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)); /+02BP
} |`:Uww+3
for(int i=0;i<nEndPos.length-1;i++) \$riwL
{ O3Ks|%1
nEndPos = nStartPos[i+1]; (MJu3t @
} =_.Zv
nEndPos[nEndPos.length-1] = nFileLength; iwrdZLE
} l ^\5Jr03
} - Nplx
T'fE4}rY
P9X/yZ42
//启动子线程 ^[^uDE <
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =0x[Sa$&,
for(int i=0;i<nStartPos.length;i++) )0qXZgs
{ VPtA %1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r95$B6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D/@:wY
nStartPos,nEndPos,i); bLaD1rnGi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l3l[jDa,2
fileSplitterFetch.start(); [dOPOA/d
} F4">go
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z1^S;#v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?A,gDk/#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8.]dThaq
nEndPos = " + nFileLength); vP88%I;
// fileSplitterFetch[nPos.length-1].start(); 2 B5kpmH:
@f{)]I +f
[4t_ 83
//等待子线程结束 f[h=>O
//int count = 0; =We}&80x
//是否结束while循环 n#Z6d`
boolean breakWhile = false; U/|B IF
LDwu?"P!
I?l*GO+pz
while(!bStop) >$HMZbsE
{ a/`fJY6rR
write_nPos(); 4.CLTy3W
Utility.sleep(500); GD~3RnGQ{
breakWhile = true; 7m@pdq5Ub
"+Xwc+v^
ad i5h
for(int i=0;i<nStartPos.length;i++) s~M!yuH
{ t2tH%%Rs
if(!fileSplitterFetch.bDownOver) |$7!u DU8
{ -D{~7&
breakWhile = false; 1`B5pcuI
break; z\fD}`^8
} |MTgKEsn
} `I_%`15>
if(breakWhile) VY~WkSi[<
break; lE=Q(QUr
]#S.L'
6mMJ$FY+
//count++; &e3z)h
//if(count>4) oaRPYgh4
// siteStop(); KJcdX9x
} B'atwgI0
9r\8 !R
P#rwYPww\
System.err.println("文件下载结束！"); q0DoR@
} w?<:`
catch(Exception e){e.printStackTrace ();} &AOw(?2
} P%B1dRa
r`wL_>"{n
5\EHu8
//获得文件长度 'HW(RC0dR
public long getFileSize() e`#Gq0}8
{ nV"[WngN
int nFileLength = -1; 5 BcuLRId:
try{ >\(Ma3S
URL url = new URL(siteInfoBean.getSSiteURL()); p*NC nD*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *.voN[$~
httpConnection.setRequestProperty("User-Agent","NetFox"); +apIp(E+
"LXLUa03
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int responseCode=httpConnection.getResponseCode(); 4ol=YGCI_
if(responseCode>=400) k]; <PF
{ sks_>BM
processErrorCode(responseCode); /=[M
return -2; //-2 represent access is error BQ_\8Qt|
} 7{az %I$h
sy/J+==
][wS}~):
String sHeader; AVNB)K"
2MB\!fh
8q_3*++D
for(int i=1;;i++) owYfrf3ZLX
{ vaR0`F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,ulNap"R
//Utility.log(in.readLine()); &WvJg#f
sHeader=httpConnection.getHeaderFieldKey(i); '#u2q=n4*
if(sHeader!=null) bis/Nfr]
{ iWQBo>x
if(sHeader.equals("Content-Length")) 3S'V>:
{ K<Ct
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %z8@;
break; ?_n.B=H`8
} CdTmL{Y1
} `2r21rVntf
else t$Irr*
break; B>a`mFM
} ]~kqPw<R
} b39;Sv|#
catch(IOException e){e.printStackTrace ();} >k_Z]J6Pd
catch(Exception e){e.printStackTrace ();} !v`q%JW(
s.GTY@t
w8FZXL
Utility.log(nFileLength); TSHp.ABf
] ^
Ds L]o
return nFileLength; |nU:
} GXJ3E"_.
`Rj i=k>
B;1wnKdj
//保存下载信息（文件指针位置） L[TL~@T
private void write_nPos() f()^^+
{ vbwEX6
try{ hw~cS7
output = new DataOutputStream(new FileOutputStream(tmpFile)); BIV]4vl-&
output.writeInt(nStartPos.length); r=&PUT+vt
for(int i=0;i<nStartPos.length;i++) 0b*a2_|8k
{ Z][?'^`^!
// output.writeLong(nPos); n!HFHy2
output.writeLong(fileSplitterFetch.nStartPos); vc^PXjX
output.writeLong(fileSplitterFetch.nEndPos); 9Cf^Q3)5o
} kQVl8KS
output.close(); ;F~GKn;}
} qc*+;Wi+5
catch(IOException e){e.printStackTrace ();} xW"J@OiKL
catch(Exception e){e.printStackTrace ();} Mh3zl
} B(^fM!_%-6
(T'inNbJe
@&EE/j^
//读取保存的下载信息（文件指针位置） 3]}W
private void read_nPos() 66Hu<3X P
{ >|z=-hqPK
try{ #/1A:ig
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wJ IJPYTK
int nCount = input.readInt(); _Q.3X[88C
nStartPos = new long[nCount]; kAy.o
nEndPos = new long[nCount]; 8 LaZ5
for(int i=0;i<nStartPos.length;i++) O8dDoP\F2
{ I X\&lV
nStartPos = input.readLong(); \dufKeiS&a
nEndPos = input.readLong(); 8|7Tk[X1j
} 6{+~B2Ef
input.close(); O5k's
} ;?n*w+6<
catch(IOException e){e.printStackTrace ();} $T3/*xN
catch(Exception e){e.printStackTrace ();} 5-]%D(y
} {MYlW0)~
4eIu@ ";!
/I6?t=?<
private void processErrorCode(int nErrorCode) hk,Q=};
{ Oa@X! \
System.err.println("Error Code : " + nErrorCode); dWm[#,Q?
} !4oYQB
#axRg=d?K
{bc<0
//停止文件下载 .v;2Q7X
public void siteStop() h)A+5^:^
{ A]=?fyPh{'
bStop = true; 70KXBu<6
for(int i=0;i<nStartPos.length;i++) {v]>sn;P1
fileSplitterFetch.splitterStop(); >O\-\L
9=JU&/!
Ud{-H_m+
} c#{<| .
} F1%' zsv
//负责部分文件的抓取 7g&_`(
**FileSplitterFetch.java OQ[>s(`*{
*/ (<%i8xu2
package NetFox; SAo"+%
Y{p *$
AA05wpu8
import java.io.*; \uanQ|Nu
import java.net.*; F7"Ihb^l
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J`"1DlH
public class FileSplitterFetch extends Thread { dYr#
lfI[r|
F ^E(AE
String sURL; //File URL u)Y#&qA
long nStartPos; //File Snippet Start Position )k7`!@ID
long nEndPos; //File Snippet End Position BY\p?79
int nThreadID; //Thread's ID %LVk%kz
boolean bDownOver = false; //Downing is over v3]q2*`G#
boolean bStop = false; //Stop identical E176O[(V=
FileAccessI fileAccessI = null; //File Access interface d3n TJX
gNZ^TeT
1p8E!c{}j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .s2d
{ 1/#N{rZ
this.sURL = sURL; DI$zyj~3
this.nStartPos = nStart; yyA/x,
this.nEndPos = nEnd; 9qqEr~
nThreadID = id; IndNR:"g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _$=xa6YA
} ;'<K}h
,#"AWQ
/pyKTZ|
public void run() ; 9'*w=V
{ s;5PHweWf
while(nStartPos < nEndPos && !bStop) *~:@xMa
{ zBjqYqZ<+
-k<.Q=]<t
t*D[Q$v
try{ <MfB;M
URL url = new URL(sURL); 2r* o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h hdn9n
httpConnection.setRequestProperty("User-Agent","NetFox"); f}+G;a9Nj
String sProperty = "bytes="+nStartPos+"-"; r/{VL3}F_e
httpConnection.setRequestProperty("RANGE",sProperty); #lB[]2]N
Utility.log(sProperty); @9c^{x\4
c/x(v=LW
v4ueFEY
InputStream input = httpConnection.getInputStream(); O%+:fJz6wI
//logResponseHead(httpConnection); %9zcc)cP
;yUY|o
)FHaJ*&d
byte[] b = new byte[1024]; _5X}&>>lhF
int nRead; f0^s*V+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <T7y85
{ [I^SKvM
nStartPos += fileAccessI.write(b,0,nRead); :X$&gsT/,
//if(nThreadID == 1) 4wBCs0NIm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `9wz:s QtP
} MWB uMF
}$UuYO/i
<4!w2vxG
Utility.log("Thread " + nThreadID + " is over!"); @FbzKHdV/
bDownOver = true; ]T*{M
//nPos = fileAccessI.write (b,0,nRead); \ _i`=dx
} (JM4W "7'
catch(Exception e){e.printStackTrace ();} gbInSp`4
} Qe4
} RCmPZ
wZOO#&X#r
10 p+e_@
//打印回应的头信息 |]I?^:I
public void logResponseHead(HttpURLConnection con) Ik}*7D
{ O=-|b kO
for(int i=1;;i++) Mv9s
{ ;pULJ}rDb
String header=con.getHeaderFieldKey(i); O}KT>84M
if(header!=null) Xz5=fj&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VyI%^S ]sS
Utility.log(header+" : "+con.getHeaderField(header)); .KB*u*h
else @E==~ b
break; ~ib#x~Db
} @L~y%#
} '17=1\Ss6;
gZPJZN/cpz
f?{Y<M~]
public void splitterStop() ", |wG7N K
{ V)0bLR
bStop = true; HSUr
} qGh rJ6R!
8l}|.Q#--
xApa+j6I
} iF 67
N..u<06j/
2`Pk@,:_
/* Lc.7:r
**FileAccess.java ~ h:^Q
*//文件访问(定位，写) ^<E,aCy
package NetFox; ^%<v| Y(X
import java.io.*; >*_?^F_
_>aesp%
JN8k x;@
public class FileAccessI implements Serializable{ s0`uSQ2X
IBuuZ.=j2h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nY*ODL
RandomAccessFile oSavedFile; m?m,w$K
long nPos; qQom=x
@TH \hr]
M)LdGN?$
public FileAccessI() throws IOException SOUA,4
{ J*;t{M5
this("",0); v |i(peA#
} PNKmI
*%fOE;-?
m83i6"!H
public FileAccessI(String sName,long nPos) throws IOException =_UPZ]
{ )0%<ZVB
oSavedFile = new RandomAccessFile(sName,"rw"); ("TI~
this.nPos = nPos; |FNP~5v
oSavedFile.seek(nPos); ;N j5NB7
} +fwq9I>L
uj]GBo=
F1+2V"~
public synchronized int write(byte[] b,int nStart,int nLen) ktS0
{ x/Ds`\
int n = -1; Q7SS<'(
try{ $:xUXEi{
oSavedFile.write(b,nStart,nLen); e@q[Dv'mu
n = nLen; +}1]8:>cq
} ooD/QZUE
catch(IOException e) '2 )d9_ w
{ c^=:]^
e.printStackTrace (); 1XZ&X]
} -p)HH@6a
NT-du$!u
pG4Hy$e
return n; ! [:K/
} /!9949XV
t=pG6U
#uH1!UQb
} HD`%Ma Yhc
*;}!WDr
7 yi>G
/* *&U9npN
**SiteInfoBean.java T0SD|'
*/ Z$pR_dazU
package NetFox; C qxP@
LCdc7
*(HH71Y
public class SiteInfoBean { c]n4vhUa5
XRz.R/
`Yut1N
private String sSiteURL; //Site's URL p"X\]g^jA>
private String sFilePath; //Saved File's Path 4dy)g)wM
private String sFileName; //Saved File's Name :wF(([&4p!
private int nSplitter; //Count of Splited Downloading File x7/2e{p uu
p\,lbrv
Bq_<v)M*
public SiteInfoBean() F{}z[0
{//nSplitter的缺省值为5 sn*s7v:
//default value of nSplitter is 5 :l7\7IT
this("","","",5); `^6}Dn
} p]>bN
d82IEhZ#
!",@,$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CZuxH
{ YGNX+6Lz
sSiteURL= sURL; zxj!ihs<
sFilePath = sPath; &,#VhT![
sFileName = sName; P"%/
this.nSplitter = nSpiltter; [oYe/<3
\myj Y
N-NwGD{
} )HU?7n.{
~\Ynih
&B3kzs
public String getSSiteURL() .f6_[cS;g
{ SGbo|Xe7:
return sSiteURL; 3Fr}8Dy
} PffwNj/l
K'71uW>
L@+j8[3BX
public void setSSiteURL(String value) ^L[Z+7|
{ jQ[Z*^"}
sSiteURL = value; 7kb`o y;(^
} 5Ut0I]h|z
BkC(9[Ei
jb*#!m.l
public String getSFilePath() m4%m0"Z
{ J=Jw"? f
return sFilePath; u}$U|Cw-;T
} p;B +g X
jLEU V
=N3~2=g~A
public void setSFilePath(String value) Mr&]RTEE
{ gNO$WY^
sFilePath = value; :bh[6F
} FTB"C[>
lF#Kg!-l
0m@S+$v
public String getSFileName() !X,S2-}"
{ .a^/r'?
return sFileName; A8A+ImwO"
} uIba{9tM"P
ck^Z,AKL+
6Z'zB&hM}
public void setSFileName(String value) p;'vOb
{ nU`;MW/^w
sFileName = value; >U}~Hv]
} `C=p7%
m+!%+S1
x^;nfqn|
public int getNSplitter() JD>!3>S)?
{ q!7\`>.2:{
return nSplitter; kC#;j=K?
} v<-D>iJ
|UBJu `%
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public void setNSplitter(int nCount) .Kv@p jOr
{ O}%=c\Pb
nSplitter = nCount; <Q8bn?Z
} Z-~^)lo
} kP|!!N
L Y M`
qaQ
/* n|F`6.G
**Utility.java .3Ap+V8?
*/ kBT cND|
package NetFox; j9qN!.~mM
b/G0EcRw+
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public class Utility { Obd!
`W/6xm(X5;
wgufk{:
public Utility() y_nh~&
{ 7X.1QSuE
ar{e<&Bny
>Te{a*`"m:
} 7eO8cPy
I?:V EN:
//线程睡眠 :DZiDJ@
public static void sleep(int nSecond) 6?Wsg`9
{ fY `A
try{ 6v1j*'
Thread.sleep(nSecond); FX'W%_f,
} Nn^el'S'
catch(Exception e) PF+`3
{ 'R$~U?i8
e.printStackTrace (); 0q3:"X
} <9Chkb|B
} Ne4A
^.4<#Qs
//日志 NfSe(rd
public static void log(String sMsg) NT nn!k
{ ]f\rB8k|&
System.err.println(sMsg); o 1b#q/
} 8=e\^Q+
?@XO*|xkSk
*7Mrng
public static void log(int sMsg) II2oV}7?
{ ;S%wPXj&
System.err.println(sMsg); :r6 bw
} >,y QG+
} c[YC}@l%a
Xak~He
m:H )b{
/* (2{1m#o
**TestMethod.java ?LW1D+
*/ 1k7E[G~G|
package NetFox; M\GS&K$lq
$pD^O!I)?
H@6
public class TestMethod { eD/?$@y
EEaFi8
|GsLcUv6
public TestMethod() Qejzp/2
{ ///xx/weblogic60b2_win.exe yZ2,AR%
try{ MdPwuXI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g,1\Gj%y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _7;#0B
SiteFileFetch fileFetch = new SiteFileFetch(bean); sI.Ezuw
fileFetch.start(); Q'rG' |
} )h/fr|
catch(Exception e){e.printStackTrace ();} >sP;B5S
3}vlj:L
jjwY{jV
} fu|I(^NV
e]5QqM7
e5AiIVlv
public static void main(String[] args) I7}[%(~Sf/
{ &2g1Oy~
new TestMethod(); D]0#A|nF
} 1\3n
} 7+z%O3k'I
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