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)); z [|:HS&
} JI3x^[(Z
for(int i=0;i<nEndPos.length-1;i++) = :/4)
{ ,<CFjtelO
nEndPos = nStartPos[i+1]; g7UZtpLTm
} )K}-z+$)k
nEndPos[nEndPos.length-1] = nFileLength; /Kd9UQU
} GXnrVI
} o*t4zF&n
QomihQnc
tH)fu%:p
//启动子线程 Pf:;iXH?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p9y@5z
for(int i=0;i<nStartPos.length;i++) kf:Nub+h t
{ z 0}JiWR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %TeH#%[g>\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |muZv!,E
nStartPos,nEndPos,i); hh[@q*C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QPyHos`
fileSplitterFetch.start(); b[2 #t
} Yh["IhjR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S]Qf p,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8Q(A1U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Bfu/w
nEndPos = " + nFileLength); eyzXHS*s;L
// fileSplitterFetch[nPos.length-1].start(); 0aqq*e'c
0O!A8FA0
<dKHZ4
//等待子线程结束 moD)^':.
//int count = 0; |vPU]R>6
//是否结束while循环 A D%9;KQ8
boolean breakWhile = false; xqpq|U
n#S?fsQN
`$Y%c1;
while(!bStop) 2@Zw#2|]
{ N5b^
write_nPos(); .^wBv 'Y
Utility.sleep(500); =bOMtQ]
breakWhile = true; U.Fs9F4M#
"9#hk3*GqX
RN2z/FUf
for(int i=0;i<nStartPos.length;i++) %F87"v~
{ re fAgS!=q
if(!fileSplitterFetch.bDownOver) `4,]Mr1b
{ ?!u9=??
breakWhile = false; ~cf)wrP
break; XZ"oOE0=
} ao"Z%#Jb~
} e\._M$l
if(breakWhile) l% p4.CX
break; "8 ?6;!,
I2gSgv%
mGoNT
//count++; N}Or+:"O:q
//if(count>4) LX}|%- iv
// siteStop(); g,B@*2Uj
} TVVu_ib
k- exqM2x=
Of#"nu
System.err.println("文件下载结束！"); \[ W`hhJ
} 1ZXRH;J40
catch(Exception e){e.printStackTrace ();} I5E5,{
} m4^VlE,`Dh
[$M l;K
rIX 40,`
//获得文件长度 nv3TxG
public long getFileSize() !iAZEOkRR
{ ceLr;}?Ws
int nFileLength = -1; $#_^uWN-M
try{ bd3>IWihp
URL url = new URL(siteInfoBean.getSSiteURL()); tPDB'S:&3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qc3?Aplj
httpConnection.setRequestProperty("User-Agent","NetFox"); +!t *LSF
0Qg%48u
!v*#E{r"g=
int responseCode=httpConnection.getResponseCode(); bBQHxH}vi
if(responseCode>=400) PAiVUGp5[
{ y*8;T v|
processErrorCode(responseCode); [n +(
return -2; //-2 represent access is error <JZa
} 4VzSqb
8g/r8u~
we?t/YB=
String sHeader; VKi3z%kwK
hG3RZN#ejq
aX~' gq>
for(int i=1;;i++) ltd'"J/r
{ "H{#ib_c_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~5Rh7
//Utility.log(in.readLine()); l> >BeZ
sHeader=httpConnection.getHeaderFieldKey(i); l`];CALA4
if(sHeader!=null) &HJ~\6r\
{ Kw>gg
if(sHeader.equals("Content-Length")) OmP(&t7
{ 2aQ}| `
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Vb2")+*:
break; (7v`5|'0
} .sUL5`
} F#{PJ#
else A3zNUad;
break; 1z[blNs&
} <JJi
} Pq( )2B
catch(IOException e){e.printStackTrace ();} ,@2d4eg4
catch(Exception e){e.printStackTrace ();} \y/+H
QLTE`t5w3'
WTh|7&
Utility.log(nFileLength); v aaZ
nzu 3BVv
Mq,_DQ
return nFileLength; *-9b!>5eD
} ?r~](l
Z8Clm:S
i@d@~M7/
//保存下载信息（文件指针位置） 4HDQj]z/
private void write_nPos() "i*Gi \U
{ k)USLA
try{ ,K[B/tD{j
output = new DataOutputStream(new FileOutputStream(tmpFile)); b;Im +9&
output.writeInt(nStartPos.length); /7zy5
for(int i=0;i<nStartPos.length;i++) **O4"+Xi8
{ AuYi$?8|5
// output.writeLong(nPos); k07) g:_
output.writeLong(fileSplitterFetch.nStartPos); Bj7\{x,?
output.writeLong(fileSplitterFetch.nEndPos); z*>CP
} f1>^kl3@P
output.close(); PX'I:B]x*
} Y<.F/iaH
catch(IOException e){e.printStackTrace ();} XT_BiZ%l5O
catch(Exception e){e.printStackTrace ();} et]*5Y6
} ikRIL2Y
@;,O V&XYn
Fk(0q/b
//读取保存的下载信息（文件指针位置） c\4n7m,y
private void read_nPos() .^.UJo;4G
{ 1y"37;x
try{ U w`LWG3T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y!!+IeReS
int nCount = input.readInt(); Da-(D<[0
nStartPos = new long[nCount]; W@$p'IBwm
nEndPos = new long[nCount]; #CQ>d8&
for(int i=0;i<nStartPos.length;i++) khv!\^&DD
{ X0Oq lAw
nStartPos = input.readLong(); ^Q:K$!
nEndPos = input.readLong(); Em"X5>;4
} Eq<#pX6
input.close(); f|^f^Hu:{
} b);}x1L.T
catch(IOException e){e.printStackTrace ();} xf]4!zE
catch(Exception e){e.printStackTrace ();} (kuZS4Af
} -% fDfjP
eu:_V+
"\=_- `
private void processErrorCode(int nErrorCode) 1aT$07G0
{ YYvs~?bAy
System.err.println("Error Code : " + nErrorCode); P*T)/A%4
} +Ae.>%}
4 z`5W,
u ?Xku8 1l
//停止文件下载 O46/[{p+8
public void siteStop() ,`7GI*Vq
{ >PJ-Z~O'
bStop = true; I.<#t(io
for(int i=0;i<nStartPos.length;i++) 5~X%*_[],
fileSplitterFetch.splitterStop(); M#>GU<4"
FTenXJ/c
rh l5r"%
} J@TM>R
} yEny2q}
//负责部分文件的抓取 e.GzGX
**FileSplitterFetch.java ]xG4T>S
*/ %dU}GYL_
package NetFox; wg1pt1 `
'x0t, ;g
Z9D4;1
import java.io.*; FTfA\/tl(;
import java.net.*; ZkJM?Fzq
-CrZ'k;4
zef,*dQY
public class FileSplitterFetch extends Thread { K0g:Q*J-
<X |h*
~e+w@ lK
String sURL; //File URL h<.[U $,
long nStartPos; //File Snippet Start Position kI'A` /Bl
long nEndPos; //File Snippet End Position 9gg,Dy
int nThreadID; //Thread's ID bZXNo
boolean bDownOver = false; //Downing is over SA1/U
boolean bStop = false; //Stop identical t>2^!vl
FileAccessI fileAccessI = null; //File Access interface ks;wc"k"
sJ/e=1*
,9qB}HG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V2,WP
{ c1J)yv1y
this.sURL = sURL; %6'D!H?d
this.nStartPos = nStart; BfT,
this.nEndPos = nEnd; H@ms43v\
nThreadID = id; I)6Sbt JV^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <\g&%c,
} ?ljod6
*h:EE6|
wWU_?Dr_~
public void run() f](uc(8Z
{ Q;/F0JDH
while(nStartPos < nEndPos && !bStop) {7>CA'>
{ @a\SR'8
~!F4JRf
y9li<u<PF
try{ Q'%o;z*
URL url = new URL(sURL); s@LNQ|'kO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -==qMrKP
httpConnection.setRequestProperty("User-Agent","NetFox"); (iOCzZ6S
String sProperty = "bytes="+nStartPos+"-"; >Ryss@o
httpConnection.setRequestProperty("RANGE",sProperty); H#6^-6;/
Utility.log(sProperty); l\;mP.!
aiZo{j<6
Df~p'N-$
InputStream input = httpConnection.getInputStream(); mv*T=N8fC
//logResponseHead(httpConnection); MlK`sH6
Gj19KQ1G
,i?!3oLT
byte[] b = new byte[1024]; C'czXZtn
int nRead; ioNa~F&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vt=(2d5:p
{ )_^WpyzF1
nStartPos += fileAccessI.write(b,0,nRead); /rxltF3
//if(nThreadID == 1) Lp`<L-s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @" 0tW:
} D5!K<G?-K
$7n#\h
BU:Ecchbr
Utility.log("Thread " + nThreadID + " is over!"); RmWfV
bDownOver = true; Q A)9
//nPos = fileAccessI.write (b,0,nRead); [j}7@Mr`\
} B >u,)
catch(Exception e){e.printStackTrace ();} >=~Fo)V!(V
} 4l ZJb
} KT];SF^Y
5+bFy.UW
?D(FNd
//打印回应的头信息 e-iYJ?
public void logResponseHead(HttpURLConnection con) U8K&Q4^
{ *hZ~i{c,7
for(int i=1;;i++) >{ECyh;
{ 4", )zDk
String header=con.getHeaderFieldKey(i); G&@-R{i
if(header!=null) *"ykTqa
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L7Qo-
Utility.log(header+" : "+con.getHeaderField(header)); pymx\Hd,
else WbQhlsc:
break; 13.{Y)
} nOoKGT
} q8?=*1g
8B*E+f0
"J P{Q
public void splitterStop() t&R!5^R
{ Gg}5$||^C
bStop = true; hGed/Yr
} .'5'0lR5
!K3i-zY
_\,rX\
} pxw{
N<aB)</
+R "AA_A?
/* #Rin*HL##
**FileAccess.java 1Q&cVxA"\
*//文件访问(定位，写) %"l81z
package NetFox; _kn]#^ucCe
import java.io.*; -l-AToO4
N@cMM1
jOBY&W0r
public class FileAccessI implements Serializable{ x*unye7
PM~bM3Ei
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q&u>7_, Du
RandomAccessFile oSavedFile; ,dHP`j ?
long nPos; *-9#/Cp
[urH a
J3H.%m!V
public FileAccessI() throws IOException C0\%QXu
{ X$BXT
this("",0); UskZ%J
} 5{')GTdX>
TT|-aS0l(u
7}<Sg
public FileAccessI(String sName,long nPos) throws IOException myD{sE2A
{ 5\VxXiy0
oSavedFile = new RandomAccessFile(sName,"rw"); 65lOX$*{-
this.nPos = nPos; +yth_9
oSavedFile.seek(nPos); ha_@Yqgh
} kfVZ=`p}
9U]pH%.9
q;p.wEbr4U
public synchronized int write(byte[] b,int nStart,int nLen) DWuRJ
{ {U(Bfe^a,
int n = -1; ]X*YAPv
try{ GL/ KB
oSavedFile.write(b,nStart,nLen); 6%>/og\%
n = nLen; 'w}p[(
} _]P a>8X*
catch(IOException e) Wt(Kd5k0'2
{ -zprNQW
e.printStackTrace (); }gCG&7C
} )eECOfmnZ
ja?s@Y}-9s
T4eWbNSs
return n; 7 xUE,)?
} 02,W~+d1
GN0duV
$iwIF7,\P
} 6Hda]y
^=k{~
O5O.><RP
/* L/)B}8m\
**SiteInfoBean.java vuZf#\zh}
*/ u-kZW1wrQ
package NetFox; xLZbU4
b]w[*<f?
G&jZ\IV
public class SiteInfoBean { n_J5zQJ
E.9^&E}PG
|e:rYLxm:
private String sSiteURL; //Site's URL AO $Wy@
private String sFilePath; //Saved File's Path w?_`/oqd|
private String sFileName; //Saved File's Name ac|/Y$\w
private int nSplitter; //Count of Splited Downloading File w [L&*
zXjwnep
'=p?
public SiteInfoBean() w]}f6VlEl
{//nSplitter的缺省值为5 #v+;:
//default value of nSplitter is 5 k1RV'
this("","","",5); ZB$NVY
} 8A!'I<S1
]hL:33
F*,5\s<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )%t7\1)B3
{ {l@WCR
sSiteURL= sURL; T=>vh*J
sFilePath = sPath; }1Z6e[K?
sFileName = sName; EWO /u.z
this.nSplitter = nSpiltter; n7S; Xve#
ni<[G0#T
AX K95eS
} >4M<W4
p_r4^p\
E?_ zZ2
public String getSSiteURL() 9$wAm89
{ !?b/-~o7S
return sSiteURL; WGPD8.
} \FXp*FbQ
#N$9u"8C
ZJvo9!DL|
public void setSSiteURL(String value) R(`]n!V2
{ ,\x$q'
sSiteURL = value; N8QH*FX/F1
} Sz)b7:
}#bZ8tm&
-"tY{}z
public String getSFilePath() b`zET^F
{ &Sa~/!M
return sFilePath; <]'|$8&jY
} 7"a4/e;^
+99Bi2H}o
G1[(F`t>
public void setSFilePath(String value) ai9
{ 8)?_{
sFilePath = value; c=aO5(i0
} yV2e5/i
| k}e&Q_/G
tah}^
public String getSFileName() R;'?;I
{ zi.mq&,]R
return sFileName; TzY*;
} &mdB\Y?^
NWaO_sm
HU9p!I.
public void setSFileName(String value) Fv@tD4I>
{ ](nH{aY!
sFileName = value; yzg9I
} (!-;T
}DHUTP2;yz
63C(Tp"
public int getNSplitter() X Ny Y$
{ +4HlRGH
return nSplitter; x=vK EyS@
} 70=(.[^+
T]uKH29.%
FJF3B)Va|
public void setNSplitter(int nCount) 4|=vxJ
{ om>VQ3
nSplitter = nCount; _Fxe|"<^
} dE GX3 -
} bs P6\'\4
:G0+;[?N
Q.1XP
/* ^}hZ'<PK
**Utility.java 3a9u"8lG
*/ LyV#j>gD
package NetFox; cyBW0wV1
p {?}g'
#@E(<Pu4`
public class Utility { g&kH'fR8
=1IEpxh%
ee^4KKsh\
public Utility() kU1 %f o
{ :l;,m}#@
!?6.!2
NZfd_? 3
} {Hr>X
\6i9q=
//线程睡眠 hR0]8l|
public static void sleep(int nSecond) G>JxIrN0
{ ]`K[W&
try{ tI'e ctn
Thread.sleep(nSecond); DP0Z*8Ia
} ,[^o9u uB
catch(Exception e) %xHu,*
{ 6# R;HbkO
e.printStackTrace (); )Yrr%f`\
} tpE3|5dZF
} "~Us#4>
bje'Oolc
//日志 @YsL*zw
public static void log(String sMsg) .C6gl]6y@
{ pIL`WE1'
System.err.println(sMsg); w2' 3S#nZ
} L^&do98
eZ[#+0J
nMeSCX
public static void log(int sMsg) r^e-.,+
{ } cRi A
System.err.println(sMsg); =g1D;
} ]2g5Ka[>w
} POkXd^pI
WI%zr2T
omr:C8T>
/* @i;LZa
**TestMethod.java N c9<X
*/ S|tA[klh
package NetFox; bl6':m+
N <ja6Ac
DM+sjn
public class TestMethod { 4{c`g$j>
u)wu=z8
Z(#XFXd
public TestMethod() }6F_2S3c
{ ///xx/weblogic60b2_win.exe *vEU}SxRuv
try{ ^Jc$BMaVg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hn*}5!^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'cWlY3%t
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3XMBu*
fileFetch.start(); jqV)V>M.
} Tey,N^=ek
catch(Exception e){e.printStackTrace ();} iG?w;
g9RzzE!
ufHuI*
} nI((ki}v
30wYc &H
\k2C 5f
public static void main(String[] args) f]O5V$!RuE
{ x0N-[//YV
new TestMethod(); (Q*2dd>
} %`t]FV^#
} 3Y.d&Nz
点击下载更多相关资料