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)); $qr6LIKGw
} Qclq^|O0
for(int i=0;i<nEndPos.length-1;i++) M|j=J{r
{ 9gdK&/ulR
nEndPos = nStartPos[i+1]; K9.Gjw
} *Ti"8^`6
nEndPos[nEndPos.length-1] = nFileLength; #qmsZHd}b
} _'ebXrbZB
} TTFs|T6`q
oGB|k]6]|
F81EZ/
//启动子线程 $2}#):`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xpO;V}M|
for(int i=0;i<nStartPos.length;i++) !zx8I7e4
{ /gl8w-6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pqb`g@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '2i !RT-
nStartPos,nEndPos,i); H8[A*uYL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UOf\pG
fileSplitterFetch.start(); ypG*41
} ~Gz9pBv1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d"miPR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @y~kQ5k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f+hHc8g
nEndPos = " + nFileLength); PU,$YPrZ
// fileSplitterFetch[nPos.length-1].start(); ls&H oJ7
M-@X&bm,S
A9 g%>
//等待子线程结束 A]5];c
//int count = 0; H\a"=&M
//是否结束while循环 *9$SFe|&n:
boolean breakWhile = false; wiZ
;m#4Q6k)V?
;aWk-
while(!bStop) Vc;[0iB
{ 5|*`} ;/y
write_nPos(); oPr`SYB
Utility.sleep(500); [%^sl>,7
breakWhile = true; B+U:=591
1n!:L!,`
1u7D:h>#
for(int i=0;i<nStartPos.length;i++) J](NCD
{ `62v5d*>a
if(!fileSplitterFetch.bDownOver) } v:YSG
{ 1J/'R37lP
breakWhile = false; !pw)sO~
break; k:run2K
} Fc5t,P
} @}g3\xLiK
if(breakWhile) CAC4A
break; 0jlM~H
"%Y=+
lMGO4U[z
//count++; >bze0`}Z
//if(count>4) q0VAkVHw4
// siteStop(); *YeQCt-l
} M=uT8JB
iLuC_.'u=
-i2rcH
System.err.println("文件下载结束！"); }#H,oy;Dz
} SK'h!Ye5Z
catch(Exception e){e.printStackTrace ();} [M~tH *4"
} KoNu{TJ
W<prY
}^Q:Q\
//获得文件长度 Zyz#xMmM
public long getFileSize() j@z IJ
{ #Z2'Y[@.
int nFileLength = -1; ylZQwICk
try{ A|r3c?q
URL url = new URL(siteInfoBean.getSSiteURL()); T3zovnR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n>y,{"J{
httpConnection.setRequestProperty("User-Agent","NetFox"); f_S$CFa@
OA3J(4!"W
PO"lY'W.U
int responseCode=httpConnection.getResponseCode(); /o;L,mcx*
if(responseCode>=400) ~k?rP}>0
{ ?lsK?>uU
processErrorCode(responseCode); 80@\e
return -2; //-2 represent access is error e`qrafa
} V)<>W_g
B&a{,.m&q6
gA(npsUHI
String sHeader; f $Agcy
H<_Tn$<zH.
4<#ItQ(
for(int i=1;;i++) vzg^tJ
{ 8{G!OBxc\.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +QFKaS<sn
//Utility.log(in.readLine()); .pUB.l$)
sHeader=httpConnection.getHeaderFieldKey(i); h(/? 81:
if(sHeader!=null) ta)gOc)r R
{ PuP"( M
if(sHeader.equals("Content-Length")) x *I'Ar
{ ]2@(^x'=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9!n:hhJM
break; ,zoHmV1Wd+
} lm4A%4-db
} L>14=Pr^(
else M +OVqTsFU
break; |M7C=z='
} "rn
} W]D YfR,
catch(IOException e){e.printStackTrace ();} fYP,V0P
catch(Exception e){e.printStackTrace ();} NRx 7S9W
$Lstq_x+
^s6~*n<fH
Utility.log(nFileLength); h2zSOY{su
aE07#
PL=v,NB
return nFileLength; pqO3(2F9
} *,X)tZ6VX
RDbNC v#
7-B|B{]
//保存下载信息（文件指针位置） %_E5B6xi{
private void write_nPos() mHMsK}=~
{ HAO-|=c4
try{ Vl1.]'p_
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6h/!,j0:t_
output.writeInt(nStartPos.length); 7RUztu\_
for(int i=0;i<nStartPos.length;i++) t_Eivm-,B
{ ,.P]5 lE
// output.writeLong(nPos); aZ~e;}w.Zq
output.writeLong(fileSplitterFetch.nStartPos); @-)S*+8
output.writeLong(fileSplitterFetch.nEndPos); : _Y^o
} G%~Vb
output.close(); l^R:W#*+U
} 7{U[cG+a#
catch(IOException e){e.printStackTrace ();} xCL)<8[R,}
catch(Exception e){e.printStackTrace ();} |5;,]lbt
} DH.`
M %zf?>])
-aJ(-Np$f
//读取保存的下载信息（文件指针位置） =Jl\^u%H(x
private void read_nPos() ;,U@zB;\%(
{ puMVvo
try{ bP$e1I3`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6'*6tS
int nCount = input.readInt(); o Rk'I
nStartPos = new long[nCount]; 5L6.7}B
nEndPos = new long[nCount]; z]g#2xD2
for(int i=0;i<nStartPos.length;i++) d >L8SL
{ qX5]\nX&G
nStartPos = input.readLong(); TCzz]?G]la
nEndPos = input.readLong(); ;t7F%cDA
} 1Mq"f7X8
input.close(); gm]q<~eMW
} >7a ENKOg:
catch(IOException e){e.printStackTrace ();} B_Wig2xH0
catch(Exception e){e.printStackTrace ();} uu4!e{K
} 7202N?a {
,FYA*}[
>*/ |tL
private void processErrorCode(int nErrorCode) \l(}8;5}
{ q@1A2L\Om
System.err.println("Error Code : " + nErrorCode); Q>yj<DR
} D3 +|Os)
B7A.~'=
`o_i+?E
//停止文件下载 3|e~YmZx
public void siteStop() +:#g6(P]
{ h Q Att
bStop = true; 'lC=k7@x
for(int i=0;i<nStartPos.length;i++) #/(L.5d[
fileSplitterFetch.splitterStop(); Z^F>sUMR
N<(rP1)`v
ViOXmK"
} U2_;
} ZnbpIJ8cV
//负责部分文件的抓取 L(y~ ,Kc
**FileSplitterFetch.java ,9:v2=C_
*/ P'5Lu
package NetFox; -K^(L#G
<1sUK4nQ,
f:t5`c.
import java.io.*; ciHTnC
import java.net.*; 10dK%/6/O
^y&2N
) \cnz
public class FileSplitterFetch extends Thread { 'wLW`GX.
T2T?)_f /
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String sURL; //File URL dZJU>o'BG
long nStartPos; //File Snippet Start Position &6Wim<*
long nEndPos; //File Snippet End Position 2zjY|g/
int nThreadID; //Thread's ID [di&N!Ao
boolean bDownOver = false; //Downing is over ^> d"D
boolean bStop = false; //Stop identical =:RNpi,
FileAccessI fileAccessI = null; //File Access interface )6he;+
,l)AYu!q4F
,(yaWd6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -fz(]d
{ H#`&!p
this.sURL = sURL; ~r]$(V n
this.nStartPos = nStart; 6`'KM/
this.nEndPos = nEnd; xiQd[[(sM
nThreadID = id; mc6W"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .O4=[wE!U
} na/,1iI<
du=[r
wlX K2D
public void run() -uK@2}NZ
{ TkjZI}]2
while(nStartPos < nEndPos && !bStop) HtI>rj/\ x
{ >3ASrM+>w
52Q~` t7F
(7PVfS>;
try{ t9kqX(!
URL url = new URL(sURL); QtqE&j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'P >h2^z
httpConnection.setRequestProperty("User-Agent","NetFox"); <dhBO
String sProperty = "bytes="+nStartPos+"-"; *7/MeE6)i
httpConnection.setRequestProperty("RANGE",sProperty); CY.i0
Utility.log(sProperty); `>$l2,
P?U}@U~9
V^p XbDRl
InputStream input = httpConnection.getInputStream(); 1A9Gf
//logResponseHead(httpConnection); 6?jSe<4x
T;JA.=I
=Cr F(wVO"
byte[] b = new byte[1024]; [;i3o?\_I
int nRead; []eZO_o6j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c"@,|wCUi
{ V_7QWIdiy>
nStartPos += fileAccessI.write(b,0,nRead); [U?a %$G>
//if(nThreadID == 1) /H[!v:U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ig,v6lqhM
} SQVyCxcX_
`BZX\LPHm
w4p<q68
Utility.log("Thread " + nThreadID + " is over!"); <q#/z&F!
bDownOver = true; Q"an6ht|
//nPos = fileAccessI.write (b,0,nRead); _:,U$W
} (&Z`P
catch(Exception e){e.printStackTrace ();} lvZ:Aw r
} ) bGzsb1\
} '@+a]kCMev
S~LTLv:>
.9;wJ9Bw[
//打印回应的头信息 \?.Tq24
public void logResponseHead(HttpURLConnection con) 27KfT]=
{ QZ51}i
for(int i=1;;i++) 0?nm`9v6
{ %phv<AW
String header=con.getHeaderFieldKey(i); R+O[,UM^I~
if(header!=null) #r_&Q`!eU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *b0f)y3RV
Utility.log(header+" : "+con.getHeaderField(header)); \;smH;m
else c,I|O' &k
break; p#95Q
} _n+./B
} kdrya
"Aq-H g
FWbA+{8
public void splitterStop() z2lEHa?w
{ *Q8d&$ ^
bStop = true; l1qWl
} Qm\VZ<6/5
{~ngI<
woqP&8a
} _ADK8a6%)
,4wZ/r> d
>@BvyZ)i
/* S?5z
**FileAccess.java .{1MM8 Q
*//文件访问(定位，写) zV }-_u.
package NetFox; ? h$>7|
import java.io.*; huau(s0um
m{bw(+r
g[P8
public class FileAccessI implements Serializable{ S/ Y1NH
.hCOi<wB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Vad| -
RandomAccessFile oSavedFile; Z=Oo%lM6B
long nPos; 24Y~x`W
RJ%~=D
@Kd lX>i
public FileAccessI() throws IOException k.DDfuKN
{ LV&tu7c
this("",0); ^zv28Wq>
} [Uezi1I
[;D4,@A
o(. PxcD
public FileAccessI(String sName,long nPos) throws IOException XY5I5H_U
{ 3`&2-
oSavedFile = new RandomAccessFile(sName,"rw"); ]OoqU-q
this.nPos = nPos; kg$<^:uX
oSavedFile.seek(nPos); (d[)U<
} 6M"]p
'$M=H.
Rp)82- .
public synchronized int write(byte[] b,int nStart,int nLen) `n7z+
{ n2R{$^JxO
int n = -1; )#r]x1[Kn
try{ tWi@_Rlx;
oSavedFile.write(b,nStart,nLen); EeKEw Sg
n = nLen; YSt']
} iuq-M?1
catch(IOException e) }@V(y9K
{ v"L<{HN
e.printStackTrace (); Cl]E rg
} <Ja>
Xb42R1
"j9,3yJT
return n; S"w$#"EJA
} "!gd)^<e
e.i5j^5u
(?&X<=|"
} J;+iW*E:
LI?rz<H!D
0vUX^<
/* HW{osav9
**SiteInfoBean.java QdG_zK>|e
*/ [[?:,6I
package NetFox; H;}V`}c<`
u|=_!$8
Ud:v3"1
public class SiteInfoBean { &M~*w~w`
0W9,uC2:N
&D uvy#J
private String sSiteURL; //Site's URL ycRy!0l
private String sFilePath; //Saved File's Path y-{^L`%Mk
private String sFileName; //Saved File's Name 1A">tgA1
private int nSplitter; //Count of Splited Downloading File sW#6B+5_k
NZ'S~Lr
/_?Ly$>'
public SiteInfoBean() xe|o(!(
{//nSplitter的缺省值为5 Tul_/`An
//default value of nSplitter is 5 VLN=9
this("","","",5); 8\`]T%h
} BM1uZJ0
G1vWHa7n;f
qp^O\>c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tv3Bej
{ :p(3Ap2TY
sSiteURL= sURL; Io{)@H"f
sFilePath = sPath; q/?#+d
sFileName = sName; ;_,=
this.nSplitter = nSpiltter; I)]wi%
%s%v|HDs
U"A]b(54
} M/ 0!B_(R
'u{m37ZJ
{$HW_\w
public String getSSiteURL() 9PVM06
{ $&='&q
return sSiteURL; pcv(P
} ^LE`Y>&m
# h]m8
{ o=4(RC
public void setSSiteURL(String value) vL`wn=
{ ^vLHs=<
sSiteURL = value; "?EA G
} @U_w:Q<9u
ce/Rzid
f[HhLAVGK`
public String getSFilePath() 3lqR(Hh3
{ k+{-iPm{
return sFilePath; '%yWz)P
} ^TJn&k
=4"D8UaHr
_y#t[|}w
public void setSFilePath(String value) cj`g)cX|
{ ((\s4-
sFilePath = value; aIpDf|~
} t(-noy)
&7!&]kA+
Ka&[ Oz<w
public String getSFileName() AdesR-e$R
{ %'nM!7w@I
return sFileName; WLQm|C,
} + O=wKsGD
7JD jJQy
5vj;lJKcd`
public void setSFileName(String value) CDQ}C=4
{ N0oBtGb
sFileName = value; Ra}%:
} ZWQrG'$?o8
B\wH`5/KW
?1K|.lr
public int getNSplitter() fHCLsI
{ {1;j1|CI
return nSplitter; N W :_)1
} UB }n=
$-[V)]h
Q"n*`#Yt'
public void setNSplitter(int nCount) MU4/arXy
{ Sg(fZ' -
nSplitter = nCount; L!Iu\_{q
} Q3vC^}Dmr
} U8KB@E
ce{(5IC
i[/g&fx
/* obKWnet
**Utility.java T$5u+4>"
*/ %Sr/'7 K
package NetFox; :p0|4g
3JVENn9
^I=c]D]);
public class Utility { (lq7 ct
Z{s&myd
#5-5N5-1
public Utility() ="<5+G
{ j}7as&
s+&Ts|c#
yBqv'Y
} 3e4; '5q;
P9=L?t.
//线程睡眠 wDswK "T
public static void sleep(int nSecond) S=H<5*]g
{ xdb9oH
try{ 7\m.xWX e
Thread.sleep(nSecond); L1A0->t
} Pw i6Ly`
catch(Exception e) 7?a@i;E<
{ ~L$B]\/A5
e.printStackTrace (); ivg:`$a[
} 8 #fzL7
} Rj 2N+59rg
}#}IR5`=E
//日志 7Gb1[3
public static void log(String sMsg) Q;{[U!\:
{ BayO+,>K
System.err.println(sMsg); 8}9|hT;
} Z0*Lm+d9z
8Q&.S)hrN
.J:04t1
public static void log(int sMsg) #RAez:BI
{ "Y0:Y?Vz"
System.err.println(sMsg); !R*%F
} ,,1H#;j
} q>:>f+4
<Y~?G:v6+
fDyFkhc
/* W:D'k^u
**TestMethod.java Q-([3%
*/ ]"bkB+I
package NetFox; :Awnj!KNCc
T \%{zz_(
UB[tYZ
public class TestMethod { [U+6Tj,
o=i)s2
6&/H XqP
public TestMethod() cx%[hM09
{ ///xx/weblogic60b2_win.exe lF-;h{
try{ `H+~LVH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i*34/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7^$PauAv
SiteFileFetch fileFetch = new SiteFileFetch(bean); H|8vW
fileFetch.start(); #N%ATV
} ]jo^P5\h>
catch(Exception e){e.printStackTrace ();} +C3IP
7oY}=281
! K? o H
} i! G^=N
q~*3Bk~
YrAaL"20
public static void main(String[] args) _nw=^zS
{ !(\OT
new TestMethod(); zTi%j$o
} -$Bom
} o6f^DG3*
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