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)); 6jyS]($q
} Kx==vq%39
for(int i=0;i<nEndPos.length-1;i++) 2#%@j6
{ >1q W*
nEndPos = nStartPos[i+1]; wK>a&`<
} us%dw&
nEndPos[nEndPos.length-1] = nFileLength; 4HG;v|Cp
} XRARgWj
} -9W)|toWb"
O~D>F*_^j
YGFE(t;lPU
//启动子线程 2NMS'"8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xvn@zi
for(int i=0;i<nStartPos.length;i++) j]Y`L?!Q
{ !:"$1kh1("
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WD.td
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hilgl<UF
nStartPos,nEndPos,i); c~ x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jRdmQmTJ
fileSplitterFetch.start(); h]WPWa)M
} `#J0@ -
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y=0D[o8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #2 Gy=GvV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7-S?\:J
nEndPos = " + nFileLength); %+gK5aVab
// fileSplitterFetch[nPos.length-1].start(); %QYW0lE
2E7vuFH4c
gkkT<hEV=
//等待子线程结束 -|_#6-9
//int count = 0; g}\G@7Q
//是否结束while循环 xb8S)zO]Q
boolean breakWhile = false; 5AFy6Ab
F%|F-6
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while(!bStop) my|]:(_0d
{ DD$YMM
write_nPos(); F{,<6/ayRz
Utility.sleep(500); E^'f'\m
breakWhile = true; hJ|zX
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aUZh_<@
for(int i=0;i<nStartPos.length;i++) SrVo0$5)
{ =*2_B~`
if(!fileSplitterFetch.bDownOver) *z852@
{ g_8A1lt
breakWhile = false; e97Ll=>
break; ZhvZe/
} bEvlk\iql
} ) oypl+y
if(breakWhile) %)o'9
break; IZ2(F,{o
2&b?NqEeZ
%mF:nU4
//count++; *.F^`]yz
//if(count>4) 1 >}x9D
// siteStop(); b9Fd}WZz
} X>-|px$vy
k4i*80
o*5iHa(Qm
System.err.println("文件下载结束！"); yq7gBkS
} ~(v7:?
catch(Exception e){e.printStackTrace ();} )/87<Y;o
} B:X,vE
=5l20 Um
_EEOBaZ
//获得文件长度 3aX/)v.:4
public long getFileSize() 2wX4e0cOI4
{ Xg4iH5!E
int nFileLength = -1; oeKVcVP|'&
try{ xa"8"8
URL url = new URL(siteInfoBean.getSSiteURL()); ~6nY5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); azBYh*s=5{
httpConnection.setRequestProperty("User-Agent","NetFox"); .dwy+BzS
e #!YdXSx
GBg~NkC7.
int responseCode=httpConnection.getResponseCode(); f$y`tT %o
if(responseCode>=400) 70Z#Ej
{ /BN_K8nb`
processErrorCode(responseCode); fex<9'e
return -2; //-2 represent access is error > a?K![R
} y]U]b G{
@'AjEl:&-_
_-+xzdGvX
String sHeader; j:>_1P/
9'" F7>d
4it^-M
for(int i=1;;i++) Ea,L04K
{ x9!3i{_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {r>iUgg
//Utility.log(in.readLine()); j0wpaIp
sHeader=httpConnection.getHeaderFieldKey(i); |d)*,O4s
if(sHeader!=null) :HiAjaA1pg
{ 9\ulS2d
if(sHeader.equals("Content-Length")) d!P3<:+R[
{ 5Q$.q&,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iZ( U]
break; a +$'ULK+r
} |O';$a1S
} "ZYdJHM
else sF4+(9=
break; *Ei(BrL/;
} ^Ay>%`hf*
} m%s&$
catch(IOException e){e.printStackTrace ();} c>b!{e@*
catch(Exception e){e.printStackTrace ();} ZZ*+Tl\ s
eJ ;a}{ 4%
b0|;v-v
Utility.log(nFileLength); f`W)Z$fN5
)Vf!U"
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return nFileLength; Abc%VRsT
} -_?U/k(Hi
x>!bvZ2
+Y! P VMF
//保存下载信息（文件指针位置） V] 0T P#
private void write_nPos() UTS.o#d
{ _c$F?9:
try{ 'c/S$_r
output = new DataOutputStream(new FileOutputStream(tmpFile)); k}&7!G@T
output.writeInt(nStartPos.length); 4 \Ig<C9
for(int i=0;i<nStartPos.length;i++) q]2t3aY%
{ S HxD(6
// output.writeLong(nPos); X/BcS[a
output.writeLong(fileSplitterFetch.nStartPos); wrhGZ=k{
output.writeLong(fileSplitterFetch.nEndPos); ^B?brH}
} eQU~A9
output.close(); SNOML7pd
} DJJd_
catch(IOException e){e.printStackTrace ();} MXa(Oi2Gg
catch(Exception e){e.printStackTrace ();} j;yKL-ycB
} p>=i'~lQ6
v$)ZoM6E
G%F}H/|R
//读取保存的下载信息（文件指针位置） uc>]-4
private void read_nPos() =@ d/SZ|(E
{ or qL0i
try{ OpD%lRl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p#aB0H3
int nCount = input.readInt(); <8iu:nR
nStartPos = new long[nCount]; fNk0&M
nEndPos = new long[nCount]; ;k:17&:8ue
for(int i=0;i<nStartPos.length;i++) y2M]z:Y U
{ &WKAg:^k)
nStartPos = input.readLong(); 1:;S6{oQ
nEndPos = input.readLong(); S;K5JBX0#
} /<VR-yr
input.close(); SH6+'7
} 5V*R Dh
catch(IOException e){e.printStackTrace ();} hX)PdRk#
catch(Exception e){e.printStackTrace ();} ^xX1G_{
} N;` jz(r
)#l&BV5
-P:o ^_)g
private void processErrorCode(int nErrorCode) eA_]%7+`
{ J{U 171
System.err.println("Error Code : " + nErrorCode); ]%2y`Jrl^W
} Y(&rlL(sPK
Y !%2vOt
:|%1i>O
//停止文件下载 8J)Kn4jq
public void siteStop() ZJ8"5RW
{ }eAV8LU
bStop = true; ><xJQeW
for(int i=0;i<nStartPos.length;i++) ?mHu eX
fileSplitterFetch.splitterStop(); tGJJ|mle>
|OiM(E(
/ ?'FSWDU
} BG8`B'i
} &3$FkU^F6
//负责部分文件的抓取 |Ae7wXOs
**FileSplitterFetch.java * hmoi
*/ *]:J@KGf
package NetFox; s`en8%
]E$bK
watTV\b
import java.io.*; Vg~10Q
import java.net.*; FQ>y2n=<d
9]vy#a#
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public class FileSplitterFetch extends Thread { `ES+$O>
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(#BOcx5J]
String sURL; //File URL M%Zh{
long nStartPos; //File Snippet Start Position w>e+UW25Y
long nEndPos; //File Snippet End Position NG8F'=<
int nThreadID; //Thread's ID <+UJgB A-
boolean bDownOver = false; //Downing is over mwutv8?
boolean bStop = false; //Stop identical =I0J1Ob
FileAccessI fileAccessI = null; //File Access interface f#McTC3C
wb>"'%
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i9Eh1A3Y
{ AC*SmQ\>!
this.sURL = sURL; PqMu2 e
this.nStartPos = nStart; wf_ $#.;m
this.nEndPos = nEnd; ;`h$xB(
nThreadID = id; .%+anVXS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dy*K;e-+
} E|A~T7G=
8 ,W*)Q
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public void run() 3^iVDbAW{
{ &b'{3o_KN
while(nStartPos < nEndPos && !bStop) @RZbo@{~
{ %~:@}C%A
9iV9q]($0
gZBb/<
try{ 2sj: &][R
URL url = new URL(sURL); ;xL8W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nErr&{C
httpConnection.setRequestProperty("User-Agent","NetFox"); 5me#/NqLHY
String sProperty = "bytes="+nStartPos+"-"; >sZ_I?YDs
httpConnection.setRequestProperty("RANGE",sProperty); 8)>4ZNXz
Utility.log(sProperty); BOD!0CR5
y;%\w-.\
M/,lP
InputStream input = httpConnection.getInputStream(); NHcA6y$Cz
//logResponseHead(httpConnection); J+TtM>
{e1sq^>|
X]D:vuB
byte[] b = new byte[1024]; a'g&1N0Rc
int nRead; 'w=aLu5dY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :`>tCYy;
{ CzIs_/
nStartPos += fileAccessI.write(b,0,nRead); 2%|n}V[
//if(nThreadID == 1) 4+89 M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [_`@V4
} k;K-6<^h
0+k..l
+R7pdi
Utility.log("Thread " + nThreadID + " is over!"); BSL+Gjj~}
bDownOver = true; Fkg%_v$
//nPos = fileAccessI.write (b,0,nRead); ^Rtxef
} IBUFXzl
catch(Exception e){e.printStackTrace ();} h;@>E:4Tg
} #ro$$I;
} 4];>O
5LZs_%#
P@Fx6
//打印回应的头信息 QX42^]({;c
public void logResponseHead(HttpURLConnection con) 2.^CIJc
{ CfVL'
for(int i=1;;i++) r?w>x`
{ jxZf,]>T
String header=con.getHeaderFieldKey(i); Dk&(QajL
if(header!=null) ~pHuh#>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h/2@4XKj
Utility.log(header+" : "+con.getHeaderField(header)); eFotV.T!#
else F&lH5
break; @NL37C
} 1!yd(p=cL
} xLms|jS
ArScJ\/Nwv
RN}joKV
public void splitterStop() D2J)qCK1)
{ C^c<s
bStop = true; bc NyB$S
} \qTp#sF
^y%8_r&
JDW/Mc1bh
} -0TI7 @
HXX9D&c4R
?B@3A)a
/* Gm &jlN
**FileAccess.java O.Y|},F
*//文件访问(定位，写) r;{ggwY&J
package NetFox; $Ld-lQsL
import java.io.*; 2 6 >9$S
&gr T@
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public class FileAccessI implements Serializable{ Y]^*mc0fE
eA{A3.f"Hz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _z1Qr?cY
RandomAccessFile oSavedFile; -8vGvI>
long nPos; 'T(Q
|onLJY7)
s Ytn'&$\
public FileAccessI() throws IOException VbTX;?
{ |`pBI0Sjo
this("",0); <WnIJum
} #DARZhU)
um%s9
'+ mI
public FileAccessI(String sName,long nPos) throws IOException 66sgs16k
{ feH&Ug4?G
oSavedFile = new RandomAccessFile(sName,"rw"); g-,lY|a
this.nPos = nPos; -[&Z{1A4x4
oSavedFile.seek(nPos); gI9nxy
} Y^C(<N$
2 E?]!9T~|
Y]Z&
public synchronized int write(byte[] b,int nStart,int nLen) deq5u>
{ 6)W8HX~+
int n = -1; JG&E"j#q
try{ 0LYf0^P
oSavedFile.write(b,nStart,nLen); +t&+f7
n = nLen; Z[l+{
} c}|} o^
catch(IOException e) .3jijc j
{ >o%X;U 3
e.printStackTrace (); &y7=tEV
} p!)PbSw#
2pvby`P4
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return n; i3KAJ@
} U#- 5",X|
1<m.Q*
TaaCl#g$?
} 3sIdwY)ZS_
'4D7:
8N$Xq\Da+>
/* *_mER`
**SiteInfoBean.java Q[%G`;e#
*/ eu8a<
package NetFox; st~l||
^UhqV"[7k
$FDGHFM
public class SiteInfoBean { P #8+1iC1
R4'>5.M
k {vd1,HZ
private String sSiteURL; //Site's URL 4E}Q<?UYSt
private String sFilePath; //Saved File's Path b|G~0[g
private String sFileName; //Saved File's Name :7X{s4AU6
private int nSplitter; //Count of Splited Downloading File Vq/hk
,\1Rf.
N)a5~<fBG
public SiteInfoBean() {?++T 0
{//nSplitter的缺省值为5 QFN9j
//default value of nSplitter is 5 M?;YpaSe+
this("","","",5); _VM}]A
} ;49sou
m6H+4@Z-;(
#Ye0*`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p&0 G
{ .wTb/x
sSiteURL= sURL; ;Xqi;EA
sFilePath = sPath; PR AP~P&^
sFileName = sName; [3ggJcUgW>
this.nSplitter = nSpiltter; K6)IBV;
I>w|80%%
'vZy-qHrV
} 9eE FX7
;PqC*iz
?5;wPDsK
public String getSSiteURL() jsF5q~F
{ ME$J?3r
return sSiteURL; .QA1'_9
} Im};wJ&
(lq%4h
j~=<O<P
public void setSSiteURL(String value) sFvYCRw /
{ ()$m9%x
sSiteURL = value; [9}<N2,9z
} ,J<+Wxz
w@YPG{"j
3h%Nd&_9
public String getSFilePath() /QCg E~
{ aI}htb{m`
return sFilePath; FPZ@6
} O-pH~E
|5q,%9_
D vN0h(?
public void setSFilePath(String value) paYS<8In
{ P1]F0fR
sFilePath = value; $]W*;MTI}
} &uV|Ie8@q
q1 BpE8
Qw_> l}k/
public String getSFileName() ;NAKU
{ o/vD]Fs
return sFileName; P]2 /}\f
} Q84XmXm|
t-iQaobF
_`laP5~
public void setSFileName(String value) hv#LKyp%
{ ^)$T`
sFileName = value; vfVF^ WOd
} )7AjRtb!/
_W,?_"[R=
rJtk4hOF
public int getNSplitter() nJ1<8 p
{ F4~O-g.<
return nSplitter; sebuuL.l0<
} jxq89x
P8w56
}XRfHQk
public void setNSplitter(int nCount) 8u"C7} N_
{ x #|t#N%
nSplitter = nCount; JuRWR0@`
} An,TunX
} .Rb1%1bdc
N>g6KgX{K
=BV_?
/* s%m?Yh3
**Utility.java bHTTxZ-%
*/ X*bOE}
package NetFox; i\4dd)p-
:Fh_Ya0
@)z?i
public class Utility { e;"%h%'
)IIWXN2A
gy#G;9p
public Utility() _?bF;R
{ EU Oa8Z
YW8Odm
8)b*q\O'
} `V*$pHo
JiXN"s^mcb
//线程睡眠 =~dXP
public static void sleep(int nSecond) K8QEHc:
{ M{Vi4ehOq
try{ + eZn
Thread.sleep(nSecond); N]|)O]/[
} $UdFm8&
catch(Exception e) 7L]Y.7>
{ :/fT8KCwo
e.printStackTrace (); Ro2!$[P
} =trLL+vGw'
} fCv.$5
-9s&OKo`({
//日志 H]M[2C7#N
public static void log(String sMsg) nQfSQMg
{ ytfr'sr/
System.err.println(sMsg); 9~l8QaK
} )S@TYzdAN
SK,UW6h
,twm)%caU
public static void log(int sMsg) G49`a*Jn
{ !4$o*{9Lx:
System.err.println(sMsg); "T>;wyGW
} }\W^$e-
} 0F&(}`V
VlxHZ
edlsS}8^
/* UGA``;f
**TestMethod.java v.Q+4 k
*/ 3nUC,T%
package NetFox; 'W~6-c9y
<2^ F'bQV
x!?$y_t
public class TestMethod { zogl2e+
E/>kvs%
5d)\Z0s
public TestMethod() 4L&Rs;
{ ///xx/weblogic60b2_win.exe l?x'R("{
try{ L@G~9{U>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M,DwBEF?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4zqO!nk
SiteFileFetch fileFetch = new SiteFileFetch(bean); u#$sO;8s
fileFetch.start(); ]"\sd"
} Cs^'g'
catch(Exception e){e.printStackTrace ();} w?R#ly
aR%E"P-6l
@ |(Tg
} "^VPe[lA
(<Kf
q]P$NeEiZ"
public static void main(String[] args) uCf _O~
{ E*}1_,q)
new TestMethod(); C4eQ.ep
} /nNrvMtv
} 0?'v|5}
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