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)); b3_P??yp
} 3n)Kzexh
for(int i=0;i<nEndPos.length-1;i++) ugXDnM[S%
{ *tT}N@<%
nEndPos = nStartPos[i+1]; PA803R74
} .7 )oWd!
nEndPos[nEndPos.length-1] = nFileLength; 9W(&g)`
} \>*.+?97
} ud(0}[
w%TrL+v
|15!D
//启动子线程 iku*\,6W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gjq7@F'
for(int i=0;i<nStartPos.length;i++) 2o9B >f&g
{ CG@Fn\J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 49>b]f,Vc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4a&8G
nStartPos,nEndPos,i); XXX y*/P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ld#x'/
fileSplitterFetch.start(); M]k Q{(
} xMQ>,nZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %{IgY{X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #"c'eG0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6ERMn"[_w
nEndPos = " + nFileLength); #wT6IU1
// fileSplitterFetch[nPos.length-1].start(); x&J\swN9
&QD)1b[U
Z~h6^h
//等待子线程结束 2!}F+^8'P
//int count = 0; 3 eF c
//是否结束while循环 Hmm0H6&u
boolean breakWhile = false; 'MX|=K!C
0+qC_ISns
o:cTc:l)
while(!bStop) ^/}4M'[w
{ cy(w*5Upu
write_nPos(); 0U/[hG"DKN
Utility.sleep(500); KyT=:f V
breakWhile = true; zd8A8]&-
a;KdkykG
|S).,B
for(int i=0;i<nStartPos.length;i++) XZ8rM4 ]
{ U!Zj%H1XQ0
if(!fileSplitterFetch.bDownOver) B*}]'
{ VHqoa>U,*
breakWhile = false; l=T;hk
break; |.RyF@N`T
} aY,Bt
} qHgtd+ I
if(breakWhile) 4qE4 i:b
break; kmTYRl )j
i)(G0/:
2DsP "q79k
//count++; ?5ZvvAi
//if(count>4) gQSVPbzK
// siteStop(); aB (pdW4
} uUx7>algF
>G"fMOOkW
EpRn,[
System.err.println("文件下载结束！"); QPLWRZu@
} h]~FYY
catch(Exception e){e.printStackTrace ();} aqqo>O3 s
} re%XaL
Hicd -'
;Qq_
//获得文件长度 r{d@74
public long getFileSize() CeOA_M
{ W3Ee3
int nFileLength = -1; S9$,.aq
try{ VFF5Tp
URL url = new URL(siteInfoBean.getSSiteURL()); j+-`P5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TlyBpG=p
httpConnection.setRequestProperty("User-Agent","NetFox"); Y~I>mc]
1Zp/EYWa{
E <j=5|0t
int responseCode=httpConnection.getResponseCode(); YR~e_cA:
if(responseCode>=400) :ln|n6X
{ Z R=[@Oi
processErrorCode(responseCode); 4<}@hk Y
return -2; //-2 represent access is error 3}phg
} z8S]FpM6
gn/]1NNfR
O^./)#!#
String sHeader; SfPQ;s'
,vvfk=-
8Vn
for(int i=1;;i++) (t5y$bc
{ _8K8Ai-~.>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iNi1+sm
//Utility.log(in.readLine()); LzLJ6A>;R
sHeader=httpConnection.getHeaderFieldKey(i); Bx}"X?%S
if(sHeader!=null) _nzq(m1@
{ ,MJddbcg
if(sHeader.equals("Content-Length")) _(gkYJ+MK
{ # SCLU9-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &,PA+#
break; .WN&]yr,
} |zfFB7}v
} y_W?7S
else @VOegf+N
break; ^J^~5q8
} ?xMTO
} !.V_?aYi8
catch(IOException e){e.printStackTrace ();} O"TVxP:
catch(Exception e){e.printStackTrace ();} 2<n18-|OQ
OPq|4xu
,-EN{ed
Utility.log(nFileLength); Brs}
>m%TUQ#%
Zp_j\B
return nFileLength; RaTNA W)v>
} NW0se DL
yVn%Bz' [
=z9,=rR4
//保存下载信息（文件指针位置） IRk)u`
private void write_nPos() j?$B@Zk
{ rDwd!Jet
try{ [{xY3WS
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fq+Cr?-
output.writeInt(nStartPos.length); xA:;wV
for(int i=0;i<nStartPos.length;i++) |p+FIr+
{ rttKj{7E
// output.writeLong(nPos); [-Y~g%M
output.writeLong(fileSplitterFetch.nStartPos); ,*lns.|n
output.writeLong(fileSplitterFetch.nEndPos); 2w1Mf<IXPo
} 5Y`4%*$
output.close(); DtGkhq;
} W2$rC5|
catch(IOException e){e.printStackTrace ();} BIx*(
catch(Exception e){e.printStackTrace ();} 8,+T[S
} buzpmRoN)
'CqAjlj
RB""(<
//读取保存的下载信息（文件指针位置） <T.R%Jys
private void read_nPos() 6-?/kY6
{ "3Dnp?gB
try{ 3kGg;z6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Dvz 6 E
int nCount = input.readInt(); VY~*QF~P
nStartPos = new long[nCount]; J'=s25OWU
nEndPos = new long[nCount]; c; .y
for(int i=0;i<nStartPos.length;i++) ]moBVRd
{ 3bC-B!{;g
nStartPos = input.readLong(); d@JavcR
nEndPos = input.readLong(); j;j~R3B
} fWfhs}_
input.close(); 13 JG[,w
} ;2fzA<RkK
catch(IOException e){e.printStackTrace ();} Edh9=sxL
catch(Exception e){e.printStackTrace ();} {nA+-=T
} j/T@-7^0
T=V{3v@zs
|yOIC,5[JW
private void processErrorCode(int nErrorCode) :|I"Em3R
{ *Y53bZ
System.err.println("Error Code : " + nErrorCode); 3~WI3ZIR
} K|~!oQ
q(s0dkrj
&2@Rc?!6_P
//停止文件下载 !m_y@~pV#u
public void siteStop() ~^Ga?Q_
{ >c:nr&yP
bStop = true; F!C<^q~!
for(int i=0;i<nStartPos.length;i++) Op9+5]XF
fileSplitterFetch.splitterStop(); pG*W>F
z:dW'U?1
,e`n2)
} V~o'L#a
} #gf0*:p
//负责部分文件的抓取 oM#+Z qP
**FileSplitterFetch.java u,YmCEd_V
*/ 8h}1t4k
package NetFox; `N}'5{I
9*n?V;E
j9Z1=z
import java.io.*; 6+>X`k%D
import java.net.*; yg|yoL'g
i}<fg*6@E
0H}O6kU
public class FileSplitterFetch extends Thread { 4.kn,s
MM@&QaK
rO1N@kd/
String sURL; //File URL DYZk1
long nStartPos; //File Snippet Start Position gK *=T
long nEndPos; //File Snippet End Position 5X]f}6kT
int nThreadID; //Thread's ID rF?QI*`Y(
boolean bDownOver = false; //Downing is over |w_l~xYV)
boolean bStop = false; //Stop identical ct(euPU
FileAccessI fileAccessI = null; //File Access interface 6@(o8i
+'[*ikxD=g
11A;z[Zk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g6SZ4WV
{ sFgsEKs
this.sURL = sURL; 8jky-r
this.nStartPos = nStart; uAk>VPuuZ
this.nEndPos = nEnd; ?6MUyH]a
nThreadID = id; 9I1`*0A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j{ri]?p
} RSjcOQ8&.w
4>HQ2S{t
!Xq5r8]
public void run() AQ"rk9Z
{ gd]k3XN$f
while(nStartPos < nEndPos && !bStop) -gb@BIV#
{ ^v3J ld
v)zxQuH]^
\/Zo*/
try{ &y3;`A7,
URL url = new URL(sURL); q?0&0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1yc$b+TH
httpConnection.setRequestProperty("User-Agent","NetFox"); `[_p,,}Ir
String sProperty = "bytes="+nStartPos+"-"; %~Wr/TOt+
httpConnection.setRequestProperty("RANGE",sProperty); 7$L*nf
Utility.log(sProperty); E|VTbEYG
8*]dAft
lb}:!Y
InputStream input = httpConnection.getInputStream(); [F27i#'I]
//logResponseHead(httpConnection); 4 `}6W>*R
niPqzi
3XUie;*`
byte[] b = new byte[1024]; Z+FhI^
int nRead; Fdx4jc13w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _#<7s`i
{ (gutDUO;
nStartPos += fileAccessI.write(b,0,nRead); (.$e@k=
//if(nThreadID == 1) r,GgMk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [&p/7
} |L <
#J$z0%P
|A)a ='Ap
Utility.log("Thread " + nThreadID + " is over!"); [Z]CBEE
bDownOver = true; ~.S/<:`U
//nPos = fileAccessI.write (b,0,nRead); $|19]3T@Z
} 3HndE~_C&
catch(Exception e){e.printStackTrace ();} lp1GK/!s
} wr6(C:
} #<w2xR]:
RE;)#t?K
G|UeR=/
//打印回应的头信息 @`SlOKz!=
public void logResponseHead(HttpURLConnection con) 3`njQvI\
{ uHt@;$9A
for(int i=1;;i++) ~2XiKY;W?
{ .`h:1FP8
String header=con.getHeaderFieldKey(i); OL@' 1$/A
if(header!=null) 2 3A)^j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S<++eu
Utility.log(header+" : "+con.getHeaderField(header)); sFRQFX0XoY
else Q3LScpp
break; l]5!$N*
} ((fFe8Rn)q
} C7MCMM|S
4+N9Ylh
,LDdL
public void splitterStop() #4^D'r>pJ
{ ~H626vT37
bStop = true; )dRBI)P
} <TEDs4 C
8H{9
8-Z|$F"
} >td\PW~X
)KN]"<jB
h]^= y.Q
/* t,yMO
**FileAccess.java D{]9s
*//文件访问(定位，写) $4>x4*
package NetFox; EvDg{M}
import java.io.*; dYp} R>+
BbNl:`
t[bZg9;
public class FileAccessI implements Serializable{ NKu*kL}W=
X}]g;|~SN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k{+Gv}Y
RandomAccessFile oSavedFile; m^1'aO_;q
long nPos; 9Qc=D"'
~qb-uT\(99
24d{ol)
public FileAccessI() throws IOException @Yzb6@g"
{ y6Ea_v
this("",0); 8G_KbS
} +(o]E3
T=T1?@2C
:>, m$XO
public FileAccessI(String sName,long nPos) throws IOException ap.L=vn
{ [gE2;J0*
oSavedFile = new RandomAccessFile(sName,"rw"); d>`s+B9K0
this.nPos = nPos; Jgzg[6
oSavedFile.seek(nPos); h1QrFPQnu
} 7j{63d`2
gib;> nuBK
ne'Y{n(8%
public synchronized int write(byte[] b,int nStart,int nLen) Jnq}SUev
{ .OvH<%g!.
int n = -1; NAEAvXj
try{ ?lQ-HOAw
oSavedFile.write(b,nStart,nLen); h Ap(1h#m
n = nLen; 2@$`xPg
} r[kmgPld
catch(IOException e) 3rVWehCv
{ Hu7WU;w
e.printStackTrace (); "v5jYz5M
} 9rM6kLD
d?1[xv;
9 IY1"j0O
return n; |F52)<\
} C3e0d~C
#w]@yL]|is
;Qdw$NuW
} Te&5IB-
~#9(Q
!l#n.Fx&3
/* FKkL%:?
**SiteInfoBean.java ,Q>wcE6v
*/ fdzaM&
package NetFox; 1<&nHFJ;[
t,R4q*
Q`[J3-Q*{
public class SiteInfoBean { Iq: G9M
iig@$ i#
($^=f}+
private String sSiteURL; //Site's URL $}Ky6sBnvO
private String sFilePath; //Saved File's Path vS+E`[
private String sFileName; //Saved File's Name tJZ3P@ L
private int nSplitter; //Count of Splited Downloading File >R2o7~
gjex;h
1A;f[Rze
public SiteInfoBean() cR/z;*wr7
{//nSplitter的缺省值为5 OE_A$8L
//default value of nSplitter is 5 ];au! _o
this("","","",5); ?<eH!MHF
} *odwg$
kU[#. y=%p
? EXYLG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fs%l j_t
{ )w&k&TY4H
sSiteURL= sURL; R{SN.%{;
sFilePath = sPath; K._* ~-A
sFileName = sName; gqQ"'SRw
this.nSplitter = nSpiltter; QAKA3{-(
Xmaj7*f>p
\tZZn~ex
} WeRX~
kJG0X%+w
0N4+6k|
public String getSSiteURL() m<| *
{ y?yWM8
return sSiteURL; @DA.$zn&
} =/L;}m)7
$VyH2+ jC
V[r1bF
public void setSSiteURL(String value) Pvu*Y0_p
{ CWS&f g%o{
sSiteURL = value; ca!DZ%y
} 4Q n5Mr@<
2g:V_%
)6 [d'2
public String getSFilePath() #a=~a=c(^
{ Z2hIoCT
return sFilePath; S|v")6
} (b>B6W\&
x#,nR]C
"qvJ-Y
public void setSFilePath(String value) W<s5rMx
{ <c$K3
sFilePath = value; Q=Y1kcTOn
} UfAN)SE"
Mg76v<mv<
?wYvBFRn7"
public String getSFileName() K1*]6x,
{ 3lD1G~
return sFileName; |\_d^U&`
} fPu,@ L
8^|lsB}x?
OXCf
public void setSFileName(String value) _vgFcE~E@
{ W2G@-`,
sFileName = value; B gB]M3Il
} z;d]=PT
h,%b>JFo
r&?i>.Kz8
public int getNSplitter() z9)I@P"
{ L>Soj|WUy(
return nSplitter; U|}Bk/0.
} JVk"M=c
-cW'g
dpWBY3(7a
public void setNSplitter(int nCount) l/F'W}
{ B2DWSp-8*
nSplitter = nCount; K\a=bA}DG
} 8KhE`C9z
} `oUuAL
mhZ60RW
{Mx3G*hr
/* 8O0E;6b
**Utility.java -^+!:0';
*/ NT}r6V(Aju
package NetFox; ~99DE78
:M'V**A(
tV5Uz&:b
public class Utility { I? o)X!
(#`1[n+b`x
v?en-,{A
public Utility() r^,XpRe&M
{ j9G1 _
a2tRmil
:`w'}h7m
} NHjZ`=Js
C/L+gU&
//线程睡眠 7xr@$-U
public static void sleep(int nSecond) w;Jby
{ N akSIGm
try{ fXJbC+
Thread.sleep(nSecond); [TFd|ywn
} 7(oX1hN
catch(Exception e) A:-r2;xB
{ quEP"
e.printStackTrace (); G^Q8B^Lg
} C_~hX G
} X|iWnz+^
':jsCeSB
//日志 9;*-y$@
public static void log(String sMsg) &>]c"?C*
{ ;5(ptXX1W
System.err.println(sMsg); 8vL2<VT;
} /PuN+M
SlRQi:
cB ,l=/?
public static void log(int sMsg) vm y?8E6+
{ bb]r
System.err.println(sMsg); 6bXR?0$*M.
} ToVi;
} Z+G.v=2q<
zj9)vr`7
/\0rRT
/* WK<:(vu.
**TestMethod.java 6pCQP c*A
*/ =KctAR;
package NetFox; 5RysN=czA
<@puWm[p
>m-VBo
public class TestMethod { {hmC=j
[_pw|BGp
MY]<^/Q
public TestMethod() 6?C|pO
{ ///xx/weblogic60b2_win.exe ?mCino
try{ X?8EPCk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >ARZ=x[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +KzbaBK
SiteFileFetch fileFetch = new SiteFileFetch(bean); `,O#r0m
fileFetch.start(); c6@7>PM
} %gb4(~E+N
catch(Exception e){e.printStackTrace ();} 1K`7
C=6.~&(
X*^^W_LH.
} $k|:V&6SV
:p@.aD5
&*4C{N
public static void main(String[] args) nbECEQ:|B
{ dpPu&m+
new TestMethod(); ZHWxU
} PqJB&:ZV
} yDil
点击下载更多相关资料