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)); nVrV6w
} PbY.8d%2/k
for(int i=0;i<nEndPos.length-1;i++) J l{My^I5
{ {qU;>;(
nEndPos = nStartPos[i+1]; U-$nwji
} &" 5Yt&{
nEndPos[nEndPos.length-1] = nFileLength; 91nB?8ZE6,
} yn20*ix{
} *y` (^kyS
cxFyN;7
6\v4#
//启动子线程 rJB/)4 mE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2z AxGX
for(int i=0;i<nStartPos.length;i++) ;!7M<T$&
{ b2j~"9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (^_INy*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2T@?&N^OD
nStartPos,nEndPos,i); : w>R|]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R((KAl]dL
fileSplitterFetch.start(); i=hA. y`
} NO/5pz}1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), et(AO)uv6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gNkBHwv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?(}~[
nEndPos = " + nFileLength); 5d# 73)x$
// fileSplitterFetch[nPos.length-1].start(); $:UD #eh0?
rd24R-6
8o).q}>&
//等待子线程结束 <K>qK]|C
//int count = 0; m,6[;
//是否结束while循环 fEtBodA)
boolean breakWhile = false; T{N8 K K
_Kh8 <$h
5`i+aH(
while(!bStop) EY c)v6[
{ 'z=d&K
write_nPos(); 6(Ntt
Utility.sleep(500); nQg_1+
breakWhile = true; \NKw,`/
Q)8I(*
H:WuMwD4
for(int i=0;i<nStartPos.length;i++) RXu`DWN
{ 9C!b f \
if(!fileSplitterFetch.bDownOver) <^942y-=
{ 9T1-{s R
breakWhile = false; 3;!!`R>e
break; #/_ VY.
} pwB>$7(_h
} r]aI=w<(f
if(breakWhile) WD*z..`
break; tbfwgK
6uk}4bdvq
TQ%F\@"
//count++; *<h)q)HS
//if(count>4) ~~m(CJ4S
// siteStop(); =8"xQ>D62
} r029E-
^7t1'A8e<
*/|<5X;xIA
System.err.println("文件下载结束！"); d7:=axo,
} Ka%#RNW
catch(Exception e){e.printStackTrace ();} i.KRw6
} kjOkPp
lg{/5gQG
1F+JyZK}w
//获得文件长度 )@=fGNDt
public long getFileSize() [dqh-7
{ `joyHKZI.
int nFileLength = -1; Wdga(8t
try{ b dC
URL url = new URL(siteInfoBean.getSSiteURL()); e+<9Sh7&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5ci1ce
httpConnection.setRequestProperty("User-Agent","NetFox"); T{=&>pNK[
'tjqfR
k/BlkjlNE
int responseCode=httpConnection.getResponseCode(); l?Ibq}[~
if(responseCode>=400) 7?);wh7`
{ T`]P5Bk8r
processErrorCode(responseCode); M~+DxnJ=
return -2; //-2 represent access is error ][YC.J
} ft4hzmuzM
/bo`@ !-#
g8"H{u
String sHeader; n?9FJOqi
d'b9.ki\
7*He 8G[W
for(int i=1;;i++) =j{Kxnv
{ 3~Ap1_9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }_7
//Utility.log(in.readLine()); 0\!v{A> I'
sHeader=httpConnection.getHeaderFieldKey(i); QiJ
if(sHeader!=null) lnF{5zc
{ {A)9ePgv!
if(sHeader.equals("Content-Length")) \BO6.;jA
{ +AFBTJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ToD_9i }6
break; 'T;;-M3*
} Yvu?M8aK!
} ,/!^ZS*
else #u +~ ^M
break; HuQdQ*Q
} vTIRydg2b
} t >.=q:
catch(IOException e){e.printStackTrace ();} 1jaK N*
catch(Exception e){e.printStackTrace ();} cIP%t pTW.
+*aC \4w
e{*yV#Wl
Utility.log(nFileLength); ;<nJBZB9u
@Qp#Tg<'
`}rk1rl6
return nFileLength; K6|R ;r5e{
} 8NTE`l=>/
Qd>\{$N
/!`xqG#
//保存下载信息（文件指针位置） uf"(b"N0
private void write_nPos() *M$'dLn
{ MT$)A:"
try{ 8Dn~U:F/?
output = new DataOutputStream(new FileOutputStream(tmpFile)); wzBw5nf\
output.writeInt(nStartPos.length); Yb1Q6[!
for(int i=0;i<nStartPos.length;i++) a>Zp?*9
{ 'rA(+-.M;
// output.writeLong(nPos); 62K#rRS
output.writeLong(fileSplitterFetch.nStartPos); bfy=
output.writeLong(fileSplitterFetch.nEndPos); qVjMflVoay
} h 9}x6t,
output.close(); Y%>u.HzL
} Pw5[X5.DX
catch(IOException e){e.printStackTrace ();} & x_ #zN]
catch(Exception e){e.printStackTrace ();} Eh$1piJG
} BO%'/2eV
-=ZDfM
0Q)YZ2
//读取保存的下载信息（文件指针位置） k|U2Mp
private void read_nPos() H6U5-
{ yhs:.h
try{ OB*V4Yv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {<?8Y
int nCount = input.readInt(); $dA]GWW5A
nStartPos = new long[nCount]; ]b:>7_la
nEndPos = new long[nCount]; 9Hd_sNUu\
for(int i=0;i<nStartPos.length;i++) ExeZj8U
{ E=`/}2
nStartPos = input.readLong(); FW|_8q?}<
nEndPos = input.readLong(); 9PMIF9"
} |--Jd$ dj
input.close(); ''3I0X*!
} q%dbx:y#
catch(IOException e){e.printStackTrace ();} ?0?3yD-!9
catch(Exception e){e.printStackTrace ();} [1O{yPV3s
} 8)ng> l
?GW}:'z
;~'&m
private void processErrorCode(int nErrorCode) W!Fc60>p@f
{ 6Rmdf>a
System.err.println("Error Code : " + nErrorCode); @PctBS<s
} (NN;1{DB8
RgZ9ZrE\
S5d
//停止文件下载 \f)GW$`
public void siteStop() %$i}[U
{ W+$G{XSr5C
bStop = true; =%c\<<]aV
for(int i=0;i<nStartPos.length;i++) PC|ul{[*}
fileSplitterFetch.splitterStop(); \-f/\P/ w
bZ``*{I/
q alrG2
} PTqia!
} _ElG&hyp
//负责部分文件的抓取 ]hoq!:>M1
**FileSplitterFetch.java k+vfZ9bD(J
*/ m/ID3_
package NetFox; k[,0kP;
*ZxurbX#
}r!hm?e
import java.io.*; 3dSC`K
import java.net.*; P,F eF'J^
-4P `:bF
o{^`Y
public class FileSplitterFetch extends Thread { x*=1C,C
* ^V?u
5;,h8vW
String sURL; //File URL E+#<WK-
long nStartPos; //File Snippet Start Position k%Vprc
long nEndPos; //File Snippet End Position S>S7\b'
int nThreadID; //Thread's ID =O-irGms*
boolean bDownOver = false; //Downing is over (z?j{J
boolean bStop = false; //Stop identical >?rMMR+A
FileAccessI fileAccessI = null; //File Access interface ic"8'Rwb
tC5-^5[y
UGj |)/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fc9@l a
{ '+27_j
this.sURL = sURL; ${eV3LSC
this.nStartPos = nStart; QWEE%}\3}
this.nEndPos = nEnd; 0U H]
nThreadID = id; \4^rb?B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (<8}un
} X6 N&:<
w( _42)v]g
ZfK[o{9>
public void run() !?/:p.
{ P^48]Kj7
while(nStartPos < nEndPos && !bStop) :9Jy/7/
{ /zoy,t-i
z|X6\8f
cD}]4
try{ H-U_
URL url = new URL(sURL); V)N{Fr)&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ] _5b
httpConnection.setRequestProperty("User-Agent","NetFox"); 3 yy5 l!fv
String sProperty = "bytes="+nStartPos+"-"; D79:L:
httpConnection.setRequestProperty("RANGE",sProperty); <aDZ{T%
Utility.log(sProperty); G\TO]c
%^vT7c>
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InputStream input = httpConnection.getInputStream(); ]JV'z<
//logResponseHead(httpConnection); ]bY]YNt{7]
(QJe-)0_y
H;l_;c`
byte[] b = new byte[1024]; b*M?\ aA
int nRead; nP]!{J]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _lFw1pa#\
{ l $"hhI8
nStartPos += fileAccessI.write(b,0,nRead); "\KBF
//if(nThreadID == 1) IA({RE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mbGma
} kFV, Fg
XclTyUGoK+
;}"Eqq:
Utility.log("Thread " + nThreadID + " is over!"); zdd-n[%@V
bDownOver = true; ,^97Ks ;
//nPos = fileAccessI.write (b,0,nRead); IT&,?u%
} %S}uCqcAK
catch(Exception e){e.printStackTrace ();} V?1 $H
} ,3y9yJQa*#
} Z>Mv$F"p:
cgSN:$p(R
<7`zc7c]#
//打印回应的头信息 FutS
public void logResponseHead(HttpURLConnection con) Mjy:k|aY"
{ a4=(z72xe
for(int i=1;;i++) S!.&#sc
{ I4{xQI
String header=con.getHeaderFieldKey(i); Cul=,;pkB
if(header!=null) q*3keB;X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Jt@lH
Utility.log(header+" : "+con.getHeaderField(header)); RbXR/Rd
else 5$D"uAp<V
break; d#H9jg15e
} PD-&(ka.
} "8{A4N1B5
}: HG)V
.'gm2
public void splitterStop() x9 %=d
{ Oo}h:3?
bStop = true; '#Au~5
} =I@t%Y
r(46jV.sD:
.Dr!\.hL
} c{BAQZVc
wG3b{0
=abcLrf2G
/* jk03 Hd
**FileAccess.java 7RL J
*//文件访问(定位，写) MQ-u9=ys
package NetFox; {;c'@U
import java.io.*; hx$61E=
:Kwu{<rJ!(
KBmOi
public class FileAccessI implements Serializable{ VP~2F E
d?2ORr|m=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Cp6S2v I
RandomAccessFile oSavedFile; T8x)i\<
long nPos; ir_XU/ve
a(~Y:v
>+P}S@
public FileAccessI() throws IOException ` 3qf}=Z`
{ <m]0!ii
this("",0); d-D,Gx]>$
} i}sAF/
G`Nw]_ Z_
m9DFnk<D
public FileAccessI(String sName,long nPos) throws IOException }kqh[`:
{ .ybmJU*Hg
oSavedFile = new RandomAccessFile(sName,"rw"); w`)5(~b
this.nPos = nPos; `$B?TNuch7
oSavedFile.seek(nPos); ]?tRO
} =9GALoGL
AafS6]y
$^ee~v;m4
public synchronized int write(byte[] b,int nStart,int nLen) tDX&~1s
{ rPaJ<>Kz
int n = -1; &q-&%~E@
try{ AG@gOm
oSavedFile.write(b,nStart,nLen); H9/!oI1P?
n = nLen; rx1u*L
} K381B5_h
catch(IOException e) -e/}DGL
{ !C#oZU]P
e.printStackTrace (); pCs3-&rI3
} FvpU]
^l!SIu
3%kUj
return n; 4>*=q*<V5E
} V]F D'XAl
"?NDN4l*
s6,~JF^
} WigtTAh4
]y_:+SHc
Z-PBCU
/* '~D4%WKT
**SiteInfoBean.java $0_K&_5w~
*/ %Jt35j@Ee
package NetFox; nqj(V
IzpE|8l
EZ)b E9
public class SiteInfoBean { .xJ54Vz
K%v:giN$l`
D$hQ-K
private String sSiteURL; //Site's URL 4=L>
private String sFilePath; //Saved File's Path L|CdTRgRCB
private String sFileName; //Saved File's Name kpgA2u7
private int nSplitter; //Count of Splited Downloading File #n>U7j9`O
.G{cx=;
3K &637
public SiteInfoBean() W{F)YyR{.
{//nSplitter的缺省值为5 z9aR/:W}
//default value of nSplitter is 5 |]?f6^|4
this("","","",5); F1#{(uW
} q`*.F#/4c
|[?Otv
>3!~U.AA'x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u#76w74
{ _J1\c~ke"
sSiteURL= sURL; zm&[K53
sFilePath = sPath; 2{79,Js0
sFileName = sName; lVvcrU
this.nSplitter = nSpiltter; ^4n#''wJ
U@OdQAX
QLY;@-jF$
} Msqqjhoy
?Y4 +3`\x
x%viCkq
public String getSSiteURL() Z/q6Q#
{ yB UQ!4e
return sSiteURL; m!FuC=e
} RE>Q5#|c
KU|W85ye
gi!_Nz
public void setSSiteURL(String value) IuXgxR%
{ c]4X`3]
sSiteURL = value; #X-C~*|>j
} dn 6]qW5
g *Js4
Cbff:IP
public String getSFilePath() oco,sxT
{ z!g$#hmL>
return sFilePath; mw"FQ?bJ
} iB)\*)
]?y~;-^
#[prG
public void setSFilePath(String value) I$;`^z
{ l U/Xi
sFilePath = value; Y#F.{i
} ;M~,S^U
Y_%:%J
xuXPVJdi
public String getSFileName() <XLae'R
{ $g>bp<9v4
return sFileName; syX?O'xJ
} clvg5{^q[
~+\=X`y
H$I~Vz[\yb
public void setSFileName(String value) M/o?D <'
{ mjD^iu8?
sFileName = value; _&-d0'+
} #}^waYAk)
: @|Rj_S;
vMz|'-rm$
public int getNSplitter() ZXnacc~s
{ u"0{) ,
return nSplitter; cEL:5*cAU}
} ?}?"m:=
[icD*N<Gc
x#0?$}f<
public void setNSplitter(int nCount) Qder8I
{ mx9vjWfy
nSplitter = nCount; s@Q7F{z
} p"0#G&-
} 1 uU$V =
}b2YX+/e$f
0nt@}\j
/* DtANb^
**Utility.java !<];N0nt#
*/ %+'Ex]B
package NetFox; {"]!zL
2^'Ec:|f
ys`-QlkB
public class Utility { fG0ZVV!
KdoI
a>v *
public Utility() m"!SyN}&9?
{ /r7xA}se^
?}Zo~]7E
# xO PF9
} R'gd/.[e
if&bp ,
//线程睡眠 +?)7l
public static void sleep(int nSecond) F3bTFFt
{ 7hk<{gnr
try{ ^Laqq%PI
Thread.sleep(nSecond); e|k]te
} QT c{7&
catch(Exception e) Wc@ ,#v
{ h7Uj "qH
e.printStackTrace (); f#ZM2!^!
} T<*)Cdid
} 94B%_
i:YX_+n
//日志 yEWm.;&3=
public static void log(String sMsg) }#7l-@{<
{ ]Za[]E8MD
System.err.println(sMsg); 3jZGO9ttnS
} {~9zuNi
$NR[U+
xb\EJ1M>
public static void log(int sMsg) ]T)N{"&N/
{ HO<|EH~lu
System.err.println(sMsg); I(M/X/
} 336ETrG^0
} T`e`nQ0nn
9n(68|^$
v?."`,e
/* V0^{Ss1M
**TestMethod.java C+'-TLeu
*/ ^}P94(oz
package NetFox; (7qlp*8.s
nXn@|J&z~U
3(oMASf
public class TestMethod { AFi_P\X
J$6WUz:?
Z]Bv
public TestMethod() P^OmJ;""D
{ ///xx/weblogic60b2_win.exe W.^zN'a
try{ #ZJ 1\Ov
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O7 ;=g!j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l73% y
SiteFileFetch fileFetch = new SiteFileFetch(bean); H~yHSm 3
fileFetch.start(); ?pZ"7kkD
} _#V&rY&@
catch(Exception e){e.printStackTrace ();} e:HORc~U
i+14!LlI
t"B3?<?]
} 8-@@QZ\N
YC1Bgz
\Vme\Ke*v)
public static void main(String[] args) +q pW"0[
{ ymm]+v5S.]
new TestMethod(); dU9;sx
} _&]7
} yP7b))AW9
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