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)); oy^-?+
} $hhXsu=
for(int i=0;i<nEndPos.length-1;i++) 0cS$S Mn{
{ U>2KjZB
nEndPos = nStartPos[i+1]; %R0 Wq4}
} GW,EyOE+~
nEndPos[nEndPos.length-1] = nFileLength; NUV">i.(
} nn7LL+h
} *D?=Ts
hIe.Mv-I)
.-Lrrk)R+
//启动子线程 >v+1v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [bhKL5l
for(int i=0;i<nStartPos.length;i++) sFpg
{ ;ElCWs->\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W=+n|1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hVzyvpw
nStartPos,nEndPos,i); @_ %RQO_X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cMY}Y [2c
fileSplitterFetch.start(); <?.eU<+O`S
} A9xeOy8e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), //63|;EEkl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Fv^zSoi2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1&boD\ 7
nEndPos = " + nFileLength); `UsJaoR#f
// fileSplitterFetch[nPos.length-1].start(); ?Lg<)B9
%1i:*~g
ojM'8z0Hn
//等待子线程结束 'nTlCYT
//int count = 0; N~!, S;w
//是否结束while循环 t"VT['8
boolean breakWhile = false; UIAazDyC
vbid>$%
V4,Gt]4
while(!bStop) 6Z_V,LD9L
{ a|t~&\@
write_nPos(); :nIMZRJ_!E
Utility.sleep(500); h#YO;m2wd
breakWhile = true; <x}wy+SG
!n-Sh<8
Q!l(2nva
for(int i=0;i<nStartPos.length;i++) Y$JVxly
{ /8l-@P.o
if(!fileSplitterFetch.bDownOver) +=($mcw#[
{ UR'[?
breakWhile = false; u@_|4Bp,"
break; VIAq$iu7
} ?|5M'o|9
} &#PPXwmR
if(breakWhile) P]Fb0X
break; >=N-P<%
DT]4C!dh
VIF43/>(
//count++; U"GxXrl
//if(count>4) KrGl}|
// siteStop(); +xYu@r%R
} YS|Dw'%g /
/b,>fK^
2y`h'z
System.err.println("文件下载结束！"); IWo'{pk
} _[6sr7H!
catch(Exception e){e.printStackTrace ();} 3yx[*'e$
} 0F)v9EK(W4
PysDDU}v
yQhO-jT
//获得文件长度 ?Bu*%+
public long getFileSize() +R*DE5dz
{ DtANb^
int nFileLength = -1; !<];N0nt#
try{ pT,8E(*l2
URL url = new URL(siteInfoBean.getSSiteURL()); 9nAP%MA`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g (w/
httpConnection.setRequestProperty("User-Agent","NetFox"); ?'k_K:_
beOMln+R
&PC6C<<f
int responseCode=httpConnection.getResponseCode(); }d%CZnY&7
if(responseCode>=400) :?xH)J,imk
{ og";mC
processErrorCode(responseCode); xT>9ZZcE
return -2; //-2 represent access is error )BJkHED{
} %"{P?V<-V
mqZK1<r
9QU\J0c/
String sHeader; : #a
-E}X`?WhD
V?EX`2S
for(int i=1;;i++) mu\1hKq;B
{ UwUHB~<oE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Zn9u&!T&
//Utility.log(in.readLine()); Wc@ ,#v
sHeader=httpConnection.getHeaderFieldKey(i); kZ5#a)U<
if(sHeader!=null) f#ZM2!^!
{ iy~h|YK;
if(sHeader.equals("Content-Length")) ST{Vi';}
{ }#7l-@{<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]Za[]E8MD
break; 3jZGO9ttnS
} iZNS? ^U
} Mxl;Im]!`.
else Hhtl~2t!0
break; D&FDPaJM
} |:C0_`M9
} a#]V|1*O
catch(IOException e){e.printStackTrace ();} $W7}Igx#
catch(Exception e){e.printStackTrace ();} j sPavY
i8?oe%9l
%Yu~56c-
Utility.log(nFileLength); (7qlp*8.s
nXn@|J&z~U
$.D)Llcq
return nFileLength; qWH^/o
} ,yC..aI
K<^p~'f4P
"mQp#d/'
//保存下载信息（文件指针位置） a]p9[Nk
private void write_nPos() VJ\qp%
{ +c%jOl
try{ uzHMQp
output = new DataOutputStream(new FileOutputStream(tmpFile)); azZtuDfv
output.writeInt(nStartPos.length); 8y27O
for(int i=0;i<nStartPos.length;i++) 'xta/@Sq
{ S TWH2_`
// output.writeLong(nPos); kl]V_ 7[
output.writeLong(fileSplitterFetch.nStartPos); vb^fx$V
output.writeLong(fileSplitterFetch.nEndPos); rN9qH
} 9]v,3'QI
output.close(); X$UK;O
} ?3~t%Q`
catch(IOException e){e.printStackTrace ();} CT'4.
catch(Exception e){e.printStackTrace ();} g(pr.Dw6
} anSZWQ
__b4dv
6rnFXZ\
//读取保存的下载信息（文件指针位置） Md4Q.8
private void read_nPos() GTLS0l)
{ 2|j=^
try{ t]SB.ja
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <TVJ9l
int nCount = input.readInt(); ;j9%D`u<
nStartPos = new long[nCount]; +.~K=.O)
nEndPos = new long[nCount]; 6CFnE7TQf
for(int i=0;i<nStartPos.length;i++) _GkLspSaU
{ f+9eB
nStartPos = input.readLong(); wn@~80)$
nEndPos = input.readLong(); Gy\]j
} (l%?YME
input.close(); }<~(9_+
} <%YW/k"o
catch(IOException e){e.printStackTrace ();} l :{q I#Q
catch(Exception e){e.printStackTrace ();} :m`D
} x1Gx9z9
2OUx@Vj
dm}1"BU<
private void processErrorCode(int nErrorCode) lW5Lwyt8
{ <-.@,HQ+
System.err.println("Error Code : " + nErrorCode); sl-wNIQ
} _]@u)$
cD]H~D}M
>/74u/&
//停止文件下载 rA ={;`
public void siteStop() se.HA
{ 2V]a+Cgk
bStop = true; J&j5@
for(int i=0;i<nStartPos.length;i++) by+xK~>
fileSplitterFetch.splitterStop(); CJk"yW[,|
Dh4Lffy
__eB 7]#E
} wb9(aS4
} ?;o0~][!
//负责部分文件的抓取 uD(C jHM>
**FileSplitterFetch.java )Wle CS_
*/ ^.:&ZsqV
package NetFox; f?:=@35
&jY| :Fe
PESvx>:
import java.io.*; Je|:\Qk
import java.net.*; |Ogh-<|<
1qR$ Yr\
k6"(\d9o
public class FileSplitterFetch extends Thread { F5X9)9S
: jkO
C7F\Y1Wj
String sURL; //File URL [;Ih I
long nStartPos; //File Snippet Start Position T;3qE1c
long nEndPos; //File Snippet End Position iT:i '\~
int nThreadID; //Thread's ID ]2l}[ w71|
boolean bDownOver = false; //Downing is over tf6-DmMH
boolean bStop = false; //Stop identical 6am6'_{
FileAccessI fileAccessI = null; //File Access interface CKHmJ]=
f/c&Ya(D~
7zx xO|p[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bM"?^\a&Q
{ P>rRD`Yy\
this.sURL = sURL; [R1|=kGU
this.nStartPos = nStart; qqo#H O
this.nEndPos = nEnd; l$1?@l$j
nThreadID = id; A{4,ih"5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }j2;B 8j
} lusUmFm'*
Pk;/4jt4
|J4sQ!%K
public void run() g4k3~,=D3
{ V'#R1x"3
while(nStartPos < nEndPos && !bStop) h!uyTgq
{ Y=|p}>.}
:l"BNT[/
U"/T`f'H z
try{ "Y^j=?1k
URL url = new URL(sURL); Zoxblk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eCR^$z=c
httpConnection.setRequestProperty("User-Agent","NetFox"); r+m.!+
String sProperty = "bytes="+nStartPos+"-"; {St-
httpConnection.setRequestProperty("RANGE",sProperty); ,mx\ -lWFy
Utility.log(sProperty); ;Q,t65+Am
rR":}LA^d
JwxKWVpWv
InputStream input = httpConnection.getInputStream(); N$Ad9W?T
//logResponseHead(httpConnection); 5.ab/uk;M
@:RoYvk$
Dqo#+_v
byte[] b = new byte[1024]; h2x9LPLBxT
int nRead; baD063P;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K"VcPDK
{ 5?HwM[`
nStartPos += fileAccessI.write(b,0,nRead); 9,~7,Py}
//if(nThreadID == 1) }wRm ~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &xB*Shp,B
} OU.}H $x"
Q*I8RAfd
CR23$<FC
Utility.log("Thread " + nThreadID + " is over!"); L3HC-
bDownOver = true; !AJkd.
//nPos = fileAccessI.write (b,0,nRead); f6K.F
} ~5N oR
catch(Exception e){e.printStackTrace ();} y akRKiz\
} pt"9zkPj
} T5|kO:CbHq
;8XRs?xyd
n_; s2,2r
//打印回应的头信息 5PZ!ZO&
public void logResponseHead(HttpURLConnection con) 0sU*3r?
{ <$ssU{5
for(int i=1;;i++) Lu6g`O:['
{ ?e6>dNw
String header=con.getHeaderFieldKey(i); wdP(MkaV
if(header!=null) ^CLQs;zXE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z" ;q w
Utility.log(header+" : "+con.getHeaderField(header)); G3:!]}
else $m#^0%
break; dq.U#Rhrx
} m-azd~r[
} UJh;Hp:
1xEOYM)
=q]!"yU[d
public void splitterStop() I ?Dp*u*
{ o$</At
bStop = true; jr0j0$BF
} d2Q*1Q@u
8cOft ;|qB
oDu6W9+
} %H\J@{f
6Jq[]l"v
,k~' S~w.
/* 1UJrPM%
**FileAccess.java V6P-?Nd
*//文件访问(定位，写) p&RC#wYu
package NetFox; 04dz?`HuB
import java.io.*; p,8~)ic_
>nSt<e
w -o#=R_
public class FileAccessI implements Serializable{ 'o}[9ZBjn
\\\8{jq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s.bo;lk
RandomAccessFile oSavedFile; \AroSy9
long nPos; @~$"&B
pml33^*<U
g=4^u*
public FileAccessI() throws IOException Gu~*ZKyJ
{ sq`Xz8u
this("",0); V($V8P/
} KWY_eY_|
"."(<c/3
0)Ephsw
public FileAccessI(String sName,long nPos) throws IOException !Nx1I
{ SC~k4&xy
oSavedFile = new RandomAccessFile(sName,"rw"); ?v M9 !
this.nPos = nPos; ecs 0iW-,
oSavedFile.seek(nPos); +`GtZnt#
} 1X5g(B
JXJ+lZmsz
u|t l@_
public synchronized int write(byte[] b,int nStart,int nLen) 8-x-?7
{ L_Gw:"-+Q
int n = -1; 70 7( LG
try{ op9dYjG7
oSavedFile.write(b,nStart,nLen); b*?u+tWP_
n = nLen; BJUj#s0$
} `5@F'tKQ
catch(IOException e) K{ar)_V/
{ .c-a$39
e.printStackTrace (); &$/ #"lW,V
} d)vP9vXy
oV:oc,
D;C';O
return n; XJe=+_K9
} ffmtTJFC5
1]G)41
~I5hV}ZT
} ~)ys,Q
m@Yc&M~
\i_E}Ii0
/* .^{%hc*w4
**SiteInfoBean.java WChP,hw
*/ hNN[djR
package NetFox; /dYv@OU?
p@G7}'|eyA
nU_O|l9
public class SiteInfoBean { 5&n{QE?Um
pjFO0h_Y
vv ,4n&D
private String sSiteURL; //Site's URL ;_(f(8BO
private String sFilePath; //Saved File's Path +>q#eUS)
private String sFileName; //Saved File's Name $].htm
private int nSplitter; //Count of Splited Downloading File D|9+:Y
*(Dmd$|0|
u)0I$Tc"
public SiteInfoBean() _h!.gZB3
{//nSplitter的缺省值为5 N;|^C{uz
//default value of nSplitter is 5 sWYnoRxu
this("","","",5); TsTc3
} b4_0XmL
|[>@Kk4
<PpvVDy3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :ZrJL&
{ T-%=tY+-
sSiteURL= sURL; Eu?z!
sFilePath = sPath; X@`a_XAfd
sFileName = sName; (P)G|2=
this.nSplitter = nSpiltter; Q|AZv>'!
27eG8
>u$8Z
} Tzex\]fw
-)}s{[]d6m
qG6s.TcG
public String getSSiteURL() sP(+Z^/
{ 5Ml=<^
return sSiteURL; HK!ecQ^+
} 6$r\p2pi0
)]1hN;Nz
6CBk=)qH
public void setSSiteURL(String value) dDPQDIx
{ _B^zm-}8|B
sSiteURL = value; ~18a&T:
} WBE>0L
C{}_Rb'x
@V*dF|# /
public String getSFilePath() q7X]kr*qx
{ OH\^j1x9I
return sFilePath; Q7865
} xR1G
4KH492Nq9
sT\:**
public void setSFilePath(String value) 7<yc:}9nx
{ |u&cN-}C d
sFilePath = value; GI%&.Vd
} F_ F"3'[
cszvt2BIg
WUYI1Ij;
public String getSFileName() 5}#wp4U
{ ,S-h~x
return sFileName; w"^h<]b
} 9"P|Csj
bx3Q$|M?
<gp?}Lk
public void setSFileName(String value) 8 t5kou]h
{ 11=$]K>
sFileName = value; 'X?xn@?
} jo`ZuN{
_VrY7Mz:r
PXb$]HV
public int getNSplitter() iEvQ4S6tD
{ U[C4!k:0
return nSplitter; Mkz_.;3
} V_+&Y$msi~
u7!9H<{>P
cSb;a\el$
public void setNSplitter(int nCount) ywa*?3?c
{ WTvUz.Et
nSplitter = nCount; wX,V:QE
} =gB5JB<}2
} ^|Q]WHNFB
":Wq<Z'
kWzN {]v
/* EbC!tR
**Utility.java >@YefNX6
*/ tEhg',2t(
package NetFox; ,EB}IG]
z5>I9R^q;
H71sxek3
public class Utility { Wc3z7xK1@
HK@ij,px
.Bm%
public Utility() [xMa^A>p
{ g*Y,.
y?$DDD
6}4})B2
} DP ? dC`
Wq1>Bj$J8
//线程睡眠 `3+i.wR
public static void sleep(int nSecond) g68p9#G
{ )[Y B&
try{ mayJwBfU
Thread.sleep(nSecond); lE:g A,
} #oUNF0L@6
catch(Exception e) VeoG[Jl
{ zCx4DN`
e.printStackTrace (); f9De!"*&
} l:85 _E
} /(N/DMl[
isQ(O
//日志 'YL[s
public static void log(String sMsg) FwCb$yE#M
{ @YJI'Hf67
System.err.println(sMsg); :D.0\.p
} z|l*5@p
+ ?1GscJ
8Lo#{`
public static void log(int sMsg) j|eA*UE
{ *r7vDc
System.err.println(sMsg); 1\.$=N
} x$Dq0FX!%_
} ;a:H-iC
)BP*|URc
K@D\5s|1|
/* )#=J<OpG
**TestMethod.java ]\$/:f-2
*/ mB?x_6#d9
package NetFox; 6 63o
%oZ:Awx
J$dwy$n
public class TestMethod { D Ez,u^
25^?|9o7
bF'rK'',
public TestMethod() -fR:W{u
{ ///xx/weblogic60b2_win.exe }lJ;|kx$
try{ hp\&g2_S0W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NxT"A)u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zkQ[<
SiteFileFetch fileFetch = new SiteFileFetch(bean); +X}i%F'
fileFetch.start(); "t@p9>
} 9Em#Ela
catch(Exception e){e.printStackTrace ();} *XVwTW[a
'D\Q$q
uV/5f#)
} {T){!UVp!
K=g</@L6R
t}EMX9SQ
public static void main(String[] args) qe~x?FO_>
{ wp[Ug2;G
new TestMethod(); $pGT1oF[E
} f:T?oR>2
} % RSZ.
点击下载更多相关资料