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)); \Oe8h#%
} YXGxE&!
for(int i=0;i<nEndPos.length-1;i++) Z$K[e
{ XBTjb
nEndPos = nStartPos[i+1]; OX.g~M ig|
} byIP]7Ld
nEndPos[nEndPos.length-1] = nFileLength; biHZyUJ
} /J&_ZDNV~
} ZgxpHo
q9(hn_X@/
NF_[q(k'
//启动子线程 9]a!1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #23($CSE
for(int i=0;i<nStartPos.length;i++) %D+NrL(
{ XC,by&nY<y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %lGg}9k'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TnPx.mwK\
nStartPos,nEndPos,i); 4'L.I%#tZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <!~NG3KW[>
fileSplitterFetch.start(); &3YXDNm
} rmhL|! Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZV~9{E8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d-#yN:}0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &t74T"(d
nEndPos = " + nFileLength); q&: t$tSS
// fileSplitterFetch[nPos.length-1].start(); !f#[4Xw
b*cVC^{Dy
*Di ;Gf@
//等待子线程结束 B|-W
//int count = 0; 8?t}S2n2
//是否结束while循环 l'"Ici#7Ls
boolean breakWhile = false; ztV%W6
bm(.(0MI
p+:MZP -%(
while(!bStop) OJ)XJL
{ Cvtz&dH
write_nPos(); iZ2nBiQ
Utility.sleep(500); F6 f
breakWhile = true; 2?c%<_jPA
;VPYWss
ljk,R G
for(int i=0;i<nStartPos.length;i++) B..> *Xb
{ zR }vw{
if(!fileSplitterFetch.bDownOver) [vcSt5R=
{ uSNlI78D
breakWhile = false; 8Y~\:3&1<
break; `FIS2sl/
} <f@ A\
} -KiI&Q
if(breakWhile) A55F*d
break; F3<Ip~K
||rZ+<
eu?DSad
//count++; [J43]
//if(count>4) Zex`n:Wl?j
// siteStop(); 4tFnZ2x
} >W=^>8u
0|`iop%(n
Ly`FU)
System.err.println("文件下载结束！"); qUG)+~g`
} QQX7p!~E
catch(Exception e){e.printStackTrace ();} {3\{aZ8)
} XM?C7/^k
3qrjb]E%}
$WZHkV
//获得文件长度 Z`{GjV3%wH
public long getFileSize() Xa&0j&AH
{ 604^~6
int nFileLength = -1; C)+%9Edg
try{ Cg%}=
URL url = new URL(siteInfoBean.getSSiteURL()); w:@W/e*9N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jg=}l1M"
httpConnection.setRequestProperty("User-Agent","NetFox"); UJrN+RtL
LKu ,H
#:}mi;{
int responseCode=httpConnection.getResponseCode(); (Z at|R.F
if(responseCode>=400) hE}y/A[
{ 9I*`~il>{
processErrorCode(responseCode); C: a</Sl
return -2; //-2 represent access is error \%]!/&>{6
} '8UhYwyr
to;cF6X
$3{I'r]
String sHeader; ,IQ%7*f;O_
{$)pkhJ
%51HJB}C]
for(int i=1;;i++) -v?)E S
{ <~35tOpv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n.xOu`gj
//Utility.log(in.readLine()); t$b{zv9C
sHeader=httpConnection.getHeaderFieldKey(i); OT}^dPQe
if(sHeader!=null) 0`"DYJ}d
{ RV, cQ K
if(sHeader.equals("Content-Length")) OJPi*i5*
{ S *K0OUq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qiyJ4^1
break; \Gz 79VW
} !9.`zW"40
} NIxtT>[+3
else #%SF2PB;
break; pDG>9P#mO
} t[b@P<F
} {DbWk>[DkG
catch(IOException e){e.printStackTrace ();} iGsD!2
catch(Exception e){e.printStackTrace ();} h v/+
|FJc'&)J"
!jyy`q=
Utility.log(nFileLength); YfU6mQ
'n!kqP
9Gk#2
return nFileLength; -v62 s
} '7>Yrzq
OiMr,
zr[|~-
//保存下载信息（文件指针位置） DO9_o9'
private void write_nPos() |bv7N@?e
{ \-R\xL
try{ *aS[^iX?s
output = new DataOutputStream(new FileOutputStream(tmpFile)); EMMp4KKOx+
output.writeInt(nStartPos.length); CGJ>j}C
for(int i=0;i<nStartPos.length;i++) Tlz~o[`&
{ r>x>aJ
// output.writeLong(nPos); be:=-B7!
output.writeLong(fileSplitterFetch.nStartPos); nSeb?|$D6
output.writeLong(fileSplitterFetch.nEndPos); tz`T#9
} }}wZ
output.close(); R'x^Y"
} -)Y[t Z^*`
catch(IOException e){e.printStackTrace ();} Dh B*k<S
catch(Exception e){e.printStackTrace ();} v!%VH?cA8
} #kPsg9Y
@w@ `-1
@1iH4RE*
//读取保存的下载信息（文件指针位置） \6K1Z!*;
private void read_nPos() L|K^w *\C
{ 5r(Y,m"?
try{ &L4>w.b"N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H4JwgQ
int nCount = input.readInt(); yDXW#q
nStartPos = new long[nCount]; IltU6=]"l
nEndPos = new long[nCount]; 53)*i\9&
for(int i=0;i<nStartPos.length;i++) Lo^gg#o
{ K8g9IZ*lT
nStartPos = input.readLong(); ]:F?k#c
nEndPos = input.readLong(); K{[N.dX(
} Q804_F F#
input.close(); pQ9~^
} ^fxS=Qs+
catch(IOException e){e.printStackTrace ();} TrmrA$5f
catch(Exception e){e.printStackTrace ();} 0%>_fMaA
} <<[\ Rv
-JfO} DRI
[eO6H2@=z
private void processErrorCode(int nErrorCode) XZ[3v9?&n
{ [Cf{2WB:7
System.err.println("Error Code : " + nErrorCode); >19j_[n@VC
} XCQPVSh
l6k.`1.In
} {<L<
//停止文件下载 `*HM5 1U
public void siteStop() "|W``&pM
{ i4r8146D[
bStop = true; =E4~/F}9/T
for(int i=0;i<nStartPos.length;i++) $SPA'63AC
fileSplitterFetch.splitterStop(); i@hW" [A
C{P:1ELYXH
>q)VHV9P
} p28=l5y+
} bx=9XZ9g
//负责部分文件的抓取 zvHeoM,
**FileSplitterFetch.java s.9_/cFWB
*/ rWD*DmY@"
package NetFox; f,QBj{M,
+a!uS0fIJi
]O.Z4+6w
import java.io.*; kCZxv"Ts
import java.net.*; 5Int,SX
t6a$ZN;
7/GL@H
public class FileSplitterFetch extends Thread { g RBbL1
F=r`'\JV[
f4r)g2Zb[
String sURL; //File URL h^=9R6im
long nStartPos; //File Snippet Start Position RqRyZ*n
long nEndPos; //File Snippet End Position +DA,|~k_
int nThreadID; //Thread's ID sRDxa5<MD
boolean bDownOver = false; //Downing is over T@\%h8@~]
boolean bStop = false; //Stop identical I18<brZJ
FileAccessI fileAccessI = null; //File Access interface tA]Y=U+Q
Q2nqA1sRk
1]]#HTwX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i :Sih"=
{ Nvj0MD{ X
this.sURL = sURL; BhC>G2 ^7
this.nStartPos = nStart; P1A5Qq
this.nEndPos = nEnd; e]@R'oM?#`
nThreadID = id; w^wh|'u^_@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J^)=8cy
} Y!w {,\3
^.~m4t`U
Tg\wBhJr|
public void run() %:/?eZ
{ `sPH7^R
while(nStartPos < nEndPos && !bStop) ewORb
{ _1kcz]]F
jRYW3a_7
Lm"zW>v
try{ (YKkJ
URL url = new URL(sURL); Xgyi}~AoaU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gfy9?sa
httpConnection.setRequestProperty("User-Agent","NetFox"); c},wW@SF2W
String sProperty = "bytes="+nStartPos+"-"; 6P U]I+
httpConnection.setRequestProperty("RANGE",sProperty); m.2=,,r<Fq
Utility.log(sProperty); %Tm8sQ)1
B7ty*)i?
1_0\_|
InputStream input = httpConnection.getInputStream(); kH}HFl
//logResponseHead(httpConnection); pIP^/H
N@G~+GCxL
(7J (.EG2e
byte[] b = new byte[1024]; G*\U'w4w|*
int nRead; /j:fc?yv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wC~LZSTt
{ $KMxq=
nStartPos += fileAccessI.write(b,0,nRead); 6h3TU,$r
//if(nThreadID == 1) fs;pX/:FR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4NxI:d$&*
} %% A==_b
*e}1KcJ
-G@:uxB
Utility.log("Thread " + nThreadID + " is over!"); jpRC6b?
bDownOver = true; 6qH^&O][
//nPos = fileAccessI.write (b,0,nRead); d gRTV<vM
} o=ULo &9
catch(Exception e){e.printStackTrace ();} I!;vy/r
} &&K"3"um
} SvN2}]Kh
gq[`g=x
_yP02a^2
//打印回应的头信息 sTChbks
public void logResponseHead(HttpURLConnection con) +#MQ8d
{ 1J @43>u{
for(int i=1;;i++) :elTqw>pn
{ kQQhZ8Ch
String header=con.getHeaderFieldKey(i); /Vy,6:$H3
if(header!=null) &L`yX/N2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h(MS>=
Utility.log(header+" : "+con.getHeaderField(header)); MR-cOPn
else =VOl *
break; E!zAUEVQm[
} T,SCK^
} PuoN<9 #
ZKco
_ pKWDMB$z
public void splitterStop() $3D#U^7i
{ cu#s}*Ip
bStop = true; [>wvVv
} :Yy8Ie#
(043G[H'.
F,>-+~L=
} tDwj~{a~
A.@Af+
rJqRzF{|P6
/* 8jz[;.jP",
**FileAccess.java F}dq~QCzw
*//文件访问(定位，写) $mZpX:7/u8
package NetFox; CY i{WV(:
import java.io.*; bf&k:.v'8
c`x[C
tF=Y3W+L
public class FileAccessI implements Serializable{ nH -1,#`g
F\(7B#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RRBBz7:~
RandomAccessFile oSavedFile; PML+$
long nPos; j+7ok 5J#
?)V}_%fVv
yNkE>
public FileAccessI() throws IOException kFsq23Ne
{ U**v'%{s
this("",0); 4C[n@p2
} hDc)\vzr
[tY+P7j9)
GYM6 `
public FileAccessI(String sName,long nPos) throws IOException 6A \Z221E
{ 5|Or,8r(C
oSavedFile = new RandomAccessFile(sName,"rw"); g7),si*
this.nPos = nPos; 6K 6uB ~
oSavedFile.seek(nPos); kx_PMpc
} i1JWdHt
Qpaan
E+|r h-M7
public synchronized int write(byte[] b,int nStart,int nLen) vspub^;5\
{ 8 y+Nl&"V
int n = -1; }j /r
try{ Q($aN-
oSavedFile.write(b,nStart,nLen); 2lm{:tS
n = nLen; *N|s+
} y/}ENUGR
catch(IOException e) "=r"c$xou
{ -yn;Jo2-
e.printStackTrace (); Up|>)WFw"
} | *J-9
#v QyECf
?g~g GQV
return n; Z6XP..
} ^&-H"jF
ZFsJeF'"
q|fZdTw
} |L"!^Y#=D
byUz
qn4jy6
/* 5{uK;Vxse
**SiteInfoBean.java ' y9yx[P
*/ Md4JaFA(
package NetFox; '5n67Hl 1
(xhwl=MX)
:5M7*s)e16
public class SiteInfoBean { xHMbtY
K@PQLL#yJp
:x<'>)6
private String sSiteURL; //Site's URL kW=GFj)L
private String sFilePath; //Saved File's Path r+WY7'c
private String sFileName; //Saved File's Name fsDwfwil*
private int nSplitter; //Count of Splited Downloading File >IzUn: 0F
td6$w:SN,l
@xI:ZtM
public SiteInfoBean() 4[]/
{//nSplitter的缺省值为5 "x)xjL
//default value of nSplitter is 5 F]SA1ry
this("","","",5); $SmmrM
} =1}Umn|ZLS
C'c9AoE5>
p#Vh[UTl^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mtON dI
{ )KLsa`RV:
sSiteURL= sURL; %4Thb\T
sFilePath = sPath; bqt*d)$
sFileName = sName; W l+[{#
this.nSplitter = nSpiltter; uKcwVEu
uM^eoh_
m% {4
} =tv,B3Mo
1E*No1
iJrF$Xw
public String getSSiteURL() {G D<s))
{ 2AAZZx +$
return sSiteURL; De(\<H#
} Hi 1@
E\(dyq/
_IOt(Zb(
public void setSSiteURL(String value) lc71Pp>
{ v3i]z9`
sSiteURL = value; U Ux]
} c_fx,; ;
v{}i`|~J
'$3]U5KOwK
public String getSFilePath() exqFwmhh
{ %Hk9.1hn5
return sFilePath; x}W,B,q
} %\ i 7
ZgcJxWC<
hZ0CnY8 '
public void setSFilePath(String value) .#,!&Lt
{ G' ~Z'
sFilePath = value; AAr[xoiYp
} 3YG[~o|4
Dg$Z5`%k8
^qaS
public String getSFileName() `!.)"BI/s
{ )@xHL]!5m
return sFileName; GIt~"X
} v:Av2y
X4:\Shb97
1jJ>(S
public void setSFileName(String value) nl)!)t=n
{ XA~Cc<v
sFileName = value; .X;zEyd
} 8X@p?43
S0\;FmLIc
>[=fbL@N<@
public int getNSplitter() ^ 2"r't
{ nVF?.c
return nSplitter; Dk!;s8}*c
} +mQMzZZTZ
9y(75Bn9
R&cOhUj22J
public void setNSplitter(int nCount) 37hs/=x
{ R#ABda9
nSplitter = nCount; GHaOFLY
} .a%D:4GYR
} ,Jy@n]x
4LRrrW
vps</f!
/* v2e*mNK5
**Utility.java =l_B58wrx
*/ )uvs%hK
package NetFox; [*<F
_;G. QwHr
,9I %t%sb
public class Utility { uXX3IE[
o5UM)g
+>#SB"'
public Utility() v=A]#O%
{ ^tS{a*Yn
y9cDPwi:b
}fps~R
} CbmT aEaP
/DG+8u
//线程睡眠 ?v4-<ewD
public static void sleep(int nSecond) ~s@PP'!
{ -a``
try{ eSNwAExm
Thread.sleep(nSecond); }Ut*Y*
} Lo^0VD!O
catch(Exception e) |H`}w2U[j
{ "|?zQ?E
e.printStackTrace (); @6eM{3E.
} nRYHp7`
} v71j1Q}6
"P)f,n
//日志 f}JiYZ
public static void log(String sMsg) {9kH<,PJ;!
{ F)ak5
System.err.println(sMsg); {:U zW\5l)
} O)y|G%O
J<g$hk
!^{0vFWE
public static void log(int sMsg) D00I!D16
{ B?BB
System.err.println(sMsg); m0}Pq{g
} B$R"Ntp
} {E6M_qZ
xbbQ)sH&m
y0!-].5UH
/* d5zv8?|X+
**TestMethod.java snPM&
*/ xq`mo
package NetFox; OF[y$<jM
MKqMH,O
T5* t~`bfU
public class TestMethod { !S0$W?*
K4\{G
,$"*X-1
public TestMethod() bXVH7Fy
{ ///xx/weblogic60b2_win.exe /.54r/FN')
try{ ZY_aE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {+`'ZU6C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c1!0Z28
SiteFileFetch fileFetch = new SiteFileFetch(bean); }I3 ZNd
fileFetch.start(); 0rM'VgB
} ;WydXQ}Q^
catch(Exception e){e.printStackTrace ();} eIZ7uSl
yQAW\0`
Y nD_:ZK
} :c4iXK0_^?
W6~aL\[
'o D31\@I
public static void main(String[] args) )uj:k*`)
{ C[E[|s*l
new TestMethod(); 6j*L]Sc
} v[k;R
} /INjP~C
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