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)); dM-cQo:
} 1(?4*v@B
for(int i=0;i<nEndPos.length-1;i++) ^&eF916H
{ ,@ 8+%KqG
nEndPos = nStartPos[i+1]; SN{+ Pk
} iNA3Y
nEndPos[nEndPos.length-1] = nFileLength; C 5.3[
} lhN@,q
} 6L<:>55
3^o(\=-JX
xPm. TPj
//启动子线程 =:WZV8@%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !,Uo{@E)Y
for(int i=0;i<nStartPos.length;i++) M5`v^>
{ +FTc/r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Lbsq\W>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AFz:%m
nStartPos,nEndPos,i); s:U:Dv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 03 @aG
fileSplitterFetch.start(); 5CkG^9
} K|P0nJT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !/is+ xp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y*i&p4Y*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2zBk#c+
nEndPos = " + nFileLength); J6Z[c*W
// fileSplitterFetch[nPos.length-1].start(); \]tBwa
@k?vbq
r6m^~Wq!}
//等待子线程结束 }e[ E
//int count = 0; x%B_v^^^
//是否结束while循环 ?Z#N9Z~\
boolean breakWhile = false; T`bYidA
,"%C.9a
&GP(yj]
while(!bStop) /s\ mV
{ }T?X6LA$I8
write_nPos(); }Ce9R2
Utility.sleep(500); gmL~n7m:K
breakWhile = true; hw DxGiU
Vm[Rp,"
.a*?Pal@@
for(int i=0;i<nStartPos.length;i++) N"S`9B1eD(
{ pi"H?EHk
if(!fileSplitterFetch.bDownOver) INg0[Lpc
{ sU_K^=6*
breakWhile = false; 5PeS/%uT@
break; !m@cTB7i
} fzSkl`K}
} smn"]K
if(breakWhile) MpCPY"WLL
break; iiPVqU%
X{-4w([
11H`WOTQF
//count++; L<F8+a7i
//if(count>4) E'AR.!
// siteStop(); s6`E.Eevm
} V"/.An|
xVxs~p1
-c`xeuzK'
System.err.println("文件下载结束！"); 2.q Zs8&
} hY"eGaoF"
catch(Exception e){e.printStackTrace ();} LE\*33k_
} (Z),gxt
V*p[6{U0
n ay\)
//获得文件长度 h,{m{Xh
public long getFileSize() RHF"$6EAFG
{ b;i*}4h!
int nFileLength = -1; h3MdQlJ&
try{ :@L7RZ`_
URL url = new URL(siteInfoBean.getSSiteURL()); }LUvh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F&Md+2
httpConnection.setRequestProperty("User-Agent","NetFox"); xIM,0xM2
`~GXK
B>2=IZ
int responseCode=httpConnection.getResponseCode(); /vQ)$;xf#
if(responseCode>=400) V}E['fzBFV
{ !nmZ"n|}p
processErrorCode(responseCode); X|of87
return -2; //-2 represent access is error <y6`8J7:
} PQHztS"
-)V0D,r$[
T^A(v(^D
String sHeader; *lfjsrPu
U2VEFm6
(m/:B=K
for(int i=1;;i++) JX59n%$@
{ K9<8FSn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r:QLU]
//Utility.log(in.readLine()); mb\T)rj
sHeader=httpConnection.getHeaderFieldKey(i); Rk$7jZdTf
if(sHeader!=null) |~9rak,
{ $fb%?n{
if(sHeader.equals("Content-Length")) lu#a.41
{ }z]d]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?^&ih:"
break; Ac_P^
} IFLphm5
} {j wv+6]U
else </I%VHP,[f
break; > X~\(|EM
} xQ9t1b|{e
} q!z?Tn#!jd
catch(IOException e){e.printStackTrace ();} *DJsY/9d}'
catch(Exception e){e.printStackTrace ();} WIWo4[(
b_+o1Zy`
`m 5\
Utility.log(nFileLength); 5_^d3LOT0x
i\xs!QU
hb[ThQ
return nFileLength; B:zx 9
} rz|T2K
&8VH m?h
!)M}(I}
//保存下载信息（文件指针位置） Y.m1d?H 1
private void write_nPos() `_J&*Kk5
{ Q& [!+s:2J
try{ H I9/
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2CC"Z
output.writeInt(nStartPos.length); c)EYXo
for(int i=0;i<nStartPos.length;i++) E~y8X9HZ)
{ |!oC7!+0^
// output.writeLong(nPos); PMQTcQ^
output.writeLong(fileSplitterFetch.nStartPos); g`y9UYeh
output.writeLong(fileSplitterFetch.nEndPos); IADSWzQ@
} B>u`%Ry&
output.close(); %|jS`kj
} `^#Rwn#
catch(IOException e){e.printStackTrace ();} =Uk#7U"P
catch(Exception e){e.printStackTrace ();} ra~=i|s
} >MYxj}I4{z
^B.Z3Y
FK BRJ5O
//读取保存的下载信息（文件指针位置） p\zqZ=s
private void read_nPos() 9/"&6,
{ +Xg:*b9So
try{ c!@|yE,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ".jO2GO^
int nCount = input.readInt(); `0upm%A
nStartPos = new long[nCount]; \3vQXt\dM$
nEndPos = new long[nCount]; O_ #++G
for(int i=0;i<nStartPos.length;i++) v&:[?<6-
{ ?>7\L'n=5I
nStartPos = input.readLong(); 0A}XhX
nEndPos = input.readLong(); aT^ $'_ G
} | .+P ;g
input.close(); d.}65{F,x
} w5Fk#zJv
catch(IOException e){e.printStackTrace ();} 5c5!\g~'
catch(Exception e){e.printStackTrace ();} QMMpB{FZ`o
} qkfof{z
3[#^$_96b
:[a*I6/^
private void processErrorCode(int nErrorCode) cc${[yj)
{ \d:Q%S
System.err.println("Error Code : " + nErrorCode); 'v'[_(pq
} 6$"IeBRO
u?>},M/
s:{[Y7\?
//停止文件下载 xWLZlUHEu
public void siteStop() ij:xr% FJ
{ 'e:4
bStop = true; ]MCH]/
for(int i=0;i<nStartPos.length;i++) U<Oc&S{]*
fileSplitterFetch.splitterStop(); Vg62HZ |
J_F\cM
E+y_te^+b
} p;4FZ$
} j*>]HNo&
//负责部分文件的抓取 "OwM' n8
**FileSplitterFetch.java :U\*4l
*/ <xBL/e %
package NetFox; +;+G+Tn
P)VQAM
km>ZhsqD
import java.io.*; /Ey%aA4v
import java.net.*; =U84*HAv
n\9IRuYO
l_k:OZ
public class FileSplitterFetch extends Thread { JQb{?C
Vu_oxL}
HnPy";{
String sURL; //File URL KyIUz9$
long nStartPos; //File Snippet Start Position 4UbqYl3|a
long nEndPos; //File Snippet End Position rFcz0
int nThreadID; //Thread's ID ~xzr8 P
boolean bDownOver = false; //Downing is over b!t[PShw^
boolean bStop = false; //Stop identical #2|biTJ
FileAccessI fileAccessI = null; //File Access interface 3]S_w[Q4
/ 8O=3
R?{_Q<17
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tF[)Y#
{ m +A4aQ9
this.sURL = sURL; 5XT^K)'
this.nStartPos = nStart; z81dm
this.nEndPos = nEnd; ~F@p}u8TV
nThreadID = id; $,Q]GIC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )fo0YpE^|
} JCxQENsVqB
cZ%tJ(&\7X
S9DXd]6q_
public void run() ;/NC[:'$D
{ 7cV G?Wr
while(nStartPos < nEndPos && !bStop) /nv*OKS|
{ )Q9Qo)D T
[1GwcXr
o(}%b8 K
try{ C D6N8n]
URL url = new URL(sURL); z,ryY'ua/I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &qY]W=9uK
httpConnection.setRequestProperty("User-Agent","NetFox"); F<h+d917
String sProperty = "bytes="+nStartPos+"-"; {$t*XTY6R
httpConnection.setRequestProperty("RANGE",sProperty); 1q=Q/L4P
Utility.log(sProperty); _{):w~zi
"+2Cs
,e|"p[z~T
InputStream input = httpConnection.getInputStream(); 7oZPb
//logResponseHead(httpConnection); z\FBN=54z
4'3;{k$z
{1=|H$wKg
byte[] b = new byte[1024]; %4` U' j
int nRead; AP z"k?D0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tvno3"
{ v?8i;[
nStartPos += fileAccessI.write(b,0,nRead); PcbhylKd
//if(nThreadID == 1) /\Cf*cJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jD<xpD
} 6 o
5{W Aw !
erv94acq
Utility.log("Thread " + nThreadID + " is over!"); nN.Gn+Cl
bDownOver = true; l(x0d
//nPos = fileAccessI.write (b,0,nRead); Bi9Q8#lh
} g/l:q&Q<
catch(Exception e){e.printStackTrace ();} XXm7rn
} ";Cf@}i>
} Fa`%MR1
|) cJ
7L:Eg
//打印回应的头信息 ,_$J-F?
public void logResponseHead(HttpURLConnection con) `uLr^G=;
{ WnGi;AGH=1
for(int i=1;;i++) ~u!V_su]GY
{ #oiU|>3Y
String header=con.getHeaderFieldKey(i); |d~'X%b%
if(header!=null) M^OYQf
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^6{op3R_
Utility.log(header+" : "+con.getHeaderField(header)); }; 7I
else '>"blfix8
break; zqt%x?l
} L1+s0g>
} DO{otn9<
y5c\\e
_'G'>X>}WU
public void splitterStop() |_g7k2oLY
{ R<I#. KD
bStop = true; E;`^`T40
} OpazWcMoo
+VQD'
:Hb`vH3x
} /? d)01
pdFO!A_t
|Wa.W0A
/* 'Qg!ww7O
**FileAccess.java }^Sk.:;n3
*//文件访问(定位，写) MBjAe!,-
package NetFox; xR$T/]/
import java.io.*; czT2f
`<~=6H
)w<Z4_!N4s
public class FileAccessI implements Serializable{ Vp1ct06^
a6xo U;T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C6F7,v62
RandomAccessFile oSavedFile; :J@3:+sr
long nPos; `#W+pO
[\eVX`it
mA.,.<xE@
public FileAccessI() throws IOException cR!M{U.q
{ Hn(Eut7%
this("",0); #Vmf 6
} V'RbTFb9Z
mrsmul{
}pf|GdL
public FileAccessI(String sName,long nPos) throws IOException pl[@U<8aw
{ F =*4]O
oSavedFile = new RandomAccessFile(sName,"rw"); }%PK %/ zI
this.nPos = nPos; o_b3G
oSavedFile.seek(nPos); |ssl0/nk
} >r\GB#\5
mT-[I<
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public synchronized int write(byte[] b,int nStart,int nLen) .Mb0++% W
{ 7BINqVS&
int n = -1; F7j/Zuj
try{ tw.GBR
oSavedFile.write(b,nStart,nLen); *aS+XnT/
n = nLen; jTg~]PQ^
} 5_](N$$
catch(IOException e) ~Gh7i>n*
{ 1anh@T.
e.printStackTrace (); 479X5Cl
} M?My+oT
2z#S|$
cNwHY Z'
return n; ~@6l7H6{
} }[lP^Qs
jDQ?b\^
-G/qfd|s/
} Fx.Ly]L
Ye$j43b
sCt)Yp+8}B
/* <FU?^*~
**SiteInfoBean.java <)!,$]S
*/ <"K*O9nst
package NetFox; z7sDaZL?_
z k}AGw
j%y{d(Q4
public class SiteInfoBean { p[xGL } +\
|kvH`&s
L~;(M6Jp
private String sSiteURL; //Site's URL rOE: ap|KL
private String sFilePath; //Saved File's Path *k8?$(
private String sFileName; //Saved File's Name 6@8t>"}
private int nSplitter; //Count of Splited Downloading File EZjtZMnj
h/{1(c}
>P@VD"U
public SiteInfoBean() T^`; wD
{//nSplitter的缺省值为5 li\=mH,Wr
//default value of nSplitter is 5 rq!*unJ
this("","","",5); (&Lt&i _
} 1,;zX^
qF`6l(
=z"+)N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jZkc yx
{ NNbdP;=:u
sSiteURL= sURL; %aw.o*@:
sFilePath = sPath; gELG/6l
sFileName = sName; `?N0?;
this.nSplitter = nSpiltter; m }HaJ
P33xt~
QM3DB
} z#o''
Y2 J-`o$5
m#8[")a$"
public String getSSiteURL() vaP`'
{ MA:5'n
return sSiteURL; /; Bmh=
} 9-{=m+|b
,I5SAd|dX
EV{Ys}3M
public void setSSiteURL(String value) (oX!D(OI
{ =(7nl#o
sSiteURL = value; egG<"e*W}N
} +ppA..1
:(X3?%
"EMW'>&m
public String getSFilePath() -c0ypz
{ 7>j~;p{
return sFilePath; 5a_8`csu
} PgK7CG7G
]r|oNGD)G
:[_msd
public void setSFilePath(String value) 1 rhZlmf[r
{ "t.`/4R2w
sFilePath = value; q{Z#}|km#
} < z2wt
A)C)5W
@lE'D":?
public String getSFileName() / }$n_N\!)
{ ;50&s .gZ
return sFileName; ,n8\y9{G
} sNo8o1Hby
i}DS+~8v
[A,^F0:h
public void setSFileName(String value) @pYEzizP7
{ iI IXv
sFileName = value; 'v V7@@
} pCh v;
*l+Dbm,u
+ tMf&BZ
public int getNSplitter() \$wkr
{ P7.bn
return nSplitter; :NF4[c
} ,?|$DY+=
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]c7X~y
public void setNSplitter(int nCount) g5@g_~ g
{ vW=L{8zu
nSplitter = nCount; 2Ckx.m&
} HTOr
} &2`p#riAS
(\{k-2t*^
3@gsKtA&H4
/* V|_ h[hXE
**Utility.java O[C4xq
*/ ^E.L8
package NetFox; m|qktLx
1Hr}n6s
22CET9iCe
public class Utility { kJ_8|
Q< :RLKVT
V9<`?[Usv
public Utility() RPW46l34
{ $mn0I69
D=#RQ-
",$_\l
} fu^W# "{
BHUI1y5t
//线程睡眠 A#=TR_@:
public static void sleep(int nSecond) <:}nd:l1
{ H3D<"4Q>
try{ XnQR(r)pR2
Thread.sleep(nSecond); Ku75YFO,5
} W#p7M[
catch(Exception e) -[=eVS.2%
{ CBEf;Ig
e.printStackTrace (); pUXoSnIq:
} \#_ymM0
} u S1O-Q>
}xk(aM_
//日志 3#>W\_FY*D
public static void log(String sMsg) oBkhb
{ sE pI)9
System.err.println(sMsg); !ajBZ>Q
} !@=S,Vc.
Cq\XLh `
<(xqw<)
public static void log(int sMsg) y?<KN0j
{ T-en|.
System.err.println(sMsg); ^viabkf C
} _p-e)J$7
} &J>e;X
\wK&wRn)
f"ndLX:'}
/* {]T?)!Vm
**TestMethod.java @Vre)OrN#
*/ 0<uek
package NetFox; Ek_5% n
y7,I10:D
=SfNA F
public class TestMethod { X7},|cmD_
mM,HMrgLqK
1!<t8,W4
public TestMethod() @8|*Ndx2
{ ///xx/weblogic60b2_win.exe MuoE~K2
try{ q!$s<n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]vvYPRV76
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bhqSqU}6~
SiteFileFetch fileFetch = new SiteFileFetch(bean); yQK{ +w
fileFetch.start(); tVAi0`DV
} heVkCM :
catch(Exception e){e.printStackTrace ();} "v8p<JfB`
V?uT5.B2
D'g,<-ahl
} NKu[6J?)
)}ev;37<C
>'*%wf[{
public static void main(String[] args) H7zN|NdNw
{ jRJG .hcB5
new TestMethod(); xZ'fer`&
} 'C1lP)S5
} ytZo0pad
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