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)); )-VpDW!%_
} +-~8t^
for(int i=0;i<nEndPos.length-1;i++) 1[p6v4qO{
{ pse$S=
nEndPos = nStartPos[i+1]; 0Lb:N]5m8
} opsjei@
nEndPos[nEndPos.length-1] = nFileLength; xl2;DFiYt
} %])U(
} 'tvX.aX2
cQ}3? v
1i3;P/
//启动子线程 v+d} _rCT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a;bmZh
for(int i=0;i<nStartPos.length;i++) ZDny=&>#
{ K93L-K^J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g?B4b7II
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qJ(XW N H
nStartPos,nEndPos,i); c(Ws3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?, B4
fileSplitterFetch.start(); K Q^CiX
} 3Gi^TXE]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =sZ58xA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )hG4,0hv&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .ni<'
nEndPos = " + nFileLength); !aQb Kp
// fileSplitterFetch[nPos.length-1].start(); AS4mJ UU9
4}4cA\B:n
8]h~jNku
//等待子线程结束 5tx!LGOK
//int count = 0; ":@\kw
//是否结束while循环 ~'1gX`o:
boolean breakWhile = false; *!oV?N[eA'
Yo%ph%e
HpP82X xj
while(!bStop) .>#X*u
{ $Mg[e*ct
write_nPos(); E<RPMd @a
Utility.sleep(500); ^+p7\D/E(
breakWhile = true; MHj RPh
6mV-+CnYC
w1Txz4JqB
for(int i=0;i<nStartPos.length;i++) )iX2r{
{ U}T{r%9
if(!fileSplitterFetch.bDownOver) s!<RWy+
{ z@I'Ryalyc
breakWhile = false; C&|K7Zp0v
break; hk+8s\%-
} (^pIB~.z
} _=Z?5{7S>
if(breakWhile) `6y=ky.,
break; S5o,\wT
hKnAWKb0
x" lcE@(
//count++; qP{Fwn
//if(count>4) 8Sxk[`qx\K
// siteStop(); bT7+$^NHf
} H2lQ(Y+H
; DXsPpZC
ff&jR71E
System.err.println("文件下载结束！"); -wa"&Q
} @yM$Et5
catch(Exception e){e.printStackTrace ();} igx~6G*
} C19}Y4r:
mUj_V#v
PctXh, =
//获得文件长度 "7q!u,u
public long getFileSize() GJ5R <f9I
{ s Poh\n
int nFileLength = -1; J6J">
try{ ?wP/l
URL url = new URL(siteInfoBean.getSSiteURL()); k?Kt*T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D%}rQ,*
httpConnection.setRequestProperty("User-Agent","NetFox"); t!-\:8n
{oSdVRI
Nj;5iy
int responseCode=httpConnection.getResponseCode(); nuH=pIq6x
if(responseCode>=400) 6(=B`Z}a
{ fUMjLA|*I<
processErrorCode(responseCode); }W)b
return -2; //-2 represent access is error Jxf>!\:AZu
} Vy=P*
3n,jrX75u
cO$xT;kK
String sHeader; !>\&*h-Cm#
5^D094J|^
ZIN1y;dJ
for(int i=1;;i++) nll=Vd[
{ i50E#+E8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7KesfH?
//Utility.log(in.readLine()); u*f`\vs
sHeader=httpConnection.getHeaderFieldKey(i); /WGD7\G'8
if(sHeader!=null) |LW5dtQ
{ [tT_ z<e`
if(sHeader.equals("Content-Length")) yh2)Pc[
{ S B~opN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zLgc j(;
break; ku4Gc6f#gG
} +e^CL#Gs
} E{0e5.{
else Qr\eT}
break; +BeA4d8b
} inY_cn?
} 0W0GSDx
catch(IOException e){e.printStackTrace ();} 3! #|hI>f
catch(Exception e){e.printStackTrace ();} ;A4qE W
egK~w8`W%
"cyRzQ6EH
Utility.log(nFileLength); (gnN</%
Atb`Q'Yrw
DKJ_g.]X
return nFileLength; b@c(Nv
} AyWdJ<OU
_aYhW{wW
#W6 6`{>
//保存下载信息（文件指针位置） p>,D F9W`
private void write_nPos() |sI@m@
{ No"i6R+
try{ ul3~!9F5F
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0C;Js\>3]
output.writeInt(nStartPos.length); 8 :WN@
for(int i=0;i<nStartPos.length;i++) h/oun2C
{ -RJ~Sky[
// output.writeLong(nPos); =igTY1|af
output.writeLong(fileSplitterFetch.nStartPos); ^vxx]Hji
output.writeLong(fileSplitterFetch.nEndPos); *^%+PQ
} ]0&X[?
output.close(); &\I<j\F2/
} m.rV1#AI
catch(IOException e){e.printStackTrace ();} B`.aQ
catch(Exception e){e.printStackTrace ();} [(2^oTSRaq
} @ R[K8
~n8UN<
#1%ahPhR+
//读取保存的下载信息（文件指针位置） RP$h;0EQG
private void read_nPos() %%|pJ%}Q>
{ Td,d9M
try{ 4qQE9fxdY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "b402"&
int nCount = input.readInt(); +.&P$`;TZj
nStartPos = new long[nCount]; ?%`Ph ?BZl
nEndPos = new long[nCount]; V@]SKbK}wN
for(int i=0;i<nStartPos.length;i++) GMg!2CIU
{ 3$xpZm60
nStartPos = input.readLong(); ~r?tFE*+
nEndPos = input.readLong(); KTt+}-vP^
} !zt>& t
input.close(); i6P}MtC1
} g4=C]\1
catch(IOException e){e.printStackTrace ();} IqV"4
catch(Exception e){e.printStackTrace ();} Ux1j+}y
} -8l(eDm"m
Gk+R,:
sZ~03QvkT
private void processErrorCode(int nErrorCode) |||m5(`S
{ ^mjU3q{;
System.err.println("Error Code : " + nErrorCode); @Co6$<
} $3B%4#s
\#JXch
%f'=9pit
//停止文件下载 Xq )7Im}?
public void siteStop() )^BZ,e
{ tvf5b8(Y-
bStop = true; ?FNgJx*\S
for(int i=0;i<nStartPos.length;i++) b1>]?.
fileSplitterFetch.splitterStop(); .rG~\Ws
w_o+;B|I
bl&9O
} P>u2""c
} )5n0P Zi
//负责部分文件的抓取 0<:rp]<,
**FileSplitterFetch.java P5h*RV>oS
*/ f[D%(
package NetFox; X31%T"
T[^&ZS]s
4CchE15
import java.io.*; 34X]b[^
import java.net.*; jygUf|
utRO?]%d !
[TQYu:e
public class FileSplitterFetch extends Thread { Ky7.&6\n
Q|P M6ta
4W|cIcU W
String sURL; //File URL @{#'y4\>
long nStartPos; //File Snippet Start Position dl[%C6
long nEndPos; //File Snippet End Position 7FkiT
int nThreadID; //Thread's ID BJ]L@L%
boolean bDownOver = false; //Downing is over FX9WXb4w
boolean bStop = false; //Stop identical *J]p/<> {
FileAccessI fileAccessI = null; //File Access interface s0]ZE\`H>
x0>N{ADXQ
"9dZ z/{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &>+5 8
{ `),U+
this.sURL = sURL; k>Fw2!mA^
this.nStartPos = nStart; *z6A ~U
this.nEndPos = nEnd; ern\QAhXX
nThreadID = id; sVFX(yx0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xs|d#WbX
} *;McX
n^$Q^[:Z
0[fBP\H"Wr
public void run() @`+\vmfD
{ ^7ID |uMr
while(nStartPos < nEndPos && !bStop) shL_{}
{ x^c,cV+*
c%O97J.5b
}"nm3\Df
try{ !SE
URL url = new URL(sURL); `n-/~7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J"< h#@`
httpConnection.setRequestProperty("User-Agent","NetFox"); FeS ,TQ4j
String sProperty = "bytes="+nStartPos+"-"; }f_@@#KB?
httpConnection.setRequestProperty("RANGE",sProperty); ^t71${w##
Utility.log(sProperty); J @~g>
o3\^9-jmp
uPbdzUk$
InputStream input = httpConnection.getInputStream(); wSCI?
//logResponseHead(httpConnection); 3N!v"2!#
\!jz1`]&{
=jh^mD&'
byte[] b = new byte[1024]; Mv/ SU">F
int nRead; nh0gT>a>@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <+r~?X_
{ p5OoDo
nStartPos += fileAccessI.write(b,0,nRead); `Ix`/k}
//if(nThreadID == 1) !5h-$;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'AWWdz
} zt9A-% \R
9=6BQ`u
Nxl#]
Utility.log("Thread " + nThreadID + " is over!"); g~,iWoY
bDownOver = true; =bP<cC=3b
//nPos = fileAccessI.write (b,0,nRead); ,SIGfd
} |:4W5>sfg
catch(Exception e){e.printStackTrace ();} }+MA*v[06
} %-$ :/N
} nv+miyvvm
ZU0*iA
4`9ROC
//打印回应的头信息 As5l36
public void logResponseHead(HttpURLConnection con) M6quPj
{ I(kEvfxc"
for(int i=1;;i++) 8-H:5E 4Y
{ oxeIh9 E
String header=con.getHeaderFieldKey(i); gBWr)R
if(header!=null) =Ez@kTvOs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AqQ5L>:Gq
Utility.log(header+" : "+con.getHeaderField(header)); 9bRUN<
else /*e<r6
break; 6{udNv X
} 5+Tx01)
} 8[t*VIXI
(4RtoYWW
7!(/7U6rP
public void splitterStop() dT&u}o3X
{ q^6#.}
bStop = true; N}[!QE
} T*Ge67
4JXvP1`
w'_|X&@H
} fWWB]h
GV) "[O
}#M>CNi'PU
/* #H |p)2k
**FileAccess.java ?-o_]!*v0/
*//文件访问(定位，写) )h>dD
package NetFox; ]oz>/\!
import java.io.*; 0|K<$e6IH
fuCt9Kjo<
XV4aR3n{Q
public class FileAccessI implements Serializable{ }X=c|]6i^
#PPHxh*S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U|.r -$|5P
RandomAccessFile oSavedFile; EBk-qd a}
long nPos; y=+OC1k\8
w8N1-D42
;o;ak.dTt
public FileAccessI() throws IOException [euR<i*I#
{ qe?Ns+j<d
this("",0); I`jG
} iqB%sIP
2!CL8hG5:
$_eJ@L#
public FileAccessI(String sName,long nPos) throws IOException S=`$w
{ GcA|JS=>
oSavedFile = new RandomAccessFile(sName,"rw"); wL]#]DiE
this.nPos = nPos; ob9od5Rf
oSavedFile.seek(nPos); 2?:OsA}
} MT)q?NcG
^r(]S%
8KkN "4'
public synchronized int write(byte[] b,int nStart,int nLen) (Rq6m`M2
{ |%#NA!e4wA
int n = -1; U7g,@/Qx
try{ q(R|3l^6T
oSavedFile.write(b,nStart,nLen); w@6y.v1I{
n = nLen; eTw9c }[
} ieWXr4@:
catch(IOException e) XhWo~zh"
{ lk81IhI
e.printStackTrace (); \Nf[8n#{
} r58<A'#
3m-g-
{%P2.:
return n; 9AQ,@xP|
} `m#G'E I
L})*ck
x;} 25A|
} UmMu|`
*V+,X
xC0y2+)|
/* R-,L"Vv
**SiteInfoBean.java ei=u$S.
*/ <}c7E3Uc
package NetFox; vpdPW%B
:f_oN3F p
0yMHU[):~
public class SiteInfoBean { mMWhUr
7Lj:m.0O^
n;vZY
private String sSiteURL; //Site's URL >o&%via}
private String sFilePath; //Saved File's Path ?8< =.,r
private String sFileName; //Saved File's Name 3fZoF`<a
private int nSplitter; //Count of Splited Downloading File S5Pn6'w
y@2"[fo3~
%1{O
public SiteInfoBean() ~ oq.yn/1
{//nSplitter的缺省值为5 hBaG*J{
//default value of nSplitter is 5 {-]K!tWda
this("","","",5); ;p<BiC$b
} iyUnxqP
Vj8-[ww!
(G$Q\>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =,qY\@fq
{ eOXu^M>:F
sSiteURL= sURL; :=!6w
sFilePath = sPath; q;f L@L@-
sFileName = sName; 'gD./|Z0
this.nSplitter = nSpiltter; []yIz1P=j
-?{g{6
xdaq` ^Bbt
} d|~'#:y@
t.O~RE
7 TM-uA$
public String getSSiteURL() k$#1T +(G
{ [ z/G
return sSiteURL; #u\~AO?h
} z-"P raP
v"%>ms"n
r9b(d]
public void setSSiteURL(String value) Q[H4l({E
{ s,/C^E
sSiteURL = value; ;<+Z}d/g9
} 4R8Qn^
0HbCT3g.
--c)!Vxzx
public String getSFilePath() LL+_zBP.
{ J_|%8N{[x
return sFilePath; R6z *!W{
} *J':U>p
gA1j'!\6l9
VJCj=jX
public void setSFilePath(String value) 8 K)GH:a
{ 6e5A8e8"]
sFilePath = value; 8-kR {9r
} BV/ ^S.~
asy:[r"
If'N0^'W
public String getSFileName() Z R~2Y?Wt9
{ 9ku|w#%I
return sFileName; [{&OcEf
} f/0k,~,*
B(eiRr3
T0b/txS
public void setSFileName(String value) d]sg9`
{ JLu$UR4
sFileName = value; !Bg^-F:N
} Su +<mW
NQiu>Sg
zNn
public int getNSplitter() 2'Kh>c2
{ qM3(OvCt
return nSplitter; X_rv}
} eE\T,u5:
KMl3`+i
9>&p:+D
public void setNSplitter(int nCount) t)O]0) s
{ 'b>3:&
nSplitter = nCount; h{jm
} I-kK^_0mV<
} fti0Tz'
_KyhX|
Ar_Yl|a
/* W%9~'pXgB
**Utility.java )lUocm
*/ q8R,#\T*
package NetFox; 'fzJw
q 4Ok$~"I
}h3[QUVf%
public class Utility { jsKKg^g
I.SMn,N
GFnwj<V+{
public Utility() LJ z6)kz
{ 1NrNTBI@
rV-Xsf7Z
/P/0\3TCi
} lX50JJwk
6aWnj*dF
//线程睡眠 `Uvc^
public static void sleep(int nSecond) ,Vz-w;oDn
{ 1n.F`%YG
try{ &,,:pL[
Thread.sleep(nSecond); n-dC!t
} Z`%^?My
catch(Exception e) _tQM<~Y]u\
{ 4T){z^"
e.printStackTrace (); AmCymT3P*e
} 2@N-#x'
} Dj0D.}`~
0juP"v$C>
//日志 QV#HN"F/K
public static void log(String sMsg) uFvR(LDb&g
{ 3?!c<^"e
System.err.println(sMsg); ]&='E.f
} e_S,N0
(8NE'd8
eG.s|0`
public static void log(int sMsg) mK^E@uxN
{ {t]8#[lo
System.err.println(sMsg); l @E {K|
} yi-0CHo
} -BwZ
,~Lx7 5{
{817Svp@
/* A9GSeW<
**TestMethod.java :j32 :/u
*/ f]Rh<N$
package NetFox; >LVGNicQ
X&M04
LMp^]*)t
public class TestMethod { 19Mu}.+;
.lSoC`HE
<?Z]h]C^o
public TestMethod() eZg>]<L
{ ///xx/weblogic60b2_win.exe |h.@Xy
try{ w,<n5dMv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7eFFKl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^=gN >xP
SiteFileFetch fileFetch = new SiteFileFetch(bean); _+Pz~_+kS
fileFetch.start(); 'PTQ S,E
} 2frwU~y
catch(Exception e){e.printStackTrace ();} Ju"c!vu~
@ykl:K%ke
Nr*o RYY
} V'K:52
+Je%8jH
`j 4>
public static void main(String[] args) 'XOWSx;Y
{ fM(~>(q&
new TestMethod(); "|E'E"_1
} @F|pKf:M+
} {!1RlW
点击下载更多相关资料