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)); #v6<9>%
} 7$IR^
for(int i=0;i<nEndPos.length-1;i++) '0I>
{ Np$ue }yr
nEndPos = nStartPos[i+1]; slP>;
} 3Lv5>[MnN
nEndPos[nEndPos.length-1] = nFileLength; y*=Ipdj
} 1/?K/gL
} )YwLj&e4tf
z"FxKN~Z
;Qc^xIPy
//启动子线程 0c,!<\B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y!q`o$nK
for(int i=0;i<nStartPos.length;i++) |nqN95'u+]
{ @`iz0DPG?Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N]\)Ok
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nFn}
nStartPos,nEndPos,i); f=8{cK0j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i4M%{]G3Y
fileSplitterFetch.start(); l=#b7rBP
} %D% Ok7s})
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j^h:*rw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7E5=Qx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T!^v^m@>y
nEndPos = " + nFileLength); Wy /5Qw~s
// fileSplitterFetch[nPos.length-1].start(); VM;vLUu!e
`-?`H>+OG
6#a82_
//等待子线程结束 z$M-UxY
//int count = 0; FiXqypT_(
//是否结束while循环 )a%E $`
boolean breakWhile = false; us.IdG
[EK^0g
8~BLTZ
while(!bStop) gQ<{NQMzvd
{ %:OX^^i;
write_nPos(); 3/]~#y%2
Utility.sleep(500); RRl`;w?
breakWhile = true; TpdYU*z_Br
QcjsQTAbk
2~vvE
for(int i=0;i<nStartPos.length;i++) j'lC]}kH
{ GXRW"4eF5
if(!fileSplitterFetch.bDownOver) |C0!mU
{ {xICR ~,*
breakWhile = false; cxx8I
break; B$S@xD $
} 46B'Ec
} ]K%d
if(breakWhile) cyh;1Q
break; !\'HKk~V
CdtCxy5
Fzn!
//count++; .z*}%,G
//if(count>4) FL&L$#X
// siteStop(); Tr;&bX5]H
} rX)_!mR
?JW/Stua
Z>dvth
System.err.println("文件下载结束！"); 7f<@+&
} &!FI!T -WH
catch(Exception e){e.printStackTrace ();} .B'ws/%5\
} Kk|)N3AV:
F;Q'R|HQ
(nYGN$qC9
//获得文件长度 ;1>V7+/
public long getFileSize() o>&-B.zq
{ 42:,*4t(
int nFileLength = -1; V >~\~H2Y
try{ mcs!A/]<
URL url = new URL(siteInfoBean.getSSiteURL()); 57_AJT hR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^Cj3\G4,
httpConnection.setRequestProperty("User-Agent","NetFox"); 3{TE6&HIa
Z2-"NB
E5Ls/ HK
int responseCode=httpConnection.getResponseCode(); N(O*"1b
if(responseCode>=400) =NWzsRl,
{ r?pN-x$M=
processErrorCode(responseCode); u)%/df qzZ
return -2; //-2 represent access is error PtGFLM9R
} "#h/sAIs
.}E@7^X
e488}h6#m
String sHeader; V@\u<LO0G
R{6M(!x
j9BcoEl:;
for(int i=1;;i++) =%B}8$.|
{ ~b%dBn]n>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8:Dkf v
//Utility.log(in.readLine()); CX; m8
sHeader=httpConnection.getHeaderFieldKey(i); MVEh<_
if(sHeader!=null) 474 oVdGx
{ hI*6f3Vn(n
if(sHeader.equals("Content-Length")) Yqv!ZJ6
{ " ^!=e72
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'CRjd~L
break; G}aM~,v
} -oY8]HrXfK
} H)Z$j&S{
else gOp81)
break; t&IWKu#
} }}Gkipp
} !P6?nS
catch(IOException e){e.printStackTrace ();} (v$ i
catch(Exception e){e.printStackTrace ();} "5<YN#
GY"c1KE$
$MM[`^~
Utility.log(nFileLength); Z`n "}{
Ij9=J1c4
0QEcJ]Qb8
return nFileLength; vF'IK,
} },O7NSG<o
V2g"5nYT
SzG?m]
//保存下载信息（文件指针位置） >VG*La'c
private void write_nPos() _6]tbni?v
{ `u8(qGg7GF
try{ \#gguq?[
output = new DataOutputStream(new FileOutputStream(tmpFile)); J?jxD/9Yb
output.writeInt(nStartPos.length); oMNBK/X_
for(int i=0;i<nStartPos.length;i++) N_(-\\mq
{ }hXmK.['
// output.writeLong(nPos); Z'd]oNF
output.writeLong(fileSplitterFetch.nStartPos); WJ\,Y} J
output.writeLong(fileSplitterFetch.nEndPos); ^xr &E
} Q{~;4+ZD
output.close(); $M1;d1e6'
} MI`<U:-lP
catch(IOException e){e.printStackTrace ();} ]=Wq&~
catch(Exception e){e.printStackTrace ();} %V(U]sbV
} i3>_E <"9
1TgD;qX
,5x9o"N!
//读取保存的下载信息（文件指针位置） I1p{(fJ
private void read_nPos() p;mV?B?oAQ
{ [9yy<Z5
try{ ?O9|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); CH6;jo]
int nCount = input.readInt(); Krr51`hZH
nStartPos = new long[nCount]; cHnd gUW]
nEndPos = new long[nCount]; c2PBYFCyC
for(int i=0;i<nStartPos.length;i++) }'uV{$
{ k40`,;}9
nStartPos = input.readLong(); ]'z 5%'
nEndPos = input.readLong(); !z5Ozm+}
} 1W7ClT_cQ
input.close(); Uu|R]azbO
} z%$M IC
catch(IOException e){e.printStackTrace ();} c >xHaA:V
catch(Exception e){e.printStackTrace ();} %~N| RSec
} v\5`n@}4
cY|@s?3NND
=ibKdPtTh^
private void processErrorCode(int nErrorCode) +Ecn
{ )ZfbM|
System.err.println("Error Code : " + nErrorCode); n9k-OGJ
} @680.+Kw
xBE}/F$45
M4t:)!dji?
//停止文件下载 RVr5^l;"
public void siteStop() *tl;0<n
{ <Q_E3lQy/
bStop = true; uFfk!
for(int i=0;i<nStartPos.length;i++) zTw<9Nf
fileSplitterFetch.splitterStop(); 12}!oS~_
n_6#Df*
IJLuu@kRm,
} ye4GHAm,p
} iz27yXHZ~
//负责部分文件的抓取 ^a7a_M
**FileSplitterFetch.java Yd<9Y\W%?
*/ 9e;:(jl^
package NetFox; $kxu-
H2yPVJ\Y)"
R3*{"!O
import java.io.*; Y,-!QFS#
import java.net.*; {3``B#}
4Gj
~pwk[Q!
public class FileSplitterFetch extends Thread { HcGbe37Xq
sl)]yCD|5
Q3[nS(#Z/=
String sURL; //File URL nd{k D>a
long nStartPos; //File Snippet Start Position +)_#j/
long nEndPos; //File Snippet End Position 4p>,
int nThreadID; //Thread's ID |W5lhx0U
boolean bDownOver = false; //Downing is over USKC,&6&}
boolean bStop = false; //Stop identical hcR^?
FileAccessI fileAccessI = null; //File Access interface }-p-(
HE+D]7^
O{EbL5p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q>WnSm5R
{ ov1#BeQ
this.sURL = sURL; k>:\4uI|<\
this.nStartPos = nStart; ,E2c9V'
this.nEndPos = nEnd; XLlJ|xhY-K
nThreadID = id; "j=E8Dd}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -9R.mG
} ESuP ZB
<,JO
"P$')uwE
public void run() lN_b&92
{ VI)hA ^S
while(nStartPos < nEndPos && !bStop) }'h\;8y
{ 8L*#zaSAf
e/$M6l$Q*4
0"iQHi
try{ X&A2:A 6\+
URL url = new URL(sURL); z\Z+>A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kE1k@h#/
httpConnection.setRequestProperty("User-Agent","NetFox"); U:8cz=#
String sProperty = "bytes="+nStartPos+"-"; _$KkSMA~_
httpConnection.setRequestProperty("RANGE",sProperty); |pE ~
Utility.log(sProperty); tD]vx`0>
LWV^'B_X-
#y1M1Og
InputStream input = httpConnection.getInputStream(); %4w#EbkSS
//logResponseHead(httpConnection); ^%qQ)>I=j
ULxgvq
u89Q2\z~"M
byte[] b = new byte[1024]; $^W|@et{ ]
int nRead; @ZtvpL}e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tNxKpA |F
{ 4!Lj\.!$
nStartPos += fileAccessI.write(b,0,nRead); vH6.;j'^
//if(nThreadID == 1) N^jr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i$H9~tPs
} 3&B- w
BuS[(
_"82W^Wi
Utility.log("Thread " + nThreadID + " is over!"); K pmq C$
bDownOver = true; cY.5z:7u~v
//nPos = fileAccessI.write (b,0,nRead); J n'SGR
} ^C;ULUn3
catch(Exception e){e.printStackTrace ();} 'NDr$Qc3
} yRt7&,}zL
} ?F|F~A8dr
*Q;?p hr
FMC]KXSd
//打印回应的头信息 v R! y#
public void logResponseHead(HttpURLConnection con) {Bb:\N8X
{ 7~VDk5Z6
for(int i=1;;i++) 1}OM"V
{ =lx~tSiS
String header=con.getHeaderFieldKey(i); _[N*k"
if(header!=null) H_w?+Rig
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'v5q/l
Utility.log(header+" : "+con.getHeaderField(header)); ~g*5."-i
else k!d<2Qp W
break; Sp[]vm8N
} >txeo17Ba\
} .$ HE
8*&YQId~
2h1P!4W85
public void splitterStop() G'{&*]Z\:
{ Raf-I+
bStop = true; X5+$:jq&
} <>V~
*C.Kdf3w
Fm+V_.H/;
} rv2;)3/*
j2mMm/kq\
TwKi_nh2m
/* r"dR}S.Uf
**FileAccess.java y8dOx=c
*//文件访问(定位，写) o 9d|XY_
package NetFox; j? Vs"d|
import java.io.*; 'a>D+A:
\ZBz]rh*
GZm=>!T
public class FileAccessI implements Serializable{ =]1g*~%
}$s QmRR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l)V646-O,~
RandomAccessFile oSavedFile; LdnTdh?
long nPos; ]hZk#rp}
'h[7AZ&)#
:N'
public FileAccessI() throws IOException B)rBM
{ F1p|^hYDW
this("",0); uxL3 8d]
} /'^BHA|h
Y@+9Ukd/
u\km_e
public FileAccessI(String sName,long nPos) throws IOException OK2\2&G
{ 1[\I9dv2
oSavedFile = new RandomAccessFile(sName,"rw"); LYTnMrM
this.nPos = nPos; m;PTO$--
oSavedFile.seek(nPos); 'Y]<1M>.g
} S5~(3I )v
D3y4e8+Z'
1U ='"
public synchronized int write(byte[] b,int nStart,int nLen) {'#7b# DB>
{ u3sr"w&
int n = -1; #q8/=,3EG
try{ Se(apQH
oSavedFile.write(b,nStart,nLen); Z1wfy\9c8
n = nLen; 4+4&}8FH
} @9\E
catch(IOException e) VYrs4IFT$
{ =UxKa`
e.printStackTrace (); S(:|S(
} Ah zV?6e
Dc]J3r
'@"A{mrE
return n; !X=93%
} " pL5j
s*vtCdrE.
yaAg!mW
} q'jInwY|x
K:Z|# i-
ppO!v?
/* !ce,^z&5
**SiteInfoBean.java e{.P2rnh
*/ cN)noGkp
package NetFox; l Ng)k1
pzU:AUW
A$TFa:O|
public class SiteInfoBean { >9[wjB2?}
&p=(0$0&-
CDDEWVd
private String sSiteURL; //Site's URL z{qn|#}
private String sFilePath; //Saved File's Path q&,uJo
private String sFileName; //Saved File's Name = Ruq
private int nSplitter; //Count of Splited Downloading File t0)hdX
x8&~
?$b*)<
public SiteInfoBean() &y~GTEP
{//nSplitter的缺省值为5 #twl
//default value of nSplitter is 5 ;AT~?o`n
this("","","",5); Tg v]30F)
} 3 FLht L
> Cx;h=
2X=*;r"{J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MUp{2_RA
{ -yY]0
sSiteURL= sURL; cA`X(Am6]g
sFilePath = sPath; =7zvp,B
sFileName = sName; _i0,?U2C
this.nSplitter = nSpiltter; G3t\2E9S
Il!#]
TzsNhrU{
} Yd<q4VJR
1!2,K ot
yzz(<s:o/
public String getSSiteURL() vrXNa8,L
{ -}Gk@=$G
return sSiteURL; L(3} H,t
} wTVd){q`.
$-_@MT~
$:*/^)L
public void setSSiteURL(String value) XNB4KjT
{ Y_M3-H=0
sSiteURL = value; J ?H|"
} |FZIUS{]
<>[]-Vq
mV'^4by
public String getSFilePath() wfBf&Z0{
{ __,}/|K2
return sFilePath; -wn(J5NnR
} !8OUH6{2
yI}_ U
!\N|$-M
public void setSFilePath(String value) 5\P3JoH:Yg
{ #6qLu
sFilePath = value; |%7OI#t^
} ? Eh)JJt
Z)H9D(Za
tvvRHvL
public String getSFileName() UNd+MHE74I
{ %%Z|6V74
return sFileName; X4:SH>U!
} BJ7m3[lz
/,#&Htk
RF.8zea{O`
public void setSFileName(String value) P :D6w){
{ +UC-
sFileName = value; dEM=U;
} rJ}k!}G
5$p7y:
Y'%k G5nF
public int getNSplitter() =f{YwtG
{ q<*UeyE S
return nSplitter; ITu5Y"x
} 7e D<(
W-ll2b
G%RhNwm
public void setNSplitter(int nCount) gw);b)&mx
{ jFMf=u&U
nSplitter = nCount; Y>: e4Q
} gzDNMM
} pJ 7="n
#GT4/Ej}W
>X!A/;$
/* kan4P@XVS
**Utility.java ^-i<TJ
*/ 51lN,VVD
package NetFox; z4yV1
$9Yk]~
R7xEE7p
public class Utility { #XJ`/\E]
t*'U|K4L/
XLNR%)l
public Utility() (jY -MF3
{ 0cBk/x^s
&=d0'3k>
zU1[+JJY"{
} (]l}QR%Bxu
-I\Y m_)
//线程睡眠 $rG~0
public static void sleep(int nSecond) ~HH6=qjU)
{ Y$SwQ;wl
try{ &7CAxU;i3
Thread.sleep(nSecond); ?Q XS?
} 9M&uQccY
catch(Exception e) c<gvUVHIxR
{ e:&(y){n(
e.printStackTrace (); }L1-2
} *j0kb"#
} g^dPAjPQ
+%hA6n
//日志 C {GSf`D!T
public static void log(String sMsg) </OZ,3J=
{ -8]M ,,?
System.err.println(sMsg); )+nY-DB(
} ARD&L$AX
c9 UJ=
; iK9'u
public static void log(int sMsg) >lRa},5(
{ ^\X-eeA
System.err.println(sMsg); ;be2sTo
} `n# {}%
} 5+gSpg]i
-2dk8]KB]
+s}"&IV%
/* UoLvc~n7
**TestMethod.java HW)4#nLhh
*/ kAEm#oz=g
package NetFox; L;7x2&
Myj 68_wf
J1?)z+t9~
public class TestMethod { /idQfff
m{/?6h 1
ng-g\&-
public TestMethod() V'";u?h#S
{ ///xx/weblogic60b2_win.exe R(?g+:eCpM
try{ tntQO!pM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =+T$1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pV>M,f
SiteFileFetch fileFetch = new SiteFileFetch(bean); '\$2+*
fileFetch.start(); cMCGaaLU
} V Q6&7@ c
catch(Exception e){e.printStackTrace ();} /e^q>>z
Ix;9D'^}
q F\a]e
} U{2[nF
{ XN"L3A
Fxu'(xa
public static void main(String[] args) &*wN@e(c
{ H1]An'qz,
new TestMethod(); Pd99vq/
} cr{;gP
} <<zYF.9L]
点击下载更多相关资料