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)); cl4_M{~
} .)WEg|D0Ku
for(int i=0;i<nEndPos.length-1;i++) s~>1TxJe
{ -O1$jBQS
nEndPos = nStartPos[i+1]; t\YM Hq<Y
} b+arnKo1fk
nEndPos[nEndPos.length-1] = nFileLength; %;u"2L0@
} L[nDjQn"
} CSW+UaE
0,@^<G8?
?tqJkL#
//启动子线程 S#yGqN0i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [.Fq l+
for(int i=0;i<nStartPos.length;i++) W)T'?b'.
{ D{y7[#$h$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Eld[z{n"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #+U1QOsz
nStartPos,nEndPos,i); gE^pOn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a(?)r[=
fileSplitterFetch.start(); Wuk8&P3
} / bH2Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W4k$m2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t18j2P>`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Os9EMU$
nEndPos = " + nFileLength); /~;!Ew|q
// fileSplitterFetch[nPos.length-1].start(); 'PFjZGaKR
-K8F$\W
r1vS~ 4Z
//等待子线程结束 ns\I Y<Yo
//int count = 0; H7Z`aQC
//是否结束while循环 |7A}LA
boolean breakWhile = false; $$o(
m`q&[:
-}!miV
while(!bStop) kFmtE dhsc
{ LA2/<:
write_nPos(); P,-5af*;
Utility.sleep(500); BV7P_!vt
breakWhile = true; cqs.[0 z#B
NR8`nc1~
YtWw)IK
for(int i=0;i<nStartPos.length;i++) a:HN#P)12
{ <pHm=q/U
if(!fileSplitterFetch.bDownOver) aL90:,V
{ GGcODjY>
breakWhile = false; b30Jr2[
break; $)9|"q6
} +0Q +0:
} 7(tsmP
if(breakWhile) Nz`v+sp
break; |Z2"pV
A4#FAFy
zG9D Ph
//count++; Y[}A4`
//if(count>4) n9J{f"`m
// siteStop(); +5Dc5Bl
} tQNrDp+
3^y<Db
3Os0<1@H
System.err.println("文件下载结束！"); ['pO=ho
} 2;:p H3
catch(Exception e){e.printStackTrace ();} 4Nt4(3Kf
} dlCYdwP
[Eu)~J*
ZxT E(BQv
//获得文件长度 X~"p]V_
public long getFileSize() vS0 ii
{ R0tT4V+
int nFileLength = -1; Ny$3$5/
try{ ?#Z4Dg 9|
URL url = new URL(siteInfoBean.getSSiteURL()); >8OY6wb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u)o-H!a
httpConnection.setRequestProperty("User-Agent","NetFox"); MO7R3PP
D^. c:
T7.SjR6X>
int responseCode=httpConnection.getResponseCode(); *xsBFCRU
if(responseCode>=400) zixG}'
{ m26YAcip}
processErrorCode(responseCode); ~v pIy-
return -2; //-2 represent access is error \'Et)uD*
} 3Xd:LDZ{
<y^_&9
FibZT1-k
String sHeader; -40X3
$,, PF/N8c
>JS^yVk
for(int i=1;;i++) ^4"AWps
{ P,'%$DLDg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *.|%uf.
//Utility.log(in.readLine()); C]5 kQ1Og
sHeader=httpConnection.getHeaderFieldKey(i); 1@KiP`DA
if(sHeader!=null) -XCs?@8EQ
{ \DZ.#=d
if(sHeader.equals("Content-Length")) SKnYeT
{ `{Q'iydU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hPBBXj/=
break; 8t*sp-cy|
} 3lpxh_
} llX `
else q: FhuOP
break; X]@"ZV[
} Po@;PR=
} |w{Qwf!2
catch(IOException e){e.printStackTrace ();} U[?_|=~7
catch(Exception e){e.printStackTrace ();} +@3+WD
5{V"!M+<
1r$-Uh
Utility.log(nFileLength); TQ4L~8
I)FFh%m<}a
~r8<|$;
return nFileLength; =#W:z.w
} {E Ay~lo
7mMGH(
(wZ!OLY%}
//保存下载信息（文件指针位置） z6E =%-`
private void write_nPos() 4mo/MK&M:
{ mXyP;k
try{ [q[37;ZEQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); ; o_0~l=-/
output.writeInt(nStartPos.length); 0!dNW,NfJ
for(int i=0;i<nStartPos.length;i++) #'s$6gT=
{ TxG@#" ^g}
// output.writeLong(nPos); [//i "Nm
output.writeLong(fileSplitterFetch.nStartPos); wX]$xZ!s
output.writeLong(fileSplitterFetch.nEndPos); *%KIq/V
} "E2 0Y"[h
output.close(); lY tt|J
} zG='U
catch(IOException e){e.printStackTrace ();} {HEWU<5
catch(Exception e){e.printStackTrace ();} 8~C}0H
} xE<H@@w
d[3me{Rs
gE\ ^ vaB
//读取保存的下载信息（文件指针位置） %BkE %ZcZ
private void read_nPos() C+s/KA%
{ a`w=0]1&*
try{ (?1$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9#:nlu9
int nCount = input.readInt(); 2w7$"N
nStartPos = new long[nCount]; Zio!j%G
nEndPos = new long[nCount]; *Sj)9mp
for(int i=0;i<nStartPos.length;i++) NzQvciJ@"
{ q%;cu1^"M
nStartPos = input.readLong(); ^vd$j-kjTP
nEndPos = input.readLong(); W$hCI)m(
} ~q566k!Ll!
input.close(); PkDt-]G.
} @9 S ::
catch(IOException e){e.printStackTrace ();} #0<pRDXj
catch(Exception e){e.printStackTrace ();} C<^i`[&P$
} &EV%g6
c2g[w;0"
{k.:DH)
private void processErrorCode(int nErrorCode) x!GDS>
{ aF?_V!#cT
System.err.println("Error Code : " + nErrorCode); PM84Z@Y
} IwnDG;+Ap
lF(v<drkB
:.g/=Q(T~
//停止文件下载 y{mt *VA4
public void siteStop() e#HPU
{ tjtvO@?1-
bStop = true; ?Sh]kJO
for(int i=0;i<nStartPos.length;i++) |"LHo H
fileSplitterFetch.splitterStop(); g]&fyB#
G]aey>)
a%`Yz"<lQ
} ++,I`x+p
} 1r>]XhRFZ
//负责部分文件的抓取 |k6+- 1~_
**FileSplitterFetch.java p)B/(%
*/ QO;Dyef7b
package NetFox; 1<m`38'
(k!7`<k!Y
GZaB z#U
import java.io.*; WZ?>F
import java.net.*; JR`$t~0t
%_s)Gw&sq
0a:oC(Ak
public class FileSplitterFetch extends Thread { B;[ .u>f
<1I4JPh>x
c9EtUv~
String sURL; //File URL #w|v.35%?
long nStartPos; //File Snippet Start Position ?QffSSj[s
long nEndPos; //File Snippet End Position K.QSt
int nThreadID; //Thread's ID hGD@v{/
boolean bDownOver = false; //Downing is over _(J#RH
boolean bStop = false; //Stop identical k vZw4Pk
FileAccessI fileAccessI = null; //File Access interface [#Apd1S_
eV}"L:bgJ
npzp/mcIe)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h'em?fN(
{ =At" Q6-O
this.sURL = sURL; tm5{h{AM
this.nStartPos = nStart; A^).i_&#
this.nEndPos = nEnd; !aUYidd
nThreadID = id; L<=Dl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =_BHpgL
} l9uocP:D
B0|W
b%MZfaU
public void run() O'(Us!aq
{ DcBAncsK
while(nStartPos < nEndPos && !bStop) ^X{U7?x
{ ?l%4 P5
MuMq%uDA"
=| T^)J
try{ z<9C-
URL url = new URL(sURL); &1<[@:;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M>5OC)E
httpConnection.setRequestProperty("User-Agent","NetFox"); "|I.j)
String sProperty = "bytes="+nStartPos+"-"; Y _`JS;
httpConnection.setRequestProperty("RANGE",sProperty); rkji#\_-FV
Utility.log(sProperty); 3m75mny
'6vo#D9M
v3cMPN
InputStream input = httpConnection.getInputStream(); OEaL2T
//logResponseHead(httpConnection); D+:s{IcL<
./;uhj
#z>I =gl
byte[] b = new byte[1024]; =&08s(A
int nRead; b?OA|JqX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >6yQuB
{ py7Zh%k
nStartPos += fileAccessI.write(b,0,nRead); IrZ\;!NK
//if(nThreadID == 1) s9"X.-!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [err$
} ]/Nt
xdbzpU
9d|8c > I
Utility.log("Thread " + nThreadID + " is over!"); v`QDms,{
bDownOver = true; [;IEZ/ZX
//nPos = fileAccessI.write (b,0,nRead); dakHH@Q
} {+#{Cha
catch(Exception e){e.printStackTrace ();} VD&wO'U
} 2?%4|@*H?
} ?bM%#x{e
T8\@CV!
!m:WoQ/
//打印回应的头信息 p5E okh
public void logResponseHead(HttpURLConnection con) ;6R9k]5P%
{ #2i$:c~
for(int i=1;;i++) XdThl
{ 7r?,wM
String header=con.getHeaderFieldKey(i); VRY(@# q
if(header!=null) |sr\SCx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5@1h^wv
Utility.log(header+" : "+con.getHeaderField(header)); jt}oq%Bf
else 5'f_~>1Wt
break; } 'xGip@W
} X\!q8KEpR&
} [sG`D-\P[
$:5h5Y#z
D3aX\ NGP
public void splitterStop() 16eP7s
{ uq9mq"
bStop = true; j%3$ytf|p
} `f}ZAX
OQ2G2>p
fhZwYx&t
} =>PX~/o
p&Nav,9x
{BM:c$3@j
/* n1|]ji[c
**FileAccess.java #]+BIr`
*//文件访问(定位，写) hb~d4J=S
package NetFox; "?k'S{;
import java.io.*; ,[p?u']yZz
NM9ViYm>P
yD3vq}U!
public class FileAccessI implements Serializable{ YdvXp/P:|
anz7ae&P'K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Kc r)W
RandomAccessFile oSavedFile; W'k&DKhTqF
long nPos; 1G`5FU
as3uz
UE_>@_T
public FileAccessI() throws IOException k(>J?\iNW
{ !#]kzS0
this("",0); V^qBbk%l>D
} w0js_P-uv
E.$//P n|1
y'f-4E<
public FileAccessI(String sName,long nPos) throws IOException i)@vHh82
{ i-0AcN./p
oSavedFile = new RandomAccessFile(sName,"rw"); \K9Y@jnr
this.nPos = nPos; gDfM}2]/
oSavedFile.seek(nPos); /Y\q&}
} ,trh)ZZYW|
z&GGa`T"
vA*NJ%&`
public synchronized int write(byte[] b,int nStart,int nLen) S#+ _HFUK{
{ gcX
int n = -1; +f]I7e:qp
try{ ,V4pFQzL
oSavedFile.write(b,nStart,nLen); . VI #
n = nLen; &n6 |L8
} =|-xj h
catch(IOException e) Z#%77!3
{ &@7|_60
e.printStackTrace (); `~=Is.V[
} ?K}KSJ6_
wL0"1Ya
~;I{d7z,;
return n; A]V<K[9:b
} H<b4B$/
SR)@'-Wd
5o(=?dXm4
} NX+ eig</-
m} =<@b:l
H~*[v"
/* ^T@-yys
**SiteInfoBean.java ?~VevD
*/ HoM8V"8B
package NetFox; M[T!AO-S$
P|)SXR
n_] OYG>U
public class SiteInfoBean { 0$nJd_gW_
1hp@.Fv
`+@%l*TQ
private String sSiteURL; //Site's URL ]zK} X!
private String sFilePath; //Saved File's Path wY}+d0Ch
private String sFileName; //Saved File's Name .~8IW,[
private int nSplitter; //Count of Splited Downloading File 3?/}
1-gX=8]]
~yf5$~Z
public SiteInfoBean() EA>$t\z
{//nSplitter的缺省值为5 <~8W>Y\m
//default value of nSplitter is 5 }#u}{
this("","","",5); X!_OOfueP8
} bm7$DKp#
]X _&
khu,P[3>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AAl`bhx'n
{ ~d5{Q?T)
sSiteURL= sURL; cRfX
sFilePath = sPath; y.eBFf
sFileName = sName; Pr/&p0@aV
this.nSplitter = nSpiltter; (}qLxZ/U
W]*wxzf!5z
3i$AR
} `") I[h
bKaV]Uy
;~q)^.K3
public String getSSiteURL() Tp6ysjao
{ !c`1~a!
return sSiteURL; ^ pR&
} BzUx@,
4* hmeS"
&boBu^,94
public void setSSiteURL(String value) e)bqE^JP
{ Tuy*Df
sSiteURL = value; +[7u>RJ
} 6u7HO-aa
y@z#Jw<
O&0R ~<n
public String getSFilePath() d16PY_
{ ,J#5Y.
return sFilePath; u60l-
} xMh&C{q
?0<3"2Db~
A,/S/_Q=
public void setSFilePath(String value) rYqvG
{ ouI0"R&@
sFilePath = value; &Gt9a-ne
} BW;u?1Xa
,5*4%*n\
3IxT2@H)
public String getSFileName() /L 4WWQ5
{ f<'C<xnf
return sFileName; 3N21[i2/m
} lb('r"*.
EIfrZg7R
4c yv 8
public void setSFileName(String value) ]9:G3vq
{ WveFB%@`;
sFileName = value; td~3N,S
} \NqC i'&
9+']`=a:
Z-?9F`}
public int getNSplitter() hdB[H8Q
{ pf_ /jR
return nSplitter; V_kE"W)
} `4qKQJw
ao!r6:&v$e
#rwR)9iC0
public void setNSplitter(int nCount) ^b~5zhY&
{ ^q`*!B9@
nSplitter = nCount; \zUsHK?L"t
} mI%/k7:sf
} u/f&Wq/
/WfxI>v
|*5nr5c_L
/* 5,Y2Lzr
**Utility.java kR]SxG9
*/ A@OV!DJe]
package NetFox; rWXW}Yg
jlBCu(.,_
%K7}yy&9C
public class Utility { 4;||g@f'[
|_*$+
I\~V0<"jI
public Utility() ]Yex#K
{ Hi9z<l=$
|Y11sDa9h
t,,^^ll
} rYQ@"o0/Y
M'iKk[Hjfx
//线程睡眠 r `dU (T!
public static void sleep(int nSecond) ?xZmm%JF
{ 1`{ib
try{ K~-XDLh5Nu
Thread.sleep(nSecond); rR~X>+K
} S+Yg!RrNqj
catch(Exception e) =1\wZuK#
{ [!mjUsut*
e.printStackTrace (); qGCg3u6
} I/jr`3Mj
} KCE-6T
[i7)E]*oTA
//日志 J *?_SnZ
public static void log(String sMsg) 9AzGk=^
{ +=Wdn)T
System.err.println(sMsg); D:tZiS=0
} q&T'x> /
[uQZD1<q
22~X~=
public static void log(int sMsg) cV,Dl`1r
{ {PtTPz
System.err.println(sMsg); 1o78e2B
} ]_8I_VcQ
} `|Z@UPHzG
%W;Gf9.w
\|`Pul$
/* Tk&9Klo
**TestMethod.java v:1Vli.
*/ h##?~!xDmq
package NetFox; .oN Sg.jG
.MARF
+N:6wZ7<f
public class TestMethod { =3dbw8I
%uqD\`-
9XvM%aHs:
public TestMethod() sNmC#,
{ ///xx/weblogic60b2_win.exe s^'#"`!v=
try{ VQjFEJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KVpAV$|e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E/$@ud|l"
SiteFileFetch fileFetch = new SiteFileFetch(bean); P3ev4DL
fileFetch.start(); 42wC."A
} Z)T@`B6
catch(Exception e){e.printStackTrace ();} ,h.Jfo54,
TxxB0
mW0&uSMD
} gdFoTcHgO|
f<4q]HCa
&t|V:_?/x
public static void main(String[] args) c0Ro3j\p
{ ^ R^N`V
new TestMethod(); $o$Ev@mi
} ^npS==Y]!.
} (VPM>ndkw
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