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)); P{n#^4
} hvw9i7#
for(int i=0;i<nEndPos.length-1;i++) OY`B{jV-
{ KN|<yF
nEndPos = nStartPos[i+1]; }<A.zwB<i
} Cr7Zi>sd<!
nEndPos[nEndPos.length-1] = nFileLength; )Wk_|zO-
} tr,W)5O@L
} (4R(5t
=9a2+v0
V+ ("kz*
//启动子线程 !g]5y=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TR0y4u[
for(int i=0;i<nStartPos.length;i++) ,-y9P
{ XJ4f;U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NVv <vu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T(7`$<TQ
nStartPos,nEndPos,i); 29RP$$gR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DQXUh#t\(]
fileSplitterFetch.start(); ?8V.iHJk
} #_ |B6!D!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }R['Zoh4I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [v"Z2F<.=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \tI%[g1M
nEndPos = " + nFileLength); ~U]g;u
// fileSplitterFetch[nPos.length-1].start(); ;AEfU^[
}UW7py!TN
luf5-XT
//等待子线程结束 I$xZV?d.
//int count = 0; /IUu-/ D
//是否结束while循环 :jl*Y-mM
boolean breakWhile = false; C:J;'[,S
XA2Ld
NZq-%bE
while(!bStop) CjQO5
{ \#9LwC"8;
write_nPos(); V^2_]VFj
Utility.sleep(500); =#G 2}8mQD
breakWhile = true; N*-tBz
{q0+PzgP
u<BU4c/p
for(int i=0;i<nStartPos.length;i++) X,|8Wpi=
{ FXof9fa_B
if(!fileSplitterFetch.bDownOver) YJ _eE
{ C$y6^/7)
breakWhile = false; !2LX+*;
break; K&|h%4O
} 15g!Q *v
} ,&t+D-s<f
if(breakWhile) te+}j7SU
break; V,&%[H [
"<ZV'z
9*)&hhBs,
//count++; dEoIVy_9R
//if(count>4) c|Ivet>3
// siteStop(); X8|H5Y:
} pr0X7 #_E5
]nTeTW
<,]:jgX
System.err.println("文件下载结束！"); JtL>mH
} Pp8S\%z~h
catch(Exception e){e.printStackTrace ();} Js,!G
} ;t&q|}x"
l76=6Vtb
n$/|r
//获得文件长度 F(G..XJQ
public long getFileSize() 0WUBj:@g
{ p/h\QG1
int nFileLength = -1; Y [`+7w
try{ *4cuWkQ,
URL url = new URL(siteInfoBean.getSSiteURL()); ^{+ry<rS>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d9f7 &
httpConnection.setRequestProperty("User-Agent","NetFox"); +K4XMf
G$<(>"Yr~$
(g##wa)L
int responseCode=httpConnection.getResponseCode(); a1cX+{W
if(responseCode>=400) |`T(:ZKXZ2
{ 7>Z|K
processErrorCode(responseCode); ')uYI;h9
return -2; //-2 represent access is error oPSPb(.
} H%wB8Y ]
HGQ</5Z
sfM"!{7
String sHeader; H5K Fm#
\QvGkcDc{
/G||_Hc
for(int i=1;;i++) > G\0Z[<v,
{ zwfft
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HXLnjXoe
//Utility.log(in.readLine()); 6>vR5pn
sHeader=httpConnection.getHeaderFieldKey(i); sf> E
if(sHeader!=null) >G]JwO
{ Q dj(D\.
if(sHeader.equals("Content-Length")) wNf:_^|}
{ h[ .
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \((iR>^|
break; dfDjOZSL
} m%HT)`>bg
} p*g Fr hm
else 02J/=AC5
break; S,&LH-ps
} ;wv[';J
} )@g[aRFa
catch(IOException e){e.printStackTrace ();} 1WUSp;JMl
catch(Exception e){e.printStackTrace ();} @.t +
BlVHP8/b
o=m5AUe?J
Utility.log(nFileLength); 7)rQf{q7
W5R/Ub@g
m}]{Y'i]R
return nFileLength; k<9,Ypa
} "-4|HA
_H+]G"k/r
H,7='n7"
//保存下载信息（文件指针位置） "#d$$ 8
private void write_nPos() P3oYk_oW
{ &[ })FI
try{ S:xXD^n#H
output = new DataOutputStream(new FileOutputStream(tmpFile)); L!Jx`zM^
output.writeInt(nStartPos.length); jD S?p)&
for(int i=0;i<nStartPos.length;i++) 2q?/aw ;Z
{ [OC(~b
// output.writeLong(nPos); f1'ByV'2
output.writeLong(fileSplitterFetch.nStartPos); CmU@8-1
output.writeLong(fileSplitterFetch.nEndPos); 6#Vl3o(E|
} &h5Vhzq(<
output.close(); #VQZ"7nI@
} }+,Q&]>~
catch(IOException e){e.printStackTrace ();} 8FsQLeOE
catch(Exception e){e.printStackTrace ();} )."ob=m
} ?^&ih:"
Ac_P^
-laH^<jm5
//读取保存的下载信息（文件指针位置） HhbBt'fH
private void read_nPos() |_53So:g
{ )~'UJPK
try{ uLdHE5vr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5wK==hZ
int nCount = input.readInt(); vl (``5{
nStartPos = new long[nCount]; uKx:7"KD
nEndPos = new long[nCount]; }8O9WS
for(int i=0;i<nStartPos.length;i++) }&v}S6T
{ _/>ktYo:
nStartPos = input.readLong(); "aGmv9\
nEndPos = input.readLong(); rZUTBLZ`j
} (kL"*y/"p
input.close(); 4 ]oe`yx
} x?i wtZ@
catch(IOException e){e.printStackTrace ();} jFQy[k-B
catch(Exception e){e.printStackTrace ();} !'$*Z(
} frcAXh9
M"z=114
>N^<Q4%2
private void processErrorCode(int nErrorCode) Bc=(1ty)
{ M+t)#O4
System.err.println("Error Code : " + nErrorCode); Zg+.`>z
} 7gX32r$%V
l$u52e!7
'/GB8L
//停止文件下载 +w0Wg.4V
public void siteStop() Ana[>wSZO@
{ -@AhJY.
bStop = true; F}Zg3#
for(int i=0;i<nStartPos.length;i++) =Uk#7U"P
fileSplitterFetch.splitterStop(); ra~=i|s
>MYxj}I4{z
^B.Z3Y
} FK BRJ5O
} p\zqZ=s
//负责部分文件的抓取 9/"&6,
**FileSplitterFetch.java A1zRzg4I
*/ c!@|yE,
package NetFox; x8lBpr
`0upm%A
\3vQXt\dM$
import java.io.*; A!Tl
import java.net.*; v&:[?<6-
'DW|a
0A}XhX
public class FileSplitterFetch extends Thread { veDv14
| .+P ;g
d.}65{F,x
String sURL; //File URL w5Fk#zJv
long nStartPos; //File Snippet Start Position 5c5!\g~'
long nEndPos; //File Snippet End Position ;(K/O?nrJ
int nThreadID; //Thread's ID qkfof{z
boolean bDownOver = false; //Downing is over smCACQ$(
boolean bStop = false; //Stop identical :[a*I6/^
FileAccessI fileAccessI = null; //File Access interface F-kjv\
j+!u=E
.#y#u={{l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C b'|
{ \BBs;z[/
this.sURL = sURL; 05F/&+V
this.nStartPos = nStart; c:Czu
this.nEndPos = nEnd; gV)/lDEM5
nThreadID = id; B1X&O d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %)i&|AV"
} U<Oc&S{]*
Vg62HZ |
zd_N' :6
public void run() E+y_te^+b
{ p;4FZ$
while(nStartPos < nEndPos && !bStop) |X{j^JP5
{ "OwM' n8
:U\*4l
<xBL/e %
try{ +;+G+Tn
URL url = new URL(sURL); P)VQAM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D <~UaHfk
httpConnection.setRequestProperty("User-Agent","NetFox"); ,{IDf
String sProperty = "bytes="+nStartPos+"-"; :X":>M;;+
httpConnection.setRequestProperty("RANGE",sProperty); e# Y{YtE
Utility.log(sProperty); (6c/)MH
3ZT3I1/D
e=XP4h
InputStream input = httpConnection.getInputStream(); e&ti(Q=
//logResponseHead(httpConnection); |HAbZd7PG
U]pE{^\w
gwNZ`_Q
byte[] b = new byte[1024]; >~d'i
int nRead; 5[2kk5,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *~U*:>hS
{ y ;mk]
nStartPos += fileAccessI.write(b,0,nRead); 5[g&0
//if(nThreadID == 1) \<I&utn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :V$\y up
} GX23c i
i^WY/ OhL
'xd8rN%T
Utility.log("Thread " + nThreadID + " is over!"); Xcfd]29
bDownOver = true; v$\<L|
//nPos = fileAccessI.write (b,0,nRead); m p_7$#{l
} a2?@OJ
catch(Exception e){e.printStackTrace ();} "E<+idoz
} v2gk1a&
} !4v>|tq!
Ot.v%D`e 5
g mWwlkf9
//打印回应的头信息 [1GwcXr
public void logResponseHead(HttpURLConnection con) L'Iw9RAJ
{ @|h9jx|
for(int i=1;;i++) RKrNmD*rk*
{ N_Ezp68Fp
String header=con.getHeaderFieldKey(i); 7r:&%?2:g
if(header!=null) |FFz $'8)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BN(=LQ2["
Utility.log(header+" : "+con.getHeaderField(header)); 1z|bQ,5
else }72\Aw5
break; I[rR-4.F]
} r4cz?e|
} o]V.6Ge-
eSIG+{;&
d@^%fVhG
public void splitterStop() Xz:ha>}C
{ ;\|GU@K{hC
bStop = true; v?8i;[
} PcbhylKd
+*Wlj8
lA4-ZQ2Zp[
} .~ uKr^%
(z;lNl(*C
R68:=E4
/* W3ms8=z
**FileAccess.java s;Bh69
*//文件访问(定位，写) ]'n4e*
package NetFox; YeT{<9p
import java.io.*; An}RD73!w
h+Lpj^<2a
34CcZEQQ
public class FileAccessI implements Serializable{ |3FGMg%
5'DY)s-K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BT}l"
RandomAccessFile oSavedFile; a Z)1SX`D
long nPos; CN` ~DD{
22ySMtxn
PI$i_3N
public FileAccessI() throws IOException yX*$PNL5w
{ U<F|A!Fg
this("",0); 6.tA$#6HP
} gT=pO`a
)sQ/$gJ
RIUJX{?
public FileAccessI(String sName,long nPos) throws IOException NKEmY-f;
{ wWx{#!W
oSavedFile = new RandomAccessFile(sName,"rw"); "{+2Q
this.nPos = nPos; y(iq
oSavedFile.seek(nPos); ->OVNmCB`+
} nT01B1/<]
%R?WkG
;:oXe*d
public synchronized int write(byte[] b,int nStart,int nLen) &'zc2
{ t%e<]2-8
int n = -1; ]Hl{(v\HO
try{ :B=Gb8?
oSavedFile.write(b,nStart,nLen); ^B%ki
n = nLen; gREk,4DAv
} s5G`?/
catch(IOException e) 5~UW=
{ ^kC!a>&
e.printStackTrace (); .>r3ZwrE'
} V=&M\58
f`;w@gR`=
?vbAaRg50s
return n; 9fs-|E[5
} Vp1ct06^
#X1a v
%t6-wWM97
} >}+R+''nR
:81d~f7
{A< 961
/* h|PC?@jp
**SiteInfoBean.java cR!M{U.q
*/ T(Yp90'6
package NetFox; G0Z5h
Vg,nNa3
\K"7U
public class SiteInfoBean { ZDL1H3;R
+w.$"dF!
XUVj<U
private String sSiteURL; //Site's URL 31 <0Nw;l
private String sFilePath; //Saved File's Path S"?fa)~
private String sFileName; //Saved File's Name |ssl0/nk
private int nSplitter; //Count of Splited Downloading File >r\GB#\5
mT-[I<
$aU.M3
public SiteInfoBean() JvvN>bg
{//nSplitter的缺省值为5 j[R.UB3J
//default value of nSplitter is 5 S[7^#O.)
this("","","",5); tw.GBR
} *aS+XnT/
jTg~]PQ^
5_](N$$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d^M*%az
{ !x ~s`z
sSiteURL= sURL; "P|n'Mx
sFilePath = sPath; M?My+oT
sFileName = sName; 2z#S|$
this.nSplitter = nSpiltter; cNwHY Z'
~@6l7H6{
}[lP^Qs
} W 2[]m>;
-G/qfd|s/
Fx.Ly]L
public String getSSiteURL() t_!p({
{ `C|];mf(#
return sSiteURL; KiI+ V;o
} <)!,$]S
<"K*O9nst
z7sDaZL?_
public void setSSiteURL(String value) z k}AGw
{ j%y{d(Q4
sSiteURL = value; g"|>^90
} `)cH(Rj
;ltk}hJ]
XKws_
public String getSFilePath() vOz1& |;D
{ -8FUR~WJ
return sFilePath; Nb9GrYIS
} >"=DN5w ,S
R3a}YwJFXF
^Y+C!I
public void setSFilePath(String value) *{+{h;p
{ #O;JV}y
sFilePath = value; rq!*unJ
} (&Lt&i _
1,;zX^
_iq62[i3^
public String getSFileName() |BZrV3;H
{ =z"+)N
return sFileName; jZkc yx
} NNbdP;=:u
6(-s@{
3 1-p/
public void setSFileName(String value) `?N0?;
{ m }HaJ
sFileName = value; P33xt~
} =c*l!."0
>L!c} Ku
_9 '_w&
public int getNSplitter() v ;}s`P\"
{ MA:5'n
return nSplitter; /; Bmh=
} n6WKk+
m Rw0R{
~I+MuI[
public void setNSplitter(int nCount) s^eiymP
{ YcDKRyrt
nSplitter = nCount; }kr?+)wB
} r)}U 'iv*%
} T#3@r0M
0&]1s
7LrmI~P
/* b\`S[
**Utility.java `a MU2
*/ 9>9EZ?4m
package NetFox; fM"*;LN!N
]"{8"+x
Lm2!<<<
public class Utility { jmkOu5@
/IRXk[
KB](W
public Utility() _,T 4DS6
{ -GCo`PR?b
/ 'qoKof
9)'f)60^
} Q7XOO3<):
wTa u.Bo
//线程睡眠 ]n|Jc_Y
public static void sleep(int nSecond) m:?"|.]
{ (XVBH1p"
try{ oXnaL)Rk
Thread.sleep(nSecond); eyyME c!
} esnq/
catch(Exception e) _i+@HXR &
{ qiOJ:'@
e.printStackTrace (); [MFnS",7c
} s||" } l
} &R%'s1]o
W/ Q*NB
//日志 byM-$l
public static void log(String sMsg) 6qH0]7maI
{ BtC*]WB"_'
System.err.println(sMsg); 'q)g,2B%
} G7nhUg
[ncK+rGAc
qy3@> 1G
public static void log(int sMsg) rtj`FH??11
{ be,Rj,-
System.err.println(sMsg); 3J+2#ML
} @;bBc
} >SK:b/i
(6S'wb
+1y$#~dl
/* ]A3
**TestMethod.java $QC1l@[sM
*/ ;Y^'$I2fR#
package NetFox; Zj_2>A
O1z]d3x
'f-r 6'_ZX
public class TestMethod { FzJ7 OE|
fu^W# "{
BHUI1y5t
public TestMethod() A#=TR_@:
{ ///xx/weblogic60b2_win.exe <:}nd:l1
try{ ;KlYiu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hWT jN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5 aA* ~\
SiteFileFetch fileFetch = new SiteFileFetch(bean); /D&&7;jJ
fileFetch.start(); hF,|()E[
} nMyl(kF[
catch(Exception e){e.printStackTrace ();} #0P_\X`E
Cd}^&z
\_ 3>v5k|
} IW0S*mO$
i7Up AHd/
}uZs)UQ|$
public static void main(String[] args) Jay"
{ yfZNL?2x
new TestMethod(); "o&8\KSs
} *5%vU|9b
} nF,F#V8l
点击下载更多相关资料