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)); Tweku}D7
} 2Ub!wee
for(int i=0;i<nEndPos.length-1;i++) J}'a|a@bk
{ /I/gbmc)
nEndPos = nStartPos[i+1]; +=N#6#1
} hYS}PE
nEndPos[nEndPos.length-1] = nFileLength; S)$iHBx{
} yTb#V"eR
} qPG>0 O
70BLd(?
$"[5]{'J
//启动子线程 zt|DHVy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yg kd1uI.
for(int i=0;i<nStartPos.length;i++) |)}&:xA%
{ +zf[Im%E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;*}tbh3;.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z&W*@(dX
nStartPos,nEndPos,i); L.tW]43K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f5ttQ&@FF
fileSplitterFetch.start(); 8.m9 =+)8
} Yfd0Np~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |%l&H/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v%$c_'d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C!z7sOu
nEndPos = " + nFileLength); {GP#/5$=
// fileSplitterFetch[nPos.length-1].start(); ^ 9`O ^
gql^Inx<
&=S<StH
//等待子线程结束 sRkPXzK
//int count = 0; ;xxu,
//是否结束while循环 %;MM+xVVX
boolean breakWhile = false; f~?4
w1J%%//(h
nc/F@HCB
while(!bStop) fDD^?/^
{ (29BS(|!
write_nPos(); VSLi{=#
Utility.sleep(500); fx3oA}
breakWhile = true; I:Q3r"1
{&,MkWgG
\;bDDTM
for(int i=0;i<nStartPos.length;i++) G'IRqO*]
{ e61e|hoX\
if(!fileSplitterFetch.bDownOver) 6s(.ul
{ jWNF3\
breakWhile = false; P?/Mrz
break; l:- <CbG
} GX0S9s
} "l[ c/q[
if(breakWhile) `*-rz<G
break; >1S39n5z.
E@[ZwTnJ
o/4U`U)Q0v
//count++; ag{cm'.
//if(count>4) 26B+qXEt
// siteStop(); #Pr w2u
} teX)!N [
fq4[/%6,O
B:rzM:BQ
System.err.println("文件下载结束！"); JrNqS[c/
} 9:JQ*O$
catch(Exception e){e.printStackTrace ();} d<_#Q7]I4
} JDP/vNq
Vqp3'=No
G7SmlFn?
//获得文件长度 Mem1X rBH
public long getFileSize() Y>Ju$i
{ B2T=O%
int nFileLength = -1; =.(~`ici~
try{ sg%Ptp
URL url = new URL(siteInfoBean.getSSiteURL()); ^E]y >Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yt[*4gF4
httpConnection.setRequestProperty("User-Agent","NetFox"); )SzgMbF6
+nz0ZQ9 a
-=4{X R3
int responseCode=httpConnection.getResponseCode(); "1z#6vw5a
if(responseCode>=400) [yx8?5
{ vocWV/
processErrorCode(responseCode); s6(bTO.
return -2; //-2 represent access is error &`I7aP|
} wu~?P`
Btyp=wfN[
-jk-ve
String sHeader; e N^6gub
XOT|:
Z3O_K
for(int i=1;;i++) K;lxPM]
{ |31/*J!@z*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); l]~mB~
//Utility.log(in.readLine()); %`\=qSf*
sHeader=httpConnection.getHeaderFieldKey(i); >)6k)$x%%
if(sHeader!=null) N7UGgn=
{ ]/[$3rPwZ
if(sHeader.equals("Content-Length")) }9~U5UXWU
{ "5@\"L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SQ-CdpT<
break; e'T|5I0K
} aSt:G*a"
} C`["4
else q{uv?{I
break; o?/fObV@(
} /|p6NK;8L
} S!8q>d,%L
catch(IOException e){e.printStackTrace ();} s[Whg!2~
catch(Exception e){e.printStackTrace ();} z8<"
-+fW/Uo
~n;U5hcB
Utility.log(nFileLength); JQDS3v=1$
Y*0j/91
n8Rsle`a
return nFileLength; F4$9r^21r
} @*=eqO
k-I U}|Xz
qo7jrY5G
//保存下载信息（文件指针位置） h3j`X'
private void write_nPos() <Y)Aez
{ 0?*":o30
try{ ~(}nd
output = new DataOutputStream(new FileOutputStream(tmpFile)); jqQGn"!
output.writeInt(nStartPos.length); ?*:BgaR_
for(int i=0;i<nStartPos.length;i++) 6+/BYN!&4
{ {w mP
// output.writeLong(nPos); `<(o;*&Gd
output.writeLong(fileSplitterFetch.nStartPos); h@@q:I=
output.writeLong(fileSplitterFetch.nEndPos); DHVfb(H5e
} juB/?'$~
output.close(); FL[w\&fp
} R= .UbY
catch(IOException e){e.printStackTrace ();} KqvM5$3
catch(Exception e){e.printStackTrace ();} 8TCbEPS@Q
} |?\2F
$k^& X `
\L"0Pmt[
//读取保存的下载信息（文件指针位置） En ]"^*
private void read_nPos() Erm]uI9`
{ %Mf3OtPiJW
try{ G\|P3j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]uXmug
int nCount = input.readInt(); tS[%C)
nStartPos = new long[nCount]; 9s#*~[E*
nEndPos = new long[nCount]; D<lVWP
for(int i=0;i<nStartPos.length;i++) w_*$wVl
{ )JOo|pr-K
nStartPos = input.readLong(); EO\- J-nM
nEndPos = input.readLong(); gW^0A)5
} U]"6KS
input.close(); {4r }jH
} 9PG3cCr?
catch(IOException e){e.printStackTrace ();} nQ;M@k&9eV
catch(Exception e){e.printStackTrace ();} 7W=s.Gy7G\
} U/jCM?~
6OZn7:)Y
(S8hr,%n
private void processErrorCode(int nErrorCode) 8r.3t\o)X
{ KQCF "
System.err.println("Error Code : " + nErrorCode); RpzW-
} BP=<TRp.
t]+h.
sM@1Qyv&0
//停止文件下载 =W"9a\m
public void siteStop() 7o9[cq w
{ HJ!P]X_J1
bStop = true; jBJ|%KM
for(int i=0;i<nStartPos.length;i++) 8>'vzc/*>
fileSplitterFetch.splitterStop(); k#x"'yZ
Mc6v
jR"ACup(
} ,p6o "-
} 90">l^HX=
//负责部分文件的抓取 G],W{<Pe
**FileSplitterFetch.java Q$x 3uH\@
*/ 43Ua@KNi
package NetFox; ADB,gap
a>egH og
ZX0!BS
import java.io.*; ~y1k2n
import java.net.*; R!2E`^{Wl
6o~CX
{$'oKJy*
public class FileSplitterFetch extends Thread { -qpe;=g&f
,Ofou8C6
+,J!xy+~,
String sURL; //File URL 4x_# 1 -
long nStartPos; //File Snippet Start Position =/bC0bb{i
long nEndPos; //File Snippet End Position URMxCL^"
int nThreadID; //Thread's ID Q;=3vUN
boolean bDownOver = false; //Downing is over RIq\IQ_|
boolean bStop = false; //Stop identical .|GnTC q
FileAccessI fileAccessI = null; //File Access interface Z"E2ZSa0
.>^U mM
=HHb ]JE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qwYq9A$+
{ g]U!]
this.sURL = sURL; |?ma?
this.nStartPos = nStart; }PzHtA,V
this.nEndPos = nEnd; I GB)
nThreadID = id; #<yKG\X?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Yw,LEXLY
} ]9~6lx3/
e.]k4K
2Y%E.){
public void run() +6f[<^K#
{ ?]0bR]}y
while(nStartPos < nEndPos && !bStop) ig4mj47wJ
{ /y-8dgv0a
@O)1Hnm
pR3K~bx^
try{ nh>lDfJV<
URL url = new URL(sURL); Z)G@ahOQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }Pj;9ivz
httpConnection.setRequestProperty("User-Agent","NetFox"); M$2lK^2L
String sProperty = "bytes="+nStartPos+"-"; h F *c
httpConnection.setRequestProperty("RANGE",sProperty); n hGh5,
Utility.log(sProperty); {r1}ACw{
#LfoG?k1K
z&Lcl{<MA
InputStream input = httpConnection.getInputStream(); DTCOhUIV
//logResponseHead(httpConnection); k4YW;6<C+
vp`s< ;CA
8Oo16LPD
byte[] b = new byte[1024]; nfS.0\z
int nRead; a<&GsDw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {GS$7n
{ P yN{
nStartPos += fileAccessI.write(b,0,nRead); 6G<gA>V
//if(nThreadID == 1) 1IWP~G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {'[S.r`
} nmUMg
qp2&Z8S\D
~A-D>.ZH
Utility.log("Thread " + nThreadID + " is over!"); F+?g0w['
bDownOver = true; \Wf1b8FW
//nPos = fileAccessI.write (b,0,nRead); 3/4r\%1b+
} ]McDN[h:
catch(Exception e){e.printStackTrace ();} 3ULn ]jA
} 7/6%92T/B
} wU/BRz8I
td(4Fw||1y
#\gx.2W7
//打印回应的头信息 dR >hb*kJ
public void logResponseHead(HttpURLConnection con) H]VoXJ\*
{ @JpkG%eK
for(int i=1;;i++) S/xCX!
{ I.u[9CI7HU
String header=con.getHeaderFieldKey(i); 3V@!}@y,F6
if(header!=null) /@+[D{_Fw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aui3Mq#f
Utility.log(header+" : "+con.getHeaderField(header)); #iP5@:!Wm~
else 9Vtn62+
break; c_FnJ_++f
} ]?(_}""1
} lH%-#2]
-*~~00w
z*G(AcS)
public void splitterStop() s?_H<u
{ u]s}@(+.
bStop = true; 6G]hsgro
} ;@V1*7y
R]"3^k*
dn:/8~B"X
} {V5eHn9/Q'
i[m-&
do=s=&T
/* SX@zDuM
**FileAccess.java F]6$4o[
*//文件访问(定位，写) )9z3T>QW
package NetFox; .0iHI3i^
import java.io.*; |ZJ<N\\h-
l[M?"<Ot;
=SLCG.
public class FileAccessI implements Serializable{ w}r~Wk^dLI
f/{*v4!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QT7PCHP
RandomAccessFile oSavedFile; ioJr2wq6
long nPos; .fD%*-
]]8^j='P'
<^fvTb&*
public FileAccessI() throws IOException iBaz1pDc
{ ZCz#B2Sf8
this("",0); eGQ-Ht,N
} _68{ {.
zHk7!|%Y
QBL|n+
public FileAccessI(String sName,long nPos) throws IOException L1YiXJ,T,
{ SRek:S,
oSavedFile = new RandomAccessFile(sName,"rw"); Pj{Y
this.nPos = nPos; B8.uzX'p
oSavedFile.seek(nPos); V3q[#.o
} XG}9)fT
%#iu
u @#fOu
public synchronized int write(byte[] b,int nStart,int nLen) (.N!(;G
{ ;T*o RS
int n = -1; x f<wM]&
try{ Y[Eq;a132
oSavedFile.write(b,nStart,nLen); ?OF9{$m3?
n = nLen; Qkb=KS%z
} DZqY=Sze
catch(IOException e) _q=ua;I&
{ NGVl/Qd
e.printStackTrace (); $c}-/U 8
} JUdQ Q
R/Z zmb{
^vha4<'-qG
return n; MkX=34oc^
} 2./;i>H[u
]3]=RuQK2
ciGJtD&P
} (0u(<qA\
")@#B=8+3^
W(\^6S)
/* ED^0t
**SiteInfoBean.java VCQo3k5 {
*/ >p 9~'
package NetFox; 1:22y:^j
xq<X:\O
RZP7h>y6@
public class SiteInfoBean { do:IkjU~
T( fcE
bk:mk[
private String sSiteURL; //Site's URL y3OF+;E
private String sFilePath; //Saved File's Path y~^-I5!_ u
private String sFileName; //Saved File's Name bW^C30m
private int nSplitter; //Count of Splited Downloading File KZ@'NnQ
b)@rp
tn}MKo
public SiteInfoBean() L :Ldk
{//nSplitter的缺省值为5 q5{h@}|M
//default value of nSplitter is 5 DB3qf>@?
this("","","",5); "/Pq/\,R|
} EO%"[k
?z&5g-/b
iF Zqoz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qKTzigjj
{ -tfUkGdx;l
sSiteURL= sURL; -ARks_\
sFilePath = sPath; hlmeT9v{
sFileName = sName; t~|J2*9l
this.nSplitter = nSpiltter; &O#,"u/q`
<iB5&
y/+IPR
} psUT2
sE&1ZJ]7
+t3o5&
public String getSSiteURL() Kc,i$FH
{ wf`A&P5tF
return sSiteURL; (eSsx/
} 6V*,nocL_+
R3%%;`c=
SDB \6[D
public void setSSiteURL(String value) Ph8@V}80"Y
{ 4w)>}
sSiteURL = value; {@6:kkd
} 3&mpn,
t YxN^VqU
nW}jTBu_K+
public String getSFilePath() &gKDw!al
{ a~ dgf:e`
return sFilePath; tQas_K5
} IqiU
vn!5@""T
BoxtP<C"
public void setSFilePath(String value) ea]qX6)UZ
{ k||dX(gl
sFilePath = value; ?U+hse3e~
} `!$6F:d_l
6l[v3l"t
lX.-qCV"B
public String getSFileName() *ow`}Q
{ =fJU+N+<
return sFileName; {*P[dyu
} %P D}VF/Y
}xBDyr63
_QEw=*.<
public void setSFileName(String value) (Gw*xsn1
{ ;!G#Y Oe
sFileName = value; +80bG(I_
} l i)6^f#
1YQYZ^11
IT{c:jo1{`
public int getNSplitter() [NAfy~X*
{ ^2);*X>
return nSplitter; vbn=ywz
} n}_}#(a
tH4q*\U
DxwR&S{
public void setNSplitter(int nCount) n~]"sTC}&
{ =yz"xWH
nSplitter = nCount; 3}!u8,P
} 8lzoiA_9
} `g3AM%3
G;flj}z
`FQ]ad Fz
/* LWm1j:0
**Utility.java B{R[z%Y
*/ l)*(UZ"
package NetFox; u*): D~A
q)L4*O
2.I|8d[
public class Utility { n@xQ-v
?tL' X
`-.2Z 0
public Utility() )~)l^0X
{ Y(bB7tR
Lc5zu7ncg
\fUX_0k9,
} bsDA&~)s
^h$*7u"^y
//线程睡眠 &>C+5`bg
public static void sleep(int nSecond) 5{k,/Z[L
{ xi(1H1KN5B
try{ wpuK?fP
Thread.sleep(nSecond); -f&vH_eK
} erW2>^My
catch(Exception e) ,AweHUEn
{ J)Y`G4l2@
e.printStackTrace (); <O 0Q]`i
} 84.L1|k
} /nQuM05*Z
~Ym_ {
//日志 T2S_> #."l
public static void log(String sMsg) XDJE]2^52?
{ e|!'
System.err.println(sMsg); EN\cwa#FU
} )gdLb}
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Hs'~)T
public static void log(int sMsg) i,r:R g~
{ P0}{xq'k9v
System.err.println(sMsg); 88v8lt;R
} 2P^|juc)sU
} Sp5:R75vI
wpM2{NTP
Kh\ 7%>K#
/* Pgr2S I
**TestMethod.java 9=ygkPY
*/ AJ7^'p9Y
package NetFox; MGm*({%
XQ}J4J~Vm
'Gl~P><e
public class TestMethod { H%@f ^
|qn2b=
/S"jO[n9b
public TestMethod() 8xO
{ ///xx/weblogic60b2_win.exe }w$2,r gA
try{ hJ{u!:4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }8x+F2i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ud`-w
SiteFileFetch fileFetch = new SiteFileFetch(bean); vd[7Pxe
fileFetch.start(); 9Vm1q!lE
} %m |I=P
catch(Exception e){e.printStackTrace ();} s;9Du|0f^
.g*N+T6O
6i[Ts0H%<!
} mp8GHV
/>S^`KSTM
ae sk.
public static void main(String[] args) gQ{ #C'
{ `xBoNQai
new TestMethod(); ;bB#Pg
} M9W zsWM
} Pz2 b
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