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)); #cB=](N
} 8dg\_H_
for(int i=0;i<nEndPos.length-1;i++) !.(Kpcrg
{ uSZCJ#'G
nEndPos = nStartPos[i+1]; dP>~ExYtm
} 6S#Y$2 P
nEndPos[nEndPos.length-1] = nFileLength; *R] Ob9X
} VR86ok
} pmm?Fq!s=
U} EaV<
2nSX90@:
//启动子线程 ;x 9_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; en"]u,!
for(int i=0;i<nStartPos.length;i++) {!? @u?M
{ !N\<QRb\q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~U] "dbQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wul$lJ?tE
nStartPos,nEndPos,i); K?;_T$^K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BCDmce`=l
fileSplitterFetch.start(); $XBn:0U
} tUS)1*{_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v'R{lXE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m5!~PG:_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^/nj2"
nEndPos = " + nFileLength); ^*CvKCS
// fileSplitterFetch[nPos.length-1].start(); DuESLMhz
3NI3b-7
pkW }\r
//等待子线程结束 NSQ}:m
//int count = 0; \Wdl1 =`
//是否结束while循环 iD*%' #u
boolean breakWhile = false; l;*/F`>c
PI KQ}aq=
]/l"
while(!bStop) "Di27Rq
{ :O`7kZ]=n
write_nPos(); ~d0:>8zQR
Utility.sleep(500); 4*k>M+o/C4
breakWhile = true; RMinZ}/
s)Gnj;
bYPkqitqz
for(int i=0;i<nStartPos.length;i++) nkI+"$Rz0
{ _n6ge*,E
if(!fileSplitterFetch.bDownOver) !n;0%"(FH
{ HaJs)j
breakWhile = false; 9Fo00"q
break; xC3h m
} {1 VHz])I
} p>4tPI}bf
if(breakWhile) gYeKeW3)
break; *QKxrg
]!7%)
?]*WVjskE
//count++; 06ndW9>wD)
//if(count>4) 0c2O'&$au
// siteStop(); W''%{A/'
} 9+:SS1_
@uh^)6i]/
A -C.Bi;/
System.err.println("文件下载结束！"); ew13qpt)<L
} `ChS$p"A
catch(Exception e){e.printStackTrace ();} mf~JolucJ
} a ~s:f5S>
_&(\>{pm
xwuGJ
//获得文件长度 -cgLEl1J
public long getFileSize() #7 )&`
{ Q6Ay$*y=D
int nFileLength = -1; ///
try{ \,UpFuU\
URL url = new URL(siteInfoBean.getSSiteURL()); {Ad4H[]|]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AnF"+<
httpConnection.setRequestProperty("User-Agent","NetFox"); Sb2hM~
/+V}.
_Y{8FN(4
int responseCode=httpConnection.getResponseCode(); Hw0S/ytY
if(responseCode>=400) |`T$Iq
{ =`MxgK +
processErrorCode(responseCode); ae%Bl[
return -2; //-2 represent access is error u+5&^"72,
} ?;GbK2\bj
YC!IIE_
.<m${yU{3
String sHeader; _GhP{C$
|IcA8[
<{ER#}b:O
for(int i=1;;i++) lEZODc+%Y
{ 6TR` O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k.."_4
//Utility.log(in.readLine()); _4#Mdnh}[
sHeader=httpConnection.getHeaderFieldKey(i); CpE LLA<
if(sHeader!=null) (DLk+N4UHA
{ ?-Qq\D^+
if(sHeader.equals("Content-Length")) I cJy$+
{ f|v5itO2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <?2g\+{s9
break; CXQ+h
} 5dvP~sw
} >(?}'pS8
else !W\za0p
break; V=i/cI\
} D`Cy]j
} w"Q/ 6#!K
catch(IOException e){e.printStackTrace ();} 1"\^@qRv#
catch(Exception e){e.printStackTrace ();} 9QXBz=Fnf
+YJpVxYmZ
T'ko =k
Utility.log(nFileLength); BvnNAi
;L*Ku'6Mt
+$uQ_ve
return nFileLength; .4[\%r\i
} _J,lF-,
'?Jz8iu-
Z|#G+$"QV
//保存下载信息（文件指针位置） MJ\^i4
private void write_nPos() euMJ c
{ Jkx_5kk/\
try{ r"_U-w
output = new DataOutputStream(new FileOutputStream(tmpFile)); g[c_rty
output.writeInt(nStartPos.length); |j2$G~B6
for(int i=0;i<nStartPos.length;i++) K^5f
{ }R9>1u}6
// output.writeLong(nPos); e0"80"D
output.writeLong(fileSplitterFetch.nStartPos); g1H$wU3eu
output.writeLong(fileSplitterFetch.nEndPos); APJVD-
} v:IpZ;^
output.close(); iW?z2%#
} <"hq}B
catch(IOException e){e.printStackTrace ();} )KdEl9o
catch(Exception e){e.printStackTrace ();} al{}_1XoU
} &cpqn2Z
{3* Ne /
l!*!)qCB(S
//读取保存的下载信息（文件指针位置） &*Z"r*
private void read_nPos() Z?f-_NHg
{ 9 df GV!Z
try{ Q,LDn%+;B*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;u?L>(b
int nCount = input.readInt(); A4tb>OM
nStartPos = new long[nCount]; t"$#KP<
nEndPos = new long[nCount]; ysH'X95
for(int i=0;i<nStartPos.length;i++) MqAN~<l [
{ 'PvOOhm,
nStartPos = input.readLong(); Mp3nR5@d$
nEndPos = input.readLong(); K'c[r0Ew
} Vr7L9%/wg
input.close(); Ln$= 8x^T
} Z]SUr`Z
catch(IOException e){e.printStackTrace ();} m4on<5s/
catch(Exception e){e.printStackTrace ();} +zg3/C4 S
} wZg~k\_lF
GK`U<.[c
w }=LC#le
private void processErrorCode(int nErrorCode) pf`vH`r
{ XS(Q)\"
System.err.println("Error Code : " + nErrorCode); Rn$TYCO
} I]-"Tw
Zs|m_O G
STL+tLJ
//停止文件下载 B%I<6E[D
public void siteStop() z7s}-w,
{ veAdk9
bStop = true; |/%X8\
for(int i=0;i<nStartPos.length;i++) S[e> 8
fileSplitterFetch.splitterStop(); Ly-}HW(
AIG5a$}&
PVi0|
} qQwf#&
} Tl L,dPM
//负责部分文件的抓取 FL[,?RU?2
**FileSplitterFetch.java YS bS.tq
*/ A~@x8
package NetFox; c=f;3N
v=~+o[
`PtfPt<{
import java.io.*; Kut@z>SK
import java.net.*; v[4-?7-
G.~Ffk
SQ057V>'=
public class FileSplitterFetch extends Thread { ,R}9n@JI^Y
ncpNesB
QT4&Ix,4T1
String sURL; //File URL sdBB(
long nStartPos; //File Snippet Start Position x3l~kZ(
long nEndPos; //File Snippet End Position qm6X5T
int nThreadID; //Thread's ID ";Q}Gs}
boolean bDownOver = false; //Downing is over 4vi[hiV
boolean bStop = false; //Stop identical C ~Doj
FileAccessI fileAccessI = null; //File Access interface ' 7H"ezt
/pWKV>tjj
+' SG$<Xv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &<EixDi4q
{ &&7&/
this.sURL = sURL; M%bD7naBq
this.nStartPos = nStart; ?h:xO\h8
this.nEndPos = nEnd; mq+x=
nThreadID = id; {n{-5Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TR9dpt+T
} -VvN1G6.x?
!>:]k?$b
g*;zVi
public void run() q4SEvP}fLx
{ LaYd7Oyf]
while(nStartPos < nEndPos && !bStop) p^s:s-"f\
{ ZKJhmk
l\37/Z
MxqIB(5k
try{ ,rX|_4n*
URL url = new URL(sURL); ~Kt2g\BSok
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <q`|,mc
httpConnection.setRequestProperty("User-Agent","NetFox"); GsoD^mjY
String sProperty = "bytes="+nStartPos+"-"; V*W H
httpConnection.setRequestProperty("RANGE",sProperty); 4t 0p!IxG
Utility.log(sProperty); M9.FtQhK/
]VaMulb4
Uka(Vr:
InputStream input = httpConnection.getInputStream(); j/F:j5O*
//logResponseHead(httpConnection); sn8l3h)
Q>I7.c-M|
SM4'3d&mf
byte[] b = new byte[1024]; CQs,G8\/
int nRead; y?UB?2VN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p2hPLq
{ v}.~m)
nStartPos += fileAccessI.write(b,0,nRead); EKUiX#p:M
//if(nThreadID == 1) Y/f8rN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zfd `Fu
} v,Z?pYYo
)3ZkKv;zY
a28`)17z
Utility.log("Thread " + nThreadID + " is over!"); [&)*jc16
bDownOver = true; QTU$mC]
//nPos = fileAccessI.write (b,0,nRead); 8{)N%r
} ;P^}2i[q>[
catch(Exception e){e.printStackTrace ();} Nv=&gOy=
} 7w}]9wCN?
} W^i[7 r
Nk<H=kw+
-PaR&0Tt
//打印回应的头信息 ;pqS|ayl
public void logResponseHead(HttpURLConnection con) v?l*jr1-2
{ fs2y$HN
for(int i=1;;i++) w& )ApfL
{ i^)JxEPr w
String header=con.getHeaderFieldKey(i); 4MoxP
if(header!=null) mOJ-M@ME
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bUe6f,8,
Utility.log(header+" : "+con.getHeaderField(header)); ,U>G$G^
else 4$+/7I \
break; R]l2,0:
} QtLd(& !v
} -HRa6
QzY5S0
@%8$k[
public void splitterStop() QC(ce)Y
{ VuuF _y;
bStop = true; oGL2uQXX
} l - ~PX
MADt$_
{d%hkbN+{
} \*Z:w3;r
5k;}I|rg%
NYeL1h)l
/* m,Mg
**FileAccess.java 2^)_XVX1
*//文件访问(定位，写) -kb;h F}.
package NetFox; rnC<(f22
import java.io.*; C|RC9b
cXNR<`
$PMD$c
public class FileAccessI implements Serializable{ db.~^][k
W(EN01d\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wq]vcY9^
RandomAccessFile oSavedFile; ~JB4s%&
long nPos; /}(\P@Z
;".]W;I*O
ufN`=IJ%
public FileAccessI() throws IOException x5k6"S"1,
{ `82^!7!
this("",0); "YN6o_*]
} dK]#..
%Lom#:L'
(R!`Z%
public FileAccessI(String sName,long nPos) throws IOException ,#hNHFa'JH
{ )!5"\eys
oSavedFile = new RandomAccessFile(sName,"rw"); HG3iK
this.nPos = nPos; jWK>=|)=c
oSavedFile.seek(nPos); [ub)`-6 u
} 58]t iP"
0+k=gO
vkLyGb7r<
public synchronized int write(byte[] b,int nStart,int nLen) +<)H2
{ gyobq'o-
int n = -1; >1q:-^
try{ 5KW n>n
oSavedFile.write(b,nStart,nLen); 6>[J^k%~w)
n = nLen; CIQ9dx7>
} G5UNW<P2C
catch(IOException e) bLO^5`6
{ 3A3WD+[L
e.printStackTrace (); pEY zB;
} =91f26c!~
|&~);>Cq2
wvH*<,8Vq
return n; '&Tz8.jp~
} nM`pnR_
uk3PoB^>
q5.5%W
} ^geY Ay
@"afEMd
$HAwd6NI
/* tY60~@YO&
**SiteInfoBean.java aL/7xa
*/ 6G:7r [
package NetFox; ;JX2ebx
P?zL`czWd
hYVy65Ea
public class SiteInfoBean { J74kK#uF=
=j8g6#'u
uy([>8uu
private String sSiteURL; //Site's URL p%5(Qqmlk
private String sFilePath; //Saved File's Path p+Fh9N<F9
private String sFileName; //Saved File's Name UbP$WIrq
private int nSplitter; //Count of Splited Downloading File ;eMb$px
WDh*8!)
BUXlHh%<R
public SiteInfoBean() -_f-j
{//nSplitter的缺省值为5 2`V(w[zTr
//default value of nSplitter is 5 1Ch0O__2L
this("","","",5); 6t4{aa!L|9
} }KV)F,`
`LJ.NY pP
!~]'&9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _J0(GuG=~
{ U)SQ3*j2D
sSiteURL= sURL; :D:J_{HJ
sFilePath = sPath; ;RW5XnVx
sFileName = sName; dDqT#N?Y
this.nSplitter = nSpiltter; z*WQ=l2
$~/x;z:
n0w0]dJ&lc
} xfA@GYCfT
?d)FYB
RY~mQ
public String getSSiteURL() a'7RzN ,]
{ vcSb:('
return sSiteURL; MwWN;_#EO)
} NZuylQ)0
":L d}~>
Ar`U/ %Cu
public void setSSiteURL(String value) BsYJIKfW
{ s+a#x(7{
sSiteURL = value; OmaG|2u
} 4x" je
R'aA\k-
8-)@q|
public String getSFilePath() }QJ6"s
{ sDXQ{*6a
return sFilePath; D#11 N^-K
} |k)Nf+(}W
k'K 1zUBj
}Q_ }c9?
public void setSFilePath(String value) ,sn 9&E
{ ZV`o:Gd
sFilePath = value; I_na^sh*
} ^/7Y3n!|3
a7e.Z9k!
nb(Od,L
public String getSFileName() y&2O)z!B
{ @*JS[w$1
return sFileName; 7/FF}d
} :qvaI,
8o,"G}Hjk
CPu~^ik
public void setSFileName(String value) Y^'mBM#j
{ XI5q>cd\Sz
sFileName = value; e;&fO[2
} (&qjY I
I>@Qfc bG
9S{0vc/2@
public int getNSplitter() <is%lx(GDX
{ Bmi9U
return nSplitter; k;vhQ=
} kj!mgu#T
nPjN\Es6
E1>zKENN;
public void setNSplitter(int nCount) j6BFh=?D
{ =T|m#*{.L
nSplitter = nCount; vtXZ`[D,l)
} YJBf~0r
} mA6Nmq%{ F
incUa;
ASaNac-3
/* tN&X1
**Utility.java ]ru UX
*/ *vu
package NetFox; LZApz}
$~:|Vj5iZ\
`MXGEJF
public class Utility { <_-8)abK
IHj9n>c)[
r~T3Ieb
public Utility() 41\V;yib
{ N"2P]Zr
x: 2 o$+v3
.$"69[1H
} ~)iQbLI
G!w?\-
//线程睡眠 ;Y`k-R:E6A
public static void sleep(int nSecond) X8(WsN
{ mjbV^^>
try{ ~9dAoILrl
Thread.sleep(nSecond); a9TKp$LP`
} go5l<:9
catch(Exception e) BY??X=
{ n;*W#c
e.printStackTrace (); 3+iQct[
} S$i3/t
} ,98`tB0
x-@6U
//日志 ZVz`-hB
public static void log(String sMsg) f}+8m .g2
{ D2Dk7//82Y
System.err.println(sMsg); `r.
} Mt+ggF.
\FjY;rqfKe
;.b^A
public static void log(int sMsg) (Kaunp5_`
{ Be2yS]U
System.err.println(sMsg); BI0 A0
} Qb&gKQtt@
} F[==vte|
RTvzS]
oHkjMqju
/* qn~:B7f
**TestMethod.java =j S
*/ !gFUC<4bu
package NetFox; kIYV%O
&p:GB_
N!^5<2z@eT
public class TestMethod { kS$m$ D
I xE}v%&
iU a `<
public TestMethod() Ems0"e
{ ///xx/weblogic60b2_win.exe 2~2j?\AEd.
try{ y,=TB[d#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P};GcV-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uM('R;<^
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?FwjbG<
fileFetch.start(); Af7&;8pM
} HU+zzTgI
catch(Exception e){e.printStackTrace ();} =CjN=FM
rgXD>yu(
K^+}__;]
} q.NvwJ
[49Ae2W`
gPg2Ve0Qy
public static void main(String[] args) nW`EBs
{ #dxS QmG
new TestMethod(); txXt<]N
} +K03yphZr
} `d.4L.],
点击下载更多相关资料