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)); J 2H$ALl
} a_z1S Z2[
for(int i=0;i<nEndPos.length-1;i++) V*d@@%u**
{ nO#a|~-))
nEndPos = nStartPos[i+1]; |K.J@zW
} n{*A<-vL
nEndPos[nEndPos.length-1] = nFileLength; Rz03he
} c^F@9{I
} i]$/& /
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xI>HY9i)
//启动子线程 rbw~Ml0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /#Gm`BT
for(int i=0;i<nStartPos.length;i++) ]broU%#"
{ r]3v.GZy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yg WwUpY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HrK7qLw7
nStartPos,nEndPos,i); 'hNRIM1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *KYh_i
fileSplitterFetch.start(); x'iBEm
} Ewq7oq5:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $z,rN\[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k*ZYT6Z?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W.sH
nEndPos = " + nFileLength); $aC%&&+wG
// fileSplitterFetch[nPos.length-1].start(); HO}eu
F9J9zs*,
19]O;
//等待子线程结束 JWsOze8#
//int count = 0; "ivSpec.V
//是否结束while循环 /St d6B*
boolean breakWhile = false; Hd ${I",
Uqd2{fji=#
lPA:ho/`:
while(!bStop) ?WBA:?=$58
{ g0k{b
write_nPos(); ;mauA#vd
Utility.sleep(500); zwgO|Qg;
breakWhile = true; ,R*YI
f)#nXTXeC
7hAc6M$h;
for(int i=0;i<nStartPos.length;i++) |IZFWZd
{ t@cImmh\T
if(!fileSplitterFetch.bDownOver) ^K?Mq1"Db
{ h,x'-]q
breakWhile = false; 28,g'k!
break; @u1mC\G
} bnxR)b~
} D8=a+!l-
if(breakWhile) D {N,7kT
break; 4>Y\Y$3
3h4'DQ.g
.]LP327u
//count++; gPY Cw?zQ
//if(count>4) $@eFSA5k,7
// siteStop(); ;hkzL_' E)
} T?EFY}f
GcHZ&m4
WXX08"
System.err.println("文件下载结束！"); *6QmYq6c<
} c n^z=?
catch(Exception e){e.printStackTrace ();} u= ydX
} Wu U_RE
='vkd=`Si
P7y.:%DGD0
//获得文件长度 <lf6gb
public long getFileSize() \Z/#s;c,4
{ i1-wzI
int nFileLength = -1; $&to(
try{ }x+s5a;!3/
URL url = new URL(siteInfoBean.getSSiteURL()); x>MY_?a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y5\=5r/
httpConnection.setRequestProperty("User-Agent","NetFox"); &BkdC,o
gB}UzEj^<
$LJCup,1"
int responseCode=httpConnection.getResponseCode(); k%h%mz
if(responseCode>=400) T)#eaz$4W
{ $#7~
processErrorCode(responseCode); rhO8v
return -2; //-2 represent access is error {"@E_{\
} +^V%D!.$@
nI<Ab_EB
|emZZj
String sHeader; ]?n~?dD{]
j[&C6l+wH
yUlYf#`H
for(int i=1;;i++) p'YNj3&u
{ z]0UW\S/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F'3-*>]P
//Utility.log(in.readLine()); ca?;!~%zA
sHeader=httpConnection.getHeaderFieldKey(i); O K2|/y
if(sHeader!=null) BZs?tbf
{ \"AzT{l!;
if(sHeader.equals("Content-Length")) zR6^rq*
{ %#-'|~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6),VN>j
break; "&N1$$
} X.hVMX2B
} YMIX|bj6Y
else 2[TssJQ
break; :P:OQ[$
} mIkc+X
} vGI?X#w3
catch(IOException e){e.printStackTrace ();} D?@e,e
catch(Exception e){e.printStackTrace ();} @g==U{k;t
_do(
<s(<ax30
Utility.log(nFileLength); ,]8$QFf
Q(7M_2e7
)ZQML0}P;
return nFileLength; D$/*Z5Z)]
} D_-<V,3t
AZ& ]@Ao
5Q.z#]Lg
//保存下载信息（文件指针位置） ,`;Dre
private void write_nPos() O*y@4AR"S
{ dRPX`%J
try{ xH/Pw?^
output = new DataOutputStream(new FileOutputStream(tmpFile)); &s<'fSI
output.writeInt(nStartPos.length); /6d:l>4
for(int i=0;i<nStartPos.length;i++) = *~Q5F
{ z{ydP Ra
// output.writeLong(nPos); XbL\l
output.writeLong(fileSplitterFetch.nStartPos); /8tF7Mmr
output.writeLong(fileSplitterFetch.nEndPos); A3c&VT6Q
} ;,Q6AS!
output.close(); /;\{zA$uC=
} YMTB4|{
catch(IOException e){e.printStackTrace ();} { 0vHgi
catch(Exception e){e.printStackTrace ();} eE-c40Bae
} (v$$`zh
1pHt3Vc(G
>5+]~[S
//读取保存的下载信息（文件指针位置） s^Wh!:>r/
private void read_nPos() ~<&47'D
{ ye-R
try{ _Vf0MU;3f+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bRb+3au_x
int nCount = input.readInt(); ~f:jI1(}
nStartPos = new long[nCount]; |m /XGr
nEndPos = new long[nCount]; =x3ZQA
for(int i=0;i<nStartPos.length;i++) E#A}J:
{ #(Ah>y
nStartPos = input.readLong(); wk (}q
nEndPos = input.readLong(); a0=5G>G9c
} 5Sfz0
input.close(); KD)+&69
} N0 F|r8xS
catch(IOException e){e.printStackTrace ();} |jwN8@
catch(Exception e){e.printStackTrace ();} p.J+~s4G
} <4QOjW
T%p/(
)i{B:w\ ^
private void processErrorCode(int nErrorCode) =(U&?1R4
{ >7^i>si
System.err.println("Error Code : " + nErrorCode); [r"`rBw
} ~Q/G_^U:
tW#=St0<.o
j/Rm~!q
//停止文件下载 ZQQ0}
public void siteStop() f}U@e0Lsb
{ %HK\
bStop = true; {Y#$
for(int i=0;i<nStartPos.length;i++) MEZc/Ru-[
fileSplitterFetch.splitterStop(); @5y ~A}Vd
hJcN*2\:
x&PVsXdt5m
} ,@*Srrw
} uY'77,G_J
//负责部分文件的抓取 i9%cpPrg8
**FileSplitterFetch.java fR6.:7&
*/ %juR6zB%8
package NetFox; F4%vEn\!
5v@-.p
ywS2`(
import java.io.*; qq1@v0
import java.net.*; Z}*{4V`R
1__Mf.A
%x G3z7;
public class FileSplitterFetch extends Thread { :?.RZKXQF
js#72T/_n
L&s|<<L
String sURL; //File URL rS3*k3
long nStartPos; //File Snippet Start Position 6s$jt-bH
long nEndPos; //File Snippet End Position /y<nAGtD&
int nThreadID; //Thread's ID K@UQ O
boolean bDownOver = false; //Downing is over TUaW'
boolean bStop = false; //Stop identical "X7;^yY
FileAccessI fileAccessI = null; //File Access interface Q lg~S1D_v
39+6ZTqx
g.re`m|Aj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w2/3\3p
{ !33)6*s
this.sURL = sURL; a~nErB
this.nStartPos = nStart; ?U;KwS]%
this.nEndPos = nEnd; JM?X]l
nThreadID = id; K V-}:u(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >TqMb8e_
} JO `KNI
ZXR#t?D
&bO5+[
public void run() lIlmXjL0
{ ^KeJ=VT
while(nStartPos < nEndPos && !bStop) ].C4RH
{ jg7WMH"`
}&{z-/;H
I3wv6xZ2
try{ ub* j&L=
URL url = new URL(sURL); X\a*q]"_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c+^#(OB
httpConnection.setRequestProperty("User-Agent","NetFox"); D<35FD,
String sProperty = "bytes="+nStartPos+"-"; ue;o:>G
httpConnection.setRequestProperty("RANGE",sProperty); m.K@g1G
Utility.log(sProperty); ^XIVWf#`H
;=?f0z<
dmkd.aP4
InputStream input = httpConnection.getInputStream(); &S8Pnb)d
//logResponseHead(httpConnection); zAxscDf'
E =7m@"0
I|#1u7X%]
byte[] b = new byte[1024]; \~#$$Q-qtU
int nRead; *Ou)P9~-L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]tzO)c)w;
{ zL<<`u?
nStartPos += fileAccessI.write(b,0,nRead); [4_JK
//if(nThreadID == 1) ;F;"Uw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1Y-m=~J7
} TL?(0]Hfe
2unaK<1s
MzY~-74aF
Utility.log("Thread " + nThreadID + " is over!"); .-Xp]>f,
bDownOver = true; 'K9{xI@N
//nPos = fileAccessI.write (b,0,nRead); 69o,T`B
} ~baVS-v
catch(Exception e){e.printStackTrace ();} mimJ_=]DC
} 0xe!tA
} tL;!!vg#V
LXm5f;
DD4fV`:kG
//打印回应的头信息 [= GVK
public void logResponseHead(HttpURLConnection con) >Mzk;TM
{ }c"1;C&{
for(int i=1;;i++) jv C.T]<B
{ .=nx5yz
String header=con.getHeaderFieldKey(i); ![{>$Q?5
if(header!=null) ;B'5B]A3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NX?IM8\t
Utility.log(header+" : "+con.getHeaderField(header)); Y)-)owx7
else (|F}B
break; c)HHc0KD
} 9b/7~w.
} )tRqt9Th*
sU/R$Nbr
7HpfHqJ7
public void splitterStop() =ca<..yh[d
{ aa'u5<<W
bStop = true; $p)7k
} huu v`$~y
*7ggw[~
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} |9;6Cp
,EAf/2C
!&3iZQGWv
/* ~is$Onf99#
**FileAccess.java q:y_#r"_y
*//文件访问(定位，写) /lC&'hT
package NetFox; sUfYEVjr
import java.io.*; >|"mhNF
_m *8f\
lO)0p2
public class FileAccessI implements Serializable{ 7^fpbrj
lYS+EVcR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 me#?1r
RandomAccessFile oSavedFile; $ON4nx
long nPos; abHW[VP9
Vu%XoI)<KY
AF=9KWqf
public FileAccessI() throws IOException 3N'fHy
{ 2f%G`4/p
this("",0); 6%p$C oR
} ^&AhWm7\
wc3OOyP@0
HOn,c@.9Y
public FileAccessI(String sName,long nPos) throws IOException C/JeD-JG
{ ?HP54G<{xz
oSavedFile = new RandomAccessFile(sName,"rw"); ],fu#pi=]
this.nPos = nPos; QJcaOXyMS
oSavedFile.seek(nPos); zH1pW(
} 5kK:1hH7
O:=%{/6&D
n9;z=
public synchronized int write(byte[] b,int nStart,int nLen) p m4g),s
{ v{N4*P.0T
int n = -1; Y1?"Ut
try{ /-#1ys#F=
oSavedFile.write(b,nStart,nLen); ^lUV^%f
n = nLen; Qg7rkRia
} aw0;
catch(IOException e) "k8Yc<`u
{ b.`<T"y
e.printStackTrace (); ;{n@hM*O
} eb])=
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Y:~A-_
return n; GwOn&EpY!
} BEQ$p) h
8sDbvVh1F
23lLoyN
} x}g5
ECO4ut.d
W>ziA
/* {*=+g>RgD
**SiteInfoBean.java UBmD 3|Zo
*/ re\@v8w~
package NetFox; LqH<HGMFD
7j>NUx=j3
?e`4 sf_~
public class SiteInfoBean { -+'fn$
19Cs 3B\4
<Rs#y:
private String sSiteURL; //Site's URL }~?B>vZS
private String sFilePath; //Saved File's Path u,zA^%
private String sFileName; //Saved File's Name x>>#<hOz[
private int nSplitter; //Count of Splited Downloading File 'IorjR@40
FS3MR9
h>'9-j6B
public SiteInfoBean() |WopsV %
{//nSplitter的缺省值为5 pjC2jlwm*
//default value of nSplitter is 5 b7 pD#v
this("","","",5); !)jw o=l}J
} W+A-<Rh\
tQSj[Yl
Qy)+YhE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Xq3n7d.
{ LvWl*:z
sSiteURL= sURL; ,0'Yj?U>
sFilePath = sPath; >m}U|#;W
sFileName = sName; ]Qo.X~]
this.nSplitter = nSpiltter; nkKiYr
56;(mbW
)'<B\P/
} ^2gDhoO_
+`EF0sux
R W=<EF&
public String getSSiteURL() 6GxQ<
{ y$n7'W6
return sSiteURL; [m9Pt]j@
} ]L'FYOfrpx
)Ir_:lk
$/\b`ID
public void setSSiteURL(String value) T ;Ga G
{ NDw+bR-
sSiteURL = value; 59?@55
} -#=y
.k{omr&Dy5
|G2hm8 Y
public String getSFilePath() xwjim7#_:
{ 1E(~x;*)
return sFilePath; N30w^W&
} %+WIv+<
Fq{Z-yVp
)V!9/d
public void setSFilePath(String value) r52X}Y
{ '~dE0ohWb
sFilePath = value; K3eYeXV
} w#?@ulr]d
8q)wT0A~
TY|5O! <
public String getSFileName() <OKzb3e
{ x+kP,v
return sFileName; -ff|Xxar{
} -{Lc?=
F1V[8I.0
U'pm5Mc\q
public void setSFileName(String value) Zk#^H*jgx
{ z3l=aAw8
sFileName = value; &*G+-cF
} mhp&; Q9
jzuOs,:R
/PP\L](
public int getNSplitter() cJEOwAN
{ TBfX1v|Z)
return nSplitter; O"otzla
} ^y@RfM=A
e=11EmN9
];bl;BP
public void setNSplitter(int nCount) Z[.+Wd\)-9
{ oB9t&yM
nSplitter = nCount; d^"dL" Q6m
} #!IezvWf
} o<`)cb }
Sz\"*W;>
^wL n
/* )4d)G5{
**Utility.java t6.hg3Y
*/ m){.{Vn]
package NetFox; q!iMc
L lP
Qm|Q0u
public class Utility { '4PAH2&n
,&S^Ryc
U @Il:\I
public Utility() u-W6 hZ$
{ :Zy7h7P,lT
-+1it
^*7~ Wxk5
} Nw'3gJ:
j@0/\:1(U
//线程睡眠 ;T0Y=yC
public static void sleep(int nSecond) c#qOK
{ |aiP7C
try{ %IS'R`;3
Thread.sleep(nSecond); ALw5M'6q0\
} ={9G.%W
catch(Exception e) [\o+I:,}wi
{ 1vTncU!
e.printStackTrace (); P)fv:a
} b\zRwp
} >uN`q1?l'
\Vis
//日志 &"dT/5}6
public static void log(String sMsg) _VU/j9<+
{ ,}M@Am0~
System.err.println(sMsg); ETP}mo
} d*26;5~\
!GkwbHr+p
im&E\`L7
public static void log(int sMsg) 0NLoqq
{ B;'Dh<J1
System.err.println(sMsg); cH>rS\|Y
} Si<9Oh
} ^7`"wj14
0_HdjK
2e}${NZN
/* fP`g#t)4Tu
**TestMethod.java /^~3Ib8Fw+
*/ $tyF(RybG
package NetFox; ?iH`-SY
Ti/t\'6
r3o_mO?X
public class TestMethod { L&1VPli
(~/VP3.S
!UE' AB
public TestMethod() D_GIj$%N[
{ ///xx/weblogic60b2_win.exe yD iL
try{ q<>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @%L4^ms
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ![WX -"lW
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nw@tlT4
fileFetch.start(); DG8LoWZ
} >;',U<Wd
catch(Exception e){e.printStackTrace ();} k%\_UYa
**rA/*Oc
`"v5bk
} .BGM1ph}~
"|CzQ&e
qkC+9Sk
public static void main(String[] args) QRnkj]b
{ ~je#gVoUR
new TestMethod(); JGPLVw
} >=hOjV;
} UhCE.# U
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