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)); g.C5r]=+&
} }5bM1h#z
for(int i=0;i<nEndPos.length-1;i++) Jqfm@Y
{ u#jC#u^M
nEndPos = nStartPos[i+1]; &u8z5pls8
} {#hVD4$b
nEndPos[nEndPos.length-1] = nFileLength; E%3TP_B3
} wahZK~,EaY
} rFu ez$
K=\&+at1
Ijedo/
//启动子线程 GdA.g w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j_Nm87i]
for(int i=0;i<nStartPos.length;i++) n1J]p#nCa.
{ `X8@/wf#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fRHKQ(a#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tXq)nfGe{
nStartPos,nEndPos,i); !OE*z $\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IXq(jhm8bL
fileSplitterFetch.start(); l(:kfR~AC
} 2\@Z5m3B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y&f\VNlT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6|=j+rScv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "H+,E_&(
nEndPos = " + nFileLength); _\zQ"y|G
// fileSplitterFetch[nPos.length-1].start(); k-jahm4
oXgdLtsu
IeTdN_8
//等待子线程结束 0k[2jh
//int count = 0; @d&H]5
//是否结束while循环 yrr) y
boolean breakWhile = false; ?R'Y?b
# cFr
GyC)EFd
while(!bStop) +5X DF
{ \l,rpVv5m
write_nPos(); 5%i:4sMx *
Utility.sleep(500); <nzN$"%
breakWhile = true; Oh; Jw
t;O1IMF
I/uy>*
for(int i=0;i<nStartPos.length;i++) 4Z5#F]OA7
{ HEY4$Lf(I
if(!fileSplitterFetch.bDownOver) @x{`\AM|%
{ j43$]'-
breakWhile = false; q|dH~BK
break; .<&s%{EW
} reiU%C
} -x]`DQUg
if(breakWhile) yoS? s
break; K*vU5S
$8=@R'
erFv(eaDK
//count++; `f`TS#V
//if(count>4) bcz-$?]
// siteStop(); ]?<n#=eW
} l]!B#{
pv# 2]v
xeA#u J
System.err.println("文件下载结束！"); bB6[Xj{
} gv.6h{Ut
catch(Exception e){e.printStackTrace ();} ;O=h$8]
} ;JTt2qQKo
M$S]}
kgW @RD|
//获得文件长度 !1Y&Y@ze
public long getFileSize() b"CAKl
{ :1aL ?
int nFileLength = -1; bS^WhZy'(
try{ @WOM#Kc
URL url = new URL(siteInfoBean.getSSiteURL()); vq'k|_Qi=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =/9^, 6Q(
httpConnection.setRequestProperty("User-Agent","NetFox"); Fx#jV\''s
p*qPcuAA
HuI`#.MpWE
int responseCode=httpConnection.getResponseCode(); \8v91g91f
if(responseCode>=400) h*l&RR:i
{ wpo1
processErrorCode(responseCode); ^k/i-%k0
return -2; //-2 represent access is error Op}ZB:
} ^DAu5|--R
0D~ Tga)
E4oz|2!m
String sHeader; m&Yi!7@(
C/@LZ OEL
fi%r<]@
for(int i=1;;i++) p{tK_ZBy]c
{ %s=Dj2+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %J7UP4
//Utility.log(in.readLine()); .#w6%c@
sHeader=httpConnection.getHeaderFieldKey(i); w#y2_
if(sHeader!=null) (Tvcq
{ SNY (*
if(sHeader.equals("Content-Length")) $dg9z}D
{ c:hK$C)T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l54 m22pfv
break; vNDu9ovs-
} 6NLW(?]
} M {a #
else \ v2H^j/
break; {6,|IGAq V
} LR&_2e^[
} tw K^I6@
catch(IOException e){e.printStackTrace ();} 1=)r@X/6d
catch(Exception e){e.printStackTrace ();} UT]?;o"
-4 Ux,9&
"IjI'c
Utility.log(nFileLength); AHbZQulC
r@}bDkx
xyeA2Y
return nFileLength; 4g` jd
} [~mGsXV
=JO^XwUOo
Paf%rv2
//保存下载信息（文件指针位置） |%7cdMC
private void write_nPos() q9*MNHg}
{ jgu*Y{ocm
try{ -"TR\/
output = new DataOutputStream(new FileOutputStream(tmpFile)); pV\YG B+
output.writeInt(nStartPos.length); LBlN2)\@
for(int i=0;i<nStartPos.length;i++) 6(V /yn~
{ IApT'QNM
// output.writeLong(nPos); >,5i60Q
output.writeLong(fileSplitterFetch.nStartPos); #/-_1H
output.writeLong(fileSplitterFetch.nEndPos); `dkV_ O0
} 2Aq~D@,9=:
output.close(); N/F$bv
} ^Z,q$Gp~P
catch(IOException e){e.printStackTrace ();} l* dV\ B
catch(Exception e){e.printStackTrace ();} vZAv_8S)
} 5er@)p_
bud&R4+
x?,9_va]
//读取保存的下载信息（文件指针位置） Lc2QXeo8
private void read_nPos() q!lP"J
{ P,xwSvO#M
try{ '+y_\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wa09$4>_w
int nCount = input.readInt(); 4B[D/kIg
nStartPos = new long[nCount]; E1V^}dn
nEndPos = new long[nCount]; 7}o/:
for(int i=0;i<nStartPos.length;i++) HIc a nk
{ rNN j0zw>
nStartPos = input.readLong(); uGH?N
nEndPos = input.readLong(); LF<wt2?*
} -_A$DM!^=w
input.close(); \Ad7 Gi~
} kBWrqZ6
catch(IOException e){e.printStackTrace ();} ](0mjE04<d
catch(Exception e){e.printStackTrace ();} GHc/Zc"iX
} ?A*Kg;IU
Fwg^(;bL
t'qL[r%?
private void processErrorCode(int nErrorCode) /BA{O&Ro^
{ al^!,ykc
System.err.println("Error Code : " + nErrorCode); x_w~G]! /
} 0BU=)Swku
ja=w5
Qs 2.ef?
//停止文件下载 <,@%*G1-
public void siteStop() #J\rv'
{ *|:Q%xr-
bStop = true; 7L(eh7
for(int i=0;i<nStartPos.length;i++) Gwec4D
fileSplitterFetch.splitterStop(); J>0b1
>4i>C
1}m3;
} IVvtX}
} -yH,5vD
//负责部分文件的抓取 UXr5aZ7y
**FileSplitterFetch.java S6i@"h5
*/ }^ FulsC
package NetFox; l$Gl'R>>*
o+O}Te
S]/b\B.h+
import java.io.*; n%%7KTqu
import java.net.*; ht97s
uXZg1F)
[3/VCYje
public class FileSplitterFetch extends Thread { %Q"(/jm?
P7 yq^|
q3e8#R)l
String sURL; //File URL }(FPV*mS
long nStartPos; //File Snippet Start Position r`'y?Bra;
long nEndPos; //File Snippet End Position R=)55qu
int nThreadID; //Thread's ID wD\ZOn_J
boolean bDownOver = false; //Downing is over f>9s!Hpu_
boolean bStop = false; //Stop identical ??qq:`s
FileAccessI fileAccessI = null; //File Access interface k)\gWPH
%CnxjtTo
a>mMvc"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @\P4/+"9
{ y*b3&%.ml
this.sURL = sURL; ;iYff N
this.nStartPos = nStart; u0s8yPA
this.nEndPos = nEnd; T/r#H__`
nThreadID = id; p]G3)s@>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w!^~<{Kz
} G7LIdn=
]2SF9p_
\fWW'
public void run() 'cZN{ZMWG
{ 4\otq%Y
while(nStartPos < nEndPos && !bStop) 0$.m_0H
{ |Bo .4lX
dE`-\J
d=*x#In
try{ MmTC=/j
URL url = new URL(sURL); D1s4`V -
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?*"srE,#JX
httpConnection.setRequestProperty("User-Agent","NetFox"); 4$6T+i2E
String sProperty = "bytes="+nStartPos+"-"; F'm(8/A$
httpConnection.setRequestProperty("RANGE",sProperty); i{c@S:&@^
Utility.log(sProperty); ;az5ZsvN D
xG2+(f#C1
8P' ana
InputStream input = httpConnection.getInputStream(); m#e3%150{
//logResponseHead(httpConnection); {D&9UZm
]88];?KS}
!c#]?b%
byte[] b = new byte[1024]; xJ8%<RR!t
int nRead; X|LxV]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;QCrHqRT`
{ H6TD@kL9Wr
nStartPos += fileAccessI.write(b,0,nRead); v4/-b4ET
//if(nThreadID == 1) ZAKeEm2A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6=hk=2]f
} RIn9(r
FqFapRX66Z
cgu~
Utility.log("Thread " + nThreadID + " is over!"); h@{_duu
bDownOver = true; |J5 =J
//nPos = fileAccessI.write (b,0,nRead); 9O*_L:4o
} H].y w9
catch(Exception e){e.printStackTrace ();} $(pF;_W
} ; 0v>Rfa
} | tQiFC
fnKY1y]2+
:aLT0q!K
//打印回应的头信息 6.1)IQkO
public void logResponseHead(HttpURLConnection con) u"xJjS
{ K0pac6]
for(int i=1;;i++) sM[I4.A3
{ _6@hTen`
String header=con.getHeaderFieldKey(i); UaG1c%7?X
if(header!=null) 3riw1r;Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n.oUVr=nX
Utility.log(header+" : "+con.getHeaderField(header)); @F*wg
else fl\aqtF
break; J8a*s`ik
} 'J)2g"T@
} `Mj}md;O"
-f1k0QwL
![6EUMx
public void splitterStop() TJ8E"t*)
{ +k<w!B*
bStop = true; x`RTp:#
} >O9o,o/6R
]q5`YB%_
3uu~p!2
} <bck~E
&QX`NO6
7}O.wUKw%
/* D#A~Nbc
**FileAccess.java }ArpPU :]
*//文件访问(定位，写) {Rq1HH
package NetFox; ~I}9;XT
import java.io.*; ?|{XZQ~
3oZ=k]\
rZPT89M6
public class FileAccessI implements Serializable{ N/QiI.V6
LK9g0_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $4FX(O0Q@
RandomAccessFile oSavedFile; 8e~|.wOL
long nPos; g?v\!/~(u
?jQ](i&
V! |qYM.
public FileAccessI() throws IOException >kZ57,
{ qB]i6*
this("",0); /.Nov
} fQK"h
/2M.~3gQ
rx"s!y{!-
public FileAccessI(String sName,long nPos) throws IOException RR;AJ8wd
{ ma$Prd
oSavedFile = new RandomAccessFile(sName,"rw"); vR6Bn
this.nPos = nPos; |H}m4-+*
oSavedFile.seek(nPos); ixm&aW6<
} iTh:N2/-vc
PYRd]%X
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public synchronized int write(byte[] b,int nStart,int nLen) zjL.Bhiud
{ $/1c= Y@
int n = -1; f&,{XZ
try{ dBV7Te4L
oSavedFile.write(b,nStart,nLen); F(#rQ_z]
n = nLen; ,bE$| x'
} y;?ie]3G
catch(IOException e) JPM))4YDR
{ Z+`{7G?4m
e.printStackTrace (); +z9@:L
} 1=7jz]t
Hy"x
;< )~Y-
return n; oY~ Dg
} ~n')&u{
Z4$cyL'$P
[ =x s4=
} Rv,JU6>i
t&Os;x?To?
/y7M lU9
/* 9mc!bj^811
**SiteInfoBean.java R2L;bGI*J
*/ vzel#
package NetFox; Y!q!5Crfi
d%I"/8-J
C9DJO:f.2y
public class SiteInfoBean { H2xeP%;$
o`zr>
I\?9+3 XnQ
private String sSiteURL; //Site's URL . #Z+Z
private String sFilePath; //Saved File's Path R:JX<Ba
private String sFileName; //Saved File's Name Ll4bdz,
private int nSplitter; //Count of Splited Downloading File C'=k&#<-
!|q<E0@w\
%S` v!*2
public SiteInfoBean() YJS{i
{//nSplitter的缺省值为5 &bz:K8c
//default value of nSplitter is 5 1pv}]&X
this("","","",5); o~FRF0f*VP
} 49Df?sx
*tOG*hwdT
GT hL/M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UmnE@H"t$\
{ e6X[vc|Y}
sSiteURL= sURL; -"Y{$/B
sFilePath = sPath; D9mz9
sFileName = sName; j#~Jxv%n
this.nSplitter = nSpiltter; gw`B"c|
Ee1LO#^_6
+#b:d=v!
} 0c.s -
}),w1/#5u8
t&5%?QyM
public String getSSiteURL() be5,U\&z
{ {u!)y?}I-
return sSiteURL; &~UJf4b|A
} nhSb~QqEh
)5JU:jNy
=K&\E2kA4
public void setSSiteURL(String value) ]`g<w#
{ rPc7(,o*
sSiteURL = value; w#JJXXQI
} M'`;{^<
y~ G.V,0
Zn,>]X
public String getSFilePath() <XTU8G
{ PN~@
return sFilePath; S.B<pjgt
} $qF0ltUQ
t:JI!DR
%dErnc$
public void setSFilePath(String value) Iu~\L0R427
{ 8,O33qwH
sFilePath = value; %xlqF<
} v{i7h|e
=.|J!x
OI} &m^IOo
public String getSFileName() d0hhMx6$
{ Y $g$x<7
return sFileName; p\C%%
} wpA`(+J
% |q0-x
G>YAJo
public void setSFileName(String value) (vR 9H(#
{ a</D_66
sFileName = value; r4x3$M c
} \^1+U JU
L.xZ_ 6
_<$>*i R
public int getNSplitter() krq/7|
{ Z'^U ad6
return nSplitter; {Z;jhR,
} jNwjK0?
/$n ~lf
c[}(OH
public void setNSplitter(int nCount) C ]Si|D
{ 6m.k;'
nSplitter = nCount; ~,D@8tv
} p3ISWJa!
} `"iY*
Q@e[5RA+]
Mcw4!{l`
/* n[Zz]IO,g
**Utility.java , "jbq~
*/ pqvOJ#?Q}=
package NetFox; gIR^)m
r _,_5 @0e
:"6q,W
public class Utility { Nf+b"&Zh`
$d+DDm1o
j9qREf9)
public Utility() f:zFFpP.j@
{ ,3v+PIcMM+
s#h8%['
Q|}aR:4
} |CgnCUv+
]U[X1W+@
//线程睡眠 #6+FY+/
public static void sleep(int nSecond) rA0,`}8\
{ N-lGa@ j
try{ 6*9}4`
Thread.sleep(nSecond); h:XzUxL\
} 8,?v?uE
catch(Exception e) -3Avs9`5
{ [LT^sb
e.printStackTrace (); IM=bK U
} 0Q1FL MLV
} @RD+xYm
#5sD{:f`
//日志 bLz*A-
public static void log(String sMsg) kH*Pn'
{ *IlaM'[*
System.err.println(sMsg); yTE%hHH]&[
} aYL|@R5;e
KDi|(
|( (zTf
public static void log(int sMsg) [#" =yzR<3
{ *y`%]Hy<
System.err.println(sMsg); j^`X~gE
} F}J-gZl
} /9Q3iV$I]
nM=e]qH
Y**|N8e
/* 4!$ M q;U
**TestMethod.java -7WW[ w
*/ HQ!Xj.y
package NetFox; puSLqouTM
fQWIw
R7oj#
public class TestMethod { %v5R#14[n
jD){I
e"-X U@`k1
public TestMethod() W[[oSqp
{ ///xx/weblogic60b2_win.exe gOT+%Ab{_
try{ )/4(e?%=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |sqZ$Mu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MB);!qy
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q_*_?yf
fileFetch.start(); L;_c|\%
} dNY"]b
catch(Exception e){e.printStackTrace ();} .=9s1~]
y$Zj?Dd#
>1L=,M
} PZ:u_*Vu`
I^*'.z!4Q
1`f_P$&Z_J
public static void main(String[] args) @ \.;b9
{ "SWMk!
new TestMethod(); -9P2`XQ^
} ,Y_{L|:w
} sfp,Lq`
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