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)); r&CiSMS*
} t0S1QC+
for(int i=0;i<nEndPos.length-1;i++) uFE)17E
{ z_HdISy0
nEndPos = nStartPos[i+1]; 3w=J'(RU
} w{KavU5W
nEndPos[nEndPos.length-1] = nFileLength; Hka2
} L,\Iasv
} \hXDO_U
KoT\pY^7\
{FkF
//启动子线程 ^W^OfY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y4-t7UlS;
for(int i=0;i<nStartPos.length;i++) 'DR!9De
{ *w&e\i|7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;uJMG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7! Nsm
nStartPos,nEndPos,i); It(_v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #"!<W0
fileSplitterFetch.start(); TH;hO).u
} TOt dUO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), & 21%zPm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZVBXx\{s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L0,'mS
nEndPos = " + nFileLength); 2G7Wi!J
// fileSplitterFetch[nPos.length-1].start(); COlqcq'qAu
>Tgv11[
ll^#JpT[S
//等待子线程结束 <I?Zk80
//int count = 0; -RwE%cr
//是否结束while循环 fC`&g~yK'
boolean breakWhile = false; c{|p.hd
dV_G1'
]^E?;1$f?
while(!bStop) la!~\wpa
{ _>+Ld6.T6
write_nPos(); lxx2H1([
Utility.sleep(500); RZLq]8pM
breakWhile = true; 3fj4%P"
vXs"Dst
tmqOJ
for(int i=0;i<nStartPos.length;i++) ?s01@f#
{ [,Gg^*umS
if(!fileSplitterFetch.bDownOver) #mdc[.
{ o!Zb0/AP)
breakWhile = false; K+eM
break; y(#e}z:
} D*jM1w_`
} pi(m7Ci"
if(breakWhile) Sjqpec8
break; 9[4xFE?|
Wr 4,YQM
XFl6M~ c
//count++; }bxs]?OW>
//if(count>4) dO'(2J8
// siteStop(); {: /}NpA$
} Txu/{M,
aE8VZ8tvq
Dt@SqX:~Ee
System.err.println("文件下载结束！"); Nn6%9PX_)
} kiEa<-]
catch(Exception e){e.printStackTrace ();} w)f#V s
} :#Wd~~d
*dQSw)R
5pX6t
//获得文件长度 f*Hr^b}`8
public long getFileSize() z{ dEC %
{ &C}*w2]0S
int nFileLength = -1; =_CzH(=f#
try{ rq{$,/6.
URL url = new URL(siteInfoBean.getSSiteURL()); -).C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )0`C@um
httpConnection.setRequestProperty("User-Agent","NetFox"); 81F9uM0
vM={V$D&
yi[x}ffdE
int responseCode=httpConnection.getResponseCode(); Rq-ZL{LR7
if(responseCode>=400) -"x$ZnHU
{ ]Wup/o
processErrorCode(responseCode); W/N7vAx X
return -2; //-2 represent access is error z{q`GwW
} ).O)p9
KNl$3nX
UMi~14& ;
String sHeader; W?&%x(6M
tQVVhXQ7
@7}W=HB
for(int i=1;;i++) 7V>M]
{ Xw1*(ffk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *~`(RV
//Utility.log(in.readLine()); h[ ZN+M
sHeader=httpConnection.getHeaderFieldKey(i); i8p6Xht
if(sHeader!=null) jXJyc'm7
{ e-;}366}
if(sHeader.equals("Content-Length")) JF]JOI6.e
{ sOY:e/_F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l/D} X
break; ;uW FHc5@B
} }p V:M{Nu&
} /r 5eWR1G
else +T ?NH9
break; 'u658Tj
} Om&Dw|xG8
} ~DWl s.
catch(IOException e){e.printStackTrace ();} vO=fP_
catch(Exception e){e.printStackTrace ();} cQ|NJ_F{1
4-w{BZuS
ZCw]m#lS
Utility.log(nFileLength); e20-h3h+
$G>.\t
]:;&1h3'7
return nFileLength; }H4RR}g
} 'w/hw'F6
]9-\~Mwh
2oW"'43X
//保存下载信息（文件指针位置） XW9!p.*.U
private void write_nPos() ,4rPg]r@
{ }Jw,>}
try{ zs;JJk^
output = new DataOutputStream(new FileOutputStream(tmpFile)); )u">it+
output.writeInt(nStartPos.length); *hrd5na
for(int i=0;i<nStartPos.length;i++) V&i;\9
{ sLFl!jX
// output.writeLong(nPos); Xj*Wu_
output.writeLong(fileSplitterFetch.nStartPos); hZ3bVi)L\
output.writeLong(fileSplitterFetch.nEndPos); E`q_bn
} #$vEGY}1
output.close(); ,Q B<7a+I
} G3]4A&h9v~
catch(IOException e){e.printStackTrace ();} E7hhew
catch(Exception e){e.printStackTrace ();} rNM;ZPF#
} ?%86/N>
w!CNRtM:~
6zkaOA46V
//读取保存的下载信息（文件指针位置） B!yr!DWv
private void read_nPos() 8MBAtVmy
{ `/g UV
try{ ^aQ"E9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g}i61(
int nCount = input.readInt(); Ru XC(qcq
nStartPos = new long[nCount]; =;k|*Ny
nEndPos = new long[nCount]; neh(<>
for(int i=0;i<nStartPos.length;i++) "b[5]Y{ U
{ l, wp4Ll
nStartPos = input.readLong(); 5f/`Q
nEndPos = input.readLong(); l2d{ 73h
} l0] EX>"E
input.close(); 4 :=]<sc,
} wzaV;ac4K
catch(IOException e){e.printStackTrace ();} ,Q,^3*HX9}
catch(Exception e){e.printStackTrace ();} Q?T]MUY(L
} VpUAeWb
&zhAh1m
8fb'yjIC
private void processErrorCode(int nErrorCode) >7r!~+B"9'
{ ,[Fb[#Qqb
System.err.println("Error Code : " + nErrorCode); O f#:
} u>$t'
X8|EHb<
%SI'BJ
//停止文件下载 `6YN3XS
public void siteStop() K^$=dLp
{ ':W[A
bStop = true; HDKbF/
for(int i=0;i<nStartPos.length;i++) P4?glh q#
fileSplitterFetch.splitterStop(); ddo#P%sH'
7rA;3?p)
8Y3I0S
} y]imZ4{/
} +RXoi2"-q@
//负责部分文件的抓取 Wm|lSisY
**FileSplitterFetch.java /bEAK-
*/ "j-CZ\]U|
package NetFox; r/sNrB1U"y
1cGmg1U;
:LTN!jj
import java.io.*; nm+s{
import java.net.*; 9cgUT@a
ca}2TT&t
l@\FWWQ
public class FileSplitterFetch extends Thread { Tr|JYLwF
*kVV+H<X|b
b\ PgVBf9
String sURL; //File URL KgG4*<
long nStartPos; //File Snippet Start Position 8_tQa^.n\
long nEndPos; //File Snippet End Position ':}\4j&{E
int nThreadID; //Thread's ID 2Hdu:"j
boolean bDownOver = false; //Downing is over ]d`VT)~vje
boolean bStop = false; //Stop identical !+njS
FileAccessI fileAccessI = null; //File Access interface DJ%PWlK5
|'.
uocGbi:V';
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kl,3IKHa
{ s7EinI{^
this.sURL = sURL; L(o15
this.nStartPos = nStart; e*!kZAf
this.nEndPos = nEnd; V,9cl,z+
nThreadID = id; 3[&Cg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4sM.C9W
} h1{3njdr
~v83pu1!2s
]HdCt3X
public void run() qa6,z.mQ
{ Jl<2>@
while(nStartPos < nEndPos && !bStop) 5coZ|O&f8
{ rH>)oThA#
875od
zT[!o j7
try{ smLQS+UE
URL url = new URL(sURL); *j-aXN/$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &0f,~ /%Z
httpConnection.setRequestProperty("User-Agent","NetFox"); `-&K~^-cH
String sProperty = "bytes="+nStartPos+"-"; Df#l8YK#
httpConnection.setRequestProperty("RANGE",sProperty); I0a<%;JJW
Utility.log(sProperty); &OBkevg
Jo}eeJ;k
vFsLY
InputStream input = httpConnection.getInputStream(); ??T#QQ
//logResponseHead(httpConnection); ETLD$=iS
oRzi>rr
Fx+*S3==%e
byte[] b = new byte[1024]; Ev P{p
int nRead; i?~3*#IpD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i LAscb
{ TPY}C
nStartPos += fileAccessI.write(b,0,nRead); E"@wek.-
//if(nThreadID == 1) tl].r|yl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;>YzEo
} BB'OCN
frQ{iUx
H.2QKws^F
Utility.log("Thread " + nThreadID + " is over!"); gNhQD*+>{
bDownOver = true; *#Wdc O`-
//nPos = fileAccessI.write (b,0,nRead); @A5?3(e
} T^v}mWCZ
catch(Exception e){e.printStackTrace ();} >*n0n!vF
} 1QJL .
} BUR*n;V`
=ruao'A
9C\Fq-
//打印回应的头信息 iIogx8[
public void logResponseHead(HttpURLConnection con) _y3Xb`0a
{ Lk$B{2^n
for(int i=1;;i++) wT\49DT"7
{ j+(I"h3
String header=con.getHeaderFieldKey(i); _~ &iq1
if(header!=null) <9%R\_@$H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g[t [/TV
Utility.log(header+" : "+con.getHeaderField(header)); * H9 8Du
else W];dD$Oqg
break; m_l[MG\
} A4ygW:
} P2*<GjV`S/
"T"h)L<
<o= 8FO
public void splitterStop() veRm2LSP
{ h-D}'R
bStop = true; +U.I( 83F
} 7!$^r$t
-tNUMi'
F3N6{ysK#
} d:{O\
e!r-+.i(
VQ{fne<
/* +'@Dz9:>
**FileAccess.java ^BL"wk
*//文件访问(定位，写) 2>H24F
package NetFox; 5BJmA2L
import java.io.*; e,5C8Q`Z
/OJ`c`>Q:
+H2-ZXr
public class FileAccessI implements Serializable{ 3Le{\}-$.
w'3iY,_ufC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -S+zmo8
RandomAccessFile oSavedFile; {u9}bx'<
long nPos; D1mfm.9_r^
2T TdH)
fg{n(TE"8
public FileAccessI() throws IOException Rx|;=-8zg
{ jZ3fKyp#
this("",0); 0P(!j_2m
} 1>&]R=
O,A{3DAe0
~3S~\0&|
public FileAccessI(String sName,long nPos) throws IOException -B\HI*u
{ zkdetrR
oSavedFile = new RandomAccessFile(sName,"rw"); :#~j:C|
this.nPos = nPos; ++#5
oSavedFile.seek(nPos); {GcO3G#FZ
} ,i@:5X/t
aoa)BNs
1&o|TT/
public synchronized int write(byte[] b,int nStart,int nLen) a+PzI x2
{ hDq`Z$_+KX
int n = -1; =iD3Yt
try{ 13=.H5
oSavedFile.write(b,nStart,nLen); ^w06<m
n = nLen; :<#nTh_@\'
} B !=F2
catch(IOException e) uc"P3,M
{ XEZF{lP
e.printStackTrace (); .@Dxp]/B}
} 0k(a VkZ I
Iy3GE[
Bng@-#`/
return n; ")HFYqP>9
} {T Ug.%u
f8.gT49I
qXjxNrK
} Q'mM3pq4r
!o[7wKrXb
=6|&Jt
/* VgC2+APg
**SiteInfoBean.java p`#R<K
*/ M|(Q0 _8
package NetFox; td3D=Y
VEw"
VD]zz ^
public class SiteInfoBean { )M//l1
h@]XBv
Bv%GJ*>>
private String sSiteURL; //Site's URL l/ ;
private String sFilePath; //Saved File's Path "4,?uPi
private String sFileName; //Saved File's Name ">jj
private int nSplitter; //Count of Splited Downloading File {Wu$YWE*sx
SrK<fAkx
ye? 'Ze
public SiteInfoBean() c>~*/%+
{//nSplitter的缺省值为5 ,V:SN~P66+
//default value of nSplitter is 5 ^J8lBLqe
this("","","",5); ~Ti'FhN
} bl(RyAgA
-701j'q{
GU8sO@S5#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !V g`
{ 4J([6<
sSiteURL= sURL; pDCeQ6?
sFilePath = sPath; KX7>^Bt&k
sFileName = sName; @w!PaP
this.nSplitter = nSpiltter; hJ#xB6
D^3vr2
e?lyH
} FA3~|Zg
EJ:%}HhA
nl,uuc*;
public String getSSiteURL() s)Cjc.Qs
{ e?=^;v%r
return sSiteURL; K$_0`>[
} aC.~&MxFC
9dUravC7
t#pS{.I
public void setSSiteURL(String value) :|8M`18lZ
{ {"QNJq#:
sSiteURL = value; Um-[~-
} 7 uKY24
`o8/(`a
spPNr
public String getSFilePath() oVfLnI;
{ &,CiM0
return sFilePath; hL;(C)(
} o,8TDg
Q_X.rUL0w
&_|#.
public void setSFilePath(String value) "#oHYz3D
{ zZ323pq
sFilePath = value; YCM]VDx4u1
} #c?j\Y9nz
+sUFv)!4
*8_wYYH
public String getSFileName() bNNr]h8y-
{ fs%.}^kn
return sFileName; doy`C)xI
} g($DdKc|g
}$Tl ?BRpU
W_8wed:b
public void setSFileName(String value) {|:;]T"y
{ 'd$P`Vw:
sFileName = value; PFne+T!2F
} 5BKt1%Pg
iJ3e1w$
c+$*$|t=v`
public int getNSplitter() C$D-Pt"+
{ ?9\EN|O^
return nSplitter; tL)t" i
} lqZ5?BD1
m?fy^>1
ZR?yDgL
public void setNSplitter(int nCount) [^e%@TV>d
{ ft KTnK.
nSplitter = nCount; $m1z-i;/
} j4`0hnqI
} D9 |n)f
MET' (m
;n=.>s*XL'
/* `a/%W4
**Utility.java giIWGa.a+
*/ ]d0tE?9
package NetFox; Sf7\;^
a\E:sPM'>
|>27B
public class Utility { 2Yn <2U/^R
ve/<=IR Zo
tlqiXh<
public Utility() /1Q(b
{ \6<=$vD
M .JoHH
sy"^?th}b
} u\{ g(li-I
=L:4i\4
//线程睡眠 _Khc3Jo
public static void sleep(int nSecond) Z99>5\k
{ D.Q=]jOs
try{ M#VE]J
Thread.sleep(nSecond); /ZPyN<@
} `~Zs0
catch(Exception e) U`d5vEhT
{ 27"%"P.1
e.printStackTrace (); "C SC
} B$!)YD;
} V'T ,4
O8u j`G 9
//日志 -}=%/|\FG
public static void log(String sMsg) ,:H\E|XeBw
{ FUOI3
System.err.println(sMsg); cmg^J
} %$Z7x\_
T'&I{L33Y
@zz1hU
public static void log(int sMsg) I`LuRlw
{ $!(pF
System.err.println(sMsg); Jjv=u
} M|qteo
} H{k^S\K
* %M3PTY\
O0No'LVu
/* xp72>*_9&
**TestMethod.java kg3EY<4i
*/ ); dT_
package NetFox; be-~\@
yo)%J
R_7 d@FQ1
public class TestMethod { vIwCJN1C
:1^R9yWA4
<U >>ZSi
public TestMethod() ?)X,0P'
{ ///xx/weblogic60b2_win.exe )'%$V%9
try{ [4C:r!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [uls8 "^/j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u1PaHgi$
SiteFileFetch fileFetch = new SiteFileFetch(bean); &c%g
fileFetch.start(); g(J&m<I
} ,@3$X=),E
catch(Exception e){e.printStackTrace ();} rJ{O(n]j
,JN8f]a^"g
yi%-7[*]=
} RYl>
cwWodPNm
lh D,\3/O
public static void main(String[] args) 9Fm"ei
{ e9[|!/./5
new TestMethod(); 5qoSEI-m
} +H#U~p$
} F>[,zN
点击下载更多相关资料