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^Wa8Q;9lX
} [J?aD`{#O
for(int i=0;i<nEndPos.length-1;i++) hYG6 pTCb
{ kY-N>E:
nEndPos = nStartPos[i+1]; Z/Dx,zIR
} ;'#8tGv=
nEndPos[nEndPos.length-1] = nFileLength; woGAf)vV#
} 0"28'
} 9 a!$z!.
x"~8*V'0
qKr8)}h
//启动子线程 ~d|A!S`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m8d!< h
for(int i=0;i<nStartPos.length;i++) Bf~vA4
{ i#vYyVr[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gc-@"wI?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G}b]w~ML~
nStartPos,nEndPos,i); #Y a4ps_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ix)M`F%P3
fileSplitterFetch.start(); $QN"wL||
} wsI`fO^A8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K;?m';z0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w"-Lc4t+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /<|%yE&KhJ
nEndPos = " + nFileLength); U`,6 * MS
// fileSplitterFetch[nPos.length-1].start(); "Q@ronP(~
-g*4(w
1mOh{:1u
//等待子线程结束 Y)*#)f
//int count = 0; Z`ID+
//是否结束while循环 5B3G @KR
boolean breakWhile = false; \fz<.l]
A$Hfr8w1u
R{<kW9!
while(!bStop) Q ayPo]O
{ )rn*iJ.e8
write_nPos(); OEA&~4&{7
Utility.sleep(500); 'vbsvT
breakWhile = true; }ppN k:B
<Tzrj1"Q3
D9^h; 8
for(int i=0;i<nStartPos.length;i++) n|Q@UPb/=
{ *x@Onj
if(!fileSplitterFetch.bDownOver) .WA-&b_
{ CQF:Rnb
breakWhile = false; 5Ha9lM2gh
break; 5q3JI
} gmw|H?]
} Lo{ E:5q
if(breakWhile) G|!Tj X7s
break; |"ls\ 7
Yvw(tj5_5
ayR-\mZ
//count++; &^ 1$^=
//if(count>4) +" .X )avF
// siteStop(); snE8 K}4
} [=6]+V83M
y\4L{GlBM
)~)J?l3{
System.err.println("文件下载结束！"); f-vCm 5f
} Dp,L/1GQ8
catch(Exception e){e.printStackTrace ();} !/'t5~x[
} <J<{l
_S<3\%(0
*+Ek0M
//获得文件长度 ,w<S|#W~+
public long getFileSize() md)c0Bg8~
{ LG{,c.Qj*
int nFileLength = -1; %9KldcQ}~
try{ N7b8m?!
URL url = new URL(siteInfoBean.getSSiteURL()); Xv ]W(f1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3%#3iZ=_
httpConnection.setRequestProperty("User-Agent","NetFox"); nv*FT
5sj4;w[
7zXvnxYE
int responseCode=httpConnection.getResponseCode(); )WNzWUfn=z
if(responseCode>=400) }7|1
{ Yb|c\[ %
processErrorCode(responseCode); 2b}t,&bv?
return -2; //-2 represent access is error Hq'`8f8N
} hZ?Rof
W <9T0sZ
,1~"eGl!
String sHeader; (y=C_wvqZ
3oF45`3FV
BTqS'NuT
for(int i=1;;i++) >?2M }TV3
{ TaZmRL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !"?#6-,Xn
//Utility.log(in.readLine()); '.IW.{;$
sHeader=httpConnection.getHeaderFieldKey(i); #++lg{
if(sHeader!=null) &FMc?wq
{ QO<jI#
if(sHeader.equals("Content-Length")) `06;
{ jl4rbzse
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K -nF lPm\
break; ~ (|5/ p7t
} !E<[JM
} (5$!MUS~9
else Ec3}_`
break; |7'df&CA
} *v;2PP[^
} -u6bAQ
catch(IOException e){e.printStackTrace ();} \:%(q/v"X
catch(Exception e){e.printStackTrace ();} T,,WoPU8t
Sq>dt[7
DrKP%BnS
Utility.log(nFileLength); |HiE@
y`Wty@
>:74%D0UF
return nFileLength; [owWiN4`s
} Ci@o|Y }tP
MK%9:wZ
"@e3EX7h
//保存下载信息（文件指针位置） =_.l8IYX$%
private void write_nPos() dN$0OS`s[
{ e>} s;H,
try{ .[]r}[lU
output = new DataOutputStream(new FileOutputStream(tmpFile)); X&tF;<m^
output.writeInt(nStartPos.length); Ep9nsX*
for(int i=0;i<nStartPos.length;i++) ;km`P|<U
{ zJq~!#pZ
// output.writeLong(nPos); j8v8uZ;x
output.writeLong(fileSplitterFetch.nStartPos); >8~.wXyoC
output.writeLong(fileSplitterFetch.nEndPos); !a{^=#qq&I
} LC,F <>w1
output.close(); b o6d)Q
} k :(SCHf
catch(IOException e){e.printStackTrace ();} ISYXH9V
catch(Exception e){e.printStackTrace ();} (ZS}G8
} ]FJjgu<
=6j&4p `
x>**;#7)
//读取保存的下载信息（文件指针位置） F%@A6'c
private void read_nPos() qk%;on&`
{ ih58<Up5
try{ 66g9l9wm(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S5gyr&dm
int nCount = input.readInt(); Yz<3JRw
nStartPos = new long[nCount]; u0JB\)(-/h
nEndPos = new long[nCount]; UFXaEl}R
for(int i=0;i<nStartPos.length;i++) QmQ=q7
{ %6|nb:Oa
nStartPos = input.readLong(); 5MroNr
nEndPos = input.readLong(); H9'$C/w
} &W|[r(
input.close(); I,E?h?6Y
} &fDIQISC
catch(IOException e){e.printStackTrace ();} Tr_w]'
catch(Exception e){e.printStackTrace ();} m]'#t)B_m
} 7o7)0l9!
]&o$b]
;;!yC
private void processErrorCode(int nErrorCode) NxkGOAOE
{ ..IfP@
System.err.println("Error Code : " + nErrorCode); VpE*(i$
} X:A^<L ~
L^r#o-H<
GB23\Yv
//停止文件下载 >@U*~Nz
public void siteStop() ] ]u s %
{ 1auIR/=-
bStop = true; KI.q@zO6|
for(int i=0;i<nStartPos.length;i++) 6/f7<
fileSplitterFetch.splitterStop(); k9<;woOBO
35h8O,Y
'F/~o1\.
} 5VfyU8)7X
} {0L1X6eg
//负责部分文件的抓取 `xKp%9
**FileSplitterFetch.java T.])diuvj-
*/ 6Pz4\uE=
package NetFox; 'K$[^V
B al`y
|-fgj'
import java.io.*; Jf{*PgP
import java.net.*; 8+~ >E
wy<\Tg^J
b(,M1.[qt
public class FileSplitterFetch extends Thread { zN[hkmh
?j'7l=94A
;!>rnxB?4
String sURL; //File URL J!AgBF N4
long nStartPos; //File Snippet Start Position I&fozO
long nEndPos; //File Snippet End Position U&g@.,Y#
int nThreadID; //Thread's ID $POu\TO
boolean bDownOver = false; //Downing is over Q0)#8Rcm
boolean bStop = false; //Stop identical oTEL?hw5
FileAccessI fileAccessI = null; //File Access interface uFX#`^r`
yks__ylrl(
q}b dxa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "0V.V>-p
{ ?1*cO:O
this.sURL = sURL; 8Q.T g.
this.nStartPos = nStart; ;o 6lf_
this.nEndPos = nEnd; WO7z
nThreadID = id; )!3V/`I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E:,/!9n
} ]MqMQLG0t
OsTc5K.U~
kVuUjP6(c
public void run() fJ=0HNmX
{ sSr&:BOsi
while(nStartPos < nEndPos && !bStop) $|zX|
{ d8DV[{^
f- K+]aZ)
V)3KS-
try{ ^\hG"5#
URL url = new URL(sURL); \q>bs|2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DRSr%d
httpConnection.setRequestProperty("User-Agent","NetFox"); RaO-H
String sProperty = "bytes="+nStartPos+"-"; w0[6t#$F
httpConnection.setRequestProperty("RANGE",sProperty); ZFA`s qT
Utility.log(sProperty); *2ZjE!A
N&.H|5
`:ArT}F
InputStream input = httpConnection.getInputStream(); Yc`o5Q\>
//logResponseHead(httpConnection); Fh)IgzFj
48J@CvU
>>QY'1Eu
byte[] b = new byte[1024]; ^gN6/>]qrY
int nRead; @T@<_ ?)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v>6"j1Z
{ ~Sdb_EZ
nStartPos += fileAccessI.write(b,0,nRead); loEPr5bL
//if(nThreadID == 1) 5A,K6f@:g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,j#XOy`mzy
} V"[g.%%Y
; 8_{e3s
LHyB3V
Utility.log("Thread " + nThreadID + " is over!"); G?9"Y%
bDownOver = true; _Ym]Mj' ln
//nPos = fileAccessI.write (b,0,nRead); zZ:>do\2
} bpOYHc6,*`
catch(Exception e){e.printStackTrace ();} 'g">LQ~a+
} ):P?
} # ncRb
l.(v^3:X
*o]L|Vu
//打印回应的头信息 >;jZa
public void logResponseHead(HttpURLConnection con) 3(``#7
{ biLs+\C
for(int i=1;;i++) Z EQ@IS:Y
{ W1WYej"
String header=con.getHeaderFieldKey(i); 4%{,] q\p
if(header!=null) zp6C3RG(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); af6M,{F
Utility.log(header+" : "+con.getHeaderField(header)); |e=,oV"
else ay4 %
break; \Yy$MLs
} ['b}QW@Fx
} 4aug{}h("
[Hx0`Nc K
tCw<Ip
public void splitterStop() %3s1z<;R[S
{ *}Xf!"I#]N
bStop = true; :Oy%a'w
} f<-Jg
Eu0akqZ
pk>^?MO
} QER?i;-wb
)"qa kT
c& <Fr[AK
/* )tG\vk=@
**FileAccess.java NxfOF
*//文件访问(定位，写) *=) cQeJ
package NetFox; E!;SL|lj.
import java.io.*; } FE>|1
3W V"U
"RedK '7g
public class FileAccessI implements Serializable{ Fzm*Pz3
FOb0uj=(v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %]\kgRr
RandomAccessFile oSavedFile; \c,ap49RC
long nPos; N>Xo_-QCY
Cwr~HY
/{Is0+)
public FileAccessI() throws IOException C^s^D:
{ Nv$R\'3
this("",0); 85>05?
} .GbX]?dN
GXcJ< v
w!#tTyk`
public FileAccessI(String sName,long nPos) throws IOException (XVw"m/ye
{ M\vwI"
oSavedFile = new RandomAccessFile(sName,"rw"); Cmu@4j&
this.nPos = nPos; `K*Q5n
oSavedFile.seek(nPos); Qd)q([
} uOKCAqYa
zy?.u.4L
N%kt3vmQ_
public synchronized int write(byte[] b,int nStart,int nLen) zofa-7'Bn
{ toLV4BtIG
int n = -1; #||}R[~P"
try{ V4hiGO[
oSavedFile.write(b,nStart,nLen); Fiv3 {.
n = nLen; ,ZaRy$?
} {SOr#{1z*
catch(IOException e) X1,I
{ GC<l#3+
e.printStackTrace (); >~#yu&*D
} B`YTl~4
LU \i0|i|
#r$cyV!k
return n; ks&*O!h
} Ki4r<>\l{H
F7A=GF'
B#exHf8
} w2;eh]k
]5mnew
Jlri*q"hE
/* 6wPaJbRtaM
**SiteInfoBean.java EH$1fvE
*/ tW.9yII
package NetFox; 26e]`]!SU
i=ea ?eT`
i% w3/m
public class SiteInfoBean { 8k2?}/+
F7 5#*
?e`^P
private String sSiteURL; //Site's URL rTM}})81
private String sFilePath; //Saved File's Path hmvfw:Nq4
private String sFileName; //Saved File's Name kC WEtbz1
private int nSplitter; //Count of Splited Downloading File oNr-Q& C,
Jk&3%^P{m
neB\q[k
public SiteInfoBean() 6q*9[<8
{//nSplitter的缺省值为5 ;i8g41qjF
//default value of nSplitter is 5 . kQkC:~9
this("","","",5); M*y)6H k~
} ^({})T0wu
%u?>#
<S\jpB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8N!b>??
{ I*%-cA%l
sSiteURL= sURL; G(Lzf(
sFilePath = sPath; o#;b
sFileName = sName; t,QyfN
this.nSplitter = nSpiltter; DD7h^-x
$g@=Z"
xRJ\E }/7
} M.Y~1c4f
S\LkL]qx
dOa+(fMe
public String getSSiteURL() !\"EFVH
{ ~F7-HaQJ
return sSiteURL; _|iSF2f,X
} KmMzH`t}`
1=t>HQ
}]e-{C}
public void setSSiteURL(String value) ?Fi=P#
{ ]|!OP
sSiteURL = value; b+,';bW
} Mxe}B'
5G::wuxk
S-P/+K6
public String getSFilePath() e_#._Pi
{ 8hXl%{6d3
return sFilePath; {`J)j6;
} Hv!U|L
`lQ3C{}
$Oq^jUJ
public void setSFilePath(String value) 5)FJ:1-
{ i;]"n;>+/
sFilePath = value; {,3>"
} XnDUa3
K:!"+q
V\{clJ\U
public String getSFileName() ~s% Md
{ q_TRq:&.
return sFileName; MTsM]o
} ?: N@!jeJ
{K <iih
jB`,u|FG
public void setSFileName(String value) `rgn<I"
{ D'7SAFOM
sFileName = value; E7NV ^4h
} }0eF~>Df
y6LWx:
lH-/L(h2
public int getNSplitter() Jzj1w}?H
{ M1 :uJkO.
return nSplitter; b8~Bazk
} C3*gn}[
I2TaT(e\
d_CKP"TA
public void setNSplitter(int nCount) 5Eg1Q YVt
{ 1|RANy
nSplitter = nCount; =5Q]m6-SgV
} 2-7IJ\
} yGWxpzmRS
bW$J~ynM
6,)[+Bl
/* Q 7
**Utility.java (mgS"zPS
*/ Ge2q%
package NetFox; *-MM<|Qt
O/,aJCe
[p{#XwN
public class Utility { s8wmCzB~
61.Brp.eP
w,w{/T+B
public Utility() j:5=s%S
{ }3o|EXx=
W"zab
Id'X*U7Q
} 8JM&(Q%#
UmNa[s
//线程睡眠 )T';qm0w
public static void sleep(int nSecond) RMK"o?
{ eb.O#Y
try{ mFg<dTx0c8
Thread.sleep(nSecond); s8-<m,*
} m6TNBX
catch(Exception e) ZNf6;%oGG
{ {)"iiJ
e.printStackTrace (); '>&^zgr
} } ~h3c|
} M*z~gOZ
iTFdN}U
//日志 )0ea+ib
public static void log(String sMsg) (5#nrF]
{ NPCs('cd>?
System.err.println(sMsg); =+ytTQc*ot
} f47Od-\-
|K6REkzr
|<#{"'/=
public static void log(int sMsg) 2Or'c`|
{ n1~o1
System.err.println(sMsg); xgpi-l
} 9^,Lc1"M>
} x97 j
bLe<G
b?TO=~k,
/* ?3*l{[@J
**TestMethod.java z54EG:x.7^
*/ Z3{>yYR+
package NetFox; 7Bb9t
v5By:z
Av"R[)
public class TestMethod { q[HTnx
lL{5SH<Q
t *1u[~=
public TestMethod() 5|l* `J)
{ ///xx/weblogic60b2_win.exe e?opkq\f
try{ IIg^FZ*]_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q7R~{5r>W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2W/?q!t
SiteFileFetch fileFetch = new SiteFileFetch(bean); \]=7!RQ\
fileFetch.start(); kB/D!1 "
} ,=tD8@a<
catch(Exception e){e.printStackTrace ();} jqv-D
Tsgk/e9K2?
b /@#}Gc
} 0(mkeIzJt/
y$@ZN~8
"iU}]e0
public static void main(String[] args) >;L6xt3
{ Gs9:6
new TestMethod(); odPL{XFj
} %K\?E98M
} c/zJv*}x?
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