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)); 39T&c85
} 3TiXYH
for(int i=0;i<nEndPos.length-1;i++) |<3Q+EB^
{ K;y\[2;}e,
nEndPos = nStartPos[i+1]; b6!Q!:GO&
} J4Z<Yt/
nEndPos[nEndPos.length-1] = nFileLength; k[ffs}
} ?Y0$X>nm
} x|v[Dxf]
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)/WA)fWkT
//启动子线程 Ec*--]j*c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $qlqWy-s
for(int i=0;i<nStartPos.length;i++) p=-B~:
{ ?%dCU~ z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bpF@}#fT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (#-=y~%
nStartPos,nEndPos,i); /[|}rqX(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <[3lV)~t
fileSplitterFetch.start(); )1Ma~8Y%r
} TFJ{fLG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Yx-l;78
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [2QY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @8M'<tr<z
nEndPos = " + nFileLength); |,a%z-l
// fileSplitterFetch[nPos.length-1].start(); RRI>bh]
`FYtiv?G
yo?g"vbE
//等待子线程结束 &Qtp"#{
//int count = 0; f=_Bx2ub
//是否结束while循环 b#Fk>j
boolean breakWhile = false; dWW-tHv#
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)-Mn"1ia
while(!bStop) G {pP}
{ kol,Qs
write_nPos(); |%:qhs,
Utility.sleep(500); )~?S0]j}
breakWhile = true; [al(>Wr9
np`gcj#
k5fH;
for(int i=0;i<nStartPos.length;i++) f0cYvL]
{ }P&1s,S8J#
if(!fileSplitterFetch.bDownOver) oz\{9Lwc
{ ,<;l"v(
breakWhile = false; M5T=Fj86
break; :\1rQT
} Lem\UD$D`
} (:&&;]sI
if(breakWhile) X|-v0 f
break; |i}+t
\]f5
q#Yg0w~
//count++; >%n8W>^^4
//if(count>4) 33{;[/4
// siteStop(); HC9vc,Fp
} M]6w^\4j9
'FPcAW^8
VeNNsg>&
System.err.println("文件下载结束！"); fXF=F,!t
} Xa{~a3Wy
catch(Exception e){e.printStackTrace ();} fw1;i
} v|4STR
nxn[ ~~
i_[ HcgT-
//获得文件长度 Q8;x9o@p
public long getFileSize() (1kn):
{ 'uP'P#
int nFileLength = -1; (opROsFh
try{ AQnJxIL:
URL url = new URL(siteInfoBean.getSSiteURL()); z&C{8aQ'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {dy` %It
httpConnection.setRequestProperty("User-Agent","NetFox"); a2cx
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a!c/5)v(
int responseCode=httpConnection.getResponseCode(); d{iu+=NXz
if(responseCode>=400) 7~!I2DV_
{ ==-7F3QP
processErrorCode(responseCode); l#2r.q^$|
return -2; //-2 represent access is error #[k~RYS3
} eHVdZ'%x
r!=]Q}`F
3i]"#wK
String sHeader; dl*_ m3T
U,%s;
Q-! i$#-
for(int i=1;;i++) RlI W&y
{ S4l)TtY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dJdD"xj
//Utility.log(in.readLine()); G zJ9N`
sHeader=httpConnection.getHeaderFieldKey(i); {+@ms$z
if(sHeader!=null) q5:0&:m$4$
{ wo7N7R5
if(sHeader.equals("Content-Length")) AI^AK0.L
{ 6pM"h5hA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W\I$`gyC/
break; Z #.GI
} i#L6UKe:Q
} 1?D8|<
else "jl1.Ah
break; {&\J)oZ
} X;s3y{ku
} t/v@vJ`vSH
catch(IOException e){e.printStackTrace ();} ~=`f]IL
catch(Exception e){e.printStackTrace ();} =,&u_>Dp
FSW3'
DHh+%|e
Utility.log(nFileLength); ppwd-^f3j
w$DG=!
]yyU)V0Iu
return nFileLength; rtB|N-
} +l2e[P+qA
hrJ$%U
+L`V[;
//保存下载信息（文件指针位置） B8bvp:Ho|
private void write_nPos() HO266M
{ 89*S?C1
try{ bh=\
output = new DataOutputStream(new FileOutputStream(tmpFile)); Tjd&^m
output.writeInt(nStartPos.length); [=XZza.z
for(int i=0;i<nStartPos.length;i++) T5K-gz7A
{ K%Usjezv&
// output.writeLong(nPos); )HJK '@
output.writeLong(fileSplitterFetch.nStartPos); + 6x"trC
output.writeLong(fileSplitterFetch.nEndPos); GAg.p?Sq
} >[Xm|A#
output.close(); 2.StG(Y!
} WafdE
catch(IOException e){e.printStackTrace ();} H"Q(2I
catch(Exception e){e.printStackTrace ();} 3mpP|b"
} jG+T.
R19'|TJ
<h'8w
//读取保存的下载信息（文件指针位置） #Y;.>mF
private void read_nPos() %3]3r*e&5
{ 21.YO]Et
try{ !&@2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K&j'c
int nCount = input.readInt(); z`\#$
nStartPos = new long[nCount]; bcq@N
nEndPos = new long[nCount]; f?2zLE>u
for(int i=0;i<nStartPos.length;i++) mcvDxjk,h
{ X tJswxw`K
nStartPos = input.readLong(); ^OHZ767v
nEndPos = input.readLong(); 'jh2**i 34
} dj?G.-
input.close(); V8-4>H}Cb/
} Wl,%&H2S<
catch(IOException e){e.printStackTrace ();} I'x$,s
catch(Exception e){e.printStackTrace ();} Q<z)q<e
} * zd.
,)Yao;Cvd
5?^]1P_
private void processErrorCode(int nErrorCode) MNkKy(Za
{ '"Bex`
System.err.println("Error Code : " + nErrorCode); $`^H:Djr
} DY$yiOH9
PqTYAN&F
'g. :MQ8
//停止文件下载 '*8
public void siteStop() {;U}:Dx
{ w+Ad$4Pf"
bStop = true; -s{R/6:
for(int i=0;i<nStartPos.length;i++) [Dnusp7e
fileSplitterFetch.splitterStop(); (&q@~ dJ
aLV~|$:2
%rFP#L
} }%_qx|(P|t
} .8-PB*vb
//负责部分文件的抓取 )8:n}w
**FileSplitterFetch.java #]"/{Z
*/ 1Pu ,:Jt
package NetFox; Q?Wr7
,Yo: &>As
{PL,VY)Z
import java.io.*; BeAk21xb
import java.net.*; 7^HpVcSM
rZ pbu>S
C=8H)Ef,l
public class FileSplitterFetch extends Thread { 8a7YHUL<3i
QT_Srw@
L+_8QK<
String sURL; //File URL wbBE@RU>!
long nStartPos; //File Snippet Start Position C2NzP& FD
long nEndPos; //File Snippet End Position {>S4#^@}
int nThreadID; //Thread's ID SzRL}}I
boolean bDownOver = false; //Downing is over 2%bhW,?I
boolean bStop = false; //Stop identical S<*';{5~
FileAccessI fileAccessI = null; //File Access interface '=$TyiU
MdLj,1_T
~Hs=z$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cnbo+U
{ 9_eS`,'
this.sURL = sURL; e!6eZ)l
this.nStartPos = nStart; *`%4loW
this.nEndPos = nEnd; ~M*7N@D
nThreadID = id; sb'lZFSP~s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sbzeY1
} 9-B@GFB;8
D^N[=q99&e
X@cSP7b
public void run() ?b5H 2W
{ eVTO#R*'|
while(nStartPos < nEndPos && !bStop) }&mj.hGv
{ {798=pC<.
AYt*'Zeg!s
]Uu aN8
try{ b"^\)|*4;
URL url = new URL(sURL); r9<V%PHv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fa"\=V2S
httpConnection.setRequestProperty("User-Agent","NetFox"); ZH% we
String sProperty = "bytes="+nStartPos+"-"; Ohc^d"[7
httpConnection.setRequestProperty("RANGE",sProperty); hRk,vB]
Utility.log(sProperty); _<XgC\4O|
0Qt~K#mr/
:|=- (z
InputStream input = httpConnection.getInputStream(); h5j<u
//logResponseHead(httpConnection); TWtC-wI;
3=IG#6)~C
$%B5$+
byte[] b = new byte[1024]; _n7%df
int nRead; h:_NA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~bWhth2*
{ JXL'\De ;
nStartPos += fileAccessI.write(b,0,nRead); m!;G/s*
//if(nThreadID == 1) ;>5,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,|A{!j`
} $<:'!#%
vpi l$Uq
&wOE\TCL
Utility.log("Thread " + nThreadID + " is over!"); 8'+7i8e
bDownOver = true; Xt\Dy
//nPos = fileAccessI.write (b,0,nRead); QOd!]*W`?m
} 'g2vX&=$A
catch(Exception e){e.printStackTrace ();} s_TD4~ $
} Y^yG/F
} FQ1arUOFW,
ghX:"vV{n
$:(z}sYQ7
//打印回应的头信息 0Lx3]"v
public void logResponseHead(HttpURLConnection con) ?H<~ac2e
{ \d:h$
for(int i=1;;i++) PFm\[2
{ )}quw"H
String header=con.getHeaderFieldKey(i); g(nK$,c
if(header!=null) 0juDuE?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w?*jdwh,'
Utility.log(header+" : "+con.getHeaderField(header)); ^zHRSO
else CGkI\E
break; 'P,,<nkr|
} ?/)lnj)e{
} u|T%Xy=LU
Fk aXA.JE
v:?o3 S
public void splitterStop() 9Eu #lV
{ sLZ>v
bStop = true; 8sH50jeP
} BO]=vH
v"/TmiZ
ZOC#i i`:
} F'rt>YvF
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",T`\8&@e
/* h^Qh9G0dn
**FileAccess.java ETe-
*//文件访问(定位，写) lAz2%s{6
package NetFox; Psp^@
import java.io.*; .N!{ U
6W$rY] h!
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public class FileAccessI implements Serializable{ BD4`eiu"
#%4=)M>^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hk~k@Wft
RandomAccessFile oSavedFile; aTG[=)xL
long nPos; VcrVaBw
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6Etss!_
public FileAccessI() throws IOException qrpb[)Ll
{ f0u56I9
this("",0); 4 A5t*e
} Oi6Eo~\f
5tMh/]IeS
$HxS:3D%D
public FileAccessI(String sName,long nPos) throws IOException l1|~
{ KXq_K:r?
oSavedFile = new RandomAccessFile(sName,"rw"); 3T?f5+@I
this.nPos = nPos; 'u1=XX h
oSavedFile.seek(nPos); +v!v[qn
} Hsgy'X%om
TOrMXcn!/
0d";Hh:
public synchronized int write(byte[] b,int nStart,int nLen) e62y
{ _;7fraqX
int n = -1; +2Z#M
try{ YNk|+A.<d
oSavedFile.write(b,nStart,nLen); Ch7Egzl7?
n = nLen; i%MA"I\9
} `zY!`G
catch(IOException e) DRp&IP<
{ nc&Jmo7
e.printStackTrace (); HA1]M`&
} O)1E$#~
S+iP^*L,c
$o"g73`3
return n; VXwPdMy*L
} ogJ<e_m
nPOO3!<{
3}j1RYtz
} Za0gs @$
St2Q7K5s{
0E1=W6UZ
/* ~{P:sjsU
**SiteInfoBean.java rd" &QB{
*/ @701S(0'7
package NetFox; ^SAq^3^P!
@/ k x er
ULIFSd Y
public class SiteInfoBean { gB >pd?d
H]]c9`ayt
~z`/9;
private String sSiteURL; //Site's URL eC;!YGZ
private String sFilePath; //Saved File's Path J.W Ho c
private String sFileName; //Saved File's Name T/NjNEd#
private int nSplitter; //Count of Splited Downloading File LXNQb6!
}PZ=`w*O
4'm q_o#4W
public SiteInfoBean() vd(dNu&,<
{//nSplitter的缺省值为5 xW\,KSK
//default value of nSplitter is 5 vK:QX$b
this("","","",5); T .hb#oO
} 7*;^UqGjz
C\A49q
,T{oy:rB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ??(Kwtx{
{ qv uxhzF
sSiteURL= sURL; '?8Tx&}U8
sFilePath = sPath; # 66e@
sFileName = sName; >XnO&hW
this.nSplitter = nSpiltter; Um\0i;7 ~4
8YKQItK
~#Aa Ldq
} r)8z#W>s
"xn|zB
LABNj{=D!
public String getSSiteURL() :Y^I]`lR"
{ ]u0Jd#@
return sSiteURL; a_{6Qdl
} 1eD.:_t4
:<%vE!$
@)b^^Fp
public void setSSiteURL(String value) .8(%4ejJ(
{ ;UpJ=?W
sSiteURL = value; :Eo8v$W\RB
} />F.Nsujy
Hk9U&j$
T>F9Hs W
public String getSFilePath() /AR]dcL@76
{ D%gGRA
return sFilePath; az2Xch]
} 0m&3?"5u
,E9d\+j
anC+r(jjg9
public void setSFilePath(String value) eO[c lB
{ |!}wF}iLc)
sFilePath = value; pX_b6%yX(
} F~R7~ZE
7kd|K b(
OD|1c6+X
public String getSFileName() ,ux+Qz5(
{ ]7vf#1i<
return sFileName; 7=3O^=Q^Q
} hy!6g n
n|C|&
agT7=hX].
public void setSFileName(String value) Q7(eq0na
{ CjKRP;5
sFileName = value; ?bI?GvSh
} J3IRP/*z
!Rqx2Q
gQ+9xTd
public int getNSplitter() ]nc2/S%
{ ._,trb>o
return nSplitter; 61|B]ei/
} mf2Mx=oy
p:tN642
km4g}~N</
public void setNSplitter(int nCount) 9I kUZW
{ jCQho-1QN
nSplitter = nCount; K(3&27sGN
} P^zy;Qs7
} A{(T'/~"
41}/w3Z4
DxfMqH[vs
/* ls @5^g
**Utility.java Ay%:@j(E
*/ wv^b_DR
package NetFox; (OqHfv
4swKjN &
1Is%]6
public class Utility { GA@ Ue9
c/'M#h)"
wko2M[
public Utility() [%~^kq=|
{ [gZDQcU
k%Eh{dA
i|4_m
} xYwkFB$$*
`xIh\q
//线程睡眠 tW(+xu36
public static void sleep(int nSecond) )eq}MaW+j
{ H&K3"Ulw
try{ 85hQk+Bu4
Thread.sleep(nSecond); 0x71%=4H^x
} y||@?Y
catch(Exception e) "5|\X<f
{ >?V<$>12
e.printStackTrace (); )&z4_l8`=
} Pi){h~B>
} <jFSj=cIL
k*Pz&8|
//日志 @h(!<Ux_
public static void log(String sMsg) c'rd$
{ [Xh\mDU.
System.err.println(sMsg); pYh!]0n
} $T/#1w P
= t-fYV
PCZ]R
public static void log(int sMsg) +6376$dC
{ @/(@/*+"
System.err.println(sMsg); LzE/g)>
} $iHoOYx]<
} ZqP7@fO_%
#TATqzA
+c r
/* &57U? oY
**TestMethod.java !qw4mN
*/ ,R}Z=w#
package NetFox; $}4K`Iu
2&x7W*
oZ-FF'
public class TestMethod { GA ik;R
8f-:d]
;dOs0/UM&
public TestMethod() Mciq-c)
{ ///xx/weblogic60b2_win.exe PI63RH8e
try{ 0Ve%.k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )-q\aX$])
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uS-3\$
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6F-JK1i
fileFetch.start(); J[r^T&o
} <A{y($
catch(Exception e){e.printStackTrace ();} OAVQ`ek
E*^9|Y[
SUc6/'Rdr
} `Hd9\;NJ
]ViOr8u
iD`k"\>9
public static void main(String[] args) HL8(lPgS
{ 5H*>
new TestMethod(); h~fWE
} r w\D>}\
} gY%&IHQ'
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