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)); `~lG5|
} Fz<1xyc(
for(int i=0;i<nEndPos.length-1;i++) e2V;6N
{ GoX<d{
nEndPos = nStartPos[i+1]; 1uKIO{d@
} <v_Wh@m
nEndPos[nEndPos.length-1] = nFileLength; A-L)2.M
} %q;y74
} daSx^/$R
+.^pAz U}R
VFnxj52<
//启动子线程 e8:O2!HW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ny`SE\B+/
for(int i=0;i<nStartPos.length;i++) mbIHzzW>
{ `k9a$@Xg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xc G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eqU y>
nStartPos,nEndPos,i); 7)x788Z6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c&#B1NN<
fileSplitterFetch.start(); s)kr=zdyo
} ]/?$DNjCc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @`rC2-V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jG/@kh*m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8qv>C)~~`
nEndPos = " + nFileLength); -N1X=4/fg
// fileSplitterFetch[nPos.length-1].start(); S2~im?^21
"lBYn2W
=O~Y6|
//等待子线程结束 S 0mt8/ M
//int count = 0; )bB Va^
//是否结束while循环 d{c06(#_
boolean breakWhile = false; E-HK=D&W/
~4`3p=$
lN[#+n
while(!bStop) o65I(`
{ _5v]69C#
write_nPos(); fvZ[eJ
Utility.sleep(500); Ihx[S!:
breakWhile = true; ME'LZ"VT
k,jcLX.
'OsRQ)E
for(int i=0;i<nStartPos.length;i++) ~.J{yrJ&
{ $%?[f;S3,
if(!fileSplitterFetch.bDownOver) }ZfdjF8N!
{ hU5_ dV
breakWhile = false; x{$/|_
break; \!Ap<
} 3Hhu]5
} X="]q|Z
if(breakWhile) ~5n?=
break; 9PJnKzQ4
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71,GrUV:
//count++; O5A]{W
//if(count>4) eY3<LVAX
// siteStop(); MUMB\K*$
} HnY.=_G
!+n'0{
4}*V=>z
System.err.println("文件下载结束！"); z]1g;j
} e}2[g
catch(Exception e){e.printStackTrace ();} Cuo"6, M
} /_tN&[
j`_tb
qex::Qf
//获得文件长度 7}vx]p2
public long getFileSize() @Zfg]L{Lr
{ SHqz&2u
int nFileLength = -1; L:Me
try{ r9~IR
URL url = new URL(siteInfoBean.getSSiteURL()); UDHMNubB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -8&P1jrI
httpConnection.setRequestProperty("User-Agent","NetFox"); J&;' gT
N7Kkz /
._`?ZJ
int responseCode=httpConnection.getResponseCode(); k(_^Lq f-
if(responseCode>=400) B'D~Q
{ h{CyYsQ
processErrorCode(responseCode); &&te(DC\
return -2; //-2 represent access is error Qe]aI7Ei
} >%85S>e
6#kK
RHuc#b0
String sHeader; cd)}a_9
}*vO&J@z
i[PksT#p
for(int i=1;;i++) nT@FSt
{ HLl"=m1/>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {\ogw0X
//Utility.log(in.readLine()); 6R!AIOD>
sHeader=httpConnection.getHeaderFieldKey(i); .a}!!\@
if(sHeader!=null) ='fN xabB
{ ]wV_xZ)l^A
if(sHeader.equals("Content-Length")) $H1igYc
{ [k7 ;^A5/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (2r808^2
break; &(~"OD
} |JTDwmR
} )Z63 cr/
else 4,:)%KB"V
break; ilFS9A3P
} 2yA+zJ 46B
} |}<!O@<|
catch(IOException e){e.printStackTrace ();} HkyN$1s
catch(Exception e){e.printStackTrace ();} #v:A-u
>RKepV(X7
&F|Wk,y
Utility.log(nFileLength); tMr$N[@r
^Rmrre`uU
G3de<?K.[V
return nFileLength; &_$xMM,X
} u1/q8'RW
4 zipgw
s7:w>,v/
//保存下载信息（文件指针位置） mH!\]fmR~
private void write_nPos() =<z~OE'lV
{ *|)O
try{ RBOhV/f
output = new DataOutputStream(new FileOutputStream(tmpFile)); [I%'\CI;
output.writeInt(nStartPos.length); ,pVq/1
for(int i=0;i<nStartPos.length;i++) ufS0UD8%H
{ V-zF'KI[
// output.writeLong(nPos); [N1[khY`
output.writeLong(fileSplitterFetch.nStartPos); WvWZzlw
output.writeLong(fileSplitterFetch.nEndPos); t++\&!F
} *uMtl'
output.close(); R|dSjEs
} mNr<=Z%b
catch(IOException e){e.printStackTrace ();} K]dX5vJw'
catch(Exception e){e.printStackTrace ();} `/eh
} p0j-$*F
Kw,ln<)2
5c3&4,,eR
//读取保存的下载信息（文件指针位置） &3'zG)
private void read_nPos() gj1l9>f>]a
{ r2>y !Q?
try{ ,ikn%l#cm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z;[Z'_B
int nCount = input.readInt(); =s[P =dU
nStartPos = new long[nCount]; ?&r>`H E
nEndPos = new long[nCount]; }J\KnaKo
for(int i=0;i<nStartPos.length;i++) "=XRonQZ
{ xm}`6B^f
nStartPos = input.readLong(); j=TG&#e
nEndPos = input.readLong(); Q-Rt
} >rzpYc'~w
input.close(); ;gv9J[R
} DSx D531[A
catch(IOException e){e.printStackTrace ();} A49HYX-l
catch(Exception e){e.printStackTrace ();} j8#B
} H1g"09?h6o
&fWYQ'\>
^LJ?GJ$g
private void processErrorCode(int nErrorCode) k84JDPu#
{ oFUP`p%[
System.err.println("Error Code : " + nErrorCode); 9:jZ3U
} $2\k| @)s
} ~#^FFe
Gn%gSH/
//停止文件下载 B#;yko
public void siteStop() eA(c{
{ DV!) n 6
bStop = true; Bn_@R`
for(int i=0;i<nStartPos.length;i++) +R?d6IjH
fileSplitterFetch.splitterStop(); [{!5{k!
3xnu SOdh
{|J'd+
} /^z5;aG
} s8<)lO<SV.
//负责部分文件的抓取 *m[ow s
**FileSplitterFetch.java ?=h{`Ci^ $
*/ ndIU0kq3
package NetFox; ^J=l] l
ard<T}|N
e.|_=Gd2/
import java.io.*; cSSrMYX2
import java.net.*; ^L1#
L)o7~M
4F+n`{~
public class FileSplitterFetch extends Thread { NN9`jP2
2$O@T]
93npzpge
String sURL; //File URL bvMa|;f1
long nStartPos; //File Snippet Start Position Ge>%?\
long nEndPos; //File Snippet End Position ]'F{uDm[
int nThreadID; //Thread's ID 'MHbXFM
boolean bDownOver = false; //Downing is over =U5lPsiv,3
boolean bStop = false; //Stop identical x_oL~~@
FileAccessI fileAccessI = null; //File Access interface ji[O?
YolO-5
#w4=kWJ[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'V5^D<1P
{ =x4:jas
this.sURL = sURL; PL#8~e;'
this.nStartPos = nStart; aNpeePF)z
this.nEndPos = nEnd; 6N&S3<c4JO
nThreadID = id; _G!lQ)1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IwIk;pB O
} d))(hk:
an 3"y6.8
q9RCXo>Y+1
public void run() \vB-0w
{ eiJO;%fl>l
while(nStartPos < nEndPos && !bStop) 4'W|'4'b
{ |#x;}_>7
%6}S'yL
8z^?PZ/
try{ 0KyujU?sF
URL url = new URL(sURL); h94SLj]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FX"%
httpConnection.setRequestProperty("User-Agent","NetFox"); EOrWax@k$}
String sProperty = "bytes="+nStartPos+"-"; ujZki.x
httpConnection.setRequestProperty("RANGE",sProperty); _7YAF,@vT
Utility.log(sProperty); z0Vd(QL
;^:9huN
X6~y+R
InputStream input = httpConnection.getInputStream(); 0}qij
//logResponseHead(httpConnection); "_ b Sy
36JVnW;
y6'Fi(2yw
byte[] b = new byte[1024]; |EaGKC(
int nRead; j?1\E9&4-Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]nN']?{7PW
{ p8BAan3
nStartPos += fileAccessI.write(b,0,nRead); j3VM!/
//if(nThreadID == 1) FpE83}@".w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); StWDNAf)
} MQ2gzKw>
y-}lz#N
C81+nR
Utility.log("Thread " + nThreadID + " is over!"); VG+Yhm<SL
bDownOver = true; ;u,%an<(
//nPos = fileAccessI.write (b,0,nRead); 3S:}fPR
} US'X9=b_
catch(Exception e){e.printStackTrace ();} Kwfrh?
} GC H= X
} d6<,R;)
{gl-tRC3
J$&!Y[0
//打印回应的头信息 Ka2U@fK"
public void logResponseHead(HttpURLConnection con) @fT*fv
{ NaG1j+LN
for(int i=1;;i++) 5|xFY/%
{ 5wRDH1z@{
String header=con.getHeaderFieldKey(i); Q <^'v>~n
if(header!=null) k$}XZ,Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kJ>l,AD/
Utility.log(header+" : "+con.getHeaderField(header)); CBs0>M/
else I o7pp(
break; <|Bh;;
} }{:H0)H*
} X~5TA)h;~
=bZ>>-<
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public void splitterStop() ]XJpy-U
{ +kH*BhSj
bStop = true; v(FO8*5DZ
} !s?vj <
wz9V)_V*
KKa"Ba$g
} p{t2pfb
zbx,qctYo$
mDvZ1aj
/* {_ww1'|A
**FileAccess.java ]$4k+)6
*//文件访问(定位，写) aIRCz=N
package NetFox; b,~4O~z
import java.io.*; wP6~HiC
bh6Mh<+
JQ%e'
public class FileAccessI implements Serializable{ -/B}XNW
lK9us
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ><TuL7+
RandomAccessFile oSavedFile; Od>Ta_
long nPos; >72j,0=e
vXR-#MS`}
a_L&*%;
public FileAccessI() throws IOException 1G=1FGvP
{ H-nk\ K<|
this("",0); ;B^G<
} {Rc/Ten
s59v* /
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public FileAccessI(String sName,long nPos) throws IOException @%O"P9;s
{ {K09U^JU
oSavedFile = new RandomAccessFile(sName,"rw"); eq<xO28z
this.nPos = nPos; zM|d9TS
oSavedFile.seek(nPos); ;jfjRcU
} T3@wNAAU
YS{])+s
e/r41
public synchronized int write(byte[] b,int nStart,int nLen) bVQLj}%
{ [~W"$sT
int n = -1; ^Gq4Yr
try{ 2rB$&>}T
oSavedFile.write(b,nStart,nLen); zg.'
n = nLen; (Vf&,b@U_
} c;xL.
catch(IOException e) d0Py[37V
{ |n \HxU3
e.printStackTrace (); al F*L
} N0O8to}V
$LRvPan`
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return n; kUUN2
} yc8iT`
c_~)#F%P
Sqed*
} W#P)v{K
-7fsfcGM$
B[Fx2r`0
/* <ap%+(!I
**SiteInfoBean.java Vk5}d[[l
*/ [c+[t3dz
package NetFox; jX-v9eaA
*NS:X7p!V
S;kI\;
public class SiteInfoBean { Zgkk%3'^'
cgNK67"(
!}[cY76_
private String sSiteURL; //Site's URL yEvuTgDv
private String sFilePath; //Saved File's Path PNn-@=%
private String sFileName; //Saved File's Name +|SvJ
private int nSplitter; //Count of Splited Downloading File c"<bq}L7S
P,"z
tR5zlm(}
public SiteInfoBean() _%s_w)
{//nSplitter的缺省值为5 FhB^E$r%
//default value of nSplitter is 5 JF*JFOb
this("","","",5); x5m .MQ J
} "F+ 9xf&r
H^Xw<Z=
( $3j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "b*.>QuZ
{ &Ko}Pv
sSiteURL= sURL; FTt7o'U
sFilePath = sPath; =&,zWNz)
sFileName = sName; q*A2>0O
this.nSplitter = nSpiltter; nJ4h9`[>V
.i/]1X*;r^
i^uC4S~
} JRA.,tQc
:>3&"T.
p\-.DRwT`
public String getSSiteURL() cF(9[8c{
{ M9&tys[KX
return sSiteURL; $s]@%6f
} %BG5[XQ7
>8JvnBFx=
GzB%vsv95
public void setSSiteURL(String value) ,o}[q92@w
{ GUp51*#XR
sSiteURL = value; ^@19cU?q
} ~o2{Wn["
=0f8W=d:Vr
):|)/ZiC'
public String getSFilePath() BuvBSLC~
{ g8x8u|
return sFilePath; Q`s(T
} ttKfZ0
5-3gsy/Mo
U)PumU+z$u
public void setSFilePath(String value) _0f[.vN
{ y(S0 2v>l
sFilePath = value; 2kgm)-z
} 'q-h kN
g Q9ff,
& vIKNGJ^
public String getSFileName() Sh*P^i.]+
{ o{hKt?
return sFileName; ;8v5 qz
} $+);!?^|:
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3TtW2h>M
public void setSFileName(String value) NAU<?q<)
{ i,HAXPi
sFileName = value; o MAK[$k;
} t(yv
\[&]kPcDl
?`XKaD! f
public int getNSplitter() 9e5UTJ
{ |eqDT,4
return nSplitter; k$>T(smh
} + ThKqC_
;$i'A&)OC
neBkwXF!
public void setNSplitter(int nCount) '$zFGq }}
{ <b\urtoJ
nSplitter = nCount; 6>Cubb>
} $3ILVT
} Bz{ g4!ku
5-*]PAC
[ n2udV
/* cPbz7
**Utility.java k.ZfjX"
*/ :]s] =q&]
package NetFox; {JgN^R<5<f
Z:_y,( 1Q
2YyZiOMSc
public class Utility { :9b RuUm
qHCs{ u
:dzU]pk%0
public Utility() "x)DE,
{ Y"qY@`
tp<VOUa
&; \v_5N6
} ho1F8TG=
d%3BJ+J
//线程睡眠 L ~w=O!
public static void sleep(int nSecond) eW0=m:6
{ 9K|lU:,
try{ D;]%
Thread.sleep(nSecond); .KN]a"]
} 1' m $_
catch(Exception e) iC]lO
{ Ao T7sy7
e.printStackTrace (); jhv1 D'>6
} M>@R=f
} !\1W*6U8;
T;@>O^
//日志 I0K!Kcu5Iu
public static void log(String sMsg) }eM<A$J
{ V%lGJ]ZEa
System.err.println(sMsg); C`wI6!
} <R>z;2c
)1Nnn
Y)}%SP>,
public static void log(int sMsg) "Q{~Bj~
{ /T[ICd2J
System.err.println(sMsg); e"#D){k#
} bK\WdG\;
} ?4e6w
@BUqQ9q:
x9l0UD*+g
/* j#t8Krd] "
**TestMethod.java ?K {1S
*/ bs EpET
package NetFox; 3]n@c?lw
FK# E7 K
1xAFu+
public class TestMethod { %@n8 ?l4
_G #"B{7
cvE.r330|
public TestMethod() AAq=,=:R<
{ ///xx/weblogic60b2_win.exe .*-w UBr
try{ :dIQV(iW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 68<Z\WP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r>~d[,^$m4
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4:&qTY)H
fileFetch.start(); RB7AI!'a?
} )|y2Q
catch(Exception e){e.printStackTrace ();} bro
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1Dya?}3
} @ Rx6 >52>
@D~+D@i$TW
_gm?FxV:
public static void main(String[] args) ,ah*!Zm.kk
{ +6hl@Fm(
new TestMethod(); WAB0e~e:|Q
} r}0C8(oq
} G/z\^Q
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