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)); p8XvfM
} 4RctYMz
for(int i=0;i<nEndPos.length-1;i++) -uN{28;@
{ 6|lsG6uf
nEndPos = nStartPos[i+1]; 8g:VfzaHu
} 0Sk~m4fj(
nEndPos[nEndPos.length-1] = nFileLength; w;Azxcw
} %AJ9fs4/
} V5-!w0{
%h(%M'm?
MtwlZg`c3
//启动子线程 :@5{*o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =^p}JhQ
for(int i=0;i<nStartPos.length;i++) 9BP'[SM%),
{ gJp6ReZ#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O`Qke Z}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T*@o?U
nStartPos,nEndPos,i); 02J(*_o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _R|_1xa=
fileSplitterFetch.start(); EKO'S+~
} :LB*l5\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ge({sy>X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &0f/F:M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &u^]YE{
nEndPos = " + nFileLength); x~uDCbL
// fileSplitterFetch[nPos.length-1].start(); 3=U#v<
>o13?-S%e
> dVhIbG
//等待子线程结束 ~-NSIV:f
//int count = 0; yp4[EqME
//是否结束while循环 p&$PsgR
boolean breakWhile = false; Ohgu*5!o
oMemF3M
UhDf6A`]
while(!bStop) l?IeZisX
{ 94O\M RQ*
write_nPos(); Z,AY<[/C
Utility.sleep(500); lO|LvJyx
breakWhile = true; y+Nw>\|S
Q}^Ip7T
1p5'.~J+Q
for(int i=0;i<nStartPos.length;i++) \:F$7 *Ne
{ fe<7D\Sp@
if(!fileSplitterFetch.bDownOver) Y=|20Y\K
{ 2%fzRXhu%
breakWhile = false; ~tTn7[!
break; [z\baL|
} &,8Qe;
} WI| -pzg
if(breakWhile) ,_H H8[&
break; ah<p_qe9|
%m/lPL
OcWKK!A
//count++; \:s%;s51
//if(count>4) \z6UWZ
// siteStop(); d 4tL
} !0? B=yA
x6JV@wA&
2gklGDJD
System.err.println("文件下载结束！"); z&n2JpLY7
} ;X]B0KFe7
catch(Exception e){e.printStackTrace ();} I)#8}[vK
} rSt5@f?
vO$cF*
m;4ti9
//获得文件长度 ceJ#>Rj
public long getFileSize() "9^b1UH<
{ \tvL<U"'
int nFileLength = -1; bh5P98s
try{ Wtw,YFT
URL url = new URL(siteInfoBean.getSSiteURL()); 6wu`;>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >`&2]Wc)
httpConnection.setRequestProperty("User-Agent","NetFox"); )N~ p4kp
r?Mf3U^G
PfU\.[l$
int responseCode=httpConnection.getResponseCode(); #>KiX84
if(responseCode>=400) NwOV2E6@OW
{ 6q'Q?Uw^
processErrorCode(responseCode); ,6MJW#~]
return -2; //-2 represent access is error Hmm0H6&u
} `peR,E
0+qC_ISns
o:cTc:l)
String sHeader; @,=pG
,J+L_S+B~
9XQE5^
for(int i=1;;i++) W+u,[_
{ -0q|AB<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wXp:XZ:]T
//Utility.log(in.readLine()); QsxvA;7%
sHeader=httpConnection.getHeaderFieldKey(i); wmVb0~[
if(sHeader!=null) Q[#8ErUY
{ 3f^jy(
if(sHeader.equals("Content-Length")) c\>I0HH;!
{ Z2g<"M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {Mb<onW
break; ng|^Zm%
} @8`I!fZ
} ORP<?SG55u
else G na%|tUz|
break; W;R6+@I[
} XNx$^I=
} WvF{`N
catch(IOException e){e.printStackTrace ();} Q\IViM
catch(Exception e){e.printStackTrace ();} ;*zLf 9i
5*A5Y E-
^1c7\"{
Utility.log(nFileLength); RFS}!_t+|
aqk$4IG
6~ y'
return nFileLength; KC; o
} [/*;}NUv
;Qq_
6RxI9{ry
//保存下载信息（文件指针位置） f^QC4hf0
private void write_nPos() Go:(R {P
{ !nJl.Y$
try{ am3JzH
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2/t;}pw8
output.writeInt(nStartPos.length); =AzkE]
for(int i=0;i<nStartPos.length;i++) 05HCr"k
{ GK,{$SC+=
// output.writeLong(nPos); t 3N}):
output.writeLong(fileSplitterFetch.nStartPos); t@#5 G* _Q
output.writeLong(fileSplitterFetch.nEndPos); (i(E~^O
} n7~3~i`D;
output.close(); t>%b[(a
} 5CcX'*P
catch(IOException e){e.printStackTrace ();} _hl| 3 eW5
catch(Exception e){e.printStackTrace ();} r90tXx
} `EMGrw_
\fC;b"j
=,ax"C?pR
//读取保存的下载信息（文件指针位置） u=s,bt,"5
private void read_nPos() a""9%./B
{ t1 9f%d
try{ e~)4v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >{~xO 6H
int nCount = input.readInt(); WdS1v%
nStartPos = new long[nCount]; wTR?8$
nEndPos = new long[nCount]; I*o6Bn |D
for(int i=0;i<nStartPos.length;i++) H'k~;
{ Jpp-3i.F#
nStartPos = input.readLong(); '>1M~B
nEndPos = input.readLong(); Z)~?foe'
} MD1X1,fk
input.close(); K\B!tk
} :O@n6%pSL
catch(IOException e){e.printStackTrace ();} (JdheCq!x
catch(Exception e){e.printStackTrace ();} y_W?7S
} (DvGA I
NRG~ya >
?xMTO
private void processErrorCode(int nErrorCode) !.V_?aYi8
{ O"TVxP:
System.err.println("Error Code : " + nErrorCode); 2<n18-|OQ
} OPq|4xu
,-EN{ed
Z|UVH
//停止文件下载 *wmkcifF;
public void siteStop() nIBeZof
{ qA!4\v={
bStop = true; /o6ido
for(int i=0;i<nStartPos.length;i++) E>*b,^J7g
fileSplitterFetch.splitterStop(); n2AoEbd
KgD$P(J:[
H*0g*(
} +RpCh!KP
} zCA8}](C^
//负责部分文件的抓取 txnH~;(
**FileSplitterFetch.java 1#"wfiW
*/ &u[F)|
package NetFox; !E00I0W-h
/>9`Mbg[G
|8k^jq
import java.io.*; F:<+}{Av
import java.net.*; >#mKM%T2MJ
:$yOic}y
MU] F'6V
public class FileSplitterFetch extends Thread { /i@.Xg@:
.L#4#IO
W"#<r
String sURL; //File URL RB""(<
long nStartPos; //File Snippet Start Position <T.R%Jys
long nEndPos; //File Snippet End Position <)O#Y76s
int nThreadID; //Thread's ID q\!"FDOl4
boolean bDownOver = false; //Downing is over vFLE%z{\o
boolean bStop = false; //Stop identical #LR6wEk
FileAccessI fileAccessI = null; //File Access interface .*YOyK3H
h \`(
O\yYCi(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6z~ [Ay
{ 3ZSU^v
this.sURL = sURL; }*-fh$QJ
this.nStartPos = nStart; p*cyW l
this.nEndPos = nEnd; Mx93D
nThreadID = id; r?0w5I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5B8/"G
} *qL2=2
}/NjZ*u
y<`:I|y
public void run() $ <[r3
{ ;*Y+.?>a
while(nStartPos < nEndPos && !bStop) t*BCpC}
{ 30Q77,Nsny
5$Kv%U
.|L9}<
try{ 60>g{1]
URL url = new URL(sURL); #vy[v22
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;Cx`RF w
httpConnection.setRequestProperty("User-Agent","NetFox"); '5T:*Yh
String sProperty = "bytes="+nStartPos+"-"; 'X&"(M
httpConnection.setRequestProperty("RANGE",sProperty); yl' IL#n]r
Utility.log(sProperty); 5c%Fb:BW=
h=YTgJ
<R2SV=]Sq#
InputStream input = httpConnection.getInputStream(); i+I.>L/S
//logResponseHead(httpConnection); }L{GwiDMDl
l_ x jsu
1dp8'f5^
byte[] b = new byte[1024]; Z$Qwn
int nRead; (l2n%LL]*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \:n<&<aVSr
{ ZS_ z
nStartPos += fileAccessI.write(b,0,nRead); T|YMU?4
//if(nThreadID == 1) Z>1yLt@ls
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [["eK9}0
} ]4*E:
ph2 _P[S'
Vn/FW?d7
Utility.log("Thread " + nThreadID + " is over!"); 4uE/!dT
bDownOver = true; >K%+h)%kI
//nPos = fileAccessI.write (b,0,nRead); 4 l+z
} V%M@zd?u.
catch(Exception e){e.printStackTrace ();} Iz#jR2:yn
} ]wbV1Y"
} !,7)ZW?*8
r:U<cLT[9
mv*M2NuhT
//打印回应的头信息 KUq(&H7
public void logResponseHead(HttpURLConnection con) ^\VVx:]
{ ]nxSVKE4p
for(int i=1;;i++) +y-3tcI)
{ E`wq`g`H<
String header=con.getHeaderFieldKey(i); li')U
if(header!=null) {t'SA]|g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \4OU+$m
Utility.log(header+" : "+con.getHeaderField(header)); 1F2(MKOo!
else gIGi7x
break; KAr5>^<zw
} 4>HQ2S{t
} !Xq5r8]
AQ"rk9Z
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public void splitterStop() -gb@BIV#
{ _w5c-\-PUM
bStop = true; ;t.)A3 PL
} XzBl }4s
56Lt "Z F
a63Ud<_a7
} $O;a~/T
j3 @Q
3?&P^{
/* %~Wr/TOt+
**FileAccess.java !i{5mc\
*//文件访问(定位，写) @GQtyl;q
package NetFox; ICWHEot
import java.io.*; V-dub{K
cS#| _
>(Wt
public class FileAccessI implements Serializable{ fzjtaH?
7zNfq.Ni~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r8_MIGM'
RandomAccessFile oSavedFile; l>7?B2^<E
long nPos; P$/Y9o
\&v)#w
"t>H B6^
public FileAccessI() throws IOException cm>+f^4?n
{ ~^g*cA t}
this("",0); %W2 o`W$
} S)^eHuXPI
jyRz53
'z};tIOKJk
public FileAccessI(String sName,long nPos) throws IOException c8o2* C$
{ 8(-N;<Ef2
oSavedFile = new RandomAccessFile(sName,"rw"); # *7ImEN
this.nPos = nPos; y(**F8>?xE
oSavedFile.seek(nPos); xUB{{8B:L
} gp^xl>E
)Y=ti~?M(
}A<fCm7
public synchronized int write(byte[] b,int nStart,int nLen) 7"])Y
{ G/_8xmsU
int n = -1; ]rO/IuB
try{ VQ2B|v
oSavedFile.write(b,nStart,nLen); &:=[\Ws R
n = nLen; //}KWz
} 3pkx3tp{
catch(IOException e) 2 3A)^j
{ S<++eu
e.printStackTrace (); sFRQFX0XoY
} RWGAxq`9f
2&<&q J
6?l|MU"Q.
return n; ~:UAL}b{\~
} ~=Fp0l)#
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"Qe2U(Un
} #\O?|bN'q
JZ"XrS0?
4m_CPe
/* DV~g
**SiteInfoBean.java idZ]d6
*/ %wmbFj}
package NetFox; o5w =
\r\wqz7
ZX40-6#O
public class SiteInfoBean { aw1f;&K4
kNUNh[
CN#2-[T
private String sSiteURL; //Site's URL T'%Rkag>
private String sFilePath; //Saved File's Path k=.pcDX
private String sFileName; //Saved File's Name 6p~8(-nG
private int nSplitter; //Count of Splited Downloading File .!g
TI637yqCU
V_H0z
public SiteInfoBean() frbeCBP&)
{//nSplitter的缺省值为5 k{+Gv}Y
//default value of nSplitter is 5 m^1'aO_;q
this("","","",5); 9Ui|8e~=
} .:TSdusr~
BHIC6i%
m/1;os5+8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R-BN}ZS
{ m)xz_Plc
sSiteURL= sURL; !;&{Q^}
sFilePath = sPath; MZ<BCRB
sFileName = sName; (L7%V !
this.nSplitter = nSpiltter; M}!E :bv'
*>7Zc
sKL"JA T
} 8FT@TUFb
ZTi KU)
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public String getSSiteURL() fzjZiBK@
{ [hKt4]R
return sSiteURL; Znh)m
} W0N*c*k
2[Bw+<YA`
|&0Cuwt
public void setSSiteURL(String value) oJor ]QYK
{ JA6#qlylL
sSiteURL = value; t;)`+K#1:
} ,gn**E
~5wT|d
@DCw(.k*
public String getSFilePath() d?1[xv;
{ 9 IY1"j0O
return sFilePath; v\Xyz )
} @"BkLF
OC_i,
r>7Dg~)V
public void setSFilePath(String value) "P8cgj C
{ ]dQ
sFilePath = value; C_V5.6T!
} 5,K*IH
Q`(.Blgm;
V=5v7Y3(j
public String getSFileName() Qon>[<]B
{ HT=-mwa_]
return sFileName; 2)+ddel<Z
} bRK[u\,
0z=^_Fb
'645Fr[lg
public void setSFileName(String value) LP5@ID2G
{ Xe:e./@
sFileName = value; hGlRf_{
} ~mu)Cw
7& G#&d
g,""j`
public int getNSplitter() =&v&qne9
{ ]sV) '-
return nSplitter; e:zuP.R
} Q%^!j_#
.V\:)\<|
Tq!.M1{&
public void setNSplitter(int nCount) s_Gf7uC
{ b0lZb'
nSplitter = nCount; Bq#B+JwX
} >r5s>A[YC
} B/ACU
E3,Nc`'m9
f|-%.,
/* uUI@!)@2
**Utility.java PvqG5-L~W
*/ " )/febBS
package NetFox; Y8%*S%yO
vHxLn/
bf-V Q7
public class Utility { i[a1ij=
CxJkT2
=@0/.oSD
public Utility() qr_:zXsob_
{ Jx4"~ 4
%tJ@)
!O*uQB
} xE%sPWbj
)NL_))\
//线程睡眠 29AWg(9?aS
public static void sleep(int nSecond) LKe~
{ t{RdqAF
try{ =6LF_=}
Thread.sleep(nSecond); $g!~T!p=
} oBZzMTPe
catch(Exception e) )-_To&S*
{ -|nHwSrCZ/
e.printStackTrace (); [nG@ 3n
} oV Hh
} \?rBtD(
&WAJ;7f
//日志 %P tdFz$
public static void log(String sMsg) i2(lqhaP
{ l!YjDm{E
System.err.println(sMsg); T9=55tpG9
} m*Q*{M_e
:Vl2\H=P
;Alw`'
public static void log(int sMsg) EwH_k
{ <\C/;
System.err.println(sMsg); }qn@8}
} i*-L_!cc:
} H_<hZUB
>lIQM3
/$,~|X;&
/* EoD[,:*
**TestMethod.java Ec;{N
*/ STY\c5
package NetFox; :r,o-D
`' "125T
l&LrcM
public class TestMethod { UpIt"+d2&
yCLDJ%8
|#_`aT"
public TestMethod() Eggdj+
{ ///xx/weblogic60b2_win.exe wEJ) h1=)^
try{ :Mq-4U.e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q=(.N>%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y] "_}
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZAcH`r*
fileFetch.start(); #Kd^t=k
} &]mZp&
catch(Exception e){e.printStackTrace ();} re;^,
HHU0Nku@ho
Q1?09
} sGdlS&08(
X=U>r
g<&n V>wF
public static void main(String[] args) -p\uW0XA
{ N! N>/9
new TestMethod(); G(6MLh1
} v;m}<3@'
} tjIT4
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