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)); }bIbMEMn
} s"*ZQ0OaD
for(int i=0;i<nEndPos.length-1;i++) xD+n2:I{
{ 5<h7+ %?t9
nEndPos = nStartPos[i+1]; HLm6BtE
} 7qj<|US
nEndPos[nEndPos.length-1] = nFileLength; $?RxmWsP
} I?c "\Fe
} OhMnG@@
0Snl_@s
TpXbJ]o9
//启动子线程 +|(-7"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q${0(#Nu
for(int i=0;i<nStartPos.length;i++) {`~uBz+dJq
{ xQ4 5B`$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9>,$q"M}?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B^Y AKbY
nStartPos,nEndPos,i); ^1y (N>W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a{*r^m'N
fileSplitterFetch.start(); b.HfxYt(
} }4G/x;D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /6)6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NKyaR_q`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o"h*@.
nEndPos = " + nFileLength); nGb%mlb
// fileSplitterFetch[nPos.length-1].start(); cb|cYCo5
M.B0)
]6JI((
//等待子线程结束 'Pk14`/
//int count = 0; `-Yo$b;:
//是否结束while循环 ,au-g)IFZ
boolean breakWhile = false; P]V/<8o.53
^|Bpo(
~J #^L*
while(!bStop) 66RqjP '2
{ ;&="aD
write_nPos(); B#Sg:L9Tr'
Utility.sleep(500); WGy3SV )
breakWhile = true; xnz(hz6
g+CTF67
kC :pal
for(int i=0;i<nStartPos.length;i++) p\xi5z
{ .4I"[$?Q
if(!fileSplitterFetch.bDownOver) i qLNX)
{ f~bZTf
breakWhile = false; >b^|SL
break; ?r< F/$/
} .Y@)3
} fMg3
if(breakWhile) /m>%=_nz
break; R 2.y=P8N
y]9PLch]vZ
<qGVOAnz+
//count++; >LqW;/&S<
//if(count>4) i,k.#Vx[m
// siteStop(); Ojea~Y]Sr
} Vs/Z8t
l;u_4`1H
/Q|guJx
System.err.println("文件下载结束！"); FPg5!O%
} CqF=5z:A
catch(Exception e){e.printStackTrace ();} u+U '|6)E
} Kr;7~`$[
R9dC$Y]\M
Q#wl1P
//获得文件长度 ^;KL`
public long getFileSize() K9-?7X
{ 6Vq]AQx
int nFileLength = -1; T*m;G(
try{ 47(/K2
URL url = new URL(siteInfoBean.getSSiteURL()); M@R_t(&=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;'\#+GZ9p
httpConnection.setRequestProperty("User-Agent","NetFox"); x{Gdr51%
^+v6?%m
jsXj9:X I
int responseCode=httpConnection.getResponseCode(); QvPG 6A]T
if(responseCode>=400) hqPpRSv'
{ KINKq`Sx
processErrorCode(responseCode); s:4<wmu4=
return -2; //-2 represent access is error i/Nd
} ^5"2s:vP
/MHml0u
=f4v: j}'|
String sHeader; Oyfc!
xe4F4FC'
>x$eKN
for(int i=1;;i++) |C MKY
{ EPY64{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n'dxa<F2|
//Utility.log(in.readLine()); EQ;,b4k?&g
sHeader=httpConnection.getHeaderFieldKey(i); \P3[_kbf1
if(sHeader!=null) "F,d}3}
{ `L-GI{EJ
if(sHeader.equals("Content-Length")) 4bT21J37
{ #U46Au
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T'n~QfU
break; `ViFY
} yNwYP%"y
} 0K0[mC}ZwM
else 4h|48</
break; $m.e}`7SF!
} '+!@c&d#%o
} "R"7'sJMI
catch(IOException e){e.printStackTrace ();} 8z?q4
catch(Exception e){e.printStackTrace ();} m{U+aqAQK
~AD%aHR
]5!}S-uJq
Utility.log(nFileLength); AWp{n
sj)$o94=
ERql^Yr
return nFileLength; R\L0
} *AO^oBeY
CC(At.dd
;8Z\bHQ>
//保存下载信息（文件指针位置） a<Ru)Q?=
private void write_nPos() H#/}FoBiS
{ !y8/El
try{ a0vg%Z@!
output = new DataOutputStream(new FileOutputStream(tmpFile)); p8%/T>hK
output.writeInt(nStartPos.length); O23dtH
for(int i=0;i<nStartPos.length;i++) 0>uMR{ #
{ ?a8 o.&`l
// output.writeLong(nPos); RHV&m()Q
output.writeLong(fileSplitterFetch.nStartPos); A4}6hG#
output.writeLong(fileSplitterFetch.nEndPos); MroJ!.9
} T.1*32cX
output.close(); QEl:>HG
} x Z3b)j2D
catch(IOException e){e.printStackTrace ();} Et\z^y
catch(Exception e){e.printStackTrace ();} I8|7~jRB
} O-rHfIxY
VA9" Au
N:#"4e
//读取保存的下载信息（文件指针位置） )qGw!^8
private void read_nPos() vT*z3
{ [B}$U|V0
try{ gZ!vRO<%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -Y#YwBy;M
int nCount = input.readInt(); f'hrS}e
nStartPos = new long[nCount]; ;a]2hd"6
nEndPos = new long[nCount]; @M[t|
for(int i=0;i<nStartPos.length;i++) Fdgu=qMm
{ %3L4&W_T
nStartPos = input.readLong(); _f9XY
nEndPos = input.readLong(); C;#-2^h
} )aW;w|#n
input.close(); \2q!2XWgK
} c/fU0cA@
catch(IOException e){e.printStackTrace ();} Lh0qB)>
catch(Exception e){e.printStackTrace ();} L&[uE;ro
} `|Aj3a3sND
MP5 vc5[
]a4rA+NFLB
private void processErrorCode(int nErrorCode) -YF]k}|
{ p^QEk~qw
System.err.println("Error Code : " + nErrorCode); SE%B&8ZD
} ZPrL)']
8lG@8tbW^
B d#D*"gx
//停止文件下载 ~b.C[s
public void siteStop() 11%<bmJ]Q3
{ 2g>4fZ
bStop = true; dso6ZRx
for(int i=0;i<nStartPos.length;i++) qmNgEz%
fileSplitterFetch.splitterStop(); J$'Q3k
q)Qd+:a7{
5F#Q1gP-
} [1pWg^
} 6Fp}U
//负责部分文件的抓取 -4 ~(*
**FileSplitterFetch.java y~,mIM$[@
*/ mmE!!J`B
package NetFox; @FC|1=+
S;pKL,d>r
Nqf6CPXE
import java.io.*; R07 7eX
import java.net.*; AoL2Wrk]\B
{51<EvyE*
;ps0wswX
public class FileSplitterFetch extends Thread { r&$r=f<
7x6q:4Ep\
BU3VXnqT[
String sURL; //File URL qfRsp rRI"
long nStartPos; //File Snippet Start Position *@2+$fgz
long nEndPos; //File Snippet End Position 4z{jWNM)N
int nThreadID; //Thread's ID yeI((2L@E2
boolean bDownOver = false; //Downing is over jv8diQ.
boolean bStop = false; //Stop identical @-^jbmu^ P
FileAccessI fileAccessI = null; //File Access interface bl/tl_.p00
rn$LZE %
w;e42.\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?^y!}(
{ R 4= ~
this.sURL = sURL; EbG`q!C
this.nStartPos = nStart; >gj%q$@
this.nEndPos = nEnd; etcpto=Mo
nThreadID = id; V_1'` F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g}uVuK;<
} z8MKGM
/'yi!:FZFC
>~+'V.CNW
public void run() {pzu1*
{ ^@"H(1Hxu/
while(nStartPos < nEndPos && !bStop) k&<cFZU
{ ap 5D6y+
4hymQ3 g
58vq5j<V
try{ Or({|S9d2
URL url = new URL(sURL); 0=WZ 8|R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?3=D-Xrb
httpConnection.setRequestProperty("User-Agent","NetFox"); gwm}19JC
String sProperty = "bytes="+nStartPos+"-"; Kuj*U'ed7t
httpConnection.setRequestProperty("RANGE",sProperty); |I0O|Zdv
Utility.log(sProperty); X+R?>xq{=h
yf lt2 R
?zS t
InputStream input = httpConnection.getInputStream(); (toN??r
//logResponseHead(httpConnection); (Lp$EC&%6
QH)uh"
Z'u:Em
byte[] b = new byte[1024]; z~Ec*
int nRead; @u4q\G\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y*f5_
{ ! u4'1jd[d
nStartPos += fileAccessI.write(b,0,nRead); {j0c)SETN
//if(nThreadID == 1) );m7;}gE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sz7|2OV"
} i&%/]Nq
Gtyy^tz[
*irYSTA$
Utility.log("Thread " + nThreadID + " is over!"); _ +"V5z
bDownOver = true; 8/tvS8I#y
//nPos = fileAccessI.write (b,0,nRead); fw[Z7`\Q5
} 4a]$4LQV
catch(Exception e){e.printStackTrace ();} 0\Q/$#3
} @~Uu]1
} CP%?,\
xDJs0P4
0Ud.u
//打印回应的头信息 t+2!"Jr
public void logResponseHead(HttpURLConnection con) 3T<aGW1
{ &4m\``//9
for(int i=1;;i++) `Dn"<-9:
{ _a?(JzLw5
String header=con.getHeaderFieldKey(i); gbl`_t/
if(header!=null) I Ceb2R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `Tt;)D
Utility.log(header+" : "+con.getHeaderField(header)); j$he5^GC
else &'0|U{|
break; *[QFIDn:
} 6oQSXB@
} 3Dm`8Xt
sK&[sN33
]:6M!+?(
public void splitterStop() 2brxV'tk
{ @u.%z# h"1
bStop = true; y1FE +EX[
} E&wz0d;gf
;:Yz7<>Y,
tr<iFT}C
} `E4+#_ v
'0\v[f{K3G
_tJm0z!
/* q0>@!1Wb
**FileAccess.java x9U(,x6r
*//文件访问(定位，写) saj%[Gsy
package NetFox; Vzs_g]V
import java.io.*; lo!.%PP|
3T|xUY)G4
gZ^'hW-{
public class FileAccessI implements Serializable{ !qQB}sAf
vpoYb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J'=iEI
RandomAccessFile oSavedFile; n;F/}:c_a
long nPos; GjfPba4>
Sp2<rI
T|L_+(M{
public FileAccessI() throws IOException +'@j~\>^yJ
{ &6#>a"?"
this("",0); C;EC4n+s
} JSAbh\Mq6
Vp.&X 8
,?k~>,{3
public FileAccessI(String sName,long nPos) throws IOException t 5{Y'
{ ,ezC}V0M
oSavedFile = new RandomAccessFile(sName,"rw"); /M3UK
this.nPos = nPos; ~hk;OB;
oSavedFile.seek(nPos); n$03##pf
} _Z>I"m
; { MK
!go$J]T
public synchronized int write(byte[] b,int nStart,int nLen) \uUd *
{ #j?SdQ
int n = -1; I/HcIBJ
try{ A@o:mZ+XN(
oSavedFile.write(b,nStart,nLen); Jj:Bi&C
n = nLen; w~n7l97Pw
} wyVQV8+&>
catch(IOException e) !VXs yH3r5
{ 9eh9@~mU"l
e.printStackTrace (); A$a>=U|Z8
} ^G*zFqa+`
2`ED?F68gH
97]$*&fH
return n; M;$LB@h
} ?vd_8C2B
@8jc|X<A
iL](w3EM
} r@.3.Q
dPtQ Sa
@S>$y5if
/* %dN',
**SiteInfoBean.java CL%+`c0
*/ |rhCQ"H
package NetFox; F\H^=P
Z`9yGaTO
,]\:]Y&?
public class SiteInfoBean { /;K?Y#mf~j
v)VhR2d3
"92Z"I~1
private String sSiteURL; //Site's URL Og8'K=O#
private String sFilePath; //Saved File's Path \kQ@G
private String sFileName; //Saved File's Name mDJg-BQ
private int nSplitter; //Count of Splited Downloading File bB#6Xx
L 2Z9g`>
eT4+O5t
public SiteInfoBean() t622b?w
{//nSplitter的缺省值为5 Y>N`(
//default value of nSplitter is 5 Q~L"Mr8>V
this("","","",5); u>cU*E4/
} ?d? cD
R\+O.vX
5ZPe=SQ{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u{/!BCKE
{ @uWPo2
sSiteURL= sURL; sHr!GF
sFilePath = sPath; |RdiM&C7
sFileName = sName; s)e'}y
this.nSplitter = nSpiltter; @Qa)@'u
h>l
z3lMD'uU3
} MvO!p
ua'dm6",:
0tzMu#
public String getSSiteURL() BU|bo")
{ c20'{kH
return sSiteURL; g@ ZZcBx
} A^a9,T
4/rdr80
e?&4;
public void setSSiteURL(String value) 9bDxml1
{ 6 s+ Z
sSiteURL = value; @Lj28&4:<
} |c]Y1WwDx
ON$^_l/c
lIN`1vX(
public String getSFilePath() h.\9a3B:r
{ 05<MsxB"w
return sFilePath; #\&jM -.-
} ye9-%~sjX
p^LUyLG`
6^L4wd7)
public void setSFilePath(String value) U 9?!|h;7
{ tXocGM{6C
sFilePath = value; <3!jra,h
} h4xRRyK
YdI|xu>0A^
((U-JeFW
public String getSFileName() kpkN GQ2
{ hr8v O"tZN
return sFileName; pvJsSX
} crJyk#_
BO b#9r
a9ab>2G?FR
public void setSFileName(String value) `]^JOw5o
{ .1yp}&e#
sFileName = value; =NH p%|
} Og`6>?>97
> dJvl|
e+z_Rj%Y;I
public int getNSplitter() bP`.teO\
{ CL*i,9:NR
return nSplitter; 7P`|wNq
} 1{oq8LB
:[iWl8
|pv:'']J
public void setNSplitter(int nCount) /?%zNkcxu
{ `e t0i.
nSplitter = nCount; g4WN+y`
} s%nx8"
} M@rknq@
:XK.A
5FJ<y"<6
/* )5r*2I
**Utility.java R 2uo ZA,
*/ SU.T0>w
package NetFox; I3QK~ V*j)
#Sj:U1x
9-Bp=M
public class Utility { dnVl;L8L3
@Y'BqDFlZ
$UMxO`F
public Utility() 9 veq
{ gG0P &9xz
LB_ylfg
+(iM]L$Fw%
} s+>VqyHgf
d]0.6T1[K
//线程睡眠 %EYh5W
public static void sleep(int nSecond) k:nR'TI
{ "q(#,,_
try{ Yxye?R-:
Thread.sleep(nSecond); wSHE~Xx
} zhbp"yju7
catch(Exception e) $\l7aA5~
{ s5T$>+ a
e.printStackTrace (); tuuc9H4B
} F gM<2$h
} je1f\N45
& IVwm"
//日志 RKsr}-18
public static void log(String sMsg) 76a+|TzR
{ +2!J3{[J
System.err.println(sMsg); U`_(Lq%5W
} +U9Gj#
J&w%lYiu5
!uLW-[F,
public static void log(int sMsg) ZcgSVMqEX
{ jA R@?X
System.err.println(sMsg); 5;5;bBo~
} Hzs]\%"
} Q6Z%T.1
$e#p -z
n<6p0w
/* Mp*")N,
**TestMethod.java n.]K"$230
*/ 6]^; s1!
package NetFox; 1UX"iOx(
Cdl#LVqs
Ql sMMIax
public class TestMethod { )tGeQXVhbJ
Um9Gjd
Uj&2'>MJ$
public TestMethod() !_rAAY
{ ///xx/weblogic60b2_win.exe WUx}+3eWv
try{ I`kaAOe
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pASNiH698
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `#B|l+baq
SiteFileFetch fileFetch = new SiteFileFetch(bean); "M5P-l$p}
fileFetch.start(); GFasGHAw
} .VN"j
catch(Exception e){e.printStackTrace ();} ko\VDyt,
p@]\N
62K7afH
} {Y-<#U~iH
d{2+> >d
$6.CN#
public static void main(String[] args) |SC^H56+
{ bI.LE/yk
new TestMethod(); ,R/HT@
} ?#"rI6
} ?{l}35Q.@
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