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)); cTn(Tv9s
} VAjl?\}6
for(int i=0;i<nEndPos.length-1;i++) {q+gm1iC
{ .@EzHe ^W
nEndPos = nStartPos[i+1]; f<$*,P
} JY"J}
nEndPos[nEndPos.length-1] = nFileLength; /.rj\,
} ,3eN&
} }.U(Gxu$
$bF+J8%D
c+7I
//启动子线程 7J`v#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;;rx)|\<R
for(int i=0;i<nStartPos.length;i++) ^&y*=6C
{ bivo7_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GUM-|[~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J#4pA{01w
nStartPos,nEndPos,i); \I/"W#\SJo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =jpRv<X|,
fileSplitterFetch.start(); 0)\(y
} ;{&4jcV*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !>!jLZ0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ubsv\[:C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7bE`P[
nEndPos = " + nFileLength); >gq=W5vN(
// fileSplitterFetch[nPos.length-1].start(); 8'zfq ]g
&U=_:]/
#nft{AN
//等待子线程结束 -kP2Brm
//int count = 0; 9-&@Y
//是否结束while循环 TNeL%s?B3
boolean breakWhile = false; @"98u$5
C~K/yLCAi
qK@,O\
while(!bStop) y?3u6q++
{ OVgak>$
write_nPos(); EG &me
Utility.sleep(500); W>?aZv
breakWhile = true; g2}aEfp!H
v;g,qO!LJ
qzHsqlof
for(int i=0;i<nStartPos.length;i++) J8@+)hn
{ `:m=rT_
if(!fileSplitterFetch.bDownOver) QkTU@T6>o
{ M&",7CPD(1
breakWhile = false; !Q%r4Nr
break; z Z~t,>
} l ObY
} H15!QxD#
if(breakWhile) &`>dY /Y
break; p<Tg}fg
GMLx$?=j
yDe*-N\'W
//count++; L"?4}U:
//if(count>4) L8zMzm=-
// siteStop(); JJM!pD\h
} ,m7Z w_.
EL2z&
2JeEmG9
System.err.println("文件下载结束！"); [!} uj`e
} B%))HLo'
catch(Exception e){e.printStackTrace ();} (U.VCSn
} nHfAx/9!
h]|2b0
i1b3>H*3
//获得文件长度 ,y/m5-D!
public long getFileSize() eCg|@d%D
{ +, rm
int nFileLength = -1; M3GFKWQI,`
try{ n4"xVDL
URL url = new URL(siteInfoBean.getSSiteURL()); h4ghMBo%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AI9=?X<kh
httpConnection.setRequestProperty("User-Agent","NetFox"); ;D4 bxz0ou
(V/!0Lj
I3l1 _
int responseCode=httpConnection.getResponseCode(); bOV]!)o
if(responseCode>=400) Nii5},
{ Ur""&@
processErrorCode(responseCode); :N xksL^
return -2; //-2 represent access is error ,>TDxI;
} `sRys oW
Q2@yUDd!
0d`lugf
String sHeader; aKRnj!4z
REk^pZ3B
vDc&m
for(int i=1;;i++) ry* 9
{ q'biTn]2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1gYvp9Ma
//Utility.log(in.readLine()); N$Tzxs
sHeader=httpConnection.getHeaderFieldKey(i); ]tbl1=|
if(sHeader!=null) }k8&T\V!
{ _.,"`U; H
if(sHeader.equals("Content-Length")) ~%: TE}
{ +]VW[$W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :?#wWF.
break; 2qKAO/_O
} G#'G9/Tm
} 'w\Gd7E
else gaL.5_1
break; K5+ONA<c
} {UhpN"'"n
} %8|?YxiZ:
catch(IOException e){e.printStackTrace ();} Az(J@
catch(Exception e){e.printStackTrace ();} /"1[qT\F
zn\$6'"
).$kp2IN
Utility.log(nFileLength); lstnxi%x
>LEp EMJ\
S?~/ V]
return nFileLength; 7{f{SIB
} !/e8x;_
r`:dUCFE
tZD^<Q7}\
//保存下载信息（文件指针位置） Lez]{%+.`[
private void write_nPos() @=l.J+lh
{ t;[?Q\
try{ piPV&ytI
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jqt|'G3
output.writeInt(nStartPos.length); ~$4!C'0
for(int i=0;i<nStartPos.length;i++) v%Su#xq/
{ T@N)BfkB
// output.writeLong(nPos); qNbgN{4
output.writeLong(fileSplitterFetch.nStartPos); :HN\A4=kc(
output.writeLong(fileSplitterFetch.nEndPos); @'?7au ''
} ery{>|k
output.close(); 28xLaob
} xEe3,tb'e
catch(IOException e){e.printStackTrace ();} 3:!5 ]
catch(Exception e){e.printStackTrace ();} 0av2w5>af
} z8w@pT
Y2y = P
BUEV+SZ4
//读取保存的下载信息（文件指针位置） I%ZSh]On
private void read_nPos() M0RVEhX
{ BH?fFe&J:`
try{ K%>3ev=y.s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p{rzP,Pb&
int nCount = input.readInt(); *3!ixDX[r
nStartPos = new long[nCount]; a[V4EX1E
nEndPos = new long[nCount]; i}ti
for(int i=0;i<nStartPos.length;i++) LGC3"z\=
{ AjO|@6
nStartPos = input.readLong(); &uu69)u
nEndPos = input.readLong(); f1/if:~6
} C;rK16cn
input.close(); xo(3<1mD
} #TY[\$BHs
catch(IOException e){e.printStackTrace ();} d0 yZ9-t
catch(Exception e){e.printStackTrace ();} [~IFg~*,
} .^?Z3iA",
~^"s.Lsb
+WFa4NZ
private void processErrorCode(int nErrorCode) !tv+,l&L
{ 0[SrRpD
System.err.println("Error Code : " + nErrorCode); .?-]+-J?`
} NiH.Pv)Oa'
%;tBWyq}_
u=!n9W~"
//停止文件下载 <o&\/uO~H
public void siteStop() $PKUcT0N9
{ Wwo`R5
bStop = true; uF\f>E)/N%
for(int i=0;i<nStartPos.length;i++) $T}Dn[.
fileSplitterFetch.splitterStop(); %KmhR2v
)u_[cEJHO
*[wj )
} L@LT*M
} WzO[-csy
//负责部分文件的抓取 V]A*' ke/
**FileSplitterFetch.java ;"DI)hdz
*/ &<S]=\
package NetFox; hvU\l`m
{}v<2bS
}VXZM7@u
import java.io.*; /7XVr"R
import java.net.*; D,;6$Pvg^
G_n~1?
yM*<BV
public class FileSplitterFetch extends Thread { $iAd)2LT
_^u^@.Q'i<
I r;Z+}4>Y
String sURL; //File URL _8nT$!\\
long nStartPos; //File Snippet Start Position +h?z7ZY^
long nEndPos; //File Snippet End Position dRnO5 7+{
int nThreadID; //Thread's ID T6p2=o&p
boolean bDownOver = false; //Downing is over sBm/9vu
boolean bStop = false; //Stop identical Fo[=Dh*AqU
FileAccessI fileAccessI = null; //File Access interface !3Me 6&$O
8qQrJFm|3*
N"o+;yR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @)p?!3{"
{ =OF]xpI'&a
this.sURL = sURL; 0w ] pDj
this.nStartPos = nStart; gpzZs<ST
this.nEndPos = nEnd; y5lhmbl: e
nThreadID = id; !7fVO2m T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dW>$C_`?
} *%`jcF
Hs6}~d
+c_8~C
public void run() [}bPkD
{ /:@X<
while(nStartPos < nEndPos && !bStop) Luu.p<
{ #sp8 !8|y
:\8&Th}Se
$ACD6u6
try{ 0}y-DCuQ
URL url = new URL(sURL); @jevY81)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %oEvp{I
httpConnection.setRequestProperty("User-Agent","NetFox"); aXO|%qX
String sProperty = "bytes="+nStartPos+"-"; /0I=?+QSo
httpConnection.setRequestProperty("RANGE",sProperty); Di8;Tq
Utility.log(sProperty); \mp5G&+/Q
%G>V .d
u9R:2ah&K
InputStream input = httpConnection.getInputStream(); 4Z<
//logResponseHead(httpConnection); y153ax
qJrMr4:F
G@;I^_gN
byte[] b = new byte[1024]; 1(12`3
int nRead; v&*}O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %R[X_n=
{ F|t_&$Is?
nStartPos += fileAccessI.write(b,0,nRead); d9sqO9Ud8
//if(nThreadID == 1) t.E3Fh!o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bZsg7[: C
} z@n779i
f.SmCgG
=3?"s(9
Utility.log("Thread " + nThreadID + " is over!"); =c(3EI'w
bDownOver = true; P",E/beV
//nPos = fileAccessI.write (b,0,nRead); 2DbM48\E
} +4%:q~C
catch(Exception e){e.printStackTrace ();} trC+Etc
} y()Si\9v
} E)7ODRVbl
Co#_Cyxg=9
#yVMC;J?W
//打印回应的头信息 &BDdJwE
public void logResponseHead(HttpURLConnection con) 2r|!:^'?W
{ qEbzF#a-:
for(int i=1;;i++) k_<8SG+`
{ #XlE_XD
String header=con.getHeaderFieldKey(i); `Gp!Y
if(header!=null) _C97G&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N>}2&'I
Utility.log(header+" : "+con.getHeaderField(header)); *PVv=SU
else L/R ES
break; hMiuv_EO!
} f:-dw6a=s
} Ew kZzVuX
t846:Z%[
a:3f>0_t
public void splitterStop() ;c_pa0L
{ 2dF:;k k
bStop = true; N%.DjH
} 5{&<X.jv
TGJ\f
zUhJr$N$
} f{DcR"
MYb^ILz H3
C8 b%r|^#
/* HKdR?HM1
**FileAccess.java !bHM:!6^
*//文件访问(定位，写) a~-^$Fzgy
package NetFox; {PCf'n
import java.io.*; E|A,NPf%I
T?Dq2UW
!cWnQRIt_F
public class FileAccessI implements Serializable{ j>0~"A
9#;UQ.qA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 igW>C2J
RandomAccessFile oSavedFile; rpNe8"sh
long nPos; ^:RDu q
Nh[{B{k
Uieg4Iro
public FileAccessI() throws IOException UT9=S21
{ j;k(AM<
this("",0); 92k}ON
} -~HlME*~f
[[[QBplJ
{:3XP<hqN
public FileAccessI(String sName,long nPos) throws IOException (Rc0l;
{ U "qO&;m
oSavedFile = new RandomAccessFile(sName,"rw"); ]PnE%
this.nPos = nPos; :-f"+v
oSavedFile.seek(nPos); '7<@(HO
} ,Wp0,>!
j{nkus2
kPVP+}cA
public synchronized int write(byte[] b,int nStart,int nLen) .F~EQ %
{ cg,_nG]i
int n = -1; }<wj~f([
try{ R<!WW9IM
oSavedFile.write(b,nStart,nLen); 8elT/Wl
n = nLen; ^w<:UE2a!
} `f:5w^A
catch(IOException e) a`w)awb
{ a91Q*X%
e.printStackTrace (); /rNY;qXM
} !HXdUAKu
+M\*C#
] 05Q4
return n; BX),U
} tc{23Rf%
b'N"?W^YQ
aNW&ib
} 2#Au6BvX
~X;(m<f2
#oYX0wvl
/* nDvny0^a
**SiteInfoBean.java >NwrJSx
*/ u%O^hcfb
package NetFox; fxLhVJ"b
`,(1'
LwUvM
public class SiteInfoBean { (D8'qx-M
&-+&`h|s
|k'I?:'
private String sSiteURL; //Site's URL jkNZv. )p
private String sFilePath; //Saved File's Path WII_s|YSt%
private String sFileName; //Saved File's Name 0EXAdRR
private int nSplitter; //Count of Splited Downloading File kmW!0hm;e
lb1(1|#
pAmTwe
public SiteInfoBean() U gB
{//nSplitter的缺省值为5 e7L;{+XI
//default value of nSplitter is 5 yh5KN_W
this("","","",5); Y@.> eS
} zck)D^,aO
U2ANu|
LM _4.J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &V( LeSI
{ CSU>nIE0
sSiteURL= sURL; $zCUQthL@
sFilePath = sPath; g{$&j*Q9
sFileName = sName; A|>a Gy
this.nSplitter = nSpiltter; 3iWLo Qm
c_^H;~^rL
`p^M\!h*O
} qrX6FI
Mdwh-Cis/
!s)2H/KM8
public String getSSiteURL() "E2 g7n&
{ . ~|^du<X
return sSiteURL; 0t4i'??
} 6!Isz1.re
N7#GK]n%/}
gdC=SFb b
public void setSSiteURL(String value) )QZ?Bf
{ kLD)<D
sSiteURL = value; ;pB?8Z
} E/GI:}YUy_
nMc-kyl{
9J]LV'f7
public String getSFilePath() G>_ZUHdI
{ &P{%C5?{
return sFilePath; d&'6l"${
} @pkozE-
&(.ZHF
Ra*9d]N@
public void setSFilePath(String value) BLJ-'8G
{ "J{,P9P6
sFilePath = value; 5d4-95['_
} -=qmYf
fCVSVn"o
jN {ED_
public String getSFileName() b'{D4/
{ P7Y[?='v
return sFileName; \|&5eeE@
} )O&$-4gL'
U&eLj"XZ
Ns9g>~
public void setSFileName(String value) Sdt @"6
{ ,vhR99g{
sFileName = value; gVl#pVO`N
} h'jnc.
yWK[@;S]%
IaF79}^
public int getNSplitter() d~_OWCg`
{ l/I W"A
return nSplitter; iCEX|Tj;
} n+i}>3'A
H5aUZ=
_88~uYG
public void setNSplitter(int nCount) '/p5tw8
{ l`u*,"$
nSplitter = nCount; eeX)JC0A
} (p2a{v}fEz
} w\QpQ~OX
[,e_2<
4i19HD_
/* 5y~[2jB:
**Utility.java UmJg-~
*/ HU'E}8%t6
package NetFox; ~p 1y+
r:o!w7C:a
\4&g5vE
public class Utility { oyd{}$71d
m8f_w
U--ER r8
public Utility() [zfGDMG&
{ 2KX *x_-
}$UFc1He\J
I'j?T.
} }l2JXf55
':[y]ep(~|
//线程睡眠 ](ninSX1w
public static void sleep(int nSecond) k{#:O=
{ D *tBbV
try{ 5u!cA4e"
Thread.sleep(nSecond); doa$ ;=wg
} Q7s1M&K
catch(Exception e) 0jyokER
{ 2,fB$5+
e.printStackTrace (); R3<+z
} $200?[
} Ylf4q/-
S&0x:VW
//日志 =osj}(
public static void log(String sMsg) 4H:WpW*r
{ M1i|qjb:l
System.err.println(sMsg); BOG )JaDW
} x{- caOH
+1y#=iM{
{xr]xcM'b
public static void log(int sMsg) Il642#Gh
{ (1o^Dn3
System.err.println(sMsg); <vrx8Q*6
} ~DD/\V
} ,yF)7fN
~:@H6Ke[
4j*}|@x
/* WAEKvM4*i0
**TestMethod.java qRFN@ID$
*/ ev3x*}d0
package NetFox; eOb`uyi
s6$3[9Vh&9
Y:a(y*y<
public class TestMethod { ^#4s/mdVO
x0d+cSw
'tbb"MEi4
public TestMethod() ymzm x$o=
{ ///xx/weblogic60b2_win.exe S;NXOsSu
try{ ![ QQF|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); { nV zN(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >&VL2xLy
SiteFileFetch fileFetch = new SiteFileFetch(bean); t'J fiGM
fileFetch.start(); }:%pOL n
} VtO+=mZV
catch(Exception e){e.printStackTrace ();} X_qXH5^%
V~=)#3]`[
y AWDk0bx
} ST3qg6Cq2J
>4\xcL
B'Wky>5)
public static void main(String[] args) o;[oy#aWl_
{ &0g,Xkr
new TestMethod(); g|P hNo
} "jHN#}
} CytpL`&^]
点击下载更多相关资料