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)); tl|ijR
} .}o~VT:!?Y
for(int i=0;i<nEndPos.length-1;i++) Nj+a2[
{ T/ik/lFI
nEndPos = nStartPos[i+1]; -$.0Dc)3!
} sa*g
nEndPos[nEndPos.length-1] = nFileLength; gNqAj# m
} >?z:2@Q)B
} H nK!aa
{@3z\wMK$
vd`O aM}#U
//启动子线程 h\(B#SN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6 Ew@L<v
for(int i=0;i<nStartPos.length;i++) RT,:hH
{ eH %Ja[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GWhE8EDT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?=<~^Lk
nStartPos,nEndPos,i); ]% K' fXj$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1B 5:s,Oyj
fileSplitterFetch.start(); \wYc1M@7V
} qe<Hfp/p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ioxbf6{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,]ga[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =NadAyv
nEndPos = " + nFileLength); ?-f,8Z|h
// fileSplitterFetch[nPos.length-1].start(); =J](.78
*r;xw
w8p8 ;@
//等待子线程结束 GF*>~_Yr
//int count = 0; @o6R[5(
//是否结束while循环 p}uncIod
boolean breakWhile = false; pr_>b`p6
28a$NP\KW
sf$o(^P9\A
while(!bStop) >TY6O.]
{ R::zuv
write_nPos(); 'S*k_vuN
Utility.sleep(500); L_~8"I_
breakWhile = true; (-,>qMQs
;r.EC}>m
Lkn4<'un
for(int i=0;i<nStartPos.length;i++) KFU%DU G
{ TkRmV6'w
if(!fileSplitterFetch.bDownOver) ziiwxx_
{ 49AW6H.JT
breakWhile = false; dxK9:IX
break; (,B#t7ka
} Ird|C[la
} 2s\BY%XY
if(breakWhile) d1c0l{JV3
break; ;'0=T0\
D/CIA8h3
.fp&MgiQ
//count++; 5pfYEofK[
//if(count>4) D<>@ %"%
// siteStop(); XRxj W
} `:p1&OS
5wv fF.v
BEUK}T K4
System.err.println("文件下载结束！"); uH:YKH':/
} V%*b@zv
catch(Exception e){e.printStackTrace ();} x6W`hpL
} ~E)fpGJ
9%tobo@J~n
F'FP0t!S
//获得文件长度 O6X"RsI}
public long getFileSize() Ch19h8M
{ v+xB7w
int nFileLength = -1; '#.#$8l
try{ Ls}7VKl'
URL url = new URL(siteInfoBean.getSSiteURL()); qtMD CXZ^n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rko M~`CT
httpConnection.setRequestProperty("User-Agent","NetFox"); .UQE{.?
2'] KTHm
<CZgQ\Mt
int responseCode=httpConnection.getResponseCode(); , jU5|2
if(responseCode>=400) e2cP *J
{ 6;iJ*2f5V
processErrorCode(responseCode); ;wHCj$q
return -2; //-2 represent access is error l1'6cLT`
} 3I $>uR
Z"y=sDO{
bm#(?
String sHeader; YlF%UPp
H,y4`p 0
-oP'4QVb
for(int i=1;;i++) \+ 0k+B4a
{ R[jEvyD>(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &%mXYj3y5
//Utility.log(in.readLine()); ?!'ZfQ:zK
sHeader=httpConnection.getHeaderFieldKey(i); iM]o"qOQm
if(sHeader!=null) Nd@~>&F
{ Ef)yQ
if(sHeader.equals("Content-Length")) 4a''Mi`u
{ h@ )
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NxA)@9Q
break; Hy_;nN+e
} 4vWkT8HQ
} .iHn5SGA
else >V$ Gx>I
break; Vsnuy8~k
} <hx+wrv
} Ig6T g ?
catch(IOException e){e.printStackTrace ();} :j^FJ@2_
catch(Exception e){e.printStackTrace ();} x@KZ]
i'#Gy,R
4 %W:
Utility.log(nFileLength); bZ1 78>J]
yuhnYR\`m
~Z'w)!h
return nFileLength; sN6N >{
} {Ui=b+
eq4C+&O&
4\M.6])_
//保存下载信息（文件指针位置） 9DQa PA6
private void write_nPos() vVl; |
{ tmUFT
try{ Z\}K{#
output = new DataOutputStream(new FileOutputStream(tmpFile)); {0"YOS`3AX
output.writeInt(nStartPos.length); *%/~mSx
for(int i=0;i<nStartPos.length;i++) ^-z=`>SrS"
{ W ~f(::
// output.writeLong(nPos); H<EQu|f&x
output.writeLong(fileSplitterFetch.nStartPos); k%]=!5F
output.writeLong(fileSplitterFetch.nEndPos); GL{57
} /3B $(
output.close(); uocHa5J
} }a AH
catch(IOException e){e.printStackTrace ();} ig}A9j?]
catch(Exception e){e.printStackTrace ();} \p{5D`HY
} !V2/A1?
?L&|Uw+
$-}e; VZb
//读取保存的下载信息（文件指针位置） z7GTaX$d
private void read_nPos() \;u@"
{ qt%D'
try{ b` Hz$8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )B,|@ynu
int nCount = input.readInt(); 1K,1X(0rL8
nStartPos = new long[nCount]; \^7C0R-hX
nEndPos = new long[nCount]; U-/{0zB
for(int i=0;i<nStartPos.length;i++) K"j_>63)
{ Ig]iT
nStartPos = input.readLong(); kVK/9dy-F
nEndPos = input.readLong(); OCZaQ33
} s,k
input.close(); LJk%#yV|_
} &F STpBu
catch(IOException e){e.printStackTrace ();} %1}K""/
catch(Exception e){e.printStackTrace ();} D(-yjY8aG
} w}Uhd,
o*U]v
s*U1
private void processErrorCode(int nErrorCode) Wjhvxk
{ &nBa=Enf
System.err.println("Error Code : " + nErrorCode); AdRX`[ik
} <\kr1qHH
iu&wO<)+?
[ i#zP
//停止文件下载 >SPh2[f
public void siteStop() ~.;< Bj
{ M9zfT!-
bStop = true; {pM?5"MMJ
for(int i=0;i<nStartPos.length;i++) hW!)w
fileSplitterFetch.splitterStop(); q[`j`8YY!R
b&1`NO
y6]vl=^L
} cuy1DDl
} zg-2C>(6a
//负责部分文件的抓取 34\(7JO
**FileSplitterFetch.java p-.n3AL
*/ !uQPc
package NetFox; (Jz;W<E
pPd#N'\*
i[wb0yL
import java.io.*; yR(x+Gs{]
import java.net.*; T)r9-wOq
a!O0,y
Q0EiEX)
public class FileSplitterFetch extends Thread { ~ vqa7~}m
>jD[X5Y
4Y[1aQ(%
String sURL; //File URL Y>'|oygHA
long nStartPos; //File Snippet Start Position cM&{+el
long nEndPos; //File Snippet End Position E[Cb|E
int nThreadID; //Thread's ID EkziAON
boolean bDownOver = false; //Downing is over jH_JmYd
boolean bStop = false; //Stop identical $56,$K`H
FileAccessI fileAccessI = null; //File Access interface xyI}y(CN1
7jdb)l\p=
As>_J=8} 3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?lP':'P
{ 9K1oZ?)_z
this.sURL = sURL; %2v4<icvq
this.nStartPos = nStart; yn#X;ja-
this.nEndPos = nEnd; lok=
nThreadID = id; \L"kV!>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =UV`.d2[
} u*hSj)vr1
>$4d7.^hb/
o}ZdTf=
public void run() 812$`5l
{ t.;LnrY
while(nStartPos < nEndPos && !bStop) G;YrF)\
{ r?/'!!4
Fi0GknQ+
i-6Z"b{
try{ ~c\e'&sc;
URL url = new URL(sURL); Qjb:WC7he
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .0es3Rj
httpConnection.setRequestProperty("User-Agent","NetFox"); p|!
String sProperty = "bytes="+nStartPos+"-"; #'y#"cmQ.
httpConnection.setRequestProperty("RANGE",sProperty); 4ecP*g
Utility.log(sProperty); NX}<*b/
R6(oZph
9g<7i
InputStream input = httpConnection.getInputStream(); EKO[!,
//logResponseHead(httpConnection); 5k.oW=
w4gJoxY-`
'ET~
byte[] b = new byte[1024]; vd[0X;
int nRead; 4M2j!Sw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *6>.!&
{ RNe^; B
nStartPos += fileAccessI.write(b,0,nRead); 76`8=!]R
//if(nThreadID == 1) }9FSO9*&}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .nVa[B|.
} BBev<
T \_]^]>
}R{ts
Utility.log("Thread " + nThreadID + " is over!"); \pVXimam
bDownOver = true; r4SXE\ G
//nPos = fileAccessI.write (b,0,nRead); lz?$f4TzA
} |AozR ~
catch(Exception e){e.printStackTrace ();} N(Tz%o4
} 2%_vXo=I
} WHj'dodS
tIuCct-
.?loO3 m
//打印回应的头信息 :s7m4!EF
public void logResponseHead(HttpURLConnection con) \hx1o\
{ i uF*.hc,%
for(int i=1;;i++) IhVO@KJI
{ vwxXgk
String header=con.getHeaderFieldKey(i); GJ_7h_4
if(header!=null) QD0"rxZJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?M\{&mlF
Utility.log(header+" : "+con.getHeaderField(header)); *=V~YF:Qb
else # mV{#B=
break; 9[.8cg*
} ,)vDeU
} _I:/ZF5
A\HxDIU
`ojoOB^L
public void splitterStop() u=`L)
{ !1$])VQWI
bStop = true; 4b98KsYg
} $\X[@E S0
sT}.v*
rustMs2p
} Z$/xy"
o!kbK#k
~f$|HP}
/* SAy=WV
**FileAccess.java e&&53?
*//文件访问(定位，写) BRgXr
package NetFox; Z{]0jhUyNh
import java.io.*; 7$CBx/X50)
HTX?,C_
E2R&[Q"%
public class FileAccessI implements Serializable{ &L'Dqew,*
{xXsBh Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >n'o*gZM
RandomAccessFile oSavedFile; t/VD31
long nPos; onz?_SAW
x!5'`A!W%
S[PE$tYT#t
public FileAccessI() throws IOException 0jy2H2
{ >0ow7Uw;
this("",0); 8%A#`)fb
} '>-gi}z7
m qMHL2~
A%KDiIA
public FileAccessI(String sName,long nPos) throws IOException CDQW !XHc
{ 0IBhb(X
oSavedFile = new RandomAccessFile(sName,"rw"); Lr$go6s
this.nPos = nPos; dfKF%27
oSavedFile.seek(nPos); ,!#*GZ.ix
} C~2F9Pg
haK3?A,"_A
gG<~-8uQ
public synchronized int write(byte[] b,int nStart,int nLen) M2OIBH4!
{ pwL;A3$|
int n = -1; < $J>9k
try{ 49GkPy#]L=
oSavedFile.write(b,nStart,nLen); .F
n = nLen; "{@A5A
} 9K{%vK
catch(IOException e) 47+&L
{ u0|8Tgf
e.printStackTrace (); }B\a<0L/
} X' H[7 ^W
RJ 8+h
dCi?SIN
return n; HN=V"a
} oM2l-[-
Wh+{mvu#
8 OY3A
} ]zE;Tw.S
>,gg5<F-E
x@P y>f2
/* $PTP/^
**SiteInfoBean.java m0ER@BXRn
*/ {o_X`rgrL
package NetFox; $WyD^|~SF
Qu?R8+"KS
%7zuQ \w
public class SiteInfoBean { _}lZ,L(w
qE&v ;
YVQN&|-
private String sSiteURL; //Site's URL BLfTsNzmt
private String sFilePath; //Saved File's Path *scVJ
private String sFileName; //Saved File's Name JD)(oK%C
private int nSplitter; //Count of Splited Downloading File <*16(!k0
tItX y
[I'0,y
public SiteInfoBean() nw-xSS{
{//nSplitter的缺省值为5 _<k\FU r
//default value of nSplitter is 5 dgR g>)V
this("","","",5); {MtpkUN
} 1C}NQ!.
]zj9A]i:a
$?Yry.2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^U `[(kz=
{ Ixb=L(V
sSiteURL= sURL; 2|3)S`WZl
sFilePath = sPath; RQ vft
sFileName = sName; ;&<{ey
this.nSplitter = nSpiltter; "+kL)]
iHeN9 cl
z:8eEq3w
} 3h;{!|-3
Y2a5bc P
h1B? 8pD
public String getSSiteURL() qaiNz S@q
{ &+Z,hs9%
return sSiteURL; !\zWF
} ?5C!<3gM)
LPZF)@|`
V=R 3)GC
public void setSSiteURL(String value) P\yDa*m
{ {P*pkc
sSiteURL = value; ah+~y,Gl
} C7rNV0.Fq
x'+T/zw
|jI#"LbF
public String getSFilePath() 3LAIl913
{ o<|cA5f\
return sFilePath; I8wXuIN_
} {@eJtF+2
l)G^cSHF.3
>p)MawT]
public void setSFilePath(String value) l1T m`7}
{ g[1gF&
sFilePath = value; F~T]u2qt
} $G8E 3|k
S{]x
SX<` {x&L
public String getSFileName() iP =V8g?L
{ d74d/l1*{
return sFileName; 2)G %)'
} -e_hrCW&9
3kw,(-'1
Ja,wfRq
public void setSFileName(String value) s3~lT.
{ &M46&^Jho
sFileName = value; kStnb?nk
} 5Sm}nH
GR&z,
.:@Ykdm4I
public int getNSplitter() fKeT,U`W
{ 'C`U"I
return nSplitter; BzkooJ
} 3L<wQ(
7op`s5i
&+cEV6vb+
public void setNSplitter(int nCount) iIMd!Q.)@
{ lpQSup
nSplitter = nCount; =y [M\m
} .n#@$ nGZ
} N*"p|yhd]
s%qF/70'
tX5"UQA
/* g l^<Q
**Utility.java CLRiJ*U
*/ 48:>NW
package NetFox; wLi4G@jJ
+fC=UAZ
@LS@cCC,a
public class Utility { wfNk=)^$
RX>xB
tmv&U;0Z
public Utility() Fpm|_f7
{ @Fluc,Il
`7 vHt`
B|R@5mjm
} Sx708`/Ep
I%r{]-Obr-
//线程睡眠 JG" R\2
public static void sleep(int nSecond) R@/"B8H
{ 5 xppKt
try{ d9B]fi}
Thread.sleep(nSecond); I/a/)No
} z2MWN\?8
catch(Exception e) eFaO7mz5V%
{ "]"|"0#i
e.printStackTrace (); 1M}5>V{
} /.3}aj;6
} Gf,`
,24p%KJ*X
//日志 }@;ep&b*
public static void log(String sMsg) ix([mQg
{ q#T/
System.err.println(sMsg); Hc>m;[M)l
} gG]Eeu+z
: ]sUpO
$K]m{
public static void log(int sMsg) [#l*_0
{ MXw hxk#E
System.err.println(sMsg); Q?nN!eT
} U*i{5/$
} qu-B| MuOa
~tBYIkvWT
)CuZDf@
/* ]!I7Y.w6
**TestMethod.java $*AYcy7
*/ o$#G0}yn
package NetFox; P,xKZ{(
q?4p)@#
-n=^U
public class TestMethod { %e-7ubW
zbk q
uW30ep'
public TestMethod() .$qnZWcgG
{ ///xx/weblogic60b2_win.exe O!P H&;H
try{ y`F3Hr c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U&Wt%U{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '^No)n\`
SiteFileFetch fileFetch = new SiteFileFetch(bean); O_ChxX0KP
fileFetch.start(); QWD'!)Zb
} -*$HddD
catch(Exception e){e.printStackTrace ();} L\@I*QP
G_0( |%
n;@bLJ$W
} d Vj_8>
z2g3FUTX)b
tKuVQH~D
public static void main(String[] args) yKa{08X:
{ 4Uphfzv3D
new TestMethod(); (BTVD,G
} Y&S24aql
} #:[t^}
点击下载更多相关资料