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)); 2.xA' \M
} nu'r`
for(int i=0;i<nEndPos.length-1;i++) 1=R6||8ws
{ e|6kgj3/
nEndPos = nStartPos[i+1]; ape\zZCV
} =IbDGw(
nEndPos[nEndPos.length-1] = nFileLength; `>.^/SGu>?
} b#h}g>l
} ~Bw)rf,
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%Y0,ww2
//启动子线程 HNFG:t9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6bv~E.
for(int i=0;i<nStartPos.length;i++) R&lJ& SgC
{ UG@9X/l}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), olHT* mr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]6:|-x:m
nStartPos,nEndPos,i); lfle7;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mp%.o}j
fileSplitterFetch.start(); p }p@])}8
} V'-}B6 3S>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?W6qwm,?L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FabDK :
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {Kbb4%P+h
nEndPos = " + nFileLength); @y"/hh_?
// fileSplitterFetch[nPos.length-1].start(); 5X4 #T&.
>#9f{
]2Vu+AP
//等待子线程结束 Z$a5vu*pg
//int count = 0; Z%rMX}
//是否结束while循环 bSG}I|
boolean breakWhile = false; %3Ba9Nmid
f1Az|h
m'j]T/WF
while(!bStop) fu=GgD*
{ <%_7%
write_nPos(); O)2==_f\
Utility.sleep(500); ?2RDd|#
breakWhile = true; G}|!Jdr
*-.{->#Y
Wqy\yS [
for(int i=0;i<nStartPos.length;i++) =sp5.-r
{ =hw&2c
if(!fileSplitterFetch.bDownOver) _m?TEqB
{ `f|Gw5R
breakWhile = false; *VP-fyJp
break; [Dzd39aKr
} t\\oGH
} [WfigqY`b*
if(breakWhile) PU& v{gn
break; B4l*]K%
2aDjt{7P
`FJ2 ?
//count++; u0o}rA
//if(count>4) %z9lCTmy
// siteStop(); $u ae8h
} `rWT^E@p5m
5.IX
>TKl`O
System.err.println("文件下载结束！"); tz6N,4J?
} tPQjjoh
catch(Exception e){e.printStackTrace ();} I`% ]1{
} B'AU~#d
XABB6J]
SV?^i`
//获得文件长度 Y&![2o.Q
public long getFileSize() =ws iC'
{ ZyJ-}[z
int nFileLength = -1; _l,_NV&T
try{ *wfb~&:}
URL url = new URL(siteInfoBean.getSSiteURL()); Y<ZaW{%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XCo3pB Wq~
httpConnection.setRequestProperty("User-Agent","NetFox"); VZhHO d
0%W0vTvL
s7789pR
int responseCode=httpConnection.getResponseCode(); *XCgl*% *
if(responseCode>=400) WDF;`o*3
{ 8kRqF?rbj
processErrorCode(responseCode); {:%A
return -2; //-2 represent access is error #Wf9`
} !gyEw1Re7
?=},%^
~MpcVI_K
String sHeader; ?=FRnpU?
,UveH` n-
aAi"
for(int i=1;;i++) U+4W9zhwo
{ bTd94
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,B'n0AO/'
//Utility.log(in.readLine()); pm4'2B|)g
sHeader=httpConnection.getHeaderFieldKey(i); -(;<Q_'s{"
if(sHeader!=null) ; *ZiH%q,
{ n N_Ylw
if(sHeader.equals("Content-Length")) -50Nd=1
{ fZ6-ap,u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QnZ7e#@UP
break; eoGGWW@[
} yGs:3KI
} jE#&u DfI
else YCBcyE}p
break; GV"X) tGo
} \'>8 (i~
} Rf4}4ixkj
catch(IOException e){e.printStackTrace ();} #;lB5) oe
catch(Exception e){e.printStackTrace ();} !RPPwvNk4
U4.-{.
Kqn{q4L
Utility.log(nFileLength); -qDM(zR
9*ek5vPB
|PaVb4j
return nFileLength; tsWzM9Yf
} 0]u=GD%
u,88V@^
C4h4W3w
//保存下载信息（文件指针位置） aj|gt
private void write_nPos() *?`<Ea
{ \Um &
try{ O={ ?c1i:
output = new DataOutputStream(new FileOutputStream(tmpFile)); GEGg S&SM
output.writeInt(nStartPos.length); FWb`F&
for(int i=0;i<nStartPos.length;i++) P.>5`^
{ },& =r= B
// output.writeLong(nPos); B s{n
output.writeLong(fileSplitterFetch.nStartPos); Be4n\c.
output.writeLong(fileSplitterFetch.nEndPos); 713)D4y}
} ixjhZki<
output.close(); 8jdEx&K
} +wpQ$)\
catch(IOException e){e.printStackTrace ();} 8j^3_lD
catch(Exception e){e.printStackTrace ();} :dML+R#Ymh
} LEgx"H=c
TPi=!*$&
-udKGrT+
//读取保存的下载信息（文件指针位置） Gc0/*8u/
private void read_nPos() nB.u5
{ B4/\RC2
try{ Z]\IQDC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?>}&,:U}
int nCount = input.readInt(); MVYf-'\^
nStartPos = new long[nCount]; Pf?zszvs
nEndPos = new long[nCount]; a'prlXr\4
for(int i=0;i<nStartPos.length;i++) (q+EP(Q
{ -+H?0XN
nStartPos = input.readLong(); g-O}e4
nEndPos = input.readLong(); |\#6?y[o
} +}Q@{@5w
input.close(); ]ff5MY 36
} YYi:d=0<SO
catch(IOException e){e.printStackTrace ();} mcm8|@Y{
catch(Exception e){e.printStackTrace ();} us2RW<Oxv
} 4/+P7.}ea-
v0uA]6:
7jtDhsVz
private void processErrorCode(int nErrorCode) .0ExHcr
{ E==vk~cz
System.err.println("Error Code : " + nErrorCode); %.mHV7c)%
} ,2/y(JX}*!
_rIFwT1]
\|< 5zL
//停止文件下载 #$*l#j"#A
public void siteStop() ]R7zvcu&
{ t9Y?0O}/
bStop = true; >SSRwYIN
for(int i=0;i<nStartPos.length;i++) n1;y"`gHk
fileSplitterFetch.splitterStop(); s<`54o ,
,EuJ0]2
{klyVb
} +1(L5Do}
} uHu(
//负责部分文件的抓取 ADW>
**FileSplitterFetch.java =3R5m>6!/
*/ 5IfyD ]<
package NetFox; tI;pdR]
|`c=`xK7'
qFwJ%(IQ
import java.io.*; r[votdFo
import java.net.*; ~L3]Wa.
@,%IVKg\
18{" @<wIs
public class FileSplitterFetch extends Thread { -<RG'I~
|-! yKB
Im0#_ \
String sURL; //File URL *j/[5J0'M
long nStartPos; //File Snippet Start Position ~K-_]*[x
long nEndPos; //File Snippet End Position 4Px
int nThreadID; //Thread's ID Q?7:XbN
boolean bDownOver = false; //Downing is over B(l8&
boolean bStop = false; //Stop identical GT(nW|v
FileAccessI fileAccessI = null; //File Access interface jn/ J-X=
UW@BAj@^@
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7]&ouT
{ 1}>uY
this.sURL = sURL; M>kk"tyM
this.nStartPos = nStart; 9p '#a:
this.nEndPos = nEnd; /:o (Ghc?
nThreadID = id; !5escR!\D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vi-mn)L6#
} %I>-_el
=3= $F%
;xMieqz
public void run() ),#hBB`ZA
{ @2eV^eO9
while(nStartPos < nEndPos && !bStop) tMQz'3,X
{ Qk_`IlSd
$Afw]F$
9YjO
try{ e|&}{JP{[
URL url = new URL(sURL); #Emz9qTsce
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SGUu\yS&s
httpConnection.setRequestProperty("User-Agent","NetFox"); LnY`f -H
String sProperty = "bytes="+nStartPos+"-"; 5J0Sc
httpConnection.setRequestProperty("RANGE",sProperty); b( qO fek
Utility.log(sProperty); ]%8f-_fSy
o 2Okc><z
Y#[>j4<T
InputStream input = httpConnection.getInputStream(); bo%v(
//logResponseHead(httpConnection); Bx&F*a;5
fj,]dQT
^,;AM(E
byte[] b = new byte[1024]; M(+;AS?;
int nRead; g\O&gNq<)-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;s(uaC3
{ v@KP~kp
nStartPos += fileAccessI.write(b,0,nRead); ))z1T8
//if(nThreadID == 1) n;+e(ob;;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XnCrxj
} Js("H
E 02l=M
lAcXi$pF
Utility.log("Thread " + nThreadID + " is over!"); R:}u(N
bDownOver = true; X8Ld\vZYn
//nPos = fileAccessI.write (b,0,nRead); v!b 8_0~u6
} :(o6^%x
catch(Exception e){e.printStackTrace ();} oy?>e1Sy*
} )rP)-op|A
} FJj#
$F,&7{^
mhXSbo9w-
//打印回应的头信息 [q5N 4&q\
public void logResponseHead(HttpURLConnection con) c'8a)j$$+
{ u|'}a3
for(int i=1;;i++) *w[\(d'T
{ J|D$
String header=con.getHeaderFieldKey(i); ZKT~\l
if(header!=null) yavoGk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5?()o}VjAO
Utility.log(header+" : "+con.getHeaderField(header)); 3{;W!/&>
else Es~|:$(N]|
break; `T \"B%
} 1; "t8.*%e
} +#|):aF
v1E=P7}\{s
i$Sq.NU
public void splitterStop() <P"4Mk7`s
{ ;& PK6G
bStop = true; $^1L|KgXp
} KOQ9K
DIU9Le
aYyUe>
} },=0]tvZG#
`Rc7*2I)l
d*A(L5;@
/* uv,_?x\'
**FileAccess.java mm5y'=#
*//文件访问(定位，写) 3nJd0E
package NetFox; U=G^wL
import java.io.*; H"g$qSx
<e:2DB&
{ta0dS;1
public class FileAccessI implements Serializable{ j+>#.22+
sMikTwR/^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W"@FRWcd
RandomAccessFile oSavedFile; MGmUgc
long nPos; E9yBa=#*c
3Q@HP;<
TBzOz:k
public FileAccessI() throws IOException }uTe(Rf
{ $YM6}D@
this("",0); +C(v4@=nd
} vGT#BS%
Du3nK"-g
N2~q\BqA
public FileAccessI(String sName,long nPos) throws IOException {Va"o~io
{ $YyN-C
oSavedFile = new RandomAccessFile(sName,"rw"); F9|\(St &
this.nPos = nPos; +[DL]e]@U
oSavedFile.seek(nPos); bS9<LQ*
} 0K&\5xXM
Viu+#J;l
l-N4RCt h
public synchronized int write(byte[] b,int nStart,int nLen) 5$T>noD
{ sPee"9%,
int n = -1; }5)sS}C
try{ onuhNn_=>
oSavedFile.write(b,nStart,nLen); e[lRY>Pe5
n = nLen; z>f>B6
} >9S@:?^&q>
catch(IOException e) dUTF0U
{ 06&:X^
e.printStackTrace (); cN{-&\ 6L
} Dw@0P
B>11
+P&;cCV`S3
return n; 'e3[m
} _TRO2p0
[,F5GW{x
r="wd
} gGiLw5o,
r# }`{C;+5
9\|n2$H:
/* -F+dRzxH
**SiteInfoBean.java "SuBtoK
*/ -n-rKN.T
package NetFox; 8qEK6-
8G>;X;W
}a(x L'F
public class SiteInfoBean { GYD`
N|,6<|
0$n0fu
private String sSiteURL; //Site's URL B@,L83
private String sFilePath; //Saved File's Path @+v;B:
private String sFileName; //Saved File's Name 8%UI<I,
private int nSplitter; //Count of Splited Downloading File SOyE$GoOsx
9M)N2+hkZ
+M+ht
public SiteInfoBean() GHMoT
{//nSplitter的缺省值为5 FuZ7xM,
//default value of nSplitter is 5 7kBULeBn|
this("","","",5); [8k7-}[
} JZ[~3swR
x}.Q9L
n=vW oU9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C} #:<Jx
{ DR`d^aBWQ
sSiteURL= sURL; 2EubMG
sFilePath = sPath; e,_b
sFileName = sName; a*}ZT,V
this.nSplitter = nSpiltter; y[*Bw)F\N
(ia(y(=C
silTL_$
} $18|@\Znj
*g^U=t
~;Ga65_6_
public String getSSiteURL() Bv^{|w
{ &)Fp
return sSiteURL; !b"#`O%`
} Hnwir!=7
"WTnC0<
;4E0%@R
public void setSSiteURL(String value) *`:zSnu
{ jUq^$+N
sSiteURL = value; 5$Yt@8;
} A f@IsCOJ
3S-nsMs.
tVUoUl
public String getSFilePath() &L,zh{Mp
{ %,rUN+vW
return sFilePath; )1a3W7
} Oo<^~d2=
r"OVu~ND
*yqEl O
public void setSFilePath(String value) !<3(+H
{ NZ`( d
sFilePath = value; d%Zt]1$
} 7d?'~}j
#/ 1
CUB=T]
public String getSFileName() M3j_sd'N
{ >3 Q%Yn
return sFileName; !Y3w]_x[:
} J7BfH,o
~S)o('
u>j:8lhtV
public void setSFileName(String value) x68$?CD
{ sm-RpZ&|
sFileName = value; "Y9 *rL
} Exox&T
'vT XR_D
A-vK0l+
public int getNSplitter() \?-`?QPux
{ PNLtpixZ
return nSplitter; ~/J:p5?L
} Mg]q^T.a
n%I%O7
/#M|)V*wn
public void setNSplitter(int nCount) eN@V?G26K
{ +Sk;
nSplitter = nCount; ]sJWiIe.
} 5QU7!jbI
} vW`{BWd
zp>q$e40
L2[|g~
/* ~qm<~T_0
**Utility.java eLcP.;Z
*/ MV5'&" ,oB
package NetFox; ;w@PnY
5_b`QO
3!^5a%u
public class Utility { q bb:)>
QD%~A0
f_X]2in
public Utility() VL"!.^'c
{ wxpE5v+f|
>}h/$bU
CZv.$H"lW
} vRYQ4B4o
XX",&cp02V
//线程睡眠 E^_P
public static void sleep(int nSecond) LX[J6YKR
{ MCU{@\?Xf
try{ :BG/]7>|V
Thread.sleep(nSecond); 3}}~(
} ncf=S(G+
catch(Exception e) KHKf+^uu
{ R| t"(6
e.printStackTrace (); 0\O*\w?
} ~hPp)-A
} n.p6+^ES
_|rrl
//日志 iPX6r4-
public static void log(String sMsg) 3 <RkUmR
{ \2)a.2mAz
System.err.println(sMsg); w<-8cvNhiz
} Fyoy)y*
8P.UB{QNe
IwhZzw w
public static void log(int sMsg) lG,/tMy
{ c%w@-n`
System.err.println(sMsg); _@jBz"aq\
} kVE% "
} <_-&{Pv
u}hQF$a"
^%wj6
/* <n< @ O5
**TestMethod.java H[?~u+
*/ IO~d.Ra
package NetFox; h[72iVn
-~ytk=
Z{RRhJ
public class TestMethod { :Jwc'y-]
gE%{#&*
rXXIpQRi$S
public TestMethod() awN{F6@ZE
{ ///xx/weblogic60b2_win.exe w-\U;&8
try{ Bt4 X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1xg^;3m2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B4 5B`Ay
SiteFileFetch fileFetch = new SiteFileFetch(bean); ",&#9
fileFetch.start(); FDM&rQ
} GCCmUR9d
catch(Exception e){e.printStackTrace ();} c'?4*O
D"_~Njf
}7YDe'5V
} c(Zar&z,E
YgiwtZ5FY
z)"7qqA
public static void main(String[] args) R>H*MvN
{ gv$6\1
new TestMethod(); MVHj?
} z5IHcZ
} Q/r0p>
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