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)); ddJQC|xR}
} !;&p"E|b#
for(int i=0;i<nEndPos.length-1;i++) jaTh^L
{ ,&]S(|2%>t
nEndPos = nStartPos[i+1]; H*RC@O_hv
} 7E r23Q
nEndPos[nEndPos.length-1] = nFileLength; 2h|MXI\g
} `18qbot
} :1cV;gJ
.0S~872
#|Y5,a,{
//启动子线程 [-65PC4aN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eJF5n#
for(int i=0;i<nStartPos.length;i++) b3&zjjQ
{ bR*-Ht+wd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1L%CJ+Q#0i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jqWu
nStartPos,nEndPos,i); FOv=!'So
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w k(VR
fileSplitterFetch.start(); /f:dv?!km
} fM]+SMZy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ypbe!Y<i]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f/ ?_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k$R~R-'
nEndPos = " + nFileLength); N=4G=0 `ke
// fileSplitterFetch[nPos.length-1].start(); s>B5l2Q4
v~f HYa>
?J%1#1L"/
//等待子线程结束 0[RL>;D:
//int count = 0; "Q}#^h]F
//是否结束while循环 Ttu2skcv
boolean breakWhile = false; ;kFDMuuO
?Nup1!D
(|[2J3ZET
while(!bStop) ;+W#5<i
{ dbwe?ksh
write_nPos(); hEA<o67
Utility.sleep(500); }6p@lla,%]
breakWhile = true; iQ tNAj
kW2sY^Rg
fV &KM*W*@
for(int i=0;i<nStartPos.length;i++) n&{Dq}q
{ 0ZT5bg_M
if(!fileSplitterFetch.bDownOver) 5m*iE*+
{ K#%&0D!
breakWhile = false; Gy9$wH@8
break; (_niMQtF}
} nG,A@/N
} #^`4DhQ/ 1
if(breakWhile) zcel|oz)
break; X^T:8npxt
-|J"s$yO4
W^0w
//count++; KX76UW
//if(count>4) NO~*T?&
// siteStop(); _K`wG}YIE
} Q}1 R5@7
6TQoqH8@U
x*![fK
System.err.println("文件下载结束！"); !9u|fnC9
} 6DM$g=/'
catch(Exception e){e.printStackTrace ();} 8qY79)vD4E
} |*oZ_gI
7FzA*
%j:]^vqFA
//获得文件长度 bt"W(m&f
public long getFileSize() ~T ]m>A!
{ D2<fw#
int nFileLength = -1; aUzBV\Yd}
try{ r;/4F/6"
URL url = new URL(siteInfoBean.getSSiteURL()); j.C`U(n}`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _a5d?Q9Z
httpConnection.setRequestProperty("User-Agent","NetFox"); T?:Rdo!:u
O;z,qo X
I CZ4A{I
int responseCode=httpConnection.getResponseCode(); t0/p]=+.p/
if(responseCode>=400) dq7x3v^"ZG
{ |2?'9<
processErrorCode(responseCode); I, -hf=-
return -2; //-2 represent access is error kjW+QT?T&
} 8 BY j
zAK+8{,
3[\iQ*d }B
String sHeader; &)8:h+&Z
ZW-yP2
_p#CwExuy
for(int i=1;;i++) ;o^eC!:/%
{ 2VF%@p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fgkajig
//Utility.log(in.readLine()); Ager$uC
sHeader=httpConnection.getHeaderFieldKey(i); Ipf|")*
if(sHeader!=null) {G|,\O1
{ 3;)>Fs;
if(sHeader.equals("Content-Length")) ?Eg(Gu.J
{ *meZ8DV2DH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +!k&Yje
break; $"`- ^
} kd=GCO
} dA-2%uJ
else RSr %n1
break; m$`RcwO
} Jpj}@,
} R?v>Q` Qi
catch(IOException e){e.printStackTrace ();} !zuxz
catch(Exception e){e.printStackTrace ();} Mx6@$tQ%
;>506jZ
e8y;.D[2
Utility.log(nFileLength); t2EHrji~
.clP#r{U
~u)}ScTp
return nFileLength; 7q?9Tj3
} LG-y]4a}
cmBB[pk\
#%`|~%`{:
//保存下载信息（文件指针位置） .9,zL=)Ba
private void write_nPos() JCz@s~f\y
{ Dakoqke
try{ 'HT7_$?*
output = new DataOutputStream(new FileOutputStream(tmpFile)); @_U;9)
output.writeInt(nStartPos.length); u*e.yN
for(int i=0;i<nStartPos.length;i++) P6E3-?4j
{ 3Th'paMG
// output.writeLong(nPos); @WJgWJm
output.writeLong(fileSplitterFetch.nStartPos); 0FGe=$vD
output.writeLong(fileSplitterFetch.nEndPos); s<*XNNE7
} 1lq(PGX)
output.close(); ]NjX?XdX<
} VK}fsOnj0
catch(IOException e){e.printStackTrace ();} =2[7 E
catch(Exception e){e.printStackTrace ();} C2@,BCR
} ^sa#8^,K
7P"| J\
9w"h
//读取保存的下载信息（文件指针位置） w<zIAQN
private void read_nPos() Q&MZN);.
{ 2}YOcnB
try{ S7=Bd[4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &@%W29:
int nCount = input.readInt(); T~QWRBO
nStartPos = new long[nCount]; dArDP[w
nEndPos = new long[nCount]; !O-T0O
for(int i=0;i<nStartPos.length;i++) y(Y!?X I
{ 7+]=-
nStartPos = input.readLong(); 8*8Zc/{
nEndPos = input.readLong(); PH`9MXh
} #6ri-n
input.close(); J%x6
} }~#pEX~j*
catch(IOException e){e.printStackTrace ();} Em?d*z
catch(Exception e){e.printStackTrace ();} :q=%1~Idla
} $P>`m$(8
p+l!6
&$"i,~q^b
private void processErrorCode(int nErrorCode) 3mYiQ2
{ :80Z6F.k`
System.err.println("Error Code : " + nErrorCode); t0z!DOODZP
} ;w'D4p= P
HOw-]JSP2
+#GQ,
//停止文件下载 $}lbT15a
public void siteStop() A6GE,FhsG
{ h]og*(
bStop = true; ^[]}R:
for(int i=0;i<nStartPos.length;i++) [PQ?#:r
fileSplitterFetch.splitterStop(); v[#9+6P=
K3m]%m2\
'6Ay&A3N]
} SxdE?uCUS
} 0dhF&*h|L
//负责部分文件的抓取 )_mr! z(S
**FileSplitterFetch.java wB.Nn/p
*/ wSb1"a
package NetFox; I"Ms-zs
m_=$0m J$
an4GSL
import java.io.*; GKvN* SU=
import java.net.*; f` :i.Sr
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dYSr4pb
public class FileSplitterFetch extends Thread { P8^hBv*
4Fp0ZVT
G"X8}:}
String sURL; //File URL .uyGYj-C
long nStartPos; //File Snippet Start Position ?"zY"*>4
long nEndPos; //File Snippet End Position _/Gczy4)#
int nThreadID; //Thread's ID D|rFu
boolean bDownOver = false; //Downing is over Z-E`>
boolean bStop = false; //Stop identical @?=|Y
FileAccessI fileAccessI = null; //File Access interface -:30:oq
SV:4GVf
T^T[$26
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RE=`
{ j'%$XvI
this.sURL = sURL; 5m?8yT}
this.nStartPos = nStart; SG-'R1 J
this.nEndPos = nEnd; f8M$45A'
nThreadID = id; `D`sr[3n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pX&pLaF
} *H?!;u=8
_@ *+~9%8p
58%#DX34M
public void run() F#5B<I
{ w=LP"bqlI
while(nStartPos < nEndPos && !bStop) bHg,1y)UC
{ 0KMctPT]p
}-~X4u#
~=8uN<
try{ K?s+3
URL url = new URL(sURL); vhsk0$f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jrg2/ee,*
httpConnection.setRequestProperty("User-Agent","NetFox"); #<e\QE'!
String sProperty = "bytes="+nStartPos+"-"; u:m]CPz
httpConnection.setRequestProperty("RANGE",sProperty); R zf
Utility.log(sProperty); X@k`3X
U f|> (C
R,9[hNHWGs
InputStream input = httpConnection.getInputStream(); jeGj<m
//logResponseHead(httpConnection); ,$'])A?$
]Ar\c["
UlAzJO6"
byte[] b = new byte[1024]; S,<EEtXQ
int nRead; {e+-vl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N@Y ljz|
{ C8vOE`U,J
nStartPos += fileAccessI.write(b,0,nRead); TjHwjRa
//if(nThreadID == 1) K'X2dG*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x9x E&
} L=q+|j1>
GN!qyT
?t+5s]
Utility.log("Thread " + nThreadID + " is over!"); wk6NG/<
bDownOver = true; hoQs @[
//nPos = fileAccessI.write (b,0,nRead); .&9 i
} oS7(s
catch(Exception e){e.printStackTrace ();} _)]+hUwY
} +hE(Ra#
} NPd%M
^s@8VAwi
Qb)C[5a}
//打印回应的头信息 ~mO62(8m
public void logResponseHead(HttpURLConnection con) 1gmt2>#v%
{ 34wkzu
for(int i=1;;i++) i&vaeP25)
{ F B?UZ
String header=con.getHeaderFieldKey(i); ;=<-5;rI
if(header!=null) Q%wY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7zHh@ B:]
Utility.log(header+" : "+con.getHeaderField(header)); wMdal:n^
else wKi^C8Z2
break; =egW
} >m#e:[N
} [Z~ 2
W -
g8w2Vz2/
public void splitterStop() "=6v&G]U4
{ /DqLrA
bStop = true; y_HN6
} -jn WZ5.
BWrv%7
yuDZ~0]R
} >~`r:0',
5Q 'i2*j
+&Hr4@pgW
/* j:,NE(DF
**FileAccess.java vjQb%/LWl
*//文件访问(定位，写) {5d9$v7k4
package NetFox; Hewd4k
import java.io.*; n @?4b8"
hUD7_arKF
vk>b#%1{
public class FileAccessI implements Serializable{ fx@j?*Qb
"H&"(=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Fe.t/amS/
RandomAccessFile oSavedFile; 0vVV%,v
long nPos; =)E,8L
H)aQ3T4N5
K]U;?h&CZc
public FileAccessI() throws IOException Q2A7mGN
{ 8E8N6
this("",0); =56T{N
} HLBkR>e
2_ :n
eeHP&1= 7
public FileAccessI(String sName,long nPos) throws IOException @xeAc0.^
{ Y!WG)u5
oSavedFile = new RandomAccessFile(sName,"rw"); #U*_1P0h
this.nPos = nPos; PG8^.)]M
oSavedFile.seek(nPos); ?-tVSRKQ
} hXb%;GL
'{[5M!B
k^ YO%_
public synchronized int write(byte[] b,int nStart,int nLen) aA'|Rg,
{ Qj3a_p$)P
int n = -1; {8R"O{
try{ h'$QC )P
oSavedFile.write(b,nStart,nLen); 0W3i()
n = nLen; 7HVZZ!>~
} 7},)]da>,'
catch(IOException e) VR
{ _:+ KMR
e.printStackTrace (); k"g._|G
} (mtoA#X1:h
U`o^mtW.
(;%|-{7e-
return n; J*l4|^i<
} (_4;') 9
L{E^?iX
yQ3OL#
} W5^.-B,(K
fK&e7j`qO
6YuY|JD
/* t+?P^Ok
**SiteInfoBean.java '+ xu#R
*/ RUr=fEH
package NetFox; k<RZKwQc
a=XW[TY1
%'L;FPxB
public class SiteInfoBean { v| z08\a[
Qq0l*)mX
(}!C4S3#
private String sSiteURL; //Site's URL km:nE: |
private String sFilePath; //Saved File's Path F5gObIJtuY
private String sFileName; //Saved File's Name _-cK{
private int nSplitter; //Count of Splited Downloading File TTI81:fku
&h$|j
MM{_Ur7Q
public SiteInfoBean() W( *V2<$o
{//nSplitter的缺省值为5 lm'Zy"~::
//default value of nSplitter is 5 5 HV)[us
this("","","",5); K.>wQA&
} 7z~Ghz
(UEXxUdQ_Q
-E&e1u,Mi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6k])KlJ2;
{ KSs1CF'i
sSiteURL= sURL; Uhh l3%p
sFilePath = sPath; XOb}<y)r~
sFileName = sName; N:+ taz-
this.nSplitter = nSpiltter; }GHxG9!z
^E>CGGS4
Kf7WcJ4b
} j kn^Z":
FT\?:wpKa
h.tY 'F
public String getSSiteURL() 0x)dnq\
{ M<8ML!N0;t
return sSiteURL; 9\O(n>
} ]j.k?P$U}
oJ;rc{n-
aSaAC7sFk
public void setSSiteURL(String value) eS!C3xC;J]
{ fu\s`W6f&
sSiteURL = value; b#Kq[}
} *FgJ|y6gk
@Gjny BJ
hol<dB
public String getSFilePath() OHp5z? z
{ z[!x:# q8`
return sFilePath; ahIE;Y\j'
} Z>A{i?#m
H30OUrD
o$_93<zc
public void setSFilePath(String value) IS_Su;w>4
{ )r!e2zc=Q
sFilePath = value; d!{7r7ob\
} oh}^?p
r4knN 2:
RtF8A5ys
public String getSFileName() z:G}>fk5
{ o42`z>~
return sFileName; r?p{LF
} ,ECAan/@
`bP?o
6M><(1fT
public void setSFileName(String value) -}<g-*m"q
{ l)@:T|)c
sFileName = value; 6$e]i|e
} f$D@*33ft
E/O5e(h
!EFBI+?&
public int getNSplitter() 3IyZunFT
{ h`?k.{})M
return nSplitter; L$JI43HZ
} R^{xwI
/7p>7q9g
|cTpw1%I~
public void setNSplitter(int nCount) #8?^C]*{0
{ z}APR@?`n8
nSplitter = nCount; t.=Oj
} 1X@b?6
} ,YlQK;
do'ORcZ
XS/n>C
/* B7 c[4
**Utility.java yh!B!v'
*/ euZ(}+N&
package NetFox; YX;nMyD?~
/2w@K_Px6
>h7$v~nra
public class Utility { |\{Nfm=:%
BJIQ zn3
5bfb!7-[i
public Utility() _;G=G5r
{ $^$ECDOTB
uC[d%v`
)F E8D
} Wm>b3:
kIM C~Z
//线程睡眠 -A;w$j6*
public static void sleep(int nSecond) okDJ(AIV+
{ 1f;or_f#k?
try{ k/^g*
Thread.sleep(nSecond); ,wTg$g-$
} ewQe/Fq
catch(Exception e) C1ZyB"{
{ jZ#UUnR%
e.printStackTrace (); B(Y.`L? %E
} Q?]w{f(
} A\g%
=h[yAf
//日志 9l l|JeNi
public static void log(String sMsg) GC?S];PL
{ T9y768%
System.err.println(sMsg); %yhI;M^
} u*k*yWdr
9fCO7AE0#
:B^mV{~
public static void log(int sMsg) #NMJZ
{ L5C2ng>
System.err.println(sMsg); 4tnjXP8
} 9<Ag1l
} T0?uC/7H
%^U"Spv;
bQV("~#
/* 25&nwz
**TestMethod.java gPp(e j7
*/ ex0oAt^
package NetFox; tx)OJY
_Z.;u0Zp8
xv&S[=Dt
public class TestMethod { qxSs ~Qc
iP,v=pS6
>F|qb*Tm7
public TestMethod() -;<>tq'3`
{ ///xx/weblogic60b2_win.exe jQs*(=ls
try{ #!1IP~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j$0zD:ppW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IO6MK&R
SiteFileFetch fileFetch = new SiteFileFetch(bean); W/a,.M
fileFetch.start(); zM\IKo_"
} gE1|lY$NL
catch(Exception e){e.printStackTrace ();} }M?|,N6
bkkSIl+Q
c+wuC,
} <H-tZDh5
-B,cB
ysl8LK
public static void main(String[] args) ,b4~!V
{ EqoASu
new TestMethod(); iA&oLu[y3
} ^+URv
} /Go>5B>
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