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)); 2*vOo^f
} VjtI1I
for(int i=0;i<nEndPos.length-1;i++) xH;qJRHa
{ C (vi ns
nEndPos = nStartPos[i+1]; A-~#ydv
} :&mYz(1q
nEndPos[nEndPos.length-1] = nFileLength; wp-5B= #:{
} )pjd*+V
} S5@/;T
9qIUBHe
$Tfq9
//启动子线程 ZwAX+0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yHurt>8b[
for(int i=0;i<nStartPos.length;i++) y<m{eDV7
{ S6B(g_D|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k;3Bv 6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GfUIF]X
nStartPos,nEndPos,i); (sW:^0p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g.kpUs
fileSplitterFetch.start(); k~>9,=::d
} /R^HRzTO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ! W$u~z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ')5W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IPbdX@FeV
nEndPos = " + nFileLength); rFM`ne<zh
// fileSplitterFetch[nPos.length-1].start(); Cnd*%CPZ
x +!<_p
V2ypmkn8&
//等待子线程结束 tv+q~TFB=Z
//int count = 0; i/Q*AG>b
//是否结束while循环 DdJxb{y7
boolean breakWhile = false; [@"H2#CQ
?;0=>3p*0
g:q+.6va"
while(!bStop) n>Y3hY
{ |b;}' *
write_nPos(); Q nDymVF
Utility.sleep(500); q =b.!AZy
breakWhile = true; /_rQ>PgSZW
(s %T18
z tHGY
for(int i=0;i<nStartPos.length;i++) &jl'1mZ
{ :@wO' o
if(!fileSplitterFetch.bDownOver) iH9g5G`O
{ l#7,<@)
breakWhile = false; V-}d-Y
break; :M`|*~V~$
} ndOPD]A'
} RI:x`do
if(breakWhile) &"._%S58V
break; .i"v([eQ
% rdW:
^OI
//count++; -fj;9('YJ
//if(count>4) wHBkaPO!
// siteStop(); 4(R O1VWsb
} a)(j68c
+N5G4t#.
UQ$dO2^
System.err.println("文件下载结束！"); m1gJ"k6 `j
} :)c >5
catch(Exception e){e.printStackTrace ();} j23OgbI
} n8w|8[uV^
tRS^|??
Gnl6>/L,
//获得文件长度 $9y]>R
public long getFileSize() k1L GT&
{ }Tu_?b`RUm
int nFileLength = -1; n #p6i
try{ bFVz ;
URL url = new URL(siteInfoBean.getSSiteURL()); 9|v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s.6S:
httpConnection.setRequestProperty("User-Agent","NetFox"); #dqZdj@
.Y&_k
6](vnS;
int responseCode=httpConnection.getResponseCode(); l'W?X '
if(responseCode>=400) 3SpDV'}
{ mppBc-#EYr
processErrorCode(responseCode); BXa1[7Z
return -2; //-2 represent access is error )3.udx
} zf$OC}|\w
b]g}h
%pc0a^iB
String sHeader; ve1jLjsB
XEfTAW#7
j*I0]!-
for(int i=1;;i++) BC(f1
{ ]gIXG`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,ZD!Qb
//Utility.log(in.readLine()); YM 7P!8Gc
sHeader=httpConnection.getHeaderFieldKey(i); U@|{RP
if(sHeader!=null) 8hQ"rrj+
{ #Q^mdv?
if(sHeader.equals("Content-Length")) [_|iW%<`
{ -gu)d5b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <9"s&G@
break; 3cT
} >%qGK-_
} ZA2y
else kC01s
break; r4J4|&ym
} _L_SNjA_
} oMLpl3pl
catch(IOException e){e.printStackTrace ();} 01H3@0Q6
catch(Exception e){e.printStackTrace ();} >/6v` 8F
/{>ds-;-
,PJl32
Utility.log(nFileLength); 5irewh'R
>Eik>dQ a
eY\tO"Hc
return nFileLength; /p<mD-:.M
} ^P"t "
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BR*""/3`
//保存下载信息（文件指针位置） eP&K]#
private void write_nPos() R j(="+SPj
{ y|.wL=;
try{ .NCQiQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); aZ5qq+1x
output.writeInt(nStartPos.length); EQ?4?
for(int i=0;i<nStartPos.length;i++) E4}MvV=
{ 4d!&.Qo9
// output.writeLong(nPos); A~*Wr+pv
output.writeLong(fileSplitterFetch.nStartPos); sFSrMI#R
output.writeLong(fileSplitterFetch.nEndPos); vIN6W
} DQ9 <N~l
output.close(); |g8 ]WFc
} d>@{!c-
catch(IOException e){e.printStackTrace ();} .a;-7|x
catch(Exception e){e.printStackTrace ();} I #1_
} 0Yfk/}5
}9Y='+.%^
~`*:E'/5k]
//读取保存的下载信息（文件指针位置） F:hJ^:BP
private void read_nPos() DMfC(w.d
{ r\_rnM)_xN
try{ CrS[FM= +W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1?7QS\`)fB
int nCount = input.readInt(); B^h]6Z/O
nStartPos = new long[nCount]; eFsku8$<
nEndPos = new long[nCount]; oWs&W
for(int i=0;i<nStartPos.length;i++) Y8\Ms^rz
{ \Q^\z
nStartPos = input.readLong(); q?}G?n4
nEndPos = input.readLong(); @m6pAo4P
} CtjjN=59
input.close(); oS_'@u.5
} :w:5;cmV
catch(IOException e){e.printStackTrace ();} ]Y;$~qQ
catch(Exception e){e.printStackTrace ();} -6+HA9zz@C
} pNVao{::5
G|3OB:
rQKBT]?y
private void processErrorCode(int nErrorCode) Bw{@YDO{
{ iW*0V3
System.err.println("Error Code : " + nErrorCode); -[^wYr=
} H{yPi7 P
hzKfYJcQ|
(O?z6g
//停止文件下载 <6v7_
public void siteStop() B-@f.NO/s
{ <@JU0Z"a=
bStop = true; 2"BlV*\lS
for(int i=0;i<nStartPos.length;i++) Hsp|<;Yg
fileSplitterFetch.splitterStop(); Qf=%%5+?8
qn+mlduU
35&&*$Jm
} M{~eI
} m#8}!u&
//负责部分文件的抓取 Bu6t3
**FileSplitterFetch.java Bm~>w`1wK
*/ I,
package NetFox; !Y\hF|[z
HnOF_Twq
/Zm@.%.
import java.io.*; ORfA]I-u
import java.net.*; Kl+*Sp!
HF47Lc*c
3P#1fI(c
public class FileSplitterFetch extends Thread { z,2m7C
$1Xg[>1g5
b[*di{?-
String sURL; //File URL veK
long nStartPos; //File Snippet Start Position d^lA52X6P
long nEndPos; //File Snippet End Position F},JP'\X
int nThreadID; //Thread's ID RKjA`cJ
boolean bDownOver = false; //Downing is over @XmMD6{<
boolean bStop = false; //Stop identical ?.4.Ubc\
FileAccessI fileAccessI = null; //File Access interface 3%cNePlr
x;b'y4kH
sjaG%f&h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5R o5Cg~
{ yM\1n
this.sURL = sURL; >fb*X'Zi%
this.nStartPos = nStart; \OY2|
this.nEndPos = nEnd; m m`:ci
nThreadID = id; xmVK{Q YT$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rNgE/=X
} 8|J%IE
}>tUkXlhJ<
-Tz9J4xU&
public void run() -nHc52,
{ E"w7/k#3}C
while(nStartPos < nEndPos && !bStop) &JF^a
{ aZBaIl6I
'i`;Frmg
$"_D"/*
try{ Z ,T TI>P
URL url = new URL(sURL); =x[`W9.D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hob%'Y5%D
httpConnection.setRequestProperty("User-Agent","NetFox"); V}aXS;(r%
String sProperty = "bytes="+nStartPos+"-"; wz:wR+
httpConnection.setRequestProperty("RANGE",sProperty); i5_gz>
Utility.log(sProperty); d}WAP m
re^1fv
0} {QQB
InputStream input = httpConnection.getInputStream(); H:~LL0Md%
//logResponseHead(httpConnection); hPEK@
$(_i>&d<
c\RDa|B,
byte[] b = new byte[1024]; ,:;_j<g`e
int nRead; VqYe0-^=P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w>m/c1
{ 4~1_%wb
nStartPos += fileAccessI.write(b,0,nRead); T?%F
//if(nThreadID == 1) _{ ?1+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cFuvi^n\
} 6lZhV[~Z/
C\fc 4
.|o7YTcR:
Utility.log("Thread " + nThreadID + " is over!"); zIm$S/Qe*
bDownOver = true; ea B-u
//nPos = fileAccessI.write (b,0,nRead); ?(R6}ab>K7
} ) tsaDG-E
catch(Exception e){e.printStackTrace ();} e`C'5`d]
} Bj\0RmVa1
} %tpt+N?
h#`qEK&u
,AM6E63
//打印回应的头信息 .}z&$:U9[
public void logResponseHead(HttpURLConnection con) 5[;p<GqGN
{ JEBx|U$'Y
for(int i=1;;i++) lRentNg0b
{ u2BVQ<SA
String header=con.getHeaderFieldKey(i); B8C"i%8V)
if(header!=null) RAxA H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1?mQ fW@G
Utility.log(header+" : "+con.getHeaderField(header)); !".@Wg$
else T}fo:aB}
break; U?@UIhtM|
} qwVpGNc45
} ;O.U-s
``zg |h
,.F,]m=
public void splitterStop() Jzfzy0$
{ s>_ne0
bStop = true; FIW*Nr
} dGHRHXi
Ag}>gbz~G
~ZL}j+L/
} A;{8\e
#&Biu}4D
K);:+s-
/* "X}!j>-
**FileAccess.java [}+ MZ
*//文件访问(定位，写) (bZ)pW/iw
package NetFox; GyT{p#l
import java.io.*; L5PN]<~T
P 7gS M
R$cg\DD
public class FileAccessI implements Serializable{ {n|Ra[9_
^oPf>\),C
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gLu#M:4N
RandomAccessFile oSavedFile; Mi:$<fEX
long nPos; [NH[n#
ZW*"Kok
W;u~}k<
public FileAccessI() throws IOException +tlTHK
{ m"jqHGFV
this("",0); aS62S9nwX
} nq A> }A
Xgop1
Xc`'i@FX
public FileAccessI(String sName,long nPos) throws IOException X}g!Lp
{ a i}8+L8-
oSavedFile = new RandomAccessFile(sName,"rw"); 0*,r
this.nPos = nPos; z<s]Z
oSavedFile.seek(nPos); pbju;h)O!|
} y{5ZC~Z<!
Wh 8fC(BE
eWcS>N
public synchronized int write(byte[] b,int nStart,int nLen) e7 5*84
{ "y>l2V,4j%
int n = -1; -/KVZ
try{ Fi1gM}>py
oSavedFile.write(b,nStart,nLen); Nluy]h &
n = nLen; 6g( 2O[n.
} ;^t<LhN:
catch(IOException e) QH#|R92:
{ @P[Tu; 4
e.printStackTrace (); qnruatA
} X[BKF8,
8?P@<Do%
+KXg&A/^
return n; Q4q3M=0
} " c}pY^(
)2u=U9
;o"}7'4*R%
} O_(/uLH
Hg]Q.SeJ(
nv@$'uQRp
/* >8oRO
**SiteInfoBean.java LlX 7g_!
*/ r|6S&Ia>
package NetFox; @dD70T
(fb&5=Wzw
C6:<.`iD87
public class SiteInfoBean { ;R 'OdQ$o
DX4uTD
zeNvg/LI^
private String sSiteURL; //Site's URL )^L+iht
private String sFilePath; //Saved File's Path q"`1cFD
private String sFileName; //Saved File's Name Y7]N.G3,]
private int nSplitter; //Count of Splited Downloading File |jF)~k6
F;5.nKo
}3 RqaIY}
public SiteInfoBean() %/-Z1Nv*#
{//nSplitter的缺省值为5 >*B/Wy
//default value of nSplitter is 5 m3\lm@`)O
this("","","",5); 0KU,M+_
} )z$VQ=]"
uFL~^vz
7*~ rhQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w\8grEj
{ Cf J@|Rh
sSiteURL= sURL; N>'1<i?
sFilePath = sPath; \0'o*nlJ
sFileName = sName; ,/ly|Dv
this.nSplitter = nSpiltter; #V*<G#B
TZ?va@2
c_vj't
} N:\I]M
;v*$6DIC5
n3jA[p:
public String getSSiteURL() x]XhWScr'
{ v-2.OS<o
return sSiteURL; 4(|x@:wxm
} =-1d m+P
Ojr{z
K{t7_i#tv
public void setSSiteURL(String value) v/}M_E
{ $ZH$x3;
sSiteURL = value; JrQ*.lJj
} G*3O5m
?)'j;1_=E3
#ZeZs31
public String getSFilePath() DNq=|?qn]
{ 6rF[eb
return sFilePath; `oXUVr
} G@BF<e{
Fpzps!(;=
"ALR)s,1,
public void setSFilePath(String value) :|EM1-lwf
{ U[u9RB
sFilePath = value; n*{e0,gp`
} CJ%bBL'.
J`Q#p%W
JyvXNV,
public String getSFileName() l;b5v]~
{ ,3!l'|0jJ
return sFileName; #]q<fhJhr$
} ^mm:u<Yt
oJvF)d@gU
=Bu d!
public void setSFileName(String value) .3Jggp
{ wk<QYLEk
sFileName = value; dNB56E)5`J
} {UT^pIP\
M#IGq
#Kyb9Qg
public int getNSplitter() Vdjf F&q
{ ac p-4g+j
return nSplitter; %19TJn%J$
} O|O#T.Tg
[Z`q7ddd^
[mYmrLs6
public void setNSplitter(int nCount) bP`yLz
{ .fk!~8b[Q+
nSplitter = nCount; Ha)eeE$
} 6(f[<V!r
} MR:Co4(
9mIq9rQ|*
w3a`G|
/* w[qWr@
**Utility.java hvnZ 2x.?d
*/ RM|<(kq
package NetFox; >t.2!Z_RQ
5lu620o
KcF2}+iM
public class Utility { xwW[6Ah
#6[FGM
Qb!9QlW
public Utility() C%85Aq*4
{ T+8F'9i`
?dVF@
T_lexX[\
} (x2I*<7P
/lCn^E6-
//线程睡眠 Z,.*!S=?h
public static void sleep(int nSecond) Vf`n>
{ m,K0BL
try{ BI?M/pIm
Thread.sleep(nSecond); g<-x"$(C&
} f>g>7OsD]
catch(Exception e) B5hk]=Ud
{ iEux`CcJ.
e.printStackTrace (); *`>(K&
} U<|kA(5
} r5xu#%hgp;
r]iec{ ^
//日志 _'JKPD[
public static void log(String sMsg) Xhe25
{ MR=>DcR
System.err.println(sMsg); zHw[`"[
} #(FG+Bk
+e. bO5Y
pP;GDW4
public static void log(int sMsg) M$dDExd~
{ KGS=(z
System.err.println(sMsg); /m%i"kki
} kep.+t[
} ~v$gk
m/r4f279
8 C@iD%
/* }A'QXtI/G
**TestMethod.java Sp: `Z1kH
*/ h`F8GNx(
package NetFox; Gdq_T*
a]|P rjPI
"15mOW(!+
public class TestMethod { `{s:lf
_V^^%$
3N|,c]|
public TestMethod() /!rH DcR
{ ///xx/weblogic60b2_win.exe dU+28
try{ tJy6\~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ':lADUt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MYFRrcu;
SiteFileFetch fileFetch = new SiteFileFetch(bean); RR<92R
fileFetch.start(); glbU\K> >
} _[zO?Div[
catch(Exception e){e.printStackTrace ();} @{\q1J>
1Rc'2Y
xw(KSPN
} SE&J)Sj]
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k)oD
public static void main(String[] args) hVo]fD|W
{ ^$c+r%9k
new TestMethod(); )"s <hR,
} eL[BH8l
} h lD0^8S
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