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)); 1nhC! jDD
} ;0(|06=
for(int i=0;i<nEndPos.length-1;i++) *6=2UJcJ
{ ,{MA90!
nEndPos = nStartPos[i+1]; /MKcS%/H/
} gF+Uj( d
nEndPos[nEndPos.length-1] = nFileLength; WQv%57+
} @U08v_,
} #G%[4.$n.
_"%mLH=!8
TC;2K,.#k
//启动子线程 4Z5ZV!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9#L0Q%,*
for(int i=0;i<nStartPos.length;i++) JJ[.K*dO
{ Hz&a~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eD5.*O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {0 d/;
nStartPos,nEndPos,i); &[ejxK"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2'UWPZgE
fileSplitterFetch.start(); Sa7bl~p\
} g0NtM%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o5)lTVQ~~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sr1`/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ")T;3/c
nEndPos = " + nFileLength); :^]rjy/|+
// fileSplitterFetch[nPos.length-1].start(); 'M+iw:R__
b"n0Yk1
{Hg.ctam
//等待子线程结束 .6z8fjttOC
//int count = 0; tJ`tXO
//是否结束while循环 w6(E$:#d
boolean breakWhile = false; C)66^l!x
PLlad\
Y3^UJe7E
while(!bStop) p(o"K@I
{ LldZ"%P
write_nPos(); _3v6c
Utility.sleep(500); }xXUCU<
breakWhile = true; 8i"v7}
_dCdyf
>qkZn7C
for(int i=0;i<nStartPos.length;i++) CR3<9=Lv>
{ YQGVQ[P
if(!fileSplitterFetch.bDownOver) I~ Q2jg2
{ ?T]3I.3 2^
breakWhile = false; ?Co)7}N
break; FJxg9!%d
} [xW;5j<87
} yh~*Kt]9Ya
if(breakWhile) 1$nlRQi
break; 4+Aht]$hC
ehehTP
~5S[Sl
//count++; &[QvMh
//if(count>4) 3fA.DK[4[
// siteStop(); WrJgU&H{
} =UY)U-
l12Pj02w
#pDWwnP[rt
System.err.println("文件下载结束！"); /,#HGu]q'
} =GH>-*qp
catch(Exception e){e.printStackTrace ();} ((OQs.
} /o@6?UH
W.u+R?a=
xv|?;Zf6w
//获得文件长度 x~3N})T5
public long getFileSize() ;\1/4;m
{ hc#LniR3$
int nFileLength = -1; nX 4WlH
try{ REqQJ7a/
URL url = new URL(siteInfoBean.getSSiteURL()); C{Y0}ZrmlF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 39Nz>Nu:
httpConnection.setRequestProperty("User-Agent","NetFox"); U~h f,Oxi
:De@_m
ktE~)G
int responseCode=httpConnection.getResponseCode(); !j8.JP}!)
if(responseCode>=400) j~DTvWg<Jl
{ EyU5r$G
processErrorCode(responseCode); ol^uM .k%_
return -2; //-2 represent access is error vlW521
} S)`%clN}J
w4I&SLm-b
haTmfh_|
String sHeader; #GoZH?MAF
7S^ba
wg-qq4Q\
for(int i=1;;i++) OGA_3|[S
{ .AHf]X0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ')G,+d^
//Utility.log(in.readLine()); =17d7#-
sHeader=httpConnection.getHeaderFieldKey(i); 0<ze'FbV]
if(sHeader!=null) 04o>POR
{ K14FY2"
if(sHeader.equals("Content-Length")) jg)+]r/hS
{ 3:H[S_q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Mk=M)d`
break; r1pj-
} >]/RlW[
} 0Wd2Z-I
else C_5o&O8Bc
break; %X|fp{C
} kh7RQbNY<I
} Z+8Q{|Ev
catch(IOException e){e.printStackTrace ();} kJP`C\4}f
catch(Exception e){e.printStackTrace ();} A[7\!bq5
p"'knZG
&|]GTN`E
Utility.log(nFileLength); m/E$0tf
9-B/n0
e^ Aw%t
return nFileLength; FqWW[Bgd
} d+m}Z>iQ1O
}Mv$Up
P]A~:Lj
//保存下载信息（文件指针位置） +Oxw?`I$
private void write_nPos() 5u5-:#sLy
{ '?gF9:
try{ l.>3gjr
output = new DataOutputStream(new FileOutputStream(tmpFile)); A r=P;6J
output.writeInt(nStartPos.length); ZBY*C;[)*P
for(int i=0;i<nStartPos.length;i++) dp|VQWCq
{ jV 'u*2&9
// output.writeLong(nPos); "z8iuF
output.writeLong(fileSplitterFetch.nStartPos); `<#Ufi*c
output.writeLong(fileSplitterFetch.nEndPos); xU6rZCqE
} " J4?Sb<
output.close(); d~QZcR
} z JBcz,
catch(IOException e){e.printStackTrace ();} +<})`(8
catch(Exception e){e.printStackTrace ();} 6?`3zdOeO
} c*!xdK
6&,{"N0T
Jc=~BT_G
//读取保存的下载信息（文件指针位置） eV5 e:9
private void read_nPos() v?@=WG
{ 6,raRg6
try{ l_lK,=cLj+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y$,j'B:;4m
int nCount = input.readInt(); =".sCV9"N
nStartPos = new long[nCount]; Dug{)h_2
nEndPos = new long[nCount]; AqZ()p*z
for(int i=0;i<nStartPos.length;i++) )x<oRHx]
{ )k~{p;Ke
nStartPos = input.readLong(); 1m{c8Z.h/d
nEndPos = input.readLong(); dq4t@:\o0
} 6uu49x_^L4
input.close(); ^1\[hyZ!
} hpBn_
catch(IOException e){e.printStackTrace ();} A+QOox]<
catch(Exception e){e.printStackTrace ();} Io*mFa?
} ~a ]R7X7
}Q1m
Fs_zNN
private void processErrorCode(int nErrorCode) Ly~s84k_po
{ cT.8&EEW
System.err.println("Error Code : " + nErrorCode); )e?6 Ncy
} 6j6P&[
@xkI?vK6
m1#,B<6
//停止文件下载 u-k!h
public void siteStop() Ir?ehA
{ 1i=p5,|
bStop = true; 4yDWVd;
for(int i=0;i<nStartPos.length;i++) y**>l{!!
fileSplitterFetch.splitterStop(); IAFj_VWC0
j"4]iI+{"
+'`I]K>
} Yw6d-5=:
} W5U;{5
//负责部分文件的抓取 i}_d&.DbF
**FileSplitterFetch.java Y{`hRz`
*/ aSMSuX8
package NetFox; XJguw/[wm
+rOfQ'lQ
Pm=i(TBS/
import java.io.*; q+1SU6x'm
import java.net.*; 52v@zDY
A5 <T7~U
nK>D& S_!
public class FileSplitterFetch extends Thread { (@3?JJ]1
hNL_e3
J]gtgt^
String sURL; //File URL ZK?:w^Z
long nStartPos; //File Snippet Start Position j=V2~ xA6
long nEndPos; //File Snippet End Position Lv<)Dur0K
int nThreadID; //Thread's ID _n12Wx{
boolean bDownOver = false; //Downing is over g7`uWAxZa
boolean bStop = false; //Stop identical lfe^_`ij(+
FileAccessI fileAccessI = null; //File Access interface e)Pm{:E
'l41];_
Vd+5an?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G&,2>qxKR
{ ibxtrt=
this.sURL = sURL; NVG`XL
this.nStartPos = nStart; Zoyo:vv&
this.nEndPos = nEnd; jx-8%dxtZ
nThreadID = id; k}908%w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0$I!\y\
} mF@DO$
B[{Ie G'
;o?Wn=J
public void run() |X0Ys8f
{ mP+rPDGp
while(nStartPos < nEndPos && !bStop) [+ N 5
{ O#@KP"8
F^}n7h=qk
r57rH^Hc
try{ _^Lg}@t
URL url = new URL(sURL); ]M.)N.T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %q5iy0~P
httpConnection.setRequestProperty("User-Agent","NetFox"); 5%%A2FrB.S
String sProperty = "bytes="+nStartPos+"-"; s[tFaB1
httpConnection.setRequestProperty("RANGE",sProperty); 1`@rAA>h'
Utility.log(sProperty); v}^ f8nVR
* ~4m!U_s
-"X} )N2
InputStream input = httpConnection.getInputStream(); 0ZpWfL
//logResponseHead(httpConnection); ^J7g)j3
VkDFR [k_
d){Al(/
byte[] b = new byte[1024]; *N?y<U
int nRead; GcA!I!j/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a&~]77)
{ )`gE-udR
nStartPos += fileAccessI.write(b,0,nRead); $C?G7Vs
//if(nThreadID == 1) Q=cbHDB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,';+A{aV
} 5jBBk*/\
_=oNQ
Gj(UA1~1
Utility.log("Thread " + nThreadID + " is over!"); n:5*Tg9
bDownOver = true; zV=(e( [
//nPos = fileAccessI.write (b,0,nRead); 6P:H`
} ;3k6_ub
catch(Exception e){e.printStackTrace ();} G9uWn%5r
} KqT~MPl
} 8L}N,6gC4_
Zjh9jvsW
/DQcM.3
//打印回应的头信息 OJ\rT.{
public void logResponseHead(HttpURLConnection con) u#m(Py
{ )#n>))
for(int i=1;;i++) ?G>#'T[
{ M[ZuXH}
String header=con.getHeaderFieldKey(i); [j`-R 0Np
if(header!=null) Cb/?hT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @5-+>\Hd^t
Utility.log(header+" : "+con.getHeaderField(header)); /,Sd
else !saKAb}d7H
break; .+cYzS]!
} sw@*N
} S.Fip_
]0wmvTR
6lc/_&0
public void splitterStop() &Jw4^ob
{ lt&30nf=
bStop = true; I NE,/a=
} ~IE5j,SC
,w/f:-y
'd@Vusq}2
} umWZ]8
7F{=bL
@tLoU%
/* 4)3!n*I
**FileAccess.java y[!4M+jj
*//文件访问(定位，写) 4';]fmf@[i
package NetFox; >MIp r
import java.io.*; ~-w
<#9zc'ED:
:`ysq
public class FileAccessI implements Serializable{ w5(GRAH
Z0e+CEzq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HG%H@uK
RandomAccessFile oSavedFile; IJnr^S8
long nPos; J}.y+b>8\
fV.43E
db!2nImNu\
public FileAccessI() throws IOException }PY? ZG
{ aUy=D:\
this("",0); OQh36BM
} r4xq%hy
B&m?3w
O:a$ U:
public FileAccessI(String sName,long nPos) throws IOException wzMWuA4vX
{ Ye}y_W
oSavedFile = new RandomAccessFile(sName,"rw"); n~d`PGs?f
this.nPos = nPos; */L;6_
oSavedFile.seek(nPos); NW9k.D%
} e-os0F
1*x4T%RF$
H\3CvFm
public synchronized int write(byte[] b,int nStart,int nLen) m(3bO[u1
{ 1Nk}W!v
int n = -1; (t9qwSS8z
try{ Tj{!Fx^H
oSavedFile.write(b,nStart,nLen); w I@ lO\
n = nLen; lm&C!{K
} 9&W\BQ
catch(IOException e) 7OOB6[.fu
{ 3RRZVc* ^
e.printStackTrace (); ,U'Er#U
} 'U)~|(\i
fXw%2wg
+WwQ!vWWd
return n; -c=IO(B/
} T[XI
5.|rzk>
w'5~GhnP+
} xL>0&R
=I/J !}.
ZF;S}1
/* 5Tpn`2F
**SiteInfoBean.java |U^ ff^]
*/ 2uWzcy ?F
package NetFox; 5Kv=;o=U
wrn[q{dX
h3p 3~xq
public class SiteInfoBean { "eQ96^'J
!*|CIxk(
y::;e#.
private String sSiteURL; //Site's URL ~9oS~fP?I
private String sFilePath; //Saved File's Path =QyO$:t
private String sFileName; //Saved File's Name IFPywL{K
private int nSplitter; //Count of Splited Downloading File ~ilbW|s?=k
(p14{
N"t,6tH
public SiteInfoBean() aXC`yQ?
{//nSplitter的缺省值为5 )hQNIt3o_
//default value of nSplitter is 5 ~N'KIP[W
this("","","",5); XE$eHx3;
} e`$v\7K
~:)$~g7>b
:M3l#`4Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O:7y-r0i
{ 6g$04C3tHi
sSiteURL= sURL; ~*B1}#;
sFilePath = sPath; z7PPwTBa
sFileName = sName; lGLZIp
this.nSplitter = nSpiltter; RFK N,oB
\\)-[4uC
/2HwK/RZ
} S|]~,l2]}
Gs?W7}<$
9$DVG/
public String getSSiteURL() Zc9 n0t[
{ I;-{#OE,
return sSiteURL; ?$n<vF>
} 1|gP :t}
KUyua~tF
~+lC%R
public void setSSiteURL(String value) =_yOX=g|
{ N%B#f\N
sSiteURL = value; 8:&@MZQ&!
} TVFGonVY
,XA;S5FE
Pm?6]] 7
public String getSFilePath() ,+X8?9v
{ c~RIl5j
return sFilePath; |ntJ+
} Pucf0 #
*q0N$}k
_~cmR<
public void setSFilePath(String value) OC>" +
{ Jx>P%>+<j
sFilePath = value; <m(nZ'Zqz2
} r\3In-(AT
huTJ a2
E>g'!
public String getSFileName() zWY6D4
{ @W @L%<
return sFileName; g{J3Ba
} 9M7P]$^
ev?>Nq+Z
d;;=s=j
public void setSFileName(String value) )nJ>kbO~8
{ @P.l8|w
sFileName = value; vGAPQg6*
} ?APzx@$D.
Qp=uiXs
cn\_;TYiJ
public int getNSplitter() %eah=e
{ lT:<ZQyjT
return nSplitter; rzTyHK[
} 3?geJlD4
?B}>[
TRq~n7Y7C
public void setNSplitter(int nCount) !c&^b@ yw
{ $o@?D^
nSplitter = nCount; U=yD!
} uo{QF5z]
} =az$WRV+7!
u3ZG;ykM
Fu`g)#Z
/* I&xRK'
**Utility.java Q.|2/6hD7[
*/ HIU@m<
package NetFox; |-|BM'Y
A|&EI-In
VC+\RB#:-
public class Utility { ;|^fAc~9{r
-12v/an]L7
1=D!C lcb
public Utility() lR(&Wc\j
{ ?SAi tQ3
fBF}-{VX(
iBi/9
} L9kP8&&KK
)} #r"!
//线程睡眠 LH_2oJ\
public static void sleep(int nSecond) CeJ|z{F\
{ A:!{+
try{ >r*Zm2($MR
Thread.sleep(nSecond); s=nds"J
} c1<g!Q&E
catch(Exception e) 7/1S5yUr|
{ ?~K2&eo
e.printStackTrace (); P:=ADW c
} B';Ob
} 'I~dJEW7
%qQ(@TG
//日志 4mAtYm
public static void log(String sMsg) %G@aZWk Sa
{ @$*c0. |z
System.err.println(sMsg); a9I8WQ
} meL'toaJdQ
"+WR[-n>\
'!I?C/49k
public static void log(int sMsg) 8tL61x{]
{ L8G4K)
System.err.println(sMsg); 4{?x(~
} 4_Jdh48-d
} c5;ROnTm
$>UzXhf}\
Jc)1}
/* Dk-L4FS
**TestMethod.java c`.:"i"k3
*/ r&[~/m8zl
package NetFox; la4,Z
HA%ye"(y8
Esjv^* v9-
public class TestMethod { W% [5~N
O,{ (
#J!? :(m:
public TestMethod() [jw o D
{ ///xx/weblogic60b2_win.exe ;Ki1nq5c#s
try{ w}0Qy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{hq.KZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $T4PC5.
SiteFileFetch fileFetch = new SiteFileFetch(bean); .+|DN"PgJ
fileFetch.start(); hLvv:C@
} O2G+ '
catch(Exception e){e.printStackTrace ();} 5dF=DCZ
,7(/Il9
`O{Uz?#*x
} <@A^C$g
"!tB";n
Mb>XM7}PU
public static void main(String[] args) +7^Ul6BB#K
{ .{-yveE
new TestMethod(); M9K).P=
} v,+@ U6i
} C\^K6,m5
点击下载更多相关资料