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)); M#Z^8(
} E 1`g8Hk'
for(int i=0;i<nEndPos.length-1;i++) H.M: cD:
{ xY)eU;*
nEndPos = nStartPos[i+1]; pS-o*!\C.
} r;b`@ .
nEndPos[nEndPos.length-1] = nFileLength; Y->sJm
} gna!Q
} q=e;P;u
<zY#qFQ2
V|A.M-XLv4
//启动子线程 8m H6?,@6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +Y*4/w[
for(int i=0;i<nStartPos.length;i++) c|:EMYS
{ aNM*=y`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y}FG5'5$13
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xN$V(ZX4
nStartPos,nEndPos,i); fFVQu\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Gnt.%y&
fileSplitterFetch.start(); {{gd}g
} k6DJ(.n'%a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E9k%:&]vd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +z9BWo!{I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |Zn;O6c#L5
nEndPos = " + nFileLength); "1""1";
// fileSplitterFetch[nPos.length-1].start(); e+#Oj
jCj8XM{c>
_[8JSw7
//等待子线程结束 iuqJPW^}
//int count = 0; >r)UDa+
//是否结束while循环 ;s~xS*(C
boolean breakWhile = false; ZwxEcs+UM
B^M L}$
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while(!bStop) 6`7`herE}
{ kLs{B
write_nPos(); =}%:4
Utility.sleep(500); lpd~U2&
breakWhile = true; o4 "HE*
1Z_]Ge<a
.rg "(I
for(int i=0;i<nStartPos.length;i++) L4+R8ojG
{ J7wwM'\
if(!fileSplitterFetch.bDownOver) r_ m|?U %
{ rx]Q,;"
breakWhile = false; ku57<kb
break; [GM!@6U
} EQ"_kJ>81Y
} rY&lx}
if(breakWhile) 6_8yQ
break; qc'KQ5w7!
MP@}G$O
FME,W&_d
//count++; MC-Z6l2
//if(count>4) =.J>'9Q
// siteStop(); -q)|I|y*7
} U3aM^
\p\p~FVS
1h162
System.err.println("文件下载结束！"); e?XGv0^qu
} U1yspHiZ
catch(Exception e){e.printStackTrace ();} -hF!_);{
} oQVm)Bn'R
oN83`Z
Ir` l*:j$
//获得文件长度 -'oxenu
public long getFileSize() Ss{5'SF)$c
{ =JTwH>fD
int nFileLength = -1; .GYdC'
try{ \'w.<)(GI
URL url = new URL(siteInfoBean.getSSiteURL()); w4^$@GtN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^eV K.
httpConnection.setRequestProperty("User-Agent","NetFox"); }f{5-iwD}
s)'+,lKw
B'B0e`
int responseCode=httpConnection.getResponseCode(); ~y 2joStx
if(responseCode>=400) vPZ0?r_5W
{ 7k#>$sY+
processErrorCode(responseCode); HWL? doM
return -2; //-2 represent access is error 0|hOoO]?q&
} v-F|#4Q=ut
D!)h92CIDm
SoCN.J30
String sHeader; Efd@\m:~>
I?q- :9:
C{-Dv-<A>
for(int i=1;;i++) X)TZ S
{ 8BY`~TZO$q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /K,@{__JP
//Utility.log(in.readLine()); |e+r~).4B
sHeader=httpConnection.getHeaderFieldKey(i); T/%k1Hsa4H
if(sHeader!=null) EcR[b@YI
{ t1#f*G5
if(sHeader.equals("Content-Length")) vl`St$$|
{ \WUCm.w6\%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *=%`f=
break; /byF:iYI
} bL:+(/:
} ldKLTO*&
else )C$Ij9<A
break; Py9:(fdS
} m KKa0"
} N>j*{]OY+{
catch(IOException e){e.printStackTrace ();} I$TD[W
catch(Exception e){e.printStackTrace ();} s,laJf
Q."rE"}<
FGo)]U
Utility.log(nFileLength); >^f]Lgp
/PBK:B
a5]]AkvA
return nFileLength; !$-QWKD4
} poZ&S
pL.~z
5tVg++I
//保存下载信息（文件指针位置） "LZv\c~v,%
private void write_nPos() esv<b>`R
{ `1 Tg8
try{ }V+&o\4
output = new DataOutputStream(new FileOutputStream(tmpFile)); M7gqoJM'Q
output.writeInt(nStartPos.length); m}m|(;T
for(int i=0;i<nStartPos.length;i++) {X\FS
{ |z)7XK
// output.writeLong(nPos); O4W2X@
output.writeLong(fileSplitterFetch.nStartPos); XQ Si
output.writeLong(fileSplitterFetch.nEndPos); M%eTNsbNm
} HM\}C.u
output.close(); [}l 1`>
} ?zXlLud8
catch(IOException e){e.printStackTrace ();} rqM_#[Y?
catch(Exception e){e.printStackTrace ();} ${UH!n{
} k~1{|HxrE
- :x6X$=
Pv$O=N6-
//读取保存的下载信息（文件指针位置） #/K71Y
private void read_nPos() ?l 0WuU
{ Nu; 9
try{ cl'qw##
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0te[i*G
int nCount = input.readInt(); $O9#4A;
nStartPos = new long[nCount]; I]~UOl
nEndPos = new long[nCount]; i:^ 8zW
for(int i=0;i<nStartPos.length;i++) *pGbcBQ
{ Js,.$t
nStartPos = input.readLong(); `b5pa`\4
nEndPos = input.readLong(); Ed"p|5~
} G7HvA46
input.close(); .!1E7\
} oPA m*
catch(IOException e){e.printStackTrace ();} s.!gsCQme
catch(Exception e){e.printStackTrace ();} V#-8[G6Ra
} 4L2TsuLw
a&`Lfw"
]u >~:
private void processErrorCode(int nErrorCode) )}\J
{ n6GB2<y
System.err.println("Error Code : " + nErrorCode); z0tm3ovp
} {,o 0N\(
Kx,<-]4
RM`iOV,Y
//停止文件下载 *i7|~q/u
public void siteStop() rge/qUr/^
{ :LR>U;2
bStop = true; )G|'PXI@,
for(int i=0;i<nStartPos.length;i++) @(e/Y/
fileSplitterFetch.splitterStop(); cfW;gFf
k`,>52
flU?6\_UC
} ?w"zW6U
} Mg{=(No
//负责部分文件的抓取 1&YkRCn0
**FileSplitterFetch.java h\OMWJ~
*/ @w[HXb
package NetFox; 0qo:M3
D +9l$**a
~jOk?^6
import java.io.*; HS 1zA
import java.net.*; 1:q5h*
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]AB4w+6!
public class FileSplitterFetch extends Thread { @avG*Mr^
p!~V@l
X~g~U|B@
String sURL; //File URL ,A!0:+
long nStartPos; //File Snippet Start Position p+1kU1F0
long nEndPos; //File Snippet End Position 'di(5
int nThreadID; //Thread's ID Eg#WR&Uq"
boolean bDownOver = false; //Downing is over ksli-Px
boolean bStop = false; //Stop identical e:RgCDWL
FileAccessI fileAccessI = null; //File Access interface XRWy#Pj
IM~2=+
[Xo[J?w],2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T [2l32
{ yK:b$S
this.sURL = sURL; hxuc4C\J
this.nStartPos = nStart; :pgpE0
this.nEndPos = nEnd; &qae+p?
nThreadID = id; rIWQD%Afm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m3 W
} 7F wot&
05o 1
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public void run() *TP>)o
{ OOj}CZ6
while(nStartPos < nEndPos && !bStop) 18gApRa
{ O3["5
S/7?6y~
UB|}+WA3
try{ 4Yya+[RY
URL url = new URL(sURL); 8~8VoU&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #\$AB_[ot>
httpConnection.setRequestProperty("User-Agent","NetFox"); 7y'2
String sProperty = "bytes="+nStartPos+"-"; P jh3=Dr
httpConnection.setRequestProperty("RANGE",sProperty); +I r
Utility.log(sProperty); <GO 5}>}p8
xg_9#
,LVZ
InputStream input = httpConnection.getInputStream(); #>dj!33
//logResponseHead(httpConnection); FkY <I]F
X_2pC|C
) i=.x+Q
byte[] b = new byte[1024]; f#b;s<G
int nRead; ])NQzgS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aLt2fB1)
{ 4 oZm0
nStartPos += fileAccessI.write(b,0,nRead); MI\35~JAN
//if(nThreadID == 1) 'yR)z\)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BDz7$k]
} x3Ze\N8w
&-hXk!A
^K'@W
Utility.log("Thread " + nThreadID + " is over!"); yw+LT,AQ.
bDownOver = true; )>U7+ Me
//nPos = fileAccessI.write (b,0,nRead); MC;2.e`
} E8]kd
catch(Exception e){e.printStackTrace ();} k?;B1D8-n
} j NkobJ1
} fKOC-%w
gis;)al
GX;~K
//打印回应的头信息 ^n&_JQIXb
public void logResponseHead(HttpURLConnection con) B'8/`0^n5
{ 5l4YYwd>v
for(int i=1;;i++) jPa"|9A
{ V3<H8pL
String header=con.getHeaderFieldKey(i); ?]PE!7H
if(header!=null) ?n(OH~@$i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +Un(VTD
Utility.log(header+" : "+con.getHeaderField(header)); QSSA)
else T?HW=v_a
break; }YCpd)@
} 0<#>LWaM_
} /Xk-xg+U
25{-GaB
+Fa!<txn
public void splitterStop() a(oa?OdJ
{ u4vyj#V
bStop = true; uJ T^=Y
} @p ZjJ<9QM
ZGj ^,?a
NWS3-iZ|8
} _T\cJcWf
)J{.z
|Q+:vb:
/* '|^x[8^
**FileAccess.java BnUWg ^E
*//文件访问(定位，写) W!t=9i
package NetFox; ble[@VW|
import java.io.*; #Ic)]0L
bYAtUEv
dTZ$92<
public class FileAccessI implements Serializable{ a]nK!;>$
?/|KM8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '8w>=9Xl
RandomAccessFile oSavedFile; AX;!-|bW
long nPos; I>JBGR`j
F<TIZ^gFP
#ADm^UT^
public FileAccessI() throws IOException vb`R+y@
{ {;vLM* '
this("",0); 03H0(ku=
} y4)iL?!J~
M>[e1y>7
z"P/Geb:O
public FileAccessI(String sName,long nPos) throws IOException `3yK<-
{ U*4r<y9R
oSavedFile = new RandomAccessFile(sName,"rw"); sm"s2Ci=}
this.nPos = nPos; ,0a\Ka{^
oSavedFile.seek(nPos); ( 4(,"
} "fu:hHq
6GA+xr=
&&g02>gE
public synchronized int write(byte[] b,int nStart,int nLen) f~ wgMp.W0
{ f0&%
int n = -1; Q$(Fma4a
try{ ZeLed[J^xJ
oSavedFile.write(b,nStart,nLen); ,49Z/P
n = nLen; bEm9hFvd
} 8PR\a!"
catch(IOException e) T>68 ,; p
{ =;"=o5g_
e.printStackTrace (); 8W Etm}
} 10_#Z~aU
YS:p(jtd
=;Dj[<mJ45
return n; ly:2XvV3~
} T~L&c
f@[qS7ok
R$X~d8o>%
} O,JS*jXl
GZ^Qt*5 {
YPW UncV
/* XY#.?<"Q8
**SiteInfoBean.java mv7W03
*/ dXfLN<nD>U
package NetFox; 0j;q^>
yd=b!\}WJ
*3)kr=x
public class SiteInfoBean { +PS jBO4!
E>+>!On)b
yzT4D>1,
private String sSiteURL; //Site's URL XBoq/kbw!
private String sFilePath; //Saved File's Path |az2vD6P
private String sFileName; //Saved File's Name )k;;O7Ck
private int nSplitter; //Count of Splited Downloading File 5|5p -B
HuJc*op-6
c?N,Cd~q
public SiteInfoBean() #_{Q&QUk
{//nSplitter的缺省值为5 /,`OF/%
//default value of nSplitter is 5 WdH/^QvTP
this("","","",5); qVfl6q5
} K)U[xS;<
inip/&P?V
`/^ _W <
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M*f]d`B
{ P?S]Q19Q4
sSiteURL= sURL; s VHk;:e>x
sFilePath = sPath; sn"z'=ch
sFileName = sName; xv&h>GOg
this.nSplitter = nSpiltter; oC-v>&bW
yzv"sd[8N
1jej7p>K
} `nKN|6o#x
^=5x1<a9$
+IO>%
public String getSSiteURL() H8B$#.
{ z:4_f:70
return sSiteURL; GC:q6}
} @$~IPg[J
n}I?.r@e
&gPP#D6A
public void setSSiteURL(String value) &O^-,n
{ [q Uv|l1
sSiteURL = value; vxHFNGI
} r! HXhl
X =%8*_
7f4O~4.[i
public String getSFilePath() x x4GP2
{ N#2ldY *
return sFilePath; =YTcWB
} - Z`RKR8C
H>A6VDu
JJM<ywPGp
public void setSFilePath(String value) mf)+ 5On
{ pQKSPr
sFilePath = value; =MMd&
} }zx ~
!1fZ7a
),-gy~
public String getSFileName() )Qd x
{ |?ssHW
return sFileName; HC/z3b;
} !3Pbu=(cte
~7U~
r4fHD~#l{
public void setSFileName(String value) c(e>Rmh
{ p |1u,N
sFileName = value; h='F,r5#2
} # )y/aA
[ r8 ZAS
U!`iKy-
public int getNSplitter() B+snHabS6
{ !TJ,:c]4{!
return nSplitter; {*AA]z?zo
} 7oWMjw\
XIbZ_G^ +D
-^lc-$0
public void setNSplitter(int nCount) 94?WL
{ UhpJGO
nSplitter = nCount; s0^(yEcq
} dw3Hk$"h
} (rd [tc
m$kQbPlatN
%KXiB6<4
/* {VL@U$'oI
**Utility.java pX ^^0
*/ !6T"J!F#
package NetFox; ~?AEtl#&"
C=/B\G/.9
{^ b2nOMv
public class Utility { ^Aq0<
G$+v |z
$KO2+^%y
public Utility() `daqzn
{ odsFgh
AQg|lKv
w8UuwFG?<
} r8Mx+r
fq]PKLW'
//线程睡眠 RhH1nf2UR
public static void sleep(int nSecond) S@FO&o 0
{ eZLEdTScM
try{ hlaN'j <C
Thread.sleep(nSecond); by X!,
} B6Vlc{c5SO
catch(Exception e) e~9O#rQI
{ BVNW1<_:
e.printStackTrace (); V@G#U[D
} N8b\OTk2
} fI613ww]
hTr5Q33y>
//日志 7{L4a\JzT
public static void log(String sMsg) Sw\*$g]
{ DAB9-[y+
System.err.println(sMsg); '7-Yo Q
} _1p8(n
6<._^hyq
w +t@G`d
public static void log(int sMsg) 50W+!'
{ <U@N^#
System.err.println(sMsg); [@vz0!@s5
} EiL#Dwx
} B7C3r9wj
(+> 2&@@<
}}JMwT
/* pk/#RUfT+
**TestMethod.java `p\=NP!n
*/ $J`O-"M
package NetFox; r9i?H
7K1-.uQ
hmO2s/~
public class TestMethod { @ _Ey"k<
Km` SR^&\
Y'iX
public TestMethod() .Pc>1#z&[
{ ///xx/weblogic60b2_win.exe OSgJj MQ
try{ 2$JGhgDI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !eLj+0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SB_Tzp
SiteFileFetch fileFetch = new SiteFileFetch(bean); z%;plMj
fileFetch.start(); zfIo]M`
} Rh!UbEPjC
catch(Exception e){e.printStackTrace ();} =q4}(
PsY![CPrW
uN|A}/hr]
} hi7_jl6
`ONjEl
aF{_"X2
public static void main(String[] args) )r2Y@+.FN
{ _gvFs%J
new TestMethod(); Jh26!%<Bl
} IC`3%^
} YG "Ta|@5
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