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)); $%R$G`.KM
} &<RpWAk{
for(int i=0;i<nEndPos.length-1;i++) ~m^ #FJu
{ ^vilgg~
nEndPos = nStartPos[i+1]; rl2&^N
} :GpDg
nEndPos[nEndPos.length-1] = nFileLength; UMl#D>:C<
} NKb1LbnZ*y
} \*f;Xaa
e[_m<e
qMt++*Ls
//启动子线程 E.|-?xQ6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YH&bD16c3
for(int i=0;i<nStartPos.length;i++) 9o*,P,j'}
{ 6(d}W2GP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rp7ntI:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rE9I>|tX
nStartPos,nEndPos,i); 5NoI~X=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /zDi9W*~1
fileSplitterFetch.start(); }v:jncp
} %wcSM~w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :+Om]#`Vls
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :0& X^]\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k@ZLg9
nEndPos = " + nFileLength); 2_vbT!_
// fileSplitterFetch[nPos.length-1].start(); B33$pUk
ABE@n%|`
:G\<y
//等待子线程结束 I$N8tn+E
//int count = 0; t58e(dgi
//是否结束while循环 )9l^O
boolean breakWhile = false; !l]dR@e
M" ^PW,k
8#!i[UFdj
while(!bStop) ;bHV
{ Vq;dJ%sY
write_nPos(); [(1c<b2r
Utility.sleep(500); >h0-;
breakWhile = true; dT,o=8fg
otggN:^Qw
[kE."#
for(int i=0;i<nStartPos.length;i++) 7i&:DePM'q
{ !,V{zTR
if(!fileSplitterFetch.bDownOver) 5waKI?4F
{ "HE^v_p
breakWhile = false; \+aC"#+0
break; 5onm]V]
} 2^i(gaXUQ
} g1t0l%_7^
if(breakWhile) ,U(1NK8o
break; i[wb0yL
yR(x+Gs{]
o sKKt?^?
//count++; a!O0,y
//if(count>4) Q0EiEX)
// siteStop(); ~ vqa7~}m
} R<OI1,..r
sc,Xw:YO
o=0]el^A
System.err.println("文件下载结束！"); =s<( P1|"
} HRB<Y mP@
catch(Exception e){e.printStackTrace ();} " Hd|7F'u=
} YnLErJ
\hCH>*x<
{%_L=2n6
//获得文件长度 "etPT@gF
public long getFileSize() j~*L~7
{ W.kM7z>G
int nFileLength = -1; 6{txm+U
try{ itC-4^
URL url = new URL(siteInfoBean.getSSiteURL()); )"pF R4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uu`G 2[t
httpConnection.setRequestProperty("User-Agent","NetFox"); S~|T4q(
@')[FEdW
9-MUX^?u
int responseCode=httpConnection.getResponseCode(); 7hsGua
if(responseCode>=400) jy'13G/b\
{ z[Xd%mhjO
processErrorCode(responseCode); P#AW\d^"B
return -2; //-2 represent access is error TqnTS0fx
} >y,-v:Vy
%n*-VAfE\
aA,!<^&}
String sHeader; K.0:C`C
Hw4%uS==V
1YH+d0UGn
for(int i=1;;i++) MG.` r{5
{ Hro-d1J7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dd\jHF>u
//Utility.log(in.readLine()); R rda# h^
sHeader=httpConnection.getHeaderFieldKey(i); '*3h!lW1.
if(sHeader!=null) (SvWvm
{ +llR204
if(sHeader.equals("Content-Length")) AB4(+S*LA
{ :8OZ#D_Hl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M]J^N#
break; O&Y*pOg
} pej|!oX
} 4T ~}
else 62zYRs\Y)X
break; 9gmW&{6q
} !_Wi!Vr_
} &wV]"&-
catch(IOException e){e.printStackTrace ();} K57&yVX
catch(Exception e){e.printStackTrace ();} qw^uPs7Uw
adR)Uq9
3xaR@xjS
Utility.log(nFileLength); cH&J{WeZa
-[wGX}}
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return nFileLength; ;<ZLcTL
} S Em Q@1
|AozR ~
N(Tz%o4
//保存下载信息（文件指针位置） @"^0%/2-
private void write_nPos() hbY5l}\5
{ tIuCct-
try{ .?loO3 m
output = new DataOutputStream(new FileOutputStream(tmpFile)); :s7m4!EF
output.writeInt(nStartPos.length); \hx1o\
for(int i=0;i<nStartPos.length;i++) &__es{;P
{ r/u A.Aou^
// output.writeLong(nPos); y#3j`. $3p
output.writeLong(fileSplitterFetch.nStartPos); ?k(7 LX0j
output.writeLong(fileSplitterFetch.nEndPos); ;;#qmGoE
} )% ~OH
output.close(); a m|F?|1
} Tu).K.p:
catch(IOException e){e.printStackTrace ();} AHXSt
catch(Exception e){e.printStackTrace ();} LhA/xf
} pu2tY7Ja
)mF5Vw"
@}}$zv6l,
//读取保存的下载信息（文件指针位置） ;6>2"{NW
private void read_nPos() ]7Tkkw$
{ YTUZoW2
try{ 7+\+DujE$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =4FXBPoQK
int nCount = input.readInt(); ;wz^gdh;
nStartPos = new long[nCount]; Utnr5^].2O
nEndPos = new long[nCount]; WE:24b6
for(int i=0;i<nStartPos.length;i++) d?A 0MKnl
{ 8Djc c z
nStartPos = input.readLong(); *%%g{ 3$
nEndPos = input.readLong(); VHIOwzC
} 0Ziw_S\d&s
input.close(); P\1L7%*lU
} ;V*l.gr'2
catch(IOException e){e.printStackTrace ();} a,k>Q`
catch(Exception e){e.printStackTrace ();} i3@)W4{
} ~a ]+#D
w9< R#y[A
&L'Dqew,*
private void processErrorCode(int nErrorCode) {xXsBh Y
{ >n'o*gZM
System.err.println("Error Code : " + nErrorCode); 1H6<[iHW
} "@iK' c^
:bwjJ}F
y1dDO2mA
//停止文件下载 n*[XR`r}
public void siteStop() ;:\<gVi:
{ L~lxXTG\
bStop = true; >\KNM@'KI
for(int i=0;i<nStartPos.length;i++) u{['<r;I
fileSplitterFetch.splitterStop(); RI(DXWM|h
9]f!'d!5
tX_R_]v3
} a7r%X -
} D1zBsi94D
//负责部分文件的抓取 p@xf^[50k
**FileSplitterFetch.java _m5uDF?[
*/ _Kl_61k
package NetFox; Oo5w?+t
`6~Aoe
J^SdH&%Z
import java.io.*; a_f~N1kq
import java.net.*; cW@Zd5&0S
+ElfZ4
hT`J1nNt
public class FileSplitterFetch extends Thread { O}-jCW;K
zzTfYf)
,(qRc(Ho
String sURL; //File URL IzikDc10
long nStartPos; //File Snippet Start Position )dbB=OZ
long nEndPos; //File Snippet End Position a{^m-fSaR"
int nThreadID; //Thread's ID gQWa24
boolean bDownOver = false; //Downing is over hYPl&^
boolean bStop = false; //Stop identical I*{4rDt
FileAccessI fileAccessI = null; //File Access interface ,':fu
P5a4ze
Mo?~_|}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V58wU:li
{ JTO~9>$ B
this.sURL = sURL; de.&`lPRf
this.nStartPos = nStart; nAW:utTB
this.nEndPos = nEnd; A9I{2qW9+Z
nThreadID = id; ($au:'kU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Cl;oi}L
} Rdvk ml@@
DFZkh^PFd
I`-8Air5f
public void run() 5na~@-9p
{ ;RDh~EV
while(nStartPos < nEndPos && !bStop) @XLy7_}
{ n0r+A^]
[Dk=? +
q)X$^oE!6
try{ OK[T3/v,
URL url = new URL(sURL); Uzz'.K(Mv|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rI= v
httpConnection.setRequestProperty("User-Agent","NetFox"); S%bCyK%p
String sProperty = "bytes="+nStartPos+"-"; & ?h#Z!
httpConnection.setRequestProperty("RANGE",sProperty); {MtpkUN
Utility.log(sProperty); 1C}NQ!.
.k,1f*%
CtyoHvw+M
InputStream input = httpConnection.getInputStream(); ciBP7>'::
//logResponseHead(httpConnection); h`KFL/fT
hn5h\M?
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byte[] b = new byte[1024]; Sg&UagBj
int nRead; HePUWL'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %<k2#6K
{ Gw>^[dmt!
nStartPos += fileAccessI.write(b,0,nRead); FQu8vwV6>
//if(nThreadID == 1) d4u})
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t2/#&J]
} lD)%s!
#pP[xE"Y
R)_%i<nq\
Utility.log("Thread " + nThreadID + " is over!"); fol,xMc&
bDownOver = true; PmkR3<=leg
//nPos = fileAccessI.write (b,0,nRead); \Jx04[=
} KK&rb~
catch(Exception e){e.printStackTrace ();} Aw}"gpL
} CJ1 7n
} G,?hp>lj
QQ%D8$k"
]RPs|R?
//打印回应的头信息 10)jsA
public void logResponseHead(HttpURLConnection con) Bp_$.!Qy
{ }YB*]<]
for(int i=1;;i++) :o|\"3
{ \w/yF4,3<w
String header=con.getHeaderFieldKey(i); `IP/d
if(header!=null) $+P>~X)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VCY\be
Utility.log(header+" : "+con.getHeaderField(header)); UJD 0K]s
else [$qyF|/K`n
break; Li!Vx1p;u.
} )m`<H>[Eb=
} Rn}l6kbM
gp5_Z-me
*,e:]!*
public void splitterStop() ]JCvyz H
{ zz+$=(T:M
bStop = true; KC/=TSSXd.
} -m)X]]~C
kStnb?nk
5Sm}nH
} GR&z,
.:@Ykdm4I
fKeT,U`W
/* 'C`U"I
**FileAccess.java _7H7 dV
*//文件访问(定位，写) !k6K?xt
package NetFox; DnC{YK
import java.io.*; E)TN,@%
6VS4y-N
A0o-:n Fu
public class FileAccessI implements Serializable{ LCZ\4g05
&|Bc7+/P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FG%X~L<d,)
RandomAccessFile oSavedFile; ?ATOXy
long nPos; W}m)cn3@
iL7DRQ1
R9'b-5q
public FileAccessI() throws IOException :yRo3c
{ KV]X@7`@
this("",0); &,}j#3<
} JW{rA6?
}T; P~aG
Tu$f?
public FileAccessI(String sName,long nPos) throws IOException WlB
{ b<a4'M
oSavedFile = new RandomAccessFile(sName,"rw"); rm5bkJcg~
this.nPos = nPos; ~ DBcIy?
oSavedFile.seek(nPos); \SN&G`o<
} ZjgsR|i
I%r{]-Obr-
!F1M(zFD
public synchronized int write(byte[] b,int nStart,int nLen) R@/"B8H
{ 5 xppKt
int n = -1; 6N",-c
try{ 43|XSyS
oSavedFile.write(b,nStart,nLen); 4[.oPK=i
n = nLen; j"}*T
} aNScF
catch(IOException e) ZG>PQA
{ V,mw[Hw
e.printStackTrace (); }j^i}^Du,
} IAw{P08+
kddZZA3`
^Y@\1fX 4e
return n; '_GrD>P)-
} xfpa]Z
,5|&A
**$LR<L
} Gcdd3W`O
"/3 db[
vK9E
/* ]Bcp;D
**SiteInfoBean.java E;Y;z
*/ )CuZDf@
package NetFox; N):tOD@B
Of"
P,xKZ{(
public class SiteInfoBean { +_; l|uhT;
-n=^U
Ont%eC\
private String sSiteURL; //Site's URL `}(b2Hc>
private String sFilePath; //Saved File's Path Jz7!4mu
private String sFileName; //Saved File's Name e8pG"`wM8
private int nSplitter; //Count of Splited Downloading File i>D.!x
qyF{f8pzq
luo
public SiteInfoBean() '^No)n\`
{//nSplitter的缺省值为5 ]~aF2LJ_q
//default value of nSplitter is 5 8vMG5#U[
this("","","",5); -*$HddD
} L\@I*QP
G_0( |%
n;@bLJ$W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fDT%!
{ W8ouO+wK
sSiteURL= sURL; VKq=7^W
sFilePath = sPath; :pGaFWkvO
sFileName = sName; Ove<mFI\
this.nSplitter = nSpiltter; l|/ep:x8
P!H_1RwXKC
.@(6Y<dN
} vgsJeV`}I
~F4fFQ-yy
E~]R2!9
public String getSSiteURL() 9fhsIe
{ ;\]b T;#
return sSiteURL; f4Xk,1Is
} ?AJKBW^
7* yzEM
*~t6(v?
public void setSSiteURL(String value) v.pBX<
{ tnPv70m
sSiteURL = value; j6Yy6X]
} K POa|$
yf[~Yl>Ogw
-=~| ."O
public String getSFilePath() _a6[{_Pc
{ l038%U~U!
return sFilePath; h|,:e;>}
} 6LalW5I
P(+&OoY2
RloK,bg
public void setSFilePath(String value) n?- })
{ {so`/EWa
sFilePath = value; [H6hyG~
} 3BtaH#ZY
bn!HUM,
l|kSsP:GO
public String getSFileName() H."EUcE{
{ d-k%{eBV
return sFileName; {]:7bV#JP
} nEJY5Bz$
KwPOO{4]g
BW 4%l
public void setSFileName(String value) 9{ >Ui
{ .^h#_[dp
sFileName = value; U56G.
} G LIi6
aqj@Cjk4Z
gk"$,\DI
public int getNSplitter() c_vqL$Dl
{ cc~O&?)i
return nSplitter; Qa-K$dm%
} sj HrPs e
I'uSp-Sfy
mt,OniU=Q
public void setNSplitter(int nCount) M<kj_.
{ B56L1^7
nSplitter = nCount; !,6c ~ w
} ~N<4L>y<
} z([ v%zf
7f0lQ
3'cE\u
/* ]pH-2_
**Utility.java %M7` Hwu
*/ ;\14b?TUH
package NetFox; 5N/%v&1
u~WVGjoQ
EfCx`3~EX
public class Utility { Hn5|B 3vN
@d mV
Exc9` 7%.
public Utility() va}Pj#=
{ G!>z;5KuS
e\!0<d
t!r A%*
} ihIVUu-M
\=:~ki=@B
//线程睡眠 )qo {c1X
public static void sleep(int nSecond) d@XV:ae
{ +n{#V;J
try{ gcdlT7F)b-
Thread.sleep(nSecond); CGY]r.O*
} -f%'
catch(Exception e) q*_/to
{ %oZ6l*
e.printStackTrace (); 925|bX6I
} glM$R&/
} 7UVzp v
s$Z _48
//日志 l49*<nkmq
public static void log(String sMsg) .Le?T&_
{ ]n_ k`
System.err.println(sMsg); GO`Ru 8
} $\]&rZVi
]:4*L
Ju96#v+:
public static void log(int sMsg) ]rWgSID
{ 8FKXSqhVM
System.err.println(sMsg); zgNc4B
} zNxW'?0Z?
} c:<005\Bg
kEOS{C%6R
"B3N*R(["
/* JBE!j-F
**TestMethod.java M>~Drul
*/ `$,GzS(
package NetFox; Ta(Y:*Ri
[d(U38BI
nbm&wa[
public class TestMethod { NG "C&v
nqI@Y)
&7PG.Ff!r
public TestMethod() nExU#/*~^
{ ///xx/weblogic60b2_win.exe wO'TBP
try{ Fl kcU `j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9 7GV2]-M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >O*IQ[r-
SiteFileFetch fileFetch = new SiteFileFetch(bean); CE#gfP
fileFetch.start(); jcuB
} ^l9N48]|?
catch(Exception e){e.printStackTrace ();} D8Ykg >B;&
95 ;x=ju
B@&4i?yJ
} CG0 M
DI:]GED"=
NdMb)l)m
public static void main(String[] args) nuk*.Su
{ =Xi07_8Ic<
new TestMethod(); 3Dng1}
} ABQ('#78
} ';3{T:I
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