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)); Z6\+
} nJ4pTOc
for(int i=0;i<nEndPos.length-1;i++) 7dsefNPb
{ 8 C[/dH
nEndPos = nStartPos[i+1]; KL$bqgc(p3
} bVP"(H]
nEndPos[nEndPos.length-1] = nFileLength; !Z VU,b>
} 'lHdOG
} K\"R&{+=
Zo1,1O
.EM`.
//启动子线程 zOg7raIa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uqz]J$
for(int i=0;i<nStartPos.length;i++) 241*!
{ gbVdOm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >pUtwIP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y0eE-5F,
nStartPos,nEndPos,i); lHgs;>U$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cGjPxG;
fileSplitterFetch.start(); 9z6XF]A
} :y7c k/>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LL:_L<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >EY3/Go>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fb^fVSh>
nEndPos = " + nFileLength); Sa2>`":d
// fileSplitterFetch[nPos.length-1].start(); oudxm[/U
$DG?M6
f^W;A"+
//等待子线程结束 E>l~-PaZY
//int count = 0; Gea\,{E9xA
//是否结束while循环 !47n[Zs
boolean breakWhile = false; wI(M^8F_Mf
a+n0|CvF
;*MLRXq
while(!bStop) eJg8,7WC
{ X&kp;W
write_nPos(); Jv^h\~*jH
Utility.sleep(500); 41&\mx
breakWhile = true; d3xmtG {i
h$2</J"
\ Yx/(e
for(int i=0;i<nStartPos.length;i++) M3.do^ss
{ @;"|@!l|
if(!fileSplitterFetch.bDownOver) |ZmUNiAa
{ (!:,+*YY
breakWhile = false; AIZ]jq
break; /'/Xvm3
} PUUwv_
} \kZ?
if(breakWhile) nR*ryv
break; mHRiugb!
FYpzQ6s~
H*}y^)x
//count++; P5UL4uyl
//if(count>4) J\b^)
// siteStop(); YuO.yh_
} d$1@4r
r8RoE`/T
" )1V]}+m
System.err.println("文件下载结束！"); rbWP78
} 'd9INz.
catch(Exception e){e.printStackTrace ();} 9P+-#B
} %V7at7>o
2fL;-\!y(
;{N!Eb`S
//获得文件长度 "~|6tQLc
public long getFileSize() 9dx/hFA
{ ;@oN s-
int nFileLength = -1; `r9!zffyS
try{ m+]K;}.}R
URL url = new URL(siteInfoBean.getSSiteURL()); X aMJDa|M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,?^ p(w
httpConnection.setRequestProperty("User-Agent","NetFox"); ,s"^kFl
N2;B-UF 7
f6&iy$@
int responseCode=httpConnection.getResponseCode(); 0Qf,@^zL*
if(responseCode>=400) P/W XaE4
{ [M=7M}f;
processErrorCode(responseCode); QTk}h_<u
return -2; //-2 represent access is error !$gR{XH$]
} GjvOM y
N5lDS
Pd_U7&w,5
String sHeader; 8}O lL,fP
at,XB.}Z]
4O^xY 6m
for(int i=1;;i++) 8;JWK3Gv
{ '-Vt|O_Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .1Dg s=|
//Utility.log(in.readLine()); )vE~'W
sHeader=httpConnection.getHeaderFieldKey(i); t.i 8 2Q
if(sHeader!=null) EM(gmWHij
{ _@ qjV~%Sy
if(sHeader.equals("Content-Length")) ;U+3w~
{ vN;N/mL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2K/4Rf0;
break; _-K2/6zy
} #lL^?|M
} .SU8)T
else ,is3&9
break; rZ}:Z'`
} X^wt3<Kbf
} 2} /aFR
catch(IOException e){e.printStackTrace ();} 0z6R'Kjy A
catch(Exception e){e.printStackTrace ();} / *#r`A
.ypL=~Rp
ZbW17@b
Utility.log(nFileLength); bN1|q|9
-b9\=U[
Bq%Jh
return nFileLength; spH7 /5}
} 61C7.EZZ;
Rq'S>#e
HdUQCugxx:
//保存下载信息（文件指针位置） {HltvO%8
private void write_nPos() un mJbY;t
{ U)]oO
try{ l*Gvf_UH
output = new DataOutputStream(new FileOutputStream(tmpFile)); NX*Q F+
output.writeInt(nStartPos.length); !C':
for(int i=0;i<nStartPos.length;i++) _7Ju
{ NvceYKp:
// output.writeLong(nPos); 3w*R&
output.writeLong(fileSplitterFetch.nStartPos); 24 'J
output.writeLong(fileSplitterFetch.nEndPos); 6jD=F ^jw
} vtg!8u4
output.close(); ?Jm^<
} q_[o"wq/
catch(IOException e){e.printStackTrace ();} MS~(D.@ZS
catch(Exception e){e.printStackTrace ();} Y8~"vuIE5
} V(I8=rVH
QOGvC[*`<T
i+ ?^8#
//读取保存的下载信息（文件指针位置） C_}]`[
private void read_nPos() J5K^^RUR
{ @1roe G
try{ pK>N-/?a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XJ;57n-?
int nCount = input.readInt(); ?=sDM& '
nStartPos = new long[nCount]; J/y83@
nEndPos = new long[nCount]; O3,jg|,
for(int i=0;i<nStartPos.length;i++) yLvDMPj
{ #CTE-W"|HE
nStartPos = input.readLong(); D0-3eV-
nEndPos = input.readLong(); &-)N'
} 0*3R=7_},o
input.close(); /l~p=PK
} ]m3HF&
catch(IOException e){e.printStackTrace ();} lfow1WRF
catch(Exception e){e.printStackTrace ();} E4jNA}3k+
} vH@ds k
2*& ^v
vm8eZG|
private void processErrorCode(int nErrorCode) ?(1y
{ rH Lm\3
System.err.println("Error Code : " + nErrorCode); &jJL"gq"
} 6Pl<'3&
F0TB<1
AO4U}?
//停止文件下载 ,?%Zc$\LW
public void siteStop() b4 6~?*
{ `Y$4 H,8L
bStop = true; GR_-9}jQP
for(int i=0;i<nStartPos.length;i++) .W%)*&WH\
fileSplitterFetch.splitterStop(); eu-*?]&Di
By!o3}~g
97*p+T<yp
} Ax7[;|2
} rglXs
//负责部分文件的抓取 -uG+BraI
**FileSplitterFetch.java +mj y<~\
*/ +~$ ]}%
package NetFox; -GrE}L
g]H<}4lgq"
%ntRG!
import java.io.*; 013x8!i
import java.net.*; aB&&YlR=n<
UB@+ck
+I|vzz`ZVr
public class FileSplitterFetch extends Thread { EV%gF
^6V[=!& H
FTUv IbT
String sURL; //File URL ?+@?Up0wGO
long nStartPos; //File Snippet Start Position {4Cmu;u
long nEndPos; //File Snippet End Position qo bc<-
int nThreadID; //Thread's ID 29.h91
boolean bDownOver = false; //Downing is over <\^8fn
boolean bStop = false; //Stop identical V**~m9f
FileAccessI fileAccessI = null; //File Access interface ( Erc3Ac8
Z@!+v19^
!_)[/q"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h*](a_0
{ n{mfn*r.
this.sURL = sURL; )3EY;
this.nStartPos = nStart; xi}skA
this.nEndPos = nEnd; ](8[}CeL
nThreadID = id; OQJ6e:BGt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Vt#.eL)Ee
} ^<2p~h0 \
s.C_Zf~3
4|DWOQ':
public void run() M .mfw#*
{ 0\P1; ak%
while(nStartPos < nEndPos && !bStop) /PIcqg
{ cVF"!.
"^%cJAnLX
SO!8Di
try{ T_4/C2
URL url = new URL(sURL); y}|s&4Sq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uVrd i?3
httpConnection.setRequestProperty("User-Agent","NetFox"); X'iWJ8
String sProperty = "bytes="+nStartPos+"-"; }BP;1y6-r
httpConnection.setRequestProperty("RANGE",sProperty); <)D$51 &0
Utility.log(sProperty); /%^#8<=|U
<Q3c[ Y
6=Otq=WH
InputStream input = httpConnection.getInputStream(); eJ-nKkg~a
//logResponseHead(httpConnection); |yPu!pfl
G"A#Q"
)Pv%#P-<
byte[] b = new byte[1024]; LKDO2N
int nRead; Zj'9rXhrM1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j0q&&9/Jj
{ #%O0[kd
nStartPos += fileAccessI.write(b,0,nRead); ;RlxD 4p
//if(nThreadID == 1) Jln:`!#fDf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); scV5PUq
} y?3;06y|
]7A'7p$Y
,I;>aE<#
Utility.log("Thread " + nThreadID + " is over!"); P]C<U aW'!
bDownOver = true; =7UsVn#o
//nPos = fileAccessI.write (b,0,nRead); -XG@'P_
} ,PDQzJY
catch(Exception e){e.printStackTrace ();} 6ik$B
} #GFr`o0$^
} wC'Szni
r<$y=B
RxQ*
//打印回应的头信息 Dw"\/p:-3
public void logResponseHead(HttpURLConnection con) 0=$T$0g
{ #w=~lq)9
for(int i=1;;i++) Q,Eo mt
{ \{NO?%s0p
String header=con.getHeaderFieldKey(i); \w8\1~#
if(header!=null) 8{ I|$*nB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4skD(au8
Utility.log(header+" : "+con.getHeaderField(header)); @ Nm@]q
else F"mmLao
break; %z$#6?OK^
} _#8MkW#]~
} 0"SU_jQzv
w32y3~
4^d?D!j
public void splitterStop() W*Y/l~x}
{ 2`-Bs
bStop = true; ),!qTjD
} 5lum$5
@(lh%@hO
d_P` qA
} GA.8@3
;FEqe49
+cRn%ioVi
/* .]K%G\*`:
**FileAccess.java A=>u 1h69
*//文件访问(定位，写) *NQ/UXE
package NetFox; (tO$aS=
import java.io.*; w2'5#`m
4&iCht =
}K9H^H@r!
public class FileAccessI implements Serializable{ 8b=_Y;
K<J9~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K,UMqAmk
RandomAccessFile oSavedFile; )pn3~t<ed
long nPos; A%-6`>
M3Kfd
paMa+jhQQ
public FileAccessI() throws IOException DV{=n C
{ hv+zGID7
this("",0); R}ecc
} :@&/kyGH
Xm&L BX
1:wQ.T
public FileAccessI(String sName,long nPos) throws IOException -$@h1Y
{ GKCroyor
oSavedFile = new RandomAccessFile(sName,"rw"); <-0]i_4sK
this.nPos = nPos; {XHh8_^&
oSavedFile.seek(nPos); PaN"sf
} B-ESFATc
mBC+6(5V
|nF8gh~}
public synchronized int write(byte[] b,int nStart,int nLen) Wez5N
{ =Runf +}
int n = -1; w=@Dv
try{ SY8C4vb'h
oSavedFile.write(b,nStart,nLen); mcok/,/
n = nLen; 5(8@%6>ruj
} aN=B]{!
catch(IOException e) F<w/PMb
{ bjS{(
e.printStackTrace (); bN88ua}k{
} Np)lIGE
=qIyqbXz
}&3~|kP~O
return n; E!AE4B1bd
} rN{ c7/|
,Lt[\_
39jG8zr=Z[
} .[ mRM
9g?(BI^z
\|ao`MMaD<
/* hpJ-r
**SiteInfoBean.java %PJQ%~ A
*/ C8\^#5
package NetFox; fxIf|9Qi`
snikn&
yiI1x*^
public class SiteInfoBean { 3yXY.>'
]0\MmAJRn
cs'{5!i]
private String sSiteURL; //Site's URL YgoBHE0#
private String sFilePath; //Saved File's Path a@*\o+Su
private String sFileName; //Saved File's Name Xs?o{]Fe
private int nSplitter; //Count of Splited Downloading File @OHm#`~
Oc; G(l(
kSh( u
public SiteInfoBean() *WT`o>
{//nSplitter的缺省值为5 fd2T=fz-
//default value of nSplitter is 5 8&aq/4:q0
this("","","",5); \'bzt"f$j
} l/awS!Q/nF
?I@W:#>o
IN G@B#Cl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m%e68c
{ @|%2f@h
sSiteURL= sURL; xF44M]i
sFilePath = sPath; #N cK X
sFileName = sName; Z)aUt Srf
this.nSplitter = nSpiltter; :[!j?)%>
C 6AUNRpl
y;H-m>*%
} hfy_3}_
,nB5/Lx
6f*CvW
public String getSSiteURL() %-0t?/>
{ 7x4PaX(
return sSiteURL; qeZ? 7#Gf
} 5N&?KA-
\)?HJ
]`+HO=0
public void setSSiteURL(String value) =>af@C.2
{ vOpKNp
sSiteURL = value; %n:k#
} .UY^oR=b{
8eHyL
8q}q{8
public String getSFilePath() ,>mrPtxN
{ RuVGG)
return sFilePath; d,n 'n
} *6DB0X_-}
v<(
6MMOf\
public void setSFilePath(String value) I75DUJqy]
{ Vt&2z)Zz
sFilePath = value; oEKvl3Hz_
} l#Y,R 0
~gZLY ls
FSW_<%
public String getSFileName() ;P%1j|7
{ !\.pq 2
return sFileName; XBu"-(
} G^4hd i3@
'=8d?aeF
z !rL s76
public void setSFileName(String value) "Nbq#w\
{ A1>OY^p3%
sFileName = value; .jT#:_
} l$pm_%@2]
JL}_72gs
c>:wd@w
public int getNSplitter() }"%?et(
{ SdxDa
return nSplitter; kr:^tbJ
} ""F5z,'
Ep3N&Imp
$OkBg0
public void setNSplitter(int nCount) 9oR@UW1
{ ^sEYOX\
nSplitter = nCount; PB`Y g
} gS]@I0y8 .
} ZWU)\}}_R
n QZwC
,I(d6
/* /quc}"__
**Utility.java `yXg{lk
*/ Z|j>gq
package NetFox; [KaAXv .X
^-Kf']hU
V0.vQ/
public class Utility { `WFw3TI
f:|1_j
6J6BF%
public Utility() .A{tQ1&_
{ QIvVcfM^
^"1n4im
~{B7 k:
} +tIF h'
j94=hJVKi
//线程睡眠 \[_t]'p
public static void sleep(int nSecond) yyRiP|hJ
{ g:D>.lKd
try{ xU>WEm2
Thread.sleep(nSecond); 37 ,
} ~f1%8z
catch(Exception e) T?soJ]A
{ wb5baY9
e.printStackTrace (); +wvWwie
} o_Z5@F
} kmsb hYM)
&5spTMw8
//日志 ;I 9&]
public static void log(String sMsg) )=Z>#iH1
{ YY((V@|K
System.err.println(sMsg); Ym{tR,g7
} _jI,)sr4ic
'4Ixqb+
v/0QOp
public static void log(int sMsg) B=yqW
{ 6]_pIf
System.err.println(sMsg); ogtEAv~e7N
} 5uNJx5g
} 4(~L#}:r!
Y. 5_6'Eo?
3yY}04[9<
/* Lh"<XYY
**TestMethod.java +0%w ;'9z
*/ `d +Da=L
package NetFox; ^f &XQQY
+p_CN*10H
UcDS9f_87
public class TestMethod { FQ2
P[#e/qnXu|
?)?Ng}
public TestMethod() 5\sd3<:+
{ ///xx/weblogic60b2_win.exe M~#gRAUJ
try{ Gg3,:A_ w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C'@i/+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E7Ul;d
SiteFileFetch fileFetch = new SiteFileFetch(bean); -M~:lK]n
fileFetch.start(); k>Vci{v
} e&F8m%t
catch(Exception e){e.printStackTrace ();} qu6D 5t
C12Fl
z'U1bMg
} C8:f_mJU
2K6qY)/_
mPK:R^RjG&
public static void main(String[] args) /-qNh>v4
{ R)(T^V`{
new TestMethod(); IH&|Tcf\
} 6NuD4Ga
} b:m88AG
点击下载更多相关资料