount = input.readInt(); N- E)b
nStartPos = new long[nCount]; S7SD$+fX
nEndPos = new long[nCount]; $agd9z,&m
for(int i=0;i<nStartPos.length;i++) T^9k,J(rM
{ @m14x}H
nStartPos = input.readLong(); SenDJv00
nEndPos = input.readLong(); 8':^tMd
} M5DW!^
input.close(); F6 ?4E"d
} ,#Y>nP0
catch(IOException e){e.printStackTrace ();} 5N=QS1<$5
catch(Exception e){e.printStackTrace ();} ?ysC7((
} mup<%@7m
NIn#
=#qf0
private void processErrorCode(int nErrorCode) Vm NCknG
{ ; ntq%
System.err.println("Error Code : " + nErrorCode); IN2FO/Y@
} ZujPk-
! Ff/RRo
x5/O.5>f
//停止文件下载 fbaQXM
public void siteStop() v{7Jzjd
{ 6BT o%
bStop = true; ;Js-27_0
for(int i=0;i<nStartPos.length;i++) fg1_D
fileSplitterFetch.splitterStop(); -ZXC^zt
x O`#a=
UR;FW`
} ^F@z+q
} /DPD,bA
//负责部分文件的抓取 +[$d9
**FileSplitterFetch.java 5e^t;
*/ $@y<.?k>UP
package NetFox; 96Kv!
Cnp\2Fu/
H4#|f n
import java.io.*; f>d aK9$(
import java.net.*; ]=T`8)_r)
k.b->U
DpG|Kl|d
public class FileSplitterFetch extends Thread { Y0`=h"g
\%fl`+`
Hk)IV"[R
String sURL; //File URL w#EP`aM2$=
long nStartPos; //File Snippet Start Position |y+<|fb,a
long nEndPos; //File Snippet End Position 'urn5[i
int nThreadID; //Thread's ID Jr/|nhGl5
boolean bDownOver = false; //Downing is over =bt/2nPV
boolean bStop = false; //Stop identical {ir8n731p
FileAccessI fileAccessI = null; //File Access interface 'xO5Le(=M
>U/m/H'
#sLyU4QV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FM\yf]'
{ Qs(WyP#
this.sURL = sURL; $ekJs/I&
this.nStartPos = nStart; qi!Nv$e
this.nEndPos = nEnd; [o]^\ay
nThreadID = id; ]F:5-[V#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IBYRuaEB
} \-A=??@H
vb 2mY
}%z {tn
public void run() e.X*x4*>~
{ 9|19ia@[\
while(nStartPos < nEndPos && !bStop) i}C9
{ hq}kAv4B=
D,FX&{TYU
p-d2HXo
try{ CF|c4oY82
URL url = new URL(sURL); ESdjDg$[u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .GG6wL<$?
httpConnection.setRequestProperty("User-Agent","NetFox"); )m .KV5K!
String sProperty = "bytes="+nStartPos+"-"; .qBL.b_`
httpConnection.setRequestProperty("RANGE",sProperty); E .2b@
Utility.log(sProperty); /:-8 ,`
YKF5|;}
H=2sT+Sp
InputStream input = httpConnection.getInputStream(); `Mj>t(
//logResponseHead(httpConnection); Y](kMNUSg
B J,U,!
di^E8egR$
byte[] b = new byte[1024]; j. 1@{H
int nRead; ` drds
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KjK.Sv{N
{ ~";GH20
nStartPos += fileAccessI.write(b,0,nRead); m0XdIC]s
//if(nThreadID == 1) fJ \bm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $]eU'!2)
} ^HpUbZpat)
[ 0?*J<d
:by EXe;3
Utility.log("Thread " + nThreadID + " is over!"); ySyA!Z
bDownOver = true; @=@7Uu-
//nPos = fileAccessI.write (b,0,nRead); a`]Dmw8@
} BEn,py7
catch(Exception e){e.printStackTrace ();} +6cOL48"
} ]w2nVC3
} 4`(b(DL]
fQZ,kl
yk1.fxik'
//打印回应的头信息 AcF6p)@_
public void logResponseHead(HttpURLConnection con) P+tnXT>nE
{ _T,X z_
for(int i=1;;i++) Yvky=RM
{ :Iy4B+
String header=con.getHeaderFieldKey(i); eC+S'Jgf
if(header!=null) 2"Oj* ;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r*e<`Is
Utility.log(header+" : "+con.getHeaderField(header)); NkWU5E!
else OMaG*fb=
break; x'Uv;mGo
} Yxe%:
} %bs6Uy5g)a
ZbS*zKEW
`/WX!4eR,
public void splitterStop() UZsn14xSA
{ E038p]M!
bStop = true; :Taequk
} 6 w"-&
+4<Ij/}p
zR)9]pJ-
} GwHp@_>
J|vriI;
Qyn~Vu43
/* Mp8BilH-T
**FileAccess.java lO?dI=}]
*//文件访问(定位，写) 0taopDi;d
package NetFox; aTJs.y-I~
import java.io.*; ?V3kIb
;xp^FKP
G5JZpB#o
public class FileAccessI implements Serializable{ {yPJYF_l
8KQD w:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &<Gs@UX~w
RandomAccessFile oSavedFile; MoIq)5/
long nPos; 7 (}gs?&w
T@V<J'
"RZVv~BD
public FileAccessI() throws IOException >5,nB<
{ Xbm\"g \
this("",0); n*7Ytz3#'
} x>Hg.%/c[
^Q)&lxlxpx
ryk(Am<
public FileAccessI(String sName,long nPos) throws IOException .i^aYbB$X
{ 6xLLIby,
oSavedFile = new RandomAccessFile(sName,"rw"); '"#W!p
this.nPos = nPos; qXI>x6?*
oSavedFile.seek(nPos); JqX+vRY;dd
} XeGtge/}T
})zYo 7
lwY2zX&%)/
public synchronized int write(byte[] b,int nStart,int nLen) KW17CJ@
{ U_1syaY!
int n = -1; #q[k"x=c
try{ *^]lFuX\&E
oSavedFile.write(b,nStart,nLen); Us5P?}
n = nLen; U9uy(KOW
} ups]k?4
catch(IOException e) 2aROY2
{ 4T]n64Yid
e.printStackTrace (); VeLuL:4I
} 6jdNQC$#B
3%"r%:fQB/
bV'^0(Zv
return n; K6C@YY(
} X`REhvT
@wzzI 7}C
u0Nag=cU
} H<hFA(M
U{^~X_?
ENmfbJ4d~
/* v6Vd V.BI
**SiteInfoBean.java h x_,>\@
*/ p5 !B
package NetFox; 4P1<Zi+<
epWTZV(1x
H)eecH$K
public class SiteInfoBean { p2(U'x c
[;rty<Z^b
nPAVrDg O
private String sSiteURL; //Site's URL g~>g])
private String sFilePath; //Saved File's Path DU@ZLk3
private String sFileName; //Saved File's Name %Ls5:Z=
private int nSplitter; //Count of Splited Downloading File L?WF[nFR
G;^},%<
{$dq7m(
public SiteInfoBean() tEj-c@`"x-
{//nSplitter的缺省值为5 Oa8lrP`(
//default value of nSplitter is 5 >?pWbL
this("","","",5); BqF%2{
} '+@q
gj\'1(Ju
n0/H2>I[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =th(Hdk17
{ -AJ$-y
sSiteURL= sURL; 0`{3|g
sFilePath = sPath; Rh=,]Y
sFileName = sName; aGl*h"&
this.nSplitter = nSpiltter; LF2@qvwD
jbDap i<
qHAZ)Tz
} 51,RbADB
l6YToYzE2
fV 6$YCf
public String getSSiteURL() BA1|%:.
{ 1$Jria5n
return sSiteURL; ,KM-DCwcG
} {iz,iv/U
p "J^
T7wy{;
public void setSSiteURL(String value) Lc0U-!{G
{ [<2#C#P:6
sSiteURL = value; ,-4SVj8$P
} 7wO0d/l_
S:\a&+og
k|O?qE1hP
public String getSFilePath() pl-2O $
{ *@EItj`
return sFilePath; dBB;dN
} _tl,-}~
}I1A4=d
H 3e(-
public void setSFilePath(String value) \`nRgYSE
{ Q|!}&=
sFilePath = value; w<m)T
} vf|lF9@U
} Fw/WD
gK`o;` ^
public String getSFileName() +IRr&J*P
{ pPC_ub
return sFileName; 0:,8Ce
} X2Z E9b
[(hB%x_"
Oq7R^t`b
public void setSFileName(String value) oj8_e xx
{ `u./2]n
sFileName = value; Ca&p;K9FR
} #P)7b,3pe
gwf*M3(
1X5*V!u
public int getNSplitter() |Lq -vs?
{ /~4wM#Yi8
return nSplitter; m]Sv>|
} i8]2y
wR x5` @
3?}W0dZ$d
public void setNSplitter(int nCount) Z5oX "Yx
{ .U66Uet>RX
nSplitter = nCount; `I\)Kk@*b9
} RR%[]M#_T
} BQs~>}(V
isdEs k#A.
Z[(V0/[]
/* 7 Q`'1oE?
**Utility.java $IuN(#
*/ EB/.M+~a
package NetFox; ?=UIx24W
eX+FtN
+cDz`)N,,
public class Utility { ^kS44pr\Q
FUq>+U!Qu
uV\ _j3,2
public Utility() d1MVhE
{ *jBn ^
R^fk :3
AADvk_R
} :4{;^|RgU
WWO@ULGY
//线程睡眠 V4('}Q!
public static void sleep(int nSecond) + lha=
{ Bn[5M[
try{ #WOb&h
Thread.sleep(nSecond); 7c:5Ey
} jq4'=L$4
catch(Exception e) 4z~%gt74O]
{ Fu K(SP3
e.printStackTrace (); ";)SA,Z
} D^E+#a 1
} [jOvy>2K]
7_AR()CM
//日志 A[,[j?wC
public static void log(String sMsg) jslfq@5v
{ R*C
System.err.println(sMsg); 12NV
} g{`rWKj
Jb~nu
m[@7!.0=
public static void log(int sMsg) \"E-z.wW=
{ P]Hcg|&
System.err.println(sMsg); Dn[iA~
} 9Q!X~L|\S
} ,W'?F9Y\
{kLL&`ii
WsA(8Ck<
/* ^:b%QO
**TestMethod.java w% Ug9
*/ g@&@]63
package NetFox; ;'o:1{Y
\XG18V&
%H-(-v^T*
public class TestMethod { #-QQ_
kUl:Yj=&
(I?CW~3#
public TestMethod() b,?@_*qv+
{ ///xx/weblogic60b2_win.exe hBSci|*f
try{ u}Q@u!~e9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ` "Gd/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V9v80e {n4
SiteFileFetch fileFetch = new SiteFileFetch(bean); t^|+|>S
fileFetch.start(); =w~phn
} SI:+I4i
catch(Exception e){e.printStackTrace ();} {y{&tzZ
67uUeCW
DhQYjC[
} #+1*g4m~B
]LvpYRU$P
%hYol89F
public static void main(String[] args) KcGM=z?:
{ +["t@Q4IQ
new TestMethod(); &{s`=IeN
} GC{)3)_ t
} x< Td
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