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)); a.?U$F
} ~Sm6{L
for(int i=0;i<nEndPos.length-1;i++) ]'Ho)Q
{ OUGkam0UK
nEndPos = nStartPos[i+1]; ;]>)6
} ]W2#8:i
nEndPos[nEndPos.length-1] = nFileLength; ,tyPZR_
} @^-Y&N!b=
} (/]#G8
CP%^)LX *
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//启动子线程 $>yfu=]?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; % C2Vga#
for(int i=0;i<nStartPos.length;i++) NR k~
{ `]6<j<' ,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .{`C>/"}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5%fWX'mS
nStartPos,nEndPos,i); _JNYvngm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r`EjD}2d
fileSplitterFetch.start(); >s"/uo
} fvi0gE@bd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6\K\d_x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y[}A4`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", * O?Yp%5NH
nEndPos = " + nFileLength); Q#qfuwz
// fileSplitterFetch[nPos.length-1].start(); u'_}4qhCC;
}Kp<w,
GQA\JYw|oY
//等待子线程结束 rrj.]^E_~
//int count = 0; m}RZ)c
//是否结束while循环 Z~-N'Lt{
boolean breakWhile = false; Y(kf<Wo
>.K%W*t
?fq!BV
while(!bStop) ]Z6? m
{ Zxqlhq/)
write_nPos(); Dr%wab"yy
Utility.sleep(500); %3#C0%{x
breakWhile = true; "Z,T%]
l,l6j";ohd
6XU p$Pd(
for(int i=0;i<nStartPos.length;i++) BU??}{
{ Gs3V]qbEP
if(!fileSplitterFetch.bDownOver) 6G"UXNa,
{ e:'56?|
breakWhile = false; qT5"r488
break; \ ya@9OA
} |#Lz0<c;
} p?ccBq
if(breakWhile) g9VY{[V
break; g\.$4N
,3f>-mP
GCO: !,1
//count++; `<>QKpAn
//if(count>4) kI@<H<
// siteStop(); IHd W!q
} "P(obk
$rr@3H+
m26YAcip}
System.err.println("文件下载结束！"); ?(d1;/0v>
} N AY3.e
catch(Exception e){e.printStackTrace ();} u?dPCgs;h
} U887@-!3
3Xd:LDZ{
3Z*o5@RI
//获得文件长度 {CBb^BP
public long getFileSize() =dKjTBR S'
{ { ,c*OR
int nFileLength = -1; kVKAG\F
try{ _]4p51r0
URL url = new URL(siteInfoBean.getSSiteURL()); *DfOm`m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `m<O!I"A
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Zd,"/RH
zN[& iKf
,z/aT6M?H
int responseCode=httpConnection.getResponseCode(); E/%"%&`8j
if(responseCode>=400) w@cW`PlF
{ C]5 kQ1Og
processErrorCode(responseCode); kV?fie<\)
return -2; //-2 represent access is error Bz-jy.
} v=lW5%r,'
!1=OaOT
!f52JQyh
String sHeader; 2 Kjd!~Z$
;2&"
breF,d$
for(int i=1;;i++) LAf#Rco4
{ O=}Rp1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1a{r1([)
//Utility.log(in.readLine()); B^P&+,\[}
sHeader=httpConnection.getHeaderFieldKey(i); &*+$38XE^
if(sHeader!=null) f?k0(rl
{ h L [eA
if(sHeader.equals("Content-Length")) -2J37
{ 0g|5s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vZTXvdF
break; ^-k"gLg
} Po@;PR=
} =r ^_D=
else ~YCH5,
break; o68i0aFW
} T pF[-fO
} DWKQ>X6
catch(IOException e){e.printStackTrace ();} *1`X}
catch(Exception e){e.printStackTrace ();} QE[<Y3M
.aY$-Y<
!KK`+ 9/
Utility.log(nFileLength); Y 2ANt w@
I)FFh%m<}a
/^nIOAeE
return nFileLength; OR~ui[w
} #Iz)Mu
J}xM+l7uY
{E Ay~lo
//保存下载信息（文件指针位置） H2R3I<j
private void write_nPos() \'j(@b,
{ S5TVfV5LI
try{ ? F #&F
output = new DataOutputStream(new FileOutputStream(tmpFile)); <YFDS;b|
output.writeInt(nStartPos.length); U0j>u*yE
for(int i=0;i<nStartPos.length;i++) qD>^aEd@4
{ _`\!+qGq
// output.writeLong(nPos); YWH>tt9
output.writeLong(fileSplitterFetch.nStartPos); ;NRh0)%|o
output.writeLong(fileSplitterFetch.nEndPos); [C6ba{9B
} n Ab~
output.close(); ?}s;,_GH
} MBA?, |9Q#
catch(IOException e){e.printStackTrace ();} 5>f"
catch(Exception e){e.printStackTrace ();} [%dsq`b#
} tjXg
ktTP~7UVi
aHW34e@ebL
//读取保存的下载信息（文件指针位置） \~,\|
private void read_nPos() *%KIq/V
{ \Yr*x7!
try{ d%'#-w'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B0Wf$ s^7t
int nCount = input.readInt(); v~L\[&|_
nStartPos = new long[nCount]; FJ~d&L\l
nEndPos = new long[nCount]; /&#y-D_
for(int i=0;i<nStartPos.length;i++) I{(!h90
{ lgU!D |v
nStartPos = input.readLong(); cHFW"g78
nEndPos = input.readLong(); )>FAtE
} "PI;/(kR
input.close(); o( zez
} *FC8=U2\X
catch(IOException e){e.printStackTrace ();} C 6 \
catch(Exception e){e.printStackTrace ();} jerU[3
} Y%"$v0D
bOr11?
a`w=0]1&*
private void processErrorCode(int nErrorCode) 6J,h}S
{ apa&'%7
System.err.println("Error Code : " + nErrorCode); :Pdh##k
} I8J>>H'#A
H;nzo3x
Zwc&4:5%
//停止文件下载 `Uz.9_6
public void siteStop() ~3:hed7:
{ YTefEG]|q
bStop = true; N+c|0
for(int i=0;i<nStartPos.length;i++) La1:WYt
fileSplitterFetch.splitterStop(); -6- sI
'69)m~B0a
W$hCI)m(
} *P*~CHx>
} :[n~(~7?
//负责部分文件的抓取 Pt5wm\
**FileSplitterFetch.java x/<]/D
*/ /r~2KZE
package NetFox; <pb
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pE<a:2J
import java.io.*; .2@T|WD!Ah
import java.net.*; 49*f=gpGj2
JE9v+a{7
ZNw|5u^N
public class FileSplitterFetch extends Thread { )m7%cyfC
x!GDS>
g3kbsi7_:
String sURL; //File URL Gpxp8[ {
long nStartPos; //File Snippet Start Position Q"FN"uQ}x
long nEndPos; //File Snippet End Position ivo><"Y(r
int nThreadID; //Thread's ID M8WjqTq
boolean bDownOver = false; //Downing is over RG45S0Ygj
boolean bStop = false; //Stop identical lF(v<drkB
FileAccessI fileAccessI = null; //File Access interface }XBF#BN
Qt4mg?X/
qWr=Oiu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _)5E=
{ 45.ks.
this.sURL = sURL; /Kli C\
this.nStartPos = nStart; OoA!N-Q
this.nEndPos = nEnd; t!rrYBSCr
nThreadID = id; -rcEG!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E6~VHQa2?
} }~@/r5Zl
SzpUCr"
&{8:XJe*,%
public void run() a%`Yz"<lQ
{ ^x O](,H
while(nStartPos < nEndPos && !bStop) Y[7prjd
{ H[KX xNYZ_
tP|/Q5s
Jp"29 )w
try{ Z]b;%:>=
URL url = new URL(sURL); .c]>*/(+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )Q`Ycz-
httpConnection.setRequestProperty("User-Agent","NetFox"); =a,qRO
String sProperty = "bytes="+nStartPos+"-"; x]wi&
httpConnection.setRequestProperty("RANGE",sProperty); `e'wWV
Utility.log(sProperty); FA,n>
H1U$ApD
bQ3<>e\%B
InputStream input = httpConnection.getInputStream(); c+3(|k-M
//logResponseHead(httpConnection); 87!jn'A
dnD@BQ
>A{Dpsi\
byte[] b = new byte[1024]; Q(w;
int nRead; pl r@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gz{%Z$A~o
{ kB@gy}
nStartPos += fileAccessI.write(b,0,nRead); _0Ea 3K
//if(nThreadID == 1) O)&W0`VY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AAa7)^R
} vcQl0+&
VCc=dME
^9,^BHlC0
Utility.log("Thread " + nThreadID + " is over!"); =A,B'n\R
bDownOver = true; `G!HGzVx;j
//nPos = fileAccessI.write (b,0,nRead); 4$VDJ
} 5OWyxO3{
catch(Exception e){e.printStackTrace ();} ++b[>};
} k vZw4Pk
} >U*p[FGW
5;KJ0N*-
-51LF=(!L
//打印回应的头信息 5T.U=_ag
public void logResponseHead(HttpURLConnection con) $>#0RzU
{ h'em?fN(
for(int i=1;;i++) 'v<v6vs
{ tcoG;ir
String header=con.getHeaderFieldKey(i); A^).i_&#
if(header!=null) fmK~?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^dLu#,;
Utility.log(header+" : "+con.getHeaderField(header)); }h Wv p
else &u&WP
break; 4#>Z.sf
} sTP\}
} ^=^\=9" b
&=)O:Jfa
q n-f&R
public void splitterStop() e bpt/q[
{ oQ-m
bStop = true; "[7-1}l
} mmJnE
O'(Us!aq
( gg )?
} AJB NM
sm'_0EUg
j=T8b
/* bDl#806PL
**FileAccess.java !0lk}Uzkh
*//文件访问(定位，写) N4,oO H~
package NetFox; F<{,W-my `
import java.io.*; mOj;0 R
tgG 8pL
m2^vH+wD
public class FileAccessI implements Serializable{ cdkEK
&ox
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +pG+ xI
RandomAccessFile oSavedFile; $=diG
long nPos; hO[_ _j8
|oU I2<"
kiJ=C2'&
public FileAccessI() throws IOException &!4E3&+2m
{ @.E9ml
this("",0); rM.Pc?Z
} _fZec+oM
h(yFr/
hK)'dG*
public FileAccessI(String sName,long nPos) throws IOException 3}s]F/e
{ D+:s{IcL<
oSavedFile = new RandomAccessFile(sName,"rw"); nuWQ3w p[e
this.nPos = nPos; VK*_pEV,}
oSavedFile.seek(nPos); RK-bsf
} dQSO8Jf
Pa0W|q#?X
0IqGy}+VU
public synchronized int write(byte[] b,int nStart,int nLen) d6*84'|!
{ >6yQuB
int n = -1; ^G`6Zg;
try{ l4i51S"
oSavedFile.write(b,nStart,nLen); GdUsv
n = nLen; <QvVPE}z
} RuYIG?J=/
catch(IOException e) 67&IaDts
{ I)1ih
e.printStackTrace (); Mj1f;$
} :(ql=+vDb4
D$4GNeB+#
'z,kxra|n
return n; \5&Mg81
} R98YGW_ dT
^@8XJ[C,_
'kj q C
} nG3SDL#(k
n\D/WLvM
`XE>Td>Bs
/* \Y"S4<"R
**SiteInfoBean.java 0cKsGDm
*/ 2;T?ry7
package NetFox; WqefH{PB
+o4o!;E)
Wjq9f;
public class SiteInfoBean { ]Xa]a}[uE
LE{@J0r#n
Sak^J.~G[
private String sSiteURL; //Site's URL |MKR&%Na
private String sFilePath; //Saved File's Path _Jg#T~
private String sFileName; //Saved File's Name {sB-"NR`K
private int nSplitter; //Count of Splited Downloading File FJH>P\+
\EU3i;BNT%
][l5S*CC_
public SiteInfoBean() GC# [&>L
{//nSplitter的缺省值为5 J?TCP%
//default value of nSplitter is 5 X=-=z5
this("","","",5); 2~/`L=L
} XdDQ$'*X
SujEF`"
VtzZ1/JE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &TRKd)wd
{ pD[&,gV$
sSiteURL= sURL; ~SBW`=aP}
sFilePath = sPath; 9;XbyA]
sFileName = sName; MVzj7~+
this.nSplitter = nSpiltter; p_BG#dRM
^PFiO 12
wuY-f4
} :_i1gY)
5P #._Em
uq9mq"
public String getSSiteURL() !QAndg{;D
{ !{V`N|0
return sSiteURL; yx`@f8Kr
} ='D%c^;O8'
bE% Hm!
'X+aYF}Ye
public void setSSiteURL(String value) H#GR*4x
{ =>PX~/o
sSiteURL = value; W (TTsnnx
} .(Ux1.0C
>.P*lT
qU6!vgM&
public String getSFilePath() gmu.8
{ b/*QV0(
return sFilePath; $I-iq @
} 3F;0a ;[
m`zd0IRTP
w7~]c,$y.
public void setSFilePath(String value) 1f^oW[w&
{ ,[p?u']yZz
sFilePath = value; BeRs;^r+
} i: -IZL\
7ojh=imY
=3hJti9[
public String getSFileName() M.5F|7
{ sCy.i/y
return sFileName; YRZw|H{>t
} =>Ae]mi7
Kc r)W
h\#4[/
public void setSFileName(String value) C`Vuw|Xl
{ 1G`5FU
sFileName = value; o+OX^F0
} _d~GY,WTdO
|af<2(d
;QuxTmWp^
public int getNSplitter() 6k,@+@]t.
{ 0|va}m`<3G
return nSplitter; V^qBbk%l>D
} :/? Op
J.2BBy
Yy[=E\z
public void setNSplitter(int nCount) ^+~$eg&js
{ uq:'`o-1
nSplitter = nCount; ]lJ#|zd8o
} >oy%qLHe~t
} )rA\+XT7
=#TQXm']Gi
Jnt r"a-4
/* tMf5TiWu@
**Utility.java K'e!BZm6Q
*/ "[A&S!
package NetFox; [uie]*^
b N>Ar
/mE:2K]C
public class Utility { c?xeBC1-
vA*NJ%&`
ZQz;EV!
public Utility() {XhpxJ__
{ )}w-;HX
.*FlB>1jy
/%?bO-
} >)+U^V
uTbMp~cYB
//线程睡眠 (o6u^#6
public static void sleep(int nSecond) W#b++}S
{ mMhe,8E&
try{ _;(QMeR
Thread.sleep(nSecond); 3joMtRB>;
} \hzx?
catch(Exception e) 3_VWtGQ
{ 8v;T_VN
e.printStackTrace (); n!b*GXb\
} $[=`*m
} ?K}KSJ6_
JLyFkV/
//日志 84Hm PPt
public static void log(String sMsg) WFeaX7\b
{ 5U<o%+^El
System.err.println(sMsg); A]V<K[9:b
} ~ C_2D?
g=v[@{9Pw
E\}Q9,Z$
public static void log(int sMsg) kr1^`>O5
{ d7c m?+
System.err.println(sMsg); XnvaT(k7Y
} ;rF:$37^
} gY=+G6;=<
6d 8n1_
N)z] F9Kg
/* 93`
**TestMethod.java T?5F0WKi
*/ `+r5I5
package NetFox; IZ4jFgpR
8J9o$Se
{24Pv#ZG#^
public class TestMethod { 'Uo:b<
~u-`L+G"6
h"nv[0!)
public TestMethod() 0$nJd_gW_
{ ///xx/weblogic60b2_win.exe U`'w{~"D%
try{ CV7.hF<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); z!j`Qoh?V9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m7mC 7x
SiteFileFetch fileFetch = new SiteFileFetch(bean); }KkH7XksF
fileFetch.start(); F{<rIR
} })w5`?Y
catch(Exception e){e.printStackTrace ();} a-DE-V Uls
:Ws3+OI'm3
Nb{oH+$b
} `wG&Cy]v
%nc+VL4
cKy%0oTla
public static void main(String[] args) |b7>kM}"
{ {k~$\J?.
new TestMethod(); 17qrBG-/MD
} ck<4_?1]
} !*#=7^#
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