http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); .Rxz;-VA
} <N^2|*3
for(int i=0;i<nEndPos.length-1;i++) E7^r3#s
{ Kxb_9y0`r
nEndPos = nStartPos[i+1]; +~RiCZt
} {4tJT25
nEndPos[nEndPos.length-1] = nFileLength; G@b|{!
} 2w93 ~j
} jLc4D'
E`.dU<8HE
5'gV_U
//启动子线程 h_L-M}{OG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t>><|~wp
for(int i=0;i<nStartPos.length;i++) ZZp6@@zyq'
{ \"i2E!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !q!.OQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e>1z1Q;_uv
nStartPos,nEndPos,i); %{s<h6{R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rWEJCFa
fileSplitterFetch.start(); BKe~y
} Kf D8S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d4F3!*@(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?"[b408-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8@ck" LUzD
nEndPos = " + nFileLength); *j RNpB{)z
// fileSplitterFetch[nPos.length-1].start(); GL'zs8AKf
0|n1O)>J
oVyOiWo\Z
//等待子线程结束 5O<7<OB
//int count = 0; GZQy~Uk~
//是否结束while循环 /<)A!Nn+F
boolean breakWhile = false; Fu:VRul=5$
s,O:l0
;QQLYT
while(!bStop) &wr0HrE\
{ ]Sg4>tp
write_nPos(); ZW n j-
Utility.sleep(500); -Zd0[& ']
breakWhile = true; }stc]L{79
q"4{GCavN
`)$'1,]u
for(int i=0;i<nStartPos.length;i++) #x!h BS!
{ Kf#9-.}?
if(!fileSplitterFetch.bDownOver) HM ;9%rtO
{ AdDlS~\?
breakWhile = false; !=M[u+-
break; FjD`bhw-
} 5SKj% %B2,
} Hy~kHBIL
if(breakWhile) raRb K8CQ
break; %_N-~zZ1E
B*#lkMr
P 0v&*y3Y
//count++; 6jT+kq)
//if(count>4) &|'k)6Rx
// siteStop(); R@Ch3l@
} n5h4]u
~ {OBRC
gwwYz]'d>r
System.err.println("文件下载结束！"); udYk 6
} :^7/+|}9p
catch(Exception e){e.printStackTrace ();} [;yEG$)K
} 60?/Z2w5
YD1 :m3l!
uBp"YX9rx
//获得文件长度 f/Cf2 K
public long getFileSize() :s|" ZR
{ \UZlFE
int nFileLength = -1; iQs7Ly"
try{ #1c%3KaZI
URL url = new URL(siteInfoBean.getSSiteURL()); H]2cw{2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I\eM8`Y$
httpConnection.setRequestProperty("User-Agent","NetFox"); T;jy2|mLo
?QuD:vck
<2Q+? L{
int responseCode=httpConnection.getResponseCode(); i!5zHn
if(responseCode>=400) znm3b8ns
{ \D Oqx
processErrorCode(responseCode); {akSK
return -2; //-2 represent access is error VnqgN
} LDilrG)
K]5@bm
CHxu%-g
String sHeader; );-?~
:5`=9_|
a'3|EWS ?
for(int i=1;;i++) };{V]f 0
{ t2V|moG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XNODDH
//Utility.log(in.readLine()); OEMYS I%
sHeader=httpConnection.getHeaderFieldKey(i); 'vbrzI5m
if(sHeader!=null) `r?xo7
{ Y|%s =0M
if(sHeader.equals("Content-Length")) -.XICKz
{ [1Cs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pGS!Nn;K2
break; 2/[J<c\G
} fGK=lT$
} T;?=,'u
else c)L1@qdZ
break; W>^WNo3YQ$
} JI"&3H")g%
} uNXKUJ V0
catch(IOException e){e.printStackTrace ();} m6iQB\ \
catch(Exception e){e.printStackTrace ();} {OGv1\ol&
Qk#`e
%D $+Z(
Utility.log(nFileLength); Kq4b`cn{_
O$,bNu/g
s:f%=4-7
return nFileLength; 1_V',0|`>
} 8D5v'[j-
_7P#?:h
PZE{-TM?W
//保存下载信息（文件指针位置） 'A)r)z{X
private void write_nPos() riz[AAB
{ ]s<}'&
try{ EN/e`S$)
output = new DataOutputStream(new FileOutputStream(tmpFile)); #24eogo~
output.writeInt(nStartPos.length); 9n!IdqKN
for(int i=0;i<nStartPos.length;i++) *r|)@K|
{ pj/w9j G6
// output.writeLong(nPos); ^!yJ;'H\
output.writeLong(fileSplitterFetch.nStartPos); jp|1S^b
output.writeLong(fileSplitterFetch.nEndPos); 8AQ@?\Rc"2
} ZGZ+BOFL
output.close(); p0Ra`*f
} |xX>AMZc)D
catch(IOException e){e.printStackTrace ();} VY]L<4BfGL
catch(Exception e){e.printStackTrace ();} zM+eb| >cr
} H){lXR/#u
hQPNxpe
ocDAg<wo
//读取保存的下载信息（文件指针位置） qG?svt
private void read_nPos() H(,D5y`k1
{ ;[R#:Rk
try{ f\]splL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HLsG<#
int nCount = input.readInt(); =&YhA}l\O
nStartPos = new long[nCount]; sBV})8]KM
nEndPos = new long[nCount]; Lj#K^c Ee
for(int i=0;i<nStartPos.length;i++) V9cKl[
{ Pt^SlX^MM
nStartPos = input.readLong(); 3qNLosm#M
nEndPos = input.readLong(); ^j>w<ljzz
} uE%$<o*#
input.close(); 5*P+c(=
} zc#$hIi
catch(IOException e){e.printStackTrace ();} ~]LkQQ'
catch(Exception e){e.printStackTrace ();} xG"*w@fs7
} 4Ow0g-{
?Ja&LNI9S
w0(1o_F7.
private void processErrorCode(int nErrorCode) N:nhS3N<L
{ 0<'Q;'2* L
System.err.println("Error Code : " + nErrorCode); EnD}|9
} SG@-b(
RP|/rd]-k
?Q#yf8
//停止文件下载 >uR0Xs;V
public void siteStop() 6xq/
{ Fh0cOp(
bStop = true; & Y Y^Bd#
for(int i=0;i<nStartPos.length;i++) BfUM+RC%5
fileSplitterFetch.splitterStop(); Al-;-t#Dc
Ww)p&don
, tb\^
} +$y%H
} HmQ.'
//负责部分文件的抓取 bpp{Z1/4
**FileSplitterFetch.java r=74'g
*/ NcMohpkq
package NetFox; CaE1h9
'h.:-1# L
i&_&4
import java.io.*; ~dz,eB
import java.net.*; K~6,xZlDWM
F)n^pT
nkTpUbS'f?
public class FileSplitterFetch extends Thread { 734f&2
]9]o*{_+(f
s:ZYiZ-
String sURL; //File URL d.3cd40Q
long nStartPos; //File Snippet Start Position ,*MAteD
long nEndPos; //File Snippet End Position ;vuqI5k
int nThreadID; //Thread's ID xmXuBp:M(R
boolean bDownOver = false; //Downing is over <reALC
boolean bStop = false; //Stop identical -g\;B
FileAccessI fileAccessI = null; //File Access interface :}*
eEl71
XDQ5qfE|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oT0TbZu%
{ 7U647G(Sg
this.sURL = sURL; [L ?^+p>
this.nStartPos = nStart; -~] q?k?
this.nEndPos = nEnd; X 7R&>Pf
nThreadID = id; N(Sc!rX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^gSZzJ5
} <{P`A%g@
pt$\pQ
Ek6z[G` O
public void run() G0~6A@>
{ 9_-6Lwj6t
while(nStartPos < nEndPos && !bStop) Ygq;jX
{ Lvd es.0|
B? Z_~Bf&
h<<uef9
try{ 4&kC8 [r
URL url = new URL(sURL); CuT50N;tk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NH'Dz6K5
httpConnection.setRequestProperty("User-Agent","NetFox"); 572{DC&T
String sProperty = "bytes="+nStartPos+"-"; _)kTlX:,
httpConnection.setRequestProperty("RANGE",sProperty); b[KZJLZ)
Utility.log(sProperty); dt||nF
35%\"Y?
.+(R,SvN%<
InputStream input = httpConnection.getInputStream(); Bwl@Muw
//logResponseHead(httpConnection); {/}%[cY=
=&I9d;7
gY&WH9sp?9
byte[] b = new byte[1024]; < Dt/JA(p
int nRead; ;-AC}jG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WZM
{ FrC)2wX
nStartPos += fileAccessI.write(b,0,nRead); Ozg,6&3ji
//if(nThreadID == 1) J9-n3o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,@kLH"a0
} gA}?X
C#LTF-$])
wxo*\WLe
Utility.log("Thread " + nThreadID + " is over!"); yV*jc`1
bDownOver = true; I(H9-!&
//nPos = fileAccessI.write (b,0,nRead); uJ`:@Z^J
} " GY3sam
catch(Exception e){e.printStackTrace ();} o3$dl`'
} H<3:1*E
} Re+oCJ
I?RUVs
1~Z
//打印回应的头信息 iJH?Z,Tjf
public void logResponseHead(HttpURLConnection con) RzU9]e
{ zZ,"HY=jN
for(int i=1;;i++) xR8y"CpE
{ +%H=+fJ2}
String header=con.getHeaderFieldKey(i); orOq5?3
if(header!=null) }@"v7X $
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `=S%!akj
Utility.log(header+" : "+con.getHeaderField(header)); WcQkeh3n
else r KYQ 8T
break; +IMt$}7[
} -24ccN;
} @Ko#nDEq
`n@;%*6/
"!_vQ^y
public void splitterStop() 3-oKY*jO
{ $&!|G-0'
bStop = true; I:w+lchAMe
} 6VS_L@
.K1wp G[4
&*bpEdkZ
} EI)2c.A
}u1h6rd `
W7;RQ
/* sgnc$x"
**FileAccess.java /EJy?TON*
*//文件访问(定位，写) scTt53v^
package NetFox; %%#bTyF
import java.io.*; Ms5R7<O.7
0fLd7*1>
8Q"1I7U
public class FileAccessI implements Serializable{ 4'tY1d
ktRGl>J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 of GoaH*h
RandomAccessFile oSavedFile; ?*[35XUd
long nPos; .;S1HOHz4
Jl6lZd(Np
|WpJen*?Y
public FileAccessI() throws IOException kem(U{m
{ :6Tv4ZUvcG
this("",0); d'H gek{T
} mi7~(V>
dPxJ`8
5y] %Cu1.u
public FileAccessI(String sName,long nPos) throws IOException uRYq.`v,
{ Kr<UPr
oSavedFile = new RandomAccessFile(sName,"rw"); lgD%
this.nPos = nPos; AX'-}5T=
oSavedFile.seek(nPos); /{/mwS"W
} d(@ ov^e-
FD~ UF;VQ
9]lyV
public synchronized int write(byte[] b,int nStart,int nLen) [Q\(kd*4
{ /d/]#T[Z9
int n = -1; bE@Eiac
try{ kY6_n4
oSavedFile.write(b,nStart,nLen); ,rF!o_7
n = nLen; )>^Ge9d]
} ):nC%0V
catch(IOException e) JoZzX{eu"
{ :XoR~syT
e.printStackTrace (); )O$S3ojZ
} ,7DyTeMpN
WS?Y8~+{5
XW\ 3ttx
return n; \PFjw9s
} ${}9/(x/^
G )`gn
}RYPr
} *J >6i2M,u
W^S]"N0u
GU9p'E
/* }_mMQg2>=
**SiteInfoBean.java SQ]M"&\{y
*/ 84i0h$ZZo
package NetFox; ?YDMl
y@7CY-1
l<ZHS'-;8
public class SiteInfoBean { x9 n(3Oa
\OWxf[
eb6y-TwY
private String sSiteURL; //Site's URL gS`Z>+V5!c
private String sFilePath; //Saved File's Path %da-/[
private String sFileName; //Saved File's Name "Vp:Sq9y
private int nSplitter; //Count of Splited Downloading File rSm#/)4A
4cJ/XgX
(v:8p!QN
public SiteInfoBean() *P5/S8c
{//nSplitter的缺省值为5 Goy[P2m
//default value of nSplitter is 5 )KkV<$
this("","","",5); 'aEN(Mdz1e
} 5~(nHCf>
#e[r0f?U
F[0~{*/|G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }#Iqq9[
{ TV0Y{x*~iH
sSiteURL= sURL; Ad>@8^
sFilePath = sPath; 322-'S3<
sFileName = sName; JRE\R&>g
this.nSplitter = nSpiltter; &zVXd
/+. m.TF
9i{(GO
} hw)z]
v;}MHl
i~M-V=Zg
public String getSSiteURL() f}ch1u>
{ s&wm^R
return sSiteURL; Rt5Xqz\6i
} <;jg/
fi&>;0?7
YG*}F|1
public void setSSiteURL(String value) l2wu>Ar7.
{ %rEP.T\i
sSiteURL = value; nvc(<Ovw
} ou]jm=4[
<$#^)]Ts
5>=4$!`
public String getSFilePath() lR`.V0xA
{ ]~ S zb
return sFilePath; _6]CT0
} 9'|_1Q.b^
R?}%rP+^e
' 8Q}pp`
public void setSFilePath(String value) 1$:O9{F
{ 9OlJC[
sFilePath = value; \`-xxhb?e
} U><$p{)
8MBY3F
SK*<H~2
public String getSFileName() F+W{R+6
{ <u?\%iJ"
return sFileName; _BCq9/
} ws U@hqS
GK3cQw
^ 7)H;$
public void setSFileName(String value) _b *gg
{ y7'9KQ
sFileName = value; -f?,%6(1
} lt\Bm<"z!1
M`)3(|4
NZ+TTMv
public int getNSplitter() {T0Au{88H
{ f%q ?
return nSplitter; `84,R!
} c;n\HYk
&,\my-4c>
i\#?M "
public void setNSplitter(int nCount) /7ykmW
{ Dh<}j3]
nSplitter = nCount; QQ %W3D@
} /8"rCh|m-
} UI~hB4V$]
Y+0GJuBf
meGLT/
/* aeEio;G1
**Utility.java *-E'$
*/ *{O[}
package NetFox; YmHu8H_Q
,=: -&~?
ROO@EQ#`Z
public class Utility { .F/s(
*De'4r 2
_auFt"n
public Utility() h"f_T [
{ K.b:ae^k
S.?DR3XLc
C>QWV[F
} %Y9CZRY9
FJn.V1
//线程睡眠 l]~IZTC
public static void sleep(int nSecond) @]Ac >&
{ x }]"jj2x
try{ >.uIp4@(
Thread.sleep(nSecond); RSnBG"
} 3`Xzp
catch(Exception e) ryb81.|
{ !1Ht{cA0
e.printStackTrace (); Q^X}7Z|T
} K87yQOjPv
} N@^:IfJ+=
{HFx+<JG
//日志 vx}BTH
public static void log(String sMsg) ClNuO
{ @gw8r[
System.err.println(sMsg); x0lAJaG
} ^z51f>C
cM]ZYi
]<S{3F=
public static void log(int sMsg) )jh~jU?c@
{ !lBK!'0
System.err.println(sMsg); R*2F)e\|
} yD@1H(yM
} T2Yc` +
gMp' S
?-tNRIPW@p
/* %"WhD'*z}
**TestMethod.java YPA$38
*/ B>@l(e)b
package NetFox; M`E}1WNQ?]
&y7xL-xP
U2v;GIo$yU
public class TestMethod { %/qwqo`Q
@Gy.p5J8
fB]NEx|o~
public TestMethod() kI2+&
{ ///xx/weblogic60b2_win.exe \[]?9Z=n
try{ p7HLSB2Rp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |kTq &^$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {|B[[W\TN
SiteFileFetch fileFetch = new SiteFileFetch(bean); WdB\n/BWB
fileFetch.start(); ZB}A^X
} F!p;]B
catch(Exception e){e.printStackTrace ();} g's!\kr
uBxoMxWm
]&dPY[~,/i
} c2?VjuB0
TKgN31`
9%bErMHL
public static void main(String[] args) w'E?L`c
{ i"pOYZW1
new TestMethod(); <0qhc$M
} ~qIr'?D
} \Hf/8!q
点击下载更多相关资料