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)); ^2}p%j>
} qvN`46c
for(int i=0;i<nEndPos.length-1;i++) aWTvowA
{ Hph$Z1{
nEndPos = nStartPos[i+1]; k0^t$J W
} )r|Pm-:A{
nEndPos[nEndPos.length-1] = nFileLength; cf{rK`Ff^
} IQNvhl.{
} @||GMA+|
UJ^MS4;I3
! a!^'2
//启动子线程 3:ELYn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xwjiNJ Gj
for(int i=0;i<nStartPos.length;i++) *\"+/
{ W6Z3UJ-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;cD&qheDV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ..a@9#D
nStartPos,nEndPos,i); d:{#Dk#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O;CC(
fileSplitterFetch.start(); 1}XESAX;0
} u|EHe"V"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kBr?Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -?Kd[Ma
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K^f&+`v6_
nEndPos = " + nFileLength); &wea]./B
// fileSplitterFetch[nPos.length-1].start(); Q35jJQ$<`
q2}6lf,J K
[Zj6v a
//等待子线程结束 ^nGKuW7\
//int count = 0; Z.E@aml\
//是否结束while循环 =?oYEO7
boolean breakWhile = false; 3`U^sr:[%
\_|g}&}6Y
=}wqo6Bn|
while(!bStop) \VAm4
{ 2{oU5e
write_nPos(); "^&Te%x_b
Utility.sleep(500); ]GH_;
breakWhile = true; gt|:K)[,6
q)QM+4
E*G{V j
for(int i=0;i<nStartPos.length;i++) ]3&BLq
{ /P koqA,
if(!fileSplitterFetch.bDownOver) }Jm~b9j
{ ipH'}~=ID
breakWhile = false; K!jMW
break; DC+l3N
} LnlDCbF;!
} 1Q6~O2a
if(breakWhile) ||^+(
break; 7?W1i{(
KbM1b
u.9syr
//count++; "*JyNwf
//if(count>4) V PaW-o
// siteStop(); rPXy(d1<`S
} ;JV(!8[
[iGL~RiXtn
>))K%\p
System.err.println("文件下载结束！"); 6#upBF:
} L7OFZ|gUz
catch(Exception e){e.printStackTrace ();} kS1?%E,)q
} !63]t?QXMG
r"bV{v
^udl&>
//获得文件长度 3u@=]0ZN
public long getFileSize() >})W5Y+
{ z 8y.@<6
int nFileLength = -1; y41,T&ja
try{ UtYwG#/w
URL url = new URL(siteInfoBean.getSSiteURL()); U C..)9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y$`@QRW
httpConnection.setRequestProperty("User-Agent","NetFox"); Y wu > k
ck\TTNA
`g^bQx
int responseCode=httpConnection.getResponseCode(); -APbN(Vi
if(responseCode>=400) A| s\5"??
{ ;nbbKQ]u
processErrorCode(responseCode); G'0JK+=o
return -2; //-2 represent access is error ,ocAB;K
} i>{.Y};
[|tlTk
DM=`hyf(v
String sHeader; (Q[(]dfc
A?4s+A@Eg
,}a'h4C
for(int i=1;;i++) &b9bb{y_$K
{ x't@Mc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); UJ7{FN=@t
//Utility.log(in.readLine()); cllnYvr3
sHeader=httpConnection.getHeaderFieldKey(i); :7[4wQDt4
if(sHeader!=null) f <pJ_
{ r O-=):2
if(sHeader.equals("Content-Length")) K_o[m!:jU
{ u5rHQA0%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^ RIWW0
break; S:{`eDk\A_
} kj/v$m
} >bbvQb+j
else iCNJ%AZH
break; I~)A!vp
} n#"N"6s
} ,KFF[z
catch(IOException e){e.printStackTrace ();} fX{Xw0
catch(Exception e){e.printStackTrace ();} e_3($pj
5KC Zg'h
l dw!G/
Utility.log(nFileLength); W,bu=2K6
4`'V%)M
?F/)<r
return nFileLength; Y_,Tm
} bmI6OIWl
bu,xIT^
a+,zXJQYq
//保存下载信息（文件指针位置） :b"&Rc&s.
private void write_nPos() MoC@n+Q+@
{ >TG#
try{ -fT}Nj\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7_CX6:
output.writeInt(nStartPos.length); 5 [X,?
for(int i=0;i<nStartPos.length;i++) P 9?I]a)G
{ -muP.h/
// output.writeLong(nPos); I/)*pzt8
output.writeLong(fileSplitterFetch.nStartPos); N?><%fra
output.writeLong(fileSplitterFetch.nEndPos); ~'VVCtA
} gPcOm b
output.close(); Ws;X;7tS
} vpz l{
catch(IOException e){e.printStackTrace ();} e`bP=7`0
catch(Exception e){e.printStackTrace ();} ~*hCTqHvN
} j5MUP&/g3
t`pbEjE0K
ZDbzH=[
//读取保存的下载信息（文件指针位置） rj/1AK
private void read_nPos() L!0}&i;u~5
{ r;@"s g
try{ FE3uNfQs|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EpB3s{B"
int nCount = input.readInt(); DA^!aJ6iF
nStartPos = new long[nCount]; yM# %UeZ\
nEndPos = new long[nCount]; OPJ(ub
for(int i=0;i<nStartPos.length;i++) ?e2G{0V
{ oq[r+E-]$@
nStartPos = input.readLong(); C=8IQl[^e
nEndPos = input.readLong(); vY);7
} 3v>w$6
input.close(); ih(Al<IS
} _@! yj
catch(IOException e){e.printStackTrace ();} V>& 1;n
catch(Exception e){e.printStackTrace ();} Yd]
} a^7QHYJ6
b]g#mQ
ccwz:7r
private void processErrorCode(int nErrorCode) g4&f2D5
{ FXh*!%"*
System.err.println("Error Code : " + nErrorCode); SS!b`
} iM M s3
?\_vqW
lY[\eQ 1:
//停止文件下载 Qb8Z+7
public void siteStop() o]@'R<F(u
{ ?G 'sb}.
bStop = true; K&BaGrR
for(int i=0;i<nStartPos.length;i++) R{UZCFZ
fileSplitterFetch.splitterStop(); Zx^R-9
gdkHaLL"
A@jBn6
} #@m6ag.
} J+l#!gk$!
//负责部分文件的抓取 &Xh=bM'/%m
**FileSplitterFetch.java uTNy{RBD+
*/ uoTc c|Kc
package NetFox; A9y@v{txN
]sJjV A
Uj^Y\w-@Z
import java.io.*; j+[oZfH
import java.net.*; |}Mthj9n
^+x,211f
]-jaIvM
public class FileSplitterFetch extends Thread { 5?*Iaw
4@=[rZb9
P5__[aTD
String sURL; //File URL 00pe4^U
long nStartPos; //File Snippet Start Position x\8gb#8
long nEndPos; //File Snippet End Position zQoJ8i>
int nThreadID; //Thread's ID R~BFZF>:
boolean bDownOver = false; //Downing is over _7<G6q2(
boolean bStop = false; //Stop identical {EJ+
FileAccessI fileAccessI = null; //File Access interface FTu<$`!1L
&Z%'xAOGR
*1h@Jb34
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0u bf]Z
{ SK5__Ix
this.sURL = sURL; zvwv7JtB
this.nStartPos = nStart; }ISR +./+
this.nEndPos = nEnd; qRXHaQi@9
nThreadID = id; \m(>Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MbeK{8~E%l
} Z/LYTo$Bz
9Us'Q{CD
vdd>\r)v
public void run() [a7S?%>Bh
{ ]L?WC
while(nStartPos < nEndPos && !bStop) |Elz{i-
{ ^ #3,*(S
M$e$%kPShE
#M<u^$Jz
try{ !}q@O-}j
URL url = new URL(sURL); AmK g;9LS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k#G+<7c<
httpConnection.setRequestProperty("User-Agent","NetFox"); *~^%s+b
String sProperty = "bytes="+nStartPos+"-"; 5")BCA
httpConnection.setRequestProperty("RANGE",sProperty); d>wG6Z,|
Utility.log(sProperty); :3D[~-/S
cd] X5)$h
dTqL[?wH?
InputStream input = httpConnection.getInputStream(); xP &@|Ag
//logResponseHead(httpConnection); W?0u_F
Hk?E0.
y1#QP3'Z1
byte[] b = new byte[1024]; 2[Xe:)d
int nRead; o3HS|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %>t4ib_8
{ *_"lXcG.
nStartPos += fileAccessI.write(b,0,nRead); orhzeOi\
//if(nThreadID == 1) 0oo_m6ie&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m}+_z^@j9
} lM.k*`$
Kir|in)r0
:@S=0|:j
Utility.log("Thread " + nThreadID + " is over!"); tDtqTB}
bDownOver = true; Qm4cuV-0{
//nPos = fileAccessI.write (b,0,nRead); 5Zl7crA[
} }DQ[C&
catch(Exception e){e.printStackTrace ();} 9`!#5i)VU8
} /Q'O]h0a
} le2 v"Y
<Ys7`e6eY
4Yd$RP
//打印回应的头信息 9g7Ok9dF
public void logResponseHead(HttpURLConnection con) CFeAKjG
{ *2Q x69`
for(int i=1;;i++) *-gmWATC6
{ $}P>_bq
String header=con.getHeaderFieldKey(i); x5,|kJ9S
if(header!=null) j&0t!f.Rv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <<6gsKP
Utility.log(header+" : "+con.getHeaderField(header)); L>!MEMqm
else 1wW4bg 5
break; c}w[T
} [yVcH3GcjI
} <n0j'P>1
:KsBJ>2ck
4}Hf"L[ l
public void splitterStop() Co`:D
{ X iM{YZ`B
bStop = true; ar@ysBy
} M+lI,j+
#J%Fi).^)
[Rzn>
} &sGLm~m#
Zk0?=f?j
?{>5IjL)en
/* \?AA:U*
**FileAccess.java EiWd =jDm
*//文件访问(定位，写) v[>8<z8
package NetFox; %Z(lTvqG
import java.io.*; B9oB5E
>Yfo $S_
sE0,b
public class FileAccessI implements Serializable{ O9Yk5b;
L'a>D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {>l`P{{y
RandomAccessFile oSavedFile; K_V$ktL
long nPos; yJw4!A 1!
/(bn+l}W
qGie~S ##
public FileAccessI() throws IOException y |Tv;v1L
{ IE&G7\>(yO
this("",0); [q!)Y:|u_>
} IF3V5Q
_x?S0R1
m\ /V0V\
public FileAccessI(String sName,long nPos) throws IOException \>4x7mF!
{ WI54xu1M
oSavedFile = new RandomAccessFile(sName,"rw"); Fprhu;h
this.nPos = nPos; 6 i]B8Ziq{
oSavedFile.seek(nPos); #^q@ra
} b!g8NG
sUsIu,1Q
V_pKe~
public synchronized int write(byte[] b,int nStart,int nLen) 5@~5RNrq2
{ LU@+O12
int n = -1; n:YA4t7S
try{ DJHE6XJ
oSavedFile.write(b,nStart,nLen); &r V
n = nLen; H$]FUv8
} sB`zk[R;
catch(IOException e) SZD@<3Nb
{ 2graLJ?9Z
e.printStackTrace (); ">S.~'ds
} +6x:+9S
^os|yRzV*M
ow,=M%x"0
return n; +#ANc;2g
} ;,:w%.
$-f(.S
j~Ubpf
} Mhg_z.Z
L@6T~
_1P8rc"Dx
/* :@+@vM;gh
**SiteInfoBean.java 7(KVA1P66
*/ "_e/O&-cH
package NetFox; GZ/vUe
'>r"+X^W
M \3Zj(E/
public class SiteInfoBean { 1(WNrVm;
%R1$M318
@0q*50
private String sSiteURL; //Site's URL l&v&a!EU
private String sFilePath; //Saved File's Path ZNG{:5u,
private String sFileName; //Saved File's Name [7SR2^uf<j
private int nSplitter; //Count of Splited Downloading File =%oKYQ
FcZ)_m6m
RDQK_Ef:
public SiteInfoBean() A+F@JpV
{//nSplitter的缺省值为5 XxE>KeP
//default value of nSplitter is 5 JZB@K6 ~dO
this("","","",5); d!]_n|B@9
} D$y-Kh
ziui
?TVR{e:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .=4k'99,
{ v"G)G)*z
sSiteURL= sURL; Tof H=d
sFilePath = sPath; uSK<{UT~3
sFileName = sName; $WK~|+"{>
this.nSplitter = nSpiltter; ~gvw6e*[
{F+iL&e)
n:[GK_
} rui]_Fn]I
-dsE9)&8DX
]AzDkKj
public String getSSiteURL() uPtS.j=
{ "+:IA|1wD
return sSiteURL; Se-n#
} \)n'Ywr
>0qe*4n|M
iu6NIy7D
public void setSSiteURL(String value) $N)b6(}F10
{ O*7`Waag
sSiteURL = value; Vy[ m%sEP
} |#=4]]>m
,BG L|5?3z
9N]V F'
public String getSFilePath() 2DTBL:?`
{ ,,[pc
return sFilePath; :IlJQ{=W
} 'VTLp.~G~
^J Y]w^u
73OYHp_j
public void setSFilePath(String value) (Cjw^P|Y@
{ _l;$<]re\k
sFilePath = value; E<XrXxS1O
} g}=opw6z
@fxDe[J:
@Iy&Qo
public String getSFileName() )~l`%+
{ @-QDp`QtI
return sFileName; ,a/<t"
} Cn>RUGoUsI
D#G(&<Q
Lcpz(W^
public void setSFileName(String value) Xi!`+N4
{ 1WW`%
sFileName = value; R s)Nz< d
} dLnMd0
9!sR}
Ki:.^
public int getNSplitter() V,CVMbn/%N
{ IDpW5Dc
return nSplitter; _Q1[t9P"
} MKN],l N
9xm'0 '
<c&6M
public void setNSplitter(int nCount) / !*+9+h
{ )2jBhT
nSplitter = nCount; 9c_h+XN?y
} vCh/%7+
} lP:ll])p2
Mli`[8@(
Iq[Z5k(K
/* 1]<wZV}.
**Utility.java `vFYeN;
*/ %"0g}tK6
package NetFox; -O?}-6,_Z
`Mp-4)mn
%IbG@}54
public class Utility { p/k6}Wl
rpu{YC1C%
mt(2HBNoz
public Utility() psZAO,p
{ .\X;VWTI
It/IDPx4ga
r g$2)z1
} +/E yX=
UoiXIf_Q
//线程睡眠 8#MiM . f
public static void sleep(int nSecond) i#%17}
{ aA-gl9
try{ Uj[E_4h
Thread.sleep(nSecond); |Vs?yW
} <8Zm}-U
catch(Exception e) nrpxZA
{ \tWFz(
e.printStackTrace (); D!oELZ3
} #K3`$^0 s
} /=bg(?nX
CI )89`
//日志 k7gm)}RKcu
public static void log(String sMsg) DJmT]Q]o)
{ 0cwb^ffN
System.err.println(sMsg); e5 ?;{H
} TEK]$%2
eaxp(VX?oy
[*k25N
public static void log(int sMsg) NJ;D Qv
{ u`]J]gE
System.err.println(sMsg); 7O,y%NWaK
} }RvP*i
} @l:o0(!W
L/VlmN_v>s
$C;)Tlh
/* dSkW[r9Z%l
**TestMethod.java E?z~)0z2`
*/ }smPP*
package NetFox; h8Bs=T
!A\Qwg>
\MA4>
public class TestMethod { d/k70Ybk
dt -=7mz#
JAK+v
public TestMethod() f2JeXsOI
{ ///xx/weblogic60b2_win.exe &ZRriqsQg
try{ EC4RA'Bg1k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .qcIl)3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); POtj6 ?a
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q3$AL@".
fileFetch.start(); ;ss,x
} uq>\pO&P
catch(Exception e){e.printStackTrace ();} /8(\AuDT
QyGTm"9l
GYX/G>-r
} 8~=<!(M)m/
'TF5CNX
02lI-xHe
public static void main(String[] args) Vk/!_)
{ 1FCHqqZ=
new TestMethod(); /7nircXj@
} \=O['#
} ;w/|5 ;{A;
点击下载更多相关资料