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)); jtS+y)2
} JihI1C
for(int i=0;i<nEndPos.length-1;i++) |Rhx&/
{ B5 C]4
nEndPos = nStartPos[i+1]; TEh]-x`
} ie 2X.#
nEndPos[nEndPos.length-1] = nFileLength; 6IctW5b
} oZA|IF8U0
} x +q"%9.c
F$ZWQ9&5U0
Z,lUO.
//启动子线程 U^+9l?ol
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^;6~=@#*C
for(int i=0;i<nStartPos.length;i++) 83412@&
{ +h9UV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2^ ^;Q:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f8#WT$Ewy
nStartPos,nEndPos,i); 28f-8B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5caYA&R
fileSplitterFetch.start(); N>/*)Frt
} [YHvyfk~_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zv@'x nY]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ojs&W]r0Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i\3BA"ZX
nEndPos = " + nFileLength); -102W{V/T
// fileSplitterFetch[nPos.length-1].start(); R`76Ae`R8
d;mQ=k 1
p? iJ'K
//等待子线程结束 c~5#)AXMT
//int count = 0; N5}vy$t_P
//是否结束while循环 1.p?P] .
boolean breakWhile = false; 9(ZzwkD'>
htX'bA
CBnD)1b\
while(!bStop) S82NU2L
{ Ook3B
write_nPos(); \#LKsQa
Utility.sleep(500); Gxi;h=J2)>
breakWhile = true; i_`YZ7Hxp
:54|Z5h|
Wq<>a;m
for(int i=0;i<nStartPos.length;i++) }ebw1G
{ rHT8a^MO
if(!fileSplitterFetch.bDownOver) M0=ZAsN
{ &I'~:nWpt
breakWhile = false; g#9w5Q
break; pqMvYF
} J:?t.c~$o
} ^nbze
if(breakWhile) s.=)p"pTd
break; Kzo{L
v 0rX/ mj
k{c~
//count++; 9'8OGCN
//if(count>4) 0a8nBo7A-X
// siteStop(); ^b-H
} {@Diig
:]y;t/
Se0/ysVB
System.err.println("文件下载结束！"); _N/]&|.. !
} d2.n^Q"?3
catch(Exception e){e.printStackTrace ();} "{z9 L+
} `3pe\s
Qbl6~>T
W.MJyem
//获得文件长度 g+ 2SB5 2D
public long getFileSize() R3?~+y&
{ Vq9hAD|k
int nFileLength = -1; o&(%:|
try{ mKe{y.
URL url = new URL(siteInfoBean.getSSiteURL()); Ic#+*W\ZW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /rvXCA)j
httpConnection.setRequestProperty("User-Agent","NetFox"); ]3d&S5zU
a Q`a>&R0
mNb+V/*x3
int responseCode=httpConnection.getResponseCode(); }s}9@kl;&
if(responseCode>=400) 3qpkMu3
{ 8^dGI9N
processErrorCode(responseCode); 7MoO2
return -2; //-2 represent access is error +QldZba
} =;Wkg4\5
PDD` eK}Fj
*k+QX
String sHeader; A: 0] n
+%U@
U}gYZi;;$
for(int i=1;;i++) JiI(?I
{ U-WrZ|-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \R79^
//Utility.log(in.readLine()); p-*BB_J"
sHeader=httpConnection.getHeaderFieldKey(i); Xo%Anqk
if(sHeader!=null) A8Jbl^7E+
{ fi bR:8
if(sHeader.equals("Content-Length")) HowlJ[km%
{ tCc}}2bC&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h$ZF[Xbfe
break; _^P>@ ^
} 1d\K{ 7i#
} }}_WZ},h
else t8?+yG;
break; []dRDe;#
} QtN0|q{af
} P]6pPS
catch(IOException e){e.printStackTrace ();} c$e~O-OVD?
catch(Exception e){e.printStackTrace ();} \s~W;m
jU4Ir{f
zcxG%? Q
Utility.log(nFileLength); OVj,qL)
8De `.!Gg
o,aI<5"
return nFileLength; e;!<3b
} NoKYHN^*w
@kqy!5)K
=A!I-@]q<
//保存下载信息（文件指针位置） 57[O)5u.+
private void write_nPos() JRodYXjE
{ m|f|u3'z$
try{ \[>Rt
output = new DataOutputStream(new FileOutputStream(tmpFile)); {|rwIRe
output.writeInt(nStartPos.length); IL>g-
for(int i=0;i<nStartPos.length;i++) Wq,UxMz
{ G53!wIW2:
// output.writeLong(nPos); NEGpf[$
output.writeLong(fileSplitterFetch.nStartPos); 4tu2%Og)?
output.writeLong(fileSplitterFetch.nEndPos); >Zr/U!W*?
} \{UiGCK
output.close(); l;|1C[V
} 0j_!)B
catch(IOException e){e.printStackTrace ();} JT_#>',
catch(Exception e){e.printStackTrace ();} P AKh v.7
} }>0UaK
x`o_&09;CG
hOwVm;:
//读取保存的下载信息（文件指针位置） [6/%ynlP
private void read_nPos() F[?t"d
{ 7 'f>
try{ D2?7=5DgS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WrG)&&d
int nCount = input.readInt(); l7x%G@1#~W
nStartPos = new long[nCount]; qY0Ic5wCY
nEndPos = new long[nCount]; |faXl3|
for(int i=0;i<nStartPos.length;i++) 0&mz'xra
{ Zmp ^!|=X!
nStartPos = input.readLong(); V'6%G:?0a
nEndPos = input.readLong(); G7),!Qol
} 5k\61(*s
input.close(); 3b[_0
} (JF\%Yj/
catch(IOException e){e.printStackTrace ();} 7vHU49DV
catch(Exception e){e.printStackTrace ();} =j}00,WH
} Ur@'X-
FD`V39##
3ea6g5kX
private void processErrorCode(int nErrorCode) sxuYwQ
{ J7l1-
System.err.println("Error Code : " + nErrorCode); ZM)a4h,kcm
} TI*uNS;-
Y)a 7osML
@|cas|U.r
//停止文件下载 r-!8in2
public void siteStop() N*$Q(K
{ -bs~{
bStop = true; CF$^we
for(int i=0;i<nStartPos.length;i++) M"V?fn'
fileSplitterFetch.splitterStop(); yt<K!=7&
icnp^2P
A46y?"]/30
} k|g~xmI;
} IPY@9+]
//负责部分文件的抓取 R_Z H+@O
**FileSplitterFetch.java H>W A?4
*/ GbMSO
package NetFox; &1VC0"YJWy
g@S"!9[;U
_$F I>
import java.io.*; 9cj:'KG)!
import java.net.*; \6sp"KqP
RE*SdazY?
m"xw5aa>
public class FileSplitterFetch extends Thread { u/``*=Y@
,c7 8O8|
rt."P20T
String sURL; //File URL Z!ub`coV[
long nStartPos; //File Snippet Start Position 0h#' 3z<
long nEndPos; //File Snippet End Position Gh@QR`xxc
int nThreadID; //Thread's ID q5QYp
boolean bDownOver = false; //Downing is over P+oZS
boolean bStop = false; //Stop identical {E!$<A9
FileAccessI fileAccessI = null; //File Access interface z?+N3p9
A!hkofQ
OHH wcJ7N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -,p(PK
{ \]o#tYN\a0
this.sURL = sURL; yyBy|7QgO
this.nStartPos = nStart; Qs*g)Yr
this.nEndPos = nEnd; Y.=v!*p?}
nThreadID = id; M3x%D)*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ga~IOlS
} Q;`#ujxL
CFn!P;.!
7]G3yt->
public void run() 5]gd,&^?>
{ ZG<<6y*.
while(nStartPos < nEndPos && !bStop) IEO5QV:u:
{ e>MC 3D`5
` 8.d
mO]>(^c
try{ ^TnBtIU-B
URL url = new URL(sURL); p"Fj6T2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LL.YkYu
httpConnection.setRequestProperty("User-Agent","NetFox"); q(_pk&/
String sProperty = "bytes="+nStartPos+"-"; 4WDh8U
httpConnection.setRequestProperty("RANGE",sProperty); 7X1T9'jI2
Utility.log(sProperty); KLlW\MF1
llI`"a
`&j5/[>v
InputStream input = httpConnection.getInputStream(); a B%DIH,
//logResponseHead(httpConnection); $I+QyKO9k
mZ*!$P:vy"
t&0pE(MO/
byte[] b = new byte[1024]; mmEr2\L
int nRead; Qnph?t>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e=TB/W_
{ b6Dve]
nStartPos += fileAccessI.write(b,0,nRead); kW5g]Q
//if(nThreadID == 1) De\&r~bTW9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ll%[}C?~]?
} $^}?98m
{_l@ws
Bo_Ivhe[m
Utility.log("Thread " + nThreadID + " is over!"); 9>\s81^
bDownOver = true; 8 <EE4y
//nPos = fileAccessI.write (b,0,nRead); xR\$2(
} 05.^MU?^U
catch(Exception e){e.printStackTrace ();} TU7Qt<
} LEWeybT
} 8`kK)iCq
Mb uD8B
XeKIue@_
//打印回应的头信息 HTvA]-AuM
public void logResponseHead(HttpURLConnection con) 8(7DW |\
{ +P81&CaY
for(int i=1;;i++) E"nIC,VZ
{ `(.K|l}
String header=con.getHeaderFieldKey(i); PiP\T.XANa
if(header!=null) -6(C^X%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :WJ[a#
Utility.log(header+" : "+con.getHeaderField(header)); O2-9Oo@#,
else G!uoKiL
break; 6ix8P;;}#
} fOtL6/?
} 8:|F'{<<b
AK} wSXF
I!|_C~I`2
public void splitterStop() ?ep93:j
{ >PGW>W$
bStop = true; ZM`6zS!
} w =^QIr%
Ao69Qn
{+F/lN@
} %!mJnc%
]ECzb/
@~qlSU&
/* n&jfJgD&g
**FileAccess.java *?VbN}g2
*//文件访问(定位，写) q okgu$2
package NetFox; py6|uGN
import java.io.*; =rMT1
nm_]2z O
?<STt 9
public class FileAccessI implements Serializable{ 4RGEg;]S
@bSxT,2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {m.l{<H
RandomAccessFile oSavedFile; yF8 av=<{
long nPos; K*xqQ]&
LJt#c+]Li
hOx'uO`x(
public FileAccessI() throws IOException & gnE"
{ ,`ST Va-
this("",0); *BF5B\[r?
} uQ=p }w
u^8:/~8K
Y!N*J
public FileAccessI(String sName,long nPos) throws IOException M{<cqxY
{ BqC!78Y/e
oSavedFile = new RandomAccessFile(sName,"rw"); w]J9Kv1)-
this.nPos = nPos; GsA/pXx
oSavedFile.seek(nPos); XCc/\
} jeXv)}
K[!OfP
SV0E7qX
public synchronized int write(byte[] b,int nStart,int nLen) 71_{FL8
{ !o1{. V9q
int n = -1; =UE/GTbl
try{ G?AZ%Yx
oSavedFile.write(b,nStart,nLen); ze@NqCF
n = nLen; aVNBF`
} DK;p6_tT
catch(IOException e) D~E1hr&Vd>
{ a|Io)Qhr
e.printStackTrace (); eKPxSN Z
} z-$bce9*
j6]+fo&3
+P:xB0Tm D
return n; ?-1r$z
} KHV5V3q4
l=,\ h&
2oyTS*2u_&
} kv{uf$X*ve
,:Qy%k}f
ZG:#r\a
/* ACm9H9:Vd
**SiteInfoBean.java 6A&e2K>A
*/ /`McKYIP
package NetFox; K<TVp;N
WDQtj$e+
#RT}-H
public class SiteInfoBean { q<Gn@xc'
e=ZwhRP
J6J[\
private String sSiteURL; //Site's URL Ysbd4rN
private String sFilePath; //Saved File's Path $fES06%
private String sFileName; //Saved File's Name Z]kk.@P
private int nSplitter; //Count of Splited Downloading File 2[6>h)
ky>0
3NAU|//J
public SiteInfoBean() _ZX"gHx
{//nSplitter的缺省值为5 G|MjKe4}
//default value of nSplitter is 5 &~gqEl6RF
this("","","",5); ^L#\z7
} k`FCyO
feU]a5%XZ
5mxHOtvtWM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :ZG^`H/X1d
{ \i_y(;
sSiteURL= sURL; e&%m[:W:<
sFilePath = sPath; |TM&:4D]^
sFileName = sName; |<tZ|
this.nSplitter = nSpiltter; XN65bq
b Lag&c)
~_<I}!j/B
} $.{CA-~%[
f0H 5 )DJf
;sJUTp5\h
public String getSSiteURL() 7yp7`|,p
{ 5y-8_)y8o
return sSiteURL; x}Qet4vV
} H^_]' ~.
]+A>*0#"
hpp>+=
public void setSSiteURL(String value) Xb +)@Y4h
{ b[p<kMTir
sSiteURL = value; ;ELQIHnD"
} DwM4/m
(}E-+:vFU
U U!M/QJ
public String getSFilePath() vQf'lEFk
{ FD>j\
return sFilePath; Zkl:^!*
} u=^0n2ez
ER,,K._?B
eBiP\
public void setSFilePath(String value) l*]9
{ /LMb~Hy,
sFilePath = value; k<W n
} $mFsf)1]]?
Jg#L8>p1
09?n5x!6
public String getSFileName() Yas!w'
{ K8E:8`_cx
return sFileName; Q|eRek
} $tvGS6p>
q@ !p
VesW7m*z
public void setSFileName(String value) s)Sa KE*d
{ _J^q|
sFileName = value; K0B J
} 86d*
^pz3L'4n
5MY+O\
public int getNSplitter() "h.}o DS
{ ^$3 ~;/|
return nSplitter; ;:xOW$
} Y ON@G5^
mY"DYYR>
pKK&+umg
public void setNSplitter(int nCount) 3$f%{~3
{ YbZ<=ZzO4
nSplitter = nCount; $4.mRS97g
} EN@LB2
} BcV;EEi
TSu^.K
4f,D3e%T|
/* ]e+IaZ[Wo
**Utility.java Q"c!%`\
*/ -eAo3
package NetFox; L^PZ\OC
q|m8G
9R.IYnq
public class Utility { (?-5p;
wqo2iRql
9/C0DDb
public Utility() j}YZl@dYV
{ @(.?e<
(zkh`8L
01I5,Dm
} R`=IYnoOA
<x@\3{{U
//线程睡眠 e2w$":6>
public static void sleep(int nSecond) ixN>KwH
{ aq3evm
try{ :6LOb f\01
Thread.sleep(nSecond); cqeId&Cg
} fX G+88:2
catch(Exception e) ,u QLXF2
{ *|AnL}GJ
e.printStackTrace (); 6Nx TW
} 2a*1q#MpAt
} :0ND0A{K:
ia|^>V>-
//日志 %_+9y??
public static void log(String sMsg) KmV#% d
{ ]OY6.m
System.err.println(sMsg); RLY Ae
} >>krH'79
Y5LESZWo
l1`Zp9I
public static void log(int sMsg) 6, ag\
{ <Xw 6m$fr:
System.err.println(sMsg); ;}K1c+m!5V
} Pb} &c
} ?>q=Nf^Q.
=Cs$0aA
pvy;L[c
/* PGT!HdX#{
**TestMethod.java mUr@w*kq|p
*/ I>/`W
package NetFox; 3D\.Sj%
^'QcP5Fv
oD{V_/pdx
public class TestMethod { A#1aO
f]T1:N*t
H#U{i
public TestMethod() sLbz@54
{ ///xx/weblogic60b2_win.exe oZ6xHdPc4
try{ WbH/K]/1)h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0x^$q? \A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a,cDj
SiteFileFetch fileFetch = new SiteFileFetch(bean); cdU2ph_
fileFetch.start(); R$,`}@VqZ3
} aSHZR
catch(Exception e){e.printStackTrace ();} y#AY+ >
U YUIpe
a0)+=*$
} 1b3Lan_2
+Q-~~v7,
(~Zg\(5#
public static void main(String[] args) EUuMSDp
{ '4Z%{.;
new TestMethod(); f+xGf6V
} w#PaN83+
} WS(@KN
点击下载更多相关资料