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)); R$zH]
} 6q 2_WX
for(int i=0;i<nEndPos.length-1;i++) q -8t'7
{ 3Hf0MAt
nEndPos = nStartPos[i+1]; .s$z/Jv
} D7_*k%;@
nEndPos[nEndPos.length-1] = nFileLength; {v3P9s(
} yDNOtC|
} HSq}7S&U
k4 F"'N
Cu6%h>@K$
//启动子线程 $1SUU F\.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TX
for(int i=0;i<nStartPos.length;i++) s&'QN=A
{ a22XDes=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q+,Q<2J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Jmx Ko+-
nStartPos,nEndPos,i); 4@xE8`+bG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1?Z4K/
fileSplitterFetch.start(); ;;&}5jcV
} -W>'^1cR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F-6c_!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \TU3rk&X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y(K" -?
nEndPos = " + nFileLength); ~i 7^P9
// fileSplitterFetch[nPos.length-1].start(); ID/F
w3$
b+Br=Fv"T
//等待子线程结束 utr:J
//int count = 0; Y))NK'B5
//是否结束while循环 ^j7azn
boolean breakWhile = false; *2jK#9"MP
r&FDEBh
Yw0[[N<SW
while(!bStop) Ewg:HX7<(
{ R##~*>#
write_nPos(); 43=,yz2Ef
Utility.sleep(500); ,a#EW+" Z
breakWhile = true; 5atYOep
8_N]e'WUh
.1LCXW=
for(int i=0;i<nStartPos.length;i++) $8BPlqBIZ
{ W%\C_
if(!fileSplitterFetch.bDownOver) r7qh>JrO
{ ElUEteZ
breakWhile = false; 6uR^%W8]
break; %j7XEh<'
} H= X|h)
} zP<pEI
if(breakWhile) <I;2{*QI2
break; c*~]zR>s!
13Lr}M&
%iw3oh&Fkm
//count++; 63A}TBC
//if(count>4) }u1O#L}F5
// siteStop(); @e{^`\l=<
} ^aW Z!gi
D+>1]ij
0iJue&
System.err.println("文件下载结束！"); yq$,,#XDD=
} tor!Dl@Mo
catch(Exception e){e.printStackTrace ();} aM;W$1h
} A~mum+[5
#Skv(IL
H*r>Y
//获得文件长度 4"Hye&O
public long getFileSize() M8u<qj&<O
{ N?.%?0l
int nFileLength = -1; 9+pmS#>_
try{ IH"6? 9nd
URL url = new URL(siteInfoBean.getSSiteURL()); Nv"EV;$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .aflsUD
httpConnection.setRequestProperty("User-Agent","NetFox"); yxc=Z0~1
V(E/'DR
$.bBFWk
int responseCode=httpConnection.getResponseCode(); h\'n**f_x
if(responseCode>=400) +U@<\kIF
{ 4!wR_@W^El
processErrorCode(responseCode); MuSUKBhM
return -2; //-2 represent access is error &zo|Lfe
} Sfr&p>{,
@/1w4'M
iJ~Vl"|m
String sHeader; GQ-Rtn4v
nWHa.H#
=lpQnj"
for(int i=1;;i++) @K!&qw
{ c;'[W60
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y3=_ec3w
//Utility.log(in.readLine()); CoA6
sHeader=httpConnection.getHeaderFieldKey(i); 8}(]]ayl
if(sHeader!=null) xL" |)A =
{ I&YSQK:b
if(sHeader.equals("Content-Length")) )K2HK&t:
{ & j+oJasI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KSrx[q
break; ?y!E-&
} $r3i2N-I
} ^53r/V}%
else c}0@2Vf
break; wT{nu[=GH*
} LWt&3
} /Js7`r=Rx
catch(IOException e){e.printStackTrace ();} CH<E,Z C1T
catch(Exception e){e.printStackTrace ();} b?'yAXk
+j4"!:N}B
'f?$"U JF
Utility.log(nFileLength); {.?/)
71{p+3Z&
k|!EDze43?
return nFileLength; O &-wxJ]S
} R`~z0d.
9cj9SB4
LA)[ip4
//保存下载信息（文件指针位置） %?Ev|:i`@
private void write_nPos() ~T89_L
{ mN19WQ(r
try{ 6!(@@^7{*
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q0ON9gqqv
output.writeInt(nStartPos.length); \0gM o&
for(int i=0;i<nStartPos.length;i++) #KiRfx4G
{ }3L@J8:D"
// output.writeLong(nPos); A\.GV1
output.writeLong(fileSplitterFetch.nStartPos); 'Un" rts
output.writeLong(fileSplitterFetch.nEndPos); )[|3ZP`
} s4uhsJL V$
output.close(); k{Aj^O3gD
} icgSe:Ci
catch(IOException e){e.printStackTrace ();} FJ6u.u
catch(Exception e){e.printStackTrace ();} }:~x7|~s:
} L:'J Bhg
5hy""i
_:"<[ >9
//读取保存的下载信息（文件指针位置） ,xxR\}
private void read_nPos() 9\DQ>V TQ
{ `9b7>Nn<
try{ fP `b>]N_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1N>|yQz
int nCount = input.readInt(); aUtnR<6
nStartPos = new long[nCount]; uF3qD|I\
nEndPos = new long[nCount]; t0T"@t#c
for(int i=0;i<nStartPos.length;i++) m RO~aD!N
{ x a06i#
nStartPos = input.readLong(); (#E.`e1#6
nEndPos = input.readLong(); smDw<slC
} u5%7}<nNi
input.close(); 5EfS^MRf\n
} G@Z?&"
catch(IOException e){e.printStackTrace ();} 7?%k7f
catch(Exception e){e.printStackTrace ();} xcf%KXJf6
} oGRhnP'PF+
M )2`+/4
x HhN
private void processErrorCode(int nErrorCode) ;{%\9nS
{ {b
System.err.println("Error Code : " + nErrorCode); ~Wa6J4B{K
} _n` a`2C|m
i|m3mcI%2
6ZQwBS0Y
//停止文件下载 Q(oN/y3,
public void siteStop() 7[}xP#Z
{ KPj\-g'A
bStop = true; =HlQ36;*
for(int i=0;i<nStartPos.length;i++) X]dwX%:Z!j
fileSplitterFetch.splitterStop(); w2'f/
pn5Q5xc
K]0JC/R6(@
} 5)MS~ii
} }dd8N5b
//负责部分文件的抓取 #hsx#x||
**FileSplitterFetch.java EL9]QI
*/ /Dj=iBO
package NetFox; &mtJRfnu
^cz(}N 6&
k<\$OoOZ
import java.io.*; &Ob!4+v/GP
import java.net.*; p ObX42
k-{<=>uM
H,u<|UMM_
public class FileSplitterFetch extends Thread { eF3,2DDC
{>)#HD
G8Y<1%`<
String sURL; //File URL % V8U(z
long nStartPos; //File Snippet Start Position #Ibp(
long nEndPos; //File Snippet End Position 2P@sn!*{1
int nThreadID; //Thread's ID F 70R1OYU
boolean bDownOver = false; //Downing is over pxh"B\"4*
boolean bStop = false; //Stop identical trp0V4b8
FileAccessI fileAccessI = null; //File Access interface [S>2ASj
~"kb7Fxp
Ot6aRk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <t \H^H!
{ N#a$t&
this.sURL = sURL; DRi<6Ob
this.nStartPos = nStart; `,(,tn_
this.nEndPos = nEnd; ZGKu>yM
nThreadID = id; q;][5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :dQ B R
} G%W8S \
/Y7<5!cS
j4uvS!
public void run() --c"0,7
{ sv&;Y\2c
while(nStartPos < nEndPos && !bStop) B2'i7Ps
{ h*u
tE`u(B,
[c|]f_ZdK
try{ &bfA.& `
URL url = new URL(sURL); Pf\D-1gi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m4l& eEp
httpConnection.setRequestProperty("User-Agent","NetFox"); 5?F__Hx*2
String sProperty = "bytes="+nStartPos+"-"; Bx4w)9+3
httpConnection.setRequestProperty("RANGE",sProperty); U_n9]Z
Utility.log(sProperty); ([m mPyp>L
Lja>8m
xY^%&n
InputStream input = httpConnection.getInputStream(); 75/(??2
//logResponseHead(httpConnection); f m)pulz
'g m0)r
:6Lx@
byte[] b = new byte[1024]; Yd=>K HVD
int nRead; qfMo7e@6*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [8*jw'W|[
{ l^pA2yh|
nStartPos += fileAccessI.write(b,0,nRead); li}1S
//if(nThreadID == 1) z;|A(*Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `</ff+Q6
} <#u=[_H
|w<H!lGe!$
2;DuHO1
Utility.log("Thread " + nThreadID + " is over!"); ~^r29'3
bDownOver = true; =06gj)8
//nPos = fileAccessI.write (b,0,nRead); UVd7 JGR
} U<_3^
catch(Exception e){e.printStackTrace ();} =pS5uR~
} fj;y}t1E]
} )W;o<:x3
4;0lvDD
5n9B?T8C
//打印回应的头信息 P'Ux%Q+B>
public void logResponseHead(HttpURLConnection con) UJCYs`y
{ (2^gVz=j
for(int i=1;;i++) 2[O&NdP\Zk
{ /2=#t-p+
String header=con.getHeaderFieldKey(i); GycSwQ ,
if(header!=null) 0+kH:dP{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); { + Zd*)M[
Utility.log(header+" : "+con.getHeaderField(header)); Pa V@aM~3
else `\#B18eU
break; `OXpU,Z 6U
} B1>/5hV}
} hPUYyjXPB
"NXB$a!:
IDB+%xl#S
public void splitterStop() D*gFV{Ws
{ =E.t`x=
bStop = true; ]%wVHC
} N`L0Vd
=WyZX 7@R
LE9(fe) fe
} ebUBrxZX
1p/3!1
V@cM|(
/* #t:S.A@
**FileAccess.java $m].8?
*//文件访问(定位，写) HUv/ ~^<
package NetFox; C9n?@D;S
import java.io.*; }%'?p<^M
hRrn$BdLX
5qZ1FE
public class FileAccessI implements Serializable{ JGsx_V1t
LYz.Ci}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vdx0i&RiL
RandomAccessFile oSavedFile; %S*{9hm/
long nPos; WJkZ!O$"j
d%RC
| r&k48@
public FileAccessI() throws IOException T`\x,` ^
{ t>urc
this("",0); :U3kW8;UMP
} qln3 k`
p?);eJtV/
c#Sa]n
public FileAccessI(String sName,long nPos) throws IOException /H(? 2IHC
{ cDFO;Dr
oSavedFile = new RandomAccessFile(sName,"rw"); %)|9E>fP]N
this.nPos = nPos; bF"G[pD
oSavedFile.seek(nPos); %,6#2X nX%
} %|g>%D3Z?
TDFkxB>
#LL?IRH9^
public synchronized int write(byte[] b,int nStart,int nLen) _aad=BrMK
{ :Q $K<)[
int n = -1; 7VqM$I
try{ /%}*Xh
oSavedFile.write(b,nStart,nLen); u09:Z{tL;@
n = nLen; -0$55pa/@:
} nrxo&9[@n
catch(IOException e) `\gnl'
{ E*V`":efS
e.printStackTrace (); s.N7qO^:E
} K1r#8Q!t
8S mCpg
H:t$'kb`
return n; K?B{rE Lp
} b\vKJ2
)vjh~ybZ
;V*R*R
} ]h* c,.
]>LhkA@V
Z&1T
/* ysxb?6
**SiteInfoBean.java 8\^}~s$$A
*/ V5sg#|&
package NetFox; =j5MFX.-o
-Zf@VW,NI
;aI[=?<x
public class SiteInfoBean { 6*B19+-
?s\:hNNY
2N~Fg^xB
private String sSiteURL; //Site's URL m?pstuUK(
private String sFilePath; //Saved File's Path "HElB9
private String sFileName; //Saved File's Name -(bXSBs#
private int nSplitter; //Count of Splited Downloading File 7'Zky2F
KIui(n#/
=XucOli6
public SiteInfoBean() ej4W{IN~:
{//nSplitter的缺省值为5 {QHVo#
//default value of nSplitter is 5 l6YtEHNG
this("","","",5); /^X/8
} I/d&G#:~
Rn`x7(WA
b$ve sJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kbTm^y"
{ f,V<;s
sSiteURL= sURL; ;1`fC@rI
sFilePath = sPath; sYe?M,
sFileName = sName; R< ,`[*Z
this.nSplitter = nSpiltter; -8eoNzut
-=)+dCyB^
@&%'4j&+
} 2z6yn?'&L
\>jLRb|7Ts
(]0%}$Fo
public String getSSiteURL() 4}_j`d/8|
{ uw[<5
return sSiteURL; *5vV6][
} M=1nQF2J
4 Y;Nm1@
6+.uU[x@
public void setSSiteURL(String value) N^HUijw<
{ 2^mJ+v<
sSiteURL = value; 9o;^[Ql-
} _,xc[ 07
QrB@cK]
KM}f:_J*lg
public String getSFilePath() qfL~Wp2E;
{ Y ;u<GOe
return sFilePath; 4wID]bKM
} 5mJJU
aGJC1x
1Ty<\bZ=
public void setSFilePath(String value) O4r0R1VQM
{ xIxn"^'
sFilePath = value; 6|aKL[%6
} jGXO\:sO
ofPHmh`
UUzYbuS>&l
public String getSFileName() =NnNN'}
{ m@"QDMHk.
return sFileName; #JgH}|&a$
} W%T>SpFl
73V|6tmgY
q}~3C1
public void setSFileName(String value) ?&|5=>u2}$
{ *+j*{>E
sFileName = value; @x"0_Qw
} ::ajlRZG
"OQ^U_
Xe<sJ.&Wf
public int getNSplitter() ]$Yvj!K*Q
{ Fs{x(_LOr
return nSplitter; &j4xgh9
} a=DcZ_M
^cczJOxB
S{;sUGcu
public void setNSplitter(int nCount) Pl=ZRKn
{ R%Q@
nSplitter = nCount; b~'"^ Bts*
} PV9pa/`@
} `S6x<J&T\/
uT}' Y)m
^Wc@oa`
/* -j73Wz
**Utility.java G]+&!4
*/ ]|MEx{BG-
package NetFox; A%`[mc]4#
k\WR ]
1#.>a$>
public class Utility { G'6@+$ppS
Qp/QaVQ+
Tav*+
public Utility() H*[M\gN$
{ X:6c}p%,!
``ou/Z
JBJhG<J
} W_kHj}dj,p
kPVO?uO
//线程睡眠 LL2=&VK
public static void sleep(int nSecond) 8g&? Cc
{ kKAP"'v
try{ .Nw=[
Thread.sleep(nSecond); a#>Yh;FA
} MC<PM6w
catch(Exception e) _(h&7P9
{ T(t+ iv
e.printStackTrace (); A<1hOSCz\
} n}'=yItVL1
} c17_2 @N
_tBTE%sO
//日志 S<4c r
public static void log(String sMsg) /% M/
{ TMig-y*[
System.err.println(sMsg); poToeagZ~Q
} 5\e9@1Rc
"tB;^jhRs
JKGc3j,+#
public static void log(int sMsg) Vm3v-=6
{ $4/yZaVb
System.err.println(sMsg); my}-s
} {vuZ{IJa
} KU8Jbl*
E=>FjCsu<-
.ox8*OO<
/* %d?cP}V
**TestMethod.java .7l&1C)i
*/ *g6n
package NetFox; P%#<I}0C
EJsM(iG]~M
.w0s%T,8}^
public class TestMethod { cUY`97bn
<Dwar>}
;\=M;Zt
public TestMethod() [N/"5 [
{ ///xx/weblogic60b2_win.exe h&--,A >
try{ >U%gctIg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \'|>p/5I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JwAYG5W
SiteFileFetch fileFetch = new SiteFileFetch(bean); fp+gyTnd3
fileFetch.start(); H[S%J3JI
} qYlhlHD
catch(Exception e){e.printStackTrace ();} T~Gvp0r}h
U-R6xxPZ
`QyO`y=?[Y
} {&\jW!&n
=5kY6%E7c
X{\F;Cb*
public static void main(String[] args) `NgAT 3zq
{ nv@8tdrc
new TestMethod(); ~c %hWt
} kic/*v\6@
} bT^I"
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