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)); @hz~9AII9
} [f8mh88r
for(int i=0;i<nEndPos.length-1;i++) 3-%F)@n
{ Qf$3!O}G
nEndPos = nStartPos[i+1]; +~ZFao qf
} f^vz
nEndPos[nEndPos.length-1] = nFileLength; v}>5!*
} l ;fO]{
} HW"';M%
It@1!_tO2
x&['g*[L0
//启动子线程 4u.v7r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5 `Mos
for(int i=0;i<nStartPos.length;i++) !#b8QER
{ W["c3c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0|L%)'F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F?3zw4Vt~
nStartPos,nEndPos,i); Ln3<r&&Jz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sf(2~BMQI
fileSplitterFetch.start(); NH$!<ffz
} 2Jl$/W 3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IT5a/;J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !^h{7NmP[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {0?]weN*
nEndPos = " + nFileLength); BQ /0z^A
// fileSplitterFetch[nPos.length-1].start(); aN,.pLe;
& 6-8$
{i!@C(M3
//等待子线程结束 kbR!iPM-;
//int count = 0; |GqKa
//是否结束while循环 {CVn&|}J
boolean breakWhile = false; Xb'UsQ
tAxS1<T4
Gd:fh5u':
while(!bStop) >ow5aOlQ&
{ ~A-1x!YiU
write_nPos(); <aVfgVS
Utility.sleep(500); ~V:@4P
breakWhile = true; ^~65M/
5m(V(@a3
?A\[EI^
for(int i=0;i<nStartPos.length;i++) w<54mGMOLr
{ o$[alh;c+W
if(!fileSplitterFetch.bDownOver) Ga9^+.j
{ q<2b,w==
breakWhile = false; z~R:!O-
break; x]X!nx6G
} 0)Wrfa
} }o{6
if(breakWhile) qEW3k),
break; )8244;
7z@Jw
x[w!buV0\
//count++; hZ;[}5T\<S
//if(count>4) p0b2n a !
// siteStop(); omEnIfQSO
} F~O}@e{
~ v21b?
,FP<# 0F*a
System.err.println("文件下载结束！"); m-h+UKt
} UrhSX!g/A>
catch(Exception e){e.printStackTrace ();} $RJpn]d j
} :t#N.[=&#
nxZ[E.-\
MNzWTn@
//获得文件长度 lgL|[ik`
public long getFileSize() Ki_8g
{ 6k%Lc4W
int nFileLength = -1; re-;s
try{ pk&;5|cCD
URL url = new URL(siteInfoBean.getSSiteURL()); 1p%75VW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &!=[.1H<
httpConnection.setRequestProperty("User-Agent","NetFox"); Y8$,So>~
xD|CQo}:
I_\#(
int responseCode=httpConnection.getResponseCode(); #;WKuRv
if(responseCode>=400) [fjP.kw;J
{ cIJqF.k
processErrorCode(responseCode); o7A+O%dX
return -2; //-2 represent access is error 7B"*< %<
} k9|8@3(h
=,4iMENm!
=Co[pt
String sHeader; ?-HLP%C('
m+7/ebj{A
]@rt/ eX
for(int i=1;;i++) 3gcDc~~=
{ 0zCmU)ng
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5?{ytNCY
//Utility.log(in.readLine()); 6bXP{,}Gp
sHeader=httpConnection.getHeaderFieldKey(i); bWe_<'N
if(sHeader!=null) /`b(} m
{ f'>270pH
if(sHeader.equals("Content-Length")) ~s[St0
{ c%bGVRhE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S#9EBw7
break; #XaTUT
} MS~|F^g
} g=gWkN <
else X-$\DXRIo
break; lNQ8$b
} '. '}
} tU :,s^E"#
catch(IOException e){e.printStackTrace ();} U fzA/
catch(Exception e){e.printStackTrace ();} 2Kg+SLU[~
H}[kit*9
|~y>R#u8pm
Utility.log(nFileLength); d;-/F b{4
0';U3:=i,
^q$m>|KI
return nFileLength; `]0E)
} REe<k<>p~
u*aFWl]=
c@]_V
//保存下载信息（文件指针位置） MBO3y&\S4
private void write_nPos() _?+gfi+
{ ]sbj8
try{ < SIe5"{
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7P!Hryy
output.writeInt(nStartPos.length); N!u(G
for(int i=0;i<nStartPos.length;i++) [It E+{U
{ 9\aR{e,1
// output.writeLong(nPos); 8!T6N2O6d
output.writeLong(fileSplitterFetch.nStartPos); =WYI|3~Cz
output.writeLong(fileSplitterFetch.nEndPos); FuKp`T-H
} lg(*:To3B
output.close(); ~G;lEp
} >C1**GQ
catch(IOException e){e.printStackTrace ();} E[Rd=/P6
catch(Exception e){e.printStackTrace ();} O$2'$44HX
} 9MmAoLm
X;hV+|Bo
F_?aoP&5
//读取保存的下载信息（文件指针位置） :JEzfI1
private void read_nPos() e{~3&
{ ~`<(T)rs
try{ /tu+L6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); me7?
int nCount = input.readInt(); %DKQ
nStartPos = new long[nCount]; +].Zs<
nEndPos = new long[nCount]; _"Bh 3 7
for(int i=0;i<nStartPos.length;i++) =xa:>Vh#
{ QNk\y@yKw
nStartPos = input.readLong(); 8l, R|$RKP
nEndPos = input.readLong(); "8'aZ.P
} }qa8o
input.close(); 4}4K6y<q
} ?0{8fGM4
catch(IOException e){e.printStackTrace ();} Q}A*{9#|
catch(Exception e){e.printStackTrace ();} ["N)=d|LS
} #K5)Rb-H
mX2(SFpJar
~ PO)>;
private void processErrorCode(int nErrorCode) *G<K@k
{ 3Pj 6(cf
System.err.println("Error Code : " + nErrorCode); 'mH9O
} uh][qMyLM
f:=y)+@1My
?D6?W6@
//停止文件下载 h=fzX.dt
public void siteStop() 7V^\fh5~
{ Y6>@zznk
bStop = true; 2]$ 7
for(int i=0;i<nStartPos.length;i++) Jj_ t0"
fileSplitterFetch.splitterStop(); Ic%c%U=i
x8#bd{
?8g*"&cn
} C6$F.v
} 9L$bJO-3
//负责部分文件的抓取 ^F>C|FJ2
**FileSplitterFetch.java Y[hTO.LF
*/ E3):8>R;1
package NetFox; 8BL]]gT-I
8>}k5Qu
+/bT4TkML
import java.io.*; ({GN.pC(
import java.net.*; _I"T(2Au
hzT,0<nw
iiWs]5
public class FileSplitterFetch extends Thread { )} I>"n
!rK,_wH
G(g.~|=EZ
String sURL; //File URL D*Cn!v$
long nStartPos; //File Snippet Start Position 0/1Ay{ns
long nEndPos; //File Snippet End Position Nq$Xe~,*
int nThreadID; //Thread's ID rF/k$_bFt
boolean bDownOver = false; //Downing is over ~^<ju6O'
boolean bStop = false; //Stop identical 6AM-^S@
FileAccessI fileAccessI = null; //File Access interface :y>$N(.8f
W^es"\
VZ#@7t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,)S(SnCF
{ +"u6+[E
this.sURL = sURL; CJ@G8>
this.nStartPos = nStart; l7+[Zn/v *
this.nEndPos = nEnd; zA~aiX
nThreadID = id; H pZD^h?L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SuO@LroxTB
} 4RLuv?,)~
6X2~30pdE
'b?Px}
public void run() ODggGB`H`
{ ^an3&
while(nStartPos < nEndPos && !bStop) $KmhG1*s
{ jjT|@\-u
QB/H
TQor-Cymz
try{ g RX`61
URL url = new URL(sURL); bv%A;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #QWG5
httpConnection.setRequestProperty("User-Agent","NetFox"); LD.^.4{c:
String sProperty = "bytes="+nStartPos+"-"; p$qpC$F
httpConnection.setRequestProperty("RANGE",sProperty); UBgheu
Utility.log(sProperty); q|;Sn
-Um|:[*I
Hn-k*Y/P
InputStream input = httpConnection.getInputStream(); +d$l1j
//logResponseHead(httpConnection); 9XH}/FcP_O
3I" <\M4x
`4@_Y<
byte[] b = new byte[1024]; uT#MVv~.
int nRead; `egyk)"aM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g9rsw7
{ x]6wiV
nStartPos += fileAccessI.write(b,0,nRead); ug|'}\LY
//if(nThreadID == 1) 3;N+5*-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /+11`B09
} UP8=V>T02
0Rme}&$
8,5H^Bi
Utility.log("Thread " + nThreadID + " is over!"); ]+OHxCj:
bDownOver = true; snl$v
//nPos = fileAccessI.write (b,0,nRead); K F:W:8
} ^2|G0d@.:
catch(Exception e){e.printStackTrace ();} *Dz<Pi^
} |?kZfr&9q
} tH}$j
[i ]
Buv4&.Z}
//打印回应的头信息 GWQ_X9+q
public void logResponseHead(HttpURLConnection con) #VLO6
{ @S-p[u
for(int i=1;;i++) -kv'C6gB
{ SviGLv;oR
String header=con.getHeaderFieldKey(i); hPM:=@N$
if(header!=null) =LUDg7P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -9L[eYn
Utility.log(header+" : "+con.getHeaderField(header)); jgkJF[t`
else y5v}EX`m&
break; MV~-']2u
} PGj?`y4
} iJr 1w&GL$
!Q0aKkMfL
Gp PlO]
public void splitterStop() `4&a"`&$
{ 5W(S~}
bStop = true; 6pKb!JJ
} E>|xv#:~DV
1\~-No
nj@l5[
} \N?,6;%xB
HoFFce7o
=Y0>b4
/* tR;? o,T
**FileAccess.java ? 7H'#l
*//文件访问(定位，写) y*AB=d^
package NetFox; #hNp1y2
import java.io.*; Rzolue 8
Ga%x(1U[&
X53TFRxnT
public class FileAccessI implements Serializable{ EJbFo682
[T5z}!_y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RgPY,\_9+
RandomAccessFile oSavedFile; q,W6wM;,E
long nPos; e/h2E dY
?]d[K>bv
XHN`f#(w
public FileAccessI() throws IOException KyqFeR
{ H,?)6pZ
this("",0); 0UHX Li47Y
} 77:s=)
d+6 by,'
U;QN+fF]u
public FileAccessI(String sName,long nPos) throws IOException x+L G4++
{ |&>!"27;w
oSavedFile = new RandomAccessFile(sName,"rw"); e-taBrl;
this.nPos = nPos; jMT];%$[
oSavedFile.seek(nPos); l9 K 3E<g
} 0Q]p#;
\[-z4Fxg|'
E2PMcT{)_
public synchronized int write(byte[] b,int nStart,int nLen) V&' :S{i
{ zeXMi:X
int n = -1; Hko(@z
try{ 7=o2$
oSavedFile.write(b,nStart,nLen); C&\vVNV;9
n = nLen; ""dX4^gtU
} K-xmLEu
catch(IOException e) +hz^( I7
{ &I[ITp6y0
e.printStackTrace (); I& `>6=)
} Rv ]?qJL
/$IF!q+C
}> 51oBgk_
return n; (N etn&
} K{ s=k/h
t*fG;YOg
`VT0wAe2;
} . k6)
)P{I<TBI;
UL/|!(s
/* xr2ew%&o
**SiteInfoBean.java u#+p6%?k
*/ [":[\D'
package NetFox; 3wS{@'
F4m Q#YlrS
fs]9HK/@\
public class SiteInfoBean { JJvf!]
!U,^+"l'GP
8e'0AI_>
private String sSiteURL; //Site's URL ;x[F4d
private String sFilePath; //Saved File's Path 0d-w<lg9
private String sFileName; //Saved File's Name ~IHjj1s
private int nSplitter; //Count of Splited Downloading File s[yIvlHw`
62BJ;/ ]
+ *YGsM`E9
public SiteInfoBean() @G vDl=.
{//nSplitter的缺省值为5 9`8\<a'rU
//default value of nSplitter is 5 ${$XJs4
this("","","",5); W#<&(s4
} w"CcWng1
6~b~[gA
9<An^lLK*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Nk-biD/J
{ /H)K_H#|;
sSiteURL= sURL; w8t,?dY
sFilePath = sPath; Z=O2tR
sFileName = sName; ~P*t_cpZ
this.nSplitter = nSpiltter; n2bL-
guC/eSxv
:E|HP#iwu
} PmtBu`OkV
vqLC?{i+
{IeW~S'&
public String getSSiteURL() )x.}B4z
{ r)|X?
return sSiteURL; p{j }%)6n
} JM{S49Lx
'3>kDH+
q+{-p?;;
public void setSSiteURL(String value) , #yE#8
{ Na^1dn
sSiteURL = value; Sf}>~z2
} <zN
=*.Nt*;;
%/dYSC
public String getSFilePath() }>JFO:v&
{ D4yJ:ATO&
return sFilePath; 9i)E<.6
} 0(s0<9s%
%zHNX4
4#uWj?u
public void setSFilePath(String value) 40pGu
{ Y[gj2vNe4g
sFilePath = value; 09"C&X~
} R@``MC0
/)SwQgK#
B&0^3iKFi
public String getSFileName() :X[(ymWNE
{ ze Qgg|;
return sFileName; &0Zn21q
} ~V?O%1)k?\
Q3#-q>;7
W|@EKE.k
public void setSFileName(String value) 4-[L^1%S[
{ KO(+%>^R
sFileName = value; -@%*~^~z'
} <ns[( Q
4KE"r F
euM7> $`
public int getNSplitter() o)KF+[^
{ (yE?)s
return nSplitter; 22|eiW/a
} |,bsMJh0
]#N2:ych
zpr`
public void setNSplitter(int nCount) i TY4X:x
{ 38!$9)
nSplitter = nCount; {*H&NI
} `pF|bZ?v
} IC+Z C
w!)B\l^+c
9iWDEk
/* EA%(+tJ^0
**Utility.java .]%PnJM9K
*/ (7x5
package NetFox; L,.Ae i9
7]YLe+Ds
m8H|cQ@Uu
public class Utility { p~I+ZYWF'
!8vHN=)z
+ex@[grsGT
public Utility() 9g+/^j^>?f
{ A!s\;C
i$)bZr\
$<2r;'?0D
} A] pLq`
ZAzn-n
//线程睡眠 CJk$o K{Q
public static void sleep(int nSecond) `@ULG>
{ +vaz gO<u
try{ $x 6Rmd{
Thread.sleep(nSecond); EtJyI&7VK
} aOfL;I
catch(Exception e) oC>e'_6_b
{ Z5;1ySn{
e.printStackTrace (); p>=YPi/d
} p*F&G=ZE
} R9D<lX0%
4&)*PKq
//日志 !>-cMI6E
public static void log(String sMsg) (=0W[@k
{ R6]/g
System.err.println(sMsg); `h_,I R<
} ;!&A
<Bb$d@c
G!k&'{2
public static void log(int sMsg) :y%%Vx~
{ @Z~lM5n$8
System.err.println(sMsg); D4<nS<8
} 64>E|w
} ln)_Jf1r
Z; Xg5
] o tjoM
/* ]p:x,%nm
**TestMethod.java br+{23&1R#
*/ EcrM`E#kaZ
package NetFox; ,x!P|\w.G{
mf6?8!O}>
-}1S6dzr
public class TestMethod { -fuSCj
~T>_}Q[M2p
T[B@7$Dp*
public TestMethod() /4+M0Pl
{ ///xx/weblogic60b2_win.exe !YSAQi;I
try{ ~F^=7oq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [t5:4 Iq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $-YS\R\9x
SiteFileFetch fileFetch = new SiteFileFetch(bean); GrjL9+|x
fileFetch.start(); L.>tJ.ID
} pa Uh+"y>
catch(Exception e){e.printStackTrace ();} 9d^o2Yo
kM|akG
y562g`"U
} Fh9`8
6tB-
dQ@e+u5
public static void main(String[] args) &e@2zfl7
{ {co(w 7
new TestMethod(); g #u1.|s&p
} (o)nN8
} @4Z>;
点击下载更多相关资料