http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); "{r8'qn
} 9tU"+
for(int i=0;i<nEndPos.length-1;i++) O Bcz'f~
{ ]E-3/r$_cO
nEndPos = nStartPos[i+1]; 1I`F?MT
} $cK}Tlq
nEndPos[nEndPos.length-1] = nFileLength; A yr,
} wgIm{;T[u
} #Lpw8b6
[Q{\Ik
?)J/uU2w
//启动子线程 JH{/0x#+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~Ni
for(int i=0;i<nStartPos.length;i++) o5p{ O>D[z
{ F{;#\Ob
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }3A~ek#*~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \?]U*)B.r
nStartPos,nEndPos,i); nKzm.D gt_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g=[OH
fileSplitterFetch.start(); rbnAC*y8'L
} pHmqwB~|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XrM+DQ;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gn=b_!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4P[MkMoC
nEndPos = " + nFileLength); kBhjqI*
// fileSplitterFetch[nPos.length-1].start(); e2v`
{daX?N|V
+HBizJ9K
//等待子线程结束 L~-/'+
//int count = 0; pDZewb&cA
//是否结束while循环 >STthPO
boolean breakWhile = false; 7bk77`qWr
dkz% Y]
uUg;v/:
while(!bStop) #<< el;n
{ L&DjNu`!9
write_nPos(); Sc]K-]1(H
Utility.sleep(500); iq*im$9J
breakWhile = true; x)*Lu">
72d|Jbd
?/OF=C#
for(int i=0;i<nStartPos.length;i++) ~*7$aj
{ 0t?o6e
if(!fileSplitterFetch.bDownOver) o3dqsQE%
{ )][U6e
breakWhile = false; I4G0!"T+
break; LWv<mtuYf
} b'\Q/;oz>
} T8a' 6otc
if(breakWhile) y<kUGsD
break; RbL?(
,Q56A#Y\
r@3-vLI!u
//count++; U}5fjY
//if(count>4) V*b/N
// siteStop(); Cu8mNB{H
} 3~T ~Bs
ekvs3a^
(O{OQk;CF
System.err.println("文件下载结束！"); fr/EkL1Dl
} ?4%H(k5A
catch(Exception e){e.printStackTrace ();} [(@K;6o
} -y-}g[`
3A!a7]fW
gZ4' w`4r
//获得文件长度 sNDo@u7
public long getFileSize() fgd2jr3T
{ x|a&wC2,{
int nFileLength = -1; VkFh(Br<{
try{ 4%J0e'iN
URL url = new URL(siteInfoBean.getSSiteURL()); ot<d FvD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p[JIH~nb
httpConnection.setRequestProperty("User-Agent","NetFox"); uC;_?Bve
3<&:av3
YSeH;<'
int responseCode=httpConnection.getResponseCode(); u9"yU:1keb
if(responseCode>=400) rS_G;}Zr
{ 2{&A)Z!I
processErrorCode(responseCode); bI &<L O
return -2; //-2 represent access is error @4*:qj?
} U`qkeNd
Mpojabsh
p qz~9y~
String sHeader; GK}52,NM
M!J7Vj?Ps
d <}'eBT'
for(int i=1;;i++) kM506U<g
{ TI DgIK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vW=-RTRH
//Utility.log(in.readLine()); 'hjEd.
sHeader=httpConnection.getHeaderFieldKey(i); h.X4x2(.
if(sHeader!=null) ML_VD*t9
{ euB1}M
if(sHeader.equals("Content-Length")) fB3Jp~$
{ pq{`WgA^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f\hMTebma$
break; ]?4;Lw
} A4tk</A
} tLy:F*1i
else ^xa, r#N:V
break; R'v~:wNTNs
} &IQ=M.!r
} uI-T]N:W8x
catch(IOException e){e.printStackTrace ();} 2|>\A.I|=
catch(Exception e){e.printStackTrace ();} 9~Dg<wQ
F-/z@tM
m=01V5_
Utility.log(nFileLength); lAU99(GXV
.nD#:86M
#-;c!<2
return nFileLength; BTkx}KK
} \P.h;|u
G]=z ![$
_Q5mPBO
//保存下载信息（文件指针位置） ~</FF'Xz
private void write_nPos() !1)aie+p6
{ +X/a+y-
try{ 5*%Gh&)
output = new DataOutputStream(new FileOutputStream(tmpFile)); m8fj\,X
output.writeInt(nStartPos.length); bp?5GU&Uy
for(int i=0;i<nStartPos.length;i++) ln82pQD2Y~
{ gyvrQ, u
// output.writeLong(nPos); ,0! 2x"Q=
output.writeLong(fileSplitterFetch.nStartPos); a!$kKOK
output.writeLong(fileSplitterFetch.nEndPos); >B{NxL3->
} cj[b^Wv:
output.close(); Ks%0!X?3q
} `*8}q!.
catch(IOException e){e.printStackTrace ();} [7@g*!+d
catch(Exception e){e.printStackTrace ();} G}pFy0W\S
} {U=J>#@G
&!8 WRJ
=npE?wK
//读取保存的下载信息（文件指针位置） tY"eoPme
private void read_nPos() 0#]fEi
{ Bg~]u+c*
try{ z+"$G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @N Yl4N
int nCount = input.readInt(); \(Sly&gL
nStartPos = new long[nCount]; KYpS4&Xh
nEndPos = new long[nCount]; gI^&z
for(int i=0;i<nStartPos.length;i++) t*(bF[?
{ x4^nT=?6_
nStartPos = input.readLong(); 9[.HWe,
nEndPos = input.readLong(); { ptdOrN
} 1b9S";ct0
input.close(); {zb'Z Yz
} cZh0\DyU
catch(IOException e){e.printStackTrace ();} !UT'4Fs
catch(Exception e){e.printStackTrace ();} ;@ePu
} c|?(>
,clbD4
#kC~qux^
private void processErrorCode(int nErrorCode) 4eHSAN"$
{ ,sL'T[tuiU
System.err.println("Error Code : " + nErrorCode); Z Ts*Y,
} y74Q(
$wUYK%.
=*\.zr
//停止文件下载 c[Fc3
public void siteStop() _KH91$iW8m
{ ,R{&x7
bStop = true; I0}.!
for(int i=0;i<nStartPos.length;i++) 64/ZfXD
fileSplitterFetch.splitterStop(); *O_fw 0jV
\L*%?~
_w\9 \<%
} 6(8F4[D
} SxRJ{m~
//负责部分文件的抓取 j[r}!;O
**FileSplitterFetch.java kk=n&M
*/ ZsP^<
package NetFox; gQ\.|'%
GeR#B;{
xvTtA61Vp
import java.io.*; Z@Rm^g]o
import java.net.*; .RxTz9(
!PA:#]J
6F(z6_<
public class FileSplitterFetch extends Thread { ^N={4'G)
o[!'JUxZ
#p(gB)o:l
String sURL; //File URL Xw4Eti._D
long nStartPos; //File Snippet Start Position *?m)VvR>|
long nEndPos; //File Snippet End Position ^Hn}\5
int nThreadID; //Thread's ID 'NtI bS
boolean bDownOver = false; //Downing is over \ja6g
boolean bStop = false; //Stop identical e/D{^*~S
FileAccessI fileAccessI = null; //File Access interface ]K(a32VCH
,j%\3g`
QEJu.o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WESD^FK
{ bsQ'kBD
this.sURL = sURL; NljpkeX'
this.nStartPos = nStart; HJl?@&l/
this.nEndPos = nEnd; 5sY$
nThreadID = id; ]KFh1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u2#q7}
} ud/!@WG
v<1@"9EH
oywiX@]~7
public void run() [piK"N
{ !4p{b f
while(nStartPos < nEndPos && !bStop) I1]YT
{ d4b! r
7\UHADr
l+Wux$6U
try{ $J6 .0O
URL url = new URL(sURL); (:bf m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /4r2B.91O
httpConnection.setRequestProperty("User-Agent","NetFox"); XC3)#D#HGh
String sProperty = "bytes="+nStartPos+"-"; o9xc$hX}
httpConnection.setRequestProperty("RANGE",sProperty); \'y]mB~k
Utility.log(sProperty); 7UBDd1
)w].m
uc,>VzdB
InputStream input = httpConnection.getInputStream(); ;u2[Ww~k
//logResponseHead(httpConnection); Mq91HmC(@
gN/!w:
Q`bXsH
byte[] b = new byte[1024]; 5p.rd0T]l3
int nRead; )?72 +X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eCI'<^
{ t!\aDkxo %
nStartPos += fileAccessI.write(b,0,nRead); w[z=x
//if(nThreadID == 1) XIIq0I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?A@y4<8R|
} u(Mbp$R'?
E3wpC#[Q1
}%XB*pzQ
Utility.log("Thread " + nThreadID + " is over!"); 0N1t.3U
bDownOver = true; ,3?=W/Um4
//nPos = fileAccessI.write (b,0,nRead); "r6qFxY
} >M5}L<
catch(Exception e){e.printStackTrace ();} f,O10`4s
} J^"_H:1[
} *9n[#2sM<
C@-Hm
8>x5|
//打印回应的头信息 [],[LkS
public void logResponseHead(HttpURLConnection con) 'ON/WKJr|W
{ le5@WG/x
for(int i=1;;i++) URVW5c
{ >)K3
String header=con.getHeaderFieldKey(i); !/}4_s`,
if(header!=null) /o4_rzR?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UA.Tp[u
Utility.log(header+" : "+con.getHeaderField(header)); s~,!E
else JlSqTfA
break; :Ou~?q%X
} 6@|!m'
} 91z=ou
l i<9nMZ<
0@_8JB ?E
public void splitterStop() $l,U)
{ GIlaJ!/
bStop = true; Cx;it/8+
} A6szTX#0
TY]0aw2]|7
<x`yoVPiZg
} E:rJi]
S[y'{;
m !:F/?B
/* Ps0Cc_
**FileAccess.java 6`9QGi,)
*//文件访问(定位，写) pRfKlTU\
package NetFox; UusAsezm:
import java.io.*; VsA_x
$idToOkw
3+>R%TX6i<
public class FileAccessI implements Serializable{ dtuCA"D
.;?ha'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 azmeJpC
RandomAccessFile oSavedFile; )-+tN>Bb
long nPos; 7'+`vt#E
kYS#P(1
/;_$:`|/
public FileAccessI() throws IOException gB#!g@
{ ${Lrj}93
this("",0); e$
} >%"TrAt
pYCMJK-H
{X,-T&
public FileAccessI(String sName,long nPos) throws IOException Rq15AR
{ ^Ip\`2^u
oSavedFile = new RandomAccessFile(sName,"rw"); uEPm[oyX
this.nPos = nPos; Le~D"d8
oSavedFile.seek(nPos); o<b
} djf8FNnn
{{A=^rr%C
nkq{_;xp
public synchronized int write(byte[] b,int nStart,int nLen) $I`,nN
{ (6[<+j&.
int n = -1; o ^w^dgJ
try{ +2E~=xX
oSavedFile.write(b,nStart,nLen); ~DLxIe
n = nLen; r(]Gd`]
} U;&s=M0[
catch(IOException e) ;Qd'G7+
{ H"+|n2E^
e.printStackTrace (); lN.&46 e
} F\+9u$=
j; /@A lZl
SFWS<H(IN
return n; 5UL5C:3R9
} `iuQ.I
3 } $9./+
7OZ0;fK
} '(ETXQ@
@bkSA
k;umLyz
/* g3n>}\xG>
**SiteInfoBean.java E#w2'(t
*/ I2{zy|&
package NetFox; .O5|d+S
#;2mP6a[
:@~3wD[y
public class SiteInfoBean { ">|L<
Qm3RXO
W*c^(W
private String sSiteURL; //Site's URL 1%.CtTi
private String sFilePath; //Saved File's Path ~O;?;@
private String sFileName; //Saved File's Name %|}7YH41
private int nSplitter; //Count of Splited Downloading File l5e`m^GK
IxG0TJ_
Qe[ai?iJkt
public SiteInfoBean() k:s86q
{//nSplitter的缺省值为5 -% B)+yq>
//default value of nSplitter is 5 k<*1mS8
this("","","",5); c1%ki%J#
} <Dnv=)Rq
#z}IW(u<
c_?!V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S r7EcT-
{ arPqVMVr
sSiteURL= sURL; :fG9p`
sFilePath = sPath; 1eqFMf
sFileName = sName; XK l3B=h
this.nSplitter = nSpiltter; h7\EN
#|xj*+)H
o AS 'Z|
} am WIA`n=
Qa16x<Xlm
xJzO?a'
public String getSSiteURL() 5geZ6]|
{ q|;+Wp?
return sSiteURL; 5[qx5|O
} fwyz|>H_Y(
j"+R*H(#
n]JfdI
public void setSSiteURL(String value) & V/t0
{ 8-vNXvl
sSiteURL = value; 0.Nik^~
} p)Q='
FCr>$
b|h`v
public String getSFilePath() g|3FJA/
{ *O-si%@]
return sFilePath; |w^nCsv
} 0wl31k{
v/Ei0}e6~
!U+XIr
public void setSFilePath(String value) 7+p=4i^@Zs
{ h "r)z6Q/
sFilePath = value; wvSaq+N
} 0/%VejZ'
R75np^
Jqi^Z*PuX
public String getSFileName() ?<$DQ%bf
{ ^$O,Gy)V
return sFileName; HQ8;d9cGir
} 4THGHS^
+l$BUX
<N;HB&mr
public void setSFileName(String value) g*#.yC1/
{ Y_&)>;
sFileName = value; G&*2h2,]
} )![?JXf
('p~h-9Vi
O7RW*V:G@
public int getNSplitter() {7X80KI
{ bc|DC,n?
return nSplitter; g)k::k)<e
} RV:%^=V-
]^^mJt.Iv
>H?{=H+/#
public void setNSplitter(int nCount) rOy-6og
{ O%kX=6
nSplitter = nCount; Hlq#X:DCn
} &P{[22dQ
} 5Y97?n+6
jz;"]k
Dos`lh
/* F\;G'dm
**Utility.java ) >SU J^u
*/ {)0"?$C_H
package NetFox; !_gHIJiq}
ZjXpMx,
3v%V\kO=F
public class Utility { &De&ZypU
<Cw)S8t
4HK#]M>yz
public Utility() ceR zHq=
{ Ol'Ct'_k,"
r6`v-TY(/
poYO
} <OEu 4,~:
?8Hr 9
//线程睡眠 !8U\GR `
public static void sleep(int nSecond) .pOTIRbA
{ xeX Pc7JG
try{ >{^&;$G+*
Thread.sleep(nSecond); W`^Zb[
} E(oI0*S.5
catch(Exception e) 7x^P74
{ 58Fan*fO
e.printStackTrace (); &pD6Qq{
} $;dSM<r
} ]I#yS=;
TnqspS2;R
//日志 Hinz6k6!
public static void log(String sMsg) viT/$7`AI
{ >I3#ALF
System.err.println(sMsg); {? jr
} O&?i8XsB
Q!:J.J
h+!Ld^'c
public static void log(int sMsg) :YU_ \EV
{ Xj&fWuA
System.err.println(sMsg); --S2lN/:T
} z5v)~+"1
} 7N/v
Nj_h+=UE!
&AI/;zru
/* pN"d~Z8
**TestMethod.java DUxj^,mf,
*/ ]N^a/&}*
package NetFox; G:QaWqUb
#AzZ4<;7
2#:h.8
public class TestMethod { 7W6tz\Y
$4y;F]
! 3O#'CV
public TestMethod() !52]'yub
{ ///xx/weblogic60b2_win.exe X9#;quco@
try{ sHSZIkB-r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {mK=Vig
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D}wM$B@S
SiteFileFetch fileFetch = new SiteFileFetch(bean); Lc!% 3,#.
fileFetch.start(); 8C2s-%:
} MS-}IHO
catch(Exception e){e.printStackTrace ();} z )2h\S
{(i>$RG_
h+Dp<b
} (7G5y7wI"
y1!c:&
NZSP*#!B
public static void main(String[] args) j^}p'w Tu{
{ yT<yy>J9l#
new TestMethod(); 18pi3i[
} q/[)Z @&(
} QXnL(z
点击下载更多相关资料