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)); p?# pT}1
} nlc.u}#
for(int i=0;i<nEndPos.length-1;i++) },@``&e
{ 5MF#&v
nEndPos = nStartPos[i+1]; 94/BG0
} )8,|-o=
nEndPos[nEndPos.length-1] = nFileLength; eSfnB_@x2
} Y@uh[aS!
} 4w93}t.z
Z[?mc|*x
]Oeh=gq
//启动子线程 h4)Bs\==mT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7TX2&kMoc
for(int i=0;i<nStartPos.length;i++) xZ.!d.rn
{ Bp?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &7>zURv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w7TJv4_
nStartPos,nEndPos,i); $B(kZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 33Az$GXFsq
fileSplitterFetch.start(); 2C=Q8ayvX
} 7DD&~ZcD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #7G*GbKY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J G$Z.s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G~,:2 o3
nEndPos = " + nFileLength); WsGths+[
// fileSplitterFetch[nPos.length-1].start(); lioc`C:
Dw6fmyJ:
b:W-l?
//等待子线程结束 E4z)Mr#
//int count = 0; (?0`d
//是否结束while循环 bHE2,;o
boolean breakWhile = false; r! %;R?c
|nUl\WRd\
78 f$6J q
while(!bStop) kz}R[7
{ @N@F,~[RR2
write_nPos(); 3gEMRy*+
Utility.sleep(500); HD>q(cK_|8
breakWhile = true; bulS&dAX
xc@Ss[
=qy@Wvj$
for(int i=0;i<nStartPos.length;i++) `G9 l
{ 5GzFoy)j>
if(!fileSplitterFetch.bDownOver) TrS8h^C
{ LeOP;#
breakWhile = false; (Z]HX@"{J
break; Kn`M4O
} <AH1i@4
} sgUud_r)4
if(breakWhile) *ISZlR\#
break; !]yO^Ob.E
KngTc(^_D
942lSyix
//count++; mHc>"^R
//if(count>4) FS6`6M.K
// siteStop(); dt@P>rel
} 2Os1C}m
Qn@Pd*DR
'a6<ixgo0
System.err.println("文件下载结束！"); O^Q7b7}y
} ~^jq(:d)
catch(Exception e){e.printStackTrace ();} CNZz]H
} &#`l;n:]+
1\*\?\T>_
T;TA7{B
//获得文件长度 @gC=$A#
public long getFileSize() l e4?jQQ@L
{ +ZMls [
int nFileLength = -1; @mP]*$00
try{ t_^X$pL
URL url = new URL(siteInfoBean.getSSiteURL()); Fb22p6r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )SF}2?7e
httpConnection.setRequestProperty("User-Agent","NetFox"); `{k"8#4:qA
x+8_4>,>Y7
afBE{
int responseCode=httpConnection.getResponseCode(); 2Y\ d<.M
if(responseCode>=400) {9Y+.46S
{ D"(L5jR8m@
processErrorCode(responseCode); g[RI.&?
return -2; //-2 represent access is error 4fk8*{Y
} y;wx?1)
ULrr=5&8
!* Ti}oIo&
String sHeader; Q1d'~e
'.Ed`?<p
-i0(2*<
for(int i=1;;i++) Un`^jw#_
{ J%09^5:-z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4;n6I)&.(
//Utility.log(in.readLine()); ,YTIC8qKr
sHeader=httpConnection.getHeaderFieldKey(i); U$]|~41#
if(sHeader!=null) vE@!{*
{ ~(!XY/0e
if(sHeader.equals("Content-Length")) &,A64y
{ ?Nf>]|K:Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gVQjL+_W
break; Nkxmm/Z
} 0"2=n.##
} m(RXJORI
else Y}#h5\
break; \%PaceH
} 1XM^8 .;
} ku$$ 1xq
catch(IOException e){e.printStackTrace ();} S}APQ
catch(Exception e){e.printStackTrace ();} JD@J[YY5R
Tc8un.
N\:. M
Utility.log(nFileLength); eP*lI<NQ1
{ eCC$&"
Y<1QY?1sd
return nFileLength; J)P$2#
} /VmR<C?h
R\o<7g-|
yFDv6yJ.
//保存下载信息（文件指针位置） m_?d=o
private void write_nPos() MZ Aij
{ R|O8RlH
try{ HGm 3+,
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6qcO?U
output.writeInt(nStartPos.length); 9Gv[8'I
for(int i=0;i<nStartPos.length;i++) 'YNT8w/3
{ =]:>"_jN
// output.writeLong(nPos); GKN%Tv:D_
output.writeLong(fileSplitterFetch.nStartPos); !vG'J\*xc
output.writeLong(fileSplitterFetch.nEndPos); WVVJ
} 'cY` w
output.close(); Y3Vlp/"rB"
} $)3%U?AP
catch(IOException e){e.printStackTrace ();} #fT*]NN
catch(Exception e){e.printStackTrace ();} m[j70jYe
} LPMU8Er
J[f;Xlh
:0s]U_h
//读取保存的下载信息（文件指针位置） x|yEtO&
private void read_nPos() vAyFmdJ^
{ m(pE5B(
try{ 7S?4XyU/o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LpR3BP@At
int nCount = input.readInt(); `rf_7
nStartPos = new long[nCount]; w)Covz'uf
nEndPos = new long[nCount]; @V03a )6,h
for(int i=0;i<nStartPos.length;i++) Eb=}FuV
{ XC.%za8
nStartPos = input.readLong(); @|Rrf*J?%
nEndPos = input.readLong(); \Y"Wu
} 2WU@*%sk"
input.close(); /yM:|`tT
} m1Y>Nj[f
catch(IOException e){e.printStackTrace ();} a4irokJv#
catch(Exception e){e.printStackTrace ();} 4:U?u
} BJ% eZ.
_YF%V;X
`FoxP
private void processErrorCode(int nErrorCode) X7s `U5'l
{ ^tXJj:wtS
System.err.println("Error Code : " + nErrorCode); zbq@pj)Qu
} 6R=W}q4
27;ci:5
J~#;<e{\"
//停止文件下载 D1__n6g[
public void siteStop() N^3N[lD{
{ Fd0%lnui
bStop = true; !?|Th5e
for(int i=0;i<nStartPos.length;i++) CiB%B`,N
fileSplitterFetch.splitterStop(); 9W(dmde>
lbpq_=
V0)fZS@tf
} 8']9$#
} s8}@=]aA
//负责部分文件的抓取 \hB5@e4i2
**FileSplitterFetch.java uDEvzk42
*/ V7/I>^X
package NetFox; Q[nEsYP
mauI42
gG/!,Q.Qh
import java.io.*; fMOU$0]$<
import java.net.*; EW3(cQbK
k1QpKn*
fl\ly`_
public class FileSplitterFetch extends Thread { j$+nKc$
TA{\PKA)
]Ux<aiY]a
String sURL; //File URL 5H ue7'LS
long nStartPos; //File Snippet Start Position 8 XU1/i7N
long nEndPos; //File Snippet End Position >Q(3*d >
int nThreadID; //Thread's ID 3+XOZh8
boolean bDownOver = false; //Downing is over 3`k;a1Z#O'
boolean bStop = false; //Stop identical Zl*X?5u
FileAccessI fileAccessI = null; //File Access interface KQ~i<1&j
7AObC4 g
[i]Ub0Dh7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SLh(9%S;
{ Dc_yM
this.sURL = sURL; @;'o2
this.nStartPos = nStart; C+TI]{t
this.nEndPos = nEnd; qzTuxo0B
nThreadID = id; )a-Du$kd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d+'p@!W_
} ariLG [:X
@7B$Yy#
.C--gQpIv
public void run() +(h\fm7*-
{ rYbpih=x
while(nStartPos < nEndPos && !bStop) ({q?d[q[
{ RO.k]x6
o#skR4lwe
Rb.SY{}C
try{ uXKERzg
URL url = new URL(sURL); Ry'= ke
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _A=$oVe
httpConnection.setRequestProperty("User-Agent","NetFox"); 1&- </G#
String sProperty = "bytes="+nStartPos+"-"; )'~6HO8Z
httpConnection.setRequestProperty("RANGE",sProperty); ={z*akn,
Utility.log(sProperty); $g sxO!G
{HCzp,Y
Rp5#clsy
InputStream input = httpConnection.getInputStream(); ?#45wC
//logResponseHead(httpConnection); 7Zh~lM
$fzaPD4.
f\jLqZY
byte[] b = new byte[1024]; e:5bzk!~
int nRead; xftBSdVE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c`o7d)_Ke
{ }b-g*dn]5
nStartPos += fileAccessI.write(b,0,nRead); ~x|F)~:0=
//if(nThreadID == 1) uH(f$A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /C6k+0ApMT
} N|6MP e
](s'L8(x
6*3.SGUY
Utility.log("Thread " + nThreadID + " is over!"); RS^lKJ1 U
bDownOver = true; L>3x9
//nPos = fileAccessI.write (b,0,nRead); eN^qG 42
} 43@{JK9G
catch(Exception e){e.printStackTrace ();} /\hzb/
} HbxL:~:}J
} |g//g\dd
]]*7\ :cb
D/Mi^5H)
//打印回应的头信息 sPR1?:0:
public void logResponseHead(HttpURLConnection con) MP>dW nl
{ v~^{{O
for(int i=1;;i++) $GTU$4u
{ fe9LEM8j
String header=con.getHeaderFieldKey(i); [Ki0b^
if(header!=null) zlEX+=3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]VD|xm:kj
Utility.log(header+" : "+con.getHeaderField(header)); QC9eUYe
else #n#@fAY
break; K[!&b0O
} IkGfnXJ
} *exS6@N]
1fZ(l"
L{8xlx`
public void splitterStop() !K'}K>iT
{ TL}++e 7+
bStop = true; %y@Hh=
} K5xX)oV
D"a~#^
uLWh|
} njWL U!
jW 3c"
/N&CaH\;^$
/* ;N0~;I
**FileAccess.java n:{qC{D-qS
*//文件访问(定位，写) uA#P'?
package NetFox; ;{U@qQD7
import java.io.*; n6BQk2l
0sfr d
U G~ba
public class FileAccessI implements Serializable{ tF{D= ;G
YJJB.hR+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a-|*?{o
RandomAccessFile oSavedFile; 4X+ifZO
long nPos; e,Uo#T6J
d~1gMz+)
M!REygyx
public FileAccessI() throws IOException v5QqS8u_C
{ LC'{p
this("",0); +PcmJ
} c+hQSm|bf)
paD!Z0v&
7r~~Y%=C|
public FileAccessI(String sName,long nPos) throws IOException t+1 %RyKFB
{ TjwBv6h
oSavedFile = new RandomAccessFile(sName,"rw"); ^$'z!+QRM
this.nPos = nPos; p IU&^yX>
oSavedFile.seek(nPos); .ZJRO>S
} +h r@#n4A
RM!<8fXYD
9*{[buZX
public synchronized int write(byte[] b,int nStart,int nLen) )~HUo9K9
{ +i@y@<l:+
int n = -1; !U'QqnT
try{ L_wk~z
oSavedFile.write(b,nStart,nLen); nh!a)]c[
n = nLen; '8{Ne!y
} -\ EP.Vtz
catch(IOException e) DUC#NZgw
{ !>zo_fP
e.printStackTrace (); 4'!c*@Y
} ?C&z]f3(:
K0}pi+=
cM$P`{QrM
return n; 8>WC5%f*
} dAkgR~
@jsDq Ln
(?(zH3
} =Q+= f
/7t>TYip!
](wvu(y\E
/* Ns7(j-
**SiteInfoBean.java xx{PespNt
*/ o'f?YZ$.
package NetFox; t ]_VG
Pyb Z)5u
LRb{hUt=
public class SiteInfoBean { p%*%n3bw
A<qTg`gA
xK6n0] A
private String sSiteURL; //Site's URL I~Zh@d%
private String sFilePath; //Saved File's Path w6{TE(]zp
private String sFileName; //Saved File's Name P#XID 2;
private int nSplitter; //Count of Splited Downloading File O]1y0BOQ
*Of4o
Z`KC%!8K
public SiteInfoBean() Nz],IG.
{//nSplitter的缺省值为5 RWgNo#<
//default value of nSplitter is 5 JQ6zVS2SSS
this("","","",5); oIb|*gX^
} Vc2A
n3D;"a3
d[V;&U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o8-^cP1
{ LS88.w\=S@
sSiteURL= sURL; Zy(W^~NT
sFilePath = sPath; 8$;=Uf,x
sFileName = sName; ]2\VweV
this.nSplitter = nSpiltter; ] 0B2# d
p|&Yku=
2L} SJUk*
} g#t[LI9(F[
}7 c[Q($K
\V*xWS
public String getSSiteURL() .5y+fL
{ |qmu_x\
return sSiteURL; gm[z[~X@
} {yB&xj[z
aM:nOt" S1
$l|qk z
public void setSSiteURL(String value) HLZ;8/|48m
{ U~j ^I^
sSiteURL = value; ZsOIH<}S
} @)4]b+8Z
.b6VQCS~9
s#tZg
public String getSFilePath() 0iwZT&O
{ ^k#P5oV
return sFilePath; k+8q{5>A<
} h_T7% #0
%]8qAtV^3j
%+K<<iyR|
public void setSFilePath(String value) |>JS!NM I
{ Wu_kx2h
sFilePath = value; 9)gC6IiW
} nY`RRC
2VJR$Pao
%^>ju;i^O
public String getSFileName() y10h#&k
{ ~ y;6W0x
return sFileName; 26k LhFS
} FcYFovS
L>a
V` 1/SQX
public void setSFileName(String value) 2h=!k|6
{ MvWaB
sFileName = value; x`dHJq`_g
} FTQ%JTgT
lAJxr8 .
`/ q|@B7
public int getNSplitter() PX n;C/
{ AG?dGj^
return nSplitter; y1bbILWej
} $a"n1ou
s+EAB{w$
Gmq/3tw
public void setNSplitter(int nCount) ?hWwj6i&
{ 9=V:&.L
nSplitter = nCount; HOE_S!N
} a8i]]1Blz
} W034N[9
|<.lW
y?a Acn$
/* Ie`13 L2
**Utility.java QZ:8+[oy
*/ PV/77{'
package NetFox; \a6^LD}B
Z]j*9#G1s
]jaQ[g$F
public class Utility { V8HnUuz
pk3<|
6u`)QUmItg
public Utility() C~N/A73gF
{ %y|)=cm[
:xh?eN&
d_)o
} ,>eMG=C;g
0\@dYPa&C
//线程睡眠 , 'ZD=4_
public static void sleep(int nSecond) LjUy*mxw
{ lq>+~zX{
try{ jp"JafS/E
Thread.sleep(nSecond); L?Qg#YSd~
} ( |PAx(
catch(Exception e) \CXQo4P
{ !\"5rNy
e.printStackTrace (); MV\|e1B}
} W'.s\e?gh
} >b6-OFJx
k?z98 >4
//日志 ?F6pEt4
public static void log(String sMsg) _',prZ*
{ ,Td!|~I|j6
System.err.println(sMsg); 'eJ+JM<0%
} bD[!/'4eJ
M5*{
C_n9T{k
public static void log(int sMsg) hvuIxqv!y
{ %9M~f*
System.err.println(sMsg); I-WhH>9
} 0em#-*|2"
} YR>B_,Gl
B,K>rCZ/
FcRW;e8-
/* _jNj-)RB_
**TestMethod.java v}tag#f5>?
*/ +AHUp)
package NetFox; W0k0$\iX
<0QH<4
=ZDAeVz3w
public class TestMethod { sm\f0P!rv
F^5?\
sp5eVAd
public TestMethod() Tjl:|F8
{ ///xx/weblogic60b2_win.exe 8&Oa_{1+Q
try{ &s$(g~ 4gC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .GsO.#p{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -Y*bSP)\
SiteFileFetch fileFetch = new SiteFileFetch(bean); zD(`B+
fileFetch.start(); VsN pHQG]
} a_ `[Lj
catch(Exception e){e.printStackTrace ();} SnFk>`
( @3\`\X
mdq;R*`
} r; xLP
{.De4]ANh
CMCO}#
public static void main(String[] args) |R56ho5C
{ Wt=|
new TestMethod(); +\|Iu;w
} _`I"0.B]
} F@*+{1R
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