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)); 1Uc/r>u9
} (I#3![q
for(int i=0;i<nEndPos.length-1;i++) I7;|`jN5K
{ fHgvh&FU
nEndPos = nStartPos[i+1]; }n k[WW
} !dwa. lZ&X
nEndPos[nEndPos.length-1] = nFileLength; WFfn:WSWU
} >%c>R'~h
} l(Uwci
5C5OLAl v
!wo
//启动子线程 ]&"01M~+K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fy>~GFk(
for(int i=0;i<nStartPos.length;i++) j HEt
{ *dxE (dP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :d|~k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N@I=X-7nh|
nStartPos,nEndPos,i); ugs9>`fF&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "|/Q5*L
fileSplitterFetch.start(); O0sLcuT$
} Z)<lPg!YAR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;esOe\zjE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \$xj>b;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CTQJ=R"
nEndPos = " + nFileLength); FlT5R*m
// fileSplitterFetch[nPos.length-1].start(); 2CV?cm
Fm[3Btn
[G"Va_A8
//等待子线程结束 CEBa,hp@
//int count = 0; o`Q.;1(Y'
//是否结束while循环 CsN^u H
boolean breakWhile = false; pL2{zW`FDh
L fZF
@el
while(!bStop) )D&xyC}
{ k\-h-0[|
write_nPos(); W@D./Th
Utility.sleep(500); ?$VkMu$2k
breakWhile = true; !i\ gCLg2_
`7R-2 w<b?
ZWQ/BgKB
for(int i=0;i<nStartPos.length;i++) @]Lu"h#u=
{ 9^@)R ED
if(!fileSplitterFetch.bDownOver) (QQkXlJ
{ -s]@8VJA"
breakWhile = false; 9T0g%&
break; -\2hSIXj
} >~_)2_j
} ;3o7>yEv
if(breakWhile) Rx?ze(
break; ;*0?C'h=
d{Owz&PL
-F MonM
//count++; .h(iyCxP
//if(count>4) <LN7+7}
// siteStop(); Zn[ppsz|
} qQ8+gZG$R
<>)N$$Rx&
_PSOT5{
System.err.println("文件下载结束！"); .br6x^\<
} 2OQ\ z;s
catch(Exception e){e.printStackTrace ();} M{4XNE]m
} l z-I[*bA
4issj$
8e1Z:axn0
//获得文件长度 x_r*<?OZ
public long getFileSize() hw(\3h()
{ B<0Kl.V
int nFileLength = -1; Sb(OG 6
try{ h}kJ,n
URL url = new URL(siteInfoBean.getSSiteURL()); ;%;||?'v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F~eY'~&H}
httpConnection.setRequestProperty("User-Agent","NetFox"); -+0kay%
^b.#4i(v
6[SIDOp*^
int responseCode=httpConnection.getResponseCode(); "lSh4X
if(responseCode>=400) bc3`x1)\^
{ `evF?t11X
processErrorCode(responseCode); &xUD(
return -2; //-2 represent access is error Qqs1%u;e8
} h~ZLULW)B
wE}Wh5
W#=,FZT
String sHeader; W1EYVXN
N1B$z3E*
XK})?LTD
for(int i=1;;i++) Keem\/
{ NpaS2q-d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IdK<:)Q
//Utility.log(in.readLine()); n2EPx(~
sHeader=httpConnection.getHeaderFieldKey(i); PcqS#!t
if(sHeader!=null) eTuKu(0 E
{ xF@&wg
if(sHeader.equals("Content-Length")) jFUpf.v2
{ >H ?k0M`L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >##Z}auY
break; D:/q<<|
} 3&nN;4~Zx6
} niKfat?
else N$x&k$w R
break; kw E2V+2
} } `5k^J$x
} tym:C7v%~
catch(IOException e){e.printStackTrace ();} ?)186dp
catch(Exception e){e.printStackTrace ();} lRb>W31"
T6QRr}8`/J
Id&e'
Utility.log(nFileLength); )BvMFwQG
4QTHBT+2`
kguZAO6
return nFileLength; b?c/J{me
} qR_>41JU"
{/H<_
CS~_>bn
//保存下载信息（文件指针位置） ~$J(it-a
private void write_nPos() ~UZ3 lN\E
{ &*%x]fQ@
try{ x~vNUyEN)
output = new DataOutputStream(new FileOutputStream(tmpFile)); GEA1y^b6"
output.writeInt(nStartPos.length); g,rmGu3v
for(int i=0;i<nStartPos.length;i++) *BdH &U
{ y.c6r> }
// output.writeLong(nPos); n:P:im?,y*
output.writeLong(fileSplitterFetch.nStartPos); h<TZJCt
output.writeLong(fileSplitterFetch.nEndPos); QS5t~rb
} E6ZkO/
output.close(); \2e^x
} `$S&:Q,
catch(IOException e){e.printStackTrace ();} .7 0
catch(Exception e){e.printStackTrace ();} 8B:y46
} o~)o/(>ox
"ayV8{m^3
%9a3$OGZX
//读取保存的下载信息（文件指针位置） BdF/(Pg
private void read_nPos() yCvtglAJ4
{ brs`R#e \
try{ ninWnQq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7HBf^N.
int nCount = input.readInt(); zh*D2/r
nStartPos = new long[nCount]; FK593z
nEndPos = new long[nCount]; 5a$EXV
for(int i=0;i<nStartPos.length;i++) [`t ;or
{ C5Q!_x(
nStartPos = input.readLong(); )iQ^HZ
nEndPos = input.readLong(); Dws) 4hH
} O~6%Iz`
input.close(); .Zv~a&GE
} nqm=snh
catch(IOException e){e.printStackTrace ();} Z$JJ0X
catch(Exception e){e.printStackTrace ();} _X~O6e-!
} (8)9S6
BEvY&3%l
bo/9k 4N3
private void processErrorCode(int nErrorCode) CV.|~K0O
{ &h5Y_no GX
System.err.println("Error Code : " + nErrorCode); fy4zBI@
} Q_|}~4_+
%DYh<U4N
"(7y%TFt:
//停止文件下载 A*?PH`bY
public void siteStop() d\l{tmte
{ rB$~,q&.V
bStop = true; ,MNv}w@
for(int i=0;i<nStartPos.length;i++) e,/]]E/o
fileSplitterFetch.splitterStop(); ZK+F<}
jDpA>{O[
94BH{9b5
} ={sjoMW
} z3K$gEve
//负责部分文件的抓取 3NLn}
**FileSplitterFetch.java g"1V]
*/ jts0ZFHc-
package NetFox; ,"(G
)>:~XA|?
A}(]J!rc
import java.io.*; pE)NSZ
import java.net.*; _&hM6N
mi7?t/D1Z
2c 0;P #ol
public class FileSplitterFetch extends Thread { AX8~w(sv
6/mz.,g2
,<t.Iz%
String sURL; //File URL fq6Obh=A#
long nStartPos; //File Snippet Start Position KtL?,zi
long nEndPos; //File Snippet End Position E6TeZ%g
int nThreadID; //Thread's ID 5 ix*wu`,
boolean bDownOver = false; //Downing is over 0BlEt1e2T
boolean bStop = false; //Stop identical f?Zjd&|Ch
FileAccessI fileAccessI = null; //File Access interface p{^:b6
4k<o
@)6b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^EX"fRwNi
{ cZNcplt8
this.sURL = sURL; M/=36{,w-
this.nStartPos = nStart; ,r w4Lo
this.nEndPos = nEnd; /B@{w-N
nThreadID = id; a31e.36g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !Ud'(iGa
} l5{60$g
UrizZ5a
w5HIR/kP
public void run() hi1Ial\Y
{ FfJ;r'eGs
while(nStartPos < nEndPos && !bStop) MF4(
{ B@&sG 5ES
Bdw33z*m
PlzM`g$A
try{ ^[xcfTN
URL url = new URL(sURL); q5SPyfE[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P[ :_"4U
httpConnection.setRequestProperty("User-Agent","NetFox"); OB(oOPH
String sProperty = "bytes="+nStartPos+"-"; x950,`zy
httpConnection.setRequestProperty("RANGE",sProperty); 1RYrUg"s"
Utility.log(sProperty); 8~C_ng-wn
VO|ECB2e
w+R/>a(]
InputStream input = httpConnection.getInputStream(); 2F:qaz
//logResponseHead(httpConnection); }8ubGMr,Y
.d1ff];
9;e!r DW,#
byte[] b = new byte[1024]; .C% 28fH
int nRead; )y,^M3$?C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^9[Q;=R
{ N;g@lyo
nStartPos += fileAccessI.write(b,0,nRead); :25LQf^nz
//if(nThreadID == 1) 'ZuS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y!#-[K:
} rL{R=0
N y'\Q"Y]
XDemdMy$
Utility.log("Thread " + nThreadID + " is over!"); Z10Vx2B
bDownOver = true; k7CKl;Fck
//nPos = fileAccessI.write (b,0,nRead); ' P?h?w^T
} faQmkO
catch(Exception e){e.printStackTrace ();} t%lat./yT
} rm[C{Pn
} >$4#G)s
$d?W1D<A
G\@pg;0|y
//打印回应的头信息 ljKIxSvCFp
public void logResponseHead(HttpURLConnection con) ,;`f* #
{ Tlw'05\{J
for(int i=1;;i++) 7Z6=e6/\
{ ,|]JaZq
String header=con.getHeaderFieldKey(i); ~#pATPW@(
if(header!=null) ==dKC;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MET9rT
Utility.log(header+" : "+con.getHeaderField(header)); YMX9Z||
else e}UQN:1
break; RuPnWx!
} pE5v~~9Ikv
} %2}fW\%'
X;I9\Cp]!
.{V"Gn9!
public void splitterStop() $'J3 /C7
{ k;l3^kTy
bStop = true; %j7b0pb
} vY4sU@+V
AQ~ xjU
N6Mr#A-{
} U)J5K
'$9o(m#
YWFE*wQ!
/* ^jL '*&l
**FileAccess.java R BYhU55B
*//文件访问(定位，写) |6E_N5~
package NetFox; }Pcm'o_wT
import java.io.*; Og\k5.! ,
9bM\ (s/
cM#rus?)+
public class FileAccessI implements Serializable{ 2e`}O
jxog8E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |toP86
RandomAccessFile oSavedFile; yb`PMjj15
long nPos; C96/
R_!.vGhkN
$YSXE :
public FileAccessI() throws IOException jeC=s~
{ c[h~=0UtJ
this("",0); 6mM9p)"$
} * ,hhX psa
NAR6q{c
pXk^EV0
public FileAccessI(String sName,long nPos) throws IOException R;< q<i_l
{ J&xZN8jW
oSavedFile = new RandomAccessFile(sName,"rw"); .GrOdDK$ns
this.nPos = nPos; `/8@Fj
oSavedFile.seek(nPos); u^Q`xd1
} '75T2Ud
i>m%hbAk
`'YX>u/
public synchronized int write(byte[] b,int nStart,int nLen) idI w7hi4
{ a1Fx|#! mq
int n = -1; $V~@w.-Z#
try{ Lljn\5!r<
oSavedFile.write(b,nStart,nLen); B~]Kqp7yU
n = nLen; Gl~l
} =X$ieXq|
catch(IOException e) w~66G
{ $dL..QH^K
e.printStackTrace (); y* +y&
} Y}?8
ula-o)S
')m!48
return n; jP+yN|
} 28MMH Q
&2tfj(ms
?.~1%l!
} &\h7E
98[uRywI
B~Sj#(WEa
/* &LLU@|
**SiteInfoBean.java &uq.k{<p\
*/ &K^0PzWWof
package NetFox; UC!mp?
tB_le>rhl
ai!u+L
public class SiteInfoBean { v3-/ [-XB:
/$~1e7W
RN$vKJk
private String sSiteURL; //Site's URL ,B <\a
private String sFilePath; //Saved File's Path +}:Z9AAMy
private String sFileName; //Saved File's Name S$mv(C
private int nSplitter; //Count of Splited Downloading File !=[Y yh
q}{E![ZTu
) c@gRb~
public SiteInfoBean() tLE8+[ SU
{//nSplitter的缺省值为5 ? x)^f+:9|
//default value of nSplitter is 5 !]4u"e
this("","","",5); r4yz{^G
} eM7@!CdA9q
f|d~=\0y
\""^'pP@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bx?3E^!T
{ @v-^j
sSiteURL= sURL; }[p{%:tP
sFilePath = sPath; h]4xS?6O
sFileName = sName; xR+vu>f
this.nSplitter = nSpiltter; N`8K1{>BH
9CDei~
%>|FJ
} 6= ?0&Bx&
;_}pIO
2#wnJdr6E
public String getSSiteURL() bWe2z~dP
{ w\buQ6pR)
return sSiteURL; (.J/Ql0Y
} MO`Y&<g~A
\/ bd
U8_{MY-9}
public void setSSiteURL(String value) hRkCB
{ |$Yk)z3
sSiteURL = value; sI>w#1.m/&
} t@%w:*&
^~4]"J};M
N?\X2J1
public String getSFilePath() (Y1*Bs[l
{ <A3%182
return sFilePath; ni;_Un~
} K~(RV4oF8B
DUOoTlp
8}QM~&&.
public void setSFilePath(String value) sW>%mnx
{ fc#9e9R
sFilePath = value; %4~"$kE
} Jqoo&T")
Yh<F-WOo2
-E-#@s
public String getSFileName() N_Us6X
{ G]lGoa}]`u
return sFileName; w2LnY1A
} osp~)icun
k+QGvgP[4@
}">r0v!3
public void setSFileName(String value) Ycr3$n]e
{ VU3RFl
sFileName = value; x ;DoQx
} *>m[ZJd%=
~Ztn(1N
+k`L8@a3&
public int getNSplitter() KzHN|8$o
{ [LVXXjkFI
return nSplitter; |$WHw*F^
} 9*"
-]3K#M)s
(HNc9QVC'W
public void setNSplitter(int nCount) %\'=Y/yP
{ vC]X>P5Px
nSplitter = nCount; *byUqY3(
} i?T-6{3I
} W;u.@I&
\Ec<ch[)c
sI,cX#h&Y
/* tU4#7b:Y
**Utility.java aCZ0-X?c
*/ ?P9aXwc
package NetFox; Ym'h vK
8h] TI_
*@rA7zPFf
public class Utility { ]d*9@+Iu
^ :VH?I=
CHnclT
public Utility() K V5 '-Sv1
{ W8W7<ml0A
>a"J);p
()lgd7|+
} EjP;P}_iK
6,t6~Uo/
//线程睡眠 [6VB&
public static void sleep(int nSecond) Z`TfS+O6
{ 1/$PxQ
try{ -2hirA<^
Thread.sleep(nSecond); c>bns/f
} b9H(w%7ucU
catch(Exception e) :82T!
{ #:6-O
e.printStackTrace (); 7Ae`>5B#
} X,Ql6uO
} x`6MAZ
s&73g0$$
//日志 (~~m8VJ>
public static void log(String sMsg) w:\} B'u
{ !5,C"r
System.err.println(sMsg); ~RR!~q
} ':.Hz]]/A
:1+Aj (
@.;+WQE
public static void log(int sMsg) *fN+wiPD
{ # ~<]z
System.err.println(sMsg); :qm\FsO
} \[9VeqMU
} )^:H{1'
m]qw8BoU`F
(.-4Jn
/* -XYvjW,|
**TestMethod.java D07M!U
*/ z:Am1B
package NetFox; ~"+"6zg
1EU4/6!C
_=g&^_ #t
public class TestMethod { 9evr!=":
n>ryS/1
'/O:@P5qY
public TestMethod() MCN>3/81
{ ///xx/weblogic60b2_win.exe ']k<'`b|
try{ )n&hO_c/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 56AC%_ g>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?L<B]!9HZt
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'i+L
fileFetch.start(); tpWGmjfo>
} xQsxc
catch(Exception e){e.printStackTrace ();} G+dq */
sq$v6x sl
DI\=udN
} 3)G~ud
wfo,r 7
^hLr9k
public static void main(String[] args) _LJF:E5L
{ 2yA)SGri
new TestMethod(); U[wx){[|
} bq/Aopfr
} kj6:P$tH
点击下载更多相关资料