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)); us/}_r74N*
} 4=BIYC"Lu
for(int i=0;i<nEndPos.length-1;i++) Ez\TwK
{ #qx$ p
nEndPos = nStartPos[i+1]; [{}Hk%wlX
} FX"j8i/N
nEndPos[nEndPos.length-1] = nFileLength; _#9F@SCA
} eflmD$]SW
} Aoi)11>
c#-o@`Po
IE^xk@
//启动子线程 ~Ox !7Lp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J@CKgE
for(int i=0;i<nStartPos.length;i++) QD2;JI2
{ ';>]7oT`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -2o_ L?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,QB]y|:
nStartPos,nEndPos,i); yYdow.b!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xr B)[kQ
fileSplitterFetch.start(); Q%_QT0H9Kz
} e-Pn,j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | e?:Uq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?M<q95pL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jDWmI%Y.
nEndPos = " + nFileLength); W@bZ~Q9
// fileSplitterFetch[nPos.length-1].start(); ] I&l0Fx
3xhGmD\SKO
%1oh+'ES F
//等待子线程结束 3qlY=5Y
//int count = 0; eYpK!9
//是否结束while循环 ;2k!KW@
boolean breakWhile = false; _~QiQDq
R^hlfKnt
V6L0\
while(!bStop) ^MXW,xqb
{ sB~|V <
write_nPos(); ++gWyzD
Utility.sleep(500); v@&UTU
breakWhile = true; :{g;J
?@>PKUv{
*!m\%*y{
for(int i=0;i<nStartPos.length;i++) xlP0?Y1Bl
{ z]49dCN
if(!fileSplitterFetch.bDownOver) 2FE13{+f
{ )8Q;u8jm1
breakWhile = false; L2Vj2o"x?
break; 2]UwIxzR
} .7<6 zG6J
} ['%$vnS5S
if(breakWhile) )w_hbU_Pb&
break; RSTA!?K/.
?!Wh ^su-
nu6p{_M
//count++; ~_]i'ii8
//if(count>4) yt4sg/]:
// siteStop(); Ai*+LSG
} .3 S9=d?
N0V`xrS
03?7kAI
System.err.println("文件下载结束！"); O:{N5+HVG
} &-c{
catch(Exception e){e.printStackTrace ();} KlGmO;k
} 3P|z`}Ka
+v)+ k
e`eh;@9p
//获得文件长度 MFtC2*
public long getFileSize() +=Y$v2BZA3
{ :m[HUh
int nFileLength = -1; -\[&<o@/D
try{ nkO4~p
URL url = new URL(siteInfoBean.getSSiteURL()); n.b_fkZNr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vPSY1NC5
httpConnection.setRequestProperty("User-Agent","NetFox"); b^'>XT~1J&
=KW~k7TaN
hbSXa'
int responseCode=httpConnection.getResponseCode(); aE2Yl
if(responseCode>=400) p_EWpSOt7
{ Q-}cB
processErrorCode(responseCode); A2%RcKY7
return -2; //-2 represent access is error AkEt=vI
} xxZO{_q
vVFT0_
?2<V./2F
String sHeader; i{7Vh0n3S-
`s\E"QeZN
G7YBo4v
for(int i=1;;i++) Z^t{m!v
{ @ [<B:Tqo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); l~n=_R3
//Utility.log(in.readLine()); l}XnCOIT,
sHeader=httpConnection.getHeaderFieldKey(i); u a_(wBipy
if(sHeader!=null) Id?2(Tg
{ DoFF<LXBt
if(sHeader.equals("Content-Length")) {S"!c.
{ Io4Ss1="
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p&lT! 5P!A
break; Og:aflS
} rds0EZ4W
} ,L;%-}#$
else 0F%V+Y\R
break; `e}6/~R`
} nq*D91Q
} <(x!P=NM-
catch(IOException e){e.printStackTrace ();} s>a(#6Q
catch(Exception e){e.printStackTrace ();} Ht7v+lY90^
T-.Bof(?w
s%@HchZ 1
Utility.log(nFileLength); Yzih-$g
PaBqv]
4@"n7/<
return nFileLength; WbHI>tt
} {AO`[
Q_FL8w9D~8
M%N_4j.
//保存下载信息（文件指针位置） >5bd!b,
private void write_nPos() "kg?Or.
{ 7=@MnF`
try{ l~$Od jf
output = new DataOutputStream(new FileOutputStream(tmpFile)); cQ`+ A|q
output.writeInt(nStartPos.length); W%P0X5YQ
for(int i=0;i<nStartPos.length;i++) S3Sn_zqG
{ =d1i<iw?-
// output.writeLong(nPos); m95;NT1N/g
output.writeLong(fileSplitterFetch.nStartPos); ~n9-
output.writeLong(fileSplitterFetch.nEndPos); 'sN (=CQ
} S0mF%"
output.close(); GFO(O
} q-nM]Gm
catch(IOException e){e.printStackTrace ();} ]?j[P=\
catch(Exception e){e.printStackTrace ();} D(^ |'1
} QTuj v<|
5: O,-b&
w\Bx=a>vc
//读取保存的下载信息（文件指针位置） #wL8=QTcNC
private void read_nPos() w@\quy:
{ ~riV9_-
try{ x#&%lJT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2 NrMse
int nCount = input.readInt(); G~|Z(}H
nStartPos = new long[nCount]; <P)0Yu
nEndPos = new long[nCount]; 62z"cFN
for(int i=0;i<nStartPos.length;i++) Q.`O;D}x
{ Q7@ m.w%`
nStartPos = input.readLong(); $XO#qOW
nEndPos = input.readLong(); _9Y7.5
} >aV Q
input.close(); YF(TG]?6
} x1nqhSaD
catch(IOException e){e.printStackTrace ();} V;t8v\
catch(Exception e){e.printStackTrace ();} )4/227b/(
} ~LuR)T=%es
~i)IY1m"
(>gAnebN L
private void processErrorCode(int nErrorCode) ,6FmU$ Kn
{ SUQk0 (M
System.err.println("Error Code : " + nErrorCode); STH?X] /
} @I$;
X6lR?6u%|
<!M ab}
//停止文件下载 N#? Ohz
public void siteStop() fooQqWC)
{ 7ZVW7%,zF
bStop = true; y 2v69nu~q
for(int i=0;i<nStartPos.length;i++) #aV2+`d
fileSplitterFetch.splitterStop(); EO[UezuU
y $K#M
ZT;:Hxv0N
} CH/*MA
} 7>Oa, \
//负责部分文件的抓取 =Nj58l
**FileSplitterFetch.java )FfJ%oT}
*/ 47c` ) *Hc
package NetFox; M~1 n#
6s"Erq5q
j4B|ktf
import java.io.*; i+z;tF`
import java.net.*; 4&c7^ 4w~
v9[[T6t/'
@9!,]n
public class FileSplitterFetch extends Thread { '"=Mw;p
jGtoc,\X
H8}}R~ZO
String sURL; //File URL .RNr^*AQ
long nStartPos; //File Snippet Start Position 6jIW)C
long nEndPos; //File Snippet End Position @fH?y Z=>
int nThreadID; //Thread's ID 3 #zwY
boolean bDownOver = false; //Downing is over G 39
boolean bStop = false; //Stop identical LK^t](F
FileAccessI fileAccessI = null; //File Access interface lilKYrUmG
: Jh
jR^>xp;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i*JbFukG
{ {bUd"Tu
this.sURL = sURL; I+Q`i:\,q
this.nStartPos = nStart; (]yOd/ru/C
this.nEndPos = nEnd; ;rj=hc
nThreadID = id; *Iu .>nw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q?=eD^]
} &&w7-
Xj\SJ*
^%v<I"<Uq5
public void run() XMM@EN
{ 6c3+q+#J2
while(nStartPos < nEndPos && !bStop) 7]q$sQ
{ ZU&I`q|Y6
I499Rrw#E
VvwQz#S
try{ r"a4;&mf
URL url = new URL(sURL); NC;4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nD\X3g`V
httpConnection.setRequestProperty("User-Agent","NetFox"); {.We%{4V
String sProperty = "bytes="+nStartPos+"-"; a; Ihv#q
httpConnection.setRequestProperty("RANGE",sProperty); i6[,m*q~2x
Utility.log(sProperty); K/ q:aMq
-IR9^)
%$ ^yot
InputStream input = httpConnection.getInputStream(); Cm;WQuv@
//logResponseHead(httpConnection); 2#nn}HEOC
LB1.N!q1
9-+6Ed^2
byte[] b = new byte[1024]; !U$ %Jz
int nRead; 'M\ou}P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $S$%avRX
{ ?K7m:Dx
nStartPos += fileAccessI.write(b,0,nRead); %Gn(b1X
//if(nThreadID == 1) r4O*0Q_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @:i>q$aF
} O'deQq[
:yvUHx
17G7r\iNYq
Utility.log("Thread " + nThreadID + " is over!"); `xkJ.,#Io
bDownOver = true; (jCE&'?}
//nPos = fileAccessI.write (b,0,nRead); =o=)EU{~
} +MOUO$;fGt
catch(Exception e){e.printStackTrace ();} io:?JnQSA
} $g#j,
} 7,|-%!p[
*#EyfMz-B
tiwhG%?2
//打印回应的头信息 ltHC+8aZ
public void logResponseHead(HttpURLConnection con) lp?geav
{ 2:i`,
for(int i=1;;i++) NS=puo
{ R\yw9!ESd
String header=con.getHeaderFieldKey(i); dOqwF iO
if(header!=null) SR~~rD|V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1S\q\kz->D
Utility.log(header+" : "+con.getHeaderField(header)); yq[C?N &N
else eUqsvF}l!
break; VX&KGG.6
} u9m"{KnV
} Czb@:l%sc
[m!\ZK
Old5E&
public void splitterStop() \I#2Mq?
{ f?[y-
bStop = true; &e_M \D
} yYWGM
IcPIOCmOc
~mK9S^[
} V}7I? G
tTF/$`Q#*
sh}=#eb
/* j4H,*fc
**FileAccess.java 9+=U&*
*//文件访问(定位，写) lpve Yz
package NetFox; 5H==m~
import java.io.*; rN$_(%m_N
athU
%S.R@C[3
public class FileAccessI implements Serializable{ 6!Ji-'\"
"=9L7.E)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E n{vCN
RandomAccessFile oSavedFile; W?F+QmD
long nPos; @(Ou;Uy
(Pc:A!}
k=w%oqpN
public FileAccessI() throws IOException '(&.[Pk:"
{ M*8Ef^-U`t
this("",0); <d$|~qS_
} Bz9!a k~4
hUB_[#8#
J'b*^K
public FileAccessI(String sName,long nPos) throws IOException o}7`SYn
{ cm6cW(x6
oSavedFile = new RandomAccessFile(sName,"rw"); e<9IwS!/
this.nPos = nPos; @aY 8VL7C0
oSavedFile.seek(nPos); ~WehG<p v[
} vUvIZa
:=T+sT~
)g9Zw_3
public synchronized int write(byte[] b,int nStart,int nLen) `kVy1WiY
{ K\5@yqy5
int n = -1; 3iR;(l}
try{ oh:g
oSavedFile.write(b,nStart,nLen); ^4_.5~(
n = nLen; ;6U=fBp7<
} &#w] 2~|
catch(IOException e) arrNx|y
{ 4nXS}bWf
e.printStackTrace (); nRPy)L{
} # 0dN!l;
}tua0{N:z
r|{h7'
return n; 1<\@i{;xsU
} M`9qo8zCi
O0i_h<T
@vCPX=c
} QDF1$,s4i
OgY4J|<
_ohZTT%l
/* YRfs8I^rg
**SiteInfoBean.java 8G6PcTqv"
*/ ?76Wg::
package NetFox; nws '%MK)
h*Rh:yCR>
2+s_*zM-
public class SiteInfoBean { <_dyUiT$J
p&>*bF,
(Ub=sC
private String sSiteURL; //Site's URL `|XE B
private String sFilePath; //Saved File's Path 1y2D]h/'
private String sFileName; //Saved File's Name =!*e; L
private int nSplitter; //Count of Splited Downloading File E3X:{h/
Vl%AN;o
V}. uF,>V
public SiteInfoBean() X};m\Bz
{//nSplitter的缺省值为5 j&6,%s-M`a
//default value of nSplitter is 5 @{iws@.
this("","","",5); 2E33m*C2
} XZEawJ0
z\Rs?v"
5|my}.TR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w},' 1
{ y>Zvose
sSiteURL= sURL; I?YTX
sFilePath = sPath; ng0IRJ:3
sFileName = sName; jL(=<R(~y
this.nSplitter = nSpiltter; Y9Q-<~\z
jV]'/X<
b'Pq[ )
} rbiNp6AdL
8c(}*,O/
G~1#kg
public String getSSiteURL() veFl0ILd
{ }`8g0DPuD9
return sSiteURL; >J_{mU
} ]sjYxe
$#2ik~]>
kMWu%,s4
public void setSSiteURL(String value) Y]/(R"-2G
{ pisk v[
sSiteURL = value; ] e!CH <N
} qR4('
h#'(i<5v
/e1m1B
public String getSFilePath() !%5ae82~3
{ >^LVj[.1
return sFilePath; ;>QED
} ML'4 2z Y
8>S"aHt 7
^"7tfo8
public void setSFilePath(String value) #P.jlpZk
{ Ja>UcE29
sFilePath = value; agQzA/Xt
} ;j])h!8X
!`q*{Ojx
Vo}3E]
public String getSFileName() lwYk`'
{ ^29w@*
return sFileName; =]&?(Gq
} +5H9mk
^prseO?A
hYMIe]kJ
public void setSFileName(String value) Yr@_X
{ Z]DO
sFileName = value; EbSH)aR
} @GqPU,RO
Z.Lm[$/edn
?Y+xuY/t
public int getNSplitter() ]vJZ v"ACn
{ 0Ge*\Q
return nSplitter; :bI4HXT3
} yaD<jc(O
x?Z)q4
kCfSF%W&
public void setNSplitter(int nCount) s^ rO I~
{ -QjdL9\[c7
nSplitter = nCount; (oX|lPD<b
} gS4zX>rqe
} i)f3\?,,
yi<&'L;
1}#v<b$
/* ?g%5 d
**Utility.java <h|XB}s+
*/ z_R^n#A~r
package NetFox; 'ah|cMRn
w{k8Y?
'c5#M,G~
public class Utility { +Q_(wR"FS
QEL^0c8~
UfjLNe}wA
public Utility() 9\i;zpN\
{ O$u;]cg
#Z<pks2 y
bcL>S$B
} / U1VE|T
FP<RoA?W
//线程睡眠 ha
public static void sleep(int nSecond) c_clpMx=
{ b\NWDH7}
try{ #<f}.P.Uc
Thread.sleep(nSecond); b9ysxuUdS
} N[X%tf\L]F
catch(Exception e) RrKAgw
{ v:1l2Y)g
e.printStackTrace (); 1Lz`.%k`:
} q# gZ\V$I
} *V#v6r7<Y/
IIeEe7%#
//日志 k$:QpTg[
public static void log(String sMsg) zk5sAHQ
{ w8:F^{
System.err.println(sMsg); GDw4=0u-
} lz\{ X
udtsq"U_%
3~6F`G
public static void log(int sMsg) i0/gyK
{ ^|xj.
System.err.println(sMsg); @iB**zR/
} T[a1S?_*T
} _/ j44q
8B;`9?CI
T'i9_V{
/* seY0"ym&e
**TestMethod.java Y?%MPaN:
*/ @dX0gHU[c
package NetFox; Wd$N[|
WhE5u&`
9F0B-aZ
public class TestMethod { p`gg
95(c{ l/
.Y'kDuUu
public TestMethod() .6!]RA5!=
{ ///xx/weblogic60b2_win.exe !? ?Cxs'
try{ %_M B-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]@l~z0^|[_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3Zsqx=w
SiteFileFetch fileFetch = new SiteFileFetch(bean); W()FKP\??!
fileFetch.start(); H:U1#bQQ:
} RTA9CR)JP4
catch(Exception e){e.printStackTrace ();} 598xV|TON
2t1WbP1
T7m rOp
} b9EJLD
/.'1i4Xa1P
W~W^$A
public static void main(String[] args) ( NjX?^
{ la)f\Nk
new TestMethod(); fouy??
} {xEX_$nv
} ~/3cQN^
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