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)); B-[SUmHr
} Xl6)&
for(int i=0;i<nEndPos.length-1;i++) 1V`]sfRK
{ AEwb'
nEndPos = nStartPos[i+1]; R7KQ-+Zb
} Vk_*]wU
nEndPos[nEndPos.length-1] = nFileLength; b,a\`%m}
} uz4mHyS6
} FGx_qBG4|
hkgPC-
T , =ga
//启动子线程 J'O`3!Oy/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V8&/O)}o
for(int i=0;i<nStartPos.length;i++) GxZQ{ \
{ (?\ZN+V)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eq/5$b(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8"LaP3U
nStartPos,nEndPos,i); =zA=D.D2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FA^x|C=$
fileSplitterFetch.start(); YLd 5
} |/fbU_d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,:\2Lf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %Y Rg1UKY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CES FkAj~
nEndPos = " + nFileLength); M]` Q4\
// fileSplitterFetch[nPos.length-1].start(); e+R.0E
eZHzo
E2*"~gL^,
//等待子线程结束 ($(1KE
//int count = 0; \S7OC
//是否结束while循环 h.=B!wKK
boolean breakWhile = false; paBGJ~{=
}2c}y7B,_
{t/!a0\HS
while(!bStop) JNp`@`0V
{ g[M@
write_nPos(); u}%&LI`.
Utility.sleep(500); <uTsXv
breakWhile = true; ,IJNuu\
@&ZTEznbyt
_TPo=}Z
for(int i=0;i<nStartPos.length;i++) +~fu-%,k
{ 6$6NVq
if(!fileSplitterFetch.bDownOver) ,;d9uG2
{ *Ra")(RnDK
breakWhile = false; Fcr@Un'
break; j=AJs<
} 2mlE;.}8
} mW-@-5Wda
if(breakWhile) =hs@W)-O
break; >rFvT>@NU
F{"%ey">
fcZOsTj
//count++; ;ZqFrHI M`
//if(count>4) '9/kDkt!
// siteStop(); :9h8q"T
} |Gf{}
&V:dcJ^Q
wwAT@=X*}
System.err.println("文件下载结束！"); ibuI/VDF
} .-|O"H$
catch(Exception e){e.printStackTrace ();} rka:.#!
} a2rv4d=
;p_X7N
5->PDp
//获得文件长度 QLUe{@ivc
public long getFileSize() OWjZ)f/
{ e"CLhaT
int nFileLength = -1; h^0mjdSp,
try{ piG1&*
URL url = new URL(siteInfoBean.getSSiteURL()); P8VU&b\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lX4p'R-h
httpConnection.setRequestProperty("User-Agent","NetFox"); Ww(_EW
I7~|!d6
31*6 ;(
int responseCode=httpConnection.getResponseCode(); /)I9+s#q9o
if(responseCode>=400) biG9?
{ ,![=_d
processErrorCode(responseCode); l17ZNDzLU
return -2; //-2 represent access is error 0|ps),
} }m H>lN
VL{#.;QQa
+Y~+o-_
String sHeader; /(V=Um^0
|u{QI3#'
=vc5,
for(int i=1;;i++) CP#79=1
{ 4cQ5E9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `+.I
//Utility.log(in.readLine()); `0^i #
sHeader=httpConnection.getHeaderFieldKey(i); 2f!oA~|2
if(sHeader!=null) HUC2RM?FN
{ jEsTw_
if(sHeader.equals("Content-Length")) ]CZLaID~
{ =b7&(x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "AouiZkh
break; T]|O/
} WO-WoPO
} AuTplO0_rE
else 5gD)2Q6
break; hzLGmWN2j8
} uC(S`Q[Bg
} RC(D=6+[C
catch(IOException e){e.printStackTrace ();} 9@Sb! 9h
catch(Exception e){e.printStackTrace ();} l,u{:JC
FA9e(Ha
Yd;r8rN
Utility.log(nFileLength); ~It+|X=Kx
f^4*.~cB
LtztjAm.
return nFileLength; r$FM8$cJ
} %-/:ps
rO$>zdmYHs
ZPsY0IzLo
//保存下载信息（文件指针位置） LDEt.,6i
private void write_nPos() %`QsX {?,
{ :EwA$`/
try{ "IG$VjgcB
output = new DataOutputStream(new FileOutputStream(tmpFile)); [7 `Dgnmq
output.writeInt(nStartPos.length); (eG]Cp@
for(int i=0;i<nStartPos.length;i++) THgzT\_zq
{ $Ds]\j*
// output.writeLong(nPos); KOEi_9i}
output.writeLong(fileSplitterFetch.nStartPos); m=\eL~h
output.writeLong(fileSplitterFetch.nEndPos); S1juAV=
} 1IQOl
output.close(); +N$7=oGC
} J+ZdZa}Ob
catch(IOException e){e.printStackTrace ();} 'Y{ux>
catch(Exception e){e.printStackTrace ();} 'eDgeWt/CQ
} D2:a
T{4fa^c2J
7]xz8t
//读取保存的下载信息（文件指针位置） jjwMvf.R
private void read_nPos() Bb[e[,ah
{ PnIvk]"Ab
try{ 5m USh3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gVA}?t;
int nCount = input.readInt(); hf^`at
nStartPos = new long[nCount]; 3b)T}g
nEndPos = new long[nCount]; s.`%ZDl@Y
for(int i=0;i<nStartPos.length;i++) ;=VK_3"
{ =R;1vUio
nStartPos = input.readLong(); *_/eAi/WG
nEndPos = input.readLong(); 8pL>wL &C
} *CY6 a
input.close(); k3/JQ]'D
} PP[)h,ZL*
catch(IOException e){e.printStackTrace ();} Q`p}X&^a
catch(Exception e){e.printStackTrace ();} v8[ek@
} J%f=A1Q
=PKt09b^
,gL)~6!A
private void processErrorCode(int nErrorCode) -=Eq/su%
{ b8{h[YJL2
System.err.println("Error Code : " + nErrorCode); TaQ "G
} ),p]n
FQ|LA[~
o eJC
//停止文件下载 G9'YgW+$7
public void siteStop() 5lHN8k=mm2
{ "l[V%f E
bStop = true; =Mu'+,dT
for(int i=0;i<nStartPos.length;i++) W:{PBb"x8
fileSplitterFetch.splitterStop(); }Cmj(k`~
d%_78nOh"
xU13fl
} kJ#[UCqzM
} }lC64;yo
//负责部分文件的抓取 ;!0.Kk 4
**FileSplitterFetch.java jWv3O&+?X
*/ {b-0_
package NetFox; @u"kX2>Eq
q]iKz%|Z/
d)hzi
import java.io.*; .sJys SA\
import java.net.*; lNA'M&
B'KXQa-$O
ek(kY6x:
public class FileSplitterFetch extends Thread { Ft"&NtXeZZ
fbHWBb
VeD+U~ d
String sURL; //File URL *fQ?A|l!x
long nStartPos; //File Snippet Start Position a_ 9|xI
long nEndPos; //File Snippet End Position +9 16ZPk
int nThreadID; //Thread's ID CSG+bqUG
boolean bDownOver = false; //Downing is over EG(`E9DZ
boolean bStop = false; //Stop identical \'It,PN
FileAccessI fileAccessI = null; //File Access interface KB%j! ?
$/<"Si&(
~ F?G5cN5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tyn?o
{ (^tr}?C
this.sURL = sURL; oRT
this.nStartPos = nStart; =qV4Sje|q
this.nEndPos = nEnd; .y %pGi
nThreadID = id; J+3\2D?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 To#E@Nw
} fW5"4,
;B|^2i1Wi
NK
public void run() u|m[(-`
{ <K DH
while(nStartPos < nEndPos && !bStop) e?^\r)1
{ PS_3Oq)
HO%E-5b9
097Fvt=#
try{ JAGi""3HG
URL url = new URL(sURL); ;xW8Z<\-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3:]{(@J
httpConnection.setRequestProperty("User-Agent","NetFox"); _XH4;uGg
String sProperty = "bytes="+nStartPos+"-"; J^+_8
httpConnection.setRequestProperty("RANGE",sProperty); g:3d<CS
Utility.log(sProperty); Lf,CxZL5
(xk.NZnF
L\/u}]dPQ
InputStream input = httpConnection.getInputStream(); RL7C YB
//logResponseHead(httpConnection); !p]T6_t]Q
8N=%X-R%
Mv/IMO0rR
byte[] b = new byte[1024]; Wphe%Of
int nRead; S+.21,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8Zcol$XS'
{ wb(*7 &eP:
nStartPos += fileAccessI.write(b,0,nRead); }G>v]bV0V
//if(nThreadID == 1) >:w?qEaE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); azao`z
} ;jRL3gAe)
O{lIs_1.Z
6V'wQqJ
Utility.log("Thread " + nThreadID + " is over!"); fkdf~Vb
bDownOver = true; Y5nz?a
//nPos = fileAccessI.write (b,0,nRead); #5'c\\?Q
} 8q_1(& O
catch(Exception e){e.printStackTrace ();} -rEeKt
} Xtuhcdzu[
} Nc G,0K
kVV\*"9y
AkxH
//打印回应的头信息 sx-EA&5-9k
public void logResponseHead(HttpURLConnection con) [:AB$l*
{ =jJ H^Y2
for(int i=1;;i++) BhqhyX\D&y
{ L_tjcfVo
String header=con.getHeaderFieldKey(i); Wr]O
if(header!=null) 5."5IjZu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \\Y,?x_0T
Utility.log(header+" : "+con.getHeaderField(header)); 5,F;j<F
else x7vq?fP0n
break; k%{ l4
} K5P Gi#
} 6{5q@9F
" <<A
TcR=GR*cJ
public void splitterStop() BmJkt3j."
{ q!ee g
bStop = true; 5iP8D<;o5
} WLE%d]'%M
_GE=kw;:
2>\b:
} $kD7y5
BqQ] x'AF
[:Be[pLC
/* qpoquWZ
**FileAccess.java E^7C _JP
*//文件访问(定位，写) D0f*eSXE{
package NetFox; 'P+f|d[
import java.io.*; E3y6c)<
Sbp
~D*b3K8X
public class FileAccessI implements Serializable{ cvhlRI%6
[w,(EE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I=U+GY:
RandomAccessFile oSavedFile; :=y0'f V(@
long nPos; xsYE=^uv
yDzdE;
9e]'OKL+
public FileAccessI() throws IOException 5bXHz5i
{ i^R{Ul[
this("",0); Bw6L;Vu
} Hc M~
kQy&I3
JfbKf~g
public FileAccessI(String sName,long nPos) throws IOException sA3UeTf
{ .xEJaID\N
oSavedFile = new RandomAccessFile(sName,"rw"); Vz'HM$
this.nPos = nPos; NaF(\j
oSavedFile.seek(nPos); 8[oYZrg
} `v~!H\q
n3'dLJH|
-xz|ayn
public synchronized int write(byte[] b,int nStart,int nLen) -]/7hN*v
{ te)n{K",
int n = -1; '[Xl>Z[
try{ A?DB#-z.r
oSavedFile.write(b,nStart,nLen); "NKf0F
n = nLen; nx B32
} p!}ZdX[u
catch(IOException e) b_|u<
{ BMpF02Y|4
e.printStackTrace (); :&9TW]*g
} IfMpY;ow=
7lR<@$q
gJh}CrU-
return n; yc[(lq.^n
} 0aogBg_@K
5KJ%]B(H2
ZjS(ad*.2
} R]Ek}1~?
Ny^'IUu
mB`D}g$
/* +;dXDZ2
**SiteInfoBean.java ETO$9}x[
*/ 3{e'YD~hP
package NetFox; Tm_8<$ 7
L,$3Yj
R*bmu
public class SiteInfoBean { _f|/*. @Q
3fp> 4;ym'
O,|\"b1(
private String sSiteURL; //Site's URL 8+>\3j
private String sFilePath; //Saved File's Path ~RInN+N#
private String sFileName; //Saved File's Name Xpl?g=B&u
private int nSplitter; //Count of Splited Downloading File "r..
MwAJ(
Jq)U</
public SiteInfoBean() ezn` _x_?
{//nSplitter的缺省值为5 9B=1Yr[
//default value of nSplitter is 5 Kt6>L5:94
this("","","",5); Ly>OLI0x_
} `Mk4sKU\a
H^ BYd%-
ah+j!e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k.GA8=]>
{ iSiDSeW8
sSiteURL= sURL; 0 iRR{a<
sFilePath = sPath; "!KpXBc,>
sFileName = sName; si(cOCj/
this.nSplitter = nSpiltter; * t!r@k
e_rzA
QDE$E.a
} #epy%>
10O$'`
aWGon]2p
public String getSSiteURL() IzUo0D*@
{ g_q<ze
return sSiteURL; re`t ]gzb
} Cj^{9'0
ipjkZG@
X+l'bp]Ry
public void setSSiteURL(String value) ;`UecLb#
{ jO8k6<l
sSiteURL = value; c-8!#~M(
} 5<+KR.W
&&7r+.Y
wa:0X)KC?
public String getSFilePath() dR+1aY;
{ &tE.6^F
return sFilePath; LM"y\q ]
} DWm SC}{.
z-,VnhLx
*e/K:k
public void setSFilePath(String value) b$-e\XB!
{ xs!p|
sFilePath = value; HOZRYIQB
} fn}UBzED\
_Qd,VE 8u
`ifiL
public String getSFileName() k;Fh4Hv
{ qf8[!5GM
return sFileName; YZE.@Rz
} L?RF;jf
YQ]\uT>}&
g^~Kze
public void setSFileName(String value) I%lE;'x
{ g/Wh,f3
sFileName = value; (^n*Am;zlH
} Q8qz*v]{
^b-18 ~s
ry0%a[[
public int getNSplitter() lE5v-z? &|
{ $_X|,v9
return nSplitter; n(vDytrj;
} ~<9{#uM
;#k-)m%
N "Wqy
public void setNSplitter(int nCount) >e&:`2%.
{ hOk00az
nSplitter = nCount; p>*i$
} xWX*tJ4
} ma& To=
;<wS+4,
,,<PVTd
/* W/+K9S25
**Utility.java o>lmst%<
*/ \%A%s*1
package NetFox; C>QIrZu
A(d5G^
\nvAa_,
public class Utility { !<\Br
s8gU7pT49
lWZuXb,G
public Utility() jE/oA<^
{ q/&y*)&'O
oFC)
%$ceJ`%1e
} eE]hy'{d<
j 6)Y
//线程睡眠 yy2I2Bv
public static void sleep(int nSecond) ;N=G=X|}
{ z;}6f
try{ :+&AY2`
Thread.sleep(nSecond); eC`pnE
} y2yKm1<Ru<
catch(Exception e) `NNf&y)y
{ Iw=Sq8
e.printStackTrace (); <:;^'x>!
} edC4BHE
} ]s1 YaNq
$1Nd_pD=
//日志 Tupiq
public static void log(String sMsg) ]<w:V`(
{ pa]"iZz
System.err.println(sMsg); 5z/Er".P
} oduDA:
DPDe>3Mi[
&eZfQ27$
public static void log(int sMsg) `S/wJ'c
{ t}p@:'
System.err.println(sMsg); g:)DNy
} x5si70BKC/
} ^>$P)=O:v
pw020}`
t-e5ld~a
/* &*,:1=p
**TestMethod.java K`KLC.j
*/ %Z]'!X
package NetFox; M#jN-ix
P&A|PY,P
U]4pA#*{|
public class TestMethod { xK%=
omX?Bl
j .A6S`
public TestMethod() o>D
{ ///xx/weblogic60b2_win.exe tykB.2f
try{ mj,fp2D;%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l5t2\Fl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dKhA$f~
SiteFileFetch fileFetch = new SiteFileFetch(bean); YE+$H%Jl!
fileFetch.start(); {{yt*7k{
} hsLzj\)6
catch(Exception e){e.printStackTrace ();} C'mL&
<eN R8(P
JqUADm
} ^U7OMl4Usq
E_ucab-Fi
HL{$ ^l#v
public static void main(String[] args) q }C+tn"\
{ 72db[
new TestMethod(); m>&HuHf
} kAzd8nJ'
} [Gr*,nVvB
点击下载更多相关资料