http断点续传简单实现（java)

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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)); Sjj>#}U
} =8Jfgq9E
for(int i=0;i<nEndPos.length-1;i++) :M3oUE{
{ dUrElXbXd
nEndPos = nStartPos[i+1]; ||7x;2e
} LW6ZAETyL
nEndPos[nEndPos.length-1] = nFileLength; y9H% Xl
} <xpph t<
} ZUm?*.g\^
\>. LW9
1/+C5Bp*
//启动子线程 {$D,?V@%_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >et-{(G
for(int i=0;i<nStartPos.length;i++) *iO u'
{ enS}A*Io
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s8"8y`u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {P%9
nStartPos,nEndPos,i); u7%D6W~m0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IY'=DePd
fileSplitterFetch.start(); `>Tu|3%\
} hg.#DxRi{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CvSIV7zYo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?Ea;J0V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jl.p'$Fbn
nEndPos = " + nFileLength); f 3V Dv9(
// fileSplitterFetch[nPos.length-1].start(); z /KK)u(q
5^<h}u9
\uqjs+
//等待子线程结束 tsOrt3
//int count = 0; MB^~%uZ2K
//是否结束while循环 C&LBr|
boolean breakWhile = false; +Mewo
P9Yy9_a|x
8 ;d$54 b
while(!bStop) {'sY|lou
{ N[]Hc
write_nPos(); 1d"Z>k:mn
Utility.sleep(500); T3UMCqc=
breakWhile = true; zLs|tJOVp
@+vXMJ$
>WJf=F`_H
for(int i=0;i<nStartPos.length;i++) K5ZC:Ks
{ l:0s2
if(!fileSplitterFetch.bDownOver) ;7]u!Q
{ 5,qj7HZF
breakWhile = false; _R'Fco
break; ZRxZume<f
} 00I}o%akO
} Ars687WB
if(breakWhile) s4Sd>D7
break; ^'CPM6J
Xp\/YJOibd
OMhef,,H
//count++; h^,8rd
//if(count>4) 1wzqGmjmt
// siteStop(); E#J';tUQ
} Wt)Drv{@ {
'w>_+jLT
#/"8F O%~p
System.err.println("文件下载结束！"); WV3|?,y]qm
} F|Mi{5G%
catch(Exception e){e.printStackTrace ();} ZUz ^!d
} Re:jVJgBz
6:GTD$Uz.
PWh^[Rd)
//获得文件长度 1c3TN#|)W
public long getFileSize() >_rha~
{ 9I1tN
int nFileLength = -1; 8h3=b[
try{ P71(
URL url = new URL(siteInfoBean.getSSiteURL()); IdYzgDH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ] h-,o R?e
httpConnection.setRequestProperty("User-Agent","NetFox"); q)H1pwxD
u p.Q>28r
l Z#o+d2Y
int responseCode=httpConnection.getResponseCode(); lzw3=H
if(responseCode>=400) ,NnhHb2\
{ sK{l 9
processErrorCode(responseCode); +iRq8aS_
return -2; //-2 represent access is error .Ha'p.
} A+y
;\EiM;Q]
WZOY)>K
String sHeader; l"\~yNgk
mj|)nOd
j4?@(u9;j
for(int i=1;;i++) q@b|F-
{ \V9Z#>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -.g|l\
//Utility.log(in.readLine()); NCxqh<
sHeader=httpConnection.getHeaderFieldKey(i); RoCfJ65
if(sHeader!=null) 0|R#Tb;Y
{ iXyO(w4D
if(sHeader.equals("Content-Length")) 91Uj}n%
{ J]m{b09F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z0|&W&&D
break; O+%WR
} W@yJAQ
} $P1O>x>LIL
else N`)$[&NG]
break; b-3*Nl_%
} TKk-;Y=N
} qwIa?!8o
catch(IOException e){e.printStackTrace ();} 4iW'kuK
catch(Exception e){e.printStackTrace ();} D:Q 21Ch
IbcZ@'RSw
)tCX y4
Utility.log(nFileLength); -n'F v@U
)c l5B{1P
Zy|Mz&
return nFileLength; sp@E8G%xO
} ,K:ll4{b
#gm)dRKm%
kId n6 Wx,
//保存下载信息（文件指针位置） A AHt218
private void write_nPos() J8Yd1.Qj
{ `%09xMPu
try{ mhW-J6u*
output = new DataOutputStream(new FileOutputStream(tmpFile)); )'*5R<#
output.writeInt(nStartPos.length); 9-]i.y
for(int i=0;i<nStartPos.length;i++) w8g,a]p
{ ^F:k3,_[
// output.writeLong(nPos); DE2a5+^
output.writeLong(fileSplitterFetch.nStartPos); rP!#RzL
output.writeLong(fileSplitterFetch.nEndPos); ]7;\E\o
} 0* /{4)r
output.close(); BTM), w2
} `/HUV&i"S
catch(IOException e){e.printStackTrace ();} WM)-J^)BJ
catch(Exception e){e.printStackTrace ();} :ss,Hl
} XUuu-wm:}
97K[(KE
ljKrj
//读取保存的下载信息（文件指针位置） a>mm+L8y
private void read_nPos() C&++VRnm
{ ~rjTF!
try{ C/(M"j M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z>w`ZD}XY
int nCount = input.readInt(); N)&4Hy
nStartPos = new long[nCount]; >DPB!XA3
nEndPos = new long[nCount]; OgF+OS
for(int i=0;i<nStartPos.length;i++) jE#O>3+.
{ H3Se={5h\A
nStartPos = input.readLong(); 5e sQ;
nEndPos = input.readLong(); *xp\4;B
} }E`dZW*!!
input.close(); G;f/Tch
} d|T!v
catch(IOException e){e.printStackTrace ();} <cA/<3k)
catch(Exception e){e.printStackTrace ();} E*?<KZe"
} \6;=$f/?t
4mn&4e
y>*xVK{D
private void processErrorCode(int nErrorCode) S$2b>#@UJ
{ K(XN-D/c
System.err.println("Error Code : " + nErrorCode); 8u!"#S#>a
} &YDK (&>
JsO *1{6g
"bDs2E+W
//停止文件下载 d&#~h:~
public void siteStop() >a3p >2
{ V5U?F6
bStop = true; vSonkJ_
for(int i=0;i<nStartPos.length;i++) ={hX}"*D
fileSplitterFetch.splitterStop(); JoSJH35=:
nI0[;'Hn,
ZylJp8U
} (|wz7AY2
} QM?#{%31
//负责部分文件的抓取 7bDHXn
**FileSplitterFetch.java fvb=#58N_
*/ tl'n->G>v
package NetFox; C{2xHd/*
m!U9m
oA1a/[#
import java.io.*; "(qw-kil
import java.net.*; fr!Pj(Q1
jF[ 1za
U\rh[0
public class FileSplitterFetch extends Thread { y,pZTlE
N?X~w <
|pa$*/!NT
String sURL; //File URL uytE^
long nStartPos; //File Snippet Start Position Et_V,s<|
long nEndPos; //File Snippet End Position 0|; .6\
int nThreadID; //Thread's ID K!,<7[MBg
boolean bDownOver = false; //Downing is over S.!UPkWH
boolean bStop = false; //Stop identical :$+-3_oLMQ
FileAccessI fileAccessI = null; //File Access interface @|'5n
S(:l+JP
t20PP4FWM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^*\XgX
{ a6kV!,.U
this.sURL = sURL; <'G~8tA%v
this.nStartPos = nStart; Xv@SxS-5l
this.nEndPos = nEnd; UJs$q\#RO
nThreadID = id; c)0amM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {)AMwq
} 4~U'TE @
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pKS {6P
public void run() {-BRt)L[
{ f3|@|' ;
while(nStartPos < nEndPos && !bStop) fqu}Le
{ \n9zw'
l]<L [Y,E-
vy,&N^P
try{ $)H@|<K
URL url = new URL(sURL); ,YhdY6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y<C<_2
httpConnection.setRequestProperty("User-Agent","NetFox"); cQ:"-!ff
String sProperty = "bytes="+nStartPos+"-"; gT/@dVV
httpConnection.setRequestProperty("RANGE",sProperty); n[YEOkiG
Utility.log(sProperty); yz2Ci0Dwy
:iR \%
!gnj]k&/c
InputStream input = httpConnection.getInputStream(); |j3'eW&=
//logResponseHead(httpConnection); 0j(M* sl
<5=JE*s$NS
/*Qq[C
byte[] b = new byte[1024]; XlI!{qj|
int nRead; R}mn*h6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^s.V;R
{ mZIoaF>t
nStartPos += fileAccessI.write(b,0,nRead); n&MG7`]N
//if(nThreadID == 1) e?bYjJq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 76.{0c
} ET];%~ ^
&uUo3qXQ5l
>yJ9U,Y
Utility.log("Thread " + nThreadID + " is over!"); ~XeFOMq
bDownOver = true; *Ei|fe$sa
//nPos = fileAccessI.write (b,0,nRead); 0q\7C[R_
} `"@X.}\
catch(Exception e){e.printStackTrace ();} m`6Yc:@E
} W(RF n`g\
} Xtq{%
?X?&~3iD%
(6v(9p
//打印回应的头信息 0b91y3R+
public void logResponseHead(HttpURLConnection con) (Toq^+`c
{ e"r)R8
for(int i=1;;i++) `]Bxn)b(
{ D|qk_2R%
String header=con.getHeaderFieldKey(i); Z`3ufXPNlO
if(header!=null) 1{_A:<VBl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HyiFy7j
Utility.log(header+" : "+con.getHeaderField(header)); .}')f;jH5<
else !se0F.K
break; W0jZOP5_.$
} 7kKy\W
} L}#0I+Ml7
0N=X74
YC]L)eafo`
public void splitterStop() ~7!7\i,Y8\
{ v&FF|)$
bStop = true; w#i[_
} ;d$qc<2uA
VGL#!4wK
~"Gf<3^y+
} d7Ur$K\=y
1xf=_F0`&
\n0Oez0z!B
/* Cc?TSZ8[
**FileAccess.java l:]Nn%U(>
*//文件访问(定位，写) ?t@v&s
package NetFox; B~'MBBD"
import java.io.*; 0:KE@=
e$c?}3E!z
2fIRlrA$
public class FileAccessI implements Serializable{ (eCFWmO
ECa$vvK m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9s +z B
RandomAccessFile oSavedFile; hgRVwX
long nPos; 8&"(WuZ@
;jK#[*y
}_QKJw6/"
public FileAccessI() throws IOException f^e6<5gdf
{ ^5=UK7e5KY
this("",0); sM1RU
} EPW7+Ve
c':ezEaC
Y<\^7\[x
public FileAccessI(String sName,long nPos) throws IOException 'cDx{?
{ cD1o"bq
oSavedFile = new RandomAccessFile(sName,"rw"); &$`hQgi
this.nPos = nPos; {+zJI-XN/
oSavedFile.seek(nPos); *5$&`&,
} AgF5-tz6x
+)nT|w45
iV.p5FD
public synchronized int write(byte[] b,int nStart,int nLen) .'[/|4H
{ ,G^[o,hS
int n = -1; v}J;ZIb
try{ i54md$Q^
oSavedFile.write(b,nStart,nLen); ^C&+ ~+
n = nLen; z41_oG7
} yj@tV2
catch(IOException e) M4Z@O3OIE
{ !}3,B28
e.printStackTrace (); P];JKE%
} u%O-;>J
f<y&\'3
09M;}4ev&7
return n; o7&4G$FX~
} BdbJ< Is
FqA3{
i`%.
} ;)DzCc/
z}}]jR\y?
]Gc3Ea;4
/* g(0;[#@
**SiteInfoBean.java P2n2Qt2
*/ MrE<vw@he
package NetFox; Ni[4OR$-O
UkR3}{i
-7'#2P<)
public class SiteInfoBean { 9CUimZ
#:3r4J%+~
%IpSK 0<Sp
private String sSiteURL; //Site's URL <2
private String sFilePath; //Saved File's Path ?BCyJ
private String sFileName; //Saved File's Name MBk"KF
private int nSplitter; //Count of Splited Downloading File #`GbHxd
}wt%1v-10U
>e5zrgV
public SiteInfoBean() o}8{Bh^
{//nSplitter的缺省值为5 t\j!K2
//default value of nSplitter is 5 0rMqWP
this("","","",5); .")b?#K
} PB~_I=
&yH#s 8^8
nR5bs;gk"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]>:^d%n,}
{ ;np_%?is
sSiteURL= sURL; i8V0Ty4~N
sFilePath = sPath; ]S8LY.Az5
sFileName = sName; n~z\?Y=*
this.nSplitter = nSpiltter; G=M] 8+h
!awh*Xj6
Oo%!>!Lt,
} 3 %(Y$8U
EHf)^]Z
sV0Z
public String getSSiteURL() l%"`{
{ <4F7@q,V
return sSiteURL; xi {|
} }F{=#Kqn^
&>}.RX]t
;cSGlE |
public void setSSiteURL(String value) MUof=EJg>u
{ +}!DP~y+
sSiteURL = value; M|CrBJv+F
} .A<sr
+802`eax
iV)ac\
public String getSFilePath() UC9{m252
{ !y vJpdsof
return sFilePath; p?myuNd[
} q@Kk\m
@[r={s\
dt-K
public void setSFilePath(String value) QJ<[Zx
{ n!.2aq
sFilePath = value; t!l%/$-
} :4;S"p
<%!J?
.:0M+Jr"
public String getSFileName() Z*bC#s?
{ me./o(!?
return sFileName; 2,AaP*,
} D3?N<9g
Qyj(L[KJ
.w'vD/q;
public void setSFileName(String value) R`He^
{ _@prmSc
sFileName = value; /_OOPt=G
} atnQC
('WY5Yps
D9^7m j?e
public int getNSplitter() Z\!rH"8
{ *( *z|2
return nSplitter; 7Dl%UG]
} <ZrFOb
hPPB45^
kME^tpji
public void setNSplitter(int nCount) rA#s
{ G.ud1,S#
nSplitter = nCount; IIP.yyh>
} 2Guvze_bU
} <|JU(B
A70(W{6a9@
_<u;4RO(s
/* >-<F)
**Utility.java Yq0# #__
*/ X8b#[40:
package NetFox; {bTeAfbf]
n#>5?W
`cO|RhD@
public class Utility { no3Z\@%
cj^bh
&|z|SY]DL
public Utility() 8*)4"rS
{ Doj(.wm~
:)LC gIQo
66dTs,C
} ;Id"n7W
I7bi@t
//线程睡眠 7sguGwg)_
public static void sleep(int nSecond) N(7u],(Om
{ 8bbVbP
try{ `$Kes;[X
Thread.sleep(nSecond); _FFv#R*4
} -$ali[
catch(Exception e) ! OfO:L7-
{ paYz[Xq
e.printStackTrace (); ^?sSx!:bZ
} V g6S/-
} !=knppY
@SQceQfB
//日志 R_9 o!sTZ
public static void log(String sMsg) =SL^>HS.fo
{ S| "TP\o
System.err.println(sMsg); PHl4 vh#E!
} uH] m]t
XC}1_VWs
:3gFHBFDj
public static void log(int sMsg) (k#t}B[
{ * 2%oZXF
System.err.println(sMsg); [U']kt
} pLJeajv)z
} ^@N`e1
5E.vje{U;
U5clQiow
/* iW-t}}Z>B
**TestMethod.java Y)v%
*/ Hq-v@@0 *
package NetFox; i2U/RXu
E]?2!)mgce
d~,n_E$q;
public class TestMethod { YOlH*cZtg
$WJy?_c
iI}nW
public TestMethod() @M9_j{A
{ ///xx/weblogic60b2_win.exe R1~7F{FW
try{ BMF3XcH~G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ',%5mF3j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MKe *f%
SiteFileFetch fileFetch = new SiteFileFetch(bean); I'P.K| "R
fileFetch.start(); P1e5uJkd
} ~"\P~cg0J
catch(Exception e){e.printStackTrace ();} .;j"+Ef
y "<JE<X
. *Z#cq0
} F-i&M1\_
78gob&p?
eNivlJ,K|@
public static void main(String[] args) <%(f9j
{ i'9eKO
new TestMethod(); 7~L|;^(
} %va[jJ
} U<|B7t4M
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