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)); P8tdT3*6/
} 6>a6;[
for(int i=0;i<nEndPos.length-1;i++) UlYFloZ
{ 4<y
nEndPos = nStartPos[i+1]; w&p+mJL.
} a5D|#9
nEndPos[nEndPos.length-1] = nFileLength; O$,Fga
} m8q4t,<J
} u^" I3u8$
<RGH+4LF
u"[f\l
//启动子线程 QNj]wm=mp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #,%bW[L<N
for(int i=0;i<nStartPos.length;i++) s2;~FK#/
{ p['RV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `JySuP2~/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )9]a
nStartPos,nEndPos,i); ]juPm8eF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <xI<^r'C9e
fileSplitterFetch.start(); 7oE0;'
} ;8sL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H+v&4}f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 77P\:xc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \T7Mt|f:5
nEndPos = " + nFileLength); J]F&4O
// fileSplitterFetch[nPos.length-1].start(); !GcBNQ1p+7
VmS_(bM
l5[5Y6c>
//等待子线程结束 )l3Uf&v^f
//int count = 0; cS ~OxAS
//是否结束while循环 )GD7rsC`<
boolean breakWhile = false; @N=vmtLP
K@JZ$
kwI``7g8*e
while(!bStop) kpm;ohd
{ Br1R++]
write_nPos(); LgqQr6y"
Utility.sleep(500); ARH~dN*C
breakWhile = true; }A)\bffH
M(%H
Q]ersA8 V>
for(int i=0;i<nStartPos.length;i++) %w`d
{ slQn
if(!fileSplitterFetch.bDownOver) ~k"+5bHa*
{ TEtmmp0OD
breakWhile = false; WtT;y|W
break; "Ep"$d
} @DN/]P
} e4z`:%vy
if(breakWhile) 19!?oeOU
break; honh'j
q m3\)9C
3I6ocj[,
//count++; ]Q^)9uE\D
//if(count>4) d0El2Ct8
// siteStop(); d"wA"*8~y
} Ji4p6$ .j-
8mI(0m'
VkQ@c;C
System.err.println("文件下载结束！"); m1$tf ^
} Myq8`/_
catch(Exception e){e.printStackTrace ();} EVmBLH-a
} s9- qR_
[doEArwn
TnrBHaxbo4
//获得文件长度 ?qh-#,O9B
public long getFileSize() fBSa8D3}`
{ ,i>`Urd
int nFileLength = -1; sSM"~_y\
try{ 5pQpzn=
URL url = new URL(siteInfoBean.getSSiteURL()); Knwy%5.Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9"~ FKMN
httpConnection.setRequestProperty("User-Agent","NetFox"); /jv/qk3i
RGW@@
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int responseCode=httpConnection.getResponseCode(); vDjH $ U
if(responseCode>=400) 0ho;L0Nr'
{ 8^7Oc,:~
processErrorCode(responseCode); dN8Mfa)
return -2; //-2 represent access is error RQVu~7d[
} VAPeMO ck
cu!%aM,/<-
dNACE*g;q
String sHeader; 0eY!Z._^
VfU"%0x
#GzALF97
for(int i=1;;i++) QiK>]xJ'
{ ?sN{U\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wZvv5:jKpu
//Utility.log(in.readLine()); mjeJoMvN)H
sHeader=httpConnection.getHeaderFieldKey(i); &Ok1j0~~
if(sHeader!=null) BT7{]2?&V
{ lQ8hY$
if(sHeader.equals("Content-Length")) +O}Ik.w
{ 0Lo8pe`DH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QLqtE;;)JK
break; -WC0W
} r:*G{m-
} Xa[k=qFo
else o1AbB?%=
break; sz9W}&(j
} $*q|}Tvl#
} dq93P%X24
catch(IOException e){e.printStackTrace ();} 5(>=};r+
catch(Exception e){e.printStackTrace ();} ^exU]5nvz
jTa\I&s,A
Pn,I^Ej.
Utility.log(nFileLength); .}==p&(
__=53]jGE
ibkB>n{(
return nFileLength; eiMP:
} '1mk;%
.a4,Lr#q.
|ADf~-AY
//保存下载信息（文件指针位置） dl4n-*h
private void write_nPos() ?eS;Yc
{ M7=,J;@
try{ <>HtXn/
output = new DataOutputStream(new FileOutputStream(tmpFile)); L}h_\1
output.writeInt(nStartPos.length); $qD\ku;'
for(int i=0;i<nStartPos.length;i++) A@V$~&JCL5
{ ~F"S]
// output.writeLong(nPos); g89@>?Mn
output.writeLong(fileSplitterFetch.nStartPos); oU\]#e^
output.writeLong(fileSplitterFetch.nEndPos); q`xc h[H
} +|/0sPW(
output.close(); &gCGc?/R#
} ebBi zc=
catch(IOException e){e.printStackTrace ();} n0KpKH<&
catch(Exception e){e.printStackTrace ();} 5r5on#O&
} | 6{JINW
9pLe8D
p%DU1+SA
//读取保存的下载信息（文件指针位置） -06G.;W\^
private void read_nPos() '{ <RX
{ ?I+{S
try{ a>47k{RSzE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h*Fv~j'p
int nCount = input.readInt(); z~t0l
nStartPos = new long[nCount]; mG~kf]Y
nEndPos = new long[nCount]; i:s=
for(int i=0;i<nStartPos.length;i++) ?t'V5$k\
{ B_[efM<R$
nStartPos = input.readLong(); 'g%:/lwA
nEndPos = input.readLong(); }u8(7
} h$8h@2%
input.close(); JCcYFtW
} ~vXbh(MX
catch(IOException e){e.printStackTrace ();} CcQc!`YC
catch(Exception e){e.printStackTrace ();} eha|cAq
} w"{DLN[Qw
9J/[7TzSZ
8\s#law
private void processErrorCode(int nErrorCode) "qgwuWbM
{ !q&Td
System.err.println("Error Code : " + nErrorCode); -riX=K>$
} ^BA I/WP
o< @![P
nP%U<$,+
//停止文件下载 !h#ZbErW
public void siteStop() /ZyMD(_J
{ /Bt!xSI
bStop = true; !7DDPJ~
for(int i=0;i<nStartPos.length;i++) )#i@DHt=
fileSplitterFetch.splitterStop(); =\lw.59
x'g4DYl
d.?}>jl
} 4x6n,:;
} >B6*`3v
//负责部分文件的抓取 x=cucZ
**FileSplitterFetch.java $wAR cS
*/ h^g0|p5
package NetFox; - VJx)g
u)<]Pb})r
V;eaQ
import java.io.*; +ydd"`
import java.net.*; ~vz%I^xW
u"&?u+1j
@<P2di
public class FileSplitterFetch extends Thread { _tHhS@
6FzB-],
) (YNNu
String sURL; //File URL ?Kgb-bXB
long nStartPos; //File Snippet Start Position !S=YM<Ad
long nEndPos; //File Snippet End Position 0Fb];:a
int nThreadID; //Thread's ID 2yJ{B
boolean bDownOver = false; //Downing is over IW~wO
boolean bStop = false; //Stop identical TR3U<:
FileAccessI fileAccessI = null; //File Access interface sQ`G'<!
y@!M<#SEzG
U>lf-iI2B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b$klm6nMvm
{ 9:p-F+
this.sURL = sURL; O2>c|=#
this.nStartPos = nStart; E[t0b5h
this.nEndPos = nEnd; Dy.i^`7\
nThreadID = id; U${W3Ra
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %g@?.YxjT
} Wu 0:X*>}p
qm$(_]R~`
!hq2AY&H)
public void run() *|S6iSn9R!
{ XHU$&t`7>g
while(nStartPos < nEndPos && !bStop) |^l_F1+w
{ 'yPKQ/y$x
ES4Wtc)&
Z$/76
try{ kL1<H%1'
URL url = new URL(sURL); b;b,t0wS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l^&#9d
httpConnection.setRequestProperty("User-Agent","NetFox"); k^Qf |
String sProperty = "bytes="+nStartPos+"-"; M/6Z,oOU
httpConnection.setRequestProperty("RANGE",sProperty); d9$RmCHe}
Utility.log(sProperty); ?C[?dg{n
D#LV&4e>.E
@#4-4.6I<x
InputStream input = httpConnection.getInputStream(); ?zBu`7j
//logResponseHead(httpConnection); ??"_o3
U|3!ixk>>w
dLp1l2h!0
byte[] b = new byte[1024]; &MSU<S?1
int nRead; }R}+8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dO82T3T
{ Kd-1EU
nStartPos += fileAccessI.write(b,0,nRead); MOD&3>NI
//if(nThreadID == 1) a6LL]_&g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F_*']:p
} w&?XsO@0W
.j:,WF<"l5
&q>8D'
Utility.log("Thread " + nThreadID + " is over!"); Lyhuyb)k5^
bDownOver = true; $Er=i }`
//nPos = fileAccessI.write (b,0,nRead); 5e+j51
} vntJe^IaFd
catch(Exception e){e.printStackTrace ();} (S!UnBb&
} +fk*c[FG
} }i!+d,|f
QH-CZ6M
t.ulG *
//打印回应的头信息 Rv&"h_"t
public void logResponseHead(HttpURLConnection con) ;NA5G:eQ
{ y5sH7`2+5
for(int i=1;;i++) \( s `=(t
{ fv7VDo8vb
String header=con.getHeaderFieldKey(i); dq '2y
if(header!=null) |<c9ZS+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z^V;B _
Utility.log(header+" : "+con.getHeaderField(header)); NAD^10
else Ve(<s
break; lBfthLBa
} %"f85VfZ
} *W8n8qG%T
>\1twd{u]
7 {92_xRL
public void splitterStop() &`qYe)1Eo
{ Yd3lL:M
bStop = true; h-PJC/>
} ^(TCUY~f&
%:~Ah6R1
a Y)vi$;]
} R%3yxnM*
=wX;OK|U(^
;((t|
/* 0hoMf=bb$
**FileAccess.java C?|sQcCE
*//文件访问(定位，写) p-"C^=l
package NetFox; \Hp!NbnF$
import java.io.*; G|jHic!
W%+02_/)
y7pBcyWTE=
public class FileAccessI implements Serializable{ a>vxox) %
]lA}5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B5 /8LEWw
RandomAccessFile oSavedFile; yr},pB
long nPos; Oey Ph9^V
O h e^{:
93n%:?l"<W
public FileAccessI() throws IOException Z><+4 '
{ 0i}.l\
this("",0); >q;| dn9
} L<dh\5#p9Y
f=91 Z_M
J <z ^C
public FileAccessI(String sName,long nPos) throws IOException _8$xsj4_
{ h*^JFZb
oSavedFile = new RandomAccessFile(sName,"rw"); d1#lC*.Sg
this.nPos = nPos; :Jyr^0`J
oSavedFile.seek(nPos); cl`kd)"v
} IgJG,!>h
8cfsl lI
=,*/Ph&
public synchronized int write(byte[] b,int nStart,int nLen) F$i50s
{ <,O|fY%
int n = -1; j(I(0Yyh
try{ '\QJ{/JV
oSavedFile.write(b,nStart,nLen); Y|mtQE?c
n = nLen; DPY+{5q2
} {6LS$3}VM
catch(IOException e) sz%]rN6$
{ |9i[*]
e.printStackTrace (); 9k93:#{WE
} M%jR`qVFg.
X%I@4 B7Ts
jKcl{',
return n; ]hlQU%&
} -AL^
D Q4O
7&etnQJ{
} CNV^,`FX
{y{O ze
b!-=L&V
/* xGOmvn^lQ
**SiteInfoBean.java v#9i|
*/ A~{vja0?
package NetFox; vx$DKQK@l\
[#aJ- Uu
\Dr( /n
public class SiteInfoBean { ,W'P8C
+bso4 }rS
"8)%XSb
private String sSiteURL; //Site's URL _TdH6[9
private String sFilePath; //Saved File's Path tw 3zw`o:
private String sFileName; //Saved File's Name owa&HW/_
private int nSplitter; //Count of Splited Downloading File sOz {spA
Le-t<6i-V#
'o=DGm2H
public SiteInfoBean() ',+Zqog92
{//nSplitter的缺省值为5 ~mHrgxQ-
//default value of nSplitter is 5 0T@axQ[%
this("","","",5); z2R?GQ5 A
} hw`pi6
w$]wd`N}
A]%*ye"NT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PXl%"O%d
{ Q4Wz5n1yp7
sSiteURL= sURL; sWTa;Qi
sFilePath = sPath; VeEa17g&
sFileName = sName; Rc93Fb-Zp
this.nSplitter = nSpiltter; u>] )q7s
oG hMO
s,mt%^x[
} /ZL6gRRA|
non5e)w3@
!mVq+_7]
public String getSSiteURL() r^E(GmW
{ _iA oNT!
return sSiteURL; kTzO4s?
} wU/fGg*M2
.2|(!a9W
1TzwXX7
public void setSSiteURL(String value) $PlMyLu7jc
{ =Y^K
sSiteURL = value; U0W2
} S6JWsi4C:,
]:n9MFv
);S8`V
public String getSFilePath() b"Nd8f[
{ Rw63{b/
return sFilePath; J`; 9Z
} K4RQ{fWpm
00>knCe6
aU.!+e%_
public void setSFilePath(String value) `PLax@]2
{ XE0b9q954
sFilePath = value; re4z>O*
} @tRDKPh
3C;;z
6xr%xk2E
public String getSFileName() zt
{ ;S&anC#E
return sFileName; 2H] 7=j
} FUL'=Xo
EIpz-"S
1=X1<@*
public void setSFileName(String value) qx0F*EH|
{ A[F@rUZp
sFileName = value; oOLj? 0t
} [T3%Xt'4
4B[uF/[
#N"QTD|i
public int getNSplitter() mYk~ ]a-
{ |~v2~
return nSplitter; ]XX>h~0
} {EVy.F
%n,_^voE
DHvZ:)aT}
public void setNSplitter(int nCount) %5n'+-XVj
{ %Yg|QBm|
nSplitter = nCount; _Wp.s]D [
} " w /Odd
} 4,=;:#n,J
ZBQ@S
1bDXv,nD
/* >C5u>@%9O
**Utility.java k|jr+hmn":
*/ tQ.H/;
package NetFox; kf95)iLo
ExFz@6@
"d0D8B7HI@
public class Utility { |WT]s B0Eq
& \C1QkI
j]mnH`#BL
public Utility() _Db&f}.`
{ Z;;A#h'%e
4)XB3$<
T}"[f/:N/
} }P\6}cK
3".#nN
//线程睡眠 D mky!Cp
public static void sleep(int nSecond) ,sg\K>H=
{ [4yw? U
try{ P*ZMbAf.
Thread.sleep(nSecond); =L?2[a$2;
} ^oE#;aS
catch(Exception e) u2[L^]|
{ d+ [2Sm(7
e.printStackTrace (); ZC^NhgX
} PH^Gjm
} C/9]TkX}q
CZ{7?:^f
//日志 ^/}&z
public static void log(String sMsg) *.T?#H
{ )tS;gn
System.err.println(sMsg); R`Hy0;X
} BJg
8WKY 4nkj
^HE@ [b
public static void log(int sMsg) Z@>kqJ%
{ s+=':Gcb(C
System.err.println(sMsg); p3T:Y_
} rJRg4Rog
} ##alzC
v}IhO~`uEq
Otf{)f
/* }iUpBn
**TestMethod.java fILvEf4b
*/ ~Jj~W+h
package NetFox; Tgbq4xR(
-]n%+,3L
y(^\]-fE
public class TestMethod { )dJx82" l
cVr+Wp7K#|
G9GLRdP
public TestMethod() ekmWYQ ~
{ ///xx/weblogic60b2_win.exe uK ,W
try{ :V_UJ3xf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Fw}|c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <zAYq=IU
SiteFileFetch fileFetch = new SiteFileFetch(bean); jmP;(j.|
fileFetch.start(); ',rK\&lL6
} (I35i!F+tY
catch(Exception e){e.printStackTrace ();} G68@(<<Z
;=6EBP%
,^DP
} B^ddi
A<(DYd1H
Ea-U+7JC
public static void main(String[] args) GY^;$?
{ {.y_{yWo
new TestMethod(); C46jVl
} #~.RJ%
} Io&HzQW^a
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