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)); 0TmZ*?3!4
} T!(sZf
for(int i=0;i<nEndPos.length-1;i++) *.o"ZVl
{ w]}f6VlEl
nEndPos = nStartPos[i+1]; ;7L;
} C;ptir1G;
nEndPos[nEndPos.length-1] = nFileLength; /eb-'m
} 7/ t:YBR
} cN5"i0xk
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bf(+ldq
//启动子线程 12-EDg/1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6P^hN%0
for(int i=0;i<nStartPos.length;i++) e+{BJN vz
{ 0X#+#[W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qW3x{L$c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bLco:-G1E1
nStartPos,nEndPos,i); L?Cjo4xS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NZP7r;u
fileSplitterFetch.start(); n>S2}y
} KJX>DL 9\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zQ_z7FJCB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7VY8CcL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2qjyFTT
nEndPos = " + nFileLength); %0zS
// fileSplitterFetch[nPos.length-1].start(); ` .$&T7
HD H
}2=hd..
//等待子线程结束 Cdmy.gx^
//int count = 0; _N@(Y:
//是否结束while循环 [[X+P 0`r
boolean breakWhile = false; =W<[Fe3
zIm-X,~I$
GL`tOD:P"
while(!bStop) \?dTH:v/E
{ [4: Yi{>
write_nPos(); *E7R(#,yC
Utility.sleep(500); _@K YF)
breakWhile = true; }#bZ8tm&
3daC;;XO
&oEyixe
for(int i=0;i<nStartPos.length;i++) |EEi&GOR(y
{ OJ>iq@>
if(!fileSplitterFetch.bDownOver) kV+ R5R
{ {Zl4C;c
breakWhile = false; }uiPvO+&p
break; UKj`_a6
} g>T
} B:nK)"{
if(breakWhile) /B[}I}X
break; ]'UgZsJ
t\%%d)d9
^)<w*iqBD
//count++; -N4z-ozhC
//if(count>4) {=iyK/Uf
// siteStop(); ?BsH{QRYQ
} 4 4`WYK l
?;RD u[eD
P5P<"
System.err.println("文件下载结束！"); yW`e |!
} }hq^+fC?
catch(Exception e){e.printStackTrace ();} lRH0)5`
} `x2,;h!:)N
/=/ HB
ZPvf-PqJl
//获得文件长度 nALnB1
public long getFileSize() ,5w]\z
{ ~j]dct7
int nFileLength = -1; y@aKNWy}$
try{ #Qsk}Gv
URL url = new URL(siteInfoBean.getSSiteURL()); ^Et,TF\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b!,ja?
httpConnection.setRequestProperty("User-Agent","NetFox"); x=vK EyS@
yKlU6t&` G
0e\y~#-
int responseCode=httpConnection.getResponseCode(); 8JP6M!F#
if(responseCode>=400) QoWR@u6a
{ RJwb@r<v
processErrorCode(responseCode); wE4;Rk1
return -2; //-2 represent access is error Bj8<@~bX:L
} r,"7%1I
03F3q4"
r@Nl2
String sHeader; _aY.
l1DI*0@
Q.1XP
for(int i=1;;i++) UO1$UF! QC
{ U3+A MVnB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -$9~xX
//Utility.log(in.readLine()); ]zcV]Qj$~
sHeader=httpConnection.getHeaderFieldKey(i); F+3!uWUK
if(sHeader!=null) qw2)v*Fn
{ VfRs[3Q
if(sHeader.equals("Content-Length")) 2m_H*1HJ
{ PLdf_/]-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0Nt%YP
break; =E1tgrW
} 8m|x#*5fQl
} Yw1Y-M
else 7PA=)a\
break; ?Nu#]u-
} KX=/B=3~
} s&0*'^'O[S
catch(IOException e){e.printStackTrace ();} /k) NP
catch(Exception e){e.printStackTrace ();} F@EZ;[
%UBPoq
,8~dz
Utility.log(nFileLength); A(NEWO
nSS}%&a:LX
a}w&dE$!-
return nFileLength; C[g&F0 6
} ]o `4Z"
7> )l{7
TG?fUD V
//保存下载信息（文件指针位置） g4Bg6<;
private void write_nPos() gkLr]zv
{ B]i+,u
try{ TD%WJ9K\
output = new DataOutputStream(new FileOutputStream(tmpFile)); \wTW?>oZ
output.writeInt(nStartPos.length); r&=r/k2
for(int i=0;i<nStartPos.length;i++) <9T [yg
{ *6'_5~G
// output.writeLong(nPos); u$\Tg3du2
output.writeLong(fileSplitterFetch.nStartPos); h%u?lW
output.writeLong(fileSplitterFetch.nEndPos); R4yJ.f
} HaS[.&\S0
output.close(); Of!|,2`(
} 80cm6?,xu
catch(IOException e){e.printStackTrace ();} f&f[La
catch(Exception e){e.printStackTrace ();} u"eZa!#
} 31H|?cg<
-)<JBs>
b\H/-7<
//读取保存的下载信息（文件指针位置） WI%zr2T
private void read_nPos() gr[D!D>
{ WtMcI>4w
try{ :LG}yq^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PVS\,
int nCount = input.readInt(); 5QNBB|X@
nStartPos = new long[nCount]; ^j1Gmv)
nEndPos = new long[nCount]; 6CCZda@
for(int i=0;i<nStartPos.length;i++) Idt@Hk5<&
{ x[zKtX
nStartPos = input.readLong(); zp}yiE!bl
nEndPos = input.readLong(); `;R|V
} l[:^TfB
input.close(); f45x%tha%
} zaQ$ Ht
catch(IOException e){e.printStackTrace ();} \t[ hg
catch(Exception e){e.printStackTrace ();} 5B_-nYJDt
} bwv/{3G,Ys
MAl{66
@DRfNJ}
private void processErrorCode(int nErrorCode) 8s\8`2=
{ ,%& LG],6
System.err.println("Error Code : " + nErrorCode); 9_I[o.q
} V7qCbd^>XJ
2&3eAJC
g9RzzE!
//停止文件下载 bf&.rJ0
public void siteStop() e-YGuWGN7
{ vy>];!Cu
bStop = true; wR`w@5,d
for(int i=0;i<nStartPos.length;i++) h'z+8X_t
fileSplitterFetch.splitterStop(); ]0at2
cN0~;!{i
~GsH8yA_P
} /S-/SF:>g
} 'M]CZ}
//负责部分文件的抓取 lyMJW}T+>
**FileSplitterFetch.java eUGmns
*/ QH~8 aE_i
package NetFox; *+4>iL*:
^H@!)+ =
;@h'Mb
import java.io.*; "RR./e)h
import java.net.*; I\F=s-VVY
8 RzF].)
UvW:#
public class FileSplitterFetch extends Thread { ePIly)=X
Z`0r]V`Ys
Huug_E+
String sURL; //File URL ,& \&::R
long nStartPos; //File Snippet Start Position wd2P/y42;;
long nEndPos; //File Snippet End Position 4q@9
int nThreadID; //Thread's ID ys~p(
boolean bDownOver = false; //Downing is over sk%:Sp
boolean bStop = false; //Stop identical XQ+-+CD
FileAccessI fileAccessI = null; //File Access interface ps{&WT3a
Y`[HjS,
^|a&%wxA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5Fl
{ 2yQ;lQ`
this.sURL = sURL; f(9$"Vi
this.nStartPos = nStart; T{v<
this.nEndPos = nEnd; ;{F;e)${M
nThreadID = id; o+6^|RP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?L~=Z\H
} K_w0+oY a
@zVBn~=i
=c5 /cpZ^
public void run() s/p>30Fg
{ u0 'pR# m|
while(nStartPos < nEndPos && !bStop) n<"a+TTU
{ J?HZ,7X:
S|u1QGB
Ow&'sR'CX
try{ {H7$uiq3:B
URL url = new URL(sURL); &&QDEDszp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %]= 'Uv^x
httpConnection.setRequestProperty("User-Agent","NetFox"); S92!jp/
String sProperty = "bytes="+nStartPos+"-"; w1!\L_::Y
httpConnection.setRequestProperty("RANGE",sProperty); N%M>,wT
Utility.log(sProperty); lG^mW\O
(^@;`8Dy8
*7D$;?"
InputStream input = httpConnection.getInputStream(); Bbe/w#Z
//logResponseHead(httpConnection); ;r@R (Squ
/EAQ.vxI
y[7xK}`_
byte[] b = new byte[1024]; ?RjKP3P
int nRead; iJp!ROI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MdTd$ 4J3
{ @SMy0:c:
nStartPos += fileAccessI.write(b,0,nRead); P A+e= %
//if(nThreadID == 1) Pt)}HF|u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4>ce,*B1
} 3E2.v5*
7!QXh;u
h/y}
Utility.log("Thread " + nThreadID + " is over!"); MH~qfH>K
bDownOver = true; .^+$w$
//nPos = fileAccessI.write (b,0,nRead); 5<GRi"7A@
} >~bj7M6t
catch(Exception e){e.printStackTrace ();} z(#hL-{c
} ';L^mxh
} j!8+|eAkk
RlPByG5K
"l;8 O2;g
//打印回应的头信息 YV!V9
public void logResponseHead(HttpURLConnection con) Q1&dB{L
{ V$F.`O!hfi
for(int i=1;;i++) \rnG 1o
{ '!L1z45
String header=con.getHeaderFieldKey(i); #3[b|cL
if(header!=null) umn~hb5O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %+W >+xRb
Utility.log(header+" : "+con.getHeaderField(header)); wdDHRW0Y
else -$|X\#R
break; =Bqa<Js
} "^e?E:( 3
} ]mT} \b
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J#Ehx|
public void splitterStop() 1E_Ui1[
{ c89vx 9
bStop = true; xi^e =:;`
} ?Pw\&q
cZT.vA#
zi[M{bm
} 2/q=l?
R2ZQBwB
^aWNtY' :
/* '*Mb .s"
**FileAccess.java AFUl
*//文件访问(定位，写) MFsy`aiS
package NetFox; x`l; ;
import java.io.*; ^TuEp$Z=
(uc)^lfX
Ou,_l
public class FileAccessI implements Serializable{ C}EDl2
r@UY$z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C2i..iD
RandomAccessFile oSavedFile; l<%~w U
long nPos; '+tT$k
%"fKZ
3(p6ak2lv
public FileAccessI() throws IOException %-|q3 ^s
{ !jnIXvT1qy
this("",0); x^skoz
} _\;#a
+Z]%@"S?
^ w1R"qE"m
public FileAccessI(String sName,long nPos) throws IOException 74Wg@!P
{ V3UGx'@^y
oSavedFile = new RandomAccessFile(sName,"rw"); l);8y5
this.nPos = nPos; W/Q%%)J
oSavedFile.seek(nPos); T bWZw
} +N_%|!F-c
dq(L1y870
^`?> Huu<w
public synchronized int write(byte[] b,int nStart,int nLen) >f8,YisH
{ 1`\kXaG
int n = -1; k@U`?7X
try{ S`KCVQ>V
oSavedFile.write(b,nStart,nLen); k<qH<<r*
n = nLen; $c47cJO)W
} :h~!#;w_
catch(IOException e) "r+<=JU>OV
{ u;}B4Rx
e.printStackTrace (); J< M;vB)
} V1;-5L75
(B#|3o
oFp&j@`k8j
return n; $@wkQ%
} iKY&gnu"
&r%3)Z8Et
c*Nbz,:
} w[-Bsf
!6C d.fpWL
k>`X! "
/* DUr1s]+P
**SiteInfoBean.java FU3B;Fn^Z(
*/ ?2;G_P+
package NetFox; $n"Llw&)
cpVi9]
hg @Jpg
public class SiteInfoBean { (6{ VMQ
wBET.l'd
i\G3 u#
private String sSiteURL; //Site's URL Ui&$/%Z|
private String sFilePath; //Saved File's Path qQ_QF
private String sFileName; //Saved File's Name 6wgOmyJx
private int nSplitter; //Count of Splited Downloading File %*nZ,r
2Mda'T8
kZNZ?A<D
public SiteInfoBean() n21J7;\/+
{//nSplitter的缺省值为5 x7?{*w&r
//default value of nSplitter is 5 x3 S
this("","","",5); 7@?b_
} -E7\.K3
JSU\Hh!
Tx(R3B+u7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "K<VZ
{ F`u~Jx8.*
sSiteURL= sURL; O}Jb,?p
sFilePath = sPath; ;l'I.j
sFileName = sName; >. Y~F(
this.nSplitter = nSpiltter; G.}yNjL8
c z|IBsa*
U VT8TN-T
} &%lhov
xph60T
fVM%.`
public String getSSiteURL() _$0Ix6y,
{ Tx5L
return sSiteURL; 1;W>ceN"
} B.?yHaMI[
c.fj[U|j
NmQ]qv
public void setSSiteURL(String value) AZa3!e/1
{ /2:r}O
sSiteURL = value; P(`IY+
} u2t<auE9^
UTPl7po5D
X'c5s~9
public String getSFilePath() &a`-NRU#
{ VV
return sFilePath; [Z0e$
} 4v>V7T.
MPt7 /
? _W*7<
public void setSFilePath(String value) ;VuIQ*@m"
{ JG[+e*8
sFilePath = value; Y%faf.$/9
} k=@Q#=;*[W
f_7p.H6\
G<-.{Gx)
public String getSFileName() Bg`b*(Q
{ 3 *G=U
return sFileName; EP[ gq
} rnr7t \a~]
v%1#y5
,'!&Z *
public void setSFileName(String value) U2aE:$oeYi
{ G>,rf ]N
sFileName = value; C?O{l%0
} "\9@gfsp)
&^<94l
-b{*8(d<I
public int getNSplitter() gor6c3i
{ x!< C0N>?z
return nSplitter; lY1m%
} ESO(~X+
Pwq} ;+
w Bl=]BW!%
public void setNSplitter(int nCount) rN}^^9
{ T>c;q%A/
nSplitter = nCount; g9gyWz
} <W?,n%
} L^=>)\R2$[
>$?Z&7Lv
+z4NxR
/* "-hgeQX
**Utility.java VHJr+BQ1K/
*/ mz#(\p=T
package NetFox; sK\?i3<?
xpV8_Gz;
H(pOR<`
public class Utility { %B~`bUHjq
lu>>~vy6
Rn}+l[]jC
public Utility() g~cWBr%>
{ $/D@=Pkc
mb&b=&
I*#~@:4*
} aqMZ%~7
3Mdg&~85
//线程睡眠 Yux7kD\c
public static void sleep(int nSecond) N+r~\[N\9
{ HloP NE&}
try{ )N}xKw|
Thread.sleep(nSecond); P017y&X
} Me8d o; G|
catch(Exception e) r}vrE ^Q
{ ue`F|
e.printStackTrace (); !0w'S>e
} [0 W^|=#K
} 9/nL3U@i1
KR{kn[2|Q
//日志 :!3P4?a
public static void log(String sMsg) Pg`^EJ+
{ UWu|w
System.err.println(sMsg); ^@6eN]
} +oyc9PoXF
5Wn6a$^
p>MX}^6
public static void log(int sMsg) M]6=Rxq1:E
{ 87*R#((
System.err.println(sMsg); au GN~"n^
} @ #V31im"N
} yX8F^iv[
6/GhQ/T%D
Sm-nb*ZyC
/* jL2f74?1
**TestMethod.java eqLETo@} *
*/ M14pg0Q
package NetFox; zis-}K<
Vv zd>yII
s cn!,
public class TestMethod { 3Hq0\Y"Y
{8t;nsdm!
~)()PO
public TestMethod() ^P]: etld9
{ ///xx/weblogic60b2_win.exe h>\}-|Ek
try{ zmuq4-.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J,E&Uz95%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PUa~Apj'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0}aJCJ9sx=
fileFetch.start(); %,>,J`
} ?lbX.+
catch(Exception e){e.printStackTrace ();} u_mm*o~)g
~r!jVK>^
dkCSqNFL)
} >0512_J+
tl#hCy
"b2Mk-qP
public static void main(String[] args) gs9f2t
{ !N!M NsyDz
new TestMethod(); <nIU]}q
} H4%wq
} );=JoRQ{
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