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)); |7n&I`#
} .yE!,^j.gB
for(int i=0;i<nEndPos.length-1;i++) AN7WMX
{ V#.;OtF]
nEndPos = nStartPos[i+1]; 'c<vj jIg
} /%C6e )7BL
nEndPos[nEndPos.length-1] = nFileLength; 8:;_MBt
} bq[j4xH0X
} b/Y9fQn
Yr@_X
}dw`[{cm
//启动子线程 0JQy-hpF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :_JZn`Cab
for(int i=0;i<nStartPos.length;i++) IG0$OtG
{ }c1Vu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nkTH#WTfR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -NtT@ +AE
nStartPos,nEndPos,i); [Av#Z)R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fN~kdm.
fileSplitterFetch.start(); Mnyg:y*=
} T0s7aw[zm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Tl5K'3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sY+U$BYB>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Kdh(vNB>
nEndPos = " + nFileLength); }1]/dCv
// fileSplitterFetch[nPos.length-1].start(); :bI4HXT3
}3:DJ(Y
3#huC=zbf
//等待子线程结束 >C y
//int count = 0; c[E{9wp v
//是否结束while循环 'Bb]<L`
boolean breakWhile = false; Epj
J01w\#62pQ
7)$U>|=
while(!bStop) J~KWn.
{ x3=W{Fv@4
write_nPos(); ^6[KzE#*
Utility.sleep(500); $fhrGe
breakWhile = true; 8v@6 &ras@
95Bw;U3E
1}#v<b$
for(int i=0;i<nStartPos.length;i++) @?iLz7SPk
{ P7QOlTQI
if(!fileSplitterFetch.bDownOver) /]"&E"X"
{ GY<ErS)2
breakWhile = false; Jfa=#`
break; H`q" _p:
} BT;hW7){9
} rHPda?&H
if(breakWhile) K];nM}<
break; O-Hu:KuIf
I\DmVc\l
eO;i1>
//count++; vF"<r,pg
//if(count>4) gP8Fe =]
// siteStop(); ta"/R@ k*
} 'c5#M,G~
[1B F8:
4"1OtBU3
System.err.println("文件下载结束！"); D}'g4Ag
} mj5$ 2J
catch(Exception e){e.printStackTrace ();} Ol H{!
} c+?L?s`"
JbpKstc;
-/|O*oZ
//获得文件长度 I7TdBe-
public long getFileSize() 2Fi>nJ
{ 0/hX3h
int nFileLength = -1; *I%r
try{ ^_6%dKLK
URL url = new URL(siteInfoBean.getSSiteURL()); ##d\|r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4NN-'Z>a
httpConnection.setRequestProperty("User-Agent","NetFox"); ms'&.u&<
=o\:@I[
c_clpMx=
int responseCode=httpConnection.getResponseCode(); v'i"Q
if(responseCode>=400) LqIMU4Ex
{ !+Z"7e nj
processErrorCode(responseCode); ANtp7ad
return -2; //-2 represent access is error X<@ytHBv
} J7$1+|"
N[X%tf\L]F
rg+28tlDn
String sHeader; nR4L4tdS
GjZ@fnF
aGVzg$
for(int i=1;;i++) "wL~E Si
{ vb/*ILS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G~_5E]8
//Utility.log(in.readLine()); ;5^grr@,4
sHeader=httpConnection.getHeaderFieldKey(i); 2!f0!<te
if(sHeader!=null) FQNhn+A
{ UXD?gK1
if(sHeader.equals("Content-Length")) 7Z5,(dH>
{ ^(m`5]qr7J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L(TO5Y]
break; >0)E\_ u
} YM{Q)115
} w8:F^{
else 5~k-c Ua
break; idnn%iO
} i,rP/A^q
} Gp9>R~$
catch(IOException e){e.printStackTrace ();} {YZ)IaqZ
catch(Exception e){e.printStackTrace ();} C.L5\"%
}hyK/QUCoN
ac>}$Uw)
Utility.log(nFileLength); b0X*+q
* 2[&26D
mXlXB#N
return nFileLength; }Bw=2 ~
} _Ptf^+
fI`T3Y!7
,'5P[-
//保存下载信息（文件指针位置） ?15k~1nA
private void write_nPos() 6;Cr92
{ +5Ir=]=T9
try{ \<|a>{`7]i
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y>t*L#i
output.writeInt(nStartPos.length); v}A] R9TY
for(int i=0;i<nStartPos.length;i++) d hiLv_/
{ yd"|HHx
// output.writeLong(nPos); $m:}{:LDCf
output.writeLong(fileSplitterFetch.nStartPos); U#G uB&V
output.writeLong(fileSplitterFetch.nEndPos); S1uW`zQ!+_
} *7oPM5J|v
output.close(); *{W5QEa
} I'"*#QOX
catch(IOException e){e.printStackTrace ();} ar+mj=m
catch(Exception e){e.printStackTrace ();} KQi9qj
} C yC<{D+
FMY r6/I
oV?tp4&
//读取保存的下载信息（文件指针位置） efMv1>{
private void read_nPos() @)&b..c?_
{ C fQj7{
try{ i051qpj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vq$%Ug/B
int nCount = input.readInt(); \F,?ptu
nStartPos = new long[nCount]; ;1S{xd*^N
nEndPos = new long[nCount]; GW'=/ z7
for(int i=0;i<nStartPos.length;i++) 6v GcM3M
{ Gcg`Knr
nStartPos = input.readLong(); Xfx(X4$9
nEndPos = input.readLong(); }@@1N3nnxV
} 0LoA-c<Ay
input.close(); ;G!X?(%+
} meR%);\
catch(IOException e){e.printStackTrace ();} v|_?qBs"
catch(Exception e){e.printStackTrace ();} X X{:$f+
} 2t1WbP1
l*_b)&CH
IaE};8a8
private void processErrorCode(int nErrorCode) )ty *_@N0
{ +<:p`%
System.err.println("Error Code : " + nErrorCode); gb@Rx
} \yb^%$hZ0
+x G](?
GY,@jp|R
//停止文件下载 0VoC|,$U
public void siteStop() ZT8. r0
{ [KWF7GQi
bStop = true; mfG|K@ODM-
for(int i=0;i<nStartPos.length;i++) pSQ3SM
fileSplitterFetch.splitterStop(); {eIE|
tRbZ^5x\@
#Vul#JHW
} #`z!f0 P
} oLruYSaD
//负责部分文件的抓取 dp)lHBV
**FileSplitterFetch.java )~d2`1zGS
*/ Uo^s]H#:
package NetFox; kKE2~ q
j])iyn~-Ke
!SJmu}OB]
import java.io.*; cJ]`/YJ
import java.net.*; t8GJ;
HLYM(Pz
v8*ZwF
public class FileSplitterFetch extends Thread { ~l6e&J
,wO5IaV
-rH4/Iby
String sURL; //File URL <py~(q
long nStartPos; //File Snippet Start Position 2yq.<Wz<
long nEndPos; //File Snippet End Position ui9gt"qS`
int nThreadID; //Thread's ID +6gS]
boolean bDownOver = false; //Downing is over b@1QE
boolean bStop = false; //Stop identical l*'8B)vN2
FileAccessI fileAccessI = null; //File Access interface 2"<}9A<Xs
Z|8f7@k{|+
KN}[N+V>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2d.I3z:[
{ 7UQD02
this.sURL = sURL; = 1}-]ctVn
this.nStartPos = nStart; _tjFb_}Q
this.nEndPos = nEnd; 5R"b1
nThreadID = id; Y#]Y$n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W:rzfO.`Z
} DT9i<kl
0QC*Z (
b17p;wS
public void run() G>:l(PW:
{ @Zq,mPaR$
while(nStartPos < nEndPos && !bStop) _LK>3Sqd
{ S^x9 2&!
+bRL.xY
Q&QR{?PMD
try{ /%xK-z,V
URL url = new URL(sURL); @ K@~4!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pY8+;w EI
httpConnection.setRequestProperty("User-Agent","NetFox"); ?erDP8
String sProperty = "bytes="+nStartPos+"-"; 2lp.Td`{
httpConnection.setRequestProperty("RANGE",sProperty); HNh=igu
Utility.log(sProperty); Rdnd|
"9WP^[
IZ2#jSDn
InputStream input = httpConnection.getInputStream(); uxh4nyE
//logResponseHead(httpConnection); k*M{?4
YRYrR|I
RhQOl9
byte[] b = new byte[1024]; Ix *KL=MG
int nRead; l^Lg"m2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]iz5VI@
{ AOWI`
nStartPos += fileAccessI.write(b,0,nRead); PTePSj1N
//if(nThreadID == 1) *=2jteG=3.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZVGw@3
} zkd#vAY(A
_K;rM7
zP9 HYS
Utility.log("Thread " + nThreadID + " is over!"); /(}V!0\?
bDownOver = true; D!Gm9Pa}
//nPos = fileAccessI.write (b,0,nRead); E'r* g{,
} -y/?w*Cx
catch(Exception e){e.printStackTrace ();} [j!0R'T
} fptW#_V2
} iww h,(
S[u<vHy
)>[(HxvfJU
//打印回应的头信息 Z].>U!7W
public void logResponseHead(HttpURLConnection con) T8KhmO
{ a"&Z!A:Z=
for(int i=1;;i++) sztnRX_
{ Mys;Il"
String header=con.getHeaderFieldKey(i); hCo&SRC/5
if(header!=null) JI*ikco-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F2:7UNy,
Utility.log(header+" : "+con.getHeaderField(header)); u8W*_;%:
else A?7%q^;E
break; "RShsJZMH
} tNUcmiY
} #g|j;{P
T\WNT#My
#qn)Nq(
public void splitterStop() F)%; gzs
{ DC$ S. {n
bStop = true; tTmFJ5
} dT|z)-Z`
UfkRY<H
#|CG %w
} PO}Q8Q3
h:GOcLYM@X
3] @<.
/* RB\WttI
**FileAccess.java W4#:_R,&,
*//文件访问(定位，写) NMj`wQ`M+
package NetFox; HOUyB's'
import java.io.*; /f6]XP\'`+
>WD^)W fa
\u/5&[;
public class FileAccessI implements Serializable{ H?~u%b@
@qe>ph[UA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 21WqLgT3 4
RandomAccessFile oSavedFile; B{K'"uC
long nPos; PIrUls0}
KYl^{F
P"]+6sm&es
public FileAccessI() throws IOException EjF}yuq[
{ CVUJ(D&Q
this("",0); tEEhSG)s%
} KW;xlJz(j
~::R+Lh(
fwnpmuJ
public FileAccessI(String sName,long nPos) throws IOException Sx~_p3_5U
{ RXof$2CZS
oSavedFile = new RandomAccessFile(sName,"rw"); pts}?
this.nPos = nPos; iwVra"y
oSavedFile.seek(nPos); K;97/"
} Xo*$|9[.
R5i8cjKZ?w
dyp]y$
public synchronized int write(byte[] b,int nStart,int nLen) q+:(@w6
{ feopO j6~+
int n = -1; jQr~@15J#
try{ 1Efl|lV
oSavedFile.write(b,nStart,nLen); "p;DQ-V
n = nLen; .{;!bw
} <s2l*mc
catch(IOException e) E*I]v
{ dSL %%
e.printStackTrace (); S]o
} ?dmMGm0T9
\}Wkj~IX
'|/_='
return n; !Q3Snu=
} ChW0vIL`
?rOb?cu-
b(yO
} FKx9$B
p%ZiTrA1&D
5HIpoj;\(
/* a"DV`jn
**SiteInfoBean.java Q)@1:(V/
*/ %~;Q_#CR/K
package NetFox; ^hHeH:@
{UmCn>c
8k1r|s@d
public class SiteInfoBean { ygW@[^g
#-Rz`Y<&
aK&+p#4t
private String sSiteURL; //Site's URL vedMzef[@>
private String sFilePath; //Saved File's Path _Ry.Wth
private String sFileName; //Saved File's Name _%2Umy|
private int nSplitter; //Count of Splited Downloading File pzax~Vp
tZYI{m{
nMa^Eq#
public SiteInfoBean() )[)]@e
{//nSplitter的缺省值为5 Yz,!#ob$
//default value of nSplitter is 5 /2cI{]B
this("","","",5); .fsk DW
} +7Lco"\w<
5>@uEebkv]
} E#+7a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j'i42-Lt/p
{ \l:g{GnoT
sSiteURL= sURL; by U\I5
sFilePath = sPath; ?iLd5 Z
sFileName = sName; ,?`1ve_K<
this.nSplitter = nSpiltter; IeB6r+4|
NslA/"*
m3(T0.j0P
} -n *>zGc
:]^P^khK
9sCk\`n
public String getSSiteURL() a!:8`X~[/$
{ WDGGT.hG
return sSiteURL; ;F""}wzn
} D;I`k L
yUW&Wgc=:
9f^PR|F
public void setSSiteURL(String value) ]`sIs= _[
{ M',D
sSiteURL = value; 6XAr8mw9
} 3NN'E$"3
J4}\V$ysN
--twkD
public String getSFilePath() j?f <hQ
{ {&#~t4
return sFilePath; D'`"_
} E)JyKm.
ow_y
6lWFxbh
public void setSFilePath(String value) e^NEj1
{ ;Zq~w
sFilePath = value; 1mJ_I|98
} uvDoo6'
1bJ]3\
~snF20
public String getSFileName() 7F(F.ut
{ S9NN.dKu
return sFileName; m_$I?F0
} +qj*P9
EOX_[ek7
06^1#M$'
public void setSFileName(String value) j 3MciQ`
{ nbASpa(
sFileName = value; uT}TSwgp
} b3b~T]]
8q [c
egvy#2b@
public int getNSplitter() }=hoATs
{ X^D9)kel
return nSplitter; 8RAeJ~e
} !049K!rP{
~BvY8\@B
BO4 K#H7
public void setNSplitter(int nCount) 9J7J/]7f
{ "b>KUzuYT
nSplitter = nCount; ! F <] T
} @ 9 {%Kn
} 2d2@J{
48CI8[T
7p.h{F'A
/* Ok>(>K<r
**Utility.java e:J'&r& 1
*/ hO/5>Zv?
package NetFox; k&A7alw
'dc+M9u)_q
Q*:h/Lhb&
public class Utility { )4~sQ^}
VS9]po>=
qggk:cN1
public Utility() Dk`4bYK
{ 43>9)t
Pc(n@'m~
rMHQzQ0%
} ?7uKP}1|
Aw4?y[{H
//线程睡眠 gr>o E#7
public static void sleep(int nSecond) (]Ye[j^"7
{ xIQ/$[&v
try{ MkDK/K$s
Thread.sleep(nSecond); ;T.s!B$Uu
} nU&NopD+*G
catch(Exception e) b6nZ55 h
{ $>r>0S#+\&
e.printStackTrace (); S\9t4Ki_'
} @0z0m;8
} @fqV0l!GR
I f3{E
//日志 A~SL5h
public static void log(String sMsg) 2;4]PRD6w
{ <!~1{`n%9J
System.err.println(sMsg); @VC .>
} LZr0]g{Pu/
FgWkcV6B
0+}EA[
public static void log(int sMsg) KQ4kZN
{ Pr5g6I'G
System.err.println(sMsg); m_m8c8{Y
} I7dm \|#
} IvTzPPP
Vvm=MBgN
QqiJun_m
/* VYamskK[G:
**TestMethod.java 7m:|u*ij2~
*/ o_Jn_3=
package NetFox; [DZqCo
DS:>/m>)
uu}`warW
public class TestMethod { JF~1'"_f:
&yxNvyA[u
AH2_#\
public TestMethod() 'tb(J3ZP
{ ///xx/weblogic60b2_win.exe ;)(Sdf[P
try{ e1 x^PT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `^7:7Wr]=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wMb)6YZs
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,VNi_.W0
fileFetch.start(); DW/1 =3
} J~Cc9"(
catch(Exception e){e.printStackTrace ();} E/mubA(&
?YF${
$#%U\mIz
} [%@2o<
4_PCqEp)
(O\U /daB
public static void main(String[] args) \ Md 3
{ Fe!D%p Qv
new TestMethod(); ^WE4*.(
} +|y*}bG
} |KL')&"
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