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)); Hr?lRaV
} A8'RM F1
for(int i=0;i<nEndPos.length-1;i++) sFpg
{ FRQ.ix2
nEndPos = nStartPos[i+1]; )U %`7(bN
} ?'> .>
nEndPos[nEndPos.length-1] = nFileLength; rN}pi@
} & kC
} /~NX<Ye&
g04^M(
(47?lw &
//启动子线程 \CjJa(vV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w}3N!jNDv
for(int i=0;i<nStartPos.length;i++) X _ZO)|
{ D6bYg `
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R-Edht|{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), syl7i>P
nStartPos,nEndPos,i); W.j^L;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _k@cs^
fileSplitterFetch.start(); $JY\q2
} [7I:Dm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dA)T>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jFN0xGZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wn[)/*(,$(
nEndPos = " + nFileLength); L$PbC!1
// fileSplitterFetch[nPos.length-1].start(); `+,?%W)
L`nW&;w'
a=MN:s?Fc0
//等待子线程结束 0s;~9>
//int count = 0; ;Nn(
//是否结束while循环 v9f+ {Y%-
boolean breakWhile = false; jEBn"]\D
dmF=8nff
q;eb
while(!bStop) #/YS
{ \!^=~` X-
write_nPos(); apL$`{>US
Utility.sleep(500); aO1^>hy
breakWhile = true; |Hf|N$
lh;fqn`
K#OL/2^ 5
for(int i=0;i<nStartPos.length;i++) FyEKqYl
{ YiZk|K_
if(!fileSplitterFetch.bDownOver) m9[ 7"I
{ nah?V" ?Y
breakWhile = false; ,WyEwc]
break; ._rPM>B?
} '4'Z
} mx9vjWfy
if(breakWhile) s@Q7F{z
break; p"0#G&-
c,1 G+.
}b2YX+/e$f
//count++; 0nt@}\j
//if(count>4) }b1G21Dc!
// siteStop(); !>9s
} pT,8E(*l2
(_pw\zk>
g (w/
System.err.println("文件下载结束！"); ?'k_K:_
} beOMln+R
catch(Exception e){e.printStackTrace ();} &PC6C<<f
} }d%CZnY&7
Vlx.C~WYn
/h53;$zK
//获得文件长度 "l&SRX?g
public long getFileSize() V|YQhd0kv
{ 89M'klZ
int nFileLength = -1; Q/|.=:~FO
try{ FAM{p=t]HT
URL url = new URL(siteInfoBean.getSSiteURL()); Au2?f~#Fv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Htgo=7!?\3
httpConnection.setRequestProperty("User-Agent","NetFox"); B{/og*xd*1
UBL{3s^"
Z1fY' f
int responseCode=httpConnection.getResponseCode(); F~Dof({:
if(responseCode>=400) GQ1/pys
{ e=&~6bs1U
processErrorCode(responseCode); BH'*I yv
return -2; //-2 represent access is error ~v8X>XDL?T
} h3`}{ w
,>B11Z}PH
?|ZbQz(bL
String sHeader; Ck/44Wfej
GFFwk4n1
7^i7U-A<A
for(int i=1;;i++) {~9zuNi
{ $NR[U+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xb\EJ1M>
//Utility.log(in.readLine()); ]T)N{"&N/
sHeader=httpConnection.getHeaderFieldKey(i); HO<|EH~lu
if(sHeader!=null) I(M/X/
{ kN/YnY*J<
if(sHeader.equals("Content-Length")) KJ+6Y9b1
{ 6/<Hx@r (
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0d+n[Go+S
break; f&CQn.K"
} TU6s~
} >5t! Xt
else 1 iox0
break; 3@":&
} AUD)=a>
} ,P9F*;Dj
catch(IOException e){e.printStackTrace ();} lrJV"H
catch(Exception e){e.printStackTrace ();} Pm%xX~H
fnq 3ic"V
ZiZ@3O6
Utility.log(nFileLength); 3t<a3"{9
]$ d ;P
L(|K{vHh]
return nFileLength; 1Le8W)J
} e:HORc~U
i+14!LlI
\a+Q5g
//保存下载信息（文件指针位置） 8-@@QZ\N
private void write_nPos() YC1Bgz
{ AO5&Y.A#
try{ |tAkv
output = new DataOutputStream(new FileOutputStream(tmpFile)); P;.roD9
output.writeInt(nStartPos.length); s4|tWfZ
for(int i=0;i<nStartPos.length;i++) 9`Qa/Y!
{ :!_l@=l
// output.writeLong(nPos); 8gavcsVE[
output.writeLong(fileSplitterFetch.nStartPos); 0U7Gl9~
output.writeLong(fileSplitterFetch.nEndPos); .F,l>wUNe
} ^'=[+
output.close(); ;j9%D`u<
} (m'-1wX.
catch(IOException e){e.printStackTrace ();} I/w;4!+)
catch(Exception e){e.printStackTrace ();} }K?b2 6`
} r[(;J0=
6?u`u t
+rv##Z
//读取保存的下载信息（文件指针位置） |mKohV qr
private void read_nPos() LF7 }gQs ^
{ l :{q I#Q
try{ =6U5^+|d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x1Gx9z9
int nCount = input.readInt(); 2OUx@Vj
nStartPos = new long[nCount]; dm}1"BU<
nEndPos = new long[nCount]; lW5Lwyt8
for(int i=0;i<nStartPos.length;i++) sl-wNIQ
{ ]r#b:W\
nStartPos = input.readLong(); D9TjjA|zS
nEndPos = input.readLong(); Ja~8ZrcY
} ;=n}61
input.close(); ho$}#o
} HWV A5E[`Y
catch(IOException e){e.printStackTrace ();} ogIu\kiZ
catch(Exception e){e.printStackTrace ();} EmaS/]X[
} -r,v3n
[s$x"Ex
6/ 5c|
private void processErrorCode(int nErrorCode) nl}LT/N
{ "*HM8\
System.err.println("Error Code : " + nErrorCode); :|9vMM^$
} 07Yak<+~
)Wle CS_
R]yce2w"z
//停止文件下载 R ?s;L r
public void siteStop() 2FZT
{ S!PG7hK2
bStop = true; rGQD+ d
for(int i=0;i<nStartPos.length;i++) >TglX t+
fileSplitterFetch.splitterStop(); Fm:Ys](
hqln6m
Qw5-/p=t
} Xps \+l%i
} YZ<zlU
//负责部分文件的抓取 qeFaY74S
**FileSplitterFetch.java 6~sU[thGW
*/ M@KQOAzt
package NetFox; +F q_w
rrz([2E2
l7uTk5
import java.io.*; `Njvk
import java.net.*; YCE *Dm
zgz!"knVx
j_d}?jh
public class FileSplitterFetch extends Thread { p>eYi \'
p@O Ip
uDND o
String sURL; //File URL Ce-= -
long nStartPos; //File Snippet Start Position }'tJc $!
long nEndPos; //File Snippet End Position |J4sQ!%K
int nThreadID; //Thread's ID g4k3~,=D3
boolean bDownOver = false; //Downing is over Y!45Kio
boolean bStop = false; //Stop identical q)9n%- YgP
FileAccessI fileAccessI = null; //File Access interface %\HE1d5;
fZpi+I
J:"@S%gy%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q>Klkd5(
{ /&|p7
this.sURL = sURL; tl /i
this.nStartPos = nStart; Odwf7>
this.nEndPos = nEnd; 9QX!HQ|5y8
nThreadID = id; 'k]~Q{K$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eYP^.U)
} 3O;H&
1K#[Ef4
OqS!y( (
public void run() im9w|P5
{ Eoixw8hz
while(nStartPos < nEndPos && !bStop) 1#cTk
{ qE2VUEv5Y
pTGGJ,
UapU:>!"`
try{ VqvjOeCbH
URL url = new URL(sURL); } r(b:}DN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;^bfLSWm{
httpConnection.setRequestProperty("User-Agent","NetFox"); @gbW:
String sProperty = "bytes="+nStartPos+"-"; IV!`~\@
httpConnection.setRequestProperty("RANGE",sProperty); a9;KS>~bq
Utility.log(sProperty); [uGsF0#e
T8Mqu`$r
l0^cdl-
InputStream input = httpConnection.getInputStream(); ,vmn{gz
//logResponseHead(httpConnection); LDEc}XXb
~b*]jZwT
/0qbRk i
byte[] b = new byte[1024]; p~3x=X4
int nRead; 0ZwXuq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k L6s49
{ /d}"s.3p
nStartPos += fileAccessI.write(b,0,nRead); +kd1q
//if(nThreadID == 1) I;"pPJ3G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nc(CGl:
} mST8+R@S
Lhp&RGy
[u!n=ev
Utility.log("Thread " + nThreadID + " is over!"); ?2#'>B
bDownOver = true; y>w;'QR&a
//nPos = fileAccessI.write (b,0,nRead); 2? yo
} Z@dVK`nD
catch(Exception e){e.printStackTrace ();} \8$~ i
} j24 3oD
} mrRid}2
izcaWt3 a
XX/s@C
//打印回应的头信息 -t S\
public void logResponseHead(HttpURLConnection con) UJh;Hp:
{ BVeMV4
for(int i=1;;i++) `dcz9 *
{ }R16WY_'
String header=con.getHeaderFieldKey(i); ;6``t+]q
if(header!=null) Z6${nUX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ur]$@N
Utility.log(header+" : "+con.getHeaderField(header)); #0T/^ #
else FHU6o910
break; L~t< 0\r
} hZHM5J~
} ";=!PL
DqQp47kp
_rB,N#{2R=
public void splitterStop() -->0e{y
{ CnL=s6XD'
bStop = true; H}kSXKO8!8
} MuOKauYa
3%?tUt
tXtNK2-1
} 8O]`3oa>
T 'c39
g|]HS4y
/* \AroSy9
**FileAccess.java l[:Aq&[o3
*//文件访问(定位，写) $4xSI"+M%
package NetFox; aA#79LS
import java.io.*; ~5&4s
1b1Ab zN
rWL;pM<
public class FileAccessI implements Serializable{ iiQn/%
_xv3UzD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 exhU!p8
RandomAccessFile oSavedFile; @T\n@M]
long nPos; X8ap
b v_UroTr
j~{cT/5Y_
public FileAccessI() throws IOException h97#(_wV>
{ a)ry}E =f
this("",0); 4{F1GW
} Kb(11$U
edo)W mn
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public FileAccessI(String sName,long nPos) throws IOException ]S&ki}i&
{ Su,:f_If,
oSavedFile = new RandomAccessFile(sName,"rw"); 1`7zYW&L
this.nPos = nPos; "QdK Md
oSavedFile.seek(nPos); To>,8E+GAb
} nte?a e
K#Ck,Y"
XJe=+_K9
public synchronized int write(byte[] b,int nStart,int nLen) ffmtTJFC5
{ eo9/
int n = -1; q_.fVn:!
try{ d:';s~
oSavedFile.write(b,nStart,nLen); sRD fA4/TF
n = nLen; _aPAn|.
} =lJ ?yuc
catch(IOException e) @M"gEeI9
{ )k,n}
e.printStackTrace (); DSz[,AaR]
} 7tcadXk0
-Ty~lZ)TDT
!}TsFa
return n; kh0cJE\_^
} 4uIYX
EpAgKzVpJ
Z71m(//*}
} D|9+:Y
*(Dmd$|0|
u)0I$Tc"
/* _h!.gZB3
**SiteInfoBean.java 7l69SQo]?
*/ 3{3@>8{w
package NetFox; gY~r{
GjhTF|
|[>@Kk4
public class SiteInfoBean { 0MHiW=
:ZrJL&
T-%=tY+-
private String sSiteURL; //Site's URL Eu?z!
private String sFilePath; //Saved File's Path X@`a_XAfd
private String sFileName; //Saved File's Name (P)G|2=
private int nSplitter; //Count of Splited Downloading File Q|AZv>'!
27eG8
>u$8Z
public SiteInfoBean() Tzex\]fw
{//nSplitter的缺省值为5 -)}s{[]d6m
//default value of nSplitter is 5 sE"s!s/
this("","","",5); :k/Xt$`
} 2 kDsIEA
`}PYltW
7s(tAbPdB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 92DM1~ *
{ ss)x fG
sSiteURL= sURL; f4f2xe7\Q
sFilePath = sPath; _B^zm-}8|B
sFileName = sName; ~18a&T:
this.nSplitter = nSpiltter; .hat!Tt9
C{}_Rb'x
@V*dF|# /
} q\6(_U#Tl
D`LBv,n
B3#G
public String getSSiteURL() !K>iSF<
{ KMRPleF
return sSiteURL; =5+*TL`
} sasurR|;
6z9 '|;,4
TQ4@|S:OF
public void setSSiteURL(String value) {6'Xz
{ 7PY$=L48A
sSiteURL = value; !__0Vk[s
} [%P#ieD4
#V!a<w4_
KrE'M
public String getSFilePath() ntW@Fm:bw>
{ 9|+6@6VY!
return sFilePath; mOE *[S)
} 3"y 6|e/5
! xCo{U=
UD.bb
public void setSFilePath(String value) r`O Yq
{ 75^6?#GS
sFilePath = value; W:d p(,L
} A'|!O:s
BN_h3|)
|9I)YD
public String getSFileName() [oLV,O|s|j
{ ^po@U"
return sFileName; gF)9a_R%p
} [qYr~:`-[
5>x_G#W
ffrIi',@
public void setSFileName(String value) {OU|'
{ {a7~P0$
sFileName = value; xe`^)2z
} vi,hWz8WB
Y?0/f[Ax,y
$coO~qvU
public int getNSplitter() X,QsE{
{ ,;)ZF
return nSplitter; JWn26,
} qA)OkR'm
cr1x CPJj
?%,NOX
public void setNSplitter(int nCount) *G19fJ[5
{ =S&`~+
nSplitter = nCount; C?<pD+]b_
} Q.mJ7T~T
} fO*jCl
q-F K=r 5
4qQ,1&!]S
/* G7%bY
**Utility.java gYKz,$
*/ 2B,O/3y
package NetFox; Ed9Uw7
/A=w`[<
6%v9o?:~l
public class Utility { -=ZL(r 1
.G0 N+)
Luq4q95]
public Utility() a{5SOe;;
{ #z `W ,^C
,erw(7}'.
;5[KZ8j6Y
} 8H!QekQZ]\
F!omkN
//线程睡眠 `9~ %6N?7#
public static void sleep(int nSecond) ,WT>"9+
{ }Z!D?(
try{ %q{q.(M#
Thread.sleep(nSecond); d1j9{
} 2QfN.<[-
catch(Exception e) drq3=2
{ ]R__$fl`8
e.printStackTrace (); kx"10Vw
} &.?XntI9O
} m~=~DMj
$<}c[Nm
//日志 #~u0R>=
public static void log(String sMsg) LFp "Waiv
{ +{J8,^z#
System.err.println(sMsg); )-C3z
} 0'QWa{dS\
P15 H[<:Fz
CD|[PkjW
public static void log(int sMsg) "LMj,qZ1!
{ %`Re{%1;
System.err.println(sMsg); 4fEDg{T
} }cKB)N BJb
} pfA6?tP`
zw0w."V
XX6Z|Y5.
/* 7>vm?a^D2&
**TestMethod.java #&Sr;hAJ
*/ X#Bb?Pv
package NetFox; :=*deZ<
9"[;ld<
v9*m0|T0M
public class TestMethod { &p0e)o~Ux
/ HTY>b
}f}.>B0#
public TestMethod() _73q,3`24
{ ///xx/weblogic60b2_win.exe ?6#won
try{ d=!:UB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gq?:n.;TY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +6m.f,14q
SiteFileFetch fileFetch = new SiteFileFetch(bean); QTV*m>D
fileFetch.start(); .n-#A
} y8Va>ul"U
catch(Exception e){e.printStackTrace ();} 7R+(3NU1A
6b|?@
G#M)5'Q]U
} C0rf
!40>LpL[
/zn=AAYb
public static void main(String[] args) o5<<vvdA
{ ~(5r+Z}*`
new TestMethod(); k9|5TLXq?
} ]I*c:(qwu
} `?Rq44=
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