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)); O$*lPA[
} 6{h\CU}"
for(int i=0;i<nEndPos.length-1;i++) J"`VA_[
{ z`{sD]
nEndPos = nStartPos[i+1]; `3;EJDEdbi
} l6 G6H$
nEndPos[nEndPos.length-1] = nFileLength; LA3m,
} F>fCp
} j-<-!jTd
O_FB^BB
Nk'<*;e
//启动子线程 4MgN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5vx 4F f
for(int i=0;i<nStartPos.length;i++) msl.{
{ W A/dt2D|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A@A8xn%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;uBGB h<
nStartPos,nEndPos,i); w1/QnV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oD2:19M@p
fileSplitterFetch.start(); _{[6hf4p
} x[0T$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nWd!ovd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); htBA.eQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dyQ7@K.E
nEndPos = " + nFileLength); k2}DBVu1
// fileSplitterFetch[nPos.length-1].start(); G6G Bqp6|
%e iV^>
@{/)k%U
//等待子线程结束 V]H(;+^P
//int count = 0; .?Eb{W)^br
//是否结束while循环 ynIe4b
boolean breakWhile = false; ]A5F}wV4
z !K2UTX
7HPwlS
while(!bStop) jSI1tW8
{ };Q}C0E
write_nPos(); vjEDd`jYZ
Utility.sleep(500); 7:4c\C0
breakWhile = true; 7`|'Om?'
|Z:yd}d
MBWoPK
for(int i=0;i<nStartPos.length;i++) LU6R"c11
{ \e86'&
if(!fileSplitterFetch.bDownOver) (0{Dn5MH
{ vk7IqlEQ
breakWhile = false; K[T0);hZR
break; VVJ0?G (?
} j7}mh
} 5rsz2;#p
if(breakWhile) ufXWK3~\
break; "Bd-h|J
9g6$"',H
[ V.67_~
//count++; OyO<A3
//if(count>4) /~,*DH$)
// siteStop(); Ao K9=F}
} <"3q5ic/Z
[jgVN w""D
hK?GIbRZ
System.err.println("文件下载结束！"); "r^RfZ;
} a%%7Ew ?
catch(Exception e){e.printStackTrace ();} - Jaee,P
} ZF7n]LgSc&
g QBS#NY
T+Yv5l
//获得文件长度 dz^HN`AlzC
public long getFileSize() }qWnn>h9xv
{ KI9Pw]]{-
int nFileLength = -1; 9PB%v.t5y
try{ |f_'(-v`E
URL url = new URL(siteInfoBean.getSSiteURL()); c.>f,vtcn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Na.C(DZ
httpConnection.setRequestProperty("User-Agent","NetFox"); &M|rRd~*
/stvNIEa
8a6.77c
int responseCode=httpConnection.getResponseCode(); xp|1yud
if(responseCode>=400) ^Mq/Cf_T
{ gC$_yd6m L
processErrorCode(responseCode); @qNY"c%HV
return -2; //-2 represent access is error By1Tum+I1
} c7CYulm
.gO|=E"
+$C9@CZM9
String sHeader; %R GZu\p
o*K7(yUL4
0>Y3xNb
for(int i=1;;i++) |k}<Zz1UM
{ K~:SLCv E%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4)iP%%JH
//Utility.log(in.readLine()); %pVsafV
sHeader=httpConnection.getHeaderFieldKey(i); "}()/
if(sHeader!=null) ';R]`vWFe
{ 2TGND-(j
if(sHeader.equals("Content-Length")) .>W [
{ lJ3VMYVrUP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;!f='QuA
break; jU-LT8y:
} 6%V:Z
} .]E(P
else `,4yGgD!4
break; |&K;*g|a
} h;q&B9
} RQ=rB9~:ZN
catch(IOException e){e.printStackTrace ();} //NV_^$y
catch(Exception e){e.printStackTrace ();} A.*e8a/6X
.6MG#N
/)[-5n{
Utility.log(nFileLength); lL zR5445)
6wpW!SWD
kk5&lak2V
return nFileLength; 8s22VL
} k2eKs*WLC
6"iNh)
9Qszr=C0
//保存下载信息（文件指针位置） kb 74:
private void write_nPos() u>;aQtK~
{ <yl@!-'J7
try{ 6n/=n%US
output = new DataOutputStream(new FileOutputStream(tmpFile)); i\lvxbp
output.writeInt(nStartPos.length); ]]y>d!
for(int i=0;i<nStartPos.length;i++) z?13~e[D
{ ], Bafz)4
// output.writeLong(nPos); <e#v9=}DI
output.writeLong(fileSplitterFetch.nStartPos); 4U\>TFO
output.writeLong(fileSplitterFetch.nEndPos); ac\aH#J_nC
} QeF:s|[
output.close(); 'bRf>=
} N5)H(<}
catch(IOException e){e.printStackTrace ();} Yt*NIwWr
catch(Exception e){e.printStackTrace ();} W/A@qo"
} Q1Qw45$
)'jGf;du
]*]*O|w
//读取保存的下载信息（文件指针位置） N5l`Rq^K
private void read_nPos() N@_y<7#C
{ o#"yFP1
try{ #IGcQY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8\E=p+C
int nCount = input.readInt(); XR8`,qH>
nStartPos = new long[nCount]; sRLjKi2D
nEndPos = new long[nCount]; b&A/S$*
for(int i=0;i<nStartPos.length;i++) ?r=`Kl
{ c\[&IlM
nStartPos = input.readLong(); N6kMl
nEndPos = input.readLong(); !!A(A^s
} |H=5Am
input.close(); mx1Bk9h%Xe
} >=rniHs=?7
catch(IOException e){e.printStackTrace ();} ~YNzSkz
catch(Exception e){e.printStackTrace ();} A##Q>|>)
} :9&@/{W
E\Wd*,/v)
ph)=:*A6&
private void processErrorCode(int nErrorCode) zxs)o}8icO
{ x$Wtkb0<
System.err.println("Error Code : " + nErrorCode); aiX4;'$x!
} wmK;0 )|H
PRYm1Y
4]zn,g?&
//停止文件下载 RKMF?:
public void siteStop() )y!gApNs"
{ oT:wGBW
bStop = true; 6_8yQ
for(int i=0;i<nStartPos.length;i++) 8>|4iT
fileSplitterFetch.splitterStop(); 8DD1wK\U~
#6y fIvap
{?w*n_T.
} Ac*)z#H
} Grw[h
//负责部分文件的抓取 2fayQY xD
**FileSplitterFetch.java %26HB w=JF
*/ <b4} B
package NetFox; _;x`6LM
aFnyhu&W'
?=?*W7
import java.io.*; \2f?)id~
import java.net.*; dhg($m
B\|^$z2
Tz:,l$
public class FileSplitterFetch extends Thread { .1h\r, #
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MjBI1|*
String sURL; //File URL Vl(id_~_
long nStartPos; //File Snippet Start Position b*Hk} !qH
long nEndPos; //File Snippet End Position b!QRD'31'j
int nThreadID; //Thread's ID ,DWq
boolean bDownOver = false; //Downing is over Rc@lGq9
boolean bStop = false; //Stop identical Z@JTZMN_
FileAccessI fileAccessI = null; //File Access interface LEg|R+6E
.ezko\nU
b V_<5PHP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rCGKE`H
{ Q[!?SSX%
this.sURL = sURL; D!)h92CIDm
this.nStartPos = nStart; P$O@G$n
this.nEndPos = nEnd; =L"I[
nThreadID = id; e=tM=i"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z0~,cO8~
} ev7A;;
Nb0T3\3W
fA V.Mj-
public void run() VK%ExMSqEh
{ PJKxh%J
while(nStartPos < nEndPos && !bStop) tOj5b7'ui
{ :-2sKD y
uW(Ngcpr
C3<_0eI
try{ w(Mi?
URL url = new URL(sURL); 6!U~dt#a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VzM (u_)
httpConnection.setRequestProperty("User-Agent","NetFox"); L'a s^Od
String sProperty = "bytes="+nStartPos+"-"; je:J`4k$
httpConnection.setRequestProperty("RANGE",sProperty); |<8g 2A{X
Utility.log(sProperty); 2fm6G).m
ZTGsZ}{5
tQMz1$
InputStream input = httpConnection.getInputStream(); > JTf0/
//logResponseHead(httpConnection); dDYor-g>
sWq}/!@&
-|czhO)R
byte[] b = new byte[1024]; F9IPA%
int nRead; $reQdN=~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0KZsWlD:L
{ cnDBT3$~Z
nStartPos += fileAccessI.write(b,0,nRead); naY#`xig
//if(nThreadID == 1) nrTCq~LO(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2Y}A9Veb
} esv<b>`R
`1 Tg8
}V+&o\4
Utility.log("Thread " + nThreadID + " is over!"); M7gqoJM'Q
bDownOver = true; m}m|(;T
//nPos = fileAccessI.write (b,0,nRead); {X\FS
} |z)7XK
catch(Exception e){e.printStackTrace ();} O4W2X@
} XQ Si
} X=k|SayE8
kgX"I ?>d
0M}Ql5+h,
//打印回应的头信息 i8/"|+Z
public void logResponseHead(HttpURLConnection con) Je#3
{ lb)i0`AN+
for(int i=1;;i++) eA9r M:
{ @^Kw\s
String header=con.getHeaderFieldKey(i); QSo48OFs
if(header!=null) [!#;QQ&M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m`,h nDp
Utility.log(header+" : "+con.getHeaderField(header)); (bogAi3<F
else ZN;fDv
break; ;Ac!"_N?7
} zL+M-2hV
} $O9#4A;
M[Jy?b)
!;U}ax;AF
public void splitterStop() I"jub kI=Z
{ WODgG@w
bStop = true; VBu6,6
} 0mT.J~}1v
qUNXT
p#dYNed]'
} ^s/f.#'
0^MRPE|f5
M`G#cEc
/* 74~%4
**FileAccess.java Xu[A,6
*//文件访问(定位，写) o l+*Oe
package NetFox; Oyjhc<6
import java.io.*; eKqo6P:#f
f:A1j\A?
*i7|~q/u
public class FileAccessI implements Serializable{ 0 !F!Y_
14Jkr)N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w5Yt mnP
RandomAccessFile oSavedFile; `HM?Fc58
long nPos; -sk!XWW+
#Ic-?2Gn4<
~w$ ^`e!]
public FileAccessI() throws IOException LZ~}*}jy
{ meyO=>
this("",0); I6 Q{ Axy
} :W1B"T<
4"%LgV`
M[ ,:NE4H
public FileAccessI(String sName,long nPos) throws IOException 09HqiROw
{ D +9l$**a
oSavedFile = new RandomAccessFile(sName,"rw"); *f+DV[DF
this.nPos = nPos; <a%RKjQvT
oSavedFile.seek(nPos); {cAGOxwd
} k iY1
>o!~T}J7
J?bx<$C@
public synchronized int write(byte[] b,int nStart,int nLen) ,A!0:+
{ p+1kU1F0
int n = -1; .|3&lb6
try{ vHx[:vuq:
oSavedFile.write(b,nStart,nLen); A]s|"Pav,
n = nLen; ^9?IS<N0]
} p#AQXIF0
catch(IOException e) kR;Hb3hb
{ V3>JZH`
e.printStackTrace (); 4#wZ#}
} T [2l32
yK:b$S
b*"%E,?
return n; +T]D\];D
} X?OH//co
.0'FW!;FV
7F wot&
} |]x>|Z?/u
</jTWc'}
qgw)SuwW
/* 77p8|63
**SiteInfoBean.java pu6@X7W"
*/ pK@8=+
package NetFox; i}r|Zo
ORo,.#<
-1tiy.^$F
public class SiteInfoBean { L+2<J,
Ex$i8fO(
o) ,1R:
private String sSiteURL; //Site's URL jZ>x5 W
private String sFilePath; //Saved File's Path F>[T)t{m=
private String sFileName; //Saved File's Name y` 6!Vj l
private int nSplitter; //Count of Splited Downloading File YS+|n%?
zqa7!ky
FWDAG$K@0
public SiteInfoBean() C{U"Nsu+1
{//nSplitter的缺省值为5 'o]8UD(
//default value of nSplitter is 5 zP|^) h5
this("","","",5); Y4I;-&d's
} 58o'Q
(od9adSehV
*t,1(Gw|7q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,\=,,1_
{ n]fMl:77
sSiteURL= sURL; wj<fi
sFilePath = sPath; w>h\643
sFileName = sName; cCbZ*
this.nSplitter = nSpiltter; M)j.Uu
&'<e9
YGf<!
} cMp#_\B
8a3h)R
6h:2,h pE
public String getSSiteURL() Av_JcH
{ j NkobJ1
return sSiteURL; fKOC-%w
} gis;)al
GX;~K
'nSo0cyQ
public void setSSiteURL(String value) k}FmdaPI'
{ =WM^i86
sSiteURL = value; 6-J%Z%yT #
} 6g&Ev'
u@pimRVo
g}n-H4LI
public String getSFilePath() db`L0JB
{ XsbYWJdds
return sFilePath; `A ^
} ME.a * v
6,a:s:$>}R
dh S7}n
public void setSFilePath(String value) xY>@GSO1
{ rc`}QoB)R
sFilePath = value; _UGR+0'Q\
} jiqE^j3;
!N'HL-oT
|Q?^Ba
public String getSFileName() XDohfa_
{ }ej>uZVe<
return sFileName; &hu>yH>j
} ~kFL[Asnaf
!\5w<*p8
liU8OXBl
public void setSFileName(String value) &OsO _F
{ <sli!rv
sFileName = value; 3>QkO.b
} #%7)a;'
(5a:O (\r
dTZ$92<
public int getNSplitter() c8Je&y8
{ 1Y'NG<d_
return nSplitter; H5>?{(m
} a&RH_LjM
)9i$ 1"a(
MUn(ZnQy|
public void setNSplitter(int nCount) |ya.c\}q
{ ohna1a^
nSplitter = nCount; qsWy <yL+
} 75^AO>gt
} 5Deo}(3
ez<V
2"6bz^>}
/* ]Bj2;<@y
**Utility.java LS]0p#
*/ sOVU>tb\'
package NetFox; y#zO1Nig`
Z5|BwM
);;UA6CD
public class Utility { T:Nc^QP|tm
z3I |jy1
/V GI@"^v
public Utility() uH]oHh!}j
{ ny1;]_X_
pZz\o
[ylRq7^e
} 7YFEyX10d
/mXxj93UA
//线程睡眠 lFl(Sww!\
public static void sleep(int nSecond) #/Bg5:
{ EKus0"|
try{ 2Gh&h(
Thread.sleep(nSecond); lg +>.^7k
} R*/s#*gmL
catch(Exception e) F3[,6%4v
{ Q[{RNab
e.printStackTrace (); 5]xSK'6W
} niqknqW<t
} $*;`$5.x^
"+E\os72|
//日志 _iL?kf
public static void log(String sMsg) )2a)$qx;
{ ]I_*+^?tI
System.err.println(sMsg); aW-6$=W
} Wdi`ZE
0SDnMij&bf
"VDMO^
public static void log(int sMsg) Al=ByX@
{ ``%yVVg}
System.err.println(sMsg); -9::M}^2
} k%BU&%?1
} .,20_<j%=
#q4uS~
df!i}L
/* ^t:dcY7
**TestMethod.java 2RQ-L
*/ Wy%FF\D.Y
package NetFox; 6$[7hlE
U*b7 Pxq;
Z?xRSi2~7
public class TestMethod { IVY)pS"pR"
|kP utB
u"4B5D
public TestMethod() Evd|_W-
{ ///xx/weblogic60b2_win.exe n*Uk<_WA
try{ )U=]HpuzI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =3 Vug2*wd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K_@?Q@#YhR
SiteFileFetch fileFetch = new SiteFileFetch(bean); $xWUzg1<U
fileFetch.start(); <Se9aD
} K{{_qFj@<y
catch(Exception e){e.printStackTrace ();} *~>p;*
GbclR:G
7f4O~4.[i
} :eSsqt9]9
$rI 1|;^
Fn7OmxfD
public static void main(String[] args) Qn,6s%n
{ _&/ {A|n
new TestMethod(); a6-.|tt#t
} r0 )ne|&Hp
} 1Dl6T\20
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