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)); !3)WW)"!r
} t!\B6!Fo
for(int i=0;i<nEndPos.length-1;i++) &3 *#h
{ ?N=`}}Ky-
nEndPos = nStartPos[i+1]; ;r}yeISf
} R(f6uO!m
nEndPos[nEndPos.length-1] = nFileLength; @?*; -]#)
} RMHJI6?LB
} e2kW,JV/<$
g(dReC
ej,R:}C%`
//启动子线程 ;)q"X>FMZe
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -8yN6 0|
for(int i=0;i<nStartPos.length;i++) (_=R<:
{ {uurLEe?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3.6Gh|7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JPM~tp?;<
nStartPos,nEndPos,i); :!wl/X ~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *tfD^nctO
fileSplitterFetch.start(); _R}yZ=di
} Lk.tEuj=82
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3F32 /_`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OMAvJzK .
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $r)NL
nEndPos = " + nFileLength); p8j*m~4B
// fileSplitterFetch[nPos.length-1].start(); Muyi2F)j
o37D~V;
0YAH[YF
//等待子线程结束 C!U$<_I\2
//int count = 0; >D%
//是否结束while循环 F+!9T
boolean breakWhile = false; aU*}.{<!
N@X(YlO
hdwF;
while(!bStop) &WZ&Tt/)/
{ z"-oD*ICw
write_nPos(); h@dy}Id
Utility.sleep(500); tLcw?aB
breakWhile = true; j/;wxKW
]f>0P3O5&
EHK+qrym
for(int i=0;i<nStartPos.length;i++) :LCyxLI
{ [\rzXE
if(!fileSplitterFetch.bDownOver) *U-:2uf
{ C;~LY&=
breakWhile = false; B!U;a=ia
break; l{*Ko~g
} e,MgR\F}
} tX6_n%/L
if(breakWhile) qWJHb Dd
break; V''fmWo7
/ ;+Mz*
U4qk<!
//count++; R_b4S%jhx
//if(count>4) b!r%4Ah
// siteStop(); qkqtPbQ 7
} c Qe3
A4(k<<xjE
w c
System.err.println("文件下载结束！"); Eihy|p
} "]|7%]
catch(Exception e){e.printStackTrace ();} }R/we`
} p`EgMzVO,
2#ZqGf.'v
Bo\~PV[
//获得文件长度 8tVSai8[
public long getFileSize() }rUAYr~VZ
{ #8~ygEa}
int nFileLength = -1; KTBtLUH]*F
try{ 9bhubx\^/
URL url = new URL(siteInfoBean.getSSiteURL()); (\o4 c0UzK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5H1N]v+
httpConnection.setRequestProperty("User-Agent","NetFox"); _l+C0lQl=
tEt46]{
w OOu/Y
int responseCode=httpConnection.getResponseCode(); P-<1vfThH
if(responseCode>=400) t+K1ArQc
{ :^U>n{
processErrorCode(responseCode); y06xl:iQwF
return -2; //-2 represent access is error OQB7C0+ &
} OM&GypP6&
4d4+%5GE
]2qKc
String sHeader; M?%x=q\<
!Kg']4
?\,^>4x?
for(int i=1;;i++) [i ~qVn2vT
{ ?zm]KxIC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lYJSg70P
//Utility.log(in.readLine()); u"*DI=pwb
sHeader=httpConnection.getHeaderFieldKey(i); Wu/#}Bw#
if(sHeader!=null) l[ $bn!_e
{ & rab,I"
if(sHeader.equals("Content-Length")) 1VlU'qY
{ ZDbe]9#Xh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q]/%Y[%|
break; QR'#]k;>%
} w"s@q$}]8M
} 60u_,@rV
else #xw*;hW<
break; !LwHKCj
} ~Q]5g7k=&
} ~<n.5q%Z
catch(IOException e){e.printStackTrace ();} )B0%"0?`8
catch(Exception e){e.printStackTrace ();} 0O>ClE~P
~;#}aQYo
Q'jw=w!|g
Utility.log(nFileLength); ikV;]ox
={zTQ+7S`
> ]^'h
return nFileLength; uI/ wR!
} qrlC U4
9DNp
tj[E!
//保存下载信息（文件指针位置） &~Hed_
private void write_nPos() !EhKg)y=
{ @ gWd
try{ ngl +`|u
output = new DataOutputStream(new FileOutputStream(tmpFile)); p|ink):
output.writeInt(nStartPos.length); Pa{
for(int i=0;i<nStartPos.length;i++) f(Of+>
{ z m$Sw0#(
// output.writeLong(nPos); Wq1 jTIQ
output.writeLong(fileSplitterFetch.nStartPos); 6~x'~T
output.writeLong(fileSplitterFetch.nEndPos); 2]]v|Z2M4
} KddCR&
output.close(); PVBz~rG
} ^x: lB>
catch(IOException e){e.printStackTrace ();} C'#)mo_@t
catch(Exception e){e.printStackTrace ();} bPU i44P
} r_#dh
zR^Gy"
gYc]z5`
//读取保存的下载信息（文件指针位置） M>]A!W=
private void read_nPos() -9i7Ja
{ sE6>JaH
try{ aLGq<6Ja
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lr$Mk#'B
int nCount = input.readInt(); {4G/HW28
nStartPos = new long[nCount]; c Rq2 re
nEndPos = new long[nCount]; VIP7j(#t_g
for(int i=0;i<nStartPos.length;i++) `Zm6e!dH-
{ 1^}I?PbqV
nStartPos = input.readLong(); Ec@n<KK#
nEndPos = input.readLong(); 2+ cs^M3
} P.,U>m
input.close(); 6p)AQTh>
} @a?7D;+<
catch(IOException e){e.printStackTrace ();} 5dj@N3ZX7;
catch(Exception e){e.printStackTrace ();} -{xk&EB^$5
} 9_?xAJ
"+ou!YK+
^Fco'nlM
private void processErrorCode(int nErrorCode) 0- )K_JV
{ Gs,:$Im
System.err.println("Error Code : " + nErrorCode); -V|"T+U
} F^75y?
0 Uropam
&xQM!f
//停止文件下载 3c=kYcj
public void siteStop() tTLg;YjN
{ 05`"U#`:
bStop = true; lb-1z]YwQ
for(int i=0;i<nStartPos.length;i++) l?U=s7s0?
fileSplitterFetch.splitterStop(); bx8](cT_
4VwF\
m0"K^p
} TmQIpeych
} pa[/6(
//负责部分文件的抓取 ~P1~:AT
**FileSplitterFetch.java ecghY=%
*/ Hsf::K x
package NetFox; _5jT}I<k
N>!:bF
H4w\e#|
import java.io.*; JNfL jfE)<
import java.net.*; ) CP
F~mIV;BP
{arqcILr
public class FileSplitterFetch extends Thread { D0r viO
147QB+cE
CI'RuR3y]Z
String sURL; //File URL iAwEnQ3h
long nStartPos; //File Snippet Start Position 50^ux:Uv+N
long nEndPos; //File Snippet End Position p+h$]CH
int nThreadID; //Thread's ID vwU1}H
boolean bDownOver = false; //Downing is over hzqJ!
boolean bStop = false; //Stop identical ?nd: :O
FileAccessI fileAccessI = null; //File Access interface hy5[ L`B
4+RR`I8$Ge
@%]A,\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4I$Y(E}
{ u5(8k_7
this.sURL = sURL; <xOX+D
this.nStartPos = nStart; Yq+1kA
this.nEndPos = nEnd; Y^eN}@]?&
nThreadID = id; 7>JTQ CJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d~LoHp
} ')y2W1
2?JV "O=
Lgg,K//g
public void run() =&WIa#!=
{ 'a['lF
while(nStartPos < nEndPos && !bStop) fE-R(9K
{ k6(7G@@}
?Y(
,QY$:f<
try{ +1ICX
URL url = new URL(sURL); 1qRquY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qb>41j9_t
httpConnection.setRequestProperty("User-Agent","NetFox"); *NmY]
String sProperty = "bytes="+nStartPos+"-"; mlnF,+s
httpConnection.setRequestProperty("RANGE",sProperty); UerbNz|
Utility.log(sProperty); fZGY'o&5
qs5>`skX
~]?:v,UIm(
InputStream input = httpConnection.getInputStream(); Aqyw
//logResponseHead(httpConnection); 1)ue-(o5
uE-(^u
<RGH+4LF
byte[] b = new byte[1024]; sTM;l,
int nRead; /eF@a!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S /hx\TzC
{ ;M:AcQZ|_
nStartPos += fileAccessI.write(b,0,nRead); No^gKh24
//if(nThreadID == 1) `2mddx8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `q^#u
} L:$4o
Bm$|XS3cD
*]$B 9zVs!
Utility.log("Thread " + nThreadID + " is over!"); DXs an
bDownOver = true; :<QknU}dwy
//nPos = fileAccessI.write (b,0,nRead); ".?4`@7F\
} XUqorE
catch(Exception e){e.printStackTrace ();} n|(lPbD
} p5G'})x
} b6D;98p
|R`"Zu`
Ipp_}tl_
//打印回应的头信息 R'>!1\?Iq
public void logResponseHead(HttpURLConnection con) ON :t"z5
{ Bn}woyJdx
for(int i=1;;i++) IPQRdBQ
{ a>wCBkD
String header=con.getHeaderFieldKey(i); Ep7MU&O0iK
if(header!=null) 6d-\+t8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4&iQo'
Utility.log(header+" : "+con.getHeaderField(header)); m2(>KMbi
else 4Yj1Etq.E
break; .ZTvOm'mB^
} 5S~ H[>A"
} z$~x 2<
F9K%f&0 a
xye-Z\-t
public void splitterStop() gjS|3ED
{ '!HTE`Aj
bStop = true; po| Ux`u
} K@JZ$
W__ArV2Z_
WyN ;lId
} 0dchOUj
Z(mUU]
\TV
/* XkaREE
**FileAccess.java 1[FN: hm
*//文件访问(定位，写) 5^B79A"}
package NetFox; J=g)rd[`
import java.io.*; O2w-nd74U
zF1!a
Q]ersA8 V>
public class FileAccessI implements Serializable{ |Y9>kXMl
i'IT,jz!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hZ&KE78?
RandomAccessFile oSavedFile; Pfd1[~,
long nPos; @\K[WqF$$q
vsY?q8+P
WtT;y|W
public FileAccessI() throws IOException 8=8hbdy;
{ lx)^wAO4
this("",0); @DN/]P
} q+ax]=w
:U6`n
e4z`:%vy
public FileAccessI(String sName,long nPos) throws IOException Q6h+.
{ <kh.fu@.Q
oSavedFile = new RandomAccessFile(sName,"rw"); -F5BJk
this.nPos = nPos; honh'j
oSavedFile.seek(nPos); $0])%
} 6u[fCGi%
Rh>B# \
$7x2TiAL
public synchronized int write(byte[] b,int nStart,int nLen) s8h*nZ)v
{ <b 5DX
int n = -1; #:K=zV\
try{ F/5&:e?( )
oSavedFile.write(b,nStart,nLen); :eN&wQ5q
n = nLen; tsXKhS;/w
} + G@N
catch(IOException e) tl#sCf!c
{ Vk2$b{VdF
e.printStackTrace (); wKJG 31I^
} '&IGdB I
I"Oq< _
oPe|Gfv\G
return n; x#1Fi$.
} [doEArwn
zakhJ
2W AeSUX
} hnj\|6L
,9&cIUH
d:kB Zrq
/* ?UnQ?F(+G<
**SiteInfoBean.java Jf YgZ\#
*/ Kz HYh
package NetFox; \8vP"Kr
a4Q@sn;]
}(EH5jZ'
public class SiteInfoBean { !fOPYgAGKn
epy2}TI
zsL@0]e&
private String sSiteURL; //Site's URL D|uvgu2
private String sFilePath; //Saved File's Path GppCrQ%Ra|
private String sFileName; //Saved File's Name ,\4]uZ<
private int nSplitter; //Count of Splited Downloading File c_8&4
<WXVUEea
x,B] J4
public SiteInfoBean() 'uL4ezTtA
{//nSplitter的缺省值为5 (x=$b(I
//default value of nSplitter is 5 F*72g)hVh
this("","","",5); RQVu~7d[
} 3j7FG%\
e@D_0OZ
'|8dt "C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <jh4P!\&j
{ MN?aPpr>
sSiteURL= sURL; *`>BOl+ro
sFilePath = sPath; ;[<(4v$
sFileName = sName; =oAS(7o
this.nSplitter = nSpiltter; `YhGd?uu$
zv]ZEWVzc
A3]A5s6
} <PLAAh8
zdN[Uc+1Bd
b:==:d:0s
public String getSSiteURL() z.Cj%N
{ o'2eSm0H
return sSiteURL; YT(N][V
} kx,.)qKk
=p5DT
]#:WL)@
public void setSSiteURL(String value) ,!orD1,'
{ h}Otz "
sSiteURL = value; `/O`%6,f1!
} 6tKrR{3#A
3H2~?CaJ
S<Dbv?
public String getSFilePath() ;V,L_"/X
{ eL3 _Lz
return sFilePath; ;;0'BdsL`
} |UTajEL
o1AbB?%=
:=Olp;+_
public void setSFilePath(String value) B+W7zv
{ P6+ B!pY
sFilePath = value; nI:M!j5s`
} 5(>=};r+
/,\V}`Lx"
-^_2{i
public String getSFileName() VF`!ks
{ fyQOF ItM
return sFileName; (b25g!
} {&5lZ<nu8A
m8sd2&4
.}==p&(
public void setSFileName(String value) f-%M~:
{ \jfK']P/H
sFileName = value; (/:m*x*6
} {JE [
eiMP:
*yBVZD|?H
public int getNSplitter() %8*:VR
{ PaCCUF
return nSplitter; BA@E
} /VYT](
"&6vFmr
^/C\:hw
public void setNSplitter(int nCount) }3 xkA
{ 'f( CN3.!
nSplitter = nCount; X1#Ar)
} s~M$Wo8
} x^ `/&+m
VYG@_fd!x
<6UXk[y
/* PUR,r%K`
**Utility.java uu6 JZp
*/ | 0
package NetFox; jQ{ @ol}n
BUXE s0]Lv
q T6y&
public class Utility { ZJDV'mC}
q`xc h[H
v>8.TE~2
public Utility() ^4`aONydl
{ 0qS/>u*
Wga2).j6
Qs1CK;+zU
} p:08q B|uQ
?%,LZw^[
//线程睡眠 T5:Q_o]
public static void sleep(int nSecond) QAkK5,`vV.
{ |=0vgwd"S
try{ 9pLe8D
Thread.sleep(nSecond); yCQvo(V[F
} OAXA<
catch(Exception e) IxbQ6
{ o GuAF q
e.printStackTrace (); !v8R(
} $Cz2b/O
} s#^0[ Rt
iT'doF
//日志 5}%R
public static void log(String sMsg) #)'Iqaq7
{ )LGVR3#
System.err.println(sMsg); . 1kB8&}
} xJ>5 ol
D!.c??
Y(UK:LZ'
public static void log(int sMsg) ,`f]mv l
{ Im6gWDdq@6
System.err.println(sMsg); v0C+DKi
} |]G%b[
} aM~IRLmK
cKTjQJ#
Ta\F~$M
/* u8c@q'_
**TestMethod.java }ny7LQ
*/ #B\s'j[A"
package NetFox; 2"D4q(@
k A3K
]Thke 4
public class TestMethod { t4oD> =,92
rl}<&aPH
KKC%!Xy
public TestMethod() n.g-%4\q
{ ///xx/weblogic60b2_win.exe 8:0/Cj
try{ h*R@ d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r^5%0_F]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8i',~[
SiteFileFetch fileFetch = new SiteFileFetch(bean); I8XP`Ccq
fileFetch.start(); ^6 wWv&G[8
} sU>IETo
catch(Exception e){e.printStackTrace ();} P*KIk~J
,sitOy}ks
o< @![P
} rd7p$e=i
lp(2"$nQ
'~Y@HRVL@|
public static void main(String[] args) _:[@zxT<x
{ kWW2N0~$
new TestMethod(); -=5~h
} ].Yz =:
} q8P&rMwy
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