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)); WbHI>tt
} 4FcY NJq
for(int i=0;i<nEndPos.length-1;i++) Yp6% @c6\
{ 2-DJ3OL]k
nEndPos = nStartPos[i+1]; %s#`Z [8,
} .!Q?TSQ+{!
nEndPos[nEndPos.length-1] = nFileLength; 4/QQX;w
} -3Auo0
} 4 moVS1
Wf9K+my
FS6I?q#tQ
//启动子线程 |&\cr\T\r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l1D"*J 2`
for(int i=0;i<nStartPos.length;i++) =>Dw,+"
{ h 7*#;j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F1b~S;lm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ku;8Mx{
nStartPos,nEndPos,i); 'Q4V(.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y[`%j\=
fileSplitterFetch.start(); m^Rf6O^
} jWerX -$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SkMBdkS9z[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IjrjLp[z$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V>B*_J,z.
nEndPos = " + nFileLength); #brV{dHV,
// fileSplitterFetch[nPos.length-1].start(); |3uE"\nfA
o,DI7sb
Jk=d5B
//等待子线程结束 nISfRXU;
//int count = 0; )jaNFJ 3
//是否结束while循环 O<`\9
boolean breakWhile = false; 82~ZPZG
OojQG
D(^ |'1
while(!bStop) ~e R6[;
{ 5wGc"JHm
write_nPos(); ^*+-0b;[G
Utility.sleep(500); .="[In'
breakWhile = true; h&6t.2<e
U\`H0'
O{44GB3
for(int i=0;i<nStartPos.length;i++) q NE(@at
{ 2a[_^v $v
if(!fileSplitterFetch.bDownOver) 2:D1<z6RQ
{ b}5hqIy
breakWhile = false; *XSHzoT*
break; bhc .UmH
} ]2'{W]m
} 'X1fb:8m8
if(breakWhile) `B71`
break; cb9q0sdf
Q.`O;D}x
09C[B+>h
//count++; 4f{(Scg
//if(count>4) ]Qb85;0)
// siteStop(); } l4d/I
} _9Y7.5
d&[.=M\E8
Ex3V[v+D(
System.err.println("文件下载结束！"); @&E{ L
} *Zi:^<hv
catch(Exception e){e.printStackTrace ();} C#x9RW
} ,T3_*:0hk!
LG3:V'|
F3V_rE<
//获得文件长度 Ah<6m5+
public long getFileSize() }Qo:;&"3
{ Dt p\T|)
int nFileLength = -1; iPoDesp
try{ _'47yq^O
URL url = new URL(siteInfoBean.getSSiteURL()); ^GN|}W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pX/,s#dY>
httpConnection.setRequestProperty("User-Agent","NetFox"); X1{U''$ K
cWG?`6xU&
STH?X] /
int responseCode=httpConnection.getResponseCode(); qX?k]m
if(responseCode>=400) nkvkHh
{ rlIDym9nY~
processErrorCode(responseCode); {=GWQn6cc
return -2; //-2 represent access is error fb||q-E
} %T:7I[f
-H;p +XAY
]$gBX=
String sHeader; @(_M\>!%M
fooQqWC)
Q-LDFnOFwp
for(int i=1;;i++) .|g67PH=
{ A(>kp=~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V`MV_zA2
//Utility.log(in.readLine()); 9e:}qO5)
sHeader=httpConnection.getHeaderFieldKey(i); zHsWj^m"
if(sHeader!=null) Q #%C)7)
{ @hE$x-TP0
if(sHeader.equals("Content-Length")) HX]pcX^K
{ h#iFp9N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZT;:Hxv0N
break; 0Zv<]xO
} ;\5^yDv[e
} &\0V*5tI
else [rt+KA
break; M)oJ06`K
} 8+7=yN(
} fm%1vM$[J
catch(IOException e){e.printStackTrace ();} H _%yh,L
catch(Exception e){e.printStackTrace ();} VD*xhuy$k
M!ra3Y
ix=H=U]Q{
Utility.log(nFileLength); (YJ]}J^
P_f>a?OL:
5wws8w
return nFileLength; #n_uELE
} `xpU
u*NU MT2
^Q\O8f[u
//保存下载信息（文件指针位置） yb(zyGe
private void write_nPos() ages-Z_X
{ oqOXRUy
try{ -gP4| r8&
output = new DataOutputStream(new FileOutputStream(tmpFile)); mfNYN4Um6
output.writeInt(nStartPos.length); (y xrK
for(int i=0;i<nStartPos.length;i++) mf>cv2+
{ > CPJp!u
// output.writeLong(nPos); L8FLHT+R-
output.writeLong(fileSplitterFetch.nStartPos); gTp){
output.writeLong(fileSplitterFetch.nEndPos); _\P9~w `
} }m~2[5q%/
output.close(); p<@0b
} O!(FNv0
catch(IOException e){e.printStackTrace ();} mj{/'
catch(Exception e){e.printStackTrace ();} fJ?$Z|
} y ~ A]
f;(]P
AF qut
//读取保存的下载信息（文件指针位置） >qSaF
private void read_nPos() 8\~IwtSk
{ r"MKkSEM
try{ G([!(8&2Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kOfu7Zj
int nCount = input.readInt(); xCd9b:jG
nStartPos = new long[nCount]; Ij_VO{]G'l
nEndPos = new long[nCount]; VS#i>nlT
for(int i=0;i<nStartPos.length;i++) @42!\1YT
{ dpBG)Xzoyv
nStartPos = input.readLong(); 4K@`>Y5g*
nEndPos = input.readLong(); Z81{v<c;
} J@{yWgLg
input.close(); $cLtAo^W
} Xjal6e)[
catch(IOException e){e.printStackTrace ();} aeESS;JxJj
catch(Exception e){e.printStackTrace ();} >o\[?QvP
} |xTf:@hgHf
l/BE~gdl
U~SOHfZ%(
private void processErrorCode(int nErrorCode) =%:mZ@x'
{ 5O9Oi:-!c
System.err.println("Error Code : " + nErrorCode); _J51:pi
} c{Ax{-'R
L7jMpz&
kMS[
//停止文件下载 "-N)TIzLX
public void siteStop() z^/aJ@gQ
{ >Hr0ScmN@"
bStop = true; -4p^wNR
for(int i=0;i<nStartPos.length;i++) 1u\fLAXn
fileSplitterFetch.splitterStop(); |4i,Vkfhe
$V"~\h8
89B1\ff
} A#mf*]'
} R{r0dK"_
//负责部分文件的抓取 2'"$Y'
**FileSplitterFetch.java 4"e7 43(
*/ y?-wjJS>
package NetFox; JF>mybB
##7,
K5Fzmo a
import java.io.*; '|e5cW6z
import java.net.*; m7 !Fb
;APpgt4
46'EZ@#s
public class FileSplitterFetch extends Thread { lqOv_q
%}G:R!4 d
DTdL|x.{
String sURL; //File URL _Y*: l7
long nStartPos; //File Snippet Start Position cI3uH1;#
long nEndPos; //File Snippet End Position )gNHD?4x
int nThreadID; //Thread's ID V#W(c_g
boolean bDownOver = false; //Downing is over |WeLmy%9
boolean bStop = false; //Stop identical r4O*0Q_
FileAccessI fileAccessI = null; //File Access interface ?-O(EY1E
^/HE_keY
uU`zbh}]L.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (tEW#l'}
{ S8" h9|
this.sURL = sURL; EX8:B.z`57
this.nStartPos = nStart; ushQWP)
this.nEndPos = nEnd; t=~5I>
nThreadID = id; Nuk\8C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FuaGr0]
} ]?U:8%
J$PE7*NU
muQ7sJ9 r
public void run() ;w?zmj<Dm
{ =5_8f
while(nStartPos < nEndPos && !bStop) 7/(C1II.Q
{ ?x]T&S{
<;x+?j
dL")E|\\k
try{ K:P gkc
URL url = new URL(sURL); bTKzwNx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MQ"<r,o?:
httpConnection.setRequestProperty("User-Agent","NetFox"); cGC&O%`i,\
String sProperty = "bytes="+nStartPos+"-"; A20_a;V
httpConnection.setRequestProperty("RANGE",sProperty); J?5O2n
Utility.log(sProperty); _'Q}Y nEv
:$[m[y7i
SsafRK$
InputStream input = httpConnection.getInputStream(); PG)dIec
//logResponseHead(httpConnection); =#1iio&
dOqwF iO
G\TyXq_4
byte[] b = new byte[1024]; 8Md*9E#J("
int nRead; wmY6&^?uS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0_Etm83Wq6
{ dW!T.S
nStartPos += fileAccessI.write(b,0,nRead); e&F,z=XJ}
//if(nThreadID == 1) bM8b3,}?n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @8@cpm
} 1kl4X3q6
g9I2SdaJ
sBF>a|
Utility.log("Thread " + nThreadID + " is over!"); bQ0m=BzF
bDownOver = true; \rADwZm
//nPos = fileAccessI.write (b,0,nRead); ~z>2`^Z"
} 05nG|
catch(Exception e){e.printStackTrace ();} ? _[gs/i}
} rMpb
} )0PUK9
50rq}-
uxVXnQQ
//打印回应的头信息 yXrFH@3
public void logResponseHead(HttpURLConnection con) Lc*i[J<s
{ ^']xkS
for(int i=1;;i++) rtf>\j+
{ `EU=u_N
String header=con.getHeaderFieldKey(i); suPQlU>2sj
if(header!=null) Z\i@Qa+r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0?SdAF[:z
Utility.log(header+" : "+con.getHeaderField(header)); ctdV4%^{
else SLz^Wg._
break; *8js{G0h
} 9+=U&*
} sP5PYNspA
R$(,~~MH
&^qD<eZ!Eq
public void splitterStop() #)=P/N1
{ lGjmw"/C
bStop = true; Hc^b}A y7
} lh~!cOm\=E
T -C2V$1
T\8|Q@
} ,+,""t
49_b)K.tB
z{``v|K
/* 6!Ji-'\"
**FileAccess.java ;2)@NH
*//文件访问(定位，写) t1g)Y|@d
package NetFox; A(Ugam~}
import java.io.*; 69r<Z
N}VKH5U|
D19uI&U4
public class FileAccessI implements Serializable{ #=7~.Y
WZ@nuK.39T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #\@*C=
RandomAccessFile oSavedFile; E;D9S
long nPos; e][U ;
IR(JBB|xNQ
GJ ZT~
public FileAccessI() throws IOException QF'N8Kla
{ [P)HVFy|l
this("",0); (tx6U.Oy
} id&;
[)#,~L3
J'b*^K
public FileAccessI(String sName,long nPos) throws IOException CdatN$/*
{ &'c1"%*%8>
oSavedFile = new RandomAccessFile(sName,"rw"); >UZfi u
this.nPos = nPos; m}Kn!21
oSavedFile.seek(nPos); 5RI"gf
} !95ZK.UT
5R/k -h^`
~WehG<p v[
public synchronized int write(byte[] b,int nStart,int nLen) 5Ee%!Pk
{ \@GA;~x.b
int n = -1; :=T+sT~
try{ ,>`wz^z
oSavedFile.write(b,nStart,nLen); 29 Yg>R!/
n = nLen; ^yu0Veypy
} p_)V@7
catch(IOException e) +VI2i~
{ vv"_u=H
e.printStackTrace (); #l+U(zH:JG
} ,g6w2y7 ]
/b@8#px
GO+cCNMa"
return n; K82pWpR
} )(_}60
V[5-A $ft
+0;6.PK
} U<KvKg
AWi~qzTZ
\=XAl >}\
/* t(/e~w
**SiteInfoBean.java +I;b,p
*/ :hwZz2Dhi
package NetFox; ]06LNE
jL6u#0
Siq2Glg_
public class SiteInfoBean { iLws;3UX;x
S c_*L<$
@F+4 NL-'P
private String sSiteURL; //Site's URL a:XVu0`(
private String sFilePath; //Saved File's Path tUDOL-Tv
private String sFileName; //Saved File's Name OgY4J|<
private int nSplitter; //Count of Splited Downloading File m3+MRy5
fOdkzD,
$[by)
public SiteInfoBean() B=jJ+R
{//nSplitter的缺省值为5 0;#%KC,
//default value of nSplitter is 5 SirjWYap
this("","","",5); kBS;SDl)
} S>/p6}3]
M-e!F+d{od
^}8(o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .a8N 5{`
{ J3Qv|w[3Y
sSiteURL= sURL; F@& R"-
sFilePath = sPath; p&>*bF,
sFileName = sName; \A6MVMF8
this.nSplitter = nSpiltter; q?nXhUD
\j+O |#`|)
[V|,O'X ~
} E!8FZv8
_[<R<&jG
>8"oO[U5>
public String getSSiteURL() /XeDN-{
{ 0k@4;BYu
return sSiteURL; &BY%<h0c
} ryB^$Kh,,
eB%KXPhMm
AE={P*g
public void setSSiteURL(String value) %g5TU 6WP
{ 9TIyY`2!
sSiteURL = value; h3Nwxj~E
} ms{:=L2$$
Kyt.[" p
1XSA3;ZEc
public String getSFilePath() &=Gz[1 L
{ jrbEJ.
return sFilePath; W2D^%;mw
} CC0@RU
AON";&dLq-
HgvgO\`]
public void setSFilePath(String value) 0&mo1 k_U
{ @zL)R b%P$
sFilePath = value; ! @{rkp
} 1P. W 34
^VK-[Sz&
:9Zu&t
public String getSFileName() :3^b>(W.
{ 11glFe
return sFileName; %<lfe<;^t
} (%}T\~`1z#
>@KQ )p' `
CoDu|M%
public void setSFileName(String value) <W~5;m
{ Q&] }`Rp=
sFileName = value; H%t/-'U?
} bW(+Aw=O
,d(F|5M:
8/,m8UOY
public int getNSplitter() uSLO"\zysX
{ dIQ7u
return nSplitter; XKp.]c wP
} "u~l+aW0
Tf7$PSupP
gcqcY
public void setNSplitter(int nCount) a*REx_gLG
{ ]W7(}~m
nSplitter = nCount; a/;u:"
} Y]/(R"-2G
} v_)a=I%o&2
IMIZ#/
+-&N<U
/* ,DK|jf
**Utility.java ;ZHKTOoK
*/ )8kcOBG^L
package NetFox; 5!$m3j_,]?
O{zY(`[
C7[ge&
public class Utility { jCDZ$W89
MH[Zw$
C9E l {f
public Utility() )A:2y +
{ %y)5:]
et(/`
-}`ES]
} rUEoz|e4a
^"7tfo8
//线程睡眠 TU&6\]yF_
public static void sleep(int nSecond) S8*VjG?T\
{ ("0@_05OH
try{ dya]^L}fL
Thread.sleep(nSecond); T=35?
} 9w'3d@
catch(Exception e) 06"p^#
{ !<H[h4g
e.printStackTrace (); !`q*{Ojx
} EF=.L{
} ZZOBMF7
v+U( #"
//日志 Ev* b
public static void log(String sMsg) ^29w@*
{ i/9QOw~
System.err.println(sMsg); )W95)]
} Q];gC{I
MzT#1~
\?c0XD
public static void log(int sMsg) ^8$CpAK]M
{ ]y3V^W#
System.err.println(sMsg); RmxgCe(2a
} pW7vY)hj
} K&0op 4&
[RCUP.
Gc>bli<-
/* ez=$]cln
**TestMethod.java [?x9NQ{
*/ WLW'.
package NetFox; s|Ls
@iK=1\-2
0h-holUf}~
public class TestMethod { biG=4?Xl
Tl5K'3
sY+U$BYB>
public TestMethod() Kdh(vNB>
{ ///xx/weblogic60b2_win.exe TJ[C,ic=D
try{ Y,RED5]t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *cxmQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9+"D8J7
SiteFileFetch fileFetch = new SiteFileFetch(bean); QW#]i
fileFetch.start(); r`XIn#o
} \s?OvqI:
catch(Exception e){e.printStackTrace ();} V2sWcV?
!Rk1q&U5
y ,isK
} `l@[8H%aw
"r @RDw
r/1:!Vu(
public static void main(String[] args) gS4zX>rqe
{ A`<#}~A
new TestMethod(); PxzeN6f
} (RG\U[
} 95Bw;U3E
点击下载更多相关资料