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)); <d2?A}<
} (~C_zG
for(int i=0;i<nEndPos.length-1;i++) W6N3u7mrb
{ '.Ww*N
nEndPos = nStartPos[i+1]; +w'"N
} x#wkODLqi
nEndPos[nEndPos.length-1] = nFileLength; 5U%J,W
} E cS+/
} ;3\oU$'
E;$;g#ksf
+sN'Y/-
//启动子线程 aT9+] Ig
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YIP /N
for(int i=0;i<nStartPos.length;i++) ^]x%z*6
{ ,`4chD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i}fAjS:W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t r)[6o#
nStartPos,nEndPos,i); ,tt .oF|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5m.{ayE
fileSplitterFetch.start(); _G$SA-W(
} pN\YAc*@:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hLs<g!*O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y|'0bujr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9\yGv
nEndPos = " + nFileLength); "c0I2wq
// fileSplitterFetch[nPos.length-1].start(); X@ zw;Se
yH\3*#+
B=EI&+F+
//等待子线程结束 |rjHH<
//int count = 0; rV yw1D
//是否结束while循环 _J|TCm
boolean breakWhile = false; [#+yL
QNH-b9u>8
nRP|Qt7>
while(!bStop) l|, Hj
{ o'oA.'ul
write_nPos(); (8Q0?SZN
Utility.sleep(500); % oPt],>
breakWhile = true; {P'_s]B)
d|P,e;m-
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for(int i=0;i<nStartPos.length;i++) K-_XdJ\
{ 74[wZDW|(
if(!fileSplitterFetch.bDownOver) \a_75^2
{ +ESEAi91
breakWhile = false; *3uBS2Ld
break; >i6sJ)2?>
} 4AIo,{(
} \wJ2>Q
if(breakWhile) :\!D 6\o6
break; fwkklg^
=:w]EpH"
`Z#0kpXk_
//count++; #9(0.!v
//if(count>4) mJ_5Vt=
// siteStop(); tzTnFV
} 2HNAB4E
~wtK(U
cEdf&*_-'I
System.err.println("文件下载结束！"); Fjs:rZ#{
} KF4D)NM|
catch(Exception e){e.printStackTrace ();} Z<yLu'48)A
} vz$_Fgsc.
xj ?#]GR
p#\JKx
//获得文件长度 0[# zn
public long getFileSize() _#dBcEH[
{ J]!&E~Y
int nFileLength = -1; VW$a(G_h
try{ ?Iin/<y
URL url = new URL(siteInfoBean.getSSiteURL()); 9wTN*y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jkQ%b.a
httpConnection.setRequestProperty("User-Agent","NetFox"); {h}0"5
z[cs/x
c\Z.V*o
int responseCode=httpConnection.getResponseCode(); ^vj}
if(responseCode>=400) s~z~9#G(6
{ hfJeVT-/v
processErrorCode(responseCode); W0I)< S
return -2; //-2 represent access is error h7P<3m}
} f-!P[6bY
'^{:HR#i
+55+%oGl
String sHeader; f@j)t%mh
_.{I1*6Y2
qk{+Y
for(int i=1;;i++) @W1F4HYds
{ m8T< x>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n9%&HDl4
//Utility.log(in.readLine()); 9n#lDL O
sHeader=httpConnection.getHeaderFieldKey(i); *QGyF`Go{
if(sHeader!=null) HM]mOmL90N
{ V JJ6q
if(sHeader.equals("Content-Length")) {f(RYj
{ m]?C @ina
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .eHOG]H
break; V0/PjD,jP
} T2dv!}7p
} QVR8b3T@
else L25v7U
break; {@&%Bq*&
} 4lF(..Ix
} rqi/nW
catch(IOException e){e.printStackTrace ();} BN~gk~t_
catch(Exception e){e.printStackTrace ();} S8dX8,qg
d7]~t|
}0oVIr
Utility.log(nFileLength); tW -f_0a.
iD${7 _
X{u\|e{
return nFileLength; Pm/Rc
} g}OZ!mKd
PC<[$~
s L=}d[
//保存下载信息（文件指针位置） 6Bf aB:
private void write_nPos() 1PUeU+
{ i",7<01
try{ 1=Z, #r
output = new DataOutputStream(new FileOutputStream(tmpFile)); rizWaw5E!8
output.writeInt(nStartPos.length); .Cz9?]jyI
for(int i=0;i<nStartPos.length;i++) _+6aD|7x
{ J3z:U&%=
// output.writeLong(nPos); Fl}{"eCF8
output.writeLong(fileSplitterFetch.nStartPos); <}Hs@`jS
output.writeLong(fileSplitterFetch.nEndPos); n)uck5
} i}gsxq%
output.close(); KK';ho,W
} #8/pYQ;
catch(IOException e){e.printStackTrace ();} V^%P}RFMc
catch(Exception e){e.printStackTrace ();} 7t3ps
} DLH|y%"
*hIjVKTu79
V%Ww;Ca]I
//读取保存的下载信息（文件指针位置） :[J'B4>9
private void read_nPos() ku5vaP(
{ sKwUY{u\M
try{ .z, ot|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {fI"p;|
int nCount = input.readInt(); H(gETRh
nStartPos = new long[nCount]; 045_0+r"@
nEndPos = new long[nCount]; `LOW)|6r`
for(int i=0;i<nStartPos.length;i++) LEC=@) B
{ I&9Itn p$
nStartPos = input.readLong(); _J X>#h
nEndPos = input.readLong(); `{1~]?-&
} @q"HZO[
input.close(); 8'*/|)Hn
} 8P*d
catch(IOException e){e.printStackTrace ();} gVI{eoJ
catch(Exception e){e.printStackTrace ();} n09P!],Xa
} *TgD{>s
[ 0z-X7=e
)?;+<,
private void processErrorCode(int nErrorCode) [?55vYt
{ )m$MC25
System.err.println("Error Code : " + nErrorCode); ;-^8lWt
} ~7>D>!!
O_ d[{e=5`
g`(3r
//停止文件下载 c<ORmg6
public void siteStop() FWW*f _L
{ d]K$0HY
bStop = true; )lH`a
for(int i=0;i<nStartPos.length;i++) ?UV|m
fileSplitterFetch.splitterStop(); $'n?V=4
]P>c{
0{(5J,/BF
} qH(HcsgD
} dC>(UDC
//负责部分文件的抓取 @xeJ$ rlu
**FileSplitterFetch.java tz9"#=}0
*/ J^-a@'`+
package NetFox; 4hx4/5[^
DJb9] ,=a
# TZ`
import java.io.*; o]DYS,v
import java.net.*; L:\>)6]Ls
CrB4%W:{
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public class FileSplitterFetch extends Thread { NwN3T]W
.q<5OE(f
SQJ+C%
String sURL; //File URL Mq='|0,
long nStartPos; //File Snippet Start Position i`w)dS
long nEndPos; //File Snippet End Position Xc$Zkfmms
int nThreadID; //Thread's ID w!jY(WKU
boolean bDownOver = false; //Downing is over PlR$s
boolean bStop = false; //Stop identical EE-wi@
FileAccessI fileAccessI = null; //File Access interface phR:=Ox|1
,uPN\`.u8
>P ~j@Lv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q[(1zG%NbA
{ 05Q4$P
this.sURL = sURL; |W*5<2Q9
this.nStartPos = nStart; I)MRAo
this.nEndPos = nEnd; {f\{{JJ]
nThreadID = id; ~KczP1p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3e9UDN2
} ]app9
#nq_R
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public void run() $Lz!04
{ =fJ /6
while(nStartPos < nEndPos && !bStop) &$ fyY:<\
{ pV O{7I
Y+h ?HS
&F8*>F^7
try{ v]#[bqB.b
URL url = new URL(sURL); 2({|LQqk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n~ZZX={a
httpConnection.setRequestProperty("User-Agent","NetFox"); ]xGpN ]u
String sProperty = "bytes="+nStartPos+"-"; niyI$OC
httpConnection.setRequestProperty("RANGE",sProperty); /!%?I#K{Wq
Utility.log(sProperty); tn;{r
X\kWJQ:
2BiFP||
InputStream input = httpConnection.getInputStream(); ZiPz~G0[^
//logResponseHead(httpConnection); \Vpv78QF;
dL~^C I
r>gf&/Pl
byte[] b = new byte[1024]; \Hw*q|
int nRead; juI)Do2_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0mNL!"
{ $/ g<h
nStartPos += fileAccessI.write(b,0,nRead); `FwE^_9d
//if(nThreadID == 1) AH?[K,3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KquuM ]5S
} 3WpQzuHPT
5uV_Pkb?8
:!^NjO
Utility.log("Thread " + nThreadID + " is over!"); Wt.['`c<
bDownOver = true; 97/4J
//nPos = fileAccessI.write (b,0,nRead); EQQ@nW{;
} ..5.":
catch(Exception e){e.printStackTrace ();} RXw1HRR$V
} b~2LD3"3
} 6z]y =J
_sn<"B%>
jO9!:L>b`
//打印回应的头信息 bokr,I3
public void logResponseHead(HttpURLConnection con) _9dW+
{ NKc<nYdK?
for(int i=1;;i++) (*kKfg4Wj
{ nd$92H
String header=con.getHeaderFieldKey(i); Ta$55K0
if(header!=null) tN.$4+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m6'9Id-:L
Utility.log(header+" : "+con.getHeaderField(header)); _2{2Xb
else \Rs9B .
break; SYh>FF"
} @urZ
} /N#=Tol
hAt4+O&P
;GKL[tI"
public void splitterStop() `q`ah_
{ zG{jRth
bStop = true; i'.D=o
} vz)R84
{Us^4Xe
YkE_7r(1
} 7rYBFSp
=oM#]M'G+(
'h^Ya?g
/* L)4~:f)B
**FileAccess.java @t0T+T3
*//文件访问(定位，写) l-Ha*>gX[j
package NetFox; UFLx'VXd
import java.io.*; `PUxR8y
s}-j.jzB{
,N;2"$+E
public class FileAccessI implements Serializable{ dkY JO!
j5og}Pq:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JH u>\{8V
RandomAccessFile oSavedFile; _s<s14+od
long nPos; HAo=t
'nq~1 >i
=qbN?a/?2
public FileAccessI() throws IOException `%^w-'
{ ^>>9?
this("",0); ,F*HZBNFZ
} A,xPA
5%4yUd#b
ng~LCffpY
public FileAccessI(String sName,long nPos) throws IOException Z"qJil}
{ ^Bo'87!.
oSavedFile = new RandomAccessFile(sName,"rw"); +FAxqCkA
this.nPos = nPos; C<(qk_
oSavedFile.seek(nPos); zbr^ulr
} <6s@eare8
@2mWNYHR*>
rA^=;?7Q
public synchronized int write(byte[] b,int nStart,int nLen) f$9|qfW'$
{ +>%51#2.Q
int n = -1; 8'_MCx(
try{ +v'2s@e` #
oSavedFile.write(b,nStart,nLen); =v'Aub
n = nLen; h_\( $"
} Bo14t*(
catch(IOException e) q`.=/O'
{ Lb?q5_
e.printStackTrace (); $06('Hg&
} 'U*#71S
dh.{lvlX|
jl]3B
return n; /I1n${{5
} 'rS\9T
zb4{nzX=
mXS"nd30bD
} R'6(eA[K
Ihr[44#
|z"$^|@d?
/* .{ZJywE<
**SiteInfoBean.java J7C?Z
*/ HG< z,gE 2
package NetFox; -T i<H9OV
C9!FnvH
`p1B58deC
public class SiteInfoBean { l'M/et{:
Q+wO\TtE
Q'!'+;&%
private String sSiteURL; //Site's URL sDR Av%w
private String sFilePath; //Saved File's Path YJ-<t6
private String sFileName; //Saved File's Name + !"YC
private int nSplitter; //Count of Splited Downloading File .C5<uW5-R
n~BQq-1
SIKaDIZ
public SiteInfoBean() w{lj'3z I
{//nSplitter的缺省值为5 :-lq Yd5^
//default value of nSplitter is 5 DU)q]'[u
this("","","",5); tQYV4h\Qj
} eK5~gnv,
2{Dnfl'k
zUDXkG*Lv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qds:*]vGS
{ C[hNngb7R
sSiteURL= sURL; Ayv:Pv@
sFilePath = sPath; V6_5v+n
sFileName = sName; );yZyWDV
this.nSplitter = nSpiltter; ,3iD/8_
0v9i43[S|J
n/ :#:
} =hd0Ui>x
tZm`(2S
+5I'? _{V
public String getSSiteURL() 6v]`s
{ 4}t&yu<P>
return sSiteURL; 1Y;.fZE
} isy[RAP<
=R 4]Kf
Y:#B0FD,gC
public void setSSiteURL(String value) [u=yl0f
{ gdoaXw;Sy
sSiteURL = value; 3Nwix_&S
} yB/F6/B~
;($xAAR
9z{g3m70@
public String getSFilePath() tS5J{j>T
{ #G?#ot2o
return sFilePath; f*88k='\W
} y29G#Y4J
@8w5Oudvx
vJct)i
public void setSFilePath(String value) v@ qDR|?^
{ 1zG6^U
sFilePath = value; ?(Tin80=r
} W1Fhx`
y`5 ?
JUj.:n2e
public String getSFileName() (CH6Q]Wi_!
{ yiXb<g+B
return sFileName; aIQC[ry
} ^c9_F9N
6[RTL2&W
1JdMw$H
public void setSFileName(String value) ~Ym*QSD
{ ]bmf}&
sFileName = value; f%1\1_^g
} 7fzH(H
M #0v# {o
PX0N7L
public int getNSplitter() 1:- M<=J?f
{ J7oj@Or9
return nSplitter; hR:i!
} )?B-en\
" W{rS4L
4 #KC\C
public void setNSplitter(int nCount) wS?Kc^2O
{ F Pjc;zNA
nSplitter = nCount; (fr=[m$`
} -^t.eZ*|
} d2US~.;>l
7QZyd-
xXI WEZA
/* 5 8L@:>"
**Utility.java ]TUoXU2<x
*/ /X0<2&v
package NetFox; lx0BKD?n
<^Y#q
tn _\E/Q
public class Utility { `s\[X-j]
kB5y}v.3 S
7h!nt=8Y
public Utility() EbVC4uY
{ nGK=Nf.5
$7xfLS8Vo
uh#E^~5S
} a #s Nd
<;>k[P'
//线程睡眠 $Jn.rX0}$
public static void sleep(int nSecond) xiQc\k$
{ "?<`]WG\
try{ /#"9!8%V
Thread.sleep(nSecond); yLnTIE3)
} bO6cv{>x
catch(Exception e) qJK9C`T%
{ e.(d?/!F_
e.printStackTrace (); ygm6(+
} |a /cw"
} %iYro8g!,
)@y'$)5s
//日志 &gC)%*I4
public static void log(String sMsg) @m:' L7+
{ P@n rcgM.
System.err.println(sMsg); t4~?m{
} 2v4&'C
5^l-3s?M
2\O!vp>|-
public static void log(int sMsg) VC Ay~,
{ dvY3=~'
System.err.println(sMsg); sT<h+[2d
} |pU>^
} p&`I#6{
ZD$I-33W
BtJF1#f
/* l+`CgYo
**TestMethod.java [{T/2IGq
*/ %4#ChlXB
package NetFox; ntL%&wY
Q'ib7R;V,
:'fK`G 6
public class TestMethod { +:c}LCI9<
,g|ht%"
U}=H1f,
public TestMethod() M3GFKWQI,`
{ ///xx/weblogic60b2_win.exe 6OQ\f,h@
try{ (f#{<^gd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )^)|b5,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;D4 bxz0ou
SiteFileFetch fileFetch = new SiteFileFetch(bean); (V/!0Lj
fileFetch.start(); I3l1 _
} Hb^ovc0
catch(Exception e){e.printStackTrace ();} mryT%zSlM
abEdZ)$
z!~{3M
} H66~!J0;a
?iaO6HD
Na.e1A&?j
public static void main(String[] args) uIJ zz4
{ &mA{_|>
new TestMethod(); z^%`sUgP
} REk^pZ3B
} !+Sd%2o
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