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)); ?6>*mdpl
} 4q:8<*W=
for(int i=0;i<nEndPos.length-1;i++) J}+N\V~
{ ;(jL`L F
nEndPos = nStartPos[i+1]; }K`KoM
} j8 `7)^
nEndPos[nEndPos.length-1] = nFileLength; M,X)rM}Q
} }_F:]lI*R
} GY.iCub
&}0QnO_mj
|@d}O8
//启动子线程 23Dld+E&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nr+~3:3
for(int i=0;i<nStartPos.length;i++) OCJt5#e~A
{ q@~{g[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Sj;~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4P=1)t?tX
nStartPos,nEndPos,i); ,G-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qa\,)<'D:
fileSplitterFetch.start(); )_n(u3'
} $CJf 0[|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cui%r!D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7ku=roPoF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m@lUJY
nEndPos = " + nFileLength); %#PWD7a\
// fileSplitterFetch[nPos.length-1].start(); ^TjC
:475FPy]
<}h<By)
//等待子线程结束 tN_=&|{WE4
//int count = 0; tIV{uVM[|D
//是否结束while循环 2y|n!p T
boolean breakWhile = false; $Ff6nc=
<Rs$d0/
fI2y(p{?
while(!bStop) hoM%|,0
{ SIKaDIZ
write_nPos(); Hz[1c4)'F
Utility.sleep(500); Yk)fBPHr
breakWhile = true; DU)q]'[u
m/jyc# L:u
eK5~gnv,
for(int i=0;i<nStartPos.length;i++) 2{Dnfl'k
{ zUDXkG*Lv
if(!fileSplitterFetch.bDownOver) Qds:*]vGS
{ UZmUYSu;
breakWhile = false; B0Ay
break; Mw"[2PA
} 8a]g>g
} 7=yjd)Iy9m
if(breakWhile) w^^l,
break; ,3iD/8_
0v9i43[S|J
n/ :#:
//count++; Iw`|,-|
//if(count>4) jcvq:i{
// siteStop(); l:bbc!3
} |Kjfh};-C
8B-mZFXpK
n7Bv~?DM
System.err.println("文件下载结束！"); Cg%Owe/E?0
} ki}Li*)7
catch(Exception e){e.printStackTrace ();} Y~Vc|zM^(
} |pbetA4&
kP/<S<h,g
&cTOrG
//获得文件长度 ?u;m ],w!
public long getFileSize() f2pA+j5[
{ ^c/3!"wK
int nFileLength = -1; "w0~f6o
try{ )E7wBNV
URL url = new URL(siteInfoBean.getSSiteURL()); L[<Y6u>m!1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =Ti@Y
httpConnection.setRequestProperty("User-Agent","NetFox"); z_'!?K{
t^>P,%$
lq]8zm<\)]
int responseCode=httpConnection.getResponseCode(); rZ5xQ#IA
if(responseCode>=400) ?(Tin80=r
{ =./PY10'
processErrorCode(responseCode); :f%kkatO
return -2; //-2 represent access is error 2~7*jA+Ab
} (CH6Q]Wi_!
yiXb<g+B
aIQC[ry
String sHeader; @Q{:m)\
nT2b"wkTT
#`U?,>2q
for(int i=1;;i++) Y,yU460T8
{ s]`6uyW"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2M\7j
//Utility.log(in.readLine()); n@h$V\&\iM
sHeader=httpConnection.getHeaderFieldKey(i); 6/Yo0D>M$
if(sHeader!=null) 4+nZ4a>LH?
{ $Q}L*4?]
if(sHeader.equals("Content-Length")) p,|)qr:M
{ @jjxgd'%&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 92R,o'#
break; F7w\ctUP
} OC-d5P
} wu11)HFL|z
else 7J`v#
break; ;;rx)|\<R
} .HGK 3
} t5S|0/f
catch(IOException e){e.printStackTrace ();} J}4RJ9
catch(Exception e){e.printStackTrace ();} &'i>d&
p\#;(pf}s
'rFLG+W
Utility.log(nFileLength); ]TUoXU2<x
/X0<2&v
lx0BKD?n
return nFileLength; L0H^S)g
} :SO4@JT{W
-:Fr($^
b"}ya/
//保存下载信息（文件指针位置） O'^AbO=,
private void write_nPos() Oml3=TV
{ [T)>RF
try{ >Wx9a"H^(
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q>;Aq!mr=
output.writeInt(nStartPos.length); W>Pcj EI
for(int i=0;i<nStartPos.length;i++) 4T"L#o1
{ V4CA*FEA
// output.writeLong(nPos); D'{o3Q,%K
output.writeLong(fileSplitterFetch.nStartPos); 'Z,7{U1P
output.writeLong(fileSplitterFetch.nEndPos); *%_M?^
} Au/'|%2#(
output.close(); \>EUa}%xn
} g2}aEfp!H
catch(IOException e){e.printStackTrace ();} v;g,qO!LJ
catch(Exception e){e.printStackTrace ();} qzHsqlof
} RtxAIMzh?
]SL+ZT
PR(KDwsT&l
//读取保存的下载信息（文件指针位置） Uvi@HB HJ
private void read_nPos() *Sbc 8Y
{ SX =^C
try{ =%>E8)Jb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jJ@@W~/)B
int nCount = input.readInt(); @n9iOf~<
nStartPos = new long[nCount]; rTJU)4I^h
nEndPos = new long[nCount]; $ntC{a>&
for(int i=0;i<nStartPos.length;i++) v$q\3#5|'
{ .{bT9Sc5
nStartPos = input.readLong(); :x3DuQP
nEndPos = input.readLong(); qT4`3nH:
} n[v`F
input.close(); @Xh8kvc81
} ,O^kZ}b
catch(IOException e){e.printStackTrace ();} -)bu&
catch(Exception e){e.printStackTrace ();} %wu,ce]*
} ;F71f#iY
" ;8kKR
)liNjY@
private void processErrorCode(int nErrorCode) =KnHa.%
{ s-&i!d
System.err.println("Error Code : " + nErrorCode); Zw/??Tq b
} K7(GdKZe
eISHV.QV
AGVipI #
//停止文件下载 aK,\e/Oo
public void siteStop() m{lS-DlRg
{ $SniQ
bStop = true; @}+B%R
for(int i=0;i<nStartPos.length;i++) -wNhbV2
fileSplitterFetch.splitterStop(); Spo[JQ%6
CJ#Yu3}
chE}`I?
} %F;uW[4r
} eR3MU]zF
//负责部分文件的抓取 +K;%sAZy
**FileSplitterFetch.java RzLeR%O
*/ OQyZ'
package NetFox; 3A\Hiy!{F
%6@m~;c0
A/j'{X!z
import java.io.*; ,p..h+l
import java.net.*; XFww|SG$
MpIP)bdq7
IY2f$YV
public class FileSplitterFetch extends Thread { 1gYvp9Ma
:ZM=P3QZ
]tbl1=|
String sURL; //File URL }k8&T\V!
long nStartPos; //File Snippet Start Position _.,"`U; H
long nEndPos; //File Snippet End Position n!NA}Oa
int nThreadID; //Thread's ID Zzr
boolean bDownOver = false; //Downing is over n0^3F1Z
boolean bStop = false; //Stop identical . vea[
FileAccessI fileAccessI = null; //File Access interface -#AO4xpI
eN<?rVZl
IF?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $')Uie<!8
{ #N\<(SD/
this.sURL = sURL; #q?:Act
this.nStartPos = nStart; HuD~(CI.
this.nEndPos = nEnd; *NIhYg6
nThreadID = id; 5*$z4O:Aa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [{+ZQd
} lJ4/bL2I/
MPsm)jqX
jSvo-
public void run() fEyc3K'5V
{ GsE =5A8
while(nStartPos < nEndPos && !bStop) $[(FCS
{ elP#s5l4
%Vsg4DRy
H<`7){iG
try{ o-]8)G>~M
URL url = new URL(sURL); o1<Z;2#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \&Oc}]
httpConnection.setRequestProperty("User-Agent","NetFox"); ]#$rTWMl'
String sProperty = "bytes="+nStartPos+"-"; ob(~4H-
httpConnection.setRequestProperty("RANGE",sProperty); k@2@%02o9C
Utility.log(sProperty); NX<Q}3cC
#~qY%X
9z?B@;lMc
InputStream input = httpConnection.getInputStream(); FzFP 0
//logResponseHead(httpConnection); o7:"Sl2AD
~T'$gl
AiV1 vD`
byte[] b = new byte[1024]; Mj |"+(
int nRead; :DBJ2n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8PW3x-+
{ sH)40QmO{
nStartPos += fileAccessI.write(b,0,nRead); Xm.["&
//if(nThreadID == 1) I;?np
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |\q@XCGei
} 9 J~KM=p
=Xb:.
RsP^T:M}$
Utility.log("Thread " + nThreadID + " is over!"); 95 X6V
bDownOver = true; fu`|@S
//nPos = fileAccessI.write (b,0,nRead); th|TwD&mO
} ebB8.(k9G3
catch(Exception e){e.printStackTrace ();} YR68'Sft[
} GG`;c?d@
} 6C*4' P9>
jR,3-JQ
Jb`yK@x
//打印回应的头信息 At8^yF
public void logResponseHead(HttpURLConnection con) 6b=7{nLF
{ >zcp(M98
for(int i=1;;i++) 5%XEybc2
{ ]4-t*Em
String header=con.getHeaderFieldKey(i); CLY>M`%?+p
if(header!=null) ]=0$-ImQ@x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fmk(}
Utility.log(header+" : "+con.getHeaderField(header)); -gLU>I7wV
else * n>YS
break; |K$EULzz
} tumYZ)nW
} i.>d#S
>]l7AZ:,
Gv}~
public void splitterStop() <o&\/uO~H
{ $PKUcT0N9
bStop = true; Y\7/`ty
} uF\f>E)/N%
l#%G~c8x
%KmhR2v
} )u_[cEJHO
~px)Jd
r*4@S~;
/* #jR1ti)p
**FileAccess.java *6P)HU@
*//文件访问(定位，写) {(qH8A
package NetFox; wg 6
import java.io.*; _,]@xFCOH
a6.0$'
,zH\&D$>u
public class FileAccessI implements Serializable{ )u(Dqu\t
/c-%+Xd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y^J/jA0\B
RandomAccessFile oSavedFile; -&_;x&k /
long nPos; +^@6{1
_'DZoOH|VE
\jThbCb
public FileAccessI() throws IOException 7 `& NB]
{ g|V0[Hnq6
this("",0); YXjWk),
} ( G#W6
^6I8a"
Q?TXM1Bp
public FileAccessI(String sName,long nPos) throws IOException ^B7C8YP
{ QDJ:LJz\
oSavedFile = new RandomAccessFile(sName,"rw"); w`r)B`!g
this.nPos = nPos; 1:d,8
oSavedFile.seek(nPos); j+>&~
} ?;)F_aHp
:~+m9r
w?zY9Fs=s
public synchronized int write(byte[] b,int nStart,int nLen) tR% &.,2
{ i$W=5B>SO
int n = -1; 14;lB.$p
try{ Z:s:NvFX
oSavedFile.write(b,nStart,nLen); Pi:=0,"XOp
n = nLen; xSoXf0zq:
} |F^h>^ x
catch(IOException e) aXO|%qX
{ /0I=?+QSo
e.printStackTrace (); ~`Xu6+1o
} %G>V .d
u9R:2ah&K
U/I+A|S[
return n; y153ax
} 1$G'Kg/
>On"BP# U
Ks-aJ+}
} h9 &V
nH^RQ'19
v"a.%"oN8
/* O:3DIT1#>
**SiteInfoBean.java i(@<KH
*/ esVZ2_eL
package NetFox; '=eE6=m^K
MW6KEiQ"
fKZgAISF
public class SiteInfoBean { <E.$4/T
{Lm%zdk*k
;NzS;C'
private String sSiteURL; //Site's URL Nt#a_
private String sFilePath; //Saved File's Path lKF<]25
private String sFileName; //Saved File's Name o{&UT VyGs
private int nSplitter; //Count of Splited Downloading File PofHe
\9t6#8
/i)1BaF
public SiteInfoBean() nmrYBw>
{//nSplitter的缺省值为5 %[C-KQH
//default value of nSplitter is 5 3V`.<
this("","","",5); _z3YB
} `Gp!Y
edy6WzxBcm
oPA [vY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fCxF3m(O
{ *PVv=SU
sSiteURL= sURL; +w pe<T
sFilePath = sPath; dECH/vJ^
sFileName = sName; |6.1uRFE2
this.nSplitter = nSpiltter; :'LG%E:b
=wy3h0k^
^."HD(
} c_r&)8
/Aq):T T
2dF:;k k
public String getSSiteURL() N%.DjH
{ 5{&<X.jv
return sSiteURL; Z/ypWoV(
} ].eY]o}=
)tV^)n[w
\!tS|h
public void setSSiteURL(String value) Lx"a#rZ
{ mTW@E#)n
sSiteURL = value; `1[GY){?)
} %g>{m2o
PNbs7f
f1RfNiW.
public String getSFilePath() /:}z*a
{ ohA@Zm8O
return sFilePath; t!Uc,mEV]
} q|A-h'
-^JGa{9*
rpNe8"sh
public void setSFilePath(String value) >5jHgs#
{ [}OL@num
sFilePath = value; *ppb4R;CW
} j;k(AM<
92k}ON
7BX%z$_)A
public String getSFileName() e]+ [lq\p@
{ c[Mz#BWG
return sFileName; (Rc0l;
} U "qO&;m
-0)So
~"*;lT5KX
public void setSFileName(String value) B43o_H|s
{ r]=3aebR.
sFileName = value; UI4Xv
} Vo%UiVHy
diLjUC`69
,QpDz{8
public int getNSplitter() A_t<SG5
{ O;A/(lPW+
return nSplitter; ]rh)AE!Y(
} "iof -b=ys
?ExfxR!~
\\D~Yg\#
public void setNSplitter(int nCount) A*h)p@3t<
{ [^gSWU
nSplitter = nCount; bz~-uHC
} _l?5GLl_F$
} ^/Hj^4~_U
wBcDL/(>
y^C;?B<
/* *4zVK/FJ
**Utility.java "z }bgy
*/ /Ki :6
package NetFox; N[}XLhbt
z^4\?R50yO
_W: S>ij(
public class Utility { TBQ`:`g^m
rrSA.J{
FFgy=F
public Utility() Jz#ZDZkm
{ ^}8_tZs8\
f ( `.q
)^!-Aj\x
} )_EobE\
Ze$:-7Czl
//线程睡眠 7l Aa6"Y68
public static void sleep(int nSecond) P|.KMtG
{ 2597#O
try{ >t8eVMMa
Thread.sleep(nSecond); r/Pg,si
} S$"A[
catch(Exception e) 7$GP#V1r/
{ @fpxGMy&
e.printStackTrace (); "`:#sF9S
} qc\o>$-:`
} }7$\F!R
!*%3um
//日志 !9o8v0ZI
public static void log(String sMsg) )K2n!Fbd
{ NUL~zb
System.err.println(sMsg); #G#gB
} O!f*@
yB.6U56
McnP>n
public static void log(int sMsg) m$J'nA
{ raJyo>xXb5
System.err.println(sMsg); `T9<}&=!
} o7 !@WOeZ3
} n?,fF(
bM^'q
72-@!Z0e
/* `hlyN]L
**TestMethod.java uR"]w7=
*/ +[2lS54"W4
package NetFox; 00pHnNoxW
1shvHmrV
!#iP)"O
public class TestMethod { f\(Kou$
jv0e&rt
>8NQ8i=]V1
public TestMethod() 5. l&nt'
{ ///xx/weblogic60b2_win.exe q>omCk%h
try{ |J}~a8o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [1vrv(u>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NM]6 o
SiteFileFetch fileFetch = new SiteFileFetch(bean); I3s}t$`y(
fileFetch.start(); 8'cDK[L
} -`?V8OwY]
catch(Exception e){e.printStackTrace ();} d'-^VxO0
Dkdm~~Rr
\aW5V:?
} Hh@mIusj
Y66 vJ<lM
A`r&"i OKA
public static void main(String[] args) Y2$%%@
{ 3]VTQl{P
new TestMethod(); t1~*q)!Mo
} #-VKk
} w|5}V6WD
点击下载更多相关资料