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)); #Iw(+%D
} $Habhw
for(int i=0;i<nEndPos.length-1;i++) jx: IK
{ w&p+mJL.
nEndPos = nStartPos[i+1]; 3 jZMXEG)
} CL=%eSsuD
nEndPos[nEndPos.length-1] = nFileLength; C0wtMD:G
} [n2B6Px
} #S}orWj
va6Fp2n<1*
.uuhoqG0
//启动子线程 EuK}L[Kl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b3ohTmy4(
for(int i=0;i<nStartPos.length;i++) YV O$`W^N
{ j9p6rD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #De>EQ%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x[(6V'
nStartPos,nEndPos,i); ?b (iWq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PsC")JS
fileSplitterFetch.start(); T8XrmR&?PX
} C= ~c`V5>r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tn]nl!_@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U'fP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {q-&!l|
nEndPos = " + nFileLength); J2bvHxb Rd
// fileSplitterFetch[nPos.length-1].start(); j#l=%H
X3.zNHN5
0a~t
//等待子线程结束 nf.Ox.kM)
//int count = 0; -@pjEI
//是否结束while循环 VW-qQe
boolean breakWhile = false; )PX VR T
-'! J?~
77P\:xc
while(!bStop) <J/ =$u/
{ d54iZ`
write_nPos(); 5 ~Wg=u<6
Utility.sleep(500); ov6xa*'a
breakWhile = true; ul~ux$a
n5:uG'L\
dljE.peL
for(int i=0;i<nStartPos.length;i++) g6GkA.!X$
{ WR;1
if(!fileSplitterFetch.bDownOver) !nvwRQ
{ L5&M@YTH
breakWhile = false; 1-2hh)
break; n(:<pz
} Q+:y
} ]; w 2YR
if(breakWhile) P`Np+E#I
break; LgqQr6y"
hlzB cz*
nV'1 $L#
//count++; V=O52?8
//if(count>4) zF1!a
// siteStop(); Abc{<4 z0?
} [9m3@Yd'
AGlBvRX7e
G@]3EP
System.err.println("文件下载结束！"); ^HKXm#vAB
} oaIk1U;g
catch(Exception e){e.printStackTrace ();} ~k"+5bHa*
} d:=' Xs
t R^f]+Up
LrB 0x>
//获得文件长度 HIg2y
public long getFileSize() '7iz5wC#
{ kSAVFzUS
int nFileLength = -1; T5XXC1+
try{ UP~28%>X
URL url = new URL(siteInfoBean.getSSiteURL()); `m,4#P-kj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [!'+}
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Yu:v
-F5BJk
honh'j
int responseCode=httpConnection.getResponseCode(); +|A`~\@N
if(responseCode>=400) P}R:o
{ -ng1RA>
processErrorCode(responseCode); mRk)5{
return -2; //-2 represent access is error ':*H#}Br-#
} i8]EIXbMX
d"wA"*8~y
G|6qL
String sHeader; 6=iHw24
BWt`l,nF
f ,F X# _4
for(int i=1;;i++) mZ)>^.N6
{ p3s i\Fm!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c%H' jB[
//Utility.log(in.readLine()); #<{v~sVp&
sHeader=httpConnection.getHeaderFieldKey(i); MIMC(<
if(sHeader!=null) X/5m}-6d]
{ X\^nV
if(sHeader.equals("Content-Length")) [doEArwn
{ )Z7Vm2a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X\^V{v^-
break; 2]!@)fio`
} xS*UY.>
} HsY5wC
else -3Kh >b)
break; w~lH2U'k}
} XwH>F7HPe
} dC=[o\
catch(IOException e){e.printStackTrace ();} 4G&`&fff]
catch(Exception e){e.printStackTrace ();} \Kl20?
S?~0)EXj(
e3I""D{)[=
Utility.log(nFileLength); /jv/qk3i
zsL@0]e&
D|uvgu2
return nFileLength; rXx#<7`
} ,\4]uZ<
c_8&4
ZW4f "
//保存下载信息（文件指针位置） e~)[I!n
private void write_nPos() 8^7Oc,:~
{ I)rnF
try{ qng ~,m
output = new DataOutputStream(new FileOutputStream(tmpFile)); y`I>|5[`
output.writeInt(nStartPos.length); ImXYI7PL
for(int i=0;i<nStartPos.length;i++) \&"C
{ \xYVnjG,
// output.writeLong(nPos); 4Aj~mA
output.writeLong(fileSplitterFetch.nStartPos); dNACE*g;q
output.writeLong(fileSplitterFetch.nEndPos); lF}[ YL
} >pq~ &)^u
output.close(); @16GF!.
} p9v:T1?
catch(IOException e){e.printStackTrace ();} $xO8?
catch(Exception e){e.printStackTrace ();} 8Qvs\TY
} `v*HH}aDO
Wjb_H (D
lM-9J?j
//读取保存的下载信息（文件指针位置） $n<a`PdH
private void read_nPos() h"FI]jK|}
{ @MSmg3&
try{ lQ8hY$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F#Lo^ 8
int nCount = input.readInt(); br I;}m
nStartPos = new long[nCount]; 80lei
nEndPos = new long[nCount]; '*J+mZtN
for(int i=0;i<nStartPos.length;i++) ]!/
{ J0xHpe
nStartPos = input.readLong(); qb>ULP0
nEndPos = input.readLong(); r:*G{m-
} zxR]+9Zh
input.close(); j=r1JV @
} ;aQ``B
catch(IOException e){e.printStackTrace ();} _ *f>UW*,
catch(Exception e){e.printStackTrace ();} @*z"Hi>4
} 'D\X$^J^
,s8/6n#
'ZbWr*bo
private void processErrorCode(int nErrorCode) *HoRYCL
{ t2[/eM.G
System.err.println("Error Code : " + nErrorCode); \VpEUU6^U
} JR!-1tnc
jTa\I&s,A
1wFu3fh@
//停止文件下载 "i0>>@NR'
public void siteStop() CsZ~LQ=DB
{ JFT$1^n
bStop = true; )qy?x7
for(int i=0;i<nStartPos.length;i++) .psb#4
fileSplitterFetch.splitterStop(); * %D_\0;
&'uP?r9c$
;cMQ0e
} Oeh A3$|#
} PaCCUF
//负责部分文件的抓取 JK$3qUDnI
**FileSplitterFetch.java g p:0Y
*/ sq|\!T
package NetFox; ^{M$S0g|N
4=Th<,<
t;* zr*
import java.io.*; x^ `/&+m
import java.net.*; +?J N_aR
9$)&b\D
ciS +.%7
public class FileSplitterFetch extends Thread { $nt&'Xnv
?fxM1<8
g89@>?Mn
String sURL; //File URL H^d?(Svh
long nStartPos; //File Snippet Start Position :-?ZU4)
long nEndPos; //File Snippet End Position Tg{5%~L]
int nThreadID; //Thread's ID #/oH #/?
boolean bDownOver = false; //Downing is over Kd:l8%+
boolean bStop = false; //Stop identical %o?)`z9-
FileAccessI fileAccessI = null; //File Access interface r=Xo;d*TE
ebBi zc=
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #b^6>
{ UarLxPQ
this.sURL = sURL; \F|)w|v
this.nStartPos = nStart; '+9<[]
this.nEndPos = nEnd; od=hCQ1>
nThreadID = id; orjtwF>^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p%DU1+SA
} sxT&T=7
o`YBz~2
cL9gaD$;)
public void run() u}du@Aq
{ "xlR>M6e
while(nStartPos < nEndPos && !bStop) vl:~&I&y;R
{ MG?,,8sO
m)A:w.o
?lC>E[
try{ gTj,I=3$?e
URL url = new URL(sURL); ,p|Q/M^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,U""m7
httpConnection.setRequestProperty("User-Agent","NetFox"); J 8 KiL
String sProperty = "bytes="+nStartPos+"-"; +La2-I
httpConnection.setRequestProperty("RANGE",sProperty); uE1;@Dm+
Utility.log(sProperty); in>+D|q c
, >7PG2 a
'g%:/lwA
InputStream input = httpConnection.getInputStream(); MT!Y!*-5
//logResponseHead(httpConnection); O>L,G)g
#Th)^Is
.i*oZ'[X
byte[] b = new byte[1024]; y8YsS4E^Q
int nRead; "^&H9.z,v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y_CYx
{ f1vD{M;
nStartPos += fileAccessI.write(b,0,nRead); }+@!c%TCx~
//if(nThreadID == 1) iq' PeVo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k]p|kutQCy
} vn}m-U XA*
{0,b[
t?"(Zb
Utility.log("Thread " + nThreadID + " is over!"); 8\s#law
bDownOver = true; SJ]6_4=y*
//nPos = fileAccessI.write (b,0,nRead); P!79{8
} fXMY.X>f
catch(Exception e){e.printStackTrace ();} |OeWM
} [q|W*[B:@
} C>|.0:[%
yksnsHs}d
D>|`+=1'0"
//打印回应的头信息 )Fx]LeI;
public void logResponseHead(HttpURLConnection con) /4T6Z[=s
{ @T^FOTW
for(int i=1;;i++) xX-r<:'tmi
{ Krae^z9R
String header=con.getHeaderFieldKey(i); Ao\P|K9MyL
if(header!=null) YrnC'o`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DgT]Nty@b
Utility.log(header+" : "+con.getHeaderField(header)); 5Npxs&Ea
else a,w|r#x]
break; ;`oK5
} ;t0q ?9
} NVRzthg%c_
^]sb=Amw
?z>J7 }w*=
public void splitterStop() (RFH.iX
{ $ 64up!
bStop = true; *Z#OfB4}
} x3i}IC
uXc;!*
$wAR cS
} 'Q=;I
q=pRe-{
jfG of*
/* m[eqTh4*
**FileAccess.java ah*{NR)
*//文件访问(定位，写) Z3JUYEAS
package NetFox; pq`uB
import java.io.*; Mz&/.A
SVo?o|<
Oa/zEH
public class FileAccessI implements Serializable{ kqCsEtm]
~vA{I%z5~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !S=YM<Ad
RandomAccessFile oSavedFile; \2kLj2!
long nPos; &%rM|
Go{,< gm
n5=U.r
public FileAccessI() throws IOException 'Ou C[$Z
{ .=;IdLO,Bf
this("",0); @dv8 F "v
} ?JZ$M
>eA@s}_8
Wh i#Ii~
public FileAccessI(String sName,long nPos) throws IOException >OaD7
{ Y'iI_cg
oSavedFile = new RandomAccessFile(sName,"rw"); Q3WI@4
this.nPos = nPos; BP9#}{kE
oSavedFile.seek(nPos); ?=9'?K/~a
} {A/^;X{N^
"jAd.x?X7e
b7>'ARdbzX
public synchronized int write(byte[] b,int nStart,int nLen) 5hmfdj6
{ o*)Sg6Yk
int n = -1; 4fsd5#
try{ yU!1q}L!
oSavedFile.write(b,nStart,nLen); dCi:@+z8
n = nLen; Ysu\CZGX
} ?5EH/yV;
catch(IOException e) GCJ[xn(_
{ k^Qf |
e.printStackTrace (); l\W|a'i
} aG]>{(~cL
5csh8i'V
5Rl\& G\
return n; 2yK">xYY@
} :C>7HEh-2_
0FOB5eBR
upuN$4m&{
} j4owo#OB-
r+bGZ
}AS/^E
/* (1'DZxJ&u
**SiteInfoBean.java Kd-1EU
*/ wS}c\!@<,
package NetFox; a%r!55.
AI2XNSV@Yl
$!_ X9)e
public class SiteInfoBean { 1*8;)#%&
1@v<
|4mvB2r
private String sSiteURL; //Site's URL c;kU|_
private String sFilePath; //Saved File's Path m,Y/ke\
private String sFileName; //Saved File's Name ZK]qQrIwy
private int nSplitter; //Count of Splited Downloading File \!\:p/f
0 SSdp<
b11I$b #
public SiteInfoBean() K[y")ooE<j
{//nSplitter的缺省值为5 vR\E;V
//default value of nSplitter is 5 w||t3!M+n
this("","","",5); OV]xo8a;
} <gwRE{6U
Q|)>9m!tt
%NQ%6B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,LA'^I?
{ ;NA5G:eQ
sSiteURL= sURL; `9r{z;UQ
sFilePath = sPath; )5b_>Uy
sFileName = sName; \( s `=(t
this.nSplitter = nSpiltter; FFqK tj's
kD#n/RBgf
Q("m*eMRt
} uU 7 <8G
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;JkIZ8!
public String getSSiteURL() h*VDd3[#
{ 3 ZOD2:(
return sSiteURL; A1p~K*[[
} %f'pAc|#
f![] :L
dT0W8oL
public void setSSiteURL(String value) sLA.bp.O
{ 4<($ZN8
sSiteURL = value; +S{m!j%B
} zls^JTE
zdwQpB,+^
@m5J%8>k
public String getSFilePath() rT`sY
{ xq;>||B
return sFilePath; fJ/INL
} j9k:!|(2'
9Vm aB
0HWSdf|w
public void setSFilePath(String value) KF'fg R
{ c$ /.Xp
sFilePath = value; ^dpM2$J
} w<B S
'aEK{#en
TIJH}Ri
public String getSFileName() 0hoMf=bb$
{ 1vo3aF
return sFileName; Tg^8a,Lt
} 9\Gk)0
eI ( S)q
2-'_Nwkl*
public void setSFileName(String value) >IS4
{ D]E=0+
sFileName = value; 6{5T^^x?<
} 'yCVB&`b
FC+-|1?C
Ou1kSG|kM
public int getNSplitter() >c0leT
{ d9JAt-6z2
return nSplitter; RP2$(%
} O.FTToh<
gba1R
_t-6m2A
public void setNSplitter(int nCount) 3YLK?X8
{ P1OYS\
nSplitter = nCount; drAJ-ii
} :WWHEZK
} 5{yg
_i ztQ78
p8 S~`fjV
/* N_ ODr]L
**Utility.java bDDP:INm.
*/ Y"t|0dO%b
package NetFox; dXDyY
q2xAx1R`sV
<,DMD
public class Utility { t?&;
aO$0[-A
7a_8007$l
public Utility() 9%kO%j,3
{ <&[` +
Lf9s'o}.R
z2V ->UK)
} ^N7cXK*
Srw`vql{(
//线程睡眠 "d-vs t5
public static void sleep(int nSecond) 5dv|NLl
{ F lVG,Z
try{ M5*Ln-qt(a
Thread.sleep(nSecond); lFuW8G,-f@
} k@fxs]Y_L
catch(Exception e) =,*/Ph&
{ 15_"U+O(/
e.printStackTrace (); @B0fRG y
} L__{U_p
} ,8DC9yM,
W ~MNst?
//日志 0>m$e(Z
public static void log(String sMsg) alRz@N
{ 5n>zJ ~
System.err.println(sMsg); WMKxGZg"
} W/RB|TMT
\=RV?mI3?
IV&5a]j
public static void log(int sMsg) :{eYm|2-
{ !}|'1HIC
System.err.println(sMsg); [GCaRk>b,
} D+AkV|
} !|9@f$Jv
0xi2VN"X
xX%{i0E
/* IRLAsb3
**TestMethod.java "$5cKbJ
*/ QX?moW6UW
package NetFox; yz3=#
^VzhjKSu
7lYf+&JZ
public class TestMethod { fvta<
}x6)}sz7
"w 4^i!\
public TestMethod() zBca$Vp
{ ///xx/weblogic60b2_win.exe V9KRA 1
try{ 9Pvv6WyKy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,W'P8C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8fQfu'LyjY
SiteFileFetch fileFetch = new SiteFileFetch(bean); $2]>{g
fileFetch.start(); t0<RtIh9e
} >t9DI
catch(Exception e){e.printStackTrace ();} 2ETv H~23
MYJMZ3qBi
?W dY{;&
} KWYjN h#*
3it*l-i\
,y0 &E8Z
public static void main(String[] args) kxrYA|x
{ SPe%9J+
new TestMethod(); |d\1xTBLp
} }]1C=~lC
} `)8SIx
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