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)); r!_-"~`7E
} Ug>~Rq]
for(int i=0;i<nEndPos.length-1;i++) `ZYoA t]C~
{ u8&Z!p\
nEndPos = nStartPos[i+1]; saBVgSd
} +hg3I8q:
nEndPos[nEndPos.length-1] = nFileLength; . qO@Q=
} 2_HNhW
} qkDI](4
^c"jH'#.L
#Z?A2r!1
//启动子线程 O_oPh]x)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `u3EU*~W
for(int i=0;i<nStartPos.length;i++) BC&S>#\
{ N{9v1`B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *2pt%eav
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Gp?a(-K5
nStartPos,nEndPos,i); [B\h$IcRv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o=1Uh,S3R
fileSplitterFetch.start(); B+P(M!m3
} 4gI/!,J(b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jS]ru-5.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p& y<I6a,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AYqX|
nEndPos = " + nFileLength); ey7 f9
// fileSplitterFetch[nPos.length-1].start(); +h|`/ &,
_{I3i:f9X8
+"\sc;6m.
//等待子线程结束 P+@/O
//int count = 0; 0L2F[TN
//是否结束while循环 DR5\45v
boolean breakWhile = false; sBj(Qd
_hAcJ{Y
8]M;T>n[
while(!bStop) 'f!8DGix
{ Pr':51(
write_nPos(); Q{sH3Y#l
Utility.sleep(500); #xsE3Wj-X
breakWhile = true; wN_Vfb
MU@UfB|;u
44ek IV+?
for(int i=0;i<nStartPos.length;i++) EH+"~-v)ae
{ gX@HO|.t
if(!fileSplitterFetch.bDownOver) >?2M }TV3
{ h5*JkRm
breakWhile = false; 1gL2ia
break; b|l:fT?&
} j/323Za+
} `uv2H$
if(breakWhile) W#9BNKL
break; tU}h~&M
@K &GJ
%a>&5V
//count++; Si2k"<5U
//if(count>4) @>r._~
// siteStop(); 7OcWC-<
} q<xCb%#Jl
[%"|G9
}"nItcp.1
System.err.println("文件下载结束！"); YqhAZp<
} 'nzg6^I7g
catch(Exception e){e.printStackTrace ();} >N^Jj:~l
} $Xv*,Bq
nsu@h
k3lS8d7
//获得文件长度 bn|I>e
public long getFileSize() F&4rO\aC"/
{ L*Tj^q!t+
int nFileLength = -1; 27eooY1
try{ Ci@o|Y }tP
URL url = new URL(siteInfoBean.getSSiteURL()); MK%9:wZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "@e3EX7h
httpConnection.setRequestProperty("User-Agent","NetFox"); =_.l8IYX$%
dN$0OS`s[
f(>p=%=O
int responseCode=httpConnection.getResponseCode(); J{.{f
if(responseCode>=400) 0.`/X66;V
{ so,t
processErrorCode(responseCode); NO*u9YH?
return -2; //-2 represent access is error @6Y?\Wx$w
} v [wb~uw\
:}He\V
7x"R3
String sHeader; +SP{hHa^
0M_ DB=
3@etRd;]Kr
for(int i=1;;i++) ep!Rf:
{ H[6:_**?o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]~Rho_mq#
//Utility.log(in.readLine()); JrJo|0Q
sHeader=httpConnection.getHeaderFieldKey(i); kKaE=H-x
if(sHeader!=null) Vh'P&W?[
{ F%@A6'c
if(sHeader.equals("Content-Length")) E-T)*`e
{ EuZ<quwWg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iw3FA4{(
break; >nJ\BPx
} F~,Mw8
} &Qf/>@ l}
else A=$04<nP8!
break; W>${zVu
} %^?fMeI|Y
} Y@;CF
catch(IOException e){e.printStackTrace ();} &C`Gg<
catch(Exception e){e.printStackTrace ();} E(*0jAvO[z
J?*1*h
DwM)r7<Ex
Utility.log(nFileLength); U\g/2dM
F6|TP.VY_.
4GkWRu1
return nFileLength; C'>|J9~Gz
} ()Y~Q(5ji
z 9vInf@M
3U<cWl@
//保存下载信息（文件指针位置） e),q0%5
private void write_nPos() ahJ`T*)HY
{ J9\Cm!H
try{ 2]z8:a
output = new DataOutputStream(new FileOutputStream(tmpFile)); X2#2C/6#u
output.writeInt(nStartPos.length); ,1y@Z 5wy
for(int i=0;i<nStartPos.length;i++) {kA0z2Fe
{ Yk'XGr)
// output.writeLong(nPos); y`L>wq,KU
output.writeLong(fileSplitterFetch.nStartPos); 8EZ$g<}
output.writeLong(fileSplitterFetch.nEndPos); |tKsgj
} Xe3U`P7(
output.close(); R4[N:~Z$|
} oI?3<M^
catch(IOException e){e.printStackTrace ();} S(k3 `;K
catch(Exception e){e.printStackTrace ();} ^%d\qd`
} OC_+("N
zykT*V
hwPw]Ln/
//读取保存的下载信息（文件指针位置） %41m~Wh2
private void read_nPos() Mer/G2#&
{ $[Sc0dzJ
try{ +cJL7=V&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8+~ >E
int nCount = input.readInt(); wy<\Tg^J
nStartPos = new long[nCount]; b(,M1.[qt
nEndPos = new long[nCount]; zN[hkmh
for(int i=0;i<nStartPos.length;i++) LGq'WU31:)
{ DF&(8NoX~
nStartPos = input.readLong(); oK9( /v
nEndPos = input.readLong(); > $O]Eu!
} Z-$[\le
input.close(); TYy?KG>:'
} eVEV}`X
catch(IOException e){e.printStackTrace ();} 4n#M
catch(Exception e){e.printStackTrace ();} 3$9s\<j
} O\ GEay2
l3{-z4mw
?U%qPv:
private void processErrorCode(int nErrorCode) >1.X*gi?-
{ dph{74Dc
System.err.println("Error Code : " + nErrorCode); '3R`lv
} $By<$
8^kGS-+^
/}((l%UE.
//停止文件下载 u0}vWkn\4
public void siteStop() L 8c0lx}Nn
{ sG(~^hJ_
bStop = true; 9Uh"iMB
for(int i=0;i<nStartPos.length;i++) g1;:KzVv
fileSplitterFetch.splitterStop(); zv|2:4H
l^! ?@Kg,z
5us:adm[pD
} Z|&MKG24
} `vU%*g&R
//负责部分文件的抓取 V)3KS-
**FileSplitterFetch.java ^\hG"5#
*/ \q>bs|2
package NetFox; DRSr%d
RaO-H
MOQ6:
import java.io.*; |-b#9JQ[A
import java.net.*; 4`lLf
[xbSYu,&
{yBs7[Wn
public class FileSplitterFetch extends Thread { $r^GE
On8v//=&
"x#-sZ=
String sURL; //File URL +UCG0D
long nStartPos; //File Snippet Start Position '<gI8W</
long nEndPos; //File Snippet End Position HNb/-e ,"
int nThreadID; //Thread's ID ~Sdb_EZ
boolean bDownOver = false; //Downing is over ^NLmgwQ
boolean bStop = false; //Stop identical 9d>-MX'
FileAccessI fileAccessI = null; //File Access interface n|6Ic,:[
aR[JD2G
/RG:W0=K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2\)xpOj
{ mWv3!i;G<s
this.sURL = sURL; hM_lsc
this.nStartPos = nStart; 99]R$eT8
this.nEndPos = nEnd; 'HO$C,1]
nThreadID = id; kF3k7,.8&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d.[8c=$
} #?RU;1)Cw
b\ X@gq
~]nRV *^
public void run() @tF\p
{ \|n- O=}=2
while(nStartPos < nEndPos && !bStop) gGR"Z]DBk
{ EHSlK5bD,
OP;v bZ
#F:p-nOq
try{ 2kqup)82e
URL url = new URL(sURL); af6M,{F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |e=,oV"
httpConnection.setRequestProperty("User-Agent","NetFox"); ay4 %
String sProperty = "bytes="+nStartPos+"-"; ]v?@g:iE
httpConnection.setRequestProperty("RANGE",sProperty); #./fY;:cj
Utility.log(sProperty); -Sqz5lo
$&Gu)4'+
?(xnSW@r
InputStream input = httpConnection.getInputStream(); J;S (>c
//logResponseHead(httpConnection); &PL8|w
!:)s"|=
bes<qy
byte[] b = new byte[1024]; 4M^=nae
int nRead; <3L5"77G6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bs+f,j-oBN
{ I.I`6(Cb
nStartPos += fileAccessI.write(b,0,nRead); SbcS]H5Sk
//if(nThreadID == 1) .[YuRLGz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]GUvV&6@(
} D,FHZDt
87=&^.~`
1}"++Z73P
Utility.log("Thread " + nThreadID + " is over!"); a a<8,;
bDownOver = true; 0`Kj25
//nPos = fileAccessI.write (b,0,nRead); )z>|4@,
} Qo>b*Ku;
catch(Exception e){e.printStackTrace ();} @<,X0S
} x-XD.qh7Hr
} Z~GL5]S
-7SAK1c$
1eA7>$w}[
//打印回应的头信息 QemyCCP+
public void logResponseHead(HttpURLConnection con) j*d yp
{ :{{F *FM;
for(int i=1;;i++) 97Lte5c6r
{ rr/B=O7
String header=con.getHeaderFieldKey(i); XWnVgY s
if(header!=null) 5CuuG<0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X3(tuqmi
Utility.log(header+" : "+con.getHeaderField(header)); |U~<3.:m:
else lVd^ ^T*fh
break; 84$nT>c
} [m+2(I1
} iyN:%ofh
'Jiw@t<o3`
9y6-/H ,
public void splitterStop() AJt+p&I[J
{ `K*Q5n
bStop = true; Qd)q([
} uOKCAqYa
zy?.u.4L
JELTou
} \$R_YKGf1G
{]*c29b>
hZdoc<
/* `CBZhI%%
**FileAccess.java :v0U|\j8/V
*//文件访问(定位，写) 16w|O|^<
package NetFox; ,k.3|aZE
import java.io.*; B{/R: Hm
FO+Zue.RS
`-.%^eIp
public class FileAccessI implements Serializable{ svsqg{9z
-#7'r<I9@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Io7]
RandomAccessFile oSavedFile; @#<D ^"
long nPos; ^pxX]G]
7X`l&7IXP
]99|KQ<s
public FileAccessI() throws IOException )}g(b=
{ XYjV.j\
this("",0); H >j
} +j#+8Ze
c7<wZ
u$h 4lIl
public FileAccessI(String sName,long nPos) throws IOException QaS1Dh
{ x%s-+&
oSavedFile = new RandomAccessFile(sName,"rw"); \?w2a$?6w
this.nPos = nPos; !6n_}I-W
oSavedFile.seek(nPos); l#m#c6;=
} hmvfw:Nq4
kC WEtbz1
oNr-Q& C,
public synchronized int write(byte[] b,int nStart,int nLen) H[{F'c[e
{ E8!e:l =Q
int n = -1; d.3E[AJa(
try{ eS{!)j_^
oSavedFile.write(b,nStart,nLen); B%" d~5Y
n = nLen; $}RJ,%~'x
} bG7O
catch(IOException e) cq5jPZ}
{ 1G"z<v B
e.printStackTrace (); ;}7Rjl#
} E08klC0
"K ~
k;2GEa]w
return n; wZG\>9~
} l-fi%Z7C
5k!g%sZ
lun#^J
} 1uG"f<TsR
"&%I)e^
0+iu(VbF
/* Y}x>t* I
**SiteInfoBean.java ht7l- AK
*/ 00'%EYO
package NetFox; :X0k]p
%WSo b@f8
s&A} h
public class SiteInfoBean { mi ik%7>W
B,<da1(a
nePfuG]Q
private String sSiteURL; //Site's URL 5*E]ETo@R
private String sFilePath; //Saved File's Path uvMy^_}L
private String sFileName; //Saved File's Name 0QFS
private int nSplitter; //Count of Splited Downloading File zxMXXm;
^2+yHw
p%#<D9S
public SiteInfoBean() FFV `P
{//nSplitter的缺省值为5 {`J)j6;
//default value of nSplitter is 5 Hv!U|L
this("","","",5); `lQ3C{}
} $Oq^jUJ
]*vdSr-J
j`oy`78O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tU4s'J
{ 3XL#0\im?s
sSiteURL= sURL; \Npxv
sFilePath = sPath; mIurA?&7!
sFileName = sName; ^]7}YF2|
this.nSplitter = nSpiltter; H+1-]'g`
,X#2\r<|
9G9fDG#F\I
} "k/;[ Wt]
w0ht
S)lkz'tdk
public String getSSiteURL() #EO9UW5
{ t=|evOz]
return sSiteURL; (gy#js#
} &{ay=Mj
5XO;N s
Q7*SE%H
public void setSSiteURL(String value) JF # # [O
{ mZk]l5Lc
sSiteURL = value; ,ek_R)&[o
} D6%J\C13`
c0PIc^R(@
|*:'TKzNS
public String getSFilePath() mX_a^_[G
{ ^.KwcXr
return sFilePath; ?>hPO73{
} ~kShq%
"*m_> IU
uZM{BgXXD
public void setSFilePath(String value) L_vISy%\b
{ U[SaY0Z
sFilePath = value; OTy.VT|
} IzsphBI
}x@2]juJ
u6T+Cg
public String getSFileName() 18~>ZR
{ (}a8"]Z
return sFileName; 9bP^`\K[N
} q-.,nMUF
SNfr"2c'h~
Px$/ _`H
public void setSFileName(String value) H(bs$C4F
{ F5?m6`g?
sFileName = value; 'd.EC#
} 5V6G=H
pNOwDJtK
qC}-_u7s
public int getNSplitter() DBPRGQ
{ y<HO:kZ8`
return nSplitter; >_e]C}QUr
} K&nE_.kbl
v 0 }@
n1JRDw"e$$
public void setNSplitter(int nCount) hn^<;av=
{ sp#p8@Cj
nSplitter = nCount; {6"Ph(I1
} "{tg8-a4)
} H$@`,{M629
k40* e\
bvS(@
/* afv~r>q(-
**Utility.java OZx W?wnd
*/ )>.&N[v
package NetFox; sArhZ[H
Y<mej][
E}Y!O"CAV
public class Utility { )f}YW/'
R<[qGt|L
:A1{d?B
public Utility() Y,WuBH
{ #cnq(S=.
L[^9E'L$
)=5ng-
} 3{ LP?w:@
1y-y6q
//线程睡眠 ;ado0-VQi'
public static void sleep(int nSecond) T^w36}a
{ LJ*q1 ;<E
try{ 86(I^=
Thread.sleep(nSecond); 5|l* `J)
} e?opkq\f
catch(Exception e) IIg^FZ*]_
{ 8S%52W|
e.printStackTrace (); MZlk0o2
} 9/hrjItV
} OlAs'TE^
Q?3Gk%T0[
//日志 *"D3E7AO
public static void log(String sMsg) 5"HVBfFk
{ ?*E'^~,H)
System.err.println(sMsg); t"k*PA
} ?mWw@6G,
q8^^H$<Db
%F!1
public static void log(int sMsg) jgbLN/_{
{ G>wqt@%r9
System.err.println(sMsg); twP,cyR
} Fb^:V4<T
} RnhL< Ywu
}RmU%IYc
kD*2~Z?;
/* Ys@}3\Mc
**TestMethod.java an|x$e7|?
*/ p8Q,@ql.
package NetFox; %;e/7`>Ma
)^4\,u\@
T(e!_VY|m
public class TestMethod { 3T"j)R_=l
2C/$Ei^t
/h*>P:i].
public TestMethod() P^w#S
{ ///xx/weblogic60b2_win.exe v1%uxthW
try{ kB'Fkqwm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1jN-4&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hg+X(0
SiteFileFetch fileFetch = new SiteFileFetch(bean); :@%4
fileFetch.start(); QS{1CC9$
} 3jlh}t>$l
catch(Exception e){e.printStackTrace ();} Svc|0Ad&
kMtwiB|7j
GFel(cx:K
} }RHn)}+
JcbwDlUb
-TM0]{
public static void main(String[] args) Eo#u#IY
{ Q(<)KZIK
new TestMethod(); VJdIHsI
} ZCB_
} r:F
点击下载更多相关资料