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)); 7z{wYCw
} -1g:3'% P
for(int i=0;i<nEndPos.length-1;i++) 8-#%l~dr
{ +J X;T(T
nEndPos = nStartPos[i+1]; g\JJkXjD#
} V0\[|E;F
nEndPos[nEndPos.length-1] = nFileLength; \n)',4mY
} Zh<;r;2
} )|F|\6:ne
+T+@g8S
h4?x_"V"
//启动子线程 FRBu8WW0L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n{;j
for(int i=0;i<nStartPos.length;i++) )u)=@@k21
{ &7aWVKon
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e`D}[G#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /~[Lr
nStartPos,nEndPos,i); 6Xlzdt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nVb@sI{{k
fileSplitterFetch.start(); 0mY Y:?v
} 5</$dcG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g7*)|FOb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I &t~o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Eah6"j!B8n
nEndPos = " + nFileLength); I{`70
// fileSplitterFetch[nPos.length-1].start(); wHc my
}{o!
gb ga"WO
//等待子线程结束 200yN+ec
//int count = 0; o\IMYT
//是否结束while循环 uepyH
boolean breakWhile = false; qLN^9PdEE
,5}U H
B`5<sW
while(!bStop) g`7XE
{ sHP-@
write_nPos(); eU?hin@X
Utility.sleep(500); RLB3 -=9t
breakWhile = true; *T|B'80
-4a9BE".
#WpkL]g2+%
for(int i=0;i<nStartPos.length;i++) {meX2Z4
{ nM )C^$3<t
if(!fileSplitterFetch.bDownOver) j2Zp#E!
{ $B+| &]a
breakWhile = false; *eVq(R9?T
break; tli.g
} )ZJvx%@i
} <j'V}|3
if(breakWhile) p\6cpf
break; aV3:{oL
-Mt 5< s
[4Z 31v>
//count++; IV QH p
//if(count>4) U2oCSo5:3N
// siteStop(); Ykbg5Z
} +]db-
}I"C4'(a
I5$P9UE+^9
System.err.println("文件下载结束！"); 'Ts:.
} qS!r<'F3dP
catch(Exception e){e.printStackTrace ();} )?L=o0
} `2~>$Tr
.J"N}
3dShznlf_*
//获得文件长度 gg;r;3u
public long getFileSize() E h%61/
{ iHK~?qd}
int nFileLength = -1; ^[L(kHOGzk
try{ )xGAe#E~j
URL url = new URL(siteInfoBean.getSSiteURL()); [M_{~1xX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 30Q p^)K
httpConnection.setRequestProperty("User-Agent","NetFox"); :QCL9QZ'
^E !v D
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int responseCode=httpConnection.getResponseCode(); bf3!|Um
if(responseCode>=400) yqK4 "F&
{ qfkHGW?1/j
processErrorCode(responseCode); \u3\TJ
return -2; //-2 represent access is error Pf?kNJ*Tv)
} *dzZOe>,
YeX*IZX8
i%glQT
String sHeader; &c`-/8c
dj|5'<l2
;|N:FG
for(int i=1;;i++) Tt[zSlIMx
{ BG{f)2F\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TQ Vk;&A
//Utility.log(in.readLine()); 2EY"[xK|
sHeader=httpConnection.getHeaderFieldKey(i); ?HZp@&
if(sHeader!=null) &v\F ah U
{ cpY{o^
if(sHeader.equals("Content-Length")) Hh<H~s [
{ ~,'{\jDrS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =bC +1 C
break; A5?"
} uGKjZi
} e5h*GKF
else H^_,e= j
break; N!A20Bv
} y!e]bvN
} }fpya2Xt
catch(IOException e){e.printStackTrace ();} fGgt[f[
catch(Exception e){e.printStackTrace ();} #%"q0"
4p_C+4
MatXhP] Fi
Utility.log(nFileLength); (iIw}f)w
bP,<^zA|X
r@r%qkh(.@
return nFileLength; 0r]n 0?x
} GnV0~?
Er~17$b
^S#;
//保存下载信息（文件指针位置） eh#37*-
private void write_nPos() E'5*w6
{ f49kf**
try{ O9gq <d
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;rh.6Dl
output.writeInt(nStartPos.length); A'qe2]
for(int i=0;i<nStartPos.length;i++) ^-;S&=
{ E(qYCafC
// output.writeLong(nPos); WSThhI
output.writeLong(fileSplitterFetch.nStartPos); +,Dc0VC?
output.writeLong(fileSplitterFetch.nEndPos); G#iQX`
} q:{#kv8
output.close(); )!y>2$20 r
} ;%|im?
catch(IOException e){e.printStackTrace ();} ;D5>iek5
catch(Exception e){e.printStackTrace ();} }E`Y.= S
} T.q2tC[bR
b`0tfXzS5
L aTcBcI
//读取保存的下载信息（文件指针位置） ` ]|X_!J-
private void read_nPos() UuG%5 ZC
{ ! VwU=5
try{ \j)Evjw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -K"'F`;W
int nCount = input.readInt(); 8(3(kZxS
nStartPos = new long[nCount]; iT@`dEZ.
nEndPos = new long[nCount]; D6SUzI1+H
for(int i=0;i<nStartPos.length;i++) |1tKQ0jg
{ FU|brSt
nStartPos = input.readLong(); Z\$HgG
nEndPos = input.readLong(); uL'f8Pqg
} N_t,n^i9>*
input.close(); PSrx!
} &\zYbGU
catch(IOException e){e.printStackTrace ();} F<4rn
catch(Exception e){e.printStackTrace ();} ,"qCz[aDN1
} "EW8ll7r
#ydold{F
#J5BHY~
private void processErrorCode(int nErrorCode) [hJ1]RW8
{ OY*y<>
System.err.println("Error Code : " + nErrorCode); 4^_6~YP7
} BU nujC
,5'o>Y
PjQl(v&O
//停止文件下载 LPs%^*8(2
public void siteStop() $+eeE
{ N#w5}It
bStop = true; pDQ f(@M[
for(int i=0;i<nStartPos.length;i++) WR+j?Fcf
fileSplitterFetch.splitterStop(); !0 7jr%-~
5C w( 4.
p^l#Wq5
} zcpL[@B
} dg D-"-O
//负责部分文件的抓取 .j6udiv5
**FileSplitterFetch.java 2j\_svw'
*/ [V}vd@*k
package NetFox; :4AQhn^;"
Fwm$0=BXL
z*3b2nV
import java.io.*; o'Bd. B
import java.net.*; 6:1`lsP
tldT(E6
[i.@q}c~E
public class FileSplitterFetch extends Thread { V:0IBbh)w
}_Bo:*9B-o
lH fZw})d
String sURL; //File URL gt4GN`-k
long nStartPos; //File Snippet Start Position ]aN9mT N
long nEndPos; //File Snippet End Position ,@"yr>Q9#6
int nThreadID; //Thread's ID *i#2>=)
boolean bDownOver = false; //Downing is over Zy0M\-Mn
boolean bStop = false; //Stop identical So5/n7
FileAccessI fileAccessI = null; //File Access interface 7o4E_ .*
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Y A.&ap
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DJ ru|2
{ B<W}:>3
this.sURL = sURL; +'H[4g`
this.nStartPos = nStart; X[z;P!U
this.nEndPos = nEnd; pj'gTQ),0
nThreadID = id; <O jK $KV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2OG/0cP
} Q0*E&;|
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public void run() *0U#Z]t
{ b"g^Jm! j
while(nStartPos < nEndPos && !bStop) G<Z}G8FW^
{ ];.5*a%*
3s\UU2yr
]0i[=
try{ L03I:IJ
URL url = new URL(sURL); %<i sdvF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b:1B >
httpConnection.setRequestProperty("User-Agent","NetFox"); 5nPvEN/
String sProperty = "bytes="+nStartPos+"-"; O:]']' /
httpConnection.setRequestProperty("RANGE",sProperty); 1N/4W6
Utility.log(sProperty); <Qq {&,Le
/%YW[oY{V
]36SF5<0r
InputStream input = httpConnection.getInputStream(); ?Ld),A/c
//logResponseHead(httpConnection); <5Vf3KoC&
BKFO^
#v c+;`X
byte[] b = new byte[1024]; aru2H6
int nRead; g5BL"Dn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cMK|t;" 3
{ jMT[+f
nStartPos += fileAccessI.write(b,0,nRead); r$<!?Z
//if(nThreadID == 1) -J]?M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y XhZWo{B
} 'O%*:'5k
HoBx0N9\2
rpk8
Utility.log("Thread " + nThreadID + " is over!"); 8%4;'[UV
bDownOver = true; AB=%yM7V*
//nPos = fileAccessI.write (b,0,nRead); }#zL)+XI
} WO>A55Xya
catch(Exception e){e.printStackTrace ();} RqROl!6
} l6zAMyau5
} EXdX%T\
^%oH LsY9
q\tr&@4iC
//打印回应的头信息 /OKp(u;)z
public void logResponseHead(HttpURLConnection con) VnuG^)S
{ %+r(*Q+0$f
for(int i=1;;i++) ^;II@n i
{ hC-uz _/3
String header=con.getHeaderFieldKey(i); hu-]SGb6
if(header!=null) hl]d99Lc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Dw=L]i :0v
Utility.log(header+" : "+con.getHeaderField(header)); #kQ! GMZH
else TjpyU:R,&|
break; IO7z}![V;
} '[r:pwE
} dX\OP>
=K@LEZZ'/<
f}dlQkZ(
public void splitterStop() l_yy;e
{ F,YPIl
bStop = true; mjOxmwo
} /}u:N:HA%
j'*.=cwsp
03?ADjO
} ]xf89[;0
\m`IgP*
ErN[maix#
/* ' !huU
**FileAccess.java hLfWDf*T|
*//文件访问(定位，写) 2
package NetFox; _Q:ot'(~0-
import java.io.*; P]"@3Z&w
?;=7{Ej
*Y1s4FXu2
public class FileAccessI implements Serializable{ /A5=L<T6F
czw:xG!&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (,"%fc7<i
RandomAccessFile oSavedFile; Q3=X#FQ
long nPos; D~inR3(}
~N/%R>(v
Sh;`<Ggi~
public FileAccessI() throws IOException %X\J%Fj
{ QM!UMqdj
this("",0); yS)k"XNb
} wgDAb#Zuk
9X[378f+(
!yg &zzP*
public FileAccessI(String sName,long nPos) throws IOException VI3fvGHat{
{ f$</BND
oSavedFile = new RandomAccessFile(sName,"rw"); t<`wK8)
this.nPos = nPos; 06NiH-0O
oSavedFile.seek(nPos); U>IsmF>m
} TrZ!E`~
C\rT'!Uk\Q
ZyDf@(z`
public synchronized int write(byte[] b,int nStart,int nLen) DmoY],9I+p
{ VK9E{~0=
int n = -1; [/ CB1//Y
try{ !d0$cF):
oSavedFile.write(b,nStart,nLen); ~#EXb?#uS
n = nLen; gISA13
} SFzoRI=qG
catch(IOException e) x1 LI&
{ uUl;}W
e.printStackTrace (); c[1{>z{G
} jKP75jm
.yzXw8~S
:wzbD,/M
return n; ?@A@;`0Y
} @#"K6
:A#'8xE/
b5p;)#
} }+ W5Snx
=M{&g
wQ-BY"cK\
/* KW0KXO06a
**SiteInfoBean.java c5CxR#O
*/ a"+VP>4
package NetFox; b6g9!
9~,!+#
i(u zb<
public class SiteInfoBean { a"+/fC`
CE183l\
yl<=_Q
private String sSiteURL; //Site's URL 9<Zm}PE32
private String sFilePath; //Saved File's Path VQ~eg wJL
private String sFileName; //Saved File's Name 84(jg P
private int nSplitter; //Count of Splited Downloading File 1_~'?'&^
7Aw <:
J_ h\tM
public SiteInfoBean() 8=\k<X{`
{//nSplitter的缺省值为5 {YzpYc1
//default value of nSplitter is 5 J(~xU0gd'
this("","","",5); ^[HX#JJ~
} |bRi bB
EY1L5Ba.
LGy!{c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Yv*i69"
{ "| oW6@
sSiteURL= sURL; (yu0iXZY
sFilePath = sPath; }Ny~.EV5^
sFileName = sName; I1ibrn
this.nSplitter = nSpiltter; ?s0")R&
n[-d~Ce2{
B*Q.EKD8s
} @S012} xH
[o'}R`5)
+w?1<Z
public String getSSiteURL() v|kL7t)}
{ QD[l 6
return sSiteURL; IetV]Ff6
} Z${@;lgP
~fA H6FdZ\
zpcm`z
public void setSSiteURL(String value) w68VOymD/
{ V[|k:($
sSiteURL = value; -}JRsQ+rgM
} atFu KYI
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I8hmn@ce
public String getSFilePath() Bq:: 5,v
{ 7"_gX
return sFilePath; =1kjKE !
} 1n ZE9;o
$r)nvf`\
Y0OVzp9 b
public void setSFilePath(String value) !91<K{#A{
{ ]_)=xF19
sFilePath = value; HPWjNwM
} PJcz] <
#`Et{6WS
[TpW$E0H
public String getSFileName() #lm1"~`5
{ 7W#9ki1
return sFileName; hmd,g>J:<
} X"G3lG
\RP=Gf
Neb%D8/Kn
public void setSFileName(String value) 785Y*.p
{ Y6@A@VJ
sFileName = value; 5h(]S[Zf3
} w3IU'(|G
gs|%3k|
o;:a6D`
public int getNSplitter() 7~q'3 N
{ W,n0'";')
return nSplitter; 0g(hY:
} )%OV|\5#
whg?X&j\V
K31rt-IIt
public void setNSplitter(int nCount) aKCXV[PO
{ A&0sD}I\K
nSplitter = nCount; Uz!cVs?-
} 7,"1%^tU
} kR-5RaW
j&?NE1D>I
PFIL)D |G
/* )Nq$~aAm
**Utility.java ~F]- +|
*/ 5B(r[Ni b
package NetFox; J`3pXc$.
1k>*
71w$i 4
public class Utility { \h"QgHzp
Im_`q\i
MgLz:2 :F
public Utility() 8YBsYKC
{ F3a"SKMW
$NWI_F4
r).S/
} !-4pr[C
C`x>)wm:
//线程睡眠 7b T5-=.
public static void sleep(int nSecond) m5LP~Gb
{ DI!l.w5P_
try{ nyPA`)5F0
Thread.sleep(nSecond); B)"WG7W E
} ~c3CyOab
catch(Exception e) ZAii"F
{ o*QhoDjc
e.printStackTrace (); ^f1}:g
} @*l}2W
} Oox5${#^
!/$BXUrd
//日志 5,qfr!hN,
public static void log(String sMsg) &e%y|{Y
{ Wm.SLr,o0
System.err.println(sMsg); rq6(^I
} p2y h
gzHjD-g-<
s\Cl3
public static void log(int sMsg) ]}G(@9
{ }EOn=*
System.err.println(sMsg); +;z4.C{gM
} 4aZsz,=
} e}}xZ%$4|
n|L.dBAs]
obX|8hTL%
/* _&JlE$ua7
**TestMethod.java Ty]CdyL$
*/ 5NeEDY2%#
package NetFox; }`
AC(}cMM+
s6).?oE
public class TestMethod { \"PlM!0du
;mo}$^49*
L1"X`Pz[}
public TestMethod() P5vMy'1X
{ ///xx/weblogic60b2_win.exe Ef$xum{
try{ -acW[$t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); } ho8d+A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JCaT^KLz
SiteFileFetch fileFetch = new SiteFileFetch(bean); "Rs^0iT7>
fileFetch.start(); K=Fcy#,f
} })bTQj7
catch(Exception e){e.printStackTrace ();} FAU^(]-5m
;Z.}~d6>!
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} g >-iBxml
.f&,~$e4
I[<C)IG
public static void main(String[] args) 8X*6i-j5E
{ WFN5&7$W
new TestMethod(); FQ(=Fnqn
} _.FxqH>
} JYKA@sZHe
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